JP2015155323A - Paper container for liquid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper container for a liquid having rigidity without a printing crack at molding, a pin hole caused by heating at sealing and the deterioration of water vapor barrier properties.

SOLUTION: In a paper container for a liquid having a square cylindrical shape, a blank consisting of a laminated sheet laminated with at least a surface resin layer 3, a base material layer 4 being cardboard, an intermediate layer 6 and a sealant layer 8 in this order has a sealant layer as an inside surface and is folded at a folding rule and sealed. The intermediate layer 6 consists of a polyester film and the sealant layer 8 is an olefin-based film having a gas barrier layer.

COPYRIGHT: (C)2015,JPO&INPIT

Description

  The present invention relates to a paper container for storing a liquid content. In particular, the present invention relates to a paper container for storing a liquid content containing hydrogen peroxide.

  2. Description of the Related Art Conventionally, for a hair color, a two-component type product using a first agent of a color drug and a second agent of an oxidizing agent has been often used. In particular, the second agent is an aqueous solution containing hydrogen peroxide as a main component and is relatively stable at a temperature around 20 ° C., but has a problem that it gradually decomposes while generating oxygen gas. .

  As the packaging container for storing the second agent, since the internal pressure in the container tends to increase due to the generation of oxygen gas, a packaging container having rigidity is used. For example, a bottle container made of polyethylene resin is used.

  However, such a bottle container has a problem that it is difficult to crush and reduce the volume when a used empty container is discarded.

  In order to solve these problems, the oxygen transmission rate of the packaging container is equal to or greater than the oxygen gas generation amount per unit time generated by the decomposition of hydrogen peroxide, and the water vapor transmission rate per unit time. There is a proposal of a packaging container made of a film set to be approximately equal to a value obtained by dividing the mass of hydrogen peroxide decomposed by the hydrogen peroxide content (Patent Document 1).

  However, this packaging container is a gusset type packaging container, and has a form in which a through hole and a connector that can be opened and closed are connected to a part of the lower part of the packaging container. The film constituting the packaging container may be selected from oxygen permeability and water vapor permeability, but the packaging form is complicated, and the packaging container is a flexible laminated film, so it is difficult to handle. There's a problem.

  There is a liquid paper container that can reduce the volume of a used empty container. Since the paper container is rigid and can be resealed, it is used to store various contents.

  However, a liquid paper container having a polyethylene layer / base material layer / sealant layer structure can permeate oxygen gas generated from the contents and suppress an increase in the internal pressure of the paper container. In order to improve the thickness, the sealant layer is thickened. However, when the sealant layer is thickened, there is a problem that printing cracks occur at a portion where a bending load is applied when the paper container is molded. Moreover, when the sealant layer is made thin, there is a concern that the sealing strength is lowered and the water vapor barrier property is lowered. In addition, there is a concern that pinholes are generated due to heating during sealing, leading to liquid leakage of the contents.

  In order to improve the occurrence of pinholes due to heating during sealing, there is one in which a polyester film is laminated on an intermediate layer. For example, it is composed of polyethylene layer / paper substrate layer / polyester film / sealant layer.

  Laminating polyester film on the intermediate layer has improved heat resistance and can prevent the occurrence of pinholes due to heating at the time of sealing, but there is a problem that printing cracks occur at the part where bending load is applied at the time of molding. is there.

  Therefore, there is a demand for a rigid liquid paper container that does not have a print hole at the time of molding or a pinhole due to heating at the time of sealing, and does not deteriorate the water vapor barrier property.

JP 2003-267454 A

  SUMMARY OF THE INVENTION In view of the problems of the background art, the present invention provides a rigid liquid paper container that does not have a print hole at the time of molding or a pinhole due to heating at the time of sealing, and does not have a decrease in water vapor barrier properties. is there.

  In order to solve the above-mentioned problems, the inventors have conducted intensive studies and completed the present invention.

