JPS61203335A - Vessel - 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] The present invention relates to a container body constituting a can-like container such as a canned container.

[Conventional technology]

Metal cans (tin cans) have traditionally been on the market in large quantities as canning containers, but these have been on the decline in recent years. This is said to be due to the coldness of the metal that makes up cans, pollution, lack of fashionability, deterioration in the taste of food, and problems with odor.

Therefore, there is a need for containers made of other materials that do not have the above-mentioned drawbacks. BACKGROUND ART A three-dimensional container (container body) that can store contents such as food is formed by molding (sheet).

One of the conventional methods for forming a container body, which is a three-dimensional solid object, from this flat multilayer film is a method called the so-called drawing IC method. In this method, the peripheral edge of the multilayer film is clamped to a support, pressure is applied to the film from above, and the film is stretched (stretched) downward.
This is a method of forming a container body having a depth that can accommodate the contents, and is usually performed by press cold rolling.

However, since this method involves stretching a multilayer film, the thickness of the A/foil becomes uneven, and pinholes and cranking tend to occur. Therefore, it is difficult to use a thin A/foil; ~about 100 μl A/
The disadvantage is that foil must be used. This is OK even though the product cost of cans and containers is high. Also, A: Since the method involves stretching the foil, it is difficult to make a container body with a deep bottom.
Another drawback is that it can only produce shallow products.

In addition, it is difficult to make the container thicker, there are problems with shape retention, and there are many restrictions in terms of logistics.

On the other hand, as a method of making a three-dimensional container body from a flat multilayer film, there is also a method of cutting the film into appropriate sizes and connecting them with an adhesive or the like. However, when using this method, the cut surface of the film, that is, the cross section of the metal and adhesive layer comes into contact with the contents of the food, etc., which is unfavorable in terms of food hygiene, and there are also disadvantages in that retortability is poor.

The purpose of the present invention is to create a thin AI that has never been attempted before!
The object of the present invention is to provide a can-like container body having an inner layer constituted by a multilayer plastic substrate having a metal foil such as a foil, and an injection molded substantially rigid outer layer. Another object of the present invention is to substantially stretch (stretch) the above-mentioned base material.
However, if the A/ foil is stretched as described above, the A/ foil will stretch and crack, making it impossible to use a thin A/ foil.
ff3 can be used, the thickness of A/ foil can be minimized, and when A/ foil is stretched, the thickness of A/ foil becomes uneven, but this can be solved and the thickness of A/ foil can be made uniform. To provide a can-like container body that is thick, has a deep bottom, and is inexpensive to manufacture.

Another object of the present invention is to provide a can-like container body that is preferable from the viewpoint of food hygiene, in which the cut surface of the multilayer plastic substrate does not come into contact with the contents of the can.

Furthermore, the purpose of the present invention is thin AI! An object of the present invention is to provide a can-like container body that can be completely combusted as a result of using foil and can solve the problem of can pollution. Another object of the present invention is to provide a can-like container body that is highly fashionable and eliminates the drawbacks of metal cans, such as deterioration in the taste of food. A further object of the present invention is to provide a can-like container main body that can be made into a sealed container by heat-melting the lid and making a tight contact with it, can be retorted, has excellent gas barrier properties, and can withstand long-term storage. It is in.

Furthermore, an object of the present invention is to provide a practical function as a can, to prevent the container from deforming and collapsing during transportation and work (stacking of containers, etc.) as a can-like container, and to improve the shelf life of the container (gas barrier). - It is an object of the present invention to provide a can-like container body with improved sealability and sealing performance.Other objects and novel features of the present invention will become clear from the following description of the specification and drawings.

[Means for solving problems]

The present invention comprises a flat multilayer base material having at least three or more layers in which the intermediate layer is a metal foil layer and heat-meltable resin layers on both sides, and a bottom part and a trunk wall part having wrinkles formed in the vertical direction. A container body of a can-like container is characterized in that a resin layer is formed by injection molding on the outer surface of a container that is molded without substantially stretching.

〔Example〕

Next, a typical outline of the present invention will be described with reference to drawings showing embodiments thereof.

FIG. 1 shows an example perspective view of the container body (round can container body) of the present invention.

