JP3375101B2 - Composite container - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite container, and more particularly to a composite container having an aroma retaining property and an excellent barrier property.

[0002]

2. Description of the Related Art Conventionally, there has been used a so-called pillar container in which a blank plate and a thermoplastic resin are integrally molded. Generally, in a pillar container, a blank plate made of a laminated sheet material in which paper and a resin are laminated is arranged in a cavity of an injection molding die, and the end portion of the blank plate is abutted to form a joint and a bottom. It is a composite container integrally molded in a state where a blank plate is held in a container shape by a resin holding frame by injecting a thermoplastic resin into a portion.

Generally, a blank plate has a laminated structure including a barrier layer made of aluminum foil and paper, and a seal layer made of polyolefin resin on the innermost surface. The seal layer on the innermost surface of this blank plate is injected. It is integrated with the thermoplastic resin by heat fusion to form a container.

Such a pillared container has both advantages as an injection molded product and as a paper container,
For example, it is widely used as a container for storing various products such as soft drinks, liquid foods such as yogurt, sake, powder detergents, and fragrances.

[0005]

However, in the conventional composite container, the sealing layer made of the polyolefin resin forming the innermost surface easily adsorbs the flavor component of the contents, and therefore, for example, fruit juice is filled in the composite container. When stored, there was a problem that the flavor of the fruit juice, which is the content, deteriorates.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a composite container having excellent aroma retaining property and barrier property for contents.

[0007]

In order to achieve such an object, the present invention provides a method in which a thermoplastic resin is injected into a cavity in which a blank plate is preliminarily arranged so that the blank plate and the resin molding portion are separated from each other. In a composite container having at least a body and a bottom obtained by being integrated, the blank plate is a barrier layer, and a sealing layer formed on the innermost surface by any one of ethylene-vinyl alcohol copolymer and copolyester. And the blank plate has a body member and a bottom.
And a member for the body, and the body is a member for the body of the blank plate.
And the pillar part of the resin molding part and the upper edge part,
The bottom part of the blank plate and the lower end of the resin molding part.
And the lower end is provided at opposite ends of the bottom,
The bottom members are opposed to each other at the bottom without a lower end.
It has a bent part at the end, and through the bent part
The body member is connected to the body member, and the bottom member is the folding member.
Between the pair of lower end portions that intersect the bending portion and face each other
A ruled line for inward folding is formed so that it is located in the approximate center.
And the body member is a member formed on the bottom member.
As an extension of both ends of the ruled line for inward folding, in the direction of the upper edge of the body
Two ruled lines for inward folding are formed with a predetermined length.
From each end of the ruled line for inward folding to the upper edge of the body
Each has a ruled line for external folding, and the ruled line for internal folding
From each switching point from the above to the ruled line for external folding
Two outer ruled lines are formed in the direction of the bottom edge.
It is configured to be a thing.

[0008]

The blank plate constituting the composite container is provided with the barrier layer and the seal layer on the innermost surface, and the thermoplastic resin is injected into the cavity in which the blank plate is previously arranged so that the blank plate and the resin molding part are integrated. The composite container does not adsorb the flavor component of the contents because the seal layer is formed of either ethylene-vinyl alcohol copolymer or copolymerized polyester.

[0009]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a perspective view showing an embodiment of the composite container of the present invention. In FIG. 1, the composite container 1 is a resin molding part 6
This is a so-called pillar container in which the blank plate 11 and the blank plate 11 are integrated to form the body portion 2 and the bottom portion 3.

The body portion 2 of the composite container 1 is composed of the pillar portion 7 of the resin molding portion 6, the upper end edge portion 8 and the body portion member 12 of the blank plate 11. In addition, the bottom 3 of the composite container 1
Is composed of the lower end portion 9 of the resin forming portion 6 and the bottom member 13 of the blank plate 11.

FIG. 2 is a plan view showing an example of the blank plate 11 used in the composite container shown in FIG. In FIG. 2, the blank plate 11 includes a body member 12 and a bottom member 13
It is a one-piece type blank plate that is equipped with and
A ruled line 14 for bending at the time of molding is provided at a boundary portion between the body member 12 and the bottom member 13. Then, this blank plate 11 is bent along a ruled line 14, the body member 12 is curved and placed in the cavity of the mold,
A thermoplastic resin is applied to the seamed portion where the ends 12a, 12a of the body member 12 are butted and the seamed portion where the end 12b of the body member 12 and the end 13a of the bottom member 13 are butted. After injection, the pillar 7 and the lower end 9
And are formed. The upper edge 8 of the resin molding 6 is formed on the upper end of the body member 12 so as to be connected to the pillar 7.

