JPH05305935A - Plastic container main body and container with metal lid - Google Patents

Abstract

PURPOSE:To provide a plastic container main body with excellent aroma retaining property and storage property, and a container with metal lid using the plastic container main body. CONSTITUTION:A plastic container main body 14 has a body part 14a, bottom part 14b and flange part 15. The body part 14a and bottom part 14b are formed by injecting a heat-melting resin 28 on the external surface of a sheet blank 26. The sheet blank 26 is constituted of 3 layers such as a polybutylene terephthalate layer 31, adhesive layer 32 and polypropylene layer 33 in this order from the inside. For the heat-melting resin 28, polypropylene is used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic container body and a container with a metal lid using the same.

[0002]

2. Description of the Related Art There are various types of metal containers, such as metal cans, which can be classified into three-piece cans and two-piece cans depending on the structure of the can body. A three-piece can is also called a tin solder can, and has a structure in which a cylindrical body, a lid and a bottom are sealed by double winding. On the other hand, the two-piece can is also called a tin punch can, and the body and bottom (container body)
It has a structure in which the lid is double-wound to the integrally molded one.

These metal cans are used as food packaging containers for various food canned foods, juices, soft drinks, jams, dried foods, etc., and are rigid containers having particularly excellent sealing and storage functions. However, the metal can has the following points to be improved. That is, there is a limit to weight reduction because it is a metal can. When it receives a shock, once it is crushed, it has no restorability and will deform. The energy cost for manufacturing the plastic container is higher than that of the plastic container. In the case where the dispressing effect of the container exterior is metal, it cannot be changed freely, and the exterior means is only by printing. It is impossible to make a transparent container that allows the contents to be confirmed without opening the can.

In order to solve the above drawbacks of conventional metal cans, a container with a metal lid has been considered in which a metal lid is attached to a plastic container body filled with contents.

When a metal lid is attached to a plastic container body, the peripheral edge of the metal lid is wound around the flange of the container body.

By the way, in general, this plastic container body is formed by injecting a hot-melt resin into a gas-barrier sheet blank in order to prevent mixing of gases such as oxygen gas and water vapor.

[0007]

As described above, the container body is generally formed by injecting a hot-melt resin into a gas-barrier sheet blank in order to improve the storage stability of the contents.

By the way, as the sheet blank constituting the container body, a multi-layered sheet blank is used, and the hot-melt resin is injected onto the surface of the sheet blank. In this case, when the hot melt resin is injected to the inner surface of the sheet blank, the innermost layer of the container body becomes the injection resin layer, and when the hot melt resin is injected to the outer surface of the sheet blank, the innermost layer of the container body becomes the inner layer of the sheet blank. ..

However, depending on the material of the innermost layer of the container body, when the innermost layer of the container body adsorbs the scent of the content of the container body and the content is taken out from the container body, the scent of the content does not escape. It may happen.

The present invention has been made in view of the above points, and an object thereof is to provide a plastic container main body excellent in aroma retention and gas barrier property and a container with a metal lid using the same. ..

[0011]

According to the present invention, a sheet blank having a polybutylene terephthalate layer arranged as an inner layer and a polypropylene layer arranged as an outer layer is provided on the inside, and a polypropylene layer is provided on the polypropylene layer surface of the sheet blank. Is a plastic container body having a flange portion formed by injecting.

[0012]

According to the present invention, since the polybutylene terephthalate layer having excellent aroma retaining property and gas barrier property is arranged in the innermost layer of the container body, the container body does not adsorb the scent of the contents, and The storability of the product can be improved.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 are views showing an embodiment of the present invention. First, the container with a metal lid according to the present invention will be described with reference to FIG. In FIG. 3, the container with a metal lid 10 is configured by winding a peripheral edge portion 12 of a metal lid 11 around a flange portion 15 provided at an upper end opening of a plastic container body 14. In this case, the container body 14 is filled with the contents 16.

The metal lid 11 is made of aluminum or tin, and the inner surface of the metal lid 11 is coated with epoxy resin in advance.

Next, the plastic container body 14 according to the present invention will be described with reference to FIG. Figure 1 (a)
1 is a partial side sectional view of the container body, and FIG.
It is a B section enlarged view of (a).

As shown in FIG. 1, the container body 14 includes a body 1
4a and the bottom part 14b and the flange part 15. Of these, the body portion 14a and the bottom portion 14b are made of a gas-barrier sheet blank 26 and a thermoplastic resin 28 injected on the outer surface of the sheet blank 26, and the flange portion 15 is made of a thermoplastic resin 28. There is. Further, a bottom edge portion 29 made of a thermoplastic resin 28 is provided so as to protrude downward on the periphery of the bottom portion 14b.

Sheet blank 26 used for the container body 14
As the above, as shown in FIG. 1B, it is possible to use a laminated sheet configured in the following order from the inside.

Polybutylene terephthalate layer (PBT)
31 / Adhesive layer 32 / Polypropylene layer (PP) 33 As such a sheet blank 26, for example, a PP sheet 33 having a thickness of 0.47 mm and a PBT having a thickness of 0.03 mm are used.
It can be obtained by stacking the sheets 31 by a dry lamination method. In this case, an extremely thin adhesive layer 32 is interposed between the PP sheet 33 and the PBT sheet 31, and the total thickness of the sheet blank 26 is about 0.5 mm.

