JP5503926B2 - Electrically peelable adhesive product and peeling method thereof - Google Patents

Description

  The present invention relates to an electric peelable adhesive product and a peeling method thereof. More specifically, the adhesive peelable product of the present invention has an adhesive force that is reduced by simply applying a voltage, and as a result, the product can be easily peeled off from the adherend.

Removable adhesive tapes are used in various applications (for example, surface protective films, coating masking tapes, removable notes, etc.). This pressure-sensitive adhesive tape generally comprises a base material and a pressure-sensitive adhesive layer laminated thereon. The adhesive layer is required to have removability as well as adhesiveness. That is, when transporting, storing, and processing the adherend, there is a demand for adhesiveness that does not peel from the adherend and removability that can be easily removed after performing the function.
As a method for realizing the contradictory properties of the adhesive property and the removability, for example, methods described in Japanese Patent Publication No. 2003-504504 (Patent Document 1), WO 2007/018239 (Patent Document 2), etc. are proposed. Has been.

In Japanese translations of PCT publication No. 2003-504504, an epoxy-based adhesive containing an epoxy-based compound having peelability when a voltage is applied is proposed. The epoxy compounds exemplified in the examples are special compounds having a disulfide bond in the molecule. It is described that an adhesive that can be peeled off when a voltage is applied can be provided by using this epoxy adhesive.
On the other hand, WO2007 / 018239 describes that an adhesive that can be peeled off when a voltage is applied can be provided by using an ionic liquid as an additive for the adhesive. In this publication, an ionic liquid is a molten salt that is liquid at room temperature, has no vapor pressure, and has properties such as high heat resistance, nonflammability, and high chemical stability.

Special table 2003-504504 gazette WO2007 / 018239

However, this bonding with an epoxy adhesive is supposed to be peeled off by maintaining it for 30 minutes under the conditions of 60 ° C. and 50 V, and heating and application of a voltage for a long time are necessary for peeling.
In addition, as described in these publications, epoxy compounds and ionic liquids are expensive because they are compounds having a special structure, and it is difficult to provide an inexpensive adhesive tape using them. It was.
Further, the above technique requires both the bonding material (adhesive tape and adherend) to have conductivity, and its application is limited.
Therefore, it can be peeled off without heating in a short time regardless of the degree of conductivity of the adherend using an inexpensive material, and the physical properties are equivalent to or better than those using epoxy compounds and ionic liquids. It has been desired to provide an electrically peelable pressure-sensitive adhesive product such as a pressure-sensitive adhesive tape.

Thus, according to the present invention, from the electrodetachable pressure-sensitive adhesive composition formed on the conductive support and comprising 100 parts by weight of the acrylic pressure-sensitive adhesive or polyester pressure-sensitive adhesive and 15 to 250 parts by weight of the electrolytic solution. Comprising an electrically peelable pressure-sensitive adhesive layer, and a conductive layer formed on the surface of the electrically peelable pressure-sensitive adhesive layer,
The electro-peelable pressure-sensitive adhesive composition has an ionic conductivity of 10 ⁻¹¹ to 10 ⁻³ S / cm,
The electrolytic solution is an organic solution containing an organic solvent and an electrolyte selected from an organic quaternary ammonium salt and an alkali metal salt;
The electrolyte is contained in the electrolyte at a concentration of 0.01 to 3 mol / l;
Wherein the conductive layer, have a patterned planar shape comprising an exposed opening of the electric-peelable pressure-sensitive adhesive layer,
The electrolytic solution contains, as the organic quaternary ammonium salt, a boron-containing organic electrolyte salt represented by the formula (R) ₄ NBF ₄ (wherein R is the same or different and is a methyl group or an ethyl group). An electrically peelable adhesive product is provided.

  Further, according to the present invention, after the above-mentioned electro-releasable pressure-sensitive adhesive product is attached on an adherend so that the electro-releasable pressure-sensitive adhesive layer faces, the conductive support and the conductive layer By applying a voltage in between, the electro-peelable pressure-sensitive adhesive product is peeled off from the adherend by providing a voltage between them.

ADVANTAGE OF THE INVENTION According to this invention, regardless of the electroconductivity grade of a to-be-adhered body, the application of a voltage can provide the electrically peelable adhesive product which can be peeled without heating in a short time by applying voltage. This effect is achieved by simultaneously providing an electro-peelable pressure-sensitive adhesive composition having specific properties and a conductive layer having a patterned planar shape having an exposed opening of the electro-peelable pressure-sensitive adhesive layer. It is an effect.
Moreover, when electrolyte solution contains a boron containing organic electrolyte salt as organic quaternary ammonium salt, peelability can be improved further.
Further, when the electrolytic solution contains, as an organic quaternary ammonium salt, a boron-containing organic electrolyte salt represented by the formula (R) ₄ NBF ₄ (wherein R is the same or different and is a methyl group or an ethyl group) Further, the peelability can be improved.

