Easily stripped and adhesive-residue-free FPC fixing adhesive tape and preparation method thereof

Abstract

The invention relates to the technical field of adhesive tapes, and provides an easy-to-peel and adhesive-residue-free FPC fixing adhesive tape and a preparation method thereof.The FPC fixing adhesive tape sequentially comprises a PI base material layer, a silica gel pressure-sensitive adhesive layer and a release layer from bottom to top, and the silica gel pressure-sensitive adhesive layer is prepared from, by weight, 35-50 parts of polysiloxane, 10-25 parts of modified MQ resin, 1-5 parts of a curing agent, 1-5 parts of a curing agent and 1-5 parts of a curing agent. The high-temperature-resistant coating is prepared from the following components in parts by weight: 3-6 parts of a silane coupling agent, 2-5 parts of a platinum catalyst, 2-5 parts of modified white carbon black, 1.5-3.5 parts of an inhibitor and 50-70 parts of an organic solvent. The FPC fixing adhesive tape is good in temperature resistance, high in cleanliness, good in flatness, good in viscosity and excellent in exhaust performance, meanwhile, the FPC fixing adhesive tape is easy to punch, die-cut and process, easy to strip, free of adhesive residues and suitable for the fields of electroplating, ultrahigh-temperature baking varnish, powder spraying and chip element end electrode processing.

Description

Technical Field

[0001] The invention belongs to the technical field of adhesive tapes, and in particular relates to an FPC fixing adhesive tape which is easy to peel off and has no residual adhesive, and a preparation method thereof. Background Art

[0002] With the rapid development of modern industrial technology, especially in the fields of electronics, automobiles, aerospace, etc., the performance requirements for materials are getting higher and higher. In these fields, the fixation and protection of flexible circuit boards (FPCs) have become particularly important. During the production and maintenance of FPCs, a tape that can fix its position is required. This tape must not only be easy to peel off, but also must not leave residual glue on the FPC when removed, so as not to affect the performance and appearance of the circuit board. Traditional FPC fixing tapes usually have some problems, such as insufficient high temperature resistance, unstable viscosity, poor exhaust, or residual glue left on the FPC when peeled off. These problems limit its application in high-end electronic manufacturing.

[0003] Chinese patent CN 103834349 B discloses a degassing organic silicone adhesive, which is composed of the following substances in percentage by mass: organic silicone adhesive 40-50%; hydroxy polysiloxane 2-3%; catalyst 3-5%; silane coupling agent KH560 1-1.5%; bis(dioctyloxypyrophosphate)ethylene titanate 1-1.5%; inhibitor 2-5%; tackifying resin 15-30%; carbon dioxide 10-15%. The organic silicone adhesive of this invention has good degassing and adsorption properties, and the micropores are hollow and have the function of adsorbing small molecules, which solves the problem of poor degassing of existing organic silicone adhesives. However, this invention does not involve research on high temperature resistance, and the temperature resistance may not meet the requirements of working in ultra-high temperature environments.

[0004] Therefore, there is an urgent need for an FPC fixing tape that is easy to peel and has no residual adhesive, so that it can have excellent high temperature resistance. Summary of the invention

[0005] In view of the existing technical problems, the purpose of the present invention is to provide an FPC fixing tape that is easy to peel and has no residual adhesive and a preparation method thereof. The FPC fixing tape of the present invention has good temperature resistance, high cleanliness, good flatness, good viscosity, and excellent exhaust performance. At the same time, the FPC fixing tape is easy to punch and die-cut, easy to peel, and has no residual adhesive, and is suitable for electroplating, ultra-high temperature baking paint, powder spraying, and chip component end electrode processing.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] On one hand, the present invention provides an FPC fixing tape that is easy to peel off and has no residual adhesive. The FPC fixing tape comprises, from bottom to top, a PI substrate layer, a silicone pressure-sensitive adhesive layer and a release layer. The silicone pressure-sensitive adhesive layer is prepared by including the following raw materials in parts by weight: 35-50 parts of polysiloxane, 10-25 parts of modified MQ resin, 3-6 parts of silane coupling agent, 2-5 parts of platinum catalyst, 2-5 parts of modified white carbon black, 1.5-3.5 parts of inhibitor, and 50-70 parts of organic solvent.

