JP2011073728A - Paper container - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper container capable of withstanding the storage over a long period of a content having strong infiltration and diffusibility while maintaining the characteristics such as the pin-hole resistance and sealability. <P>SOLUTION: The paper container is formed by working a layered body in which an outermost layer, a paper base material layer, an adhesive resin layer, a barrier layer, a resin film layer consisting of polyethylene terephthalate or nylon, an anchor coat layer and an innermost layer are successively layered, and the anchor coat layer is formed by coating aqueous dispersion element containing the specified acid modification polyolefin resin on the film layer and drying it. The paper container is suitable for packaging the content having strong infiltration and diffusibility such as a liquid bath agent, wine, or spice. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a paper container suitable for packaging contents having strong permeability and diffusibility such as liquid baths, wine, spices and the like.

  Laminates in which polyethylene is laminated on the surface of a paper substrate are widely used as packaging materials for various products. Among them, products such as alcoholic beverages, shampoos, rinses, liquid detergents, etc. that have a relatively long distribution period and require barrier properties are mainly outermost layers / paper substrate layers / adhesive resin layers / barrier layers / resin films. A laminate having a layer / innermost layer, for example, polyethylene / paper / adhesive resin / aluminum foil / polyethylene terephthalate / polyethylene or polyethylene / paper / adhesive resin / aluminum deposited film / polyethylene terephthalate / polyethylene A paper container is used (see, for example, Patent Documents 1 and 2).

JP-A-9-327888 JP 2003-335362 A

As described above, a laminate used for a conventional paper container is generally a laminate in which an outermost layer, a paper base layer, an adhesive resin layer, a barrier layer, a resin film layer, and an innermost layer are laminated in this order. The resin film layer is mainly composed of polyethylene terephthalate film, but this resin film layer is laminated for the purpose of reinforcing the barrier layer, and prevents cracking and pinholes of the barrier layer due to external physical stress, There is also a heat resistance effect. The reason why the resin film layer is laminated on the inner side of the container than the barrier layer is that the barrier layer is damaged by hot air blown when the laminated body is boxed, and cracks or pinholes are generated at the time of sealing. This is to reduce the above.
However, when the paper container configured as described above is filled with contents having strong permeability and diffusibility such as liquid bathing agent, wine, spices, etc. and stored for a long time, it is a polyethylene terephthalate film and the innermost layer. It was confirmed that the content penetrated between polyethylene and delamination occurred, and it could not function as a paper container.
Accordingly, the present invention has been made in view of the above circumstances, and provides a paper container that can withstand long-term storage of contents having strong permeability and diffusibility such as liquid bath agents, wine, spices, and the like. With the goal.

The present inventors have produced a laminate by dry lamination or extrusion coating because the cause of delamination in a conventional paper container is that the polyethylene terephthalate film is nonpolar (has no functional group). In this case, it was considered that the adhesion between the polyethylene terephthalate film and the material constituting the other layer would be insufficient.
Based on the above considerations, the present inventors have made various studies on an anchor coating agent having excellent adhesion to a resin film layer made of polyethylene terephthalate or nylon.For an aqueous dispersion of a specific acid-modified polyolefin, By using an anchor coating agent composed of an aqueous dispersion to which at least one of a polyester resin and a polyurethane resin is added at a specific ratio, the resin film layer and the innermost layer are firmly adhered to each other, such as a liquid bath agent. It has been found that delamination due to penetration of contents having high permeability, high diffusibility and high swellability can be prevented, and the present invention has been completed.
That is, the first invention for achieving the above object is to sequentially laminate an outermost layer, a paper base layer, an adhesive resin layer, a barrier layer, a resin film layer made of polyethylene terephthalate or nylon, an anchor coat layer, and an innermost layer. A paper container formed by boxing the laminated body, wherein the anchor coat layer contains 0.01% by mass to 20% by mass of an unsaturated carboxylic acid or its anhydride as a constituent component, and has a number average particle size Is an aqueous dispersion of an acid-modified polyolefin resin having a melt flow rate measured in accordance with JIS K7210 of 0.01 g / 10 min to 100 g / 10 min from a group consisting of a polyester resin and a polyurethane resin. An aqueous dispersion added with 1% by mass to 10% by mass of at least one selected is applied to the resin film layer and dried. A paper container, characterized in that to those were.