Further, when the electrolytic solution contains an organic solvent having a relative dielectric constant of 30 or more, the peelability can be further improved.
Furthermore, when the electrolytic solution contains an organic solvent having a relative dielectric constant of 30 or more selected from ethylene carbonate, propylene carbonate, γ-butyrolactone, and N-methyl-2-pyrrolidone, the peelability can be further improved.
Further, when the acrylic pressure-sensitive adhesive contains a copolymer of an alkyl (meth) acrylate having an alkyl group having 1 to 8 carbon atoms, a carboxyl group-containing acrylic monomer, and a hydroxyl group-containing acrylic monomer, further peeling Can be improved.
Furthermore, when the conductive layer has a surface resistance value of 1000Ω / □ or less, the peelability can be further improved.
In addition, the peeling of the electrically peelable pressure-sensitive adhesive product of the present invention utilizes the fact that the adhesiveness of the electrically peelable pressure-sensitive adhesive layer is reduced by applying a voltage between the conductive support and the conductive layer. Can be easily peeled off without heating in a short time.

It is a schematic explanatory drawing of the shape of the conductive layer of an Example. It is a schematic explanatory drawing of the measuring method of the surface resistance of an Example. It is a schematic explanatory drawing of the voltage application method of an Example. It is a graph which shows the relationship between the adhesive force of Example 19, and a voltage application time.

The electro-releasable pressure-sensitive adhesive product of the present invention comprises a conductive support, an electro-releasable pressure-sensitive adhesive layer comprising an electro-releasable pressure-sensitive adhesive composition formed thereon, and a conductive material formed on the surface of the electro-releasable pressure-sensitive adhesive layer. With layers.
(A) Electrically peelable adhesive layer The electrically peelable adhesive layer is composed of an electrically peelable adhesive composition (hereinafter simply referred to as an adhesive composition) containing an acrylic adhesive or a polyester adhesive and an electrolyte. The acrylic pressure-sensitive adhesive and the polyester-based pressure-sensitive adhesive are not particularly limited as long as the electrodetachable pressure-sensitive adhesive layer has adhesiveness. These pressure-sensitive adhesives may be newly synthesized pressure-sensitive adhesives or commercially available pressure-sensitive adhesives.

The pressure-sensitive adhesive preferably has a viscosity of 1000 mPa · s or more when the solid content is 40% by weight from the viewpoint of imparting pressure-sensitive adhesiveness to the electro-peelable pressure-sensitive adhesive layer. By having this viscosity, it is possible to ensure adhesiveness when no voltage is applied. A more preferable viscosity is 2000 to 10000 mPa · s.
The viscosity is a value measured by adjusting the temperature of the pressure-sensitive adhesive composition to 25 ° C., and then using a BH viscometer manufactured by Tokimec Co., Ltd. under a rotation speed of 10 rpm.

(Acrylic adhesive)
As the acrylic pressure-sensitive adhesive, for example, a pressure-sensitive adhesive obtained by polymerizing an acrylic monomer optionally in the presence of a polymerization initiator or a commercially available pressure-sensitive adhesive can be used. As the acrylic pressure-sensitive adhesive, any pressure-sensitive adhesive can be used as long as it can at least adhere to the adherend. Usually, from the viewpoint of adhesiveness, an adhesive containing an acrylic polymer having a weight average molecular weight in the range of 10,000 to 5,000,000 can be used as the acrylic adhesive. A more preferred weight average molecular weight is 100,000 to 2,000,000.
The weight average molecular weight means a value calculated using a GPC System 21 manufactured by Shodex and assuming the mobile phase as tetrahydrofuran. This value is a weight average molecular weight in terms of polystyrene.

(1) Acrylic monomer The acrylic monomer preferably contains an alkyl (meth) acrylate having an alkyl group having 1 to 10 carbon atoms as a main component (50% by weight or more). In addition, (meth) acrylate means a methacrylate or an acrylate.

  Examples of the alkyl (meth) acrylate having an alkyl group having 1 to 14 carbon atoms include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl ( (Meth) acrylate, sec-butyl (meth) acrylate, t-butyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isononyl (meth) acrylate, dodecyl ( And (meth) acrylate. These alkyl (meth) acrylates may be used alone or in combination of two or more. Among these alkyl (meth) acrylates, alkyl (meth) acrylates having an alkyl group having 1 to 8 carbon atoms are preferred, alkyl (meth) acrylates having an alkyl group having 1 to 4 carbon atoms are more preferred, and n-butyl ( (Meth) acrylate is more preferred, and n-butyl acrylate is particularly preferred.

  Other acrylic monomers include carboxyl group-containing monomers such as acrylic acid, methacrylic acid, carboxyethyl acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate And hydroxyl group-containing monomers such as 6-hydroxyhexyl (meth) acrylate and (4-hydroxymethylcyclohexyl) -methyl acrylate. These other (meth) acrylates may be used alone or in combination of two or more. The (meth) acrylate preferably contains both a carboxyl group-containing monomer and a hydroxyl group-containing monomer.

