JP7187779B2 - Packaging materials, packaging containers and lids - Google Patents

Description

TECHNICAL FIELD The present invention relates to packaging materials, packaging containers, and lids.

Packaging materials are sometimes decorated with a high-brightness metallic luster from the viewpoint of producing a sense of quality and splendor of the objects to be packaged and creating a beautiful appearance. As such decoration means, for example, forming a metal layer such as a metal deposition film or a metal foil is generally performed.

However, a packaging material using a metal layer has a problem of increased cost. In addition, among the metal layers, the vapor-deposited metal film cannot be produced in-line with the other layers that make up the packaging material, so there is a problem of poor manufacturing efficiency, and among the metal layers, the metal foil is difficult to handle. There is a problem.
Furthermore, when packaging materials using a metal layer are heated in a microwave oven, the microwaves inside the microwave oven are reflected on the surface of the metal layer, generating sparks, which may lead to failure or accidents of the microwave oven. There is also the problem that the contents in the packaging container cannot be sufficiently heated.

For this reason, for example, Patent Document 1 proposes a packaging material in which a glossy layer is formed with an ink agent containing aluminum paste of a predetermined concentration instead of the metal layer.

JP 2017-81589 A

However, metal flakes such as aluminum flakes contained in the aluminum paste limit the colors that can be expressed. For example, aluminum flakes, which are typical examples of metal flakes, have a silvery white color. Therefore, Patent Document 1 describes preparing a gold ink by mixing a coloring agent with an aluminum paste (paragraph 0026 of Patent Document 1).

However, the glossy layer formed from the ink in which the coloring agent is mixed with the metallic flakes does not always have a high level of designability, although the expression range of shades is widened.

The present invention has been made to solve the above technical problems, and a packaging material having a high level of designability due to metallic luster without using a metal layer, and a packaging container using the packaging material and The object is to provide a lid.

That is, the present invention provides the following [1] to [4].
[1] A packaging material having a configuration in which a plastic film, a pattern layer and a sealant layer are laminated in this order from the outer layer side, wherein at least a part of the pattern layer contains a binder resin and metal flakes. It has a configuration in which a glittering printed layer and a chromatic underlayer are laminated in this order from the outer layer side, and the glittering printed layer substantially contains particles with a size of 380 nm or more other than the metal flakes. No, packaging.
[2] A packaging container at least partially formed of the packaging material described in [1] above.
[3] A lidded container comprising a container body having an accommodating portion and a lid joined to the container body so as to seal the accommodating portion, wherein the lid is formed of the packaging material. The packaging container according to [2] above.
[4] A lid made of the packaging material described in [1] above.

ADVANTAGE OF THE INVENTION According to this invention, the packaging material, packaging container, and lid|cover which have high-level designability by metallic luster can be provided, without using a metal layer.

1 is a schematic cross-sectional view showing an example of a laminated structure of a packaging material of the present invention; FIG. 1 is a schematic cross-sectional view showing an example of a laminated structure of a packaging material of the present invention; FIG. 1 is a schematic cross-sectional view showing an example of a laminated structure of a packaging material of the present invention; FIG. FIG. 2 is an image diagram of a cross section of a design layer portion of the packaging material of Example 1; FIG. 10 is an image diagram of a cross section of a design layer portion of the packaging material of Comparative Example 1; It is a sectional view showing an example of a pouch for microwave ovens among packaging containers of the present invention. 1 is a top view showing an example of a lidded container among packaging containers of the present invention. FIG. FIG. 8 is a sectional view along IV-IV in FIG. 7; FIG. 4 is a schematic cross-sectional view showing another example of the laminated structure of the packaging material of the present invention; Fig. 2 is a schematic plan view showing another example of a pouch for microwave ovens in the packaging container of the present invention. 11 is a cross-sectional view taken along line XI-XI of FIG. 10; FIG.

Hereinafter, the packaging material of the present invention, and the packaging container and lid using the packaging material will be described in detail. Note that the notation of a numerical range of "AA to BB" in this specification means "from AA to BB".

[Packaging material]
The packaging material of the present invention is a packaging material having a configuration in which a plastic film, a pattern layer and a sealant layer are laminated in this order from the outer layer side, and at least a part of the pattern layer contains a binder resin and It has a structure in which a glittering printed layer containing metal flakes and a chromatic undercoat layer are laminated in this order from the outer layer side, and particles having a size of 380 nm or more other than the metallic flakes are contained in the glittering printed layer. It does not contain substantially.

<Lamination structure>
1 to 3 show an outline of the laminated structure in the thickness direction of the packaging material 1 of the present invention. 1 to 3, the upper side is the outer layer side and the lower side is the inner layer side. The packaging material 1 has a plastic film 2, a picture layer 3, and a sealant layer 4 laminated in this order from the outer layer side, and at least a partial region of the picture layer 3 contains a binder resin and metal flakes. The printed layer 3a and the chromatic underlayer 3b may be laminated in this order from the outer layer side, and other layers may be included as constituent layers.
For example, as shown in FIGS. 1 to 3, an intermediate substrate layer 5 may be laminated between the pattern layer 3 and the sealant layer 4 with an adhesive layer 6 interposed on both sides. Further, as shown in FIG. 2, a non-glitter printed layer 3c may be provided in parallel with the area where the glitter printed layer 3a and the chromatic underlayer 3b are laminated. Further, as shown in FIG. 2, the pattern layer 3 may have an achromatic solid print layer 3 d on the inner layer side of the pattern layer 3 .
Further, as shown in FIG. 3, a non-glitter printed layer 3c may be provided in a partial region on the outer layer side of the glitters printed layer 3a.

Further, the packaging material 1 may have a gas barrier layer (not shown) formed between the plastic film 2 and the picture layer 3 or between the picture layer 3 and the sealant layer 4 .
Specifically, the packaging material of the present invention can be exemplified by the following laminated structure in order from the outer layer side. In addition, "/" means the boundary of each layer.
(1) Plastic film/picture layer/intermediate base layer/sealant layer (2) Plastic film/gas barrier layer/picture layer/sealant layer (3) Plastic film/gas barrier layer/picture layer/intermediate base layer/sealant layer ( 4) Plastic film/picture layer/gas barrier layer/intermediate base material layer/sealant layer From the viewpoint of making the picture layer 3 visible from the outside, the layer formed on the outer layer side of the picture layer 3a is a light-transmitting layer. shall have the nature of

<Plastic film>
The plastic film 2 plays a role as a base material on the outer layer side of the packaging material 1, and is made of a material having optical transparency so that the pattern layer 3 can be visually recognized from the outside.
Specifically, polyolefin resins such as polyethylene (PE) and polypropylene (PP), cyclic polyolefin resins, polystyrene resins, acrylonitrile-styrene copolymer (AS) resins, acrylonitrile-butadiene-styrene copolymers (ABS) resin, poly (meth) acrylic resin, polycarbonate resin, polyvinyl alcohol resin, ethylene-vinyl alcohol copolymer (EVOH), ethylene-vinyl ester copolymer saponified product, polyethylene terephthalate (PET) and poly Polyester resins such as butylene terephthalate (PBT) and polyethylene naphthalate (PEN), polyamide resins such as various nylons (Ny), polyurethane resins, acetal resins, cellulose resins, polyvinylidene chloride resins (PVDC), etc. is mentioned. The plastic film may be uniaxially or biaxially oriented. Also, a composite film in which two or more of the above resin films are laminated may be used. These plastic films may be formed by an inflation method or a melt extrusion coating method.

