Anti-fouling wear-resistant silicone rubber and preparation method thereof

Abstract

The application relates to the field of silicone rubber, and discloses an anti-fouling wear-resistant silicone rubber mixing rubber and a preparation method thereof. The anti-fouling wear-resistant silicone rubber mixing rubber is prepared from the following raw materials in parts by weight: methylphenyl vinyl silicone rubber 38-48 parts, vinyl silicone oil 20-25 parts, vinyl MQ silicone resin 12-18 parts, fumed silica 10-16 parts, anti-fouling wear-resistant agent 8-15 parts and hydroxyl silicone oil 3-6 parts; the anti-fouling wear-resistant agent is prepared from wollastonite powder, a silane coupling agent and a vinyl dispersant; and the preparation method is that the raw materials are mixed and rubberized to obtain the silicone rubber mixing rubber. The silicone rubber mixing rubber prepared by the application has good flexibility, wear resistance and anti-fouling property, has moderate cost, and is suitable for sports wristbands, smart watches and the like.

Description

Technical Field

[0001] This application relates to the field of silicone rubber, and more specifically, to a stain-resistant and abrasion-resistant silicone rubber compound and a method for its preparation. Background Technology

[0002] With the continuous upgrading of wearable devices such as fitness trackers and smartwatches, the performance requirements for casing and strap materials are becoming increasingly stringent. Silicone compound, as a commonly used material, is widely applied in these devices due to its excellent flexibility, resistance to high and low temperatures, and biocompatibility.

[0003] However, sports wristbands made with silicone rubber tend to accumulate dirt and grease on their surface due to prolonged contact with human sweat, which reduces their performance and can lead to aging, wear, and cracking over time.

[0004] To address these issues, existing technologies involve adding substances such as fluororubber and large amounts of fumed silica to silicone rubber compounds to improve their stain resistance and abrasion resistance. However, fluororubber is expensive and has limited applicability in silicone rubber compounds. Furthermore, the addition of fumed silica can reduce the flexibility of silicone rubber compounds, thereby decreasing the comfort of using the product. Summary of the Invention

[0005] To address the issue that existing silicone rubber compounds cannot adequately balance long-term wear resistance, stain resistance, and flexibility, this application provides a stain-resistant and wear-resistant silicone rubber compound and its preparation method.

[0006] In a first aspect, this application provides a stain-resistant and wear-resistant silicone rubber compound, which adopts the following technical solution:

[0007] A stain-resistant and wear-resistant silicone compound is prepared from the following raw materials in parts by weight:

[0008] 38-48 parts of methyl phenyl vinyl silicone rubber

[0009] 20-25 parts vinyl silicone oil

[0010] 12-18 parts vinyl MQ silicone resin

[0011] 10-16 parts of fumed silica

[0012] 8-15 parts of anti-fouling and wear-resistant agent

[0013] 3-6 parts of hydroxyl silicone oil;

[0014] The antifouling and wear-resistant agent is prepared from wollastonite powder, silane coupling agent and vinyl dispersant.

[0015] By adopting the above technical solution, this application uses methyl phenyl vinyl silicone rubber, vinyl silicone oil, vinyl MQ silicone resin, and hydroxyl silicone oil to form a silicone system. The resulting silicone compound exhibits good flexibility and abrasion resistance. To further enhance the stain resistance and abrasion resistance of the silicone compound, fumed silica and an anti-fouling and abrasion-resistant agent are added to the silicone system. These two agents work synergistically within the silicone system, improving both stain resistance and abrasion resistance while simultaneously enhancing flexibility without reducing flexibility due to the addition of fumed silica. The anti-fouling and abrasion-resistant agent, prepared from wollastonite powder, silane coupling agent, and vinyl dispersant, imparts excellent stain resistance and abrasion resistance to the silicone compound. Furthermore, the agent is further dispersed within the silicone system during application for cross-linking, improving flexibility. The system does not require the addition of fluorosilicone rubber or large amounts of fumed silica, maintaining good stain resistance, abrasion resistance, and flexibility at a moderate cost, making it particularly suitable for wearable devices such as fitness trackers and smartwatches.

[0016] Preferably, the antifouling and wear-resistant 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).

[0017] 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 modify the wollastonite powder in a better ratio, thereby improving the dispersion uniformity and crosslinking performance of the obtained antifouling and wear-resistant agent in the silicone system, and thus improving the flexibility, antifouling performance and wear resistance of the silicone compound.