[0008] The reaction mechanism and effects of the present invention are as follows:

[0009] 1.MQ silicone resin is a silicone resin with excellent low temperature resistance, film-forming properties and flexibility, and is widely used in polysiloxane pressure-sensitive adhesives; however, the heat resistance of MQ silicone resin needs to be further improved so that it can be used in extremely high temperature environments.

[0010] The present invention uses a coupling agent to modify MQ silicone resin, introduces a furan ring and a urea structure, on the one hand, the aromaticity of the furan ring gives the MQ silicone resin good thermal stability; on the other hand, the diamine structure and large steric hindrance of the urea group will increase the reactivity of the methoxy group and promote curing, thereby accelerating the curing rate of the pressure-sensitive adhesive and improving the coating efficiency; at the same time, the urea group has a strong polarity, thereby improving the adhesion of the tape to various materials such as metals and plastics, and the MQ silicone resin component therein has good compatibility with non-polar materials, and has good adhesion to non-polar materials such as silicone and polytetrafluoroethylene. Therefore, the silicone pressure-sensitive adhesive of the present invention has excellent adhesion and suitable peel strength to various polar or non-polar substrates, so that the two properties of adhesion and peel strength reach a reasonable balance range. In addition, the applicant optimizes the viscosity by regulating the ratio of polysiloxane and modified MQ resin, and then introduces a silane coupling agent to further improve the adhesion of the silicone pressure-sensitive adhesive layer to the substrate.

[0011] 2. Silica gel is a white, non-toxic, amorphous, fine powdered inorganic silicon compound with good chemical stability and high temperature resistance. The present invention uses unsaturated silane coupling agent, 1,4-butanediol diacrylate and itaconic anhydride to jointly modify silica gel, so that silica gel can be better dispersed in the system and play its role of high temperature resistance. On the one hand, the unsaturated silane coupling agent introduces ester bonds and double bonds after combining with silica gel through silicon-hydrogen bonds; on the other hand, the applicant uses the addition reaction of unsaturated double bonds to make 1,4-butanediol diacrylate and itaconic anhydride form a uniform and effective isolation network when the silicone oil base encounters high temperature, which can absorb heat in time, quickly cool down and isolate the air, which is beneficial to improve the high temperature resistance of the FPC fixing tape. In addition, modified silica gel as a filler can improve the cohesion and thermal stability of the silicone pressure-sensitive adhesive layer, while reducing impurities in the adhesive layer, thereby improving the cleanliness.

[0012] 3. The PI substrate layer, silicone pressure-sensitive adhesive layer and release layer of the present invention can be coated evenly, and the release force is stable with a small variation range, which helps to maintain the overall flatness; at the same time, the PI substrate layer has good mechanical properties and can be easily die-cut.

[0013] 4. The silicone pressure-sensitive adhesive layer of the present invention has good self-bubble exhaust performance, can quickly and effectively exhaust air during lamination, and the edge of the tape is not easy to warp after lamination, so that the tape has excellent flatness and sealing properties.

[0014] In some embodiments, the silane coupling agent is a combination of 3-(2,3-epoxypropyloxy)propyltrimethoxysilane and vinyltrimethoxysilane.

[0015] Preferably, the mass ratio of 3-(2,3-epoxypropoxy)propyltrimethoxysilane to vinyltrimethoxysilane is (2-4):1.

[0016] In some embodiments, the method for preparing the modified MQ resin comprises the following steps:

[0017] Q1. Mix 3-amino-1-(furan-2-ylmethyl)urea and N,N-dimethylacetamide to obtain a liquid; add dihydro-3-[3-(triethoxysilyl)propyl]furan-2,5-dione and N,N-dimethylacetamide to a reaction kettle, stir, add the liquid dropwise in an ice-water bath at 0-5°C while stirring, react at room temperature for 18-24h after the addition is completed, add triethylamine, stir, add fluoroacetic anhydride, react at room temperature for 18-24h, rotary evaporate, and distill under reduced pressure to obtain a coupling agent;

[0018] Q2. Mix hexamethyldisiloxane, ethyl orthosilicate, toluene and hydrochloric acid, stir for 0.5-1.5h, add pure water, raise the temperature to 95-105℃ after the addition, react for 5-6h, lower the temperature to 80-90℃, drop the coupling agent, add platinum catalyst, react for 1.5-2.5h, add sodium bicarbonate aqueous solution to adjust the pH to 6-7, filter, extract with toluene, wash, and rotary evaporate to obtain modified MQ resin.

