Modified rubber with wide temperature range and low friction performance for sealing element as well as preparation method and application of modified rubber

Abstract

The invention relates to modified rubber with wide temperature range and low friction performance for a sealing element as well as a preparation method and application of the modified rubber. The modified rubber is prepared from the following raw materials in parts by weight: 50 to 70 parts of rubber base material, 20 to 40 parts of white carbon black, 0.5 to 2 parts of vinyl silicone oil, 5 to 20 parts of lubricating filler, 2 to 10 parts of heat-resistant filler, 0.8 to 1.5 parts of peroxide vulcanizing agent and 0.5 to 2.0 parts of coupling agent. Wherein the rubber base material is selected from any one or a mixture of two of silicone rubber and phenyl silica gel. Compared with the prior art, the sealing element prepared from the modified rubber has the advantages of excellent dustproof performance, wide use temperature range and lower friction coefficient.

Description

Technical Field

[0001] The present invention relates to the technical field of seals, and in particular to a modified rubber for seals with a wide temperature range and low friction performance, and a preparation method and application thereof. Background Art

[0002] Rubber sealing rings have the advantages of simple installation and low leakage, and are widely used in various media seals. They are widely used in aerospace, machinery, ships, rail transportation, automobiles and other fields.

[0003] The rubber seal is compressed during installation, so that it fits tightly with the sealing surface. The resilience of the rubber makes it difficult for the medium to leak. The surface of the rubber material often has a large sliding friction coefficient, which makes it have a large friction force when it moves relative to the surface. It is easy to cause locking problems in the dynamic sealing system and motor overload. Therefore, when using rubber seals on the end faces with relative movement, its surface friction coefficient must be reduced. Summary of the invention

[0004] The purpose of the present invention is to overcome the defect of the existing rubber materials having a large friction coefficient and to provide a modified rubber for sealing parts having a wide temperature range and low friction performance, and a preparation method and application thereof.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] One of the technical solutions of the present invention is to provide a modified rubber for sealing parts with wide temperature range and low friction performance, the raw materials include the following components in parts by weight:

[0007] 50-70 parts of rubber base material, 20-40 parts of white carbon black, 0.5-2 parts of vinyl silicone oil, 5-20 parts of lubricating filler, 2-10 parts of heat-resistant filler, 0.8-1.5 parts of peroxide vulcanizer, 0.5-2.0 parts of coupling agent;

[0008] Wherein, the rubber substrate is selected from any one of silicone rubber and phenyl silicone rubber or a mixture of the two.

[0009] In some specific embodiments, the average number average molecular weight of the silicone rubber is greater than 500,000, and the phenyl silicone rubber is a low-phenyl silicone rubber, that is, the phenyl content of the low-phenyl silicone rubber is generally less than 5%;

[0010] When the rubber substrate is a mixture of the two, the weight ratio of the silicone rubber to the phenyl silicone rubber is 2:8 to 8:2.

[0011] In some specific embodiments, the heat-resistant filler is selected from any one or more of red iron oxide, cerium oxide, and tin dioxide.

[0012] In some specific embodiments, the lubricating filler is selected from any one or more of graphite, tetrafluoroethylene powder, and molybdenum disulfide.

[0013] In some specific embodiments, the peroxide curing agent is selected from any one or more of diisopropylbenzene oxide, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, and bis(2,4-dichlorobenzoyl) peroxide.

[0014] In some specific embodiments, the coupling agent is selected from any one or more of KH550, KH560, and A151.

[0015] The second technical solution of the present invention is to provide a method for preparing a modified rubber for sealing parts having a wide temperature range and low friction performance as described in one of the above technical solutions.

[0016] The heat-resistant filler and coupling agent are sequentially added to the rubber base material, and then the lubricating filler and vulcanizing agent are added, and the modified rubber is obtained by heating and pressurizing the reaction.

[0017] In some specific embodiments, the heating temperature is 160-230° C., the pressurizing pressure is 5-15 MPa, and the reaction time is 5-25 min.

[0018] A third technical solution of the present invention is to provide an application of the modified rubber as described in one of the above technical solutions in the preparation of a seal.

[0019] A fourth technical solution of the present invention is to provide a seal having a wide temperature range and low friction performance, which is prepared from the modified rubber described in one of the above technical solutions.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] (1) The modified rubber of the present invention is based on silicone rubber, phenyl silicone rubber or their blends and has a wide operating temperature range. The main chain of silicone rubber is composed of alternating silicon and oxygen atoms, and the silicon atom is usually connected to a rubber with two organic groups. Silicone rubber is mainly composed of silicon-oxygen chain segments containing methyl and a small amount of vinyl. The most notable features of silicone rubber are heat resistance and high-temperature stability. Although the strength of silicone rubber is relatively low at room temperature, silicone rubber can still maintain a certain flexibility, resilience and surface hardness in a high-temperature environment above 200°C, and the mechanical properties do not change significantly. Silicone rubber can withstand high temperatures above 300°C for a short period of time.

[0022] Phenyl silicone rubber is obtained by introducing diphenylsiloxane chain segments or methylphenylsiloxane chain segments into the molecular chain of vinyl silicone rubber. The introduction of phenyl groups can improve the high and low temperature resistance of silicone rubber.

[0023] (2) The wear-resistant filler and heat-resistant filler used in the present invention are industrial products, which are low-priced and widely available, do not require complicated special treatment, meet environmental protection requirements, and reduce production costs.

[0024] (3) The rubber compound and the product prepared by the present invention adopt a general rubber mixing process and a vulcanization process, and the production method is simple.

