KR101832522B1 - Composition for forming adhesive film, adhesive film before light curing for further processing, adhesive film and electronic paper display - Google Patents

Abstract

Phenoxy thermosetting resin; Cyclic epoxy photocurable compounds; Isocyanate-based thermosetting agents; And a cationic photoinitiator.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composition for forming an adhesive film, a pressure sensitive adhesive film for use in photocuring, an adhesive film, and an electronic paper display device. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure-

A composition for forming an adhesive film, a pressure sensitive adhesive film for photocuring, an adhesive film, and an electronic paper display device.

BACKGROUND ART In general, a digital paper display has been spotlighted as a next generation display device following a liquid crystal display, a plasma display panel, and an organic luminescence display. Type display device.

In particular, electronic paper is a display device that can display characters or images using a flexible substrate such as a thin plastic plate in which millions of beads are scattered in an oil hole. The electronic paper is used to reproduce millions of times And it is expected to be a substitute for existing print media such as books, newspapers and magazines in the future. In addition, electronic paper is much less expensive than conventional flat display panels, and it can be driven with very little energy because it does not require backlighting or constant recharging, which is far superior to energy efficiency. In addition, e-paper is very clear and has a wide viewing angle, and it has a memory function that does not completely disappear even if there is no power, so it is likely to be widely used in public bulletin boards, advertisements, electronic books and the like.

The electronic paper may include an ink layer using a solvent, and a sealing film may be laminated on the ink layer to seal the ink layer. Due to such a structure, the sealing film is brought into contact with the solvent. However, the sealing composition for forming the sealing film has poor chemical resistance to the solvent, and consequently, the reliability and durability of the electronic paper at high temperature have deteriorated.

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

Another embodiment of the present invention provides an adhesive film for photocuring which has excellent chemical resistance to a solvent.

Another embodiment of the present invention provides an adhesive film produced 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 present invention, a phenoxystyle thermosetting resin; Cyclic epoxy photocurable compounds; Isocyanate-based thermosetting agents; And a cationic photoinitiator.

The phenoxystyrene thermosetting resin may have a glass transition temperature of 90 to 120 ° C.

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

The phenoxy-based thermosetting resin may be at least one selected from the group consisting of bisphenol A phenoxy resin, bisphenol F phenoxy resin, bisphenol AF phenoxy resin, bisphenol S phenoxy resin, brominated bisphenol A phenoxy resin, brominated bisphenol F phenoxy resin, A phosphorus-containing phenoxy resin, and a combination thereof.

The cyclic epoxy-based photo-curing compound may have a glass transition temperature of 90 to 120 ° C.

The cyclic epoxy-based photo-curing compound is a compound 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 the like.

The content ratio of the phenoxy-based thermosetting resin and the cyclic epoxy-based photo-curing compound may be 1: 1.5 to 1: 2.5.

The cationic photoinitiator may be an onium salt ultraviolet cleavable initiator.

The cationic photoinitiator may be included in an amount of 5 to 15 parts by weight based on 100 parts by weight of the cyclic epoxy-based photo-curable compound.

The isocyanate-based heat curing agent And 0.1 part by weight to 1.0 part by weight based on 100 parts by weight of the thermosetting resin.

The composition for forming an adhesive film may further comprise at least one additive comprising at least one selected from the group consisting of silane coupling agents, inorganic binders, polishes, wettability improvers, pigments, deodorants, defoamers, antioxidants, organic flame retardants, thickeners, plasticizers, .

In another embodiment of the present invention, there is provided a pressure-sensitive adhesive film for photocuring which is formed by drying and thermosetting the resin composition for forming an adhesive film by heat treatment, and which is further curable.

The adhesive film for photocuring may be a mixture of a cured product of the solid phenoxy thermosetting resin and the cyclic epoxy photo-curable compound in a liquid phase.

The adhesive film for photocuring can have a degree of curing of 95 to 98%.

The adhesive film for photocuring may be in a state in which the solid phase phenoxy thermosetting resin is impregnated with an epoxy-based photo-curable compound containing a cyclic ring in the main chain of the liquid phase.

The adhesive film for photocuring can have a tack adherence measurement value of 30 gf to 80 gf measured at a speed of about 100 mm / min against a stainless steel plate by a looftack measuring instrument at 60 ° C .

In another embodiment of the present invention, there is provided an adhesive film produced by performing photo-curing on the adhesive film for photocuring.

