Nitrile rubber sealing material as well as preparation method and application thereof

Abstract

The invention discloses a nitrile rubber sealing material as well as a preparation method and application thereof, and relates to the technical field of sealing materials. The nitrile rubber sealing material is prepared from the following raw materials in parts by weight: 100 parts of nitrile rubber, 60-90 parts of carbon black, 15-25 parts of a plasticizer, 3-10 parts of zinc oxide, 1-5 parts of an anti-aging agent, 1-5 parts of tackifying resin, 1-5 parts of paraffin, 1-5 parts of a dispersing agent, 1-5 parts of stearic acid, 1-5 parts of an accelerant and 0.5-2 parts of a vulcanizing agent. The nitrile rubber sealing material prepared by the invention meets the environmental protection requirements of European Union RoHS2.0 and REACH, has excellent processability, has the characteristics of low compression deformation and high rebound resilience, has good oil resistance and aging resistance, and is suitable for producing O-shaped rings for automobile oil seals and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of sealing materials, and in particular to a nitrile rubber sealing material and a preparation method and application thereof. Background Art

[0002] An automotive oil seal is a mechanical component used to seal the oil in an automotive transmission system. Its main function is to isolate the transmission components that require lubrication from the output components to prevent lubricating oil leakage, while also blocking external impurities such as dust and moisture from invading the interior of the equipment.

[0003] Nitrile rubber (NBR) is a copolymer made from acrylonitrile and butadiene monomers. It exhibits excellent oil resistance, wear resistance, heat resistance, sealing properties, and adhesion. It is widely used in the manufacture of various rubber products and is an essential elastic material in the automotive, aviation, and petroleum industries. Therefore, using NBR as an oil seal material imparts excellent oil resistance, wear resistance, and heat resistance, enabling the seal to maintain excellent sealing performance even in harsh operating conditions.

[0004] However, nitrile rubber also has many disadvantages, such as poor rebound resilience and weak dynamic performance, which makes it suitable for static sealing rather than high-frequency dynamic scenarios; poor aging resistance, ultraviolet rays and oxidizing environments will accelerate the aging of nitrile rubber; limited heat resistance, long-term use temperature is usually between 100 and 120°C, and permanent deformation is likely to occur above this temperature; insufficient cold resistance, it is easy to harden and lose elasticity in low temperature environments. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a nitrile rubber sealing material and a preparation method thereof, reduce the preparation cost of the sealing material by filling a large amount of carbon black, while improving the mechanical properties, wear resistance and aging resistance of the sealing material, and apply the sealing material to the processing of automobile oil seals.

[0006] The technical problem to be solved by the present invention is achieved by adopting the following technical solutions:

[0007] One of the objects of the present invention is to provide a nitrile rubber sealing material, which is made from the following raw materials in parts by weight:

[0008] 100 parts of nitrile rubber, 70-90 parts of carbon black, 15-25 parts of plasticizer, 3-8 parts of zinc oxide, 2-5 parts of antioxidant, 1-3 parts of tackifying resin, 1-3 parts of paraffin, 1-3 parts of dispersant, 1-3 parts of stearic acid, 2-5 parts of accelerator, and 0.5-2 parts of vulcanizing agent.

[0009] Carbon black primarily acts as a reinforcing agent and filler in rubber, forming physical and chemical bonds with rubber molecular chains to enhance its mechanical properties and wear resistance. It also reduces rubber viscosity and improves its processing properties. Carbon black also has certain adsorption and shielding properties, absorbing ultraviolet rays, slowing the aging process of rubber and extending its service life.

[0010] Zinc oxide can increase the reaction activity during the vulcanization process, accelerate the reaction speed, and improve the degree of vulcanization of rubber; it can also accelerate the rate of the vulcanization reaction, shorten the vulcanization time, and thus increase the vulcanization speed; it can also improve the mechanical properties of rubber and improve the heat resistance, cold resistance and aging resistance of rubber.

[0011] Stearic acid primarily acts as a vulcanization activator, plasticizer, and lubricant in rubber, having multiple functions, including softening and plasticizing, promoting filler diffusion, and accelerating the vulcanization reaction. Stearic acid reacts with zinc oxide to activate vulcanization activity and acts as a secondary accelerator to accelerate the hardening process.

[0012] Paraffin wax can improve the plasticity and demoulding properties of rubber, improve the processing performance of rubber; it can also enhance the wear resistance of rubber and improve the anti-aging performance of rubber.