[0025] (4) The seal prepared by the present invention has excellent dustproof performance, a wide operating temperature range (-60-150°C), and a low friction coefficient (the friction torque of the simulated tooling within the above temperature range is less than 1.5N*m). DETAILED DESCRIPTION

[0026] The present invention provides a modified rubber for a seal having a wide temperature range and low friction performance. The raw materials include the following components in parts by weight:

[0027] 50-70 parts of rubber base material, 20-40 parts of white carbon black, 0.5-2 parts of vinyl silicone oil, 5-20 parts of lubricating filler, 2-10 parts of heat-resistant filler, 0.8-1.5 parts of peroxide vulcanizer, 0.5-2.0 parts of coupling agent;

[0028] Wherein, the rubber substrate is selected from any one of silicone rubber and phenyl silicone rubber or a mixture of the two.

[0029] Preferably, the average number average molecular weight of the silicone rubber is greater than 500,000, and the phenyl silicone rubber is a low-phenyl silicone rubber, that is, the phenyl content of the low-phenyl silicone rubber is usually less than 5%;

[0030] When the rubber substrate is a mixture of the two, the weight ratio of the silicone rubber to the phenyl silicone rubber is 2:8 to 8:2.

[0031] Preferably, the heat-resistant filler is selected from any one or more of red iron oxide, cerium oxide, and tin dioxide.

[0032] Preferably, the lubricating filler is selected from any one or more of graphite, tetrafluoroethylene powder, and molybdenum disulfide.

[0033] Preferably, the peroxide curing agent is selected from any one or more of diisopropylbenzene oxide, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, and bis(2,4-dichlorobenzoyl) peroxide.

[0034] Preferably, the coupling agent is selected from any one or more of KH550, KH560, and A151.

[0035] The present invention provides a method for preparing a modified rubber for a seal having a wide temperature range and low friction, comprising the following steps:

[0036] The heat-resistant filler and coupling agent are sequentially added to the rubber base material, and then the lubricating filler and vulcanizing agent are added, and the sealing member is obtained by heating and pressurizing the reaction.

[0037] Preferably, the heating temperature is 160-230° C., the pressurizing pressure is 5-15 MPa, and the reaction time is 5-25 min.

[0038] The invention provides a modified rubber for preparing a sealing element.

[0039] The present invention is described in detail below with reference to specific embodiments and comparative examples.

[0040] The materials used in the following specific examples and comparative examples are as follows:

[0041] The silicone rubber is Dongjue 110-2 silicone rubber, and the phenyl silicone rubber is Xin'an wphs-3140.

[0042] The components and their weights of the mixed rubber (modified rubber) for preparing the seal with wide temperature range and low friction in Examples 1 to 3 and Comparative Examples are shown in Table 1:

[0043] Table 1

[0044]

[0045] The temperature of the mixed rubber vulcanization molding is 160° C., the pressure is 8 MPa, and the time is 20 min to obtain a modified rubber.

[0046] The modified rubbers prepared in Examples 1 to 3 and Comparative Example 1 were prepared into the same type of seals, and Comparative Example 2 was a commercially available cold-resistant self-lubricating nitrile rubber seal. According to the national standard test standard, the following performance tests were conducted, and the results are shown in Table 2.

[0047] Table 2

[0048]

[0049]

[0050] The special tool is a combination of a torque sensor and a simulated sealing device, and outputs a signal to a computer. It is a conventional tool for detecting friction torque in the art.

[0051] As can be seen from Table 2, the seals prepared from silicone rubber, phenyl silicone rubber or a mixture thereof used in the present invention have a wider operating temperature range than cold-resistant nitrile rubber seals. The lubricating filler used enables the seals prepared in the present invention to achieve a good effect of reducing friction torque in a wide temperature range.

[0052] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A modified rubber for sealing parts having a wide temperature range and low friction performance, characterized in that: The raw materials include the following components in parts by weight: 50-70 parts of rubber base material, 20-40 parts of white carbon black, 0.5-2 parts of vinyl silicone oil, 5-20 parts of lubricating filler, 2-10 parts of heat-resistant filler, 0.8-1.5 parts of peroxide vulcanizer, 0.5-2.0 parts of coupling agent; Wherein, the rubber substrate is selected from any one of silicone rubber and phenyl silicone rubber or a mixture of the two.

2. The modified rubber according to claim 1, characterized in that The average number average molecular weight of the silicone rubber is greater than 500,000, and the phenyl silicone rubber is low phenyl silicone rubber. When the rubber substrate is a mixture of the two, the weight ratio of the silicone rubber to the phenyl silicone rubber is 2:8 to 8:

2.

3. The modified rubber according to claim 1, characterized in that The heat-resistant filler is selected from any one or more of red iron oxide, cerium oxide, and tin dioxide.

4. The modified rubber according to claim 1, characterized in that The lubricating filler is selected from any one or more of graphite, tetrafluoroethylene powder, and molybdenum disulfide.

5. The modified rubber according to claim 1, characterized in that The peroxide curing agent is selected from any one or more of diisopropylbenzene oxide, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, and bis(2,4-dichlorobenzoyl) peroxide.

6. The modified rubber according to claim 1, characterized in that The coupling agent is selected from any one or more of KH550, KH560, and A151.

7. A method for preparing a modified rubber according to any one of claims 1 to 6, characterized in that: The heat-resistant filler and coupling agent are sequentially added to the rubber base material, and then the lubricating filler and vulcanizing agent are added, and the modified rubber is obtained by heating and pressurizing the reaction.

8. The preparation method according to claim 7, characterized in that: The heating temperature is 160-230° C., the pressurizing pressure is 5-15 MPa, and the reaction time is 5-25 min.

9. Use of the modified rubber according to any one of claims 1 to 6 in preparing sealing components.

10. A seal with wide temperature range and low friction performance, characterized in that: The modified rubber is prepared based on any one of claims 1 to 6.

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