JP2015214093A - Paper container for fluid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper container for fluid capable of storing a content containing cysteamine of 7% or more, because although some kinds of reducers, namely curling agents or the like, containing cysteamine of 7% or more for hair are used at a beauty salon or the like, such reducers or curling agents cannot be stored in a paper container for fluid due to defects such as fluid spill and cave-in of a port plug occur.SOLUTION: Provided is the paper container for fluid for storing a content containing cysteamine, the paper container for fluid is formed of a packaging material which is formed by laminating at least a front resin layer, paper layer, barrier layer, and sealant layer in the order. An adhesive agent between the barrier layer and sealant layer includes a XDI biuret.

Description

  The present invention relates to a liquid paper container for dealing with uses such as a liquid having strong permeability.

  Conventionally, paper containers have been put into practical use instead of bottles and cans as liquid containers for beverages such as milk and alcoholic beverages. Tea, juice, coffee, soup, soba soup, etc. are packed in square or cylindrical paper containers and sold through various distribution channels such as supermarkets.

  Liquid paper containers have excellent filling suitability in factories, can save space in transportation and storage, and are also suitable for recycling after use. Because of these advantages, liquid paper containers are indispensable for daily life in modern society.

  However, for beverages that are highly permeable, such as alcoholic beverages, the material design, layer structure, and manufacturing method of the paper container are compatible with the contents so that it can withstand transportation and long-term storage. ing.

JP2013-95501A

  In recent years, application development of liquid paper containers in the non-food field has been promoted, but in non-food applications, some contents have strong permeability. Examples of using hexamethylene diisocyanate or xylylene diisocyanate as an adhesive for laminates used in paper containers are described in the above-mentioned patent documents because liquid bathing agents and spices have strong permeability.

  However, in the case of a reducing agent for hair used in beauty salons, so-called curling agents, etc., there are those containing 7% or more of cysteamine, and even if the method described in the patent document is used, Due to a problem, the liquid paper container could not be used. Problems include, for example, peeling of the sealant layer, liquid leakage from the paper container, and depression of the plug.

  This invention is made | formed in view of such a situation, and it aims at providing the liquid paper container which can accommodate the content which contains 7% or more of cysteamine.

As a means for solving the above-mentioned problems, the invention according to claim 1 is a liquid paper container containing contents containing cysteamine, wherein at least a surface resin layer, a paper layer, a barrier layer, and a sealant layer are provided. A liquid paper container comprising a packaging material laminated in order, wherein the adhesive between the barrier layer and the sealant layer contains an XDI biuret.

Since the adhesive of XDI biuret has a high solid content viscosity, the initial adhesion immediately after bonding is high, the coating amount is easily processed uniformly, and the self-cohesion is high, so that the adhesion can be increased. For this reason, according to this invention, it becomes possible to provide the liquid paper container which can accommodate the content which contains 7% or more of cysteamine.

FIG. 1 is a partial sectional view of an embodiment of a liquid paper container according to the present invention.

  Hereinafter, an embodiment for carrying out the present invention will be described in detail with reference to FIG.

  The liquid paper container of the present invention is essentially composed of a packaging material in which a surface resin layer, a paper layer, a barrier layer, and a sealant layer are laminated. The packaging material shown in FIG. , Surface resin layer (1) to which printing ink (8) has been applied, paper layer (2), adhesive layer (3), barrier layer (4), adhesive (5), adhesive layer (6), sealant layer ( 7) is composed of a laminated body (10) laminated. The adhesive layer (3) bonds the paper layer (2) and the barrier layer (4), and the adhesive (5) includes the sealant layer (7) together with the adhesive layer (6) extruded by the extruder. And the barrier layer (4).

  For the surface resin layer (1), low density polyethylene (LDPE) or linear low density polyethylene (LLDPE) can be used. These can be coated on the surface of the paper layer (2) using an extruder. When printing on the surface with the printing ink (8), the surface resin layer (1) surface may be subjected to corona treatment in order to improve adhesion.

Paper layer (2) may be selected from the range of basis weight ^{200g / m 2 ~500g / m 2} , a density ^{0.6g / cm 3 ~1.1g / cm 3} .

  The adhesive layer (3) is extruded by an extruder to bond the paper layer (2) and the barrier layer (4). High density polyethylene (HDPE), low density polyethylene (LDPE), medium density polyethylene (MDPE), linear low density polyethylene (LLDPE), ethylene methacrylic acid (EMAA), ethylene-ethyl acrylate copolymer (EAA) ), Ionomer, polypropylene (PP), and the like. The thickness is preferably in the range of 10 μm to 60 μm, and if it is 10 μm or less, sufficient adhesive strength cannot be obtained. Furthermore, in order to increase the adhesive strength, corona treatment, ozone treatment and anchor coating can be performed on the paper layer (2) and the barrier layer (4).

