High-stability silicone rubber and preparation method thereof

Abstract

The invention belongs to the technical field of silicone rubber, and particularly discloses high-stability silicone rubber. The silicone rubber is prepared from the following components in parts by weight: 60 to 70 parts of rubber mixed methyl vinyl raw rubber, 30 to 40 parts of fumed silica, 2 to 3 parts of carbon hexadecanol, 0.2 to 0.7 part of hydroxyl silicone oil, 0.12 to 0.17 part of methoxyl silicone oil, 0.1 to 0.2 part of 171 and 0.001 to 0.003 part of blue paste. The invention further provides a preparation method of the high-stability silicone rubber, and the preparation method is simple, wide in raw material source and suitable for large-scale production.

Description

Technical Field

[0001] The present invention belongs to the technical field of silicone rubber, and particularly relates to a highly stable silicone rubber and a preparation method thereof. Background Art

[0002] In methyl vinyl silicone rubber, the content of silanol groups directly affects the heat resistance and mechanical properties of the product, etc. A high content of silanol groups will lead to poor heat resistance, while a low content improves heat resistance. In a free radical vulcanization system, silanol groups have a negative impact on the mechanical properties and aging resistance of silicone rubber. The higher the content, the greater the harm to the properties. And the stability of the silicone rubber formulation is one of the key factors for maintaining its performance under high or low temperature usage conditions. Since silicone rubber can still maintain good flexibility, resilience and surface hardness, as well as excellent insulation performance at high or low temperatures, it is necessary to ensure the stability of the compounding agents at high or low temperatures during formulation design.

[0003] At present, some silicone rubber formulations have deficiencies in aspects such as the use of silicone rubber raw materials, additives, and the control of the proportion of each component, which affect various properties of the products. At the same time, it causes some substances to precipitate when the products are used in high or low temperature environments, affecting the use and even endangering the health of users. Therefore, it is particularly important to develop a silicone rubber product with excellent basic performance and high stability. Summary of the Invention

[0004] The purpose of the present invention is to provide a highly stable silicone rubber; the present invention also provides a preparation method of the highly stable silicone rubber. The preparation method is simple, the raw materials are widely available, and it is suitable for large-scale production.

[0005] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0006] A highly stable silicone rubber is composed of the following components in parts by weight:

[0007]

[0008] Further, preferably, the highly stable silicone rubber is composed of the following components in parts by weight:

[0009]

[0010] In the present invention, the mixed methyl vinyl raw rubber is compounded from 110-7s, 110-2s and 110-8s of Nanjing Dongjue Sales Co., Ltd. according to the weight ratio of (0.1-0.3):(3-5):1.

[0011] The fumed silica is QS-102 of Tokuyama Corporation, Japan.

[0012] The cetyl alcohol is Procter & Gamble cetyl alcohol of Procter & Gamble Company, Malaysia.

[0013] The hydroxy silicone oil used is the general-purpose hydroxy silicone oil from Huizhou Tianyi Environmental Protection Materials Co., Ltd.

[0014] The methoxy silicone oil used is the methoxy silicone oil from Zhejiang Zhenghe Silicon Materials Co., Ltd.

[0015] The 171 used is SICO-V171 from Shandong Sike New Materials Co., Ltd.

[0016] The blue paste used is 1520 from Kailexing. Adding the blue paste in the present invention can prevent the prepared silicone rubber products from turning white after being boiled in water.

[0017] The present invention also provides a preparation method for the high-stability silicone rubber, which mainly includes the following steps:

[0018] S1 Preparation of modified silica

[0019] Put the fumed silica, cetyl alcohol, part of the hydroxy silicone oil, and part of the methoxy silicone oil into the reaction kettle, maintain the temperature at 240 °C and the pressure at 3×106 Pa, take it out after 3 - 4 hours to obtain the modified silica.

