KR20240116774A - Adhesive layer and/or adhesive layer - Google Patents

Abstract

A pressure-sensitive adhesive layer and/or adhesive layer that has excellent handling properties before adhesion or adhesion to a member and excellent flexibility after adhesion or adhesion to a member is provided. Provided is an adhesive layer and/or an adhesive layer in which stress is reduced by external stimulation. It is desirable that the stress does not increase after reduction. The ratio [S1(100)/S2(100)] of the 100% strain stress before external stimulation (S1(100)) and the 100% strain stress after external stimulation (S2(100)) is preferably less than 0.95.

Description

Adhesive layer and/or adhesive layer

The present invention relates to an adhesive layer and/or an adhesive layer, more specifically, to an adhesive layer capable of exhibiting adhesiveness and/or an adhesive layer capable of exhibiting adhesiveness.

Among optical devices such as displays, thin, flexible displays such as OLED are composed of a plurality of optical films or thin layer devices laminated. Additionally, devices that require flexibility, such as pressure-sensitive sensors, are constructed by stacking a pressure-sensitive member and a substrate (Patent Document 1). Liquid curing resins, adhesives, and adhesives are selected as interlayer fillers in these laminates. From the viewpoints of improving workability, bending due to curing shrinkage, and improving flexibility due to stress dispersion, adhesives or adhesives (adhesives, etc.) are selected. It is preferably used.

The adhesive, etc., plays the function of dispersing and relieving stress generated by bending and folding, especially in flexible members, and this function is expressed more efficiently as the adhesive, etc., becomes more flexible (Patent Document 2). Flexible adhesives, etc. are used.

Japanese Patent Publication No. 2012-159463 Japanese Patent Publication No. 2020-109177

On the other hand, flexible adhesives, etc. are greatly deformed even by slight stress, and for example, when cutting with a punching blade, glue protrudes, glue is missing, and process contamination occurs due to these. Problems may arise at the time of processing. In addition, with these adhesives, problems such as glue protruding due to its own weight during storage and glue missing due to vibration or contact may occur during transportation.

For this reason, there is a demand for a pressure-sensitive adhesive layer or adhesive layer that has excellent handling properties before adhesion or adhesion to a member during manufacturing, processing, storage, transportation, etc., and has excellent flexibility during use, that is, after adhesion or adhesion to a member.

The present invention is intended to solve such problems, and its purpose is to provide an adhesive layer and/or adhesive layer that has excellent handling properties before adhesion or adhesion to a member and excellent flexibility after adhesion or adhesion to a member. It is there.

The present inventors have made diligent efforts to solve the above problems, and as a result, the adhesive layer and the adhesive layer in which stress is reduced by external stimulation have excellent handling properties before adhesion or adhesion to a member, and adhesion or adhesion to a member. Later, it was discovered that it had excellent flexibility. The present invention was completed based on these findings.

That is, the present invention provides a pressure-sensitive adhesive layer and/or adhesive layer in which stress is reduced by external stimulation. Since the adhesive layer or adhesive layer has the property of reducing stress due to external stimulation, the stress can be relatively high before external stimulation is applied, and before use of the adhesive layer or adhesive layer, that is, the adhesive layer or adhesive layer is adhered to the member. Alternatively, before gluing, it is difficult for the glue to stick out or the glue to come off, so it can be made to have excellent handling properties. On the other hand, after applying an external stimulus, the stress can be lowered compared to before applying, and when using a pressure-sensitive adhesive layer or adhesive layer, that is, when the pressure-sensitive adhesive layer or adhesive layer is adhered or adhered to a member, flexibility can be excellent. .

It is desirable that the stress does not increase after reduction. The flexibility of such an adhesive layer or the like does not increase in stress when the adhesive layer or the like is adhered or adhered to a member.

The ratio [S2(100)/S1(100)] of the 100% strain stress before external stimulation (S1(100)) and the 100% strain stress after external stimulation (S2(100)) is preferably less than 0.95. Such an adhesive layer shows that the relatively weak tensile stress is further reduced by applying an external stimulus, and the repulsion force when stretched is low, making it suitable for applications with relatively low load, such as folding members.

It is preferable that the 100% strain stress (S2(100)) after external stimulation is 10 MPa or less. Such an adhesive layer and the like have even more excellent flexibility after external stimulation is applied.

The adhesive layer and the like are preferably used for optical purposes.

The pressure-sensitive adhesive layer and/or adhesive layer of the present invention has excellent handling properties before adhesion or adhesion to a member, and has excellent flexibility after adhesion or adhesion to a member.

Figure 1 shows a cross-sectional schematic diagram of a pressure-sensitive adhesive sheet or adhesive sheet 10 with a release liner in which the pressure-sensitive adhesive layer or adhesive layer 1 of the present invention is formed on a release liner 2.

[Adhesive layer, adhesive layer]

In this specification, “adhesion” refers to the adhesion of two surfaces based on the cohesive force based on the chemical structure of the composition by reduced pressure from the outside (e.g., a slight pressure), and the ability to separate when necessary. It refers to the nature of something. On the other hand, “adhesion” refers to the property in which a composition chemically reacts (cures) to produce a cured product, and two surfaces can be firmly joined without peeling off. In addition, in this specification, “adhesive layer” is a layered adhesive layer that does not have fluidity, and “adhesive layer” is a layered adhesive layer that does not have fluidity.

The adhesive layer and/or adhesive layer of the present invention has the property of reducing stress due to external stimulation. The stress is preferably, for example, a stress (strain stress) measured by a tensile compression tester and stretched at an arbitrary magnification. The stress (strain stress) when stretched at the specific magnification can be reduced as long as the stress (strain stress) when stretched at at least one magnification. Among these, it is preferable that the strain stress at at least one point among the tensile magnifications of 100 to 500% is reduced, and the strain is reduced at one or more tensile magnifications selected from the group consisting of 100%, 200%, 300%, and 500%. It is particularly desirable for stress to be reduced. Hereinafter, the preferred range of stress at each tensile magnification is described, but these values are preferred ranges when fracture does not occur at each tensile magnification.

It is desirable that the stress does not increase after reduction. The flexibility of such an adhesive layer or the like does not increase in stress when the adhesive layer or the like is adhered or adhered to a member.

1 is a cross-sectional schematic diagram of one embodiment of the adhesive layer of the present invention. The pressure-sensitive adhesive layer or adhesive layer 1 shown in FIG. 1 is laminated on the release-treated surface of the release liner 2, and a pressure-sensitive adhesive sheet or adhesive sheet 10 with a release liner is formed.

The pressure-sensitive adhesive layer of the present invention has a ratio of the stress (100% strain stress) (S1 (100)) before external stimulation and the stress (100% strain stress) (S2 (100)) after external stimulation (S2 (100)). /S1(100)] is preferably less than 0.95 (for example, 0.1 or more and less than 0.95), more preferably 0.9 or less, and even more preferably 0.8 or less. Such an adhesive layer shows that the relatively weak tensile stress is further reduced by applying an external stimulus, and the repulsive force when stretched is low, making it suitable for applications with relatively low load, such as folding members.

The pressure-sensitive adhesive layer, etc. of the present invention preferably has a stress (100% strain stress) (S1(100)) of 0.01 MPa or more (for example, 0.01 to 10 MPa) before external stimulation is applied, and more preferably 0.03 MPa or more ( For example, 0.03 to 6 MPa), more preferably 0.05 MPa or more (for example, 0.05 to 3 MPa). Such adhesive layers and the like have even more excellent flexibility after external stimulation is applied.

The pressure-sensitive adhesive layer or the like of the present invention preferably has a stress (100% strain stress) (S2(100)) of 10 MPa or less (e.g., 0.01 to 10 MPa) after external stimulation, and more preferably 6 MPa or less ( For example, 0.02 to 6 MPa), more preferably 3 MPa or less (for example, 0.03 to 3 MPa). Such an adhesive layer and the like have even more excellent flexibility after external stimulation is applied.

The adhesive layer of the present invention has a ratio of the stress (200% strain stress) (S1 (200)) before external stimulation and the stress (200% strain stress) (S2 (200)) after external stimulation (S2 (200)). /S1(200)] is preferably less than 0.95 (for example, 0.1 or more and less than 0.95), more preferably 0.8 or less, and even more preferably 0.7 or less. Such an adhesive layer shows that the relatively weak tensile stress is further reduced by applying an external stimulus, and the repulsive force when stretched is low, making it suitable for applications with relatively low load, such as folding members.

The pressure-sensitive adhesive layer of the present invention, etc. preferably has a stress (200% strain stress) (S1 (200)) of 0.03 MPa or more (for example, 0.03 to 10 MPa) before external stimulation is applied, and more preferably 0.04 MPa or more ( For example, 0.04 to 4 MPa), more preferably 0.06 MPa or more (for example, 0.06 to 2 MPa). Such an adhesive layer and the like have even more excellent flexibility after external stimulation is applied.

The pressure-sensitive adhesive layer of the present invention preferably has a stress (200% strain stress) (S2(200)) of 10 MPa or less (e.g., 0.01 to 10 MPa) after external stimulation, and more preferably 4 MPa or less ( For example, 0.03 to 4 MPa), more preferably 2 MPa or less (for example, 0.04 to 2 MPa). This adhesive layer has even more excellent flexibility after external stimulation is applied.

The adhesive layer of the present invention has a ratio of the stress (300% strain stress) (S1 (300)) before external stimulation and the stress (300% strain stress) (S2 (300)) after external stimulation (S2 (300)). /S1(300)] is preferably less than 0.950 (for example, 0.1 or more and less than 0.950), more preferably 0.8 or less, and even more preferably 0.7 or less. Such an adhesive layer shows that the tensile stress is reduced by applying an external stimulus, and is suitable for relatively low-load applications such as folding members.

The pressure-sensitive adhesive layer of the present invention, etc. preferably has a stress (300% strain stress) (S1 (300)) of 0.03 MPa or more (for example, 0.03 to 10 MPa) before external stimulation is applied, and more preferably 0.05 MPa or more ( For example, 0.05 to 4 MPa), more preferably 0.07 MPa or more (for example, 0.07 to 2 MPa). Such an adhesive layer and the like have even more excellent flexibility after external stimulation is applied.

The pressure-sensitive adhesive layer or the like of the present invention preferably has a stress (300% strain stress) (S2(300)) of 10 MPa or less (e.g., 0.01 to 10 MPa) after external stimulation, and more preferably 4 MPa or less ( For example, 0.03 to 4 MPa), more preferably 2 MPa or less (for example, 0.04 to 2 MPa). Such an adhesive layer and the like have even more excellent flexibility after external stimulation is applied.

The adhesive layer and the like have a ratio of the stress (500% strain stress) (S1 (500)) before the external stimulus is applied and the stress (500% strain stress) (S2 (500)) after the external stimulus is applied [S2 (500)/ S1(500)] is preferably less than 0.950 (for example, 0.1 or more and less than 0.950), more preferably 0.8 or less, and even more preferably 0.7 or less. This adhesive layer, etc. shows that relatively strong tensile stress is reduced by applying an external stimulus, and the repulsion force when stretched is low, so it is suitable for applications with relatively high and low loads, such as folding type (particularly, winding type such as rollable) members. Suitable.

The pressure-sensitive adhesive layer, etc. of the present invention preferably has a stress (500% strain stress) (S1 (500)) of 0.05 MPa or more (for example, 0.05 to 10 MPa) before external stimulation is applied, and more preferably 0.07 MPa or more ( For example, 0.07 to 4 MPa), more preferably 0.1 MPa or more (for example, 0.1 to 2 MPa). Such adhesive layers and the like have even more excellent flexibility after external stimulation is applied.

The pressure-sensitive adhesive layer or the like of the present invention preferably has a stress (500% strain stress) (S2(500)) of 10 MPa or less (for example, 0.01 to 10 MPa) after external stimulation, and more preferably 4 MPa or less ( For example, 0.03 to 4 MPa), more preferably 2 MPa or less (for example, 0.04 to 2 MPa). Such an adhesive layer and the like have even more excellent flexibility after external stimulation is applied.

In particular, the pressure-sensitive adhesive layer of the present invention has a reduced strain stress at a tensile ratio of 100%, and the ratio [S2(100)/S1(100)] is less than 0.95, or the strain stress of 100% before external stimulation is It is preferably 0.03 to 0.4 MPa.

Additionally, the pressure-sensitive adhesive layer of the present invention may have the property of reducing the peak intensity (stress peak intensity) or breaking point stress in the stress-strain curve due to external stimulation.

