Optical grade double sided adhesive tape, its preparation method and use

Abstract

The application provides an optical double-sided adhesive tape and a preparation method and application thereof, and provides a general and simple bonding scheme for bonding of a touch display screen glass module. The optical double-sided adhesive tape comprises an application adhesive film layer and a release film layer. The application adhesive film layer is a "sandwich" structure formed by an optical acrylic pressure-sensitive adhesive layer, an optical PET film layer and an optical organic silicon pressure-sensitive adhesive layer. The acrylic pressure-sensitive adhesive is used to enhance the light transmittance of the adhesive, reduce the haze and improve the air exhaust performance by introducing special monomers and a suitable formula process system. The organic silicon pressure-sensitive adhesive is used to meet the performance requirements of various products by a special formula system. The optical double-sided adhesive tape has good light transmittance, good air exhaust performance, no "snowflake" crystal points in bonding, excellent bonding performance and good long-term stability, and is mainly used for bonding of components of various touch screen glass display modules.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of optical grade pressure sensitive adhesive, in particular to an optical grade double-sided adhesive tape for bonding components of a touch screen glass display module and a preparation method and application thereof. BACKGROUND

[0002] With the development of electronic and display touch screen industry, the demand for components of touch screen glass display module in electronic consumer market is growing rapidly, thereby driving the development of ITO glass industry, touch screen manufacturing and processing industry, adhesive and pressure sensitive adhesive tape industry. Electronic products such as mobile phones, notebook computers, tablet computers, industrial computers and the like use touch display screens, which can be divided into traditional flat panel touch screens and curved touch screens. In order to achieve better display effect and experience, touch screens develop from traditional flat panel screens to 2.5D / 3D curved touch screens, which become the mainstream products in the market. Therefore, the touch screen glass display module industry needs to be updated accordingly, and the optical grade pressure sensitive adhesive tape for touch screen process has higher requirements. During the bonding of 2.5D / 3D curved touch screen glass, due to the incomplete filling of the printing ink concave-convex area of the glass, bubbles and rebound occur, and the panel and the edge have a certain curvature, especially in the edge of 2.5D / 3D curved touch screen glass, which is more prone to rebound and bubbling, resulting in product defects. Therefore, the bonding solution for flat panel touch screen and 2.5D / 3D curved touch screen glass module is an urgent problem to be solved in the touch screen industry. SUMMARY

[0003] In order to solve the outstanding problems of touch screen glass module bonding scheme, the present application provides an optical grade double-sided adhesive tape and a preparation method thereof. The optical double-sided adhesive tape has good light transmittance, good exhaust performance, no "snowflake" crystal point during bonding, excellent bonding performance, anti-rebound, good long-term stability, and is suitable for traditional flat panel touch screen and 2.5D / 3D curved screen, and solves the problems existing in the touch screen industry.

[0004] The technical solution adopted by the present application to solve the technical problem is: an optical grade double-sided adhesive tape is used, which comprises an application adhesive film layer and a release film layer. The application adhesive film layer is a "sandwich" type structure composed of an optical grade acrylate pressure sensitive adhesive layer, an optical grade PET film layer and an optical grade organic silicon pressure sensitive adhesive layer.

[0005] Further, the present application also provides an optical grade organic silicon pressure sensitive adhesive, which comprises the following components by mass fraction:

[0006]

[0007] Preferably, the silicone rubber is hydroxyl-terminated polydimethylsiloxane 107 silicone rubber with a molecular weight of 500,000-1,200,000 and a content of reactive end group functional groups of 1%-2%.

[0008] Preferably, the silicone resin is MQ type silicone resin with a ratio of M groups to Q groups of 0.9-1.2 and a content of reactive end group functional groups of 1%-1.5%.

[0009] Preferably, the catalyst is a platinum gold catalyst or an organotin catalyst.

[0010] Preferably, the anchor agent is a reactive anchor agent containing an epoxy group and / or an acyloxy group. Preferably, the solvent is a mixed solvent of ethyl acetate and toluene.

