Anti-warping water-based optical cement for optical diffusion film as well as preparation method and application of anti-warping water-based optical cement

Abstract

The invention discloses anti-warping water-based optical cement for an optical diffusion film as well as a preparation method and application of the anti-warping water-based optical cement, and belongs to the technical field of optical diffusion films. The preparation method of the anti-warping water-based optical cement for the optical diffusion film comprises the following steps: mixing trimethylbenzene and ethylene glycol monobutyl ether to obtain a mixed solvent; adding an acrylic monomer and an initiator into the mixed solvent, and carrying out a heating reaction to obtain a reactant; the anti-warping water-based optical cement for the optical diffusion film is obtained by adding a neutralizing agent into reactants for a neutralization reaction, then adding water, stirring and mixing, the water-based optical cement can replace traditional optical cement to be applied to the optical diffusion film, the surface of a PET film is coated with the water-based optical cement, and a water-based optical cement thin film is formed after curing. The water-based optical cement film and the PET film form the optical diffusion film and then the optical diffusion film is applied to the display screen, the stress generated by the water-based optical cement in the curing process is small, the PET film can be prevented from warping, and therefore the performance of the optical diffusion film is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of optical diffusion films, and in particular to an anti-warping water-based optical adhesive for optical diffusion films, and a preparation method and application thereof. Background Art

[0002] With the rapid development of various flat panel display technologies and products, flat panel displays such as LCD and LED display technologies have been widely used in various fields such as televisions and mobile phones. LCD and LED display screens require backlight modules to provide sufficient brightness and uniform light sources to display images. As an extremely important component of the backlight module, the optical diffusion film has the function of distributing line light sources or point light sources into surface light sources, thereby providing a uniform surface light source for the flat panel display screen.

[0003] One type of optical diffusion film is prepared by coating optical glue on a PET film so that the light is evenly dispersed when it passes through. The main body of the optical glue is resin and light diffusion particles. Traditional oily optical glue uses oily resin as a binder, which contains a large amount of ketone and ester solvents. These solvents evaporate into the air or remain in the coating after drying during the preparation, stirring and circulation process, which is very harmful to the human body. Water-based optical glue uses water-based resin as a binder, and water and ethanol can be used as diluents, which is harmless to the human body. Water-based resins have long been used in various industries, such as the home market, and industries related to people are moving towards a green and environmentally friendly direction.

[0004] The water-based resin on the market will cause the PET to warp after being coated and cured in the preparation of optical adhesive. This unevenness directly affects the uniform distribution of light. The reason for this phenomenon is that the water-based resin is distributed in the form of latex particles in water. There are large gaps between the particles, and there is a large stress during the curing process, which leads to shrinkage and warping.

[0005] Therefore, it is extremely important to develop an environmentally friendly, safe, and optical water-based optical adhesive that does not cause warping of the PET film. Summary of the invention

[0006] The main purpose of the present invention is to provide an anti-warping water-based optical adhesive for optical diffusion film, a preparation method and an application thereof, so as to solve the technical problem in the prior art that the water-based resin optical adhesive is coated on the surface of the PET film, which will cause the PET film to warp after curing.

[0007] To achieve the above object, the present invention provides a method for preparing an anti-warping water-based optical adhesive for an optical diffusion film, comprising the following steps:

[0008] S10: mixing trimethylbenzene and ethylene glycol monobutyl ether to obtain a mixed solvent;

[0009] S20: adding an acrylic acid monomer and an initiator to a mixed solvent, and performing a heating reaction to obtain a reactant;

[0010] S30: adding a neutralizing agent to the reactants to perform a neutralization reaction. After the neutralization reaction is completed, adding water, stirring and mixing to obtain an anti-warping water-based optical adhesive for an optical diffusion film.

[0011] In some embodiments of the present invention, the acrylic monomer includes a first monomer, a second monomer and a third monomer, the first monomer includes methyl methacrylate; the second monomer includes at least one of n-butyl acrylate, 2-ethylhexyl acrylate, and lauryl methacrylate; the third monomer includes at least one of methacrylic acid, methyl methacrylate, 2-hydroxyethyl methacrylate, and 2-hydroxypropyl methacrylate.

