JP5082874B2 - Lid material - Google Patents

Description

  The present invention relates to a lid member, and more specifically, a lid member used for sealing an opening of a plastic molded container such as a tray shape or a cup shape, a paper cup container, a tube container, etc., wherein the lid material is at least Formed from the outside, a laminate comprising a base material layer, an adhesive layer, a barrier layer, an anchor coat layer, and a polyolefin resin layer laminated in this order. Even if the material has permeability to the polyolefin resin layer, which is the sealant layer of the material, or contains a material that is easily absorbed, there is no delamination of the sealant layer, and the laminate strength is reduced. It is related with the lid | cover material which can store the contents safely.

Conventionally, as a lid for a container having a barrier property, for example, a plastic film or paper is used as a base material, and a barrier layer and a sealant layer (usually a polyolefin-based resin layer) are respectively formed on one surface thereof as an adhesive layer or It has been used as a lid material by using a laminate laminated through an anchor coat layer and punching it out in accordance with the shape of the flange provided at the periphery of the opening of the container.
However, even with such lids, if the contents sealed and packaged inside the container contain substances that are likely to penetrate or be absorbed into the sealant layer, these substances may be removed during long-term storage. Soaks or is absorbed, penetrates the adhesive layer or the anchor coat layer, or stays between the barrier layer and the anchor coat layer or the adhesive layer, and so-called delamination occurs in which the sealant layer is peeled off from the barrier layer. There was a problem. In addition, even when no delamination occurs, there is a problem that the laminate strength is greatly reduced, and delamination is likely to occur due to impact or the like.
As a substance containing a substance that easily penetrates into the sealant layer or a substance that is easily absorbed, specifically, a bath agent containing a fragrance, boric acid, glycols, etc., a high-concentration alcohol aqueous solution such as alcohol for disinfection (for example, ethanol 80% by volume aqueous solution), car cleaners containing alkaline substances, surfactants, etc., hair dyes containing oxidative hair dyes or alkaline agents (for example, 28% ammonia water) of diamine dyes, 1-menthol and tinctures Toothpaste that contains oil, etc. Furthermore, as a content assuming foods such as oiliness, acidity, etc., there is a test liquid mixture in which ketchup, vinegar, and edible oil are mixed at a mass ratio of 1: 1: 1. It is done.

As a method for laminating the sealant layer on the barrier layer, generally, an anchor coat layer is provided as an adhesive layer on the barrier layer surface, and the resin of the sealant layer is extruded and laminated thereon, or the anchor layer is anchored on the barrier layer surface. By an extrusion laminating method in which a coat layer is provided, a film of a sealant layer previously formed into a film is opposed to the surface, a polyolefin resin similar to the sealant layer is extruded between them as an adhesive layer, and bonded by pressure bonding A lamination method or a film of a sealant layer previously formed into a film on the barrier layer surface is bonded by a dry lamination method using an adhesive for a dry laminate such as a two-component curable polyurethane adhesive as an adhesive layer. The method of laminating is used.
And as an anchor coat agent (henceforth AC agent) used for the said anchor coat layer, organic titanium system AC agent, isocyanate system AC agent (urethane system), polyethyleneimine system AC agent, polybutadiene system AC agent, etc. AC agents are marketed and used, but when the contents contain a substance that easily penetrates into the sealant layer or a substance that is easily absorbed, the resistance to these is insufficient, and the contents are sealed and packaged. As a storage stability test of a container with a lid material, when a storage test was performed at 40 ° C. for 3 months, there was a problem that the sealant layer of the lid material peeled off from the barrier layer. The same applies to the case where the sealant layer is extrusion coated on the surface of the anchor coat layer and laminated by the extrusion laminating method.
Similarly, when a sealant layer is bonded to the barrier layer of the lid by the dry lamination method, the dry laminate adhesive is insufficiently resistant, and the sealant peels off from the barrier layer by the storage test, or There was a problem that the laminate strength of the sealant layer was lowered.
Furthermore, the AC agent and the adhesive for dry laminating, except for some of them, use an organic solvent for the coating solution, and the organic solvent is discharged at the time of coating, and there is a problem that adversely affects the environment. there were.