In another embodiment of the present invention, an upper electrode; A lower electrode spaced apart from the upper electrode; An ink receiving layer disposed between the upper electrode and the lower electrode, the ink receiving layer forming a micro space defined by the barrier ribs and containing ink in the micro space; And a sealing film formed by adhering the upper electrode and the ink receiving layer and photo-curing the pressure sensitive adhesive film for photocuring.

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

The sealing film may be 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 the dodecane solvent may be 5% by weight or less .

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

The above-mentioned adhesive film is excellent in chemical resistance to solvents, and the electronic paper display device in which the above-mentioned adhesive film is applied as a sealing film is excellent in 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, the present invention is not limited thereto, and the present invention is only defined by the scope of the following claims.

In one embodiment of the present invention, a phenoxystyle thermosetting resin; Cyclic epoxy photocurable compounds; Isocyanate-based thermosetting agents; And a cationic photoinitiator.

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

The adhesive film formed from the composition for forming an adhesive film has excellent high-temperature reliability and chemical resistance to an organic solvent. Accordingly, the above-mentioned adhesive film can be usefully applied as a sealing film for an electronic paper display device.

The composition for forming an adhesive film contains a thermosetting resin and a photo-curable compound at the same time, and a specific type of thermosetting resin and a photo-curable compound of a certain kind are selected and combined to improve the high- temperature reliability and the chemical resistance to an organic solvent And tack adhesion can be minimized.

The phenoxy-terminated thermosetting resin is not particularly limited as long as it is a compound containing a bisphenol structure in the structure of the compound. Specific examples thereof include bisphenol A phenoxy resin, bisphenol F phenoxy resin, bisphenol AF phenoxy resin, bisphenol S phenoxide A bisphenol A bromide type phenoxy resin, a brominated bisphenol F type phenoxy resin, a phosphorus containing phenoxy resin, or the like, or a combination thereof.

When the phenoxy-based thermosetting resin is thermally cured, the phenoxy structure may be crosslinked to form a film (corresponding to a pressure sensitive adhesive film for photocuring or a B-stage processed film to be described later). The phenoxystyrene thermosetting resin exhibits excellent chemical resistance properties and is densely crosslinked at the time of film formation to form a film having hydrophilicity, so that even when exposed to an organic solvent such as halocarbon, the film coat can be prevented from falling down. Due to these properties, the electronic paper of the present invention can be usefully applied as a composition for forming a sealing film for a display device.

The glass transition temperature of the phenoxy-based thermosetting resin may be about 90 to about 120 ° C. By using a phenoxy-based thermosetting resin having a glass transition temperature as high as the above range, the adhesive film-forming composition can impart excellent chemical resistance to a film formed by heat treatment or thermosetting.

The weight average molecular weight of the phenoxy thermosetting resin may be from about 40,000 g / mol to about 60,000 g / mol. When the weight average molecular weight is less than the above range, the viscosity becomes too low, which makes it difficult to form a uniform coating film upon coating the composition, and when the sealing film in the electronic paper display device is left as residual volatile matter after thermosetting, , There is a possibility that the chemical resistance deteriorates over time. In the case of exceeding the above range, it takes a long time for thermal curing or there is a possibility that the molecular weight between the curing points becomes large due to the formation of the network structure after the curing, and the chemical resistance is lowered, and the viscosity becomes very high, There may be a problem that the appearance quality deteriorates.

The cyclic epoxy-based photo-curable compound is a compound capable of polymerizing by irradiation with ultraviolet rays or an electron beam, and may be in the form of a monomer, oligomer or polymer, and may have a cyclic structure containing a cyclic ring in its main chain Epoxy-based photo-curing compounds may 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 combinations of these.

The composition for forming an adhesive film includes a cyclic epoxy-based photo-curing compound in combination with a phenoxy-based thermosetting resin in order to compensate for physical properties that can not be obtained when the phenoxy-based thermosetting resin is used alone. As described above, when the phenoxy-based thermosetting resin is thermally cured to form a film, the photocurable cyclic epoxy-based photo-curable compound is evenly distributed among the thermosetting phenoxy-based thermosetting resins to impart tack adhesion. Thereafter, photocuring of such a film results in curing of an evenly distributed cyclic epoxy photo-curable compound and a part of phenoxy structure to realize chemical resistance characteristics.