[0012] In some embodiments of the present invention, the weight ratio of the first monomer to the second monomer is 1:(1.5-5); and / or the weight ratio of the first monomer to the third monomer is 1:(0.45-0.9).

[0013] In some embodiments of the present invention, the initiator comprises tert-butyl peroxide; and / or the neutralizer comprises N,N-dimethylethanolamine.

[0014] In some embodiments of the present invention, calculated by weight, the weight ratio of trimethylbenzene, ethylene glycol monobutyl ether, acrylic acid monomer and initiator is (1-2): (1-2): (8-10): (0.05-0.2).

[0015] In some embodiments of the present invention, the temperature of the heating reaction is 120°C to 140°C.

[0016] The present invention also provides an anti-warping water-based optical adhesive for optical diffusion films prepared by the method for preparing the anti-warping water-based optical adhesive for optical diffusion films as described above.

[0017] In some embodiments of the present invention, the solid content of the anti-warping water-based optical adhesive for optical diffusion film is 45%-50%;

[0018] And / or, the pH of the anti-warping water-based optical adhesive for the optical diffusion film is 7.5 to 8.0;

[0019] And / or, the viscosity of the anti-warping water-based optical adhesive for the optical diffusion film is 200mPa.s to 2500mPa.s.

[0020] The present invention also provides an application of the above-mentioned anti-warping water-based optical adhesive for optical diffusion films in the field of optical diffusion films.

[0021] Beneficial effects of the present invention:

[0022] The water-based optical adhesive prepared by the preparation method of the present invention can be applied to the field of optical diffusion films, replacing traditional optical adhesives, and the water-based optical adhesive is coated on the surface of the PET film and cured to form a water-based optical adhesive film. The water-based optical adhesive film and the PET film form an optical diffusion film, and the optical diffusion film can be applied to the display screen. The water-based optical adhesive of the present invention generates less stress during the curing process, which can prevent the PET film from warping, thereby improving the performance of the optical diffusion film. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0024] Figure 1 FIG. 4 is a schematic diagram of a method for preparing a warping-resistant water-based optical adhesive for an optical diffusion film according to an embodiment of the present invention.

[0025] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0026] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] In the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0029] In view of this, the present invention provides a method for preparing a warping-resistant water-based optical adhesive for an optical diffusion film, wherein the warping-resistant water-based optical adhesive for an optical diffusion film of the present invention can also be referred to as water-based optical adhesive. Figure 1 , the preparation method comprises the following steps:

[0030] S10: mixing trimethylbenzene and ethylene glycol monobutyl ether to obtain a mixed solvent;

[0031] S20: adding an acrylic acid monomer and an initiator to a mixed solvent, and performing a heating reaction to obtain a reactant;

[0032] S30: adding a neutralizing agent to the reactants to perform a neutralization reaction. After the neutralization reaction is completed, adding water, stirring and mixing to obtain an anti-warping water-based optical adhesive for an optical diffusion film.

[0033] In step S10, trimethylbenzene and ethylene glycol monobutyl ether are mixed to prepare a mixed solvent, which can dissolve acrylic monomer and initiator better, promote acrylic monomer and initiator to react better to obtain emulsion reactants, provide better texture for preparing optical adhesive film, and reduce the warpage of PET film. In addition, trimethylbenzene in the mixed solvent has oily properties. Even if water is added for dilution in the subsequent step S30, the entire water-based optical adhesive system is not easily dispersed. When the water-based optical adhesive is coated on the PET film and cured to form an optical adhesive film, it is easy to form a uniform and continuous optical adhesive film due to the system with good emulsification, thereby reducing the warpage of the PET film.

[0034] In some embodiments of step S10, trimethylbenzene and ethylene glycol monobutyl ether may be first injected into the reactor, stirred and mixed, and then heated to the heating reaction temperature of step S20 and kept warm for 0.5 h to 0.6 h.