[0020] S2 Powdered rubber

[0021] Control the powdering temperature at 50 - 80 °C. First, add the mixed methyl vinyl raw rubber, then add part of the modified silica treated in S1, the remaining hydroxy silicone oil and the remaining methoxy silicone oil, then add 171, and finally pour the blue paste above the modified silica and start stirring. After stirring into a dough, continue to add the remaining modified silica and stir evenly;

[0022] S3 Placement

[0023] Take out the stirred rubber compound in S2 and place it for 24 - 36 hours;

[0024] S4 Internal mixing

[0025] Put the placed rubber compound into the internal mixer, add cetyl alcohol, and carry out internal mixing until the rubber compound is stirred into a large smooth mass on the surface.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. The high-stability silicone rubber of the present invention has excellent basic properties, a new high level of stability, does not turn white when boiled under high-temperature conditions, and no other substances precipitate under low-temperature conditions, which can greatly improve the sealing performance of silicone rubber products.

[0028] 2. The preparation method of the high-stability silicone rubber of the present invention is simple, the raw materials are widely available, and it is suitable for large-scale production. Specific embodiments

[0029] The present invention will be further described below in conjunction with specific embodiments, but it is not limited thereto.

[0030] In an embodiment of the present invention, a highly stable silicone rubber is composed of the following components in parts by weight:

[0031]

[0032] Among them: the mixed methyl vinyl raw rubber is compounded from 110-7s, 110-2s and 110-8s of Nanjing Dongjue Sales Co., Ltd. according to a weight ratio of 0.2:4:1; the fumed silica is QS-102 of Tokuyama, Japan; the cetyl alcohol is Procter & Gamble cetyl alcohol of Procter & Gamble Malaysia; the hydroxy silicone oil is a general-purpose hydroxy silicone oil of Huizhou Tianyi Environmental Protection Materials Co., Ltd.; the methoxy silicone oil is a methoxy silicone oil of Zhejiang Zhenghe Silicon Materials Co., Ltd.; 171 is SICO-V171 of Shandong Sike New Materials Co., Ltd.; the blue paste is 1520 of Kailexing.

[0033] The specific embodiment of the present invention also provides a preparation method of the highly stable silicone rubber, and the specific steps are as follows:

[0034] S1 Preparation of modified fumed silica

[0035] Put the fumed silica, cetyl alcohol, part of the hydroxy silicone oil, part of the methoxy silicone oil into the reaction kettle, keep the temperature at 240 °C and the pressure at 3×106 Pa, take it out after 3-4 h to obtain the modified fumed silica.

[0036] S2 Powder rubber

[0037] Control the powder feeding temperature at 50-80 °C, first add the mixed methyl vinyl raw rubber, then add part of the modified fumed silica treated by S1, the remaining hydroxy silicone oil and the remaining methoxy silicone oil, then add 171, and finally pour the blue paste above the modified fumed silica, start stirring, continue to add the remaining modified fumed silica after stirring into a mass and stir evenly;

[0038] S3 Placement

[0039] Take out the stirred rubber compound in S2 and place it for 24-36 h;

[0040] S4 Internal mixing

[0041] Put the placed rubber compound into an internal mixer, add cetyl alcohol, and carry out internal mixing until the rubber compound is stirred into a large smooth mass on the surface.

[0042] Embodiment

[0043] In Examples 1-3 of the present invention, 3 groups of experiments on highly stable silicone rubber are provided, and the specific formulations and dosages are shown in Table 1:

[0044] Table 1 Raw material composition of high-stability silicone rubber in Examples 1-3 (unit: parts by weight)

[0045]

[0046]

[0047] Comparative Example

[0048] Three groups of silicone rubber experiments were also provided in Comparative Examples 1-3. The specific formulations and dosages are shown in Table 2:

[0049] Table 2 Raw material composition of silicone rubber in Comparative Examples 1-3 (unit: parts by weight)

[0050] Component Comparative Example 1 Comparative Example 2 Comparative Example 3 Mixed methyl vinyl raw rubber 64 64 64 Fumed silica 35 35 35 Cetyl alcohol 0 1 4 Hydroxy silicone oil 0.5 0.5 0.5 Methoxy silicone oil 0.14 0.14 0.14 171 0.15 0.15 0.15 Blue paste 0.002 0.002 0.002

[0051] Performance Test

[0052] Six groups of silicone rubber products were prepared according to the formulations in Examples 1-3 of Table 1 and Comparative Examples 1-3 of Table 2 by the above preparation method of high-stability silicone rubber, and were routinely tested according to the standards in Table 3.