The cyclic epoxy photocurable compound may have a glass transition temperature of about 70 to about 120 < 0 > C. By using the cyclic epoxy-based photo-curing compound having a glass transition temperature as high as the above range, the adhesive film formed from the composition for forming an adhesive film has excellent high-temperature reliability and chemical resistance to organic solvents, Can be minimized.

The cyclic epoxy-based photo-curing compound is cured to exhibit a transparent property, has excellent oxidation resistance, does not cause yellowing due to light, and can be applied as a composition for forming a sealing film for an electronic paper display device, In addition, tack adhesion is minimized, minimizing the problem of adhering charged particles in the ink composition upon contact with an ink composition used in an electronic paper display.

The cyclic epoxy-based photo-curable compound imparts hydrophilicity to the film during film formation, thereby minimizing exposure of the hydrophobic solvent upon contact with the hydrophobic solvent, thereby improving the chemical resistance to the solvent.

The weight ratio of the phenoxy-based thermosetting resin and the cyclic epoxy-based photo-curing compound may be about 1: 1.5 to about 1: 2.5. The adhesive film formed from the composition for forming an adhesive film containing the phenoxy-based thermosetting resin and the cyclic epoxy-based photo-curing compound having the above-mentioned content ratio is excellent in high-temperature reliability and excellent chemical resistance to organic solvents, Can be minimized.

The composition for forming an adhesive film 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 an isocyanate group-containing compound, and the isocyanate group can undergo urethane polymerization reaction with a hydroxyl group.

Specifically, the isocyanate group in the isocyanate-based thermosetting agent is subjected to urethane polymerization reaction with a hydroxyl group in the phenoxy-terminated thermosetting resin in the composition for forming an adhesive film to cross-link the phenoxy-terminated thermosetting resin to densify the B- Thereby facilitating processing into a film.

When the cyclic epoxy-based photo-curable compound is cured, a hydroxy group is generated. By the urethane polymerization reaction with such a hydroxy group, the film can be formed more densely.

Specifically, the isocyanate-based thermosetting agent Block diisocyanate, block isocyanate, isophorone diisocyanate, 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 an isocyanate-based thermosetting agent relative to 100 parts by weight of the phenoxystyrene-based thermosetting resin. The composition for forming an adhesive film containing the isocyanate-based thermosetting agent in the above content is easy to process into a film and can impart appropriate strength to the adhesive film produced therefrom.

The cationic photoinitiator absorbs light energy such as electron beam, visible light or ultraviolet energy to generate positive ions, thereby effectively initiating the epoxy in the photopolymerization reaction.

As the cationic photoinitiator, for example, an onium salt based ultraviolet cleavable initiator may be used.

Specific examples of the onium salt ultraviolet cleavable type initiator include diaryliodonium salts, triarylsulfonium salts, triarylselenonium salts, tetraarylphosphonium salts and aryldiazonium salts, An antimony-based ultraviolet cleavage initiator, a boron-based ultraviolet cleavage-type initiator containing a boron atom, and the like can be used.

For example, the diaryliodonium salt may be a compound represented by Y ₂ I ⁺ X ^- (wherein Y is an aryl group which may have a substituent, and X ^- is a non-nucleophile or a non-basic anion). 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 triarylselenonium salt, the tetraarylphosphonium salt and the aryldiazonium salt may be the respective compounds corresponding to the diaryliodonium salt. Specifically, they are preferably selected from the group consisting of Y ₃ S ⁺ X ^- , Y ₃ Se ⁺ X ^- , Y ₄ P ⁺ X ^-, and Y ₃ S ⁺ YN ₂ ⁺ X ^- (wherein Y is an aryl group having a substituent, and X ^- is a non-nucleophile or a non-basic anion).

The composition for forming an adhesive film may include about 5 parts by weight to about 15 parts by weight of a cationic photoinitiator, based on 100 parts by weight of the cyclic epoxy photo-curable compound. By keeping the photopolymerization initiator in the above range, it is possible to secure the durability of the adhesive film produced from the composition for forming an adhesive film because many molecules having short bonding lengths are not generated.

The composition for forming an adhesive film may further contain additives such as a silane coupling agent, an inorganic binder, a polish agent, a wettability improver, a pigment, a deodorant, a defoamer, an antioxidant, an organic flame retardant, a thickener, have.

In another embodiment of the present invention, there is provided a pressure-sensitive adhesive film for photocuring which is formed by drying and thermosetting the resin composition for forming an adhesive film by heat treatment, and which is further curable.

The resin composition for forming an adhesive film may be coated on the release film to form a coating layer, followed by heat treatment to produce the adhesive film for photocuring.

