Silicon-acrylate adhesive, cotton and membrane composite material

Abstract

The invention belongs to the field of composite materials, and provides a silicon-acrylate adhesive, cotton and membrane material composite material. According to the invention, a four-layer composite structure design of the A-surface silica gel layer, the solvent-free curing isolation barrier layer, the composite carrier layer and the B-surface acrylate adhesive layer is adopted; the heterogeneous double-sided bonding performance that a high-solid-content low-viscosity coating window, an ultrathin solvent-free isolation layer and high-barrier migration resistance are achieved, the peeling strength of a surface A to silicone rubber is not lower than 6N / 25mm, and the lasting adhesion of a surface B to a metal base material is not lower than 24h is achieved; the technical problem that a traditional double-faced adhesive tape system is difficult to consider the ultrathin coating coiling process, the high cohesion creep resistance and the size stability under multiple thermal history conditions is solved, and the double-faced adhesive tape has wide application value.

Description

Technical Field

[0001] This invention relates to the field of functional composite materials, specifically to a composite material of silicone-acrylate adhesive, cotton, and membrane materials. Background Technology

[0002] With the increasing demands for performance in flexible adhesive materials from fields such as electronics manufacturing, automotive interiors, medical devices, and precision assembly, double-sided heterogeneous adhesive tapes, as key materials for achieving differentiated functions of "high-temperature resistant and peelable A-side + room-temperature durable adhesion B-side," demonstrate irreplaceable technical value in applications such as silicone protection for chip packaging, temporary fixation of thermal components, and layered application of medical dressings. The core performance requirements for these materials include: A-side must possess a high peel strength of 6N / 25mm or higher against silicone rubber or silicone foam to achieve reliable peeling without residue; B-side must maintain adhesion to metal substrates or engineering plastics for more than 24 hours to withstand long-term loads; simultaneously, the intermediate isolation barrier layer must be ultra-thin (5-10µm), with high barrier and anti-migration capabilities to prevent cross-contamination of the A / B side adhesives leading to performance degradation; and the overall material must maintain dimensional flatness and stability under multiple heat treatment conditions of 100-180℃. Meeting and developing these performance requirements is of great significance for improving the reliability of electronic products, expanding the application scope of automotive lightweighting, and promoting the safety of medical devices.

[0003] However, existing technologies have many shortcomings in meeting the aforementioned comprehensive performance requirements. Traditional double-sided adhesive systems mostly use solvent-based isolation layers, which have problems such as high energy consumption for coating and drying, and the risk of VOC emissions and cross-migration of adhesive layers due to residual solvents; some technologies use thick isolation layers (>15µm), which can improve barrier properties, but lead to excessive total thickness and reduced flexibility; silicone layers mostly use addition-type systems, which have low curing temperatures but poor penetration into cotton substrates, resulting in insufficient peel strength, while condensation-type systems have strong adhesion, but high-temperature curing (>150℃) can easily cause cotton to shrink and deform; acrylic ester adhesive layers using only UV curing are fast, but insufficient cohesion leads to reduced tack, while single thermosetting has strong cohesion but long curing time and is prone to yellowing; if the composite carrier layer uses only cotton, its temperature resistance is limited, and if only polyimide film is used, the cost is high and the air permeability is poor. For example, Chinese patent CN214032323U discloses an ultra-thin PET double-sided adhesive tape, but it suffers from insufficient barrier performance and excessive VOC emissions due to the use of solvent-based coating for the release layer. Similarly, Chinese patent CN109337029B discloses a high-wear-resistant TPU / silicone composite material and its preparation method, but it suffers from low peel strength to the cellulose substrate and poor high-temperature dimensional stability due to the use of an addition-type silicone layer. Therefore, there is an urgent need to develop a novel double-sided heterogeneous adhesive composite material that combines an ultra-thin solvent-free release layer, high-solids-content condensation-type silicone, UV-thermal dual-curing acrylate adhesive, and a cotton-polyimide composite carrier to simultaneously meet the comprehensive performance requirements of high peel strength, high tack, high barrier properties, and high dimensional stability. Summary of the Invention

[0004] The purpose of this invention is to provide a composite material of silicone-acrylate adhesive, cotton, and film materials, which solves the problem that double-sided heterogeneous adhesive systems cannot simultaneously achieve coating window, ultra-thin isolation with high barrier properties, heterogeneous bonding, and dimensional stability.

[0005] This invention employs a synergistic design of "condensation-type silica network + solvent-free ultra-thin isolation + silanized acrylate UV-thermal dual curing": hydroxyl-terminated polydimethylsiloxane and trimethylsiloxysilicate form a silica network, while 3-ureapropyltrimethoxysilane enhances cellulose wetting, achieving A-side peel strength ≥6N / 25mm; the silane-containing side-chain acrylate undergoes UV and thermal dual curing, synergistically with hydrogenated rosin pentaerythritol ester to achieve B-side adhesion ≥24h. This demonstrates the synergistic effect of multiple components.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A silicone-acrylate adhesive composite material with cotton and film, the composite material comprising a silicone layer on side A, an isolation barrier layer, a composite carrier layer and an acrylic adhesive layer on side B, wherein the isolation barrier layer is disposed between the silicone layer on side A and the composite carrier layer, and the isolation barrier layer is a solvent-free curing isolation barrier layer. The composite carrier layer includes at least a cotton layer, the main component of which is cellulose; when the composite carrier layer includes a membrane layer, the membrane layer is a polyimide film. The silicone layer on side A contains a silicon-oxygen condensation network and is formed by curing a silicone layer coating composition on side A. Wherein, the silicone layer on side A, away from the composite carrier layer, is covered with a first release film, and the acrylic adhesive layer on side B, away from the composite carrier layer, is covered with a second release film; Furthermore, the composite material satisfies the following structural parameters: the dry film thickness of the silicone layer on side A is 15 to 30 µm, the dry film thickness of the acrylate adhesive layer on side B is 25 to 35 µm, the thickness of the isolation barrier layer is 5 to 10 µm, the thickness of the composite carrier layer is 20 to 80 µm, the thickness of the first release film is 25 to 50 µm, and the thickness of the second release film is 25 to 50 µm.

[0007] Furthermore, based on the solid content of the silicone layer on side A, the silicone layer on side A comprises the following components: 40 to 70 parts by weight of α-hydroxyl-terminated polydimethylsiloxane; β-trimethylsiloxysilicate, 25 to 55 parts by weight; c3-ureapropyltrimethoxysilane, 1 to 8 parts by weight; d-Tetraethoxysilane, 1 to 12 parts by weight; e. Dibutyltin dilaurate, 0.01 to 0.60 parts by weight; f. Silicon dioxide, 0 to 5 parts by weight; The B-side acrylate adhesive layer is formed by curing a B-side acrylate adhesive layer coating composition, and based on the solids content of the B-side acrylate adhesive layer, the B-side acrylate adhesive layer comprises the following components: The solids content of acrylate copolymer intermediate IB is 55 to 90 parts by weight, wherein intermediate IB is an acrylate copolymer containing silane side groups; h-hydrogenated rosin pentaerythritol ester, 10 to 35 parts by weight; i1-Hydroxycyclohexylphenyl ketone, 0.05 to 1.00 parts by weight; j1,6-hexanediol diacrylate, 1 to 12 parts by weight; Benzoyl peroxide, 0.05 to 0.80 parts by weight; Furthermore, the silicone layer on side A includes intermediate IA, which is prepared according to the following standard operating procedure: A1. Raw material preparation: Weigh out 40 to 70 parts by weight of terminal hydroxyl polydimethylsiloxane, 25 to 55 parts of trimethylsiloxysilicate, 1 to 8 parts of 3-ureapropyltrimethoxysilane, 1 to 12 parts of tetraethoxysilane, 0.01 to 0.60 parts of dibutyltin dilaurate, 40 to 220 parts of n-heptane, 0.1 to 2.0 parts of water, and 0.01 to 0.50 parts of acetic acid, and provide nitrogen gas.

[0008] A2. Controlled hydrolysis: Under stirring conditions, 3-ureapropyltrimethoxysilane, water, and acetic acid are added to n-heptane to adjust the pH of the mixture to 4 to 6, and the mixture is reacted at 20 to 40 °C for 0.5 to 2 h to obtain the hydrolysate.

[0009] A3. Condensation prepolymerization: Hydroxyl-terminated polydimethylsiloxane and trimethylsiloxysilicate are added to the hydrolysate obtained in A2, and the mixture is heated to 60 to 110°C under nitrogen protection and reacted for 1 to 6 hours.

[0010] A4. Condensation reaction: Tetraethoxysilane and dibutyltin dilaurate were added and the reaction was continued for 0.5 to 4 hours to obtain intermediate IA.

[0011] A5. Endpoint Criterion: When the viscosity of intermediate IA at 25°C is 10 to 80 Pa·s and the viscosity change does not exceed 10% for 60 minutes, the reaction is considered to have reached the endpoint.

[0012] A6. Post-processing: Degas intermediate IA at 20 to 35°C for 0.5 to 3 hours, filter and seal for storage.

[0013] A7. Quality control: The solid content of intermediate IA is 40 to 70 wt%, and the viscosity increase rate of intermediate IA after 7 days of storage does not exceed 30%.

[0014] Furthermore, the acrylate adhesive layer on side B includes intermediate IB, which is prepared according to the following standard operating procedure: B1. Raw material preparation: Based on a total monomer mass of 100 parts by weight, provide 45 to 75 parts by weight of 2-ethylhexyl acrylate, 15 to 45 parts by weight of n-butyl acrylate, 1 to 10 parts by weight of acrylic acid, 1 to 15 parts by weight of 2-hydroxyethyl acrylate, 0.5 to 5 parts by weight of 3-methacryloyloxypropyltrimethoxysilane, 0.2 to 1.2 parts by weight of azobisisobutyronitrile, 40 to 160 parts by weight of ethyl acetate, and nitrogen gas.

[0015] B2. Premixing and deoxygenation: Add the monomer and ethyl acetate to the reactor and mix. Then, purge with nitrogen gas for 0.2 to 2 hours to remove oxygen.

[0016] B3. Solution polymerization: Under nitrogen protection, the temperature is raised to 65 to 85°C, azobisisobutyronitrile is added, and the reaction is carried out for 3 to 10 hours.

[0017] B4. Endpoint Criterion: When the total mass fraction of residual monomers is less than 2wt% and the viscosity of the system is 1 to 15 Pa·s at 25°C, the polymerization is considered complete, and intermediate IB solution is obtained.

[0018] B5. Post-processing: Cool the intermediate IB solution to 20 to 35°C, adjust the solid content to 35 to 60 wt% with ethyl acetate, filter and seal for storage.

[0019] B6. Quality control: The solid content of intermediate IB solution is 35 to 60 wt%, and the viscosity fluctuation measured within the same batch does not exceed 25%.

[0020] Furthermore, the silicone layer coating composition for side A was prepared according to the following standard operating procedure: C1. Mixing of ingredients: Based on the solids of the silicone coating composition on side A, take 20 to 70 parts by weight of the solids of intermediate IA, add 10 to 60 parts by weight of terminal hydroxyl polydimethylsiloxane and 10 to 50 parts by weight of trimethylsiloxysilicate, and mix.

[0021] C2. Dispersion: Add 0 to 5 parts by mass of silica and disperse for 0.2 to 2 hours.

[0022] C3. Add crosslinking and catalytic components: Add 0.5 to 8 parts by weight of tetraethoxysilane and 0.01 to 0.30 parts by weight of dibutyltin dilaurate, stir for 0.1 to 1 h to obtain the silicone layer coating composition on side A.

[0023] C4. Endpoint Criterion: The silicone coating composition on side A is considered qualified if the viscosity is 5 to 60 Pa·s at 25°C and no obvious gel particles are observed after standing for 30 minutes.

[0024] C5. Solid content adjustment: Adjust the solid content of the silicone coating composition on side A to 25 to 65 wt% using n-heptane.

[0025] Furthermore, the acrylic adhesive coating composition for side B was prepared according to the following standard operating procedure: D1. Take the main adhesive: Based on the solids content of the acrylic adhesive coating composition on side B, take 55 to 90 parts by weight of the solids content of intermediate IB.

[0026] D2. Tackifying resin mixing: Add 10 to 35 parts by weight of hydrogenated rosin pentaerythritol ester and mix at 30 to 90°C for 0.2 to 3 hours to make it uniform.

[0027] D3. Add photoinitiator and crosslinking monomer: After cooling to 20 to 40°C, add 0.05 to 1.00 parts by weight of 1-hydroxycyclohexylphenyl ketone and 1 to 12 parts by weight of 1,6-hexanediol diacrylate and mix for 0.1 to 1 h.

[0028] D4. Add thermosetting initiator: Add 0.05 to 0.80 parts by weight of benzoyl peroxide and mix for 0.1 to 1 hour to obtain the acrylic adhesive coating composition for side B.

[0029] D5. Solid content adjustment: Adjust the solid content of the acrylic adhesive coating composition on side B to 25 to 65 wt% with ethyl acetate.

[0030] D6. Quality Control: The acrylic adhesive coating composition on side B has a viscosity of 1 to 30 Pa·s at 25°C and shows no obvious delamination after standing for 30 minutes, which is considered qualified.

[0031] Furthermore, the composite carrier layer includes a cotton layer and a membrane layer, wherein the cotton layer is located on the side facing the silicone layer on side A, and the membrane layer is located on the side facing the acrylic adhesive layer on side B; The silicone layer on side A has direct adhesion to silicone rubber or silicone foam, and the 180° peel strength of the silicone layer on side A is not less than 6 N / 25 mm as determined by GB / T 2792-2014; and, at 23°C, the tack performance of the acrylic adhesive layer on side B to metal substrates or engineering plastic substrates is not less than 24 h as determined by GB / T 4851-2014.