  According to the present invention, not only the contents that can be stored for a long time in a conventional paper container, but also the strong permeability such as a liquid bath agent or a spice that cannot be stored for a long time in a conventional paper container. And a paper container that can withstand long-term storage of diffusible contents.

It is a schematic cross section of the laminated body for forming the paper container which concerns on embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a schematic cross-sectional view of a laminate for forming a paper container according to an embodiment. As shown in FIG. 1, the laminate in the present embodiment includes an outermost layer 1, a paper base layer 2, an adhesive resin layer 3, a barrier layer 4, a resin film layer 5 made of polyethylene terephthalate or nylon, and an anchor coat layer 6. The innermost layer 7 is laminated in this order. The laminate according to the present embodiment contains 0.01% by mass to 20% by mass of an unsaturated carboxylic acid or its anhydride as a constituent component as an anchor coat agent for forming the anchor coat layer 6, and has a number average particle size. A group consisting of a polyester resin and a polyurethane resin for an aqueous dispersion of an acid-modified polyolefin resin having a diameter of 0.5 μm or less and a melt flow rate measured according to JIS K7210 of 0.01 g / 10 min to 100 g / 10 min. It is characterized by using an aqueous dispersion to which at least one selected from 1 to 10% by mass is added. By using such an anchor coat agent, the adhesion between the resin film layer 5 and the innermost layer 7 can be strengthened without impairing physical properties such as pinhole resistance and sealability, and delamination due to penetration of the contents can be achieved. Can be prevented.

The outermost layer 1 and the innermost layer 7 in the present invention are made of a resin material that can be melted by heat and fused together. Specific examples of such materials include polypropylene, medium density polyethylene, high density polyethylene, high pressure low density polyethylene, Ziegler low density polyethylene, linear low density polyethylene, and linear low density polyethylene using a metallocene catalyst. Etc. Among these materials, it is preferable to use a high-pressure method low-density polyethylene in terms of excellent sealing properties and slipping properties. The thickness of the outermost layer 1 is preferably 5 μm to 50 μm. The innermost layer 7 preferably has a thickness of 30 μm to 100 μm. In the outermost layer 1 and the innermost layer 7, an antioxidant, an ultraviolet absorber, an antistatic agent, an antiblocking agent, a flame retardant, a dye, a pigment, and the like are appropriately added within a range not impairing the effects of the present invention. May be.
Moreover, it is preferable that the extrusion temperature of resin at the time of laminating the innermost layer 7 is 300 degreeC-330 degreeC. When the extrusion temperature is less than 300 ° C., the adhesive strength is weakened, and delamination tends to occur when a highly penetrating content is filled. Moreover, when it exceeds 330 degreeC, since the sealing performance fall by generation | occurrence | production of a polyethylene odor and decomposition | disassembly of polyethylene is recognized, it is not preferable.

As the paper base material constituting the paper base material layer 2 in the present invention, known paper such as paperboard such as coated ball, card paper, ivory paper, and Manila ball, milk carton base paper, cup base paper, kraft paper, and high-quality paper is used. Can be used. The basis weight of the paper substrate may be suitably determined depending on the form of paper container, it is ^{usually, 100g / m 2 ~500g / m} 2.
Further, before laminating the outermost layer 1 or the adhesive resin layer 3 on the paper base material layer 2, the surface of the paper base material to be the paper base material layer 2 is subjected to corona discharge treatment, flame treatment, ozone treatment, imine anchor coating. An agent treatment or the like may be performed. By performing these treatments, the adhesive strength between the layers can be improved. The corona discharge treatment can be performed by using a known corona discharge treatment device and passing the paper substrate through the generated corona atmosphere. The corona discharge output at this time is preferably 1.0 kW to 10.0 kW. The frame processing can be performed by using a known frame processing device and burning the surface of the paper substrate with fire. The frame output at this time is preferably 50% to 100%. The ozone treatment can be performed by passing a paper substrate through a generated ozone atmosphere using a known ozone treatment device. The ozone concentration at this time is preferably 10 g / Nm ^{3 to} 30 g / Nm ³ . The imine anchor coating agent treatment can be performed by applying a known imine anchor coating agent to the surface of the paper substrate by gravure printing or the like.

