JPS59229337A - Packing material which is easily torn off - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a laminated material containing a resin with excellent gas permeability resistance, and a packaging material that is easy to tear. This invention relates to an easily tearable packaging material using a saponified vinyl copolymer film.

When the intermediate layer is a laminated film using a saponified unstretched ethylene-vinyl acetate copolymer film, the exterior is a polyester film or nylon film, and the inner layer is a polyethylene film, the adhesive strength between the outer layer and the intermediate layer is 2.
00~1000g/15rrrm (180° peeling)
Therefore, the tearability of the laminated film was sufficiently suitable for practical use.

However, if the outer layer is a stretched polypropylene film,
Since the outer layer is destroyed, the adhesive strength between the outer layer and the middle layer is 2.
Since the value of 0 to 150ji715M (180° peeling) was small, the outer layer and the intermediate layer would peel off during tearing, and the tearability of the intermediate layer and the inner layer would be different, resulting in insufficient tearability.

The object of the present invention is that the outer layer is a stretched polypropylene film,
To obtain a packaging material having good tearability without modifying the film, with a laminated film in which the middle layer is an unstretched saponified ethylene-vinyl acetate copolymer film and the inner layer is a polyethylene film.

The present invention uses an adhesive to laminate the outer layer with a stretched polypropylene film, the middle layer with an unstretched saponified ethylene-vinyl acetate copolymer film, and the inner layer with a polyethylene film. hundreds~
An adhesive layer coated with 0.5 to 2 g/m of a solvent-free adhesive made of polyester resin or polyether resin having several thousand isocyanate-1 groups at the end, and an intermediate layer and an inner layer made of urethane. This is a packaging material with good tearability that is bonded together using a type of anchor coating agent.

The present invention will be described in detail below with reference to the drawings.

As shown in Figure 1, the lower surface of the outer layer (1) made of a stretched polypropylene film with a printed layer (2) on the back surface is made of polyester resin or polyether resin with a molecular weight of 500 to 3000 and an isocyanate group at the end. An intermediate layer (4) consisting of an unstretched saponified ethylene-vinyl acetate copolymer film is inserted through a solvent-free adhesive layer (3) consisting of
) with a molecular weight of 10,000 on the lower surface of the intermediate layer (4).
An easily tearable packaging material in which an inner layer (6) made of polyethylene film is laminated via an anchor coat layer (5) made of a polyester resin or a polyether resin having an incyanate group at the end of ~30,000 It is.

Here, the adhesive layer (3) is made of polyester resin.
AD-76F-287 (Toyo Morton Acid) is suitable as a polyether resin for T-1122 (Toyo Morton Acid), and the appropriate coating amount is in the range of 05 to 2 ji/m, and furthermore, 80 to 1200 G when applying. Heat to a range of .

Moreover, the anchor coat layer (5) is BH3-123/13
A mixture of T-TS3623/BTTS-2DD (both manufactured by Toyo Morton Acid) is suitable, and the coating amount is in the range of 1 to 2 g#, and this is applied at room temperature.

3- Further, the inner layer (6) is preferably provided on the anchor coat layer (5) by extrusion and shimination, and the inner layer (6) is not only made of one layer but also of the same resin or different polyethylenes by co-extrusion. It does not matter if it is multi-layered.

The above polyethylene includes not only low density polyethylene and high density polyethylene, but also ethylene-vinyl acetate copolymer,
It also contains ethylene copolymers such as ionomer resins, and may further contain additives such as antistatic agents and ultraviolet inhibitors.

The ethylene-vinyl acetate copolymer film used for the intermediate layer (4) is made of a resin having an ethylene content of 25 to 50 mol% and a saponification degree of 96% or more.

Then, when laminating the stretched polypropylene film as the outer layer and the unstretched saponified ethylene-vinyl acetate copolymer film as the intermediate layer via the solvent-free adhesive layer, the adhesive surface of the outer layer or the intermediate layer is treated with a primer coat. It may be laminated later.

Since the packaging material of the present invention has the above structure,
Conventionally, the problem of tearability has been solved with a laminated film in which the intermediate layer is made of an unstretched saponified ethylene-vinyl acetate copolymer film and the outer layer is made of a stretched polypropylene film.

As a result, a material with excellent gas barrier properties can be obtained in a laminated material made of a stretched polypropylene film, which is generally used as an outer layer, and can be widely used in food packaging bags.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an example of the packaging material of the present invention. 1... Outer layer 2... Printing layer 3...
Adhesive layer 4...Intermediate layer 5...Anchor coat layer 6...Inner layer Patent applicant Toppan Printing Co., Ltd.

Claims (1)

[Scope of Claims] (11) An intermediate layer consisting of a saponified polyvinyl copolymer film having an incyanate group at its terminal under an outer layer consisting of a stretched polypropylene film, further comprising an incyanate group at its terminal at the lower end of the intermediate layer An easy-to-tear packaging material in which an inner layer made of polyethylene film is laminated from a polyester resin or a polyether-based resin via an anchor coat layer. (2) The adhesive layer is made of a polyester resin with a molecular weight in the range of 500 to 60 DO. (3) The anchor coat layer has a molecular weight of 10,000 to 10,000.
The easily tearable packaging material according to claim 1 or 2, which is made of a polyester resin having a molecular weight of 30,000.