Low-viscosity high-performance liquid silicone rubber and preparation method thereof

Abstract

The invention provides low-viscosity high-performance liquid silicone rubber and a preparation method thereof.The silicone rubber comprises a rubber A and a rubber B. The rubber A comprises, by weight, 100 parts of base rubber, 6-10 parts of polyvinyl silicone oil, 6-10 parts of low-viscosity vinyl silicone oil and 0.1-0.5 part of a catalyst; the glue B comprises the following components in parts by weight: 100 parts of base glue, 4-15 parts of hydrogen-containing silicone oil, 4-15 parts of low-viscosity vinyl silicone oil and 0.1-0.4 part of an inhibitor; the base adhesive is prepared from 100 parts of vinyl-terminated silicone oil, 2 to 8 parts of silane coupling agent, 0.5 to 5 parts of water, 15 to 40 parts of hydrophilic precipitated white carbon black, 8 to 20 parts of hexamethyldisilazane, 2 to 5 parts of low polyvinyl silane and 15 to 30 parts of compatibilizing filler. The prepared liquid silicone rubber has the advantages of low viscosity, low cost and high mechanical strength, and is used in the field of organic silicon synthesis.

Description

Technical Field

[0001] The invention relates to the technical field of organic silicon materials, and in particular to a low-viscosity and high-performance liquid silicone rubber and a preparation method thereof. Background Art

[0002] Liquid silicone rubber has the advantages of fast curing time, greater safety and environmental protection, high and low temperature resistance, weather resistance, electrical insulation, air permeability and good waterproofness. It is a material with outstanding performance and is widely used. It plays an increasingly important role in modern industry and life.

[0003] As we all know, the strength of the vulcanized silicone rubber without reinforcing fillers is quite low. Most of the silicone rubbers used in practice are silicone rubber composites with reinforcing fillers. The most commonly used silicone rubber reinforcing fillers are fumed silica or precipitated silica. Within an appropriate range, the strength of vulcanized silicone rubber increases accordingly with the increase in the amount of silica filling. There are a considerable number of silanol groups on the surface of silica particles. The hydrogen bonding between silanol groups and silicone polymers leads to the thickening of liquid silicone rubber and the structuring of semi-solid silicone rubber, which in turn affects the storage stability and production processability of liquid silicone rubber. In addition, depending on the quality, the price of fumed silica is usually tens of thousands or hundreds of thousands of yuan per ton, and its cost as a filler is very high.

[0004] Therefore, there is an urgent need for a liquid silicone rubber with low viscosity, low cost and good performance, which can not only meet the operability of production but also ensure product performance. Summary of the invention

[0005] In view of the above problems, the present invention provides a low-viscosity, high-performance liquid silicone rubber and a preparation method thereof. The specific scheme is as follows: A low-viscosity, high-performance liquid silicone rubber, comprising A glue and B glue, wherein the A glue comprises: 100 parts of base glue, 6-10 parts of polyvinyl silicone oil, 6-10 parts of low-viscosity vinyl silicone oil and 0.01-0.5 parts of catalyst by weight; The B glue comprises: 100 parts of base glue, 4-15 parts of hydrogenated silicone oil, 4-15 parts of low-viscosity vinyl silicone oil and 0.1-0.4 parts of inhibitor; The base rubber comprises: 100 parts of vinyl-terminated silicone oil, 2-8 parts of silane coupling agent, 0.5-5 parts of water, 15-40 parts of hydrophilic precipitated white carbon black, 8-20 parts of hexamethyldisilazane, 2-5 parts of low-polyvinyl silane and 15-30 parts of volume-increasing filler.

[0006] The low-polyvinyl silane is a vinyl silane oligomer obtained by copolymerizing methyldimethoxyvinyl silane and aminopropyltrimethoxysilane under the catalysis of organic tin; the low-polyvinyl silane has a number average molecular weight of 850-950 and a viscosity of 3-3.5 mPa·s.

[0007] The viscosity of the vinyl-terminated silicone oil is 2000-100000 mPa·s, and the vinyl content is 0.04-0.8%; The polyvinyl silicone oil is a silicone oil containing vinyl groups at both the terminal group and the side group, with a viscosity of 100-2000 mPa·s and a vinyl content of 2%-10%; The low-viscosity vinyl silicone oil has a viscosity of 500-5000 mPa·s and a vinyl content of 0.23-0.45%; The hydrogen content of the hydrogen-containing silicone oil is 0.6%-0.8%.

