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CN-121991516-A - Preparation method of high-resilience high-temperature-resistant solid silica gel

CN121991516ACN 121991516 ACN121991516 ACN 121991516ACN-121991516-A

Abstract

The invention discloses a preparation method of high-resilience high-temperature-resistant solid silica gel. The invention prepares a base rubber component by compounding high-molecular-weight methyl vinyl silicone rubber, medium-molecular-weight methyl vinyl silicone rubber and methyl phenyl vinyl silicone rubber, mixes gas-phase white carbon black, reactive white carbon black, spherical silica micropowder, core-shell cerium oxide/silica composite particles and hydroxyl silicone oil to obtain a filler component, banburying the base rubber component and the filler component, standing to obtain master batch, and then adding a peroxide vulcanizing agent to prepare the high-resilience high-temperature-resistant solid silica gel through secondary vulcanization. According to the invention, a dual-phase network structure is constructed through a ternary compound raw rubber system, and the interface chemical bonding enhancement of the reactive white carbon black and the long-acting heat-resistant effect of the core-shell composite particles are combined, so that the synergistic unification of high rebound and high temperature resistance is realized, and the obtained product has the advantages of high tensile strength, excellent rebound rate, high thermal decomposition temperature, good heat aging resistance and wide application prospect.

Inventors

  • YANG CHAO
  • LingHu Birong
  • LU YI

Assignees

  • 东莞宏强新材料有限公司

Dates

Publication Date
20260508
Application Date
20260324

Claims (7)

  1. 1. The preparation method of the high-resilience high-temperature-resistant solid silica gel is characterized by comprising the following steps of: Step 1, weighing 68-74 parts of high molecular weight methyl vinyl silicone rubber, 8-14 parts of medium molecular weight methyl vinyl silicone rubber and 8-14 parts of methyl phenyl vinyl silicone rubber according to parts by weight, and mixing to obtain a base rubber component; step 2, weighing 24-30 parts of gas-phase white carbon black, 4-8 parts of reactive white carbon black, 5-10 parts of spherical silica micropowder, 1.0-3.0 parts of core-shell cerium oxide/silica composite particles and 2-4 parts of hydroxyl silicone oil according to parts by weight, and mixing to obtain a filler component; step 3, putting the base rubber component into an internal mixer, premixing for 10-30min at 90-110 ℃, adding the filler component in batches, mixing for 1-3h at 120-145 ℃, discharging and standing for 4-24h to obtain master batch; And 4, after the masterbatch is thinned on an open mill, adding 0.6-1.5 parts of peroxide vulcanizing agent, uniformly mixing, and then performing secondary vulcanization to obtain the high-resilience high-temperature-resistant solid silica gel.
  2. 2. The method for preparing high-resilience and high-temperature-resistant solid silica gel according to claim 1, wherein the weight average molecular weight of the high-molecular-weight methyl vinyl silicone rubber is 60-90 ten thousand, the mass fraction of vinyl is 0.08-0.30%, the weight average molecular weight of the medium-molecular-weight methyl vinyl silicone rubber is 25-45 ten thousand, the mass fraction of vinyl is 0.20-0.80%, the mass fraction of phenyl in the methyl phenyl vinyl silicone rubber is 5-15%, and the mass fraction of vinyl is 0.10-0.60%.
  3. 3. The preparation method of the high-resilience high-temperature-resistant solid silica gel according to claim 1, wherein the preparation method of the reactive white carbon black is characterized in that gas-phase white carbon black is dispersed in an organic solvent, vinyltriethoxysilane and vinyltrimethoxysilane are added, the reaction is carried out for 1-4 hours at 50-90 ℃, and the reactive white carbon black is obtained through filtration and drying.
  4. 4. The preparation method of the high-resilience high-temperature-resistant solid silica gel according to claim 1, wherein the preparation method of the core-shell cerium oxide/silicon dioxide composite particles is characterized in that cerium oxide nano particles are dispersed in an alcohol/water mixed system, a silicon source is added for hydrolysis condensation reaction, a coating layer is formed, and then the core-shell cerium oxide/silicon dioxide composite particles are obtained through washing and drying.
  5. 5. The method for preparing the high-resilience and high-temperature-resistant solid silica gel according to claim 1, wherein the filler component is added in two steps, wherein the total amount of the filler component is 60% -80% of the total amount of the filler component added in the first step, the filler component is added in the second step, and the filler component is continuously mixed for 30-90min after the filler component is added in the second step.
  6. 6. The method for preparing high resilience and high temperature resistant solid silica gel according to claim 1, wherein said peroxide vulcanizing agent is 2, 5-dimethyl-2, 5-bis (t-butylperoxy) hexane.
  7. 7. The method for preparing the high-resilience and high-temperature-resistant solid silica gel according to claim 1, wherein the secondary vulcanization is carried out for 5-10min at 165-175 ℃ and then for 2-6h at 200-230 ℃.

