JPS5832926Y2 - Heat sealable lid material - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a heat-sealable lid material for a cup or container made of paper, plastic, aluminum foil, or a laminate thereof.

In recent years, with the spread of instant foods, there has been an increase in the number of types of packaging in which foods are enclosed in paper containers, simple plastic containers, or composite containers made of composite materials such as paper, aluminum foil, and plastic films for commercial sale. .

Also known are thermoplastic resin bottles filled with milk, lactic acid bacteria drinks, juices, pepper oil, sauces, etc.

Since the contents of these containers are food, if the lids of these containers are not properly closed, there are problems such as leakage, loss of flavor due to oxygen and moisture in the air, and deterioration of quality.

Thirdly, complete sealing performance with strong adhesion is required.

Conventionally, as this type of lid material, aluminum foil coated with a hot melt adhesive has been used for sealing the mouth of a thermoplastic resin bottle.

However, since the bottle is made of thermoplastic resin, the hot melt adhesive for the lever needs to be thermally bonded at about 70 to 110 degrees Celsius, and as a result, hot melt adhesive mainly composed of ethylene copolymer and wax agent was used.

However, this hot melt adhesive lacks adhesion to aluminum foil, so first an ethylene film with a good adhesive undercoat is applied to the aluminum foil surface, an ethylene film is laminated on that surface, and the desired The method required a large number of steps to coat the parts with hot melt adhesive, resulting in a multi-layered structure with three layers of adhesive alone.

This type of lid material is not only expensive due to its multilayer structure, but also because some of the copolymers of this type of hot melt adhesive are questionable in terms of food hygiene. It is considered undesirable to use it in direct contact with food.

The inventors of the present invention have conducted various studies to solve the above-mentioned problems, and have discovered that good results can be obtained by layering wax on 11-inch oil, which has thermal fusion properties with wax, and have developed the present invention. completed.

The present invention will be explained below with reference to the drawings.

In the present invention, as shown in FIG. 1, two layers of heat-fusible resin with wax are formed on aluminum foil 1 as a base material, and wax 3 is formed on the upper surface of the resin 2.

As shown in FIGS. 2 and 3, the base material is made by laminating paper 4 or plastic film 5 and paper 4 on aluminum foil 1, and printing 6 on the top surface as necessary.
Furthermore, as shown in FIG. 4, various configurations may be used, such as forming seven layers of thermosetting resin on aluminum foil 1, and the adhesive layer is applied to one surface of the aluminum foil of these base materials to obtain the lid material of the present invention.

When the lid material of this invention is constructed in this way and is heated under pressure, the wax fuses with the heat-fusible resin and the wax instantly transforms into a strong adhesive with high viscosity, making it easy to attach to containers and bottles. Strongly heat adhere to the mouth.

To explain specifically the thermal fusion that transforms into a strong adhesive,
The wax with a low melting point starts to melt first, and most of the part that is in contact with the mouth adhesive part is removed from the adhesive part by applying pressure.

The small amount of wax that is in contact with the surface of the thermoplastic heat-fusible resin layer is thermally fused, turning it into a strong adhesive with high viscosity, which is unattainable with conventional hot-melt adhesives. adhesive can be created instantly.

Note that when pressurized and heated, no pressure is applied to the parts of the lid that do not touch the mouth of the container, so the resin and wax do not fuse and remain in their original structure.

FIG. 5 shows the state when the lid material is adhered to the container.

In the figure, 8 indicates a container, and A indicates a heat fusion part. In the present invention, examples of resins that can be thermally fused with wax include olefin resins, acrylic resins, polyvinyl chloride, polyvinyl acetate, ionomer resins, polyamide resins, and copolymers thereof.

Further, as the wax, ordinary wax or microwax is used, and these can be used in pure form.

The heat fusible resin layer is not particularly limited, but preferably has a thickness of about 3 to 5 microns.

Similarly, the wax layer is preferably 20-30 microns.

In the present invention, the thermofusible resin can be appropriately selected, and the temperature during thermal bonding can be selected from a wide range depending on the pressure, time, equipment, etc.
40-180°C is preferred.

The lid material of the present invention has the advantage of being waterproof, moisture-proof, and hygienic since the surface that comes into contact with food is covered with wax.

Further, as shown in FIG. 5, since the wax 3 is bonded to the wall of the container 8 in a raised manner, the sealing effect is enhanced, and the seal at the opening is more complete, which has many advantages.

[Brief explanation of drawings]

FIG. 1 is an enlarged sectional view of the lid material of the present invention, and FIGS. 2, 3, and 4 are enlarged sectional views showing other embodiments of the lid material of the present invention.
FIG. 5 is an explanatory diagram showing the state of the lid material of the present invention when it is adhered. In the figure, 1... aluminum foil, 2... thermofusible resin, 3... wax, 4... paper, 5... plastic Film, 7...
・Thermosetting resin, 8... Represents a container.

Claims (1)

[Scope of utility model registration request] A resin layer that is heat-fusible to wax is formed on the aluminum foil surface of a base material made of aluminum foil or aluminum foil laminated with paper or plastic film. A heat-sealable lid material that is heat-fused to form a strong adhesive.