WO2015080428A1

WO2015080428A1 - Composition for forming adhesive film, adhesive film for processing prior to photo-curing, adhesive film, and electronic paper display device

Info

Publication number: WO2015080428A1
Application number: PCT/KR2014/011161
Authority: WO
Inventors: 김상환; 이용훈; 김대현; 최원구; 김장순
Original assignee: (주)엘지하우시스
Priority date: 2013-11-29
Filing date: 2014-11-20
Publication date: 2015-06-04
Also published as: KR101832522B1; TW201520291A; CN105579547B; KR20150062695A; CN105579547A; JP6529963B2; JP2017504664A; TWI530542B

Abstract

Provided is a composition for forming an adhesive film, comprising: a phenoxy-based thermosetting resin; a cyclic epoxy-based photo-curable compound; an isocyanate-based heat hardening agent; and a cationic photoinitiator.

Description

A composition for forming an adhesive film, an adhesive film for photocuring processing, an adhesive film, and an electronic paper display device

The present invention relates to a composition for forming an adhesive film, a pressure-sensitive adhesive film for photocuring, an adhesive film, and an electronic paper display device.

In general, a digital paper display is spotlighted as a next-generation display device following a liquid crystal display, a plasma display panel, and an organic luminescence display. It is evaluated as an ideal ideal device as a type display device.

In particular, electronic paper is a display element that enables characters and images to be displayed by using a flexible substrate such as a thin plastic in which millions of beads are scattered in oil holes. It is expected to be a material that will replace existing print media such as books, newspapers and magazines in the future. In addition, electronic paper is much cheaper to produce than conventional flat display panels, and does not require backlighting or continuous recharging, so it can be driven with very little energy. In addition, the electronic paper is very clear, has a wide viewing angle, and even has a memory function that does not completely disappear even if there is no power source, so it can be widely used in public bulletin boards, advertisements, and e-books.

The electronic paper may include an ink layer using a solvent, and may be formed to have a structure in which an ink layer is sealed by stacking a sealing film thereon. Due to this structure, the sealing film is in contact with the solvent, and the adhesive composition forming the sealing film has a problem in that chemical resistance to the solvent is lowered, and as a result, high temperature reliability and durability of the electronic paper are lowered.

One embodiment of the present invention provides a composition for forming an adhesive film having excellent chemical resistance to a solvent.

Another embodiment of the present invention provides a pressure-sensitive adhesive film for photo-curing processing excellent in chemical resistance to the solvent.

Another embodiment of the present invention provides an adhesive film prepared from the composition for forming an adhesive film.

Another embodiment of the present invention provides an electronic paper display device manufactured using the adhesive film as a sealing film.

In one embodiment of the invention, the phenoxy clock thermosetting resin; Cyclic epoxy photocurable compounds; Isocyanate-based thermosetting agents; It provides a composition for forming an adhesive film comprising a; and a cationic photoinitiator.

The phenoxy clock thermosetting resin may have a glass transition temperature of 90 to 120 ℃.

The weight average molecular weight of the phenoxy clock thermosetting resin may be 40,000 g / mol to 60,000 g / mol.

The phenoxy clock thermosetting resins include bisphenol A type phenoxy resin, bisphenol F type phenoxy resin, bisphenol AF type phenoxy resin, bisphenol S type phenoxy resin, brominated bisphenol A type phenoxy resin, brominated bisphenol F type phenoxy resin, It may include at least one selected from the group consisting of phosphorus-containing phenoxy resins and combinations thereof.

The glass transition temperature of the cyclic epoxy photocurable compound may be 90 to 120 ℃.

The cyclic epoxy photocurable compound is a group consisting of a bisphenol A type epoxy compound, a bisphenol F type epoxy compound, a bisphenol S type epoxy compound, a dicyclopentadiene type epoxy compound, an alicyclic epoxy compound, a brominated epoxy compound, and a combination thereof It may include at least one selected from.

The content ratio of the phenoxy clock thermosetting resin and the cyclic epoxy photocurable compound may be 1: 1.5 to 1: 2.5.

The cationic photoinitiator may be an onium salt-based ultraviolet cleavage initiator.

The cationic photoinitiator may be included in 5 parts by weight to 15 parts by weight relative to 100 parts by weight of the cyclic epoxy-based photocurable compound.

The isocyanate-based thermosetting agent is It may be included as 0.1 parts by weight to 1.0 parts by weight relative to 100 parts by weight of the phenoxy clock thermosetting resin.

The composition for forming an adhesive film may further include an additive including at least one selected from the group consisting of a silane binder, an inorganic binder, a brightener, a wettability improving agent, a pigment, a deodorant, an antifoaming agent, an antioxidant, an organic flame retardant, a thickener, a plasticizer, and a combination thereof. It may include.

In another embodiment of the present invention, the resin composition for forming the adhesive film is formed by drying and heat curing by heat treatment, to provide a pressure-sensitive adhesive film for photocuring pre-curable further photocurable.

The photocurable pressure-sensitive adhesive film may be a mixture of a cured product of the solid phenoxy thermosetting resin and the liquid cyclic epoxy photocurable compound.

