JP2000168766A - Paper container for liquid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper container for liquid to facilitate the recycling and disposal of the resources of used containers by providing a laminate body to form the paper container comprising an outer layer mainly consisting of paper and an inner layer mainly consisting of plastics. SOLUTION: A paper container is formed of a laminate body comprising a thermoplastic resin layer 1, a paper layer 2, an adhesive resin layer 3, a peelable layer 4, a plastic film layer 5, a gas barrier layer 6 comprising an aluminum foil or a vapor deposition layer, an adhesive layer and a thermoplastic resin layer 7 successively in this order from an outer surface, and the laminate body is separated into an outer layer mainly consisting of paper and an inner layer mainly consisting of plastics by peeling these layers between the peelable layer 4 and the plastic film layer 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention makes it possible to separate used paper containers by separating a laminate constituting a container into an outer layer mainly composed of paper and an inner layer mainly composed of plastic. The present invention relates to a liquid paper container having an excellent gas barrier property and easy to dispose.

[0002]

2. Description of the Related Art Recently, recycling of packaging materials has become a topic of concern for environmental protection, and it has been used in packaging of milk or the like made of a polyethylene / paper / polyethylene laminate even in a gobel-top type paper container. Paper containers
Recycling activities are being carried out and resources are being reused for effective use. On the other hand, in the case of a goebel top type paper container used for packaging of alcohol, wine, coffee, etc., a paper container having excellent gas barrier properties is used for protection of contents, distribution means, and extension of distribution period. Necessary, polyethylene / paper / ethylene-acrylic acid copolymer / aluminum foil / adhesive / biaxially stretched polyethylene terephthalate /
A laminate made of polyethylene is generally used. Further, recently, a laminate having a structure in which the layer composed of aluminum foil / adhesive / biaxially stretched polyethylene terephthalate in the above-described configuration is a biaxially stretched polyethylene terephthalate having an aluminum vapor deposition layer or a silicon oxide vapor deposition layer has been used. . However, in a paper container made of a laminate having the above-described structure, it is necessary to separate the outer layer mainly composed of paper and the inner layer mainly composed of plastic because the adhesive strength between the layers of the laminate is strong. It is extremely difficult, and it is difficult to reuse a used paper container. Further, since the paper container is extremely rigid, it is difficult to fold and discard the paper container.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to make a laminated body constituting a paper container separable into an outer layer mainly composed of paper and an inner layer mainly composed of plastic, so that a used paper container can be separated. An object of the present invention is to provide a liquid paper container having excellent gas barrier properties, which makes it possible to reuse the paper and facilitates disposal.

[0004]

A liquid paper container comprising a laminate composed of a thermoplastic resin layer, a paper layer, an adhesive resin layer, a release layer, a plastic film layer, a gas barrier layer, and a thermoplastic resin layer in order from the outer surface. By peeling the laminate between the release layer and the plastic film layer, an outer layer mainly composed of paper comprising a thermoplastic resin layer, a paper layer, an adhesive resin layer and a release layer, a plastic film layer and a gas barrier Can be separated into a plastic-based inner layer consisting of a layer and a thermoplastic resin layer, so that the paper-based outer layer can be reused and the plastic-based inner layer has reduced bulk and is easier to discard Becomes

In the above-mentioned liquid paper container, the release layer is made of an ethylene-vinyl acetate copolymer resin, an acrylic resin, a vinyl chloride-vinyl acetate copolymer resin, a cellulose resin, or a polyamide resin. ,
By peeling between the release layer and the plastic film layer, the laminate can be easily separated into an outer layer mainly composed of paper and an inner layer mainly composed of plastic.

In the above-mentioned liquid paper container, the gas barrier layer is made of an aluminum foil, an aluminum vapor deposition layer, a silicon oxide vapor deposition layer, or an aluminum oxide vapor deposition layer.
A liquid paper container having an excellent gas barrier property suitable for packaging alcohol, wine, coffee and the like can be provided.