  The adhesive resin layer 3 in the present invention is mainly composed of an acid-modified resin material such as ethylene and methacrylic acid. Specific examples of such materials include ethylene-acrylic acid ester copolymers, ethylene-ethyl acrylate copolymers, ethylene-methacrylic acid ester copolymers, ethylene-ethyl methacrylate copolymers, ethylene-methacrylic acid. -A methacrylic acid ester copolymer, an ionomer resin, etc. are mentioned. Among these materials, the barrier layer 4 (metals and inorganic oxides) and strong adhesion can be obtained, and at the same time, the processability is superior from the viewpoint of equipment, and the price of these materials is compared. In terms of low cost, ethylene-acrylic acid ester copolymer, ethylene-ethyl acrylate copolymer, ethylene-methacrylic acid ester copolymer, ethylene-ethyl methacrylate copolymer, ethylene-methacrylic acid-methacrylic acid An acid ester copolymer is preferable, and an ethylene-methacrylic acid ester copolymer having an acid content of about 1% to 15% is most preferable. The thickness of the adhesive resin layer 3 is preferably 5 μm to 80 μm.

The barrier layer 4 in the present invention is made of a material having a property of shielding sunlight or the like and a property of not allowing water vapor, water, gas, etc. to pass through. Specific examples of such materials include aluminum foil, but instead of aluminum foil, a metal such as aluminum or inorganic oxide such as silica or alumina formed on resin film layer 5 by vacuum deposition or sputtering. The vapor deposition film may be used. In addition, among the materials described above, by using a material having good thermal conductivity such as aluminum, the heat of the hot air blown to the laminated body is easily diffused during box making, and the sealing performance can be further improved. it can.
When using aluminum foil as the barrier layer 4, it is preferable to laminate | stack on the resin film layer 5 using adhesives for lamination, such as a urethane type adhesive agent, a vinyl adhesive agent, an acrylic adhesive agent, an epoxy adhesive agent. The thickness of the aluminum foil is preferably 3 μm to 20 μm. The coating amount of the adhesive may be appropriately set so that the thickness of the adhesive is 0.1g / m ² ~5g / m ² as a dry film. Aluminum also has a mirror surface and a matte surface, but the matte surface has a variety of adhesives and adhesive resin layers due to the difference in surface properties between the mirror surface and the matte surface (difference in anchor effect due to surface roughness). It has stronger adhesion to Therefore, when the adhesiveness with the resin film layer 5 is desired to be increased, the mat surface is directed toward the resin film layer 5, and when the adhesiveness with the adhesive resin layer 3 is desired to be increased, the mat surface is directed toward the adhesive resin layer 3. It is desirable. In the present invention, the “mirror surface” of the aluminum foil means a glossy surface produced when the foil comes into contact with the rolling roll when the aluminum foil is produced by over rolling, and “mat surface”. The term “glossy surface” means a non-glossy surface caused by contact between foils.
When using a metal vapor deposition film or an inorganic oxide vapor deposition film as the barrier layer 4, it is preferable that the thickness of a metal vapor deposition film or an inorganic oxide vapor deposition film is 100 to 1000 mm.

The resin film layer 5 in the present invention is composed of polyethylene terephthalate or nylon film or the like. The thickness of the resin film layer 5 is preferably 5 μm to 30 μm.
In addition, as the resin film layer 5, when a resin film that has been subjected to easy adhesion treatment on one side, for example, Unitika PTMB, is used as a resin film layer 5, lamination is performed by attacking contents on the easy adhesion treatment surface. Since the strength is likely to decrease, it is preferable to laminate the easily adhesive-treated surface facing the barrier layer 4 and the untreated surface or the corona treated surface facing the anchor coat layer 6. Further, the untreated surface of such a resin film may be appropriately subjected to corona treatment in-line.