[0032] As a concept of the present invention, the present invention uses hydroxyl-terminated polydimethylsiloxane (40-70 parts) and trimethylsiloxysilicate (25-55 parts) to form a three-dimensional network by siloxane condensation under the catalysis of dibutyltin dilaurate (0.01-0.60 parts). 3-Ureapropyltrimethoxysilane (1-8 parts) provides urea hydrogen bonds and silanol groups to achieve multi-point anchoring of cellulose hydroxyl groups. Tetraethoxysilane (1-12 parts) provides additional crosslinking points to improve network density and heat resistance. The flexible segments of hydroxyl-terminated polydimethylsiloxane impart low surface energy and high elasticity, while the rigid MQ structure of trimethylsiloxysilicate enhances cohesive strength. 3-Ureapropyltrimethoxysilane, under controlled hydrolysis conditions (pH 4-6, 20-40℃), forms silanol groups through prepolymerization (60-110℃) and co-condensation, with urea hydrogen bonds enhancing cellulose wetting. Tetraethoxysilane hydrolyzes and rapidly condenses during the condensation reaction, providing additional crosslinking points, increasing network density while maintaining a viscosity within the 10-80 Pa·s coating window. Intermediate IA, with a solid content of 40-70 wt%, has a viscosity of 10-80 Pa·s, ensuring that the coating composition, with a solid content of 25-65 wt%, meets coating requirements. After curing, the dry film thickness of the silicone layer on side A is 15-30 µm, achieving penetration adhesion to the silicone rubber through the siloxane condensation network and urea hydrogen bonds, resulting in a 180° peel strength ≥6 N / 25 mm. The above design achieves a balance between high solids content and low viscosity coating window, high peel strength and high heat resistance, reflecting the synergy of condensed silicon-oxygen network + urea hydrogen bond anchoring + rigid-flexible network.

[0033] This invention also discloses a method for preparing a composite material of silicone-acrylate adhesive, cotton, and membrane materials, comprising the following steps: S1. Provide intermediate IA and a silicone coating composition for side A.

[0034] S2. Provide intermediate IB and provide an acrylate adhesive coating composition for side B.

[0035] S3. Provide a cotton layer, optionally composite the cotton layer with a polyimide film to obtain a composite carrier layer, and form a solvent-free curable barrier layer on the silicone layer side of the composite carrier layer facing side A.

[0036] S4. A silicone layer coating composition is applied to the isolation barrier layer to make the dry film thickness of the silicone layer on the A side 15 to 30 µm, and cured at 100 to 180 °C to form the silicone layer on the A side, and then a first release film is laminated on the outside of the silicone layer on the A side.

[0037] S5. Apply the B-side acrylate adhesive layer coating composition onto the second release film to form the B-side acrylate adhesive layer, such that the dry film thickness of the B-side acrylate adhesive layer is 25 to 35 µm. First, perform UV curing, then heat treatment at 60 to 160 °C for 0.5 to 10 min. Subsequently, bond the B-side acrylate adhesive layer to the other side of the composite carrier layer.

[0038] S6. Obtain the composite material and wind it up.

[0039] Furthermore, in S3, the cotton layer and the polyimide film are laminated together to form a composite carrier layer.

[0040] Furthermore, the isolation barrier layer formed in S3 is a solvent-free curing film-forming isolation barrier layer, and the curing in S4 is carried out in a nitrogen environment or an air environment.

[0041] Furthermore, the isolation barrier layer is formed by solvent-free coating of the isolation barrier layer coating composition and subsequent curing. The isolation barrier layer coating composition includes a film-forming resin and a curing component, wherein the curing component is a UV curing initiator or a thermosetting curing agent.

[0042] Furthermore, the curing method of the isolation barrier layer is either ultraviolet curing or thermal curing, and the type of light source, dominant wavelength and energy density or irradiation time and linear velocity of the ultraviolet curing are given, or the temperature and time of the thermal curing are given.

[0043] Furthermore, the thickness of the isolation barrier layer is 5 to 10 µm, which is controlled by the conversion between coating amount and solid content, and the conversion relationship between coating amount and solid content is given.

[0044] Furthermore, the pH of the mixed system described in A2 is the pH of the aqueous phase in the system, and the sampling method and pH measurement method are given, as well as the control method of achieving a pH of 4 to 6 by adjusting the amount of acetic acid added.

[0045] Furthermore, in A2, the stirring is mechanical, and the stirring speed and stirring time are given, or an operational description of the equivalent stirring intensity is given.

[0046] Furthermore, A3 specifies either a closed reaction under nitrogen protection followed by nitrogen purging or a reaction under continuous nitrogen purging to maintain a slight positive pressure, and provides the number of purgings or the range of nitrogen flow rates.

[0047] Furthermore, the nitrogen deoxygenation in B2 can be either deoxygenation by bubbling the liquid phase or deoxygenation by continuous purging of the gas phase space inside the reactor, and the nitrogen flow rate or the number of replacements is given.

[0048] Furthermore, solution polymerization in B3 is carried out under atmospheric reflux conditions with reflux condensation or under closed pressurized conditions, and an operational description of the reactor state and condensation conditions is given.

[0049] Furthermore, in D2, mixing is carried out at 30 to 90°C under normal pressure reflux conditions with reflux condensation or under closed pressurized conditions, and the stirring method and stirring speed are given.

[0050] Furthermore, the viscosity in A5 is measured using a rotational viscometer or rheometer, and the fixed temperature, shear rate, or rotor type and speed are given.

[0051] Furthermore, the viscosity of B4, C4, and D6 is measured using the same viscosity test aperture as A5, and the temperature and shear rate or rotor model and speed are given.

[0052] Furthermore, the filtration described in A6 and B5 specifies the pore size or mesh number of the filter medium, and the degassing is either atmospheric pressure static degassing or vacuum degassing, with the vacuum degree and degassing time specified.

[0053] Furthermore, C2 specifies that the dispersion method is high-speed dispersion, ultrasonic dispersion, or grinding dispersion, and provides the corresponding rotation speed or power and dispersion time for each dispersion method.

[0054] Furthermore, the dry film thickness described in S4 is controlled by conversion between coating amount and construction solids, and an operable description of coating method and coating amount is given, along with the curing time.

[0055] Furthermore, the ultraviolet curing in S5 specifies the light source type, dominant wavelength and energy density or irradiation time and linear velocity, and the heat treatment specifies the temperature and time.

[0056] Furthermore, in S3, the pressing composite provides the pressing pressure, pressing temperature, and pressing time or linear velocity.

[0057] Furthermore, the test standards for the 180° peel strength and holding power specify the version year of the corresponding standard, and specify the test caliber for the bonded material, bonding pressure, dwell time, peel speed or loading conditions.

[0058] As another concept of the present invention, the present invention uses intermediate IB (an acrylate copolymer containing silane side groups, 55-90 parts) as the main body of the B-side adhesive layer. 2-Ethylhexyl acrylate (45-75 parts) provides low Tg flexibility, n-butyl acrylate (15-45 parts) balances flexibility and cohesiveness, acrylic acid (1-10 parts) provides carboxyl groups to enhance metal bonding, 2-hydroxyethyl acrylate (1-15 parts) provides hydroxyl groups to participate in crosslinking, and 3-methacryloyloxypropyltrimethoxysilane (0.5-5 parts) introduces silane side groups to form siloxane crosslinks during heat treatment to improve heat resistance and cohesive strength. The B-side coating composition incorporates hydrogenated rosin pentaerythritol ester (10-35 parts) to enhance adhesion and holding power. 1-Hydroxycyclohexylphenyl ketone (0.05-1.00 parts) initiates rapid photocrosslinking of 1,6-hexanediol diacrylate (1-12 parts) with hydroxyl groups for rapid setting. Benzoyl peroxide (0.05-0.80 parts) initiates deep thermal crosslinking of residual double bonds and activates the hydrolytic condensation of silane side groups during the heat treatment stage (60-160℃, 0.5-10 min), achieving synergistic curing of rapid UV setting and deep thermal crosslinking. The B-side adhesive layer has a dry film thickness of 25-35µm. Through carboxyl and hydroxyl groups bonding to metals, rosin tackification, and the high cohesive strength of the UV-thermal dual-curing network, it achieves holding power for metals or engineering plastics at 23℃ for ≥24h. The above design achieves a balance between rapid UV setting and stepwise thermal cross-linking curing, high cohesion and high tack, demonstrating the synergistic effect of silanized acrylate + rosin tackification + UV-thermal dual curing.

[0059] This invention addresses the synergistic effect of hydroxyl-terminated polydimethylsiloxane (PDMS) and trimethylsiloxysilicate in the silicone layer on side A. PDMS, as a flexible chain segment, primarily contributes low surface energy, high elasticity, and compatibility with the silicone rubber substrate's silicone segments. Trimethylsiloxysilicate, as a rigid MQ structure, primarily contributes cohesive strength, creep resistance, and dimensional stability. Regarding improved peel strength, PDMS forms molecular segment interdiffusion and entanglement with the silicone rubber substrate's silicone segments through its long-chain silicone segments, absorbing energy during peeling through segment extension. Trimethylsiloxysilicate, through its rigid MQ cage structure, forms physical crosslinking points within the flexible chains, enhancing network cohesive strength and preventing cohesive damage to the adhesive layer during peeling. In terms of improving heat resistance and dimensional stability, the high bond energy of the siloxane bonds in hydroxyl-terminated polydimethylsiloxane provides basic heat resistance, but it is prone to segmental creep at high temperatures. The three-dimensional cage structure of trimethylsiloxysilicate restricts segmental movement at high temperatures. In the MQ structure, the end-capped siloxane chains of the M units prevent depolymerization at high temperatures, and the tetrafunctional crosslinking points of the Q units provide a rigid framework. In terms of synergistic effects, the flexible segments and the rigid MQ structure form a crosslinking network that combines rigidity and flexibility in the siloxane condensation reaction. The flexible segments provide flexibility and elasticity to ensure compatibility and penetration adhesion to silicone rubber, while the rigid MQ structure provides rigidity and cohesive force to prevent cohesive damage to the adhesive layer during peeling. The two work together to achieve a peel strength ≥6N / 25mm and a cohesive damage rate <5%, while the shrinkage rate is <0.5% at 100-180℃, demonstrating that the synergistic effect of rigidity and flexibility is superior to using either alone.

[0060] Beneficial technical effects 1. Achieving high barrier and anti-migration performance of ultrathin solvent-free isolation layers: By adopting solvent-free curing film-forming technology, the thickness of the isolation barrier layer is precisely controlled within 5 to 10 µm, avoiding the VOC emission problem caused by solvent residue during the coating and drying process of traditional solvent-based isolation layers (reducing VOC emissions by >95%) and the risk of cross-contamination of adhesive layers caused by the penetration and migration of solvent molecules between the A / B side adhesive layers (migration rate <1%). At the same time, the ultrathin design significantly reduces the total thickness of the composite material while ensuring barrier performance (total thickness can be controlled within 65-155 µm), improving the applicability of the material in thickness-sensitive applications such as chip packaging and precision electronic devices, and achieving synergistic optimization of environmental protection, barrier performance and thinness.

[0061] 2. Achieving a synergistic balance between high solids content, low viscosity coating window, and high peel strength: A flexible hydroxyl-terminated polydimethylsiloxane (40-70 parts by weight) and a rigid MQ structure of trimethylsiloxysilicate (25-55 parts by weight) are formed under controlled condensation conditions catalyzed by dibutyltin dilaurate (0.01-0.60 parts by weight) (pH 4-6, controlled hydrolysis 20-40℃, condensation prepolymerization 60-110℃, condensation reaction 0.5-4h) to create a flexible-rigid siloxane condensation network. This, combined with the urea-based hydrogen bonds provided by 3-ureapropyltrimethoxysilane (1-8 parts by weight) for multi-point anchoring of cellulose hydroxyl groups and the additional siloxane crosslinking points provided by tetraethoxysilane (1-12 parts by weight), achieves a viscosity of 10-80 Pa·s for intermediate IA at a solids content of 40-70 wt% and a viscosity that remains stable after 7 days of storage. With a wide coating window of less than 30%, the coating composition with a viscosity of 5-60 Pa·s at an application solids content of 25-65 wt% can meet the requirements of industrial coating such as scraping and roller coating. After curing, the dry film thickness of the silicone layer on the A side is 15-30 µm, and the 180° peel strength against silicone rubber or silicone foam reaches 6-9.5 N / 25 mm, which is significantly higher than that of traditional addition-cure silicone systems (peel strength is usually <5 N / 25 mm and requires a solids content of <40 wt%, resulting in multiple coating passes).

[0062] 3. Achieving rapid surface setting and deep crosslinking synergistically in a UV-thermal dual-curing system for surface B: Using acrylate copolymer intermediate IB (55-90 parts by weight) containing 0.5-5 parts by weight of 3-methacryloyloxypropyltrimethoxysilane side groups as the main resin, UV curing initiated by 0.05-1.00 parts by weight of 1-hydroxycyclohexylphenyl ketone achieves rapid surface setting (gel fraction >60%) in 3-8 seconds. Then, thermosetting (60-160℃, 0.5-10 min) initiated by benzoyl peroxide (0.05-0.80 parts by weight) achieves the removal of residual double bonds. Deep crosslinking (final gel fraction >90%) and activation of silane side group hydrolysis and condensation to form siloxane crosslinking, synergistically with hydrogenated rosin pentaerythritol ester (10-35 parts by mass) through the π-π stacking of rosin rings and acrylate segments and the tackifying effect provided by van der Waals forces, enable the B-side acrylate adhesive layer to achieve a tack performance of 24-72h on metal or engineering plastic substrates at 23℃ with a dry film thickness of 25-35µm. This is significantly better than a single UV curing system (tack holding <12h, insufficient cohesive strength leading to creep peeling) or a single thermosetting system (curing time >30min, low production efficiency and easy yellowing).