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

The releasing film is not limited as long as it can be easily peeled off so as not to leave a residual material when peeling the coating layer of the adhesive film for photocuring process. The release film may be, for example, polyethylene terephthalate coated with a silicone release agent, or polyethylene terephthalate coated with a fluorine-containing agent depending on the wettability of the coating layer of the adhesive film for photocuring. In addition, since the release film should not be deformed by heat when heat treatment is performed on the coating layer formed on the release film, it is also possible to use polyimide, polynaphthalene terephthalate or the like coated with a release agent depending on the drying temperature.

Thus, the adhesive resin composition for forming an adhesive film can be dried and thermally cured by heat treatment to form a pressure-sensitive adhesive film for photocuring (a B-stage processed film).

The above-mentioned adhesive film for photocuring is used in the processing step before forming the adhesive film layer in the electronic part to be applied.

First, the resin composition for forming an adhesive film is heat-treated to form a film, so that it can be used in a form that can be easily processed. The adhesive film for photocuring can be additionally cured and further cured, For example, an adhesive film can be formed in an article such as an electronic part.

The adhesive film for photocuring can be a state in which a cured product of the solid phase phenoxy thermosetting resin and the cyclic epoxy photo-curable compound in a liquid state are mixed. That is, the adhesive film for photocuring can be efficiently produced at a ratio of phenoxy thermosetting resin to photocurable epoxy at a ratio of about 1: 1.5 to about 1: 2.5. When the resin composition for forming an adhesive film is heat-treated, the phenoxy thermosetting resin is thermally cured to form a solid film, and the phenoxy thermosetting resin of the solid film is in a state of uniformly distributing the cyclic epoxy photo- : Structure), the adhesive film for photocuring can be formed.

The adhesive film for photocuring can be made from the composition for forming an adhesive film, so that the degree of curing of the phenoxy-terminated thermosetting resin can be maximized.

The degree of curing represents the degree of curing, which can be defined in Equation (1).

[Equation 1]

Hardening degree (%) = {1- (W _i -W _f ) / W _i } 100

In the above formula, W _i means the weight of the cured sample before immersing it in a solvent of a sample obtained by cutting the sample to a predetermined size, W _f means that the specimen is immersed in the solvent for a certain period of time, . The type of the solvent and the period of immersing the sample in the solvent may vary depending on the cured product to be measured.

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 determined by determining a suitable reference solvent. The time period in which the specimen is immersed in the solvent may be appropriately selected, and may be, for example, about one day to one week, but is not limited thereto.

As the calculated value of the degree of cure increases, it may mean that the polymer structure of the cured product is closely networked.

Specifically, the curing degree of the photocurable adhesive film for photocuring was determined by immersing in a mixed solvent in which halocarbon oil and dodecane oil were mixed at a weight ratio of about 3: 7 for 24 hours, 1 may be about 95 to about 98%. As described above, since the adhesive film for photocuring and electric processing has a high degree of curing, superior chemical resistance can be realized for driving an electronic paper display.

On the other hand, the tack adhesive force of the photocurable electroconductive adhesive film can be minimized as described above. Specifically, Loop Tech was measured using a tensile tester (Model 4443, manufactured by Instron). The adhesive film for photocuring was prepared as a sample having a size of about 3 cm x 10 cm and then left in a chamber of about 60 ° C for about 1 hour or more. The adhesive film was then adhered to a stainless steel plate at a rate of about 100 mm / The measured value of the tack adherence measured at about 60 DEG C may be about 30 gf to 80 gf.

In another embodiment of the present invention, there is provided an adhesive film produced by performing photo-curing on the adhesive film for photocuring.

Since the adhesive film is produced from the above-mentioned composition for forming an adhesive film, it has a very high hydrophilicity and is excellent in chemical resistance to a specific organic solvent.

In another embodiment of the present invention, an upper electrode;

A lower electrode spaced apart from the upper electrode;

An ink receiving layer disposed between the upper electrode and the lower electrode, the ink receiving layer forming a micro space defined by the barrier ribs and containing ink in the micro space; And

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

And an electronic paper display device.

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

1, the sealing film 20 is used to adhere the upper electrode 30 while sealing the micro space in which the ink composition of the ink receiving layer 10 is housed in the electronic paper display device 100, And a photocurable electrophotographic adhesive film formed from the composition for forming an electrophotographic photosensitive member is interposed between the ink receiving layer 10 and the upper electrode 30, and then photocured.