[0019] In some embodiments, the molar ratio of dihydro-3-[3-(triethoxysilyl)propyl]furan-2,5-dione to 3-amino-1-(furan-2-ylmethyl)urea in step Q1 is 1:(1.05-1.15).

[0020] In some embodiments, the mass ratio of tetraethyl orthosilicate, hexamethyldisiloxane, and coupling agent in step Q2 is 1: (0.65-0.85): (0.75-0.95).

[0021] In some embodiments, the method for preparing the modified silica comprises the following steps:

[0022] T1. The unsaturated silane coupling agent and the mixed solvent are mixed and stirred to obtain a solution;

[0023] T2. The solution obtained in step T1 and white carbon black are added to a reaction kettle, heated to 50-60 ° C, stirred for 3-5h, filtered, washed, and dried to obtain a reactant;

[0024] T3. Add the reactants obtained in step T2, 1,4-butanediol diacrylate, itaconic anhydride and azobisisobutyronitrile into the reactor, heat to 70-85°C, react for 3-4h, filter, wash and dry to obtain modified silica.

[0025] In some embodiments, the mass ratio of the unsaturated silane coupling agent to white carbon black in the solution in step T2 is (0.1-0.3):1.

[0026] In some embodiments, the mass ratio of the reactant, 1,4-butanediol diacrylate and itaconic anhydride in step T3 is 1:(0.25-0.32):(0.1-0.16).

[0027] In some embodiments, the inhibitor is any one or more of acetylene cyclohexanol, maleic alcohol, and propargyl alcohol.

[0028] In some embodiments, the organic solvent is any one or more of ethanol, n-propanol, isopropanol, tert-butanol, propylene glycol ethyl ether, propylene glycol butyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, dipropylene glycol ethyl ether, dipropylene glycol butyl ether, tetrahydrofuran, cyclohexanone, dimethyl phthalate and isobutane.

[0029] In some embodiments, the release layer is a single silicon release layer.

[0030] Another aspect of the present invention provides a method for preparing an easily peelable and adhesive-free FPC fixing tape, comprising the following steps:

[0031] S1. The polysiloxane, modified MQ resin, silane coupling agent, platinum catalyst, inhibitor, modified silica, organic solvent are mixed and stirred to obtain a silicone pressure-sensitive adhesive;

[0032] S2. The silicone pressure-sensitive adhesive prepared in step S1 is applied to the lower surface of the release layer by a coating machine, the thickness is adjusted, and dried to obtain a silicone pressure-sensitive adhesive layer;

[0033] S3. Compounding the PI substrate layer with the lower surface of the silicone pressure-sensitive adhesive layer obtained in step S2, curing, and cutting to obtain an FPC fixing tape.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] 1. The FPC fixing tape of the present invention has good temperature resistance, high cleanliness, good flatness, good viscosity, and excellent exhaust performance. At the same time, the FPC fixing tape is easy to punch and die-cut, easy to peel, and has no residual glue. It is suitable for electroplating, ultra-high temperature baking paint, powder spraying, and chip component end electrode processing fields.

[0036] 2. The modified MQ silicone resin of the present invention has excellent adhesion and suitable peel strength to a variety of polar or non-polar substrates, and can also effectively improve high temperature resistance.

[0037] 3. The modified silica of the present invention has good dispersibility and chemical stability, thereby improving the high temperature resistance of the FPC fixing tape. DETAILED DESCRIPTION

[0038] The present invention will be described below in conjunction with specific embodiments. It should be noted that the following embodiments are examples of the present invention and are only used to illustrate the present invention, rather than to limit the present invention. Other combinations and various modifications within the concept of the present invention may be performed without departing from the spirit or scope of the present invention.

[0039] According to the ratios of the raw materials and the preparation methods specified in the following examples and comparative examples, various FPC fixing tapes were prepared.

[0040] In order to facilitate those skilled in the art to implement the present invention, some raw material manufacturers of the embodiments and comparative examples are described as follows:

[0041] α,ω-dihydroxy polysiloxane: purchased from Qingdao Baisenmao New Materials Co., Ltd., model BSM207;

[0042] Platinum catalyst: purchased from Wuhan Lanabai Pharmaceutical Chemical Co., Ltd.;

[0043] MQ resin: purchased from Shandong Bosheng Chemical Co., Ltd., model number AM-8080;

[0044] Hydrochloric acid: industrial grade, 36wt%;

[0045] Other raw materials are not specially specified and can be purchased from the market.