  The acrylic monomer contains an alkyl (meth) acrylate having an alkyl group having 1 to 10 carbon atoms as a main component. Therefore, the acrylic monomer may be composed only of alkyl (meth) acrylate without using any other acrylic monomer. Further, from the viewpoint of easily obtaining a pressure-sensitive adhesive composition having desired performance, other acrylic monomers are preferably contained in an amount of less than 50% by weight and 1% by weight or more, and contained in an amount of 5 to 30% by weight. More preferably, it is more preferably 5 to 15% by weight.

  Moreover, when both the carboxyl group-containing monomer and the hydroxyl group-containing monomer are included, the content of both is preferably in the range of 1 to 20 parts by weight when the total monomer amount is 100 parts by weight. Adhesive properties can be improved by using both monomers within this range. Furthermore, the range of 1 to 10 parts by weight is more preferable.

  Furthermore, you may add a vinyl-type monomer to (meth) acrylate as needed. Examples of vinyl monomers include itaconic acid, maleic acid, crotonic acid; maleic anhydride, itaconic anhydride, vinyl acetate, N-vinyl pyrrolidone, N-vinyl carboxylic acid amides, styrene, N-vinyl caprolactam, and the like. It is done. These vinyl monomers may be used alone or in combination of two or more.

(2) Polymerization initiator As an optional polymerization initiator, for example, 2,2′-azobisisobutyronitrile, 2,2′-azobis (2-methylpropionamidine) disulfide, 2, 2'-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (2-methylbutyronitrile), 1 , 1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis (2,4,4-trimethylpentane), dimethyl-2,2′-azobis (2-methylpropionate), 2, 2'-azobis [2-methyl-N- (phenylmethyl) -propionamidine] dihydrochloride, 2,2'-azobis [2- (3,4,5,6-tetrahydropyrimidin-2-yl) pro Azo-based polymerization initiators such as dihydrochloride and 2,2′-azobis [2- (2-imidazolin-2-yl) propane]; persulfate-based polymerization initiators such as potassium persulfate and ammonium persulfate; Benzoyl peroxide, hydrogen peroxide, t-butyl hydroperoxide, di-t-butyl peroxide, t-butyl peroxybenzoate, dicumyl peroxide, 1,1-bis (t-butylperoxy) -3, Start of peroxide polymerization such as 3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) cyclododecane, 3,3,5-trimethylcyclohexanoyl peroxide, t-butylperoxypivalate Agents: Redox polymerization initiators composed of persulfate and sodium hydrogen sulfite. These polymerization initiators may be used alone or in combination of two or more.

  The polymerization initiator is preferably used in the range of 0.005 to 1 part by weight with respect to 100 parts by weight of the acrylic monomer. By using a polymerization initiator in this range, an acrylic pressure-sensitive adhesive having improved adhesive properties can be formed. Furthermore, the amount of the polymerization initiator used is more preferably in the range of 0.1 to 0.5 parts by weight.

(3) Other component As another component, the organic solvent may be contained from a viewpoint of the ease of use of the adhesive composition on a base | substrate. The organic solvent is not particularly limited, and examples thereof include known organic solvents that can be used for the pressure-sensitive adhesive composition. Examples thereof include aliphatic hydrocarbons such as hexane and heptane, esters such as methyl acetate, ethyl acetate, and propyl acetate, and aromatic hydrocarbons such as toluene, xylene, and ethylbenzene. These organic solvents may be used alone or in combination of two or more.
In addition, when using an organic solvent, it is preferable to prepare the usage-amount so that the solid content content which consists of an acrylic adhesive may be 10 weight% or more. Furthermore, it is more preferable that the use ratio is adjusted so that the solid content is 20 to 50% by weight.

(Polyester adhesive)
Examples of the polyester-based pressure-sensitive adhesive include XI series (manufactured by Nippon Synthetic Industry Co., Ltd.) pressure-sensitive adhesives such as XI-001, XI-0002, and XI-1001.

(Electrolyte)
The electrolytic solution has an ionic conductivity of 10 ⁻⁶ to 10 ⁻² S / cm. By having an ionic conductivity in this range, sufficient peelability can be imparted by applying a voltage to the pressure-sensitive adhesive composition. More preferable ionic conductivity is 10 ⁻³ to 10 ⁻² S / cm. The measuring method of ionic conductivity is described in the column of an Example.
The electrolytic solution is composed of an organic solution containing an organic quaternary ammonium salt or alkali metal salt as an electrolyte and an organic solvent.

(1) Electrolyte (a) Organic Quaternary Ammonium Salt As the organic quaternary ammonium salt, (R) ₄ NX (wherein R is the same or different, an alkyl group having 1 to 4 carbon atoms, X is halogen) Atom, ClO ₄ , BF ₄ or PF ₆ ), [(R) ₄ N] ₂ Y (wherein R is the same as above, and Y is SO ₄ ).
When X is a halogen atom, for example, ammonium bromide or ammonium chloride such as tetrabutyl, tetrapropyl, tetraethyl, tetramethyl, triethylbutyl, triethylpropyl, triethylmethyl and the like can be mentioned.