As a means for solving the above problems, in the method of laminating the barrier layer by extruding and coating the resin of the sealant layer, without using an anchor coat layer on the barrier layer surface, an aluminum foil is used as the barrier layer, A random copolymer of ethylene-methacrylic acid (hereinafter referred to as EMAA resin), which is said to exhibit excellent adhesion to metals such as aluminum foil, is used as the resin for the sealant layer and extruded directly onto the aluminum foil surface. As a result of producing the lid material laminate by coating and laminating, and producing the lid material of the container using the laminate, the container using the lid material easily penetrates the sealant layer as described above. In addition, the sealant layer peels off from the barrier layer even if the contents containing easily absorbed substances are sealed and packaged and the storage test is performed. No Rukoto, it could be produced cover material with good adhesion.
However, even with this container with a lid, the peeling (delamination) of the sealant layer by the storage test can be prevented, but the laminate strength itself of the sealant layer with respect to the barrier layer is not always sufficient. There was a problem that the laminate strength of the sheet was lowered.

  In order to solve the above-described problems, as a result of various studies on AC agents used for laminating a sealant layer to the barrier layer by extrusion coating, etc., as a result, 0.01% of unsaturated carboxylic acid or its anhydride was obtained. An aqueous dispersion in which a polyolefin copolymer resin containing ˜5% by mass is dispersed so that its number average particle size is as small as 1 μm or less, and the aqueous dispersion contains a non-volatile aqueous agent. By applying the aqueous dispersion formed in such a manner as an AC agent so that the thickness upon drying becomes 0.1 to 2 μm, the coating surface of the barrier layer is a metal foil such as an aluminum foil, aluminum, oxidation The vapor-deposited surface of a vapor-deposited film obtained by vapor-depositing aluminum, silicon oxide, etc. on a biaxially-stretched polyethylene terephthalate film, etc. Even if it is a plastic film surface such as an ethylene terephthalate film, it adheres well to the surface, and a polyolefin resin layer laminated by extrusion coating as a sealant layer on the surface is also firmly adhered. The container lid made using the laminate produced using the above-mentioned material is hermetically packaged with a content containing a substance that easily penetrates or is absorbed into the sealant layer as described above. The present inventors have found that the sealant layer does not peel even when a storage test is performed, and that the laminate strength of the sealant layer is slightly reduced and good, and the present invention has been completed.

It should be noted that there is no prior art document relating to a container lid that can be sealed and packaged for a long period of time with a content containing a substance that is permeable to the sealant layer or easily absorbed.
There is a patent document relating to an aqueous dispersion of polyolefin resin having the above-described structure and a method for producing the same, and a coating composition and an adhesive composition containing the aqueous dispersion are also described. It is also described that it has excellent properties (for example, see Patent Document 1).
However, the coating film of the aqueous polyolefin resin dispersion described in Patent Document 1 has permeability to the sealant layer or is excellent in resistance to a substance that is easily absorbed, and is used for a container lid. In the production of a body, it is not described that a lid material having excellent resistance as described above can be produced by using this aqueous dispersion as an AC agent in laminating a sealant layer.
Japanese Patent No. 3699935 (pages 1 to 15)

  The present invention has been made in order to solve the above-described problems, and a problem thereof is a lid member used for sealing the openings of various containers, the lid member being at least from the outside. It is formed of a laminate that is made by laminating a polyolefin-based resin layer of a base layer, an adhesive layer, a barrier layer, an anchor coat layer, and a sealant layer in this order, and is stored in a container using this lid material. Even if the contents are permeable to the sealant layer of the lid material as described above or contain a substance that is easily absorbed, the container in which the contents are hermetically sealed should be kept at 40 ° C. for 3 months. Even if a storage test is performed under various conditions, the polyolefin resin layer of the sealant layer of the lid material does not peel off, and the laminate strength does not greatly decrease, and has excellent content resistance. , Lid material Emissions of the organic solvent in manufacturing a laminate also being able to reduce, with excellent performance, is to provide a lid of the small containers adverse effect to the environment.

