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CN-121592186-B - Silicone rubber composition and preparation method thereof

CN121592186BCN 121592186 BCN121592186 BCN 121592186BCN-121592186-B

Abstract

The invention relates to the technical field of high polymer materials and discloses a silicone rubber composition and a preparation method thereof, wherein the silicone rubber composition comprises 100 parts of methyl phenyl vinyl silicone rubber, 30-60 parts of gas-phase white carbon black, 4-10 parts of a structural control agent, 3-5 parts of phenyl silicone resin, 5-7 parts of platinum flame retardant and 0.05-0.15 part of nano zinc oxide, wherein the methyl phenyl vinyl silicone rubber is taken as a base polymer, the rest components are taken as references, the phenyl content of the methyl phenyl vinyl silicone rubber is 6-20%, the vinyl content is 0.05-2%, and the molecular weight is 60-75 ten thousand. Compared with the existing product, the silicone rubber composition adopts a new formula, reduces the content of phenyl, controls the cost, and has the advantages that the flame retardance can reach V0 level, the light transmittance reaches 90 percent, the cost is low and the mechanical property of the product is good.

Inventors

  • YOU XIAOZI
  • LU HANG
  • ZHU KAIQI
  • CHEN KAIXUAN
  • YANG LIANKE
  • ZHANG PUZHUO

Assignees

  • 浙江新安化工集团股份有限公司

Dates

Publication Date
20260508
Application Date
20260130

Claims (6)

  1. 1. A silicone rubber composition is characterized by comprising the following components in parts by mass: 100 parts of methyl phenyl vinyl silicone rubber raw rubber; 30-60 parts of gas-phase white carbon black; 4-10 parts of a structuring control agent; 3-5 parts of phenyl silicone resin; 5-7 parts of platinum flame retardant; 0.05-0.15 part of nano zinc oxide; The raw methyl phenyl vinyl silicone rubber is used as a base polymer, the rest components are based on the raw methyl phenyl vinyl silicone rubber, the phenyl content of the raw methyl phenyl vinyl silicone rubber is 6-20%, the vinyl content is 0.05-2%, the molecular weight is 60-75 ten thousand, phenyl vinyl silicone resin is adopted as phenyl vinyl silicone resin, the viscosity is 2000-20000cP, the vinyl content is 0.5-5%, the refractive index is 1.4560-1.5450, the structuring control agent comprises at least one of diphenyl silicon glycol or phenyl trimethoxy silane, the platinum flame retardant is prepared from the following raw materials of 2.5 parts of platinum catalyst, 2 parts of benzotriazole and 100 parts of gas-phase rubber compound, and the platinum content is 500ppm.
  2. 2. The silicone rubber composition according to claim 1, wherein the fumed silica has a specific surface area of 200 to 400m2/g.
  3. 3. The silicone rubber composition according to claim 1, wherein the particle size of the nano zinc oxide is 50-500nm and the whiteness is 90% or more.
  4. 4. The silicone rubber composition according to claim 1, wherein the raw methyl phenyl vinyl silicone rubber has a phenyl content of 6 to 10%, a vinyl content of 0.1 to 1.5% and a molecular weight of 60 to 70 ten thousand.
  5. 5. The silicone rubber composition according to claim 1, wherein the phenyl vinyl silicone resin has a viscosity of 5000-20000cP and a vinyl content of 0.5-3%.
  6. 6. A method for preparing a silicone rubber composition for preparing the silicone rubber composition according to any one of claims 1 to 5, comprising: step 1, methyl phenyl vinyl silicone rubber raw rubber, a structuring control agent, phenyl silicone resin and nano zinc oxide are put into a kneader according to a proportion; Step 2, putting the gas-phase white carbon black into a kneader for 3-10 times, and uniformly mixing each time of adding; Step 3, heating the kneader to 130-150 ℃, vacuumizing to < -0.07Mpa, and refining for 1-3 hours; And 4, cooling to room temperature, adding a platinum flame retardant, uniformly mixing and discharging to obtain the silicone rubber composition.