[0013] Furthermore, the plasticizer includes but is not limited to one or more of DPHP, DOTP, TOTM, and ATBC. Plasticizers can reduce the intermolecular forces of rubber, increase the plasticity of rubber, and improve the processing performance and mechanical properties of rubber.

[0014] Furthermore, the antioxidant includes, but is not limited to, one or more of antioxidant RD, antioxidant 4010NA, antioxidant MB, antioxidant SP, antioxidant 2246, and antioxidant 4020. Antioxidants in rubber delay or inhibit the aging process of rubber caused by factors such as oxidation, heat, light, ozone, and metal ions, thereby extending the service life of the rubber and maintaining stable rubber properties.

[0015] Furthermore, the tackifying resin includes, but is not limited to, one or more of tackifying resin HM601, tackifying resin 1102, tackifying resin SP1068, and tackifying resin T6000. The tackifying resin cross-links with rubber molecules to form a network structure or binds to adsorption points, thereby increasing the viscosity and tackiness of the rubber and improving the processing properties of the rubber.

[0016] Furthermore, the dispersant includes, but is not limited to, one or more of dispersant FL, dispersant PEG, dispersant FS, dispersant WB212, dispersant H60EF, and dispersant KT-8A. The dispersant has good dispersibility for fillers, can improve the fluidity of the rubber compound, and can also improve the demolding properties of the rubber.

[0017] Furthermore, the vulcanizing agent is S-80. The core function of the vulcanizing agent is to promote the crosslinking of rubber molecular chains, forming a three-dimensional network structure, thereby imparting high strength, high elasticity, and durability to the rubber. S-80 is a granular vulcanizing agent composed of 80% sulfur and 20% carrier material. The sulfur is pre-dispersed using carriers such as EPDM and acrylic rubber, effectively resolving the brown spotting problem on the product surface caused by the uneven dispersion of traditional sulfur powder. Its low Mooney viscosity improves the processing fluidity of the rubber compound, demonstrating higher vulcanization efficiency and safety in the production of dynamically stressed rubber products.

[0018] Furthermore, the accelerator includes, but is not limited to, one or more of accelerator CZ, accelerator TT, accelerator TMTD, accelerator D, accelerator DM, accelerator DZ, accelerator NA-22, and accelerator NS. When added to the vulcanization system, the accelerator activates the vulcanizer and accelerates the cross-linking reaction between the vulcanizer and rubber molecules, thereby shortening the vulcanization time and lowering the vulcanization temperature, thereby improving vulcanization efficiency and reducing costs.

[0019] A second object of the present invention is to provide a method for preparing the nitrile rubber sealing material, comprising the following steps:

[0020] (1) putting the nitrile rubber into an internal mixer for mixing, then putting zinc oxide, stearic acid, antioxidant, paraffin, dispersant and tackifying resin into the mixer for mixing, then putting carbon black and plasticizer into the mixer for mixing, unloading, discharging the sheet through an open mixer, and parking to obtain a mixed rubber;

[0021] (2) putting the first-stage rubber mix into an internal mixer, adding an accelerator and a vulcanizing agent, mixing, unloading, turning the rubber through an open mixer, and sheeting to obtain a second-stage rubber mix;

[0022] (3) vulcanizing the second-stage mixed rubber on a flat vulcanizing machine to obtain a nitrile rubber sealing material.

[0023] Furthermore, the vulcanization temperature is 150-180° C., the vulcanization pressure is 10-15 MPa, and the vulcanization time is 10-30 min.

[0024] A third object of the present invention is to provide application of the nitrile rubber sealing material in automobile oil seals.

[0025] The beneficial effects of the present invention are: the nitrile rubber sealing material prepared by the present invention complies with the environmental protection requirements of EU RoHS2.0 and REACH, has excellent processing performance, and has the characteristics of low compression deformation and high resilience, and has good oil resistance and aging resistance, and is suitable for producing O-rings for automotive oil seals, etc. DETAILED DESCRIPTION

[0026] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below in conjunction with specific embodiments.

[0027] Nitrile rubber 3350 was purchased from Nanjing Jinpu Yingsa Synthetic Rubber Co., Ltd.

[0028] Carbon black 774 and carbon black 550 were purchased from Hebei Longxing Chemical Co., Ltd.

[0029] Zinc oxide was purchased from Anhui Jinhua Zinc Oxide Co., Ltd.