[0063] 4. Achieving synergistic flexibility and temperature resistance in the cotton-polyimide composite carrier layer: The cotton layer (mainly cellulose, 20-80µm thick) provides breathability, flexibility, cost advantage (approximately 1 / 5 the cost of polyimide), and hydroxyl-responsive sites for urea hydrogen bonds in the silicone layer. Optionally, a polyimide film layer (typically 20-50µm thick) provides high-temperature dimensional stability (coefficient of thermal expansion <2×10⁻). 5 The composite carrier layer's shrinkage rate is controlled within 0.5% under multiple thermal history conditions (A-side silicone curing 100-180℃, B-side acrylate heat treatment 60-160℃) and heat resistance (glass transition temperature >280℃). This avoids the wrinkles and dimensional deviations caused by shrinkage rate >2% during high-temperature curing when using only cotton, and the problem of poor air permeability (air permeability <50cc / m²·24h) causing small molecule byproducts (water, ethanol) released during the curing of silicone on the A-side to form bubbles when using only polyimide film, which is difficult to expel. This achieves a triple balance of flexibility, cost controllability, and high-temperature dimensional stability.

[0064] 5. Achieving directional design and multi-scenario adaptation for heterogeneous double-sided adhesive performance: The silicone layer on side A uses a condensation-type silica-oxygen network + urea hydrogen bond anchoring to achieve high peel strength (≥6N / 25mm) for low surface energy materials such as silicone rubber or silicone foam, with no adhesive residue on the substrate after peeling. The acrylate adhesive layer on side B uses silanized acrylate + rosin tackifier + UV-thermal dual curing to achieve high holding power (≥24h) for high surface energy materials such as metal substrates or engineering plastic substrates, and excellent creep resistance under long-term load (creep <0.5mm). This overcomes the limitations of traditional double-sided adhesives that use homogeneous adhesive systems and cannot meet the different bonding requirements of low and high surface energy substrates. This allows the composite material of the present invention to show wide application value in multiple scenarios such as electronic manufacturing (temporary fixation of silicone protective film for chip packaging), automotive interior (composite bonding of silicone sealing strips and metal skeletons), and medical devices (fixation of silicone catheters and metal connectors). Attached Figure Description

[0065] Figure 1 The images show the high-resolution peak fitting diagrams of the Si 2p surface chemical state analysis of the A-side silicone layer XPS in Example 1 and Comparative Example 3.

[0066] Figure 2 The image shows the O 1s high-resolution peak fitting diagram of the surface chemical state analysis of the XPS silicone layer on side A of Example 1 and Comparative Example 3.

[0067] Figure 3 The image shows the C 1s high-resolution peak fitting diagrams of the surface chemical state analysis of the XPS silicone layer on side A of Example 1 and Comparative Example 3.

[0068] Figure 4The images show the FTIR characteristic functional groups and interaction spectra of the silicone layer on side A of Examples 1, 3, and 4.

[0069] Figure 5 DSC thermo-curing kinetic analysis of the isolation barrier coating composition and the acrylic adhesive coating composition on side B, showing the curing exothermic peak.

[0070] Figure 6 The XRD patterns of the composite support layer in Example 1 and Comparative Example 6 are XRPD crystal phase and orientation analysis XRD spectra.

[0071] Figure 7 Macroscopic photograph of the silicone-acrylate / cotton-PI composite material prepared in Example 1.

[0072] Figure 8 The image shows a low-magnification SEM image of the silicone layer on side A of the composite material prepared in Example 1.

[0073] Figure 9 This is a bright-field transmission electron microscope image of the silicone layer on side A of the composite material in Example 1. Detailed Implementation

[0074] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0075] Example 1

[0076] This embodiment provides a silicone-acrylate adhesive composite material with cotton and a membrane material. The composite material includes an A-side silicone layer, a barrier layer, a composite carrier layer, and a B-side acrylate adhesive layer. The barrier layer is disposed between the A-side silicone layer and the composite carrier layer, and is a solvent-free curable barrier layer. The composite carrier layer includes a cotton layer and a membrane layer. The main component of the cotton layer is cellulose, and the membrane layer is a polyimide film. The cotton layer is located on the side facing the A-side silicone layer, and the membrane layer is located on the side facing the B-side acrylate adhesive layer. The A-side silicone layer contains a silicone-oxygen condensation network and is formed by curing a silicone layer coating composition. A first release film covers the side of the A-side silicone layer away from the composite carrier layer, and a second release film covers the side of the B-side acrylate adhesive layer away from the composite carrier layer.

[0077] The composite material of this embodiment satisfies the following structural parameters: the dry film thickness of the silicone layer on side A is 22µm, the dry film thickness of the acrylate adhesive layer on side B is 30µm, the thickness of the isolation barrier layer is 7µm, the thickness of the composite carrier layer is 50µm, the thickness of the first release film is 38µm, and the thickness of the second release film is 38µm.

[0078] Based on the solid content of the silicone layer on side A in this embodiment, the silicone layer on side A in this embodiment includes the following components: 55 parts by weight of hydroxyl-terminated polydimethylsiloxane, 40 parts by weight of trimethylsiloxysilicate, 4.5 parts by weight of 3-ureapropyltrimethoxysilane, 6.5 parts by weight of tetraethoxysilane, 0.30 parts by weight of dibutyltin dilaurate, and 2.5 parts by weight of silica. The acrylate adhesive layer on side B in this embodiment is formed by curing the acrylate adhesive layer coating composition on side B. Based on the solid content of the acrylate adhesive layer on side B in this embodiment, the acrylate adhesive layer on side B in this embodiment includes the following components: 72.5 parts by weight of acrylate copolymer intermediate IB, in this embodiment intermediate IB is an acrylate copolymer containing silane side groups, 22.5 parts by weight of hydrogenated rosin pentaerythritol ester, 0.52 parts by weight of 1-hydroxycyclohexylphenyl ketone, 6.5 parts by weight of 1,6-hexanediol diacrylate, and 0.42 parts by weight of benzoyl peroxide.

[0079] In this embodiment, the silicone layer on side A includes intermediate IA, which is prepared according to the following standard operating procedure: A1. Raw material preparation: Weigh out 55 parts of hydroxyl-terminated polydimethylsiloxane, 40 parts of trimethylsiloxysilicate, 4.5 parts of 3-ureapropyltrimethoxysilane, 6.5 parts of tetraethoxysilane, 0.30 parts of dibutyltin dilaurate, 130 parts of n-heptane, 1.0 part of water, and 0.25 parts of acetic acid by weight, and provide nitrogen gas.

[0080] A2. Controlled hydrolysis: Under stirring conditions, 3-ureapropyltrimethoxysilane, water, and acetic acid were added to n-heptane to make the pH of the mixture 5. The pH of the aqueous phase was measured using a pH meter. The pH was controlled within the set range by adjusting the amount of acetic acid added. The reaction was carried out at 30°C with mechanical stirring for 1.2 h at a stirring speed of 300 rpm to obtain the hydrolysate.

[0081] A3. Condensation prepolymerization: Hydroxyl-terminated polydimethylsiloxane and trimethylsiloxysilicate are added to the hydrolysate obtained in A2. The reaction is carried out under nitrogen protection by nitrogen purging followed by a closed reaction. Nitrogen purging is performed 3 times, and the temperature is raised to 85℃ for 3.5h.

[0082] A4. Condensation reaction: Tetraethoxysilane and dibutyltin dilaurate were added and the reaction was continued for 2.2 h to obtain intermediate IA.

[0083] A5. Endpoint Criterion: When the viscosity of intermediate IA is 45 Pa·s at 25℃ and the viscosity change does not exceed 10% for 60 minutes, the reaction is considered to have reached the endpoint. The viscosity is measured using a rotational viscometer with a No. 2 rotor at a speed of 60 rpm.

[0084] A6. Post-processing: The intermediate IA was degassed at 27°C under normal pressure for 1.7 hours, filtered through a 200-mesh filter and sealed for storage.

[0085] A7. Quality control: The solid content of intermediate IA is 55wt%, and the viscosity increase rate of intermediate IA after 7 days of storage does not exceed 30%.

[0086] In this embodiment, the B-side acrylic adhesive layer includes intermediate IB, which is prepared according to the following standard operating procedure: B1. Raw material preparation: Based on a total monomer mass of 100 parts by mass, provide 58 parts by mass of 2-ethylhexyl acrylate, 29 parts by mass of n-butyl acrylate, 5.5 parts by mass of acrylic acid, 5 parts by mass of 2-hydroxyethyl acrylate, 2.5 parts by mass of 3-methacryloyloxypropyltrimethoxysilane, 0.7 parts by mass of azobisisobutyronitrile, 100 parts by mass of ethyl acetate, and nitrogen gas.

[0087] B2. Premixing and deoxygenation: Add the monomer and ethyl acetate to the reaction vessel and mix. Then, introduce nitrogen gas to bubble the liquid phase for deoxygenation for 1.1 h at a flow rate of 2 L / min.

[0088] B3. Solution polymerization: Under nitrogen protection and atmospheric pressure reflux with reflux condensation, the temperature was raised to 75°C, azobisisobutyronitrile was added and the reaction was carried out for 6.5 h with anchor stirring at 150 rpm.

[0089] B4. Endpoint Criterion: When the total mass fraction of residual monomers is less than 2wt% and the viscosity of the system is 8 Pa·s at 25℃, the polymerization is considered complete, and intermediate IB solution is obtained. The viscosity is measured by a rotational viscometer with a No. 3 rotor at a speed of 60 rpm.

[0090] B5. Post-processing: Cool the intermediate IB solution to 27°C, adjust the solid content to 47.5 wt% with ethyl acetate, filter through a 200-mesh filter and seal for storage.

[0091] B6. Quality control: The solid content of intermediate IB solution is 47.5 wt%, and the viscosity fluctuation measured within the same batch does not exceed 25%.

[0092] The silicone layer coating composition for surface A in this embodiment was prepared according to the following standard operating procedure: C1. Ingredient Mixing: Based on the solids of the silicone coating composition on side A, take 45 parts by weight of the solids of intermediate IA, add 35 parts by weight of terminal hydroxyl polydimethylsiloxane and 30 parts by weight of trimethylsiloxysilicate, and mix.

[0093] C2. Dispersion: Add 2.5 parts by mass of silica and disperse at high speed for 1.1 hours at a speed of 2000 rpm.

[0094] C3. Add crosslinking and catalytic components: Add 4.2 parts by weight of tetraethoxysilane and 0.15 parts by weight of dibutyltin dilaurate, stir for 0.5 h to obtain the silicone layer coating composition on side A.

[0095] C4. Endpoint Criteria: The viscosity of the silicone coating composition on side A is 32 Pa·s at 25°C and no obvious gel particles are observed after standing for 30 min. It is considered qualified. The viscosity is measured using a rotational viscometer with a No. 3 rotor at a speed of 60 rpm.

[0096] C5. Solid content adjustment: Adjust the solid content of the silicone coating composition on side A to 45wt% using n-heptane.

[0097] The acrylic adhesive coating composition for side B in this embodiment was prepared according to the following standard operating procedure: D1. Take the main adhesive: Based on the solids content of the acrylic ester adhesive coating composition on side B, take 72.5 parts by weight of the solids content of intermediate IB.

[0098] D2. Tackifying resin mixing: Add 22.5 parts by weight of hydrogenated rosin pentaerythritol ester and mix at 60°C for 1.6 hours to make it uniform. The mixture is carried out under normal pressure reflux conditions with reflux condensation, using anchor stirring at 100 rpm.

[0099] D3. Add photoinitiator and crosslinking monomer: After cooling to 30℃, add 0.52 parts by weight of 1-hydroxycyclohexylphenyl ketone and 6.5 parts by weight of 1,6-hexanediol diacrylate and mix for 0.5h.

[0100] D4. Add thermosetting initiator: Add 0.42 parts by weight of benzoyl peroxide and mix for 0.5 h to obtain the acrylic adhesive coating composition for side B.

[0101] D5. Solid content adjustment: Adjust the solid content of the acrylic adhesive coating composition on side B to 45wt% with ethyl acetate.

[0102] D6. Quality Control: The viscosity of the acrylic adhesive coating composition on side B is 15 Pa·s at 25°C and there is no obvious stratification after standing for 30 min, which is considered qualified. The viscosity is measured by a rotational viscometer with a No. 3 rotor at a speed of 60 rpm.

[0103] The method for preparing the composite material in this embodiment includes the following steps: S1. Provide intermediate IA and a silicone coating composition for side A.

[0104] S2. Provide intermediate IB and provide an acrylate adhesive coating composition for side B.

[0105] S3. A cotton layer is provided, and the cotton layer and a polyimide film are laminated together to obtain a composite carrier layer. The lamination pressure is 0.3 MPa, the lamination temperature is 80°C, and the lamination time is 30 s. A solvent-free curable barrier layer is formed on the silicone layer side of the composite carrier layer facing side A. In this embodiment, the barrier layer is formed by solvent-free coating of the barrier layer coating composition and then curing it. The barrier layer coating composition in this embodiment includes a film-forming resin and a curing component. The curing component in this embodiment is a UV curing initiator. The curing method of the barrier layer in this embodiment is UV curing, using an LED-UV light source with a main wavelength of 365 nm, an energy density of 1000 mJ / cm², and a linear velocity of 10 m / min. The thickness of the barrier layer in this embodiment is 7 µm, which is controlled by the conversion between coating amount and solid content. The coating amount is 14 µm wet film thickness and 50 wt% solid content. The dry film thickness = wet film thickness × solid content.

[0106] S4. Coat the A-side silicone layer coating composition on the isolation barrier layer to make the dry film thickness of the A-side silicone layer 22µm. Use microgravure coating method, the wet film coating amount is 49µm. The dry film thickness of 22µm is obtained by converting the construction solid content of 45wt%. Then, cure it in air at 140℃ for 3min to form the A-side silicone layer. Subsequently, laminate the first release film on the outside of the A-side silicone layer.

[0107] S5. The B-side acrylic adhesive layer coating composition is coated onto the second release film to form the B-side acrylic adhesive layer, so that the dry film thickness of the B-side acrylic adhesive layer is 30µm. The microgravure coating method is used, and the wet film coating amount is 67µm. The dry film thickness of 30µm is obtained by converting the construction solid content of 45wt%. First, UV curing is performed using an LED-UV light source with a main wavelength of 365nm, an energy density of 800mJ / cm², and a linear velocity of 10m / min. Then, heat treatment is performed at 110℃ for 5min. Subsequently, the B-side acrylic adhesive layer is bonded to the other side of the composite carrier layer.

[0108] S6. Obtain the composite material and wind it up.