From the viewpoint of heating in a microwave oven and retort treatment, the plastic film preferably has excellent heat resistance. Polyester-based resins, polyamide-based resins, and the like are examples of resins that constitute plastic films having excellent heat resistance.
Specific examples of plastic films having excellent heat resistance include a single polyester film, a single polyamide film such as nylon, and a composite film containing one or more of a polyester film and a polyamide film. Examples of the composite film include a coextruded stretched film composed of PET/Ny/PET and PET/Ny from the outer layer side. As the composite film, it is also preferable to combine one or more of polyester film and polyamide film with one or more of ethylene-vinyl alcohol copolymer film and polyvinylidene chloride film.

The thickness of the plastic film is not particularly limited, and can be appropriately set according to the use of the packaging material. is 12-25 μm.

The plastic film preferably has a total light transmittance of 85% or more, more preferably 90% or more, according to JIS K7361-1:1997. The haze of the plastic film according to JISK7136:2000 is preferably 1.0% or less, more preferably 0.5% or less, even more preferably 0.3% or less.
By setting the total light transmittance and the haze within the above ranges, it is possible to easily improve the design property due to the metallic luster.

Both surfaces of the plastic film preferably have an arithmetic mean roughness Ra of 0.1 μm or less, more preferably 0.05 μm or less at a cutoff value of 0.8 mm measured according to JIS B0601:1994. . By setting the Ra of both surfaces of the plastic film to the range described above, it is possible to easily improve the metallic luster of the design.

<Pattern layer>
The packaging material of the present invention has a pattern layer between the plastic film and the sealant layer. Furthermore, the packaging material of the present invention has a configuration in which a glittering print layer containing a binder resin and metal flakes and a chromatic base layer are laminated in this order from the outer layer side on at least a partial region of the pattern layer.
The region in which the glitter print layer 3a and the chromatic base layer 3b are laminated in this order from the outer layer side may be provided on the entire surface of the packaging material as shown in FIGS. may be present only on a portion of the packaging material, as shown in .
The pattern layer may have a non-glitter printed layer 3c or the like on the outer layer side of the glitter printed layer 3a. At least part of the layer to be applied shall be a glitter printing layer.
The pattern layer is composed of characters, figures, symbols, etc. by a single region in which the glitter printed layer 3a and the chromatic color base layer 3b are laminated, or a combination of the above region and a region having the non-glitter printed layer 3c. , patterns, etc. can be formed.

<<Glitter printing layer>>
The glitter print layer contains a binder resin and metal flakes. In addition, the glitter print layer does not substantially contain particles having a size of 380 nm or more other than metal flakes in the layer.
By configuring the glitter printed layer as described above and having the chromatic color base layer on the inner layer side of the glitter printed layer, it is possible to impart a high degree of designability with metallic luster. The reason for this will be explained below.

4 is a cross-sectional image diagram of the pattern layer portion of the packaging material of Example 1, and FIG. 5 is a cross-sectional image diagram of the pattern layer portion of the packaging material of Comparative Example 1. FIG. In FIGS. 4 and 5, X indicates metal flakes and Y indicates colored particles having a size of 380 nm or more. While the glittering print layer 3a of the pattern layer of Example 1 satisfies the constituent requirements of the present invention, the glittering print layer 3a of Comparative Example 1 has colored particles with a size of 380 nm or more, which is the present invention. does not meet the configuration requirements of
Comparing the angular distribution of reflected light when external light is incident on the pattern layers in FIGS. 4 and 5, the pattern layer in FIG. , whereas the pattern layer in FIG. 5 has a wide angle range of the reflected light. 4 and 5, solid-line arrows indicate the incident light, dotted-line arrows indicate the specularly reflected light of the incident light, and dashed-dotted line arrows indicate the angular range of the reflected light. Also, in FIGS. 4 and 5, the length of the arrow indicates the intensity of the reflected light.
The reason why the angle range of the reflected light is widened in FIG. 5 is that the light reflected in the specular direction by the metal scales with high reflectance collides with the colored particles Y before the light is emitted from the glittering print layer 3a and is diffused. It is for In particular, the colored particles Y having a size of 380 nm or more exhibit strong diffusion because the size of the particles is larger than the lower limit (380 nm) of the wavelength of visible light. On the other hand, the reason why the angle of the reflected light is concentrated in a narrow range near the regular reflection direction of the incident light in FIG. This is because the light is emitted from the glittering print layer 3a without any
Specifically referring to the design properties of FIGS. 4 and 5, in the case of the configuration of FIG. 5, the angle distribution of the reflected light spreads, resulting in a decrease in the intensity of the reflected light. In general, the narrower the angle distribution of the reflected light, the stronger the glossiness of a person. Therefore, the angle distribution of the reflected light shown in FIG. Therefore, in the case of the configuration of FIG. 5, although the colored particles Y can expand the expression range of metallic luster, it cannot be said to have a high level of metallic luster.
On the other hand, in the case of FIG. 4, the angle distribution of the reflected light is concentrated in a narrow range near the specular reflection direction to impart a high level of metallic luster, while the chromatic underlayer 3b on the inner layer side provides a range of expression of metallic luster. can be expanded. Therefore, the packaging material of the present invention can be provided with a high level of designability due to metallic luster.

Further, in the packaging material of the present invention, since the glitter printed layer is formed on the inner layer side of the plastic film, if the surface shape of the plastic film is smooth, the surface shape of the glitter printed layer as seen from the viewer side Since the surface becomes smooth, diffusion due to surface unevenness can also be suppressed. That is, the packaging material in which the glitter printed layer is formed on the inner layer side of the plastic film as in the present invention is preferable in that it is easy to obtain the effects described above.

<<Metal Scale>>
Materials for the metal scales include metals and alloys such as aluminum, gold, silver, brass, titanium, chromium, nickel, nickel-chromium, and stainless steel.
The material of the metal flakes is not particularly limited, but aluminum or an alloy containing aluminum is preferable from the viewpoint of increasing the degree of freedom in adjusting the metallic color tone of the chromatic underlayer because of its low color. As the material of the metal flakes, when silver-colored metal flakes such as aluminum, silver, titanium, nickel and stainless steel, or alloys containing these are used, a yellow layer is used as the chromatic underlayer, which will be described later. It is preferable in that it can express the metallic luster of

The metal scales preferably have an average thickness of 0.01 to 0.50 μm, more preferably 0.02 to 0.25 μm, even more preferably 0.03 to 0.15 μm.
By setting the average thickness of the metal flakes to 0.01 μm or more, it is possible to suppress the metal flakes from gathering on one side during the process of forming the glitter printing layer (for example, when the glitter printing layer forming ink is applied to the plastic film, In the case of coating to form a glittering printed layer, it is possible to suppress the accumulation of metal flakes on the inner layer side of the packaging material, making it easier to see the chromatic underlayer. In addition, by setting the average thickness of the metal scales to 0.50 μm or less, excessive tilting of the metal scales in the glitter print layer can be suppressed, and the reflection intensity in the vicinity of the regular reflection direction for incident light can be increased. . In addition, suppression of metal scales from gathering on one side in the process of forming the glitter print layer, and suppression of excessive tilting of the metal scales in the glitter print layer contributes to improving the usability of the microwave oven. also connected.

The metal scales preferably have an aspect ratio of 10 to 500, more preferably 20 to 250, even more preferably 30 to 100, as defined by [average length/average thickness].
By setting the aspect ratio of the metal flakes to 10 or more, the metal flakes can be prevented from being excessively inclined in the glitter print layer, and the intensity of reflection of incident light in the vicinity of the regular reflection direction can be increased. Suppression of excessive tilting of the metal flakes in the glitter print layer also leads to improvement in usability of the microwave oven. In addition, by setting the aspect ratio of the metal flakes to 500 or less, when the metal flakes are tilted in the glitter print layer, they are less likely to come into contact with other metal flakes, making it easy to improve the usability of the microwave oven.