[0030] Paraffin wax was purchased from Shijiazhuang Pinyu New Materials Co., Ltd.

[0031] Tackifying resin HM601 was purchased from Shanghai Changyu Chemical Co., Ltd.

[0032] Tackifying resin SP1068 was purchased from Dongguan Yuebang Rubber Technology Co., Ltd.

[0033] Dispersant FL was purchased from Shanghai Changyu Chemical Co., Ltd.

[0034] S-80 was purchased from Anhui Jinhua Zinc Oxide Co., Ltd.

[0035] Example 1

[0036] (1) 100 parts of nitrile rubber 3350 were put into an internal mixer and mixed at 50°C for 1 min. Then, 5 parts of zinc oxide, 1 part of stearic acid, 1.5 parts of antioxidant RD, 1.5 parts of antioxidant 4010NA, 1.5 parts of paraffin wax, 1 part of dispersant FL and 1.5 parts of tackifying resin HM601 were added and mixed for 30s. Then, 70 parts of carbon black 774, 20 parts of carbon black 550 and 20 parts of plasticizer DPHP were added and mixed for 5min. When the temperature of the internal mixer reached 130°C, the materials were unloaded, the sheets were discharged through an open mixer and kept for 24h to obtain a mixed rubber.

[0037] (2) The first-stage rubber mix was put into an internal mixer, and 1.3 parts of accelerator CZ, 1.3 parts of accelerator TT and 0.82 parts of vulcanizer S-80 were added and mixed at 50°C for 3 minutes. The material was unloaded and thinly turned over on an open mixer for 2 minutes. The sheet was produced to obtain the second-stage rubber mix.

[0038] (3) The second-stage mixed rubber was vulcanized on a flat vulcanizer at a vulcanization temperature of 160°C, a vulcanization pressure of 15 MPa, and a vulcanization time of 10 min to obtain a nitrile rubber sealing material.

[0039] Example 2

[0040] (1) 100 parts of nitrile rubber 3350 were put into an internal mixer and mixed at 60°C for 1 min. Then, 5 parts of zinc oxide, 2 parts of stearic acid, 2 parts of antioxidant RD, 1 part of antioxidant 4010NA, 2 parts of paraffin wax, 1 part of dispersant FL and 2 parts of tackifying resin HM601 were added and mixed for 1 min. Then, 60 parts of carbon black 774, 25 parts of carbon black 550 and 25 parts of plasticizer DPHP were added and mixed for 5 min. When the temperature of the internal mixer reached 130°C, the materials were unloaded, the sheets were discharged through an open mixer and kept for 24 hours to obtain a mixed rubber.

[0041] (2) The first-stage rubber mix was put into an internal mixer, and 2 parts of accelerator CZ, 1 part of accelerator TT and 1 part of vulcanizer S-80 were added and mixed at 60°C for 3 minutes. The material was unloaded and thinly turned over on an open mixer for 2 minutes. The sheet was produced to obtain the second-stage rubber mix.

[0042] (3) The second-stage mixed rubber was vulcanized on a flat vulcanizer at a vulcanization temperature of 150°C, a vulcanization pressure of 12 MPa, and a vulcanization time of 20 min to obtain a nitrile rubber sealing material.

[0043] Example 3

[0044] (1) 100 parts of nitrile rubber 3350 were put into an internal mixer and mixed at 65°C for 1 min. Then, 8 parts of zinc oxide, 3 parts of stearic acid, 2 parts of antioxidant RD, 2 parts of antioxidant 4010NA, 1 part of paraffin wax, 2 parts of dispersant FL and 2 parts of tackifying resin HM601 were added and mixed for 1 min. Then, 50 parts of carbon black 774, 30 parts of carbon black 550 and 20 parts of plasticizer DOTP were added and mixed for 5 min. When the temperature of the internal mixer reached 130°C, the materials were unloaded, the sheets were discharged through an open mixer and kept for 24 hours to obtain a mixed rubber.

[0045] (2) The first-stage rubber mix was put into an internal mixer, and 2 parts of accelerator CZ, 1 part of accelerator DM and 1 part of vulcanizer S-80 were added and mixed at 65°C for 3 minutes. The material was unloaded and thinly turned over on an open mixer for 2 minutes. The sheet was produced to obtain the second-stage rubber mix.

[0046] (3) The second-stage mixed rubber was vulcanized on a flat vulcanizer at a vulcanization temperature of 150°C, a vulcanization pressure of 15 MPa, and a vulcanization time of 15 min to obtain a nitrile rubber sealing material.

