JP5306594B2 - Composite container - Google Patents

Description

  The present invention relates to a composite container, and in particular, even if the contents to be stored are volatile substances or alkaline substances such as alcoholic beverages, bathing agents, permanent liquids, cleaning agents, developing solutions, etc. It is related with the composite container excellent in the preservability which can prevent.

  As a container for storing contents such as beverages and powders, it is a sequential laminate of a heat seal layer, a paper layer, a barrier layer, and a heat seal layer, and the heat seal layer on the barrier layer side is the innermost layer. The composite container to be formed is used. In general, in such a container, the barrier layer and the sealant layer that is the innermost layer are bonded and laminated by dry lamination via an adhesive layer.

The bonding surface between the barrier layer and the sealant layer is extremely important for maintaining the function of the laminate. Generally, (1) an anchor coat layer is provided as an adhesive layer on the barrier layer surface, and a polyolefin resin is extruded thereon. A method of laminating and laminating, or (2) a film for forming a sealant layer that has been formed into a film in advance using a dry laminating adhesive such as a two-component curable polyurethane adhesive as an adhesive layer on the barrier layer surface. A method of laminating and laminating by the dry lamination method is employed.
First, in the extrusion laminating method of (1), the anchor coat layer is formed by an anchor coat agent-forming composition such as an organic titanium-based, isocyanate-based, polyethyleneimine-based, or polybutadiene-based agent. When alcohol or a strong alkaline substance is contained, the resistance of the anchor coat layer is insufficient, and there is a problem that the sealant layer is peeled off from the barrier layer.

Further, as in the case where a sealant layer is bonded to the barrier layer of (2) by the dry lamination method, the resistance of the dry laminating adhesive is insufficient, and the barrier layer and the sealant layer are separated after long-term storage. There is a problem of peeling.
Further, the anchor coating agent and the adhesive for dry laminating generally contain an organic solvent, and during the work, the organic solvent is released and the work environment is deteriorated.

  However, in the case of alcoholic beverages, bathing agents, permanent liquids, cleaning agents, those containing liquid substances such as essential oils and strong alkaline substances such as developer, these substances easily penetrate the sealant layer, The function of the anchor coat agent and the adhesive for dry lamination is hindered, and the sealant layer as the innermost layer causes delamination from the barrier layer. In severe cases, the adhesive layer is exposed and comes into contact with the contents, so that there is a problem that the contents are altered or the flavor components are adsorbed by the adhesive layer and the flavor is impaired.

  In the present invention, when the contents to be stored are volatile substances or strong alkaline substances such as alcoholic beverages, bathing agents, perm liquids, cleaning agents, developers, etc., they have excellent storage stability that can prevent alteration of the contents. It is an object to provide a composite container.

The composite container of the present invention is a sequential laminate of a heat-sealable polyethylene resin layer , a paper layer, a barrier layer, an anchor coat layer, and a heat-sealable polyethylene resin layer , wherein the barrier layer is an aluminum foil. Or a composite container formed of a metal or metal oxide vapor-deposited film and having a heat-sealable polyethylene resin layer on the barrier layer side as the innermost layer, wherein the anchor coat layer comprises an unsaturated carboxylic acid, Alternatively, an aqueous dispersion containing an anhydride thereof in a range of 0.01 to 5% by mass and containing polyolefin copolymer resin particles having a number average particle diameter of 1 μm or less and substantially free of non-volatile aqueous additive. Ri coated and dried layer der to the barrier layer surface, the contents in the composite container, alcoholic beverage containing alcohol or essential oils and strong alkaline substance, bath agent, Over Ma liquid, detergent, or wherein the developer der Rukoto.
The heat sealable polyethylene resin layer formed as the innermost layer is an extrusion coating layer on the surface of the anchor coating layer, or is obtained by extrusion lamination of a polyethylene resin film using a melt-extruded polyethylene resin. To do.
The sequential laminate is a sequential laminate of a heat-sealable polyethylene resin layer, a paper layer, a polyethylene resin layer, a polyethylene terephthalate resin layer, a barrier layer, an anchor coat layer, and a heat-sealable polyethylene resin layer. And

  The composite container of the present invention comprises an unsaturated carboxylic acid or an anhydride thereof in the range of 0.01 to 5% by mass and is composed of polyolefin copolymer resin particles having a number average particle size of 1 μm or less, and is a non-volatile water-based auxiliary. By using an anchor coat layer consisting of a coating layer of an aqueous dispersion substantially free of an agent for adhesion between the barrier layer and the sealant layer, adhesion to a metal foil such as an aluminum foil or a barrier layer such as a vapor deposition film In addition, the adhesion between the sealant layer and the extrusion coating layer can be improved. In addition, even if volatile substances such as alcoholic beverages, bathing agents, perm liquids, cleaning agents, developers, etc. are stored, strong adhesion to the barrier layer, and the sealant layer and adhesive layer will not be corroded. There is no delamination between the barrier layer and the sealant layer, and the composite container is excellent in storage stability of the contents. In addition, the amount of organic solvent discharged during the production of the laminate is small, and the exhaust gas treatment facility can be simplified.

