JP2014188723A - Laminate and package using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminate having superior non-adhesiveness and allowing a user to completely take out liquid or gel-like contents such as food and toiletry products and to use the contents, and to provide a package.SOLUTION: In the laminate, a heat adhesive polyolefin resin layer 2 is laminated on one surface of a base material 1. On the surface of the heat adhesive polyolefin resin layer 2, a plurality of unit shapes 3 having one shape of a convex shape and a concave shape are formed. The longest distance L of the bottom part cross section of the unit shape 3 is 0.2-1,000 μm, the height H from the bottom part to the top is (0.25 to 5)L, and the interval X between adjacent unit shapes is 2L or less.

Description

  TECHNICAL FIELD The present invention relates to a laminate for packaging food contents, pharmaceutical products and toiletry products, in particular liquid contents and gel contents, and a package using the same.

  Conventionally, various forms of packaging have been put to practical use for packaging liquid contents such as shampoo, rinse, kitchen detergent, sauce, pasta sauce, soup, dressing, and yogurt. ing.

  As an example of various packaging bodies, for example, a container base material made of a single plastic, a laminated body of plastic, and a composite laminated body of plastic and paper was formed by a molding method such as blow molding, injection molding, or pressure molding. A package obtained by heat-sealing a container and a flange portion of the container with a lid is known (Patent Document 1).

  The package as described above is filled with the contents in the formed container, and then heat-sealed using a lid material and distributed to the market.

  However, in the case of the conventional packaging body as described above, particularly when the contents are liquid contents or gel contents, the contents adhere to the inner surface of the packaging body, and it is difficult to take out and use up to the end. There is a problem. Further, even when the packaging body that has become unnecessary after use is discarded, it is necessary to remove the contents adhering to the inner surface of the packaging body by washing or the like, which requires unnecessary labor from the consumer.

  For these problems, for example, a packaging material in which one surface of a thermal bonding layer is laminated on a base material layer and hydrophobic oxide particles are attached to the other surface has been proposed (Patent Document 2). ). Since this packaging material has hydrophobic oxide particles attached to the other surface of the thermal adhesive layer, the hydrophobic oxide particles present on the region to be thermally bonded are embedded in the thermal adhesive layer. Does not disturb. On the other hand, since the hydrophobic oxide particles present outside the region to be thermally bonded are present in the thermal bonding layer as they are, high non-adhesiveness can be exhibited with respect to the contents.

  However, in the above proposal, since the hydrophobic oxide particles are adhered to the surface of the thermal adhesive layer, the hydrophobic oxide particles are not easily bonded in the non-thermally bonded region due to insufficient binding force of the hydrophobic oxide particles during storage. There is a problem that oxide particles fall off and mix into the contents.

JP 2001-158064 A Japanese Patent No. 4348401

  An object of the present invention is to provide a laminate and a packaging body excellent in non-adhesiveness that can take out and use liquid or gel-like contents such as food and toiletry products to the end.

The present invention has been made in view of the solution of the above problems, and the invention according to claim 1 is a laminate formed by laminating a heat-adhesive polyolefin resin layer on one surface of a substrate,
The surface of the thermal adhesive polyolefin resin layer is formed with a plurality of unit shapes of either a convex type or a concave type,
And the longest distance L of the bottom cross section of the unit shape is 0.2 to 1000 μm, the height H from the bottom to the apex is (0.25 to 5) L, and the distance X between the adjacent unit shapes is 2 L or less. It is a laminated body characterized by being.

  The invention according to claim 2 is the laminate according to claim 1, wherein the unit shape is any one of a hemisphere, a semi-ellipsoid, a cone, and a polygonal cone.

  Moreover, the invention which concerns on Claim 3 uses the laminated body in any one of Claims 1-3, It is a package body characterized by the above-mentioned.

  According to the first aspect of the present invention, a plurality of convex or concave unit shapes are formed in the heat-adhesive polyolefin resin layer, and the longest distance L of the bottom cross section of the unit shape is 0.2 to 0.2. 1000 μm, height H from the bottom to the apex is 0.25 L to 5 L, and the distance X between the adjacent unit shapes is 2 L or less, so that the surface area can be expanded and a structural water repellency effect is provided. Can do.

  According to claim 2, when the unit shape is any one of a hemisphere, a semi-ellipsoid, a cone, and a polygonal pyramid, the surface area can be expanded more efficiently and structural water repellency is achieved. Can have an effect.