[0047] Example 4

[0048] (1) 100 parts of nitrile rubber 3350 were put into an internal mixer and mixed at 55°C for 1 min. Then, 5 parts of zinc oxide, 1.5 parts of stearic acid, 1.5 parts of antioxidant RD, 2 parts of antioxidant 4010NA, 2 parts of paraffin wax, 1.5 parts of dispersant PEG4000 and 2 parts of tackifying resin SP1068 were added and mixed for 30s. Then, 40 parts of carbon black 774, 30 parts of carbon black 550 and 15 parts of plasticizer DPHP were added and mixed for 5min. When the temperature of the internal mixer reached 130°C, the materials were unloaded, the sheets were discharged through an open mixer and kept for 24h to obtain a mixed rubber.

[0049] (2) The first-stage rubber mix was put into an internal mixer, and 2 parts of accelerator CZ, 1.5 parts of accelerator DZ and 1.5 parts of vulcanizer S-80 were added and mixed at 55°C for 3 minutes. The material was unloaded and the rubber was thinly turned over on an open mixer for 2 minutes. The sheet was produced to obtain the second-stage rubber mix.

[0050] (3) The second-stage mixed rubber is vulcanized on a flat vulcanizer at a vulcanization temperature of 180°C, a vulcanization pressure of 10 MPa, and a vulcanization time of 10 min to obtain a nitrile rubber sealing material.

[0051] Example 5

[0052] (1) 100 parts of nitrile rubber 3350 were put into an internal mixer and mixed at 50°C for 1 min. Then, 6 parts of zinc oxide, 2 parts of stearic acid, 1.5 parts of antioxidant RD, 1.5 parts of antioxidant 4010NA, 1 part of paraffin, 2 parts of dispersant PEG4000 and 3 parts of tackifying resin SP1068 were added and mixed for 30s. Then, 50 parts of carbon black 774, 20 parts of carbon black 550 and 20 parts of plasticizer DPHP were added and mixed for 5 minutes. When the temperature of the internal mixer reached 130°C, the materials were unloaded, the sheets were discharged through an open mixer and kept for 24 hours to obtain a mixed rubber.

[0053] (2) The first-stage rubber mix was put into an internal mixer, and 2 parts of accelerator CZ, 3 parts of accelerator TT and 2 parts of vulcanizer S-80 were added and mixed at 50°C for 3 minutes. The material was unloaded and the rubber was thinly turned over on an open mixer for 2 minutes. The sheet was produced to obtain the second-stage rubber mix.

[0054] (3) The second-stage mixed rubber was vulcanized on a flat vulcanizer at a vulcanization temperature of 150°C, a vulcanization pressure of 12 MPa, and a vulcanization time of 30 min to obtain a nitrile rubber sealing material.

[0055] Comparative Example 1

[0056] The method of Example 1 is followed, except that the dispersant FL is deleted.

[0057] (1) 100 parts of nitrile rubber 3350 were put into an internal mixer and mixed at 50°C for 1 min. Then, 5 parts of zinc oxide, 1 part of stearic acid, 1.5 parts of antioxidant RD, 1.5 parts of antioxidant 4010NA, 1.5 parts of paraffin wax and 1.5 parts of tackifying resin HM601 were added and mixed for 30 seconds. Then, 70 parts of carbon black 774, 20 parts of carbon black 550 and 20 parts of plasticizer DPHP were added and mixed for 5 minutes. When the temperature of the internal mixer reached 130°C, the materials were unloaded, the sheets were discharged through an open mixer and kept for 24 hours to obtain a mixed rubber.

[0058] (2) The first-stage rubber mix was put into an internal mixer, and 1.3 parts of accelerator CZ, 1.3 parts of accelerator TT and 0.82 parts of vulcanizer S-80 were added and mixed at 50°C for 3 minutes. The material was unloaded and thinly turned over on an open mixer for 2 minutes. The sheet was produced to obtain the second-stage rubber mix.

[0059] (3) The second-stage mixed rubber was vulcanized on a flat vulcanizer at a vulcanization temperature of 160°C, a vulcanization pressure of 15 MPa, and a vulcanization time of 10 min to obtain a nitrile rubber sealing material.

[0060] Comparative Example 2

[0061] The method of Example 1 was followed, except that the tackifying resin HM601 was deleted.