The anchor coat layer 6 in the present invention contains 0.01% by mass to 20% by mass, preferably 0.1% by mass to 10% by mass of an unsaturated carboxylic acid or its anhydride as a constituent component, and has a number average particle size. Is 0.5 μm or less, preferably 0.01 μm to 0.2 μm, and the melt flow rate measured according to JIS K7210 is 0.01 g / 10 min to 100 g / 10 min, preferably 0.1 g / 10 min to 50 g / An aqueous dispersion obtained by adding 1% by mass to 10% by mass of at least one selected from the group consisting of a polyester resin and a polyurethane resin is added to the resin film layer 5 with respect to the aqueous dispersion of the acid-modified polyolefin resin for 10 minutes. It is formed by applying and drying. When the content of the unsaturated carboxylic acid or anhydride thereof in the acid-modified polyolefin resin is less than 0.01% by mass, the content resistance suitability is lowered. On the other hand, when the content exceeds 20% by mass, the acid-modified polyolefin resin particles Aggregates easily. When the number average particle diameter of the acid-modified polyolefin resin exceeds 0.5 μm, the acid-modified polyolefin resin particles are difficult to disperse. In addition, when the melt flow rate of the acid-modified polyolefin resin is less than 0.01 g / 10 minutes, the acid-modified polyolefin resin particles are likely to aggregate, whereas when it exceeds 100 g / 10 minutes, the suitability for content resistance decreases. . An aqueous dispersion containing such an acid-modified polyolefin resin is commercially available, for example, Arrow Base (registered trademark) series (SE-1200J2) manufactured by Unitika Ltd. The coating amount of the aqueous dispersion containing the acid-modified polyolefin resin is preferably a dry thickness of ^{0.01g / m 2 ~5.0g / m 2} , more preferably 0.1g / m ² ~3g / m ² What is necessary is just to set suitably so that it may become. Although the coating method of the aqueous dispersion containing acid-modified polyolefin resin is not specifically limited, Gravure printing, a roll coater system, etc. are mentioned.

The laminate in the present embodiment can be manufactured using the above-described materials by a method known in the packaging material field, for example, an extrusion lamination method, a coextrusion lamination method, a dry lamination method, a wet lamination method, or the like. Further, when performing lamination, each layer may be subjected to corona discharge treatment, flame treatment, ozone treatment, imine anchor coating agent treatment, and the like, if necessary.
The obtained laminate can be boxed to produce paper containers of various shapes such as a gable top type and a brick type. Specifically, first, a blank sheet is obtained by punching the laminate into a predetermined shape and simultaneously providing ruled lines at necessary places. Next, the resin material constituting the innermost layer 7 or the outermost layer 1 is melted by a frame seal or a hot air seal, and the body portion is bonded to obtain a cylindrical sleeve. Subsequently, the cylindrical sleeve is supplied to a filling machine, and after forming a bottom part on the filling machine, it can be manufactured by a known method of filling a liquid bath agent and sealing the top part.

  Paper containers manufactured in this way can be used for packaging general contents with strong penetrability and diffusibility, such as liquid baths, wines, fragrances, spices, non-foods, and contents with added solvents. Can be used. In particular, it is suitable for the packaging of liquid products containing naturally derived essential oil components such as plant extracts, herbal medicines and herbs.

[Example 1]
Using a two-component curable urethane adhesive, the 6 μm thick aluminum foil (barrier layer) matte side is laminated to a 12 μm thick polyethylene terephthalate film (resin film layer) by the dry lamination method. Produced. The amount of adhesive applied at this time was such that the thickness of the adhesive was 3 g / m ² as a dry film. On the other hand, a high-pressure low-density polyethylene (outermost layer) having a thickness of 20 μm is laminated on one surface of a paperboard (paper base material layer) having a basis weight of 400 g / m ² by an extrusion lamination method, and an imine-based material is applied to the other surface of the paperboard. The anchor coating agent was applied so that the dry weight was 0.5 g / m ² . Subsequently, the aluminum surface of the previously produced laminate film was made to face the surface of the paperboard on which the imine-based anchor coating agent was applied, and an ethylene-methacrylic acid copolymer (N0908C manufactured by Mitsui DuPont Polychemical Co., Ltd.) having a thickness of 20 μm therebetween. , Acid content 9%) (adhesive resin layer) extruded and sand laminated, high pressure method low density polyethylene / paperboard / ethylene-methacrylic acid copolymer / (mirror surface) aluminum foil (mat surface) / polyethylene terephthalate film layer A sand laminate film having a structure was prepared.
Next, on the polyethylene terephthalate film surface of the sand laminate film, the content of unsaturated carboxylic acid or anhydride thereof: 15% by mass, number average particle size of 0.5 μm or less, melt flow rate measured according to JIS K7210: 30 g / 10 The water after adding 8% by mass of polyester resin to the aqueous dispersion of acid-modified polyolefin resin (Unitika Ltd. Arrow Base (registered trademark) SE-1200J2) so that the thickness after drying is 0.3 μm. It is applied and dried by heating to form an anchor coat layer. On the surface of this anchor coat layer, a 60 μm-thick low-density polyethylene (LC520 manufactured by Nippon Polyethylene Co., Ltd.) is applied by extrusion lamination while applying ozone treatment. Laminated, high pressure low density polyethylene / paperboard / ethylene-meta A laminate having a layer configuration of crylic acid copolymer / (mirror surface) aluminum foil (matte surface) / polyethylene terephthalate film / anchor coat layer / low density polyethylene was obtained. After printing the desired pattern and display on the obtained laminate by the offset printing method, it is punched into a predetermined shape, and at the same time, ruled lines are provided at the necessary locations to form a blank sheet, and then the body is pasted with a frame seal The cylindrical sleeve is combined, and this cylindrical sleeve is supplied to a filling machine. After the bottom part is formed on the filling machine, the contents are filled, and the top part is sealed to thereby seal the top part. A paper container was made.