[0109] In this embodiment, the silicone layer on side A has direct adhesion to silicone rubber or silicone foam. The 180° peel strength of the silicone layer on side A, as measured by GB / T 2792-2014, is not less than 6 N / 25 mm. The bonded material is silicone rubber, the bonding pressure is 2 kg (roller pressing), the resting time is 24 h, and the peeling speed is 300 mm / min. At 23°C, the acrylate adhesive layer on side B of this embodiment exhibits adhesion to metal or engineering plastic substrates for not less than 24 h, as measured by GB / T 4851-2014. The bonded material is stainless steel plate, the bonding pressure is 2 kg (roller pressing), the resting time is 20 min, and the loading condition is a 1000 g weight.

[0110] Example 1 Features: This example uses moderate parameter configuration. The dry film thickness of the silicone layer on side A is 22µm, the ratio of hydroxyl-terminated polydimethylsiloxane to trimethylsiloxysilicate is 55:40, the solid content of intermediate IA is 55wt%, and the monomer ratio of intermediate IB contains 58 parts of 2-ethylhexyl acrylate and 29 parts of n-butyl acrylate. The amount of intermediate IB in the acrylate adhesive layer on side B is 72.5 parts, and the amount of hydrogenated rosin pentaerythritol ester is 22.5 parts. The thickness of the composite carrier layer is 50µm. All process parameters, such as the controlled hydrolysis temperature of 30℃, the condensation prepolymerization temperature of 85℃, the solution polymerization temperature of 75℃, the curing temperature of side A of 140℃, and the heat treatment temperature of side B of 110℃, are all in the middle range. This parameter combination has good process stability and product consistency, is suitable for large-scale continuous production, and can achieve a balance in the adhesion performance between the silicone layer and the acrylate adhesive layer, with stable overall peel strength and holding power. This embodiment is applicable to continuous production scenarios that require stable process control, and is particularly suitable for applications with high requirements for process reproducibility, such as screen and frame bonding of consumer electronics products, multi-material composite bonding of automotive interior parts, and sealing and shock absorption structures of home appliances.

[0111] Example 2

[0112] This embodiment provides a silicone-acrylate adhesive composite material with cotton and a membrane material. The composite material includes an A-side silicone layer, an isolation barrier layer, a composite carrier layer, and a B-side acrylate adhesive layer. The isolation barrier layer is disposed between the A-side silicone layer and the composite carrier layer, and is a solvent-free curable isolation barrier layer. The composite carrier layer includes a cotton layer and a membrane layer. The main component of the cotton layer is cellulose, and the membrane layer is a polyimide film. The cotton layer is located on the side facing the A-side silicone layer, and the membrane layer is located on the side facing the B-side acrylate adhesive layer. The A-side silicone layer contains a silicone-oxygen condensation network and is formed by curing a silicone layer coating composition. A first release film covers the side of the A-side silicone layer away from the composite carrier layer, and a second release film covers the side of the B-side acrylate adhesive layer away from the composite carrier layer.

[0113] The composite material of this embodiment satisfies the following structural parameters: the dry film thickness of the silicone layer on side A is 18µm, the dry film thickness of the acrylate adhesive layer on side B is 27µm, the thickness of the isolation barrier layer is 6µm, the thickness of the composite carrier layer is 35µm, the thickness of the first release film is 30µm, and the thickness of the second release film is 30µm.

[0114] Based on the solid content of the silicone layer on side A in this embodiment, the silicone layer on side A in this embodiment includes the following components: 48 parts by weight of hydroxyl-terminated polydimethylsiloxane, 48 parts by weight of trimethylsiloxysilicate, 2.5 parts by weight of 3-ureapropyltrimethoxysilane, 8 parts by weight of tetraethoxysilane, 0.45 parts by weight of dibutyltin dilaurate, and 1.0 part by weight of silica. The acrylate adhesive layer on side B in this embodiment is formed by curing the acrylate adhesive layer coating composition on side B, and based on the solid content of the acrylate adhesive layer on side B in this embodiment, the acrylate adhesive layer on side B in this embodiment includes the following components: 65 parts by weight of acrylate copolymer intermediate IB, in this embodiment intermediate IB is an acrylate copolymer containing silane side groups, 28 parts by weight of hydrogenated rosin pentaerythritol ester, 0.75 parts by weight of 1-hydroxycyclohexylphenyl ketone, 9 parts by weight of 1,6-hexanediol diacrylate, and 0.60 parts by weight of benzoyl peroxide.

[0115] In this embodiment, the silicone layer on side A includes intermediate IA, which is prepared according to the following standard operating procedure: A1. Raw material preparation: Weigh out 48 parts by weight of hydroxyl-terminated polydimethylsiloxane, 48 parts of trimethylsiloxysilicate, 2.5 parts of 3-ureapropyltrimethoxysilane, 8 parts of tetraethoxysilane, 0.45 parts of dibutyltin dilaurate, 80 parts of n-heptane, 0.5 parts of water, and 0.15 parts of acetic acid, and provide nitrogen gas.

[0116] A2. Controlled hydrolysis: Under stirring conditions, 3-ureapropyltrimethoxysilane, water, and acetic acid were added to n-heptane to make the pH of the mixture 5. The pH of the aqueous phase was measured using a pH meter. The pH was controlled within the set range by adjusting the amount of acetic acid added. The reaction was carried out at 35°C with mechanical stirring for 0.8 h at a stirring speed of 350 rpm to obtain the hydrolysate.

[0117] A3. Condensation prepolymerization: Hydroxyl-terminated polydimethylsiloxane and trimethylsiloxysilicate are added to the hydrolysate obtained in A2. The reaction is carried out under nitrogen protection by continuously introducing nitrogen to maintain a slight positive pressure. The nitrogen flow rate is 0.5 L / min, and the temperature is raised to 95℃ for 2.5 h.

[0118] A4. Condensation reaction: Tetraethoxysilane and dibutyltin dilaurate were added and the reaction was continued for 1.5 h to obtain intermediate IA.

[0119] A5. Endpoint Criterion: When the viscosity of intermediate IA is 30 Pa·s at 25℃ and the viscosity change does not exceed 10% for 60 minutes, the reaction is considered to have reached the endpoint. The viscosity is measured using a rotational viscometer with a No. 2 rotor at a speed of 60 rpm.

[0120] A6. Post-processing: The intermediate IA was degassed under vacuum at 30°C for 1.0 h with a vacuum degree of -0.08 MPa, filtered through a 200-mesh filter and sealed for storage.

[0121] A7. Quality control: The solid content of intermediate IA is 60wt%, and the viscosity increase rate of intermediate IA after 7 days of storage does not exceed 30%.

[0122] In this embodiment, the B-side acrylic adhesive layer includes intermediate IB, which is prepared according to the following standard operating procedure: B1. Raw material preparation: Based on a total monomer mass of 100 parts by mass, provide 50 parts by mass of 2-ethylhexyl acrylate, 38 parts by mass of n-butyl acrylate, 3 parts by mass of acrylic acid, 7 parts by mass of 2-hydroxyethyl acrylate, 2.0 parts by mass of 3-methacryloyloxypropyltrimethoxysilane, 0.9 parts by mass of azobisisobutyronitrile, 70 parts by mass of ethyl acetate, and nitrogen gas.

[0123] B2. Premixing and deoxygenation: Add the monomer and ethyl acetate to the reactor and mix. Purge the gas phase space inside the reactor with nitrogen gas for 0.5 h to deoxygenate. The nitrogen gas flow rate is 3 L / min.

[0124] B3. Solution polymerization: Under nitrogen protection and atmospheric pressure reflux with reflux condensation, the temperature was raised to 80°C, azobisisobutyronitrile was added and reacted for 5 hours, using an anchor stirrer at 180 rpm.

[0125] B4. Endpoint Criterion: When the total mass fraction of residual monomers is less than 2wt% and the viscosity of the system is 5 Pa·s at 25℃, the polymerization is considered complete, and intermediate IB solution is obtained. The viscosity is measured by a rotational viscometer with a No. 3 rotor at a speed of 60 rpm.

[0126] B5. Post-processing: Cool the intermediate IB solution to 30°C, adjust the solid content to 52 wt% with ethyl acetate, filter through a 200-mesh filter and seal for storage.

[0127] B6. Quality control: The solid content of intermediate IB solution is 52wt%, and the viscosity fluctuation measured within the same batch does not exceed 25%.

[0128] The silicone layer coating composition for surface A in this embodiment was prepared according to the following standard operating procedure: C1. Ingredient Mixing: Based on the solids of the silicone coating composition on side A, take 30 parts by weight of the solids of intermediate IA, add 45 parts by weight of terminal hydroxyl polydimethylsiloxane and 35 parts by weight of trimethylsiloxysilicate, and mix.

[0129] C2. Dispersion: Add 1.0 part by weight of silica and disperse by ultrasonication for 0.5 h at a power of 500 W.

[0130] C3. Add crosslinking and catalytic components: Add 6 parts by mass of tetraethoxysilane and 0.22 parts by mass of dibutyltin dilaurate, stir for 0.3 h to obtain the silicone layer coating composition on side A.

[0131] C4. Endpoint Criteria: The silicone coating composition on side A has a viscosity of 20 Pa·s at 25°C and no obvious gel particles after standing for 30 min, which is considered qualified. The viscosity is measured using a rotational viscometer with a No. 2 rotor at a speed of 60 rpm.

[0132] C5. Solid content adjustment: Adjust the solid content of the silicone coating composition on side A to 50wt% using n-heptane.

[0133] The acrylic adhesive coating composition for side B in this embodiment was prepared according to the following standard operating procedure: D1. Take the main adhesive: Based on the solids content of the acrylic ester adhesive coating composition on side B, take 65 parts by weight of the solids content of intermediate IB.

[0134] D2. Tackifying resin mixing: Add 28 parts by weight of hydrogenated rosin pentaerythritol ester and mix at 75°C for 1.0 h to make it uniform. The mixture is carried out under normal pressure reflux conditions with reflux condensation, using anchor stirring at 120 rpm.

[0135] D3. Add photoinitiator and crosslinking monomer: After cooling to 25°C, add 0.75 parts by weight of 1-hydroxycyclohexylphenyl ketone and 9 parts by weight of 1,6-hexanediol diacrylate and mix for 0.3 h.

[0136] D4. Add thermosetting initiator: Add 0.60 parts by weight of benzoyl peroxide and mix for 0.3 h to obtain the acrylic adhesive coating composition for side B.

[0137] D5. Solid content adjustment: Adjust the solid content of the acrylic adhesive coating composition on side B to 52wt% with ethyl acetate.

[0138] D6. Quality control: The viscosity of the acrylic ester adhesive coating composition on side B is 10 Pa·s at 25°C and there is no obvious stratification after standing for 30 min. It is judged to be qualified. The viscosity is measured by a rotational viscometer with a No. 3 rotor and a rotation speed of 60 rpm.

[0139] The method for preparing the composite material in this embodiment includes the following steps: S1. Provide intermediate IA and a silicone coating composition for side A.

[0140] S2. Provide intermediate IB and provide an acrylate adhesive coating composition for side B.

[0141] S3. A cotton layer is provided, and the cotton layer and a polyimide film are laminated together to obtain a composite carrier layer. The lamination pressure is 0.4 MPa, the lamination temperature is 90°C, and the lamination time is 20 s. A solvent-free curable barrier layer is formed on the silicone layer side of the composite carrier layer facing side A. In this embodiment, the barrier layer is formed by solvent-free coating of the barrier layer coating composition and then curing it. The barrier layer coating composition in this embodiment includes a film-forming resin and a curing component. The curing component in this embodiment is a thermosetting curing agent. The curing method of the barrier layer in this embodiment is thermosetting, with a temperature of 120°C and a time of 2 min. The thickness of the barrier layer in this embodiment is 6 µm, which is controlled by the conversion between coating amount and solid content. The coating amount is 10 µm wet film thickness and 60 wt% solid content. The dry film thickness = wet film thickness × solid content.

[0142] S4. Coat the A-side silicone layer coating composition on the isolation barrier layer to make the dry film thickness of the A-side silicone layer 18µm. Use microgravure coating method, the wet film coating amount is 36µm. The dry film thickness of 18µm is obtained by converting the construction solid content of 50wt%. Then, cure it at 160℃ in a nitrogen environment for 2min to form the A-side silicone layer. Subsequently, laminate the first release film on the outside of the A-side silicone layer.

[0143] S5. The B-side acrylic adhesive layer coating composition is coated onto the second release film to form the B-side acrylic adhesive layer, so that the dry film thickness of the B-side acrylic adhesive layer is 27µm. The microgravure coating method is used, and the wet film coating amount is 52µm. The dry film thickness of 27µm is obtained by converting the construction solid content of 52wt%. First, UV curing is performed using an LED-UV light source with a main wavelength of 365nm, an energy density of 1200mJ / cm², and a linear velocity of 15m / min. Then, heat treatment is performed at 135℃ for 3min. Subsequently, the B-side acrylic adhesive layer is bonded to the other side of the composite carrier layer.

[0144] S6. Obtain the composite material and wind it up.

[0145] In this embodiment, the silicone layer on side A has direct adhesion to silicone rubber or silicone foam. The 180° peel strength of the silicone layer on side A, as measured by GB / T 2792-2014, is not less than 6 N / 25 mm. The bonded material is silicone foam, the bonding pressure is 2 kg (roller pressing), the resting time is 24 h, and the peeling speed is 300 mm / min. At 23°C, the acrylate adhesive layer on side B of this embodiment exhibits adhesion to metal or engineering plastic substrates for not less than 24 h, as measured by GB / T 4851-2014. The bonded material is polycarbonate sheet, the bonding pressure is 2 kg (roller pressing), the resting time is 20 min, and the loading condition is a 1000 g weight.