[0062] (1) 100 parts of nitrile rubber 3350 were put into an internal mixer and mixed at 50°C for 1 min. Then, 5 parts of zinc oxide, 1 part of stearic acid, 1.5 parts of antioxidant RD, 1.5 parts of antioxidant 4010NA, 1.5 parts of paraffin wax and 1 part of dispersant FL were added and mixed for 30 seconds. Then, 70 parts of carbon black 774, 20 parts of carbon black 550 and 20 parts of plasticizer DPHP were added and mixed for 5 minutes. When the temperature of the internal mixer reached 130°C, the materials were unloaded, the sheets were discharged through an open mixer and kept for 24 hours to obtain a mixed rubber.

[0063] (2) The first-stage rubber mix was put into an internal mixer, and 1.3 parts of accelerator CZ, 1.3 parts of accelerator TT and 0.82 parts of vulcanizer S-80 were added and mixed at 50°C for 3 minutes. The material was unloaded and thinly turned over on an open mixer for 2 minutes. The sheet was produced to obtain the second-stage rubber mix.

[0064] (3) The second-stage mixed rubber was vulcanized on a flat vulcanizer at a vulcanization temperature of 160°C, a vulcanization pressure of 15 MPa, and a vulcanization time of 10 min to obtain a nitrile rubber sealing material.

[0065] The performance tests were conducted on the nitrile rubber sealing materials prepared in Examples 1 to 5 and Comparative Examples 1 to 2. The test results are shown in Table 1.

[0066] The tensile strength test refers to GB / T 528-2009. The compression set refers to GB / T 7759.1-2015.

[0067] Table 1

[0068]

[0069] It can be seen from Table 1 that, compared with Comparative Example 1 and Comparative Example 2, the nitrile rubber sealing materials prepared in Examples 1 to 5 have better mechanical properties and higher heat resistance.

[0070] In order to further improve the performance of the nitrile rubber sealing material, the present invention further adds acrylonitrile-dimethylphenyl vinyl silane copolymer to replace part of the nitrile rubber.

[0071] The present invention provides a nitrile rubber sealing material, which is made from the following raw materials in parts by weight:

[0072] 80-90 parts of nitrile rubber, 10-20 parts of acrylonitrile-dimethylphenyl vinyl silane copolymer, 70-90 parts of carbon black, 15-25 parts of plasticizer, 3-8 parts of zinc oxide, 2-5 parts of antioxidant, 1-3 parts of tackifying resin, 1-3 parts of paraffin, 1-3 parts of dispersant, 1-3 parts of stearic acid, 2-5 parts of accelerator, and 0.5-2 parts of vulcanizing agent.

[0073] Furthermore, the number average molecular weight of the acrylonitrile-dimethylphenylvinylsilane copolymer is 100,000 to 200,000, and the molecular weight distribution coefficient is 1.5 to 3.

[0074] Furthermore, the acrylonitrile-dimethylphenylvinylsilane copolymer is prepared by emulsion polymerization, and the mass ratio of monomers acrylonitrile to dimethylphenylvinylsilane is (7-8):(2-3).

[0075] Furthermore, the plasticizer includes but is not limited to one or more of DPHP, DOTP, TOTM, and ATBC.

[0076] Furthermore, the antioxidant includes but is not limited to one or more of antioxidant RD, antioxidant 4010NA, antioxidant MB, antioxidant SP, antioxidant 2246, and antioxidant 4020.

[0077] Furthermore, the tackifying resin includes but is not limited to one or more of tackifying resin HM601, tackifying resin 1102, tackifying resin SP1068, and tackifying resin T6000.

[0078] Furthermore, the dispersant includes but is not limited to one or more of dispersant FL, dispersant PEG, dispersant FS, dispersant WB212, dispersant H60EF, and dispersant KT-8A.

[0079] Furthermore, the vulcanizing agent is S-80.

[0080] Furthermore, the accelerator includes but is not limited to one or more of accelerator CZ, accelerator TT, accelerator TMTD, accelerator D, accelerator DM, accelerator DZ, accelerator NA-22, and accelerator NS.

