JPH0221226Y2 - - Google Patents

Description

[Detailed Description of the Invention] A. Field of Industrial Application The present invention relates to a laminate material for extruded tubes of toothpaste and the like.

B. Prior Art Conventionally, it has been common practice to form extruded tube bodies for containing fluid substances such as toothpaste, cosmetics, and foods from a laminated material of metal foil and synthetic resin layers.

Normally, in this laminated material, the synthetic resin layer on the inner surface of the tube is required to have sufficient barrier properties for the contained material and adhesion to metal foil, and also to have heat sealability from the tube molding. As shown in Japanese Utility Model Publication No. 54-22770, for example, a method that satisfies this condition is to laminate polyethylene resin, ionomer resin, or polyethylene resin on one side of metal foil, and to Laminated materials with a decorative protective layer on one side are known.

C. Problems to be solved by the invention When polyethylene resin, ionomer resin, and polyethylene resin are sequentially laminated on one side of the metal foil described above, the metal foil and polyethylene resin are not bonded well unless a suitable anchor coating agent is used. In addition, although relatively uniform adhesion is possible between polyethylene resin and ionomer resin, the adhesion strength is still not sufficient, and the polyethylene resin layer There was a problem in that the alcohol component in the penetrating contents often caused delamination, and this caused stress cracks in the ionomer resin layer.

D. Means for solving the problems In order to solve the above-mentioned problems when an ionomer resin sandwiched with a polyethylene resin layer is provided on one side of the metal foil, the present invention aims to directly apply ethylene under specific conditions to one side of the metal foil. - After laminating the carboxylic acid copolymer resin layer, a polyolefin resin outer layer is provided to obtain a laminated material with high interlayer adhesion strength and excellent barrier properties.

In other words, the laminated material of the present invention has a carboxylic acid content on one side of the metal foil 1, as shown in the cross-sectional view of the drawing.
The first layer 2 is an ethylene/carboxylic acid copolymer resin with a melt index (hereinafter referred to as MI) of 20 to 50% by weight and a melt index (hereinafter referred to as MI) of 100 to 500, and the second layer is a carboxylic acid copolymer resin with a carboxylic acid content of
A second layer 3 of ethylene-carboxylic acid copolymer resin with a carboxylic acid content of 2-9% by weight and an MI of 1-7. This is a laminated material for extruded tubes in which a third layer 4 of polymeric resin is laminated in sequence, and then a polyolefin resin outer layer 5 is provided, and an appropriate decorative protective layer 6 is provided on the other side of metal foil 1. .

In the above, the metal foil is generally 7~
100μ thick aluminum foil is preferably used, but other metal foils can also be used.

As the ethylene/carboxylic acid copolymer resin, it is preferable to use acrylic acid or methacrylic acid as the carboxylic acid component.
It adheres strongly to metal foil, has particularly excellent barrier properties, and has a carboxylic acid content of 2 to 9.
Those having an MI of 1 to 7 in weight percent have strong adhesion to polyethylene resin and have sufficient flexibility. By interposing an intermediate layer with a carboxylic acid content of 10 to 19% by weight and an MI of 8 to 99, the ethylene/carboxylic acid copolymer resin layer is strongly integrated as a whole, and the barrier layer is is formed. Usually, this ethylene/carboxylic acid copolymer resin layer has a total thickness of 10 to 100μ.
The thickness of each layer may be appropriately adjusted so as to increase the thickness, but if the copolymer resin layer with a high carboxylic acid content is thick as a whole, rigidity will be obtained, and if it is small, the layer will be flexible. These layers are made using extrusion coating method,
It can be formed by a film lamination method, a liquid coating method, or the like.

As the polyolefin resin for the outer layer, polyethylene or polypropylene can be used, but particularly preferred is a polyethylene resin with MI2 to 12 and a density of 0.915 to 0.945, and the resin layer can be formed by extrusion coating,
It is preferable to form a layer with a thickness of 10 to 100 μm by a film lamination method.