[0007] The liquid paper container is a goebel top type having a front plate, a rear plate, both side plates, a top forming plate and a bottom forming plate, and the outer surfaces of the top forming plate and the bottom forming plate are thermally bonded. By forming the adhesive strength adjusting layer partially in the region to be heat-bonded, the heat-bonded portions of the top and bottom outer surfaces are easily separated from each other, the top and bottom are disassembled, and the laminate is separated from the edge. By peeling between the layers and the plastic film layer, it becomes easy to separate into an outer layer mainly composed of paper and an inner layer mainly composed of plastic.

In the above-mentioned liquid paper container, the both side plates are formed by forming vertical folding curves at the center portions of the top forming plate and the bottom forming plate connected vertically above and below the both side plates. It is easy to fold inside and fold.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing a laminated structure according to an embodiment of the present invention, FIG. 2 is a plan view showing a state of a surface of a blank plate of a gobel top type container, and FIG. FIG. 4 is a partial perspective view showing a procedure for peeling and disassembling an adhesive portion, FIG. 4 is a perspective view showing a folded state of a gobel top type container, and FIG. 5 is a diagram for separating a laminate from an end portion of the container into an outer layer and an inner layer. FIG. 6 is a perspective view showing a state in which the outer layer has been peeled over the entire length of the container, and FIG. 7 is a perspective view showing another method for creating a trigger for peeling the outer layer and the inner layer. , 7 is a polyethylene layer, 2 is a paper layer, 3 is an adhesive resin layer, 4 is a release layer,
5 is a plastic film layer, 6 is a gas barrier layer, 8,
9 is an adhesive strength adjusting layer, 11, 12, 13, 14 are side plates, 11a, 1
2a, 13a and 14a are top forming plates, 11b, 12b, 13b and 14b are bottom forming plates, 15 is an adhesive plate, 16 and 17 are bent curves, and 18 is a bottom edge bonding portion.

As shown in FIG. 1, the laminated structure of the embodiment of the liquid paper container of the present invention is such that a polyethylene layer 1, a paper layer 2, an adhesive resin layer 3, a release layer 4, a plastic film layer 5, a gas In this configuration, the barrier layer 6 and the polyethylene layer 7 are laminated. The print pattern is provided on the outer surface of the polyethylene layer 1. With the above configuration, the laminate is peeled between the release layer 4 and the plastic film layer 5, and the outer layer including the polyethylene layer 1, the paper layer 2, the adhesive resin layer 3, and the release layer 4, and the plastic film layer Since it can be separated into an inner surface layer composed of 5, a gas barrier layer 6 and a polyethylene layer 7, it is easy to reuse resources or dispose of used containers.

The release layer 4 in the laminate of the embodiment is formed using an ethylene-vinyl acetate copolymer resin, an acrylic resin, a vinyl chloride-vinyl acetate copolymer resin, a cellulose resin, or a polyamide resin. One layer or two layers made of different resins. By printing on a plastic film surface such as a biaxially stretched polyethylene terephthalate film using an ink made of the above resin to form a release layer 4 and laminating the adhesive resin layer 3 on the release layer 4 surface by extrusion coating, The surface of the release layer 4 and the adhesive resin layer 3 adhere well, and the adhesive strength between the release layer 4 and the plastic film layer 5 can be set to a peelable strength.

As the adhesive resin layer 3 in the laminate of the embodiment, low-density polyethylene, ionomer, ethylene-
Acrylic acid copolymer (EAA), ethylene-methacrylic acid copolymer (EMAA), ethylene-methyl acrylate copolymer (EMA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methyl methacrylate copolymer Although a polymer (EMMA) can be used, it is preferable to use low-density polyethylene in view of cost and workability.

[0013] With the laminated structure of the embodiment, the adhesive strength between the release layer 4 and the plastic film layer 5 is 10
１００100 g / 15 mm width, so that practically no problematic strength can be obtained when a liquid paper container such as a goebel top type is obtained, and it can be peeled between the release layer 4 and the plastic film layer 5. become. By peeling off the edge of the paper container manufactured using the laminate of the embodiment at the interface between the adhesive resin layer 3 and the plastic film layer 4, the polyethylene layer 1, the paper layer 2, and the adhesive resin can be separated. It can be separated into an outer layer composed of a layer 3 and a release layer 4 and an inner layer composed of a plastic film layer 5, a gas barrier layer 6, and a polyethylene layer 7, and the outer layer mainly composed of paper reuses resources. The inner layer mainly made of plastic is easily disposed of.