[0011] Further, the present application also provides a preparation method of an optical grade silicone pressure-sensitive adhesive, comprising the following steps: (1) adding silicone rubber, ethyl acetate and toluene into an opening container and stirring for 0.5-3 hours until the silicone rubber is completely dissolved, then adding silicone resin, anchor agent, catalyst and the like in a formula proportion in sequence, and fully stirring to be uniform, to obtain colorless or light yellow silicone pressure-sensitive adhesive.

[0012] (2) coating the above-mentioned silicone pressure-sensitive adhesive on a 50 μm PET substrate layer, drying to form a pressure-sensitive adhesive layer, and then combining a release film layer to obtain an optical grade pressure-sensitive adhesive tape single side.

[0013] Further, the present application also provides an optical grade acrylate pressure-sensitive adhesive, comprising the following components in mass fraction:

[0014]

[0015] Preferably, the acrylate soft monomer comprises one or more of butyl acrylate, isooctyl acrylate and isobornyl acrylate.

[0016] Preferably, the acrylate hard monomer comprises one or more of vinyl acetate, methyl methacrylate and styrene.

[0017] Preferably, the itaconic acid alkyl ester monomer comprises one or more of dibutyl itaconate, monobutyl itaconate, diisooctyl itaconate and monoisooctyl itaconate.

[0018] Preferably, the acrylic functional monomer comprises one or more of hydroxyethyl acrylate, hydroxypropyl acrylate, acrylic acid and acrylamide.

[0019] Preferably, the initiator comprises one or more of azobisisobutyronitrile, benzoyl peroxide and isomontanoyl peroxide.

[0020] Preferably, nitrogen is introduced into the reaction kettle, the amount of nitrogen is 5-20L / min, and the reaction temperature is 76-80℃.

[0021] Preferably, the curing agent is an epoxy curing agent or an isocyanate curing agent.

[0022] Preferably, the solvent is a mixed solvent of ethyl acetate and toluene.

[0023] Further, the present application also provides a preparation method of the optical grade acrylate pressure-sensitive adhesive, comprising the following steps: (1) loading a solvent into a reaction kettle provided with a thermometer, a condenser and an emulsifying tank, and adding part of acrylate soft monomers, acrylate hard monomers, acrylic functional monomers, itaconic acid alkyl ester monomers and an appropriate amount of solvent into the reaction kettle provided with the thermometer, the condenser and the emulsifying tank, and controlling the monomer content to be 50%-65%; and introducing nitrogen into the reaction kettle, dissolving an initiator, adding 25% of an initiator solution into the reaction kettle, starting to stir and heat, heating to 78-80℃, and reacting for 90 minutes, then starting to drop 50% of the initiator solution and the remaining monomer solution, dropping for 90 minutes, and then keeping warm for 3h, then dropping 25% of the initiator solution for 5-10 minutes, and continuing to keep warm for 3-5h, and diluting to 40%-45% of solid content, to obtain a colorless transparent viscous acrylate pressure-sensitive adhesive liquid;

[0024] (2) adding 70 parts of the above optical grade acrylate pressure-sensitive adhesive, 0.1-2 parts of a curing agent and 10-30 parts of a solvent into an opening container, stirring uniformly, then coating on a single material layer of the above optical grade silicone-based adhesive tape, drying to form a pressure-sensitive adhesive layer, and then combining a release film layer to obtain an optical grade pressure-sensitive adhesive tape.

[0025] The advantage of the present application is to provide a complete solution for the bonding of the touch screen glass module, the optical grade acrylate pressure-sensitive adhesive is prepared by introducing special monomers such as isobornyl acrylate, lauryl acrylate and itaconic acid alkyl ester and a suitable formula process system to enhance the light transmittance of the adhesive, reduce the haze and improve the exhaust performance, the optical grade silicone pressure-sensitive adhesive is prepared by using special formula systems such as silicone rubber, special silicone resin, anchoring agent and curing agent, and the formula system can be adjusted to meet the performance requirements of various products, the optical double-sided adhesive tape has good light transmittance, good exhaust performance, no "snowflake" crystal points after bonding, excellent bonding performance, anti-rebound, good long-term stability, and is not only suitable for traditional flat panel touch screens but also suitable for 2.5D / 3D curved screens, and solves the problems existing in the manufacturing process and products of the touch screen industry. DETAILED DESCRIPTION

[0026] In order to more clearly describe the present application, the present application is further described below in combination with examples.