The pressure-sensitive adhesive layer or the like of the present invention preferably has a peak intensity (stress peak intensity) (breaking point stress in the case of fracture) in the stress-strain curve before external stimulation is 0.07 MPa or more, more preferably 0.1 MPa or more, More preferably, it is 0.2 MPa or more. If the stress peak intensity is 0.07 MPa or more, the adhesive layer or the like has appropriate hardness before external stimulation is applied and has better handleability.

The pressure-sensitive adhesive layer of the present invention preferably has a peak intensity (stress peak intensity) (breaking point stress in the case of fracture) in the stress-strain curve after external stimulation is 0.01 to 1.0 MPa, more preferably 0.03 to 1.0 MPa. 0.8 MPa, more preferably 0.04 to 0.5 MPa. If the stress peak intensity is within the above range, flexibility is superior after external stimulation is applied, step followability, adhesion, etc. are superior.

The adhesive layer of the present invention is the ratio of the peak intensity in the stress-strain curve before external stimulation and the peak intensity in the stress-strain curve after external stimulation (in case of fracture, the ratio of the stress at breaking point) [external After stimulation/before external stimulation] is preferably less than 0.95 (e.g. 0.05 or more and less than 0.95), more preferably 0.8 or less (e.g. 0.1 to 0.8), even more preferably 0.7 or less (e.g. For example, 0.3 to 0.7). In this case, the flexibility, level difference followability, and adhesion of the adhesive layer etc. tend to change more significantly before and after external stimulation is applied.

As described above, the adhesive layer of the present invention has the property of reducing stress due to external stimulation. Examples of the pressure-sensitive adhesive layer having such properties include, for example, a pressure-sensitive adhesive layer containing a polymer having a decomposable bond in the molecule whose bonds are cleaved by an external stimulus. The polymer may contain only one type or may contain two or more types. In addition, in this specification, a polymer having a decomposable bond in the molecule whose bonds are cleaved by the external stimulus is sometimes referred to as “polymer (A).” The number of the above degradable bonds may be one, or two or more types may be used.

The degradable bonds in the polymer (A) include bonds that are cleaved by an external stimulus and can then recombine (reversible decomposable bonds), and bonds that are cleaved by an external stimulus and do not recombine thereafter ( irreversible degradable bonds). When the decomposable bond of the polymer (A) is a reversible bond, the pressure-sensitive adhesive layer of the present invention also contains a compound that inhibits the recombination. In addition, in this specification, the polymer (A) having the above-mentioned reversibly decomposable bond in the molecule is referred to as “polymer (A1)”, the polymer having the above-mentioned irreversible decomposable bond in the molecule is referred to as “polymer (A2)”, and the compound that inhibits the above-mentioned recombination are sometimes referred to as “recombination-inhibiting compounds (B).”

The external stimulus is appropriately selected depending on the stress reduction means, and examples include active energy ray irradiation, heat, and the like. In particular, in the case where the polymer (A) is a heat-curable resin or an active energy ray-curable resin, the thermal curing reaction or the active energy ray curing reaction and the above-mentioned cleavage can be separately generated when the polymer (A) has curability. It is preferable that the external stimulus is different from the type of hardenability. Specifically, the external stimulus is preferably active energy ray irradiation when the polymer (A) is a heat-curable resin, and heat is preferable when the polymer (A) is an active energy ray-curable resin.

The active energy rays are not particularly limited, but include ionizing radiation such as α-rays, β-rays, γ-rays, neutron rays, and electron beams, ultraviolet light, and visible light. In particular, ultraviolet rays are preferred. The irradiation energy, irradiation time, irradiation method, etc. of the active energy ray are not particularly limited. Additionally, examples of light sources for irradiating ultraviolet light or visible light include low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, metal halide lamps, and LED lamps.

As the reversibly decomposable bond in the polymer (A1), known or commonly used bonds can be used, preferably a bond that cleaves as a radical, and particularly preferably a disulfide bond (-S-S-).

As the irreversible decomposable bond in the polymer (A2), any known or commonly used bond can be used, and a bond containing a nitrobenzyl group is preferable. In this case, it is easy to introduce irreversible degradable bonds into the polymer. As the bond containing the nitrobenzyl group, an ester bond formed from nitrobenzyl alcohol (preferably 2-nitrobenzyl alcohol) and a carboxylic acid having a polymerizable functional group is preferable.

Examples of the polymer (A) include thermoplastic resins, thermosetting resins, and active energy ray-curing resins. Among them, thermoplastic resins and thermosetting resins are preferable. An adhesive layer containing a thermoplastic resin, for example, can exhibit adhesiveness that adheres under pressure from the outside. An adhesive layer containing a thermosetting resin can adhere to an adherend by, for example, curing by heating.

Examples of the thermosetting resin include both a resin having thermosetting properties (thermosetting resin) and a resin obtained by curing the thermosetting resin. The thermosetting resin has a thermosetting functional group. The number of thermosetting functional groups in the thermosetting resin is preferably 2 or more (for example, 2 to 4). Examples of the thermosetting resin include phenol-based resin, epoxy-based resin, urethane-based resin, melamine-based resin, and alkyd-based resin.

Examples of the thermoplastic resin include polystyrene-based resin, vinyl acetate-based resin, polyester-based resin, polyolefin-based resin (polyethylene-based resin, polypropylene-based resin composition, etc.), polyimide-based resin, and acrylic resin. there is. Among them, acrylic resin is preferable because it can provide cohesion and appropriate flexibility to the adhesive layer and the like.

The design of acrylic resins varies depending on the purpose, and the monomer species and copolymer composition ratio are determined according to the target values of unique characteristics such as mechanical properties such as flexibility and elastic modulus, thermal properties such as glass transition point, and adhesives such as adhesive strength and adhesion. , it is desirable to appropriately select molecular weight, molecular weight distribution, crosslinking agent, and mixing ratio.

Acrylic resin is a resin containing an acrylic monomer (a monomer having a (meth)acryloyl group in the molecule) as a monomer component constituting the resin. That is, the acrylic resin contains structural units derived from acrylic monomers. The acrylic resin is preferably a polymer containing a (meth)acrylic acid alkyl ester as a monomer component constituting the polymer. In addition, in this specification, “(meth)acryl” refers to “acryl” and/or “methacryl” (either or both of “acryl” and “methacryl”), and the same applies to others.

As the above-mentioned (meth)acrylic acid alkyl ester as an essential monomer component, (meth)acrylic acid alkyl ester having a straight-chain or branched alkyl group is preferably used. In addition, only one type of the above-mentioned (meth)acrylic acid alkyl ester may be used, or two or more types may be used.

The (meth)acrylic acid alkyl ester having a linear or branched alkyl group is not particularly limited, but examples include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, and isopropyl (meth)acrylate. , n-butyl (meth)acrylate, isobutyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, isopentyl (meth)acrylate, hexyl (meth)acrylate , heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, ( Isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate (lauryl (meth)acrylate), tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, Hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, octadecyl (meth)acrylate (stearyl (meth)acrylate), isostearyl (meth)acrylate, nonadecyl (meth)acrylate, (meth)acrylic acid Examples include (meth)acrylic acid alkyl esters having a straight or branched alkyl group having 1 to 20 carbon atoms, such as eicosyl.

Among them, (meth)acrylic acid alkyl esters having a straight or branched alkyl group include those having a straight or branched alkyl group having 2 or more carbon atoms (preferably 2 to 18, more preferably 2 to 5). (meth)acrylic acid alkyl ester is preferred.

The content ratio of the structural unit derived from alkyl (meth)acrylate in the acrylic resin is preferably 70% by mass or more, more preferably 80% by mass or more, based on the total amount of 100% by mass of the monomer components constituting the acrylic resin. am. The content ratio is preferably 99% by mass or less, and more preferably 98% by mass or less. In addition, of course, depending on the application or required characteristics, etc., the content ratio of the structural unit derived from alkyl (meth)acrylate in the acrylic resin is less than 70% by mass with respect to the total amount of 100% by mass of the monomer components constituting the acrylic resin. There are cases where this happens.

As a monomer component constituting the resin, the acrylic resin may contain, together with the alkyl (meth)acrylate, another monomer (copolymerizable monomer) copolymerizable with the alkyl (meth)acrylate. That is, the acrylic resin may contain a copolymerizable monomer as a structural unit. The copolymerizable monomer may be used alone or in combination of two or more.

Examples of the copolymerizable monomer include carboxyl group-containing monomers, hydroxy group-containing monomers, epoxy group-containing monomers, keto group-containing monomers, alkoxy group-containing monomers, sulfonic acid group-containing monomers, phosphoric acid group-containing monomers, vinyl ester-based monomers, vinyl ether-based monomers, Examples include isocyanate group-containing monomers, aromatic vinyl compounds, alicyclic monomers, aromatic ring-containing (meth)acrylates, chlorine-containing monomers, and nitrogen-containing monomers.

The content ratio of structural units derived from copolymerizable monomers in the acrylic resin is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, based on 100% by mass of the total amount of monomer components constituting the acrylic resin. The content ratio is preferably 30% by mass or less, more preferably 15% by mass or less, and more preferably 10% by mass or less. In addition, of course, depending on the application or required characteristics, etc., the content ratio of the structural unit derived from the copolymerizable monomer in the acrylic resin may be less than 0.1% by mass with respect to the total amount of 100% by mass of the monomer components constituting the acrylic resin. .

In the adhesive layer of the present invention, etc., it is preferable that the polymer (A) forms a network structure. Network structure refers to a state in which molecules are entangled, or a state in which molecular chains form large molecules through some kind of bonding. That is, the polymer (A) is preferably a polymer that forms a network structure by bonding or entanglement of molecules. An adhesive layer with such a structure forms a network structure by bonding or entanglement of polymers, and can have appropriate hardness. When the decomposable bond is broken down by an external stimulus, the polymer structure is shredded, Flexibility is improved.

The fact that molecules are entangled means that the polymers are forming a network structure without covalent bonds. In order to form such an entangled structure, it is preferable to contain different types of polymers that are difficult to cause crosslinking reactions, and from the viewpoint of ease of production, thermoplastic resins, or thermosetting resins and thermoplastic resins form an entangled structure, It is desirable to have Since this configuration does not involve covalent bonds, it is suitable for a relatively flexible adhesive layer before external stimulation is applied.

The state in which the molecular chains form a long molecule through some kind of bond indicates that the polymer is polymerized from a single polymer. In order to form such a long molecule, it is preferable to contain a single polymer, and preferably to contain the above-mentioned thermosetting resin. In this configuration, because the molecular chains are covalently bonded to each other, a relatively hard adhesive layer can be formed, and since the number of parts cleaved by an external stimulus increases, an adhesive layer with a difference in flexibility before and after the external stimulus is formed. Suitable for etc.

Polymer (A1) is preferably a thermosetting resin. The polymer (A1), which is a thermosetting resin, may be a resin in which a thermosetting resin and a thermoplastic resin are entangled to form a network structure. As the thermosetting resin, epoxy resin is preferable. When the polymer (A1) contains an epoxy resin, the epoxy resin is a resin containing at least an epoxy monomer and a compound (a1) described later as a monomer component constituting the resin, and/or compound (a1) It is preferable that it is a resin that acts as a crosslinking agent and crosslinks epoxy resins. Acrylic resin is preferable as the thermoplastic resin. In addition, in this specification, the “crosslinking agent” refers to a compound that can form crosslinking of the resin, and is sometimes referred to as a “curing agent.”

The polymer (A2) is preferably a thermoplastic resin, and more preferably an acrylic resin. When the polymer (A2) is an acrylic resin, the acrylic resin is preferably a resin that contains at least an acrylic monomer and a compound (a2) described later as a monomer component constituting the resin.

When the adhesive layer or the like of the present invention contains a thermosetting resin as the polymer (A1), the content ratio of the thermosetting resin is not particularly limited, but provides an appropriate initial hardness to the adhesive layer, etc. and hardness after external stimulation. From the viewpoint, the amount is preferably 3 to 95% by mass, more preferably 5 to 90% by mass, and even more preferably 6 to 85% by mass, based on 100% by mass of the total amount of the adhesive layer of the present invention. When the pressure-sensitive adhesive layer or the like of the present invention contains a thermosetting resin as a base polymer, the content ratio is preferably 50 to 95% by mass, more preferably 60 to 90% by mass, and still more preferably 65 to 85% by mass. am. When the pressure-sensitive adhesive layer or the like of the present invention contains a thermoplastic resin as a base polymer, the content ratio is preferably 3 to 80% by mass, more preferably 5 to 50% by mass, and still more preferably 6 to 30% by mass. am. Additionally, the amount of the thermosetting resin includes the thermosetting resin, its raw material monomer, the crosslinking agent, and the amount of structural portions derived from the crosslinking agent.