[0146] Example 2 Features: This example uses a rapid curing-guided parameter configuration. The dry film thickness of the silicone layer on side A is 18µm. The ratio of trimethylsiloxysilicate to hydroxyl-terminated polydimethylsiloxane is 48:48. Tetraethoxysilane is 8 parts, dibutyltin dilaurate is 0.45 parts, and n-heptane is 80 parts. The controlled hydrolysis temperature is 35℃ and the time is 0.8h. The condensation prepolymerization temperature is 95℃ and the time is 2.5h. The solid content of intermediate IA is 60wt%. The monomer ratio of intermediate IB includes 50 parts of 2-ethylhexyl acrylate, 38 parts of n-butyl acrylate, and 0.9 parts of azobisisobutyronitrile. The solution polymerization temperature was 80℃ for 5 hours. The acrylate adhesive layer on side B contained 0.75 parts of 1-hydroxycyclohexylphenyl ketone, 9 parts of 1,6-hexanediol diacrylate, and 0.60 parts of benzoyl peroxide. Side A was cured at 160℃ for 2 minutes. Side B underwent UV curing with an energy density of 1200 mJ / cm² and a heat treatment temperature of 135℃ for 3 minutes. This parameter combination, by increasing the amount of catalyst, crosslinking agent, curing temperature, and photoinitiator, achieved rapid curing and high production efficiency, making it suitable for high-speed continuous coating processes. The lower viscosity is beneficial for coating uniformity. This embodiment is applicable to high-volume manufacturing scenarios with high production efficiency requirements, and is particularly suitable for applications with strict production cycle requirements, such as rapid assembly of smart wearable devices, automated bonding production lines for consumer electronics, and high-speed mounting processes for automotive electronic modules.

[0147] Example 3

[0148] This embodiment provides a silicone-acrylate adhesive composite material with cotton and a membrane material. The composite material includes an A-side silicone layer, an isolation barrier layer, a composite carrier layer, and a B-side acrylate adhesive layer. The isolation barrier layer is disposed between the A-side silicone layer and the composite carrier layer, and is a solvent-free curable isolation barrier layer. The composite carrier layer includes a cotton layer and a membrane layer. The main component of the cotton layer is cellulose, and the membrane layer is a polyimide film. The cotton layer is located on the side facing the A-side silicone layer, and the membrane layer is located on the side facing the B-side acrylate adhesive layer. The A-side silicone layer contains a silicone-oxygen condensation network and is formed by curing a silicone layer coating composition. A first release film covers the side of the A-side silicone layer away from the composite carrier layer, and a second release film covers the side of the B-side acrylate adhesive layer away from the composite carrier layer.

[0149] The composite material of this embodiment satisfies the following structural parameters: the dry film thickness of the silicone layer on side A is 26µm, the dry film thickness of the acrylate adhesive layer on side B is 33µm, the thickness of the isolation barrier layer is 8.5µm, the thickness of the composite carrier layer is 65µm, the thickness of the first release film is 45µm, and the thickness of the second release film is 45µm.

[0150] Based on the solid content of the silicone layer on side A in this embodiment, the silicone layer on side A in this embodiment includes the following components: 62 parts by weight of hydroxyl-terminated polydimethylsiloxane, 32 parts by weight of trimethylsiloxysilicate, 6.5 parts by weight of 3-ureapropyltrimethoxysilane, 3 parts by weight of tetraethoxysilane, 0.18 parts by weight of dibutyltin dilaurate, and 4.0 parts by weight of silica. The acrylate adhesive layer on side B in this embodiment is formed by curing the acrylate adhesive layer coating composition on side B, and based on the solid content of the acrylate adhesive layer on side B in this embodiment, the acrylate adhesive layer on side B in this embodiment includes the following components: 82 parts by weight of acrylate copolymer intermediate IB, in this embodiment intermediate IB is an acrylate copolymer containing silane side groups, 14 parts by weight of hydrogenated rosin pentaerythritol ester, 0.25 parts by weight of 1-hydroxycyclohexylphenyl ketone, 3 parts by weight of 1,6-hexanediol diacrylate, and 0.20 parts by weight of benzoyl peroxide.

[0151] In this embodiment, the silicone layer on side A includes intermediate IA, which is prepared according to the following standard operating procedure: A1. Raw material preparation: Weigh out 62 parts by weight of hydroxyl-terminated polydimethylsiloxane, 32 parts of trimethylsiloxysilicate, 6.5 parts of 3-ureapropyltrimethoxysilane, 3 parts of tetraethoxysilane, 0.18 parts of dibutyltin dilaurate, 180 parts of n-heptane, 1.5 parts of water, and 0.35 parts of acetic acid, and provide nitrogen gas.

[0152] A2. Controlled hydrolysis: Under stirring conditions, 3-ureapropyltrimethoxysilane, water, and acetic acid were added to n-heptane to make the pH of the mixture 4.5. The pH of the aqueous phase was measured using a pH meter. The pH was controlled within the set range by adjusting the amount of acetic acid added. The reaction was carried out at 25°C with mechanical stirring for 1.6 h at a stirring speed of 250 rpm to obtain the hydrolysate.

[0153] A3. Condensation prepolymerization: Hydroxyl-terminated polydimethylsiloxane and trimethylsiloxysilicate are added to the hydrolysate obtained in A2. The reaction is carried out under nitrogen protection by nitrogen purging followed by a closed reaction. The nitrogen is purged 4 times and the temperature is raised to 75°C for 5 hours.

[0154] A4. Condensation reaction: Tetraethoxysilane and dibutyltin dilaurate were added and the reaction was continued for 3 hours to obtain intermediate IA.

[0155] A5. Endpoint Criterion: When the viscosity of intermediate IA is 60 Pa·s at 25℃ and the viscosity change does not exceed 10% for 60 minutes, the reaction is considered to have reached the endpoint. The viscosity is measured using a rotational viscometer with a No. 3 rotor at a speed of 30 rpm.

[0156] A6. Post-processing: The intermediate IA was degassed under vacuum at 24℃ for 2.3h with a vacuum degree of -0.09MPa, filtered through a 200-mesh filter and sealed for storage.

[0157] A7. Quality control: The solid content of intermediate IA is 48wt%, and the viscosity increase rate of intermediate IA after 7 days of storage does not exceed 30%.

[0158] In this embodiment, the B-side acrylic adhesive layer includes intermediate IB, which is prepared according to the following standard operating procedure: B1. Raw material preparation: Based on a total monomer mass of 100 parts by mass, provide 68 parts by mass of 2-ethylhexyl acrylate, 20 parts by mass of n-butyl acrylate, 8 parts by mass of acrylic acid, 2 parts by mass of 2-hydroxyethyl acrylate, 2.0 parts by mass of 3-methacryloyloxypropyltrimethoxysilane, 0.4 parts by mass of azobisisobutyronitrile, 140 parts by mass of ethyl acetate, and nitrogen gas.

[0159] B2. Premixing and deoxygenation: Add the monomer and ethyl acetate to the reactor and mix. Then, introduce nitrogen gas to bubble and deoxygenate the liquid phase for 1.6 hours at a flow rate of 1.5 L / min.

[0160] B3. Solution polymerization: Under nitrogen protection and closed pressurization, the temperature was raised to 70°C, the reactor pressure was 0.05 MPa, azobisisobutyronitrile was added and the reaction was carried out for 8.5 h. Anchor stirring was used at a speed of 130 rpm.

[0161] B4. Endpoint Criterion: When the total mass fraction of residual monomers is less than 2wt% and the viscosity of the system is 12 Pa·s at 25℃, the polymerization is considered complete, and intermediate IB solution is obtained. The viscosity is measured by a rotational viscometer with a No. 4 rotor at a speed of 30 rpm.

[0162] B5. Post-processing: Cool the intermediate IB solution to 23°C, adjust the solid content to 40 wt% with ethyl acetate, filter through a 200-mesh filter and seal for storage.

[0163] B6. Quality control: The solid content of intermediate IB solution is 40wt%, and the viscosity fluctuation measured within the same batch does not exceed 25%.

[0164] The silicone layer coating composition for surface A in this embodiment was prepared according to the following standard operating procedure: C1. Ingredient Mixing: Based on the solids of the silicone coating composition on side A, take 58 parts by weight of the solids of intermediate IA, add 18 parts by weight of terminal hydroxyl polydimethylsiloxane and 15 parts by weight of trimethylsiloxysilicate, and mix.

[0165] C2. Dispersion: Add 4.0 parts by weight of silicon dioxide and disperse by grinding for 1.6 hours. The grinding medium is zirconia beads.

[0166] C3. Add crosslinking and catalytic components: Add 1.5 parts by weight of tetraethoxysilane and 0.08 parts by weight of dibutyltin dilaurate, stir for 0.7 h to obtain the silicone layer coating composition on side A.

[0167] C4. Endpoint Criteria: The viscosity of the silicone coating composition on side A is 48 Pa·s at 25°C and no obvious gel particles are observed after standing for 30 min. It is considered qualified. The viscosity is measured using a rotational viscometer with a No. 3 rotor at a speed of 30 rpm.

[0168] C5. Solid content adjustment: Adjust the solid content of the silicone coating composition on side A to 38wt% using n-heptane.

[0169] The acrylic adhesive coating composition for side B in this embodiment was prepared according to the following standard operating procedure: D1. Take the main adhesive: Based on the solids of the acrylic ester adhesive coating composition on side B, take 82 parts by weight of the solids of intermediate IB.

[0170] D2. Tackifying resin mixing: Add 14 parts by weight of hydrogenated rosin pentaerythritol ester and mix at 45°C for 2.3 hours to make it uniform. The mixture is carried out under closed and pressurized conditions with a pressure of 0.02 MPa and a paddle stirrer at a speed of 80 rpm.

[0171] D3. Add photoinitiator and crosslinking monomer: After cooling to 35℃, add 0.25 parts by weight of 1-hydroxycyclohexylphenyl ketone and 3 parts by weight of 1,6-hexanediol diacrylate and mix for 0.7h.

[0172] D4. Add thermosetting initiator: Add 0.20 parts by weight of benzoyl peroxide and mix for 0.7 h to obtain the acrylic adhesive coating composition for side B.

[0173] D5. Solid content adjustment: Adjust the solid content of the acrylic adhesive coating composition on side B to 38 wt% with ethyl acetate.

[0174] D6. Quality Control: The viscosity of the acrylic adhesive coating composition on side B is 22 Pa·s at 25°C and there is no obvious stratification after standing for 30 min, which is considered qualified. The viscosity is measured by a rotational viscometer with a No. 3 rotor at a speed of 60 rpm.

[0175] The method for preparing the composite material in this embodiment includes the following steps: S1. Provide intermediate IA and a silicone coating composition for side A.

[0176] S2. Provide intermediate IB and provide an acrylate adhesive coating composition for side B.

[0177] S3. A cotton layer is provided, and the cotton layer and a polyimide film are laminated together to obtain a composite carrier layer. The lamination pressure is 0.5 MPa, the lamination temperature is 100°C, and the lamination time is 60 s. A solvent-free curable barrier layer is formed on the silicone layer side of the composite carrier layer facing side A. In this embodiment, the barrier layer is formed by solvent-free coating of the barrier layer coating composition and subsequent curing. The barrier layer coating composition in this embodiment includes a film-forming resin and a curing component. The curing component in this embodiment is an ultraviolet curing initiator. The curing method of the barrier layer in this embodiment is ultraviolet curing, using a mercury lamp UV light source with a main wavelength of 365 nm, an energy density of 1500 mJ / cm², and a linear velocity of 8 m / min. The thickness of the barrier layer in this embodiment is 8.5 µm, which is controlled by the conversion between coating amount and solid content. The coating amount is a wet film thickness of 17 µm, and the solid content is 50 wt%. The dry film thickness = wet film thickness × solid content.

[0178] S4. Coat the A-side silicone layer coating composition on the isolation barrier layer to make the dry film thickness of the A-side silicone layer 26µm. Use a doctor blade coating method to make the wet film coating amount 68µm. The dry film thickness of 26µm is obtained by converting the construction solid content of 38wt%. Then, cure it in air at 120℃ for 4min to form the A-side silicone layer. Subsequently, laminate the first release film on the outside of the A-side silicone layer.

[0179] S5. The B-side acrylic adhesive layer coating composition is coated onto the second release film to form the B-side acrylic adhesive layer, so that the dry film thickness of the B-side acrylic adhesive layer is 33µm. The wet film coating amount is 87µm using a doctor blade coating method. The dry film thickness of 33µm is calculated by converting the construction solids content of 38wt%. First, UV curing is performed using a mercury lamp UV light source with a main wavelength of 365nm, an energy density of 600mJ / cm², and a linear velocity of 8m / min. Then, heat treatment is performed at 85℃ for 7min. Subsequently, the B-side acrylic adhesive layer is bonded to the other side of the composite carrier layer.

[0180] S6. Obtain the composite material and wind it up.

[0181] In this embodiment, the silicone layer on side A has direct adhesion to silicone rubber or silicone foam. The 180° peel strength of the silicone layer on side A, as measured by GB / T 2792-2014, is not less than 6 N / 25 mm. The bonded material is silicone rubber, the bonding pressure is 2 kg (roller pressing), the resting time is 24 h, and the peeling speed is 300 mm / min. At 23°C, the acrylate adhesive layer on side B of this embodiment exhibits adhesion to metal or engineering plastic substrates for not less than 24 h, as measured by GB / T 4851-2014. The bonded material is aluminum alloy plate, the bonding pressure is 2 kg (roller pressing), the resting time is 20 min, and the loading condition is a 1000 g weight.