The above problems can be solved by the following present invention.
That is, the invention described in claim 1 is a lid used for sealing the opening of the container, and the lid is at least from the outside, a base material layer, an adhesive layer, a barrier layer, A polyolefin copolymer resin which is formed of a laminate obtained by laminating an anchor coat layer and a polyolefin resin layer in this order, and the anchor coat layer contains 0.01 to 5% by mass of an unsaturated carboxylic acid or an anhydride thereof. Is an aqueous dispersion in which the number average particle diameter is 1 μm or less, and the aqueous dispersion is formed so that the aqueous dispersion does not substantially contain a non-volatile aqueous additive. Is applied to the barrier layer surface so as to have a dry thickness of 0.1 to 2 μm, and dried by heating. Further, the polyolefin resin layer is formed of a polyolefin resin on the anchor coat layer surface. It is made of a lid material characterized by being formed by a method of extrusion coating or a method of extruding and laminating a polyolefin resin film using a similar polyolefin resin.
The polyolefin copolymer resin of the anchor coat layer is preferably an ethylene-acrylic acid ester-maleic anhydride terpolymer or an ethylene-methacrylic acid ester-maleic anhydride terpolymer.
Further, the invention described in claim 2 is that the barrier layer is an aluminum foil or a vapor deposition film obtained by vapor-depositing at least one of aluminum, aluminum oxide, or silicon oxide on a plastic film of a base material. It consists of the cover material of Claim 1 characterized by the above-mentioned.
The invention described in claim 3 comprises the lid material according to claim 1 or 2, wherein the innermost polyolefin resin layer of the lid material is an easy-peeling polyolefin resin layer.

According to the first aspect of the present invention, since the container lid is configured as described above, the following effects can be obtained.
(1) Since the barrier layer is provided on the laminated body forming the lid material, the barrier material of the lid material is good, the permeation of the contents can be surely blocked, and the storage stability of the contents can be improved.
(2) Since the sealant layer of the laminate of the lid material is formed of a polyolefin-based resin, it is possible to obtain a lid material having excellent heat sealability and relatively high content resistance to a variety of contents.
(3) Since the anchor coat layer provided on the barrier layer surface when the polyolefin resin layer of the sealant layer is laminated on the barrier layer is configured as described above, the anchor coat layer lamination surface of the barrier layer is a metal such as an aluminum foil. Even if it is a foil or a vapor-deposited surface of a vapor-deposited film or the plastic film surface on the opposite side, a uniform anchor coat layer with no defects such as pinholes is formed, and various penetrable contents The barrier property against physical components is also improved.
Also, when laminating the polyolefin resin layer of the sealant layer on the anchor coat layer, the polyolefin resin is extrusion coated or the polyolefin resin film is extruded and laminated using the same polyolefin resin. Since they are laminated, the sealant layer is firmly heat bonded to the anchor coat layer surface, and the laminate strength of the sealant layer becomes excellent.
Therefore, a container using the lid material of the present invention is hermetically packaged with a content containing a substance that is permeable to the sealant layer as described above or is easily absorbed, and is sealed at 40 ° C. Even if a storage test such as a month is performed, there is no delamination of the sealant layer of the lid material, and there is an effect that it is possible to provide a lid material with less decrease in the laminate strength of the sealant layer.
(4) Further, since the anchor coat layer is formed of the aqueous dispersion of polyolefin copolymer resin as described above, the discharge amount of the organic solvent during the production of the laminate can be reduced, and there is little adverse effect on the environment. can do.

  According to the invention described in claim 2, in the configuration of the lid material of the invention described in claim 1, the barrier layer is made of an aluminum foil or at least one of aluminum, aluminum oxide, or silicon oxide. In addition to the operation and effect of the invention described in claim 1, the barrier property of the lid can be further improved, and the contents of the contents can be improved. Storage stability can be further improved.

  According to the invention described in claim 3, in the configuration of the lid material of the invention described in claim 1 or 2, the innermost polyolefin resin layer of the lid material is an easy peel polyolefin resin layer. In addition to the function and effect of the invention described in claim 1 or 2, the lid is provided with easy-openability, and when the contents sealed in the container are taken out, the lid is easily peeled off. Can be opened.

