JP2005088298A - Packaging material, packaging bag using it, and lid body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a packaging material for heat sealing which can reduce the volume of a container, facilitate the disposal of the container, and give enough alkali resistance and peelability. <P>SOLUTION: In the packaging material, at least three layers of a barrier layer, a thermoplastic resin layer, and a sealant layer are formed on a substrate. The thermoplastic resin layer and the sealant layer are formed by coextrusion. No layer exists between the three layers. The thermoplastic resin layer contains an ethylene-α,β-unsaturated carboxylic acid copolymer, and the sealant layer contains a component A of polyethylene or an ethylene-α,β-unsaturated carboxylic acid copolymer and a component B of α,β-polyethylene. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a heat-sealable packaging material, a packaging bag formed by heat-sealing a laminated sheet, and a lid that can be heat-sealed to a molded container.

  For example, when containing contents that have the property of embrittlement of many resins, such as highly alkaline solutions used in hair coloring agents, it is molded using a resin that is resistant to the contents. Bottle type containers such as plastic bottles and glass bottles have been employed.

  In recent years, from the viewpoint of reducing the volume of the container and making it easy to dispose of the container, a container using a packaging material that can be sealed by heat sealing from such a bottle-shaped container, such as a container for a highly alkaline solution, for example, a molded container A combination with a lid and a transition to a packaging bag is being studied. In the case of a molded container and a lid, practically, easy peelability when peeling the lid from the molded container is further required. In the case of a packaging bag, for example, when it is formed into a multi-chamber type having two or more storage chambers, the storage chambers can be easily communicated and the contents in the storage chambers can be mixed. The partition provided between the chambers is further required to be easily peelable.

  For example, as an easily peelable sealant layer, there is a laminated packaging material using a general-purpose polymer alloy (see, for example, Patent Document 1). However, a highly alkaline solution cannot be accommodated as a content because it strongly embrittles incompatible resin components such as polystyrene, ethylene vinyl acetate, and a tackifier that are blended with the base resin.

In addition, as an adhesion method between the base material layer and the sealant layer, a dry laminating method using a polyurethane-based, polyethyleneimine-based or organic titanium-based adhesive, or interposing such an adhesive as a surface modifier. There is a laminated packaging material by a melt extrusion laminating method in which a resin is extruded. These adhesive layers are bonded to each other mainly using hydrogen bonding, thermal bonding, or the cohesive force of the adhesive itself, and the packaging material via such an adhesive layer is like a hair coloring agent. When a strong strongly osmotic solution having high alkalinity is stored, the solution passes through the sealant layer and stops at the surface of the barrier layer, resulting in a decrease in adhesive strength due to dissociation of hydrogen bonds in the adhesive layer and swelling of the resin. However, there is a problem that the adhesive layer there is swelled and embrittled, delamination occurs due to a decrease in laminate strength between the barrier layer and the sealant layer, and the content liquid leaks out. Therefore, there is a demand for a packaging material that does not cause delamination and does not cause a decrease in the adhesive strength between the barrier layer and the sealant layer even after the contents of these strongly permeable substances are packaged and stored for a long period of time.
JP 2002-240209 A

  The present invention has been made in view of the above circumstances, and its purpose is to reduce the volume of the container and to make it easy to dispose of it, and to provide a heat seal having sufficient alkali resistance and easy peelability. Is to provide a simple packaging material.

  Another object of the present invention is to provide a packaging bag that can reduce the volume and easily dispose of the container and has sufficient alkali resistance.

  Still another object of the present invention is to provide a lid for a molded container capable of reducing the capacity and easily disposing of the container, having sufficient alkali resistance, and capable of heat sealing with easy peeling. There is to do.

  The packaging material of the present invention includes a base material, a barrier layer provided on the base material, and a heat containing the ethylene-α, β unsaturated carboxylic acid copolymer provided in contact with the barrier layer. A component made of polyethylene or ethylene-α, β unsaturated carboxylic acid copolymer and B component made of α, β-polyethylene formed by coextrusion of the plastic resin layer and the thermoplastic resin layer And a sealant layer.