Below, the composite container of this invention is demonstrated with reference to drawings.
FIG. 1 is a cross-sectional view for explaining an example of a laminate used for manufacturing the composite container of the present invention.
The laminate 10 forming the composite container of the present invention includes at least a paper layer 11, a polyolefin-based resin layer 12 formed on at least the outside of the paper layer 11, and a barrier layer 13 formed on the inside of the paper layer 11. And a sealant layer 15 formed inside the barrier layer 13, and the barrier layer 13 and the sealant layer 15 are laminated via an anchor coat layer 14.
The anchor coat layer 14 of the present invention comprises an unsaturated carboxylic acid or an anhydride thereof in the range of 0.01 to 5% by mass, and consists of polyolefin resin particles having a number average particle diameter of 1 μm or less, for example, 50 nm to 200 nm. An aqueous dispersion substantially free of an emulsifier or the like is applied. This aqueous dispersion is described in JP-A-2004-9504, and is a polyolefin resin (A) composed of an unsaturated carboxylic acid or its anhydride, an olefin compound, and a (meth) acrylic ester. An aqueous dispersion and an aqueous dispersion of a polyester resin (B) having an anionic group of 20 to 700 (equivalent / 10 ⁶ g), and the mass ratio of the resin content in each aqueous dispersion is (A) / ( B) = 90/10 to 20/80, which is produced by mixing, and is commercially available from Unitika as Arrow Base SA-1200, SB-1200, SE-1200, TB-2010, etc. Are illustrated.
Non-volatile aqueous additives such as emulsifiers remain in the coating even after drying, and even if a small amount, it has a great effect on the adhesive interface and decreases the adhesion and water resistance. In other words, in the production process of the aqueous dispersion, a non-volatile aqueous additive such as an emulsifier is not added for the purpose of promoting aqueous formation or stabilizing the aqueous dispersion.

The anchor coat layer is applied to be thin so that the thickness when dried is 0.1 to 2 μm, so that a polyolefin film is applied to a metal foil such as an aluminum foil as a barrier layer or a deposition surface such as SiO ₂ or Al ₂ O _3. Adhesion of the extrusion coating layer made of resin can be made favorable.

  Further, inside the paper layer 11, a polyolefin resin layer 16, for example, a polyethylene resin layer is further laminated between the paper layer 11 and the barrier layer 13. Further, a resin layer 17 such as a polyethylene terephthalate resin layer is further formed between the polyolefin resin layer 16 and the barrier layer 13. Moreover, the thickness of the polyolefin resin layer 22 is preferably 5 to 50 μm, and the thickness of the resin layer 32 is preferably 5 to 50 μm.

The paper layer 11 preferably has a basis weight of 120 to 500 g / m ² , more preferably 150 to 450 g / m ² . Examples of the polyolefin resin layer 12 laminated on at least the outside of the paper layer 11 include polypropylene and polyethylene. Among various polyolefin resins, low density polyethylene is preferable. Moreover, 5-50 micrometers is preferable and, as for the thickness of polyolefin resin 12, it is more preferable to set it as 10-40 micrometers.
The paper layer 11 and the polyolefin resin 12 are laminated by a lamination means such as extrusion lamination.

  A barrier layer 13 is formed inside the paper layer 11. The barrier layer 13 is a metal foil such as aluminum, a metal vapor-deposited film, an oxide vapor-deposited film such as silicon oxide (SiOx) or aluminum oxide. In order to obtain a sufficient gas barrier property, the thickness of the barrier layer 13 is preferably about 2 to 20 μm, more preferably 6 to 12 μm in the case of a metal foil. Moreover, in the case of an oxide vapor deposition layer, it is preferable to set it as 20-150 nm.