[0046] Preparation Example 1

[0047] The preparation method of modified MQ resin A comprises the following steps:

[0048] Q1. Mix 0.22 mol of 3-amino-1-(furan-2-ylmethyl)urea and 400 mL of N,N-dimethylacetamide to obtain a liquid; add 0.2 mol of dihydro-3-[3-(triethoxysilyl)propyl]furan-2,5-dione and 400 mL of N,N-dimethylacetamide to a reactor, stir for 30 min, add the liquid dropwise in a 2°C ice-water bath while stirring, control the temperature below 10°C, react at room temperature for 20 h after the addition is completed, add 0.4 mol of triethylamine, stir for 30 min, add 0.4 mol of fluoroacetic anhydride, react at room temperature for 20 h, rotary evaporate, and distill under reduced pressure to obtain a coupling agent;

[0049] Q2. 18.8 g of hexamethyldisiloxane, 25 g of ethyl orthosilicate, 11 g of toluene and 6 g of hydrochloric acid were mixed, stirred for 1 h, 12.4 g of pure water was added dropwise, the temperature was raised to 100 ° C. after the addition was complete, the reaction was performed for 5 h, the temperature was lowered to 85 ° C., 21.3 g of the coupling agent obtained in step Q1 was added dropwise, 4 g of platinum catalyst was added, the reaction was performed for 2 h, and then 10 wt % of sodium bicarbonate aqueous solution was added to adjust the pH value to 6, filtered, extracted with toluene, washed with pure water until neutral, and distilled under reduced pressure to obtain modified MQ resin A.

[0050] Preparation Example 2

[0051] The preparation method of modified MQ resin B is the same as that of Preparation Example 1, and the amount of 3-amino-1-(furan-2-ylmethyl)urea added in step Q1 is 0.17 mol.

[0052] Preparation Example 3

[0053] The preparation method of modified MQ resin C is the same as that of Preparation Example 1, and the amount of coupling agent added in step Q2 is 16.3 g.

[0054] Preparation Example 4

[0055] The preparation method of modified silica A comprises the following steps:

[0056] T1. 20 g of unsaturated silane coupling agent KH-570, 10 ml of deionized water and 70 ml of methanol were mixed and stirred for 30 min to obtain a solution;

[0057] T2. The solution obtained in step T1 and 100 g of white carbon black were added to a reactor, heated to 55 ° C, stirred for 5 h, filtered, washed with methanol and deionized water three times each, and dried at 85 ° C for 6 h to obtain a reactant;

[0058] T3. Add 50 g of the reactant obtained in step T2, 14 g of 1,4-butanediol diacrylate, 6.5 g of itaconic anhydride, and 0.5 g of azobisisobutyronitrile to the reactor, heat to 78°C, react for 3.5 hours, filter, wash with deionized water three times, and dry at 95°C for 12 hours to obtain modified silica A.

[0059] Preparation Example 5

[0060] The preparation method of modified silica B is the same as that of Preparation Example 4, except that the amount of unsaturated silane coupling agent added in step T1 is 8 g.

[0061] Preparation Example 6

[0062] The preparation method of modified silica C is the same as that of Preparation Example 4, except that the amount of 1,4-butanediol diacrylate added in step T3 is 11 g.

[0063] Preparation Example 7

[0064] The preparation method of modified silica D is the same as that of Preparation Example 4, except that in step T1, an equal amount of silane coupling agent KH-560 is used to replace the unsaturated silane coupling agent KH-570.

[0065] Example 1

[0066] An easy-to-peel FPC fixing tape with no residual adhesive, the FPC fixing tape comprises a PI substrate layer, a silicone pressure-sensitive adhesive layer and a release layer from bottom to top, and the silicone pressure-sensitive adhesive layer is prepared by including the following raw materials in parts by weight: 42.5 parts of α,ω-dihydroxy polysiloxane, 17.5 parts of modified MQ resin A, 4.5 parts of silane coupling agent, 3.5 parts of platinum catalyst, 2.5 parts of acetylene cyclohexanol, 3.5 parts of modified white carbon black A, and 60 parts of isopropanol;

[0067] The silane coupling agent comprises the following raw materials: 3.4 parts of 3-(2,3-epoxypropoxy)propyltrimethoxysilane and 1.1 parts of vinyltrimethoxysilane;