  The packaging bag of the present invention includes a base material, a barrier layer provided on the base material, and a heat containing the ethylene-α, β unsaturated carboxylic acid copolymer provided in contact with the barrier layer. A component made of polyethylene or ethylene-α, β unsaturated carboxylic acid copolymer and B component made of α, β-polyethylene formed by coextrusion of the plastic resin layer and the thermoplastic resin layer And a sealing portion formed by using a laminated sheet including a sealant layer to be heat-sealed with the sealant layers arranged opposite to each other.

  The lid of the present invention includes a base material, a barrier layer provided on the base material, and a heat containing the ethylene-α, β unsaturated carboxylic acid copolymer provided in contact with the barrier layer. A component made of polyethylene or ethylene-α, β unsaturated carboxylic acid copolymer and B component made of α, β-polyethylene formed by coextrusion of the plastic resin layer and the thermoplastic resin layer And a sealant layer.

  By using the present invention, it is possible to obtain a packaging material that has sufficient alkali resistance and can be easily sealed as required, and that is heat-sealable as compared with a bottle-type container. In addition, a packaging bag that can be reduced in volume after use and can be easily discarded, and a lid for a molded container are obtained.

  The packaging material of the present invention includes a structure in which a barrier layer, a thermoplastic resin layer, and a sealant layer are sequentially laminated on a base material, and the thermoplastic resin mainly includes an ethylene-α, β unsaturated carboxylic acid copolymer. As a component, the sealant layer contains an A component made of polyethylene or an ethylene-α, β unsaturated carboxylic acid copolymer and a B component made of α, β-polyethylene.

  The barrier layer used in the present invention is provided in direct contact with the thermoplastic resin layer, and no other layer is interposed between the barrier layer and the thermoplastic resin. Moreover, the sealant layer and the thermoplastic resin layer used in the present invention are formed by coextrusion, and no other layers are interposed between the sealant layer and the thermoplastic resin layer.

  The packaging bag of the present invention is formed by using a laminated sheet in which a barrier layer, a thermoplastic resin layer, and a sealant layer are laminated in order as described above. A sealed portion.

  Furthermore, the lid body of the present invention is formed using the above-mentioned laminated sheet and having a shape suitable for the molded container to be applied. The lid can be heat-sealed around the opening of the molded container, for example, to close the opening.

  In the packaging material according to the present invention, the three layers of the sealant layer, the thermoplastic resin layer, and the barrier layer, which have the property of not embrittled by an alkaline solution, are between these layers, that is, between the sealant layer and the thermoplastic resin layer In addition, the thermoplastic resin and the barrier layer are laminated without any functional layers such as an adhesive layer and a surface modification layer.

  The polyethylene or ethylene-α / β-unsaturated carboxylic acid copolymer used in the sealant layer is a non-polar structure that does not have a bulky polar group in the side chain such as polystyrene. Resistant to attack, and unsaturated carboxylic acid copolymers have high cohesive strength because the carboxyl groups are cross-linked by hydrogen bonds, and have high barrier properties against strong penetrating components. At the joint interface between the extruded sealant layer and the thermoplastic resin layer, both base resins, that is, the component A, are polyethylene resins. Therefore, by co-extrusion of similar resins, adhesion to different resin layers or adhesive layers Since it has higher adhesive strength and interfacial adhesion than the interface, it adheres firmly and does not peel off due to alkaline substances. The alkaline solution accommodated as the contents hardly infiltrates the sealant layer, and even when a small amount of the alkaline solution infiltrates, further infiltration is prevented at the bonding interface between the sealant layer and the thermoplastic resin layer.

