Shenyang SUNNYJOINT as a supplier of Rubber Additives, It is well known that MBS/NOBS, TMTD, DTDM and other promoters will decompose nitrosamine carcinogens in the intermediate products of the vulcanization reaction. How to choose alternatives? I want to use the environmentally friendly vulcanization system to deal with the EU, see below!
Vulcanization accelerators commonly used in tire production include sulfenamide accelerators and thiazole accelerators. The thiazole accelerator is non-toxic, but its scorch time is short, and the slow vulcanization rate determines that the production in the tire mainly occurs as a secondary accelerator, and the actual amount is small. The main applications are promoters M and DM.
The comprehensive performance of sulfenamide accelerators with good processing safety, fast vulcanization speed and high physical and mechanical properties occupies the first place in the tire production accelerators. Common accelerators include MBS/NOBS, TBBS/NS, CBS/CZ, DCBS. /DZ.
MBS produces nitrosamines, which have been discontinued by tire companies in developed countries and regions in the West. This product is still used in China. A small amount of thiuram accelerator is often added as a second accelerator in tire production. The commonly used product is tetramethylthiuram TMTD, which produces nitrosamines. A commonly used variety in sulfur donors is dithiodimorpholine DTDM, which also produces nitrosamines.
The three raw materials indicated above can produce nitrosamines harmful to human body. The REACH regulations promulgated by the European Union have clearly stipulated that the products exported to the EU are prohibited from using the above raw materials. The following are several suitable environmentally friendly alternatives for reference:
1. TBBS/NS can be used instead, but more scorch retarder CTP needs to be added;
2. TBSI can be used instead of N-tert-butyl-bis(2-benzothiazole) sulfenamide. The scorch is between NOBS and DZ, and the price is relatively low. The TBSI chemical name N-tert-butyl-bis(2-benzothiazole) accelerator, abbreviated TBSI, is also a sulfenamide accelerator. This product is used in the compound to extend the scorch time and slow down the vulcanization rate. Compared with TBBS, TBSI has a high molecular weight, good thermal stability, and a melting point higher than TBSS by more than 30 ° C. It has the advantages of long scorch time and fast vulcanization speed. At present, TBSS is often shared with the scorch retarder CTP, and TBSI can be used alone instead of TBBS+CTP. In addition, TBSI also has water-stable stability and easy storage; it can significantly improve the resistance of rubber to sulfur reduction when vulcanizing natural rubber; it performs well in rubber-steel bonded compounds; it can be used in all elastomers, especially for anti-reduction requirements. High thickness and other advantages.
3. It can be replaced by CBBS, and it will not produce an accelerator for N-nitrosamines. When it is replaced by NOBS in an equal amount, the vulcanization rate is completely equal. The scorch performance is slightly better than NOBS and CZ. The physical properties of vulcanizate are similar to those of NOBS, and are widely used in city tires and other rubber products.
4. XT580 can be used instead of N-fatty benzothiazole sulfenamide, its performance is completely equivalent to NOBS, no toxicity, the price is lower than NOBS.