In addition, the following three types were used as contents.
・ Liquid bathing agent (gardenia extract, yuzu extract, camphor root extract, tea leaf extract, rosemary extract, lemongrass oil, geranium oil, palmarosa oil, lemon oil, ethanol, glycerin, menthol, sorbitol, polyglyceryl-10 laurate, citrus Acid, sodium citrate, magnesium ascorbyl phosphate, water etc.)
・ Red wine (including sulfite as an additive)
·cloves

[Comparative Example 1]
Using a two-component curable urethane adhesive, the 6 μm thick aluminum foil (barrier layer) matte side is laminated to a 12 μm thick polyethylene terephthalate film (resin film layer) by the dry lamination method. Produced. The amount of adhesive applied at this time was such that the thickness of the adhesive was 3 g / m ² as a dry film. On the other hand, a high-pressure low-density polyethylene (outermost layer) having a thickness of 20 μm is laminated on one surface of a paperboard (paper base material layer) having a basis weight of 400 g / m ² by an extrusion lamination method, and an imine-based material is applied to the other surface of the paperboard. The anchor coating agent was applied so that the dry weight was 0.5 g / m ² . Subsequently, the aluminum surface of the previously produced laminate film was made to face the surface of the paperboard on which the imine-based anchor coating agent was applied, and an ethylene-methacrylic acid copolymer (N0908C manufactured by Mitsui DuPont Polychemical Co., Ltd.) having a thickness of 20 μm therebetween. , Acid content 9%) (adhesive resin layer) extruded and sand laminated, high pressure method low density polyethylene / paperboard / ethylene-methacrylic acid copolymer / (mirror surface) aluminum foil (mat surface) / polyethylene terephthalate film layer A sand laminate film having a structure was prepared.
Next, on the polyethylene terephthalate film surface of the sand laminate film, the content of unsaturated carboxylic acid or anhydride thereof: 23% by mass, number average particle diameter of 0.5 μm or less, melt flow rate measured according to JIS K7210: 300 g / 10 An aqueous dispersion containing an acid-modified polyolefin resin is applied so that the thickness after drying is 0.3 μm, and dried by heating to form an anchor coat layer. The anchor coat layer has a thickness as an innermost layer. 60 μm low density polyethylene (LC520 manufactured by Nippon Polyethylene Co., Ltd.) was laminated by extrusion lamination while ozone treatment, and high pressure method low density polyethylene / paperboard / ethylene-methacrylic acid copolymer / (mirror surface) aluminum foil (mat) Surface) / polyethylene terephthalate film / anchor coat A laminate having a layer configuration of G layer / low density polyethylene was obtained. After printing the desired pattern and display on the obtained laminate by the offset printing method, it is punched into a predetermined shape, and at the same time, ruled lines are provided at the necessary locations to form a blank sheet, and then the body is pasted with a frame seal A cylindrical sleeve is combined, this cylindrical sleeve is supplied to a filling machine, a bottom part is formed on the filling machine, the same contents as in Example 1 are filled, and the top part is sealed to make a comparative example 1 gable top type paper container was produced.

