A matt base glue for silicone leather coating and a preparation method thereof

Abstract

This application relates to the field of leather coating materials, specifically disclosing a matte base adhesive for silicone leather coatings and its preparation method. The matte base adhesive for silicone leather coatings is prepared from the following raw materials in parts by weight: 30-40 parts vinyl silicone oil, 15-25 parts pretreated silica, and 10-20 parts vinyl MQ silicone resin. The pretreated silica is prepared from silica, an aqueous ethanol solution, a silane coupling agent, a vinyl polydimethylsiloxane / polymethylsiloxane silsesquioxane crosslinking polymer, a hydroxyl-terminated polymethylvinylsiloxane-polydimethylsiloxane copolymer, and glycidyl ethers. The matte base adhesive prepared in this application, when applied to silicone leather coatings, exhibits good matte texture and flexibility. The resulting silicone leather coating maintains good wear resistance and stability over long-term use, is not prone to cracking, and can be widely used in automotive seats, home furnishings, medical applications, and other fields.

Description

Technical Field

[0001] This application relates to the field of leather coating materials, and more specifically, it relates to a matte base adhesive for silicone leather coating and a method for preparing the same. Background Technology

[0002] Compared to PVC and PU leather, silicone leather boasts superior texture, softness, and environmental friendliness, making it widely used in automotive products such as car seats; home furnishings such as furniture and sofas; 3C electronic products such as computer and mobile phone cases; and medical applications. Silicone leather typically consists of a base fabric layer, an adhesive layer, and a silicone leather coating. The silicone leather coating imparts excellent texture, softness, stain resistance, and abrasion resistance. The silicone leather coating is generally prepared through a hydrosilylation reaction of vinyl silicone oil, hydrogen-containing silicone oil, platinum catalyst, and additives. To impart superior performance to the silicone leather coating, the proportions of each silicone oil component and additive need to be repeatedly adjusted, resulting in a high cost for the entire experimental process.

[0003] To address the aforementioned technical challenges, the raw materials for the silicone leather coating are first formulated into a base adhesive. This base adhesive is then used in downstream formulations, allowing for direct application with reaction aids without requiring repeated adjustments to the entire formulation's components. This saves downstream R&D costs and time. Consequently, the performance requirements for the base adhesive are quite stringent.

[0004] The base adhesive in the existing technology is generally composed of vinyl silicone oil and fillers. Although it can give the base adhesive a certain texture and wear resistance, when applied to silicone leather coating materials, the resulting silicone leather is easily affected by environmental factors after a period of use, which makes the leather surface prone to wear and cracking. Therefore, the performance of the base adhesive needs to be further improved. Summary of the Invention

[0005] To address the problem that existing base adhesives used in silicone leather coatings are prone to wear and cracking during long-term use, this application provides a matte base adhesive for silicone leather coatings and its preparation method.

[0006] In a first aspect, this application provides a matte adhesive for silicone leather coatings, employing the following technical solution:

[0007] A matte base adhesive for silicone leather coating is prepared from the following raw materials in parts by weight:

[0008] 30-40 parts vinyl silicone oil

[0009] Pretreatment: 15-25 parts silica, 10-20 parts vinyl MQ silicone resin;

[0010] The pretreated silica is prepared from silica, aqueous ethanol solution, silane coupling agent, vinyl polydimethylsiloxane / polymethylsiloxane silsesquioxane crosslinked polymer, hydroxyl-terminated polymethylvinylsiloxane-polydimethylsiloxane copolymer, and glycidyl ethers.