Description

Silicone rubber composition and preparation method thereof Technical Field The invention relates to the technical field of high polymer materials, in particular to a silicone rubber composition and a preparation method thereof. Background The transparent flame-retardant silicone rubber has good optical performance and can provide flame-retardant protection under the condition of not affecting light transmission. This makes it particularly advantageous in some areas where transparency is required, such as electronic displays, optical instruments, etc. Although silicone rubber itself has a certain flame retardancy, in order to meet the flame retardant requirement of higher standards, a flame retardant needs to be added to improve its flame retardant property. By adopting a proper flame-retardant strategy, the transparent flame-retardant silicone rubber can self-extinguish or delay combustion when encountering a fire source, and the occurrence and spread of fire are reduced, so that key guarantee is provided for the safe operation of precision equipment. The prior technical proposal is that the technical proposal for improving the flame retardance of the silicone rubber is mainly to add flame retardant, polymer modification, nanotechnology and crosslinking technology, and the specific steps are as follows: The addition of flame retardants is a common method of improving the flame retardant properties of silicone rubber. Suitable flame retardants may be selected, such as halogen-based flame retardants, phosphorus-based flame retardants, nitrogen-based flame retardants, inorganic flame retardants, etc., and added to the silicone rubber by means of physical blending or chemical reaction. Different types of flame retardants have different flame retarding mechanisms and effects and need to be selected according to specific application requirements. The polymer modification is to carry out surface modification on the silicon rubber and is also a method for improving the flame retardant property of the silicon rubber. The compatibility and the binding force of the silicone rubber with the flame retardant can be improved by carrying out surface treatment on the silicone rubber by using a silane coupling agent and the like, so that the flame retardant effect is improved, and the flame retardant effect is improved by modifying the polymer, such as introducing phenyl groups and the like. Nanotechnology is to improve flame retardancy and transparency by nanofillers. The crosslinking technology is to optimize the crosslinking density and the crosslinking network structure, so that the thermal stability and the char formation of the material can be improved, and the intrinsic flame retardant performance is improved. Patent application document with publication number CN103059574A describes that methyl phenyl vinyl silicone rubber raw rubber with phenyl content of 20-40% is taken as a main body, a reinforcing agent, a vulcanizing agent and a structuring control agent are compounded to obtain transparent flame-retardant silicone rubber, and an LED full-color screen transparent silica gel mask is provided, meanwhile, the problems of flame retardance, transparency and transmittance performance are met, in principle, the higher the phenyl content is, the better the flame retardance effect is, but the cost is increased along with the improvement, and the cost is increased. Patent application document with publication number of CN109504091A describes a flame-retardant silicone rubber with low smoke and high light transmittance, which is prepared by taking methyl vinyl silicone rubber as a main body, nanometer aluminum hydroxide, nanometer titanium dioxide and gas phase white carbon black as fillers. The high light transmittance here refers to the light transmittance of smoke, and the light intensity transmitted through the smoke/incident light intensity is related to the smoke density and is mainly affected by the smoke. Patent application publication No. CN114316605A describes that 0.5-4 parts of platinum catalyst and 0.05-2 parts of flame retardant synergist are added into silicone rubber to obtain transparent flame retardant silicone rubber, wherein the flame retardant synergist is a compound of base silicone rubber and flame retardant material, and the flame retardant material is phosphite esters selected from one or more of tri (2, 4-di-tert-butylphenyl) phosphite ester, bis (2, 4-di-tert-butylphenol) pentaerythritol diphosphite, pentaerythritol dioctadecyl phosphite ester, poly (dipropylene glycol) phenyl phosphite ester, triphenyl phosphite and diphenyl isooctyl phosphite. The flame retardance of the product can reach V1 level, and the light transmittance is about 80%. Patent application document with publication number CN111117187A discloses a high-transparency organosilicon flame-retardant polycarbonate material, wherein the organosilicon flame retardant is polysilsesquioxane, and the dosage is 0.05-3 parts. The flame ret