Polypropylene composition for producing bottle cap of carbonated beverage

Abstract

The invention relates to a polypropylene composition for producing a bottle cap of a carbonated beverage. The composition comprises the following substances: 30-60 parts of homopolymerized polypropylene with an isotacticity higher than 99% and an MFR of 1-30g / 10 min; 30-60 parts of block copolymerized polypropylene with an MFR of 1-15g / 10 min; 4-20 parts of polyethylene with a density of 0.955-0.968 g / cm<3> and an MFR of 1-15 g / 10 min; 5-15 parts of polyolefin elastomer; 0.05-0.2 part of nucleating agent; and 0.3-1 part of slipping agent. The product has excellent rigidity, good impact resistance and good stress whitening resistance.

Description

technical field [0001] The present invention relates to a polypropylene composition, in particular to a polypropylene composition with excellent rigidity, good impact resistance and good stress whitening resistance. Background technique [0002] According to the performance requirements of the bottle caps used for packaging carbonated beverages, the materials are required to have excellent hygienic properties, high deformation resistance, good crack resistance, drop crack resistance and stress whitening resistance. At present, the raw materials used in the production of carbonated beverage bottle caps are mostly block copolymerized polypropylene and high-density polyethylene. In the past, homopolypropylene was also used to produce carbonated beverage bottle caps. The bottle cap has good rigidity and bleaching resistance, but the anti-theft ring of the bottle cap has poor toughness and is prone to cracking. Later, people used block copolymerized polypropylene to produce carbo...

AI Technical Summary

Problems solved by technology

In the past, homopolypropylene was also used to produce carbonated beverage bottle caps. The bottle cap has good rigidity and bleaching resistance, but the anti-theft ring of the bottle cap has poor toughness and is prone to cracking. Later, people used block copolymerized polypropylene to produce carbonated beverage bottles. Cap, which solves the brittle phenomenon of the anti-theft ring of the bottle cap well, but the bottle cap deforms and the color of the thread of the bottle cap turns white under pressure

Some people also blend some polyethylene into block copolymerized polypropylene to improve the whitening phenomenon of the material, but due to the incompatibility of polypropylene and polyethylene, the bottle cap will crack and the deformation resistance of the bottle cap will be reduced under harsh conditions.

Images