When the adhesive layer, etc. of the present invention contains a thermoplastic resin, the content ratio of the thermoplastic resin is not particularly limited, but from the viewpoint of providing an appropriate initial hardness to the adhesive layer, etc. and hardness after external stimulation, the present invention It is preferably 50% by mass or more, more preferably 70% by mass or more, based on 100% by mass of the total amount of the adhesive layer, etc. Additionally, the amount of thermoplastic resin includes the thermoplastic resin, its raw material monomer, crosslinking agent, and the amount of structural portions derived from the crosslinking agent.

When the adhesive layer of the present invention, etc. contains a thermoplastic resin as the polymer (A1), the content ratio of the thermoplastic resin is preferably 20 to 97% by mass with respect to the total amount of 100% by mass of the adhesive layer of the present invention, etc. , more preferably 50 to 95 mass%, and even more preferably 70 to 93 mass%. When the adhesive layer or the like of the present invention contains a thermosetting resin as a base polymer, the content ratio is preferably 30% by mass or less, and may be 10% by mass or less, 5% by mass or less, 1% by mass or less, or 0% by mass. It's okay.

When the adhesive layer of the present invention, etc. contains a thermoplastic resin as the polymer (A2), the content ratio of the thermoplastic resin is preferably 50% by mass or more with respect to the total amount of 100% by mass of the adhesive layer of the present invention, etc., More preferably, it is 70 mass% or more, further preferably, is 80 mass% or more, and particularly preferably is 90 mass% or more.

It is preferable that the shear storage modulus (G') of the adhesive layer or the like of the present invention is reduced by external stimulation (particularly, active energy ray irradiation). The flexibility of these adhesive layers, etc. is improved by external stimulation. Additionally, it is preferable that the shear storage modulus (G') does not increase after the decrease.

The adhesive layer of the present invention preferably has a shear storage modulus (G') at 25°C before external stimulation of 1.0×10 ³ to 1.0×10 ⁸ Pa, more preferably 1.0×10 ⁴ to 1.0×10. ⁷ Pa, more preferably 1.0×10 ⁴ to 1.0×10 ⁶ Pa, particularly preferably 2.0×10 ⁴ to 1.0×10 ⁵ Pa. The adhesive layer or the like having the shear storage modulus has appropriate hardness before external stimulation is applied and is excellent in handling properties.

The adhesive layer of the present invention preferably has a shear storage modulus (G') at 50°C before external stimulation of 1.0×10 ³ to 5.0×10 ⁷ Pa, more preferably 7.0×10 ³ to 1.0×10 ⁶ Pa, more preferably 1.0×10 ⁴ to 1.0×10 ⁵ Pa. The pressure-sensitive adhesive layer or the like having the above-mentioned shear storage modulus has appropriate hardness before external stimulation is applied even when the temperature is slightly elevated due to the environment, for example, and is excellent in handleability.

The adhesive layer of the present invention preferably has a shear storage modulus (G') at 85°C before external stimulation of 1.0×10 ² to 1.0×10 ⁶ Pa, more preferably 1.0×10 ³ to 1.0×10 ⁵ Pa, more preferably 5.0×10 ³ to 1.0×10 ⁵ Pa. Even when applied under a high-temperature environment, for example, the adhesive layer having the above-described shear storage modulus has appropriate hardness before external stimulation is applied, and has superior handleability.

The adhesive layer and the like of the present invention preferably have a shear storage modulus (G') at 25°C after external stimulation of 1.0×10 ² to 5.0×10 ⁶ Pa, more preferably 1.0×10 ³ to 5.0×10. ⁵ Pa, more preferably 3.0×10 ³ to 1.0×10 ⁵ Pa, particularly preferably 5.0×10 ³ to 5.0×10 ⁴ Pa. If the shear storage modulus is within the above range, the adhesive layer of the present invention has better flexibility, step followability, adhesion, etc. after external stimulation is applied.

The adhesive layer and the like of the present invention preferably have a shear storage modulus (G') at 50°C after external stimulation of 1.0×10 ² to 1.0×10 ⁶ Pa, more preferably 5.0×10 ² to 3.0×10. ⁵ Pa, more preferably 1.0×10 ³ to 1.0×10 ⁵ Pa, particularly preferably 2.0×10 ³ to 8.0×10 ⁴ Pa. If the shear storage modulus is within the above range, after external stimulation is applied, for example, when the temperature is slightly raised due to the environment, flexibility is superior, step followability, adhesion, etc. are superior.

The adhesive layer and the like of the present invention preferably have a shear storage modulus (G') at 85°C after external stimulation of 1.0×10 ² to 8.0×10 ⁵ Pa, more preferably 3.0×10 ² to 1.0×10. ⁵ Pa, more preferably 5.0×10 ² to 1.0×10 ⁵ Pa, particularly preferably 1.0×10 ² to 7.0×10 ⁴ Pa. If the shear storage modulus is within the above range, after external stimulation is applied, for example, when applied under a high temperature environment, flexibility is superior, step followability, adhesion, etc. are superior.

The adhesive layer and the like of the present invention have a ratio of the shear storage modulus (G') at 25°C before external stimulation and the shear storage modulus (G') at 25°C after external stimulation [after external stimulation/applied external stimulation]. Total] is preferably less than 0.95 (e.g., 0.01 or more and less than 0.95), more preferably 0.8 or less (e.g., 0.05 to 0.8), even more preferably 0.7 or less (e.g., 0.1 to 0.7), especially Preferably it is 0.6 or less (for example, 0.2 to 0.6). In this case, the flexibility, level difference followability, and adhesion of the adhesive layer and the like at around room temperature tend to change more significantly before and after external stimulation is applied.

The adhesive layer and the like of the present invention have a ratio of the shear storage modulus (G') at 50°C before external stimulation and the shear storage modulus (G') at 50°C after external stimulation [after external stimulation/applied external stimulation]. Total] is preferably less than 0.95 (e.g., 0.01 or more and less than 0.95), more preferably 0.8 or less (e.g., 0.05 to 0.8), even more preferably 0.7 or less (e.g., 0.1 to 0.7), especially Preferably it is 0.6 or less (for example, 0.2 to 0.6). In this case, the flexibility, step followability, and adhesion of the adhesive layer etc. around 50°C tend to change more significantly before and after external stimulation is applied.

The adhesive layer and the like of the present invention have a ratio of the shear storage modulus (G') at 85°C before external stimulation and the shear storage modulus (G') at 85°C after external stimulation [after external stimulation/applied external stimulation]. Total] is preferably less than 0.95 (e.g., 0.01 or more and less than 0.95), more preferably 0.8 or less (e.g., 0.05 to 0.8), even more preferably 0.7 or less (e.g., 0.1 to 0.7), especially Preferably it is 0.6 or less (for example, 0.2 to 0.6). In this case, the flexibility, step followability, and adhesion of the adhesive layer etc. in a high temperature environment before and after the application of an external stimulus tend to change more significantly.

The adhesive layer of the present invention preferably has the property of reducing hardness due to external stimulation. It is preferable that the hardness does not increase after reduction. The flexibility of such an adhesive layer, etc. is maintained without an increase in hardness when the adhesive layer, etc. is adhered or adhered to a member.

The hardness is preferably Young's modulus measured by, for example, a tensile compression tester. That is, the adhesive layer of the present invention has a property in which the Young's modulus is reduced by external stimulation.

In other words, it is preferable that the Young's modulus of the adhesive layer of the present invention, etc., after the external stimulus is applied is lower than the Young's modulus before the external stimulus is applied. Such an adhesive layer or the like has excellent handling properties before applying an external stimulus, and is superior in flexibility, impact resistance, and resistance to shape deformation at high speeds after applying an external stimulus.

The adhesive layer of the present invention, etc. preferably has a Young's modulus (E1) of 200 MPa or less (for example, 0.03 to 200 MPa) before external stimulation is applied. In addition, the pressure-sensitive adhesive layer, etc. preferably has a Young's modulus (E2) of 50 MPa or less (for example, 0.001 to 50 MPa) after external stimulation is applied. The adhesive layer or the like having the Young's modulus has appropriate hardness before external stimulation is applied, and has superior workability in manufacturing, processing, storage, transportation, etc. In addition, the pressure-sensitive adhesive layer having the above-mentioned Young's modulus has excellent flexibility after external stimulation, and is superior in step followability, adhesion, etc.

The adhesive layer preferably has a Young's modulus (E1) before external stimulation of 0.03 to 1.5 MPa, more preferably 0.05 to 1.0 MPa, and even more preferably 0.1 to 0.8 MPa. The pressure-sensitive adhesive layer having the above-mentioned Young's modulus (E1) has appropriate hardness before external stimulation is applied and is superior in handleability.

The adhesive layer preferably has a Young's modulus (E1) before external stimulation of 0.1 to 200 MPa, more preferably 0.3 to 100 MPa, and still more preferably 0.5 to 20 MPa. The adhesive layer having the above-mentioned Young's modulus has appropriate hardness before external stimulation is applied, and is superior in workability such as manufacturing, processing, storage, and transportation.

The adhesive layer preferably has a Young's modulus (E2) after external stimulation of less than 1.0 MPa (e.g., 0.001 MPa or more and less than 1.0 MPa), more preferably 0.5 MPa or less (e.g., 0.005 to 0.5 MPa), and further. Preferably it is 0.3 MPa or less (for example, 0.01 to 0.3 MPa). The adhesive layer having the Young's modulus (E2) has excellent flexibility after external stimulation, excellent resistance to micro-deformation, excellent impact resistance, resistance to shape deformation at high speeds, step followability, and adhesion.

The adhesive layer preferably has a Young's modulus (E2) after external stimulation of 50 MPa or less (e.g., 0.01 MPa or more and less than 50 MPa), more preferably 10 MPa or less (e.g., 0.05 to 10 MPa), More preferably, it is 5 MPa or less (for example, 0.1 to 5 MPa). The adhesive layer having the above-mentioned Young's modulus has excellent flexibility after external stimulation, and is superior in step followability, adhesion, etc.

The adhesive layer of the present invention has a ratio of Young's modulus (E1) before external stimulation and Young's modulus (E2) after external stimulation (Young's modulus (E2)/Young's modulus (E1)) of less than 0.95 (e.g., 0.1 to 0.95). It is preferable, more preferably 0.8 or less (for example, 0.2 to 0.8), and even more preferably 0.7 or less (for example, 0.3 to 0.7). In this case, the flexibility of the adhesive layer and the like before and after external stimulation is excellent, the resistance to micro-deformation is excellent, and the impact resistance, resistance to shape deformation at high speeds, step followability, adhesion, etc. are excellent.

It is preferable that the breaking elongation of the adhesive layer or the like of the present invention after the external stimulus is applied is higher than the breaking elongation before the external stimulus is applied. Additionally, the adhesive layer and the like do not have to break when stretched to 500% before or after external stimulation is applied. Such an adhesive layer and the like have excellent handling properties before applying an external stimulus, and are excellent in resistance to micro-deformation, impact resistance, and resistance to shape deformation in a high-speed range after application of an external stimulus.

The adhesive layer or the like of the present invention preferably has a breaking elongation (B1) of 100 to 2000% before external stimulation, more preferably 100 to 1000%, further preferably 120 to 900%, particularly preferably 150 to 150%. It is 850%. The pressure-sensitive adhesive layer or the like having the breaking elongation (B1) has appropriate hardness before external stimulation is applied and is superior in handling properties.

The adhesive layer or the like of the present invention preferably has a breaking elongation (B2) of 100 to 1300% after external stimulation, more preferably 130 to 1100%, and still more preferably 160 to 1000%. The adhesive layer or the like having the Young's modulus (B2) has excellent flexibility after external stimulation, excellent resistance to micro-deformation, and excellent impact resistance and shape deformation resistance in the high-speed range.

In the adhesive layer of the present invention, the ratio of the breaking elongation (B1) before external stimulation and the breaking elongation (B2) after external stimulation (elongation at break (B2)/elongation at break (B1)) exceeds 1.1 (for example, exceeds 1.1). It is preferably 2.0 or less), more preferably 1.2 or more (for example, 1.2 to 1.8), and even more preferably 1.3 or more (for example, 1.3 to 1.6). In this case, the flexibility of the adhesive layer and the like before and after external stimulation is excellent, the resistance to micro-deformation is excellent, and the impact resistance and shape deformation resistance in the high-speed range are superior.