FIG. 3 is a schematic sectional view showing an example of a blank plate 11 that can be used in the composite container 1 of the present invention. In FIG. 3, the blank plate 11 includes a barrier layer 24 bonded to the paper layer 22 through a thermoplastic resin layer (outermost surface layer) 21, a paper layer 22, and an adhesive resin layer 23 in order from the outside of the composite container 1. The seal layer (innermost surface layer) 25 has a laminated structure.

Thermoplastic resin layer 21 constituting a blank plate
Can be formed using a thermoplastic resin such as polyethylene resin, polypropylene resin, polystyrene resin, polybutylene terephthalate resin, polyethylene terephthalate resin, polyacrylonitrile resin and polyamide resin such as nylon. The thickness of such a thermoplastic resin layer 21 is preferably about 10 to 40 μm.

The paper layer 22 forming the blank plate 11 preferably has a basis weight of about 200 to 400 g / m ² .

The barrier layer 24 is made of silicon oxide (SiO 2).
_It can be formed of a film having an inorganic vapor deposition film such as _x ) formed thereon, a polyamide resin such as nylon, or a metal foil such as aluminum. A biaxially stretched resin film is preferable as the film for forming the inorganic vapor deposition film. Specifically, a film formed by biaxially stretching a resin such as a polyester resin, a polyamide resin, a polycarbonate resin, an acrylic resin, or a polystyrene resin is used. You can In particular, a film formed by biaxially stretching a resin having heat resistance such as polybutylene terephthalate resin, polyethylene terephthalate resin, and polyacrylonitrile resin is preferable.

The thickness of the barrier layer 24 is 5 to 3
About 0 μm is preferable.

The adhesive resin layer 23 used for adhering the paper layer 22 and the barrier layer 24 can be formed using, for example, a carboxyl group-containing polyethylene resin.
Specific examples of the carboxyl group-containing polyethylene resin include ethylene-acrylic acid copolymer (EAA), ethylene-methacrylic acid copolymer (EMAA), ionomer resin, ethylene-maleic anhydride copolymer, ethylene-
Examples thereof include ethyl acrylate-maleic anhydride copolymer. The thickness of the adhesive resin layer 23 is 10 to 3
About 0 μm is preferable.

The seal layer 25 is formed of either an ethylene-vinyl alcohol copolymer or a copolyester. All of these resins have excellent fragrance retaining performance.

Here, the copolyester is an amorphous or low crystalline saturated polyester resin having a glass transition temperature of 40 ° C. or higher, and a dialcohol component such as ethylene glycol, propylene glycol or 1,4-cyclohexanedimethanol. And a dicarboxylic acid component such as an aliphatic dicarboxylic acid such as adipic acid or sebacic acid or an aromatic dicarboxylic acid such as terephthalic acid, isophthalic acid or diphenyldicarboxylic acid. Specifically, by co-condensation polymerization of a combination of ethylene glycol and terephthalic acid, ethylene glycol and isophthalic acid and terephthalic acid, 1,4-cyclohexanedimethanol and ethylene glycol and terephthalic acid, propylene glycol and isophthalic acid and terephthalic acid, etc. In addition to the resulting polyester resin or ethylene glycol and terephthalic acid as basic raw materials, a trivalent carboxylic acid such as trimellitic acid is used as part of the acid component, or trimethylolpropane is used as part of the alcohol component. And a polyester resin obtained by using a trivalent carboxylic acid and a trivalent alcohol for a part of the acid component and a part of the alcohol component.

[0021] The copolyester is not preferable when the aliphatic dicarboxylic acid component in the acid component is 10% by weight or more, because the aroma-retaining performance is deteriorated.

The thickness of the sealing layer 25 as described above is 20 to
It is preferably about 80 μm.