The lid material of the present invention is suitably used for sealing openings of plastic molded containers, paper cup containers, laminated tube containers, etc., but is particularly limited because the lid material itself has barrier properties. However, in order to take advantage of the barrier property, it is more preferable that the container also has the barrier property.
Accordingly, when the container is a molded container made of polypropylene, it may be a molded container made of polypropylene alone, for example, polyethylene layer or polypropylene layer / adhesive resin layer / ethylene-vinyl alcohol copolymer layer (barrier layer) / adhesive resin. More preferably, the container is formed by sheet-forming a multilayer laminated sheet such as a layer / polypropylene layer. Further, when the container is a paper cup container, for example, it is preferably a paper cup container formed by molding a laminated sheet in which at least an aluminum foil and a polyethylene layer are laminated on the inner surface of a paper such as a cup base paper.
Moreover, the material of the surface to which the lid of the container is thermally bonded is preferably polyethylene or polypropylene alone or a copolymer thereof from the viewpoint that the thermal bonding of the lid can be improved.

Further, the lid material of the present invention is particularly characterized by the configuration of the laminate used for the production of the lid material. For example, the laminate is produced with the configuration as shown in FIG. It can be manufactured by punching in accordance with the shape of the part.
実 際 In actual use, as described above, it is used as a single-sheet lid material punched in advance according to the shape of the opening of the container, and a wound-type lid material is supplied to the filling and sealing device. In many cases, after being heat sealed to the flange at the periphery of the opening of the container filled with the contents, it is used in a method of punching into individual shapes in-line.

Hereinafter, the present invention will be specifically described with reference to the drawings.
FIG. 1 is a schematic cross-sectional view showing the configuration of an embodiment of a laminate used for the lid member of the present invention.
FIGS. 2A and 2B are plan views showing the configuration of an embodiment of the lid member of the present invention.
In addition, this invention is not limited to these drawings, unless the summary is exceeded.

A laminated body 10 shown in FIG. 1 includes a base material layer 1, an adhesive layer 2, a barrier layer 3, an anchor coat layer (AC layer) 4, and a polyolefin resin layer 5 serving as a sealant layer in this order from the top. It is configured as follows.
In the laminated body 10 shown in FIG. 1, the base material layer 1 needs to be excellent in various strengths, for example, a biaxially stretched polyester film such as a biaxially stretched polyethylene terephthalate film or a biaxially stretched polyethylene naphthalate film. In addition, a biaxially stretched polyamide film or a biaxially stretched polypropylene film obtained by biaxially stretching a film of nylon 6, nylon 66, MXD-6, or the like can be suitably used, and paper or synthetic paper can also be used. These may be used alone or in combination.
In particular, when paper is used as the base material layer 1, the rice basis weight is preferably in the range of 60 to 400 g / m ² , and although not shown in the figure, the surface water resistance is improved and contamination is prevented. For the purpose, a resin layer such as an overprint layer and a film layer such as a biaxially stretched polyethylene terephthalate film can be laminated on the paper layer.
In the present invention, the barrier layer 3 is a metal foil such as an aluminum foil, or a base material such as a biaxially stretched polyethylene terephthalate film, at least one of a metal such as aluminum and an inorganic oxide such as aluminum oxide and silicon oxide. A vapor deposition film formed by vapor deposition on a film, a polyacrylonitrile film, or the like can be used.
When using the said vapor deposition film, the range of 150-2000 mm is suitable for the thickness of a vapor deposition layer.
The adhesive layer 2 between the base material layer 1 and the barrier layer 3 differs depending on the method of laminating the base material layer 1 and the barrier layer 3, and when both are pasted by the dry laminating method, a two-component curable type for dry laminating. Use low-density polyethylene or polyethylene-based copolymer, etc., when using polyurethane-based adhesive, etc., and laminate by extrusion lamination method. In that case, an emulsion adhesive such as an ethylene-vinyl acetate copolymer can be used as the adhesive layer 2.

  Next, as described above, the anchor coat layer 4 (hereinafter referred to as AC layer) 4 provided on the side of the barrier layer 3 on which the polyolefin-based resin layer 5 is laminated has 0 unsaturated carboxylic acid or its anhydride as described above. An aqueous dispersion in which a polyolefin copolymer resin containing 0.01 to 5% by mass is dispersed so that the number average particle diameter thereof is 1 μm or less, and the non-volatile aqueous agent is substantially contained in the aqueous dispersion. The aqueous dispersion formed so as not to be contained is applied to the surface of the barrier layer 3 so as to have a dry thickness of 0.1 to 2 μm, and dried by heating.

