Stain-resistant and wear-resistant silicone rubber compound and preparation method thereof

Abstract

The invention relates to the field of silicone rubber, and discloses an anti-fouling wear-resistant silicone rubber compound and a preparation method thereof. The anti-fouling and wear-resistant silicone rubber compound is prepared from the following raw materials in parts by weight: 38-48 parts of methyl phenyl vinyl silicone rubber, 20-25 parts of vinyl silicone oil, 12-18 parts of vinyl MQ silicone resin, 10-16 parts of fumed silica, 8-15 parts of an anti-fouling and wear-resistant agent and 3-6 parts of hydroxyl silicone oil. The anti-pollution and wear-resistant agent is prepared from wollastonite powder, a silane coupling agent and a vinyl dispersant; the preparation method comprises the following steps: mixing the raw materials and refining rubber. The silica gel rubber compound prepared by the invention has relatively good flexibility, wear resistance and pollution resistance, is moderate in cost, and is suitable for sports bracelets, smart watches and the like.

Description

Technical Field

[0001] The present application relates to the field of silicone rubber, and more specifically, to an anti-fouling and wear-resistant silicone rubber compound and a preparation method thereof. Background Art

[0002] As wearable devices like fitness trackers and smartwatches evolve, the performance requirements for casing and strap materials are becoming increasingly demanding. Silicone compound, a commonly used material, is widely used in these devices due to its excellent flexibility, high and low temperature resistance, and biocompatibility.

[0003] However, sports bracelets made of silicone compound are prone to absorbing stains and grease on the surface due to long-term contact with human sweat during long-term use, which reduces the performance of the product. In addition, they are prone to aging, wear and cracking during long-term use.

[0004] In order to improve the above-mentioned problems, the prior art adds fluororubber, a large amount of fumed silica and other substances to silicone rubber compounds to improve the anti-fouling and wear resistance of silicone rubber compounds. However, fluororubber is relatively expensive and has low applicability in silicone rubber compounds. The addition of fumed silica can easily reduce the flexibility of the silicone rubber compound, thereby reducing the comfort of use of the product. Summary of the Invention

[0005] In order to solve the problem that the existing silicone rubber compound cannot well balance the long-term wear resistance, stain resistance and flexibility, the present application provides an anti-stain and wear-resistant silicone rubber compound and a preparation method thereof.

[0006] In the first aspect, the present application provides an anti-fouling and wear-resistant silicone rubber compound, which adopts the following technical solution: A stain-resistant and wear-resistant silicone rubber compound is prepared from the following raw materials in parts by weight: 38-48 parts of methylphenyl vinyl silicone rubber 20-25 parts vinyl silicone oil 12-18 parts of vinyl MQ silicone resin 10-16 parts of fumed silica 8-15 parts of anti-fouling and anti-wear agent 3-6 parts of hydroxy silicone oil; The anti-fouling and anti-wear agent is prepared from wollastonite powder, a silane coupling agent and a vinyl dispersant.

[0007] By adopting the above technical scheme, the present application forms a silica gel system by combining methylphenyl vinyl silicone rubber, vinyl silicone oil, vinyl MQ silicone resin and hydroxy silicone oil, and the prepared silica gel compound has good flexibility and wear resistance; In order to further improve the anti-fouling and wear resistance of silica gel compound, by adding fumed silica and anti-fouling and wear-resistant agent to the silica gel system, the two play a good synergistic effect in the silica gel system, while improving the anti-fouling and wear resistance of silica gel compound, the flexibility of silica gel compound can be improved, and the flexibility of silica gel compound will not be reduced due to the addition of fumed silica; Anti-fouling and wear-resistant agent is made from wollastonite powder, silane coupling agent and vinyl dispersant, while being able to give silica gel compound excellent anti-fouling and wear resistance, anti-fouling and wear-resistant agent can be further dispersed in silica gel system for cross-linking when applied, improving flexibility. There is no need to add fluorosilicone rubber and a large amount of fumed silica in the system, which can maintain good anti-fouling, wear resistance and flexibility, and the cost is moderate, and it is particularly suitable for wearable devices such as sports bracelets and smart watches.

