Generally include organic acids (such as benzoic acid, phthalic anhydride, etc.), nitroso compounds (such as N-nitrosodiphenylamine, etc.) and thioimides (such as N-cyclohexyl thio-phthalimide). Commonly used are oxalic acid, succinic acid, lactic acid, phthalic anhydride, salicylic acid, benzoic acid, oleic acid, etc., of which 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. Some accelerators for a certain rubber also has the role of preventing scorching (such as TMTM and TMTD on neoprene rubber). Commonly used anti-scorch agent CTP (N-cyclohexylthiophthalamide) has a good anti-scorch effect, through the common amount, can effectively control the scorching time
1, organic acids. Such as salicylic acid, benzoic acid, o-acetic acid benzoic acid, phthalic anhydride. Such chemicals anti-coking ability is weak, the promoter species selective, will reduce the speed of vulcanization and vulcanized rubber performance, skin irritation. One of the more commonly used is phthalic anhydride, can be used for light-colored rubber products, and only on the alkaline accelerator DPG, MBT accelerator is effective, NOBS, TMTD is invalid.
2, nitroso compounds, N-nitrosodiphenylamine, N-nitroso-phenyl-β-naphthylamine, N-nitroso-2,2,4-trimethyl-1,2-dihydroquinoline polymer. Of these, N-nitrosodiphenylamine (NDPA) is commonly used. Unlike organic acids, this type of anti-coking agent has a better anti-coking effect on the commonly used thiazoles and sub-sulfonamide accelerators.
3, thioimides. Is a series of compounds containing S-N bonding, with different R groups can be obtained with different performance of the anti-coking agent. One of the anti-coking agent CTP (PVI) is a better anti-coking agent.