JPS59123662A - Heat-shrinkable laminated film - 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 relates to a heat-shrinkable laminated film, which has excellent gas barrier properties and pinhole resistance, and has an I:IJ printing layer that is suitable for packaging hams, sausages, etc. This invention relates to a shrinkable laminated film.

Sausage packaging involves filling flavored processed meat into a heat-shrinkable tube-shaped case film.
It is common practice to sterilize hams and sausages by boiling them in hot water at gO to qO<0>C for several minutes to several hours, and at the same time shrink the tubular case film to tightly package hams and sausages. Such packaging is coated with composite films of various configurations using polyamide resins or saponified ethylene-vinyl acetate copolymers as gas barrier materials, and vinylidene chloride resin films.

However, vinylidene chloride resin films have the disadvantage that they are too soft and difficult to absorb, and composite films with the above structure still have the problem of generating holes during tight packaging.

The printed layer can also be incorporated into the composite film by printing a product name, etc. on one side of the inner layer of the composite film. may be damaged.

The present invention'tl is a heat-shrinkable laminated film having a printed layer that solves the above-mentioned drawbacks, and its gist is as follows:
A printing layer/(by manufacturing process) is provided with ethylene-vinegar 1 sovinyl copolymer layer S, and immediately outside of the ethylene-vinyl acetate copolymer layer is a saponified ethylene-vinyl acetate copolymer layer S.
and/or a heat-shrinkable laminated film provided with a gas barrier layer consisting of a polyamide resin layer 3, and further provided with an ethylene-vinyl acetate copolymer layer immediately outside the gas barrier layer.

Examples of the ethylene-vinyl acetate copolymer (hereinafter referred to as REVA J) used in the layer film of the present invention include those with a vinyl acetate content of 76% by weight or less;
The Sara K is 5% by weight of rods, which I like.

The saponified ethylene-vinyl acetate copolymer (hereinafter referred to as "EV OH") 3 used for the gas barrier layer has an ethylene content of 2S to 75 mol% and a saponification degree of about qq mol% or oxygen barrier properties. It is suitable because it has excellent properties and extrusion moldability. Polyamide resin (hereinafter referred to as "PA") 3, which is also used for the gas barrier layer, is:
These are nylon Otsu, nylon 6 Otsu, nylon/2, nylon Otsu-Otsu Otsu, etc.

Next, the laminated film according to the present invention will be explained in detail with reference to the drawings. FIG. 1 is an enlarged sectional view showing an example of the heat-shrinkable laminated film of the present invention, FIG.
■EV A/PA/EV A/Printing layer/EV
A / P A / E V A and the product 1 in Fig. 2
- Composition of film ■EVA/EV OH/P
A/EVA/Printing layer/EVA/PA/
EVOH/EVA.

Excluding the printing layer, ■ is the Otsu layer weight, ■ is the g layer weight, and while the gas barrier layer of ■ is only PA, in ■ it is P layer weight.
A and EV OH are used together to improve gas barrier properties.

In addition, for EVA layers and 2 VC sandwiched with 1m of printing, after printing on one EVA layer, use an adhesive with good heat resistance such as a urethane-based reactive adhesive, and then attach the other EVA layer. Do something wrong with this. The EVA layer provided as the outermost layer of the laminated film is used as a sealant layer, but the same composition as the EVA layer in the center may be used. Regarding the thickness structure of each layer of the laminated film according to the present invention, the total thickness of one gas barrier layer is preferably thinner than the total thickness of the EVA layer, and is preferably in the range of about % to % of the total thickness of the EVA layer. For each gas barrier layer, the thickness of the PA layer (■) is approximately 3 μm each, and the thickness of the EV OH layer is approximately 3 μm, and the thickness of the PA layer (・'! E V O
If the thickness of the H layer is about twice as large, performance such as gas barrier properties and pinhole resistance can be ensured.

In addition, the method for producing a laminated film according to the present invention (・Ma,
Although not particularly limited, first, a biaxially stretched laminated stretched film consisting of an EVA layer/one gas barrier layer/an EVA layer is produced by a normal co-pressing method, extrusion lamination method, etc., and then one side of the film is Gravure printing (
Print with a number of shapes, interpose adhesive on this printed surface side,
A method of pressure bonding the same laminated stretched film as above, or another method is to manufacture a laminated stretched film with the above structure by coextrusion inflation method, then flatten this tubular film and print on one side. An example of this method is to provide an adhesive layer, then cut and invert the film and laminate the film so that the printed surface is in the center.

In the above method, the stretching conditions for the film are as follows: the stretching ratio in the machine direction (film glue 1 cut direction) and in the transverse direction (-1
= direction of writing and direction perpendicular to each other) are preferably 2 times to 3 times S, and a stretching temperature in the range of 70°C to 30°C is effective. As mentioned above, the laminated film according to the present invention has a gas barrier layer of one layer or two. The film is divided into two zones, with a flexible EVA layer sandwiched between them, so it deforms flexibly even when the film is bent or wrinkled, and does not cause pinholes. Even if this occurs and the gas barrier properties of the layer deteriorate, the other layers should serve to compensate for the performance and prevent the composite film itself from drastically deteriorating in performance. Furthermore, since the EVA layer provided just outside the gas barrier layer serves to protect the gas barrier layer, pinholes and the like can be prevented from occurring in the gas barrier layer. In addition, when the film is heated and shrunk, the EVA layer with the printed layer is deformed due to flow and the printed surface becomes distorted.

As mentioned above, the product of the present invention is a laminated film having a printed layer and having excellent performance as a packaging material for ham, sausage, etc., and its effects are extremely large.

[Brief explanation of the drawing]

FIG. 1 is an enlarged sectional view showing one example of the heat-shrinkable laminated film of the present invention, and FIG. 2 is an enlarged sectional view showing another example. /... Printing layer, Ri... Ethylene-vinyl acetate copolymer layer 3-
... Polyamide resin layer 6 ... Ethylene-vinyl acetate copolymer saponified material layer 1 Figure 2

Claims (1)

[Claims] Printing: An ethylene-vinyl acetate copolymer layer 2 is provided across the ethylene-vinyl acetate copolymer layer, and saponified ethylene-1\F-acid vinyl copolymer N s is placed on both outer sides of the ethylene-vinyl acetate copolymer layer. and/or a heat-shrinkable film having a gas barrier layer 3 made of a polyamide resin layer 3, and further provided with ethylene-vinyl acetate copolymer layers on both sides of the gas barrier layer.