White carbon black is white powder with acidic surface, odorless and tasteless. It has good high temperature resistance, electrical insulation, etc. It is second only to carbon black in reinforcing effect in rubber products. In actual production, there are mainly two types of white carbon black commonly used in the rubber industry: precipitation method white carbon black and gas phase method white carbon black.Among them, precipitation method silica is hydrated silica, and the silica content is 87%-95%; fumed silica is anhydrous silica, and the silica content is above 99.8%.
1. The difference white carbon black and carbon black
Compared with carbon black, white carbon black has finer particles, larger specific surface area, high viscosity and poor processing performance; the structure of white carbon black is higher than that of carbon black, and the silanol group contained on the surface gives the white carbon black very Strong hydrophilicity, which is different from the hydrophobicity of carbon black 2YLYY421. For rubber products, the hydrophilicity of silica not only affects its reinforcement in the rubber compound, but high moisture content can also easily cause the rubber compound to scorch, and the surface acidity will delay vulcanization.
2. The role of white carbon black in rubber products
(1) Reinforcement: The tear strength of rubber reinforced with silica can be significantly improved. Therefore, about 10-25 parts of silica is usually added to the tread rubber of many large-size tires to significantly improve the tire tread. The performance of anti-cutting, chipping and cracking. It should be noted that when silica is used to improve the tear resistance of rubber products, as the amount of silica increases, the rubber abrasion resistance will decrease, so the amount of silica should be controlled reasonably.
(2) Adhesion: The white carbon black has active silanol on the surface, which is an important part of the m-methyl white adhesion system. In actual production, the methylene white bonding system can significantly improve the bonding strength rubber and skeleton materials (including cotton, nylon, polyester, steel wire, etc.).
3. Tips for using white carbon black in rubber products
When using silica to reinforce, it is recommended to use a silane coupling agent to modify the silica and change its hydrophilicity to hydrophobicity to further improve the reinforcing effect of silica in rubber products. After the silane coupling agent is used to modify the white carbon black in the tire tread rubber, the tear resistance and abrasion resistance of the tread rubber are significantly improved. In actual production, silica is modified by Si-69. The reinforcing performance of silica in vulcanized rubber is close to that of carbon black. When used in tire production, it can significantly reduce rolling resistance and improve tire wet skid resistance. , And then extend the service life of the tire.
White carbon black is an important compounding agent in the production of rubber products. It can not only improve the mechanical strength of the rubber compound, but also improve the adhesion the rubber and the skeleton material. In actual production, white carbon black is mostly used in light-colored rubber products, rubber products that require a skeleton material, or rubber products that have strict requirements for tear resistance. When using reclaimed rubber to reduce the production cost of rubber products, rubber product manufacturers can also add an appropriate amount of white carbon black for reinforcement, especially light-colored latex reclaimed rubber products. I will continue to discuss with you later.
Exclusive original article [commercial authorization] reprint, excerpt and excerpt in any form are prohibited without written authorization. Focus on Hongyun rubber: learn the process formula and raw material technology of producing rubber products from recycled rubber to help you reduce costs and increase profits