[0008] Preferably, the anti-fouling and anti-wear agent is composed of wollastonite powder, silane coupling agent and vinyl dispersant in a weight ratio of 5: (0.3-0.6): (0.8-1.2).

[0009] By adopting the above technical solution, the dosage of wollastonite powder, silane coupling agent and vinyl dispersant is optimized, so that the silane coupling agent and vinyl dispersant can modify the wollastonite powder in a better ratio, thereby improving the dispersion uniformity and cross-linking performance of the anti-fouling and wear-resistant agent in the silica gel system, thereby improving the flexibility, anti-fouling and wear resistance of the silica gel compound.

[0010] Preferably, the silane coupling agent is composed of a polyamino long-chain alkylsilane and methyl vinyl dibutyl ketoxime silane in a weight ratio of (2-4):1, and the polyamino long-chain alkylsilane is diethylenetriaminopropyltrimethoxysilane and / or N-β-aminoethyl-γ-aminopropylmethyldimethoxysilane.

[0011] By adopting the above technical solution, using a relatively optimal weight ratio of polyamino long-chain alkylsilane and methyl vinyl dibutyl ketoxime silane as a silane coupling agent, the dispersibility and compatibility of wollastonite powder in the silicone rubber compound can be improved. At the same time, the long-chain polyamino and branched silane structures can give the silicone rubber compound excellent anti-fouling and wear resistance, while not easily reducing the flexibility of the silicone rubber compound.

[0012] Preferably, the vinyl dispersant is composed of 2-octenylsuccinic anhydride and 4-vinylphenyl glycidyl ether in a weight ratio of (1.5-2.5):1.

[0013] By adopting the above technical solution, using 2-octenylsuccinic anhydride and 4-vinylphenyl glycidyl ether in a relatively optimal weight ratio as vinyl dispersants, it is possible to improve the uniformity of the dispersion of the anti-fouling and wear-resistant agent in the silica gel system, while further cross-linking with the silica gel system, thereby improving the dispersion density of the anti-fouling and wear-resistant agent and fumed silica in the silica gel system, thereby improving the flexibility, wear resistance and anti-fouling properties of the prepared silica gel compound.

[0014] Preferably, the antifouling and wear-resistant agent is prepared by the following steps: adding a silane coupling agent to wollastonite powder, heating and kneading and dispersing the mixture, and then adding a vinyl dispersant and kneading and dispersing the mixture to prepare the antifouling and wear-resistant agent.

[0015] By adopting the above technical solution, the silane coupling agent is first added to the wollastonite powder for kneading and dispersion, so that the silane coupling agent can be fully coated on the surface of the wollastonite powder, and then the vinyl dispersant is added for kneading and dispersion, thereby improving the anti-fouling and wear resistance of the silicone rubber compound.

[0016] Preferably, the vinyl silicone oil is end-side vinyl silicone oil with a vinyl content of 1.1-1.3% and a viscosity of 180-250 cp.

[0017] By adopting the above technical solution, the introduction of end-side vinyl silicone oil makes the silicone rubber compound have better cross-linking properties. When its vinyl mass content is 1.1-1.3%, it can effectively improve the flexibility and wear resistance of the material. At the same time, the viscosity is controlled in the range of 180-250cp, which ensures the fluidity of the rubber compound during the processing and avoids the problems of operational difficulties caused by too high viscosity or poor structural stability caused by too low viscosity.

[0018] Preferably, the vinyl MQ silicone resin has an M / Q value of 0.8-0.9, a vinyl content of 0.6-0.9%, and a viscosity of 5000-10000 cp.

[0019] By adopting this technical solution, the vinyl MQ silicone resin used in the anti-fouling and wear-resistant silicone rubber compound has a specific M / Q value, vinyl mass content, and viscosity range. This specific M / Q value range optimizes the cross-linking structure, improving the material's flexibility and wear resistance. Controlling the vinyl mass content helps increase the cross-linking density of the silicone rubber, further enhancing its wear resistance and anti-fouling properties.