The photo-curing can be performed, for example, by UV irradiation.

The UV irradiation carried out for photocuring can be carried out for about 10 seconds to about 15 seconds with a metal halide lamp, which is a commonly used metal halide lamp.

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 to include, for example, an ITO electrode.

The micro space may be formed of microcapsules or microcups. 1 shows an electronic paper display device using a microcup (5) structure. For example, the microcups 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 contains the ink composition including the ink particles 1 and the charged particles 2 dispersed in the organic solvent 3 in the micro space.

The upper electrode 30 and the lower electrode 40 are positioned on the upper and lower portions of the micro space and when the voltage is applied, the charged particles 2 dispersed in the organic solvent 3 are moved and arranged, Is implemented.

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

The barrier ribs 4 distinguish pixels from pixels and maintain the space of the microcups 5 constant. In addition, when applied to a flexible display device, the barrier rib 4 serves as a support for keeping the space of the microcup 5 constant, and even when the barrier rib 4 is bent, 40).

If the barrier ribs 4 are separated from the upper and lower ITO electrodes 30, the charged particles 2 arranged in the pixel space of each microcup 5 move to the surrounding microcups 5 The image quality becomes unstable, the pixels are detached, and as a result, the defectiveness of the product itself increases.

The sealing film 20 should be adhered to the upper electrode 30 so as not to cause such a problem.

The sealing film 20 formed from the composition for forming an adhesive film is excellent in adhesion strength so as to be well adhered to the barrier ribs and the upper electrode 30 and the tack adhering force is minimized, 20 can be minimized.

The sealing film 20 is brought into direct contact with the ink compositions 1 and 2 contained in the ink receiving layer 10 located below and the sealing film 20 is formed from the above composition for forming an adhesive film Therefore, excellent high-temperature reliability and excellent chemical resistance to organic solvents 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 in particular a halocarbon solvent or The chemical resistance of the dodecane solvent is excellent.

Specific examples of the halocarbon solvent include compounds in which methane is substituted with a halogen group other than hydrogen, Halocarbon Oil 0.8, Halocarbon 1.8 sold by Halocarbon Co., and the dodecane solvent specifically includes n-dodecane Lt; / RTI >

The sealing film 20 may be formed of a transparent film having a thickness of about 5 占 퐉 to about 10 占 퐉. The sealing film 20 formed in the thickness range has good adhesion with the barrier ribs 4 while sealing the ink receiving layer 10 well, and can be realized transparently.

The chemical resistance can be evaluated by measuring the elution amount of the sealing film 20 with respect to the halocarbon or dodecane solution. Specifically, the elution amount (X) can be obtained by the following equation (2).

[Equation 2]

Elution amount (X) [%] = [(initial weight of sealing film - weight of sealing film after immersion in solvent for a certain time) / initial weight of sealing film] × 100

In the above formula, the solvent may be a mixed solvent of halocarbon and dodecane, and the immersion time may be, for example, from about 24 to about 48 hours at room temperature, and may be carried out at high temperature, for example, Lt; RTI ID = 0.0 > conditions. ≪ / RTI >

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

After the initial weight of the sealing film 20 is measured, it is immersed in a halocarbon solvent or a dodecane solvent commonly used as a solvent of the ink composition used for the electron species utilization display device for about 24 to about 48 hours , And dried at about 110 ° C. for about 3 to 5 hours to measure the residual weight, and the value obtained by the elution amount (X) according to the formula 2 may be about 5% or less. As described above, the sealing film 20 can exhibit excellent chemical resistance of about 5% or less in the elution amount according to the formula (2).

Further, the surface of the sealing film produced by the composition for forming an adhesive film is hydrophilic by a hydroxy group generated by opening the epoxy while being photocured with a secondary alcohol -OH group of a phenoxy structure. For example, The contact angle may be about 95 deg. Or less.

Hereinafter, examples and comparative examples of the present invention will be described. The following embodiments are only examples of the present invention, and the present invention is not limited to the following embodiments.

( Example )

Example  One

A phenoxy thermosetting resin having a weight average molecular weight of 52,000 g / mol and a glass transition temperature of about 94 ° C was prepared by dissolving PKHH (trade name) of Inchem Co. in a methylcellosolve solvent in a concentration of 30 wt% ). (PKHH content: 6.6 g), 15.4 g of cyclic epoxy compound S-28 (bis- (3,4-epoxycyclohexyl) adipate) from Synasia, an isocyanate type curing agent 0.06 g of Asahi Kasei MFA-75X and 2.3 g of a cationic photoinitiator UVI-6974 (manufactured by Momentive Co., Ltd., containing triallyl sulfonium hexafluoroantimonate salt as a main component) were mixed with stirring to prepare a composition for forming an adhesive film .