The pressure-sensitive adhesive film for photocuring processing may be 95 to 98%.

The photocurable adhesive film may be in a state in which the solid phenoxy clock thermosetting resin is impregnated with an epoxy photocurable compound containing a cyclic ring in the liquid main chain.

The adhesive film for photo-curing processing may have a measured value of tack adhesive force measured at a rate of about 100 mm / min on a stainless steel plate by a rooftack measuring instrument at 60 ° C. at a temperature of 30 gf to 80 gf. .

In another embodiment of the present invention, to provide an adhesive film prepared by performing a photocuring with respect to the pressure-sensitive adhesive film for photo-curing processing.

In another embodiment of the invention, the upper electrode; A lower electrode spaced apart from the upper electrode; An ink receiving layer disposed between the upper electrode and the lower electrode, forming a microcavity separated by a partition, and accommodating ink in the microcavity; And a sealing film formed by adhering the upper electrode to the ink receiving layer and photocuring the pressure-sensitive adhesive film for photo-curing processing.

The sealing film may be a transparent film having a thickness of 5 μm to 10 μm.

The sealing film may be dipped in a halocarbon solvent, a dodecane solvent, or a mixed solvent thereof at 90 ° C. for 12 hours, and the elution amount of the sealing film eluted with the halocarbon solvent or dodecane solvent may be 5 wt% or less. .

The surface of the sealing film may have a contact angle of 105 ° or less.

The adhesive film has excellent chemical resistance to solvents, and the electronic paper display device applying the adhesive film as a sealing film has excellent high temperature reliability.

1 is a schematic view of a cross section of the electronic paper display device.

Hereinafter, embodiments of the present invention will be described in detail. However, this is presented as an example, by which the present invention is not limited and the present invention is defined only by the scope of the claims to be described later.

Phenoxy clock thermosetting resin in one embodiment of the present invention; Cyclic epoxy photocurable compounds; Isocyanate-based thermosetting agents; It provides a composition for forming an adhesive film comprising a; and a cationic photoinitiator.

The composition for forming an adhesive film may be formed of a pressure-sensitive adhesive film for photo-curing processing used for adhesion between components constituting an electronic device, and the film may then be formed into an adhesive film by photocuring.

The adhesive film formed from the composition for forming an adhesive film is excellent in high temperature reliability and chemical resistance to an organic solvent. Accordingly, the adhesive film may be usefully applied as a sealing film for electronic paper display devices.

The composition for forming an adhesive film may include a thermosetting resin and a photocurable compound at the same time, and a specific kind of thermosetting resin and a specific kind of photocurable compound may be selected and combined to improve high temperature reliability and chemical resistance to an organic solvent. And tack adhesion can be minimized.

The phenoxy clock thermosetting resin is not particularly limited as long as it is a compound containing a bisphenol structure in the structure of the compound, and specifically, bisphenol A type phenoxy resin, bisphenol F type phenoxy resin, bisphenol AF type phenoxy resin, bisphenol S type phenoxy Cyanide resin, bisphenol bromide A type phenoxy resin, bisphenol bromide F-type phenoxy resin, phosphorus containing phenoxy resin, and the like, and may include at least one selected from the group consisting of a combination thereof.

When the phenoxy clock thermosetting resin is thermoset, the phenoxy structure may be cross-linked to be formed as a film (corresponding to an adhesive film for photocuring or a B-stage processed film described later). The phenoxy clock thermosetting resin exhibits excellent chemical resistance properties, is densely crosslinked during film formation with a film, and forms a hydrophilic film, thereby preventing the film coating from collapsing even when exposed to an organic solvent such as halocarbon. Due to these characteristics, it can be usefully applied as a composition for forming the sealing film for electronic paper display device of the present invention.

The glass transition temperature of the phenoxy clock thermosetting resin may be about 90 to about 120 ℃. By using a phenoxy clock thermosetting resin having a high glass transition temperature as in the above range, excellent chemical resistance can be imparted to the film in which the composition for forming an adhesive film is formed by heat treatment or thermosetting.

The weight average molecular weight of the phenoxy clock thermosetting resin may be about 40,000 g / mol to about 60,000 g / mol. If the weight average molecular weight is less than the above range, the viscosity becomes so low that it is very difficult to form a uniform coating film when coating the composition, and continuously contact with the ink when it remains as residual volatiles after thermal curing when forming the sealing film in the electronic paper display device. This may dissolve and deteriorate the chemical resistance over time. In addition, in the case of exceeding the above range, it takes a long time during the heat curing or when the network structure is formed after curing, the molecular weight between the curing point is increased, the chemical resistance may be lowered, the viscosity is very high, the thickness becomes uneven when coating the thin film There may be a problem of poor appearance quality.

The cyclic epoxy photocurable compound is a compound which can be polymerized by irradiation of ultraviolet rays or electron beams, etc., and may be in the form of a monomer, an oligomer or a polymer, and has a cyclic structure including a cyclic ring in a main chain thereof. Epoxy-based photocurable compounds can be used without limitation.

