Hard rubber is the product of combination of rubber hydrocarbon and a large amount of sulfur. Natural rubber, styrene butadiene rubber, nitrile rubber and other diene rubber can be made into hard rubber with a large amount of sulfur, such as battery rubber shell; Natural rubber or styrene butadiene rubber can be used when high mechanical strength, low water absorption, good electrical insulation and chemical corrosion resistance are required. When natural rubber is used as the main raw material to produce hard rubber, reasonable selection of rubber raw materials and auxiliary materials can further optimize the quality of finished products and reduce production costs.
1. Which rubbers can be mixed with natural rubber and hard rubber
When hard rubber is produced with natural rubber as the main raw material, a proper amount of general synthetic rubber can be used. Compared with natural rubber, SBR hard rubber has less heat generation in vulcanization reaction when the sulfur content is appropriate, and it is easier to control the temperature during vulcanization reaction; The combination of natural rubber and styrene butadiene rubber can complement each other. The finished product has high mechanical strength, good heat resistance, and is not easy to deform when vulcanized. In the preparation of natural rubber hard rubber, recycled rubber, such as latex recycled rubber and tire recycled rubber, can also be mixed appropriately to further reduce the cost.
At present, most hard rubbers are black or dark brown. If hard rubbers of other colors are prepared, it is recommended to use white recycled rubber when mixing recycled rubber.
2. Key points for selection of formula ingredients of natural rubber and hard rubber
Sulfur is generally used as the vulcanizing agent in the preparation of hard rubber from natural rubber, and it is recommended to use sulfur without free sulfurous acid when the requirements for electrical insulation are high; The combination of sulfur and selenium can not only promote vulcanization, but also improve the heat resistance and electrical insulation of hard rubber; It is recommended to use thiazole accelerator when recycled rubber and hard rubber powder are widely used in hard rubber.
Natural rubber hard rubber generally does not use reinforcing agent, but can use filler in large quantities; Common fillers include clay, talc powder, barite powder and hard rubber powder.
Mineral oil, Vaseline, asphalt, paraffin, Gumarone resin, etc. can be used in the softening system of hard rubber produced by natural rubber. Asphalt and coumarone resin as softener 2ELYY1216 can increase the viscosity of rubber compound; Paraffin and Vaseline as softeners, the deformation of hard glue is small; In addition, the use of paraffin, rapeseed oil or flaxseed oil in the softener can give the natural rubber hard glue better brightness.
3. Natural rubber/recycled rubber shall be used to prepare lining rubber for miner's cap
100 portions of natural rubber, 30 portions of recycled rubber, 35 portions of sulfur, 1.9 portions of accelerator, 5 portions of magnesium oxide, 40 portions of calcium carbonate, 60 portions of clay, 5 portions of soft carbon black, 1.4 portions of stearic acid, and 4 portions of industrial ester; Total: 282.3 copies.
When preparing hard rubber with natural rubber as the main raw material, it is recommended to mix styrene butadiene rubber or recycled rubber appropriately to improve the processing performance of rubber compound and the use performance of finished products and reduce the cost of more raw materials. Later, the editor will continue to discuss relevant issues with you.
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