[0008] The specific surface area of ​​the hydrophilic precipitated silica is 110-300m 2 / g; The volume-increasing filler is a mixture of one or more of calcium carbonate, talc, kaolin, diatomaceous earth, alumina powder, silica powder or glass powder; The silane coupling agent is a mixture of one or more of KH-550, KH-560, KH-570, D90 or tetraethyl orthosilicate.

[0009] The inhibitor is an acetylenic alcohol inhibitor, including at least one of 1-ethynylcyclohexanol, 2-methyl-3-butynol or 3-methyl-dodecynol; The catalyst is a platinum catalyst, including chloroplatinic acid, a reaction product of chloroplatinic acid and hydroxy alcohols, or a complex of chloroplatinic acid and olefins, with a concentration of 2000-5000 ppm.

[0010] A method for preparing low-viscosity high-performance liquid silicone rubber comprises the following steps: S1: Preparation of oligovinylsilane: Methyldimethoxyvinylsilane and aminopropyltrimethoxysilane are mixed, water and anhydrous methanol are added as solvents, and oligovinylsilane is obtained by copolymerization under the catalysis of organic tin. S2: Preparation of base glue: S21: kneading and mixing the vinyl-terminated silicone oil, water and silane coupling agent; S22: adding precipitated white carbon black and hexamethyldisilazane in batches, adding the extender filler and hexamethyldisilazane in batches, and then adding low-polyvinylsilane, kneading in vacuum at room temperature, and setting the temperature of the reaction system to 140°C; S23: When the temperature of S12 material rises to >100°C, add end-vinyl silicone oil and continue vacuum high-temperature kneading; S24: After the product of S13 is cooled, a base rubber is obtained; S3: Preparation of glue A and glue B: Adding polyvinyl silicone oil, catalyst and low-viscosity vinyl silicone oil to the base glue, stirring under vacuum, to obtain glue A; Add hydrogen-containing silicone oil, inhibitor and low-viscosity vinyl silicone oil to the base rubber, and stir under vacuum to obtain rubber B; S4: Mix glue A and glue B in a weight ratio of 1:1 and vulcanize to obtain low-viscosity and high-performance liquid silicone rubber.

[0011] Specifically, S1 is as follows: 3-8 parts of methyldimethoxyvinylsilane, 1-2 parts of aminopropyltrimethoxysilane and 0.01-0.04 parts of organotin are uniformly mixed, a mixture of water and anhydrous methanol is uniformly added dropwise to the reaction system, reacted at 50-100° C. for 3-5 hours, and then continued to react at 80-130° C. under reduced pressure for 1-2 hours to copolymerize and obtain low-polyvinylsilane.

[0012] The S4 is specifically as follows: after uniformly mixing 100 parts by mass of the rubber A and 100 parts by mass of the rubber B, vulcanizing at 140-160° C. for 10 min.

[0013] A low-viscosity, high-performance liquid silicone rubber for use in the field of silicone synthetic leather.

[0014] The beneficial effects of the present invention are: 1. Select suitable vinyl silicone oil and precipitated silica, and after modification and optimization of hexamethyldisilazane, the base rubber has lower viscosity but higher mechanical properties.

[0015] 2. The reinforcing filler is hydrophilic precipitated silica, which has a much lower cost than fumed silica. At the same time, the use of volume-increasing fillers can greatly reduce the cost of liquid silicone rubber while maintaining the mechanical properties.

[0016] 3. By adding polyvinyl silicone oil, the hardness and tear strength of liquid silicone rubber are improved.

[0017] 4. Methyldimethoxyvinylsilane is copolymerized with aminopropyltrimethoxysilane to prepare low-molecular-weight vinylsilane. The copolymer has a low molecular weight and good fluidity and can be well dispersed in the silicone rubber system. The powder is modified by reacting with silanol groups, which reduces the polarity of the powder and introduces two active groups, vinyl and amino, which can effectively improve the crosslinking density and friction resistance of the system. DETAILED DESCRIPTION

[0018] The embodiments of the present invention will be described in detail below with reference to examples. The following examples are only used to illustrate the present invention and should not be construed as limiting the scope of the present invention.