Specifically, the cyclic epoxy photocurable compound may be a bisphenol A type epoxy compound, a bisphenol F type epoxy compound, a bisphenol S type epoxy compound, a dicyclopentadiene type epoxy compound, an alicyclic epoxy compound, a brominated epoxy compound, and the like. At least one selected from the group consisting of a combination thereof.

The adhesive film-forming composition includes a cyclic epoxy-based photocurable compound mixed together to supplement physical properties that are difficult to obtain when using a phenoxy clock thermosetting resin alone. As described above, when the phenoxy clock thermosetting resin is thermoset to form a film, the cyclic epoxy photocurable compound before photocuring is evenly distributed between the thermosetting phenoxy clock thermosetting resins to impart tack adhesion. Then, when the film is photocured, evenly distributed cyclic epoxy-based photocurable compound and some phenoxy structure can be hardened to implement chemical resistance properties.

The glass transition temperature of the cyclic epoxy photocurable compound may be about 70 to about 120 ℃. By using the cyclic epoxy-based photocurable compound having a high glass transition temperature as in the above range, the adhesive film formed from the composition for forming the adhesive film is excellent in high temperature reliability, chemical resistance to organic solvents and tack adhesion Can be minimized.

The cyclic epoxy-based photocurable compound is cured to exhibit a transparent property, excellent in oxidation resistance, yellowing does not occur due to light can be usefully applied as a composition for forming a sealing film for electronic paper display devices, In addition, since the tack adhesion is minimized, the problem that the charged particles in the ink composition adhere to the ink composition used in the electronic paper display device may be minimized.

The cyclic epoxy-based photocurable compound may impart hydrophilicity when forming a film, thereby minimizing exposure of the hydrophobic solvent when contacted with the hydrophobic solvent, thereby improving chemical resistance to the solvent.

The weight ratio of the phenoxy clock thermosetting resin and the cyclic epoxy photocurable compound may be about 1: 1.5 to about 1: 2.5 ratio. The adhesive film formed from the composition for forming an adhesive film comprising the phenolic thermosetting resin and the cyclic epoxy-based photocurable compound in the content ratio has excellent high temperature reliability and excellent chemical resistance to an organic solvent, and has a tack adhesive force. Can be minimized.

The adhesive film-forming composition may include an isocyanate-based thermosetting agent as a thermosetting agent.

The isocyanate-based thermosetting agent may be used without limitation as long as it is a compound having an isocyanate group, and the isocyanate group may react with a hydroxyl group and a urethane polymerization.

Specifically, the isocyanate group in the isocyanate-based thermosetting agent crosslinks the phenoxy clock thermosetting resin by urethane polymerization of the hydroxyl group in the phenoxy clock thermosetting resin in the composition for forming an adhesive film, thereby densely pre-curing the B-stage film. To facilitate processing into a film.

In addition, when the cyclic epoxy-based photocurable compound is cured, a hydroxy group is generated, and the film can be more densely formed by performing a urethane polymerization reaction with such a hydroxy group.

Specifically, the isocyanate-based thermosetting agent is Block isocyanate, isophorone dicyanate, alkyl diisocyanate, trifunctional isocyanate (HDI trimer) and the like, and may include at least one selected from these.

The composition for forming an adhesive film may include about 0.1 part by weight to about 1.0 part by weight of isocyanate-based thermosetting agent relative to 100 parts by weight of the phenoxy clock thermosetting resin. The composition for forming an adhesive film containing an isocyanate-based thermosetting agent in the above content can be easily processed into a film, and can impart appropriate strength to the adhesive film prepared therefrom.

The cationic photoinitiator efficiently initiates epoxy in the photopolymerization reaction by absorbing light energy such as electron beam, visible light or ultraviolet energy to generate cations.

The cationic photoinitiator may be, for example, an onium salt-based ultraviolet cleavage initiator.

Specific examples of the onium salt-based ultraviolet cleavage initiator include a diaryl iodonium salt, a triarylsulfonium salt, a triaryl selenium salt, a tetraarylphosphonium salt, an aryldiazonium salt, and the like, and further contain an antimony atom. An antimony ultraviolet ray cleavage initiator, a boron ultraviolet ray cleavage initiator containing a boron atom, etc. can be used.

For example, the diaryl iodonium salt is Y ₂ I ⁺ X ^- may be a compound represented by ^(the non-nucleophilic (non- nucleophile) or being non-basic anion of the Y may have a substituent, an aryl group, X). The X anion of the non-nucleophilic or non-basic ^- is, for _{^{_{^{example, SbF 6 -, SbCl 6 -}}}} , BF 4 -, [B (C 6 H 5) 4] -, [B (C 6 F 5) 4 ] ^- , [B (C ₆ H ₄ CF ₃ ) ₄ ] ^- , [(C ₆ F ₅ ) ₂ BF ₂ ] ^- , [C ₆ F ₅ BF ₃ ] ^- , [B (C ₆ H ₃ F ₂ ) _{^{_{^{4] -, AsF 6 -,}}}} PF 6 -, HSO 4 -, ClO 4 - , and the like.