  In addition, the thermoplastic resin layer used in the present invention can be directly formed on the barrier layer by polar bonding between the carboxyl group irregularly present in the molecular chain and the surface of the aluminum foil or the inorganic thin film. The ethylene-α, β-unsaturated carboxylic acid copolymer used in the thermoplastic resin layer shortens the distance of hydrogen bonds between the molecules obtained by crosslinking, and intervenes a surface modifier layer such as polyethylene. In comparison with the case of high density, the cohesive force of the molecule is high, the alkali resistance is good, and since the cohesive force is high, the polar group of the ethylene-α, β unsaturated carboxylic acid copolymer is Are densely bonded to the surface of the barrier layer more strongly, and peeling due to a strong osmotic solution such as an alkaline solution hardly occurs. In addition, since aluminum can form an amphoteric compound in the bond to the aluminum foil, it is several times to several hundred times the bond energy of hydrogen bonds with an acid such as ethylene-methacrylic acid copolymer. Adhesive force is generated by an acid-base interaction having a binding energy of.

  As described above, when the packaging material of the present invention is used, even if an alkaline solution is contained as a content, undesired peeling does not occur anywhere between the base material layer and the sealant layer, and it is stable for a long time. Contents can be saved.

  In addition, when the packaging material of the present invention is used, a packaging bag that can be easily stored at a low volume, can be easily reduced in volume after use, and can form an easily peelable sealing portion, It can be used for molded containers that can be easily reduced in volume or recycled after use, and can form a lid that can form an easily peelable seal, so it is discarded compared to conventional bottle-type containers. Is easy.

  Here, the easy peelability means that the contents can be sufficiently retained and have a peel strength that can be easily opened at the time of opening. Such peel strength is, for example, 2 N / 15 mm to less than 10 N / 15 mm in the 90 degree peel test. On the other hand, the peel strength of the portion where easy peelability is not required can be 10 N / 15 mm or more in the 90-degree peel test.

  The alkaline solution used in the present invention has a pH of about 8 or more, and examples thereof include one agent such as a two-component perm solution and a two-component oxidation reaction hair coloring solution. For example, in the case of a coloring agent, the first agent is a solution having a pH of about 11 containing ammonia, and the second agent is a solution containing a hydrogen peroxide solution. Can be hair.

  An example of the components contained in the first and second liquids for hair coloring is shown below.

Coloring agent 1 liquid composition (pH 11)
Ascorbic acid
Ammonia water
Edetate
Stearyltrimethylammonium chloride
Fragrance
purified water
Cetanol
Concentrated glycerin
paraffin
Isopropyl palmitate
Propylene glycol
Polyoxyethylene cetyl ether
Anhydrous sodium bisulfite
Metaaminophenol
2,4-Diaminophenoxyethanol hydrochloride
Orthoaminophenol
Paraaminophenol
Toluene sulfate-2,5-diamine
Resorcin
Coloring agent 2 component composition Cetyltrimethylammonium chloride
Hydrogen peroxide
Butyl stearate
purified water
Government-designated denatured alcohol
Cetanol
Turpinal SL
paraffin
Polyoxyethylene lauryl ether
Isopropyl myristate
phosphoric acid
Disodium hydrogen phosphate
Hereinafter, the present invention will be specifically described with reference to the drawings.

  FIG. 1 shows a cross-sectional view illustrating an example of the packaging material of the present invention.

  As illustrated, the packaging material 10 has a configuration in which a barrier layer 2, a thermoplastic resin layer 3, and a sealant layer 4 are sequentially laminated on a base material 1. The thermoplastic resin layer 3 is laminated on the barrier layer 2 by a rudder process without using a surface modifier or an adhesive layer, and the thermoplastic resin layer 3 and the sealant layer 4 are laminated by coextrusion. .

  As the barrier layer, a substrate having a desired oxygen impermeability, a desired water vapor impermeability, and an alkali resistance can be selected depending on the contents. As such a barrier layer, for example, a film obtained by vapor-depositing silica, a vapor-deposited film obtained by vapor-depositing alumina, or the like can be used on a base film made of a synthetic resin. When a film on which silica is deposited is used, there is an advantage that water vapor permeability and oxygen permeability are lowered, and the packaging material can be made transparent. Moreover, in the case of an alumina vapor deposition film, there exists an advantage that water vapor permeability and oxygen permeability fall more.