When X is BF ₄ , for example, ammonium tetrafluoroborate such as tetrabutyl, tetrapropyl, tetraethyl, tetramethyl, triethylbutyl, triethylpropyl, triethylmethyl and the like can be mentioned.
When X is PF ₆ , for example, ammonium hexafluorophosphate such as tetrabutyl, tetrapropyl, tetraethyl, tetramethyl, triethylbutyl, triethylpropyl, triethylmethyl and the like can be mentioned.

When X is ClO ₄ , for example, ammonium perchlorate such as tetrabutyl, tetrapropyl, tetraethyl, tetramethyl, triethylbutyl, triethylpropyl, triethylmethyl and the like can be mentioned.
When Y is SO ₄ , for example, ammonium sulfate such as tetrabutyl, tetrapropyl, tetraethyl, tetramethyl, triethylbutyl, triethylpropyl, triethylmethyl and the like can be mentioned.
The said organic quaternary ammonium salt may be used only 1 type, and may be used in combination of 2 or more type. Moreover, you may use it in combination with the alkali metal salt demonstrated below.

(B) Alkali metal salt Examples of the alkali metal salt include LiCl, Li ₂ SO ₄ , LiBF ₄ , LiPF ₆ , LiClO ₄ , LiAsF ₆ , LiCF ₃ SO ₃ , LiN (SO ₂ CF ₃ ) ₂ , LiN (SO ₂ C ₂ F ₅ ) ₂ , LiC (SO ₂ CF ₃ ) _{3 and the} like. In addition, although these illustrations are lithium salts, a sodium salt and potassium salt may be sufficient. These alkali metal salts may be used alone or in combination of two or more.
Of the alkali metal salts, LiN (SO ₂ CF ₃ ) ₂ is preferable. When these preferable alkali metal salts are used, the electric peeling property can be further improved.

(C) Amount used The electrolytic solution contains an electrolyte at a concentration of 0.01 to 3 mol / l. By including the electrolyte in this concentration range, it is possible to achieve both high levels of securing peelability during voltage application and ensuring adhesiveness when no voltage is applied. A more preferable concentration is 0.1 to 2.0 mol / l, and a further preferable concentration is 0.5 to 2.0 mol / l.

(2) Organic solvent The organic solvent is not particularly limited as long as it is an organic solvent that does not impair the peelability when the voltage of the pressure-sensitive adhesive composition is applied and the adhesiveness when no voltage is applied. For example, cyclic carbonates such as ethylene carbonate, propylene carbonate and butylene carbonate, chain carbonates such as dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate, lactones such as γ-butyrolactone and γ-valerolactone, methyl propionate and methyl pivalate , Chain carboxylic esters such as octyl pivalate, ethers such as tetrahydrofuran, 2-methyltetrahydrofuran, 1,4-dioxane, 1,2-dimethoxyethane, 1,2-diethoxyethane, 1,2-dibutoxyethane , Nitriles such as acetonitrile, amides such as dimethylformamide and N-methyl-2-pyrrolidone. These organic solvents may be used alone or in combination of two or more.

  Among the organic solvents, it is preferable to use an organic solvent having a relative dielectric constant of 30 or more. By using an organic solvent having this relative dielectric constant, the peelability at the time of voltage application can be further improved. Examples of the organic solvent having this relative dielectric constant include ethylene carbonate (89.8), propylene carbonate (64.92), γ-butyrolactone (39.1), and N-methyl-2-pyrrolidone (32.2). (The value in parentheses means the relative dielectric constant at about 25 ° C.). A more preferable range of the relative dielectric constant is 60 or more.

(Use ratio of adhesive and electrolyte)
The electrolytic solution is used in the range of 15 to 250 parts by weight with respect to 100 parts by weight of the adhesive (solid content). By using in this range, it is possible to achieve both securing peelability when applying a voltage and securing adhesiveness when no voltage is applied. A more preferable usage rate of the electrolytic solution is 40 to 120 parts by weight.

(Other ingredients)
You may make it bridge | crosslink by making a crosslinking agent act on an acrylic adhesive. Examples of the crosslinking agent include isocyanate crosslinking agents such as toluene diisocyanate and methylene bisphenyl isocyanate. The use ratio of the crosslinking agent is preferably 0.2 weight or more with respect to 100 parts by weight of the acrylic pressure-sensitive adhesive. When the pressure-sensitive adhesive composition is formed as a layer on the support by crosslinking, the creep resistance and shear resistance of the layer can be improved. A more preferable usage rate is 2 to 15 parts by weight.

(Ionic conductivity of adhesive composition)
The pressure-sensitive adhesive composition preferably has an ionic conductivity of 10 ⁻¹¹ to 10 ⁻³ S / cm. When the ionic conductivity is within this range, it is possible to ensure both peelability when a voltage is applied and secure adhesiveness when no voltage is applied. More preferable ionic conductivity is in the range of 10 ⁻⁵ to 10 ⁻³ S / cm.