[0035] In some embodiments of step S10, after the mixing of trimethylbenzene and ethylene glycol monobutyl ether is completed, an inert gas may be introduced to drive out the oxygen in the reactor to prevent the oxygen from affecting the subsequent reaction.

[0036] In some embodiments, the inert gas includes at least one of nitrogen and argon.

[0037] In some embodiments, trimethylbenzene and ethylene glycol monobutyl ether are injected into a reaction kettle, stirred and heated to a heating reaction temperature, nitrogen is injected to drive out oxygen, and the temperature is kept for 0.5 h to 1 h.

[0038] In some embodiments, the acrylic monomer includes a first monomer, a second monomer, and a third monomer, the first monomer includes methyl methacrylate; the second monomer includes at least one of n-butyl acrylate, 2-ethylhexyl acrylate, and lauryl methacrylate; the third monomer includes at least one of methacrylic acid, 2-hydroxyethyl methacrylate, and 2-hydroxypropyl methacrylate.

[0039] The first monomer contains a rigid group, which can improve the rigidity, hardness and strength of the water-based optical adhesive film.

[0040] The second monomer contains a flexible group, which can improve the flexibility and adhesion of the water-based optical adhesive film, so that the formed water-based optical film has good flexibility and adhesion and can be firmly attached to the surface of the PET film, thereby reducing the warping rate of the PET film.

[0041] The third monomer can provide a hydrophilic group and a curing cross-linking point, so that when water is added for dilution in step S30, the entire product system of the water-based optical adhesive will not be turbid and stratified, which is conducive to obtaining a uniform water-based optical adhesive. When applied to the preparation of a water-based optical adhesive film, it is easy to obtain a uniform and continuous water-based optical adhesive film, which is conducive to reducing the warpage of the PET film. In addition, the abundant curing cross-linking points can promote the cross-linking reaction to form a strong cross-linking network, thereby improving the mechanical properties and chemical resistance of the water-based optical adhesive film.

[0042] By compounding the above first monomer, second monomer and third monomer, a water-based optical adhesive in an emulsion state with good fluidity can be obtained. The water-based optical adhesive is coated on the surface of a PET film. The water-based optical adhesive film obtained after curing can not only better balance rigidity and flexibility, but also has good adhesion. Improvements in multiple aspects can greatly reduce the warpage rate of the PET film.

[0043] In some embodiments, the weight ratio of the first monomer to the second monomer is 1: (1.5-5). Under the above mass ratio conditions, the rigidity and flexibility of the water-based optical adhesive film can be well balanced, and the water-based optical adhesive film can also have good adhesion and firmly adhere to the surface of the PET film. Improvements are made from multiple aspects to greatly reduce the warpage of the PET film. Further, in some embodiments, the mass ratio of the first monomer to the third monomer is 1: (0.45-0.9). Under the above mass ratio conditions, the rigidity and flexibility of the water-based optical adhesive film can be well balanced, and the water-based optical adhesive film can also have good adhesion and firmly adhere to the surface of the PET film. Improvements are made from multiple aspects to greatly reduce the warpage of the PET film.

[0044] In some embodiments, the initiator includes tert-butyl peroxide, which can undergo a cross-linking reaction with acrylic acid monomers to obtain a reactant in an emulsion state.

[0045] In some embodiments, the temperature of the heating reaction is 120°C to 140°C, and can be any value in the range of 120°C to 140°C, such as 120°C, 130°C, 140°C, etc. Under the above heating reaction temperature conditions, the cross-linking reaction of the acrylic monomer and the initiator is promoted to form a strong cross-linking network, thereby reducing the warping rate of the PET film and improving the mechanical properties and chemical resistance of the water-based optical adhesive film.

[0046] In some embodiments, the heating reaction time is 4 hours to 20 hours, which is conducive to promoting the complete reaction of the acrylic acid monomer and the initiator and improving the product yield. The above reaction time is calculated from the time when the acrylic acid monomer and the initiator are mixed with the mixed solvent in step S10.