The water vapor permeability of the barrier layer is preferably 0 to 100 g / m ² / day, more preferably 0 to 20 g / m ² / day under the conditions of a temperature of 40 ° C. and a humidity of 90%. The oxygen transmission rate is preferably 0 to 30 cc / m ² / day, more preferably 0 to 30 cc / m ² / day when dried at a temperature of 20 ° C. Within this range, it is possible to store one liquid such as a two-component perm solution or a two-component oxidation reaction coloring agent.

  The sealant layer contains an A component made of polyethylene or an ethylene-α, β unsaturated carboxylic acid copolymer and a B component made of α, β-polyethylene, and exhibits easy peelability after heat sealing. The B component is blended with the A component and has an action of reducing the cohesive force of the A component.

  As the ethylene-α, β unsaturated carboxylic acid copolymer, for example, an ethylene-methacrylic acid copolymer and an ethylene-acrylic acid copolymer can be used.

  The ethylene-methacrylic acid copolymer preferably has a methacrylic acid content of 6 to 20% by weight, and the ethylene-acrylic acid copolymer preferably has an acrylic acid content of 3 to 10%. .

  The weight ratio of the A component and the B component is preferably 99: 1 to 50:50.

  Examples of the substrate used in the present invention include stretched nylon, stretched polyester, and stretched polypropylene.

  In the packaging bag of the present invention, in order to arrange the sealant layers facing each other, for example, two laminated sheets having the same shape may be prepared and overlapped, or one laminated sheet may be folded and overlapped at an arbitrary position. Also good.

  Moreover, the shape of a packaging bag can be made into the shape of the multiple chamber which has two or more accommodation chambers other than the bag shape of a single chamber.

  FIG. 2 is a front view illustrating an example of the packaging bag of the present invention, and FIG. 3 is a front view illustrating another example of the packaging bag of the present invention.

  As shown in FIG. 2, the packaging bag 20 has a single-chamber bag shape. The packaging bag 20 has a rectangular shape with a size of 80 mm × 150 mm, for example, and prepares a pair of laminated sheets having the same laminated structure as in FIG. It is obtained by heat-sealing the end portions corresponding to the three sides and, for example, filling the contents made of an alkaline solution and then sealing the end portions corresponding to the remaining one side with a heat seal. At this time, the heat seal width is, for example, 15 mm. The obtained packaging bag 20 has the sealing part 21 formed in the outer edge part by heat sealing. In the laminated sheet used for the packaging bag, the thickness of the base material, the barrier layer, the thermoplastic resin layer, and the sealant layer is, for example, 15 μm, 15 μm, 30 μm, and 20 μm, respectively.

  As shown in FIG. 3, the packaging bag 30 is a two-chamber packaging bag having two storage chambers divided into two by a partition wall. This two-chamber packaging bag has the same thickness as the above-mentioned laminated sheet, for example, a pair of rectangular laminated sheets having a size of 150 mm × 150 mm, for example, is prepared, the sealant layers are arranged oppositely, and aligned, The end portions 25 and 26 corresponding to two opposite sides of the rectangle are heat-sealed with a width of 15 mm, for example, to form a cylindrical body having both ends opened, and then the cylindrical body is roughly inserted between, for example, two openings. For example, a sealing portion 23 that is heat-sealed in a strip shape having a width of 7 mm is formed so as to be divided into two to obtain two storage chambers 27 and 28. , Both the openings are obtained by, for example, heat sealing with a width of 15 mm and sealing. As shown in the drawing, the obtained packaging bag 30 has a sealing portion 23 between the outer edge portion and the two storage chambers 27 and 28.