[0068] The thickness of the PI substrate layer is 25 μm, the thickness of the silicone pressure-sensitive adhesive layer is 50 μm, and the thickness of the release layer is 50 μm;

[0069] The preparation method of the FPC fixing tape of this embodiment comprises the following steps:

[0070] S1. Mix α,ω-dihydroxy polysiloxane, modified MQ resin A, silane coupling agent, platinum catalyst, acetylene cyclohexanol, modified silica A, and isopropanol, and stir for 2h to obtain a silicone pressure-sensitive adhesive;

[0071] S2. The silicone pressure-sensitive adhesive prepared in step S1 is applied to the lower surface of the release layer by a coating machine, the thickness is adjusted, and the mixture is baked at 70° C. for 5 min to obtain a silicone pressure-sensitive adhesive layer;

[0072] S3. Compound the PI substrate layer on the lower surface of the silicone pressure-sensitive adhesive layer prepared in step S2, age at 50° C. for 60 h, and cut to obtain an FPC fixing tape.

[0073] Example 2

[0074] An easy-to-peel, adhesive-free FPC fixing tape, the FPC fixing tape comprising a PI substrate layer, a silicone pressure-sensitive adhesive layer and a release layer from bottom to top, the silicone pressure-sensitive adhesive layer comprising the following raw materials in parts by weight: 35 parts of α,ω-dihydroxy polysiloxane, 10 parts of modified MQ resin A, 3 parts of silane coupling agent, 2 parts of platinum catalyst, 1.5 parts of acetylene cyclohexanol, 2 parts of modified white carbon black A, and 50 parts of isopropanol;

[0075] The silane coupling agent comprises the following raw materials: 2 parts of 3-(2,3-epoxypropoxy)propyltrimethoxysilane and 1 part of vinyltrimethoxysilane;

[0076] The thickness of the PI substrate layer is 25 μm, the thickness of the silicone pressure-sensitive adhesive layer is 50 μm, and the thickness of the release layer is 50 μm.

[0077] The preparation method of the FPC fixing tape of this embodiment is the same as that of Embodiment 1.

[0078] Example 3

[0079] An easy-to-peel, adhesive-free FPC fixing tape, the FPC fixing tape comprising, from bottom to top, a PI substrate layer, a silicone pressure-sensitive adhesive layer and a release layer, the silicone pressure-sensitive adhesive layer comprising the following raw materials in parts by weight: 50 parts of α,ω-dihydroxy polysiloxane, 25 parts of modified MQ resin A, 6 parts of silane coupling agent, 5 parts of platinum catalyst, 3.5 parts of acetylene cyclohexanol, 5 parts of modified white carbon black A, and 70 parts of isopropanol;

[0080] The silane coupling agent comprises the following raw materials: 4.8 parts of 3-(2,3-epoxypropoxy)propyltrimethoxysilane and 1.2 parts of vinyltrimethoxysilane;

[0081] The thickness of the PI substrate layer is 25 μm, the thickness of the silicone pressure-sensitive adhesive layer is 50 μm, and the thickness of the release layer is 50 μm.

[0082] The preparation method of the FPC fixing tape of this embodiment is the same as that of Embodiment 1.

[0083] Example 4

[0084] An easy-to-peel, adhesive-free FPC fixing tape and a preparation method thereof, wherein the specific implementation manner is the same as that of Example 1, except that an equal amount of modified MQ resin B is used to replace modified MQ resin A.

[0085] Example 5

[0086] An easy-to-peel, adhesive-free FPC fixing tape and a preparation method thereof, wherein the specific implementation manner is the same as that of Example 1, except that an equal amount of modified MQ resin C is used to replace modified MQ resin A.

[0087] Example 6

[0088] An easy-to-peel, adhesive-free FPC fixing tape and a preparation method thereof, wherein the specific implementation manner is the same as that of Example 1, except that an equal amount of modified silica B is used to replace modified silica A.

[0089] Example 7

[0090] An easy-to-peel, adhesive-free FPC fixing tape and a preparation method thereof, wherein the specific implementation manner is the same as that of Example 1, except that an equal amount of modified silica C is used to replace modified silica A.

[0091] Example 8

[0092] An easy-to-peel, adhesive-free FPC fixing tape and a preparation method thereof, wherein the specific implementation manner is the same as that of Example 1, except that an equal amount of modified silica D is used to replace modified silica A.