The thickness of the adhesive layer of the present invention is not particularly limited, but is, for example, about 5 to 250 μm, more preferably 7 to 200 μm, further preferably 10 to 100 μm, particularly preferably 10 to 250 μm. It is 50㎛.

Polymer (A) can be obtained using a compound (sometimes referred to as “compound (a)”) capable of introducing the above degradable bond into a polymer. Examples of the compound (a) include monomer components, oligomer components, and crosslinking agents having the above decomposable bond. That is, the polymer (A) may contain a structural unit derived from a monomer component and/or an oligomer component having a decomposable bond, and may contain a structural moiety derived from the crosslinking agent. When compound (a) is a monomer component or an oligomer component, polymer (A) having the degradable bond is obtained by polymerizing or copolymerizing the monomer component or oligomer component with another monomer component. The compound (a) may be used alone or in combination of two or more.

When compound (a) is a monomer component or an oligomer component, the degradable bond may be present in the portion constituting the side chain of the polymer (A) or may be present in the portion constituting the main chain. When it is present in the part constituting the side chain, it is preferable from the viewpoint of making it difficult to apply stress when greatly deformed and maintaining handling properties in the actual use temperature range (assuming room temperature). On the other hand, when it is present in the part constituting the main chain, it is preferable from the viewpoint that the molecular weight of the polymer is further reduced after cleavage of the degradable bond, flexibility is further improved, and a significant change in physical properties can be exhibited.

Compound (a) preferably has a functional group (functional group (L1)) other than the above decomposable bond. When having two or more functional groups (L1), compound (a) functions as a crosslinking agent. Additionally, when the functional group (L1) is a polymerizable functional group, compound (a) functions as a monomer component or an oligomer component.

Examples of the polymerizable functional group include cationic polymerizable groups, anionic polymerizable groups, and radical polymerizable groups. Among them, a radical polymerizable group is preferable. Examples of the radically polymerizable group include radically polymerizable carbon-carbon double bonds such as (meth)acryloyl group and vinyl group.

Functional groups (L1) other than the polymerizable functional groups include thiol groups, carboxyl groups, hydroxy groups, amino groups, epoxy groups, and isocyanate groups, from the viewpoint of ensuring a certain degree of flexibility of the adhesive layer and the like by ensuring an appropriate crosslinking density.

The number of functional groups in the compound (a) increases the molecular weight after introduction into the polymer (A), giving the polymer a certain hardness before applying an external stimulus, while lowering the molecular weight of the polymer after cleavage to demonstrate flexibility. From this point of view, it is preferable to have two or more. On the other hand, as the number of functional groups increases, it becomes crosslinked with many polymers, making it difficult to obtain the effect due to cleavage of degradable bonds. Therefore, from the viewpoint of ensuring a certain degree of flexibility of the adhesive layer, etc. by adjusting the crosslinking density, the number of functional groups is Four or less is preferable, and more preferably three or less.

Compound (a) (sometimes referred to as “compound (a1)”) having the above reversibly decomposable bond includes a compound having a disulfide bond. Examples of the compounds having the disulfide bond include 4,4'-dithioibutyric acid, 4,4'-dithiodiphenol (bis(4-hydroxyphenyl)disulfide), 2,2'-dithiodianiline, 4, Examples include 4'-dithiodianiline, 3,3'-dithiodipropionic acid, and dithiodiethanol. Among these, 4,4'-dithioibutyric acid, 4,4'-dithiodiphenol, and 4,4'-dithiodianiline are particularly preferred from the viewpoint of better solubility.

The compound (a1) is preferably one that does not have an aromatic ring from the viewpoint of suppressing coloring of the adhesive layer or the like over time. On the other hand, compound (a1) may preferably have an aromatic ring when adjusting other properties such as the refractive index.

The compound (a) (sometimes referred to as “compound (a2)”) having the irreversible decomposable bond is preferably a monomer (nitrobenzyl-based monomer) in which a nitrobenzyl group and a polymerizable functional group are bonded through a linking group. The linking group is not particularly limited, but an ester bond is preferable. A nitrobenzyl-based monomer in which the linking group is an ester bond may be referred to as a “nitrobenzyl ester-based monomer.” Examples of the nitrobenzyl ester monomer include esters of a compound having a nitrobenzyl alcohol skeleton and a compound having a polymerizable functional group and a carboxyl group, or esters of a compound having a nitrophenylacetic acid skeleton and a compound having a polymerizable functional group and a hydroxy group. Examples include cargo, etc.

Compounds having the nitrobenzyl alcohol skeleton include 2-nitrobenzyl alcohol and 2-nitro-1,3-bis(hydroxymethyl)benzene. Examples of the compound having the nitrophenylacetic acid skeleton include 2-nitroisophthalic acid. As the nitrobenzyl ester monomer, 2-nitro-1,3-bis((meth)acryloyloxymethylene)benzene is preferable.

The nitrobenzyl ester monomer is obtained by esterifying a carboxylic acid (for example, (meth)acrylic acid) having a polymerizable functional group and a compound having a nitrobenzyl alcohol skeleton, or a compound having a polymerizable functional group and a hydroxy group and nitrophenylacetic acid. It can be produced by esterifying a compound having a skeleton.

The content ratio of polymer (A) in the adhesive layer of the present invention, etc. is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably It is 65 mass% or more, especially preferably 70 mass% or more. Additionally, the amount of the polymer (A) includes the polymer (A), its raw material monomer, the crosslinking agent, and the amount of structural portions derived from the crosslinking agent.

When the adhesive layer, etc. of the present invention contains polymer (A1), the content ratio of polymer (A1) in the adhesive layer, etc. of the present invention is 30 to 99% by mass with respect to the total amount of 100% by mass of the adhesive layer, etc. of the present invention. is preferable, more preferably 40 to 97 mass%, further preferably 50 to 95 mass%, and particularly preferably 70 to 95 mass%. If the content is 30% by mass or more, adhesion is easily imparted to the adhesive layer and the like. If the content is 99% by mass or less, it is easy to design the composition by mixing a crosslinking agent or a recombination inhibitory compound (B). Additionally, the amount of the polymer (A1) includes the polymer (A1), its raw material monomer, the crosslinking agent, and the amount of structural portions derived from the crosslinking agent.

When the adhesive layer, etc. of the present invention contains polymer (A2), the content ratio of polymer (A2) in the adhesive layer, etc. of the present invention is 50% by mass or more with respect to the total amount of 100% by mass of the adhesive layer, etc. of the present invention. It is preferable, more preferably 70 mass% or more, further preferably 80 mass% or more, and particularly preferably 90 mass% or more. Additionally, the amount of the polymer (A2) includes the polymer (A2), its raw material monomer, the crosslinking agent, and the amount of structural portions derived from the crosslinking agent.

The content ratio of one or more selected from the group consisting of structural units derived from compound (a1) and structural parts derived from compound (a1) in polymer (A1) is from the viewpoint of demonstrating sufficient flexibility by being cleaved and shredded after external stimulation is applied. is preferably 0.5% by mass or more, more preferably 1.0% by mass or more, and still more preferably 1.5% by mass or more, based on the total amount of 100% by mass of polymer (A1). In addition, in order to make the crosslinking density appropriate and provide appropriate flexibility to the resin before external stimulation is applied, it is preferably 50% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less. In addition, in this specification, when two or more types of polymers are entangled, the entangled polymer is converted into one polymer.

When the pressure-sensitive adhesive layer of the present invention contains polymer (A1), the content of the cross-linking agent and/or the structural portion derived from the cross-linking agent in the pressure-sensitive adhesive layer of the present invention is 0.5 to 40% based on 100% by mass of the total amount of polymer (A1). The mass % is preferable, more preferably 1 to 35 mass %, and even more preferably 1.5 to 30 mass %. In addition, when compound (a1) is a crosslinking agent, the above content includes the amount of compound (a1) and the structural moiety derived from compound (a1).

The content ratio of at least one selected from the group consisting of structural units derived from compound (a2) and structural parts derived from compound (a2) in polymer (A2) is from the viewpoint of demonstrating sufficient flexibility by being cleaved and shredded after external stimulation is applied. is preferably 0.1 to 15% by mass, more preferably 0.2 to 10% by mass, further preferably 0.5 to 5% by mass, especially preferably 1 to 3% by mass, based on the total amount of 100% by mass of polymer (A2). %am.

When the pressure-sensitive adhesive layer of the present invention contains polymer (A2), the content of the cross-linking agent and/or the structural portion derived from the cross-linking agent in the pressure-sensitive adhesive layer of the present invention is 0.1 to 15% based on 100% by mass of the total amount of polymer (A2). The mass % is preferable, more preferably 0.2 to 10 mass %, further preferably 0.5 to 5 mass %, and particularly preferably 1 to 3 mass %. In addition, when compound (a2) is a crosslinking agent, the above content includes the amount of compound (a2) and the structural moiety derived from compound (a2).

The recombination-inhibiting compound (B) is a compound capable of inhibiting the recombination of cleavage of the polymer (A1) caused by an external stimulus, and is not particularly limited, but when radicals are generated by cleavage of the polymer (A1), the radical Compounds with trapping ability (radical entrapment agents) are preferred. Examples of the radical trapping agent include a radical photopolymerization initiator, a spin trapping agent, an antioxidant, a polymerization inhibitor, and a hydrogen donor.

The radical photopolymerization initiator is not particularly limited, and examples include benzoin ether-based photopolymerization initiators, acetophenone-based photopolymerization initiators, α-ketol-based photopolymerization initiators, aromatic sulfonyl chloride-based photopolymerization initiators, and photoactivators. Oxime-based photopolymerization initiator, benzoin-based photopolymerization initiator, benzyl-based photopolymerization initiator, benzophenone-based photopolymerization initiator, ketal-based photopolymerization initiator, thioxanthone-based photopolymerization initiator, acylphosphine oxide-based photopolymerization initiator, etc. You can.

Examples of the benzoin ether-based photopolymerization initiator include benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, and 2,2-dimethoxy-1,2. -Diphenylethan-1-one, anisole methyl ether, etc. are mentioned. Examples of the acetophenone-based photopolymerization initiator include 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexylphenyl ketone, and 4-phenoxydichloroacetophenone. , 4-(t-butyl)dichloroacetophenone, etc. Examples of the α-ketol photopolymerization initiator include 2-methyl-2-hydroxypropiophenone, 1-[4-(2-hydroxyethyl)phenyl]-2-methylpropan-1-one, etc. I can hear it. Examples of the aromatic sulfonyl chloride-based photopolymerization initiator include 2-naphthalenesulfonyl chloride. Examples of the photoactive oxime-based photopolymerization initiator include 1-phenyl-1,1-propanedione-2-(o-ethoxycarbonyl)-oxime. Examples of the benzoin-based photopolymerization initiator include benzoin. Examples of the benzyl-based photopolymerization initiator include benzyl and the like. Examples of the benzophenone-based photopolymerization initiator include benzophenone, benzoylbenzoic acid, 3,3'-dimethyl-4-methoxybenzophenone, polyvinylbenzophenone, and α-hydroxycyclohexylphenyl ketone. . Examples of the ketal-based photopolymerization initiator include benzyldimethylketal. Examples of the thioxanthone-based photopolymerization initiator include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, and 2,4- Diisopropylthioxanthone, dodecylthioxanthone, etc. can be mentioned. Examples of the acylphosphine oxide-based photopolymerization initiator include bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide and bis(2,4,6-trimethylbenzoyl)-2,4-di-n-. Butoxyphenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, etc.

The content of the recombination-inhibiting compound (B) is 1 selected from the group consisting of compound (a1), a structural unit derived from compound (a1), and a structural moiety derived from compound (a1) from the viewpoint of exhibiting an appropriate recombination-inhibiting effect. It is preferably 10 to 1000 parts by mass, more preferably 50 to 500 parts by mass, further preferably 75 to 400 parts by mass, and particularly preferably 100 to 300 parts by mass, based on the above total amount of 100 parts by mass.