  According to the third aspect of the present invention, the inner wall side of the package directly touching the liquid or gel-like contents can bring about the structural water-repellent effect of the heat-adhesive polyolefin resin layer having an uneven shape. That is, for example, by suppressing the adhesion of the contents to the wall surface in the package, the contents can be taken out and used up to the end. Even when the laminate is used as a container lid, it is possible to prevent liquid or gel-like contents from adhering to the lid at the time of opening.

  As described above, according to the present invention, it is possible to provide a package having excellent non-adhesiveness that can take out and use liquid or gel-like contents such as food and toiletry products to the end.

It is a section schematic diagram showing one embodiment of the layered product of the present invention. It is a plane schematic diagram showing one embodiment of a layered product of the present invention.

  Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1, in the present invention, a heat-adhesive polyolefin resin layer 2 is laminated on one surface of a base material 1, and a plurality of convex or concave unit shapes 3 are formed on the surface. It is a laminate composed of a mold or a concave shape.

As the convex or concave shape, the longest distance L of the bottom cross section is 0.2 to 1000 μm, the height H from the bottom to the apex is (0.25 to 5) L, and the distance X between the adjacent unit shapes is X. It is preferable to make it 2L or less. The shape is preferably a hemisphere, a semi-ellipsoid, a cone, or a polygonal cone. By satisfy | filling the shape of this range, a surface area can be expanded and a structural water-repellent effect can be brought about.

  As the base material 1 according to the present invention, paper or a plastic film can be used, and the material, thickness, and the like can be appropriately selected according to workability and required quality. The paper and the plastic film may be each simple substance or a laminate thereof. Moreover, the said base material 1 may be printed with the character and the decoration pattern previously.

  The paper used for the substrate 1 is not particularly limited, but depending on the processing suitability and required quality required, high-quality paper, special high-quality paper, coated paper, art paper, cast coated paper, imitation paper, kraft paper Paper or the like can be used.

  Moreover, as a plastic film used for the said base material 1, although a polyethylene terephthalate (PET), nylon, an extending | stretching polypropylene (OPP), a cellophane, etc. can be used, it does not specifically limit.

  Moreover, when barrier property is requested | required, base materials excellent in barrier property, such as aluminum foil, an aluminum vapor deposition film, and an inorganic oxide vapor deposition film, can be used.

  Further, as the heat-adhesive polyolefin resin layer according to the present invention, low density polyethylene (LDPE), linear low density polyethylene (LLDPE), and polypropylene (PP) resin, which are generally known as sealant materials for packaging bodies, are used. Alternatively, a resin obtained by blending these resins can be used.

  Moreover, when easy peelability is required for the package, ethylene-vinyl acetate copolymer resin (EVA), ethylene-methacrylic acid copolymer resin (EMAA), ethylene-acrylic acid copolymer resin (EAA) ), An ethylene-methyl acrylate copolymer resin (EMA), an ethylene-butyl acrylate copolymer resin (EBA), and an ionomer resin. Can be controlled. The easy peelability according to the present invention refers to a region that is heat-sealed with a second base material surface (such as a flange portion of a container) facing the sealant layer surface when the water-repellent packaging material of the present invention is used as a lid. However, it means that it can peel easily.

  Next, a method for forming a convex or concave shape 3 in which a plurality of convex or concave unit shapes are formed on the thermal adhesive polyolefin resin layer 2 will be described.

  FIG. 1 is a schematic cross-sectional view showing an embodiment of the laminate of the present invention, and FIG. 1 (a) shows a convex shape. FIG. 2B shows a concave shape. Any of them can be formed by transferring the shape to the heat-adhesive polyolefin resin layer 2 using a stamper in which a plurality of unit shapes 3 of either a convex type or a concave type are formed on a smooth substrate 1.

  FIG. 2 is a schematic plan view showing an embodiment of the laminate of the present invention, and shows the arrangement of the irregular shapes. FIG. 2A shows an example in which concavo-convex shapes are arranged in an orthogonal manner, and FIG. 2B shows an arrangement in which concavo-convex rows are shifted by a half pitch. In any case, the distance between adjacent unit shapes is arranged with the shortest distance X.

  The substrate used for the stamper is not particularly limited as long as it has characteristics required for a stamper such as heat resistance, durability, and workability in addition to smoothness. Moreover, about the formation method of uneven | corrugated shape, you may engrave directly on the said board | substrate and you may use the photolitho method.