  For the barrier layer (4), a polyethylene terephthalate (PET) film subjected to alumina vapor deposition, silica vapor deposition, or aluminum vapor deposition is used. The film thickness is preferably 6 μm to 25 μm, and the deposition thickness is preferably 5 nm to 100 nm. The vapor deposition surface may face the sealant surface or the paper layer (2) side.

  A barrier layer (4) is completed by providing a coating layer by laminating on the vapor deposition surface of a polyethylene terephthalate (PET) film. The coating layer contains at least one metal alkoxide and polyvinyl alcohol (PVA) or ethylene-vinyl alcohol (EVA) copolymer, and may contain a silane coupling agent or a silane monomer. The coating layer is a coating film made of a gas barrier composition obtained by polycondensation by a sol-gel method. By providing this coat layer, the barrier property is improved, and the adhesive force with the adhesive (5) is further increased, and problems such as liquid leakage can be prevented.

For the adhesive (5), an isocyanate group compound which is a monomer having an isocyanate group or a derivative thereof is used. As the isocyanate group compound used in the present invention, XDI biuret is mainly used. As a result, the adhesive strength between the sealant layer (7) and the barrier layer (4) can be greatly increased, and the resistance to cysteamine can be increased.

For the purpose of further reinforcing the adhesive strength, the surface of the barrier layer (4) may be subjected to anchor coating, ozone treatment, corona treatment or the like. The XDI biuret is applied to the barrier layer (4) and dried before use. The XDI biuret is positioned between the adhesive layer (6) and the barrier layer (4) by extrusion, and the barrier layer (4) Adhesion with the sealant layer (7) is performed to form the liquid paper container laminate (10). Barrier film when applied to (4), the solid content of 3% to 15%, the amount of coating is good in the range of ^{0.5g / m 2 ~3.0g / m 2} .

  The adhesive layer (6) is extruded by an extruder and is between the barrier layer (4) and the sealant layer (7), and bonds the barrier layer (4) and the sealant layer (7) together with the adhesive (5). High density polyethylene (HDPE), low density polyethylene (LDPE), medium density polyethylene (MDPE), linear low density polyethylene (LLDPE), ethylene methacrylic acid (EMAA), ethylene-ethyl acrylate copolymer (EAA) ), Ionomer, polypropylene (PP), and the like. The thickness is preferably in the range of 10 μm to 60 μm, and if it is 10 μm or less, sufficient adhesive strength cannot be obtained. Furthermore, in order to increase the adhesive strength, the surface of the adhesive layer (6) can be subjected to corona treatment, ozone treatment and anchor coating.

  High density polyethylene (HDPE), low density polyethylene (LDPE), medium density polyethylene (MDPE), and linear low density polyethylene (LLDPE) can be used for the sealant layer (7). Among these, linear low density polyethylene (LLDPE) is more preferable, and the density is 0.925 or less and the melt index (MI) is 4 or more. The sealant layer (7) has a thickness of 30 μm to 100 μm and is formed by a T-die or an inflation method. The sealant layer (7) is used so as to be inside the liquid paper container (12).

  A liquid paper container laminate (10) having the structure of FIG. 1 was prototyped with the structures of Examples 1 to 6 and Comparative Examples 1 and 2, a liquid paper container was prepared, and the contents were put in and evaluated.

<Example 1>
An XDI biuret is used for the adhesive (5).
Silica was used for the vapor deposition layer of the barrier layer (4).
Tetraethoxysilane (TEOS) and polyvinyl alcohol (PVA) were used for the coating layer of the barrier layer (4).
In the laminating method of the barrier layer (4) and the sealant layer (7), an adhesive (5) was provided on the barrier layer (4), and then the sealant layer (7) was extruded by an adhesive layer (6) by an extruder. .

<Example 2>
An XDI biuret is used for the adhesive (5).
Silica was used for the vapor deposition layer of the barrier layer (4).
For the coating layer of the barrier layer (4), tetraethoxysilane (TEOS) and polyvinyl alcohol (PVA) were added with a silane coupling agent.
In the laminating method of the barrier layer (4) and the sealant layer (7), an adhesive (5) was provided on the barrier layer (4), and then the sealant layer (7) was extruded by an adhesive layer (6) by an extruder. .

<Example 3>
An XDI biuret is used for the adhesive (5).
Alumina was used for the vapor deposition layer of the barrier layer (4).
Tetraethoxysilane (TEOS) and polyvinyl alcohol (PVA) were used for the coating layer of the barrier layer (4).
In the laminating method of the barrier layer (4) and the sealant layer (7), an adhesive (5) was provided on the barrier layer (4), and then the sealant layer (7) was extruded by an adhesive layer (6) by an extruder. .