The adhesive layer or the like of the present invention may contain other components other than the components described above as needed. Examples of the other components include resins other than polymer (A), curing catalysts, crosslinking agents (including polyfunctional (meth)acrylates), crosslinking accelerators, polymerization initiators, tackifying resins (rosin derivatives, polyterpene resins) , petroleum resins, oil-soluble phenols, etc.), oligomers, anti-aging agents, fillers (metal powders, organic fillers, inorganic fillers, etc.), colorants (pigments, dyes, etc.), antioxidants, plasticizers, softeners, surfactants, antistatic agents, surface lubricants. , leveling agent, light stabilizer, ultraviolet absorber, sensitizer, polymerization inhibitor, granular material, thin material, flame retardant, silane coupling agent, ion trap agent, etc. As for the other components mentioned above, only one type may be used or two or more types may be used.

Examples of the curing catalyst include organic titanium compounds and organic zirconium compounds. Examples of the organic titanium compound include titanium alkoxide, titanium chelate, and titanium acylate. Examples of the organic zirconium compound include zirconium alkoxide, zirconium chelate, and zirconium acylate. Examples of titanium alkoxide include tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, and tetraoctyl titanate. Examples of titanium chelates include titanium acetylacetonate, titanium tetraacetylacetonate, titanium ethylacetoacetate, and titanium octylene glycolate. Examples of titanium acylate include titanium isostearate. Examples of zirconium alkoxide include normal propyl zirconate and normal butyl zirconate. Examples of zirconium chelates include zirconium tetraacetylacetonate and zirconium monoacetylacetonate. Examples of zirconium acylate include zirconium stearate.

The content ratio of the curing catalyst is not particularly limited, but is 0.005 to 3 mass% with respect to 100% by mass of the total amount of the adhesive layer of the present invention, from the viewpoint of providing appropriate initial hardness to the adhesive layer and the like and hardness after external stimulation. % is preferable, more preferably 0.01 to 1 mass %, and even more preferably 0.05 to 1 mass %.

The crosslinking agent is not particularly limited as long as it crosslinks the polymer, and includes polyisocyanate compounds, epoxy compounds, polyol compounds (polyphenol-based compounds, etc.), aziridine compounds, melamine-based crosslinking agents, oxazoline-based crosslinking agents, and polyfunctional (meth) Acrylates, etc. can be mentioned. Polyfunctional (meth)acrylates include (meth)acrylic acid esters having more than two functionality, such as trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, and pentaerythritol tetra(meth)acrylate. ) Acrylate, dipentaerythritol hexa(meth)acrylate, etc. can be mentioned.

<Adhesive composition, adhesive composition>

The adhesive layer of the present invention is formed from an adhesive composition. Additionally, the adhesive layer is formed from the adhesive composition. The adhesive composition and the like preferably contain at least a base polymer and/or a raw material monomer thereof. Among these, it is preferable to include a base polymer from the viewpoint of exhibiting adhesiveness to the resulting adhesive layer. The base polymer is polymer (A) and/or another polymer (i.e., a polymer that does not have a degradable bond). When the base polymer is any of the other polymers mentioned above, the pressure-sensitive adhesive composition, etc. further contains compound (a). Only one type of the base polymer may be used, or two or more types may be used.

When the base polymer is any of the other polymers mentioned above, the pressure-sensitive adhesive composition, etc. further contains compound (a). Additionally, in this case, a monomer component (sometimes referred to as “monomer component (c)”) that has further reactivity with the compound (a) may be included. Compound (a) is reactive with the other polymer and/or monomer component (c). When the compound (a) is reactive with the other polymers, the other polymers and the compound (a) react with heat or active energy ray irradiation in the adhesive layer, etc. to form, for example, polymer chains, and the polymer The chains and the other polymers are combined to form a network structure, and an adhesive layer containing the polymer (A) is obtained. When the compound (a) and the monomer component (c) are included, the compound (a) and the monomer component (c) react in the adhesive layer or the like by heat or active energy ray irradiation to form, for example, a polymer chain, The polymer chains and the other polymers are entangled to form a network structure, and an adhesive layer containing the polymer (A) is obtained. Only one type of monomer component (c) may be used, or two or more types may be used.

When the pressure-sensitive adhesive composition or the like contains the raw material monomer, compound (a) is introduced into the base polymer when polymerizing the raw material monomer, and polymer (A) is formed. Alternatively, the above-mentioned raw material monomer is polymerized to form the above-described other polymer, and then reacted with compound (a) to form polymer (A).

The adhesive composition, etc. mainly includes (i) an adhesive composition containing the polymer (A), (ii) an adhesive composition containing the polymer (A) and the other polymers mentioned above, and (iii) the other polymers and compounds mentioned above. (a), a pressure-sensitive adhesive composition containing a monomer component (c) as needed, and (iv) a pressure-sensitive adhesive composition containing a raw material monomer, a compound (a), and a monomer component (c) as needed. In addition, when the polymer (A) is polymer (A1), the adhesive compositions (i) to (iv) and the like further contain a recombination inhibitory compound (B).

Therefore, the polymer (A) may be a reactant of the other polymer, compound (a), and monomer (c), or may be a reactant of the other polymer and the other polymer and compound (a) (particularly, an entangled polymer). ) It may be a polymer. Additionally, when the base polymer is polymer (A), the adhesive layer, etc. may include unreacted compound (a) and/or unreacted monomer (c).

The adhesive composition and the like may contain components other than the components described above. Examples of the other components include those exemplified and explained as other components that may be included in the adhesive layer of the present invention, and solvents such as organic solvents. As for the other components mentioned above, only one type may be used or two or more types may be used.

(Adhesive composition, etc. (M1))

The pressure-sensitive adhesive composition, etc., which forms the pressure-sensitive adhesive layer or the like of the present invention containing the polymer (A1) (sometimes referred to as “the pressure-sensitive adhesive composition, etc. (M1)”) further contains a recombination-inhibiting compound (B). The base polymer that the adhesive composition, etc. (M1) may contain is preferably the other polymers mentioned above.

Examples of the base polymer include the thermoplastic resin, the thermosetting resin, and the active energy ray-curable resin. Among them, thermoplastic resins and thermosetting resins are preferable. An adhesive layer containing a thermoplastic resin, for example, can exhibit adhesiveness that adheres under pressure from the outside. An adhesive layer containing a thermosetting resin can adhere to an adherend by, for example, curing by heating.

Examples of compound (a1) include monomer components, oligomer components, cross-linking agents, etc. having the above reversibly decomposable bond, as described above. Among these, a crosslinking agent is preferable, and a crosslinking agent having a disulfide bond is more preferable.

As the functional group (L1) of the compound (a1) as the crosslinking agent, a hydroxy group and a carboxyl group are preferable, especially from the viewpoint of ensuring an appropriate crosslinking density of the polymer (A1).

When compound (a1) is reactive with the other polymers, the other polymers have a functional group (L2) that can react with the functional group (L1) in compound (a1). The functional group (L2) is appropriately selected depending on the type of the functional group (L1) described above, and examples include groups containing cyclic ethers such as carboxyl groups and epoxy groups, aziridyl groups, hydroxy groups, isocyanate groups, (meth)acryloyl groups, Amino group, aldehyde group, etc. are mentioned.

Combinations of the functional group (L1) and the functional group (L2) include a group containing a carboxyl group and a cyclic ether, a group containing a cyclic ether and a carboxyl group, a carboxyl group and an aziridyl group, an aziridyl group and a carboxyl group, a hydroxy group and an isocyanate group, an isocyanate group and a hydroxy group, ( Examples include a meth)acryloyl group, a (meth)acryloyl group, a hydroxy group and an amino group, an amino group and a hydroxy group, a group containing a cyclic ether and a hydroxy group, and a group containing a hydroxy group and a cyclic ether. Among these, from the viewpoint of ease of reaction tracking, a combination of a group containing a carboxyl group and a cyclic ether, a combination of a group containing a cyclic ether and a carboxyl group, a combination of a group containing a cyclic ether and a hydroxy group, and a group containing a hydroxy group and a cyclic ether. A combination of is preferable. That is, a group (particularly an epoxy group) in which the functional group (L1) contains a hydroxy group or a carboxyl group and the functional group (L2) contains a cyclic ether is preferable.

The number of functional groups (L2) in the above-mentioned other polymers having functional groups (L2) is 2 from the viewpoint of increasing the molecular weight after introduction into the polymer (a1) and lowering the molecular weight of the polymer after cleavage. There may be more than one (for example, 2 to 4). On the other hand, from the viewpoint of ensuring a certain degree of flexibility of the adhesive layer and the like by maintaining an appropriate crosslinking density, the number of functional groups (L2) is preferably 3 or less, and more preferably 2.

The monomer component (c) is a compound having two or more polymerizable functional groups. The polymerizable functional group is preferably a functional group (L3) that can react with the functional group (L1) of compound (a1) as a crosslinking agent. As a result, the monomer (c) can be polymerized and crosslinked by the compound (a1) to form a polymer chain having a reversible decomposable bond within the molecule. Additionally, it is preferable that the functional group (L3) can react with the functional group (L2). The functional group (L3) is appropriately selected depending on the type of the functional group (L1) or functional group (L2) described above. For example, a group containing cyclic ethers such as a carboxyl group and an epoxy group, an aziridyl group, a hydroxy group, an isocyanate group, (meth) ) Acryloyl group, amino group, aldehyde group, etc. can be mentioned.

Examples of the combination of the functional group (L1) and the functional group (L3) include those exemplified and explained as the combination of the functional group (L1) and the functional group (L2) described above. Among them, from the viewpoint of ease of reaction tracking, a combination of a group containing a carboxyl group and a cyclic ether, a combination of a group containing a cyclic ether and a carboxyl group, a combination of a group containing a cyclic ether and a hydroxy group, and a group containing a hydroxy group and a cyclic ether. A combination of is preferable. That is, a group (particularly an epoxy group) in which the functional group (L1) contains a hydroxy group or a carboxyl group and the functional group (L3) contains a cyclic ether is preferred.

The number of functional groups (L3) in the monomer component (c) is 2 or more (for example, from the viewpoint of increasing the molecular weight after introduction into the polymer (A1) and lowering the molecular weight of the polymer after cleavage. For example, 2 to 4) may be sufficient. On the other hand, from the viewpoint of ensuring a certain degree of flexibility of the adhesive layer and the like by maintaining an appropriate crosslinking density, the number of functional groups (L3) is preferably 3 or less, and more preferably 2.

As the functional group (L3), a group having a cyclic ether group is preferable, and an epoxy group is particularly preferable. That is, an epoxy compound is preferable as the monomer component (c). Examples of such epoxy compounds include 4,4'-isopropylidene dicyclohexanol and (chloromethyl)oxirane.

The equivalent weight of the polymerizable functional group of the monomer component (c) is preferably 100 to 10,000 eq/g, more preferably 150 to 9,000 eq/g, from the viewpoint of making the crosslinked structure appropriate and not too dense.

When the base polymer is the other polymers mentioned above, the content of the monomer component (c) in the pressure-sensitive adhesive composition, etc. (M1) is preferably 5 to 600 parts by mass, more preferably 7 to 600 parts by mass, based on 100 parts by mass of the total amount of the base polymer. It is 500 parts by mass. When the other polymer is a thermosetting resin, the content is preferably 200 to 600 parts by mass, more preferably 300 to 500 parts by mass, and still more preferably 350 to 450 parts by mass. When the other polymer is a thermoplastic resin, the content is preferably 5 to 80 parts by mass, more preferably 5 to 50 parts by mass, and even more preferably 7 to 30 parts by mass.

When the base polymer is a polymer (A1), the content of the monomer component (c) in the adhesive composition (M1) is preferably 5 to 95% by mass, more preferably 5 to 95% by mass, based on 100% by mass of the total amount of the polymer (A1). is 7 to 90 mass%. When the polymer (A1) is a thermosetting resin, the content ratio is preferably 50 to 95% by mass, more preferably 60 to 90% by mass, and still more preferably 65 to 85% by mass. When the polymer (A1) is a thermoplastic resin, the content ratio is preferably 3 to 50% by mass, more preferably 5 to 40% by mass, and still more preferably 6 to 30% by mass.

The content ratio of the above-mentioned other polymers in the adhesive composition, etc. (M1) is 5 to 5% by mass based on 100% by mass of the total amount of the adhesive composition, etc. (M1) (excluding components that do not remain during layer formation, such as organic solvents). 99% by mass is preferable, more preferably 10 to 95% by mass. When the other polymer is a thermosetting resin, the content ratio is preferably 5 to 50% by mass, more preferably 7 to 40% by mass, and still more preferably 10 to 30% by mass. When the other polymer is a thermoplastic resin, the content ratio is preferably 30 to 99% by mass, more preferably 50 to 95% by mass, and still more preferably 60 to 90% by mass. If the content is 5% by mass or more, adhesiveness is easily imparted to the adhesive layer and the like. If the content is 99% by mass or less, it is easy to design the composition by mixing a crosslinking agent or a recombination inhibitory compound (B) component.

