JPS6219449A - Sheet for molding and molding vessel using said sheet - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a sheet used for making containers by vacuum or pressure forming, and a molded container made from the sheet.

C. Prior art and its problems] Vacuum or pressure forming is a method in which a thermoplastic synthetic resin sheet is heated and softened, and then molded along the inside of a mold by the action of vacuum pressure or pressurized air. It is known as a method that allows efficient molding into any shape without using a large press machine.

However, according to this method, the raw material sheet must have sufficient plasticity during molding, so it was believed that thin aluminum foil could not be used because it would break or tear. Therefore, when using molded containers made by this method for packaging tableware, medicine, etc., in order to provide barrier properties, it is necessary to laminate a synthetic resin such as polyvinylidene chloride or polyvinyl alcohol with another thermoplastic synthetic resin. Various methods have been adopted, such as coating the container with a solid body, applying metal vapor deposition, or mixing various pigments and fillers, but none of these methods have yielded a container with sufficient barrier properties, especially good barrier properties against light. do not have.

[Problem of invention]

Therefore, an object of the present invention is to provide a sheet for vacuum or pressure forming using aluminum foil that has sufficient barrier properties against moisture, light, humidity, air, and other gases, and a container formed from the sheet. It is.

[Means of problem solving]

In order to solve the above problems, in the present invention, a base material having barrier properties is formed by laminating a heat-shrinkable synthetic resin film on at least one side of an aluminum foil through an intermittent adhesive layer. After heat-shrinking the material, a sheet was formed by providing a thermoplastic synthetic resin layer on at least one side of the base material alone or in composite form.

Further, this sheet was vacuum- or pressure-formed to form a container having a bottom wall and a peripheral wall surrounding the bottom wall.

[Effect]

As mentioned above, when the base material is heat-shrinked, many fine wrinkles are generated in the aluminum foil due to the shrinkage of the heat-shrinkable synthetic resin film. However, the aluminum foil absorbs this spreading through its wrinkles and no breaks or tears occur.

〔Example〕

First, the base material having barrier properties will be explained based on FIGS. 1 to 7.

As shown in FIG. 1, a base material 1 is attached to an aluminum foil 2.
A heat-shrinkable synthetic resin film 4 is applied via an intermittent adhesive layer 3.
It is a layered structure.

The heat-shrinkable synthetic resin film 4 is polyethylene-based,
It is preferable to use a resin made of polypropylene, vinyl chloride, etc., which has a shrinkage rate as high as possible, for example, about 50%.The film 4 may be a single film or a laminate of two or more films. There may be.

The intermittent adhesion layer 3 consists of an aluminum foil 2 and a film 4.
In addition to adhesives, heat fusion or ultrasonic fusion may be used by utilizing the properties of the film 4. The pattern of this adhesive layer 3 may be It may be linear as shown in Figure 2 (A), dotted as shown in (B), or grid-like as shown in (C), etc. The point is that the intermittent portions 5 are present without being provided on the entire surface. Any pattern is fine.

As shown in FIG. 3, the heat-shrinkable synthetic resin film 4
may be bonded to both sides of the aluminum foil 2, or a printed or colored layer 6 may be provided on the surface of the aluminum foil 2, as shown in FIG. Furthermore, as shown in FIG. 5, a plurality of aluminum foils 2 may be bonded together.

In the figure, 7 is an adhesive layer.

When the base material 1 as described above is heated, the film 4 shrinks as shown in FIG. On the other hand, since the aluminum foil 2 is bonded to the film 4 via the intermittent adhesive layer 3, as the film 4 shrinks, it is pulled together at each of the intermittent portions 5, producing fine wrinkles.

As shown in FIG. 7, two sheets of the base material 1 shown in FIG. 6 may be bonded together and used as the base material. The bonding method may be any method such as extrusion lamination, heating and pressing, as well as using an adhesive. In the figure, 7' is an adhesive layer.

A thermoplastic synthetic resin layer 8 capable of being pressurized or vacuum formed was provided on one side of the base material 1 having fine wrinkles in this way, and a contoured forming sheet 10 shown in FIG. 7 was formed.

To laminate the base material 1 and the resin layer 8, in addition to extrusion, heat-pressing, etc., an adhesive described later may be used.

As shown in FIG. 8, the resin N8 may be provided on both sides of the base material 1.

Further, as shown in FIG. 9, the resin layer 8 may be a laminate of two types of synthetic resins N8' and 8''.