[0020] Preferably, the hydroxy silicone oil is a double-terminal hydroxy silicone oil with a hydroxyl content of 8.5-10% and a viscosity of 25-35 mm 2 / s.

[0021] By adopting the above technical solution, the addition of better-specification double-ended hydroxyl silicone oil can effectively improve the flexibility of the silicone rubber compound, while improving the dispersion performance of the anti-fouling and anti-wear agent and fumed silica in the system.

[0022] In a second aspect, the present application provides a method for preparing a stain-resistant and wear-resistant silicone rubber compound, which adopts the following technical solution: A method for preparing an anti-fouling and wear-resistant silicone rubber compound comprises the following steps: using a rubber mixing device to mix and refine methylphenyl vinyl silicone rubber, vinyl silicone oil, vinyl MQ silicone resin, fumed silica, hydroxy silicone oil and an anti-fouling and wear-resistant agent to obtain the anti-fouling and wear-resistant silicone rubber compound.

[0023] By adopting the above technical solution, when methylphenyl vinyl silicone rubber, vinyl silicone oil, vinyl MQ silicone resin, fumed silica, hydroxy silicone oil and anti-fouling and wear-resistant agent are mixed and refined in the rubber mixing equipment, the components can be fully and evenly dispersed, so that a dense network structure is formed inside the material, thereby improving the wear resistance and anti-fouling properties of the silicone rubber compound.

[0024] Preferably, the mixing temperature is 100-120° C., and the mixing time is 1.5-3.5 h.

[0025] By adopting the above technical solution, the optimal mixing temperature and time can effectively promote the uniform mixing and interweaving of the raw material components, thereby improving the comprehensive performance of the prepared silicone rubber compound.

[0026] In summary, this application includes at least one of the following beneficial technical effects: 1. The anti-fouling and wear-resistant silicone compound of the present application is prepared by the synergistic effect of methylphenyl vinyl silicone rubber, vinyl silicone oil, vinyl MQ silicone resin, fumed silica, hydroxy silicone oil and anti-fouling and wear-resistant agent. The anti-fouling and wear-resistant agent is prepared from wollastonite powder, silane coupling agent and vinyl dispersant. It not only significantly improves the anti-fouling performance of the silicone compound, but also enhances the overall wear resistance while maintaining the flexibility of the material, effectively solving the problem that traditional materials are prone to adsorbing stains and aging and wear during long-term use. It has moderate cost and can be used in smart wearable products such as sports bracelets and smart watches.

[0027] 2. The silane coupling agent is composed of polyamino long-chain alkyl silane and methyl vinyl dibutyl ketoxime silane, which can improve the dispersibility and bonding strength of wollastonite powder in silica gel compound.

[0028] 3. The 2-octenylsuccinic anhydride and 4-vinylphenyl glycidyl ether in the vinyl dispersant work synergistically with the wollastonite powder to improve the uniformity of the dispersion of the anti-fouling and wear-resistant agent in the silica gel system. At the same time, they can further cross-link with the silica gel system to improve the dispersion density of the anti-fouling and wear-resistant agent and fumed silica in the silica gel system, thereby improving the flexibility, wear resistance and anti-fouling properties of the prepared silica gel compound. DETAILED DESCRIPTION

[0029] The present application is further described in detail below with reference to embodiments and application examples.

[0030] The following are the sources and specifications of some raw materials of this application. The raw materials used in the preparation examples and examples of this application can be obtained from commercial sources, including but not limited to the following models and manufacturers. Raw materials with equivalent performance can be used: 1. Methylphenyl vinyl silicone rubber: Mingyi Silicon Industry, model MY120, phenyl content 5%, vinyl content 0.2%, molecular weight 400,000; 2. End-side vinyl silicone oil: Jipeng silicone-fluorine material, JP-02V series; 2. Fumed silica: Cabot, CAB-O-SIL TG-811F; 3. Wollastonite powder: 2000 mesh.