[0047] In some embodiments, the acrylic acid monomer and the initiator may be mixed to form a precursor solution, and then the precursor solution may be added to the mixed solvent in step S10, which is beneficial to promote the complete reaction of the acrylic acid monomer and the initiator.

[0048] In some embodiments, the precursor solution formed by mixing acrylic acid monomer and initiator is added dropwise to the mixed solvent of step S10 for 10 hours, and then kept warm for 4 hours under the temperature condition of heating reaction. The heat preservation treatment can make the unreacted acrylic acid monomer and initiator react completely.

[0049] In some embodiments, after the insulation is completed, the initiator can be supplemented in multiple times to improve the conversion rate of the acrylic acid monomer. After each supplement of the initiator, the insulation can be carried out for 0.5h to 2h, so that the initiator and the acrylic acid monomer can react more completely.

[0050] In some embodiments, the neutralizing agent includes N,N-dimethylethanolamine, and the addition of the neutralizing agent can neutralize the pH of the reactants in step S20.

[0051] In step S30, after the neutralization reaction is completed, the reactants are relatively thick and are diluted by adding water. After adding water, stirring can be performed to promote uniform mixing of the entire water-based optical adhesive, thereby forming a uniform water-based optical adhesive film and reducing the warping rate of the PET film.

[0052] In some embodiments, water can be added to the reactant system after the neutralization reaction by dropwise addition, which is beneficial to the uniform mixing of the entire water-based optical adhesive, thereby forming a uniform water-based optical adhesive film and reducing the warping rate of the PET film.

[0053] In some embodiments, calculated by weight, the weight ratio of trimethylbenzene, ethylene glycol monobutyl ether, acrylic acid monomer, and initiator is (1-2): (1-2): (8-10): (0.05-0.2).

[0054] In the present invention, the amount of water added in step S30 can be adjusted according to the required consistency of the water-based optical adhesive.

[0055] After completing the treatment in step S30, the material can be discharged at 40°C.

[0056] In some embodiments, the solid content of the anti-warping water-based optical adhesive for optical diffusion film is 45%-50%. The present invention can control the solid content by controlling the addition amount of the reaction raw materials trimethylbenzene, ethylene glycol monobutyl ether, acrylic acid monomer, initiator and water.

[0057] In some embodiments, the pH of the anti-warping water-based optical adhesive for the optical diffusion film is 7.5-8.0. The pH can be controlled by adding a neutralizer.

[0058] In some embodiments, the viscosity of the anti-warping water-based optical adhesive for optical diffusion film is 200mPa.s to 2500mPa.s. The viscosity can be controlled by controlling the addition amount of the reaction raw materials, trimethylbenzene, ethylene glycol monobutyl ether, acrylic acid monomer, initiator and water.

[0059] The present invention reduces the warpage rate when the optical diffusion film is prepared on a PET film by controlling the solid content, pH and viscosity of the anti-warping water-based optical adhesive used for the optical diffusion film, so that the prepared optical diffusion film and the PET film have a better bonding effect.

[0060] The anti-warping water-based optical adhesive for optical diffusion film of the present invention can be applied to the field of optical diffusion film. The anti-warping water-based optical adhesive for optical diffusion film is coated on the surface of PET film and cured to obtain a water-based optical adhesive film, and the water-based optical adhesive film and PET film together constitute an optical diffusion film.

[0061] The technical solution of the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the following specific embodiments are only used to explain the present invention, and are not used to limit the present invention.

[0062] Example 1

[0063] S10: inject 10 parts of trimethylbenzene and 10 parts of ethylene glycol monobutyl ether into a reaction kettle, stir and mix, heat to about 120° C., inject nitrogen to drive out oxygen, and keep warm for about 0.5 hour to obtain a mixed solvent.

[0064] S20, referring to Table 1, add 10 parts of acrylic acid monomer and 1 part of initiator tert-butyl peroxide into the monomer tank. Add the mixture of acrylic acid monomer and initiator dropwise into the mixed solvent in the reactor of step S10, control the dropping time to be 10 hours, the heat preservation time to be 4 hours, and the process temperature to be 120° C. to obtain a reactant.