The polyethylene layer 1 is made of low-density polyethylene, and the polyethylene layer 7 is made of low-density polyethylene, medium-low-density polyethylene, linear low-density polyethylene, and ethylene-polymerized using a single-site catalyst.
α-olefin copolymer or the like is used. As the paper layer 2, a paperboard having a basis weight of 250 to 450 g / m ² is used. As the gas barrier layer 6, an aluminum foil, an aluminum deposition layer, a silicon oxide deposition layer, or an aluminum oxide deposition layer is used. When an aluminum foil is used as the gas barrier layer 6, the plastic film layer 5 is laminated with a urethane-based adhesive or the like. When an aluminum vapor-deposited layer, a silicon oxide vapor-deposited layer, or an aluminum oxide vapor-deposited layer is used as the gas barrier layer 6, It is preferable to perform an adhesion stabilizing treatment such as an anchoring treatment with the plastic film layer 5. As the plastic film layer 5, a biaxially stretched film such as biaxially stretched polyethylene terephthalate, biaxially stretched nylon, or biaxially stretched polypropylene which is excellent in vapor deposition workability and heat resistance can be suitably used.

The shape of the liquid paper container of the present invention may be any shape such as a Goebel top type container or a flat top type container. Hereinafter, the Goebel top type container will be described. As shown in FIG. 2, a blank plate for producing a goebel top type container is composed of side plates 11, 12, 13, 14 and an adhesive plate 15.
Are connected via creases, and the side plates 11,1
Top forming plates 11a, 12a, 13a, 14a and bottom forming plates 11b, 12b, 13b, 14b are connected to the upper and lower edges of 2, 13, 14 via folds, respectively. In the center, a folding curve 16 is formed in the vertical direction, and the top forming plates 12a and 14a and the bottom forming plate
In the center of 12b, 14b, a folding curve 17 is formed in the longitudinal direction, and the side plates 11, 12, 13, 14 and the top forming plates 11a, 12a, 13a, 14a or the bottom forming plates 11b, 12b, 13b, 14b are connected. It is formed in a state excluding predetermined dimensions above and below the folded rule. Bottom forming plate 11
b, 12b, 13b, and 14b have a partial adhesive strength adjustment layer 9 and a partial adhesive strength in a region where the surfaces of the top forming plates 11a, 12a, 13a, and 14a are thermally bonded. An adjustment layer 8 is formed. The printed pattern layer is formed on the surface of the blank except for the region to be thermally bonded.

The adhesive strength adjusting layers 8 and 9 are made of ethylene-vinyl acetate copolymer, chlorinated ethylene-vinyl acetate copolymer,
It is formed by printing using a resin ink composed of chlorinated polyethylene, chlorinated polypropylene, cyclized rubber, polyamide resin, urethane resin, acrylic resin, cellulose resin, alkyd resin alone or a mixture thereof. However, it is most preferable to use a low melting point acrylic resin. The area where the adhesive strength adjusting layers 8 and 9 are formed is 40 to 100% of the area where the surfaces of the bottom forming plates 11b, 12b, 13b and 14b and the top forming plates 11a, 12a, 13a and 14a are thermally bonded. It is good to do.

The blank plate shown in FIG. 2 is formed into a tubular shape by heat bonding the side plate 11 and the adhesive plate 15, and the bottom forming plates 11b, 12b,
After the bottoms are formed by bending and heat-bonding 13b and 14b, the tops are formed by bending and heat-bonding the top forming plates 11a, 12a, 13a and 14a to obtain a Goebel top type container. When discarding the goebel top type container, the top forming plates 12a, 14a provided with the adhesive strength adjusting layer 8 are provided.
Of the bottom forming plates 12b, 13b, 14b provided with the adhesive strength adjusting layer 9 are peeled off the portions of the bottom formed plates 12b, 13b, 14b where the surfaces are thermally bonded, thereby removing After dismantling the top and bottom parts,
Is bent inward at a folding curve 16 at the center in the width direction, and the top forming plates 12a, 14a and the bottom forming plates 12b, 14b are bent inward at the folding curve 17 at the center in the width direction, respectively. , Can be folded as shown in FIG.

