JP4155426B2 - Packaging materials for paper containers - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a packaging material for paper containers.
More specifically, a continuous paper wrapping material is formed into a tube shape in the longitudinal direction, and the tube-shaped wrapping material is filled with filling materials such as fruit juice, tea, liquid dairy products, and the transverse direction of the tubular wrapping material. Brick-shaped paper packaging containers obtained by applying horizontal line seals at predetermined intervals and cutting the packaging material along the horizontal line seal portions, and cutting the paper packaging materials into predetermined shapes, The present invention relates to a gable-top (roof-type) paper container packaging material obtained by sealing a blank, sealing the bottom of the blank, filling a liquid product to be filled from the upper opening, and sealing the top.
[0002]
[Prior art]
A packaging container for milk, juice or other beverages is, for example, a paper / plastic laminated crease-lined wrapping material formed into a tube shape with a longitudinal vertical line seal, and the wrapping formed into a tube shape. Fill the material with the material to be filled, seal it horizontally in the transverse direction of the tube-shaped wrapping material, and first form it into a cushion-shaped or pillow-shaped primary shape. Then, it is folded along the crease line and formed into a final shape. The final shape includes a brick shape (parallel hexahedron), a polygonal column shape exceeding a square, a hexagonal column shape, an octagonal column shape, a quadrangular prism shape, and a tetrahedron shape having four triangular surfaces.
[0003]
Furthermore, in a gable top-like (roof-type) paper packaging container, a paper packaging material is cut into a predetermined shape to obtain blanks sealed in the longitudinal direction of the container, and the bottom opening of the blanks is sealed in the filling machine. To be filled with milk, juice or other beverage fillings and sealed at the top. On these surfaces, the appearance design of the packaging container product is printed on these packaging materials.
[0004]
[Problems to be solved by the invention]
When a metallized (metal-like) appearance is applied to a conventional packaging container product, a metal-like ink is applied to the surface of the packaging material. However, for printing with metal-like ink, expensive printing ink materials must be used.
In contrast, a metal (for example, aluminum) vapor-deposited plastic film (for example, an OPP film) is laminated with a paper substrate with low density polyethylene (LDPE) extruded from an extruder, and printed on the surface of the OPP film with ink. It has been proposed to obtain a metallized (metal-like) packaging material and form a paper container from the packaging material. However, the metallic appearance such as gloss, brightness and color is not always good. Moreover, the adhesion between the metal deposition surface and the paper substrate and the adhesion between the plastic film surface and the ink layer are not good, and a gap occurs at the interface during the manufacturing process or in the distribution process, That is, inconvenience of peeling may occur.
[0005]
The present invention has been made on the basis of the above-mentioned background. The object of the present invention is to produce a packaging material and a paper container at a low price without using an expensive printing ink material, and to achieve gloss, brightness, and color. Good metal-like appearance such as, adhesion between the metal vapor-deposited surface and the paper substrate, and excellent adhesion between the plastic film surface and the ink layer, during the manufacturing process or in the distribution process It is to provide a packaging material for a paper container in which the packaging material or the paper container has no separation between the interfaces.
[0006]
[Means for Solving the Problems]
The above problems are solved by the present invention. That is, the intermediate packaging material for paper containers used in the present invention is composed of the above-mentioned constituent layers of the paper base material layer, the adhesive layer, the metal vapor deposition layer, the transparent polyester film layer, the corona discharge treatment layer, and the anchor agent coating layer. After being stacked in order.
[0007]
In a preferred embodiment of the intermediate packaging material for paper containers used in the present invention, an anchor agent coating layer is laminated between the paper base material layer and the adhesive layer.
[0008]
In a preferred embodiment of the intermediate packaging material for paper containers used in the present invention, the adhesive layer is an ethylene methacrylic acid copolymer having a layer thickness of 10 μm to 18 μm, and the polyester film layer has a layer thickness of 8 μm to 16 μm.
[0009]
In a preferred embodiment of the intermediate packaging material for a paper container used in the present invention, the metal vapor-deposited layer and the polyester film layer resin layer are obtained by depositing metal on a polyester film.
[0010]
In a preferred embodiment of the intermediate packaging material for a paper container used in the present invention, the metal vapor deposition layer is an aluminum vapor deposition layer.
