Generally, it includes organic acids (such as benzoic acid, phthalic anhydride, etc.), nitroso compounds (such as N-nitroso diphenylamine, etc.) and thioimides (such as N-cyclohexylthio phthalobenzene) Dicarboximide) etc. Commonly used are oxalic acid, succinic acid, lactic acid, phthalic anhydride, salicylic acid, benzoic acid, oleic acid, etc. Among them, phthalic anhydride and salicylic acid are used more. However, these substances affect the physical and mechanical properties of the finished product, and should not be used more often. Some accelerators also have the effect of preventing scorch on certain rubbers (such as TMTM and TMTD for neoprene). The commonly used anti-scorch agent CTP (N-cyclohexyl thiophthalamide) has a good anti-scorch effect, and the scorch time can be effectively controlled by the usual dosage.

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-nitrosodiphenylamine, N-nitroso-phenyl-β-naphthylamine, N-nitroso-2,2,4-trimethyl-1,2-dihydroquinoline polymer. 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. Thioimides. It is a series of compounds containing S-N bonds, and different R groups can obtain scorch retarders with different properties. Among them, the anti-scorch agent CTP (PVI) is a better anti-scorch agent. The first two types of anti-scorch agents have weak anti-scorch ability and strong selectivity to accelerators, which are not as good as CTP's anti-scorch effect (excerpted from "Rubber Additives Handbook").

  Anti-scorch agents should meet the requirements of rubber processing performance, that is, have good anti-scorch performance; small selectivity for different accelerators and coke species, insensitive to other compounding agents, and have no adverse effects on the vulcanization characteristics of rubber compounds and vulcanizate properties Influence, storage stability and good operating performance, no agglomeration, no flying, easy to disperse, no frost, in line with process safety and hygiene requirements.