Of course, a laminate of 27i or more can also be used. In addition,
9.9 in the figure is an adhesive layer for bonding the base material 1 and the resin layer 8. In this case, if the adhesive surface of the base material 1 and the adhesive surface of the resin layer 8 are vinyl-based, a vinyl-based or urethane-based adhesive can be used, and if the adhesive surface is polypropylene-based, for example, a polyurethane-based adhesive can be used. preferable. In both cases, it is preferable to use an adhesive that provides strong adhesion and retains some degree of thermoplasticity.

When the molding sheet thus obtained is subjected to vacuum or pressure forming, a molded container 20 as shown in FIG. 10 is obtained, for example. The peripheral wall 23 is a flange provided around the opening.

The shape of the container 20 may be any shape, such as a zero circle, an ellipse, or a polygon, and the flange may be formed as necessary.

More detailed examples will be described below.

Now, aluminum foils with a thickness of 7μ and 9μ were used, and a two-wheel stretched shrinkable vinyl chloride film with a thickness of 20μ was laminated on both sides using a dry lamination adhesive applied in dots, and then placed in a hot air atmosphere at 120℃. A base material is formed by shrinking the base material, and two
Vinyl chloride sheets having a thickness of 50 μm and 100 μm were bonded under heat and pressure to obtain moldable sheets.

Next, a biaxially stretched polypropylene film of the same thickness was bonded to both sides of the two types of aluminum foils of the same thickness as above in the same manner, and was shrunk in a hot air atmosphere at 140°C to form a base material. Each thick polypropylene sheet was heat-pressed to obtain a sheet for molding.

The four types of molding sheets obtained in this way were vacuum formed, and the outer diameter of the bottom was 58 mm, the inner diameter of the opening was 64 mm, and the height was 20 fi.
A circular container was created.

These containers had the same performance as general aluminum molded containers in terms of light transmittance and moisture resistance.

〔effect〕

According to this invention, as described above, a heat-shrinkable film is pasted on aluminum foil, the film is heat-shrinked, fine wrinkles are formed on the aluminum foil, and a thermoplastic synthetic resin layer is provided on this. Therefore, even if the aluminum foil is spread by vacuum or pressure forming, the wrinkles in the aluminum foil will absorb the elongation.
No breakage occurs, and therefore the excellent barrier properties of the aluminum foil are maintained, resulting in a container with extremely good barrier properties.

[Brief explanation of drawings]

1, 3 to 5 are cross-sectional views showing some examples of base materials used in the molding sheet of the present invention, FIG. 2 is a plan view showing patterns of the adhesive layer, and FIGS. Fig. 7 is a cross-sectional view showing the same base material as above which has been heat-shrinked, Figs. 8 to 10 are cross-sectional views showing some examples of molding sheets, and Fig. 11 is a cross-sectional view of a molded container. be. 1... Base material, 2... Aluminum foil,
3... Intermittent adhesive layer, 4... Heat-shrinkable synthetic resin film, 5... Intermittent portion, 8...
... thermoplastic synthetic resin layer, 10 ... molding sheet, 20 ... molded container, 21 ... bottom wall, 22 ... peripheral wall. Patent Applicant Toyo Aluminum Co., Ltd. Agent Patent Attorney Kama 1) Statement Two Procedural Amendments (Self-Regulation October 1985 7B Patent Application No. 160766 of 1985 2) Title of Invention Molding Sheet and Molding Using the Sheet Container 3, Person making the amendment Relationship to the case Patent applicant address: 1, 4-25, Minamikutabe-cho, Higashi-ku, Osaka (Part 1) Toyo Aluminum Co., Ltd. 5゜Showa Year, Month, Day (Delivery date) Added as shown in the attached sheet. Correct Contents 1. Correct "Can't come" on page 2, line 12 of the specification to "Can't do it." 2. Similarly, "Figure 7" on the 6th line of page 6 has been changed to "Figure 8", "Figure 8" on page 11100 has been changed to "Figure 9", page 13
Correct "Figure 9" in line 1 to "Figure 10" and correct "Figure 10" in line 5 of page 7 to "Figure 11." 3. Similarly, “for contraction” on page 7, line 15 is changed to “contractability”
will be corrected.

Claims (2)

[Claims] (1) A base material in which a heat-shrinkable synthetic resin film is laminated on at least one side of aluminum foil via an intermittent adhesive layer,
A sheet for molding, which is heat-shrinked and then provided with a thermoplastic synthetic resin layer on at least one side of the base material alone or in composite form. (2) In a container in which a molding sheet is formed by vacuum or pressure forming and is provided with a bottom wall and a rising peripheral wall connected to the bottom wall, the molding sheet is heat-shrinkable on at least one side of the aluminum foil through an intermittent adhesive layer. Laminated synthetic resin films,
1. A molded container comprising a heat-shrinkable base material or a composite material, and a thermoplastic synthetic resin layer provided on at least one side of the base material.