Method for preparing high tenacity and high impact polypropylene resins

Abstract

A method for preparing high tenacity and high impact polypropylene resins comprises the step of melting, mixing and granulating the mixture after uniformly mixing the base material of the polypropylene resins and an additive to obtain the polypropylene resin products, wherein the melting heating temperature is controlled between 145 DEG C and 210 DEG C. The base material of the polypropylene resins is propylene-ethylene random copolymer, wherein the content of ethylene in the copolymer is 5-20wt%. The melt flow rate is 1-10g / 10min. The additive include a nucleating agent A, a nucleating agent B, a lubricating agent and an antioxidant, wherein the nucleating agent A is aromatic amide and the nucleating agent B is ortho dicarboxylic acid salt. The weight ratio of the base material of the polypropylene resins to the additive is 1000:1-10. The weight ratio of the nucleating agent A to the nucleating agent B in the additive is 1:0.2-1. When the total content of the nucleating agent A and the nucleating agent B is 1 part by weight, the lubricating agent is 2-6 parts by weight and the antioxidant is 1-5 parts by weight. The proportion of the beta crystal form in the crystalline region of the prepared polypropylene resins can be more than 85% (DSC method).

Description

technical field [0001] The invention relates to a preparation method of polypropylene resin, in particular to preparing high toughness and high impact resistance modified polypropylene resin by melt mixing and adding additives such as nucleating agent, lubricant and antioxidant. Background technique [0002] Polypropylene resin has become one of the most widely used general-purpose plastics due to its abundant raw material sources, simple synthesis process, low price, and good comprehensive performance. However, polypropylene resin has fatal defects of low toughness and poor impact resistance. The introduction of an appropriate amount (generally 5-20wt%) of comonomer ethylene into the molecular chain to form a block copolymer can significantly improve the toughness and resistance of polypropylene resin. Impact properties, but this chemical modification method will be restricted by poor thermal deformation resistance and rigidity reduction, that is, it can only improve the to...

AI Technical Summary

Problems solved by technology

There is a common defect in the preparation methods of these existing β crystal formation nucleating agents, that is, at most the crystal region formed by polypropylene or polypropylene-ethylene copolymer contains 70% to 80% of the β crystal formation (measurement method is DSC method, that is, differential thermal method), so that the modification of polypropylene to improve toughness and impact resistance is not ideal.

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