The average length of the metal flakes is preferably 0.2 to 50 μm, more preferably 0.5 to 20 μm, even more preferably 1 to 10 μm.
By setting the average length to 0.2 μm or more, aggregation can be easily suppressed, and by setting the average length to 50 μm or less, when the metal flakes are tilted in the glitter print layer, other metal flakes can be easily separated from each other. It becomes difficult to come into contact with them, and the usability of the microwave oven can be easily improved.

Let the average length and average thickness of a metal scale be the average value of 20 metal scales. The length and thickness of each metal scale can be measured by using a laser interference three-dimensional shape analysis device in a state in which the metal scales are dispersed on a smooth base material. The length of each metal scale means the maximum diameter of each metal scale observed from the plane in any direction, and the thickness of each metal scale means the thickness of each metal scale when observed from the cross-sectional direction. means maximum thickness. In addition, the maximum diameter when observing the individual metal scales from the plane in an arbitrary direction means that the direction in which the maximum diameters of the individual metal scales are measured is unified. For example, when the X-axis direction on the screen obtained by image processing the measurement results of the three-dimensional shape analysis device is set as an arbitrary direction (measurement direction), the maximum diameter shall be measured in a direction parallel to the X-axis. Even if the maximum diameter exists in a direction not parallel to the X-axis, it is not regarded as the maximum diameter.
As a three-dimensional shape analysis device of laser interference type, for example, the trade name “Shape Analysis Laser Microscope VK-X Series” manufactured by Keyence Corporation can be mentioned.

Metal flakes can be obtained, for example, by (i) peeling off a metal thin film obtained by vacuum-depositing the above metal or alloy on a plastic film from the plastic film, pulverizing and stirring the peeled metal thin film, and (ii) the above metal or alloy. can be obtained by mixing the powder and a solvent, and spreading and/or pulverizing the powder with a medium stirring mill, ball mill, attritor, or the like.

The thickness, length and aspect ratio of the metal flakes can be adjusted by the thickness of the metal thin film, the time and intensity of pulverization and stirring, etc. in the case of the method (i) above, and can be adjusted according to the method (ii) above. In the case of the method, it can be adjusted by the particle size of the raw material metal powder, the size of the bearing ball, the time and intensity of spreading and/or pulverization, and the like.

Metal scales are preferably non-leafing type metal scales. In the non-leafing type metal scales, the metal scales are uniformly dispersed in the layer during the formation process of the glitter printed layer. In other words, the non-leafing type metal scales can suppress the metal scales from gathering on one side during the formation process of the glitter printed layer. Therefore, the use of non-leafing type metal flakes is preferable in that the colored base layer can be easily visually recognized.
In addition, the non-leafing type metal scales are suppressed from becoming narrow enough to cause sparks and overheating even if the metal scales are tilted in the bright printed layer. It is also suitable in that it can suppress the deterioration of
The non-leafing type metal flakes are metal flakes that are not surface-treated with stearic acid. A piece etc. are mentioned.

The metal scales are preferably resin-coated on the surface of the metal scales. The resin-coated metal flakes prevent the gaps between the metal flakes from narrowing enough to cause sparks or overheating, even if the metal flakes are tilted in the bright printed layer. can be suppressed.
When a packaging container subjected to a high temperature treatment of 130° C. or higher (so-called “high retort treatment”) is heated in a microwave oven, a hole may be formed in the portion having the glitter printed layer. The reason for this is that the coating film is softened by high temperature treatment at 130 ° C. or higher, and the metal scales flow in the coating film, creating places where the intervals between the metal scales become narrow. This is thought to be due to the occurrence of sparks and overheating during heating. However, metal flakes whose surfaces are coated with resin and non-leafing type metal flakes (particularly resin-coated metal flakes) suppress sparks and overheating of the bright printed layer in microwave heating after high retort treatment. It is preferable in that it is easy and it is easy to suppress deterioration of the packaging material.

The type of resin forming the resin coat is not particularly limited as long as it is a resin having insulating properties, and general-purpose resins can be used. From the viewpoint of heat resistance, the resin constituting the resin coat is preferably a cured product of a curable resin composition.

The curable resin composition preferably contains monomers and/or oligomers having two or more polymerizable double bonds in the molecule.
For the purpose of adjusting the viscosity, the curable resin composition contains radically polymerizable unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, and fumaric acid, esters of the unsaturated carboxylic acids, and the like. Monomers and/or oligomers having one polymerizable double bond in the molecule, such as nitriles of unsaturated carboxylic acids, may also be included.
The curable composition preferably contains a general-purpose thermal polymerization initiator and photopolymerization initiator.

Examples of monomers and oligomers having two or more polymerizable double bonds in the molecule include divinylbenzene, allylbenzene, diallylbenzene, epoxidized 1,2-polybutadiene, ethylene glycol di(meth)acrylate, 1,3-butanediol di (Meth)acrylate, neopentyl glycol di(meth)acrylate, (meth)acrylic-modified polyester, (meth)acrylic-modified polyether, (meth)acrylic-modified urethane, (meth)acrylic-modified epoxy, trimethylolpropane tri(meth) acrylates, tetramethylolpropane tri(meth)acrylate, tetramethylolpropane tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate and the like.

The resin-coated metal scale preferably has a resin coating amount of 3 to 40 parts by mass, more preferably 5 to 20 parts by mass, per 100 parts by mass of the metal scale.
By setting the amount of the resin coating to 3 parts by mass or more, the resistance to microwave ovens can be easily improved.

Resin-coated metal scales can be produced by the methods described in, for example, JP-A-62-253668, JP-A-64-40566, JP-A-2003-213157, and JP-A-2012-241039. .

The content of metal flakes in the glitter print layer is selected from the viewpoint of improving the aesthetic appearance of the glitter print layer and the viewpoint of suppressing the generation of sparks and local overheating when heating in a microwave oven. It is preferably 3 to 50% by mass, more preferably 5 to 40% by mass, and still more preferably 10 to 30% by mass of the total solid content.

<<Particles with a size of 380 nm or more other than metal scales>>
The packaging material of the present invention does not substantially contain particles with a size of 380 nm or more other than metal flakes in the glitter print layer.
In the present specification, "substantially free of AA in the glitter print layer" means that the content of AA is 1% by mass or less of the total solid content of the glitter print layer, preferably 0.5% by mass. Below, it is more preferably 0.1% by mass or less, still more preferably 0.01% by mass or less, and even more preferably 0% by mass.
By substantially not containing particles having a size of 380 nm or more other than metal flakes in the glitter print layer, it is possible to impart a high degree of designability due to metallic luster.
The size of the particles other than the metal flakes can be determined, for example, by taking a cross-sectional photograph of the glitter printed layer and considering the length of the cross section of each particle as the size of each particle.
In addition, as particles with a size of 380 nm or more other than metal scales, colored particles such as yellow lead, titanium yellow, red iron oxide, cadmium red, ultramarine, cobalt blue, inorganic pigments such as titanium oxide and zinc oxide, and organic pigments; translucent particles such as silica and resin beads;

In addition, it is preferable that the glitter printing layer does not substantially contain dyes and particles having a size of 100 nm or more and less than 380 nm. Dyes do not diffuse, and particles with sizes greater than 100 nm and less than 380 nm diffuse poorly. However, since the dye absorbs light of a specific wavelength, it reduces the intensity of the light reflected by the glitter print layer. Also, although particles with a size of 100 nm or more and less than 380 nm are weak in diffusion, they still reduce the intensity of reflected light. For this reason, from the viewpoint of further enhancing the metallic luster design, it is preferable that the glitter printing layer does not substantially contain dyes and colored particles having a size of 100 nm or more and less than 380 nm.