[0027] Example 1

[0028] (1) Preparation of optical grade silicone pressure sensitive adhesive and single-sided adhesive tape: 21 parts of silicone rubber with a molecular weight of 600,000 was added to 18 parts of ethyl acetate, 18 parts of toluene into the opening container and stirred for 0.5-3 hours until the silicone rubber was completely dissolved, then 2 parts of silicone resin, 0.15 parts of anchor agent, 0.2 parts of catalyst were added in proportion according to the formula and stirred uniformly to obtain colorless or light yellow silicone pressure sensitive adhesive. The above optical grade silicone pressure sensitive adhesive was coated on a 50 μm PET substrate layer, the adhesive film thickness was 30 μm, dried at 105±5℃ for 2 min, then dried at 150±5℃ for 2 min to form a pressure sensitive adhesive layer, and then the optical grade pressure sensitive adhesive tape was obtained by compounding the release film layer.

[0029] (2) Preparation of optical grade acrylate pressure sensitive adhesive and double-sided adhesive tape:

[0030] 40 parts of ethyl acetate solvent was loaded into a reaction kettle with a thermometer, condenser and emulsifying tank, 20 parts of isooctyl acrylate, 4.2 parts of vinyl acetate, 1.5 parts of acrylic acid, 1.5 parts of dibutyl itaconate, 8 parts of toluene and 20 parts of ethyl acetate were mixed uniformly and then added to the reaction kettle; nitrogen was introduced into the reaction kettle, stirring was started and heating was started, after heating to 78℃, 0.04 parts of azobisisobutyronitrile initiator dissolved in ethyl acetate was added, the reaction was controlled at 78-79℃ for 90 minutes; 15 parts of isooctyl acrylate, 2 parts of vinyl acetate, 2 parts of hydroxyethyl acrylate, 1.5 parts of dibutyl itaconate, 0.08 parts of azobisisobutyronitrile initiator dissolved in ethyl acetate were added to the emulsifying tank and stirred uniformly, and then dropped for 90 minutes, and then 0.04 parts of azobisisobutyronitrile initiator dissolved in ethyl acetate was added, and the dropping was completed within 10 minutes, and then the temperature was kept for 3-5 hours, and then the solvent toluene and ethyl acetate were added to dilute to 40%-45% solid content, and then a light yellow transparent viscous acrylate pressure sensitive adhesive liquid was obtained.

[0031] When the adhesive was adjusted, 70 parts of the above optical grade acrylate pressure sensitive adhesive, 1.5 parts of epoxy curing agent and 20 parts of solvent were added to the opening container and stirred uniformly, and then coated on the optical grade pressure sensitive adhesive tape single-sided substrate layer, the adhesive film thickness was 40 μm, dried at 105±5℃ for 2 min to form a pressure sensitive adhesive layer, and then the optical grade pressure sensitive adhesive tape was obtained by compounding the release film layer.

[0032] Example 2

[0033] (1) Preparation of optical grade silicone pressure sensitive adhesive and adhesive tape single side: 19 parts of silicone rubber with a molecular weight of 800,000 was added to 18 parts of ethyl acetate, 18 parts of toluene into the opening glue container and stirred for 0.5-3 hours until the silicone rubber was completely dissolved, then 4 parts of silicone resin, 0.15 parts of anchor agent, 0.2 parts of catalyst were added in proportion according to the formula and stirred uniformly to obtain colorless or light yellow silicone pressure sensitive adhesive. The above optical silicone pressure sensitive adhesive was coated on the 50 μm PET substrate layer, the adhesive film thickness was 30 μm, dried at 105±5℃ for 2 min, then dried at 150±5℃ for 2 min to form a pressure sensitive adhesive layer, and the optical pressure sensitive adhesive tape single side was obtained by compounding the release film layer.