[0011]
The method for producing an intermediate packaging material for paper containers used in the present invention includes the following steps.
(A) a step of drawing a paper base material from a base paper roll and applying an anchor agent to the outer surface of the paper base material layer to form an anchor agent application layer;
(B) a step of drawing the film from a roll of a metal vapor-deposited polyester film comprising a metal vapor-deposited layer and a transparent polyester film layer resin layer, and laminating the metal vapor-deposited layer surface and the anchor agent-coated surface with an adhesive;
(C) a step of applying a corona discharge treatment to the surface of the polyester film layer of the obtained laminate to form a corona discharge treatment layer; and (d) applying an anchor agent to the surface of the corona discharge treatment layer and applying the anchor agent. Forming a layer;
[0012]
In a preferred embodiment of the method for producing an intermediate packaging material for paper containers used in the present invention, the metal vapor-deposited layer surface and the anchor agent-coated surface are laminated by an adhesive supplied from an extruder.
[0013]
The packaging material for paper containers used in this invention is
Intermediate packaging material formed by laminating the constituent layers of the paper base material layer, anchor agent coating layer, adhesive layer, metal vapor deposition layer, transparent polyester film layer, corona discharge treatment layer, and anchor agent coating layer in the above order. When,
An ink layer by printing provided on the outer surface of the intermediate packaging material ;
And an outer resin layer having sealing properties formed on the outer surface of the ink layer.
[0014]
The packaging material for paper containers used in the present invention includes an inner resin layer applied to the inner surface of the intermediate packaging material .
[0015]
The packaging material for paper containers of this invention has a barrier layer between the intermediate packaging material and the inner resin layer or on the inner surface of the inner resin layer.
[0016]
In a preferred embodiment of the packaging material for paper containers according to the present invention, the barrier layer comprises an aluminum foil, an inorganic oxide thin film, an ethylene vinyl alcohol copolymer layer (EVOH layer), a nylon layer, a polyvinylidene chloride film, and a polyvinylidene chloride coated film. It consists of at least one selected from.
[0017]
In a preferred embodiment of the packaging material for a paper container of the present invention, the ink layer contains a component that is partially in common with the component contained in the anchor agent layer that adheres to the ink layer.
[0018]
In the paper container to which the present invention can be applied, the constituent layers of the paper base layer, the anchor agent coating layer, the adhesive layer, the metal vapor deposition layer, the transparent polyester film layer, the corona discharge treatment layer, and the anchor agent coating layer are in the above order. An intermediate wrapping material laminated with
An ink layer by printing provided on the outer surface of the intermediate packaging material ;
An outer resin layer having sealing properties formed on the outer surface of the ink layer;
It is formed from a paper container packaging material including at least an inner sealing resin layer provided inside the intermediate packaging material .
[0019]
[Action]
The paper container packaging material according to the present invention having the above-described configuration operates and operates as follows.
In this invention, the intermediate packaging material for a paper container is a paper base material layer, an anchor agent coating layer, an adhesive layer, a metal vapor deposition layer, a transparent polyester film layer, a corona discharge treatment layer, and an anchor agent laminated in a preferred embodiment. Each constituent layer of the coating layer is laminated in the above order. The anchoring agent coating layer of the preferred embodiment improves the adhesion of the paper substrate layer surface, and the improved adhesion further improves the adhesion of the adhesive to the metal deposition layer. Since a polyester film with excellent transparency and various mechanical properties is used, a metal-like appearance such as a metallic luster, brightness, and color by metal deposition deposited on one surface of the polyester film is imparted to the paper container appearance. .
[0020]
The corona discharge treatment layer provided on the surface of the polyester film layer improves the adhesion to the polyester film, and the anchor agent coating layer is provided on the corona discharge treatment layer, so that the adhesion of the polyester film is maintained and maintained. The production from the paper container intermediate packaging material to the packaging material does not need to be carried out continuously or without any time, and the production can be temporarily stored at a different place or the paper container intermediate packaging material .
[0021]
DETAILED DESCRIPTION OF THE INVENTION
It shows how this invention is implemented.
