Chloramine-resistant silicone rubber and preparation method thereof

Abstract

The invention belongs to the technical field of silicone rubber, and particularly discloses chloramine-resistant silicone rubber. The silicone rubber is prepared from 140 to 160 parts of mixed methyl vinyl raw rubber, 50 to 70 parts of precipitated white carbon black, 0.5 to 0.7 part of carbon hexadecanol, 2 to 3 parts of hydroxyl silicone oil, 5 to 7 parts of methoxy silicone oil and 0.2 to 0.3 part of zinc stearate. The chloramine-resistant silicone rubber is high in cost performance and excellent in chloramine-resistant effect; the invention further provides a preparation method of the chloramine-resistant 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 chloramine-resistant silicone rubber and a preparation method thereof. Background Art

[0002] Rubber products can be used to manufacture sealing components for various products, especially for sanitary products. Due to the strong corrosiveness of seawater and various cleaning agents used in modern life on rubber sealing components, higher requirements for the chloramine resistance of rubber sealing components are needed. At present, the raw materials for chloramine-resistant sanitary sealing components used more include fluororubber and silicone rubber. Due to its unique chemical structure, fluororubber exhibits good seawater corrosion resistance, can maintain stable physical and chemical properties in seawater, and will not undergo significant degradation or corrosion. Therefore, it is widely used in the manufacture of sealing products that need to be used in seawater environments. However, the price of fluororubber is relatively expensive, 4-6 times that of silicone rubber; while the commonly used silicone rubber is cost-effective but has slightly poor chloramine resistance, and there is still great room for improvement in the selection of rubber compound formulations and materials.

[0003] At present, existing technologies have improved the corrosion resistance of silicone rubber products in seawater environments by selecting appropriate silicone rubber materials, adding preservatives, using composite materials, surface treatment, optimizing design and maintenance strategies, etc. However, considering from the perspectives of cost and performance, these methods are not the best choices, because: the cost of composite materials is relatively high, the adaptability of surface treatment to silicone rubber seals is not high, and optimizing design and maintenance strategies are tasks after product delivery, increasing the workload.

[0004] Therefore, it is particularly important to develop a silicone rubber product with low cost, simple materials and high chloramine resistance. Summary of the Invention

[0005] The purpose of the present invention is to provide a cost-effective chloramine-resistant silicone rubber. The present invention also provides a preparation method of the chloramine-resistant silicone rubber, which is simple, has a wide range of raw material sources, and is suitable for large-scale production.

[0006] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0007] A chloramine-resistant silicone rubber is composed of the following components in parts by mass:

[0008]

[0009] Further, preferably, the chloramine-resistant silicone rubber is composed of the following components in parts by mass:

[0010]

[0011] In the present invention, the mixed methyl vinyl raw rubber is compounded from 110-2s and 110-7s of Nanjing Dongjue Sales Co., Ltd. at a weight ratio of (13 to 15):1.

[0012] The precipitated silica selected is SK658B of Fujian Cisco Silicon Materials Co., Ltd.

[0013] The cetyl alcohol is the Procter & Gamble cetyl alcohol of Procter & Gamble Malaysia.

[0014] The hydroxyl silicone oil selected is the general-purpose hydroxyl silicone oil of Huizhou Tianyi Environmental Protection Materials Co., Ltd.

[0015] The methoxy silicone oil selected is the methoxy silicone oil of Zhejiang Zhenghe Silicon Materials Co., Ltd.

[0016] The zinc stearate selected is the zinc stearate of Azelis Chemicals (Guangzhou) Co., Ltd. In the present invention, adding zinc stearate enables the produced silicone rubber products to be demolded better.

[0017] The present invention also provides a preparation method of the chloramine-resistant silicone rubber, which mainly includes the following steps:

[0018] S1 Powdered rubber

[0019] First, add the mixed methyl vinyl raw rubber, then add part of the precipitated silica. Pour the hydroxyl silicone oil, methoxy silicone oil, and zinc stearate above the precipitated silica, control the temperature at 50 to 80 °C, start stirring. After stirring into a mass, continue to add the remaining precipitated silica and stir evenly.