[0019] Example 1 Preparation of low-density vinyl silane: 1320.2 g of methyldimethoxyvinylsilane (MVEDMS), 358.6 g of aminopropyltrimethoxysilane (APTMS), and 2.3 g of dibutyltin dilaurate were added to a glass reaction flask equipped with electromagnetic stirring, a thermometer, oil bath heating, and a reflux condenser. The speed was set to 200 rpm and stirred evenly at room temperature. The temperature was raised to 70°C, and a mixture of 72 g of deionized water and 821 g of anhydrous methanol was uniformly added to the reaction system through a constant pressure dropping funnel. The dropping time was controlled within 3 hours. After the dropwise addition was completed, the material in the reaction flask was continued to react at 80°C for 1 hour under reduced pressure (vacuum degree -0.1MPa) to obtain a vinyl silane oligomer. Preliminary tests showed that the number average molecular weight of the vinyl silane oligomer was 872 and the viscosity was 3.2 mPa·s.

[0020] Preparation of base rubber: Add 90 parts of vinyl-terminated silicone oil (viscosity 100000 mPa·s, vinyl content 0.04%-0.08%), 2 parts of silane coupling agent KH-570, and 1.2 parts of deionized water into a kneader and knead and mix at room temperature. Then add 30 parts of hydrophilic precipitated silica (specific surface area 300m 2 / g) and 5 parts of hexamethyldisilazane were mixed and added to the kneader in 3 batches, with an interval of 30 minutes between each batch and a stirring speed of 50 rpm; after the feeding was completed, the kneading was continued for 30 minutes, and then 15 parts of the volume-increasing filler (silicon powder) and 5 parts of hexamethyldisilazane were mixed and added to the kneader in 3 batches, with an interval of 30 minutes between each batch and a stirring speed of 50 rpm; after the feeding was completed, the kneading was continued for 30 minutes, and 2 parts of low-polyvinylsilane were added. After vacuum kneading for 60 minutes at room temperature, the reaction system temperature was set to 140°C. When the material temperature rose to above 100°C, 10 parts of terminal vinyl silicone oil (viscosity 100000 mPa·s, vinyl content 0.04%-0.08%) were added to the kneader, and vacuum high-temperature kneading was continued for 2 hours. After the product was cooled, the base rubber was obtained.

[0021] Preparation of glue A: Add 100 parts by mass of the above-mentioned base glue, 8 parts of polyvinyl silicone oil (1000 mPa·s, vinyl content 2-4%), 8 parts of low-viscosity vinyl silicone oil (viscosity 5000 mPa·s, vinyl content 0.23-0.45%) and 0.05 parts of platinum catalyst (content 5000 ppm) into a planetary mixer, and stir under vacuum at room temperature for 30 minutes at a stirring speed of 50 rpm to obtain glue A.

[0022] Preparation of glue B: Add 100 parts by mass of the above-mentioned base glue, 4.5 parts of hydrogenated silicone oil (hydrogen content 0.6%-0.8%, model RH-LHC-3, manufacturer Zhejiang Runhe), 11.5 parts of low-viscosity vinyl silicone oil (viscosity 500 mPa·s, vinyl content 0.23-0.45%), and 0.1 part of inhibitor (1-ethynylcyclohexanol) into a planetary mixer, and stir under vacuum at room temperature for 30 minutes to obtain glue B.

[0023] Example 2 Preparation of base rubber: The difference from Example 1 is that the viscosity of the vinyl-terminated silicone oil is 60000 mPa·s and the vinyl content is 0.05%-0.1%. The rest is the same as Example 1.

[0024] Preparation of Glue A: Same as Example 1.

[0025] Preparation of glue B: Add 100 parts by mass of the above-mentioned base glue, 6 parts by mass of hydrogenated silicone oil (hydrogen content 0.6%-0.8%), 10 parts by mass of low-viscosity vinyl silicone oil (viscosity 500 mPa·s, vinyl content 0.23-0.45%), and 0.1 parts by mass of inhibitor (1-ethynylcyclohexanol) into a planetary mixer, and stir under vacuum at room temperature for 30 minutes to obtain glue B.

[0026] Example 3 Preparation of base rubber: The difference from Example 1 is that the viscosity of the vinyl-terminated silicone oil is 10000 mPa·s and the vinyl content is 0.1%-0.2%. The rest is the same as Example 1.