In addition, the triarylsulfonium salt, the triaryl selenium salt, the tetraaryl phosphonium salt, and the aryldiazonium salt may be respective compounds corresponding to the diaryl iodonium salt. Specifically, these are triarylsulfonium salt, triaryl seleno salts, tetra aryl phosphonium salts, and aryl diazonium salts as, _{^{^{respectively, Y 3 S + X -,}}} Y 3 Se + X -, Y 4 P + X - and YN ₂ ⁺ X ⁻ (Y may have a substituent, X ⁻ may be a compound represented by a non-nucleophile or a nonbasic anion).

The composition for forming an adhesive film may include about 5 parts by weight to about 15 parts by weight of cationic photoinitiator relative to 100 parts by weight of the cyclic epoxy photocurable compound. Since the photopolymerization initiator maintains the above range, many molecules having a short bond length are not generated, thereby ensuring durability of the adhesive film prepared from the composition for forming an adhesive film.

The composition for forming an adhesive film may further include additives such as silane binder, inorganic binder, gloss agent, wettability improving agent, pigment, deodorant, antifoaming agent, antioxidant, organic flame retardant, thickener, plasticizer, etc. in a range that does not lose inherent properties. have.

The adhesive composition for forming the adhesive film may be coated on top of a release film to form a coating layer, and then heat-treated to prepare the pressure-sensitive adhesive film for photocuring.

The heat treatment may be performed, for example, by drying with hot air at about 110 to about 130 ° C. for about 3 to 5 minutes.

The release film is not limited as long as the release film is easy to peel so that no residual material remains when the coating layer of the adhesive film for processing before photocuring is left. For the release film, for example, polyethylene terephthalate coated with a silicone release agent, or polyethylene terephthalate coated with a fluorine release agent may be used depending on the wettability of the coating layer of the pressure-sensitive adhesive film for photocuring. In addition, since the release film should not be deformed by heat when heat-treating the coating layer formed on the release film, it is also possible to use a polyimide coated with a release agent, polynaphthalene terephthalate, or the like according to a drying temperature.

In this manner, the resin composition for forming the adhesive film may be dried and thermally cured by heat treatment to form an adhesive film for photocuring (B-stage processed film).

The pressure-sensitive adhesive film for photocuring is used in the processing step before forming the adhesive film layer in the electronic component to be applied.

First, the resin composition for forming the adhesive film may be heat-treated to form a film, and thus may be used in an easy form. The adhesive film for pre-curing processing may be further photocurable, and the adhesive performance may be given by performing additional photocuring. For example, an adhesive film can be formed in an applied article such as an electronic component.

The photocurable adhesive film may be in a state in which a cured product of the solid phenoxy thermosetting resin and the cyclic epoxy photocurable compound in a liquid state are mixed. That is, the ratio of the phenoxy thermosetting resin and the photocurable epoxy may be efficiently prepared at about 1: 1.5 to about 1: 2.5. When the resin composition for forming the adhesive film is heat-treated, the phenoxy thermosetting resin is thermoset to form a solid film, and the phenoxy thermosetting resin of the solid film is evenly distributed in the cyclic epoxy photocurable compound (IPN (Structure) may be formed an adhesive film for photo-curing processing.

As the adhesive film for photo-curing processing is manufactured from the composition for forming an adhesive film, the curing degree of the phenoxy clock thermosetting resin may be maximized.

The degree of cure may be defined in Equation 1 below to indicate the degree of cure.

[Calculation 1]

Hardness (%) = {1- (W _i -W _f ) / W _i } × 100

In the above formula, W _i denotes the weight before dipping the cured sample to a predetermined size in the solvent of the specimen, W _f is the specimen left after immersing the specimen in the solvent for a certain period of time, and then filtered using a strainer Means the weight of. The type of the solvent and the period of leaving the specimen soaked in the solvent may vary depending on the cured product to measure the degree of curing.

For example, the solvent may be an alkyl acetate solvent, a ketone solvent, an aromatic solvent, a halocarbon oil solvent, or the like, and may be measured by determining a suitable reference solvent. The period of time in which the specimen is immersed in the solvent may be appropriately selected, and may be, for example, about 1 day to 1 week, but is not limited thereto.

As the value calculated as the degree of cure increases, the polymer structure of the cured product may mean that the network is densely formed.

Specifically, the degree of curing after photocuring of the adhesive film for photocuring is soaked for 24 hours using a mixed solvent in which a halocarbon oil and a dodecane oil are mixed at a weight ratio of about 3: 7 for 24 hours. The value obtained by 1 may be about 95 to about 98%. As such, since the adhesive film for photocuring processing has a high degree of curing, excellent chemical resistance may be realized to drive a display for an electronic paper.

On the other hand, the pressure-sensitive adhesive film for photo-curing processing, as described above, can minimize the tack (tack) adhesive force, specifically, Looptec was measured using a tensile tester (Instron, model name: 4443). After preparing the adhesive film for photocuring as a sample having a size of about 3cm x 10cm, it is left in the chamber at about 60 ° C for about 1 hour or more, and then tack adhesion at a rate of about 100mm / min on a stainless steel plate. As a result of the measurement, the measured value of the measured tack adhesive force at about 60 ° C. may be about 30 gf to 80 gf.