[0031] Preparation example of anti-fouling and anti-wear agent Preparation Example 1 Preparation Example 1 discloses an anti-fouling and wear-resistant agent, which is prepared by the following steps: adding 0.3 kg of silane coupling agent (composed of vinyltrimethoxysilane in a weight ratio of 2:1) to 5 kg of wollastonite powder, heating to 90°C and kneading and dispersing for 60 minutes, then adding 1.2 kg of vinyl dispersant, kneading and dispersing at a temperature of 60°C for 40 minutes to obtain an anti-fouling and wear-resistant agent.

[0032] Preparation Example 2-3 The difference between Preparation Example 2-3 and Preparation Example 1 is that the amount of raw materials used and the preparation conditions are different. Please refer to Table 1 below for details.

[0033] Table 1 Parameters of Preparation Examples 1-3 Preparation Example 4 The difference between Preparation Example 4 and Preparation Example 1 is that the silane coupling agent is different. The silane coupling agent in Preparation Example 4 is composed of a polyamino long-chain alkyl silane and methyl vinyl dibutyl ketoxime silane in a weight ratio of 2:1, and the polyamino long-chain alkyl silane is diethylenetriaminepropyltrimethoxysilane. The rest is the same as Preparation Example 1.

[0034] Preparation Example 5 The difference between Preparation Example 5 and Preparation Example 4 is that the silane coupling agent in Preparation Example 5 is composed of a polyamino long-chain alkylsilane and methyl vinyl dibutyl ketoxime silane in a weight ratio of 4:1, and the polyamino long-chain alkylsilane is diethylenetriaminepropyltrimethoxysilane. The rest is the same as Preparation Example 4.

[0035] Preparation Example 6 The difference between Preparation Example 6 and Preparation Example 5 is that the vinyl dispersant consists of 2-octenylsuccinic anhydride and 4-vinylphenyl glycidyl ether in a weight ratio of 1.5:1, and the rest is the same as Preparation Example 5.

[0036] Preparation Example 7 The difference between Preparation Example 7 and Preparation Example 5 is that the vinyl dispersant consists of 2-octenylsuccinic anhydride and 4-vinylphenyl glycidyl ether in a weight ratio of 2.5:1, and the rest is the same as Preparation Example 5.

[0037] Preparation Comparative Example 1 The difference between Preparation Comparative Example 1 and Preparation Example 1 is that the vinyl dispersant is replaced by an equal amount of a silane coupling agent, and the rest is the same as Preparation Example 1. Example

[0038] Example 1 Example 1 discloses an anti-fouling and wear-resistant silica gel compound, which is prepared by the following steps: A rubber mixer was used to prepare 3.8 kg of methylphenyl vinyl silicone rubber, 2 kg of end-side vinyl silicone oil with a vinyl content of 1.3% and a viscosity of 180 cp, 1.2 kg of vinyl MQ silicone resin with an M / Q value of 0.9, a vinyl content of 0.6% and a viscosity of 10000 cp, 1 kg of fumed silica, 0.3 kg of hydroxyl content of 9% and a viscosity of 30 mm 2 / s of hydroxy silicone oil and 1.2 kg of the anti-fouling and wear-resistant agent prepared in the preparation example were mixed and refined at a mixing temperature of 100° C. for 3.5 h to obtain an anti-fouling and wear-resistant silica gel compound.

[0039] Example 2-3 The difference between Example 2-3 and Example 1 is that the amount of raw materials used and the preparation conditions are different, see Table 2 below for details.

[0040] Table 2 Parameters of Examples 1-3 Examples 4-7 The difference between Examples 4-7 and Example 1 is that the sources of the anti-fouling and anti-wear agents are different. Please refer to Table 3 below for details.

[0041] Table 3 Sources of antifouling and antiwear agents of Examples 4-7 Example Sources of anti-fouling and anti-wear agents Example 4 Preparation Example 4 Example 5 Preparation Example 5 Example 6 Preparation Example 6 Example 7 Preparation Example 7 Example 8 The difference between Example 8 and Example 1 is that the end-side vinyl silicone oil is replaced by an equal amount of double-end vinyl silicone oil, the vinyl mass percentage is 1.2%, and the viscosity is 110 cp. Other aspects are the same as Example 1.