  As a method for transferring the concavo-convex shape to the heat-adhesive polyolefin resin layer 2 using the stamper having the concavo-convex shape, an extrusion method, for example, using a general extruder, the stamper is applied to the cooling roll. Can be formed by extruding the heat-adhesive polyolefin resin 2 heated and melted thereon and cooling it.

  Moreover, it can also form by the embossing method which heat-presses the said stamper using the thermoadhesive polyolefin resin formed into a film form previously.

  In addition, the laminate according to the present invention has a structural water-repellent effect due to the concavo-convex shape by forming the concavo-convex shape on the heat-adhesive polyolefin resin layer having the concavo-convex shape and then providing a water-repellent layer thereon. In addition, it is possible to provide non-adhesiveness with further improved water repellency. Hereinafter, the water repellent layer will be described.

  The water repellent layer can be formed using a composition containing hydrophobic particles and an inorganic binder.

  The hydrophobic particles are a method of applying a fluorine-based or silicone-based coating material on the surface of particles made of a heat-adhesive polyolefin resin, or a method of imparting a hydrophobic functional group by a CVD method using fluorine gas or the like. However, it is not particularly limited.

  The average particle size of the hydrophobic particles is preferably 5 nm to 10 μm, and the particle size distribution is not particularly limited. However, the presence of particles having various particle sizes forms an uneven shape such as a fractal structure. Higher water repellency can be obtained. The average particle size and particle size distribution can be measured by a Coulter method, a dynamic light scattering method, or a laser scattering method.

Further, as the inorganic binder, a metal alkoxide or a hydrolyzate thereof can be used. For example, tetraethyl orthosilicate Si (OC ₂ H ₅ ) ₄ , tripropylaluminum Al (OC ₃ H ₇ ) _{3 and the} like are preferable.

  The blending ratio and film thickness of the hydrophobic particles and the inorganic binder constituting the water repellent layer are appropriately adjusted according to the adhesion to the laminate and the required water repellency. As the coating method, known methods such as roll coating and gravure coating can be used.

  Moreover, adhesiveness can be improved more by forming the said water-repellent layer in the said thermoadhesive polyolefin resin layer 2 through an anchor coat layer. As the anchor coat layer, generally used resin compositions such as polyester resin, EVA resin, acrylic resin, urethane resin, and modified olefin resin can be used.

  Next, the packaging form made using the laminate of the present invention will be described below. For example, it can be obtained by heat-sealing the outer peripheral edge of various forms as a general bag container to provide a gap for holding the contents. At this time, a plug can be provided in a part of the seal portion. As the form of the seal, a three-way seal, a four-method seal, a pillow, a gusset pillow, a standing pouch, and the like can be obtained. Moreover, the laminated body of the present invention can be used as a lid material, and sealed with a flange portion of a molded container such as a heat-sealable cup to produce a package. Any packaging form can give the characteristic which was excellent in the non-adhesiveness of the contents.

  The present invention will be described more specifically with reference to the following examples.

<Example 1>
An aliphatic ester-based isocyanate adhesive was applied to one surface of a 15 μm-thick nylon film as a base material by a dry laminating method so that the coating amount at the time of drying was 3 g / m ^2. The foil was laminated. Next, using an extruder in which a stamper having the following shape is attached to a cooling drum, an LDPE (low density polyethylene) resin is extruded on an aluminum foil with a film thickness of 60 μm with the substrate side held by a cooling roll. Thus, a laminate in which a heat-adhesive polyolefin resin layer having a convex semi-elliptical shape as a unit shape was laminated was produced.

(Stamper)
A stamper whose unit shape shown in FIG. 1B is a concave semi-ellipsoid (L 20 μm, H 40 μm, X 20 μm) and whose arrangement is shown in FIG.

<Example 2>
A laminate was produced in the same manner as in Example 1 except that the stamper was a convex semi-ellipsoid (L 20 μm, H 40 μm, X 10 μm) shown in FIG.

<Example 3>
A laminate was produced in the same manner as in Example 1 except that the stamper was a concave semi-ellipsoid (L1 μm, H2 μm, X1 μm).

<Example 4>
A laminate was produced in the same manner as in Example 1 except that the stamper was a concave semi-ellipsoid (L600 μm, H100 μm, X300 μm).

<Example 5>
A laminate was produced in the same manner as in Example 1 except that the stamper was a concave semi-ellipsoid (L 20 μm, H 10 μm, X 10 μm).