[0018] Preferably, the silane coupling agent is composed of a polyamino long-chain alkyl silane and a methyl vinyl dibutyl ketone oxime silane in a weight ratio of (2-4):1, wherein the polyamino long-chain alkyl silane is diethylenetriaminepropyltrimethoxysilane and / or N-β-aminoethyl-γ-aminopropylmethyldimethoxysilane.

[0019] By adopting the above technical solution, using polyamino long-chain alkyl silanes and methyl vinyl dibutyl ketone oxime silanes in a better weight ratio as silane coupling agents, the dispersibility and compatibility of wollastonite powder in silicone rubber can be improved. At the same time, the long-chain polyamino and branched silane structures can endow silicone rubber with excellent anti-fouling and abrasion resistance, while not easily reducing the flexibility of silicone rubber.

[0020] Preferably, the vinyl dispersant is composed of 2-octenyl succinic anhydride and 4-vinylphenyl glycidyl ether in a weight ratio of (1.5-2.5):1.

[0021] By adopting the above technical solution, using 2-octenyl succinic anhydride and 4-vinylphenyl glycidyl ether in a better weight ratio as vinyl dispersants, it is possible to improve the uniformity of dispersion of antifouling and abrasion-resistant agents in the silicone system, and further crosslink with the silicone system, thereby improving the dispersion density of antifouling and abrasion-resistant agents and fumed silica in the silicone system, and thus improving the flexibility, abrasion resistance and antifouling properties of the prepared silicone compound.

[0022] Preferably, the antifouling and wear-resistant agent is prepared by the following steps: adding a silane coupling agent to wollastonite powder, heating and kneading to disperse, and then adding a vinyl dispersant for kneading and dispersing to obtain the antifouling and wear-resistant agent.

[0023] By adopting the above technical solution, the silane coupling agent is first added to the wollastonite powder for kneading and dispersion, which enables the silane coupling agent to be fully coated on the surface of the wollastonite powder. Then, the vinyl dispersant is added for kneading and dispersion, which improves the stain resistance and wear resistance of the silicone rubber compound.

[0024] Preferably, the vinyl silicone oil is an end-sided vinyl silicone oil with a vinyl content of 1.1-1.3% and a viscosity of 180-250 cp.

[0025] By adopting the above technical solution, the introduction of end-side vinyl silicone oil gives the silicone rubber compound better crosslinking performance. When its vinyl 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 within the range of 180-250cp, which ensures the fluidity of the compound during processing and avoids the problems of difficult operation due to excessive viscosity or poor structural stability due to excessively low viscosity.

[0026] Preferably, the vinyl MQ silicone resin has an M / Q value of 0.8-0.9, a vinyl content of 0.6-0.9% by mass, and a viscosity of 5000-10000 cp.

[0027] By adopting the above technical solution, the vinyl MQ silicone resin used in the anti-fouling and wear-resistant silicone compound has a specific M / Q value, vinyl mass content, and viscosity range. This specific range of M / Q values ​​can optimize the crosslinking structure, improve the flexibility and wear resistance of the material; controlling the vinyl mass content helps to enhance the crosslinking density of the silicone rubber, further improving its wear resistance and anti-fouling properties.

[0028] Preferably, the hydroxyl silicone oil is a double-hydroxyl-terminated silicone oil with a hydroxyl content of 8.5-10% and a viscosity of 25-35 mm. 2 / s.

[0029] By adopting the above technical solution, the addition of superior-grade double-hydroxyl-terminated silicone oil can effectively improve the flexibility of silicone rubber compound, while enhancing the dispersion performance of anti-fouling and abrasion-resistant agents and fumed silica in the system.

[0030] Secondly, this application provides a method for preparing a stain-resistant and wear-resistant silicone rubber compound, which adopts the following technical solution:

[0031] A method for preparing a stain-resistant and wear-resistant silicone compound includes the following steps: mixing methyl phenyl vinyl silicone rubber, vinyl silicone oil, vinyl MQ silicone resin, fumed silica, hydroxyl silicone oil and stain-resistant and wear-resistant agent using a rubber mixing equipment to obtain a stain-resistant and wear-resistant silicone compound.