[0034] (2) Preparation of optical grade acrylate pressure sensitive adhesive and adhesive tape double side:

[0035] 40 parts of ethyl acetate solvent was loaded into a reaction kettle with a thermometer, condenser and emulsifying tank, 16 parts of isooctyl acrylate, 4.2 parts of vinyl acetate, 1.5 parts of acrylic acid, 1.5 parts of monobutyl itaconate, 4 parts of isobornyl acrylate, 8 parts of toluene and 20 parts of ethyl acetate were mixed uniformly and then added to the reaction kettle; nitrogen was introduced into the reaction kettle, stirring was started and heating was started, the temperature was raised to 78℃, then 0.04 parts of azobisisobutyronitrile initiator dissolved in ethyl acetate was added, the reaction was carried out for 90 minutes, and the reaction temperature was controlled at 78-79℃; 15 parts of isooctyl acrylate, 2 parts of vinyl acetate, 2 parts of hydroxyethyl acrylate, 1.5 parts of dibutyl itaconate, 0.08 parts of azobisisobutyronitrile initiator dissolved in ethyl acetate were added to the emulsifying tank and stirred uniformly, then the dropping was started and completed in 90 minutes, 0.04 parts of azobisisobutyronitrile initiator dissolved in ethyl acetate was added for 3-5 hours of heat preservation, then the solvent toluene and ethyl acetate were added to dilute to 40%-45% solid content, and a light yellow transparent viscous acrylate pressure sensitive adhesive liquid was obtained.

[0036] When the glue was adjusted, 70 parts of the above optical grade acrylate pressure sensitive adhesive, 1.5 parts of epoxy curing agent and 20 parts of solvent were added to the opening glue container and stirred uniformly, then coated on the optical pressure sensitive adhesive tape single side substrate layer, the adhesive film thickness was 40 μm, dried at 105±5℃ for 2 min to form a pressure sensitive adhesive layer, and the optical pressure sensitive adhesive tape was obtained by compounding the release film layer.

[0037] Example 3

[0038] (1) Preparation of optical grade silicone pressure sensitive adhesive and adhesive tape single side: 15 parts of silicone rubber with a molecular weight of 600,000 was added to 18 parts of ethyl acetate, 18 parts of toluene into the opening glue container and stirred for 0.5-3 hours until the silicone rubber was completely dissolved, then 8 parts of silicone resin, 0.15 parts of anchor agent, 0.2 parts of catalyst were added in proportion according to the formula and stirred uniformly to obtain colorless or light yellow silicone pressure sensitive adhesive. The above optical silicone pressure sensitive adhesive was coated on the 50 μm PET substrate layer, the adhesive film thickness was 30 μm, dried at 105±5℃ for 2 min, then dried at 150±5℃ for 2 min to form a pressure sensitive adhesive layer, and the optical grade pressure sensitive adhesive tape single side was obtained by compounding the release film layer.

[0039] (2) Preparation of optical acrylate pressure sensitive adhesive and adhesive tape single side:

[0040] 40 parts of ethyl acetate solvent was loaded into a reaction kettle with a thermometer, condenser and emulsifying tank, 16 parts of isooctyl acrylate, 4.2 parts of vinyl acetate, 1.5 parts of acrylic acid, 1.5 parts of dibutyl itaconate, 4 parts of lauryl acrylate, 8 parts of toluene and 20 parts of ethyl acetate were mixed uniformly and then added to the reaction kettle; nitrogen was introduced into the reaction kettle, stirring was started and heating was started, the temperature was raised to 78℃, then 0.04 parts of azobisisobutyronitrile initiator dissolved in ethyl acetate was added, the reaction was carried out for 90 minutes, the reaction temperature was controlled at 78-79℃; 15 parts of isooctyl acrylate, 2 parts of vinyl acetate, 2 parts of hydroxyethyl acrylate, 1.5 parts of dibutyl itaconate, 0.08 parts of azobisisobutyronitrile initiator dissolved in ethyl acetate were added to the emulsifying tank and stirred uniformly, then the dropping was started and completed in 90 minutes, 0.04 parts of azobisisobutyronitrile initiator dissolved in ethyl acetate was added for 10 minutes, then the temperature was kept for 3-5 hours, then the solvent toluene and ethyl acetate were added to dilute to 40%-45% solid content, and a light yellow transparent viscous acrylate pressure sensitive adhesive liquid was obtained.

[0041] When the glue was adjusted, 70 parts of the above optical grade acrylate pressure sensitive adhesive, 1.5 parts of epoxy curing agent and 20 parts of solvent were added to the opening glue container and stirred uniformly, then coated on the optical grade pressure sensitive adhesive tape single side substrate layer, the adhesive film thickness was 40 μm, dried at 105±5℃ for 2 min to form a pressure sensitive adhesive layer, and the optical grade pressure sensitive adhesive tape was obtained by compounding the release film layer.

