A kind of production method of polypropylene film with low haze and high barrier property

Abstract

The invention discloses a production method of a polypropylene film with low haze and high barrier properties. The isotactic polypropylene-b-polyethylene glycol diblock is used as a compatibilizer for isotactic polypropylene and polyvinyl alcohol. Vinyl alcohol has excellent oxygen barrier properties. After isotactic polypropylene-b-polyethylene glycol diblock is used as a compatibilizer, it has good compatibility between tactic polypropylene and polyvinyl alcohol. Polyvinyl alcohol The phase can be uniformly dispersed in the polypropylene resin to form a sub-continuous phase or lamellar structure, which significantly improves the barrier properties of the blend film. After adding a nucleating agent to the polypropylene, the crystallization ratio and fineness are improved by water bath and stretching. The crystallization greatly improves its mechanical and load-bearing properties. After the crystals are refined, the transparency of the film is relatively high and the haze is low. After adding a stiffening agent, it can fill the gaps between the crystals and improve the product quality. Excellent barrier properties; silica is a very effective anti-blocking agent, the refractive index is very close to that of polypropylene, and has little effect on optical properties.

Description

technical field [0001] The invention relates to the technical field of packaging materials, in particular to a production method of a polypropylene film with low haze and high barrier properties. Background technique [0002] The barrier performance of the polypropylene packaging film in the prior art is not good, and substances such as oxygen, carbon dioxide, water vapor, aroma and small organic molecules are easy to pass through the polypropylene film and affect the performance and life of the packaged object. At present, there are mainly four methods for preparing high-barrier polypropylene films: multilayer composite, surface coating, nanocomposite modification and blend modification. These four methods all have their own defects and deficiencies. Problems such as residues, waste separation and post-processing difficulties; surface coating equipment is expensive, high cost, and film layer is uneven; nanocomposites are prone to particle agglomeration, resulting in decreas...

AI Technical Summary

Problems solved by technology

Since the barrier resins used are all polar polymers, and polypropylene is a non-polar polymer lacking functional groups, coupled with its semi-solid properties, and the relative properties of barrier resins and polypropylene Poor capacity, unable to disperse evenly in the polypropylene matrix, greatly weakening its barrier effect