[0182] Example 3 Features: This example uses high-strength adhesive-guided parameter configuration. The dry film thickness of the silicone layer on side A is 26µm. It contains 62 parts of hydroxyl-terminated polydimethylsiloxane, 6.5 parts of 3-ureapropyltrimethoxysilane, 4.0 parts of silica, and 180 parts of n-heptane. Controlled hydrolysis is performed at pH 4.5, temperature 25℃, and time 1.6h. The condensation prepolymerization temperature is 75℃, time 5h, and condensation reaction time is 3h. Intermediate IA has a viscosity of 60 Pa·s and a solid content of 48wt%. Intermediate IB monomers include 68 parts of 2-ethylhexyl acrylate, 8 parts of acrylic acid, and 140 parts of ethyl acetate. Solution polymerization is performed at 70℃ for 8.5h. The IB layer has a viscosity of 12 Pa·s and a solid content of 40 wt%. The B-side acrylic adhesive layer intermediate IB is used in 82 parts, with a dry film thickness of 33 µm and a composite carrier layer thickness of 65 µm. The A-side curing temperature is 120℃ for 4 min, and the B-side heat treatment temperature is 85℃ for 7 min. This parameter combination, achieved by increasing the content of terminal hydroxyl polydimethylsiloxane, the amount of silane coupling agent, the amount of silica filler, the amount of acrylic copolymer, the amount of acrylic monomer, and extending the reaction and curing times, achieves a high degree of cross-linking of the siloxane condensation network and high cohesive strength of the acrylic adhesive layer. This is suitable for applications with stringent requirements for adhesive strength and holding power. This embodiment is applicable to demanding applications with extremely high requirements for adhesive reliability, particularly suitable for structural bonding of new energy vehicle power battery modules, heavy-duty vibration damping structures of industrial automation equipment, precision component fixing of high-end medical equipment, and lightweight composite material bonding in the aerospace field—areas with extremely high requirements for long-term durability and mechanical strength.

[0183] Example 4

[0184] This embodiment provides a silicone-acrylate adhesive composite material with cotton and a membrane material. The composite material includes an A-side silicone layer, an isolation barrier layer, a composite carrier layer, and a B-side acrylate adhesive layer. The isolation barrier layer is disposed between the A-side silicone layer and the composite carrier layer, and is a solvent-free curable isolation barrier layer. The composite carrier layer includes a cotton layer and a membrane layer. The main component of the cotton layer is cellulose, and the membrane layer is a polyimide film. The cotton layer is located on the side facing the A-side silicone layer, and the membrane layer is located on the side facing the B-side acrylate adhesive layer. The A-side silicone layer contains a silicone-oxygen condensation network and is formed by curing a silicone layer coating composition. A first release film covers the side of the A-side silicone layer away from the composite carrier layer, and a second release film covers the side of the B-side acrylate adhesive layer away from the composite carrier layer.

[0185] The composite material of this embodiment satisfies the following structural parameters: the dry film thickness of the silicone layer on side A is 28µm, the dry film thickness of the acrylate adhesive layer on side B is 31µm, the thickness of the isolation barrier layer is 7.5µm, the thickness of the composite carrier layer is 42µm, the thickness of the first release film is 32µm, and the thickness of the second release film is 42µm.

[0186] Based on the solid content of the silicone layer on side A in this embodiment, the silicone layer on side A in this embodiment includes the following components: 42 parts by weight of hydroxyl-terminated polydimethylsiloxane, 50 parts by weight of trimethylsiloxysilicate, 3.5 parts by weight of 3-ureapropyltrimethoxysilane, 10 parts by weight of tetraethoxysilane, 0.50 parts by weight of dibutyltin dilaurate, and 1.5 parts by weight of silica. The acrylate adhesive layer on side B in this embodiment is formed by curing the acrylate adhesive layer coating composition on side B, and based on the solid content of the acrylate adhesive layer on side B in this embodiment, the acrylate adhesive layer on side B in this embodiment includes the following components: 60 parts by weight of acrylate copolymer intermediate IB, in this embodiment intermediate IB is an acrylate copolymer containing silane side groups, 32 parts by weight of hydrogenated rosin pentaerythritol ester, 0.35 parts by weight of 1-hydroxycyclohexylphenyl ketone, 10 parts by weight of 1,6-hexanediol diacrylate, and 0.65 parts by weight of benzoyl peroxide.

[0187] In this embodiment, the silicone layer on side A includes intermediate IA, which is prepared according to the following standard operating procedure: A1. Raw material preparation: Weigh out 42 parts of terminal hydroxyl polydimethylsiloxane, 50 parts of trimethylsiloxysilicate, 3.5 parts of 3-ureapropyltrimethoxysilane, 10 parts of tetraethoxysilane, 0.50 parts of dibutyltin dilaurate, 200 parts of n-heptane, 0.8 parts of water, and 0.20 parts of acetic acid by weight, and provide nitrogen gas.

[0188] A2. Controlled hydrolysis: Under stirring conditions, 3-ureapropyltrimethoxysilane, water, and acetic acid were added to n-heptane to make the pH of the mixture 5.5. The pH of the aqueous phase was measured using a pH meter. The pH was controlled within the set range by adjusting the amount of acetic acid added. The mixture was mechanically stirred at 32°C for 1.3 h at a stirring speed of 280 rpm to obtain the hydrolysate.

[0189] A3. Condensation prepolymerization: Hydroxyl-terminated polydimethylsiloxane and trimethylsiloxysilicate were added to the hydrolysate obtained in A2. The reaction was carried out under nitrogen protection by continuously introducing nitrogen to maintain a slight positive pressure. The nitrogen flow rate was 0.8 L / min, and the temperature was raised to 90 °C for 4 h.

[0190] A4. Condensation reaction: Tetraethoxysilane and dibutyltin dilaurate were added and the reaction was continued for 2.5 h to obtain intermediate IA.

[0191] A5. Endpoint Criterion: When the viscosity of intermediate IA is 38 Pa·s at 25℃ and the viscosity change does not exceed 10% for 60 minutes, the reaction is considered to have reached the endpoint. The viscosity is measured using a rotational viscometer with a No. 2 rotor at a speed of 60 rpm.

[0192] A6. Post-processing: The intermediate IA was degassed under vacuum at 28°C for 1.8 hours with a vacuum degree of -0.085 MPa, filtered through a 200-mesh filter and sealed for storage.

[0193] A7. Quality control: The solid content of intermediate IA is 58 wt%, and the viscosity increase rate of intermediate IA after 7 days of storage does not exceed 30%.

[0194] In this embodiment, the B-side acrylic adhesive layer includes intermediate IB, which is prepared according to the following standard operating procedure: B1. Raw material preparation: Based on a total monomer mass of 100 parts by mass, provide 72 parts by mass of 2-ethylhexyl acrylate, 17 parts by mass of n-butyl acrylate, 6 parts by mass of acrylic acid, 3 parts by mass of 2-hydroxyethyl acrylate, 2.0 parts by mass of 3-methacryloyloxypropyltrimethoxysilane, 0.6 parts by mass of azobisisobutyronitrile, 90 parts by mass of ethyl acetate, and nitrogen gas.

[0195] B2. Premixing and deoxygenation: Add monomer and ethyl acetate to the reactor and mix. Purge nitrogen gas into the liquid phase for deoxygenation for 0.9 h at a flow rate of 2.5 L / min.

[0196] B3. Solution polymerization: Under nitrogen protection and atmospheric pressure reflux with reflux condensation, the temperature was raised to 73°C, azobisisobutyronitrile was added and reacted for 7 hours, using an anchor stirrer at 160 rpm.

[0197] B4. Endpoint Criterion: When the total mass fraction of residual monomers is less than 2wt% and the viscosity of the system is 9 Pa·s at 25℃, the polymerization is considered complete, and intermediate IB solution is obtained. The viscosity is measured by a rotational viscometer with a No. 3 rotor at a speed of 60 rpm.

[0198] B5. Post-processing: Cool the intermediate IB solution to 26°C, adjust the solid content to 50 wt% with ethyl acetate, filter through a 200-mesh filter and seal for storage.

[0199] B6. Quality control: The solid content of intermediate IB solution is 50wt%, and the viscosity fluctuation measured within the same batch does not exceed 25%.

[0200] The silicone layer coating composition for surface A in this embodiment was prepared according to the following standard operating procedure: C1. Ingredient Mixing: Based on the solids of the silicone coating composition on side A, take 38 parts by weight of the solids of intermediate IA, add 25 parts by weight of terminal hydroxyl polydimethylsiloxane and 38 parts by weight of trimethylsiloxysilicate, and mix.

[0201] C2. Dispersion: Add 1.5 parts by mass of silica and disperse at high speed for 0.8 hours at a speed of 2200 rpm.

[0202] C3. Add crosslinking and catalytic components: Add 7 parts by weight of tetraethoxysilane and 0.25 parts by weight of dibutyltin dilaurate, stir for 0.6 h to obtain the silicone layer coating composition on side A.

[0203] C4. Endpoint Criteria: The viscosity of the silicone coating composition on side A is 28 Pa·s at 25°C and no obvious gel particles are observed after standing for 30 min. It is considered qualified. The viscosity is measured using a rotational viscometer with rotor No. 2 and a rotation speed of 60 rpm.

[0204] C5. Solid content adjustment: Adjust the solid content of the silicone coating composition on side A to 42wt% using n-heptane.

[0205] The acrylic adhesive coating composition for side B in this embodiment was prepared according to the following standard operating procedure: D1. Take the main adhesive: Based on the solids content of the acrylic ester adhesive coating composition on side B, take 60 parts by weight of the solids content of intermediate IB.

[0206] D2. Tackifying resin mixing: Add 32 parts by weight of hydrogenated rosin pentaerythritol ester and mix at 68°C for 1.2 h to make it uniform. The mixture is carried out under normal pressure reflux conditions with reflux condensation, using anchor stirring at 110 rpm.

[0207] D3. Add photoinitiator and crosslinking monomer: After cooling to 28℃, add 0.35 parts by weight of 1-hydroxycyclohexylphenyl ketone and 10 parts by weight of 1,6-hexanediol diacrylate and mix for 0.6h.

[0208] D4. Add thermosetting initiator: Add 0.65 parts by weight of benzoyl peroxide and mix for 0.6 hours to obtain the acrylic adhesive coating composition for side B.

[0209] D5. Solid content adjustment: Adjust the solid content of the acrylic adhesive coating composition on side B to 48 wt% with ethyl acetate.

[0210] D6. Quality Control: The viscosity of the acrylic adhesive coating composition on side B is 18 Pa·s at 25°C and there is no obvious stratification after standing for 30 minutes. It is judged to be qualified. The viscosity is measured by a rotational viscometer with a No. 3 rotor and a rotation speed of 60 rpm.

[0211] The method for preparing the composite material in this embodiment includes the following steps: S1. Provide intermediate IA and a silicone coating composition for side A.

[0212] S2. Provide intermediate IB and provide an acrylate adhesive coating composition for side B.

[0213] S3. A cotton layer is provided, and the cotton layer and a polyimide film are laminated together to obtain a composite carrier layer. The lamination pressure is 0.35 MPa, the lamination temperature is 85°C, and the lamination time is 40 s. A solvent-free curable barrier layer is formed on the silicone layer side of the composite carrier layer facing side A. In this embodiment, the barrier layer is formed by solvent-free coating of the barrier layer coating composition and subsequent curing. The barrier layer coating composition in this embodiment includes a film-forming resin and a curing component. The curing component in this embodiment is a UV curing initiator. The curing method of the barrier layer in this embodiment is UV curing, using an LED-UV light source with a main wavelength of 365 nm, an energy density of 1100 mJ / cm², and a linear velocity of 9 m / min. The thickness of the barrier layer in this embodiment is 7.5 µm, which is controlled by the conversion between coating amount and solids content. The coating amount is a wet film thickness of 13.6 µm and a solids content of 55 wt%. The dry film thickness = wet film thickness × solids content.

[0214] S4. Coat the A-side silicone layer coating composition on the isolation barrier layer to make the dry film thickness of the A-side silicone layer 28µm. Use microgravure coating method, the wet film coating amount is 67µm. The dry film thickness of 28µm is obtained by converting the construction solid content of 42wt%. Then, cure it in air at 170℃ for 2.5min to form the A-side silicone layer. Subsequently, laminate the first release film on the outside of the A-side silicone layer.

[0215] S5. The B-side acrylic adhesive layer coating composition is coated onto the second release film to form the B-side acrylic adhesive layer, so that the dry film thickness of the B-side acrylic adhesive layer is 31µm. Microgravure coating method is used, the wet film coating amount is 65µm, and the dry film thickness of 31µm is obtained by converting the construction solid content of 48wt%. First, UV curing is performed using LED-UV light source, main wavelength 365nm, energy density 1000mJ / cm², linear velocity 12m / min, and then heat treatment is performed at 125℃ for 4min. Subsequently, the B-side acrylic adhesive layer is bonded to the other side of the composite carrier layer.

[0216] S6. Obtain the composite material and wind it up.

[0217] In this embodiment, the silicone layer on side A has direct adhesion to silicone rubber or silicone foam. The 180° peel strength of the silicone layer on side A, as measured by GB / T 2792-2014, is not less than 6 N / 25 mm. The bonded material is silicone rubber, the bonding pressure is 2 kg (roller pressing), the resting time is 24 h, and the peeling speed is 300 mm / min. At 23°C, the acrylate adhesive layer on side B of this embodiment exhibits adhesion to metal or engineering plastic substrates for not less than 24 h, as measured by GB / T 4851-2014. The bonded material is stainless steel plate, the bonding pressure is 2 kg (roller pressing), the resting time is 20 min, and the loading condition is a 1000 g weight.

[0218] Example 4 Features: This example uses a parameter configuration with an expanded process window. The dry film thickness of the silicone layer on side A is 28µm. The components include 42 parts of hydroxyl-terminated polydimethylsiloxane, 50 parts of trimethylsiloxysilicate, 10 parts of tetraethoxysilane, 0.50 parts of dibutyltin dilaurate, and 200 parts of n-heptane. Controlled hydrolysis is performed at pH 5.5, temperature 32℃, and time 1.3h. Condensation prepolymerization temperature is 90℃, and time is 4h. The solid content of intermediate IA is 58wt%. The monomer ratio of intermediate IB includes 72 parts of 2-ethylhexyl acrylate, 17 parts of n-butyl acrylate, and 90 parts of ethyl acetate. The solution polymerization temperature is 73℃. The curing time was 7 hours, the intermediate IB had a solid content of 50 wt%, and the B-side acrylate adhesive layer consisted of 32 parts hydrogenated rosin pentaerythritol ester, 10 parts 1,6-hexanediol diacrylate, and 0.65 parts benzoyl peroxide. The A-side curing temperature was 170℃ for 2.5 minutes, and the B-side heat treatment temperature was 125℃ for 4 minutes. This parameter combination, by using some parameters close to the boundary values, verified the adaptability and robustness of the technical solution under fluctuating process parameters, while keeping other key parameters within a safe range to ensure product quality stability. This is suitable for process parameter optimization and scale-up verification in industrial production. This embodiment is applicable to multi-variety, small-batch production scenarios that require flexible adjustment of process parameters. It is particularly suitable for applications requiring differentiated bonding of customized electronic products, new material formulation development in research institutions, process parameter exploration in the industrial pilot production stage, and bonding of outdoor electronic devices with wide requirements for environmental temperature and humidity adaptability, etc., which require a wide process window.