[0042] Example 4

[0043] (1) Preparation of optical grade silicone pressure sensitive adhesive and adhesive tape single side: 17 parts of silicone rubber with a molecular weight of 600,000 was added to 18 parts of ethyl acetate, 18 parts of toluene into the opening glue container and stirred for 0.5-3 hours until the silicone rubber was completely dissolved, then 6 parts of silicone resin, 0.15 parts of anchor agent, 0.2 parts of catalyst were added in proportion according to the formula and stirred uniformly to obtain colorless or light yellow silicone pressure sensitive adhesive. The above optical silicone pressure sensitive adhesive was coated on the 50 μm PET substrate layer, the adhesive film thickness was 30 μm, dried at 105±5℃ for 2 min, then dried at 150±5℃ for 2 min to form a pressure sensitive adhesive layer, and the optical grade pressure sensitive adhesive tape single side was obtained by compounding the release film layer.

[0044] (2) Preparation of optical acrylate pressure sensitive adhesive and adhesive tape single side:

[0045] 40 parts of ethyl acetate solvent was loaded into a reaction kettle with a thermometer, condenser and emulsifying tank, 16 parts of isooctyl acrylate, 4.2 parts of vinyl acetate, 1.5 parts of acrylic acid, 1.5 parts of dibutyl itaconate, 2 parts of lauryl acrylate, 2 parts of isobornyl acrylate, 8 parts of toluene and 20 parts of ethyl acetate were mixed uniformly and then added to the reaction kettle; nitrogen was introduced into the reaction kettle, stirring was started and heating was started, the temperature was raised to 78℃, then 0.04 parts of azobisisobutyronitrile initiator dissolved in ethyl acetate was added, the reaction was carried out for 90 minutes, and the reaction temperature was controlled at 78-79℃; 15 parts of isooctyl acrylate, 2 parts of vinyl acetate, 2 parts of hydroxyethyl acrylate, 1.5 parts of dibutyl itaconate, 0.08 parts of azobisisobutyronitrile initiator dissolved in ethyl acetate were added to the emulsifying tank and stirred uniformly, then the dropping was started and completed in 90 minutes, 0.04 parts of azobisisobutyronitrile initiator dissolved in ethyl acetate was added for 3h, then 0.04 parts of azobisisobutyronitrile initiator dissolved in ethyl acetate was added for 10 minutes, and the temperature was kept for 3-5h, then the solvent toluene and ethyl acetate were added to dilute to 40%-45% solid content, and a light yellow transparent viscous acrylate pressure sensitive adhesive liquid was obtained.

[0046] When the glue is adjusted, 70 parts of the above optical grade acrylate pressure sensitive adhesive, 1.5 parts of epoxy curing agent and 20 parts of solvent are added to the opening glue container and stirred uniformly, then coated on the optical grade pressure sensitive adhesive tape single side substrate layer, the adhesive film thickness is 40 μm, dried at 105±5℃ for 2 min to form a pressure sensitive adhesive layer, and the optical grade pressure sensitive adhesive tape finished product is obtained by compounding the release film layer.

[0047] Comparative Example 1

[0048] (1) Preparation of optical grade silicone pressure-sensitive adhesive and single-sided adhesive tape: 15 parts of silicone rubber with a molecular weight of 600,000 were added to 18 parts of ethyl acetate and 18 parts of toluene in a glue opening container and stirred for 0.5-3 hours until the silicone rubber was completely dissolved. Then, 8 parts of silicone resin, 0.15 parts of anchor agent, and 0.2 parts of catalyst were added in the proportion of the formula and stirred uniformly to obtain colorless or light yellow silicone pressure-sensitive adhesive. The optical silicone pressure-sensitive adhesive was coated on a 50 μm PET substrate layer, the adhesive film thickness was 30 μm, and the adhesive tape was dried at 105±5°C for 2 min and then at 150±5°C for 2 min to form a pressure-sensitive adhesive layer, and the optical grade pressure-sensitive adhesive tape was obtained by combining the release film layer.