[0032] By adopting the above technical solution, when methyl phenyl vinyl silicone rubber, vinyl silicone oil, vinyl MQ silicone resin, fumed silica, hydroxyl silicone oil and anti-fouling and wear-resistant agent are mixed and compounded 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 compound.

[0033] Preferably, the rubber mixing temperature is 100-120℃ and the mixing time is 1.5-3.5h.

[0034] By adopting the above technical solutions, the optimal mixing temperature and time can effectively promote the uniform mixing and interweaving of various raw material components, thereby improving the overall performance of the prepared silicone rubber compound.

[0035] In summary, this application includes at least one of the following beneficial technical effects:

[0036] 1. The anti-fouling and wear-resistant silicone compound of this application utilizes the synergistic effect of methyl phenyl vinyl silicone rubber, vinyl silicone oil, vinyl MQ silicone resin, fumed silica, hydroxyl silicone oil, and an anti-fouling and wear-resistant agent. The anti-fouling and wear-resistant agent is prepared from wollastonite powder, silane coupling agent, and vinyl dispersant. This not only significantly improves the anti-fouling performance of the silicone compound but also enhances its overall wear resistance while maintaining the flexibility of the material. It effectively solves the problem of traditional materials easily absorbing stains and aging and wearing out during long-term use. The cost is moderate, and it can be applied to smart wearable products such as fitness trackers and smartwatches.

[0037] 2. The silane coupling agent is composed of polyamino long-chain alkyl silanes and methyl vinyl dibutyl ketone oxime silanes, which can improve the dispersibility and binding force of wollastonite powder in silica gel compound.

[0038] 3. The 2-octenyl succinic anhydride and 4-vinylphenyl glycidyl ether in the vinyl dispersant work synergistically with wollastonite powder to improve the uniformity of dispersion of the antifouling and abrasion-resistant agent in the silicone system, and further crosslink with the silicone system to improve the dispersion density of the antifouling and abrasion-resistant agent and fumed silica in the silicone system, thereby improving the flexibility, abrasion resistance and antifouling properties of the prepared silicone compound. Detailed Implementation

[0039] The present application will be further described in detail below with reference to embodiments and application examples.

[0040] 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:

[0041] 1. Methylphenyl vinyl silicone rubber: Mingyi Silicon Industry, model MY120, phenyl content 5%, vinyl content 0.2%, molecular weight 400,000;

[0042] 2. End-side vinyl silicone oil: Jipeng Silicone Fluorine Materials, JP-02V series;

[0043] 2. Fumed silica: Cabot, CAB-O-SIL TG-811F;

[0044] 3. Wollastonite powder: 2000 mesh.

[0045] Preparation example of antifouling and wear-resistant agent

[0046] Preparation Example 1

[0047] Preparation Example 1 discloses an antifouling and wear-resistant agent, which is prepared by the following steps: 0.3 kg of silane coupling agent (made of vinyltrimethoxysilane in a weight ratio of 2:1) is added to 5 kg of wollastonite powder, heated to 90°C and kneaded and dispersed for 60 min, then 1.2 kg of vinyl dispersant is added, and kneaded and dispersed at 60°C for 40 min to obtain the antifouling and wear-resistant agent.

[0048] Preparation Examples 2-3

[0049] The difference between Preparation Example 2-3 and Preparation Example 1 lies in the amount of raw materials used and the preparation conditions, as detailed in Table 1 below.

[0050] Table 1. Parameters for Preparation Examples 1-3

[0051]

[0052] Preparation Example 4

[0053] 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 ketone oxime silane in a weight ratio of 2:1. The polyamino long-chain alkyl silane is diethylenetriaminepropyltrimethoxysilane. The rest is the same as in Preparation Example 1.

[0054] Preparation Example 5

[0055] 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 alkyl silane and a methyl vinyl dibutyl ketone oxime silane in a weight ratio of 4:1. The polyamino long-chain alkyl silane is diethylenetriaminepropyltrimethoxysilane. The rest is the same as in Preparation Example 4.

[0056] Preparation Example 6

[0057] The difference between Preparation Example 6 and Preparation Example 5 is that the vinyl dispersant is composed of 2-octenyl succinic anhydride and 4-vinylphenyl glycidyl ether in a weight ratio of 1.5:1, while the rest is the same as Preparation Example 5.

[0058] Preparation Example 7

[0059] The difference between Preparation Example 7 and Preparation Example 5 is that the vinyl dispersant is composed of 2-octenyl succinic anhydride and 4-vinylphenyl glycidyl ether in a weight ratio of 2.5:1, while the rest is the same as Preparation Example 5.

