JP5375037B2 - Paper container - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper container tolerable of the long storage of a content having strong permeability and diffusibility such as a liquid bath agent, wine, and a condiment while maintaining characteristics such as anti-pinhole properties, and sealing properties. <P>SOLUTION: The paper container is obtained by processing a laminate into a box, the laminate being composed of an outermost layer 1, a paper substrate layer 2, an adhesive resin layer 3a, a resin film layer 4, a barrier layer 5, an adhesive resin layer 3b, and an innermost layer 6 laminated in this order. This paper container is suitable for packaging a content having strong permeability and diffusibility such as a liquid bath agent, wine, and a condiment. <P>COPYRIGHT: (C)2010,JPO&amp;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 base material layers / adhesive resin layers / barrier layers / resin films. A laminate comprising a layer / innermost layer, for example, a laminate of 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 a polyethylene terephthalate film (hereinafter referred to as a PET film), and this resin film layer is laminated for the purpose of reinforcing the barrier layer, and the barrier layer of the barrier layer due to external physical stress. In addition to preventing cracks and pinholes, it also has 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 a highly permeable or diffusible content such as a liquid bathing agent, wine, spices, etc. and stored for a long time, it is between the PET film and polyethylene. It was confirmed that the contents penetrated and delamination occurred, and the contents could not function as a paper container.
Accordingly, the present invention has been made in view of the above circumstances, and maintains strong penetrability and diffusivity such as liquid bath agents, wine, spices and the like while maintaining properties such as pinhole resistance and sealability. The object is to provide a paper container that can withstand long-term storage of the contents it has.

The present inventor found that the cause of delamination in the conventional paper container is that the PET film mainly used as a constituent material of the resin film layer is nonpolar (has no functional group), and therefore dry lamination. When a laminate was produced by extrusion coating or extrusion coating, it was considered that the adhesion between the PET film and the material constituting the other layer would be insufficient. In addition, the present inventor found that aluminum foil, aluminum vapor deposition film, or inorganic oxide vapor deposition film such as silica and alumina, which is mainly used as a constituent material of the barrier layer, has a strong polarity (there are many functional groups). It was thought that strong adhesion with various materials constituting the layer would be obtained.
Based on the above considerations, the present inventor has variously studied the layer structure of the laminate, and by laminating the resin film layer on the outside of the container rather than the barrier layer, the resin film is secured while ensuring the barrier properties of the barrier layer. The barrier layer is reinforced by the layer to prevent the occurrence of cracks and pinholes, and at the same time, by interposing an adhesive resin layer made of a specific copolymer between the barrier layer and the innermost layer, It was found that the inner layer and the innermost layer are firmly adhered to each other, and delamination due to the permeation of the contents having high permeability, high diffusibility and high swellability such as a liquid bath agent can be prevented. It came to be completed.
That is, the first invention for achieving the above object comprises an outermost layer , a paper base material layer , an adhesive resin layer , a resin film layer , an aluminum foil, a metal vapor deposition film, or an inorganic oxide vapor deposition film. a barrier layer, an ethylene - acrylic acid ester copolymer, ethylene - ethyl acrylate copolymer, ethylene - methacrylic acid ester copolymer or ethylene - an adhesive resin layer consisting of methacrylic acid ethyl acrylate copolymer, and an innermost layer It is a paper container which is formed by box-producing laminated bodies sequentially laminated.
Here, tree fat film layer preferably made of polyethylene terephthalate or nylon.

  According to the present invention, while maintaining characteristics such as pinhole resistance and sealing properties, it is impossible to store for a long period of time in a conventional paper container as well as contents that could be stored for a long time in a conventional paper container. Thus, it is possible to provide a paper container that can withstand long-term storage of contents having strong permeability and diffusibility, such as liquid bathing agents and spices.

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 3a, a resin film layer 4, a barrier layer 5, an adhesive resin layer 3b, and an innermost layer 6. They are laminated in order. The laminate according to the present embodiment is characterized in that the resin film layer 4 is laminated on the outside of the container rather than the barrier layer 5. By laminating the resin film 4 at such a position, adhesion between the barrier layer 5 and the innermost layer 6 can be strengthened without impairing the reinforcing effect on the barrier layer 5, and delamination due to penetration of the contents can be prevented. .

  The outermost layer 1 and the innermost layer 6 in the present invention are made of a resin material that can be melted by heat and fused to each other. 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. Moreover, it is preferable that the thickness of the innermost layer 6 is 10 μm to 100 μm. In the outermost layer 1 and the innermost layer 6, 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.

