Modified auxiliary capable of improving printing compound performance of polypropylene film, preparation method and application

Abstract

The invention discloses a modified auxiliary capable of improving the printing compound performance of a polypropylene film, a preparation method and an application, belonging to the technical field of processing auxiliaries for polypropylene for food packaging. The auxiliary comprises the following components by weight percent: 10-40 wt% of flake-shaped vermiculite, 55-85 wt% of EVA (ethylene-vinyl acetate copolymer) and 5-15 wt% of polypropylene-grafted glycidyl methacrylate+styrene modified (PP-g-GMA / PS). The preparation method comprises the following steps of: dissolving the EVA resin by a solvent, and then intercalating while crushing the vermiculite and the EVA solution in a ball mill; and then adding the PP-g-GMA / PS, drying to obtain the auxiliary. The polypropylene film modified by the auxiliary disclosed by the invention is greatly improved in mechanical property, slightly increased in tensile yield stress and Young modulus, and greatly increased in tensile elongation at break; and moreover, the film is greatly enhanced in compound strength and ink adhesive force, and greatly reduced in frictional coefficient.

Description

technical field [0001] The invention provides a processing aid for polypropylene used in food packaging. The processing aid is composed of flaky intercalated vermiculite, ethylene-vinyl acetate copolymer, polypropylene grafted with glycidyl methacrylate (styrene as a comonomer); the mechanical properties and printing composite properties of the polypropylene flexible packaging film prepared by using the polypropylene modification aid provided by the invention are greatly improved. Background technique [0002] In my country, the annual consumption of biaxially stretched polypropylene (BOPP) and cast polypropylene (CPP) films in composite flexible packaging has reached 2 million tons, but the printing and composite properties of polypropylene films are poor, which is manifested in the post-printing performance of BOPP films. Low ink adhesion and low composite strength (peel strength) between CPP film and other films have plagued my country's food packaging industry. [0003] ...

AI Technical Summary

Problems solved by technology

[0002] In my country, the annual consumption of biaxially stretched polypropylene (BOPP) and cast polypropylene (CPP) films in composite flexible packaging has reached 2 million tons, but the printing and composite properties of polypropylene films are poor, which is manifested in the post-printing performance of BOPP films. Low adhesion of ink, low composite strength (peel strength) of CPP film and other films, these problems have been plaguing my country's food packaging production industry

For example, CN102276908 introduces the addition of vermiculite with a particle size of 50-200 meshes, and melt blends the vermiculite with ethylene-vinyl acetate copolymer (EVA) to obtain a polypropylene modification additive, which improves the barrier properties of polypropylene films; but The vermiculite powder provided by this patent is micron-sized, and there is no mention of whether the lamellar structure of vermiculite is peeled off, and the addition of vermiculite modifier is very large (2-15%), which also indirectly proves that CN102276908 modifier no peeling

In addition, our invention patent ZL200810215584.9 discloses a polypropylene grafted glycidyl methacrylate (GMA) + styrene modifier (PP-g-GMA / PS), which is used to improve the Printing and composite performance: the peel strength of unmodified PP composite film is only 2.5 Newtons, the peel strength of polypropylene composite film modified by PP-g-GMA can be increased by 16-68%, and the adhesion fastness of ink can be increased by 1.1- 3.8 times, but the mechanical properties are somewhat reduced

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