Note that the decorative protective layer provided on the other side of the metal foil may have any layer structure, such as one in which paper, a printing base layer, a printed pattern, and a transparent protective layer are sequentially laminated via an adhesive, Alternatively, it may simply consist of a colored resin layer, but if the tube is to be molded by heat sealing, the surface layer must be made of a heat sealing material suitable for this purpose.

E. Effect As mentioned above, the laminated material of the present invention has an ethylene/carboxylic acid copolymer resin layer firmly adhered directly to one side of the metal foil, and an ethylene/carboxylic acid copolymer resin layer firmly adhered to the outer polyolefin resin layer. but,
Since the resin layer is strongly bonded and integrated with the intermediate ethylene/carboxylic acid copolymer resin layer, it has sufficient barrier properties against highly permeable substances, and has excellent stress cracking properties for durability. It is possible to obtain extruded tubes with great properties.

F. Example A coating solution where ethylene/acrylic acid copolymer resin powder with an acrylic acid content of 20% by weight and MI2600 was partially saponified with sodium hydroxide to form an emulsion on the foil surface of an aluminum foil with paper etc. pasted on one side in advance. was roll coated, dried at 120℃ and melted to form a 0.2μ thick ethylene film.
Provides a film of partially saponified acrylic acid copolymer,
On top of this, an ethylene/acrylic acid copolymer resin with an acrylic acid content of 9% by weight and an MI10 is extrusion coated to a thickness of 20 μm, and on top of this, an ethylene/acrylic acid copolymer resin with an acrylic acid content of 7% by weight and an MI5 is extrusion coated. Extrusion coat polymer resin to a thickness of 30μ,
After forming the ethylene/acrylic acid copolymer resin layer, 40μ of polyethylene resin with MI6.5 and density 0.916 is applied.
A laminate was obtained by extrusion coating to a thick layer.

When the peel strength between each layer of this laminate was measured, none of the layers could be peeled off.

This laminated material is made into a tube, a polyethylene mouth mold body with a screw cap is attached to make an extruded tube, and this is filled with a toothpaste containing an alcohol component such as menthol or other permeable material.
A specified test was conducted at 50℃ for 3 months, but there was no delamination between the layers.
Cracks were not allowed at all. Furthermore, the test was conducted for a period of 6 months, but no abnormalities were found.

On the other hand, when a similar test was conducted on a conventional product with an ionomer resin layer, no problems occurred after 3 months, but in a 6-month test, peeling occurred between the ionomer resin layer and the polyethylene resin layer, and the ionomer resin layer A stress crack occurred.

G. Effects of the invention As explained above, the laminated material of the invention can be used for toothpaste, cosmetics, fragrances, etc. containing penetrating agents.
A durable extruded tube suitable as a food or other container can be obtained.

[Brief explanation of the drawing]

The drawing is a cross-sectional view of the laminate for extruded tubes of the present invention. 1...Metal foil, 2...First layer of ethylene/carboxylic acid copolymer resin, 3...Second layer of ethylene/carboxylic acid copolymer resin, 4...Third layer of ethylene/carboxylic acid copolymer resin , 5... Polyolefin resin outer layer, 6... Makeup protective layer.

Claims (1)

[Scope of utility model registration request] On one side of the metal foil, an ethylene/carboxylic acid copolymer resin layer with a carboxylic acid content of 20 to 50% by weight and an MI of 100 to 5000, followed by an ethylene/carboxylic acid copolymer resin layer with a carboxylic acid content of 10 to 19% by weight and an MI of 8 to 99. An ethylene/carboxylic acid copolymer resin layer with a carboxylic acid content of 2 to 9% by weight and an MI of 1 to 7, followed by an outer polyolefin resin layer. A laminate material for extruded tubes having a structure and having a suitable decorative protective layer on the other side of the metal foil.