Terpolymer used for hard polyvinyl chloride and preparation method thereof

Abstract

The invention belongs to the processing auxiliary agent field used for hard polyvinyl chloride, and concretely relates to a terpolymer used for hard polyvinyl chloride and a preparation method thereof. The terpolymer is characterized in that a core layer and a shell layer with mass ratio of 3: 1-4: 1 are prepared by employing a grafting emulsion polymerisation technology, wherein the core layer is prepared by a vinyl acetate monomer, deionized water, a dispersant, an emulsifier, an alkalescence medium and an initiator; and the shell layer is prepared by methyl methacrylate, butyl acrylate monomer, the emulsifier and the initiator. According to the invention, yield is high as more than 98%, the emulsion stability is good, melt-strength and balance torque are greatly increased, water resistance, alkali resistance and heat resistance of the copolymer are increased, production cost is greatly reduced, and cost performance can be increased. The invention also provides a preparation method which has the advantages of simple process and simple operation.

Description

technical field [0001] The invention belongs to the field of processing aids for rigid polyvinyl chloride, and in particular relates to a terpolymer for rigid polyvinyl chloride and a preparation method thereof. Background technique [0002] my country is the world's largest producer and consumer of rigid polyvinyl chloride PVC, and related PVC products have a broad market environment, both powerful and broad. Based on the rapid development of urban and rural construction engineering, transportation engineering, environmental engineering, energy and water conservancy engineering, etc., the market demand for PVC building materials and engineering materials is increasing day by day, and it is currently one of the plastic varieties with the largest output in my country. Rigid PVC does not contain softeners, so it is easy to form, not brittle, non-toxic and pollution-free, and has a long storage time. Great development and application value. [0003] During processing, PVC nee...

AI Technical Summary

Problems solved by technology

Methyl methacrylate-butyl acrylate (or ethyl acrylate) copolymer has the advantages of excellent processing performance, heat resistance, wide processing temperature range, high melt strength, good surface Smoothness and dimensional stability; compared with acrylate processing modifiers, styrene-acrylonitrile processing modifiers have obvious cost advantages, but because styrene contains unsaturated double bonds, the anti-ultraviolet and anti-aging properties Generally, at the same time, the compatibility of styrene and PVC is relatively poor, the processing range is narrow, the melt plasticization is slow, and the surface finish of the product is not good; the blended resin mixed with nano-modified inorganic fillers is modified by the above two types of processing Based on the agent, it is combined with fillers such as nano-calcium carbonate, silicon dioxide, mica powder, etc., so as to reduce the product price

The greater the amount added, the more obvious the decline in mechanical properties of rigid PVC products, such as increased brittleness of products, slow melt plasticization during processing, decreased surface finish, and dimensional stability that cannot meet expected indicators, etc.

[0004] The present inventor found in the process of researching the technical route and market application of PVC processing modifiers that alkyl methacrylates, alkyl acrylates resins, acrylonitrile, and styrene resins are effective in improving the compatibility of processing aids and PVC. And plasticization has certain advantages, but with the rising price of petrochemical raw materials, the production and application of PVC processing modifiers have to add a large amount of inorganic fillers to reduce costs and seek business development

Eventually, a vicious circle was formed, which seriously hindered the overall level of the rigid PVC products industry and deviated from the national overall plan of "replacing steel with plastic and wood with plastic".