[0219] Comparative Example 1: Basically the same as Example 1, except that the amount of hydroxyl-terminated polydimethylsiloxane is 37 parts by mass, while the amounts of other components and preparation conditions remain unchanged.

[0220] Comparative Example 2: It is basically the same as Example 1, except that the amount of hydroxyl-terminated polydimethylsiloxane is 73 parts by mass, while the amounts of other components and preparation conditions remain unchanged.

[0221] Comparative Example 3: It is basically the same as Example 1, except that the amount of 3-ureapropyltrimethoxysilane is 0.8 parts by mass, while the amounts of other components and preparation conditions remain unchanged.

[0222] Comparative Example 4: It is basically the same as Example 1, except that the amount of tetraethoxysilane used is 0.4 parts by mass, while the amounts of other components and preparation conditions remain unchanged.

[0223] Comparative Example 5: It is basically the same as Example 1, except that the thickness of the isolation barrier layer is 4.2µm, while the amount of other components and the preparation conditions remain unchanged.

[0224] Comparative Example 6: It is basically the same as Example 1, except that the curing temperature of the silicone layer on side A is 95°C, while the amount of other components and preparation conditions remain unchanged.

[0225] Comparative Example 7: Basically the same as Example 1, except that the amount of 2-ethylhexyl acrylate in intermediate IB is 78 parts by mass and the amount of n-butyl acrylate is 15 parts by mass, while the amounts of other components and preparation conditions remain unchanged.

[0226] Comparative Example 8: Basically the same as Example 1, except that no isolation barrier layer was added, and the silicone layer on side A was directly coated on the composite carrier layer. The amount of other components and preparation conditions remained unchanged.

[0227] Performance testing: 180° Peel Strength Test of Silicone Layer A: The test object is the adhesion strength of the silicone layer A of the composite material of this invention to silicone rubber or silicone foam. The purpose of the test is to evaluate the direct adhesion and cohesive strength of the silicone layer A. The test principle is to determine the peel force per unit width under standard peel angle and speed. In the experiment, the silicone layer A of the composite material is bonded to a silicone rubber sample, rolled with a 2kg roller, and after resting for 24 hours, a 180° peel test is performed on a universal testing machine at a speed of 300mm / min. The average peel force of the stable section is recorded. Key parameters are: test temperature 23±2℃, relative humidity 50±5%RH, sample width 25mm, peel speed 300±10mm / min. Data processing: the average value is taken for each group of samples after 3 tests. Peel strength = average peel force / sample width, in N / 25mm.

[0228] Adhesion Holding Performance Test of Acrylic Adhesive Layer on Side B: The test object is the creep resistance and adhesion ability of the acrylic adhesive layer on side B of the composite material of this invention to metal or engineering plastic substrates. The purpose of the test is to evaluate the shear slip resistance time of the acrylic adhesive layer on side B under constant load. The test principle is to determine the time when the sample experiences shear failure under standard temperature and load. In the experiment, the acrylic adhesive layer on side B is bonded to a stainless steel plate or polycarbonate plate with an area of ​​25mm × 25mm. A 2kg roller is used for pressing, and after resting for 20 minutes, a 1000g weight is suspended at 23℃, and the time when displacement or detachment occurs is recorded. Key parameters are: test temperature 23±2℃, relative humidity 50±5%RH, bonding area 25mm × 25mm, and load 1000g. Data processing involves testing each group of samples three times and taking the average value. The adhesion time is expressed in hours (h).

[0229] Coating Composition Viscosity and Application Suitability Test: The test subjects were a silicone coating composition (side A) and an acrylic adhesive coating composition (side B). The purpose of the test was to evaluate the rheological properties and coating processing window of the coating composition under high solids content conditions. The test principle was to measure the apparent viscosity at different shear rates using a rotational viscometer and assess the application suitability. The experimental method involved testing the coating composition at 25°C using a rotational viscometer with rotor No. 3 selected. The viscosity change curve was measured from 10 rpm to 100 rpm, and the viscosity stability within the application solids content range was recorded. Key parameters were: test temperature 25 ± 0.5°C, rotor type and speed, and application solids content range. Data processing was performed using viscosity units of Pa·s, and viscosity-shear rate curves were plotted to calculate the viscosity range corresponding to the suitable coating window.

[0230] Anti-migration performance test of the isolation barrier layer: The test object is the solvent-free cured film-forming isolation barrier layer of the composite material of this invention. The purpose of the test is to evaluate the ability of the isolation barrier layer to prevent the migration of low molecular weight siloxanes and catalysts from the silicone layer on side A to the acrylate adhesive layer on side B. The test principle is to characterize the barrier effect by the changes in the adhesion performance and chemical composition of the acrylate adhesive layer on side B before and after aging. The experimental method is to age the composite material at 80℃ for 168h, and test the tack performance of the acrylate adhesive layer on side B and the silicon content on the XPS surface before and after aging, and compare it with Comparative Example 8 without an isolation barrier layer. The key parameters are aging temperature 80±2℃, aging time 168h, and XPS test depth 0-10nm surface layer. Data processing is as follows: tack performance retention rate = (after aging / before aging) × 100%, and the increase in the percentage of silicon atoms reflects the degree of migration.

[0231] Dimensional stability and flatness testing of composite materials: The test object is the dimensional change and warpage of the composite material of this invention under multiple thermal history conditions. The purpose of the test is to evaluate the dimensional flatness stability of the composite material after high-temperature curing of silicone and UV-heat treatment of acrylate. The test principle is to measure the change rate of length and width of the sample and the surface flatness before and after preparation. The experimental method is to cut a 300mm×300mm composite carrier layer sample, mark the baseline, and after the complete S3 to S5 process flow, measure the length and width changes and evaluate the warpage height. Flatness is measured using a micrometer or laser displacement sensor. Key parameters are: test temperature 23±2℃, sample size 300mm×300mm, measurement accuracy ±0.01mm, and thermal history conditions including silicone curing at 120-180℃ and acrylate heat treatment at 60-160℃. Data processing is as follows: dimensional change rate = absolute change / original size × 100%, warpage = maximum warpage height / sample diagonal length × 100%.

[0232] XPS Surface Chemical State Analysis: The test object was the surface chemical composition and elemental chemical state of the silicone layer on side A and the acrylate adhesive layer on side B of the composite material of this invention. The purpose of the test was to verify the interfacial reaction of the silane coupling agent and the formation mechanism of the silicon-oxygen condensation network. The test principle was to use X-ray photoelectron spectroscopy to analyze the elemental composition and chemical state binding energy within a depth of 0-10 nm on the surface. The experimental method used an XPS instrument with an Al Kα ray source and an analysis chamber vacuum degree better than 5 × 10⁻⁻⁻⁴. 7 Pa was used to scan the Si 2p, O 1s, and C 1s peaks of the silica gel layer on side A, and the C 1s, O 1s, and Si 2p peaks of the acrylate adhesive layer on side B. Gaussian-Lorentzian mixing functions were used to fit the peaks and distinguish different chemical states. Key parameters included an Al Kα X-ray source of 1486.6 eV, a scanning range of 0-1200 eV for both full-spectrum and high-resolution narrow-scan, an energy step of 0.1 eV, and a pass energy of 50 eV. Data processing involved deriving the peak positions and atomic percentages of each element, plotting high-resolution spectra, and analyzing the network structure formation through the binding energies of characteristic peaks such as Si-O-Si, Si-C, and CO.

[0233] Figure 1 The XPS surface chemical state analysis of the silica gel layer on side A in Example 1 and Comparative Example 3 shows the high-resolution peak fitting diagrams of Si 2p. The basic parameters are: Al Kα radiation source 1486.6 eV, analysis depth 0–10 nm, energy step 0.1 eV, pass energy 50 eV, and Gaussian-Lorentzian mixing function peak fitting. The variable parameter is the amount of 3-ureapropyltrimethoxysilane used: 4.5 parts in Example 1 and 0.8 parts in Comparative Example 3. The results show that the Si-O-Si component peak at 103.5 eV has a higher proportion in Example 1, and the Si-C component peak at 101.8 eV is more obvious, while the Si-OH component peak at 102.5 eV is relatively lower. The conclusion is that sufficient ureapropylsilane promotes the cross-linking of the silicon-oxygen condensation network and increases the Si-C bond formation rate at the interface, which proves that the interfacial bridging and silicon-oxygen network formation mechanism is reasonable from the perspective of surface chemical state.

[0234] Figure 2 The high-resolution peak fitting diagrams of O 1s on the surface of the A-side silica gel layer in Example 1 and Comparative Example 3 are shown. The basic parameters are the same: Al Kα radiation source 1486.6 eV, analysis depth 0–10 nm, energy step size 0.1 eV, pass energy 50 eV, and peak fitting is performed. The variable parameter is the difference in the amount of 3-ureapropyltrimethoxysilane used: 4.5 parts in Example 1 and 0.8 parts in Comparative Example 3. The results show that the O 1s main peak component related to the silicon-oxygen network is more dominant in Example 1, while the component related to hydroxyl groups is relatively weakened. The conclusion is that Example 1 has a higher degree of silicon-oxygen condensation and less residual silanol, which further supports the rationality of silane coupling agent participating in condensation and improving network density.

[0235] Figure 3 The high-resolution C 1s spectrum peak fitting diagrams for the surface chemical state analysis of the A-side silicone layer XPS in Example 1 and Comparative Example 3 are shown. The basic parameters are: Al Kα radiation source 1486.6 eV, analysis depth 0–10 nm, energy step size 0.1 eV, pass energy 50 eV, and Gaussian-Lorentzian mixture function fitting. The variable parameters are: 3-ureapropyltrimethoxysilane content: 4.5 parts in Example 1 and 0.8 parts in Comparative Example 3. The results show that the peak intensity and area fraction of components related to oxygen- and nitrogen-containing functional groups are more prominent in Example 1 and relatively weaker in Comparative Example 3. The conclusion is that sufficient urea-related structures are more fully retained and participate in interfacial interactions, which is consistent with the Si-C and Si-O-Si enhancement shown in Si 2p, thus proving that the interfacial bridging enhancement effect has a chemical basis.

[0236] Figure 4 The FTIR characteristic functional group and interaction analysis spectra of the A-side silicone layer in Examples 1, 3, and 4 are shown. The basic parameters are the wavenumber range of 4000–650 cm⁻¹, with a focus on the Si-O-Si stretching vibration region of 1020–1100 cm⁻¹, the urea C=O stretching vibration of 1650–1680 cm⁻¹, and the urea C=O stretching vibration of 1550–1580 cm⁻¹. The NH bending vibration of cm⁻¹ was measured, with the variable parameters being the amount of 3-ureapropyltrimethoxysilane used in Comparative Example 3 (0.8 parts, lower than 4.5 parts in Example 1) and the amount of tetraethoxysilane used in Comparative Example 4 (0.4 parts, lower than 6.5 parts in Example 1). The results showed that Example 1 exhibited stronger absorption in the Si-O-Si characteristic region and clearer urea-related peaks, accompanied by peak position changes caused by hydrogen bonding. In contrast, Comparative Examples 3 and 4 showed characteristics of insufficient interfacial interaction and insufficient network crosslinking, respectively. The conclusion is that the silane coupling agent and tetraethoxysilane are the key contributors to the interfacial bridging and condensation crosslinking density, respectively, proving that the synergistic design is valid at the functional group level.

[0237] Figure 5 To analyze the thermal curing kinetics of the barrier layer coating composition and the acrylate adhesive layer coating composition on the B side, the curing exothermic peaks were obtained using DSC. The basic parameters were a scan rate of 10℃ / min and a temperature range of 25–250℃. The positions and areas of the curing exothermic peaks were recorded to characterize the reaction process. The variable parameters were the system type: the barrier layer was a UV-curing rapid film-forming system, while the acrylate adhesive layer on the B side was a UV-thermal dual-curing system. The results showed that the exothermic peak shapes and temperatures of the two were different, with the B side system showing a more significant contribution to thermal curing, while the barrier layer was more inclined to rapid network formation. The conclusion is that the rapid film formation and densification of the barrier layer and the deep cross-linking curing of the adhesive layer on the B side are kinetically distinguishable and do not conflict with each other, proving that the mechanism of solvent-free rapid network formation to form a dense barrier layer is reasonable.

[0238] Figure 6 The XRD patterns of the composite carrier layers in Example 1 and Comparative Example 6 are shown for phase and orientation analysis. The basic parameters are Cu Kα radiation, scanning range 5–60°, step size 0.02°, and scanning rate 2° / min. The characteristic diffraction peaks of cellulose type I at 2θ=15.5° and 22.5° and the amorphous background of polyimide are analyzed. The variable parameter is the curing temperature of the silicone layer on the A side, which is 140°C in Example 1 and 95°C in Comparative Example 6, resulting in differences in thermal history response. The results show that the characteristic peak positions and relative intensities of cellulose in Example 1 are more stable, while Comparative Example 6 is more prone to peak intensity changes and background morphology differences. The conclusion is that appropriate curing temperature and thermal history management help maintain the stability of the microcrystalline phase structure of the cotton and polyimide composite carrier layer, which is corroborated by the macroscopic dimensional stability results, proving that the carrier layer structural stability control scheme is reasonable and effective.

[0239] Figure 7 Macroscopic photographs of the silicone-acrylate / cotton-PI composite material prepared for Example 1 show the typical appearance of the sample in the state of double-sided release film coating. The sample as a whole exhibits a milky white to light amber translucent state, which is caused by the light scattering effect of the internal cotton fiber network and the intrinsic color of the polyimide film. The surface exhibits high gloss due to the PET release film coating. Slight curling is observed at the edges of the sample in the photographs, reflecting the differences in internal stress generated by the different materials in the multilayer fabrication process. At the same time, small random defects are visible on the surface, reflecting the characteristics of a real fabricated sample.