The invention according to claim 1 of the present invention uses a paperboard as a base material layer, and at least a blank made of a laminated sheet in which a surface resin layer / base material layer / intermediate layer / sealant layer are laminated in order, and a sealant layer as an inner surface. In a square cylindrical liquid paper container formed by folding and sealing a crease line,
The intermediate layer is made of a polyester film,
In the liquid paper container, the sealant layer is an olefin film having a gas barrier layer.

  The invention according to claim 2 of the present invention is the liquid paper container according to claim 1, wherein the gas barrier layer is arranged on the polyester film side.

The invention according to claim 3 of the present invention is a blank made of a laminated sheet in which a paperboard is used as a base material layer, and at least a surface resin layer / a base material layer / an intermediate layer / a sealant layer is laminated in order, and the sealant layer is an inner surface. In a square cylindrical liquid paper container formed by folding and sealing a crease line,
The intermediate layer consists of an olefin-based film having a polyester film and a gas barrier layer,
In the liquid paper container, the sealant layer is made of an olefin film.

  The invention according to claim 4 of the present invention is the liquid paper container according to any one of claims 1 to 3, wherein the gas barrier layer is formed of an inorganic oxide vapor deposition layer.

  The invention according to claim 5 of the present invention is the liquid paper container according to claim 4, wherein the inorganic oxide is aluminum oxide or silicon oxide.

  The liquid paper container of the present invention has rigidity with no pinholes due to printing cracks during molding or heating during sealing, and without deterioration of water vapor barrier properties. In particular, even when the hair color second agent is stored, the water vapor barrier property is good and the swelling of the paper container is suppressed.

Further, a polyolefin sheet having a paper base layer and at least a base layer / intermediate layer / sealant layer having a polyethylene layer, the intermediate layer being made of a polyester film, and the sealant layer having a gas barrier layer By comprising a film, the thickness of the sealant layer, that is, the polyolefin film can be reduced, and printing cracks during molding can be prevented. Moreover, the thing without a pinhole by the heating at the time of sealing is obtained.

  Moreover, since it has a gas barrier layer, even if the thickness of a polyolefin-type film is reduced, the fall of water vapor | steam barrier property can be prevented. Water vapor barrier properties can be maintained.

  In addition, the gas barrier layer is disposed on the polyester film side, so that stable seal strength can be obtained.

  In addition, the intermediate layer is made of an olefin film having a polyester film and a gas barrier layer, and the sealant layer is made of an olefin film, so that the thickness of the sealant layer, that is, the polyolefin film can be reduced. Can prevent printing cracks. Furthermore, a stable seal strength can be obtained.

  Further, since the gas barrier layer is made of an inorganic oxide vapor deposition layer, the water vapor barrier property can be improved, and a metal detector can be used for foreign matter inspection. In addition, used empty containers are easy to dispose. In addition, since the inorganic oxide vapor deposition layer is made of aluminum oxide or silicon oxide, the production cost is low and the productivity is high.

It is explanatory drawing which shows an example of a laminated constitution of a laminated sheet. It is explanatory drawing which shows an example of the laminated | multilayer film of a structure of an intermediate | middle layer / adhesion layer / sealant layer. It is explanatory drawing which shows an example of the blank for forming the liquid paper container of this invention. It is explanatory drawing which shows an example of the liquid paper container (gable top type) of this invention. It is explanatory drawing which shows an example of the liquid paper container (flat top type) of this invention.

  Hereinafter, modes for carrying out the present invention will be described.

  FIG. 1 is an explanatory diagram illustrating an example of a layer configuration of a laminated sheet. It is a lamination sheet which forms the liquid paper container of this invention. The laminated sheet 1 uses paperboard as a base material layer, and is composed of a printing layer 2 / surface resin layer 3 / base material layer 4 / adhesive resin layer 5 / intermediate layer 6 / adhesive layer 7 / sealant layer 8. Further, the configuration of the intermediate layer 6 / adhesive layer 7 / sealant layer 8 will be described in detail. Reference numeral 10 indicates a laminated film having a configuration of the intermediate layer 6 / adhesive layer 7 / sealant layer 8.

