Processing aid of polyolefine for food flexible packing, preparation method and application thereof, and modified polyolefine adopting processing aid

Abstract

The invention relates to a processing aid of polyolefine resin for food flexible packing, a preparation method and application thereof, and a modified polyolefine material used in the food flexible packing and adopting the processing aid. The processing aid consists of nano silicon dioxide and ethylene-vinyl acetate copolymer and is prepared through adopting a coprecipitation method. The processing aid can reduce the melt viscosity of polyolefine and obviously improve the processing performance of the polyolefine; and meanwhile, the processing aid increases the polarity of the polyolefine while improving the composite performance and printing performance of the polyolefine.

Description

technical field [0001] The invention belongs to the preparation of nanomaterials and the modification of polymer materials, and specifically relates to a polyolefin processing aid for food flexible packaging, its preparation method, its use in polyolefin modification, and the use of the processing aid to modify Polyolefins for flexible food packaging. Background technique [0002] As we all know, plastic packaging has the characteristics of light weight, softness, less waste, small space occupation, low cost and high cost effectiveness, so packaging materials have become the largest part of plastic consumption. Taking the United States, Japan and Germany, where the plastic industry is the most developed, as examples, packaging plastics account for 27.2%, 32.8% and 27.2% of the total plastic consumption, respectively, and plastic packaging materials also account for about 25% of plastic consumption in my country. [0003] At present, plastic packaging is gradually developing...

AI Technical Summary

Problems solved by technology

[0005] However, because LDPE has more branched chains (larger branching degree) in the molecule, the molecular arrangement is not tight, the crystallinity is low, and the density is also small, so that LDPE has good toughness, transparency, and environmental resistance. While it has the advantages of stress cracking, it also has the disadvantages of low tensile strength and poor thermal stability.

Therefore, in the process of using domestic LDPE film as a packaging material, there are several problems in the following aspects: low tensile strength, large stretching rate, and difficulty in overprint alignment; It is easy to deform in the medium; the compatibility between the film and the conventional slip agent is poor, and the slip agent is very easy to migrate to the surface of the film, resulting in problems such as poor adhesion of the ink and a decrease in the bond strength of the adhesive to the film (for composite films) ; The surface polarity is low, and the adhesion to ink is poor; the surface polarity is unstable after corona treatment, and the surface polarity is easy to disappear during storage

[0006] As a flexible packaging material, the above-mentioned problems of LDPE film have not been well resolved. They have seriously affected the quality of flexible packaging products, resulting in a high scrap rate, and the automatic canning production line cannot operate at full capacity.

However, the nano-SiO obtained by all these methods 2 The polarity of the surface is still high (relative to the chain segment of polyethylene). At this time, even if the nanomaterials are well dispersed in the matrix (nano-dispersion), the intermolecular force between the nanoparticles and the LDPE chain segment is still weak. , and the cost is higher

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