[0093] Example 9

[0094] An easy-to-peel, adhesive-free FPC fixing tape and a preparation method thereof, wherein the specific implementation manner is the same as that of Example 1, except that 4.5 parts of vinyl trimethoxy silane are used to replace 3.4 parts of 3-(2,3-epoxypropoxy)propyl trimethoxy silane and 1.1 parts of vinyl trimethoxy silane.

[0095] Comparative Example 1

[0096] An easy-to-peel, adhesive-free FPC fixing tape and a preparation method thereof, wherein the specific implementation manner is the same as that of Example 1, except that an equal amount of MQ resin is used to replace the modified MQ resin A.

[0097] Comparative Example 2

[0098] An easy-to-peel, adhesive-free FPC fixing tape and a preparation method thereof, wherein the specific implementation manner is the same as that of Example 1, except that an equal amount of commercially available white carbon black is used to replace modified white carbon black A.

[0099] Effect evaluation:

[0100] The FPC fixing tapes prepared in the above-mentioned Examples 1-9 and Comparative Examples 1-2 were tested and analyzed, and the specific results are shown in Table 1.

[0101] Performance Test:

[0102] (1) Peel force: The 180° peel force performance test of SUS sheet was carried out according to ASTM D3330 pressure-sensitive tape peel force test standard;

[0103] (2) High temperature resistance: The adhesive surface was bonded to a SUS sheet and hot pressed at 180°C and 0.3 MPa for 30 min. The tape was then kept at 180°C for 1 h and cooled to room temperature. The tape was subjected to a shear force of 500 g and the time required for the tape to fall off the SUS sheet was measured in a 280°C oven.

[0104] (3) Removability: The test sheet is SUS / PE (sandwich structure with tape); the tape size is 12 mm × 110 mm, the pressing condition is 0.25 MPa, the pressure is maintained for 10 s, the immersion time is 24 h, the test environment is 23 ± 1 ° C, 50 ± 5% RH, the tape is pulled and removed at an angle of 30° and a removal rate of 300 mm / min. It is recorded whether the tape breaks during the removal process and whether there is residual adhesive on the sheet.

[0105] Table 1

[0106]

[0107] From the results in Table 1, it can be seen that the FPC fixing tapes prepared in Examples 1-3 have suitable peeling force, good removability, and a long high-temperature adhesion time, that is, good temperature resistance, and have good market value.

[0108] Examples 4-5 and Comparative Example 1 Compared with Example 1, when preparing the modified MQ resin, Example 4 changes the molar ratio of dihydro-3-[3-(triethoxysilyl)propyl]furan-2,5-dione and 3-amino-1-(furan-2-ylmethyl)urea, and the adhesion is weakened. Example 5 changes the mass ratio of tetraethyl orthosilicate, hexamethyldisiloxane and coupling agent, and the thermal stability of the modified MQ silicone resin decreases, which in turn affects the peel force and high-temperature adhesion time of the tape; Comparative Example 1 replaces the modified MQ resin A with an equal amount of MQ resin, which greatly reduces the high-temperature adhesion time, and thus the peel strength is reduced.

[0109] Examples 6-8 and Comparative Example 2 Compared with Example 1, when preparing modified silica, Example 6 changes the mass ratio of unsaturated silane coupling agent and silica, and the dispersibility is weakened. Example 7 changes the mass ratio of reactants, 1,4-butanediol diacrylate and itaconic anhydride, and the heat resistance decreases. Example 8 changes the type of silane coupling agent, and the cross-linking effect is weakened, which will affect the peeling force, removability and high-temperature adhesion time of the tape. Comparative Example 2 replaces modified silica A with an equal amount of silica, which affects the peeling force, removability and high-temperature adhesion time of the tape.

[0110] Compared with Example 1, Example 9 only uses one silane coupling agent, which is not conducive to the removal of the tape.

[0111] The above is only a preferred embodiment of the present invention and does not constitute any form of limitation to the present application. Although the present application is disclosed as above in the preferred embodiment, it is not intended to limit the present application. Any technician familiar with the profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution.

Claims

1. An easy-to-peel, adhesive-free FPC fixing tape, characterized in that: The FPC fixing tape comprises a PI substrate layer, a silicone pressure-sensitive adhesive layer and a release layer from bottom to top. The silicone pressure-sensitive adhesive layer is prepared by comprising the following raw materials in parts by weight: 35-50 parts of polysiloxane, 10-25 parts of modified MQ resin, 3-6 parts of silane coupling agent, 2-5 parts of platinum catalyst, 2-5 parts of modified white carbon black, 1.5-3.5 parts of inhibitor, and 50-70 parts of organic solvent.