The polyolefin-based resin layer 5 laminated on the AC layer 4 is a sealant layer of a lid material, and a method of extruding and coating a polyolefin-based resin on the surface of the AC layer 4 or a polyolefin-based resin film with a similar polyolefin It can laminate by the method of extrusion laminating using a system resin.
Examples of the polyolefin resin include low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, ethylene-α / olefin copolymer and ethylene-acrylic acid copolymer (polymerized using a single-site catalyst ( EAA resin), EMAA resin, ionomer copolymer such as ionomer, and polypropylene or propylene-ethylene random or block copolymer can be used. A suitable material can be selected and used according to the material.

In addition, when making the sealant layer of the lid material, that is, the polyolefin resin layer 5 easy peel, the polyolefin resin layer 5 differs depending on the material of the adherend surface of the target container. When the landing surface is polypropylene, the polyolefin-based resin layer 5 of the lid material has a two-layer structure, and the surface in contact with the AC layer 4 is an ethylene-α / olefin copolymer polymerized using a single-site catalyst. The mixed resin layer in which polybutene-1 is mixed at a ratio of 30 to 80 parts by mass with low-density polyethylene or ethylene-based copolymer with respect to 100 parts by mass of the surface to be thermally bonded to the adherend surface of the container As a result, good easy peel properties can be imparted.
Further, in the case where the adherend surface of the container is polyethylene, the polyolefin-based resin layer 5 of the lid material also has a two-layer structure, and the surface on the side in contact with the AC layer 4 is low-density polyethylene or single-site catalyst. The ethylene-α / olefin copolymer layer polymerized by using a polymer, and the surface to be thermally bonded to the adherend surface of the container is 30 to 70 parts by mass of polybutene-1 with respect to 100 parts by mass of low-density polyethylene. Good easy peel properties can be imparted by forming a mixed resin layer mixed at a ratio.

2A and 2B are plan views showing the configuration of an embodiment of the lid material of the present invention. The lid materials 100 and 200 shown in FIGS. The laminate 10 having the configuration shown in FIG. 1 can be punched out.
The lid member 100 shown in FIG. 2A is composed of a circular lid member body 11a and a knob 12a extending at one end around the lid member main body 11a. Naturally, such a lid member 100 is used for a container having a circular thermal bonding portion at the periphery of the opening.
The lid member 200 shown in FIG. 2B is composed of a substantially square lid body body 11b and a knob 12b extending at one corner. Such a lid member 200 is used for a container having a square thermal bonding portion at the periphery of the opening. Thus, the shape of the lid body portion is not particularly limited as long as it is formed in accordance with the shape of the thermal bonding portion at the periphery of the opening of the container.
Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples.

The laminate for the cover material having the structure shown in FIG. 1 is formed by using a biaxially stretched polyethylene terephthalate film (hereinafter referred to as a PET film) (thickness 12 μm) as the base material layer 1 and an aluminum foil (hereinafter referred to as the PET layer). (Referred to as “AL foil”) (thickness 7 μm), an AC layer of an isocyanate-based AC agent is applied to the bonding surface of the PET film so that the dry thickness is 0.5 μm, and dried to form an AC layer. Then, a low density polyethylene (hereinafter referred to as LDPE) is bonded as an adhesive layer 2 between the two by an extrusion laminating method of extruding to a thickness of 15 μm at an extrusion temperature of 330 ° C., and then the AL foil surface As an AC layer 4, an aqueous dispersion of a polyolefin copolymer resin containing 2% by mass of maleic anhydride (dispersed resin number average particle diameter 0.6 μm, non-volatile water) Coating agent is used so that the thickness upon drying is 0.5 μm, and dried by heating to form an AC layer 4, and a polyolefin resin layer 5 as a sealant layer thereon, LDPE was extrusion coated at an extrusion temperature of 330 ° C. to a thickness of 25 μm to produce a laminate for the lid material of Example 1.
(Structure of the laminate for the lid material)
PET film (thickness 12 μm) / isocyanate-based AC layer (thickness 0.5 μm) / LDPE layer (thickness 15 μm) / AL foil (thickness 7 μm) / AC layer (thickness 0.5 μm) / LDPE layer with the aqueous dispersion ( Thickness 25μm)

