Resin composition for optically transparent adhesive and preparing method of the same

Abstract

To provide an optically transparent adhesive which has excellent optical characteristics, mechanical characteristics and hydrolysis stability, is stable and has low modulus, and a synthesis method of the same.SOLUTION: An optically transparent adhesive (OCA) contains a polymer resin composition. The polymer resin composition contains 30 to 60 wt.% of a thiol monomer, 20 to 60 wt.% of an allyl monomer, and 10 to 30 wt.% of a bifunctional aliphatic urethane oligomer. The polymer resin composition further contains 1 to 3 wt.% of a hydrolysis stabilizer additive, 0.01 to 0.03 wt.% of a wetting agent, 1 to 5 wt.% of an adhesion-promoting monomer, 0.05 to 2 wt.% of an adhesion-promoting base, and 0.5 to 2 wt.% of a photoinitiator.SELECTED DRAWING: Figure 1

Description

background

[0001] Advances in plastic-based electronics are driving a trend toward durable, lightweight, and foldable designs. Addressing these trends requires significant innovation in the development of materials compatible with flexible applications. For example, optically clear adhesives (OCAs) help maintain resilience by reducing stress on display components over a wide temperature range during folding. These materials are typically designed to offer high optical transparency (>90%) and long-term reliability characteristics, including minimal yellowing due to heat, moisture, and / or ultraviolet (UV) exposure.

[0002] Currently, polyacrylate-based technologies have difficulty achieving the desired modulus in the temperature range of -20°C to 60°C. Furthermore, the use of acrylate polymers reduces the stability of the polymer network of OCA when exposed to extreme heat aging conditions. It is difficult to maintain the desired optical and thermomechanical properties over long periods of time under high humidity and high temperature conditions. It is also difficult to achieve high adhesion to various substrate surfaces, such as glass, DOP, and PET. Therefore, based on the above discussion, it is necessary to overcome these drawbacks. [Brief explanation of the drawings]

[0003] For a more complete understanding of the features and advantages of the present disclosure, reference should be made to the following detailed description taken in conjunction with the drawings, in which corresponding reference numerals refer to corresponding parts in the different views.

[0004] [Figure 1] 1 is a cross-sectional view of an optical stack according to a specific embodiment of the present disclosure. [Figure 2] 1 is a cross-sectional view of a flexible display according to a specific embodiment of the present disclosure.

[0005] The illustrated diagrams are for illustrative purposes only and are not intended to assert or imply any limitations with respect to the environment, architecture, design, or process in which different embodiments may be implemented. DETAILED DESCRIPTION OF THE INVENTION

[0006] This disclosure relates generally to materials related to the field of resin compositions for flexible display technology, and more particularly to the creation of stable, low-modulus, optically clear adhesives with excellent optical properties, mechanical properties, and hydrolytic stability. In this disclosure, the term "adhesive" includes both permanent and pressure-sensitive adhesives. Pressure-sensitive adhesives are repositionable and can function as permanent adhesives through post-application treatment, such as ultraviolet light irradiation or heat.

[0007] In this disclosure, "optically clear" refers to a material having a haze value of approximately 2% or less over the wavelength range of 400 to 700 nm and a visible light transmittance of approximately 90% or more. Haze can be measured in accordance with JIS K 7136 (2000), and visible light transmittance can be measured in accordance with JIS K 7361 (1997). Furthermore, the term "optically clear" generally refers to a state in which no bubbles are visible to the naked eye.

[0008] In this disclosure, "storage modulus (G')" refers to the storage modulus of a material in a 1.0 Hz shear mode within a temperature range of -20°C to 60°C when measured at a temperature ramp rate of 5°C / min.

[0009] While the making and using of various embodiments of the present disclosure are described in detail below, it should be understood that the present disclosure provides many inventive concepts that can be implemented in a variety of specific contexts. The specific embodiments discussed are illustrative only and do not limit the scope of the present disclosure. In the interest of clarity, not all features of an actual embodiment are described in this disclosure.