  The adhesive resin layers 3a and 3b in the present invention are 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 (metals and inorganic oxides) and strong adhesion can be obtained, and at the same time, the processability is excellent from the viewpoint of equipment, and the price is relatively low among these materials. In terms of being inexpensive, ethylene-acrylic acid ester copolymer, ethylene-ethyl acrylate copolymer, ethylene-methacrylic acid ester copolymer, ethylene-ethyl methacrylate copolymer, ethylene-methacrylic acid-methacrylic acid Ester copolymers are preferred. In addition, although the resin material which comprises two layers 3a and 3b may be the same and may differ, in order to improve the adhesiveness between the paper base material layer 2 and the resin film layer 4, it adheres. It is preferable to use an ethylene-methacrylic acid-methacrylic acid ester copolymer which is a ternary copolymer for the resin layer 3a. The adhesive resin layer 3b is preferably a binary copolymer in order to further improve the adhesion to the aluminum foil, and the acid content of the binary copolymer is preferably about 9% to 15%. The thickness of the adhesive resin layers 3a and 3b is preferably 5 μm to 80 μm.

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 3a 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, anchor coating agent treatment. Etc. may be applied. 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 anchor coating agent treatment can be performed by applying a known aqueous anchor coating agent to the surface of the paper substrate by gravure printing or the like.

  The resin film layer 4 in the present invention is made of a resin material having heat resistance capable of withstanding the heat of hot air blown to the laminate when boxing and having high physical strength. Specific examples of such a material include polyethylene terephthalate and nylon. The thickness of the resin film layer 4 is preferably 5 μm to 30 μm.

The barrier layer 5 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 the resin film layer 4 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 5, it is preferable to laminate | stack on the resin film layer 4 using adhesives for lamination, such as a urethane type adhesive agent, a vinyl adhesive agent, an acrylic adhesive agent, and an epoxy adhesive agent. Further, when laminating the aluminum foil, in order to improve the adhesive strength between the layers, the aluminum foil is laminated with the mirror surface facing the resin film layer 4 and the matte surface of the aluminum foil facing the adhesive resin layer 3b. It is preferable. 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.
Moreover, when using a metal vapor deposition film or an inorganic oxide vapor deposition film as the barrier layer 5, it is preferable to form a vapor deposition film on the resin film layer 4 by which the anchor coating agent process was carried out. The thickness of the metal vapor deposition film or the inorganic oxide vapor deposition film is preferably 100 to 1000 mm.

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 lamination is performed, each layer may be subjected to corona discharge treatment, flame treatment, ozone treatment, anchor coating agent treatment, and the like as 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, a resin material constituting the innermost layer 6 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.

  The paper container manufactured in this way can be used for packaging of general contents having strong penetrability and diffusibility such as liquid baths, wines, fragrances, spices, etc. It is suitable for packaging liquid products containing natural oil components such as herbs.