(Method for producing pressure-sensitive adhesive composition)
The pressure-sensitive adhesive composition can be obtained by stirring the pressure-sensitive adhesive, the electrolytic solution, and optionally the crosslinking agent by a known method.
(B) Conductive support As the conductive support, for example, a foil (thickness of less than 100 μm) made of a metal such as aluminum, copper, silver, gold, an alloy of these metals, or a conductive metal oxide (ITO, etc.) A cloth containing a fiber mixed with or coated with these metals or alloys, such as a metal plate or a plate (thickness of 100 μm or more), a resin sheet containing these metals or alloys, these metals, alloys or conductive metal oxides A resin plate provided with a layer is mentioned.

(C) Conductive layer The conductive layer has a patterned planar shape including the exposed opening of the electro-releasable pressure-sensitive adhesive layer. In the present invention, the adhesiveness of the adhesive product is secured by the adhesive layer exposed in the opening, and the peelability of the adhesive product is secured by applying a voltage between the conductive support and the conductive layer.
The conductive layer usually contains mainly a metal component. Examples of the metal component include metals such as gold, silver, copper, aluminum, and nickel, alloys of these metals, and metal oxides such as indium / tin oxide, tin oxide, and zinc oxide. In addition to metal components, conductive materials such as carbon, conductive metal oxides, and conductive polymers can also be used. The conductive layer preferably contains a metal component from the viewpoint of further improving peelability.

Although a conductive layer may consist only of a metal component, it is preferable that it is a composite body with a resin component from a viewpoint of ease of manufacture. The content ratio of the metal component in the composite is preferably 30 to 99% by weight, more preferably 40 to 95% by weight, from the viewpoint of ensuring ease of manufacture and electrical conductivity.
Examples of the composite include a mixture of a metal component and a resin component, and a composite obtained by coating the surface of a woven fabric resin component with a metal component. The former mixture can be formed by printing a paste containing a metal component and a resin component on a release paper in a predetermined shape. The latter composite can be formed by depositing a metal component on the surface of the resin component by vapor deposition or sputtering. Among these, the former mixture is preferable because it can be easily patterned and can be easily present on the surface of the pressure-sensitive adhesive layer without being included in the pressure-sensitive adhesive layer.

It does not specifically limit as a resin component, Both a thermosetting resin and a thermoplastic resin can be used. Among these, the thermosetting resin (for example, polyester, phenol, epoxy, acrylic, etc.) component suppresses deterioration of the resin component (for example, increase in the surface resistance value of the conductive layer) received from components other than the resin. Therefore, it is preferable from the viewpoint of improving the stability of the pressure-sensitive adhesive product.
An acrylic resin may be added to the conductive layer forming paste in order to improve the coating surface of the conductive layer. The amount added is preferably 10 parts by weight or less, and more preferably 5 parts by weight or less with respect to 100 parts by weight of the paste.

When continuously producing the conductive layer in a roll shape, silicone may be added to the paste for forming the conductive layer in order to reduce bubbles generated in the conductive material. The amount added is preferably 5 parts by weight or less, more preferably 2 parts by weight or less, based on 100 parts by weight of the paste.
The conductive layer includes the exposed opening of the pressure-sensitive adhesive layer. The ratio of the opening is preferably 20 to 90% and more preferably 30 to 70% of the surface area of the pressure-sensitive adhesive layer from the viewpoint of achieving both conductivity and adhesiveness.

The shape of the opening may be any shape as long as both conductivity and adhesiveness can be achieved, and examples thereof include a polygon such as a triangle, a quadrangle, a pentagon, and a hexagon, a circle, and an indefinite shape.
Moreover, although there are usually a plurality of openings, the shapes of the openings may be the same or different, and their areas may be the same or different. Here, in order to achieve both conductivity and adhesiveness on the entire surface of the pressure-sensitive adhesive layer, the shape and area of the opening are preferably the same. The area of the opening is preferably 0.5 to 4.0 mm ² / piece, more preferably 1.0 to 2.0 mm ² / piece from the viewpoint of achieving both conductivity and adhesiveness. . Furthermore, the conductive regions located between the openings may have the same or different width. From the viewpoint of achieving both conductivity and adhesiveness at a high level, the width of the conductive region is preferably the same. For example, the width of the conductive region is preferably 0.05 to 1.0 mm, and more preferably 0.1 to 0.5 mm.

(D) Others It is preferable to provide a terminal for applying a voltage to the conductive layer at the end of the conductive layer. By providing the terminal, the pressure-sensitive adhesive product of the present invention can be used regardless of whether the adherend is conductive or insulating. The shape of the terminal is not particularly limited. Further, the number is not particularly limited. The terminal can be formed from a metal such as gold, silver, copper, or aluminum, or an alloy of these metals.
(E) Shape of electro-peelable pressure-sensitive adhesive product The shape of the pressure-sensitive adhesive product is not particularly limited, and is determined according to the shape of the conductive support. For example, when the conductive support is a foil, the product is an adhesive tape.