[0011] By adopting the above technical solution, the matte adhesive of this application is prepared from vinyl silicone oil, pretreated silica and vinyl MQ silicone resin. Vinyl silicone oil is used as the matrix and is compounded with vinyl MQ silicone resin to form a stable network structure, which significantly improves the flexibility and wear resistance of the matte adhesive. Silica was modified using an aqueous ethanol solution, a silane coupling agent, a vinyl polydimethylsiloxane / polymethylsiloxane-silsesquioxane crosslinking polymer, a hydroxyl-terminated polymethylvinylsiloxane-polydimethylsiloxane copolymer, and glycidyl ethers to prepare pretreated silica with good dispersion uniformity. The addition of pretreated silica reinforces the network molecular structure, further enhancing the matte texture and flexibility of the resulting matte adhesive. In application, it can be directly used with reaction aids such as hydrogen-containing silicone oil and platinum catalysts to form a stable and dense network crosslinked macromolecular structure, thereby endowing the resulting silicone leather coating with excellent matte texture, flexibility, and wear resistance. It is not prone to cracking after long-term use and can be widely used in automotive seats, home furnishings, medical applications, and other fields.

[0012] Preferably, the pretreated silica is prepared from the following raw materials in parts by weight:

[0013] 100-120 parts of silicon dioxide

[0014] 60-100 parts of 50-85wt% ethanol aqueous solution

[0015] 3-5 parts of silane coupling agent

[0016] 20-30 parts of vinyl polydimethylsiloxane / polymethylsiloxane silsesquioxane crosslinked polymer

[0017] 15-25 parts of hydroxyl-terminated polymethylvinylsiloxane-polydimethylsiloxane copolymer

[0018] 10-20 parts of glycidyl ethers.

[0019] By employing the above technical solution, silica is surface-hydroxylated using an ethanol-water solution. Subsequently, a silane coupling agent, a vinyl polydimethylsiloxane / polymethylsiloxane-silsesquioxane crosslinking polymer, a hydroxyl-terminated polymethylvinylsiloxane-polydimethylsiloxane copolymer, and glycidyl ethers are added to modify the surface-hydroxylated silica. The vinyl polydimethylsiloxane / polymethylsiloxane-silsesquioxane crosslinking polymer exhibits a good synergistic effect with silica, improving the matte texture and abrasion resistance of the resulting matte adhesive. The silane coupling agent, hydroxyl-terminated polymethylvinylsiloxane-polydimethylsiloxane copolymer, and glycidyl ethers further synergize and uniformly adsorb onto the surfaces of silica and the vinyl polydimethylsiloxane / polymethylsiloxane-silsesquioxane crosslinking polymer, further improving the dispersion uniformity of silica and the vinyl polydimethylsiloxane / polymethylsiloxane-silsesquioxane crosslinking polymer, thereby endowing the resulting matte adhesive with better flexibility and abrasion resistance. When the prepared matte base adhesive is applied, the pretreated silica can further synergize with the matte base adhesive system and reaction aids to produce better crosslinking performance, improve the crosslinking density of the prepared silicone leather coating, and thus improve the wear resistance and crack resistance of the prepared silicone leather coating.

[0020] Preferably, the silane coupling agent is composed of γ-mercaptopropyltrimethoxysilane coupling agent and dodecyltrimethoxysilane in a weight ratio of 1:(2-3).

[0021] By adopting the above technical solution, using γ-mercaptopropyltrimethoxysilane coupling agent and dodecyltrimethoxysilane in a better weight ratio as silane coupling agents, the compatibility and dispersion uniformity of silica and vinyl polydimethylsiloxane / polymethylsiloxane silsesquioxane crosslinked polymers in hydroxyl-terminated polymethylvinylsiloxane-polydimethylsiloxane copolymers and glycidyl ethers can be further improved. This improves the modification efficiency of pretreated organosilicon, thereby improving the overall flexibility and tear resistance of the prepared matte base adhesive. As a result, the prepared organosilicon leather coating is less prone to wear and cracking during long-term use.

[0022] Preferably, the glycidyl ether is composed of 1,2-cyclohexanediol diglycidyl ether and 4-vinylphenyl glycidyl ether in a weight ratio of (1.5-2.5):1.

[0023] By adopting the above technical solution, 1,2-cyclohexanediol diglycidyl ether and 4-vinylphenyl glycidyl ether are compounded in a specific ratio to improve the dispersion performance of pretreated silica, thereby enhancing the overall flexibility and abrasion resistance of the matte base adhesive and further reducing the wear and cracking problems that easily occur in silicone leather coatings during long-term use.