[0010] Unless otherwise indicated, all numerical values ​​in this specification and the related claims expressing quantities of ingredients, properties such as molecular weights, reaction conditions, and the like, are understood to be modified by the word "about." Accordingly, unless otherwise indicated, the numerical parameters set forth in this specification and the appended claims are approximations that may vary depending upon the properties of interest. At the very least, and without intending to limit the scope of the doctrine of equivalents to the scope of the claims, each numerical parameter should be construed based on the number of reported significant digits and by applying ordinary rounding approaches. It should be noted that when "about" appears at the beginning of a numerical series, the term "about" applies to every number in that series. Furthermore, in describing numerical ranges, the stated lower limit may be greater than the upper limit, but one of ordinary skill in the art will recognize that he or she must select an upper limit that is greater than the selected lower limit.

[0011] Disclosed herein is an optically clear adhesive (OCA) having a polymer resin composition intended for application in flexible display technology. The polymer resin composition includes 30-60 wt% thiol monomer, 20-60 wt% allyl monomer, and 10-30 wt% difunctional aliphatic urethane oligomer. The polymer resin composition further includes 1-3 wt% hydrolysis stabilizer additive, 0.01-0.03 wt% wetting agent, 1-5 wt% adhesion-promoting monomer, 0.05-2 wt% adhesion-promoting base, and 0.5-2 wt% photoinitiator. For application in flexible display technology, the polymer resin composition is cured into a film.

[0012] Further disclosed herein is an optical laminate comprising a first substrate layer having a first surface, a second substrate layer having a second surface, and an adhesive layer, wherein the adhesive layer comprises the optically transparent adhesive described in the preceding paragraph, is disposed between the first surface of the first substrate layer and the second surface of the second substrate layer, and is configured to adhere the first surface of the first substrate layer to the second surface of the second substrate layer.

[0013] Further disclosed herein is a flexible display comprising a window layer, a polarizer layer, a display layer, a support film layer, and a plurality of adhesive layers, each of which comprises the optically transparent adhesive described in the preceding paragraph, wherein a first adhesive layer of the plurality of adhesive layers is disposed between a first surface of the window layer and a first surface of the polarizer layer, a second adhesive layer is disposed between a second surface of the polarizer layer and a first surface of the display layer, and a third adhesive layer is disposed between the second surface of the display layer and a first surface of the support film layer, and configured to adhere the first surface of the window layer to the first surface of the polarizer layer, the second surface of the polarizer layer to the first surface of the display layer, and the second surface of the display layer to the first surface of the support film layer.

[0014] According to one embodiment of the present disclosure, an optically clear adhesive (OCA) comprises a polymer resin composition configured for application in flexible display technology. The adhesive composition utilizes specific monomer and additive ratios configured to improve the stability and performance of conventional OCAs. The polymer resin composition includes 30-60 wt% thiol monomer, 20-60 wt% allyl monomer, and 10-30 wt% difunctional aliphatic urethane oligomer. The polymer resin composition further includes 1-3 wt% hydrolysis stabilizer additive, 0.01-0.03 wt% wetting agent, 1-5 wt% adhesion-promoting monomer, 0.05-2 wt% adhesion-promoting base, and 0.5-2 wt% photoinitiator.

[0015] In flexible display technology applications, the polymer resin composition is cured into a film, and the polymer resin composition has a strength of substantially 4 J / cm at temperatures between room temperature and 80°C. 2 The resulting film is cured using UVA light at a temperature of 1000°C (1200°F). The resulting film has a low modulus, with a first storage modulus of between 0.05 and 0.2 MPa at -20°C and a second storage modulus of between 0.015 and 0.15 MPa at 60°C. Furthermore, the film exhibits excellent optical properties, including a haze of less than 1%, a yellowing index of less than 1, and a light transmittance of up to 94% in the wavelength range of 400 nm to 700 nm. Furthermore, the film maintains its optical and thermomechanical properties even when stored in a high humidity (90%) and high temperature (65°C) environment for up to 240 hours.

