Laminate

Abstract

A laminate prepared by pretreating at least one side of a substrate of a plastic film by plasma treatment and then directly laminating a thermoplastic resin on a surface treated by pretreatment.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This is a Continuation application of PCT Application No. PCT / JP2007 / 067017, filed Aug. 31, 2007, which was published under PCT Article 21(2) in Japanese.[0002]This application is based upon and claims the benefit of priority from prior Japanese Patent Applications No. 2006-244513, filed Sep. 8, 2006; and No. 2007-094833, filed Mar. 30, 2007, the entire contents of both of which are incorporated herein by reference.BACKGROUND OF THE INVENTION[0003]1. Field of the Invention[0004]The present invention relates to a laminate which exhibits strong interlaminar adhesiveness upon extrusion lamination of a thermoplastic resin onto a plastic film or a substrate including a plastic film. More particularly, the present invention relates to a laminate which exhibits strong adhesiveness by direct extrusion lamination of a thermoplastic resin onto a plastic film or a substrate without applying an anchor coating agent, an adhesive or the like to the pla...

AI Technical Summary

Benefits of technology

The present invention provides a laminate that can effectively stick a thermoplastic resin directly onto a plastic film without the need for an anchor coating or ozonation. This is achieved by pretreating the film with plasma treatment before extrusion laminating the thermoplastic resin onto it. The laminate can be used with a variety of thermoplastic resins and can be used for a variety of applications such as food packaging. The invention also provides a gas barrier coating layer that can be used with the laminate.

Problems solved by technology

However, which such thermoplastic resin is directly laminated onto a plastic film as a substrate, they show poor adhesiveness.

However, the AC agent is applied after dilution with an organic solvent such as ethyl acetate or toluene as a diluent, and thus generally has problems such as compliance with the regulation by Fire Defense Law, deterioration in working conditions, an increase in production costs due to use of a relatively expensive coating agent, and an odor of a residual organic solvent in final products.

On the other hand, when usual facilities for extrusion lamination of a thermoplastic resin onto one side of a substrate are used to produce a laminate of such structure, there is a problem that the number of steps should be increased.

In these methods, however, resins and substrates that can be used are limited, and thus a combination of a general plastic substrate and a thermoplastic resin such as a polyethylene resin is not applicable.

In this method, the adhesiveness of a resin is improved by blowing ozone to the resin, but ozone has problems such as a very bad smell and toxicity to require attention on safety, and difficulty in confirming whether ozonation is uniformly conducted.

However, this method always requires a printed layer and is hardly applicable to a constitution not provided with a printed layer.

Even if the steps of lamination with a printed layer and of surface treatment are conducted in line, there is a problem that the steps and costs are increased in the constitution not requiring a printed layer.

However, when the adhesiveness between the gas barrier coating layer and a resin extrusion-laminated thereon is to be exhibited, there is the same problem as in the case of the substrate described above.

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