[0024] Preferably, the particle size of the silica is 50-100 nm.

[0025] By adopting the above technical solution, silica with a better particle size can give the silicone leather coating a delicate matte texture, can be better dispersed in the matte base adhesive, and enhance the mechanical strength and abrasion resistance of the prepared silicone leather coating.

[0026] Preferably, the pretreated silica is prepared by the following steps:

[0027] A1. Add silicon dioxide to an aqueous ethanol solution, mix and stir, filter, and obtain hydroxylated silicon dioxide;

[0028] A2. Hydroxylated silica, silane coupling agent, vinyl polydimethylsiloxane / polymethylsiloxane silsesquioxane crosslinking polymer, hydroxyl-terminated polymethylvinylsiloxane-polydimethylsiloxane copolymer, and glycidyl ethers are added to a reaction apparatus for kneading and dispersion to obtain pretreated silica.

[0029] By adopting the above technical solution, pretreated silica with good dispersion uniformity and compatibility was prepared.

[0030] Preferably, the vinyl silicone oil has a vinyl content of 0.9-1.2% and a viscosity of 60-100 cst.

[0031] By adopting the above technical solution, vinyl silicone oil with optimal vinyl content and viscosity can effectively improve the mechanical strength and fluidity of matte base adhesive, thereby enhancing the abrasion resistance and crack resistance of silicone leather when used in combination with pretreated silica and vinyl MQ silicone resin, while ensuring good processing performance and soft leather texture.

[0032] Preferably, the vinyl MQ silicone resin has a vinyl content of 1.2-1.5%, a viscosity of 80-200 cst, and an MQ ratio of 0.8-0.9.

[0033] By adopting the above technical solution, the specific vinyl content, viscosity and MQ ratio of vinyl MQ silicone resin have a moderate network cross-linking structure, which can significantly improve the overall stability and mechanical strength of the matte base adhesive, thereby effectively enhancing the wear resistance and durability of the prepared silicone leather coating and reducing wear and cracking caused by environmental factors during long-term use.

[0034] Secondly, this application provides a method for preparing a matte-based adhesive for silicone leather coatings, employing the following technical solution:

[0035] A method for preparing a matte adhesive for silicone leather coating includes the following steps: adding vinyl silicone oil, pretreated silica and vinyl MQ silicone resin into a reaction device for kneading to obtain a matte adhesive for silicone leather coating.

[0036] By adopting the above technical solution, the resulting matte base adhesive exhibits good wear resistance and crack resistance when applied to silicone leather coatings, thus extending the service life of the silicone leather coating.

[0037] Preferably, the kneading temperature is 55-75℃ and the kneading time is 1-3 hours.

[0038] By adopting the above technical solution, the optimal kneading temperature and time can effectively promote the uniform dispersion of vinyl silicone oil, pretreated silica and vinyl MQ silicone resin, and improve the stability and mechanical properties of matte base adhesive.

[0039] In summary, this application includes at least one of the following beneficial technical effects:

[0040] 1. This application uses vinyl silicone oil, pretreated silica and vinyl MQ silicone resin to prepare a matte base adhesive. The prepared matte base adhesive has good matte texture, wear resistance and flexibility. When applied to silicone leather coating, it solves the problem of wear and cracking that silicone leather coating is prone to during long-term use. It can be widely used in automotive seats, home furnishings, medical and other fields.

[0041] 2. By using an ethanol-water solution to hydroxylate the surface of silica, followed by the addition of a silane coupling agent, a vinyl polydimethylsiloxane / polymethylsiloxane-silsesquioxane crosslinking polymer, a hydroxyl-terminated polymethylvinylsiloxane-polydimethylsiloxane copolymer, and glycidyl ethers to modify the surface-hydroxylated silica, the resulting pretreated silica can synergistically crosslink with the matte adhesive system during application, further enhancing the matte texture, flexibility, and abrasion resistance of the resulting matte adhesive.