The glitter print layer preferably contains inorganic particles having an average primary particle diameter of 1 nm or more and less than 100 nm (hereinafter sometimes referred to as "inorganic fine particles").
By containing inorganic fine particles in the glitter printing layer, it is suppressed that the metal scales sink to the side of the coating surface of the glitter printing layer forming ink during the formation process of the glitter printing layer, and the metal flakes are in the glitter printing layer. This is preferable in that the chromatic color base layer can be easily visually recognized because it can be easily arranged uniformly. In addition, even if the metal flakes are uniformly arranged in the glitter print layer, even if the metal flakes are tilted in the glitter print layer, it is possible to prevent the intervals between the metal flakes from narrowing enough to cause sparks or overheating. Therefore, it is also suitable in that deterioration of the packaging material can be suppressed when the microwave oven is used.
The average primary particle size of the inorganic fine particles is more preferably 2 to 50 nm, even more preferably 5 to 30 nm. The average primary particle size of the inorganic fine particles is determined as the mass average value d50 in particle size distribution measurement by laser light diffraction.

The content of the inorganic fine particles in the glitter print layer is preferably 0.5 to 50 parts by mass, more preferably 2 to 40 parts by mass, more preferably 5 to 30 parts by mass with respect to 100 parts by mass of the metal flakes. Parts by mass are more preferred.

Examples of inorganic fine particles include silica, alumina, zirconia and titania. Among these, silica having excellent transparency is preferable. In addition, since silica and alumina are excellent in insulating properties, they are also preferable in that they can improve resistance to microwave ovens.

The thickness of the glitter printed layer is preferably 0.5 to 10.0 μm, more preferably 0.8 to 7.0 μm, from the viewpoint of giving a sufficient impression of metallic luster. It is preferably 1.0 to 5.0 μm.

The glitter printing layer 3a, and pattern layers such as a chromatic undercoat layer 3b, a non-glitter printing layer 3c, and an achromatic solid printing layer 3d, which will be described later, are applied, for example, on a plastic film 2, a sealant layer 4, or the like, and a gravure layer. It can be formed by a known printing method such as a printing method, an offset printing method, a letterpress printing method, a silk screen printing method, or the like, using a known ink.
The picture layer is preferably formed by reverse printing on the inner layer side surface of the plastic film 2 or the gas barrier layer. Alternatively, it may be formed by surface printing on the outer surface of the intermediate substrate layer 5 or the sealant layer 4 and then laminating it to the plastic film 2 or the gas barrier layer via an adhesive layer. . Further, the packaging material 1 may be printed entirely or partially.

The pattern layer forming ink usually contains a vehicle comprising a binder resin and a solvent as a main component. To these vehicles, metal flakes are added in the glitter printing layer 3a, and coloring agents such as dyes and pigments are added in the chromatic underlayer 3b, the non-glitter printing layer 3c, and the achromatic solid printing layer 3d. is used as the ink for each layer. The colorants for the printed layer may be used singly or in combination of two or more.

Examples of binder resins include polyolefin resins such as polyethylene resins and chlorinated polypropylene resins, poly(meth)acrylic resins, polyvinyl chloride resins, polyvinyl acetate resins, and vinyl chloride-vinyl acetate copolymers. , polystyrene resin, styrene-butadiene copolymer, vinylidene fluoride resin, polyvinyl alcohol resin, polyvinyl acetal resin, polyvinyl butyral resin, polybutadiene resin, polyester resin, polyamide resin, alkyd resin, epoxy resin, unsaturated polyester resin, thermosetting poly(meth)acrylic resin, melamine resin, urea resin, polyurethane resin, phenol resin, xylene resin, maleic acid resin, nitrocellulose, ethyl cellulose, acetyl Examples include cellulose-based resins such as butyl cellulose and ethyloxyethyl cellulose, rubber-based resins such as chlorinated rubber and cyclized rubber, petroleum-based resins, and natural resins such as rosin and casein.

Moreover, the binder resin for the glitter print layer preferably has a melting point of 130° C. or higher from the viewpoint of suppressing the flow of metal flakes in the glitter print layer during high retorting.
The melting point of the binder resin in the glitter print layer is more preferably 140° C. or higher, more preferably 150° C. or higher.
In the present specification, the resin having a melting point of AA°C or higher includes not only resins having a melting point of AA°C or higher, but also resins whose melting point is not observed at lower than AA°C or higher than AA°C. shall be taken.

Moreover, it is preferable that the binder resin of the glitter print layer is a non-hydrophilic resin.
By using a non-hydrophilic resin as the binder resin for the glitter print layer, it is possible to more easily suppress generation of sparks and local overheating when heated in a microwave oven.
The non-hydrophilic resin means a resin having a contact angle of 90 degrees or more with respect to pure water when a coating film is formed only from the resin. The contact angle of the non-hydrophilic resin is preferably 110 degrees or more, more preferably 130 degrees or more, and still more preferably 150 degrees or more.

The printing layer forming ink may further contain, if necessary, for example, a filler, a stabilizer, a plasticizer, an antioxidant, a light stabilizer such as an ultraviolet absorber, a dispersant, a thickener, a drying agent, a lubricant, Optional additives such as antistatic agents and cross-linking agents can be added.

As the solvent contained in the ink of the printing layer, a solvent used in ordinary pigment ink can be applied, for example, alcohol solvents such as methanol, ethanol, normal propanol, isopropanol, propylene glycol monomethyl ether, acetone and methyl ethyl ketone. , ketone solvents such as methyl isobutyl ketone, ester solvents such as methyl acetate, ethyl acetate, and normal propyl acetate, aliphatic hydrocarbon solvents such as normal hexane, normal heptane, and normal octane, cyclohexane, methylcyclohexane, cycloheptane, etc. alicyclic hydrocarbon solvents, aromatic solvents such as toluene and xylene, and mineral spirits. These may be used individually by 1 type, or may use 2 or more types together.

<<Chromatic underlayer>>
The chromatic underlayer 3b is formed on the inner layer side of the glitter printed layer 3a.
The chromatic underlayer 3b may be formed only in a part of the area where the glitter printed layer 3a exists, but as shown in FIGS. 1 to 3, it is formed in the entire area where the glitter printed layer 3a exists. preferably.

Colorants for the chromatic underlayer include general-purpose dyes and pigments (for example, inorganic pigments such as yellow lead, titanium yellow, red iron oxide, cadmium red, ultramarine blue, and cobalt blue; quinacridone red, isoindolinone yellow, phthalocyanine blue, etc.); organic pigments or dyes) can be used.

Although the content of the colorant in the chromatic underlayer is not particularly limited, it is preferably 5 to 70% by mass, more preferably 15 to 65% by mass, of the total solid content of the chromatic underlayer. More preferably, 20 to 60% by mass is even more preferable.

The thickness of the chromatic underlayer is not particularly limited, and is preferably about 1.0 to 5.0 μm, more preferably 1.0 to 3.0 μm.