[0081] The present invention provides a method for preparing a nitrile rubber sealing material, comprising the following steps:

[0082] (1) putting the nitrile rubber into an internal mixer for mixing, then putting acrylonitrile-dimethylphenyl vinyl silane copolymer, zinc oxide, stearic acid, antioxidant, paraffin wax, dispersant and tackifying resin into the mixer for mixing, then putting carbon black and plasticizer into the mixer for mixing, unloading, discharging the sheet through an open mixer, and stopping to obtain a mixed rubber;

[0083] (2) putting the first-stage rubber mix into an internal mixer, adding an accelerator and a vulcanizing agent, mixing, unloading, turning the rubber through an open mixer, and sheeting to obtain a second-stage rubber mix;

[0084] (3) vulcanizing the second-stage mixed rubber on a flat vulcanizing machine to obtain a nitrile rubber sealing material.

[0085] Furthermore, the vulcanization temperature is 150-180° C., the vulcanization pressure is 10-15 MPa, and the vulcanization time is 5-30 min.

[0086] The present invention provides application of the nitrile rubber sealing material in automobile oil seals.

[0087] Example 6

[0088] The method of Example 1 was followed, except that 100 parts of nitrile rubber 3350 were replaced by 80 parts of nitrile rubber 3350 and 20 parts of acrylonitrile-dimethylphenylvinylsilane copolymer.

[0089] (1) The preparation method of acrylonitrile-dimethylphenylvinylsilane copolymer is as follows: under nitrogen protection, 70 parts of acrylonitrile, 30 parts of dimethylphenylvinylsilane, 3 parts of alkylphenol polyoxyethylene ether OP-10, 0.5 parts of potassium persulfate and 100 parts of water are stirred and reacted at 70°C for 8 hours, heating is stopped, cooling to room temperature, and vacuum freeze-drying is performed to obtain acrylonitrile-dimethylphenylvinylsilane copolymer with a number average molecular weight of 150,000 and a molecular weight distribution coefficient of 2.4.

[0090] (2) 80 parts of nitrile rubber 3350 were put into an internal mixer and mixed at 50°C for 1 min. Then, 20 parts of acrylonitrile-dimethylphenylvinylsilane copolymer, 5 parts of zinc oxide, 1 part of stearic acid, 1.5 parts of antioxidant RD, 1.5 parts of antioxidant 4010NA, 1.5 parts of paraffin wax, 1 part of dispersant FL and 1.5 parts of tackifying resin HM601 were added and mixed for 30s. Then, 70 parts of carbon black 774, 20 parts of carbon black 550 and 20 parts of plasticizer DPHP were added and mixed for 5 minutes. When the temperature of the internal mixer reached 130°C, the materials were unloaded, the sheets were discharged through an open mixer and kept for 24 hours to obtain a mixed rubber.

[0091] (3) The first-stage rubber mix was put into an internal mixer, and 1.3 parts of accelerator CZ, 1.3 parts of accelerator TT and 0.82 parts of vulcanizer S-80 were added and mixed at 50°C for 3 minutes. The material was unloaded and thinly turned over on an open mixer for 2 minutes. The sheet was produced to obtain the second-stage rubber mix.

[0092] (4) The second-stage mixed rubber was vulcanized on a flat vulcanizer at a vulcanization temperature of 160°C, a vulcanization pressure of 15 MPa, and a vulcanization time of 10 min to obtain a nitrile rubber sealing material.

[0093] Example 7

[0094] The method of Example 1 was followed, except that 100 parts of nitrile rubber 3350 were replaced by 85 parts of nitrile rubber 3350 and 15 parts of acrylonitrile-dimethylphenylvinylsilane copolymer.

[0095] (1) The preparation method of acrylonitrile-dimethylphenylvinylsilane copolymer is as follows: under nitrogen protection, 80 parts of acrylonitrile, 20 parts of dimethylphenylvinylsilane, 3 parts of alkylphenol polyoxyethylene ether OP-10, 1 part of potassium persulfate and 100 parts of water are stirred and reacted at 70°C for 8 hours, heating is stopped, cooling to room temperature, and vacuum freeze-drying is performed to obtain acrylonitrile-dimethylphenylvinylsilane copolymer with a number average molecular weight of 120,000 and a molecular weight distribution coefficient of 1.8.

[0096] (2) 85 parts of nitrile rubber 3350 were put into an internal mixer and mixed at 50°C for 1 min. Then, 15 parts of acrylonitrile-dimethylphenylvinylsilane copolymer, 5 parts of zinc oxide, 1 part of stearic acid, 1.5 parts of antioxidant RD, 1.5 parts of antioxidant 4010NA, 1.5 parts of paraffin wax, 1 part of dispersant FL and 1.5 parts of tackifying resin HM601 were added and mixed for 30s. Then, 70 parts of carbon black 774, 20 parts of carbon black 550 and 20 parts of plasticizer DPHP were added and mixed for 5 minutes. When the temperature of the internal mixer reached 130°C, the materials were unloaded, the sheets were discharged through an open mixer and kept for 24 hours to obtain a mixed rubber.

