In the process of vulcanization, the double two four vulcanizing agent will produce toxic gas, but it is not very serious.

Double 25 curing agent and double 24 curing agent are the two main silicone rubber curing agents. They have both differences and similarities.

Double 25 vulcanizing agent has high decomposition temperature and good coke burning performance. Since no products with carboxyl groups are produced during decomposition, the thermal stability of the compound is not affected. Double 25 vulcanizing agent can be used for rubber containing carbon black, with a wide range of applications. When the double-25 curing agent is used, the compression deformation of the vulcanizate is low and the elongation is high. At the same time, the double-25 curing agent is a special vinyl curing agent.

The advantages of di-4 vulcanizing agent are low decomposition temperature and fast decomposition speed. Therefore, it is a common vulcanizing agent for extrusion compound. However, due to the low decomposition temperature of BIS, BIS and tetra sulfide, the coke burning performance is not good, so the dosage should be as small as possible. The decomposition products are 2.4-dichlorobenzoic acid and 2.4-dichlorobenzene, which are toxic and affect the heat resistance of rubber products. Because carbon black interferes with the vulcanization of the double two four vulcanizing agent, it can not be used in the compound containing carbon black: the double two four vulcanizing agent can be used as a general vulcanizing agent.

In addition, when the amount of peroxide exceeds the appropriate amount, the elongation and tear strength of vulcanizate will be reduced, and the effect of double two four will be greater. Double 24 is generally used for extrusion and double 25 is used for molding. Double two four is generally used in extrusion calendering process. The vulcanization temperature is generally 120 ℃, double two five is generally used for molding, and the vulcanization temperature is 170 ℃. Another difference is that Shuang 25 is a special vinyl curing agent. Double two four is universal

Let's briefly popularize platinum silica gel products and double 24 silica gel products from three aspects, hoping to help you identify when purchasing such products:

1. Transparency

In general, platinum silica gel products will use gas-phase silica gel with good or particularly high transparency as the primer, and the transparency of the products produced is very good; The double 24 silica gel products mostly use precipitated silica gel as raw material, and the products are translucent.

2. Odor

Platinum vulcanized silica gel products are basically free of residual smell, tasteless and non-toxic, reaching the EU food level; The silica gel products with double disulfide will leave a lot of pungent smell, which will still exist after long-term exposure and volatilization, so it is easy to distinguish the smell difference between the two.

3. See the surface volatilization during storage

Generally, silica gel products obtained by platinum vulcanization will not form frost on the surface after being stored for a period of time; However, the frost spitting of silica gel products with double 24 vulcanization will be quite serious. Of course, some manufacturers will add secondary vulcanization in the process according to the requirements of customers before production and shipment to reduce the occurrence of frost spitting in the later stage. It can be said that if there are a large number of frost spitting silica gel products on the surface for a period of time, they must be ordinary silica gel products with double 24 vulcanization.