Nano modified polyethylene flexible packing material

Abstract

The invention provides a processing auxiliary agent composition of polyolefin for food packing. The processing auxiliary agent composition is a mixture of nano silicon dioxide and ethylene-vinyl acetate copolymer, wherein the mass of the nano silicon dioxide accounts for 1 to 20 percent of the total mass of the processing auxiliary agent composition, and the mass of the ethylene-vinyl acetate copolymer accounts for 80 to 99 percent of the total mass of the processing auxiliary agent composition. The invention also provides a polyethylene flexible packing material modified by using the processing auxiliary agent composition. The results show that the toughness of the polyethylene flexible packing material modified by using the processing auxiliary agent composition is greatly improved, and the polarity of the material is well improved at the same time; and the adsorption of the modified polyethylene on methylbenzene and ethyl acetate is greatly reduced, and the friction coefficient of a film is also greatly reduced. Therefore, the service performance of the nano modified polyethylene serving as the flexible packing material is greatly improved.

Description

technical field [0001] The present invention relates to a polyolefin processing aid composition for flexible food packaging and a modified polyolefin food flexible packaging material, more specifically, the application relates to a polyolefin processing aid for flexible food packaging containing nano silicon dioxide Composition and nano-modified polyolefin material for food flexible packaging, especially polyethylene material. 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. Even in my country, plastic packaging materials account for about 25% of the plasti...

AI Technical Summary

Problems solved by technology

[0005] (1) Low tensile strength (small Young's modulus, low tensile yield stress), high expansion rate, and difficult overprint adjustment

[0006] (2) Due to the poor heat resistance of LDPE, the composite film prepared with it is prone to deformation at higher temperatures (during the cooking and disinfection process, or in the drying tunnel of printing equipment)

[0007] (3) The friction coefficient of the film is too high to meet the requirements of the automatic filling production line. In order to reduce the friction coefficient of the film, a slip agent is often added

The addition of a slip agent will cause problems such as a decrease in the ink adhesion fastness and a decrease in the bond strength of the composite film.

In addition, if the slippery agent seeps out excessively, the production speed of the automatic filling production line will also decrease.

Therefore, the amount of slip agent is difficult to control

[0008] (4) The oil resistance is not good, it needs to be compounded with other films, and the thickness of LDPE needs to be increased when used as a heat-sealing layer

[0009] (5) It is easy to generate static electricity and easily detonate the volatile organic solvents in the workshop

[0010] (6) The gas barrier property is poor, and it needs to be combined with other films to have a high gas barrier property

[0011] (7) Low surface polarity and poor adhesion to ink

The current solution is to perform surface treatment (such as corona treatment, etc.) before printing to increase the number of polar groups, but there is a time limit after corona treatment (generally about 15 days)

[0012] (8) It is very easy to absorb organic solvents in adhesives and inks, resulting in excessive solvent residue indicators in flexible packaging

[0013] In the application field of packaging materials, the above-mentioned problems of LDPE film have not been well resolved. They have seriously affected the quality of product packaging, resulting in high scrap rates, automatic canning production lines cannot operate at full capacity, and the safety of operators cannot be guaranteed. Guaranteed, it also poses a serious threat to food quality and causes food safety problems

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