[0016] Thiol monomers are a major component of the OCA polymer resin composition. In certain embodiments, the thiol monomers are difunctional or trifunctional. For reference herein, "difunctional" monomers are intended to include species containing two thiolic unsaturated sites. Similarly, "trifunctional" monomers are intended to include species containing three thiolic unsaturated sites. Examples of usable difunctional thiols include, but are not limited to, 1,4-bis(3-mercaptobutyroyloxy)butane, ethylene glycol bis-mercaptoacetate, ethylene bis(3-mercaptopropionate), 2,2'-(ethylenedioxy)diethanethiol, or 1,10-decanedithiol. In one embodiment, 1,4-bis(3-mercaptobutyroyloxy)butane or ethylene bis(3-mercaptopropionate) are included. Examples of suitable trifunctional thiols include, but are not limited to, trimethylolpropane tris(3-mercaptopropionate) or tris[2-(3-mercaptopropionyloxy)ethyl]isocyanurate. In one embodiment, tris[2-(3-mercaptopropionyloxy)ethyl]isocyanurate.

[0017] Allyl monomers are another major component of the OCA polymer resin composition. In certain embodiments, the allyl monomers are difunctional or trifunctional (this concept is understood with reference to the previous paragraph). Examples of diallyl monomers that can be used include, but are not limited to, diallyl isophthalate, trimethylolpropane diallyl ether, or triethylene glycol divinyl ether. In one embodiment, the species includes triethylene glycol divinyl ether. Examples of triallyl monomers that can be used include, but are not limited to, 1,3,5-triallyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione or pentaerythritol triallyl ether. In one embodiment, the species includes 1,3,5-triallyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione.

[0018] Difunctional aliphatic urethane oligomers are another major component of the OCA polymer resin composition. Examples of suitable difunctional aliphatic urethane oligomers include, but are not limited to, diallyltrimethylhexamethylenediurethane.

[0019] In embodiments, the OCA achieves an adhesion to glass of greater than 1000 gf / inch when treated with either air plasma or corona. This adhesion is achieved by treating the OCA alone with plasma or corona, or by treating both the OCA and the substrate to which it is applied.

[0020] FIG. 1 is a cross-sectional view of an optical laminate 1 according to a specific embodiment of the present disclosure. As shown, the optical laminate 1 includes an adhesive layer 6 containing an OCA, which is disposed between and in contact with a first surface of a first substrate layer 2 and a second surface of a second substrate layer 4. The adhesive layer 6 may be in direct contact with the first surface of the first substrate layer 2 and the second surface of the second substrate layer 4. In other embodiments, the adhesive layer 6 may be in indirect contact with one or more additional layers (not shown) disposed between the adhesive layer 6 and the first surface of the first substrate layer 2 and the second surface of the second substrate layer 4. The additional layers include, but are not limited to, a hard coat layer, a primer layer, a polarizing layer, a light-emitting layer, or a color filter layer. It is further noted that the adhesive layer 6 may be any embodiment of an OCA disclosed herein.

[0021] 2 is a cross-sectional view of a flexible display 200 according to a specific embodiment of the present disclosure. As shown, the flexible display 200 includes multiple layers commonly associated with flexible displays, including a window layer 202, a polarizer layer 204, a display layer 208, and a support film layer 210. An adhesive layer 206 containing an OCA is disposed between each layer pair (202 / 204, 204 / 208, and 208 / 210). More specifically, one adhesive layer 206 of the multiple adhesive layers 206 is disposed between and in contact with a first surface of the window layer 202 and a first surface of the polarizer layer 204, another adhesive layer 206 is disposed between and in contact with a second surface of the polarizer layer 204 and a first surface of the display layer 208, and yet another adhesive layer 206 is disposed between and in contact with a second surface of the display layer 208 and a first surface of the support film layer 210.

