JP2554687Y2 - Gas barrier laminated stretch film - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stretch film used for stretch packaging. Especially,
It is suitably used for stretch packaging of commodities requiring gas barrier properties such as foods.

[0002]

2. Description of the Related Art As a stretch film, polyvinylidene chloride, polyvinyl chloride, high-pressure polyethylene, linear low-density polyethylene, ethylene-vinyl acetate copolymer, polybutadiene, or the like is provided with self-adhesiveness. Single layer films have been used. In particular, stretch films made of polyvinylidene chloride resin are excellent in gas barrier properties, and thus have been suitably used for packaging products such as foods that require a gas barrier. However, these films generate toxic gases when incinerated after use, and have been shunned as destroying the natural environment.

[0003] Regarding the laminated stretch film,
Laminated stretch films consisting only of polyolefin resins are disclosed in JP-A-60-79932 and JP-A-3-7664.
5, JP-A-3-86544 and the like, and a laminated stretch film having a polyvinylidene chloride layer is described in JP-B-3-23097.

Therefore, a laminated stretch film having a gas barrier resin other than polyvinylidene chloride as a core layer can be considered as a stretch film having excellent gas barrier properties and not causing environmental pollution. However, gas barrier resins other than polyvinylidene chloride, for example, saponified ethylene-vinyl acetate copolymer, polyamide resin, or polyethylene terephthalate resin, etc. are generally strong, and preferred resins for use as a stretch film. Absent. That is, a laminated stretch film using these resins is easily peeled off due to the strength of the stiffness of the film itself, even if the stretched film is closely adhered and covered by the self-adhesiveness of the bent film surface.

[0005]

[Problems to be solved by the present invention] The present invention has an excellent gas barrier property, and does not cause environmental pollution even when incinerated after use, and furthermore, has a self-adhesive property when used for stretch packaging. It is an object of the present invention to provide a gas-barrier laminated stretch film that does not peel off a wrapped portion in close contact.

[0006]

In order to solve the above-mentioned problems, the present invention takes the following measures. That is, a gas-barrier resin core layer other than polyvinylidene chloride, which is narrower than the surface layer, is sandwiched between the self-adhesive resin surface layers on both sides at an interval from both ends of the surface layer. The distance from both ends of the self-adhesive resin surface layer to the end of the gas barrier resin core layer is 20 to 100 mm, respectively.
Preferably, the gas barrier resin core layer is a single layer of a saponified ethylene-vinyl acetate copolymer or a polyamide resin, or a polyethylene terephthalate resin, or a laminate of these resins is used. Can be Further, as the self-adhesive resin surface layer, a laminate of an adhesive resin layer having adhesiveness to both the self-adhesive resin surface layer and a gas barrier resin core layer other than polyvinylidene chloride can also be used. .

Hereinafter, the contents of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of the gas-barrier laminated stretch film of the present invention, and FIG. 2 is a cross-sectional view taken along aa 'of FIG. Self-adhesive resin surface layers (1) on both sides,
A gas barrier resin core layer other than polyvinylidene chloride (3) is sandwiched between (1 ′), and the gas barrier resin core layer is formed from both ends (2) and (2 ′) of the self-adhesive resin surface layer. The layers are stacked at intervals (L) and (L ′) to the ends of the layers. The distance (L) and (L ') from the end of the self-adhesive resin surface layer to the end of the gas barrier resin core layer is 20.
To 100 mm is preferred.

As the gas barrier resin core layer (3) other than polyvinylidene chloride, a saponified ethylene-vinyl acetate copolymer, a polyamide resin, a polyethylene terephthalate resin, or the like is used. If the distance (L) from the end of the self-adhesive resin surface layer to the end of the gas barrier resin core layer (L) or (L ') is less than 20 mm, self-adhesion occurs when used for stretch packaging. The edge of the film that is in contact with and wraps is easily peeled off, and 100 m
If it exceeds m, not only wasteful parts will increase but also the packaging finish will not be beautiful.

FIG. 3 shows that the self-adhesive resin surface layers (1) and (1 ') on both sides have adhesiveness to both the self-adhesive resin surface layer and the gas barrier resin core layer other than polyvinylidene chloride. It is sectional drawing of the gas-barrier laminated stretch film which is a laminated body with adhesive resin layers (4) and (4 '). FIG. 4 shows two or three types of gas barrier resin core layers other than polyvinylidene chloride, that is, other gas barrier resin layers on both sides of the gas barrier resin layer (5), (6),
It is sectional drawing of a gas-barrier laminated stretch film when (6 ') is laminated.