Bottom forming plate provided with adhesive strength adjusting layer 9
The procedure of disassembling the bottom of the Goebel top type container by peeling off the parts of the surfaces of 12b, 13b, and 14b which are thermally bonded is as shown in FIG. 3, from the state shown in FIG. The edge bonding portion 18 is peeled off from the bottom forming plate 13b and raised.
The state shown in (b) is assumed. Further, the portions of the bottom forming plates 12b and 14b where the surfaces are thermally bonded are separated from each other to separate the edge bonding portions 18, thereby obtaining the state shown in FIG. Next, the side plate
12 and 14 are bent inward at the fold curve 16 at the center in the width direction, and the top forming plates 12a and 14a are bent inward at the fold curve 17 at the center in the width direction to form a gauber top type. The container can be in the folded state shown in FIG.

In the folded state of the paper container shown in FIG. 4, the edge of the laminated body at the side end portion bonded to the adhesive plate 15 of the rear plate 11, the top forming plate 11a and the bottom forming plate 11b is exposed. By bending the corners of the portion, the laminate can be peeled between the release layer 4 and the plastic film layer 5, so that the top forming plate 11a and the bottom forming plate 11a as shown in FIG.
The peeling is started from the corner end of 11b, and as shown in FIG. 6, the laminated body is peeled over the entire length of the side end of the rear plate 11, the top forming plate 11a, and the bottom forming plate 11b. It can be separated into an outer layer composed of a layer 2, an adhesive resin layer 3, and a release layer 4, and an inner layer composed of a plastic film layer 5, a gas barrier layer 6, and a polyethylene layer 7. Further, as shown in FIG. 7, after peeling off the adhesive portion between the outer surfaces of the top thermal adhesive portion, the opposing corners are grasped and pulled diagonally, whereby the laminate is placed between the release layer 4 and the plastic film layer 5. The laminate can be separated into an outer surface layer and an inner surface layer using the portion as a trigger. Separated polyethylene layer 1, paper layer 2, and adhesive resin layer 3
The outer layer mainly composed of paper consisting of the release layer 4 and the inner layer mainly composed of plastic consisting of the plastic film layer 5, the gas barrier layer 6 and the polyethylene layer 7 can be reused in the same manner as a milk container. The layer is less bulky and easier to discard.

[0020]

EXAMPLE 1 A 12 μ biaxially stretched polyethylene terephthalate film and a 7 μ aluminum foil were laminated by dry lamination using a urethane adhesive, and a 60 μ polyethylene film was used on the aluminum foil surface using a urethane adhesive. Then, a lamination film was formed by dry lamination, and a release layer was formed to a thickness of 1 μm on the surface of the biaxially stretched polyethylene terephthalate film using an ink having the following composition to prepare a laminated film. [Composition of ink to form release layer (parts by weight)] Ethylene-vinyl acetate copolymer 10 (Evaflex 220, Mitsui DuPont Polychemical) Toluene (solvent) 90 Then, one side of 400 g of paperboard has 30 μm polyethylene Are laminated by extrusion, and the other surface of the paperboard and the release layer surface of the laminated film prepared above are laminated by extrusion lamination of 25 μm thick polyethylene to obtain polyethylene 30μ / paperboard 400g / polyethylene 25μ /
Release layer / biaxially oriented polyethylene terephthalate 12μ /
A laminate composed of urethane-based adhesive / aluminum foil 7 μ / urethane-based adhesive / polyethylene film 60 μ was prepared.