K, who will explain an example of the manufacturing method of this container body, first punch out a multilayer base material 1, the cross section of which is shown in Fig. 2, into the required size.
A disk 2 as shown in FIG. 3 is obtained.

In the multilayer base material 1, the intermediate layer 3 is a metal foil layer with a thickness of less than 40μ, and a heat-meltable resin layer 4 is laminated on one side (upper surface) of the intermediate layer 3, and a heat-meltable resin layer 4 is laminated on one side (lower surface) of the intermediate layer 3. layer 5
has.

The disc 2 is set between a male mold 8 and a female mold 9 in which vertical grooves 6 and 7 are formed, respectively, and the male mold 8 is pushed into the hollow part of the female mold 9, and the multilayer base material is By absorbing the excess portion in the vertical direction as wrinkles 10, the flange portion 11, body wall portion 12, and bottom portion 13 can be formed without substantially stretching the multilayer base material.
(Figures 4 and 5A)
figure). In this case, the respective grooves of the male mold 8 and the female mold 9 are
Preferably, they are arranged in an interlocking manner.

The container 14 is attached to the male mold part of the injection mold 15 as shown in FIG. 6, and the mold 17 having the gate 16 is clamped as shown in FIG.
When the resin 18 is injected from the gate 16 of FIG. 7, the resin layer +8 made of the injected resin and the opposing surfaces of the container 14 are welded over the entire surface, forming an integrated, rigid container body 19 as shown in FIG. 8A. It is formed. The overall external appearance of this container body 19 is as shown in FIG.

In the above, during injection, the inner surface of the container 14 is pressed against the mold 15 by the resin pressure during injection molding, and the inner surface wrinkles 10 are smoothed.

In FIG. 5, the wrinkle IO is shown by a thick line, and in FIG. 1, the wrinkle 10 is shown by a thin line, and the entire state of such smoothing is schematically shown.

This container body 19 [, a sectional view is shown in FIG. 9A, and 1i9B
As shown in the overall external view in the figure, the lid body 20 can be attached by heat sealing or the like and used as a closed container 21.

In addition, in FIG. 9B, the lid body 20 is partially protruded from the flange portion to form a drop-lid type round can container that can be easily opened.

In addition, in order to ensure heat sealability, a multilayer base material part 14' and an injection resin part 18' are provided in the flange of the container body, as shown in FIG. 8B, so that two types of heat sealing can be performed at the same time. As shown in FIG. 9C, a lid 20 can be attached to the container body 19/ having such a flange structure by heat sealing or the like, and the container can be used as a container 21' with an even higher sealing function. I can do it.

By the way, in the above example, a round can container [container body] was illustrated, but the present invention is also applicable to a square can container body 211 etc. as shown in FIG. May be applied to

Although the square can container body 21' is illustrated as having a square shape in FIG. 10, it may have a shape other than squares, such as a diagonal or hexagonal shape.

Next, to explain the materials constituting the container body of the present invention, the multilayer base material 1t and the constituting metal foil 3 can be made of various metal materials, but for the purpose of the present invention, A/ Foil is exemplified as a typical example.

The thickness of the metal foil 3 should be less than 100μ.

However, since the present invention does not undergo a stretching process, the thickness of the multilayer base material, especially the metal foil, is uniform from beginning to end, and thin-walled materials can also be used.
It is preferably less than μ.

For example, the container body can be made of an extremely thin material with a thickness of 7 μm.

Various resins can be used as the resin constituting the heat-meltable resin layer 4.5 of the multilayer base material 1, but synthetic resins such as high temperature,
Polyolefins such as ethylene propylene copolymer have excellent heat resistance, oil resistance, and heat sealability required for high-pressure retort sterilization, and there is no migration of plasticizers or stabilizers from the resin into the food. Synthetic resins are exemplified.

Various types of resins can be used for the injection resin 18 (18'), but examples include synthetic resins such as polyolefin synthetic resins such as polypropylene and ethylene polypropylene copolymer, which have excellent heat resistance against high temperatures during retort sterilization. be done.

In the present invention, an inorganic filler may be mixed with the injection resin. Mixing an inorganic filler has the following advantages.

■ Improved dimensional stability of can-like containers (can-like container bodies),
This is advantageous because the shrinkage rate decreases.

■ Improved heat resistance and increased heat distortion temperature, which is advantageous for retorting.