In addition, the paper layer 11 and the barrier layer 13 can be bonded by extrusion lamination or dry lamination using an isocyanate adhesive. Examples of the isocyanate-based adhesive include a two-component curing type adhesive in which a polyester polyurethane-based adhesive and a polyether polyurethane-based adhesive are used as a main agent, and a curing agent such as tolylene diisocyanate and xylene diisocyanate is added to the main agent. . The adhesive preferably has a thickness of 0.3 to 8 g / m ² , more preferably 0.8 to 5 g / m ² .
Inside the barrier layer 13, a sealant layer 15 is formed via an anchor coat layer 14 obtained by applying and drying an aqueous dispersion made of an ethylene-unsaturated carboxylic acid copolymer.

  The sealant layer 15 is an innermost layer and can be formed from a polyolefin-based resin such as polyethylene or polypropylene, but is preferably formed from low-density polyethylene. The thickness of the sealant layer 15 is preferably 3 to 100 μm.

The barrier layer 13, the anchor coat layer 14 and the sealant layer 15 are laminated by forming a three-layer laminate by extruding or sealing the sealant layer 15 on one surface of the barrier layer 13 with the anchor coat layer 14. Is done by.
Then, the barrier layer 13 of the obtained three-layer laminate is adhered to the paper layer 11 of the two-layer laminate obtained by laminating the above-mentioned paper and the synthetic resin film with an adhesive or the like, and a laminate is further produced. During this time, another plastic layer may be formed.

As shown in FIG. 1, the strength of the composite container can be further increased by adopting a structure in which a resin layer is further laminated as an intermediate layer.
The barrier layer 13 and the polyethylene resin layer 16 are dry-laminated or extruded and laminated with an adhesive to create a laminate, and the barrier layer 13 is extrusion-coated or sand-laminated with an anchor coat layer 14 and laminated. To do. As shown in FIG. 1, when the resin layer 17 is further provided, the polyolefin-based resin layer 16 and the resin layer 17 are laminated by extrusion lamination or dry lamination.
Thereafter, a laminate of the paper layer 11 and the polyolefin resin layer 12 is extruded and laminated on the polyolefin resin layer 16 to obtain a laminate.

As a form of the composite container composed of the laminated body having such a configuration, for example, a Gobeltop-type bottomed container 20 as shown in FIG. 2 can be cited. The composite container can be suitably used for a carton filled with a volatile substance such as an alcoholic beverage, a bath agent, a permanent liquid, a cleaning agent, a developer, or an alkaline substance.
Next, an Example is shown and this composite container is demonstrated in detail.

Example 1
Biaxially stretched polyethylene terephthalate film (Toyobo Co., Ltd., E5100, thickness 12 μm) and aluminum foil (Toyo Aluminum Co., Ltd., thickness 9 μm) are two-component curable urethane adhesive (Mitsui Chemical Polyurethane, A -310 / A-3, coating amount of 3.5 g / m ² ) to dry laminate to prepare a two-layer laminate of a polyester layer and a barrier layer.

Next, on the aluminum foil surface of the two-layer laminate, a polyolefin-based water dispersion anchor coating agent (SE-1200 manufactured by Unitika Co., Ltd.) was applied and dried so as to have a thickness of 0.5 μm after drying, Low density polyethylene (manufactured by Nippon Polyethylene Co., Ltd., LC520) was extruded and laminated to form a polyolefin resin layer having a thickness of 60 μm.
On the other hand, a urethane-based anchor coating agent (Mitsui Chemical Polyurethane Co., Ltd., A-310 / A-3, coating amount 0.2 g / m ² ) is applied on the biaxially stretched polyethylene terephthalate film surface of the two-layer laminate. Then, low density polyethylene (manufactured by Nippon Polyethylene Co., Ltd., LC520) was extruded and laminated to form a polyethylene resin layer having a thickness of 15 μm.

Next, on one side of a paper having a basis weight of 340 g / m ² , a polyolefin resin layer surface obtained by extruding and laminating low density polyethylene (manufactured by Nippon Polyethylene Co., Ltd., LC520) while corona-treating the paper surface is used. Sandra was done. Then, low-density polyethylene (manufactured by Nippon Polyethylene Co., Ltd., LC520) was extruded and laminated on the other surface of the paper layer to form a polyolefin resin layer having a thickness of 20 μm to obtain a laminate for preparing a composite container.
The layer structure of the obtained laminate was PE (60 μm) / AC (anchor coat layer of the present invention) / AL foil (9 μm) / AC (urethane system) / PET (12 μm) / AC (urethane system) from the inside of the container. ) / PE (15 μm) / PE (15 μm) / paper layer / PE (20 μm).