[0065] S30, adding 2 parts of neutralizing agent N, N-dimethylethanolamine to the reactants of step S20, stirring for reaction, adding 77 parts of deionized water dropwise after the reaction is completed, while keeping the reactor in a stirring state, controlling the dropping time for 2 hours, cooling to below 40°C and discharging the material to obtain the final product, a warping water-based optical adhesive for optical diffusion film.

[0066] Sampling analysis mainly measures appearance, solid content, viscosity and other indicators, and tests pH to ensure that the pH is between 7.5 and 8.0. If the pH value is insufficient, fine-tuning is required to add neutralizing agent N,N-dimethylethanolamine to maintain the pH of the final water-based optical adhesive at 7.5 to 8.0.

[0067] Table 1

[0068]

[0069] Performance Testing

[0070] Prepare glue: mix 10 parts of deionized water and 2 parts of aqueous isocyanate curing agent with 10 parts of the aqueous optical glue of Examples 1 to 3, Comparative Example 1 and Comparative Example 2 respectively, and obtain 6 parts of coating glue.

[0071] Coating and curing: Use a No. 30 wire rod to evenly coat 6 portions of coating glue on a 38-micron transparent Dongcai PET film, dry at 85°C for 2 minutes, and then age at 50°C for 24 hours. After the ageing is completed, test according to the following table items.

[0072] 1. Alcohol resistance test

[0073] Test method: Friction tester test, use a dust-free cloth dipped in alcohol, load 100g, rub back and forth 10 times, the optical adhesive diffusion film does not turn white or fall off.

[0074] Requirements: Wipe with 100g alcohol for >10 times. If the requirement is met, mark √; if not, mark ×.

[0075] 2. Yellowing resistance test

[0076] Test method: Put the film made of water-based glue into a high-temperature oven for aging test, and use a chromatographic illuminometer to test the coordinates of the product before and after the test.

[0077] Requirements: High temperature 85℃ / 240h, color coordinate shift <0.008. If the requirements are met, mark √, otherwise mark ×.

[0078] 3. Adhesion test

[0079] Test method: Use a 100-grid knife for testing.

[0080] Requirements: Adhesion on PET film surface ≥5B,

[0081] 4. Warpage test

[0082] Test method: 1) Put the thin film test piece made of water-based glue into a high-temperature oven, adjust the temperature of the test box to 85℃, bake for 2 hours, take it out and place it on a glass plate at room temperature to test the warpage. 2) Put the thin film test piece made of water-based glue into a low-temperature box, set the temperature to -40℃, freeze it for 2 hours and then test the warpage.

[0083] Requirements: Warpage ≤ 2mm. If it meets the requirements, mark √, otherwise mark ×.

[0084] 5. Boiling test

[0085] Test method: Boil in 85℃ water for 5h.

[0086] Requirements: After the test, the optical diffusion film must not fall off or deteriorate. If it meets the requirements, mark √; if it does not meet the requirements, mark ×.

[0087] 6. Silk screen test

[0088] Test method: Screen print the ink on the optical diffusion film, cure it at 75℃ for 15min and then test it. Adhesion 5B is required. Boil it in 85℃ water for 5h.

[0089] Requirements: After the test, the optical diffusion film must not fall off or deteriorate. If it meets the requirements, mark √; if it does not meet the requirements, mark ×.

[0090] The results of the above tests are shown in Table 2.

[0091] Table 2

[0092] Inspection items Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Commercially available products Solid content 48％ 45 49％ 42％ 46％ 47％ pH 7.5～8.0 7.5～8.0 7.5～8.0 7.5～8.0 7.5～8.0 7.5～8.0 Viscosity 2250mPa.s 2300mPa.s 2350mPa.s 2150mPa.s 2100mPa.s 2540mPa.s Alcohol resistance √ √ √ √ √ √ Yellowing resistance √ √ √ √ √ × Adhesion test √ √ √ × √ √ Warpage test √ √ √ × × × Boiling test √ √ √ √ √ √ Silk screen test √ √ √ √ √ √

[0093] From Table 1 and Table 2, it can be seen that the anti-warping water-based optical adhesive for optical diffusion film prepared in Examples 1 to 3 is applied to PET film to prepare optical diffusion film, which not only passes the warping test, but also performs well in alcohol resistance test, yellowing resistance test, adhesion test, water boiling test and silk screen printing test.