[0022] In other embodiments, adhesive layer 206 is in indirect contact with the first surface of window layer 202, the first surface of polarizer layer 204, the second surface of polarizer layer 204, the first surface of display layer 208, the second surface of the display layer, and the first surface of support film layer 210. In this case, one or more additional layers (not shown) are disposed between adhesive layer 206 and the above-mentioned surfaces. Additional layers include, but are not limited to, a hard coat layer, a primer layer, a polarizing layer, a light-emitting layer, or a color filter layer. It is further noted that adhesive layer 206 may be any embodiment of an OCA disclosed herein. Furthermore, those skilled in the art will understand and appreciate that embodiments of flexible display 200 may include additional layers used in flexible displays and separated by additional adhesive layer 206.

[0023] In any of the disclosed embodiments, adhesive layer 6 / adhesive layer 206 comprises a thickness of 25 μm to 500 μm. In one embodiment, adhesive layer 6 / adhesive layer 206 each comprises a thickness of 50 μm.

[0024] According to one embodiment of the present disclosure, the method for synthesizing the adhesion-promoting monomer of OCA is carried out using the steps shown in Reaction Scheme 1 below.

[0025] [ka]

[0026] The reactants involved in Equation 1 include R 1 and R 2 where R 1 is a compound of formula 2 or formula 3.

[0027] [ka]

[0028] [ka]

[0029] and R 2 is a methoxy or ethoxy functional group.

[0030] The process involves mixing an aliphatic alcohol with a 3-isocyanatopropyltrialkoxysilane in the presence of a trace amount (0.02-0.03 wt%) of dibutyltin dilaurate as a catalyst. The reaction is carried out at room temperature for 12 hours and does not require a solvent (solvent-free reaction). The adhesion-promoting monomer produced by Reaction 1 comprises a trialkoxysilane and at least one photopolymerizable alkene with a functionality greater than one. These adhesion-promoting monomers are particularly advantageous over monofunctional acrylate-based silanes in that they can be incorporated into polymer networks without chain termination, which can adversely affect the mechanical and optical performance of the polymer network (material).

[0031] When the aliphatic alcohol contains an allyl group, the allyl group is orthogonal to the isocyanate-alcohol coupling reaction, allowing the reaction to proceed without the formation of by-products or solvent residues. This thermal coupling process produces versatile, non-chain-terminated, multifunctional trialkoxysilane monomers with excellent hydrolytic stability. In embodiments, this particular monomer can be activated by various methods, such as acid or base hydrolysis, to improve the adhesion of the OCA. By combining this method with an appropriate adhesion-promoting amine base, it is possible to achieve adhesion strengths of over 600 gf / in between the OCA and different substrates, such as glass, DOP, and PET, without pre- or post-treatment.

[0032] In embodiments, the aliphatic alcohol comprises a photopolymerizable functional group including either an allyl, alkyne, acrylate, or thiol.

[0033] In an embodiment, the process includes at least one of a multifunctional diallyl monomer or a multifunctional thiol monomer, and (in addition to the at least one of a multifunctional diallyl monomer or a multifunctional thiol monomer) a crosslinker. In one embodiment, when the process includes a multifunctional diallyl monomer, the process includes a first ratio of first allyl groups in the multifunctional diallyl monomer to second allyl groups in the crosslinker of 5:1 to 10:1, and when the process includes a multifunctional thiol monomer, the process includes a second ratio of first thiol groups in the multifunctional thiol monomer to second allyl groups in the crosslinker of 5:1 to 10:1. As discussed above, these ratios contribute to the crosslink density and storage modulus of the product of Reaction Scheme 1 within a temperature range of -20°C to 60°C.