[0042] Comparative Example Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that the anti-fouling and anti-wear agent in Comparative Example 1 is derived from the preparation of Comparative Example 1, and the rest is the same as Example 1.

[0043] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that the anti-fouling and anti-wear agent is replaced by fumed silica in equal amounts, and the rest is the same as Example 1.

[0044] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that the methylphenyl vinyl silicone rubber is replaced by methyl vinyl silicone rubber in equal amounts. The methyl vinyl silicone rubber is 110 raw rubber with a molecular weight of 650,000 and a vinyl content of 0.16%. Other aspects are the same as Example 1.

[0045] Application Examples Application Example 1 Application Example 1 discloses a test tape, which is prepared by the following steps: 2 kg of the anti-fouling and wear-resistant silicone rubber compound prepared in Example 1, 0.2 kg of hydrogen-containing silicone oil, 0.05 kg of platinum catalyst, and 0.003 kg of 1-ethynylcyclohexanol as an inhibitor are added to a mixer, mixed evenly, and then pressed into sheets, cut, and placed in a molding and vulcanizing machine. Molding and vulcanization are carried out at a temperature of 130°C for 15 minutes to obtain a test tape with a thickness of 5 mm and a width of 15 mm; the hydrogen-containing silicone oil is end-hydrogenated silicone oil with a hydrogen content of 1.2%, and the platinum content in the platinum catalyst is 8000 ppm.

[0046] Application Example 2-11 The difference between Application Example 2-11 and Application Example 1 is that the sources of the anti-fouling and wear-resistant silicone rubber compound are different. For details, please refer to Table 4 below.

[0047] Table 4 Sources of anti-fouling and wear-resistant silicone rubber compounds for application examples 1-11 Application Examples Source of anti-fouling and wear-resistant silicone rubber compound 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 Example 8 Application Example 9 Comparative Example 1 Application Example 10 Comparative Example 2 Application Example 11 Comparative Example 3 Performance test The following test strips corresponding to use cases 1-11 are used for performance test: 1. Water drop angle test: Soak the test tape in standard artificial sweat for 60 minutes, take it out, wash it with water and dry it, then wipe it three times with anhydrous ethanol. After the anhydrous ethanol evaporates, use a water drop angle tester, place the test tape on the test platform, test the water drop angle, test and record the test results. The larger the water drop angle, the better the anti-fouling effect.

[0048] 2. Wear resistance test: Immerse the test tape in standard artificial sweat for 60 minutes. After washing and drying, use an abrasion tester with Bangstar #0000 steel wool. Apply a 1kg load to the indenter and rub the tape back and forth at a speed of 60 times / minute with a stroke of 20mm. Stop the test when wear marks appear on the surface of the test tape and record the number of frictions.

[0049] 3. Elongation at break test: The test tape was immersed in standard artificial sweat for 60 minutes, and then washed and dried. The elongation at break (unit: %) of the test tape was measured using a tensile testing machine, and the test results were recorded.

[0050] The following are the performance data of the test tapes of Application Examples 1-11, see Table 5 below for details.

[0051] Table 5 Performance data of test tape Combined with Application Examples 1-3, Application Examples 4-7 and Application Examples 9-10, it can be concluded that the anti-fouling and wear-resistant agent prepared using the wollastonite powder, silane coupling agent and vinyl dispersant of the present application has good wear resistance, anti-fouling and flexibility. Compared with Application Example 1, Application Example 9-10 does not add vinyl dispersant, while Application Example 10 replaces the anti-fouling and wear-resistant agent with fumed silica. The water drop angle of the test tape obtained is significantly reduced, the number of wear times is also significantly reduced, and the elongation at break is also significantly reduced. Compared with Application Example 1, Application Example 4-5 further optimizes the type and proportion of the silane coupling agent in the anti-fouling and wear-resistant agent, and the wear resistance, anti-fouling and flexibility of the prepared silicone rubber compound are all improved. Compared with Application Example 4, Application Examples 6-7 further optimized the type and proportion of vinyl dispersants, and the wear resistance, anti-fouling and flexibility of the prepared silicone compound were all improved. This shows that the anti-fouling and wear-resistant agent prepared by combining the vinyl dispersant, silane coupling agent and wollastonite powder in the preferred ratio of this application has a significant improvement on the anti-fouling and wear resistance of the silicone compound rubber of this application, and can also improve flexibility.