<Example 4>
For the adhesive (5), an HDI biuret is used in addition to the XDI biuret.
Silica was used for the vapor deposition layer of the barrier layer (4).
Tetraethoxysilane (TEOS) and polyvinyl alcohol (PVA) were used for the coating layer of the barrier layer (4).
In the laminating method of the barrier layer (4) and the sealant layer (7), an adhesive (5) was provided on the barrier layer (4), and then the sealant layer (7) was extruded by an adhesive layer (6) by an extruder. .

<Example 5>
In addition to XDI biuret, an isophorone diisocyanate nurate type is used for the adhesive (5).
Silica was used for the vapor deposition layer of the barrier layer (4).
Tetraethoxysilane (TEOS) and polyvinyl alcohol (PVA) were used for the coating layer of the barrier layer (4).
In the laminating method of the barrier layer (4) and the sealant layer (7), an adhesive (5) was provided on the barrier layer (4), and then the sealant layer (7) was extruded by an adhesive layer (6) by an extruder. .

<Example 6>
As the adhesive (5), an adduct type of isophorone diisocyanate is used in addition to XDI biuret.
Silica was used for the vapor deposition layer of the barrier layer (4).
Tetraethoxysilane (TEOS) and polyvinyl alcohol (PVA) were used for the coating layer of the barrier layer (4).
In the laminating method of the barrier layer (4) and the sealant layer (7), an adhesive (5) was provided on the barrier layer (4), and then the sealant layer (7) was extruded by an adhesive layer (6) by an extruder. .

<Comparative Example 1>
An HDI biuret is used for the adhesive (5).
Silica was used for the vapor deposition layer of the barrier layer (4).
Tetraethoxysilane (TEOS) and polyvinyl alcohol (PVA) were used for the coating layer of the barrier layer (4).
In the laminating method of the barrier layer (4) and the sealant layer (7), an adhesive (5) was provided on the barrier layer (4), and then the sealant layer (7) was extruded by an adhesive layer (6) by an extruder. .

<Comparative Example 2>
For the adhesive (5), a urethane two-component type is used.
Silica was used for the vapor deposition layer of the barrier layer (4).
Tetraethoxysilane (TEOS) and polyvinyl alcohol (PVA) were used for the coating layer of the barrier layer (4).
The method of laminating the barrier layer (4) and the sealant layer (7) is as follows.
The laminate of the adhesive layer (6) and the sealant layer (7) was dry laminated.

  Table 1 shows a summary of Examples 1-6 and Comparative Examples 1-2.

<Evaluation 1>
Put the curling agent (strong penetrability: 7% cysteamine content) into the prototype liquid paper container and store it for 1.5 months in an environment of 60 ° C and 30% RH (accelerated test), then laminate between the barrier layer and sealant The strength was measured using a tensile tester. The pulling speed was 300 mm / min.

<Result>
The test results are shown in Table 2. The unit is N / 15 mm, and the evaluation result is indicated by ○ ×.

Compared with Examples 1 to 6, Comparative Examples 1 and 2 are not able to satisfy the required quality as a liquid paper container due to the significant decrease in strength after the accelerated test.

<Evaluation 2>
In the liquid paper container filling machine, the level of the filling seal temperature was set to a seal temperature of −30 ° C. to + 30 ° C. with respect to the standard production conditions, and liquid leakage at the bottom of the liquid paper container was confirmed.

<Result>
The test results are shown in Table 3. In addition, 5/100 in the table indicates that liquid leakage occurred in 5 out of 100 confirmations. The evaluation results are indicated by ○ ×.

In Examples 1 to 6, there is no occurrence of liquid leakage in a wide temperature range of standard production conditions + 30 ° C. to −30 ° C., and filling suitability is good. Compared with this, in Comparative Examples 1 and 2, the occurrence of liquid leakage was observed, and the filling suitability was insufficient.

  As a result of the above, it is possible to provide a liquid paper container that can contain contents containing 7% or more of cysteamine by including an XDI biuret in the adhesive between the barrier layer and the sealant layer. I was able to verify.

DESCRIPTION OF SYMBOLS 1 ... Surface resin layer 2 ... Paper layer 3 ... Adhesive layer 4 ... Barrier layer 5 ... Adhesive 6 ... Adhesive layer 7 ... Sealant layer 8 ... Printing ink 10 ... Liquid paper container stack 12 ... Inside of container

Claims (1)

  A liquid paper container containing contents containing cysteamine, comprising a packaging material in which at least a surface resin layer, a paper layer, a barrier layer, and a sealant layer are laminated in this order, and between the barrier layer and the sealant layer A liquid paper container, wherein the adhesive contains an XDI biuret.