In the structure of the laminate of Example 1, the PET film of the base material layer 1 was replaced with high-quality paper (rice basis weight 81.4 g / m ² ), and the AL foil (thickness 7 μm) of the barrier layer 3 on one side thereof Are bonded together by an extrusion laminating method in which LDPE is extruded as an adhesive layer 2 at a temperature of 330 ° C. and bonded to a thickness of 15 μm, and the sealant layer is polyolefin-based. In order to make the resin layer 5 an easy-peeling polyolefin-based resin layer, the polyolefin-based resin layer 5 has a two-layer structure, and the surface on the side in contact with the AC layer 4 is polymerized using a single-site catalyst. The surface of the olefin copolymer layer (thickness 30 μm) which is thermally bonded to the adherend surface of the container is 45% of polybutene-1 with respect to 100 parts by mass of LDPE. The lid of Example 2 was processed in the same manner as in Example 1 except that the mixed resin layer (thickness 10 μm) was mixed at a ratio of parts and both were laminated on the surface of the AC layer 4 by coextrusion coating. A laminate for the material was produced.
(Structure of the laminate for the lid material)
Polymerization using fine paper (rice basis weight 81.4 g / m ² ) / LDPE layer (thickness 15 μm) / AL foil (thickness 7 μm) / AC layer (thickness 0.5 μm) by the aqueous dispersion / single-site catalyst Ethylene-α / olefin copolymer layer (thickness 30 μm) / LDPE (100 parts by mass) and polybutene-1 (45 parts by mass) mixed resin layer (thickness 10 μm)

[Comparative Example 1]
The laminate for the lid material is made of PET film (thickness 12 μm) for the base material layer 1, AL foil (thickness 7 μm) for the barrier layer 3, and linear low density polyethylene for the polyolefin resin layer 5 of the sealant layer. Using a film (thickness: 40 μm) (hereinafter referred to as L·LDPE), each of the two-component curable polyurethane adhesives for dry lamination so that the coating amount when dried is 3.5 g / m ² The laminated body for the cover material of the comparative example 1 was produced by bonding together using the dry lamination method.
(Structure of the laminate for the lid material)
PET film (thickness 12 μm) / adhesive layer for dry lamination (application amount 3.5 g / m ² ) / AL foil (thickness 7 μm) / adhesive layer for dry lamination (application amount 3.5 g / m ² ) / L LDPE film (thickness 40μm)

[Comparative Example 2]
In the structure of the laminate for a lid material of Example 1, the LDPE layer (thickness 25 μm) of the sealant layer was extruded and laminated on the AL foil (thickness 7 μm) surface of the barrier layer 3 through the AC layer 4. However, on the AL foil surface, an ethylene-methacrylic acid random copolymer (EMAA resin) was directly extruded as a sealant layer without providing an AC layer, and extruded and coated at a temperature of 295 ° C. to a thickness of 25 μm. Were all processed in the same manner as in Example 1 to produce a laminate for the lid material of Comparative Example 2.
(Structure of the laminate for the lid material)
PET film (thickness 12 μm) / isocyanate AC layer (thickness 0.5 μm) / LDPE layer (thickness 15 μm) / AL foil (thickness 7 μm) / EMAA resin layer (thickness 25 μm)

[Evaluation test of laminate for lid material]
Using the laminates for the lid materials of Examples 1 and 2 and Comparative Examples 1 and 2 prepared as described above, first, a multilayer laminated sheet (barrier layer having a barrier layer coated surface formed of polyethylene). (1) a powder bath containing (1) fragrance, boric acid, glycols, etc. as a content in a molded container formed by sheet-molding into a cup-shaped container provided with a flange on the periphery of the opening; (2) ethanol 80 Car wash (pH14) containing volume% aqueous solution, (3) alkaline substance, surfactant, etc. (4) hair dye containing oxidative hair dye of diamine dye, alkaline agent (28% ammonia water) ( pH 9), (5) 1-menthol, toothpaste containing tinctures, (6) a mixture of ketchup, vinegar and edible oil mixed in a mass ratio of 1: 1: 1, respectively, On the flange of the opening of the molding container As the lid material, the laminates for the lid materials produced in Examples 1 and 2 and Comparative Examples 1 and 2 are overlapped with the sealant layer surfaces facing each other, and a seal temperature is 200 ° C. and a pressure is 100 kPa using a ring sealer. Then, a cup-shaped container package in which the contents were hermetically sealed by heat-sealing under the conditions of 1 second was produced.
All of the cup-shaped container packages produced above had good sealing properties, and no leakage of contents, tearing of the lid material, etc. were observed.
Next, the container and package were placed with the lid on the bottom so that the contents were always in contact with the lid, and stored at 40 ° C. for 3 months. After storage, the lid material is opened, and the presence or absence of delamination between the barrier layer and the sealant layer of the lid material is examined. If there is no delamination, the laminate strength of the sealant layer is measured. Are summarized in Table 1.
In addition, since the laminated body for the lid material of Example 2 has a structure in which an easy peel property is imparted to the sealant layer (polyolefin resin layer), it is easy to manually open the lid material after the storage. The lid was peeled off and opened.
The laminate strength of the sealant layer was measured using a tensile test apparatus (Tensilon) at a tensile speed of 50 mm / min and a sample width of 15 mm.