  FIG. 2 is an explanatory diagram showing an example of a laminated film having a configuration of an intermediate layer / adhesive layer / sealant layer. As shown in FIG. 2A, the laminated film 10 has a configuration of polyester film 11 / adhesive layer 7 / gas barrier layer 12 / sealant layer 13 (linear low density polyethylene). A sealant layer 13 (linear low density polyethylene) having a gas barrier layer 12 is used and bonded to a polyester film 11 as an intermediate layer through an adhesive layer 7.

  FIG. 2-2 is of the polyester film 11 / adhesive layer 7 / low density polyethylene 14 / gas barrier layer 12 / sealant layer 13 (linear low density polyethylene). A sealant layer 13 (linear low density polyethylene) having a gas barrier layer 12 is used and bonded to a polyester film via a low density polyethylene 14. The adhesive layer 7 is used as an anchor coat. FIGS. 2-1 and 2-2 are examples in which a sealant layer having a gas barrier layer is stacked.

  FIG. 2-3 shows the gas barrier layer 12 / linear low density polyethylene 15 / adhesive layer 7 / polyester film 11 / adhesive layer 7 / sealant layer 13 (linear low density polyethylene). FIG. 2-3 is an example in which the intermediate layer is composed of an olefin film having a polyester film and a gas barrier layer.

  FIG. 3 is an explanatory view showing an example of a blank for forming the liquid paper container of the present invention. FIG. 3A shows the surface of the blank. The blank 20 includes a back panel 110, a left panel 120, a front panel 130, a right panel 140, and a back panel 150 through a vertical crease line a. Each panel has a lateral crease line b. The body part C is formed, the top part B is formed on the top part of the body part C, and the bottom part D is formed on the bottom part of the body part C. Further, a crease line c is formed at the top of the left panel 120 and the right panel 140, and a top seal portion A is formed at the top of the top B, respectively. Further, a plug mounting hole 160 for mounting a plug is formed on the top B of the front panel 130.

  FIG. 3-2 shows the back side of the blank. In the blank 20, an olefin film having a polyester film and a gas barrier layer is laminated inside the base material layer. The area | region 200 (it shows with dot shape) where the olefin-type film which has a gas barrier layer is laminated | stacked is shown.

  FIG. 4 is an explanatory view showing an example of a liquid paper container (gable top type) in which the blank of FIG. 3 is assembled. FIG. 4A is a perspective view of the liquid paper container 30. After sealing the outer surface of the blank back panel and the inner surface of the back panel to form a square cylindrical sleeve (not shown), seal the bottom D, fill the contents, and seal the top seal A This is a sealed gable-top liquid paper container 30. In order to facilitate the pouring of the contents, a cap 170 is attached to the top B of the front panel. The liquid paper container of the present invention is a paper container having rigidity without cracking of the printed layer at the time of molding, pinholes due to heating at the time of sealing, and without deterioration of the water vapor barrier property. Moreover, the oxygen gas generated from the contents is permeated appropriately and suppresses the increase in the internal pressure of the paper container. FIG. 4B shows a region 200 (shown in a dotted shape) where an olefin film having a gas barrier layer is laminated.

  FIG. 5 is an explanatory view showing an example of the liquid paper container (flat top type) of the present invention. The liquid paper container of the present invention can also be a flat top liquid paper container shown in FIG. FIG. 5-2 shows a region 200 (shown as a dot) in which an olefin film having a gas barrier layer is laminated.

  Furthermore, the form for implementing this invention is demonstrated.

As the base material layer 4 used in the present invention, a paperboard having a basis weight of 200 to 500 g / m ² and a density of 0.6 to 1.1 g / cm ³ can be used. For example, milk base paper or cardboard can be used.