The intermediate packaging material for paper containers of a preferred embodiment used in the present invention is a paper base material layer, an anchor agent coating layer, an adhesive layer, a metal vapor deposition layer, a polyester film layer, a corona discharge treatment layer, and an anchor agent coating layer. The constituent layers are stacked in the above order.
The paper substrate that can be used in the present invention is usually made from kraft pulp and is required to have excellent strength and low water absorption. The types include bleached paper (FBL), unbleached paper (UBL), bleached and unbleached combined paper (DUPLEX), clay-coated paper and multilayered laminated paper (MB). Either is acceptable.
[0022]
The anchor agent coating layer that can be used in the present invention is formed by a gravure printing method, a roll coater or the like using an anchor agent such as polyethyleneimine, polybutadiene, alkyl titanate, or polyurethane.
[0023]
The adhesive layer that can be used in the present invention is, for example, a synthetic resin such as ethylene methacrylic acid copolymer (EMAA) or ionomer (IO) that has adhesiveness to a metal by an extrusion laminating method. Are laminated as an adhesive layer. It is preferable to use an adhesive layer having a thickness of about 10 to 50 μm. Preferably, the adhesive layer is an ethylene methacrylic acid copolymer having a layer thickness of 10 to 18 μm.
[0024]
The polyester film layer that can be used in the present invention has a layer thickness of 8 to 30 μm, preferably a layer thickness of 8 to 16 μm. In this invention, the polyester film is transparent so that the metallic luster is visible from the outside of the container. In a preferred embodiment of the present invention, the metal vapor-deposited layer and the polyester film layer resin layer are obtained by vapor-depositing a metal, more preferably aluminum, on a polyester film. The metal vapor deposition method and the thickness of the vapor deposition layer can be performed by various methods.
[0025]
The packaging material for paper containers according to the present invention includes the above-described intermediate packaging material , an ink layer formed by printing provided on the outer surface of the intermediate packaging material , and an outer resin layer having a sealing property formed on the outer surface of the ink layer. At least. Examples of the ink include water-based or oil-based inks for flexographic printing, oil-based inks for gravure printing, and curable inks for offset printing. In a preferred embodiment of the packaging material for paper containers of the present invention, the ink layer is the ink layer. And a component (for example, imine-based) that is partially in common with the component contained in the anchor agent layer that adheres to the substrate.
[0026]
The aspect of the packaging material for paper containers of this invention includes an inner resin layer applied to the inner surface of the intermediate packaging material . This resin layer is, for example, a polyolefin resin such as polyethylene, polypropylene, and an ethylene copolymer. In addition to low density polyethylene (LDPE) that has been conventionally used for the innermost layer, the resin layer has resistance to oil (oil resistance, Examples thereof include linear low density polyethylene (LLDPE) excellent in acid resistance, penetration resistance, and the like, and coextruded films containing medium density polyethylene and polyethylene.
[0027]
In a preferred embodiment of the packaging material for a paper container according to the present invention, a barrier layer is provided between the intermediate packaging material and the inner resin layer or on the inner surface of the inner resin layer. The barrier layer is made of at least one selected from an aluminum foil, an inorganic oxide thin film, an ethylene vinyl alcohol copolymer layer (EVOH layer), a nylon layer, a polyvinylidene chloride film, and a polyvinylidene chloride coated film. Here, as a vapor deposition film of an inorganic oxide as a barrier layer, for example, a silicon oxide, a tin oxide, an oxide is applied to a thermoplastic resin film having a thickness of about 10 to 30 μm such as polyolefin, nylon, polyester, polyvinyl alcohol or the like. A thin film layer having a thickness of 100 to 5000 mm, preferably about 200 to 1000 mm, made of an inorganic oxide such as zinc, indium oxide, titanium oxide, or aluminum oxide was formed by vacuum deposition, sputtering, chemical vapor deposition, plasma chemical vapor deposition (PCVD), or the like. Things are used.
[0028]
The paper container to which this invention can be applied is the above-described intermediate packaging material , an ink layer by printing provided on the outer surface of the intermediate packaging material , and an outer resin layer having a sealing property formed on the outer surface of the ink layer, It is formed from a paper container packaging material including at least an inner sealing resin layer provided inside the intermediate packaging material .
