Rubber scorch is an early vulcanization phenomenon that occurs during the processing of rubber or during the parking process before vulcanization, also known as self-sulfur. The so-called anti-coke agent is a substance that can prevent or delay the early vulcanization of rubber in the process and storage before vulcanization, also known as vulcanization retardant.

1. The necessity of adding anti-coking agent for recycled rubber products
Rubber and semi-finished products in the processing and storage process before vulcanization, due to the mechanical action of the heat and high temperature environment, may reduce the plasticity of rubber, many rubber products manufacturers in order to improve production efficiency, on the one hand, in the formulation of high-temperature fast vulcanization system, on the other hand, and improve the mixing, calendering and other operating temperatures, so that the rubber is more sensitive to early vulcanization.

2. Ideal anti-coke agent needs to have the performance characteristics
(1) to improve the safety of processing and storage process, effective prevention of scorching at the same time should not affect the vulcanization speed after the start of vulcanization, not to extend the total vulcanization time;

(2) anti-coke agent itself does not have cross-linking effect.
(3) No adverse effect on the appearance quality, chemical properties and physical and mechanical properties of vulcanized rubber.
(4) Non-toxic and harmless, low cost.

3. Several anti-coking agents commonly used in the production of recycled rubber products
The use of recycled rubber production of rubber products, commonly used anti-coke agent can be divided into three categories: (1) organic acid anti-coke agent, characterized by small pollution but anti-coke performance is slightly worse, and slow down the vulcanization speed, promote product aging and other shortcomings; common salicylic acid, phthalic acid, phthalic anhydride, etc..
(2) nitroso compounds, characterized by the greatest anti-coke effect at processing temperature, and basically no effect on the vulcanization speed at vulcanization temperature; common anti-coke agent NA, anti-coke agent NDPA.
(3) anti-coking agent CTP, the best anti-coking effect for the vulcanization system containing hyposulfenamide, the dosage is small, between 0.1 and 0.5 parts.