(F) Manufacturing method of electrically peelable pressure-sensitive adhesive product As a manufacturing method of pressure-sensitive adhesive product, for example, (1) A pressure-sensitive adhesive layer is formed by applying a pressure-sensitive adhesive composition on a conductive support, and separately from this. Formed by printing a conductive layer on a substrate for forming a conductive layer (release liner) and transferring the conductive layer onto a pressure-sensitive adhesive layer. (2) Conducting after printing a conductive layer on a substrate for forming a conductive layer For example, a method of forming an adhesive layer on the layer and placing a conductive support on the adhesive layer may be used. In addition, when the conductive layer is composed of only a metal component, or when it is a layer that is not formed by a coating method, such as when it is composed of a composite in which the surface of a woven resin component is coated with a metal component, for example, a conductive support An example is a method in which a pressure-sensitive adhesive layer is formed thereon by a coating method, and a conductive layer is placed on the pressure-sensitive adhesive layer.

(G) Use of electro-releasable pressure-sensitive adhesive product The pressure-sensitive adhesive product may be used for bonding a metal material (for example, aluminum or noble metal) that needs to be recycled to another member. In this application, the metal material can be easily recovered by applying a voltage, which is useful for home appliance recycling, for example.
Moreover, the adhesion | attachment use of a sensor and a to-be-adhered body is mentioned. This application is economical because the sensor can be easily recovered by applying a voltage, and the sensor can be used repeatedly.

Furthermore, the use of the collar used for the animal tracking marker is mentioned. In this application, when the tracking is not necessary, the collar can be removed from the animal by applying a voltage to the portion where the collar is joined by remote control.
During the manufacturing process, adhesive products can be used for temporary fixing of parts. For example, it can be used for temporarily fixing a wafer when dicing an LSI chip. In this application, the temporarily fixed state can be easily released by applying a voltage.

  It can be used to bond both satellites when separating them from their enclosures. Conventionally, a method such as jet injection, which is difficult to perform delicate control, has been used for separation. However, if the pressure-sensitive adhesive product of the present invention is used, fine control can be performed by applying a voltage, and physical damage to the artificial satellite can be reduced.

(H) Peeling method The said adhesive product can be made to adhere to a to-be-adhered body. The adherend is not particularly limited, and may have conductivity or insulation. Since the pressure-sensitive adhesive product of the present invention includes a conductive layer, an insulating adherend can also be used.
Peeling of the adhesive product from the adherend can be performed by applying a voltage between the conductive support and the conductive layer. Specifically, it can be peeled from the adherend by connecting a terminal to the conductive support and the conductive layer and applying a voltage between the terminals.

  The applied voltage is not particularly limited as long as it can be peeled off, but is preferably 3 V or more. The upper limit of the voltage is not particularly defined from the viewpoint of peeling, but it is preferably 200 V or less in consideration of the influence on the voltage application device and the adherend. The application time is preferably 5 minutes or less, for example. The upper limit of the application time is not particularly defined from the viewpoint of peeling, but it is preferably 10 minutes considering the influence on the adherend. Furthermore, the temperature at the time of peeling may be room temperature (about 25 ° C.), or may be lower or higher than room temperature. It is preferable to carry out at normal temperature from the ease of peeling work.

EXAMPLES Hereinafter, although this invention is further demonstrated using an Example, this invention is not limited to a following example.
Example 1
(Preparation of acrylic adhesive)
A monomer mixture composed of 91 parts by weight of n-butyl acrylate (manufactured by Mitsubishi Chemical), 8 parts by weight of acrylic acid (manufactured by Mitsubishi Chemical), and 1 part by weight of 2-hydroxyethyl methacrylate (manufactured by Nippon Shokubai Co., Ltd.), and a polymerization initiator Azobisisobutyronitrile (AIBN, manufactured by Junsei Chemical Co., Ltd.) 0.2 part by weight and solvent (ethyl acetate: toluene (weight ratio) = 9: 1) 150 parts by weight in a nitrogen stream at 85 ° C. Was subjected to a polymerization reaction for 5 hours to obtain an acrylic pressure-sensitive adhesive. The obtained acrylic pressure-sensitive adhesive contained 40% by weight of a resin component (solid content: acrylic polymer: weight average molecular weight of about 800,000), and had a viscosity of 7000 mPa · s.

(Electrolyte)
Propylene carbonate (PC) (Toyo Gosei Co., Ltd.) containing 1.0 M (mol / l) tetraethylammonium tetrafluoroborate (Et ₄ NBF ₄ ) was used as the quaternary ammonium salt electrolyte.
(Preparation of adhesive composition)
To 100 parts by weight of the acrylic pressure-sensitive adhesive (40 parts by weight of acrylic polymer), 4 parts by weight of Coronate L-55E (manufactured by Nippon Polyurethane Co., Ltd.) as an isocyanate-based crosslinking agent and 16 parts by weight of the electrolytic solution are added. The mixture was stirred for 10 minutes and defoamed to obtain an adhesive composition.