[Example 1]
Using a two-component curable urethane adhesive, a 12 μm thick polyethylene terephthalate film (resin film layer) and a 6 μm thick aluminum foil (barrier layer) consisting of a mirror surface and a mat surface are laminated by the dry lamination method. A laminate film was prepared. 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) with 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 anchor coat is applied to the other surface of the paperboard. The agent was applied at a dry weight of 0.5 g / m ² . Subsequently, while the polyethylene terephthalate film surface of the laminate film prepared above was subjected to corona discharge treatment and ozone treatment in-line, it was made to face the surface coated with the anchor coat agent of the paperboard, and in the meantime, 20 μm thick ethylene-methacrylic acid- A methacrylate copolymer (AN 4228C, Mitsui DuPont Polychemical Co., Ltd., acid content 4%) (adhesive resin layer) was extruded and sand-laminated, and high pressure low density polyethylene / paperboard / ethylene-methacrylic acid-methacrylic ester copolymer A sand laminate film having a layer structure of coalescence / polyethylene terephthalate film / (mirror surface) aluminum foil (matt surface) was produced.
Next, on the aluminum foil surface of the sand laminate film, an ethylene-methacrylic acid ester copolymer (N1108C, Mitsui Dupont Polychemical Co., Ltd., N1108C, acid content 11%) (adhesive resin layer) and a high pressure of 40 μm thickness are formed. Low density polyethylene (innermost layer) is laminated by coextrusion lamination method, high pressure method low density polyethylene / paperboard / ethylene-methacrylic acid-methacrylic acid ester copolymer / polyethylene terephthalate film / (mirror surface) aluminum foil (mat) Surface) / ethylene-methacrylic acid ester copolymer / high pressure low density polyethylene layered product 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-based adhesive, a polyethylene terephthalate film having a thickness of 12 μm and an aluminum foil having a mirror surface and a mat surface having a thickness of 6 μm were laminated by a dry lamination method to produce a laminate film. 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 having a thickness of 20 μm is laminated on one surface of a paperboard having a basis weight of 400 g / m ² by an extrusion lamination method, and an anchor coating agent is dried on the other surface of the paperboard by 0.5 g / m in dry weight. It applied so that it might become ² . Subsequently, the aluminum foil surface of the previously produced laminate film was subjected to in-line corona discharge treatment while facing the surface coated with the anchor coat agent of the paperboard, and an ethylene-methacrylate copolymer having a thickness of 20 μm ( Mitsui Dupont Polychemical Co., Ltd. N0908C, acid content 9%) extruded and sand laminated, high pressure method low density polyethylene / paperboard / ethylene-methacrylate copolymer / (mirror surface) aluminum foil (mat surface) / polyethylene A sand laminate film having a layer structure called a terephthalate film was produced.
Next, on the polyethylene terephthalate surface of the sand laminate film, a 20 μm thick ethylene-methacrylic acid-methacrylic acid ester copolymer (AN4228C, Mitsui DuPont Polychemical Co., Ltd., acid content 4%) and a 40 μm thick high pressure method High density low density polyethylene / paperboard / ethylene-methacrylic acid ester copolymer / (mirror surface) aluminum foil (matte surface) / polyethylene terephthalate film / ethylene-methacrylic acid-methacrylic A laminate having a layer structure of acid ester copolymer / high pressure method 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-based adhesive, a polyethylene terephthalate film having a thickness of 12 μm and an aluminum foil having a mirror surface and a mat surface having a thickness of 6 μm were laminated by a dry lamination method to produce a laminate film. 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 having a thickness of 20 μm is laminated on one surface of a paperboard having a basis weight of 400 g / m ² by an extrusion lamination method, and an anchor coating agent is dried on the other surface of the paperboard by 0.5 g / m in dry weight. It applied so that it might become ² . Subsequently, the aluminum foil surface of the previously produced laminate film was subjected to in-line corona discharge treatment while facing the surface coated with the anchor coat agent of the paperboard, and an ethylene-methacrylate copolymer having a thickness of 20 μm ( Mitsui Dupont Polychemical Co., Ltd. N0908C, acid content 9%) extruded and sand laminated, high pressure method low density polyethylene / paperboard / ethylene-methacrylate copolymer / (mirror surface) aluminum foil (mat surface) / polyethylene A sand laminate film having a layer structure called a terephthalate film was produced.
Next, an anchor coating agent was applied to the polyethylene terephthalate surface of the sand laminate film so that the dry weight was 0.5 g / m ² . The surface of the sand laminate film coated with the anchor coating agent is opposed to a high-pressure method low-density polyethylene film having a thickness of 40 μm, and a high-pressure method low-density polyethylene having a thickness of 20 μm is extruded between them. -A laminate having a layer structure of methacrylate copolymer / (mirror surface) aluminum foil (matte surface) / polyethylene terephthalate film / high pressure method low density polyethylene / high pressure method low density polyethylene film 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.

[Comparative Example 3]
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 anchor coating agent is applied to the other surface of the paperboard. It was applied so that the dry weight was 0.5 g / m ² . Subsequently, an aluminum foil composed of a mirror surface and a mat surface having a thickness of 6 μm is subjected to in-line corona discharge treatment and ozone treatment while facing the surface coated with the anchor coating agent of the paperboard, and 20 μm thick ethylene-methacrylic acid therebetween. Acid ester copolymer (N0908C, Mitsui Dupont Polychemical Co., Ltd., acid content 9%) is extruded and sand-laminated, and high pressure method low density polyethylene / paperboard / ethylene-methacrylate copolymer / (mirror surface) aluminum foil A sand laminate film having a layer configuration of (matt surface) was produced.
Next, an ethylene-methacrylic acid ester copolymer (N1108C, Mitsui Dupont Polychemical Co., Ltd., N1108C, acid content: 11%) having a thickness of 40 μm and a high-pressure method low-density polyethylene having a thickness of 40 μm (on the aluminum foil surface of the sand laminate film) The innermost layer) is laminated by a coextrusion lamination method, and a high pressure method low density polyethylene / paperboard / ethylene-methacrylate copolymer (N0908C) / (mirror surface) aluminum foil (matt surface) / ethylene-methacrylic acid copolymer weight A laminate having a layer structure of coalescence (N1108C) / high pressure method 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 Three 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 to 3, and a test piece having a width of 15 mm and a length of 100 mm was cut out from these, and the measurement target was taken 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 aluminum foil and the ethylene-methacrylic acid ester copolymer, but the laminate strength was too high and the substrate was destroyed (unpeelable). .
In the laminate of Comparative Example 1, when the laminate strength between the polyethylene terephthalate film and the ethylene-methacrylic acid-methacrylic acid ester copolymer was measured, it was 1.3 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).
In the laminate of Comparative Example 3, an attempt was made to measure the laminate strength between the aluminum foil and the ethylene-methacrylic acid ester copolymer (N1108C), but the laminate strength was too high and the substrate was destroyed (peeling). impossible).