Further, a heat resistant layer may be formed between the barrier layer 24 and the thermoplastic resin layer 25 located on the innermost surface of the blank plate. The heat-resistant layer is for preventing the barrier layer from being broken by the influence of the pressure and heat of the thermoplastic resin injected during the formation of the composite container, and causing the barrier layer to break. Examples of such a heat resistant layer include a biaxially stretched polyester resin film such as a polyethylene terephthalate film, a polyamide resin film such as a nylon film, and a stretched polyolefin resin film such as a polypropylene film. The thickness of such a heat-resistant layer is preferably about 10 to 30 μm.

The thickness of the blank plate as described above is 300
It is preferably about 600 μm.

As the thermoplastic resin which is integrated with the body member 12 and the bottom member 13 of the blank plate 11 as described above to form the composite container 1, polyethylene resin, polypropylene resin, polystyrene resin, polybutylene terephthalate is used. Examples thereof include resins, polyethylene terephthalate resins, polyacrylonitrile resins, polyamide resins such as nylon, and the like. Further, in the composite container of the present invention, as the thermoplastic resin, the ethylene-vinyl alcohol copolymer or copolymer polyester used in the above-mentioned seal layer 25 can be used.

In the composite container of the present invention as described above, since the seal layer is formed of either ethylene-vinyl alcohol copolymer or copolymer polyester, the flavor component of the contents is not adsorbed. Further, by using an ethylene-vinyl alcohol copolymer or a copolyester having a fragrance retaining property as the thermoplastic resin used for injection molding, the fragrance retaining property can be further enhanced.

Further, the composite container 1 of the present invention may be one in which the blank plate 11 is formed with folding ruled lines. That is, as shown in FIGS. 4 and 5, the body part member 12 of the blank plate 11 forming the body part 2 has the outer folding ruled lines 15a and 15b and the inner folding ruled line 15c.
Are formed respectively. In addition, a ruled line 15d for inward folding is provided on the bottom member 13 of the blank plate 11 that constitutes the bottom 3.
Are formed.

The formation of the ruled lines is carried out by placing a groove formed on the press board on a base plate as a female die, and placing a blank plate on the female die at a position corresponding to the groove of the press board. In, the blank plate can be pressed from above with a metal blade.

The composite container provided with ruled lines in this way is
As shown in FIG. 6, the body part member 12 is bent to the outside of the container along the outer folding ruled lines 15a and 15b, and at the same time, the inner folding ruled line 15c and the inner folding ruled line 15d are cut along the body part. The lower portion of the working member 12 and the bottom member 13 can be easily folded by folding them inside the container. Therefore, the bulk of the container at the time of disposal can be significantly reduced.

The formation position of the folding ruled line formed on the composite container of the present invention is not limited to that shown in FIGS. 4 to 6, and it can be easily folded according to the shape of the composite container. Can be set as appropriate.

FIG. 7 is a plan view showing another example of a blank plate that can be used in the composite container of the present invention. In FIG. 7, the blank plate 31 is a two-piece type blank plate provided with the body member 32 and the bottom member 33 as separate bodies. Then, the curved body member 32 and bottom member 33
Is disposed at a predetermined position in the cavity of the mold, and the joint portions where the ends 32a, 32a of the body member 32 are abutted, and the periphery of the end portion 32b of the body member member 32 and the bottom member 33. A pillar resin container can be obtained by injecting a thermoplastic resin into a joint portion where the end portion 33a is butted.

The body member 32 and the bottom member 33 constituting the blank plate 31 are also folded ruled lines 35a, 35b, 35c, 3 as shown by phantom lines.
5d can be provided. In this case, the ruled lines 35a, 3
By forming 5b for external folding and forming ruled lines 35c, 35d for internal folding, the molded composite container can be easily folded into the state shown in FIG.

Further, the container may be folded more easily by forming a thin portion in advance at a predetermined portion of the resin molding portion 6 that is bent when the composite container is folded. For example, a thin-walled portion can be formed at the upper end edge portion 8 (the portion indicated by the arrow a in FIG. 4) on the extension line of the ruled line 15b in FIG.

The thin portion as described above can be formed in the resin molding portion 6 by subjecting the die to a predetermined process. In addition, the resin injection gate in the mold, for example,
Two-point gates are provided at two locations where the pillar portion 7 and the lower end portion 9 intersect (the location indicated by the arrow b in FIG. 4),
By making the resin flowing from each gate meet at the center of the upper edge 8 in FIG.
It can also be a thin portion.