[0020] S2 Placement

[0021] Take out the stirred rubber compound in S1 and place it for 12 to 24 h;

[0022] S3 Internal mixing

[0023] Put the placed rubber compound into an internal mixer, add cetyl alcohol, and conduct internal mixing until the rubber compound is stirred into a large smooth mass on the surface. The conditions for the internal mixing are: start timing from 120 °C, open the lid and knead for 1.5 to 2 h, and control the treatment temperature at 165 to 195 °C.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. The chloramine-resistant silicone rubber of the present invention has high cost performance and can meet the relevant usage requirements of bathroom sealing silicone rubber products that resist the corrosion of bathroom cleaners and use seawater as domestic water.

[0026] 2. The preparation method of the chloramine-resistant silicone rubber of the present invention is simple, the raw material cost is low, and it is suitable for large-scale production. Specific embodiments

[0027] The present invention will be further described below in conjunction with specific embodiments, but is not limited thereto.

[0028] In an embodiment of the present invention, a chloramine-resistant silicone rubber is composed of the following components in parts by mass:

[0029]

[0030] Among them: the mixed methyl vinyl raw rubber is compounded from 110-2s and 110-7s of Nanjing Dongjue Sales Co., Ltd. according to a weight ratio of 14:1; the precipitated silica is SK658B of Fujian Cisco Silicon Materials Co., Ltd.; the cetyl alcohol is Procter & Gamble cetyl alcohol of Procter & Gamble Malaysia; the hydroxy silicone oil is the general-purpose hydroxy silicone oil of Huizhou Tianyi Environmental Protection Materials Co., Ltd.; the methoxy silicone oil is the methoxy silicone oil of Zhejiang Zhenghe Silicon Materials Co., Ltd.; the zinc stearate is the zinc stearate of Azelis Chemicals (Guangzhou) Co., Ltd.

[0031] The specific embodiment of the present invention also provides a preparation method of the chloramine-resistant silicone rubber, and the specific steps are as follows:

[0032] S1 Powder rubber

[0033] First add the mixed methyl vinyl raw rubber, then add part of the precipitated silica. Pour the hydroxy silicone oil, methoxy silicone oil, and zinc stearate above the precipitated silica, control the temperature at 50-80°C, start stirring, and continue to add the remaining precipitated silica after stirring into a mass and stir evenly.

[0034] S2 Placement

[0035] Take out the stirred rubber compound in S1 and place it for 12-24h;

[0036] S3 Internal mixing

[0037] Put the placed rubber compound into an internal mixer, add cetyl alcohol, and conduct internal mixing until the rubber compound is stirred into a large smooth mass on the surface. The conditions for the internal mixing are: start timing from 120°C, open the lid and knead for 1.5 hours, and control the treatment temperature at 165-195°C.

[0038] Example

[0039] In Examples 1-3 of the present invention, 3 groups of experiments on chloramine-resistant silicone rubber are provided, and the specific formulations and dosages are shown in Table 1:

[0040] Table 1 Raw material composition of chloramine-resistant silicone rubber in Examples 1-3 (unit: parts by weight)

[0041] Components Example 1 Example 2 Example 3 Mixed methyl vinyl raw rubber 150 150 150 Precipitated silica 60 60 60 Cetyl alcohol 0.5 0.6 0.7 Hydroxy silicone oil 2.7 2.7 2.7 Methoxy silicone oil 6 6 6 Zinc stearate 0.25 0.25 0.25

[0042] Comparative example

[0043] Three groups of silicone rubber experiments were also provided in Comparative Examples 1-3. The specific formulations and dosages are shown in Table 2:

[0044] Table 2 Raw material composition of silicone rubber in Comparative Examples 1-3 (unit: parts by weight)

[0045]

[0046]

[0047] Performance testing

[0048] Six groups of silicone rubber products were prepared according to the formulations of Examples 1-3 in Table 1 and Comparative Examples 1-3 in Table 2 by the above preparation method of chloramine-resistant silicone rubber, and were subjected to routine tests according to the standards in Table 3.