In the liquid food filling field implemented by the present invention, a continuous paper wrapping material is formed into a tube shape in the longitudinal direction, and the tube-shaped wrapping material is filled with a filling material such as fruit juice, tea, liquid dairy product, etc. Brick-shaped paper packaging container obtained by applying horizontal line seals at predetermined intervals in the transverse direction of the packaging material and cutting the packaging material along the horizontal line seal part, and cutting the paper packaging material into a predetermined shape Then, the blanks sealed in the vertical direction of the container are obtained, the bottom of the blanks is sealed, the liquid product is filled from the top opening, and the top is sealed, and the gable top (roof type) paper is obtained. Such as a packaging container.
[0029]
Subsequently, the manufacturing method of the intermediate packaging material for paper containers used for this invention is demonstrated.
This manufacturing method includes the following steps.
(A) A step of drawing a paper substrate from a base paper roll and applying an anchor agent to the outer surface of the paper substrate layer to form an anchor agent coating layer, (b) a metal comprising a metal vapor deposition layer and a polyester film layer resin layer A step of drawing the film from the roll of the vapor-deposited polyester film, and laminating the metal vapor-deposited layer surface and the anchor agent-coated surface with an adhesive; (c) applying a corona discharge treatment to the surface of the polyester film layer of the obtained laminate. A step of forming a corona discharge treatment layer; and (d) a step of applying an anchor material to the surface of the corona discharge treatment layer to form an anchor agent coating layer.
[0030]
Examples of the method for forming the layer include a dry lamination method, a wet lamination method, a hot lamination method, an extrusion lamination method, a coextrusion lamination method, and the like, and these are applied according to the characteristics. When forming a resin layer or an adhesive layer, an extrusion lamination method or a sandwich extrusion lamination method that is advantageous in terms of cost is used. As described above, as the resin layer and the adhesive layer, for example, polyolefin resins such as polyethylene, polypropylene, and ethylene copolymers, ionomer resins, and the like are generally used, and polyolefin resins are preferable from the viewpoint of cost. In a preferred embodiment of the method for producing an intermediate packaging material for paper containers according to the present invention, the metal vapor deposition layer surface and the anchor agent application surface are laminated by an adhesive supplied from an extruder.
[0031]
【Example】
The present invention will be specifically described by the following examples.
Example 1
A roll of an aluminum vapor-deposited PET film in which metal aluminum is vapor-deposited on one side of a PET film having a thickness of 12 .mu.m and a roll of a paper base having a basis weight of 320 to 400 g / m @ 2, for example, are prepared. The paper base material is pulled out from the roll of the paper base material, and the anchor agent is applied to the outer surface of the paper base material and fed out to the laminating station.
On the other hand, a roll of aluminum-deposited PET film is also conveyed from the opposite direction to the paper substrate to the same laminating station. In this laminating station, the anchor agent-coated surface of the paper substrate and the vapor-deposited surface of the aluminum vapor-deposited PET film are opposed to each other, and laminated with an ethylene methacrylic acid copolymer (EMAA) therebetween. The layer thickness of this EMAA is 15 μm. By this step, a laminate of laminate configuration: paper base material / anchor agent coating layer / EMAA / aluminum vapor deposition layer / PET film layer is obtained.
[0032]
Subsequently, a corona discharge treatment is performed on the outer surface of the PET film, and then an anchor agent is applied to the corona discharge treatment surface and wound by a winder to obtain an intermediate packaging material . As a result, an intermediate packaging material laminate of a laminated structure: paper base material / anchor agent coating layer / EMAA / aluminum vapor deposition layer / PET film layer / corona discharge treatment layer / anchor agent coating layer is obtained.
[0033]
The roll of the intermediate packaging material is conveyed to a printing machine, characters and designs are printed by the offset printing method on the surface of the anchor agent coating layer outside the PET film layer, a hole for a straw or spout is made at a predetermined location, and A broken line (crease) for forming the final paper container shape is provided. The packaging material after printing has a layer structure of paper base material / anchor agent coating layer / EMAA / aluminum vapor deposition layer / PET film layer / corona discharge treatment layer / anchor agent coating layer / ink layer.
