JPS5931460B2 - multilayer container - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a multilayer container that has excellent gas barrier properties and easy incineration properties, and also has excellent squeeze properties.

BACKGROUND ART Conventionally, aluminum tubes or glass bottles have been used as containers for contents such as line drawing brushes, cosmetic creams, and other fragrances, and high-viscosity liquids that are susceptible to deterioration.

In addition, tubes made of laminated materials laminated with various films were used, but in the case of aluminum,
Although it has excellent barrier properties, it is weak against bending when squeezed.
Cracks tend to occur, and deformation during transportation was prevented by wrapping the product in paper cartons or the like. In comparison, although the above-mentioned problems can be solved using a single polyethylene tube, the gas barrier property is insufficient and it cannot be used for these contents. Laminated tubes are made by combining aluminum foil, paper, and polyethylene, but their uses are limited because they require large equipment and cannot be mass-produced, and the shape of the container is restricted. The present invention solves these problems and provides a multilayer container that has excellent barrier properties, squeezability, and easy processing properties, and allows for various container shapes.
In particular, the object is to obtain a tubular container. The present invention will be explained in detail below.

In the container of the present invention, the outer layer is made of a resin with excellent gas barrier properties consisting of either a saponified ethylene-vinyl acetate copolymer having an ethylene content of 25 to 50 mol% and a degree of saponification of 96% or more, or nylon.

Preferably, the outer layer is 0.5 to 30% by weight of the total weight. The middle layer contains 5 to 50% of nonflammable inorganic materials such as aluminum hydroxide, calcium carbonate, and magnesium hydroxide hydrate.
It consists of polyolefins modified with 50% by weight of unsaturated carboxylic acids or derivatives thereof.

Examples of monomers used in the polyolefin to be modified include maleic acid fumarate, itaconic acid, maleic anhydride, fumaric anhydride, itaconic anhydride, monoethyl maleate, and monomethyl fumarate. Magnesium hydroxide hydrate and magnesium hydroxide are preferable when the contents are used for foods, toothpaste, and other items that are ingested in the mouth.

For other uses, calcium carbonate and gypsum are preferred. Furthermore, since a modified polyolefin such as maleic anhydride-modified low-density polyethylene or maleic anhydride polypropylene is used for the intermediate layer, nonflammable inorganic components are well dispersed.

This intermediate layer is in the range of 30-90% of the container weight, preferably in the range of 50-90%. Unlike ordinary polyolefins such as polyethylene, this nonflammable inorganic content-containing polyolefin has low recovery properties when squeezed, so it is possible to extrude the contents to the end.

In addition, auxiliary agents that enhance the fusion between the polyolefin intermediate layer and the inner and outer layers and the elasticity of the parison, such as saponified ethylene monovinyl acetate copolymer, ionomer resin, ethylene monovinyl acetate copolymer, or ethylene-ethyl One type of acrylate copolymer may also be added.

This loading is preferably in the range 1 to 20% by weight. The inner layer is preferably an ionomer resin having a melt index (MI) of 1.0 or less.

Claims (1)

[Scope of Claims] 1. A multilayer container in which the outer layer is made of a saponified ethylene-vinyl acetate copolymer or nylon, the middle layer is made of polyolefins containing a nonflammable inorganic substance and necessary additives, and the inner layer is made of an ionomer resin. 2 The weight ratio of the outer layer, middle layer, and inner layer is 0.5 to 30, 9
2. The multilayer container according to claim 1, wherein the particle size is in the range of 0 to 20 and 0.5 to 40. 3. Claims 1 and 2 in which the intermediate layer is made of polyolefins modified with an unsaturated carboxylic acid or a derivative thereof containing 5 to 50% by weight of nonflammable inorganic substances such as aluminum hydroxide and calcium carbonate. Multilayer container as described. 4 The middle layer is a saponified ethylene-vinyl acetate copolymer,
Claims 1 and 3 contain 1 to 20% by weight of any one of ionomer resin, ethylene-vinyl acetate copolymer, or ethylene-ethyl acrylate copolymer and a nonflammable inorganic component. Multilayer container as described.