■ Burned calories are reduced and combustion furnaces are not damaged, which is advantageous in terms of pollution prevention.

■ It can provide rigidity, which is advantageous for product distribution.

■ Good heat conduction, which is advantageous for retorting.

■ Cost) k can be reduced.

As the inorganic filler, any filler that is widely used in the fields of synthetic resins and rubbers may be used. These inorganic fillers are preferably inorganic compounds that have good food hygiene properties, do not react with oxygen and water, and do not decompose during kneading and molding. Examples of inorganic fillers include compounds such as metal oxides, their hydrates (hydroxides), sulfates, carbonates, and silicates;
It is broadly classified into these double salts and mixtures thereof. Typical examples of the inorganic fillers include aluminum oxide (alumina), its hydrate, calcium hydroxide, magnesium oxide (magnesia), magnesium hydroxide, zinc oxide (zinc white), red lead, and lead white. oxide, magnesium carbonate, calcium carbonate, basic magnesium carbonate, white carbon, asbestos, mica, talc,
Glass heating fiber, glass powder, glass peas, clay, diatomaceous earth, silica, wollastonite, iron oxide, antimony oxide, titanium oxide (titania), lithopone, pumice powder, aluminum sulfate (gypsum, etc.), silica zirconium,
Examples include zirconium oxide, barium carbonate, dolomite, molybdenum disulfide and iron sand. Among these inorganic light-emitting agents, those in powder form are preferably those having a diameter of 20 μm or less (preferably 10 μm or less).

In addition, in the case of a fibrous material, the diameter is 15500 microns (preferably 1 to 300 microns) and the length is 0.1 to 61 microns.
11 m (preferably 0.1-5 Ill) is desirable. Furthermore, the flat filler preferably has a diameter of 30 μm or less (preferably 10 μm or less). Among these inorganic fillers, flat (flake-like) and powdered fillers are particularly preferred. It is.

Other various additives may be added to the injection resin.

Next, the lid body 20 (20') when forming a sealed container
As an example, the intermediate layer is a metal foil, and the injection resin 1 of the container body 19 (197) is placed on one side of the metal foil (container body side).
8 (18') or one of the resin layers 4 of the multilayer base material 1, and has a resin layer that can be peeled off when used from the container body. It will be done.

The metal foil can be the same as the metal foil 3, and A
/7f3 is exemplified. Further, as the resin constituting the resin layer, it is preferable to use, for example, an olefin-based synthetic resin such as ethylene propylene copolymer, which has excellent heat resistance during retort sterilization.

A preferable example of the lid 20 (20') includes a metal foil as the intermediate layer, the polyolefin synthetic resin layer on one side (container body attachment side), and the other side IIIki (
For example, there is a sandwich structure having a resin layer made of polyester on the outer surface.

In addition, as the lid body 20 (2G), Japanese Patent Application No. 58-90750 and Japanese Patent Application No. 58-104 filed by the present applicant are available.
No. 185 and Japanese Patent Application No. 59-146943, No. 59-1
For example, an easy-open container St as shown in FIG. 11 in a plan view and in FIG.

This container lid 22 is made by, for example, injecting a resin 24 similar to the resin 18 onto a base material 23 having a structure similar to that of the multilayer base material 1, and then forming an opening part 26 through a cutout part 25. The outer peripheral part 27 is separated from the outer peripheral part 27, and a treated layer 2 is applied to the whole or part of the part where the back surface of the pull-top part 28 and the surface of the base material 23 are in contact with each other, for the purpose of making the pull-top part easily removable.
9 is formed, and by inserting a finger into the groove 30 and lifting the pull-top part 28, the pull-top part 28 is easily peeled off from the base material 23, and the pull-top part 28 is wedged inward at the position 31, and the pull-top part 28 is inserted into the base material. A hole is made in 23 along the notch 25 so that the container lid can be easily opened.

In the present invention, as shown in FIG.
It is also possible to fold only a part of the extra υ part 52-t-corner to form a square can container main body container.

〔Effect of the invention〕

(1) According to the present invention, as shown in FIG. 4, a multilayer base material is set between male and female molds, and the multilayer base material is slid into the hollow part of one of the molds. Unlike processing, a flat multilayer base material is made into a three-dimensional container without substantially stretching, so it is possible to produce multilayer plastics with metal foils such as Al foils, which are thinner than 40μ, which has never been tried before. It was possible to provide a container body made of a base material.

