The preparation method of pvc resin modifier

Abstract

The invention discloses a preparation method of a PVC resin modifier, which comprises the following process: using two-stage emulsions, in the presence of deionized water, an emulsifier, an initiator, and a molecular weight regulator, to carry out copolymerization at 40°C-90°C, The copolymerized emulsion is spray-dried to obtain a PVC resin modifier; one of the two-stage emulsions is acrylate and methacrylate in parts by weight of 40-80, and the other is styrene, acrylonitrile and acrylate in parts by weight of 20-60 . It can significantly improve the plasticizing processing performance of PVC resin and improve the processing fluidity of PVC resin. Compared with ordinary processing ACR, the plasticizing time is significantly shortened, and the dosage is only 30‑60% of ordinary ACR processing aids. It is used on pipes and pipe fittings that require fast plasticizing performance and good processing fluidity. The modified PVC resin product has high surface gloss, tensile strength and Vicat softening point.

Description

technical field [0001] The invention relates to the technical field of polymer compound compositions, in particular to a preparation method of a PVC resin modifier. Background technique [0002] PVC is one of the general-purpose thermoplastics with the largest output in my country, but it also has many shortcomings, such as poor thermal stability, need to add PVC heat stabilizer, poor toughness, add impact modifier, poor lubricity, add PVC inside and outside Lubricant, poor processing performance Add PVC processing modifier. In the process of processing PVC profiles and pipes, it is generally necessary to add 1-2 parts of processing modifiers. If the amount added is small, the plasticization of the processed materials will be poor, the dimensional stability will be deteriorated, and the surface finish of the materials will be deteriorated. And because the material of the PVC processing modifier itself is more expensive than PVC, the cost of adding a large amount of material ...

AI Technical Summary

Problems solved by technology

[0002] PVC is one of the general-purpose thermoplastics with the largest output in my country, but it also has many shortcomings, such as poor thermal stability, need to add PVC heat stabilizer, poor toughness, add impact modifier, poor lubricity, add PVC inside and outside Lubricant, poor processing performance Add PVC processing modifier

During the processing of PVC profiles and pipes, it is generally necessary to add 1-2 parts of processing modifiers. If the amount added is small, the plasticization of the processed materials will be poor, the dimensional stability will be deteriorated, and the surface finish of the materials will be deteriorated.

And because the material of PVC processing modifier itself is more expensive than PVC, the cost of adding a large amount of material will increase accordingly

Especially in the application of pipe fittings, the amount of domestic pipe fitting additives (such as calcium carbonate) is relatively large. In order to improve the plasticizing performance and processing fluidity of PVC, most domestic manufacturers have been adding plasticizers such as DOP and DBP, and these On the one hand, liquid plasticizers are not as easy to measure as solid ones. Even though the addition of plasticizers improves the processing performance and fluidity, the Vicat temperature of pipe fittings decreases rapidly, resulting in the Vicat temperature of most manufacturers rarely reaching the national standard. It causes disadvantages such as long production cycle, slow cooling, and high energy consumption; what is fatal is that the added plasticizer will slowly precipitate over time, reducing the performance of the pipe fittings

Foreign pipe fittings manufacturers avoid this situation. In order to improve the plasticizing performance and processing fluidity of PVC, they can only greatly reduce the content of additives and greatly increase the content of processing modifiers, resulting in a substantial increase in raw material costs. For a long time, researchers at home and abroad have done a lot of work in order to improve the plasticizing performance and processing fluidity of PVC, and have used various methods to improve performance or reduce costs. Although some effects have been achieved, they have not been fundamentally changed.

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