[0034] In an additional embodiment, when the process includes a polyfunctional diallyl monomer, the process includes a first ratio of first allyl groups in the polyfunctional diallyl monomer to second allyl groups in the crosslinker of 5:1 to 10:1, and a weight percentage of the aliphatic urethane oligomer of 10 wt% to 25 wt%. In this case, the modulus of elasticity of the product of Reaction Scheme 1 is maintained less than 0.11 MPa within a temperature range of -20°C to 60°C. In another embodiment, when the process includes a polyfunctional thiol monomer, the process includes a second ratio of first thiol groups in the polyfunctional thiol monomer to second allyl groups in the crosslinker of 5:1 to 10:1, and a weight percentage of the aliphatic urethane oligomer of 10 wt% to 25 wt%. In this case, the modulus of elasticity of the product of Reaction Scheme 1 is maintained less than 0.11 MPa within a temperature range of -20°C to 60°C.

[0035] It should be noted that the adhesion-promoting monomer in the process is configured to be synthesized without solvents and is also configured to be stable and safe under normal / typical conditions, addressing potential safety concerns in large-scale chemical handling scenarios. Cured samples of the polymer resin composition exhibited high resistance to thermal decomposition, with a 1% mass loss occurring at temperatures above 180°C and a 5% mass loss occurring at temperatures above 310°C. Regarding the synthesized adhesion-promoting monomer, for long-term storage purposes, the adhesion-promoting monomer may be stored under an inert atmosphere, which may simplify safe handling and storage of the synthesized adhesion-promoting monomer.

[0036] One or more embodiments of the present disclosure provide materials for building higher quality and performance flexible display technologies relative to other flexible display technologies.

[0037] It should be noted that the optically clear adhesives (OCA) / polymer resins presented herein may be used in displays / display devices / display panels, which may or may not be flexible. The optically clear adhesives (OCA) / polymer resins are incorporated into one or more layers of the display / display device / display panel, including, but not limited to, a sealing layer, a cathode layer, a light-emitting layer, an adhesive layer, a conductive layer, an anode layer, a substrate layer, and any layers mentioned in connection with FIG. 2. It should be understood that the display / display device / display panel may include additional film layers not mentioned herein.

[0038] In one embodiment of the present disclosure, an electronic device is provided, and one or more optically clear adhesives (OCAs) / polymer resins of the present disclosure are used in the display / display device / display panel of the electronic device. For example, the electronic device may be a smartphone, a mobile phone, a video phone, a camera, a wearable device (e.g., electronic clothing, electronic accessories, smart watches, head-worn devices, electronic bracelets, electronic necklaces, electronic tattoos), a personal digital assistant (PDA), a desktop computer (PC), a laptop PC, a netbook PC, a portable multimedia player (PMP), a digital audio player, a portable medical device, an e-reader, or the like. In an additional embodiment, the electronic device is a smart home appliance including a display / display device / display panel. For example, the smart home appliance may be an electronic key, a stereo, a television, a set-top box, a TV box, a video recorder, a game console, a vacuum cleaner, a digital video disc (DVD) player, a refrigerator, an air conditioner, an oven, a dryer, an air purifier, a microwave oven, a washing machine, an electronic dictionary, an electronic photo frame, or the like.

[0039] The exemplary systems, methods, and operations described in the above embodiments are illustrative, and in other embodiments, certain operations may be performed in a different order, in parallel with one another, omitted entirely, or combined between different exemplary embodiments, and certain additional operations may be performed, without departing from the scope and spirit of each embodiment. Accordingly, such other embodiments are also included in the description herein.

[0040] As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly indicates otherwise. It will be further understood that, as used herein, the terms "comprises" and / or "comprising" identify the presence of stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. As used herein, phrases such as "between X and Y" and "between about X and Y" should be interpreted to include X and Y. A phrase such as "between about X and Y" means "between about X and about Y." As used herein, expressions such as "from about X to Y" mean "from about X to about Y."

[0041] The above-disclosed embodiments are presented as examples to enable those skilled in the art to practice the disclosure, and are not intended to limit or be exhaustive. Numerous minor modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the disclosure. The claims are intended to broadly encompass the disclosed embodiments and such modifications. Furthermore, the following aspects represent other embodiments of the present disclosure and should be included within the scope of the present disclosure.