That is, in the case of conventional stretching, pinholes and cracks occur when thin KL foil is used, but according to the present invention, such problems do not occur and it is possible to use thin A/2 foil, and the thickness of A/2 foil can be reduced. I was able to make it the smallest.

Moreover, when using A/q stretching, A/K5
However, according to the present invention, a container main body having a metal foil (A/foil) with a uniform thickness could be obtained.

As a result, the metal foil, which accounts for a large amount of weight when using a multilayer base material, can be regulated to the minimum thickness at the required level of barrier properties, and the manufacturing cost can also be reduced. Furthermore, as a result of being able to use thin A/foil, complete combustion was possible and ink pollution could be eliminated during can pollution.

(2) According to the present invention, when making a three-dimensional container from a flat multilayer base material, there is inevitably a surplus, but this can be used as wrinkles (folds, wrinkles) as it is.
The container to be wrinkled is transferred to injection molding. Therefore, there is virtually no need to stretch the multilayer base material, and the wrinkles are pressed against the mold surface by the injection resin pressure, so uneven wrinkles inside the container are flattened, and convex wrinkles are flattened. is crushed and smoothed. By injecting such resin, the cut surface does not come into contact with the contents of the can, unlike the conventional case where the film is cut to an appropriate size and then connected with adhesive to form the container body. In addition, since injection molding is used, the injected resin comes into close contact with the outer surface of the container, making it an integral part, resulting in a container body with high strength. It can prevent deformation, crushing, etc. during transportation and work (such as stacking containers), and has practical functional properties.Also, due to its strong adhesion, retort processing is possible.

(3) The container main body of the present invention has good heat-sealability because the polyolefin synthetic resin is present on the outer surface (and a lid made of an appropriate material can be easily attached by heat-sealing, etc., making it possible to form a closed container. , retort processing is possible,
It also has good gas barrier properties and can be used in a wide range of applications, such as can-like containers that can withstand long-term storage, such as cans, soup cans, and various beverage cans.

(4) According to the present invention, since the surface of the multilayer base material is a resin layer, it is possible to provide a can-like container body that eliminates the drawbacks of metal cans, such as deterioration in the taste of foods.

Furthermore, it can be made more fashionable by selecting various resins and designs.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a container body showing an embodiment of the present invention;
The figure is a sectional view showing an example of the structure of the multilayer base material used in the present invention, FIG. 3 is a perspective view of the same multilayer base material (disk), and FIG. 4 is an explanatory diagram of the container forming process according to the present invention. FIG. 5 is a perspective view of a container having wrinkles according to the present invention, FIG. 6 is a diagram of the container being attached to a mold, and FIG. 7 is an explanatory diagram of the injection process.
8A and 88 are cross-sectional views of a container body showing an embodiment of the present invention, FIG. 9A is a cross-sectional view of a lid attached to the container body, and FIG. 9B is a perspective view of a round can container that can be opened easily. Figure 390 is a cross-sectional view of the container body with a lid added;
10 is a perspective view of a container showing another embodiment of the present invention, FIG. 11 is a plan view showing another example of the lid, FIG. 12 is a sectional view taken along the line x-x' in FIG. 11, and FIG. The figure is a perspective view showing a modification of the present invention. 1... Multilayer base material 3... Metal foil layer 4... Resin layer 5... Resin layer 10... Wrinkle 11... Flange portion 12... Trunk wall portion 13... Bottom portion 14 .14I... Container 18.18/... Injection resin 19.19'... Container body 20.20'... Lid Patent applicant Showa Denko K.K. Representative Patent Attorney Yoshihiro Sato No. 1 Figure 10 Figure 8B Figure 9C Figure 11 Figure 12

Claims (1)

[Claims] Substantially stretching a bottom part and a trunk wall part having wrinkles formed in the longitudinal direction from a flat multilayer base material having at least three or more layers in which the intermediate layer is a metal foil layer and heat-meltable resin layers on both sides. A container body of a can-like container characterized in that a resin layer is formed by injection molding on the outer surface of the container, which is molded without molding.