(Measurement of ionic conductivity)
The ionic conductivity of the pressure-sensitive adhesive composition was measured as follows. The measurement was performed by the AC impedance method using a Solartron 1260 frequency response analyzer. Specifically, the pressure-sensitive adhesive composition is sandwiched between stainless steel using a bipolar cell (manufactured by Toyo System Co., Ltd.), and a certain area (1.3 cm ² ) and thickness (0.004 cm) by a Teflon spacer. It was controlled in a disk shape. The resistance is obtained by applying a Cole-Cole plot obtained by applying a voltage of 10 mV to this cell and changing the frequency defining the amplitude from 1 MHz to 0.1 Hz using an equivalent circuit. It was. By substituting the area A, the thickness L, and the resistance Rb into the following formula, the ionic conductivity σ of the pressure-sensitive adhesive composition was calculated.
(Formula) σ = L / (Rb × A)

(Preparation of conductive layer)
Silver paste A (Dotite FA-353N, thermosetting polyester resin, containing 69% by weight of silver, manufactured by Fujikura Kasei Co., Ltd.) 100 parts by weight, acrylic resin (BYK-350 manufactured by Big Chemie Japan Co., Ltd.) (leveling agent for surface adjustment) ) 2 parts by weight and 1 part by weight of silicone (BYK-066N manufactured by Big Chemie Japan) (antifoaming agent) were mixed uniformly. The obtained mixed solution was subjected to gravure printing on a PET film which had been subjected to silicone release treatment using a plate having the pattern (1) in FIG. 1, thereby obtaining a conductive layer. In FIG. 1, a means the width of the opening (dot width), and b means the width of the conductive region (line width).

(Preparation of electro-releasable adhesive products)
The pressure-sensitive adhesive composition was applied onto a release liner, and the obtained coating film was dried at 100 ° C. for 2 minutes to obtain an electro-peelable pressure-sensitive adhesive layer having a thickness of 40 μm, and then a conductive support. As an aluminum foil base material (thickness: 100 μm), an electrodetachable pressure-sensitive adhesive layer was bonded. Thereafter, it was cured at 40 ° C. for 3 days. Thereafter, the release liner was peeled off, and the electroconductive layer produced above was pasted to obtain an electrically peelable adhesive product (adhesive tape).
The obtained electrically peelable adhesive product was subjected to the following evaluation. The results are shown in Tables 1 and 2. In the table, “parts” means parts by weight.

(Evaluation of electrical peelable adhesive products)
(1) Measurement of surface resistance The surface resistance on the conductive pattern material alone and the adhesive tape was measured.
Two stainless steel electrodes X (width A: 2.5 cm) are placed on the measurement object W with a certain distance L (3.0 cm) apart, and a 1 kg weight Y is placed on each electrode (FIG. 2). Thereafter, a resistance value R (Ω) between the electrodes was obtained using a tester Z. The surface resistance (Ω / □) was calculated from the formula: surface resistance (Ω / □) = R (Ω) × A (cm) / L (cm).

(2) Measurement of adhesive strength The obtained adhesive tape was cut into a width of 25 mm and a length of 250 mm to obtain a sample piece. A sample piece is placed on a PET plate (adhered body: manufactured by Engineering Test Service Co., Ltd.), and the sample piece is reciprocated once in the length direction of the sample piece at a speed of 300 mm / min using a 2 kg rubber roller. An evaluation sample was obtained. 30 minutes after pressure bonding, in accordance with JIS Z-0237, the force required for peeling (180 ° peel) at an angle of 180 ° at a tensile speed of 300 mm / min using an autograph AGS-H manufactured by Shimadzu Corporation (Adhesive strength: N / 25 mm) was measured.

After 30 minutes of pressure bonding of the sample sample prepared in the same manner as described above, an electrode was attached to the conductive support and adherend of the evaluation sample as shown in FIG. 3, and a voltage of 100 V was applied for 3 minutes. After application, the force required to peel 180 ° was measured in the same manner as described above.
FIG. 3 is a schematic sectional view of the voltage application method. In the figure, 1 is a conductive support, 2 is an electro-releasable pressure-sensitive adhesive layer, 3 is a conductive layer, 4 is an adherend, and 5 is a DC power source.

(2) Evaluation of electrical peelability The electrical peelability was evaluated based on the degree of decrease in adhesive strength after voltage application (100 V for 3 minutes). The ratio (%) of the adhesive strength after voltage application to the adhesive strength before voltage application is calculated as the adhesive strength maintenance rate. When the retention rate is 20% or less, it is marked as ◎ as easy to peel off by applying voltage, when it is larger than 20% and 50% or less, it is marked as possible, and when larger than 50%, peeling is difficult. It was marked as x.

Examples 2-18 and Comparative Examples 1-4
An electrically peelable adhesive product was obtained in the same manner as in Example 1 except that the conductive layer and the adhesive layer shown in Table 1 were used. The obtained electrically peelable adhesive product was evaluated in the same manner as in Example 1. The results are shown in Tables 1 and 2. However, in Comparative Example 3 in which the amount of electrolytic solution added was large, film formation itself could not be performed.