In each of the above-mentioned examples, the bottom portion is composed of a blank plate, but the composite container of the present invention is not limited to this. For example, only the body portion is composed of a blank plate and the bottom portion is It may be resin-molded.

Next, the present invention will be described in more detail with reference to experimental examples. (Experimental Example) Acid-resistant paper having a basis weight of 230 g / m ² was used as a support, and a low-density polyethylene resin was extrusion-laminated on one surface of the acid-resistant paper to form a thermoplastic resin layer having a thickness of 15 μm. It was created.

An isocyanate adhesive is applied to the polyester film side of a biaxially stretched polyester film (thickness = 12 μm) having a vapor-deposited film (thickness 50 nm) of silicon oxide (SiO _x ) as a barrier layer, Thereafter, an ethylene-vinyl alcohol copolymer film (thickness: 30 μm) was laminated on this adhesive layer to form a seal layer, thereby forming a three-layer laminate.

Next, an ethylene-methacrylic acid copolymer (EM) was applied to one surface of the above-mentioned two-layer laminate, on which the acid-resistant paper was exposed.
While extruding AA) in a thickness of 15 μm, the silicon oxide (SiO _x ) vapor deposition film side of the above three-layer laminate was adhered to form a laminate.

Next, this laminated body was punched into a shape as shown in FIG. 5 to obtain a one-piece type blank plate.
Further, a press board with grooves formed is installed as a female mold on the base plate, and the blank plate is placed on the female mold. By compressing with a blade, folding ruled lines as shown in FIG. 5 were formed. Then, after disposing this blank plate in the cavity of the injection mold, injection molding is performed using a high-density polyethylene resin for injection, and the internal volume 22 as shown in FIG.
A 0 cc composite container (Sample 1) was prepared.

A composite container (Sample 2) was prepared in the same manner as Sample 1 except that a copolymerized polyester (thickness = 30 μm) was used in place of the ethylene-vinyl alcohol copolymer as the sealing layer forming resin. It was created.

A composite container (Sample 3) was prepared in the same manner as Sample 1 except that an ethylene-vinyl alcohol copolymer was used as the thermoplastic resin for injection instead of the high-density polyethylene resin.

For comparison, a composite container for comparison (comparative) was prepared in the same manner as the composite container described above except that the seal layer was formed of a low-density polyethylene resin film (thickness: 30 μm) and ruled lines for folding were not formed. Sample 1) was prepared.

Further, a seal layer (30 μm) made of an ethylene-vinyl alcohol copolymer was obtained by two-layer coextrusion with an ethylene-vinyl alcohol copolymer using an ethylene-methacrylic acid copolymer (EMAA) as an intermediate adhesive layer.
To prepare a two-layer laminate. Then, this two-layer laminate was used in place of the three-layer laminate used in the preparation of Sample 1, and no ruled lines for folding were formed. A container (Comparative Sample 2) was prepared.

Each composite container thus prepared (Samples 1 to 1)
3, Comparative Samples 1 and 2) were filled with 180 cc of orange juice, the opening was sealed with a metal plate, and the aromatic content and gas barrier property of the orange juice as the content were evaluated as follows. The results are shown in Table 1.

(Evaluation of aroma of contents) After storing in an atmosphere of 7 to 8 ° C. for 5 days, it was opened and evaluated by a sensory test.

Evaluation Criteria: A ... Good, B ... Normal, C ... Poor (evaluation of gas barrier property) Using Oxytran manufactured by Modern Control Co., the oxygen permeability per container was measured at room temperature and atmospheric pressure.

[0047]

[Table 1] As shown in Table 1, the composite container of the present invention has excellent fragrance retention and high barrier properties, but Comparative Sample 1 is inferior in fragrance retention, and Comparative Sample 2 is somewhat good. Although it had an aroma retaining property, deterioration of the gas barrier property was observed.

Samples 1 to 3 were provided with ruled lines on the blank plate and could be easily folded, and this folding greatly reduced the bulk of the container. On the other hand, comparative sample 1,
In No. 2, it was difficult to fold, and the restoring force to the original state was strong even after folding, and the decrease in the bulk of the container was slight.

