Specializing In The Development And Manufacture Of Rubber Additives
Introduction to the categories and properties of anti-scorch agents
There are three types of chemicals that can be used as rubber scorch retarders, namely organic acids, nitroso compounds and sulfenamides.
(1) Organic acids such as salicylic acid, benzoic acid, phthalic acid, phthalic anhydride. Such chemicals have weak anti-scorch ability and large selectivity for accelerator varieties, which will reduce the vulcanization speed and vulcanizate performance, and have a stimulating effect on the skin. Among them, phthalic anhydride is more commonly used, which can be used for light-colored rubber products, and is only effective for alkaline accelerators DPG and MBT accelerators, but not for NOBS and TMTD.
(2) Nitroso compounds N-nitroso diphenylamine, N-nitroso-phenyl-β-naphthylamine, N-nitroso-2,2,4-trimethyl-1,2- Dihydroquinoline polymers. Among them, N-nitrosodiphenylamine (NDPA) is commonly used. Different from organic acids, this kind of anti-scorch agent has better anti-scorch effect on commonly used thiazole and sulfenamide accelerators.
(3) Sulfenamide anti-scorch agent is a series of compounds containing S-N bond, the general formula of molecular structure is as follows:
Depending on the R group, anti-scorch agents with different properties can be obtained. Among them, commercial CTP or PVI are excellent scorch retarders.
Any anti-scorch agent should meet the requirements of rubber processing performance, that is, it has excellent anti-scorch performance; small selectivity to different accelerators and coke species; insensitivity to other compounding agents; no adverse effects on the vulcanization characteristics of rubber compounds and vulcanizate properties Influence; stable storage and good operating performance; no agglomeration, no flying, easy to disperse, no frosting; meet the requirements of process safety and hygiene.