[0049] (2) Preparation of optical acrylate pressure-sensitive adhesive and double-sided adhesive tape:

[0050] 40 parts of ethyl acetate solvent were loaded into a reaction kettle with a thermometer, condenser, and emulsifying tank. 21.5 parts of isooctyl acrylate, 4.2 parts of vinyl acetate, 1.5 parts of acrylic acid, 8 parts of toluene, and 20 parts of ethyl acetate were mixed uniformly and then added to the reaction kettle. Nitrogen was introduced into the reaction kettle, stirring was started, and heating was started. When the temperature reached 78°C, 0.04 parts of azobisisobutyronitrile initiator dissolved in ethyl acetate was added, and the reaction was controlled at 78-79°C for 90 minutes. 16.5 parts of isooctyl acrylate, 2 parts of vinyl acetate, 2 parts of hydroxyethyl acrylate, and 0.08 parts of azobisisobutyronitrile initiator dissolved in ethyl acetate were added to the emulsifying tank and stirred uniformly. The dropwise addition was started and completed in 90 minutes. Then, 0.04 parts of azobisisobutyronitrile initiator dissolved in ethyl acetate was added, and the dropwise addition was completed in 10 minutes. The reaction was continued for 3-5 hours. Solvent toluene and ethyl acetate were added to dilute to 40%-45% solid content. A light yellow transparent viscous acrylate pressure-sensitive adhesive liquid was obtained.

[0051] When the glue was adjusted, 70 parts of the above optical grade acrylate pressure-sensitive adhesive, 1.5 parts of epoxy curing agent, and 20 parts of solvent were added to the glue opening container and stirred uniformly. Then, the adhesive film thickness was 40 μm, and the adhesive tape was dried at 105±5°C for 2 min to form a pressure-sensitive adhesive layer. The optical grade pressure-sensitive adhesive tape was obtained by combining the release film layer.

[0052] The optical grade double-sided adhesive tape was prepared by the above-mentioned example method, and the corresponding performance test data are shown in Table 1 below.

[0053] Performance test method

[0054] 1. 180° peeling force: According to the standard of GB / T 2792—2014 “Test method for peeling strength of adhesive tape”, the peeling force tensile testing machine was used to measure the adhesive tape width of 25 mm, and the 25 μm PET substrate layer was used as backing reinforcement, and the peeling rate was 300 mm / min.

[0055] 2. Initial tack: According to GB / T 4852-2002 "Test Method for Initial Tack of Pressure-Sensitive Adhesive Tape by Rolling Ball Method", the initial tack was measured by an initial tack tester at an inclination angle of 30°.

[0056] 3. Holding power: According to GB / T 4851-2014, the holding power was measured by vertically hanging the sample to be adhered with the pressure-sensitive adhesive tape on a test rack, and hanging a weight of a specified mass. The displacement of the sample to be adhered or the time for the sample to be adhered to completely separate was used to represent the holding power of the pressure-sensitive adhesive.

[0057] 4. Air release: In a dust-free environment, the release film on the surface of the optical-grade acrylic pressure-sensitive adhesive was gently torn off, and then was attached to a black glass plate with a smooth surface. Then, the release film on the surface of the optical-grade silicone pressure-sensitive adhesive was torn off, and then a special touch screen test glass was attached to the surface of the silicone pressure-sensitive adhesive. The wetting speed and effect were observed, and the film attachment operation was repeated.

[0058] Air release A+: The automatic air release area was 90% or more, the air release time was 1-10 s, and there was no bubble, white edge, indentation, or incomplete air release after air release, which was determined as A+.

[0059] Air release A: The automatic air release area was 80% or more, the air release time was 10-20 s, and there were some bubbles, white edges, indentations, or incomplete air release after air release, which was determined as A.

[0060] Air release A-: less than the A index, which was determined as A-.

[0061] 5. Light transmittance / haze: The light transmittance / haze of the double-sided adhesive tape sample was tested by a light haze meter. The higher the light transmittance value, the lower the haze value, and the better the optical performance of the sample.

[0062] Table 1-Test results of optical-grade double-sided adhesive tape

[0063]

[0064] Note: The single side in the table represents the silicone data of the double-sided adhesive tape, and the double side represents the acrylic pressure-sensitive adhesive data of the double-sided adhesive tape.

