A, accelerator NOBS alternatives
Produce nitrosamines, which are commonly used in tire factories NOBS release the highest concentration of nitrosamines, the most harmful. Western developed countries and some parts of the tire companies have stopped using the accelerator, the domestic still use this product. Tire production often add a small amount of colchicine class accelerator as the second accelerator, commonly used varieties of tetramethyl colchicine disulfide TMTD (TT), the product can produce nitrosamines. The commonly used variety in the sulfur donor is dithiobimorpholine DTDM, which can also produce nitrosamines.
The three raw materials indicated above can produce nitrosamines, which are harmful to human health, and the REACH regulation issued by the European Union has explicitly prohibited the use of these raw materials in products exported to the EU. The following provides several environmentally friendly alternatives for reference:
1, TBBS (NS) can be used instead, but need to add more coking agent CTP; which is used to replace the NOBS green product NS has become the first big variety of accelerator, the United States NS production and consumption is the largest, accounting for thiazole sulfide chemicals (including vulcanizing agent and vulcanization accelerant) of the total amount of 40%. 40%. China's radial tire development is faster, the supporting requirements for accelerator NS is more urgent. NS belongs to the after-effect accelerator, can be used for natural rubber and recycled rubber, male rubber, isoprene rubber, styrene-butadiene rubber vulcanization, is recommended in recent years to replace the NOBS product of choice in China.
2, can be replaced by TBSI, chemical name N-tert-butyl-bis (2-benzothiazole) subsulfonamide, is also a subsulfonamide accelerator. Scorch between NOBS and DCBS, the price is relatively low. This product is used in the rubber material with the characteristics of prolonging the scorch time and slowing down the vulcanization rate.TBSI has the advantages of long scorch time and fast vulcanization speed compared with TBBS due to its high molecular weight, good thermal stability, and the melting point is more than 30℃ higher than that of TBBS. At present, TBBS is often used with CTP***, and TBSI can completely replace TBBS+CTP to be used alone. In addition TBSI also has water stability, easy to store; in the vulcanization of natural rubber to significantly improve the rubber's resistance to vulcanization reduction; in the rubber and steel wire bonding compounds with good performance; can be used for all elastomers, especially for the anti-reduction requirements of the thicker products with high requirements and other advantages.
3, can be replaced by CBBS, does not produce N-nitrosamines accelerator, it is equal to replace NOBS, its vulcanization speed is completely equivalent. Scorch performance is slightly better than NOBS and CBS, the physical properties of vulcanized rubber and NOBS is also comparable, widely used in city tires and other rubber products.
4, XT580 can be used instead of N-aliphatic benzothiazole subsulfonamide, its performance is completely comparable with NOBS, and non-toxic, the price is lower than NOBS.
The second, the accelerator TMTD substitutes
Can be used in place of TBzTD (tetrabenzyltetracosyltetramethylene disulfide), with a better scorching safety and resistance to regeneration; Due to TBzTD molecular weight, high melting point, difficult to decompose, so it will not produce nitrosamines, especially TBzTD only slightly lower than the speed of vulcanization of TMTD, other physical properties are almost the same as TMTD, has become a new species of columbia vulcanization accelerators with great potential for development.
TBzTD still belongs to the thiuram category, but because of the generation of dibenzylnitrosamine molecular weight, is neither volatile nor water-soluble non-carcinogenic substances, and the generation of the amount of small, because of the non-polar, there will be no frost phenomenon.TBzTD also has the advantages of vulcanization of a long period of scorching, good operating safety, for natural rubber, butyl rubber, styrene-butadiene rubber, nitrile rubber, TBzTD is suitable for the vulcanization of natural rubber, SBR, SBR, NBR, NBR, butyl rubber, EPDM and latex, and is widely used in the manufacture of wires and cables, tires, adhesive tapes, coloring transparent products, footwear and heat-resistant products, etc. It can be used to replace the Tyulanum accelerators such as TMTD and TETD.
Three, the substitution of vulcanizing agent DTDM
1, can be used instead of DTDC (CLD) (N, N′-dithiocaprolactam), white crystalline form, melting point of 120 ~ 122 ℃, the active sulfur mass fraction of more than 0 19. To replace the vulcanizing agent DTDM with the same amount of, no need to change the formulation of the rubber material and process. The same as the vulcanizing agent DTDM, the vulcanizing agent DTDC can completely or partially replace the sulfur yellow to form an effective or semi-effective vulcanization system. As vulcanizing agent DTDC can release active sulfur under general vulcanizing conditions, and form single and double sulfur bonds with added sulfur yellow between rubber molecules, this rubber vulcanization network structure can give vulcanized rubber excellent heat resistance, compression resistance and high constant elongation stress. Vulcanizing agent DTDC also has the characteristics of no spraying frost, scorch safety and fast vulcanization, which is the best vulcanizing agent for large model rubber products such as tires, heat-resistant rubber products, hygienic rubber products and colored rubber products.
2, can be used instead of alkyl phenol disulfide (VULTAC-5), alkyl phenol disulfide, suitable for different polarity rubber and system and white tire side.
3, can be replaced by fat-based polysulfide.
Four, accelerator MTT
This product is a thiazole heterocyclic compounds, containing active sulfur atoms, halogen-containing polymers to produce cross-linking, suitable for chlorinated butyl rubber, chloroprene rubber vulcanization cross-linking, in particular, can be used as a highly effective promoter of chloroprene rubber. Compared with NA-22, this product maintains the good physical properties and aging resistance of NA-22 vulcanized chloroprene rubber, and at the same time, it also improves the burning performance of the rubber and operational safety, and has faster vulcanization characteristics. This product is easy to disperse in rubber, no pollution, no discoloration, usually used in the manufacture of cables, rubber cloth, rubber shoes, tires, colorful products.
Fifth, the accelerator TiBTM
Columnum class super-accelerator TMTM (a sulfurized tetramethylcolumnum) and carbamate ZDC, etc. will produce carcinogenic nitrosamines, and its main substitutes TiBTM (sulfurized tetra-isobutylcolumnum) has been gradually industrialized, but the market is still more in the understanding, and did not have a large number of applications.
Six, accelerator AS-100
Environmentally friendly, nitrogen-free. Does not produce nitrosamines, and TBzTD and replace TMTD, DM. for NR, SBR products. Helps to improve abrasion resistance. Used in automobile seals, hoses, shoe soles and other products.
Seven, plasticizer DBD
In Europe and the United States and other countries have stopped using, its main alternative is plasticizer DBD (2,2′-dibenzoylaminodiphenyl disulfide). Pentachlorothiophenol chemical plasticizer alternative plasticizer DBD production technology in the country has been a number of factories to develop successful and achieve mass production, the future must increase its substitution efforts.
Eight, antioxidant 264
Odorless, non-toxic rubber and plastic universal antioxidant, antioxidant A, butyl, RD, 246, 4010, SP, WH-02 ideal alternative. Natural rubber, styrene butadiene, nitrile butadiene, chloroprene, isoamyl rubber, etc. have better protection against heat, light, ozone, curvature and cracking aging. Especially in neoprene rubber and food packaging, medical and health care products, rubber parts, light color and colorful rubber products, high-level cable rubber materials, as well as polyether, high-grade lubricating oil industry varieties have other common antioxidant unparalleled advantages.