[0094] In Comparative Example 1, the first monomer is more and the second monomer is less, the rigidity is stronger and the flexibility is insufficient. In the warping test, the warping rate does not meet the requirement of ≤2mm, and the performance is poor in the adhesion test.

[0095] The weight ratio of the first monomer and the second monomer of the aqueous optical adhesive prepared in Comparative Example 2 is 1:1.34, and the flexible monomer is insufficient. When applied to a PET film to prepare an optical diffusion film, in a warping test, the warping rate of the optical diffusion film does not meet the requirement of ≤2 mm.

[0096] Commercially available water-based acrylic resins also failed to meet the requirement of a warpage rate of ≤2 mm in the warpage test and failed the yellowing resistance test.

[0097] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for preparing an anti-warping water-based optical adhesive for an optical diffusion film, characterized in that: The following steps are involved: S10: mixing trimethylbenzene and ethylene glycol monobutyl ether to obtain a mixed solvent; S20: adding an acrylic acid monomer and an initiator to a mixed solvent, and performing a heating reaction to obtain a reactant; S30: adding a neutralizing agent to the reactants to perform a neutralization reaction. After the neutralization reaction is completed, adding water, stirring and mixing to obtain an anti-warping water-based optical adhesive for an optical diffusion film.

2. The method for preparing the anti-warping water-based optical adhesive for optical diffusion film according to claim 1, characterized in that: The acrylic monomer includes a first monomer, a second monomer and a third monomer, wherein the first monomer includes methyl methacrylate; the second monomer includes at least one of n-butyl acrylate, 2-ethylhexyl acrylate and lauryl methacrylate; and the third monomer includes at least one of methacrylic acid, 2-hydroxyethyl methacrylate and 2-hydroxypropyl methacrylate.

3. The method for preparing the anti-warping water-based optical adhesive for optical diffusion film according to claim 2, characterized in that: The weight ratio of the first monomer to the second monomer is 1:(1.5-5); And / or, the weight ratio of the first monomer to the third monomer is 1:(0.45-0.9).

4. The method for preparing the anti-warping water-based optical adhesive for optical diffusion film according to claim 1, characterized in that: The initiator includes tert-butyl peroxide.

5. The method for preparing the anti-warping water-based optical adhesive for optical diffusion film according to claim 1, characterized in that: The neutralizing agent includes N,N-dimethylethanolamine.

6. The method for preparing the anti-warping water-based optical adhesive for optical diffusion film according to claim 1, characterized in that: Calculated by weight, the weight ratio of trimethylbenzene, ethylene glycol monobutyl ether, acrylic acid monomer and initiator is (1-2): (1-2): (8-10): (0.05-0.2).

7. The method for preparing the anti-warping water-based optical adhesive for optical diffusion film according to claim 1, characterized in that: The temperature of the heating reaction is 120°C to 140°C. 8 . An anti-warping water-based optical adhesive for optical diffusion films prepared by the method for preparing the anti-warping water-based optical adhesive for optical diffusion films according to any one of claims 1 to 7 .

9. The anti-warping water-based optical adhesive for optical diffusion film according to claim 8, characterized in that: The solid content of the anti-warping water-based optical adhesive for optical diffusion film is 45%-50%; And / or, the pH of the anti-warping water-based optical adhesive for the optical diffusion film is 7.5 to 8.0; And / or, the viscosity of the anti-warping water-based optical adhesive for the optical diffusion film is 200mPa.s to 2500mPa.s.

10. Use of the anti-warping water-based optical adhesive for optical diffusion films according to claim 8 or 9 in the field of optical diffusion films.

Images