<Example 6>
A laminate was produced in the same manner as in Example 1 except that the stamper was a concave semi-ellipsoid (L 20 μm, H 20 μm, X 10 μm).

<Example 7>
A laminate was produced in the same manner as in Example 1 except that PP (polypropylene) resin was extruded onto the base aluminum foil.

<Example 8>
On the base aluminum foil, an LLDPE (linear low density polyethylene) film having a thickness of 60 μm is laminated via an adhesive, and the LLDPE film surface is formed from a concave semi-ellipsoid (L 20 μm, H 40 μm, X 20 μm). The resulting stamper was heated and pressed (embossed) to produce a laminate.

<Example 9>
A laminate was produced in the same manner as in Example 1 except that the stamper was a concave semi-ellipsoid (L 20 μm, H 40 μm, X 10 μm). Thereafter, an anchor coat layer (main agent: polyester resin, curing agent: isocyanate system) was formed to a thickness of 0.5 μm on the LDPE resin surface.

Next, using the composition for forming a water repellent layer having the following composition, the outermost surface was coated and dried (at 80 ° C. for 1 minute) so that the coating amount after drying was 1 g / m ² on the LDPE surface. A laminate having a water repellent layer was obtained.

(Water repellent layer forming composition)
It consists of (A) / (B) = 1/2 of the following composition.
(A) Hydrophobic particle solution: methanol solution of silica having dimethylpolysiloxane as a functional group
(Silica average particle size 50 nm, solid content 5 mass%)
(B) Inorganic binder liquid: Hydrolysis solution of tetraethylorthosilicate (TEOS)
(Solid content 5% by mass in terms of SiO ₂ )

<Example 10>
A laminate having a water repellent layer on the outermost surface was obtained in the same manner as in Example 9, except that an aqueous polyolefin resin dispersion (trade name: Allobase SA1200) was used as the anchor coat layer.

<Comparative Example 1>
A laminate was obtained in the same manner as in Example 1 except that the stamper was not attached and the cooling roll of the extruder was used as it was.

<Comparative example 2>
A laminated body having a water-repellent layer on the outermost surface was obtained in the same manner as in Example 9 except that the stamper was not attached and the cooling roll of the extruder was used as it was.

<Evaluation>
About the laminated body obtained in Examples 1-10 and Comparative Examples 1-2, the contact angle of water and the falling angle of yogurt were evaluated by the following methods as substitute characteristics for judging the non-adhesiveness of the liquid contents. The evaluation results are shown in Table 1 below.
-Contact angle of water-5 μl of ultrapure water was dropped on the surface of the laminate and measured using a contact angle meter.
-Yogurt falling angle-A laminate was placed on a flat table, 1 ml of yogurt was dropped on it, and then the flat table was tilted, and the angle when the yogurt started to fall was measured.

<Comparison result>
The products of the present invention obtained in Examples 1 to 10 showed good results both with a water contact angle of 130 degrees or more and a yogurt falling angle of 10 degrees or less. In particular, in Examples 9 to 10, more excellent water repellency and non-adhesiveness were obtained by providing a water repellent layer in addition to the uneven shape according to the present invention. On the other hand, in the comparative product obtained in Comparative Example 1, the contact angle of water was 90 degrees, and partial adhesion was observed at the fall angle of yogurt. In Comparative Example 2, the contact angle of water was 130 degrees and the fall of yogurt The angle was as large as 30 degrees, and practically no water repellency and non-adhesiveness were obtained.

  By using the laminate of the present invention for packaging the contents of a liquid or gel, the contents can be taken out with minimal loss, providing excellent water repellency and non-adhesiveness in taking out the contents.

DESCRIPTION OF SYMBOLS 1 ... Base material 2 ... Thermal adhesive polyolefin resin layer 3 ... Convex type or concave type of unit shape

Claims (3)

A laminate formed by laminating a heat-adhesive polyolefin resin layer on one surface of a substrate,
The surface of the thermal adhesive polyolefin resin layer is formed with a plurality of unit shapes of either a convex type or a concave type,
In addition, the longest distance L of the bottom cross section of the unit shape is 0.2 to 1000 μm, the height H from the bottom to the apex is 0.25 L to 5 L, and the distance X between the adjacent unit shapes is 2 L or less. A featured laminate.   The laminate according to claim 1, wherein the unit shape is any one of a hemisphere, a semi-ellipsoid, a cone, and a polygonal pyramid.   A package comprising the laminate according to any one of claims 1 to 3.