[0027] Preparation of Glue A: Same as Example 1.

[0028] Preparation of glue B: Add 100 parts by mass of the above-mentioned base glue, 7.2 parts of hydrogenated silicone oil (hydrogen content 0.6%-0.8%, model RH-LHC-3, manufacturer Zhejiang Runhe), 10.8 parts of low-viscosity vinyl silicone oil (viscosity 500 mPa·s, vinyl content 0.23-0.45%), and 0.1 part of inhibitor (1-ethynylcyclohexanol) into a planetary mixer, and stir under vacuum at room temperature for 30 minutes to obtain glue B.

[0029] Example 4 Preparation of base rubber: The difference from Example 1 is that the viscosity of the vinyl-terminated silicone oil is 5000 mPa·s and the vinyl content is 0.1%-0.25%. The rest is the same as Example 1.

[0030] Preparation of Glue A: Same as Example 1.

[0031] Preparation of glue B: Add 100 parts by mass of the above-mentioned base glue, 8 parts of hydrogenated silicone oil (hydrogen content 0.6%-0.8%, model RH-LHC-3, manufacturer Zhejiang Runhe), 8 parts of low-viscosity vinyl silicone oil (viscosity 500 mPa·s, vinyl content 0.23-0.45%), and 0.1 part of inhibitor (1-ethynylcyclohexanol) into a planetary mixer, and stir under vacuum at room temperature for 30 minutes to obtain glue B.

[0032] Example 5 Preparation of base rubber: The difference from Example 1 is that the viscosity of the vinyl-terminated silicone oil is 2000 mPa·s and the vinyl content is 0.21%-0.43%. The rest is the same as Example 1.

[0033] Preparation of Glue A: Same as Example 1.

[0034] Preparation of glue B: Add 100 parts by mass of the above-mentioned base glue, 9.1 parts of hydrogenated silicone oil (hydrogen content 0.6%-0.8%, model RH-LHC-3, manufacturer Zhejiang Runhe), 6.9 parts of low-viscosity vinyl silicone oil (viscosity 500 mPa·s, vinyl content 0.23-0.45%), and 0.1 part of inhibitor (1-ethynylcyclohexanol) into a planetary mixer, and stir under vacuum at room temperature for 30 minutes to obtain glue B.

[0035] Example 6 Preparation of base rubber: Add 20 parts of vinyl-terminated silicone oil (100000 viscosity, vinyl content 0.04%-0.08%), 40 parts of vinyl-terminated silicone oil (5000 viscosity, vinyl content 0.1%-0.25%), 30 parts of vinyl-terminated silicone oil (2000 viscosity, vinyl content 0.21%-0.43%), 2 parts of silane coupling agent KH-570, and 1.2 parts of deionized water into a kneader and knead and mix at room temperature. Then add 30 parts of hydrophilic precipitated silica (specific surface area 300m 2 / g) and 5 parts of hexamethyldisilazane are mixed and added to the kneader in 3 batches, with an interval of 30 minutes between each batch and a stirring speed of 50 rpm; after the feeding is completed, continue to knead for 30 minutes, then mix 20 parts of the volume-increasing filler (silicon powder) and 5 parts of hexamethyldisilazane and add them to the kneader in 3 batches, with an interval of 30 minutes between each batch and a stirring speed of 50 rpm; after the feeding is completed, continue to knead for 30 minutes, add 2 parts of low-polyvinylsilane, and after vacuum kneading for 60 minutes at room temperature, set the reaction system temperature to 140°C. When the material temperature rises to above 100°C, add 10 parts of terminal vinyl silicone oil (viscosity 2000 mPa·s, vinyl content 0.21%-0.43%) to the kneader, and continue to knead at high temperature in vacuum for 2 hours. After the product is cooled, the base rubber is obtained.

[0036] Preparation of Glue A: Same as Example 1.

[0037] Preparation of glue B: Add 100 parts by mass of the above-mentioned base glue, 10.2 parts of hydrogenated silicone oil (hydrogen content 0.6%-0.8%, model RH-LHC-3, manufacturer Zhejiang Runhe), 5.8 parts of low-viscosity vinyl silicone oil (viscosity 500 mPa·s, vinyl content 0.23-0.45%), and 0.1 part of inhibitor (1-ethynylcyclohexanol) into a planetary mixer, and stir under vacuum at room temperature for 30 minutes to obtain glue B.

