thiazoles, thiurams, Sulfenamides, and Guanidines, Dithiocarbamates, Organic Amine, Xanthates and Thioureas.

Thiazoles 

(1) 2 thiol-based benzothiazole trade name for accelerator M. This product is a light yellow powder, with an extremely bitter taste, non-toxic, stable storage. It is a general-purpose accelerator, with a fast promotion effect on natural rubber and diene general synthetic rubber, with the good flatness of vulcanisation, the critical temperature of **5℃ of vulcanisation, and the possibility of brain inflammation burn when mixing. Easy to disperse in the rubber, not polluted, but not suitable for food rubber products. The dosage of the first accelerator is 1~2 parts, and the dosage of the second accelerator is 0.2~0.5 parts. It can also be used as a plasticizer of natural rubber.

2, This kind of accelerator is acidic. It is a super speed accelerator. Including a sulfide of autumnal, disulfide autumnal and polysulfide autumnal. Desulfurized autumn rum can be used for sulfur-free yellow vulcanization with a vulcanizing agent. As an accelerator, it is generally used as a second accelerator, together with thiazole and hyposulfonamide accelerators to increase the vulcanization speed. When used with a hyposulfonamide accelerator, it can delay the reaction time of the rubber material, and the reaction can be carried out particularly fast after the vulcanization starts, and the vulcanization degree of vulcanized rubber is also higher. This system is particularly important in low sulfur vulcanization. The physical and mechanical properties and ageing resistance of vulcanized rubber with Tyuram accelerator are influenced by the ratio of accelerator and sulfur yellow dosage. Generally speaking, the amount of sulfur yellow is normal, the tensile strength of vulcanized rubber is high, and other physical and mechanical properties are also good; when the amount of sulfur yellow is low and the amount of accelerator is large, the heat-resistant ageing properties of vulcanized rubber can be improved. It can be used as a promoter and vulcanizing agent for the most common species of thiuram, the trade name is TMTD, TT for short. The dosage is generally 0.2~0.3 parts when used as an accelerator.

This is a class of late-acting accelerators, acidic. It has the characteristics of long scorching time and large vulcanization activity. The vulcanization degree of vulcanized rubber is relatively high, the physical and mechanical properties are excellent, and the ageing resistance is quite good. The rubber has a wide vulcanization flatness. Due to the development of synthetic rubber and a large number of applications and the promotion of the application of highly dispersible furnace method carbon black, especially the need for a good late-effect accelerator. Therefore, this type of accelerator occupies a rather important position, becoming the fastest growing in recent years, but also the most promising class of accelerators. At present, the world uses a variety of accelerators, remote to the main sub-transverse amide class, which a large number of applications are CZ, NOBS, NS, DZ and OTOS, etc., they are thiol-based benzothiazole derivatives.

(2) N-oxyethylene**-benzothiazole hyposulfonamide or *-(*-morpholinylthio) benzothiazole trade name for the accelerator NOBS. This product is a light yellow powder, non-toxic. Specific gravity is 1.*4~1.*0. The melting point is *0℃~*6℃. It decomposes gradually when exposed to heat, so it should be stored at a low temperature. When the storage time is more than 6 months, the scorching of the rubber will increase, and the critical temperature of vulcanization is above **8℃, so the scorching time is longer than that of accelerator CZ, and the operation is safer. The product is easy to disperse in the rubber material, with no frosting and slight discolouration. The general dosage range is 0.5~2.5 parts and 2~0.5 parts of sulfur yellow.

(4) N, N-Dicyclohexyl***2 benzothiazole hyposulfonamide Trade name is accelerator DZ. It is brownish-yellow powder, odourless. Specific gravity is 1.2. The melting point is not less than *0℃. Stable in storage. It has good dispersion in rubber. Vulcanization flattening performance is similar to that of accelerator CZ. The dynamic physical and mechanical properties of vulcanized rubber are relatively good, with high elasticity and fixed tensile strength. However, because of the bitter taste of vulcanized rubber, it cannot be used in the manufacture of products in contact with food. Its dosage range is generally 0.5~1 part, and sulfur yellow is 2.5 parts. 