[0042] Aspect 1. An optically clear adhesive (OCA) comprising a polymer resin composition, the polymer resin composition comprising 30-60 wt% of a thiol monomer, 20-60 wt% of an allyl monomer, and 10-30 wt% of a difunctional aliphatic urethane oligomer.

[0043] Aspect 2. 10. The optically clear adhesive of claim 1, wherein the polymeric resin composition comprises 1-3 wt. % of a hydrolysis stabilizer additive; 0.01-0.03 wt. % of a wetting agent; 1-5 wt. % of an adhesion promoting monomer; and 0.05-2 wt. % of an adhesion promoting base. and 0.5 to 2 wt. % of a photoinitiator, and an optically clear adhesive.

[0044] Aspect 3. 2. The optically clear adhesive of embodiment 1, wherein the polymer resin composition is cured into a film.

[0045] Aspect 4. 4. The optically clear adhesive of claim 3, wherein the polymer resin composition has a viscosity of substantially 4 J / cm 2 An optically clear adhesive is cured to the film using UVA light having an intensity of 1000 .mu.m at a temperature between room temperature and 80.degree.

[0046] Aspect 5. 4. The optically transparent adhesive according to claim 3, wherein the film has a first storage modulus of 0.05 to 0.2 MPa at -20°C and a second storage modulus of 0.015 to 0.15 MPa at 60°C.

[0047] Aspect 6. 2. The optically clear adhesive of embodiment 1, wherein the thiol monomer is difunctional or trifunctional.

[0048] Aspect 7. The optically clear adhesive of embodiment 1, wherein the allyl monomer is difunctional or trifunctional.

[0049] Aspect 8. 4. The optically clear adhesive of embodiment 3, wherein the film comprises less than 1% haze.

[0050] Aspect 9. 4. The optically clear adhesive of embodiment 3, wherein the film comprises a yellowing index of less than 1.

[0051] Aspect 10. 4. The optically transparent adhesive according to claim 3, wherein the film has a light transmittance of up to 94% in the wavelength range of 400 nm to 700 nm.

[0052] Aspect 11. 4. The optically clear adhesive of claim 3, wherein the film has an adhesion to glass of greater than 1000 gf / inch when treated with at least one of air plasma or corona.

[0053] Aspect 12. 1. An optical laminate comprising: a first substrate layer having a first surface; a second substrate layer having a second surface; and an adhesive layer, wherein the adhesive layer comprises an optically clear adhesive (OCA), the optically clear adhesive comprising a polymer resin composition comprising 30 to 60% by weight of a thiol monomer, 20 to 60% by weight of an allyl monomer, and 10 to 30% by weight of a difunctional aliphatic urethane oligomer, and the adhesive layer is disposed between the first surface of the first substrate layer and the second surface of the second substrate layer, and bonds the first surface of the first substrate layer to the second surface of the second substrate layer.

[0054] Aspect 13. 13. The optical laminate of claim 12, wherein the polymer resin composition further comprises 1 to 3 wt. % of a hydrolysis stabilizer additive, 0.01 to 0.03 wt. % of a wetting agent, 1 to 5 wt. % of an adhesion-promoting monomer, 0.05 to 2 wt. % of an adhesion-promoting base, and 0.5 to 2 wt. % of a photoinitiator.

[0055] Aspect 14. A method for synthesizing the adhesion-promoting monomer of embodiment 2, comprising carrying out the steps shown in Scheme 1 below. TIFF2025160138000005.tif31141

[0056] Aspect 15. The method of embodiment 14, wherein R 1 is a compound of Formula 2 or Formula 3. TIFF2025160138000006.tif25141TIFF2025160138000007.tif18141

[0057] Aspect 16. 15. The method of embodiment 14, wherein R2 is a methoxy or ethoxy functional group.

[0058] Aspect 17. 15. The method of embodiment 14, wherein the step is carried out solventlessly.