[0053] Table 3 Performance requirements for routine testing

[0054]

[0055]

[0056] Routine testing found that all data of Examples 1-3 and Comparative Examples 1-2 were within the standards in Table 3, meeting the test standards; while the test data of plasticity, tensile strength, tear strength, and elongation of the silicone rubber prepared in Comparative Example 3 were all lower than the ranges in the table; and after baking at 200°C for 4 hours in two stages, the hardness increased by 7-10 degrees, and other performance data decreased by 20% - 30%, resulting in the material being unusable.

[0057] Stability Test

[0058] The specific steps of the stability test in this specific embodiment are as follows:

[0059] 1. Test Preparation

[0060] Sample selection: Prepare the silicone rubber samples to be tested, and determine the specifications and quantities of the samples according to the actual application scenarios and test requirements. If it is a silicone rubber material for a specific product, the samples can be prepared according to the size and shape of the product.

[0061] Test equipment: Prepare glass containers to ensure that the containers can hold the silicone rubber samples and add enough water; prepare heating equipment and thermometers for measuring the water temperature.

[0062] Selection of water: Use deionized water or distilled water for the test to avoid the influence of impurities in the water on the test results.

[0063] 2. Test process

[0064] Measurement and recording: Before the start of the test, carefully observe the appearance of the silicone rubber sample, including color, surface condition, etc., and measure the initial weight and dimensions of the sample.

[0065] Boiling water operation: Place the silicone rubber sample in a prepared container, add an appropriate amount of water to ensure that the sample is completely immersed in the water, use a heating device to heat the water to boiling, and maintain the boiling state for a certain period of time;

[0066] Temperature control: During the boiling water process, use a thermometer to monitor the water temperature in real time to ensure that the water temperature remains near the boiling point.

[0067] Observation of phenomena: During the boiling water process, closely observe whether there is any white substance precipitated in the water and the changes on the surface of the silicone rubber sample; observations can be made at regular intervals (such as every 5 or 10 minutes).

[0068] 3. Post-test treatment

[0069] Sample cleaning: After the boiling water test is completed, carefully take out the silicone rubber sample and rinse it thoroughly with deionized water or distilled water to remove any possible residual impurities on the surface.

[0070] Measurement and recording again: After the sample is dried, measure the weight and dimensions of the sample again, compare with the data before the test, and observe whether there are any changes. At the same time, carefully observe the appearance of the sample, including color, surface condition, etc., and record.

[0071] Result determination: Based on the observed phenomena and measurement data, determine whether the silicone rubber sample meets the requirement of not turning white after boiling in water. If there is no obvious white substance precipitated in the water, the color and state of the surface of the silicone rubber sample have no obvious changes, and the weight and dimension changes are within a reasonable range, then it can be considered that the silicone rubber sample has passed the test of not turning white after boiling in water.

[0072] The silicone rubbers of Examples 1-3 and Comparative Examples 1-3 were subjected to a stability test, and the test results are recorded as follows:

[0073] The silicone rubber in Example 1 did not precipitate white substances in the high-temperature water bath test for 25 minutes; under the condition of maintaining a low temperature of -18°C, no white substances were precipitated after 48 hours; the color and state of the surface of the rubber sample had no obvious changes, and the weight and dimension changes were within a reasonable range.

[0074] The silicone rubber in Example 2 did not precipitate white substances in the high-temperature water bath test for 25 minutes; under the condition of maintaining a low temperature of -18°C, no white substances were precipitated after 48 hours; the surface color and state of the rubber sample did not change significantly, and the weight and size changes were within a reasonable range.