As the adhesive film is prepared from the above-described composition for forming an adhesive film, hydrophilicity is very high, and chemical resistance to a specific organic solvent is excellent.

In another embodiment of the invention, the upper electrode;

A lower electrode spaced apart from the upper electrode;

An ink receiving layer disposed between the upper electrode and the lower electrode, forming a microcavity separated by a partition, and accommodating ink in the microcavity; And

A sealing film formed by adhering the upper electrode to the ink receiving layer and photocuring the pressure-sensitive adhesive film for photocuring;

It provides an electronic paper display device comprising a.

In FIG. 1, the sealing film 20 is to bond with the upper electrode 30 while sealing the micro space in which the ink composition of the ink receiving layer 10 is accommodated in the electronic paper display device 100. The adhesive film for pre-curing processing formed from the composition for forming may be interposed between the ink receiving layer 10 and the upper electrode 30 and then photocured.

The photocuring can be carried out, for example, by UV irradiation.

UV irradiation performed for the photocuring may be performed for about 10 seconds to about 15 seconds with a metal halide lamp that is commonly used.

The amount of UV irradiated light is preferably about 0.5 J / cm ² to about 2.0 J / cm ² , and more preferably about 1.0 J / cm ² to about 1.5 J / cm ² .

The upper electrode 30 and the lower electrode 40 may be formed, for example, including an ITO electrode.

The microspace may be formed as a microcapsule or microcup. 1 shows an electronic paper display device using the microcup 5 structure. For example, the micro cup 5 may have a height of about 15 to 30 μm, and a length and a width of about 5 to 180 μm.

The ink receiving layer 10 includes the microcavities arranged therein, and contains an ink composition including ink particles 1 and charged particles 2 dispersed in the organic solvent 3 in the microcavities.

The upper electrode 30 and the lower electrode 40 are positioned above and below the microcavity, respectively, and when a voltage is applied, the charged particles 2 dispersed in the organic solvent 3 are moved and arranged so that black and white or color Is implemented.

In the microcup type electronic paper display device, the partition 4 is formed to prevent the charged particles 2 from moving in parallel.

The partition 4 separates the pixel from the pixel, and serves to keep the space of the micro cup 5 constant. In addition, when applied to the flexible display device, the partition 4 serves as a support for keeping the space of the micro cup 5 constant, and even when the partition 4 is bent, the partition 4 is formed by the upper electrode 30 and the lower electrode ( It should be glued without falling off 40).

If the partition wall 4 is lifted apart from the upper and lower ITO electrodes 30, the charged particles 2 disposed in the pixel space of each micro cup 5 move to the other micro cup 5 around. As a result, the image quality becomes unstable, the pixels fall, and as a result, a problem of increasing the defectiveness of the product itself occurs.

In order to prevent such a problem from occurring, the sealing film 20 should be well bonded to the upper electrode 30.

The sealing film 20 formed from the composition for forming an adhesive film has excellent adhesive strength so as to be well adhered to the partition wall and the upper electrode 30, but since the tack adhesion is minimized, the charged particles 2 are formed in the sealing film ( The phenomenon fixed to 20 can be minimized.

In addition, the sealing film 20 is in direct contact with the ink composition (1, 2) accommodated in the ink receiving layer 10 located below, the sealing film 20 is prepared from the composition for forming the adhesive film described above Therefore, excellent high temperature reliability and excellent chemical resistance to the organic solvent can be exhibited.

The ink composition often contains a solvent 3 such as, for example, a halocarbon solvent or a dodecane organic solvent, and the sealing film 20 is particularly such a halocarbon solvent or The chemical resistance is very excellent with respect to the dodecane solvent.

Specifically, the halocarbon solvent may be a compound substituted with a halogen group instead of hydrogen in methane, and may be Halocarbon Oil0.8, Halocarbon1.8, etc., sold by Halocarbon, and the dodecane solvent is specifically n-dodecane. Can be.

The sealing film 20 may be formed of a transparent film having a thickness of about 5 μm to about 10 μm. The sealing film 20 formed in the thickness range is excellent in adhesion with the partition 4 while sealing the ink receiving layer 10 well, and may be implemented transparently.

By measuring the elution amount of the halocarbon or dodecane solution of the sealing film 20, it is possible to evaluate the chemical resistance performance. Specifically, the elution amount (X) can be obtained by the following formula (2).

[Calculation 2]

Elution Amount (X) [%] = [(Initial Weight of Sealing Film-Weight of Sealing Film After Soaking in Solvent) / Initial Weight of Sealing Film] × 100

In the above formula, the solvent may use a mixed solvent of halocarbon and dodecane, the immersion time may be, for example, about 24 to about 48 hours at room temperature, high temperature conditions, for example about 40 to about 60 ℃ It can be eluted by dipping under conditions.

The elution amount (%) is an adhesive film after UV curing of the adhesive composition to indicate the degree of chemical resistance to the halocarbon and dodecane solvent as the crosslinking density, the lower the elution amount (X) is excellent in chemical resistance, The elution amount X is closely related to the high temperature durability at the time of driving an applied device such as an electronic paper display device.