<<Non-Glitter Printed Layer>>
The pattern layer may have a non-glare printed layer 3c.
The non-glittering printed layer 3c may be any layer as long as it can be distinguished from the glittering printed layer 3a. The coloring agent for the non-glare printing layer is a general-purpose dye or pigment (for example, yellow lead, titanium yellow, red iron oxide, cadmium red, ultramarine blue, cobalt blue, titanium oxide, inorganic pigments such as zinc oxide, quinacridone red, isoind Organic pigments or dyes such as linon yellow, phthalocyanine blue, etc.) can be used.
The thickness of the non-glare print layer is not particularly limited, and is preferably about 1.0 to 5.0 μm, more preferably 1.0 to 3.0 μm.

<<Achromatic solid print layer>>
The packaging material of the present invention may have an achromatic solid print layer 3d as the pattern layer 3 on the inner layer side of the pattern layer 3, as shown in FIG.
By forming an achromatic solid print layer, the appearance of the packaged item can be improved depending on the type of the packaged item. The color of the achromatic solid print layer may be black, but it is preferably white, which does not impair the color of the glitter print layer and has excellent hiding properties. That is, the achromatic solid print layer is preferably a white solid print layer. The white solid print layer may contain a small amount of dyes and pigments other than the white pigment as a coloring agent in order to adjust the color.

The achromatic solid print layer may be formed only on a part of the surface of the packaging material. preferably formed.
A general-purpose coloring agent can be used as the coloring agent for the achromatic solid print layer. In the case of a white solid print layer, it is preferable to use at least one selected from white pigments such as titanium dioxide, barium sulfate, magnesium oxide, calcium carbonate, zinc oxide, lead white, etc., as the colorant.
The thickness of the achromatic solid print layer is not particularly limited, and is preferably about 1.0 to 6.0 μm, more preferably 1.0 to 4.0 μm.

<Sealant layer>
The surface of the sealant layer 4 on the inner layer side comes into direct contact with the object to be packaged, and plays a role of protecting the object to be packaged. In particular, when the packaging material 1 forms a packaging container for a liquid, the sealant layer 4 is preferably made of a material that does not allow the liquid to permeate. Moreover, it is preferable that the innermost layer of the sealant layer 4 has heat sealability for pouching.

Materials constituting the sealant layer 4 include, for example, low density PE (LDPE), linear low density PE (LLDPE), medium density PE (MDPE), high density PE (HDPE), ethylene-vinyl acetate copolymer , propylene homopolymers, ethylene-propylene block copolymers, ethylene-propylene random copolymers, and other polyolefin resins, and one or more of these resins can be used. The sealant layer 4 may be composed of a single layer or multiple layers of two or more layers. It should be noted that the sealant layer is preferably a non-stretched film made of the aforementioned resin in order to suppress shrinkage during heat sealing.

From the viewpoint of heating in a microwave oven and retort processing, the sealant layer is preferably made of a resin having excellent heat resistance in order to increase heat resistance. Specifically, propylene homopolymer, ethylene-propylene block copolymer Propylene-based resins such as coalesced, ethylene-propylene random copolymers, and HDPE are preferred.
Moreover, it is preferable to use the propylene-based resin properly according to the purpose. Specifically, ethylene-propylene block copolymers are preferred when cold resistance is emphasized (for example, packaging materials for frozen foods), and ethylene-propylene random copolymers are preferred when transparency is emphasized. Propylene homopolymer is preferable when the property is important. Further, in the case of a container equipped with an automatic vaporization mechanism, an ethylene-propylene block copolymer is preferable from the viewpoint that vapor can be easily escaped by reducing the sealing strength at high temperatures.

Moreover, when the lid of a lidded container is formed from the packaging material 1, the sealant layer 4 preferably has an easy peel property.
For example, when the sealant layer 4 of the packaging material 1 of the lid of the lidded container is joined to the container body, the easy peel property is the property that the lid can be easily peeled off from the container body when the lidded container is opened. say.
The sealant layer having easy peelability uses two or more resins, one resin (resin having good adhesion to the container body) and another resin (not having good adhesion to the container body). It can be formed by mixing one resin and an incompatible resin). Such a resin varies depending on the material of the container, so it cannot be generalized. By forming a sealant layer from a resin mixed with one or more selected from PE, polybutene and polystyrene, which are resins (resins that do not have good adhesion to the container body and are incompatible with the first resin), Easy peelability can be imparted to PP containers.
The sealant layer may have a multi-layer structure, and the easy peel property may be imparted only to the side of the sealant layer that is joined to the container body (the innermost layer in the packaging material).

The thickness of the sealant layer 4 is not particularly limited, and is appropriately set according to the use of the packaging material 1 and the type and properties of the object to be packaged, but it is usually preferably about 10 to 200 μm. In the case of pouches (particularly retort pouches), the thickness of sealant layer 4 is more preferably 20 to 150 μm, and even more preferably 30 to 100 μm. In the case of a container with a lid, the thickness of the sealant layer 4 is more preferably 15-80 μm, more preferably 20-60 μm.

<Gas barrier layer>
A gas barrier layer can be provided anywhere between the plastic film 2 and the sealant layer 4 as required. The gas barrier layer plays a role of blocking permeation of oxygen, water vapor, and the like between an object to be packaged by the packaging material 1 and the external environment of the packaging material 1 . In addition, it may also have a light-shielding property that blocks the transmission of visible light, ultraviolet rays, and the like. The gas barrier layer may be composed of only one layer, or may be composed of two or more layers.
When the gas barrier layer is formed on the outer layer side of the pattern layer 3 , it is made of a material having optical transparency so that the pattern layer 3 can be visually recognized from the outside, as with the plastic film 2 .

The gas barrier layer can be formed as a vapor deposition film or a coating film by a known method. The surface on which the gas barrier layer is to be formed may be previously surface-treated from the viewpoint of improving the adhesion of the gas barrier layer. Examples of the surface treatment include corona discharge treatment, ozone treatment, low-temperature plasma treatment using oxygen gas, nitrogen gas, glow discharge treatment, oxidant treatment, application of an anchor coating agent, and the like.

[Deposition film]
Examples of vapor deposition films that are examples of gas barrier layers include silicon (Si), aluminum (Al), magnesium (Mg), calcium (Ca), potassium (K), tin (Sn), sodium (Na), boron ( B), inorganic substances such as titanium (Ti), lead (Pb), zirconium (Zr), yttrium (Y), or oxides thereof. Among these, when the packaging material is for a microwave oven, silicon oxide, aluminum oxide, and magnesium oxide are used from the viewpoint of enabling the food, etc. to be packaged to be sufficiently heated by the microwaves of the microwave oven. Inorganic oxides such as
Examples of methods for forming a deposited film include physical vapor deposition (PVD) methods such as vacuum deposition, sputtering, and ion plating, and chemical vapor deposition (CVD) methods such as plasma chemical vapor deposition, thermal chemical vapor deposition, and photochemical vapor deposition. law, etc.

The film thickness of the deposited film varies depending on the forming material, the required gas barrier performance, etc., but is generally preferably about 5 to 200 nm, more preferably 5 to 150 nm, further preferably 10 to 100 nm. In the case of inorganic oxides such as silicon oxides and aluminum oxides, the thickness is preferably about 5 to 100 nm, more preferably 5 to 50 nm, still more preferably 10 to 30 nm.

[Gas barrier coating film]
^A gas barrier _coating film, which is an example of ^a _gas ^barrier layer, may be represented by the general ^formula : n is an integer of 0 or more, m is an integer of 1 or more, and n+m is the valence of M.) and at least one or more alkoxides represented by ), a polyvinyl alcohol resin and/or ethylene-vinyl A coating solution obtained by polycondensing an alcohol copolymer by a sol-gel method in the presence of a sol-gel method catalyst, acid, water and an organic solvent is applied, and the temperature is reduced to 0 at 50 to 300 ° C. It can be formed by heat treatment for 0.05 to 60 minutes.
Examples of the coating method include roll coating such as a gravure roll coater, spray coating, spin coating, dipping, brush coating, bar coating, and coating means such as an applicator. It is preferable that the dry film thickness of the coated film is about 0.01 to 30 μm, more preferably 0.05 to 20 μm, and still more preferably 0.1 to 10 μm by coating once or multiple times.
From the viewpoint of improving gas barrier properties, the gas barrier coating film is preferably formed on the surface of the deposited film.