  A surface resin layer is provided on the surface of the paperboard. As the surface resin layer 3, low density polyethylene (LDPE), linear low density polyethylene (LLDPE), or the like can be used. Using these resins, the base material layer is formed into a film by an extruder and laminated. The range of 15-30 micrometers is preferable.

  Moreover, the printing layer 2 can be provided on the surface of the surface resin layer 3. Adhesion with the printed layer can be improved by corona treatment and ozone treatment of the surface resin layer surface.

As a method of forming the printing layer 2, a commonly used printing method such as gravure printing, offset printing, flexographic printing, inkjet printing, silk screen printing, or the like can be used.

  The adhesive resin layer 5 adheres the base material layer and the intermediate layer. As the adhesive resin layer 5, low density polyethylene (LDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), linear low density polyethylene (LLDPE), ethylene-methacrylic acid copolymer (EMMA), ethylene -Olefin resins such as acrylic acid copolymer (EAA), ionomer, cyclic polyolefin, and polypropylene can be used. Using these resins, the base material layer and the intermediate layer are bonded together by the sand polyethylene method. The thickness of the adhesive resin layer is preferably in the range of 10 to 60 μm.

  Examples of the olefin film 6 having a gas barrier layer include low density polyethylene (LDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), linear low density polyethylene (LLDPE), and ethylene. -Acrylic acid copolymer (EAA), ethylene-ethyl acrylate copolymer, ethylene-methacrylic acid copolymer (EMMA), ethylene-propylene copolymer, methylpentene polymer, polybutene polymer, ionomer, cyclic polyolefin, polypropylene An ethylene-unsaturated carboxylic acid copolymer such as an ethylene-acrylic acid copolymer or an ethylene-methacrylic acid copolymer can be used. The olefin-based film having a gas barrier layer can be laminated as a sealant layer or laminated as an intermediate layer.

  When used as the sealant layer 13, a resin such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), or high-density polyethylene (HDPE) is formed by an extruder. Can be used. It may be a single layer or multiple layers. A linear low density polyethylene (LLDPE) resin is preferable. The thickness is preferably in the range of 30 to 100 μm. Moreover, when using as an intermediate | middle layer, the range of 20-40 micrometers is preferable, and what is necessary is just to determine suitably so that the printing crack at the time of shaping | molding may not arise especially.

  The gas barrier layer 12 is preferably an inorganic oxide vapor deposition layer. A metal detector having a water vapor barrier property and a foreign object inspection can be used. Moreover, the used empty container has easy disposal property.

  As the inorganic oxide, diatom oxide, aluminum oxide, magnesium oxide, calcium, potassium, tin, sodium, boron, titanium, lead, zirconium, yttrium and the like can be used. Of these, silicon oxide and magnesium oxide are preferable in terms of productivity and price. The thickness of the vapor deposition layer is preferably in the range of 5 to 300 nm, and more preferably in the range of 5 to 100 nm.

  The adhesive layer 7 is for bonding the intermediate layer and the sealant layer together. The adhesive layer 7 can be dry laminated using an adhesive. As the adhesive, for example, a polyurethane adhesive or a two-component curable adhesive composed of an organic polyol and a polyfunctional polyisocyanate can be used. Moreover, you may bond together using an anchor coat agent (adhesive), extruding a sealant layer with an extruder.

  Specific examples of the present invention will be described below.

A low density polyethylene resin (LDPE) was extruded and laminated on the surface of a paperboard having a basis weight of 380 g / m ² using an extruder. A polyethylene film having a thickness of 18 μm was laminated. Gravure printing was performed on the surface of the polyethylene film to provide a printing layer.

  Next, a laminated film composed of an intermediate layer / adhesive layer / sealant layer is formed. As the sealant layer, a linear low density polyethylene film (LLDPE) 60 μm on which aluminum oxide was deposited was used. The thickness of aluminum oxide was 30 nm.