[0034]
The laminated body that has finished printing is wound into a roll again and sent to a laminator. In the laminator, the low-density polyethylene supplied to the extruder is extruded from the T-die at a high temperature, and the outermost layer of the low-density polyethylene is laminated on the outer surface of the ink layer. The aluminum foil is laminated with a low-density polyethylene layer by the method, and two low-density polyethylene innermost layers are formed on the inner surface of the aluminum foil. The resulting packaging material is: low density polyethylene innermost layer / low density polyethylene layer / aluminum foil / low density polyethylene layer / paper base material / anchor agent coating layer / EMAA / aluminum vapor deposition layer / PET film layer / corona discharge treatment layer / It has a layer structure of anchor agent coating layer / ink layer / low density polyethylene outermost layer. As described above, the manufactured packaging material is wound into a roll shape, sent to a slitter, and the slit width and slit position are confirmed, wound to a specified length, and stored.
[0035]
The obtained packaging material is a packaging material with a crease line, and this packaging material is formed into a tube shape by a longitudinal line seal in the longitudinal direction, and the filling material is filled into the packaging material formed in the tube shape. Then, a horizontal line seal is applied in the transverse direction of the tube-shaped packaging material. First, it is formed into a cushion-shaped or pillow-shaped primary shape, and when the packaging material is in a band shape, it is cut individually at regular intervals and folded along the crease line. Folded into a brick (parallelepiped) final shape.
[0036]
Example 2
A packaging material was produced in the same manner as in Example 1 except that the paper base material was fed to the laminating station without applying an anchor agent to the outer surface of the paper base material.
The obtained packaging material had an excellent effect as in Example 1.
[0037]
Example 3
In the same manner as in Example 1, except that an ionomer (IO) adhesive layer is laminated between the aluminum foil and the innermost layer when forming the inner layer of the low density polyethylene on the inner surface of the aluminum foil. The material was manufactured.
The obtained packaging material had an excellent effect as in Example 1.
[0038]
【The invention's effect】
According to the present invention demonstrated in the above-described embodiments, the following effects can be obtained.
(A) Since an expensive printing ink material is not used, a packaging material and a paper container can be manufactured inexpensively.
(B) Since a polyester film excellent in transparency and various mechanical properties is used, a metal-like appearance such as a metallic luster, brightness, and color due to metal deposition deposited on one surface of the polyester film is shown in a paper container appearance. Can be granted.
[0039]
(C) Since the corona discharge treatment layer provided on the surface of the polyester film layer improves the adhesion of the polyester film, and the anchor agent coating layer is provided on the corona discharge treatment layer, the adhesion of the polyester film is maintained.・ There is no need to carry out the production from the intermediate packaging material for paper containers to the packaging material continuously or in less time, and the production can be temporarily stored in different places or in an intermediate packaging material for paper containers. .
[0040]
(D) Excellent adhesion between the metal vapor-deposited surface and the paper substrate and between the plastic film surface and the ink layer, and the interface between the packaging material and the paper container during the production process or distribution process Peeling can be eliminated.
(E) The anchor agent coating layer laminated in a preferred embodiment improves the adhesion of the paper substrate layer surface, and the improved adhesion further improves the adhesion of the adhesive to the metal deposition layer.
[0041]
(E) In a preferred aspect of the present invention, the ink layer contains a component (for example, imine) that is partially in common with the component contained in the anchor agent layer that adheres to the ink layer. The adhesion between the ink and the printing ink layer is improved.

Claims (2)

Intermediate packaging material formed by laminating the constituent layers of the paper base material layer, anchor agent coating layer, adhesive layer, metal vapor deposition layer, transparent polyester film layer, corona discharge treatment layer, and anchor agent coating layer in the above order. When,
An ink layer by printing provided on the outer surface of the intermediate packaging material ;
Including at least an outer resin layer having sealing properties formed on the outer surface of the ink layer,
Including an inner resin layer applied to the inner surface of the intermediate packaging material ,
A paper container packaging material having a barrier layer between the intermediate packaging material and the inner resin layer or on the inner surface of the inner resin layer. 2. The paper container packaging according to claim 1, wherein the barrier layer comprises at least one selected from an aluminum foil, an inorganic oxide thin film, an ethylene vinyl alcohol copolymer layer, a nylon layer, a polyvinylidene chloride film, and a polyvinylidene chloride coated film. Wood.