In these examples and comparative examples in Tables 1 and 2, silver paste B is Dotite XA-824 (resin component: thermosetting phenol resin, 45% by weight of silver, manufactured by Fujikura Kasei Co., Ltd.), polyester adhesive is XI-0002 (manufactured by Nippon Synthetic Chemical Industry Co., Ltd .: solid content 50 wt%: viscosity 6000 mPa · s), quaternary ammonium salt electrolyte contains 1.8 M triethylmethylammonium tetrafluoroborate (Et ₃ MeNBF ₄ ) Propylene carbonate (PC) (manufactured by Toyo Gosei Co., Ltd.) was used, and (1-hexylpyridinium bis (trifluoromethanesulfone) imide) (manufactured by Kanto Chemical Co., Inc.) was used as the ionic liquid A. For the adherend, polycarbonate (manufactured by Engineering Test Service), glass, and polyimide (Upilex manufactured by Ube Industries) were used.

(Evaluation results)
Example 1 in which 16 parts by weight of 1.0 M Et ₄ NBF ₄ -PC (electrolyte) was added to 100 parts of acrylic pressure-sensitive adhesive, and silver paste A (containing thermosetting polyester resin) was used as a conductive layer forming material In -6, the surface resistance was low, and the adhesive strength was significantly reduced by applying a voltage of 100 V for 3 minutes to the PET adherend. Furthermore, even when the adherend was changed to polycarbonate (Example 7), glass (Example 8), and polyimide (Example 9), the adhesive strength was also significantly reduced.
In Comparative Example 1 containing no electrolyte and Comparative Example 2 containing a small amount of electrolyte, the adhesive strength did not decrease.
In Example 13 in which the electrolyte was changed to 1.8 M Et ₃ MeNBF ₄ -PC, the adhesive strength was significantly reduced by voltage application.
In Comparative Example 4 in which the electrolyte was changed to ionic liquid A, the adhesive strength did not decrease.
In Example 18 in which the resin component in the silver paste was a thermosetting phenol, the surface resistance was low, and it was confirmed that the adhesive strength was reduced by voltage application.

Example 19
Four evaluation samples were collected from the electrically peelable adhesive products of Examples 6 to 9, and the adhesive force after applying a voltage of 100 V for 1 minute and 3 minutes to each evaluation sample was measured. The measurement method was the same as in Example 1. The obtained results are shown in FIG. FIG. 4 also shows the adhesive strength before voltage application. In FIG. 4, the two-dot chain line is a graph with polycarbonate, the dotted line with polyimide, the solid line with PET, and the one-dot chain line with glass as an adherend.
From FIG. 4, it can be seen that the adhesive strength of the example of the electro-releasable adhesive product significantly decreased in a short time regardless of the type of adherend.

a width of opening (dot width), b width of conductive region (line width), A electrode width, L distance between electrodes, W measurement object, X electrode, Y weight, Z tester, 1 conductive support, 2 electricity Peelable adhesive layer, 3 conductive layer, 4 adherend, 5 DC power supply

Claims (6)

An electro-releasable pressure-sensitive adhesive layer comprising an electro-releasable pressure-sensitive adhesive composition formed thereon and comprising 100 parts by weight of an acrylic pressure-sensitive adhesive or polyester pressure-sensitive adhesive and 15 to 250 parts by weight of an electrolyte. And a conductive layer formed on the surface of the electrodetachable pressure-sensitive adhesive layer,
The electro-peelable pressure-sensitive adhesive composition has an ionic conductivity of 10 ⁻¹¹ to 10 ⁻³ S / cm,
The electrolytic solution is an organic solution containing an organic solvent and an electrolyte selected from an organic quaternary ammonium salt and an alkali metal salt;
The electrolyte is contained in the electrolyte at a concentration of 0.01 to 3 mol / l;
Wherein the conductive layer, have a patterned planar shape comprising an exposed opening of the electric-peelable pressure-sensitive adhesive layer,
The electrolytic solution contains, as the organic quaternary ammonium salt, a boron-containing organic electrolyte salt represented by the formula (R) ₄ NBF ₄ (wherein R is the same or different and is a methyl group or an ethyl group). Electrically peelable adhesive product characterized by The electro-peelable pressure-sensitive adhesive product according to claim 1 , wherein the electrolytic solution contains an organic solvent having a relative dielectric constant of 30 or more. The electro-peelable pressure-sensitive adhesive product according to claim 1 or 2 , wherein the electrolytic solution contains an organic solvent having a relative dielectric constant of 30 or more selected from ethylene carbonate, propylene carbonate, γ-butyrolactone, and N-methyl-2-pyrrolidone. . The acrylic adhesive, and the alkyl (meth) acrylate having an alkyl group of 1 to 8 carbon atoms, claim 1-3 comprising a carboxyl group-containing acrylic monomer, a copolymer of hydroxyl group-containing acrylic monomer The electrically peelable adhesive product according to any one of the above. The electrically peelable adhesive product according to any one of claims 1 to 4 , wherein the conductive layer has a surface resistance value of 1000 Ω / □ or less. After sticking the electric peelable adhesive product according to any one of claims 1 to 5 on an adherend so that the electric peelable adhesive layer faces, the conductive support and the A method for peeling an electrically peelable adhesive product, comprising peeling off the electrically peelable adhesive product from the adherend by applying a voltage between the conductive layer and the conductive layer.

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