  Next, the vapor deposition layer of the said linear low density polyethylene film (LLDPE) and 12 micrometers of polyester films which are an intermediate | middle layer were bonded together by the dry lamination method using the two-component hardening type urethane type adhesive agent. In this way, a laminated film was formed.

  Next, the polyester film surface of the laminated film was bonded to the back surface of the paperboard by a low-density polyethylene resin (LDPE) using an extruder, and bonded by the sand polyethylene method. The thickness of the sand polyethylene film (LDPE) was 30 μm. In this way, a laminated sheet was prepared.

  A laminated film is formed. A linear low density polyethylene film (LLDPE) 40 μm on which aluminum oxide was deposited by 30 nm and a polyester film 12 μm were extruded with a low density polyethylene resin (LDPE) using an extruder, and bonded together by the sand polyethylene method. The thickness of the sand polyethylene film (LDPE) was 20 μm. The vapor deposition layer was arranged on the sand polyethylene film side. In this way, a laminated film was formed.

  Next, the laminated film was processed in the same manner as in Example 1 to produce a laminated sheet.

  A laminated film is formed. A linear low-density polyethylene film (LLDPE) 20 μm on which aluminum oxide was deposited by 30 nm and a polyester film 12 μm were bonded together by a dry laminating method using a two-component urethane adhesive. A linear low density polyethylene film (LLDPE) surface and a polyester film surface were bonded together.

  Next, the polyester film surface and a linear low-density polyethylene film (LLDPE) 30 μm were bonded together by a dry laminating method using a two-component curable urethane adhesive. In this way, a laminated film was formed.

  Next, the laminated film was processed in the same manner as in Example 1 to produce a laminated sheet.

  A laminated film is formed. As the sealant layer, a linear low density polyethylene film (LLDPE) of 60 μm in which silicon oxide was deposited by 30 nm was used.

  Next, the vapor deposition layer of the said linear low density polyethylene film (LLDPE) and 12 micrometers of polyester films which are an intermediate | middle layer were bonded together by the dry lamination method using the two-component hardening type urethane type adhesive agent. In this way, a laminated film was formed.

  Next, the laminated film was processed in the same manner as in Example 1 to produce a laminated sheet.

  Below, the comparative example of this invention is demonstrated.

<Comparative Example 1>
A laminated film is formed. A polypropylene film 20 μm on which aluminum oxide was deposited at a thickness of 30 nm and a linear low density polyethylene film (LLDPE) 30 μm were extruded with a low density polyethylene resin (LDPE) by an extruder and bonded together by the sand polyethylene method. The thickness of the sand polyethylene film (LDPE) was 20 μm.

  Next, 12 μm of the polyester film and the vapor deposition layer of the polypropylene film were bonded together by a dry laminating method using a two-component curable urethane adhesive. In this way, a laminated film was formed.

  Next, the laminated film was processed in the same manner as in Example 1 to produce a laminated sheet.

<Comparative Example 2>
A laminated film is formed. Aluminum foil 6 μm and polyester film 12 μm were bonded together by a dry lamination method using a two-component curable urethane adhesive.

  Next, the polyester film surface and a linear low density polyethylene film (LLDPE) 60 μm were bonded together by a dry laminating method using a two-component curable urethane adhesive. In this way, a laminated film was formed.

  Next, the laminated film was processed in the same manner as in Example 1 to produce a laminated sheet.

<Comparative Example 3>
A laminated film is formed. A high-density polyethylene film (HDPE) 60 μm and a polyester film 12 μm were bonded together by a dry laminating method using a two-component curable urethane adhesive.

  Next, the polyester film surface and a linear low density polyethylene film (LLDPE) of 80 μm were bonded together by a dry laminating method using a two-component curable urethane adhesive. In this way, a laminated film was formed.

  Next, the laminated film was processed in the same manner as in Example 1 to produce a laminated sheet.