[0042] 3. Using γ-mercaptopropyltrimethoxysilane coupling agent and dodecyltrimethoxysilane as silane coupling agents, and 1,2-cyclohexanediol diglycidyl ether and 4-vinylphenyl glycidyl ether as glycidyl ethers, can further improve the dispersion uniformity of the pretreated silica and further improve the flexibility and wear resistance of the matte adhesive. Detailed Implementation

[0043] The present application will be further described in detail below with reference to the embodiments.

[0044] The following are some of the sources and specifications of the raw materials used in this application. The raw materials used in the preparation examples and embodiments of this application can all be obtained commercially, including but not limited to the following models and manufacturers of raw materials. Raw materials with equivalent performance can also be used:

[0045] 1. Silica: Fumed silica, with a particle size of 50-100nm;

[0046] 2. Vinyl silicone oil: vinyl content 0.9-1.2%, viscosity 60-100 cst;

[0047] 3. Vinyl MQ silicone resin: vinyl content 1.2-1.5%, viscosity 80-200 cst, MQ ratio 0.8-0.9;

[0048] 4. Vinyl polydimethylsiloxane / polymethylsiloxane silsesquioxane crosslinked polymer: Model KSP101;

[0049] 5. Hydroxyl-terminated polymethylvinylsiloxane-polydimethylsiloxane copolymer: OF6051, Sisbo Organosilicon.

[0050] Example of Pretreated Silica Preparation

[0051] Preparation Example 1

[0052] Preparation Example 1 discloses a pretreated silica, which is prepared by the following steps:

[0053] A1. Add 10 kg of silica to 6 kg of 50 wt% ethanol aqueous solution, heat to 50 °C, mix and stir for 60 min, filter, and obtain hydroxylated silica.

[0054] A2. The hydroxylated silica obtained in step A1, 0.3 kg of silane coupling agent (composed of vinyltrimethoxysilane and dodecyltrimethoxysilane in a weight ratio of 1:2), 3 kg of vinyl polydimethylsiloxane / polymethylsiloxane silsesquioxane crosslinking polymer, 1.5 kg of hydroxyl-terminated polymethylvinylsiloxane-polydimethylsiloxane copolymer, and 2 kg of glycidyl ether (composed of ethylene glycol diglycidyl ether and 1,2-cyclohexanediol diglycidyl ether in a weight ratio of 1:1) are added to a reaction vessel and kneaded and dispersed at a temperature of 70°C for 2 hours to obtain pretreated silica.

[0055] Preparation Examples 2-3

[0056] The difference between Preparation Examples 2-3 and Preparation Example 1 lies in the different preparation parameters, as detailed in Table 1 below.

[0057] Table 1. Preparation parameters for preparation examples 1-3

[0058]

[0059]

[0060] Preparation Example 4

[0061] The difference between Preparation Example 4 and Preparation Example 1 is that the silane coupling agent is composed of γ-mercaptopropyltrimethoxysilane coupling and dodecyltrimethoxysilane in a weight ratio of 1:2, while the rest is the same as Preparation Example 1.

[0062] Preparation Example 5

[0063] The difference between Preparation Example 5 and Preparation Example 1 is that the silane coupling agent is composed of γ-mercaptopropyltrimethoxysilane and dodecyltrimethoxysilane in a weight ratio of 1:3, while the rest is the same as Preparation Example 1.

[0064] Preparation Example 6

[0065] The difference between Preparation Example 6 and Preparation Example 4 is that the glycidyl ether is composed of 1,2-cyclohexanediol diglycidyl ether and 4-vinylphenyl glycidyl ether in a weight ratio of 1.5:1, while the rest is the same as Preparation Example 4.

[0066] Preparation Example 7

[0067] The difference between Preparation Example 7 and Preparation Example 4 is that the glycidyl ether is composed of 1,2-cyclohexanediol diglycidyl ether and 4-vinylphenyl glycidyl ether in a weight ratio of 2.5:1, while the rest is the same as Preparation Example 4.