[0060] Preparation of Comparative Example 1

[0061] The difference between Comparative Example 1 and Preparation Example 1 is that the vinyl dispersant was replaced with an equal amount of silane coupling agent, while the rest was the same as Preparation Example 1.

[0062] Example

[0063] Example 1

[0064] Example 1 discloses a stain-resistant and wear-resistant silicone compound, which is prepared by the following steps:

[0065] The following materials were mixed using a rubber mixing mill: 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, and 0.3 kg of hydroxyl content of 9% and a viscosity of 30 mm. 2 / s of hydroxyl silicone oil and 1.2kg of the anti-fouling and wear-resistant agent prepared in the preparation example were mixed and compounded at a compounding temperature of 100℃ for 3.5h to obtain an anti-fouling and wear-resistant silicone compound.

[0066] Example 2-3

[0067] The difference between Examples 2-3 and Example 1 lies in the amount of raw materials used and the preparation conditions, as detailed in Table 2 below.

[0068] Table 2 Parameter table for Examples 1-3

[0069]

[0070]

[0071] Examples 4-7

[0072] The difference between Examples 4-7 and Example 1 is that the sources of the antifouling and wear-resistant agents are different, as detailed in Table 3 below.

[0073] Table 3. Sources of antifouling and wear-resistant agents in Examples 4-7

[0074] Example Sources of antifouling and wear-resistant agents Example 4 Preparation Example 4 Example 5 Preparation Example 5 Example 6 Preparation Example 6 Example 7 Preparation Example 7

[0075] Example 8

[0076] The difference between Example 8 and Example 1 is that the end-side vinyl silicone oil is replaced with an equal amount of double-end vinyl silicone oil, with a vinyl mass percentage of 1.2% and a viscosity of 110 cp. Everything else is the same as in Example 1.

[0077] Comparative Example

[0078] Comparative Example 1

[0079] The difference between Comparative Example 1 and Example 1 is that the antifouling and wear-resistant agent in Comparative Example 1 is derived from the preparation of Comparative Example 1, while the rest is the same as in Example 1.

[0080] Comparative Example 2

[0081] The difference between Comparative Example 2 and Example 1 is that the anti-fouling and wear-resistant agent is replaced with an equal amount of fumed silica, while the rest is the same as Example 1.

[0082] Comparative Example 3

[0083] The difference between Comparative Example 3 and Example 1 is that methyl phenyl vinyl silicone rubber was replaced with an equal amount of methyl vinyl silicone rubber. The methyl vinyl silicone rubber was 110 raw rubber with a molecular weight of 650,000 and a vinyl content of 0.16%. Everything else was the same as in Example 1.

[0084] Application examples

[0085] Application Example 1

[0086] Application Example 1 discloses a test strip, which is prepared by the following steps: 2 kg of 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 inhibitors are added to a mixer, mixed evenly, pressed into sheets, cut, and placed in a molding and vulcanizing machine. The sheets are molded and vulcanized at a temperature of 130°C for 15 min to obtain a test strip with a thickness of 5 mm and a width of 15 mm. The hydrogen-containing silicone oil is end-hydrogen-containing silicone oil with a hydrogen content of 1.2%, and the platinum catalyst contains 8000 ppm of platinum.

[0087] Application Example 2-11

[0088] The difference between Application Example 2-11 and Application Example 1 is that the source of the anti-fouling and wear-resistant silicone compound is different, as detailed in Table 4 below.

[0089] Table 4. Sources of anti-fouling and abrasion-resistant silicone rubber compounds in Application Examples 1-11

[0090] Application examples Sources 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

[0091] Performance testing will be conducted on the test strips corresponding to test cases 1-11 below:

[0092] 1. Water droplet angle test:

[0093] Immerse the test strip in standard artificial sweat for 60 minutes, then remove, wash and dry it. Wipe it three times with anhydrous ethanol. After the anhydrous ethanol evaporates, use a water droplet angle tester to place the test strip on the test platform and test the water droplet angle. Test and record the results. The larger the water droplet angle, the better the anti-fouling effect.