[0049] Table 3 Performance requirements for routine testing

[0050]

[0051] Routine testing found that all the 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 the plasticity, tensile strength, tear strength, and elongation of the silicone rubber prepared in Comparative Example 3 did not meet the standards and did not meet the production standards. Therefore, it is not necessary to conduct chloramine resistance testing on Comparative Example 3 anymore.

[0052] After routine testing, the high-temperature baking conditions of 200 °C for 4 h in the second stage were kept consistent, and then chloramine resistance testing was carried out according to the ASTM D6284-09 standard, and the test results were recorded in Table 4.

[0053] The chloramine resistance test solutions mainly selected sodium hypochlorite solution, chloramine solution, and trichloroisocyanuric acid solution with a concentration of 50 ppm each. The test conditions were: soaking in water change every day at a temperature of 70 °C for 7 weeks (a total of 50 days), and observation was carried out during this period.

[0054] Table 4 Experimental results of chloramine resistance test

[0055]

[0056]

[0057] The results show that: in Comparative Example 1 and Comparative Example 2, bubbles appeared in the 2nd - 3rd week, and the chloramine resistance test did not meet the standard; in Examples 1 - 3, bubbles or white spots did not appear until after the 5th week, and the chloramine resistance performance was good; moreover, they performed well in the weight change and volume change tests. The requirement for weight change is within 3%, and the requirement for volume change is within 5%. The cleaning agent test is relatively difficult, and most products cannot pass. However, for the silicone rubber prepared in Examples 1 - 3 of the present invention, both the weight change and volume change in the cleaning agent test are less than 5%, showing excellent performance. It can meet the relevant usage requirements of bathroom sealing silicone rubber products for resisting the corrosion of bathroom cleaners and in areas where seawater is used as domestic water.

Claims

1. A chloramine-resistant silicone rubber, characterized in that It is composed of the following components by mass:

2. The chloramine-resistant silicone rubber according to claim 1, characterized in that It is composed of the following components by mass:

3. The chloramine-resistant silicone rubber according to claim 1, characterized in that The mixed methyl vinyl raw rubber is compounded by 110-2s and 110-7s of Nanjing Dongjue Sales Co., Ltd. in a weight ratio of (13-15):

1.

4. The chloramine-resistant silicone rubber according to claim 1, characterized in that The precipitated silica is SK658B produced by Fujian Cisco Silicon Materials Co., Ltd.

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

6. The chloramine-resistant silicone rubber according to claim 1, characterized in that The hydroxy silicone oil is the general-purpose hydroxy silicone oil of Huizhou Tianyi Environmental Protection Materials Co., Ltd.; the methoxy silicone oil is the methoxy silicone oil of Zhejiang Zhenghe Silicon Materials Co., Ltd.; and the zinc stearate is the zinc stearate of Azelis Chemical (Guangzhou) Co., Ltd.

7. A method for preparing the chloramine-resistant silicone rubber according to any one of claims 1 to 6, characterized in that The following steps are involved: S1 powder glue Add mixed methyl vinyl rubber, then add part of precipitated silica, pour hydroxy silicone oil, methoxy silicone oil and zinc stearate on top of precipitated silica, control the temperature at 50-80℃, start stirring, and continue to add the remaining precipitated silica after stirring into a mass and stir evenly; S2 placement Take out the mixed rubber in S1 and let it stand for 12 to 24 hours; S3 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.

8. The method for preparing the chloramine-resistant silicone rubber according to claim 7, characterized in that The conditions of the banburying are: start timing from 120°C, open the cover and knead for 1.5 to 2 hours, and control the processing temperature at 165 to 195°C.

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