[0097] (3) The first-stage rubber mix was put into an internal mixer, and 1.3 parts of accelerator CZ, 1.3 parts of accelerator TT and 0.82 parts of vulcanizer S-80 were added and mixed at 50°C for 3 minutes. The material was unloaded and thinly turned over on an open mixer for 2 minutes. The sheet was produced to obtain the second-stage rubber mix.

[0098] (4) The second-stage mixed rubber was vulcanized on a flat vulcanizer at a vulcanization temperature of 160°C, a vulcanization pressure of 15 MPa, and a vulcanization time of 10 min to obtain a nitrile rubber sealing material.

[0099] Example 8

[0100] The method of Example 1 was followed, except that 100 parts of nitrile rubber 3350 were replaced by 90 parts of nitrile rubber 3350 and 10 parts of acrylonitrile-dimethylphenylvinylsilane copolymer.

[0101] (1) The preparation method of acrylonitrile-dimethylphenylvinylsilane copolymer is as follows: under nitrogen protection, 75 parts of acrylonitrile, 25 parts of dimethylphenylvinylsilane, 5 parts of alkylphenol polyoxyethylene ether OP-10, 2 parts of potassium persulfate and 100 parts of water are stirred and reacted at 70°C for 8 hours, heating is stopped, cooling to room temperature, and vacuum freeze-drying is performed to obtain acrylonitrile-dimethylphenylvinylsilane copolymer with a number average molecular weight of 160,000 and a molecular weight distribution coefficient of 2.3.

[0102] (2) 90 parts of nitrile rubber 3350 were put into an internal mixer and mixed at 50°C for 1 min. Then, 10 parts of acrylonitrile-dimethylphenylvinylsilane copolymer, 5 parts of zinc oxide, 1 part of stearic acid, 1.5 parts of antioxidant RD, 1.5 parts of antioxidant 4010NA, 1.5 parts of paraffin wax, 1 part of dispersant FL and 1.5 parts of tackifying resin HM601 were added and mixed for 30s. Then, 70 parts of carbon black 774, 20 parts of carbon black 550 and 20 parts of plasticizer DPHP were added and mixed for 5min. The material was unloaded when the internal mixer temperature reached 130°C, and the sheet was discharged through an open mixer and kept for 24h to obtain a mixed rubber.

[0103] (3) The first-stage rubber mix was put into an internal mixer, and 1.3 parts of accelerator CZ, 1.3 parts of accelerator TT and 0.82 parts of vulcanizer S-80 were added and mixed at 50°C for 3 minutes. The material was unloaded and thinly turned over on an open mixer for 2 minutes. The sheet was produced to obtain the second-stage rubber mix.

[0104] (4) The second-stage mixed rubber was vulcanized on a flat vulcanizer at a vulcanization temperature of 160°C, a vulcanization pressure of 15 MPa, and a vulcanization time of 10 min to obtain a nitrile rubber sealing material.

[0105] Comparative Example 3

[0106] The method of Example 8 was followed, except that the acrylonitrile-dimethylphenylvinylsilane copolymer was replaced by an acrylonitrile-styrene copolymer.

[0107] (1) The preparation method of acrylonitrile-styrene copolymer is as follows: under nitrogen protection, 75 parts of acrylonitrile, 25 parts of styrene, 5 parts of alkylphenol polyoxyethylene ether OP-10, 2 parts of potassium persulfate and 100 parts of water are stirred and reacted at 70°C for 8 hours, heating is stopped, cooling to room temperature, and vacuum freeze-drying is performed to obtain an acrylonitrile-styrene copolymer with a number average molecular weight of 140,000 and a molecular weight distribution coefficient of 2.8.

[0108] (2) 90 parts of nitrile rubber 3350 were put into an internal mixer and mixed at 50°C for 1 min. Then, 10 parts of acrylonitrile-styrene copolymer, 5 parts of zinc oxide, 1 part of stearic acid, 1.5 parts of antioxidant RD, 1.5 parts of antioxidant 4010NA, 1.5 parts of paraffin wax, 1 part of dispersant FL and 1.5 parts of tackifying resin HM601 were added and mixed for 30s. Then, 70 parts of carbon black 774, 20 parts of carbon black 550 and 20 parts of plasticizer DPHP were added and mixed for 5 minutes. When the temperature of the internal mixer reached 130°C, the materials were unloaded, the sheets were discharged through an open mixer and kept for 24 hours to obtain a mixed rubber.

