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CN-122011643-A - Valve chamber cover gasket and preparation method thereof

CN122011643ACN 122011643 ACN122011643 ACN 122011643ACN-122011643-A

Abstract

The application relates to the technical field of rubber sealing materials, and particularly discloses a valve chamber cover gasket and a preparation method thereof. The preparation raw materials of the valve chamber cover gasket comprise acrylic rubber, a curing cross-linking agent, modified carbon black, silica, a high-temperature plasticizer, an anti-aging agent, a release agent and a flow aid, wherein the preparation raw materials of the modified carbon black comprise carbon black, a coating monomer and an initiator, and the mass ratio of the carbon black to the coating monomer to the initiator is 1 (0.1-0.2) (0.01-0.03). The application can effectively improve the mechanical property of the acrylate rubber in a wide temperature range and reduce the hardening and embrittlement of the material.

Inventors

  • ZHOU WENTAO
  • WU BINGLIN

Assignees

  • 广东亿达汽车密封件股份有限公司

Dates

Publication Date
20260512
Application Date
20260311

Claims (10)

  1. 1. The valve chamber cover gasket is characterized by being prepared from the following raw materials in parts by weight: 80-100 parts of acrylate rubber, 2.07-3.07 parts of curing cross-linking agent, 55-65 parts of modified carbon black, 10-13 parts of silica, 3.75-4.25 parts of high-temperature plasticizer, 1-2 parts of anti-aging agent, 2.94-4.94 parts of release agent and 2.6-3.4 parts of flow aid; the preparation raw materials of the modified carbon black comprise carbon black, coating monomer and initiator, wherein the mass ratio of the carbon black to the coating monomer to the initiator is 1 (0.1-0.2) (0.01-0.03).
  2. 2. The valve cover gasket of claim 1, wherein said coating monomer comprises methyl methacrylate, hexyl acrylate, acrylic acid, diethylene glycol diacrylate and diethylene glycol monomethyl ether acrylate in a mass ratio of 1 (0.5-0.55): (0.03-0.05): (0.1-0.15): (0.2-0.3).
  3. 3. The valve cover gasket of claim 1, wherein said modified carbon black is prepared by a process comprising the steps of: adding water and an emulsifying agent into a reaction vessel, stirring uniformly, adding a coating monomer, stirring and emulsifying uniformly, adding carbon black, stirring and emulsifying, heating and continuously stirring and emulsifying, heating, adding an initiator for reaction, cooling and filtering a product after the reaction is finished, and drying to obtain the modified carbon black.
  4. 4. A valve cover gasket according to claim 3, wherein the mass ratio of the emulsifier to the carbon black is (0.3-0.4): 1, the emulsifier comprises emulsifier OP-10 and sodium dodecyl sulfate in a mass ratio of (0.8-1), and the initiator is potassium persulfate.
  5. 5. The valve cover gasket of claim 1 wherein said acrylate rubber is a carboxyl acrylate rubber.
  6. 6. The valve cover gasket of claim 1, wherein the curing cross-linking agent is an amine curing cross-linking agent comprising one or both of hexamethylenediamine carbamate and di-o-toluene guanidine.
  7. 7. The valve cover gasket of claim 1, wherein said high temperature plasticizer comprises one or more of Ai Dike RS-705, ai Dike RS-107, rombin TP-95, rombi TP-759.
  8. 8. The valve cover gasket of claim 1, wherein the anti-aging agent comprises one or more of anti-aging agent 445, anti-aging agent RD, anti-aging agent MB, anti-aging agent 264.
  9. 9. The valve cover gasket of claim 1, wherein said mold release agent comprises one or both of stearic acid and PE wax, and said flow aid comprises one or both of isotetraol stearate and flow aid WS 180.
  10. 10. A method for manufacturing a valve cover gasket according to any one of claims 1 to 9, comprising the steps of: The preparation method comprises the steps of melting and mixing acrylate rubber, modified carbon black, silica, high-temperature plasticizer, anti-aging agent, release agent and flow aid at 140-150 ℃ to obtain premix, adding a curing cross-linking agent into the premix, uniformly mixing, vulcanizing and forming at 150-180 ℃, and performing secondary vulcanization after water gap repair to obtain the valve chamber cover gasket.