The content of the crosslinking agent and/or the structural portion derived from the crosslinking agent in the adhesive composition, etc. (M1) is preferably 0.5 to 40 parts by mass, more preferably 0.5 to 40 parts by mass, based on 100 parts by mass of the total amount of the other polymer and/or monomer component (c). is 1 to 35 parts by mass, more preferably 1.5 to 30 parts by mass. In addition, when compound (a1) is a crosslinking agent, the above content includes the amount of compound (a1).

(Adhesive composition, etc. (M2))

The base polymer that the adhesive composition, etc. (sometimes referred to as “adhesive composition, etc. (M2)”) forming the adhesive layer, etc. of the present invention containing polymer (A2) may contain is, among others, polymer (A2). It is preferable that it contains, and it is more preferable that it contains polymer (A2) and the other polymers mentioned above. Additionally, it is preferable that the polymer (A2) is a curable resin. The curability of the curable resin is appropriately selected depending on the type of irreversible decomposable bond, and if the irreversible decomposable bond can be cleaved by active energy rays, it is preferable to use a thermosetting resin.

The polymer (A2), which is the curable resin, is preferably a resin (prepolymer) having a polymerizable functional group. When the polymer (A2) has a polymerizable functional group, when forming an adhesive layer, etc., polymerization of the polymerizable functional groups proceeds by heat or active energy ray irradiation after application of the adhesive composition, etc., thereby forming the polymer with the other polymers above. Through entanglement, a network structure can be formed. That is, the polymer (A2) is preferably a polymer that can form the above network structure.

Examples of the base polymer include the thermoplastic resin, the thermosetting resin, and the active energy ray-curable resin. Among these, the polymer (A2) as the base polymer is preferably a curable resin, and more preferably a thermosetting resin. As the other polymers mentioned above, thermoplastic resins are preferable. An adhesive layer containing a thermoplastic resin, for example, can exhibit adhesiveness that adheres under pressure from the outside. An adhesive composition containing a curable resin can form a network structure by curing, for example, by heating. In addition, the other polymer may be a curable resin. In this case, the polymer (A2), which is also a curable resin, and the other polymer are bonded to each other by heat or active energy ray irradiation, etc. to form a network structure. It becomes possible to do so.

As described above, examples of compound (a2) include monomer components, oligomer components, cross-linking agents, etc. having the irreversible decomposable bond. Among these, the monomer component (that is, the compound having the polymerizable functional group) is preferable, more preferably the nitrobenzyl-based monomer, and even more preferably the nitrobenzyl ester-based monomer.

The content ratio of the polymer (A2) in the base polymer is preferably 10 to 90% by mass, more preferably 30 to 70% by mass, and still more preferably 40 to 40% by mass, based on the total amount (100% by mass) of the base polymer. It is 60% by mass. If the content is 10% by mass or more, a sufficient amount of irreversible decomposable bonds are cleaved by external stimulation. If the content is 90% by mass or less, appropriate tackiness and/or adhesiveness can be maintained even after external stimulation is applied.

The content ratio of the other polymers in the base polymer is preferably 10 to 90% by mass, more preferably 30 to 70% by mass, and still more preferably 40 to 40% by mass, based on the total amount (100% by mass) of the base polymer. It is 60% by mass. If the content is 10% by mass or more, appropriate tackiness and/or adhesiveness can be maintained even after external stimulation is applied. If the content is 90% by mass or less, the polymer (A2) can be sufficiently blended, and as a result, a sufficient amount of irreversible decomposable bonds are cleaved by external stimuli.

The content ratio of the structural unit derived from compound (a2) in polymer (A2) is preferably 0.2 to 30% by mass, more preferably 0.5 to 15% by mass, based on 100% by mass of the total amount of polymer (A2). Preferably it is 0.8 to 10 mass%. When the adhesive composition, etc. (M2) contains the raw material monomer constituting the base polymer, it is preferable that the content ratio of compound (a2) in the total monomer components constituting the polymer (A2) is within the above range.

When the polymer (A2) is the acrylic resin described above, the content ratio of structural units derived from acrylic monomers in the polymer (A2) is preferably 70 to 99.8% by mass, more preferably 70 to 99.8% by mass, based on 100% by mass of the total amount of the polymer (A2). Preferably it is 85 to 99.5 mass%, more preferably 90 to 99.2 mass%. When the adhesive composition or the like (M2) contains the raw material monomer constituting the base polymer, it is preferable that the content ratio of the acrylic monomer in the total monomer components constituting the polymer (A2) is within the above range.

The content ratio of the structural unit derived from compound (a2) in the base polymer is preferably 0.1% by mass or more based on the total amount of 100% by mass of the base polymer in order to demonstrate sufficient flexibility by being cleaved and shredded after external stimulation. It is more preferably 0.2% by mass or more, further preferably 0.5% by mass or more, and particularly preferably 1% by mass or more. In addition, in order to make the crosslinking density appropriate and provide appropriate flexibility to the resin before external stimulation is applied, it is preferably 15% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less. When the adhesive composition, etc. (M2) contains the raw material monomer constituting the base polymer, it is preferable that the content ratio of compound (a2) in all monomer components constituting the base polymer is within the above range.

When the base polymer is the acrylic resin, the content ratio of structural units derived from acrylic monomers in the base polymer is preferably 85 to 99.9% by mass, more preferably 90 to 99.9% by mass, based on 100% by mass of the total amount of the base polymer. It is 99.8 mass %, more preferably 95 to 99.5 mass %. When the pressure-sensitive adhesive composition, etc. (M2) contains the raw material monomer constituting the base polymer, it is preferable that the content ratio of the acrylic monomer in all monomer components constituting the base polymer is within the above range.

The content ratio of the base polymer in the adhesive composition, etc. (M2) is 50% by mass or more based on 100% by mass of the total amount of the adhesive composition, etc. (M2) (excluding components that do not remain during layer formation, such as organic solvents). This is preferable, more preferably 70 mass% or more, further preferably 80 mass% or more, and particularly preferably 90 mass% or more.

<Release liner>

The release liner protects the adhesive surface and/or adhesive surface in contact with the adhesive layer of the present invention, etc. until use, and is peeled off when the adhesive layer, etc. is used.

Examples of the base material for the release liner include polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, and polyethylene naphthalate film. , polybutylene terephthalate film, polyurethane film, ethylene vinyl acetate film, ionomer resin film, ethylene/(meth)acrylic acid copolymer film, ethylene/(meth)acrylic acid ester copolymer film, polystyrene film, polycarbonate. Film, polyimide film, fluororesin film, etc. can be mentioned. Additionally, these crosslinked films can also be mentioned. Additionally, these laminated films may be used.

It is preferable that a peeling treatment is applied to the peeling surface of the peeling liner (particularly the surface in contact with the adhesive layer, etc.). Examples of the release agent used in the release treatment include alkyd-based, silicone-based, fluorine-based, unsaturated polyester-based, polyolefin-based, and wax-based release agents.

The thickness of the release liner is not particularly limited, but is, for example, about 20 to 150 μm.

One embodiment of a method for producing an adhesive layer or the like of the present invention will be described. For example, the adhesive sheet with a release liner or the adhesive sheet 10 shown in FIG. 1 can be produced by the following method. An adhesive composition forming the adhesive layer, etc. 1 is applied to the base material layer or the release-treated surface of the release liner 2 on which the release treatment has been performed to form an applied layer, followed by desolvation by heating, heat curing, Alternatively, it can be produced by performing curing by irradiation with active energy rays and solidifying the application layer. In addition, when performing active energy ray irradiation, it is performed after attaching a separate release liner on the application layer.

The adhesive composition and the like may be in any form as long as the effect of the present invention is not impaired. For example, the adhesive composition may be of an emulsion type, solvent type (solution type), heat melt type (hot melt type), etc. Among them, the solvent type is preferable because it is easy to obtain a highly productive adhesive layer.

When the pressure-sensitive adhesive composition, etc. contains a polymer (A), the pressure-sensitive adhesive layer, etc. is formed by heating to solidify the application layer. In addition, when the pressure-sensitive adhesive composition, etc. contains the other polymers and/or raw material monomers and compound (a), the raw material monomers are polymerized as necessary from heating or active energy ray irradiation when solidifying the coating layer. , the compound (a) forms a bond with the polymer of the raw material monomer or the other polymers, and the polymer (A) is formed, and at the same time, the adhesive layer and the like are formed. The adhesive layer, etc. may be subsequently subjected to heating or irradiation with active energy rays, or, if the polymer (A) is a curable resin, may be subjected to a curing treatment. In this way, the pressure-sensitive adhesive sheet or adhesive sheet 10 with a release liner shown in FIG. 1 is obtained.

The use of the adhesive layer of the present invention is not particularly limited and can be used for all purposes. The adhesive layer of the present invention can be used, for example, for optical purposes, that is, for bonding to optical members. The adhesive layer or the like of the present invention is used, for example, in optical members of electrical and electronic devices, etc., when installing (mounting) various members or parts to a predetermined site (for example, a housing, etc.). Additionally, “electrical and electronic equipment” refers to equipment that corresponds to at least one of electrical equipment and electronic equipment. Examples of the electrical and electronic devices include image display devices such as liquid crystal displays, electroluminescence displays, and plasma displays, and portable electronic devices. Examples of the image display device include image display devices in the portable electronic device and displays (roll displays) inside and outside of vehicles such as trains and buses.

Examples of the portable electronic devices include mobile phones, smartphones, tablet-type personal computers, notebook-type personal computers, and various wearable devices (e.g., wrist wear types worn on the wrist such as a wrist watch, and attached to the body with a clip or strap, etc.). Modular type that is attached to a part, eyewear type including glasses type (monocular or binocular type, including head-mounted type), clothing type that is installed as an accessory, such as on a shirt, socks, hat, etc., and earphones. ear-wear type, etc.), digital cameras, digital video cameras, audio devices (portable music players, IC recorders, etc.), calculators (electronic calculators, etc.), portable game devices, electronic dictionaries, electronic notebooks, electronic books, vehicle mounted devices Examples include portable information devices, portable radios, portable TVs, portable printers, portable scanners, and portable modems. In addition, in this specification, “carrying” is not sufficient simply to be able to carry, but means having a level of portability that allows an individual (a standard adult) to carry with relative ease.

The adhesive layer of the present invention has excellent handling properties before adhesion or adhesion to a member, such as during manufacturing/processing, storage, transportation, etc., and has excellent flexibility after adhesion or adhesion to a member. For this reason, for example, when cutting with a punching blade, it is possible to prevent glue sticking out, glue missing, and process contamination resulting from these. Additionally, when stored, the glue is unlikely to protrude due to its own weight, and when transported, glue is unlikely to fall off due to vibration or contact. And, after adhesion or adhesion to a member, for example, when used by joining to a member, flexibility is excellent, so that adhesion (adhesion), adhesive force, bendability, folding resistance, bending resistance, etc. can be excellent. In addition, since the pressure-sensitive adhesive layer of the present invention can reduce stress due to external stimulation, the adhesion force and adhesion force can be varied.

[Adhesive sheet, adhesive sheet]

A pressure-sensitive adhesive sheet and/or adhesive sheet can be obtained using the pressure-sensitive adhesive layer of the present invention. In addition, in this specification, the adhesive sheet and/or the adhesive sheet may be referred to as “adhesive sheet, etc.” The above-described adhesive sheets, etc. may be so-called “base-less type” adhesive sheets that do not have a base material (base layer), or may be a type that has a base material, etc. In addition, in this specification, a “base-free type” adhesive sheet, etc. may be referred to as a “base-free adhesive sheet, etc.”, and a base-containing type adhesive sheet, etc. may be referred to as a “base-equipped adhesive sheet, etc.” there is. Examples of the inorganic adhesive sheets, etc. include double-sided adhesive sheets made only of the adhesive layer of the present invention, adhesive layers of the present invention, etc. (adhesive layers other than the adhesive layer of the present invention, etc.) A double-sided adhesive sheet made of, etc. can be mentioned. In addition, the adhesive sheet with a base material, etc. is an adhesive sheet containing a base material and an adhesive layer of the present invention formed on at least one side of the base material, for example, having an adhesive layer of the present invention, etc. on one side of the base material. A single-sided adhesive sheet, etc., a double-sided adhesive sheet having an adhesive layer of the present invention on both sides of the substrate, etc., a adhesive layer of the present invention on one side of the substrate, and another adhesive layer on the other side, etc. A double-sided adhesive sheet having a, etc. can be mentioned. In addition, the above-mentioned “substrate (base layer)” is a support, and when an adhesive sheet or the like is used (attached) to an adherend, it is a part that is attached to the adherend together with the adhesive layer or the like. The above description does not include a release liner that peels off when using (attaching) an adhesive sheet or the like.