[0240] Figure 8 This is a low-magnification SEM image of the silicone layer on side A of the composite material prepared in Example 1. This image, at low magnification, characterizes the macroscopic film-forming effect of the microgravure coating process, showing that the silicone layer forms a continuous and complete coverage on the carrier surface, with no exposed fibers or broken coating areas. The surface exhibits characteristic weak coating flow marks and no obvious macroscopic defects or pores, proving that the coating process parameters were set reasonably, achieving good coating uniformity and appearance quality.

[0241] Figure 9 This is a bright-field transmission electron microscope (TEM) image of the silicone layer on side A of the composite material in Example 1. The image shows the internal microstructure of the silicone layer on side A based on mass-thickness contrast. The baseline parameter is a polymer matrix background with weak contrast, and the variable parameters are the spatial dispersion morphology and aggregate size of the SiO2 nanofiller. The image clearly shows SiO2 existing as nanoscale primary particles and submicron-sized aggregates formed by sintering, uniformly distributed within the field of view, with no significant aggregates larger than 1 micrometer observed. The conclusion demonstrates that this preparation process successfully achieved good dispersion of the nanofiller in the silicone soft matrix, providing a microstructural basis for the uniformity of material properties.

[0242] Table 1. Performance comparison data between the examples and comparative examples.

[0243] As can be seen from the performance of the embodiments and comparative examples in Table 1, all embodiments are significantly better than most comparative examples in terms of peel strength of the silicone layer on side A and tack performance of the acrylic adhesive layer on side B, which proves the synergistic effect of the technical solution of the present invention. In Comparative Example 1, the amount of terminal hydroxyl polydimethylsiloxane used was below the lower limit, resulting in insufficient crosslinking density of the siloxane condensation network, and a decrease in both peel strength and holding power. In Comparative Example 2, the amount of this component was above the upper limit, resulting in excessively high system viscosity, which affected the coating uniformity. In Comparative Example 3, the amount of silane coupling agent 3-ureapropyltrimethoxysilane was insufficient, resulting in weakened interfacial bonding. In Comparative Example 4, the amount of crosslinking agent tetraethoxysilane was too low, resulting in insufficient network crosslinking. In Comparative Example 5, the thickness of the isolation barrier layer was below the lower limit, resulting in a significant decrease in barrier migration ability to 78%. In Comparative Example 6, the curing temperature of surface A was too low, resulting in incomplete siloxane condensation reaction, and a significant decrease in peel strength and holding power. In Comparative Example 7, the imbalance of the monomer ratio of intermediate IB resulted in insufficient cohesive strength of the acrylate adhesive layer, and the holding power was only 18h. In Comparative Example 8, the absence of the isolation barrier layer caused low molecular weight siloxane to migrate to surface B, resulting in a barrier rate of only 45% and a significant decrease in holding power to 12h. Example 3 achieved the highest peel strength of 9.5 N / 25 mm and holding power of 42 h by optimizing the ratio of hydroxyl-terminated polydimethylsiloxane to silane coupling agent, increasing the silica filler content, and extending the reaction time. However, the coating viscosity was correspondingly increased to 48 Pa·s, making it suitable for applications with extremely high requirements for bonding reliability. Example 2 achieved rapid curing and low viscosity of 20 Pa·s by increasing the catalyst dosage and curing temperature, making it suitable for high-speed continuous coating processes. Examples 1 and 4 used moderate parameter configurations and achieved a good balance between peel strength, holding power, coating viscosity, and dimensional stability.

[0244] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that any equivalent structural transformations made under the concept of the present invention and using the contents of the specification and drawings of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A composite material of silicone-acrylate adhesive, cotton, and membrane materials, characterized in that, The composite material includes a silicone layer on side A, an isolation barrier layer, a composite carrier layer, and an acrylic adhesive layer on side B. The isolation barrier layer is disposed between the silicone layer on side A and the composite carrier layer. The isolation barrier layer is a solvent-free curing isolation barrier layer. The composite carrier layer includes at least a cotton layer, the main component of which is cellulose; when the composite carrier layer includes a membrane layer, the membrane layer is a polyimide film. The silicone layer on side A contains a silicon-oxygen condensation network and is formed by curing a silicone layer coating composition on side A. Wherein, the silicone layer on side A, away from the composite carrier layer, is covered with a first release film, and the acrylic adhesive layer on side B, away from the composite carrier layer, is covered with a second release film; Furthermore, the composite material satisfies the following structural parameters: the dry film thickness of the silicone layer on side A is 15 to 30 µm, the dry film thickness of the acrylate adhesive layer on side B is 25 to 35 µm, the thickness of the isolation barrier layer is 5 to 10 µm, the thickness of the composite carrier layer is 20 to 80 µm, the thickness of the first release film is 25 to 50 µm, and the thickness of the second release film is 25 to 50 µm.

2. The composite material according to claim 1, characterized in that, Based on the solid content of the silicone layer on side A, the silicone layer on side A comprises the following components: α-hydroxyl-terminated polydimethylsiloxane, 40 to 70 parts by weight; β-trimethylsiloxysilicate, 25 to 55 parts by weight; c3-ureapropyltrimethoxysilane, 1 to 8 parts by weight; d-Tetraethoxysilane, 1 to 12 parts by weight; e. Dibutyltin dilaurate, 0.01 to 0.60 parts by weight; f. Silicon dioxide, 0 to 5 parts by weight; The B-side acrylate adhesive layer is formed by curing a B-side acrylate adhesive layer coating composition, and based on the solids content of the B-side acrylate adhesive layer, the B-side acrylate adhesive layer comprises the following components: The solids content of acrylate copolymer intermediate IB is 55 to 90 parts by weight, wherein intermediate IB is an acrylate copolymer containing silane side groups; h-hydrogenated rosin pentaerythritol ester, 10 to 35 parts by weight; i1-Hydroxycyclohexylphenyl ketone, 0.05 to 1.00 parts by weight; j1,6-hexanediol diacrylate, 1 to 12 parts by weight; K-benzoyl peroxide, 0.05 to 0.80 parts by weight.

3. The composite material according to claim 1, characterized in that, The silicone layer on side A includes intermediate IA, which is prepared according to the following standard operating procedure: A1. Raw material preparation: Weigh out 40 to 70 parts by weight of hydroxyl-terminated polydimethylsiloxane, 25 to 55 parts of trimethylsiloxysilicate, 1 to 8 parts of 3-ureapropyltrimethoxysilane, 1 to 12 parts of tetraethoxysilane, 0.01 to 0.60 parts of dibutyltin dilaurate, 40 to 220 parts of n-heptane, 0.1 to 2.0 parts of water, and 0.01 to 0.50 parts of acetic acid, and provide nitrogen gas; A2. Controlled hydrolysis: Under stirring conditions, 3-ureapropyltrimethoxysilane, water, and acetic acid are added to n-heptane to adjust the pH of the mixture to 4 to 6, and the mixture is reacted at 20 to 40 °C for 0.5 to 2 h to obtain the hydrolysate; A3. Condensation prepolymerization: Hydroxyl-terminated polydimethylsiloxane and trimethylsiloxysilicate are added to the hydrolysate obtained in A2, and the mixture is heated to 60 to 110°C under nitrogen protection and reacted for 1 to 6 hours. A4. Condensation reaction: Tetraethoxysilane and dibutyltin dilaurate were added and the reaction was continued for 0.5 to 4 hours to obtain intermediate IA; A5. Endpoint Criterion: When the viscosity of intermediate IA is 10 to 80 Pa·s at 25°C and the viscosity change does not exceed 10% for 60 minutes, the reaction is considered to have reached the endpoint. A6. Post-processing: Degas intermediate IA at 20 to 35°C for 0.5 to 3 hours, filter and seal for storage; A7. Quality control: The solid content of intermediate IA is 40 to 70 wt%, and the viscosity increase rate of intermediate IA after 7 days of storage does not exceed 30%.

4. The composite material according to claim 1, characterized in that, The B-side acrylate adhesive layer includes intermediate IB, which is prepared according to the following standard operating procedure: B1. Raw material preparation: Based on a total monomer mass of 100 parts by weight, provide 45 to 75 parts by weight of 2-ethylhexyl acrylate, 15 to 45 parts by weight of n-butyl acrylate, 1 to 10 parts by weight of acrylic acid, 1 to 15 parts by weight of 2-hydroxyethyl acrylate, 0.5 to 5 parts by weight of 3-methacryloyloxypropyltrimethoxysilane, 0.2 to 1.2 parts by weight of azobisisobutyronitrile, 40 to 160 parts by weight of ethyl acetate, and nitrogen gas; B2. Premixing and deoxygenation: Add the monomer and ethyl acetate to the reaction vessel and mix, then purge with nitrogen for 0.2 to 2 hours for deoxygenation; B3. Solution polymerization: Under nitrogen protection, heat to 65 to 85°C, add azobisisobutyronitrile and react for 3 to 10 hours; B4. Endpoint criterion: When the total mass fraction of residual monomers is less than 2wt% and the viscosity of the system is 1 to 15 Pa·s at 25°C, the polymerization is considered complete, and intermediate IB solution is obtained; B5. Post-processing: Cool the intermediate IB solution to 20 to 35°C, adjust the solid content to 35 to 60 wt% with ethyl acetate, filter and seal for storage; B6. Quality control: The solid content of intermediate IB solution is 35 to 60 wt%, and the viscosity fluctuation measured within the same batch does not exceed 25%.

5. The composite material according to claim 1, characterized in that, The silicone layer coating composition for side A was prepared according to the following standard operating procedure: C1. Ingredient mixing: Based on the solids of the silicone coating composition on side A, take 20 to 70 parts by weight of the solids of intermediate IA, add 10 to 60 parts by weight of terminal hydroxyl polydimethylsiloxane and 10 to 50 parts by weight of trimethylsiloxysilicate and mix. C2. Dispersion: Add 0 to 5 parts by weight of silica and disperse for 0.2 to 2 hours; C3. Add crosslinking and catalytic components: Add 0.5 to 8 parts by weight of tetraethoxysilane and 0.01 to 0.30 parts by weight of dibutyltin dilaurate, stir for 0.1 to 1 h to obtain the silicone layer coating composition on side A; C4. Endpoint Criterion: The silicone coating composition on side A is considered qualified if the viscosity is 5 to 60 Pa·s at 25°C and no obvious gel particles are observed after standing for 30 minutes. C5. Solid content adjustment: Adjust the solid content of the silicone coating composition on side A to 25 to 65 wt% using n-heptane.

6. The composite material according to claim 1, characterized in that, The acrylic adhesive coating composition for side B was prepared according to the following standard operating procedure: D1. Take the main adhesive: Based on the solids content of the acrylic adhesive layer coating composition on side B, take 55 to 90 parts by weight of the solids content of intermediate IB; D2. Tackifying resin mixing: Add 10 to 35 parts by weight of hydrogenated rosin pentaerythritol ester and mix at 30 to 90°C for 0.2 to 3 hours to make it uniform; D3. Add photoinitiator and crosslinking monomer: After cooling to 20 to 40°C, add 0.05 to 1.00 parts by weight of 1-hydroxycyclohexylphenyl ketone and 1 to 12 parts by weight of 1,6-hexanediol diacrylate and mix for 0.1 to 1 h; D4. Add thermosetting initiator: Add 0.05 to 0.80 parts by weight of benzoyl peroxide and mix for 0.1 to 1 hour to obtain the acrylic adhesive coating composition for side B; D5. Solid content adjustment: Adjust the solid content of the acrylic adhesive coating composition on side B to 25 to 65 wt% using ethyl acetate; D6. Quality Control: The acrylic adhesive coating composition on side B has a viscosity of 1 to 30 Pa·s at 25°C and shows no obvious delamination after standing for 30 minutes, which is considered qualified.

7. The composite material according to claim 1, characterized in that, The composite carrier layer includes a cotton layer and a membrane layer. The cotton layer is located on the side facing the silicone layer on side A, and the membrane layer is located on the side facing the acrylic adhesive layer on side B. The silicone layer on side A has direct adhesion to silicone rubber or silicone foam, and the 180° peel strength of the silicone layer on side A is not less than 6 N / 25 mm as determined by GB / T 2792-2014; and, at 23°C, the tack performance of the acrylic adhesive layer on side B to metal substrates or engineering plastic substrates is not less than 24 h as determined by GB / T 4851-2014.

8. The method for preparing a composite material of silicone-acrylate adhesive, cotton, and membrane materials according to claim 1, characterized in that, Includes the following steps: S1. Provide intermediate IA and a silicone layer coating composition for side A; S2. Provide intermediate IB and provide an acrylate adhesive coating composition for side B; S3. Provide a cotton layer, optionally composite the cotton layer with a polyimide film to obtain a composite carrier layer, and form a solvent-free curable barrier layer on the silicone layer side of the composite carrier layer facing side A; S4. Coating an A-side silicone layer coating composition onto an isolation barrier layer, such that the dry film thickness of the A-side silicone layer is 15 to 30 µm, and curing it at 100 to 180 °C to form the A-side silicone layer, and then laminating a first release film onto the outside of the A-side silicone layer. S5. Apply the B-side acrylate adhesive layer coating composition onto the second release film to form the B-side acrylate adhesive layer, such that the dry film thickness of the B-side acrylate adhesive layer is 25 to 35 µm. First, perform UV curing, then heat treat at 60 to 160 °C for 0.5 to 10 min, and then bond the B-side acrylate adhesive layer to the other side of the composite carrier layer. S6. Obtain the composite material and wind it up.

9. The preparation method according to claim 8, characterized in that, In S3, the cotton layer and the polyimide film are laminated together to form a composite carrier layer.

10. The preparation method according to claim 8, characterized in that, The isolation barrier layer formed in S3 is a solvent-free curing film, and the curing in S4 is carried out in a nitrogen or air environment.

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