〔Test results〕
As is apparent from the test results shown in Table 1, the laminates for the lid materials of Examples 1 and 2 have good content resistance against any of the above contents, and the sealant layer The laminate strength of the sealant layer is not significantly different between before and after the storage test, and a relatively high strength of 4.1 to 4.9 N / 15 mm width is maintained even after the test. It was excellent in resistance to contents as described above.
On the other hand, among the laminated bodies for the lid materials of Comparative Examples 1 and 2, the laminated body for the lid material of Comparative Example 1 was (80) an 80% by volume ethanol aqueous solution of (2) as a content in the storage test. 3) The car cleaner (pH 14), the hair dye (pH 9) of (4), and the toothpaste of (5) filled with the toothpaste, and peeling of the sealant layer occurred. Even in the laminated body, peeling of the sealant layer occurs with the car cleaner (pH 14) of (3) and the hair dye (pH 9) of (4). Moreover, even in the case where peeling did not occur, neither of them was preferable in that the laminate strength of the sealant layer after the storage test was greatly reduced and the content resistance was poor.

  As described above, the lid material of the present invention includes a bathing agent containing a fragrance, boric acid, glycols and the like, a high-concentration alcohol aqueous solution (for example, ethanol 80) as the contents sealed and packaged in a container using the lid material. Car wash containing alkaline substance, surfactant, etc., hair dye containing oxidative hair dye or alkaline agent (for example, 28% ammonia water), 1-menthol, tincture, etc. Containing toothpaste, including ketchup, vinegar and edible oil mixed in a mass ratio of 1: 1: 1, including a substance that easily penetrates or is absorbed into the sealant layer Although it can be used particularly suitably as a lid for containers for packaging products, there are no particular restrictions on the contents and usage as long as the performance can be used effectively

It is a schematic cross section which shows the structure of one Example of the laminated body used for the cover material of this invention. (A), (b) is a top view which shows the structure of one Example of the cover material of this invention, respectively.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base material layer 2 Adhesion layer 3 Barrier layer 4 Anchor coat layer (AC layer)
5 Polyolefin-based resin layer (sealant layer)
DESCRIPTION OF SYMBOLS 10 Laminated body 11a, 11b Cover material main-body part 12a, 12b Knob part 100, 200 Cover material

Claims (3)

A lid member used for sealing an opening of a container, and the lid member includes, from at least the outside, a base layer, an adhesive layer, a barrier layer, an anchor coat layer, and a polyolefin resin layer having excellent strength in this order. The anchor coat layer is formed of a laminated body, and the number average particle diameter of the polyolefin copolymer resin containing 0.01 to 5% by mass of unsaturated carboxylic acid or anhydride thereof is 1 μm or less. The aqueous dispersion formed as described above, and the aqueous dispersion formed so as to contain substantially no non-volatile aqueous additive, has a thickness when dried on the barrier layer surface. It is formed by applying and heating and drying so as to be 0.1 to 2 μm, and the polyolefin resin layer is a method of extruding and coating a polyolefin resin on the surface of the anchor coat layer, or A lid material formed by a method of extruding and laminating a polyolefin resin film using a similar polyolefin resin. 2. The lid according to claim 1, wherein the barrier layer is an aluminum foil or a vapor deposition film obtained by vapor-depositing at least one of aluminum, aluminum oxide, or silicon oxide on a plastic film as a base material. The lid material according to claim 1 or 2, wherein the polyolefin resin layer as the innermost layer of the lid material is an easy-peeling polyolefin resin layer.

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