[0109] (3) The first-stage rubber mix was put into an internal mixer, and 1.3 parts of accelerator CZ, 1.3 parts of accelerator TT and 0.82 parts of vulcanizer S-80 were added and mixed at 50°C for 3 minutes. The material was unloaded and thinly turned over on an open mixer for 2 minutes. The sheet was produced to obtain the second-stage rubber mix.

[0110] (4) The second-stage mixed rubber was vulcanized on a flat vulcanizer at a vulcanization temperature of 160°C, a vulcanization pressure of 15 MPa, and a vulcanization time of 10 min to obtain a nitrile rubber sealing material.

[0111] The performance tests were performed on the nitrile rubber sealing materials prepared in Examples 6 to 8 and Comparative Example 3. The test results are shown in Table 2.

[0112] The tensile strength test refers to GB / T 528-2009. The compression set refers to GB / T 7759.1-2015.

[0113] Table 2

[0114]

[0115] As shown in Table 2, compared with Example 1 and Comparative Example 3, Examples 6 to 8 can further improve the mechanical properties and heat resistance of the nitrile rubber sealing material by adding acrylonitrile-dimethylphenylvinylsilane copolymer to replace part of the nitrile rubber.

[0116] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A nitrile rubber sealing material, characterized in that: The composition comprises the following raw materials in parts by weight: 100 parts of nitrile rubber, 70-90 parts of carbon black, 15-25 parts of plasticizer, 3-8 parts of zinc oxide, 2-5 parts of antioxidant, 1-3 parts of tackifying resin, 1-3 parts of paraffin, 1-3 parts of dispersant, 1-3 parts of stearic acid, 2-5 parts of accelerator, and 0.5-2 parts of vulcanizing agent.

2. The nitrile rubber sealing material according to claim 1, wherein: The plasticizer is one or more of DPHP, DOTP, TOTM, and ATBC.

3. The nitrile rubber sealing material according to claim 1, wherein: The antioxidant is one or more of antioxidant RD, antioxidant 4010NA, antioxidant MB, antioxidant SP, antioxidant 2246, and antioxidant 4020.

4. The nitrile rubber sealing material according to claim 1, wherein: The tackifying resin is one or more of tackifying resin HM601, tackifying resin 1102, tackifying resin SP1068, and tackifying resin T6000.

5. The nitrile rubber sealing material according to claim 1, wherein: The dispersant is one or more of dispersant FL, dispersant PEG, dispersant FS, dispersant WB212, dispersant H60EF, and dispersant KT-8A.

6. The nitrile rubber sealing material according to claim 1, wherein: The vulcanizing agent is S-80.

7. The nitrile rubber sealing material according to claim 1, wherein: The accelerator is one or more of accelerator CZ, accelerator TT, accelerator TMTD, accelerator D, accelerator DM, accelerator DZ, accelerator NA-22, and accelerator NS.

8. The method for preparing the nitrile rubber sealing material according to any one of claims 1 to 7, characterized in that: The following steps are involved: (1) putting the nitrile rubber into an internal mixer for mixing, then putting zinc oxide, stearic acid, antioxidant, paraffin, dispersant and tackifying resin into the mixer for mixing, then putting carbon black and plasticizer into the mixer for mixing, unloading, discharging the sheet through an open mixer, and parking to obtain a mixed rubber; (2) putting the first-stage rubber mix into an internal mixer, adding an accelerator and a vulcanizing agent, mixing, unloading, turning the rubber through an open mixer, and sheeting to obtain a second-stage rubber mix; (3) vulcanizing the second-stage mixed rubber on a flat vulcanizing agent to obtain a nitrile rubber sealing material.

9. The preparation method according to claim 8, characterized in that: The vulcanization temperature is 150-180° C., the vulcanization pressure is 10-15 MPa, and the vulcanization time is 10-30 minutes.

10. Use of the nitrile rubber sealing material according to any one of claims 1 to 7 or the nitrile rubber sealing material obtained by the preparation method according to any one of claims 8 to 9 in automobile oil seals.

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