[0049]

As described above in detail, according to the present invention, a blank plate having a perfume-preventing property, in which the innermost seal layer is formed of either ethylene-vinyl alcohol copolymer or copolyester, is provided. A thermoplastic resin is injected into a pre-arranged cavity to integrate a blank plate and a resin molding portion to form a composite container, and the composite container has a high aroma retaining property for contents.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a composite container of the present invention.

FIG. 2 is a plan view showing an example of a blank plate used for the composite container shown in FIG.

FIG. 3 is a schematic cross-sectional view showing an example of a blank plate that can be used in the composite container of the present invention.

FIG. 4 is a perspective view showing another embodiment of the composite container of the present invention.

5 is a plan view showing an example of a blank plate that can be used in the composite container shown in FIG.

6 is a perspective view showing a state in which the composite container shown in FIG. 4 is folded.

FIG. 7 is a schematic cross-sectional view showing another example of a blank plate that can be used in the composite container of the present invention.

[Explanation of symbols]

1 ... Composite container 2 ... Body 3 ... bottom 11, 31 ... Blank plate 12, 32 ... Body member 13, 33 ... Bottom member 15a, 15b, 15c, 15d ... Ruled lines 6 ... Resin molding part 7 ... Pillar part 8 ... Top edge 9 ... Lower end 21 ... Thermoplastic resin layer 22 ... Paper layer 23 ... Adhesive resin layer 24 ... Barrier layer 25 ... Seal layer

Front page continuation (72) Inventor Jun Iijima 1-1-1, Ichigaya-Kagacho, Shinjuku-ku, Tokyo Within Dai Nippon Printing Co., Ltd. Nakayama Kogyo Co., Ltd. (56) Reference JP 61-217234 (JP, A) JP 5-51023 (JP, A) JP 6-166135 (JP, A) JP 3-63114 ( JP, A) JP 60-58821 (JP, A) JP 6-219434 (JP, A) JP 47-4687 (JP, A) JP 3-148451 (JP, A) SHO 61-29067 (JP, U) Actual Kaihei 6-6215 (JP, U) Patent 3276763 (JP, B2) (58) Fields investigated (Int.Cl. ⁷ , DB name) B29C 45/14 B65D 3 / 28 B65D 5/42 B65D 6/28 B65D 6/34

Claims (6)

(57) [Claims] 1. A composite container having at least a body and a bottom obtained by injecting a thermoplastic resin into a cavity in which a blank plate is previously arranged to integrate the blank plate and a resin molding portion. in the blank plate and barrier layer, an ethylene - and a seal layer formed on the innermost surface by any of the vinyl alcohol copolymer and copolymerized polyester, the bran
The plate has a body member and a bottom member, and the body is
Body part of rank plate, pillar part of resin molding part, upper edge
The bottom part of the blank plate and the tree part.
It consists of the lower end of the oil molding part, and the lower end opposes the bottom part.
The bottom member is provided at the lower end
Has a bent portion at the opposite ends of the bottom portion, and
The body member is continuously provided via the bent portion, and the bottom member intersects the bent portion and faces each other.
One so that it is located approximately in the center between the pair of lower ends
Inner folding lines are formed, and the body member is the inner folding member formed on the bottom member.
Specified in the direction of the upper edge of the body as an extension of both ends of the ruled line
Two ruled lines for internal folding are formed with the length of
From each end of the ruled line to the upper edge of the body
A ruled line for external folding is formed, and from the ruled line for internal folding
From each switching point to the ruled line for external folding, a set of the bottom
Two ruled lines for external folding are formed in the end direction.
And a composite container. 2. The composite container according to claim 1, wherein the thermoplastic resin is either an ethylene-vinyl alcohol copolymer or a copolyester. 3. The barrier layer is formed by forming an inorganic vapor deposition film on a resin film.
Alternatively, the composite container according to claim 2. 4. The composite container according to claim 3, wherein the resin film is a resin film having heat resistance. 5. The composite container according to any one of claims 1 to 4 , wherein the resin molding portion forming the body portion is provided with a thin portion for folding. Wherein said resin molding portion constituting the bottom, composite container according to any one of claims 1 to 5, characterized in that the thin portion for folding is provided.