Description

Valve chamber cover gasket and preparation method thereof Technical Field The invention relates to the technical field of rubber sealing materials, in particular to a valve chamber cover gasket and a preparation method thereof. Background The valve chamber cover gasket is a key sealing part between the cylinder cover and the valve chamber cover of the automobile engine, and mainly aims to prevent engine oil leakage and isolate high-temperature gas and external impurities of a combustion chamber, and the sealing performance of the valve chamber cover gasket is directly related to the running reliability and the service life of the engine. The acrylate rubber is used as a polymer elastomer prepared by crosslinking acrylate with a small amount of monomers, and has excellent high temperature resistance and oil resistance, so that the acrylate rubber is a common material in the field of automobile sealing products, and the basic sealing requirement of an engine under a complex working condition is met. In the prior art, valve chamber cover gaskets are generally made of acrylate rubber materials through a mould pressing or injection molding process. However, the molecular structure of the acrylate rubber can be gradually aged in response to extreme temperature fluctuation, especially in a low-temperature environment, so that the material is hardened and embrittled, and the problems of sealing failure, engine oil leakage and the like are easily caused after long-term operation. Disclosure of Invention In order to improve the mechanical property of acrylate rubber in a wide temperature range and reduce material hardening and embrittlement, the application provides a valve chamber cover gasket and a preparation method thereof. In a first aspect, the valve chamber cover gasket provided by the application adopts the following technical scheme: The valve chamber cover gasket is prepared from the following raw materials in parts by weight: 80-100 parts of acrylate rubber, 2.07-3.07 parts of curing cross-linking agent, 55-65 parts of modified carbon black, 10-13 parts of silica, 3.75-4.25 parts of high-temperature plasticizer, 1-2 parts of anti-aging agent, 2.94-4.94 parts of release agent and 2.6-3.4 parts of flow aid; the preparation raw materials of the modified carbon black comprise carbon black, coating monomer and initiator, wherein the mass ratio of the carbon black to the coating monomer to the initiator is 1 (0.1-0.2) (0.01-0.03). By adopting the technical scheme, the valve chamber cover gasket disclosed by the application adopts the acrylate rubber as the base rubber, and adopts the modified carbon black and the silica to cooperatively reinforce the acrylate rubber. The modified carbon black has good filling property and stability, can improve the physical properties of materials, and improves the compatibility and dispersibility with acrylate rubber due to the modification of the carbon black by the unique coating monomer. Specifically, the coating monomer is combined with the carbon black in a certain proportion, so that a specific chemical structure is formed on the surface of the carbon black, and the interaction between the carbon black and the rubber matrix is enhanced. When the modified carbon black and the silica are combined, on one hand, the integral strength and toughness of the material are improved, and on the other hand, the stability of the material at extreme temperature is improved, and the hardening and embrittlement phenomena of the acrylate rubber in a low-temperature environment are reduced. Meanwhile, under the action of the cross-linking agent, the molecular chain of the acrylate rubber can be effectively cross-linked to form a stable three-dimensional network structure, and the modified carbon black and the silica are uniformly dispersed in the network, so that the mechanical property and the thermal stability of the network are further enhanced. Specifically, the amine curing cross-linking agent can react with active groups on an acrylic rubber molecular chain to construct a compact and flexible cross-linking system, and the system is not easy to harden due to limited movement of the molecular chain in a low-temperature environment, but can buffer stress caused by temperature change through a flexible chain segment introduced by a modified carbon black surface coating monomer, and can be matched with the filling and supporting effects of silica, so that the valve chamber cover gasket can keep good elasticity and sealing performance in a wide temperature range. Preferably, the coating monomer comprises methyl methacrylate, hexyl acrylate, acrylic acid, diethylene glycol diacrylate and diethylene glycol monomethyl ether acrylate with the mass ratio of 1 (0.5-0.55) (0.03-0.05) (0.1-0.15) (0.2-0.3). According to the technical scheme, functional complementation can be realized by adopting the coating monomer combination of the proportion, the methyl methacrylate is endowed with moderate rigi