[0068] Preparation of Comparative Example 1

[0069] The difference between Comparative Example 1 and Preparation Example 1 is that the vinyl polydimethylsiloxane / polymethylsiloxane silsesquioxane crosslinked polymer was replaced with an equal amount of silicon dioxide, while the rest was the same as Preparation Example 1.

[0070] Preparation of Comparative Example 2

[0071] The difference between Comparative Example 2 and Preparation Example 1 is that the hydroxyl-terminated polymethylvinylsiloxane-polydimethylsiloxane copolymer was replaced in equal amounts with hydroxyl-terminated polydimethylsiloxane. OF0025, Sisbo organosilicon, otherwise the same as in Preparation Example 1.

[0072] Preparation of Comparative Example 3

[0073] The difference between Comparative Example 3 and Preparation Example 1 is that glycidyl ethers were replaced with silane coupling agents in equal amounts; otherwise, they were the same as Preparation Example 1.

[0074] Preparation of Comparative Example 4

[0075] The difference between Comparative Example 4 and Preparation Example 1 is that glycidyl ethers were replaced with polyethylene glycol 800 in equal amounts; otherwise, they were the same as Preparation Example 1.

[0076] Example

[0077] Example 1

[0078] Example 1 discloses a matte base adhesive for silicone leather coating, which is prepared by the following steps: 3 kg of vinyl silicone oil, 1.5 kg of pretreated silica prepared in Example 1 and 2 kg of vinyl MQ silicone resin are added to a mixer for kneading. The kneading temperature is 55°C and the kneading time is 3 h to obtain the matte base adhesive for silicone leather coating.

[0079] Example 2-3

[0080] The difference between Examples 2-3 and Example 1 lies in the amount of raw materials used and the preparation parameters, as detailed in Table 2 below.

[0081] Table 2 Parameter table for Examples 1-3

[0082]

[0083]

[0084] Examples 4-7

[0085] The difference between Examples 4-7 and Example 1 is that the source of the pretreated silica is different, as detailed in Table 3 below.

[0086] Table 3. Source of pretreated silica in Examples 4-7

[0087] Example Pretreatment silica source Example 4 Preparation Example 4 Example 5 Preparation Example 5 Example 6 Preparation Example 6 Example 7 Preparation Example 7

[0088] Comparative Example

[0089] Comparative Examples 1-4

[0090] The difference between Comparative Examples 1-4 and Example 1 is that the source of the pretreated silica is different, as detailed in Table 4 below.

[0091] Table 4. Sources of pretreated silica in Comparative Examples 1-4

[0092] Comparative Example Pretreatment silica source Comparative Example 1 Preparation of Comparative Example 1 Comparative Example 2 Preparation of Comparative Example 2 Comparative Example 3 Preparation of Comparative Example 3 Comparative Example 4 Preparation of Comparative Example 4

[0093] Comparative Example 5

[0094] The difference between Comparative Example 5 and Example 1 is that the pretreated silica was replaced with an equal amount of fumed silica, while the rest was the same as Example 1.

[0095] Application examples

[0096] Application Example 1

[0097] Application Example 1 discloses an organosilicon leather coating material, prepared by the following steps: 10 kg of the matte base adhesive from Example 1, 0.8 kg of hydrogen-containing silicone oil, 0.2 kg of platinum catalyst, and 0.02 kg of 1-ethynylcyclohexanol as an inhibitor are added to a mixer and mixed evenly to obtain the organosilicon leather coating material; the hydrogen-containing silicone oil is an end-hydrogen-containing silicone oil, model number... HF2030-M134 contains 1.5% hydrogen and 5000ppm platinum in the platinum catalyst.

[0098] Application Example 2-12

[0099] The difference between Application Example 2-12 and Application Example 1 is that the source of the matte base adhesive is different, as detailed in Table 5 below.