[0075] The silicone rubber in Example 3 did not precipitate white substances in the high-temperature water bath test for 25 minutes; under the condition of maintaining a low temperature of -18°C, no white substances were precipitated after 48 hours; the surface color and state of the rubber sample did not change significantly, and the weight and size changes were within a reasonable range.

[0076] The silicone rubber in Comparative Example 1 precipitated white substances in the high-temperature water bath test for 10 minutes; under the condition of maintaining a low temperature of -18°C, white substances were precipitated after 2 hours; the surface color of the rubber sample turned white and the state changed significantly, and the weight became lighter and the size became smaller.

[0077] The silicone rubber in Comparative Example 2 precipitated white substances in the high-temperature water bath test for 20 minutes; under the condition of maintaining a low temperature of -18°C, white substances were precipitated after 20 hours; the surface color of the rubber sample turned white and the state changed significantly, and the weight became lighter and the size became smaller.

[0078] The silicone rubber in Comparative Example 3 did not precipitate white substances in the high-temperature water bath test for 25 minutes; under the condition of maintaining a low temperature of -18°C, no white substances were precipitated after 48 hours; the surface color and state of the rubber sample did not change significantly, and the weight and size changes were within a reasonable range; however, the conventional properties of the material did not meet the standards and it could not be used.

[0079] In summary, it can be seen that the silicone rubber products produced by using the modified fumed silica in Examples 1-3 of the present invention do not turn white when boiled under high-temperature conditions and no other substances are precipitated under low-temperature conditions, which can greatly improve the product stability and thus improve the sealing performance of the silicone rubber products.

Claims

1. A high stability silicone rubber, characterized in that It is composed of the following components in parts by weight:

2. The high stability silicone rubber according to claim 1, characterized in that It is composed of the following components in parts by weight:

3. The high stability silicone rubber according to claim 1, characterized in that The mixed methyl vinyl raw rubber is compounded by mixing 110-7s, 110-2s and 110-8s of Nanjing Dongjue Sales Co., Ltd. in a weight ratio of (0.1-0.3):(3-5):

1.

4. The high stability silicone rubber according to claim 1, characterized in that The fumed silica is QS-102 from Tokuyama, Japan.

5. The high stability silicone rubber according to claim 1, characterized in that The hexadecanol is selected from Procter & Gamble Co., Ltd. of Malaysia.

6. The high stability silicone rubber according to claim 1, characterized in that The hydroxy silicone oil is the general-purpose hydroxy silicone oil produced by Huizhou Tianyi Environmental Protection Materials Co., Ltd.; the methoxy silicone oil is the methoxy silicone oil produced by Zhejiang Zhenghe Silicon Materials Co., Ltd.

7. The high stability silicone rubber according to claim 1, characterized in that The 171 is SICO-V171 produced by Shandong SICO New Materials Co., Ltd.

8. The high stability silicone rubber according to claim 1, characterized in that The blue paste is 1520 from Kailexing.

9. A method for preparing the high-stability silicone rubber according to any one of claims 1 to 8, characterized in that The following steps are involved: S1 Preparation of modified white carbon black Put fumed silica, hexadecanol, part of hydroxy silicone oil, part of methoxy silicone oil into the reactor and keep the temperature at 240℃ and the pressure at 3×10 6 Pa, take it out after 3 to 4 hours to obtain modified white carbon black. S2 Powder Glue The powder feeding temperature is controlled at 50-80℃. First, add the mixed methyl vinyl rubber, then add part of the modified silica treated with S1, the remaining hydroxy silicone oil and the remaining methoxy silicone oil, and then add 171. Finally, pour the blue paste on top of the modified silica and start stirring. After stirring into a mass, continue to add the remaining modified silica and stir evenly. S3 placement Take out the mixed rubber in S2 and leave it for 24 to 36 hours; S4 Secret Refining Put the rubber material after standing into the internal mixer, add hexadecanol, and mix until the rubber material is stirred into a large mass with a smooth surface.

10. The method for preparing the high-stability silicone rubber according to claim 9, characterized in that The kneading conditions are: start timing from 120°C, open the cover and knead for 2-3 hours, and control the processing temperature at 165-195°C.

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