Guide for the use of flex pu catalysts

The catalyst used by polyurethane, its use principle should not only be based on the size of the catalytic activity of the catalyst, but also consider the use of state, chemical toxicity, and other raw material components of miscible ability, use concentration and cost price, chemical stability in the storage and transportation of the reaction raw material system, catalyst residues in the products have harmful effects on polymer properties and other factors. The tertiary amine catalysts usually used for polyurethane soft bulk foam are triethylenediamine, dimethyl ethanolamine, diether, etc., the recommended dosage is 0.1~0.3 copies (refers to 1oo mass of polyol based, the same below), can be used alone, but a variety of catalysts used together, the catalytic effect is better. Commonly used organotin catalysts are stannous caprylate and dibutyltin dilaurate. They must be dissolved in some plasticizer (such as dioctyl phthalate) before use. They can effectively accelerate the gel of the foam body, but the dosage should be controlled at the lower limit, otherwise the gel will be too fast, resulting in shrinkage, cracking and other phenomena. The Maxfoam technology equipment is used to produce polyurethane soft foam. The friction of the side wall makes the convex part of the surface of the foam more gentle, reduces the waste edge rate, and improves the compression and deformation performance of the foam. For the production of polyester polyurethane soft foams, the recommended dosage of N-ethylmorpholine,N, n-dimethylhexadecylamine and n-coconutmorpholine are 0.1%~0.3% and 0.5%~1.2%, respectively. High resilience molding foam body High resilience molding foam products have the characteristics of cold curing forming in the mold and high resilience, so it requires that the raw materials must have high reactivity, the mixed slurry has good fluidity in the mold cavity, that is, the foaming white time should be long, the curing gel time should be short, the selection of catalyst must also meet the needs of the specific process. Therefore, it is recommended to use delayed catalyst. At present, the catalysts often used in the production of such foams are triethylenediamine, diether,N,N' -dimethylpiperazine, dimorpholine ethyl ether and so on. Dimorpholine ethyl ether has high activity at high temperature, and has some delayed catalysis, which can improve the fluidity of mixed materials in the cavity. In order to improve the mold utilization rate of foam products, 0.01~0.03 parts dialkyl tin mercaptan catalyst can be used. Dibutyltin dilaurate catalysts can also be used in the production of bulk high rebound foams. During the transition period to replace CFCS foaming agents, low-density foams can be produced using an all-water foaming formulation system. It is recommended to use tertiary amine catalysts in the formulation to replace N-ethylmorph in the traditional polyester polyurethane foam formulation. These tertiary amine catalysts have low odor and low volatility. The machinability of foam casting and heat resistance of products have been improved.