[Comparative Example 2]
Using a two-component curable urethane adhesive, the 6 μm thick aluminum foil (barrier layer) matte side is laminated to a 12 μm thick polyethylene terephthalate film (resin film layer) by the dry lamination method. Produced. The amount of adhesive applied at this time was such that the thickness of the adhesive was 3 g / m ² as a dry film. On the other hand, a high-pressure method low-density polyethylene (outermost layer) having a thickness of 20 μm is laminated on one surface of a paperboard with a basis weight of 400 g / m ² by an extrusion lamination method, and an imine anchor coating agent is dried on the other surface of the paperboard. And 0.5 g / m ² . Subsequently, the mirror surface of the aluminum foil of the previously produced laminate film was subjected to in-line corona discharge treatment while facing the surface on which the imine anchor coating agent of the paperboard was applied, and an ethylene-methacrylic acid copolymer having a thickness of 20 μm was interposed therebetween. Extruded polymer (N0908C, Mitsui Dupont Polychemical Co., Ltd., acid content 9%), sand laminated, high pressure method low density polyethylene / paperboard / ethylene-methacrylic acid copolymer / (mirror surface) aluminum foil (mat surface) / A sand laminate film having a layer structure of polyethylene terephthalate film was prepared.
Next, an isocyanate anchor coating agent was applied to the surface of the polyethylene terephthalate film of the sand laminate film so that the dry weight was 0.2 g / m ² . While the surface of the sand laminate film coated with an isocyanate anchor coating agent is opposed to a high-pressure method low-density polyethylene film (innermost layer) having a thickness of 40 μm, the high-pressure method low-density polyethylene having a thickness of 20 μm is subjected to ozone treatment. Extrusion, high pressure method low density polyethylene / paperboard / ethylene-methacrylic acid copolymer / (mirror surface) aluminum foil (matte surface) / polyethylene terephthalate film / anchor coat layer / high pressure method low density polyethylene / high pressure method low density polyethylene film A layered laminate was obtained. After printing the desired pattern and display on the obtained laminate by the offset printing method, it is punched into a predetermined shape, and at the same time, ruled lines are provided at the necessary locations to form a blank sheet, and then the body is pasted with a frame seal A cylindrical sleeve is combined, this cylindrical sleeve is supplied to a filling machine, a bottom part is formed on the filling machine, the same contents as in Example 1 are filled, and the top part is sealed to make a comparative example Two gable top type paper containers were prepared.

<Durability evaluation>
First, the laminate strength of the laminate before filling with the liquid bath was confirmed. Specifically, each of the laminates was prepared in the same manner as in Example 1 and Comparative Examples 1 and 2, and a test piece having a width of 15 mm and a length of 100 mm was cut out from these, and the measurement object was measured from one end of the cut out test piece. The interlayer was peeled off by 50 mm and chucked on both chucks of the Tensilon tensile tester. In a 25 ° C. atmosphere, the film was peeled in the 180 ° direction at a pulling rate of 50 mm / min, and the maximum load was measured.
In the laminate of Example 1, an attempt was made to measure the laminate strength between the polyethylene terephthalate film and the low density polyethylene. However, the laminate strength was too high, and the substrate was broken (not peelable).
In the laminate of Comparative Example 1, the laminate strength between the polyethylene terephthalate film and the low density polyethylene was measured and found to be 3.5 N / 15 mm width.
In the laminate of Comparative Example 2, an attempt was made to measure the laminate strength between the polyethylene terephthalate film and the high-pressure low-density polyethylene. However, the laminate strength was too high, and the substrate was broken (not peelable).

  Next, after storing the paper container of Example 1 and Comparative Examples 1-2 at 50 ° C. for 2 weeks to 4.5 months, the paper container was disassembled, and a test piece having a width of 15 mm and a length of 100 mm was cut out. The laminate strength was confirmed by the same method as described above. The results are shown in Tables 1-3.

  An attempt was made to measure the laminate strength between the polyethylene terephthalate film and the low density polyethylene in the test piece cut out from the paper container of Example 1 after storing the contents for 2 weeks to 4.5 months. The material filled with any of the agent, red wine, and clove content was too high in strength to cause substrate destruction (non-peelable).