The adhesive strength between the release layer made of the ethylene-vinyl acetate copolymer and the biaxially stretched polyethylene terephthalate film in the obtained laminate is 20 g / 15 mm.
Width, the laminate has sufficient adhesive strength as a laminate for producing a Goebel top type container, and has such strength that it can be peeled between the release layer and the biaxially stretched polyethylene terephthalate. / Board paperboard / polyethylene / release layer and an inner layer consisting of biaxially stretched polyethylene terephthalate / urethane-based adhesive / aluminum foil / urethane-based adhesive / polyethylene film. After forming a printed pattern on the 30 μm polyethylene surface of the laminate and forming an adhesive strength adjusting layer on a predetermined area by printing, a blank plate for a gobel-top type container is prepared by punching, and the blank plate is formed into a tube. The top and the bottom were adhered to each other by thermal bonding to produce a Goebel top type container. By peeling off the adhesive portions between the outer surfaces of the top and bottom of the Goebel top type container obtained above and folding the container, and bending the corner end, the laminated body is made of polyethylene / polyethylene from the corner end of the folded container. An outer layer composed of paperboard / polyethylene / release layer and an inner layer composed of biaxially stretched polyethylene terephthalate / urethane-based adhesive / aluminum foil / urethane-based adhesive / polyethylene film could be separated.

Example 2 An ethylene-methacrylic acid copolymer was extruded to a thickness of 15 μm on the aluminum-deposited layer surface of a 12 μm biaxially stretched polyethylene terephthalate film having an aluminum vapor-deposited layer formed thereon, and a 45 μm polyethylene film was extruded and laminated by lamination. At the same time, a biaxially stretched polyethylene terephthalate film is printed to a thickness of 1 μm using ink A having the following composition, and ink B having the following composition is further printed thereon.
Was used to produce a laminated film in which two layers were formed by printing to a thickness of 1 μm. [Composition of ink A forming release layer (parts by weight)] Acrylic resin (Dianal DR-80, Mitsubishi Rayon) 30 Toluene (solvent) 70 [Composition of ink B forming release layer (parts by weight)] Ethylene-acetic acid Vinyl copolymer 10 (Evaflex 220, Mitsui DuPont Polychemical) Toluene (solvent) 90 30 μ polyethylene is laminated by extrusion coating on one surface of 400 g of paperboard, and the other surface of the paperboard and the laminated film produced above By extruding polyethylene to a thickness of 25μ and laminating it with a release layer surface made of an ethylene-vinyl acetate copolymer, polyethylene 30μ / paperboard 40
A laminate comprising 0 g / polyethylene 25 μ / 2 release layers / biaxially stretched polyethylene terephthalate 12 μ / aluminum deposition layer / ethylene-methacrylic acid copolymer 15 μ / polyethylene film 45 μ was prepared. The adhesive strength between the release layer made of acrylic resin and the biaxially stretched polyethylene terephthalate film of the obtained laminate was 15 g /
It has a width of 15 mm, has a sufficient adhesive strength as a laminate for producing a göbel top type container, and easily peels the laminate between a release layer made of an acrylic resin and biaxially stretched polyethylene terephthalate. Was completed.
A Goebel top type container was prepared in the same manner as in Example 1,
By peeling off the adhesive portion between the outer surfaces at the top and bottom, the container is folded, and the corner end is bent, so that the laminate is formed from an acrylic resin release layer and biaxially stretched polyethylene terephthalate from the corner end of the folded container. Peeling between films to separate into an outer layer consisting of polyethylene / paperboard / polyethylene / release layer and an inner layer consisting of biaxially stretched polyethylene terephthalate / aluminum deposited layer / ethylene-methacrylic acid copolymer / polyethylene film Was completed.

[0023]