When the adhesive sheet of the present invention is an adhesive sheet with a base material, the base material is not particularly limited, but includes, for example, plastic films, anti-reflection (AR) films, anti-glare (AG) films, polarizers, retardation plates, and other optical devices. You can take film. In addition, examples of the substrate include porous materials such as paper, cloth, and non-woven fabric, nets, foam sheets, and metal foil. Materials such as the plastic film include, for example, polyester resins such as polyethylene terephthalate (PET), acrylic resins such as polymethyl methacrylate (PMMA), polycarbonate, triacetylcellulose (TAC), and polyester. Sulfone, polyarylate, polyimide, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, ethylene-propylene copolymer, brand name “Atone” (cyclic olefin polymer, manufactured by JSR Corporation), brand name “Zeonoa” (Cyclic olefin polymer, manufactured by Nippon Zeon Co., Ltd.) and other plastic materials such as cyclic olefin polymers. Additionally, only one type of these plastic materials may be used, or two or more types may be used.

The thickness of the substrate is not particularly limited, but is preferably, for example, 10 to 150 μm, more preferably 15 to 125 μm, and still more preferably 25 to 100 μm. Additionally, the substrate may have either a single layer or a multi-layer form. Additionally, the surface of the substrate may be appropriately subjected to known surface treatments such as physical treatments such as corona discharge treatment and plasma treatment, and chemical treatments such as primer treatment.

The adhesive sheet or the like may have a release liner provided on the surface (adhesive side or adhesive surface) of the adhesive layer or the like until use. In addition, when the adhesive sheet, etc. is a double-sided adhesive sheet, each adhesive surface or adhesive surface may be protected by two release liners, or may be protected in roll form by one release liner with both sides being release surfaces. It may be protected in a wound form (wound body). The release liner is used as a protective material such as an adhesive layer, and is peeled off when affixed to an adherend. Additionally, when the adhesive sheet or the like is an inorganic adhesive sheet, the release liner also serves as a support for the adhesive layer or the like. Additionally, a release liner does not necessarily need to be provided.

The embodiments described above are described to facilitate understanding of the present invention and are not intended to limit the present invention.

Example

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples at all. In addition, the evaluation results indicated by "-" in Table 1 indicate that it was difficult to obtain reliable data and measurement was impossible due to the strain being too large at the draw ratio. The evaluation result indicated by "-" in Table 2 indicates that no evaluation was performed. In addition, the numerical values of each monomer component constituting the prepolymer shown in Table 3 are parts by mass.

Example 1

100 parts by mass of epoxy monomer (brand name "HBE100", manufactured by Nippon Rika Co., Ltd., equivalent to monomer component (c)), 25 parts by mass of epoxy resin (brand name "1256B40", manufactured by Mitsubishi Chemical Corporation), epoxy curing agent. 20 parts by mass of 4,4'-dithioibutyric acid (manufactured by Tokyo Chemical Industry Co., Ltd., equivalent to compound (a1)), a radical capture agent (brand name "Omnirad TPO H", manufactured by IGM Resins B.V., recombination inhibitor compound (B) ) 25 parts by mass, 0.1 parts by mass of a curing catalyst (brand name "ZC700", manufactured by Matsumoto Fine Chemicals Co., Ltd.), and 3 parts by mass of acetylacetone (AcAc) are each added to 500 parts by mass of methyl ethyl ketone and mixed. A mixed solution was prepared by stirring.

This mixed solution was applied to a 38-μm-thick release liner R1 (product name “MRF #38”, manufactured by Mitsubishi Chemical Corporation), where one side of the polyester film is a release surface, and dried in an oven at 100°C for 5 minutes. . After drying, the coated surface is covered with a 38-μm-thick release liner R2 (product name "MRE #38", manufactured by Mitsubishi Chemical Corporation), where one side of the polyester film is a release surface, to coat the coated surface with a heat-curable resin ( An adhesive sheet with a thickness of 50 μm containing polymer (equivalent to A1) was produced. In addition, in this specification, “adhesion” refers to having both adhesive and adhesive properties.

Example 2

An adhesive sheet containing a thermosetting resin (equivalent to polymer (A1)) was produced in the same manner as in Example 1 except that the brand name "jER828" (manufactured by Mitsubishi Chemical Corporation) was used as the epoxy monomer.

Example 3

An adhesive sheet containing a thermosetting resin (equivalent to polymer (A1)) was produced in the same manner as in Example 2, except that the brand name "Omnirad 651" (manufactured by IGM Resins B.V.) was used as a radical entrapment agent.

Example 4

An adhesive sheet containing a thermosetting resin (equivalent to polymer (A1)) was produced in the same manner as in Example 1 except that 4,4'-dithiodiphenol (manufactured by Tokyo Kasei Kogyo Co., Ltd.) was used as an epoxy curing agent. did.

Example 5

An adhesive sheet containing a thermosetting resin (corresponding to polymer (A1)) was produced in the same manner as in Example 2 except that 4,4'-dithiodiphenol (manufactured by Tokyo Kasei Kogyo Co., Ltd.) was used as an epoxy curing agent. did.

Comparative Example 1

An adhesive sheet containing a thermosetting resin (equivalent to polymer (A1)) was produced in the same manner as in Example 2 except that the radical entrapment agent was not used.

Comparative Example 2

An adhesive sheet containing a thermosetting resin was produced in the same manner as in Example 1 except that 4,4'-ethylidene bisphenol was used as an epoxy curing agent.

Comparative Example 3

An adhesive sheet containing a thermosetting resin was produced in the same manner as in Comparative Example 2 except that the radical entrapment agent was not used.

Example 6

(Preparation of acrylic polymer)

In a reaction vessel equipped with a stirrer, thermometer, reflux condenser, and nitrogen gas introduction tube, 95 parts by mass of n-butylacrylate (BA), 5 parts by mass of acrylic acid (AA), and 2,2'- as a polymerization initiator. A mixture containing 0.2 parts by mass of azobisisobutyronitrile (AIBN) and 122 parts by mass of ethyl acetate as a solvent was stirred at 60°C for 7 hours under a nitrogen atmosphere. As a result, a polymer solution containing an acrylic polymer was obtained. The weight average molecular weight (Mw) of the acrylic polymer in this polymer solution was 600,000.

(Formation of adhesive sheet)

To 100 parts by mass of the acrylic polymer (dissolved in ethyl acetate), 0.1 part by mass of a crosslinking agent (brand name "Tetrad C", manufactured by Mitsubishi Gas Chemical Co., Ltd.), 0.1 part by mass of an epoxy monomer (brand name "HBE100", Shin-Nippon Rika Co., Ltd.) 100 parts by mass of epoxy curing agent (equivalent to monomer component (c)), 2 parts by mass of epoxy curing agent (4,4'-dithioibutyric acid, equivalent to compound (a1)), curing catalyst (product name "ZC700", Matsumoto Fine Chemical Co., Ltd. 0.1 parts by mass of acetone, 3 parts by mass of acetone, and 5 parts by mass of a radical trapping agent (trade name "Omnirad TPO H", manufactured by IGM Resins B.V.) were added, mixed and stirred to prepare a mixed solution. This mixed solution was applied to a 38-μm-thick release liner R1 (product name “MRF #38”, manufactured by Mitsubishi Chemical Corporation), where one side of the polyester film is a release surface, and dried in an oven at 100°C for 5 minutes. . After drying, the coated surface is covered with a 38-μm-thick release liner R2 (product name “MRE #38”, manufactured by Mitsubishi Chemical Corporation), where one side of the polyester film is the release surface, to form a thermosetting resin ( An adhesive sheet with a thickness of 50 μm containing polymer (equivalent to A1) was produced.

Example 7

An adhesive sheet containing a thermosetting resin (equivalent to polymer (A1)) was produced in the same manner as in Example 6, except that the brand name "jER828" (manufactured by Mitsubishi Chemical Corporation) was used as the epoxy monomer.

Comparative Example 4

To 100 parts by mass of the acrylic polymer (dissolved in ethyl acetate) prepared in Example 6, 0.1 parts by mass of a crosslinking agent (trade name "Tetrad C", manufactured by Mitsubishi Gas Chemical Co., Ltd.) was added and mixed and stirred to prepare a mixed solution. An adhesive adhesive sheet was produced in the same manner as in Example 6 except that this mixed solution was used.

Comparative Example 5

An adhesive sheet containing a thermosetting resin (equivalent to polymer (A1)) was produced in the same manner as in Example 6 except that the radical entrapment agent was not used.

Comparative Example 6

An adhesive sheet containing a thermosetting resin (equivalent to polymer (A1)) was produced in the same manner as in Example 7 except that the radical entrapment agent was not used.

Preparation example 1

(Synthesis of nitrobenzyl ester monomer precursor)

Under a nitrogen atmosphere, 72 g (341 mmol) of 2-nitroisophthalic acid and 400 g of tetrahydrofuran (THF) were added to a 5L flask and mixed and stirred to dissolve 2-nitroisophthalic acid. The solution was cooled to 2°C, 0.9M (162 mmol) of boron tetrahydrofuran complex (manufactured by Tokyo Kasei Kogyo Co., Ltd.) was added dropwise thereto, the temperature was raised to room temperature, and the mixture was stirred for 48 hours. After that, methanol was added dropwise, the solvent was distilled off under reduced pressure (50°C, 25 mmHg), diluted with ethyl acetate for extraction, and the organic phase was washed with 900 g of water three times in total. Then, 70 g of magnesium sulfate was added to the organic phase, dehydrated, filtered, and washed with ethyl acetate. The solvent in the filtrate was distilled off under reduced pressure (50°C, 25 mmHg), and 41 g of nitrobenzyl ester monomer precursor (light yellow crystals) was obtained.

Preparation example 2

(Synthesis of nitrobenzyl ester monomer)

Next, 21.0 g (115 mmol) of the monomer precursor, 33.2 g (460 mmol) of acrylic acid, 9.3 g (76.7 mmol) of 4-dimethylaminopyridine (DMAP), and 210 mL of dichloromethane were added to a 1 L flask, and acetone was added. / 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC hydrochloride) (manufactured by Tokyo Kasei Kogyo Co., Ltd.) 84.9 g (574) while cooling with an ice mixing bath and maintaining the internal temperature below 5°C. mmol) was added in portions and mixed and stirred to carry out the reaction. After completion of the reaction, the reaction solution was purified twice using silica gel chromatography (developing solvent: dichloromethane). 0.004 g of hydroquinone monomethyl ether (MEHQ) was added to the aliquot, the solvent was distilled off under reduced pressure (30°C or less, 30 mmHg), then ice-cooled to precipitate, and dried under reduced pressure at 30°C to obtain nitrobenzyl ester monomer ( 11.4 g of 2-nitro-1,3-bis(acryloyloxymethylene)benzene, light yellow crystals) was obtained.

Preparation example 3

(Synthesis of acrylic polymer P1)

In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen gas introduction tube, 95 parts by mass of n-butylacrylate (BA), 5 parts by mass of acrylic acid (AA), 0.2 parts by mass of AIBN as a polymerization initiator, and a solvent. A mixture containing 122 parts by mass of ethyl acetate was stirred at 60°C for 7 hours under a nitrogen atmosphere to perform a polymerization reaction. As a result, a polymer solution containing acrylic polymer P1 was obtained. The weight average molecular weight (Mw) of acrylic polymer P1 in this polymer solution was 600,000.

Example 8

(Synthesis of acrylic polymer P2)

In a reaction vessel equipped with a stirrer, thermometer, reflux condenser, and nitrogen gas introduction tube, 95 parts by mass of butyl acrylate (BA) and 5 parts by mass of nitrobenzyl ester monomer (equivalent to compound (a2)) prepared in Preparation Example 2 , 2.83 parts by mass of brand name "C12TCSS" (manufactured by Nippon Terpene Chemical Co., Ltd.) as a chain transfer agent, 0.28 parts by mass of 2,2'-azobisisobutyronitrile (AIBN) as a polymerization initiator, and 301 parts by mass of ethyl acetate as a solvent. The mixture containing parts was stirred at 60°C for 6 hours under a nitrogen atmosphere to carry out a polymerization reaction. As a result, a polymer solution containing acrylic polymer P2 (equivalent to polymer (A2)), which is a prepolymer having an acryloyl group, was obtained.