The composition was formed into a coating layer having a thickness of 10 탆 on a PET release film and then dried with hot air at 140 캜 for 3 minutes to prepare a pressure-sensitive adhesive film for photocuring.

The above-prepared pressure sensitive adhesive film for photocuring was irradiated for 10 seconds with a 200 mW UV curing apparatus to obtain an adhesive film. When the photocuring irradiation dose is as small as 0.5 J / cm ² or less, tack may remain on the surface after photocuring, so that the measurement is performed at the same light quantity.

Example  2

In Example 2, an adhesive film was formed in the same manner as in Example 1 except that the phenoxy resin was changed to increase the glass transition temperature.

A phenoxy thermosetting resin having a weight average molecular weight of 60,000 g / mol and a glass transition temperature of about 98 ° C was prepared by dissolving PKEF (trade name) of Inchem Co. in a methylcellosolve solvent in a 30 wt% solution, Were prepared. , 15.0 g of a cyclic epoxy compound S-28 (bis- (3,4-epoxycyclohexyl) adipate) of Synasia, which is a cyclic epoxy compound, 15.0 g of an isocyanate-based curing agent 0.06 g of Asahi Kasei MFA-75X and 2.3 g of a cationic initiator UVI-6974 (manufactured by Momentive Co., Ltd., containing triallyl sulfonium hexafluoroantimonate salt as a main component) were mixed with stirring to prepare a composition for forming an adhesive film Respectively.

The composition was formed into a coating layer having a thickness of 10 탆 on a PET release film and then dried with hot air at 140 캜 for 3 minutes to prepare a pressure-sensitive adhesive film for photocuring.

The above-prepared pressure sensitive adhesive film for photocuring was irradiated for 10 seconds with a 200 mW UV curing apparatus to obtain an adhesive film. When the photocuring irradiation dose is as small as 0.5 J / cm ² or less, tack may remain on the surface after photocuring, so that the measurement is performed at the same light quantity.

Comparative Example  One

A phenoxy thermosetting resin having a weight average molecular weight of 52,000 g / mol and a glass transition temperature of 94 ° C was obtained by dissolving PKHH (trade name) of Inchem Co. in a methylcellosolve solvent in a 30 wt% solution and filtering the phenoxy solution (P1) Prepared. , 15.4 g of triallyl isocyanurate (TAIC, manufactured by Nippon Kasei), 15.0 g of polyfunctional thiol compound (trade name: PEMP, pentaerythritol tetra (3-mercaptoethanol) (2.3 g) and Irgacure 184 (BASF) as a radical initiator were mixed to prepare an adhesive film forming composition, and an adhesive film was formed in the same manner as in Example 1, except that the composition for forming an adhesive film was used Respectively. In Comparative Example 1, a radical initiator was used together because PEMP was used as the photo-curable compound.

Comparative Example  2

Except that 6.6 g of an epoxy acrylate compound (PE-210, manufactured by Miwon Specialty Co., Ltd.) was added to 15.4 g of methyl cellosolve, a polyfunctional thiol compound (trade name: PEMP, pentaerythritol tetra (TAIC, manufactured by Nippon Kasei) and 2.3 g parts by weight of a radical initiator Irgacure 184 (Basf) were mixed to prepare a composition for forming an adhesive film, , An adhesive film was formed in the same manner as in Example 1. [ Also in Comparative Example 2, PEMP was used as the photo-curable compound, so that a radical initiator was used together.

evaluation

Experimental Example  1: Rate of elution

The adhesive films prepared in Example 1-2 and Comparative Example 1-2 were immersed in a mixed solvent of halocarbon oil (halocarbon halocarbon oil 0.8) and n-dodecane oil mixed at a weight ratio of 3: 7 for 12 hours The mixture was filtered through a 300-mesh sieve and dried at 110 ° C for 3 hours, and the weight was measured. The elution amount (X) [%] was measured according to the following formula 2 and is shown in Table 1 below.