This type of accelerator is an alkaline, medium speed accelerator used earlier. Vulcanization flatness is poor, the start of vulcanization is slow, short scorching time, vulcanization operation safety is poor, with pollution. It is seldom used alone or as the first accelerator. Generally, it is also used as the second accelerator. The tensile strength and elasticity of vulcanized rubber are relatively high, and the heat generation is low. The main varieties commonly used are diphenyl guanidine, the trade name is accelerator D or accelerator DCP. The product is a white powder, non-toxic, but irritating when in contact with skin, specific gravity is 1.*3~1.*9. The melting point is not less than **4℃. The critical temperature of vulcanization of this product is **1℃, and the flatness of the vulcanization is poor. It is not suitable for white light-coloured products and rubber products in contact with food because it is polluting. The dosage is 1~2 when used as the first accelerator, and 0.1~0.5 when used as the second accelerator with a thiazole type accelerator. 

This is a kind of super-super speed accelerator, acidic. Vulcanization speed is particularly fast, the flat range of the vulcanization curve is small, short scorching time, so the processing process is easy to produce early vulcanization of the rubber, vulcanization operation is not safe. Vulcanization conditions are not appropriate, it is easy to occur under sulfur or over sulfur phenomenon. If used properly, the physical and mechanical properties and ageing resistance of vulcanized rubber are superior and do not pollute. It is suitable for the vulcanization of thin products vulcanized at high temperature for a short time, room temperature vulcanized products and latex products, and is most commonly used like the following zinc salt varieties: zinc dimethyl dithiocarbamate, also known as accelerator PZ, also known as accelerator ZDMC, is a white powder, tasteless and non-toxic. However, contact with skin can cause inflammation. Specific gravity is 1.*5~1.*4. The melting point is **0~**5℃. The critical temperature of vulcanization is about **0℃, and the vulcanization activity is similar to that of TT, but the activity is larger at low temperatures, and the tendency of scorching is large. It is easy to disperse in rubber, and the products are tasteless, non-toxic and non-polluting. It is mainly used in latex products, natural vulcanized rubber paste, rubber cloth products and cold vulcanized products, light-coloured and coloured products, and edible rubber products. The amount in the latex rubber material is generally 0.3~1.5 parts. 

Organic Amine

(1) Hexamethylenetetramine trade name for promoter H. It is white to light yellow crystalline powder, almost odourless, bitter taste. It has an irritating effect on the skin. It has a specific gravity of 1.3. It will sublimate and partially decompose when heated to **3°C. It is slightly deliquescent. Slightly deliquescent. The critical temperature is **0℃, it is not too active when the vulcanization temperature is low, and the danger of scorching is small. Mostly used as a second accelerator. No discolouration, no pollution, not easy to decompose. Mainly used for transparent and thick-walled products. 

7, Xanthates

8,Other new varieties of accelerators are currently committed to the study of new accelerators, to produce high efficiency of vulcanization promotion, good processing safety, good anti-return performance, and high ageing resistance of accelerators. In addition, the variety of sulfur yellow giving bodies is gradually increasing, and a non-sulfur cross-linking system is emerging. And is recognized as a toxic accelerator such as ethylene thiourea is being eliminated. 

(2) thiocarbamoyl subsulfonamide This kind of accelerator mainly has N-oxyethylene-thiocarbamoyl-N-oxyethylene-subsulfonamide, which has high operational safety, fast vulcanization speed and large promotion effect. It is suitable for SBR, NBR, EPDM rubber and other general synthetic rubber. The vulcanization speed of 0.*7 parts of rubber is faster than that of 1 part of the hyposulfonamide accelerator. And can get satisfactory operation safety performance. **9 ℃ above the activity is very large, and below is **9 ℃ can add a small amount of accelerator NOBS, M or DM.