[0094] 2. Abrasion resistance test:

[0095] Immerse the test strip in standard artificial sweat for 60 minutes, then remove, wash and dry. Use an abrasion tester with Bangshida #0000 steel wool to apply a 1kg load to the indenter at a speed of 60 times / minute and a stroke of 20mm. Rub the test strip back and forth on the surface of the test strip. Stop the test when abrasion marks appear on the surface of the test strip and record the number of rubbing times.

[0096] 3. Elongation at break test:

[0097] Immerse the test strip in standard artificial sweat for 60 minutes, remove it, wash and dry it, and then use a tensile testing machine to test the elongation at break (unit: %) of the test strip. Test and record the test results.

[0098] The following are the performance data of the test band for Application Example 1-11, see Table 5 below for details.

[0099] Table 5 Performance data of the test strip

[0100]

[0101] Combining Application Examples 1-3, 4-7, and 9-10, it can be concluded that using the wollastonite powder, silane coupling agent, and vinyl dispersant of this application to prepare an antifouling and abrasion-resistant agent results in a silicone rubber compound with good abrasion resistance, stain resistance, and flexibility. Compared to Application Example 1, Application Example 9 does not add a vinyl dispersant, while Application Example 10 replaces the antifouling and abrasion-resistant agent with fumed silica. The resulting test strips show a significantly reduced water droplet angle, a significantly reduced number of abrasion cycles, and a significantly reduced elongation at break. Compared to Application Example 1, Application Examples 4-5 further optimize the type and proportion of the silane coupling agent in the antifouling and abrasion-resistant agent, improving the abrasion resistance, stain resistance, and flexibility of the resulting silicone rubber compound. Compared to Application Example 4, Application Examples 6-7 further optimized the type and proportion of vinyl dispersant, resulting in improved wear resistance, stain resistance, and flexibility of the prepared silicone rubber compound. This indicates that the combination of the vinyl dispersant, silane coupling agent, and wollastonite powder in the preferred ratio of this application significantly improves the stain resistance and wear resistance of the silicone rubber compound, while also improving its flexibility.

[0102] Based on Application Examples 1, 8 and 11, it can be concluded that using the end-side vinyl silicone oil and methyl phenyl vinyl silicone rubber of this application in combination with vinyl silicone oil and vinyl MQ silicone resin can significantly improve the flexibility and abrasion resistance of the prepared silicone compound, while also slightly improving its stain resistance.

[0103] 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 stain-resistant and wear-resistant silicone compound, characterized in that, It is prepared from the following raw materials in parts by weight: 38-48 parts of methyl phenyl vinyl silicone rubber 20-25 parts vinyl silicone oil 12-18 parts vinyl MQ silicone resin 10-16 parts of fumed silica 8-15 parts of anti-fouling and wear-resistant agent 3-6 parts of hydroxyl silicone oil; The vinyl silicone oil is an end-sided vinyl silicone oil with a vinyl content of 1.1-1.3% and a viscosity of 180-250 cp. The antifouling and wear-resistant 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); The silane coupling agent is composed of a polyamino long-chain alkyl silane and a methyl vinyl dibutyl ketone oxime silane in a weight ratio of (2-4):1, wherein the polyamino long-chain alkyl silane is diethylenetriaminepropyltrimethoxysilane. The vinyl dispersant is composed of 2-octenyl succinic anhydride and 4-vinylphenyl glycidyl ether in a weight ratio of (1.5-2.5):

1.

2. The anti-fouling and wear-resistant silicone rubber compound according to claim 1, characterized in that, The antifouling and wear-resistant agent is prepared by the following steps: adding a silane coupling agent to wollastonite powder, heating and kneading to disperse, and then adding a vinyl dispersant for kneading and dispersing to obtain the antifouling and wear-resistant agent.

3. The anti-fouling and wear-resistant silicone rubber 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 content of 0.6-0.9% by mass, and a viscosity of 5000-10000 cp.

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

5. A method for preparing a stain-resistant and wear-resistant silicone compound as described in any one of claims 1-4, characterized in that, Includes the following steps: The anti-fouling and wear-resistant silicone rubber compound is prepared by mixing methyl phenyl vinyl silicone rubber, vinyl silicone oil, vinyl MQ silicone resin, fumed silica, hydroxyl silicone oil and anti-fouling and wear-resistant agent using a rubber mixing equipment.

6. The method for preparing a stain-resistant and wear-resistant silicone rubber compound according to claim 5, characterized in that, The mixing temperature is 100-120℃, and the mixing time is 1.5-3.5h.

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