After measuring the initial weight of the sealing film 20, and then immersed in a halocarbon solvent or dodecane solvent commonly used as a solvent of the ink composition used in the electronic paper display device for about 24 to about 48 hours After drying for about 3 to 5 hours at about 110 ° C. and measuring the residual weight, the value obtained as the elution amount (X) by the above formula 2 may be about 5% or less. As described above, the sealing film 20 may implement excellent chemical resistance of about 5% or less in the amount of leaching according to Formula 2.

In addition, the surface of the sealing film prepared by the composition for forming an adhesive film is hydrophilic by a hydroxyl group generated by ring opening of epoxy while photocuring a secondary alcohol-OH group having a phenoxy structure, for example, in water The contact angle with respect to can be implemented at about 95 ° or less.

Hereinafter, examples and comparative examples of the present invention are described. Such following examples are only examples of the present invention, and the present invention is not limited to the following examples.

(실시예)(Example)

Example 1

The phenoxy thermosetting resin having a weight average molecular weight of 52,000 g / mol and a glass transition temperature of about 94 ° C. was filtered by dissolving Inchem's PKHH (trade name) in a solution of 30 wt% concentration in a methyl cellosolve solvent with 300 mesh to filter out phenoxy solution (P1 ) Was prepared. 22.0 g of the phenoxy solution (P1) (of which PKHH content: 6.6 g), 15.4 g of S-28 (bis- (3,4-epoxycyclohexyl) adipate) of Synasia, which is a cyclic epoxy compound, and an isocyanate curing agent A composition for forming an adhesive film was mixed by stirring with phosphorus Asahi Kaze MFA-75X 0.06 g and 2.3 g of cationic photoinitiator UVI-6974 (manufactured by Momentive, including triallylsulfonium hexafluoroantimonate salt as a main component) Prepared.

The composition was formed into a 10 μm thick coating layer on a PET release film and then dried at 140 ° C. for 3 minutes with hot air to prepare a pressure-sensitive adhesive film for photocuring.

The prepared pressure-sensitive adhesive film for photocuring was irradiated with a 200mW ultraviolet curing machine for 10 seconds to obtain an adhesive film. When the photocuring irradiation amount was less than 0.5 J / cm ² , since a tack may remain on the surface after photocuring, the measurement was performed at the same amount of light.

Example 2

Example 2 formed the adhesive film in the same manner as in Example 1 except that the phenoxy resin was used by changing the glass transition temperature.

The phenoxy thermosetting resin having a weight average molecular weight of 60,000 g / mol and a glass transition temperature of about 98 ° C. was filtered by dissolving Inchem's PKFE (trade name) in a 30 wt% solution in a methyl cellosolve solvent with 300 mesh to filter out phenoxy solution (P2). Was prepared. 22.0 g of phenoxy solution (P2) (of which PKFE content: 6.6 g), 15.4 g of S-28 (bis- (3,4-epoxycyclohexyl) adipate) of Synasia, which is a cyclic epoxy compound, and an isocyanate curing agent Asahi Kaze MFA-75X 0.06 g, and 2.3 g of a cationic initiator UVI-6974 (manufactured by Momentive, including triallylsulfonium hexafluoroantimonate salt as a main component) were mixed with stirring to prepare a composition for forming an adhesive film. It was.

Comparative Example 1

The phenoxy thermosetting resin having a weight average molecular weight of 52,000 g / mol and a glass transition temperature of 94 ° C. filtered phenoxy solution (P1) by filtering 300 mesh of Inchem's PKHH (trade name) in a methyl cellosolve solvent with a 30 wt% solution. Ready. 22.0 g of phenoxy solution (P1) (of which PKHH content: 6.6 g), triallyl isocyanurate (TAIC, manufactured by Nippon Kasei) 15.4 g, polyfunctional thiol compound (trade name PEMP, pentaerythritol tetra (3-mer) Capto-propionate)) 2.3g and 2.3g of Irgacure184 (BASF), a radical initiator, were mixed to form a composition for forming an adhesive film, and an adhesive film was formed in the same manner as in Example 1 except for the use. It was. In Comparative Example 1, since PEMP was used as the photocurable compound, a radical initiator was used together.

Comparative Example 2

A thermosetting resin was not used, and in 15.4 g of methyl cellosolve, 6.6 g of an epoxy acrylate compound (PE-210 from Miwon Specialty, Inc.), a polyfunctional thiol compound (trade name PEMP, pentaerythritol tetra (3-mercapto-pro) Cationate)) 2.3g, triallyl isocyanurate (TAIC, manufactured by Nippon Kasei) 15.4g by weight, Irgacure184 (Basf) 2.3g by weight of the radical initiator was mixed to prepare a composition for forming an adhesive film Except for forming an adhesive film in the same manner as in Example 1. In Comparative Example 2, since PEMP was used as the photocurable compound, a radical initiator was used together.

평가evaluation

실험예 1: 용출량 평가Experimental Example 1: Evaluation of elution amount

The adhesive films prepared in Example 1-2 and Comparative Example 1-2 were immersed in a mixed solvent in which halocarbon oil (Halocarbon oil Halocarbon oil 0.8) and n-dodecane oil were mixed in a 3: 7 weight ratio for 12 hours. The sieve of 300 mesh was dried at 110 ° C. for 3 hours, and weighed.