The adhesive resin layers (4) and (4 ') having adhesiveness to both the self-adhesive resin surface layer and the gas barrier resin core layer other than polyvinylidene chloride are produced by a dry lamination method. In this case, an adhesive generally used conventionally is used, and when produced by a co-extrusion method, an unsaturated fatty acid-modified polyolefin resin or the like generally used conventionally can be used. When the gas-barrier resin core layer is a laminate, a laminate composed of at least one of the above-mentioned saponified ethylene-vinyl acetate copolymer, a polyamide resin, and a polyethylene terephthalate resin is used. For example, in the case of a two-layer and three-layer body composed only of a gas barrier resin as shown in FIG. 4, a laminated structure in which a saponified ethylene-vinyl acetate copolymer layer is provided in the center layer and a polyamide resin layer is provided on both sides thereof. A body or the like is used.

The method for producing the gas-barrier laminated stretch film of the present invention is as follows. The gas-barrier resin is formed into a film narrower than the surface layer film between two self-adhesive resin surface layer films. A method of extruding and laminating can be suitably used. It can also be manufactured by a conventional dry lamination method or thermocompression bonding method. The laminate of the self-adhesive resin surface layer and the gas barrier core layer is preferably obtained by a co-extrusion method.

As a method of stretch packaging using the gas-barrier laminated stretch film of the present invention, a method generally used conventionally can be used as it is. However, at the time of stretch packaging, the portions having no gas barrier resin core layer at both edges of the film are overlapped with and tightly adhered to the portion having the gas barrier resin core layer to wrap the packaged object. Covering is necessary to enhance the gas barrier properties of the resulting package.

The gas-barrier laminated stretch film of the present invention is also applied to a stretch shrink wrapping which increases the tightness of the wrapping body by being stretch-wrapped and then passed through a heat shrink tunnel to be thermally shrunk. It can be used.

[0014]

The gas barrier laminated stretch film of the present invention has no gas barrier resin core layer other than polyvinylidene chloride at both edges, so that the stiffness of the portion is weak and the stretch film required as a stretch film is not used. Has a waist. In addition, this part is necessary for covering the films in close contact with each other in stretch packaging. Therefore, the stretch film of the present invention can perform good stretch packaging even when a strong gas barrier resin such as an ethylene-vinyl acetate copolymer is used.

Further, since the self-adhesive resin surface layer is provided on both sides of the gas barrier resin core layer, even if pinholes are formed in the gas barrier resin core layer, the gas barrier property is significantly reduced. Does not occur. Furthermore,
By forming a resin layer having a gas barrier property by laminating resins having different gas barrier properties, it is possible to have an optimum gas barrier property for various gases required by the packaged object.

[0016]

The gas barrier laminate stretch film of the present invention is a film excellent in gas barrier properties and also excellent in adhesion required for stretch packaging. In addition, there is no generation of toxic gas which causes environmental destruction even if incinerated after use.

[Brief description of the drawings]

FIG. 1 is a perspective view of a gas-barrier laminated stretch film of the present invention.

FIG. 2 is a sectional view taken along line a-a 'of FIG.

FIG. 3 is a cross-sectional view of a gas barrier laminated stretch film in which a self-adhesive resin surface layer on both sides is a laminate with an adhesive resin layer.

FIG. 4 is a cross-sectional view of a gas-barrier laminated stretch film in which a gas-barrier resin core layer is a laminate.

[Explanation of symbols]

1.1 '. Self-adhesive resin surface layer 2.2 '. 2. Edge of self-adhesive resin surface layer Gas barrier resin core layer other than polyvinylidene chloride 4.4 '. 4. An adhesive resin layer having adhesiveness to both the self-adhesive resin surface layer and the gas barrier resin core layer other than polyvinylidene chloride. Gas barrier resin layer 6.6 '. Other gas barrier resin layers L '. Distance from the edge of the self-adhesive resin surface layer to the edge of the gas barrier resin core layer

Continued on the front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical display location B32B 27/36 B32B 27/36 B65D 65/40 B65D 65/40 A

Claims (4)

(57) [Scope of request for utility model registration] 1. A self-adhesive resin surface layer (1) having a predetermined width,
(1 ′) the self-adhesive resin surface layer (1) during
(1 ′) A gas barrier resin core layer (3) other than polyvinylidene chloride having a smaller width than the self-adhesive resin surface layer (1), from both ends (2) and (2 ′) of the (1 ′). A gas-barrier laminated stretch film sandwiched at intervals (L) and (L '). 2. Self-adhesive resin surface layer (1), (1 ′)
2. The gas-barrier laminated stretch film according to claim 1, wherein distances (L) and (L ') from both ends of the resin-barrier resin core layer (3) other than polyvinylidene chloride are 20 to 100 mm, respectively. 3. A gas barrier resin core layer other than polyvinylidene chloride (3) is a single layer made of a saponified ethylene-vinyl acetate copolymer, a polyamide resin, or a polyethylene terephthalate resin, or is made of such a resin. The gas-barrier laminated stretch film according to claim 1, which is a laminate. 4. Self-adhesive resin surface layer (1), (1 ′)
Is a laminate of adhesive resin layers (4) and (4 ′) having adhesiveness to both the self-adhesive resin surface layer and the gas barrier resin core layer other than polyvinylidene chloride. Gas barrier laminated stretch film.