Considering the specific structure of the gas barrier layer, the packaging material of the present invention can be exemplified by the following lamination structures (1′) to (4′) in order from the outer layer side. In addition, "/" means the boundary of each layer.
(1') plastic film/deposited film/picture layer/sealant layer (2') plastic film/deposited film/gas barrier coating film/picture layer/sealant layer (3') plastic film/picture layer/deposited film/intermediate substrate Material layer/sealant layer (4′) plastic film/pattern layer/gas barrier coating film/evaporated film/intermediate substrate layer/sealant layer

<Intermediate base material layer>
The intermediate base material layer is used as necessary for the purpose of improving the strength of the packaging material 1, improving the processability, changing the texture of the packaging material, or using it as a base material for forming other layers. It is a layer provided Examples of the constituent material of the intermediate base material layer include plastic films and paper.
In the case of a plastic film, the same plastic film as described above formed on the outer layer side of the pattern layer 3 can be used.
In the case of paper, the packaging material 1 can be imparted with properties such as formability, bending resistance, and rigidity. processed paper or the like can be used. The basis weight of the paper is preferably about 50-600 g/m ² , more preferably 60-500 g/m ² , still more preferably 70-450 g/m ² . When the packaging material 1 is used for flexible packaging, it is preferably less than 150 g/m ² , and when used for paper containers such as paper cups and paper containers for liquids, it is preferably 200 g/m ² or more.

In consideration of heating in a microwave oven and retort treatment, the intermediate base material layer preferably has excellent heat resistance in order to increase the heat resistance of the packaging material. Specific examples of the intermediate substrate layer having excellent heat resistance include paper and various plastic films exemplified as plastic films having excellent heat resistance.

<Adhesive layer>
In the packaging material 1, each component layer may be laminated via an adhesive layer 6 from the viewpoint of improving the bonding strength between the layers. The adhesive layer can be formed by a method using a known adhesive for dry lamination.
Examples of dry laminate adhesives include polyvinyl acetate adhesives, polyacrylate adhesives, cyanoacrylate adhesives, ethylene copolymer adhesives, cellulose adhesives, polyester adhesives, and polyamide adhesives. Adhesives, polyimide adhesives, amino resin adhesives such as urea resins and melamine resins, phenol resin adhesives, epoxy adhesives, polyurethane adhesives (for example, cured products of polyols and isocyanate compounds), reactions Examples include (meth)acrylic acid-based adhesives, rubber-based adhesives such as chloroprene rubber, nitrile rubber, and styrene-butadiene rubber, silicone-based adhesives, and inorganic adhesives such as alkali metal silicate and low-melting glass.

<Thermosoftening resin layer>
The packaging material 1 may have a heat-softening resin layer 7 in a partial region between the plastic film and the sealant layer, as shown in FIG.
As shown in FIG. 9, the thermosoftening resin layer 7 is formed in a portion near the edge of the packaging material 1, and the thermosoftening resin layer has a predetermined strength in a temperature environment below room temperature. , By making it from a resin whose predetermined strength decreases in a high temperature environment, when it is heated in a microwave oven and the pressure inside the packaging container rises, part of the sealant layer breaks and the heat softening resin Some of the layers interfacially delaminate or cohesively fail, allowing vapor to escape. Details will be described in the second embodiment of the automatic vaporization mechanism.

A thermosoftening resin, that is, a resin that has a predetermined strength in a temperature environment of room temperature or lower but decreases in a predetermined strength in a high temperature environment, has a melting point of 60 to 110°C, preferably a melting point of 60 to 90°C. Specific examples include ethylene-vinyl acetate copolymer resins, polyamide, nitrocellulose and polyethylene wax, and mixed resins of polyamide, nitrocellulose and polyethylene wax are preferred. As the resin containing polyamide, nitrocellulose, and polyethylene wax, MWOP varnish (softening point: 105° C.) manufactured by DIC Graphics Corporation can be used.

The thickness of the thermosoftening resin layer is preferably 1 to 5 μm. By setting the thickness of the thermosoftening resin layer to 1 μm or more, the thermosoftening resin layer and the sealant layer can be easily broken when heated in a microwave oven. Further, by setting the thickness of the thermosoftening resin layer to 5 μm or less, when the film-like packaging material is wound into a roll, it is possible to suppress the expansion of the packaging material due to the occurrence of swelling in a part of the packaging material.

The packaging material of the present invention described above can be used for various packaging materials, and can be suitably used for food and cosmetic packaging materials, etc., because it can impress the purchaser with a high-class feeling of the contents. .
Moreover, the packaging material of the present invention can be suitably used as a packaging material for microwave ovens because it can be given a high degree of designability based on metallic luster without using a metal layer.

[Packaging container]
At least a part of the packaging container of the present invention is formed of the packaging material of the present invention described above.
By forming at least a part of the packaging container from the packaging material of the present invention, it is possible to obtain a packaging container with a high-class appearance due to metallic luster, even if metal itself is not used.
The packaging material of the present invention may be applied to a desired portion of the packaging container where it is desired to impart a high-class feeling due to metallic luster. The packaging material may be used for

The type and use of the packaging container of the present invention are not particularly limited, but when selling the contents housed in the packaging container, it is possible to impress the purchaser with the high-class feeling of the contents. For example, it can be suitably used for food containers, cosmetic containers, and the like.
Packaging containers include pouches and lidded containers, as well as cups and trays. These packaging containers partially include the packaging material described above. That is, these packaging containers may be formed of a packaging material containing paper as an intermediate base material layer.
A specific shape of the pouch is, for example, the shape of a pouch for a microwave oven shown in FIG. 6, which will be described later. The pouch may be a retort container (a container that has been sterilized at high temperature and high pressure), or may be a packaging container for microwave ovens or a container other than a retort container.
As a specific shape of the container with a lid, it has a configuration including a container body having an accommodating portion and a lid joined to the container body so as to seal the accommodating portion, and the lid is the Examples include those formed of packaging materials.
The packaging container can be suitably used for microwave ovens as described above. The packaging container can also be used as a retort container. Of course, the packaging container can also be used as a retort container for microwave ovens.

When the packaging container is a container for a microwave oven or a retort container, it is preferable that the packaging material constituting the container has any one of the laminated structures of (1) to (4) described above.
In this case, as the plastic film, it is preferable to use a single polyester film, a single polyamide film such as nylon, or a composite film containing one or more of a polyester film and a polyamide film.
In this case, as the intermediate substrate, it is preferable to use a single polyester film, a single polyamide film such as nylon, a composite film containing one or more of polyester film and polyamide film, and paper.
In this case, the sealant layer is preferably made of propylene-based resin such as propylene homopolymer, ethylene-propylene block copolymer, ethylene-propylene random copolymer, or HDPE.
More specifically, in the case of a retort container or a container for a microwave oven, the packaging material constituting the container preferably has any one of the following laminated structures (A1) to (A12). In addition, "/" means the boundary of each layer. In (A1) to (A12), PET and Ny are preferably stretched films.