[0100] Table 5. Source of matte adhesives in Application Examples 1-12

[0101] Application examples Source table of matte base adhesive Application Example 1 Example 1 Application Example 2 Example 2 Application Example 3 Example 3 Application Example 4 Example 4 Application Example 5 Example 5 Application Example 6 Example 6 Application Example 7 Example 7 Application Example 8 Comparative Example 1 Application Example 9 Comparative Example 2 Application Example 10 Comparative Example 3 Application Example 11 Comparative Example 4 Application Example 12 Comparative Example 5

[0102] Performance testing was conducted on the silicone leather coating materials prepared according to the following test cases 1-12:

[0103] An organosilicon adhesive (Conlib, KL-2620) was applied to the surface of a base fabric and dried to form an organosilicon layer. The organosilicon leather coating obtained in Application Examples 1-12 was then applied to the surface of the organosilicon layer. After curing and drying, a 10 μm thick organosilicon leather coating was formed, thus obtaining organosilicon leather. The obtained organosilicon leather was subjected to the following tests:

[0104] 1. Gloss test

[0105] The gloss (unit: GU) of silicone leather was tested using a gloss meter. The lower the gloss, the better the matte effect. The test results were recorded.

[0106] 2. Abrasion resistance test

[0107] Using a Martindale abrasion tester, under normal temperature (25℃) conditions, a load of 595g was applied at a speed of 50r / min and a stroke of 24mm. The wear of the silicone leather after 30,000 tests was calculated, and the wear mass (unit: g) was recorded. If the leather was worn through to the bottom, it was recorded as worn through and the wear mass did not need to be calculated. The test results were then recorded.

[0108] 3. Temperature resistance test

[0109] Place the silicone leather in a constant temperature and humidity chamber at 50℃ and 85% for 7 days. Calculate the wear of the silicone leather after 30,000 tests and record the wear mass (unit: g). If the leather is worn through to the bottom, record it as worn through and do not need to calculate the wear mass. Test and record the test results.

[0110] 4. Sweat resistance test

[0111] Neutral standard artificial sweat will be added to the silicone leather. One drop of artificial sweat will be added for every 10,000 tests. The wear of the silicone leather after 30,000 tests will be calculated and the wear mass (unit: g) will be recorded. If the leather is worn through to the bottom, it will be recorded as worn through and the wear mass does not need to be calculated. Test and record the test results.

[0112] The following are the performance test data of the silicone leather coating in Application Examples 1-12, as detailed in Table 6 below.

[0113] Table 6 Performance test data of silicone leather coatings in Application Examples 1-12

[0114]

[0115] Combining Application Examples 1-3 and 4-5 with Table 6, it can be concluded that optimizing the type and ratio of silane coupling agents can improve the matte properties and abrasion resistance of the prepared matte base adhesive. Compared to Application Example 1, Application Example 4-5 shows improved matteness and significantly reduced wear quality. This is likely because the optimal weight ratio of γ-mercaptopropyltrimethoxysilane coupling agent and dodecyltrimethoxysilane as silane coupling agents can improve the uniformity of dispersion of pretreated silica in the matte base adhesive system, thereby enhancing the matte texture and abrasion resistance of the prepared silicone leather coating.

[0116] Combining Application Examples 4-5 and 6-7 with Table 6, it can be concluded that optimizing the type and proportion of glycidyl ethers can further improve the abrasion resistance of the prepared matte base adhesive. In Application Examples 6-7, compared to Application Example 4, the use of a more optimized weight ratio of 1,2-cyclohexanediol diglycidyl ether and 4-vinylphenyl glycidyl ether as glycidyl ethers resulted in a significant reduction in wear quality. This is likely because the selection of the superior glycidyl ethers further improved the compatibility and flexibility of the pretreated silica in the matte base adhesive, thereby enhancing the abrasion resistance of the resulting silicone leather coating.