The peel strength of the sealing portion can be appropriately adjusted depending on the composition of the sealant layer to be used and the heat seal width. When the sealing part which becomes a partition between the first storage chamber and the second storage chamber is required to be easily peelable, the strength of the sealing part between the storage chambers is higher than the strength of the sealing part of the outer edge. In order to make it low, the heat seal width | variety can be made narrower than the heat seal width | variety of the sealing part of an outer edge. Further, as shown in the figure, the easy peelability can be improved by providing a concave constriction in the sealing portion during heat sealing. Such a sealing portion between the first storage chamber and the second storage chamber is easily peeled off when pressure is applied to the contents of one of the storage chambers in use, and the two storage chambers communicate with each other. The contents of both storage chambers can be thoroughly mixed. In addition, the shape of the sealing part can sufficiently function as a partition wall for the two storage chambers during storage, in addition to a belt-like shape having a concave constriction, and can be easily peeled off during communication to allow the two storage chambers to communicate with each other. Any shape is possible if possible. The above-mentioned two-chamber packaging bag can be manufactured and filled in one line, and the equipment is smaller than the two bottle container manufacturing and filling lines. Is possible.

  FIG. 4 is a cross-sectional view illustrating an example of the lid body of the present invention.

  As shown in the figure, the lid 40 has a configuration in which an adhesive layer 6, a barrier layer 7, a thermoplastic resin layer 8, and a sealant layer 9 are laminated in this order on a base material layer 5 made of, for example, stretched nylon.

  This lid 40 is formed on the base material layer 5 by the gravure coating method, and then the solvent component in the adhesive is blown off by oven heating, and then combined with the base material layer. It is obtained by adhering the barrier layer 7 to the base material layer 5 by passing through, and then forming the thermoplastic resin layer 8 by an extrusion lamination method.

  FIG. 5 is a view for explaining a combination of an example of the lid of the present invention and an example of a molded container to which the lid can be applied.

As shown in the figure, the molded container 50 has, for example, a rectangular bottom portion 11, a side wall 12 surrounding the bottom portion, an opening 13 defined by a side wall end opposite to the bottom portion, and an opening 13 from the side wall 12 end. The sealing surface 14 extended outside the opening 13 along the containing surface is included. The lid 40 has, for example, a rectangle having sides that are approximately the same size as the end of the sealing surface 14. After injecting the contents into the container, the molded container can be sealed by aligning the four sides with the end of the sealing surface 14 and performing heat sealing with the sealing surface 14. The packaging bags and containers shown in 3 and 5 can contain any contents such as solids and liquids, but these packaging bags and containers can contain alkaline solutions having a pH of 8 or more. Long-term storage is possible. For example, even when an alkaline solution having a pH of about 11 used as one agent such as a two-component perm solution or a two-component oxidation reaction coloring solution is accommodated, undesired peeling or the like does not occur due to erosion of the contents.

Example Example 1
Formation of molded container A laminated sheet obtained by laminating a polyvinyl alcohol film having a thickness of 100 μm, a polypropylene having a thickness of 350 μm, and a low-density polyethylene on a polypropylene film having a thickness of 350 μm was formed by vacuum forming. A molded container having a size of 40 mm × 70 mm × depth 25 mm and having a sealing surface extending from the side wall and having the same shape as the container 50 of FIG. 5 was obtained.

Formation of lid material As a base material, 15 μm-thick stretched nylon with an adhesive layer formed on one side is prepared, and 15 μm aluminum foil is bonded onto this adhesive layer with a two-component curable dry adhesive. did. As shown in Table 1 below, a resin A separately blended with an ethylene-methacrylic acid copolymer having a methacrylic acid component content of 11% by weight as a thermoplastic resin layer material and a weight ratio of 80:20 as a sealant layer material. The low density polyethylene as the component and the polybutene as the incompatible resin B component are each introduced into a co-extruder, and the thermoplastic resin layer and the sealant layer are co-extruded on the aluminum foil adhered to the substrate. Lamination was performed to obtain a laminated sheet for lids. The obtained laminated sheet for lids was cut in accordance with the size of the sealing surface of the molding container to obtain a lid.

Encapsulation of contents 50 cc of a coloring agent solution having a pH of 11 was introduced into the molding container.

  Next, the obtained lid was positioned and placed on the sealing portion of the container in which the contents were put, and the contents were sealed in the container by heat sealing at 180 ° C. for 2 seconds.