According to the present invention, there is provided a liquid paper container constituted by a laminate comprising a thermoplastic resin layer, a paper layer, an adhesive resin layer, a release layer, a plastic film layer, a gas barrier layer and a thermoplastic resin layer in this order from the outer surface. The laminate is peeled between the release layer and the plastic film layer, and the outer layer mainly composed of paper comprising a thermoplastic resin layer, a paper layer, an adhesive resin layer and a release layer, a plastic film layer, a gas barrier layer, and a thermoplastic resin. Since the inner layer mainly composed of a resin layer can be separated into plastic-based inner layers, the outer layer mainly composed of paper can be reused, and the inner layer mainly composed of plastic has a reduced bulk and can be easily disposed of. In the above liquid paper container, the release layer is formed of an ethylene-vinyl acetate copolymer resin, an acrylic resin, a vinyl chloride-vinyl acetate copolymer resin,
1 made of cellulose resin and polyamide resin
By forming a layer or two different layers, the laminate can be easily separated into an outer layer mainly composed of paper and an inner layer mainly composed of plastic by peeling between the release layer and the plastic film layer. In the above-mentioned liquid paper container, the gas barrier layer is formed of an aluminum foil, an aluminum vapor deposition layer, a silicon oxide vapor deposition layer, and an aluminum oxide vapor deposition layer, so that a gas barrier suitable for packaging sake, wine, coffee and the like. A liquid paper container having excellent properties can be obtained. The liquid paper container has a shape of a goebel top including a front plate, a rear plate, both side plates, a top forming plate, and a bottom forming plate, and a region where the outer surfaces of the top forming plate and the bottom forming plate are thermally bonded to each other. By forming the adhesive strength adjusting layer partially on the outer surface, the heat bonding portion between the outer surfaces of the top and the bottom is easily peeled off, the top and the bottom are disassembled, and the laminate is bonded to the adhesive resin layer from the edge. By peeling between the release layers, it becomes easy to separate into an outer layer mainly composed of paper and an inner layer mainly composed of plastic. In the above-mentioned liquid paper container, the both side plates are folded inward by forming a vertical folding curve at the center of the top forming plate and the bottom forming plate connected vertically above and below the both side plates. It becomes easy to fold.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a laminated configuration according to an embodiment of the present invention.

FIG. 2 is a plan view showing a state of a surface of a blank plate of the goebel top type container.

FIG. 3 is a partial perspective view showing a procedure of peeling and disassembling an adhesive portion between outer surfaces of a bottom forming plate of a goebel top type container.

FIG. 4 is a perspective view showing a folded state of the goebel top type container.

FIG. 5 is a perspective view showing a state in which the laminate is separated from an end portion of the container into an outer surface layer and an inner surface layer.

FIG. 6 is a perspective view showing a state where the outer surface layer is peeled over the entire length of the container.

FIG. 7 is a perspective view showing another method for creating a trigger for peeling the outer layer and the inner layer.

[Explanation of symbols]

 1, 7 polyethylene layer 2 paper layer 3 adhesive resin layer 4 release layer 5 plastic film layer 6 gas barrier layer 8, 9 adhesive strength adjustment layer 11, 12, 13, 14 side plates 11a, 12a, 13a, 14a top forming plate 11b , 12b, 13b, 14b Bottom forming plate 15 Bonding plate 16, 17 Folded curve 18 Bottom edge bonding portion

 ──────────────────────────────────────────────────の Continuing on the front page F term (reference) 3E060 AA05 AB04 BC01 BC04 DA20 DA30 EA03 4F100 AA19E AA20E AB10E AB33E AK01A AK01E AK04 AK15C AK22C AK25C AK42 AK46C AK51 AK68C AL01C AT00D BA05B10 BA10 BA01BA10BA10E JD02E JK06 JL14 JL14C

Claims (5)

[Claims] 1. A liquid comprising a laminate composed of a thermoplastic resin layer, a paper layer, an adhesive resin layer, a release layer, a plastic film layer, a gas barrier layer, and a thermoplastic resin layer in order from the outer surface. Paper container. 2. The method according to claim 1, wherein the release layer comprises an ethylene-vinyl acetate copolymer resin, an acrylic resin, a vinyl chloride-vinyl acetate copolymer resin, a cellulose resin, or a polyamide resin. The liquid paper container according to the above. 3. The gas barrier layer according to claim 1, wherein the gas barrier layer is an aluminum foil, an aluminum deposition layer, a silicon oxide deposition layer, or an aluminum oxide deposition layer.
A liquid paper container according to claim 1. 4. The liquid paper container according to any one of claims 1 to 3, wherein the shape of the liquid paper container is a goebel top type including a front plate, a rear plate, both side plates, a top forming plate, and a bottom forming plate. A liquid paper container, wherein an adhesive strength adjusting layer is partially formed in a region where the outer surfaces of the forming plate and the bottom forming plate are thermally bonded. 5. The liquid paper container according to claim 4, wherein
A liquid paper container having a structure in which a vertical folding curve is formed at the center of the top forming plate and the bottom forming plate connected vertically above and below the both side plates, respectively.