[Equation 2]

Elution amount X% [%] = [(initial weight of adhesive film - weight of adhesive film after immersing in solvent for a certain time) / initial weight of adhesive film] × 100

Experimental Example  2: Chemical resistance evaluation

A mixture of halocarbon oil (Halocarbon halocarbon oil 0.8) and n-dodecane oil in a weight ratio of 3: 7 was coated on the adhesive film prepared in Example 1-2 and Comparative Example 1-2 with 1 drop And then allowed to stand in an oven at 60 DEG C for 12 hours. Then, whether or not blurring occurred was observed and evaluated in Table 2 below. When the blurring phenomenon occurs, it means that the adhesive film has poor chemical resistance to halocarbon. That is, in this 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 are easily separated in the electron species utilization display and are easily peeled off even after rubbing with polyester wipes and faces used in cleanrooms after application of methyl ethyl ketone (MEK) do. It was judged that the cross-linking density of the adhesive film was wet and expanded due to the halocarbon mixture and the cross-linking density of the film was considerably decreased, and the chemical resistance of the specific solvent was deteriorated.

Experimental Example  3: Water Contact angle  evaluation

One drop of distilled water was dropped onto the adhesive film prepared in Example 1-2 and Comparative Example 1-2, and contact angle was measured at room temperature using a contact angle analyzer. The results are shown in the following Table 1 .

Experimental Example  4: Adhesion ( tack ) evaluation

A sample of the adhesive film for photocuring and electrophotography produced in Example 1-2 and Comparative Example 1-2 was cut into a size of 3 cm x 10 cm by using a Loop Tek tester of Texture Analysis product, After left standing, the tack adhesive strength was measured at a speed of 100 mm / min against a stainless steel plate. The results are shown in Table 1.

Experimental Example  5: Evaluation of adhesion

The microcupsheet used for the electron species utilization display device was prepared and coated with the halocarbon mixture, and then laminated with the adhesive film for photocuring and electrophotography produced in Example 1-2 and Comparative Example 1-2 at 70 ° C with lamination The adhesive strength was measured by using a spring gauge after photocuring with the photocuring conditions as shown in Example 1-2 and Comparative Example 1-2, and the results are shown in Table 1.

Experimental Example  6: Contrast ratio  ( CR ) Measurement evaluation

The adhesive films for photocuring prepared in Examples 1-2 and 1-2 were immersed in a microcup sheet filled with an ink composition (a mixture of Carbon Black, a mixture of TiO ₂ beads and a halocarbon solvent, manufactured by Imige & The laminate was laminated by thermal lamination. The laminate was photocured and left at 60 DEG C for 24 hours. Then, the reflectance of Black and the reflectance of Black were measured using Minolta CM-3700A.

The white reflectance / black reflectance of the adhesive films prepared in Example 1-2 and Comparative Example 1-2 were calculated and the contrast ratio (CR) values are shown in Table 1 below.

Experimental Example  7: High-temperature reliability evaluation

The electronic paper display device having the structure shown in Fig. 1 was produced for the pressure-sensitive adhesive film for photocuring produced in Example 1-2 and Comparative Example 1-2. The photo-curable composition of the sealing film was prepared in the same manner as described in Example 1. After displaying the electron species display device, the display device was left at 60 ° C for 240 hours, and the contrast ratio was measured by measuring the White / Black reflectance using Minolta CM-3700A. The contrast ratio was measured after being left at high temperature . The results are shown in Table 1 below

≪ Criteria for judging the contrast change rate &

Good: less than 5%

Defective: more than 5%

division Elution amount (X,%) Chemical resistance
(Whether to blur) Water contact angle (˚) High temperature Tack
(gf cm < 2 >) High temperature
responsibility adhesiveness
(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, the elution amounts of Example 1 and Example 2 were measured to be less than 5% and the contact angle to water after photo-curing was within about 90 °. Unlike Comparative Examples 1 and 2 in Examples 1 and 2, since the epoxy-based photo-curing compound is photo-cured to contain a hydroxy group, the hydrophilic property becomes more hydrophilic and the change in the contact angle after the photo- Could know.

It is understood that Examples 1 and 2 show excellent chemical resistance to a low contact angle and solvent compared to Comparative Examples 1 and 2 by using a phenoxy thermosetting resin having an appropriate molecular weight and a glass transition temperature.

In Comparative Example 2, although the photo-curable epoxy compound was not a cyclic epoxy photo-curable compound, the results of evaluation of physical properties were inferior to those of Example 1 and Example 2, even though a photo-curable epoxy-based photo- In Comparative Example 1 and Comparative Example 2, the hydroxyl group content was relatively small, and the contact angle became large after the photo-curing, so that exposure to the hydrophobic solvent became severe, which was inferior in evaluation of the chemical resistance to the solvent.