[0052] In combination with Application Example 1, Application Example 8 and Application Example 11, it can be concluded that the use of the end-side vinyl silicone oil, methylphenyl vinyl silicone rubber in combination with vinyl silicone oil and vinyl MQ silicone resin in this application can significantly improve the flexibility and wear resistance of the prepared silicone compound, and can also slightly improve the anti-fouling properties.

[0053] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A stain-resistant and wear-resistant silicone rubber compound, characterized in that: It is prepared from the following raw materials in parts by weight: 38-48 parts of methylphenyl vinyl silicone rubber 20-25 parts vinyl silicone oil 12-18 parts of vinyl MQ silicone resin 10-16 parts of fumed silica 8-15 parts of anti-fouling and anti-wear agent 3-6 parts of hydroxy silicone oil; The anti-fouling and anti-wear agent is prepared from wollastonite powder, a silane coupling agent and a vinyl dispersant.

2. The anti-fouling and wear-resistant silica gel compound according to claim 1, characterized in that: The anti-fouling and anti-wear agent consists of wollastonite powder, a silane coupling agent and a vinyl dispersant in a weight ratio of 5:(0.3-0.6):(0.8-1.2).

3. The anti-fouling and wear-resistant silica gel compound according to claim 2, characterized in that: The silane coupling agent is composed of a polyamino long-chain alkylsilane and methyl vinyl dibutyl ketoxime silane in a weight ratio of (2-4):1, and the polyamino long-chain alkylsilane is diethylenetriaminopropyltrimethoxysilane and / or N-β-aminoethyl-γ-aminopropylmethyldimethoxysilane.

4. The anti-fouling and wear-resistant silica gel compound according to claim 2, characterized in that: The vinyl dispersant consists of 2-octenylsuccinic anhydride and 4-vinylphenyl glycidyl ether in a weight ratio of (1.5-2.5):

1.

5. The anti-fouling and wear-resistant silica gel compound according to claim 1, characterized in that: The anti-fouling and anti-wear agent is prepared by the following steps: adding a silane coupling agent to wollastonite powder, heating the mixture for kneading and dispersion, and then adding a vinyl dispersant for kneading and dispersion to prepare the anti-fouling and anti-wear agent.

6. The anti-fouling and wear-resistant silica gel compound according to claim 1, characterized in that: The vinyl silicone oil is a terminal vinyl silicone oil with a vinyl content of 1.1-1.3% and a viscosity of 180-250 cp.

7. The anti-fouling and wear-resistant silica gel compound according to claim 1, characterized in that: The vinyl MQ silicone resin has an M / Q value of 0.8-0.9, a vinyl mass content of 0.6-0.9%, and a viscosity of 5000-10000 cp.

8. The anti-fouling and wear-resistant silica gel compound according to claim 1, characterized in that: The hydroxy silicone oil is a double-terminal hydroxy silicone oil with a hydroxyl content of 8.5-10% and a viscosity of 25-35 mm 2 / s.

9. A method for preparing an anti-fouling and wear-resistant silica gel compound according to any one of claims 1 to 8, characterized in that: The following steps are involved: The anti-fouling and wear-resistant silicone rubber compound is prepared by mixing and refining methylphenyl vinyl silicone rubber, vinyl silicone oil, vinyl MQ silicone resin, fumed silica, hydroxy silicone oil and anti-fouling and wear-resistant agent using a rubber refining device.

10. The method for preparing a stain-resistant and wear-resistant silica gel compound according to claim 9, characterized in that: The mixing temperature is 100-120°C and the mixing time is 1.5-3.5h.

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