(A1) PET/pattern layer/Ny/ethylene-propylene block copolymer (A2) PET/gas barrier layer/pattern layer/Ny/ethylene-propylene block copolymer (A3) PET/pattern layer/gas barrier layer/Ny/ Ethylene-propylene block copolymer (A4) PET/pattern layer/PET/ethylene-propylene block copolymer (A5) PET/gas barrier layer/pattern layer/PET/ethylene-propylene block copolymer (A6) PET/pattern Layer / gas barrier layer / PET / ethylene-propylene block copolymer (A7) co-extruded stretched film (PET / Ny / PET) PET / pattern layer / PET / ethylene-propylene block copolymer (A8) co-extruded stretched film ( PET/Ny/PET)/gas barrier layer/picture layer/PET/ethylene-propylene block copolymer (A9) coextruded stretched film (PET/Ny/PET)/picture layer/gas barrier layer/PET/ethylene-propylene block copolymer Polymer (A10) PBT/picture layer/Ny/ethylene-propylene block copolymer (A11) PBT/gas barrier layer/picture layer/Ny/ethylene-propylene block copolymer (A12) PBT/picture layer/gas barrier layer/ Ny/ethylene-propylene block copolymer

In the case of containers for microwave ovens, the ethylene-propylene block copolymers for the sealant layers (A1) to (A12) may be polyethylene resins such as LDPE, LLDPE, MDPE and HDPE.
In addition, when adopting the configuration of the automatic steaming mechanism of the second embodiment described later in the container for microwave oven, the above-described heat-softening resin layer is formed in a part between the plastic film and the sealant layer. Just do it.

(pouch)
FIG. 6 shows an example of a pouch, which is one embodiment of the packaging container of the present invention. The pouch 10 shown in FIG. 6 is for a microwave oven, and is a standing pouch formed by heat-sealing a body portion 11 and a bottom portion 12 . As shown in FIG. 6, the body portion 11 includes a pair of principal sheets 13 composed of a front principal sheet 13a and a back principal sheet 13b, which are arranged to face each other. The sheets 13 are heat-sealed to each other near the side edges 14 . A bottom sheet 16 forming the bottom 12 is arranged between the lower edges 15 of the pair of main sheets 13 .
A storage space 17 for storing contents is formed in a region surrounded by the pair of main sheet 13 and bottom sheet 16 . The bottom sheet 16 is bent in a convex shape toward the accommodation space 17 side, and the vicinity of the peripheral edge thereof is heat-sealed together with the overlapping lower part of the main sheet 13 . Since the bottom sheet 16 retains the shape of the lower ends of the pair of main sheets 13, the pouch 10 can be made self-supporting and can be a standing pouch.
The pouch 10 of FIG. 6 has an opening 19 formed between the upper edges 18 of the front main sheet 13a and the back main sheet 13b, and the contents can be stored through the opening 19. As shown in FIG. After containing the contents, the packaging container can be sealed by heat-sealing the vicinity of the upper edge 18 where the opening 19 is formed. When taking out the contents from the pouch 10, the notch 23 is opened by tearing the vicinity of the upper edge 18.例文帳に追加

The front main sheet 13 a , back main sheet 13 b and bottom sheet 16 of the pouch 10 can be formed from the packaging material 1 . All of these sheets may be formed of the packaging material 1 having the glittering printed layer 3a containing metal flakes, and only one of the sheets required to have metallic luster is formed of the packaging material 1. good too. FIG. 6 shows that the front main sheet 13a is formed of the packaging material 1 having a laminated structure as shown in FIG. ing.
In addition, sheets other than the sheet for which the packaging material 1 is used can be, for example, the packaging material 1 in which the glitter printed layer 3a containing the metal scales is not formed, or the sheet that does not include the printed layer. .

(automatic steaming mechanism)
If the container is for a microwave oven, when the pressure inside the pouch rises due to the steam generated by cooking the contents such as food, the steam inside the storage space is automatically released to the outside to prevent the pouch from bursting. It is preferable to have an automatic vaporization mechanism for The automatic steaming mechanism is preferably formed near the periphery of the container.

A first embodiment of the automatic steaming mechanism will be described with reference to FIG. The microwave pouch shown in FIG. 6 has a first unsealed region 21 that is not heat-sealed in the vicinity of the upper side edge 14 of the container (pouch). The first unsealed area 21 has an opening 22 down to the side edge 14 . Also, the first unsealed area 21 protrudes toward the housing space 17 . Further, the heat-sealed portion 25 protrudes toward the housing space 17 so as to surround the first unsealed region 21 that protrudes toward the housing space 17, forming a projecting portion 25a. More specifically, the first unsealed region 21 and the accommodation space 17 are separated from each other, and an overhanging portion 25a is formed so as to be continuous with the heat-sealing portion 25 for sealing the pouch. .
In the microwave pouch shown in FIG. 6, the opening 22, the first unsealed region 21, and the heat-sealed portion (projecting portion 25a) projecting toward the housing space 17 form the automatic steaming mechanism 20. It is Specifically, when the pressure inside the container rises due to heating, the overhanging portion 25a of the heat-sealed portion 25 receives a strong load, and the overhanging region 25 peels off first. The space 17 and the first unsealed area 21 communicate with each other, allowing steam to escape to the outside.
Further details of the automatic vaporization mechanism of the type shown in FIG.

In addition, in the container 10 shown in FIG. 6, a second unsealed area 23 is formed on the side edge 14 opposite to the first unsealed area 21 . The second unsealed area 23 is formed from the viewpoint of improving the yield of forming the openings 22 of the first unsealed area 21 when cutting one by one after forming a plurality of retort containers 10 continuously. and does not necessarily have to be formed.

A second embodiment of the automatic vaporization mechanism will be described with reference to FIGS. 9-11.
The packaging container (pouch) 10 shown in FIG. 10 is the edge of the packaging material shown in FIG. The periphery of the part is heat-sealed to form a pouch. 11 is a cross-sectional view of the heat-sealed portion 25 around the edge of the packaging container 10 of FIG. 10 taken along line XI-XI.
As shown in FIG. 10, the thermosoftening resin layer 7 is formed in at least a partial region of the heat-sealed portion 25 of the packaging container 10 from the inner edge to the outer edge of the heat-sealed portion 25 for sealing the pouch. It is necessary that The strength of the thermosoftening resin layer 7 provided at such a position is lowered by being heated in a microwave oven to a high temperature.
As shown in FIG. 11, when the heat-softening resin layer 7 is heated in a microwave oven or the like and the internal pressure rises due to the expansion of the air in the packaging container 10 or the water vapor contained in the contents, the heat-softening resin layer 7 closes to the inner edge of the heat-sealed portion 25 . A portion of the sealant layer 4 is broken, and a portion of the thermosoftening resin layer 7 is interfacially peeled or cohesively broken starting from an arbitrary point "A" of the sealant layer 4 (the dashed line of symbol B indicates the sealant A virtual line where the layer 4 breaks and a virtual line where the thermosoftening resin layer 7 undergoes interfacial peeling or cohesive failure). As a result, air and water vapor are released from the broken portion, and the internal pressure of the packaging container 10 can be reduced.
The automatic steaming mechanism of the second embodiment can also be applied to a container with a lid, which will be described later.

As the packaging material that constitutes the container having the second embodiment of the automatic steaming mechanism, it is preferable to select a resin that easily collapses as the resin that constitutes the sealant layer. Specifically, LLDPE is preferred. Moreover, the packaging material constituting the container equipped with the second embodiment of the automatic steaming mechanism preferably has any one of the following laminated structures (B1) to (B6). In addition, "/" means the boundary of each layer. In (B1) to (B6), PET and Ny are preferably stretched films.