(Synthesis of adhesive composition)

The polymer solution containing the acrylic polymer P1 produced in Preparation Example 3 and the polymer solution containing the acrylic polymer P2 were mixed at a ratio of 100 parts by mass of the acrylic polymer P2 relative to 100 parts by mass of the acrylic polymer P1, and the mixture was heated at 2000 rpm. The mixture was stirred for 5 minutes, and further stirred and degassed at 2200 rpm for 5 minutes to prepare an adhesive composition.

(Formation of adhesive sheet)

The above adhesive composition was applied to the peeling surface of a polyethylene terephthalate film (product name “MRF 38”, manufactured by Mitsubishi Chemical Corporation) that had been peeled with a silicone-based release agent so that the thickness of the adhesive layer after drying was 25 μm. , This was left to stand at room temperature for 5 minutes and then dried at 130°C for 3 minutes. An adhesive adhesive sheet was obtained by sufficiently volatilizing and removing ethyl acetate contained as a solvent.

Comparative Example 7

(Synthesis of acrylic polymer P3)

In a reaction vessel equipped with a stirrer, thermometer, reflux condenser, and nitrogen gas introduction tube, 95 parts by mass of butyl acrylate (BA), 5 parts by mass of 1,6-hexanediol diacrylate, and the brand name "C12TCSS" as a chain transfer agent ( A mixture containing 2.83 parts by mass of Nippon Terpene Chemical Co., Ltd. (manufactured by Nippon Terpene Chemical Co., Ltd.), 0.28 parts by mass of 2,2'-azobisisobutyronitrile (AIBN) as a polymerization initiator, and 301 parts by mass of ethyl acetate as a solvent was prepared at 60°C. The polymerization reaction was performed by stirring under a nitrogen atmosphere for 6 hours. As a result, a polymer solution containing acrylic polymer P3, which is a prepolymer having an acryloyl group, was obtained.

(Synthesis of adhesive composition)

The polymer solution containing the acrylic polymer P1 prepared in Preparation Example 3 and the polymer solution containing the acrylic polymer P3 were mixed at a ratio of 100 parts by mass of the acrylic polymer P3 relative to 100 parts by mass of the acrylic polymer P1, and the mixture was heated at 2000 rpm. The mixture was stirred for 5 minutes, and further stirred and degassed at 2200 rpm for 5 minutes to prepare an adhesive composition.

(Formation of adhesive sheet)

An adhesive sheet was produced in the same manner as in Example 8, except that the adhesive composition prepared above was used.

Comparative Example 8

(Synthesis of acrylic polymer P4)

In a reaction vessel equipped with a stirrer, thermometer, reflux condenser, and nitrogen gas introduction tube, 100 parts by mass of butyl acrylate (BA), 2.83 parts by mass of brand name "C12TCSS" (manufactured by Nippon Terpene Chemical Co., Ltd.) as a chain transfer agent, A mixture containing 0.28 parts by mass of 2,2'-azobisisobutyronitrile (AIBN) as a polymerization initiator and 301 parts by mass of ethyl acetate as a solvent was stirred at 60°C for 6 hours under a nitrogen atmosphere to perform a polymerization reaction. did. As a result, a polymer solution containing acrylic polymer P4, which is a prepolymer having an acryloyl group, was obtained.

(Synthesis of adhesive composition)

The polymer solution containing the acrylic polymer P1 prepared in Preparation Example 3 and the polymer solution containing the acrylic polymer P4 were mixed at a ratio of 100 parts by mass of the acrylic polymer P4 with respect to 100 parts by mass of the acrylic polymer P1, and the mixture was stirred at 2000 rpm. The mixture was stirred for 5 minutes, and further stirred and degassed at 2200 rpm for 5 minutes to prepare an adhesive composition.

(Formation of adhesive sheet)

An adhesive sheet was produced in the same manner as in Example 8, except that the adhesive composition prepared above was used.

Example 9

(Preparation of acrylic polymer)

In a reaction vessel equipped with a stirrer, thermometer, reflux condenser, and nitrogen gas introduction tube, 63 parts by mass of 2-ethylhexyl acrylate (2EHA), 15 parts by mass of N-vinylpyrrolidone (NVP), and methylmethacrylate 9 parts by mass of acrylate (MMA), 13 parts by mass of hydroxyethyl acrylate (HEA), 0.2 parts by mass of 2,2'-azobisisobutyronitrile (AIBN) as a polymerization initiator, and 122 ethyl acetate as a solvent. The mixture containing the mass was stirred at 60°C for 7 hours under a nitrogen atmosphere. As a result, a polymer solution containing an acrylic polymer was obtained. The weight average molecular weight (Mw) of the acrylic polymer in this polymer solution was 600,000.

(Formation of adhesive sheet)

To 100 parts by mass of the acrylic polymer (dissolved in ethyl acetate), 4 parts by mass of a crosslinking agent (brand name “Takenate D110N”, manufactured by Mitsui Chemicals Co., Ltd.), a curing agent (4,4'-dithiodianiline, compound (a1) Equivalent to) 1 part by mass, a crosslinking catalyst (brand name “ZC700”, manufactured by Matsumoto Fine Chemicals Co., Ltd.), 0.1 part by mass, acetylacetone (AcAc) 2 parts by mass, and a radical capture agent (brand name “Omnirad TPO H”, IGM Resins) 4 parts by mass (manufactured by B.V.) were added and mixed and stirred to prepare a mixed solution. This mixed solution was applied to a 38-μm-thick release liner R1 (product name “MRF #38”, manufactured by Mitsubishi Chemical Corporation), where one side of the polyester film is a release surface, and dried in an oven at 100°C for 5 minutes. . After drying, the coated surface is covered with a 38-μm-thick release liner R2 (product name “MRE #38”, manufactured by Mitsubishi Chemical Corporation), where one side of the polyester film is the release surface, to form a thermosetting resin ( An adhesive sheet with a thickness of 50 μm containing polymer (equivalent to A1) was produced.

Comparative Example 9

An adhesive adhesive sheet containing a thermosetting resin (equivalent to polymer (A1)) was produced in the same manner as in Example 9 except that the radical entrapment agent was not used.

Example 10

(Formation of adhesive sheet)

To 100 parts by mass of the acrylic polymer prepared in Example 6 (dissolved in ethyl acetate), 4 mass of 1,3-bis(4,5-dihydro-2-oxazolyl)benzene (manufactured by Tokyo Kasei Kogyo Co., Ltd.) as a crosslinking agent was added. 4 parts by mass of a curing agent (4,4'-dithiodiphenol, equivalent to compound (a1)), and 5 parts by mass of a radical capture agent (trade name "Omnirad TPO H", manufactured by IGM Resins B.V.) were added, mixed and stirred. A mixed solution was prepared. This mixed solution was applied to a 38-μm-thick release liner R1 (product name “MRF #38”, manufactured by Mitsubishi Chemical Corporation), where one side of the polyester film is a release surface, and dried in an oven at 100°C for 5 minutes. . After drying, the coated surface is covered with a 38-μm-thick release liner R2 (product name “MRE #38”, manufactured by Mitsubishi Chemical Corporation), where one side of the polyester film is the release surface, to form a thermosetting resin ( An adhesive sheet with a thickness of 50 μm containing polymer (equivalent to A1) was produced.

Example 11

An adhesive adhesive sheet was produced in the same manner as in Example 10, except that 4,4'-dithioibutyric acid (equivalent to compound (a1)) was used as a curing agent.

Comparative Example 10

An adhesive sheet containing a thermosetting resin (equivalent to polymer (A1)) was produced in the same manner as in Example 10 except that the radical entrapment agent was not used.

Comparative Example 11

An adhesive sheet containing a thermosetting resin (equivalent to polymer (A1)) was produced in the same manner as in Example 11 except that the radical entrapment agent was not used.

Comparative Example 12

An adhesive adhesive sheet containing a thermosetting resin (equivalent to polymer (A1)) was produced in the same manner as in Example 10 except that no curing agent was used.

<Evaluation>

The following evaluations were performed on the adhesive sheets produced in Examples and Comparative Examples before and after UV irradiation, respectively. The results are shown in the table. In addition, UV irradiation was performed by the following method.

(UV irradiation)

For the adhesive sheets obtained in the examples and comparative examples, a UV-LED irradiation device manufactured by Quark Technology (model number "QEL-350-RU6W-CW-MY") was used in a state in which a release liner was further bonded to the exposed adhesive surface. Using a UV-LED lamp with a wavelength of 365 nm as a light source, ultraviolet irradiation was performed with the cumulative amount of irradiated light in the wavelength range of 320 to 390 nm being 8000 mJ/cm2.

(1) Shear storage modulus

The adhesive sheets were laminated to produce a sample for measurement with a thickness of approximately 1.0 mm, and dynamic viscoelasticity measurement was performed using the “Advanced Rheometric Expansion System (ARES)” manufactured by Rheometric Scientific under the following conditions. Then, the shear storage modulus at 25°C, 50°C, and 80°C was calculated.

(Measuring conditions)

Deformation Mode: Torsion

Measurement frequency: 1Hz

Temperature increase rate: 5℃/min

Measurement temperature: -50 to 150℃

Shape: Parallel plate 8.0mmϕ

(2) Tensile test

The 50-μm-thick adhesive sheet obtained by laminating as necessary was cut into 10 mm x 30 mm, and a rectangular sample with a length of 30 mm was produced with the release liner removed. This upper and lower 10 mm portion was fixed with the chuck jig of a tensile compression tester (product name "Autograph AGS-50NX", manufactured by Shimazu Seisakusho Co., Ltd.), and a tensile test was performed under the conditions of a distance between chucks of 10 mm and a tensile speed of 300 mm/min. was carried out.

(3) Young’s modulus E

From the spectrum obtained in the above tensile test, the amount of change in stress σ relative to strain ε in the elastic strain region was calculated (E=Δσ/Δε).

(4) Breaking point stress or stress peak intensity

For the spectrum obtained in the above tensile test, the peak value in the upward convex shape was taken as the stress peak intensity. However, in the case where the upwardly convex peak was not obtained and the adhesive sheet was fractured, the breaking point stress was adopted.

(5) strain stress

For the spectrum obtained in the above tensile test, the stress at each strain (%) was taken as strain stress.

As shown in Tables 1 to 5, the stress of the adhesive sheet of the example was reduced by 100% strain stress by irradiation with ultraviolet rays. For this reason, it was judged that the handleability was excellent before and after ultraviolet irradiation, and the flexibility was excellent because the stress was reduced after ultraviolet irradiation.

Hereinafter, variations of the invention related to this disclosure are described.

[Appendix 1] Adhesive layer and/or adhesive layer in which stress is reduced by external stimulation.

[Appendix 2] The pressure-sensitive adhesive layer and/or adhesive layer according to Appendix 1, wherein the stress does not increase after reduction.

[Appendix 3] The ratio [S2(100)/S1(100)] of the 100% strain stress before external stimulation (S1(100)) and the 100% strain stress after external stimulation (S2(100)) is less than 0.95. , the pressure-sensitive adhesive layer and/or adhesive layer described in Appendix 1 or 2.

[Appendix 4] The pressure-sensitive adhesive layer and/or adhesive layer according to any one of Appendices 1 to 3, wherein the 100% strain stress (S2(100)) after external stimulation is 10 MPa or less.

[Appendix 5] The pressure-sensitive adhesive layer and/or adhesive layer according to any one of Appendices 1 to 4 used for optical purposes.

1: Adhesive layer or adhesive layer
2: Release liner
10: Adhesive sheet or adhesive sheet with release liner

Claims (5)

An adhesive layer and/or adhesive layer in which stress is reduced by external stimulation. According to paragraph 1,
An adhesive layer and/or adhesive layer in which the stress does not increase after reduction. According to paragraph 1,
The ratio [S2(100)/S1(100)] of the 100% strain stress before external stimulation (S1(100)) and the 100% strain stress after external stimulation (S2(100)) is less than 0.95, and /or adhesive layer. According to paragraph 1,
A pressure-sensitive adhesive layer and/or adhesive layer, wherein the 100% strain stress (S2(100)) after external stimulation is 10 MPa or less. According to any one of claims 1 to 4,
Adhesive layer and/or adhesive layer used for optical purposes.

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