1: ink particle
2: charged particle
3: Organic solvent
4:
5: Micro space
10:
20: sealing film
30: upper electrode
40: lower electrode
100: Electronic paper display device

Claims (21)

Phenoxy thermosetting resin;
Cyclic epoxy photocurable compounds;
Isocyanate-based thermosetting agents; And
Cationic photoinitiators;
Lt; / RTI >
The weight-average molecular weight of the phenoxy-terminated thermosetting resin is 40,000 g / mol to 60,000 g / mol,
Wherein the content ratio of the phenoxy-based thermosetting resin and the cyclic epoxy-based photo-curable compound is 1: 1.5 to 1: 2.5.
The method according to claim 1,
The phenoxy-terminated thermosetting resin has a glass transition temperature of 90 to 120 DEG C
(2).
delete The method according to claim 1,
The phenoxy-based thermosetting resin may be at least one selected from the group consisting of bisphenol A phenoxy resin, bisphenol F phenoxy resin, bisphenol AF phenoxy resin, bisphenol S phenoxy resin, brominated bisphenol A phenoxy resin, brominated bisphenol F phenoxy resin, At least one selected from the group consisting of phosphorus-containing phenoxy resins and combinations thereof
(2).
The method according to claim 1,
Wherein the cyclic epoxy-based photo-curable compound has a glass transition temperature of 90 to 120 ° C
(2).
The method according to claim 1,
The cyclic epoxy-based photo-curing compound is a compound 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, ≪ RTI ID = 0.0 >
(2).
delete The method according to claim 1,
The cationic photoinitiator is an onium salt ultraviolet cleavable initiator
(2).
The method according to claim 1,
The cationic photoinitiator is contained in an amount of 5 to 15 parts by weight based on 100 parts by weight of the cyclic epoxy-based photo-
(2).
The method according to claim 1,
The isocyanate-based heat curing agent And 0.1 part by weight to 1.0 part by weight relative to 100 parts by weight of the phenoxystyrene thermosetting resin
(2).
The method according to claim 1,
Further comprising an additive comprising at least one selected from the group consisting of silane coupling agents, inorganic binders, polishes, wettability improvers, pigments, deodorants, defoamers, antioxidants, organic flame retardants, thickeners, plasticizers,
(2).
A composition for forming an adhesive film according to any one of claims 1, 2, 4, 6, and 8 to 11, which is formed by drying and thermosetting by heat treatment, Adhesive film for photographic processing.
13. The method of claim 12,
The cured product of the phenoxystyrene thermosetting resin in the solid phase and the cyclic epoxy-based photo-curable compound in the liquid phase are mixed
Adhesive film for photographic processing.
13. The method of claim 12,
Having a degree of hardening of 95 to 98%
Adhesive film for photographic processing.
13. The method of claim 12,
Wherein the solid phase phenoxy thermosetting resin is in a state of being impregnated with the cyclic epoxy-based photo-
Adhesive film for photographic processing.
13. The method of claim 12,
The measured value of the tack adherence measured at a speed of 100 mm / min against a stainless steel plate by a looftack measuring instrument at 60 ° C was 30 gf to 80 gf
Adhesive film for photographic processing.
An adhesive film produced by photo-curing a pressure-sensitive adhesive film for photocuring according to claim 12.
An upper electrode;
A lower electrode spaced apart from the upper electrode;
An ink receiving layer disposed between the upper electrode and the lower electrode, the ink receiving layer forming a micro space defined by the barrier ribs and containing ink in the micro space; And
A sealing film formed by adhering the upper electrode to the ink receiving layer and photo-curing the pressure-sensitive adhesive film for photocuring according to claim 12;
And the electronic paper display device.
19. The method of claim 18,
The sealing film is a transparent film having a thickness of 5 to 10 [micro] m
Electronic paper display device.
19. The method of claim 18,
The sealing film is immersed in a halocarbon solvent, a dodecane solvent or a mixed solvent thereof at 90 DEG C for 12 hours, and the amount of elution of the sealing film with the halocarbon solvent or dodecane solvent is 5% by weight or less
Electronic paper display device.
19. The method of claim 18,
The surface of the sealing film has a contact angle of 105 DEG or less
Electronic paper display device.

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