  In the test piece cut out from the paper container of Comparative Example 1 after storage of the liquid bathing agent for 2 weeks, the sample filled with any of the liquid bathing agent, red wine, and clove was between the polyethylene terephthalate film and the low density polyethylene ( Delamination occurred in layer B).

  In the test piece cut out from the paper container of Comparative Example 2 after storing the liquid bathing agent for 2 weeks, the laminate strength between the polyethylene terephthalate film and the high-pressure method low-density polyethylene (interlayer C) was measured to be 0.4 N / Although the width was 15 mm, after the storage for one month, peeling occurred between the polyethylene terephthalate film and the high-pressure low-density polyethylene (interlayer C). In the test piece cut out from the paper container of Comparative Example 2 after storage of red wine for 2 weeks and 1 month, the laminate strength between the polyethylene terephthalate film and the high pressure method low density polyethylene (interlayer C) was measured. Although it was 5 N / 15 mm width and 0.1 N / 15 mm width, peeling occurred between the polyethylene terephthalate film and the high-pressure low-density polyethylene (interlayer C) after storage for 1.5 months. Further, in the test piece cut out from the paper container of Comparative Example 2 after storing the clove for 2 weeks, the laminate strength between the polyethylene terephthalate film and the high-pressure method low-density polyethylene (interlayer C) was measured. Although the width was 15 mm, after the storage for one month, peeling occurred between the polyethylene terephthalate film and the high-pressure low-density polyethylene (interlayer C).

  Based on the above, the paper container of Example 1 shows no delamination or leakage of contents even when stored for a long period of time, such as liquid bathing agents, wine, spices, etc., which have strong penetrating and diffusing contents. It is clear that it is excellent in durability compared with the paper containers of Comparative Examples 1 and 2.

<Sealability evaluation>
Paper containers were produced by changing the temperature at which the top and bottom parts of the paper container were sealed in a filling machine in the range of 250 ° C. to 400 ° C., and the sealing properties of the paper container were evaluated according to the following criteria. The results are shown in Table 4.
◎: Seal is good and liquid bath agent does not leak ○: Seal is good and liquid bath agent does not leak, but whitening phenomenon of aluminum foil △: Seal is weak, but liquid bath agent does not leak ×: Liquid There is a bathing agent leak (however, leaks in the low temperature range are caused by poor sealing, and leaks in the high temperature range are caused by aluminum cracks or pinholes)

  From the above, the paper container of Example 1 has the same pinhole resistance as the paper containers of Comparative Examples 1 and 2.

  DESCRIPTION OF SYMBOLS 1 Outermost layer, 2 Paper base material layer, 3 Adhesive resin layer, 4 Barrier layer, 5 Resin film layer, 6 Anchor coat layer, 7 Innermost layer.

Claims (3)

An outermost layer, a paper base layer, an adhesive resin layer, a barrier layer, a resin film layer made of polyethylene terephthalate or nylon, an anchor coat layer, and a paper container formed by boxing a laminate in which the innermost layer is laminated in order,
The anchor coat layer contains 0.01% by mass to 20% by mass of an unsaturated carboxylic acid or an anhydride thereof as a constituent component, and has a number average particle size of 0.5 μm or less and a melt flow measured according to JIS K7210. 1% by mass to 10% by mass of at least one selected from the group consisting of a polyester resin and a polyurethane resin is added to an aqueous dispersion of an acid-modified polyolefin resin having a rate of 0.01 g / 10 min to 100 g / 10 min. A paper container formed by applying the dried aqueous dispersion to the resin film layer and drying it.   The paper container according to claim 1, wherein the aqueous dispersion of the acid-modified polyolefin resin contains at least one crosslinking agent selected from the group consisting of an isocyanate compound, an epoxy compound, and a silane coupling agent. .   The adhesive resin layer is an ethylene-acrylic acid ester copolymer, an ethylene-ethyl acrylate copolymer, an ethylene-methacrylic acid ester copolymer, an ethylene-ethyl methacrylate copolymer or an ethylene-methacrylic acid-methacrylic acid ester. The paper container according to claim 1 or 2, comprising a copolymer.

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