[Calculation 2]

Elution amount (X) [%] = [(Initial weight of adhesive film-weight of adhesive film after immersion in solvent for some time) / Initial weight of adhesive film] × 100

실험예 2: 내화학성 평가Experimental Example 2: Evaluation of Chemical Resistance

1 drop of a mixed solvent in which a halocarbon oil (Halocarbon oil Halocarbon oil 0.8) and n-dodecane oil were mixed at a weight ratio of 3: 7 on the adhesive films prepared in Examples 1-2 and Comparative Examples 1-2. After dropping, the resultant was left in a 60 ° C. oven for 12 hours to observe and evaluate the presence of bleeding. If bleeding occurs, it means that the adhesive film is poor in chemical resistance to halocarbon. That is, in such a case, the halocarbon penetrates into the cured film, and the adhesive film is easily wetted and expanded by the halocarbon. Such wet and expanded films within an electronic paper display are easily separated, and the film is easily peeled off even when rubbed with polyester wipes and cotton for use in the clean room after applying methyl ethyl ketone (MEK). do. In the case of being easily peeled off, the crosslink density of the adhesive film was wetted and expanded by the halocarbon mixture, and thus the crosslink density of the film was markedly dropped.

실험예 3: 물 접촉각 평가Experimental Example 3: Evaluation of Water Contact Angle

After dropping 1 drop of distilled water with an eyedropper on the adhesive films prepared in Examples 1-2 and Comparative Examples 1-2, the contact angle was measured using a contact angle analyzer at room temperature, and the results are shown in Table 1 below. It is described in.

실험예 4: 점착력 (tack) 평가Experimental Example 4: Evaluation of Tack

After a sample prepared by cutting the pressure-sensitive adhesive film for photo-curing process prepared in Example 1-2 and Comparative Example 1-2 to 3cm x 10cm in size using a Looptec tester of Texture Analysis product, 1 hour in a 60 ℃ chamber After standing, the tack adhesion was measured at a rate of 100 mm / min on a stainless steel plate, and the results are shown in Table 1 below.

실험예 5: 접착력 평가Experimental Example 5: Evaluation of Adhesion

After preparing a micro cup sheet used for an electronic paper display device and applying a halocarbon mixture, the microcup sheet was laminated with the adhesive film and the thermal lamination prepared in Example 1-2 and Comparative Example 1-2 at 70 ° C. Then, after photocuring and bonding under the photocuring conditions shown in Example 1-2 and Comparative Example 1-2, the adhesive force was measured using a spring gauge, the results are shown in Table 1.

실험예 6:콘트라스트비 (CR) 측정 평가Experimental Example 6: Evaluation of Contrast Ratio (CR) Measurement

The micro-cup sheet filled with the ink composition (a mixture of carbon black and TiO ₂ beads and a halocarbon solvent, manufactured by Imige & Material Co., Ltd.) was prepared using the pressure-sensitive adhesive film prepared in Example 1-2 and Comparative Example 1-2. After lamination by thermal lamination, and left for 24 hours at 60 ℃ after photocuring, the white reflectance and the black reflectance were measured using Minolta's CM-3700A.

White reflectance / Black reflectance was calculated for the adhesive films prepared in Examples 1-2 and Comparative Examples 1-2, and the contrast ratio (CR) values are shown in Table 1 below.

실험예 7: 고온 신뢰성 평가Experimental Example 7: Evaluation of High Temperature Reliability

An electronic paper display device having the structure of FIG. 1 was manufactured with respect to the pressure-sensitive adhesive film prepared in Example 1-2 and Comparative Example 1-2. Photocuring shipbuilding of the sealing film was prepared under the same conditions as described in Example 1. After manufacturing an electronic paper display device and leaving it at 60 ° C. for 240 hours, the white / black reflectance was measured using Minolta's CM-3700A, and the contrast ratio was measured. . The evaluation was performed according to the following criteria and the results are shown in Table 1 below.

Good: less than 5%

Poor: 5% or more

Table 1

division	Elution amount (X,%)	Chemical resistance (smear)	Water contact angle (˚)	High Temperature Tack (gf cm2)	High temperature reliability	Adhesive force (gf / cm2)	CR (White / Black)
Example 1	3.0	none	85	75	Good	80	11.2
Example 2	1.0	none	75	50	Good	65	12.4
Comparative Example 1	28.0	has exist	120	100	Bad	120	6.2
Comparative Example 2	20.0	has exist	110	80	Bad	103	6.0

Referring to Table 1, Example 1 and Example 2 was measured to be less than 5% elution, it can be seen that the contact angle with respect to water after photocuring is within about 90 °. In the case of Examples 1 and 2, unlike the Comparative Examples 1 and 2, the epoxy-based photocurable compound is photocured to include a hydroxy group, thereby exhibiting hydrophilicity, so that the change in contact angle is small even after photocuring for a highly hydrophobic solvent. Could know.

In addition, for Examples 1 and 2, it is understood that phenoxy thermosetting resins having an appropriate molecular weight and glass transition temperature show excellent chemical resistance against low contact angles and solvents compared to Comparative Examples 1 and 2.