Description

Preparation method of high-resilience high-temperature-resistant solid silica gel Technical Field The invention relates to the technical field of silica gel preparation, in particular to a preparation method of high-resilience high-temperature-resistant solid silica gel. Background The high-resilience high-temperature-resistant solid silica gel belongs to a high-performance organic silicon elastomer material, has excellent high-low temperature resistance, electrical insulation performance and weather resistance of the organic silicon material, and simultaneously requires the material to have higher elastic recovery capability after dynamic stress or compression deformation, so that the high-resilience high-temperature-resistant solid silica gel is widely applied to the fields of high-temperature sealing elements, shock absorbing elements, rollers, high-temperature dynamic rebound parts and the like. The existing material is generally prepared by taking methyl vinyl silicone rubber as base rubber and matching with white carbon black reinforcement, heat-resistant auxiliary agents and a peroxide vulcanization system. At present, in order to improve the heat resistance of solid silica gel, heat resistant components such as phenyl silicone rubber, cerium oxide and the like are generally introduced, or white carbon black is subjected to surface treatment to improve the reinforcing effect, and in order to improve the rebound performance, the molecular weight distribution is mostly adjusted, the filler loss is reduced, and the crosslinking density is optimized. However, the high rebound and high temperature resistance in the prior art are difficult to be combined, after the consumption of the heat-resistant component and the inorganic filler is increased, the hysteresis loss of the material is easy to be increased, the rebound is reduced, and meanwhile, the compression set is increased after high-temperature aging, so that the long-term use reliability is influenced. Therefore, development of a new preparation method of high-resilience high-temperature-resistant solid silica gel is needed, and the rebound performance, the rebound retention rate after heat aging and the compression set resistance of the material are improved while the high-temperature resistance of the material is ensured by carrying out collaborative design on a base rubber system, a reinforced filler interface structure and a heat-resistant particle structure so as to meet the application requirements under the high-temperature dynamic working condition. Disclosure of Invention Aiming at the problems, the invention provides a preparation method of high-resilience high-temperature-resistant solid silica gel, which is characterized in that a biphase base colloid system consisting of high-molecular-weight methyl vinyl silicone rubber, medium-molecular-weight methyl vinyl silicone rubber and methyl phenyl vinyl silicone rubber is constructed, and the synergistic effect of reactive white carbon black and core-shell cerium oxide/silicon dioxide composite particles is combined, so that the rebound performance and the high-temperature resistance of the material are improved. The invention can be realized by the following technical scheme: a preparation method of high-resilience high-temperature-resistant solid silica gel comprises the following steps: Step 1, weighing 68-74 parts of high molecular weight methyl vinyl silicone rubber, 8-14 parts of medium molecular weight methyl vinyl silicone rubber and 8-14 parts of methyl phenyl vinyl silicone rubber according to parts by weight, and mixing to obtain a base rubber component; step 2, weighing 24-30 parts of gas-phase white carbon black, 4-8 parts of reactive white carbon black, 5-10 parts of spherical silica micropowder, 1.0-3.0 parts of core-shell cerium oxide/silica composite particles and 2-4 parts of hydroxyl silicone oil according to parts by weight, and mixing to obtain a filler component; step 3, putting the base rubber component into an internal mixer, premixing for 10-30min at 90-110 ℃, adding the filler component in batches, mixing for 1-3h at 120-145 ℃, discharging and standing for 4-24h to obtain master batch; And 4, after the masterbatch is thinned on an open mill, adding 0.6-1.5 parts of peroxide vulcanizing agent, uniformly mixing, and then performing secondary vulcanization to obtain the high-resilience high-temperature-resistant solid silica gel. Preferably, the weight average molecular weight of the high molecular weight methyl vinyl silicone rubber is 60 ten thousand to 90 ten thousand, the vinyl mass fraction is 0.08 to 0.30 percent, the weight average molecular weight of the medium molecular weight methyl vinyl silicone rubber is 25 ten thousand to 45 ten thousand, the vinyl mass fraction is 0.20 to 0.80 percent, the phenyl mass fraction in the methyl phenyl vinyl silicone rubber is 5 to 15 percent, and the vinyl mass fraction is 0.10 to 0.60 percent. Preferably, the preparation meth