Delamination Test A total of 10 containers each containing the contents as described above were prepared.

  After storing this container at 50 ° C. for one month, the presence or absence of peeling of the lid and the site where peeling occurred were examined. The obtained results are shown in Table 2 below.

Easily peelable test As a result of the delamination test, the lid body without peeling was opened and examined for easy peelability. The obtained results are shown in Table 2 below.

Example 2
As the thermoplastic resin layer material, an ethylene-acrylic acid copolymer having an acrylic acid component content of 7.5% by weight, and as the resin A component, an ethylene-acrylic acid copolymer having an acrylic acid component content of 7.5% by weight, And the container which enclosed the contents was carried out similarly to Example 1 except having used polypropylene as a resin B component and making the weight ratio of A component and B component into 60:40.

  Similarly, a delamination test and an easy peelability test were performed using the obtained container.

  The results are shown in Table 2 below.

Comparative Examples 1 to 4
A container enclosing the contents was prepared in the same manner as in Example 1 except that the thermoplastic resin layer material, the resin A component, and the resin B component shown in Table 1 were used.

  The surface modifier used in Comparative Example 2 is a two-component curable anchor coating agent using polyester polyurethane as a resin system.

  Similarly, a delamination test and an easy peelability test were performed using the obtained container.

The results are shown in Table 2 below.

  The packaging material of the present invention can be used for a heat-sealed container that can contain contents such as foods, drugs, and particularly highly alkaline solutions.

Sectional drawing showing an example of the packaging material of this invention Front view showing an example of the packaging bag of the present invention Front view showing another example of the packaging bag of the present invention Sectional drawing showing an example of the cover body of this invention The figure for demonstrating the combination of an example of the lid of this invention, and an example of the shaping | molding container which can apply this lid

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,5 ... Base material, 2,7 ... Barrier layer, 3,8 ... Thermoplastic resin layer, 4,9 ... Sealant layer, 6 ... Adhesive layer, 10 ... Packaging material, 11 ... Bottom part, 12 ... Side wall, 13 ... Opening, 14 ... sealing surface, 20, 30 ... packaging bag, 21, 22, 23, 25, 26 ... sealing part, 24 ... concave constriction, 26, 27 ... storage chamber, 40 ... lid, 50 ... molding container

Claims (6)

A substrate;
A barrier layer provided on the substrate;
A thermoplastic resin layer provided in contact with the barrier layer and containing an ethylene-α, β-unsaturated carboxylic acid copolymer;
A sealant layer formed by co-extrusion with the thermoplastic resin layer and containing a component A made of polyethylene or an ethylene-α, β-unsaturated carboxylic acid copolymer and a component B made of α, β-polyethylene; A packaging material comprising:   The packaging material according to claim 1, wherein the content of the component A is 50 to 99% by weight of the total amount of the component A and the component B. A substrate;
A barrier layer provided on the substrate;
A thermoplastic resin layer provided in contact with the barrier layer and containing an ethylene-α, β-unsaturated carboxylic acid copolymer;
A sealant layer containing a component A made of polyethylene or an ethylene-α, β-unsaturated carboxylic acid copolymer and a component B made of α, β-polyethylene formed by coextrusion with the thermoplastic resin layer; Formed using a laminated sheet containing,
A packaging bag comprising a sealing portion that is heat-sealed with the sealant layers disposed opposite to each other.   The packaging bag according to claim 3, wherein the content of the A component is 50 to 99 wt% of the total amount of the A component and the B component. A substrate;
A barrier layer provided on the substrate;
A thermoplastic resin layer provided in contact with the barrier layer and containing an ethylene-α, β-unsaturated carboxylic acid copolymer;
A sealant layer formed by co-extrusion with the thermoplastic resin layer and containing a component A made of polyethylene or an ethylene-α, β-unsaturated carboxylic acid copolymer and a component B made of α, β-polyethylene; A lid characterized by comprising.   The lid according to claim 5, wherein the content of the A component is 50 to 99% by weight of the total amount of the A component and the B component.

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