[0117] Combining Application Examples 1-3 and 8-12 with Table 6, it can be concluded that in Application Example 8, replacing the vinyl polydimethylsiloxane / polymethylsiloxane-silsesquioxane crosslinking polymer with silica significantly improved the matte finish of the resulting silicone leather coating, but also significantly reduced its abrasion resistance. The abrasion resistance test revealed the bottom layer showing through, possibly because the synergistic effect between silica and the vinyl polydimethylsiloxane / polymethylsiloxane-silsesquioxane crosslinking polymer was reduced. In Application Example 9, replacing the hydroxyl-terminated polymethylvinylsiloxane-polydimethylsiloxane copolymer with hydroxyl-terminated polydimethylsiloxane resulted in poor abrasion resistance of the resulting silicone leather coating. This may be because the crosslinking performance between the pretreated silica and the base adhesive system and the hydrogen-containing silicone oil was reduced, thus decreasing abrasion resistance and causing the bottom layer to show through after the abrasion resistance test. Furthermore, in Application Examples 10-11, changing the application of the silane coupling agent and glycidyl ethers resulted in reduced abrasion resistance of the resulting silicone leather coating. In Application Example 12, silica was directly used for compounding. The resulting silicone leather coating not only had a significantly reduced matte finish, but also showed signs of showing through and cracking. This may be because the silica was not evenly dispersed in the base adhesive system, resulting in uneven matte finish in some areas of the silicone leather coating, as well as the problems of showing through and cracking.

[0118] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A matte-based adhesive for use in silicone leather coatings, characterized in that: It is prepared from the following raw materials in parts by weight: 30-40 parts vinyl silicone oil 15-25 parts of pretreated silica 10-20 parts of vinyl MQ silicone resin; The pretreated silica is prepared from the following raw materials in parts by weight: 100-120 parts of silicon dioxide 60-100 parts of 50-85wt% ethanol aqueous solution 3-5 parts of silane coupling agent 20-30 parts of vinyl polydimethylsiloxane / polymethylsiloxane silsesquioxane crosslinked polymer 15-25 parts of hydroxyl-terminated polymethylvinylsiloxane-polydimethylsiloxane copolymer 10-20 parts of glycidyl ethers; The silane coupling agent is composed of γ-mercaptopropyltrimethoxysilane coupling agent and dodecyltrimethoxysilane in a weight ratio of 1:(2-3); The glycidyl ethers are composed of 1,2-cyclohexanediol diglycidyl ether and 4-vinylphenyl glycidyl ether in a weight ratio of (1.5-2.5):

1. The pretreated silica is prepared by the following steps: A1. Add silicon dioxide to an aqueous ethanol solution, mix and stir, filter, and obtain hydroxylated silicon dioxide; A2. Hydroxylated silica, silane coupling agent, vinyl polydimethylsiloxane / polymethylsiloxane silsesquioxane crosslinking polymer, hydroxyl-terminated polymethylvinylsiloxane-polydimethylsiloxane copolymer, and glycidyl ethers are added to a reaction apparatus for kneading and dispersion to obtain pretreated silica.

2. The matte adhesive for silicone leather coating according to claim 1, characterized in that: The silica has a particle size of 50-100 nm.

3. The matte adhesive for silicone leather coating according to claim 1, characterized in that: The vinyl silicone oil has a vinyl content of 0.9-1.2% and a viscosity of 60-100 cst.

4. A matte adhesive for silicone leather coating according to claim 1, characterized in that: The vinyl MQ silicone resin has a vinyl content of 1.2-1.5%, a viscosity of 80-200 cst, and an MQ ratio of 0.8-0.

9.

5. A method for preparing a matte adhesive for silicone leather coating as described in any one of claims 1-4, characterized in that: Includes the following steps: Vinyl silicone oil, pretreated silica, and vinyl MQ silicone resin are added to a reaction apparatus and kneaded to obtain a matte base adhesive for silicone leather coating.

6. The method for preparing a matte base adhesive for silicone leather coating according to claim 5, characterized in that: The kneading temperature is 55-75℃, and the kneading time is 1-3 hours.

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