[0065] According to the test results, the optical-grade double-sided adhesive tape prepared by the application has good light transmittance, good air release, no "snowflake" crystal points, anti-rebound, excellent adhesion, and good long-term stability.

[0066] The preferred embodiments of the application are described in detail above, of course, the application can also use different forms from the above embodiments, and the equivalent changes or corresponding modifications made by those skilled in the art without deviating from the spirit of the application should be within the protection scope of the application.

Claims

1. An application of optical grade double-sided adhesive tape to an assembly of a touch screen glass display module, characterized in that The touch screen is a 2.5D or 3D curved screen, and the optical-grade double-sided adhesive tape comprises an application adhesive film layer and a release film layer, characterized in that the application adhesive film layer is a "sandwich" structure composed of an optical-grade acrylic pressure-sensitive adhesive layer, an optical-grade PET film layer and an optical-grade silicone pressure-sensitive adhesive layer. The optical-grade acrylic pressure-sensitive adhesive layer comprises the following components by mass fraction: Acrylate soft monomer 30-50 parts; Acrylate hard monomer 3-15 parts; Alkyl itaconate monomer 2-10 parts; Acrylic functional monomer 0-5 parts; Initiator 0.1-2 parts; Solvent 40-70 parts; The alkyl itaconate monomer comprises one or more of dibutyl itaconate and monobutyl itaconate; The optical-grade silicone pressure-sensitive adhesive layer comprises the following components by mass fraction: Silicone rubber 10-40 parts; Silicone resin 1-20 parts; Anchor agent 0.05-5 parts; Catalyst 0.02-3 parts; Solvent 40-70 parts; The silicone rubber is hydroxyl-terminated polydimethylsiloxane with a molecular weight of 500,000-1,200,000 and a reactive end group functional group content of 1%-2%; the silicone resin is MQ type with an M group to Q group ratio of 0.9-1.2 and a reactive end group functional group content of 1%-1.5%.

2. Use according to claim 1, wherein The acrylate soft monomer comprises one or more of butyl acrylate, isooctyl acrylate, lauryl acrylate and isobornyl acrylate; the acrylate hard monomer comprises one or more of methyl methacrylate, styrene and vinyl acetate; and the acrylic functional monomer comprises one or more of acrylic acid, hydroxyethyl acrylate and hydroxypropyl acrylate.

3. Use according to claim 1, characterized in that, The anchor agent is a polysiloxane additive type anchor agent containing acyloxy and epoxy groups; and the catalyst is a platinum or organotin catalyst.

4. Use according to any one of claims 1 to 3, characterized in that, The preparation method of the optical-grade acrylic pressure-sensitive adhesive comprises the following steps: adding part of the acrylate soft monomer, the acrylate hard monomer, the acrylic functional monomer, the alkyl itaconate monomer and an appropriate amount of solvent into a reaction kettle provided with a thermometer, a condenser and an emulsifying tank, controlling the monomer content to be 50%-65%, introducing nitrogen into the reaction kettle, dissolving an initiator, adding 40% of the initiator solution into the reaction kettle, starting stirring and heating, heating to 78-80°C and reacting for 90 minutes, then starting dropwise addition of 40% of the initiator solution and the remaining monomer solution, completing dropwise addition in 90 minutes, keeping warm for 3 hours, then dropwise adding 20% of the initiator solution, completing dropwise addition in 5-10 minutes, continuing to keep warm for 3-5 hours, diluting to 40%-45% solid content, and obtaining colorless and transparent viscous acrylic pressure-sensitive adhesive.

5. The application of any one of claims 1 to 3, wherein the optical-grade double-sided adhesive tape is used for bonding an optical-grade double-sided adhesive tape and a 2.5D or 3D curved screen. The preparation method of the optical-grade silicone pressure-sensitive adhesive comprises the following steps: adding the silicone rubber, ethyl acetate and toluene into an opening container and stirring for 0.5-3 hours until the silicone rubber is completely dissolved, then adding the silicone resin, the anchor agent and the catalyst in the formula proportion in sequence, fully stirring and uniformly, and obtaining colorless or light yellow silicone pressure-sensitive adhesive.

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