2. The easy-to-peel, adhesive-free FPC fixing tape according to claim 1, characterized in that: The silane coupling agent is a composition of 3-(2,3-epoxypropoxy)propyltrimethoxysilane and vinyltrimethoxysilane.

3. The easy-to-peel, adhesive-free FPC fixing tape according to claim 1, characterized in that: The preparation method of the modified MQ resin comprises the following steps: Q1. Mix 3-amino-1-(furan-2-ylmethyl)urea and N,N-dimethylacetamide to obtain a liquid; add dihydro-3-[3-(triethoxysilyl)propyl]furan-2,5-dione and N,N-dimethylacetamide to a reaction kettle, stir, add the liquid dropwise in an ice-water bath at 0-5°C while stirring, react at room temperature for 18-24h after the addition is completed, add triethylamine, stir, add fluoroacetic anhydride, react at room temperature for 18-24h, rotary evaporate, and distill under reduced pressure to obtain a coupling agent; Q2. Hexamethyldisiloxane, ethyl orthosilicate, toluene and hydrochloric acid were mixed, stirred for 0.5-1.5h, and pure water was added dropwise. After the addition, the temperature was raised to 95-105°C, and the reaction was performed for 5-6h. The temperature was lowered to 80-90°C, and the coupling agent obtained in step Q1 was added dropwise. A platinum catalyst was added, and the reaction was performed for 1.5-2.5h. Then, an aqueous sodium bicarbonate solution was added to adjust the pH value to 6-7, filtered, extracted with toluene, washed, and rotary evaporated to obtain a modified MQ resin.

4. The easy-to-peel, adhesive-free FPC fixing tape according to claim 3, characterized in that: The molar ratio of dihydro-3-[3-(triethoxysilyl)propyl]furan-2,5-dione to 3-amino-1-(furan-2-ylmethyl)urea in step Q1 is 1:(1.05-1.15).

5. The easily peelable and adhesive-free FPC fixing tape according to claim 3, characterized in that: The mass ratio of tetraethyl orthosilicate, hexamethyldisiloxane and coupling agent in step Q2 is 1: (0.65-0.85): (0.75-0.95).

6. The easy-to-peel, adhesive-free FPC fixing tape according to claim 1, characterized in that: The preparation method of the modified white carbon black comprises the following steps: T1. The unsaturated silane coupling agent and the mixed solvent are mixed and stirred to obtain a solution; T2. The solution obtained in step T1 and white carbon black are added to a reaction kettle, heated to 50-60 ° C, stirred for 3-5h, filtered, washed, and dried to obtain a reactant; T3. Add the reactants obtained in step T2, 1,4-butanediol diacrylate, itaconic anhydride and azobisisobutyronitrile into the reactor, heat to 70-85°C, react for 3-4h, filter, wash and dry to obtain modified silica.

7. The easy-to-peel, adhesive-free FPC fixing tape according to claim 6, characterized in that: The mass ratio of the unsaturated silane coupling agent to white carbon black in the solution in step T2 is (0.1-0.3):

1.

8. The easily peelable and adhesive-free FPC fixing tape according to claim 6, characterized in that: The mass ratio of the reactant, 1,4-butanediol diacrylate and itaconic anhydride in step T3 is 1:(0.25-0.32):(0.1-0.16).

9. The easily peelable and adhesive-free FPC fixing tape according to claim 1, characterized in that: The inhibitor is any one or more of acetylene cyclohexanol, maleic alcohol and propynyl alcohol.

10. A method for preparing the easily peelable and adhesive-free FPC fixing tape according to any one of claims 1 to 9, characterized in that: The following steps are included: S1. The polysiloxane, modified MQ resin, silane coupling agent, platinum catalyst, inhibitor, modified silica, organic solvent are mixed and stirred to obtain a silicone pressure-sensitive adhesive; S2. The silicone pressure-sensitive adhesive prepared in step S1 is applied to the lower surface of the release layer by a coating machine, the thickness is adjusted, and dried to obtain a silicone pressure-sensitive adhesive layer; S3. Compounding the PI substrate layer with the lower surface of the silicone pressure-sensitive adhesive layer obtained in step S2, curing, and cutting to obtain an FPC fixing tape.

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