[0059] Aspect 18. 15. The method of embodiment 14, wherein the adhesion-promoting monomer comprises a trialkoxysilane.

[0060] Aspect 19. 15. The method of embodiment 14, wherein the adhesion-promoting monomer comprises at least one photopolymerizable alkene having more than one functional group.

[0061] Aspect 20. 15. The method of claim 14, wherein the process comprises at least one of a multifunctional diallyl monomer or a multifunctional thiol monomer, and a crosslinker; and wherein, when the process comprises a multifunctional diallyl monomer, the process comprises a first ratio of first allyl groups in the multifunctional diallyl monomer to second allyl groups in the crosslinker of 5:1 to 10:1; and, when the process comprises a multifunctional thiol monomer, the process comprises a second ratio of first thiol groups in the multifunctional thiol monomer to second allyl groups in the crosslinker of 5:1 to 10:1.

[0062] Aspect 21. 15. The method of claim 14, wherein the adhesion-promoting monomer is cured, and further wherein the cured adhesion-promoting monomer comprises a weight loss rate of 1% at a temperature greater than 180°C.

[0063] Aspect 22. a first adhesive layer of the plurality of adhesive layers disposed between a first surface of the window layer and a first surface of the polarizer layer; a second adhesive layer of the plurality of adhesive layers disposed between a second surface of the polarizer layer and a first surface of the display layer; and a third adhesive layer of the plurality of adhesive layers disposed between the second surface of the display layer and a first surface of the support film layer, the first surface of the window layer adhering to the first surface of the polarizer layer, the second surface of the polarizer layer adhering to the first surface of the display layer, and the second surface of the display layer adhering to the first surface of the support film layer.

[0064] Aspect 23. 23. The flexible display of embodiment 22, wherein the polymer resin composition further comprises 1 to 3 wt. % of a hydrolysis stabilizer additive, 0.01 to 0.03 wt. % of a humectant, 1 to 5 wt. % of an adhesion-promoting monomer, 0.05 to 2 wt. % of an adhesion-promoting base, and 0.5 to 2 wt. % of a photoinitiator.

Claims

1. An optically clear adhesive (OCA), comprising: a polymer resin composition, the polymer resin composition comprising: 30 to 60 wt. % of a thiol monomer; 20 to 60% by weight of an allyl monomer; and 10 to 30 wt. % of a difunctional aliphatic urethane oligomer; 1. An optically clear adhesive comprising:

2. 2. The optically clear adhesive of claim 1, wherein the polymer resin composition comprises: 1-3 wt. % of a hydrolysis stabilizer additive; 0.01 to 0.03 wt. % of a wetting agent; 1 to 5 wt. % of an adhesion promoting monomer; 0.05 to 2 wt. % of an adhesion-promoting base, and 0.5 to 2 wt. % of a photoinitiator; 10. The optically clear adhesive, further comprising:

3. 10. The optically clear adhesive of claim 1, wherein the polymer resin composition is cured into a film.

4. 4. The optically clear adhesive of claim 3, wherein the polymer resin composition has a viscosity of substantially 4 J / cm ２ an optically clear adhesive that is cured to the film using UVA light having an intensity of 1000 .ANG. at a temperature between room temperature and 80.degree.

5. 4. The optically transparent adhesive of claim 3, wherein the film has a first storage modulus of 0.05 to 0.2 MPa at −20° C. and a second storage modulus of 0.015 to 0.15 MPa at 60° C.

6. 10. The optically clear adhesive of claim 1, wherein the thiol monomer is difunctional or trifunctional.

7. 10. The optically clear adhesive of claim 1, wherein the allylic monomer is difunctional or trifunctional.

8. 4. The optically clear adhesive of claim 3, wherein the film comprises a haze of less than 1%.

9. 4. The optically clear adhesive of claim 3, wherein the film comprises a yellowing index of less than 1.

10. 4. The optically clear adhesive of claim 3, wherein the film comprises a maximum light transmittance of 94% in the wavelength range of 400 nm to 700 nm.