Although the cyclic epoxy-based photocurable compound was not used in Comparative Example 2, the physical property evaluation results were inferior to those of Examples 1 and 2, although the photocurable epoxy-based photocurable compound was used. In Comparative Examples 1 and 2, the hydroxyl group content was relatively small, resulting in a large contact angle after photocuring, which resulted in severe exposure to hydrophobic solvents, which was inferior in chemical resistance evaluation of the solvent.

[Description of the code]

1: ink particles

2: charged particles

3: organic solvent

4: bulkhead

5: micro space

10: ink receiving layer

20: sealing film

30: upper electrode

40: lower electrode

100: electronic paper display device

Claims

Phenoxy clock thermosetting resins;

Cyclic epoxy photocurable compounds;

Isocyanate-based thermosetting agents; And

Cationic photoinitiators;

Adhesive film forming composition comprising a.
The method of claim 1,

The phenoxy clock thermosetting resin has a glass transition temperature of 90 to 120 ℃

A composition for forming an adhesive film.
The method of claim 1,

The weight average molecular weight of the phenoxy clock thermosetting resin is 40,000 g / mol to 60,000 g / mol

A composition for forming an adhesive film.
The method of claim 1,

The phenoxy clock thermosetting resin may be a bisphenol A phenoxy resin, a bisphenol F phenoxy resin, a bisphenol AF phenoxy resin, a bisphenol S phenoxy resin, a brominated bisphenol A phenoxy resin, a brominated bisphenol F phenoxy resin, At least one selected from the group consisting of phosphorus-containing phenoxy resins and combinations thereof

A composition for forming an adhesive film.
The method of claim 1,

The glass transition temperature of the cyclic epoxy-based photocurable compound is 90 to 120 ℃

A composition for forming an adhesive film.
The method of claim 1,

The cyclic epoxy photocurable compound is a group consisting of a bisphenol A type epoxy compound, a bisphenol F type epoxy compound, a bisphenol S type epoxy compound, a dicyclopentadiene type epoxy compound, an alicyclic epoxy compound, a brominated epoxy compound, and a combination thereof At least one selected from

A composition for forming an adhesive film.
The method of claim 1,

The content ratio of the phenoxy clock thermosetting resin and the cyclic epoxy photocurable compound is 1: 1.5 to 1: 2.5

A composition for forming an adhesive film.
The method of claim 1,

The cationic photoinitiator is an onium salt-based ultraviolet cleavage initiator

A composition for forming an adhesive film.
The method of claim 1,

The cationic photoinitiator is contained in 5 parts by weight to 15 parts by weight relative to 100 parts by weight of the cyclic epoxy photocurable compound

A composition for forming an adhesive film.
The method of claim 1,

The isocyanate-based thermosetting agent is 0.1 parts by weight to 1.0 part by weight relative to 100 parts by weight of the phenoxy clock thermosetting resin

A composition for forming an adhesive film.
The method of claim 1,

Further comprising an additive comprising at least one selected from the group consisting of silane binders, inorganic binders, brighteners, wetting properties, pigments, deodorants, defoamers, antioxidants, organic flame retardants, thickeners, plasticizers and combinations thereof.

A composition for forming an adhesive film.
The adhesive film for photocuring preprocessing which is formed by drying and thermosetting the resin composition for adhesive film formation of any one of Claims 1-11 by heat processing, and which is further photocurable.
The method of claim 12,

The cured product of the solid phenoxy thermosetting resin and the liquid cyclic epoxy photocurable compound are mixed.

Adhesive film for photocuring before processing.
The method of claim 12,

Curing degree is 95 to 98%

Adhesive film for photocuring before processing.
The method of claim 12,

The solid phenoxy clock thermosetting resin is in a state of being impregnated with the liquid cyclic epoxy photocurable compound.

Adhesive film for photocuring before processing.
The method of claim 12,

The measured value of tack adhesive force measured at a speed of about 100 mm / min on a stainless steel plate by a rooftack measuring instrument at 60 ° C. was 30 gf to 80 gf.

Adhesive film for photocuring before processing.
An adhesive film prepared by performing photocuring on the pressure-sensitive adhesive film for photocuring processing according to claim 12.
Upper electrode;

A lower electrode spaced apart from the upper electrode;

An ink receiving layer disposed between the upper electrode and the lower electrode, forming a microcavity separated by a partition, and accommodating ink in the microcavity; And

A sealing film formed by adhering the upper electrode and the ink receiving layer and photocuring the pressure-sensitive adhesive film for photocuring processing according to claim 12;

Electronic paper display device comprising a.
The method of claim 18,

The sealing film is a transparent film of 5 ㎛ to 10 ㎛ thickness

Electronic paper display.
The method of claim 18,

The sealing film was immersed in a halocarbon solvent, a dodecane solvent, or a mixed solvent thereof at 90 ° C. for 12 hours, and the elution amount of the sealing film eluted with the halocarbon solvent or dodecane solvent was 5% by weight or less.

Electronic paper display.
The method of claim 18,

The surface of the sealing film has a contact angle of 105 ° or less

Electronic paper display.