[0038] Example 7 Compared with Example 6, no oligovinylsilane was added; the rest was the same as Example 1.

[0039] Example 8 Compared with Example 6, 2 parts of KH-570 are replaced by 1 part of D90 + 1 part of KH-570; the rest is the same as Example 1.

[0040] Example 9 Compared with Example 6, the silicon powder is replaced by glass powder; the rest is the same as Example 1.

[0041] Comparative Example 1 Compared with Example 6, 50 parts of precipitated silica and 10 parts of hexamethyldisilazane were added, but no mixed extending filler (silicon powder) and hexamethyldisilazane were added; the rest was the same as Example 6.

[0042] Comparative Example 2 Compared with Example 6, the precipitated silica was replaced by hydrophilic fumed silica (350 m 2 / g); the rest are the same as in Example 6.

[0043] Comparative Example 3 Compared with Example 6, instead of adding the mixed precipitated silica and hexamethyldisilazane, 40 parts of the volume-increasing filler (silicon powder) and 10 parts of hexamethyldisilazane were added; the rest was the same as Example 6.

[0044] Test analysis: 100 parts by mass of glue A and 100 parts by mass of glue B were added to a planetary mixer, mixed evenly at room temperature, and then vulcanized in a flat vulcanizer at a vulcanization temperature of 140°C for 10 minutes to obtain a low-viscosity, high-performance liquid silicone rubber. The results are shown in Table 1.

[0045] Performance testing method: Hardness(HA): IS0 48-4 Viscosity: DIN 53019-1 Tensile strength: JIS K6251 Type 1 Elongation at break: JIS K6251 Type 1 Tear strength: IS0 34-IDie B.

[0046] Table 1 Analysis and test data of the above examples and comparative examples

[0047] Result analysis: By comparing the test results of Examples 1-6, it can be seen that when preparing the base rubber, the greater the viscosity of the base vinyl silicone oil, the more serious the component swelling; at the same time, since the viscosity of the base vinyl silicone oil is smaller and the vinyl content is higher, the cross-linking density of the silicone rubber is greater, which is manifested in increased tensile strength, hardness and tear strength, and reduced viscosity and elasticity. In addition, the use of vinyl silicone oils of different viscosities can improve the overall performance.

[0048] By comparing Example 7 with Example 1, it can be seen that low-polyvinyl silane has a significant effect on the modification of the powder. When it is not added, the viscosity and mechanical properties are reduced. By comparing Example 8 with Example 6, it can be seen that the mixture of silane coupling agent D90 and KH-570 is better than the use of KH-570 alone. By comparing Example 9 with Example 6, it can be seen that the glass powder has a finer particle size and higher purity than the silicon micropowder, and the glass powder has a better reinforcement effect. However, since the oil absorption value of the glass powder is higher than that of the silicon micropowder, the viscosity of the system is larger when the glass powder is used.

[0049] From the comparison between Comparative Example 1, Comparative Example 2 and Example 6, it can be seen that when using fumed silica or only using precipitated silica for reinforcement, the base rubber viscosity is higher when the mechanical properties are equivalent.

[0050] Comparison between Comparative Example 3 and Example 6 shows that the mechanical properties of the extended filler alone are very poor. The extended filler has a low reinforcing performance, but due to its large particle size, it plays a role in reducing viscosity and cost in the process of joint reinforcement with white carbon black.

Claims

1. A low-viscosity, high-performance liquid silicone rubber, characterized in that: It comprises glue A and glue B. Calculated by weight, the glue A comprises: 100 parts of base glue, 6-10 parts of polyvinyl silicone oil, 6-10 parts of low-viscosity vinyl silicone oil and 0.01-0.5 parts of catalyst; The B glue comprises: 100 parts of base glue, 4-15 parts of hydrogenated silicone oil, 4-15 parts of low-viscosity vinyl silicone oil and 0.1-0.4 parts of inhibitor; The base rubber comprises: 100 parts of vinyl-terminated silicone oil, 2-8 parts of silane coupling agent, 0.5-5 parts of water, 15-40 parts of hydrophilic precipitated white carbon black, 8-20 parts of hexamethyldisilazane, 2-5 parts of low-polyvinyl silane and 15-30 parts of volume-increasing filler.