  Next, after storing the paper container of Example 1 and Comparative Examples 1-3 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 aluminum foil and the ethylene-methacrylate copolymer in the test piece cut out from the paper container of Example 1 after storing the contents for 2 weeks to 4.5 months. However, the one filled with the contents of the liquid bath, red wine, and clove also had a laminate strength that was too high to cause the substrate to break (not peelable).

  In the test piece cut out from the paper container of Comparative Example 1 after storing the liquid bath agent for 2 weeks, the laminate strength between the polyethylene terephthalate film and the ethylene-methacrylic acid-methacrylic acid ester copolymer (interlayer B) was measured. However, although it was 0.1 N / 15 mm width, peeling occurred between the polyethylene terephthalate film and the ethylene-methacrylic acid-methacrylic acid ester copolymer (interlayer B) after storage for 1 month. . For the test piece cut out from the paper container of Comparative Example 1 after storage of red wine for 2 weeks and 1 month, the laminate strength between the polyethylene terephthalate film and the ethylene-methacrylic acid-methacrylic acid ester copolymer (interlayer B) was measured. As a result, it was 0.8 N / 15 mm width and 0.1 N / 15 mm width, respectively, but after storage for 1.5 months, the polyethylene terephthalate film and the ethylene-methacrylic acid-methacrylic acid ester copolymer Separation occurred between the layers (interlayer B). Moreover, in the test piece cut out from the paper container of Comparative Example 1 after storing the clove for 2 weeks, the laminate strength between the polyethylene terephthalate film and the ethylene-methacrylic acid-methacrylic acid ester copolymer (interlayer B) was measured. However, although it was 0.02 N / 15 mm width, peeling occurred between the polyethylene terephthalate film and the ethylene-methacrylic acid-methacrylic acid ester copolymer (interlayer B) after storage for 1 month. .

  In the test piece cut out from the paper container of Comparative Example 2 after storing the liquid bath 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 0.04 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. Moreover, when the laminate strength between the polyethylene terephthalate film and the high-pressure method low-density polyethylene (interlayer C) was measured on the test piece cut out from the paper container of Comparative Example 2 after storing the clove for 2 weeks, 0.01 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).

  With the test piece cut out from the paper container of Comparative Example 3 after storing the contents for 2 weeks to 4.5 months, the laminate strength between the aluminum foil and the ethylene-methacrylate copolymer (N1108C) will be measured. However, the laminate filled with any of the contents of the liquid bath agent, red wine and clove was too strong in the laminate, causing the substrate to break (not peelable). However, leakage of the contents of the paper container of Comparative Example 3 was recognized due to a pinhole in the ruled line portion. Since the laminate of Comparative Example 3 does not have a PET film, the pressure resistance is low, and pinholes are easily generated when ruled lines are provided.

  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 to 3.

<Sealability evaluation>
Paper containers were produced by changing the ring temperature when sealing the top and bottom parts of the paper container 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 aluminum foil is damaged △: Seal is weak, but liquid bath agent does not leak ×: Liquid bath There is a leakage of the agent (however, the leakage in the low temperature region is caused by poor sealing, and the leakage in the high temperature region is caused by aluminum cracks or pinholes)

  From the above, the paper container of Example 1 has a pinhole resistance equivalent to that of the paper containers of Comparative Examples 1 and 2, and has a sealing property as compared with the paper containers of Comparative Examples 1 and 2. It is clear that it is excellent. Further, the paper container of Example 1 has the same sealing performance as the paper container of Comparative Example 3, but has excellent pinhole resistance in a high temperature region.

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

Explanation of symbols

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

Claims (5)

Outermost and the paper base layer, and the adhesive resin layer, and the resin film layer, a barrier layer made of aluminum foil, a metal deposited film or an inorganic oxide deposited film, ethylene - acrylic ester copolymer, ethylene - acrylic acid ethyl acrylate copolymer, ethylene - to the adhesive resin layer consisting of methacrylic acid ethyl acrylate copolymer, characterized by being obtained by Seihako a laminate obtained by sequentially laminating the innermost layer - methacrylic acid ester copolymer or ethylene Paper container. 2. The paper container according to claim 1, wherein an acid content of a copolymer constituting the adhesive resin layer between the barrier layer and the innermost layer is 9% to 15%. The adhesive resin layer between the paper substrate layer and the resin film layer is, e styrene - methacrylic acid - paper container according to claim 1 or 2, characterized in that it consists of methacrylic acid ester copolymer.   The paper container according to any one of claims 1 to 3, wherein the resin film layer is made of polyethylene terephthalate or nylon. The paper container according to any one of claims 1 to 4, wherein the paper container is used for packaging a content having strong permeability and diffusibility.

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