  Next, using the laminated sheets prepared in Examples 1 to 4 and Comparative Examples 1 to 3, a blank as shown in FIG. 3 is formed, the blank is molded with a filling molding machine, and the hair color second agent (peroxidation) Hydrogen concentration: 6%). A 70-square, 500-ml stoppered gable-top liquid paper container was prepared.

  The prepared liquid paper container was evaluated by the following method.

<Evaluation method>
-Confirmed printing cracks during molding. A sample having no print cracking was rated as “Good”. The thing with a crack was set as x.
-The water vapor permeability of the laminated sheet was evaluated. If the water vapor transmission rate was 2.0 {g / m ² · day} or less, it was evaluated as ◯. The above is x. MOCON company PERMATRAN-W3 / 33 was used for the measuring apparatus. Measurement conditions were 40 ° C. and 90% RH.
-The oxygen permeability of the laminated sheet was evaluated. If the oxygen permeability was 50 {cc / m ² · day} or more, it was evaluated as ◯. The following was marked with x. MOCON OXTRAN-2 / 21 was used as a measuring device. Measurement conditions were 20 ° C. and 60% RH.

  The evaluation results are shown in Table 1.

In Examples 1 to 4, printing cracks at the time of molding were not observed. However, it was observed in Comparative Example 1 and Comparative Example 3. This is probably because printing cracks occurred because the thickness of the polyolefin film on the wetted side of the polyester film was thicker. Further, in Comparative Example 2, since the aluminum foil was laminated, the oxygen permeability was low, and the internal pressure of the paper container was increased by oxygen to cause swelling.

  The liquid paper container of the present invention has rigidity with no pinholes due to printing cracks during molding or heating during sealing, and without deterioration of water vapor barrier properties. Even when the second hair color agent is stored, the water vapor barrier property is good and the swelling of the paper container is suppressed.

DESCRIPTION OF SYMBOLS 1: Laminated sheet 2: Printing layer 3: Front resin layer 4: Base material layer 5: Adhesive resin layer 6: Intermediate layer 7: Adhesive layer 8: Sealant layer 9: Inorganic oxide vapor deposition layer 10: Multilayer film (intermediate layer / Adhesive layer / sealant layer)
11: Polyester film 12: Gas barrier layer 13: Sealant layer (linear low density polyethylene)
14: Low density polyethylene layer 15: Linear low density polyethylene layer 20: Blank for forming the liquid paper container of the present invention 30: Liquid paper container of the present invention (gable top type)
40: Liquid paper container of the present invention (flat top type)
110: Back panel 120: Left panel 130: Front panel 140: Right panel 150: Back panel 160: Hole for plug attachment 170: Plug 200: Area possessed by olefin-based film having gas barrier layer (shown in dotted form)
A: Top seal part B: Top part C: Body part D: Bottom part a: Vertical crease line b: Horizontal crease line c: Crease line

Claims (5)

A square formed by using a paperboard as a base material layer, and at least a blank made of a laminated sheet in which a surface resin layer / base material layer / intermediate layer / sealant layer are sequentially laminated, with the sealant layer as an inner surface, a crease line folded, and sealed In a cylindrical liquid paper container,
The intermediate layer is made of a polyester film,
The liquid paper container, wherein the sealant layer is an olefin film having a gas barrier layer.   The liquid paper container according to claim 1, wherein the gas barrier layer is disposed on the polyester film side. A square formed by using a paperboard as a base material layer, and at least a blank made of a laminated sheet in which a surface resin layer / base material layer / intermediate layer / sealant layer are sequentially laminated, with the sealant layer as an inner surface, a crease line folded, and sealed In a cylindrical liquid paper container,
The intermediate layer consists of an olefin-based film having a polyester film and a gas barrier layer,
The liquid paper container, wherein the sealant layer is made of an olefin film.   The liquid paper container according to any one of claims 1 to 3, wherein the gas barrier layer is formed of an inorganic oxide vapor deposition layer.   5. The liquid paper container according to claim 4, wherein the inorganic oxide is aluminum oxide or silicon oxide.