2. The low-viscosity, high-performance liquid silicone rubber according to claim 1, characterized in that: The low-polyvinyl silane is a vinyl silane oligomer obtained by copolymerizing methyldimethoxyvinyl silane and aminopropyltrimethoxysilane under the catalysis of organic tin; the low-polyvinyl silane has a number average molecular weight of 850-950 and a viscosity of 3-3.5 mPa·s.

3. The low-viscosity, high-performance liquid silicone rubber according to claim 1, characterized in that: The viscosity of the vinyl-terminated silicone oil is 2000-100000 mPa·s, and the vinyl content is 0.04-0.8%; The polyvinyl silicone oil is a silicone oil containing vinyl groups at both the terminal group and the side group, with a viscosity of 100-2000 mPa·s and a vinyl content of 2%-10%; The low-viscosity vinyl silicone oil has a viscosity of 500-5000 mPa·s and a vinyl content of 0.23-0.45%; The hydrogen content of the hydrogen-containing silicone oil is 0.6%-0.8%.

4. The low-viscosity, high-performance liquid silicone rubber according to claim 1, characterized in that: The specific surface area of ​​the hydrophilic precipitated white carbon black is 110-300m 2 / g; The volume-increasing filler is a mixture of one or more of calcium carbonate, talc, kaolin, diatomaceous earth, alumina powder, silica powder or glass powder; The silane coupling agent is a mixture of one or more of KH-550, KH-560, KH-570, D90 or tetraethyl orthosilicate.

5. The low-viscosity, high-performance liquid silicone rubber according to claim 1, characterized in that: The inhibitor is an acetylenic alcohol inhibitor, including at least one of 1-ethynylcyclohexanol, 2-methyl-3-butynol or 3-methyl-dodecynol; The catalyst is a platinum catalyst, including chloroplatinic acid, a reaction product of chloroplatinic acid and hydroxy alcohols, or a complex of chloroplatinic acid and olefins, with a concentration of 2000-5000 ppm.

6. The method for preparing a low-viscosity high-performance liquid silicone rubber according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1: Preparation of oligovinylsilane: Methyldimethoxyvinylsilane and aminopropyltrimethoxysilane are mixed, water and anhydrous methanol are added as solvents, and oligovinylsilane is obtained by copolymerization under the catalysis of organic tin. S2: Preparation of base glue: S21: kneading and mixing the vinyl-terminated silicone oil, water and silane coupling agent; S22: adding precipitated white carbon black and hexamethyldisilazane in batches, adding the extender filler and hexamethyldisilazane in batches, and then adding low-polyvinylsilane, kneading in vacuum at room temperature, and setting the temperature of the reaction system to 140°C; S23: When the temperature of S12 material rises to >100°C, add end-vinyl silicone oil and continue vacuum high-temperature kneading; S24: After the product of S13 is cooled, a base rubber is obtained; S3: Preparation of glue A and glue B: Adding polyvinyl silicone oil, catalyst and low-viscosity vinyl silicone oil to the base glue, stirring under vacuum, to obtain glue A; Add hydrogen-containing silicone oil, inhibitor and low-viscosity vinyl silicone oil to the base rubber, and stir under vacuum to obtain rubber B; S4: Mix glue A and glue B in a weight ratio of 1:1 and vulcanize to obtain low-viscosity and high-performance liquid silicone rubber.

7. The method for preparing low-viscosity high-performance liquid silicone rubber according to claim 6, characterized in that: Specifically, S1 is as follows: 3-8 parts of methyldimethoxyvinylsilane, 1-2 parts of aminopropyltrimethoxysilane and 0.01-0.04 parts of organotin are uniformly mixed, a mixture of water and anhydrous methanol is uniformly added dropwise to the reaction system, reacted at 50-100° C. for 3-5 hours, and then continued to react at 80-130° C. under reduced pressure for 1-2 hours to copolymerize and obtain low-polyvinylsilane.

8. The method for preparing low-viscosity high-performance liquid silicone rubber according to claim 6, characterized in that: The S4 is specifically as follows: after uniformly mixing 100 parts by mass of the rubber A and 100 parts by mass of the rubber B, vulcanizing at 140-160° C. for 10 min.

9. An application of low-viscosity high-performance liquid silicone rubber, characterized in that: Used in the field of silicone synthetic leather.

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