11. 4. The optically clear adhesive of claim 3, wherein the film has an adhesion to glass of greater than 1000 gf / inch when treated with at least one of air plasma or corona.

12. An optical laminate, a first substrate layer having a first surface; a second substrate layer having a second surface; and an adhesive layer; Including, the adhesive layer comprises an optically clear adhesive (OCA); the optically clear adhesive comprises a polymer resin composition; The polymer resin composition comprises: 30 to 60 wt. % of a thiol monomer; 20 to 60% by weight of an allyl monomer; and 10 to 30 wt. % of a difunctional aliphatic urethane oligomer; Including, an adhesive layer disposed between a first surface of the first substrate layer and a second surface of the second substrate layer, and adhering the first surface of the first substrate layer to the second surface of the second substrate layer;

13. 13. The optical laminate according to claim 12, wherein the polymer resin composition is 1-3 wt. % of a hydrolysis stabilizer additive; 0.01 to 0.03 wt. % of a wetting agent; 1 to 5 wt. % of an adhesion promoting monomer; 0.05 to 2 wt. % of an adhesion-promoting base, and 0.5 to 2 wt. % of a photoinitiator; The optical laminate further comprises:

14. 3. A method for synthesizing the adhesion-promoting monomer of claim 2, comprising carrying out the steps shown in Reaction Scheme 1 below.

15. 15. The method of claim 14, wherein R １ is a compound of formula 2 or formula 3.

16. 15. The method of claim 14, wherein R ２ is a methoxy or ethoxy functional group.

17. 15. The method of claim 14, wherein the process is carried out solvent-free.

18. The method of claim 14, wherein the adhesion promoting monomer comprises a trialkoxysilane.

19. 15. The method of claim 14, wherein the adhesion-promoting monomer comprises at least one photopolymerizable alkene having more than one functional group.

20. 15. The method of claim 14, wherein the process includes at least one of a multifunctional diallyl monomer or a multifunctional thiol monomer, and a crosslinker; and when the process includes a multifunctional diallyl monomer, the process further comprises: a first ratio of first allyl groups in the multifunctional diallyl monomer to second allyl groups in the crosslinker is from 5:1 to 10:1; Further, when the process includes a multifunctional thiol monomer, the process further comprises a second ratio of first thiol groups in the multifunctional thiol monomer to second allyl groups in the crosslinker of from 5:1 to 10:

1.

21. 15. The method of claim 14, wherein the adhesion promoting monomer is cured, and further wherein the cured adhesion promoting monomer comprises a weight loss rate of 1% at temperatures above 180°C.

22. A flexible display, a window layer; a polarizer layer; and a display layer; and a support film layer; and a plurality of adhesive layers; Including, each of the plurality of adhesive layers comprises an optically clear adhesive (OCA); the optically clear adhesive comprises a polymer resin composition; The polymer resin composition comprises: 30 to 60 wt. % of a thiol monomer; 20 to 60% by weight of an allyl monomer; and 10 to 30 wt. % of a difunctional aliphatic urethane oligomer; Including, A flexible display, wherein a first adhesive layer of the plurality of adhesive layers is disposed between the first surface of the window layer and the first surface of the polarizer layer, a second adhesive layer is disposed between the second surface of the polarizer layer and the first surface of the display layer, and a third adhesive layer is disposed between the second surface of the display layer and the first surface of the support film layer, bonding the first surface of the window layer to the first surface of the polarizer layer, the second surface of the polarizer layer to the first surface of the display layer, and the second surface of the display layer to the first surface of the support film layer.

23. 23. The flexible display of claim 22, wherein the polymer resin composition comprises: 1-3 wt. % of a hydrolysis stabilizer additive; 0.01 to 0.03 wt. % of a wetting agent; 1 to 5 wt. % of an adhesion promoting monomer; 0.05 to 2 wt. % of an adhesion-promoting base, and 0.5 to 2 wt. % of a photoinitiator; The flexible display further includes:

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