A kind of auxiliary agent for PVC processing and preparation method thereof

Abstract

The invention discloses an auxiliary agent for PVC processing and a preparation method thereof. The PVC processing aid has a core-shell structure with calcium maleate-styrene copolymer as the core and alkyl methacrylate as the shell, and its intrinsic viscosity is 3.0-10.0. The preparation method of the auxiliary agent for PVC processing comprises the following steps: (1) adding distilled water, calcium maleate monomer, initiator A, emulsifier, dispersant, styrene monomer into the reaction kettle, stirring to obtain pre-emulsified (2) Introduce N2, and raise the temperature to 40~90°C, and keep stirring for 0.5~5 hours to obtain the core layer emulsion; (3) Add initiator B, methacrylic acid alkyl to the core layer emulsion Base ester monomer, heat up to 50~95°C, stir and react at constant temperature for 1~5 hours, cool to ≤40°C, and then spray dry to obtain PVC processing additives. The auxiliary agent for PVC processing of the invention can promote the uniform plasticization of PVC, improve melt strength, heat resistance and rigidity, reduce production cost to the greatest extent, and have remarkable economic benefits.

Description

technical field [0001] The present invention relates to a polymer additive, in particular to a PVC processing aid which is added to PVC and can improve its processing performance, with calcium maleate-styrene copolymer as the core and alkyl methacrylate as the shell. agent and its preparation method. Background technique [0002] Polyvinyl chloride (PVC) resin is widely used in building materials, industrial products, daily necessities, floor leather, floor tiles, artificial leather, pipes, wires and cables, packaging films, bottles, foaming materials, sealing materials, fibers, etc. widely used. PVC has a low decomposition temperature, is easy to decompose during processing, and has poor heat resistance, weather resistance, and impact resistance. Therefore, various auxiliary materials need to be added during processing to improve overall performance. [0003] Liquid plasticizers are generally added to the formula of PVC soft products or semi-hard products, which can reduc...

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Problems solved by technology

Methacrylate-acrylate random copolymers have excellent processing properties, can endow products with a wide processing temperature range, high melt strength, and good surface finish, but their price is the highest among the four types ; Styrene-acrylonitrile random copolymers and acrylate-styrene blend resins have significant price advantages, but because of the poor compatibility of styrene and PVC, the plasticizing efficiency is low and the processing range is narrow , the surface finish of the product is not very good; the blended resin mixed with modified nano-inorganic fillers is based on the above two types of processing modifiers, and then adds fillers such as nano-calcium carbonate and silica to reduce product prices, but Inorganic fillers have poor compatibility with PVC, which will have a negative impact on the performance of PVC products, and the proportion of these inorganic fillers is relatively large, which will increase the volume cost of the product and fail to achieve the desired effect

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