  The manufactured laminate is punched into a predetermined shape, and the body is skived hemmed, and then bonded together with a frame sealer to prepare a sample of a bevel-top type bottomed container having a size of 70 mm × 70 mm and a capacity of 1 liter. The bottom container sample was filled with a powder bath agent, whiskey (alcohol content 39%), and a car cleaner (pH 14), and stored at 40 ° C. for 6 months. Thereafter, the state of the seal was visually observed to evaluate the storage stability of the container. As a result, no abnormality such as deterioration or peeling was observed in the sealing layer of the container when filling any of the contents.

Example 2
In Example 1, instead of the point that “low density polyethylene (manufactured by Nippon Polyethylene Co., Ltd., LC520) was extruded and laminated to form a polyolefin resin layer having a thickness of 60 μm.” [0021], polyolefin water dispersion On the body anchor coat agent (Unitika Co., Ltd. SE-1200) layer, a 40 μm-thick low density polyethylene film (Tosero Co., Ltd. “FC-S”), low density polyethylene (Nihon Polyethylene Co., Ltd., LC520) was extruded to a thickness of 20 μm and bonded together by an extrusion laminating method to form a laminate for preparing a composite container in the same manner as in Example 1 except that a polyolefin resin layer was formed.
The layer structure of the obtained laminate was PE (40 μm) / PE (20 μm) / AC (anchor coat layer of the present invention) / AL foil (9 μm) / AC (urethane-based) / PET (12 μm) from the inside of the container. / AC (urethane type) / PE (15 μm) / PE (15 μm) / paper layer / PE (20 μm).
The obtained laminate was manufactured in the same manner as in Example 1 to produce a goblet top-type bottomed container, and the storage stability of the container was evaluated. As a result, no abnormality such as deterioration or peeling was observed in the sealing layer of the container when filling any of the contents.

Comparative Example 1
In Example 1, instead of the anchor coat layer of the present invention, a urethane anchor coat agent (“EL-540” manufactured by Toyo Morton Co., Ltd.) layer (dry film thickness 0.5 μm) was used in the same manner. It was set as the laminated body for composite container preparation.
The obtained laminate was manufactured in the same manner as in Example 1 to produce a goblet top-type bottomed container, and the storage stability of the container was evaluated. When any of the contents was filled, delamination occurred between the aluminum foil / PE layers.

  In the composite container of the present invention, the sealant layer is provided on the surface of the barrier layer via the anchor coat layer of the present invention, so that even in the case of a content containing alcohol or strong alkaline liquid having high permeability to the sealant layer. The adhesiveness between the layer and the sealant layer is stable, and a composite container that does not cause problems such as delamination over a long period of time can be obtained.

FIG. 1 is a cross-sectional view for explaining an example of a laminate used for manufacturing the composite container of the present invention. FIG. 2 is a perspective view showing an example of the composite container.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Laminated body, 11 ... Paper layer, 12 ... Polyolefin resin layer, 13 ... Barrier layer, 14 ... Anchor coat layer, 15 ... Sealant layer, 16 ... Polyolefin resin layer, 17 ... Resin layer, 20 ... Bottomed container

Claims (3)

A sequential laminate of a heat-sealable polyethylene resin layer , a paper layer, a barrier layer, an anchor coat layer, and a heat-sealable polyethylene resin layer , wherein the barrier layer is an aluminum foil, or a metal or metal oxide In the composite container in which the heat-sealable polyethylene resin layer on the barrier layer side is formed as the innermost layer , the anchor coat layer contains an unsaturated carboxylic acid or an anhydride thereof in an amount of 0.00. and it comprises in the range of 01-5 wt%, wherein the number-average particle diameter of less polyolefin copolymer resin particles 1 [mu] m, coating and drying to the barrier layer surface of the aqueous dispersion is substantially free of non-aqueous aid Sodea is, the contents in the composite container, alcoholic beverage containing alcohol or essential oils and strong alkaline substance, bath agent, perm solution, detergent, or Composite container, wherein the developer der Rukoto is. The heat sealable polyethylene resin layer formed as the innermost layer is an extrusion coating layer on the surface of the anchor coating layer, or is obtained by extrusion lamination of a polyethylene resin film using a melt-extruded polyethylene resin. The composite container according to claim 1. The sequential laminate is a sequential laminate of a heat-sealable polyethylene resin layer, a paper layer, a polyethylene resin layer, a polyethylene terephthalate resin layer, a barrier layer, an anchor coat layer, and a heat-sealable polyethylene resin layer. The composite container according to claim 1.

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