Four factors to consider when choosing accelerator
1. Use of promoters
Each accelerator has its own characteristics, in order to meet the rubber in the process of operation has good technological performance and vulcanized rubber has excellent physical and chemical properties, can be used several, each other learn from each other.
Rubber properties because of the characteristics of the accelerator different-promoter main promoter and sub-promoter. The main promoter, also known as the first promoter, is usually an acid promoter (called type A) or A neutral promoter (called type N). thiazoles and chulam are the most abundant. The burning time sequence of thiazoles is M<DM<MZ<secondary sulfonamides. Qiulam main promoter is only used for thin film products or model products with very short curing time. Dithiocarbamate main promoter, often used in latex products, as well as ethylene – propylene rubber, butyl rubber and other low unsaturated rubber.
Secondary promoters, also known as the second promoter or the third promoter, generally use alkaline promoters (known as type B), with guanidines (such as promoters DPG, DOTG, etc.) for the most part. Accelerator H is also used to prolong the burning time. The amount of secondary accelerator varies with the type of main accelerator. Sub-sulfonamide promoter itself is a co-promoter. At the curing temperature, promoter M and amine compounds will be decomposed to form the AB co-promoter system. Therefore, generally can not choose the auxiliary accelerator. Of course, according to the process needs, can also use a small amount of accelerator DPG or qiulam type accelerator.
2. Coordinating effect
When choosing accelerator, also consider the interaction with other rubber auxiliaries, rubber raw materials and other factors.
3. Economy
The selection of accelerators should take into account the ease of procurement of the product in the market, and pay attention to the impact of large use of unusual accelerators or difficult to purchase on production.
The purchasing price should also be considered for the promoters commonly seen in the market. The use cost of promoters is one of the key issues for the formulation engineer.
4. Confidentiality
Common rubber products to find a formula is easy, but for special or technical content of rubber products, formula design cost a lot energy and financial resources, design a rubber formula and keep secret, for the development of enterprises is very important. And formula confidentiality is bound to involve the selection of accelerator product confidentiality, which is also one of the important issues considered by formula engineers and even company principals.