The thickness of the PBT sheet 31 is 0.03.
However, the present invention is not limited to this, and may be 0.015 mm or more. On the contrary, if the thickness is 0.015 mm or less, the PBT sheet may soften and break.

Next, as shown in FIG. 2, the sheet blank 26 is formed into a container shape in advance by using a vacuum pressure forming machine and is inserted between the cavity 17 and the core 30. However, not limited to this, a flat sheet blank having a portion corresponding to the bottom portion 14b of the container body 14 and a portion corresponding to the body portion 14a is inserted between the cavity 17 and the core 30 while being assembled into a container shape. May be.

Further, as shown in FIG. 1, the sheet blank 2
Polypropylene is injected as the heat-melting resin 28 onto the outer surface of 6, that is, the surface of the polypropylene layer 33, and the container body 14 is molded.

Next, a method of manufacturing the container body and the container with a metal lid will be described.

First, the sheet blank 26 which has been formed into a container shape in advance is provided in the core 30 as shown in FIG.
1 is pulled and attached.

Sheet blank 2 attached to core 30
No. 6 is inserted into the cavity 17 as it is, and polypropylene as the heat-melting resin 28 is introduced from the gate 17a. The heat-meltable resin 28 is the sheet blank 26.
Is injected onto the outer surface of the container to form the body portion 14a, the bottom portion 14b, the flange portion 15, and the bottom edge portion 29, and thus the container body 14 is obtained.

Next, the contents 16 are stored inside the container body 14, and the peripheral edge portion 12 of the metal lid 11 is wound around the flange portion 15 of the container body 14.

According to this embodiment, since the innermost layer of the container body 14 is the polybutylene terephthalate layer 31 having a fragrance retaining property, the polybutylene terephthalate layer 31 does not adsorb the scent of the contents 16. .. Therefore, even if the metal lid 11 is removed from the container body 14 and the contents 16 are taken out, the scent of the contents 16 does not escape. Moreover, since the polybutylene terephthalate layer 31 has a gas barrier property, the storage stability of the contents 16 can be improved. Furthermore, since inexpensive polypropylene is used as the heat-melting resin 28 and this polypropylene is injected onto the surface of the sheet blank 26 on the side of the polypropylene layer 33, the container body having improved adhesion between the heat-melting resin 28 and the sheet blank 26. 14 can be obtained at low cost.

Although the sheet blank having the above-mentioned layer structure is used, the polybutylene terephthalate layer 31 and the polypropylene layer 33 may be bonded by dry lamination without disposing the adhesive layer 32. Further, an ethylene vinyl alcohol copolymer layer having an excellent gas barrier property may be interposed between the polybutylene terephthalate layer 31 and the polypropylene layer 33.

Next, polybutylene terephthalate (PB
The aroma retaining property of the T) layer will be described with reference to the following table and FIG.

The table below compares the aroma retention properties of PBT and various films. That is, PBT film, PET
Film (polyethylene terephthalate), and LD
10 cm for PE film (low density polyethylene)
Create a bag from a film with a thickness of × 10 cm × 20μ,
Each sample was sealed in each bag and then placed in a closed container.
Then, the closed container was opened and the time until the odor was felt was measured.

The measurement results are shown in the table below.

[0031]

[Table 1] As is clear from the above table, the PBT film exhibits excellent fragrance retention together with the PET film.

Next, with respect to the PBT film and the LDPE film, orange juice was enclosed in a bag made of each film, and the adsorbed amount of d-limonene in the orange juice was measured.

The results are shown in FIG. As shown in FIG. 4, it can be seen that PBT has a smaller adsorbed amount of d-limonene than LDPE, that is, has a good aroma retaining property.

[0034]

As described above, according to the present invention,
Since the container body does not adsorb the scent of the contents, the scent of the contents can be reliably retained. Moreover, since the gas barrier property of the container body can be improved, the storability of the contents can be improved. Furthermore, since inexpensive polypropylene is used as the heat-melting resin and is injected into the polypropylene layer side of the sheet blank, the adhesiveness between the injection resin and the sheet blank can be improved and the container body can be made inexpensive. It can be molded.

[Brief description of drawings]

FIG. 1 is a sectional view showing a plastic container body according to the present invention.

FIG. 2 is a view showing a cavity and a core for molding a container body.

FIG. 3 is a side sectional view showing a container with a metal lid according to the present invention.

FIG. 4 is a diagram showing the amount of adsorbed d-limonene in orange juice of various films.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Metal lid container 11 Metal lid 12 Peripheral part 14 Container body 15 Flange part 16 Contents 26 Sheet blank 28 Thermofusible resin 31 Polybutylene terephthalate layer 32 Adhesive layer 33 Polypropylene layer

Claims (2)

[Claims] 1. A sheet blank having a polybutylene terephthalate layer arranged as an inner layer and a polypropylene layer arranged as an outer layer is provided inside, and a flange portion formed by injecting polypropylene on the polypropylene layer surface of the sheet blank is provided. Having a plastic container body. 2. A container body with a metal lid, which is formed by winding a peripheral edge portion of a metal lid around a flange portion of the plastic container body according to claim 1.