Heat-Shrinkable Laminated Film, Molded Product and Heat-Shrinkable Label Employing the Film, and Container

Abstract

The present invention provides a heat-shrinkable laminated film, which exhibits excellent film rigidity, shrink finishing quality, transparency of the recycled film, and a small natural shrinkage, with suppressed film interlayer peeling and shrinking stress, and which is applicable to shrinkable packing, shrinkable bond-packing, shrinkable label and the like. The heat-shrinkable laminated film comprises: a surface layer (S layer) composed of a polyester series resin composition containing a polyvalent carboxylic acid residue and a polyvalent alcohol residue; a middle layer (M layer) composed of a styrene series resin composition; and an adhesive layer (AD layer) which contains a copolymer of styrene series hydrocarbon and a conjugated dienic hydrocarbon or hydrogenated derivatives thereof, and having a styrene series hydrocarbon content rate to the entire copolymer or hydrogenated derivatives is 5˜40 mass % or less. An elongation modulus of the film in a direction perpendicular to a main shrinking direction of the film is 1200 MPa or more, and a shrinking stress in the main shrinking direction of the film is 8 MPa or less or a rupture elongation at 23° C. is 40% or more.

Description

TECHNICAL FIELD [0001] The present invention relates to a heat-shrinkable laminated film, a molded product and a heat-shrinkable label employing the film, and a container. More particularly, the present invention related to a heat-shrinkable laminated film, which exhibits excellent shrink finishing quality, film rigidity (stiffness at room temperature), transparency at a time of addition as a reclamation material, and a small natural shrinkage and reduction of mechanical strength over time, with suppressed film interlayer peeling and shrinking stress, and which is applicable to shrinkable packing, shrinkable bond-packing, shrinkable label and the like, and a molded product and a heat-shrinkable label employing the film, and a container. BACKGROUND ART [0002] These days, soft drinks such as juice are sold in a form that the drink is filled in containers such as glass bottles or SET (polyethylene terephthalate) bottles. When the drinks are on sale, in order to differentiate the goods ...

AI Technical Summary

Benefits of technology

[0025] According to the present invention, a heat-shrinkable laminated film, which exhibits excellent shrink finishing quality, film rigidity (stiffness at room temperature), transparency at a time of addition of a reclamation material, and a small natural shrinkage and reduction of mechanical strength over time, with suppressed film interlayer peeling and shrinking stress, and which is applicable to shrinkable packing, shrinkable bond-packing, shrinkable label and the like, can be provided.

[0026] Further, according to the invention, a molded product and a heat-shrinkable label, which has sufficient film rigidity, exhibits excellent shrink finishing quality and transparency at a time of addition of a reclamation material, and a small reduction of mechanical strength over time, and which is applicable to shrinkable packing, shrinkable bond-packing, shrinkable label and the like, can be provided. Moreover, according to the invention, a container to which products can be adhesively fixed with desired shrinking stress at a desired position no matter what kind of shape the fitting product is, and on which a transparent and clear-looking the above molded product or the heat-shrinkable label is fitted without having any troubles such as occurrence of wrinkles, pocks, and insufficient shrinking, is provided.

Problems solved by technology

Among the above materials, polyvinyl chloride series heat-shrinkable film has problems such as lack of heat resistance and emission of hazardous gas like hydrogen chloride when it is burnt after its use.

However, the polystyrene series heat-shrinkable film also exhibits large natural shrinkage and low film rigidity (i.e. stiffness at room temperature), this film causes problems such as fitting defect due to the label bending during the label fitting process.

However, the shrink finishing quality of polyester series heat-shrinkable film is not as good as that of polyvinyl chloride series film (in other words, when the film is fitted as a label onto a container, by heat shrinkage, spots and wrinkles can be easily occurred.

), and this film causes problems such as significant drop of its mechanical strength over time.

Among the problems, embrittlement of the film over time tends to be caused when the film is stored for long term under an atmosphere of relatively high temperature, particularly at 30° C. or more.

However, since shrinking stress of these heat-shrinkable films is not sufficiently reduced, the shrink finishing quality of both films is not as good as that of styrene series heat-shrinkable film.

Therefore, the above films have a problem that reduction of the mechanical strength thereof over time becomes remarkable.

Nevertheless, this shrinkable label has a problem in insufficient interlayer adhesion, thus, in secondary fabrication, interlayer peeling can be easily caused at a time of printing.

However, this film has a lack of compatibility between the block copolymer of vinyl aromatic hydrocarbon and the conjugated dien derivatives for inner layer and an ethylene-vinyl acetate copolymer for the adhesive layer.

When recycled resin obtained by trimming loss like heels of films and the like is added (hereinafter, refer to “addition of a reclamation material”), there is a problem that transparency of the entire film tends to become poor.

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