(B1) PET/pattern layer/thermosoftening resin layer/LLDPE
(B2) PET/gas barrier layer/pattern layer/thermosoftening resin layer/LLDPE
(B3) PET/pattern layer/gas barrier layer/thermosoftening resin layer/LLDPE
(B4) Ny/pattern layer/thermosoftening resin layer/LLDPE
(B5) Ny/gas barrier layer/pattern layer/thermosoftening resin layer/LLDPE
(B6) Ny/pattern layer/gas barrier layer/thermosoftening resin layer/LLDPE

(Container with lid)
7 and 8 show an example of an embodiment of the lidded container of the present invention. 7 is a top view, and FIG. 8 is a sectional view taken along line IV--IV of FIG. A lidded container 30 shown in FIGS. 7 and 8 includes a container main body 32 having an accommodating portion 31 formed therein, and a lid 33 joined to the container main body 32 so as to seal the accommodating portion 31 of the container main body 32. ing. In FIG. 7, the shape of the container body 32 is substantially rectangular, but is not particularly limited. The container body 32 is not particularly limited in its molding method, and may be, for example, a tray molded by injection molding or a container formed by deep drawing.
In addition, since the material of the container body 32 is to be joined to the lid 33, it is usually thermoplastic resin such as PP or PET. PP is preferably used from the viewpoint of heat resistance and the like.

It is preferable that the lid 33 of the lidded container 30 is made of the packaging material 1 of the present invention. FIG. 7 shows that the lid 33 is formed of the packaging material 1 having a laminated structure as shown in FIG. ing.

The lid 33 has an easy peel property, as described in the description of the sealant layer 4 of the packaging material 1, from the viewpoint of facilitating the opening of the lidded container 30 by being peeled off from the container body 32. is preferred.
Specifically, the lid 33 and the container body 32 are joined together at a joint line 35 of the flange portion 34 of the container body 32 . The joining line 35 may be formed, for example, by heat-sealing the lid 33 and the flange portion 34, or may be formed by a separate component such as an adhesive layer.

When the lidded container 30 is used for a microwave oven, when the pressure in the lidded container 30 rises due to the steam generated by cooking the food or the like, which is the content contained in the container body 32, the lidded container 30 is heated. It is preferable to have an automatic vaporization mechanism (third embodiment of the automatic vaporization mechanism) that automatically releases the steam in the container 30 to the outside to prevent the lidded container 30 from bursting.
For example, the flange portion 34 has a protruding portion 34a that protrudes toward the center of the container body 32, and along this protruding portion 34a, the joint line 35 also protrudes toward the center of the container. It has a line 35a. Since the joint line 35 is formed in such a form, it becomes easier for the joint line 35 to separate from the projecting line 35a as the pressure inside the lidded container 30 rises due to heating. The housing portion 31 of 32 can be communicated with the outside, and the steam in the lidded container 30 can be released to the outside.
In the lidded container 30 shown in FIGS. 7 and 8, the projecting portions 34a are formed on the opposite long sides of the flange portion 34, but two projecting portions 34a are not necessarily formed. may

As the lid 33 constituting the lidded container 30, the packaging material shown in FIG. 9 (a packaging material having a heat-softening resin layer in a part near the edge between the plastic film and the sealant layer) is used. By using , steam can escape when heated in a microwave oven for the same reason as explained in the second embodiment of the automatic steaming mechanism.

<Lid body>
The lid of the present invention is formed of the packaging material of the present invention described above.

It is preferable that the packaging material that constitutes the lid has a laminated structure of any one of (1) to (4) described above.
Further, when the lid is used as a microwave oven or a retort container, the plastic film may be a single polyester film, a single polyamide film such as nylon, or a composite film containing one or more of a polyester film and a polyamide film. preferable.
In addition, when the lid is used as a microwave oven or a retort container, the intermediate base layer may be a single polyester film, a single polyamide film such as nylon, a composite film containing one or more of a polyester film and a polyamide film, and , preferably paper.
Moreover, when the lid is used as a microwave oven or a retort container, it is preferable to use a resin film having both heat resistance and easy peelability as the sealant layer. Such a film varies depending on the type of container, but when the container is a general-purpose propylene-based resin, it is preferable to use a film made of a resin in which PP is mixed with one or more selected from PE, polybutene and polystyrene. . The sealant layer may have a multi-layer structure, and the easy peel property may be imparted only to the side of the sealant layer that is joined to the container body (the innermost layer in the packaging material).

More specifically, the packaging material constituting the lid for a microwave oven preferably has any one of the following laminated structures (C1) to (C11). In addition, "/" means the boundary of each layer. In (C1) to (C11), PET and Ny are preferably stretched films.
(C1) PET/pattern layer/Ny/easy peel sealant layer (C2) PET/gas barrier layer/pattern layer/Ny/easy peel sealant layer (C3) PET/pattern layer/gas barrier layer/ Ny/sealant layer with easy peel property (C4) PET/pattern layer/PET/sealant layer with easy peel property (C5) PET/gas barrier layer/pattern layer/PET/sealant layer with easy peel property ( C6) PET/pattern layer/gas barrier layer/PET/sealant layer with easy peel properties (C7) Ny/pattern layer/Ny/sealant layer with easy peel properties (C8) Ny/gas barrier layer/pattern layer/Ny / Sealant layer with easy peelability (C9) Ny / Pattern layer / Gas barrier layer / Ny / Sealant layer with easy peelability (C10) Ny / Pattern layer / EVOH / Sealant layer with easy peelability (C11 ) Ny/EVOH/pattern layer/sealant layer with easy peelability

In addition, when the configuration of the second embodiment of the automatic steaming mechanism described above is adopted for the lid, the above-described heat-softening resin layer may be formed partially between the plastic film and the sealant layer.

EXAMPLES The present invention will be described in detail below with reference to Examples, but the present invention is not limited to these.

1. Preparation of packaging material [Example 1]
One surface of a 12 μm-thick plastic film (PET film, both surfaces having Ra of 0.05 μm or less) was subjected to a corona discharge treatment, and then a 10 nm-thick vapor deposition film of silicon oxide was formed. Furthermore, after plasma treatment with a mixed gas of oxygen and argon, a coating solution containing ethyl silicate and polyvinyl alcohol as main components was applied with a gravure roll coater to form a gas barrier coating film with a dry film thickness of 300 nm. did.
Next, the following Glitter Printed Layer Forming Ink 1 was gravure printed on the entire surface of the gas barrier layer and dried to form a Glitter Printed Layer having a dry film thickness of 1.5 μm.
Next, an organic yellow pigment ink (average particle diameter of the organic yellow pigment: 0.6 μm, the ratio of the organic yellow pigment to the total solid content of the ink is 25% by mass) is applied to the entire surface of the glitter printing layer by gravure. It was printed and dried to form a chromatic underlayer with a dry film thickness of 1.5 μm.
Next, a white pigment ink (ratio of white pigment to the total solid content of the ink is 40% by mass) is gravure-printed on the entire surface of the chromatic underlayer and dried to form a solid white printed layer having a dry film thickness of 1.5 μm. formed.
Next, an intermediate substrate layer (stretched Ny, thickness 15 μm) was attached to the surface of the white solid printed layer by a dry lamination method using a polyurethane adhesive.
Next, a sealant layer (CPP, ethylene-propylene block copolymer monolayer film, thickness 70 μm) is laminated on the surface of the intermediate base material layer by a dry lamination method using a polyurethane adhesive. Got the packaging.
The packaging material of Example 1 comprises, from the outer layer side, a plastic film, a vapor deposition film, a gas barrier coating film, a glittering printed layer, a white background printed layer, an adhesive layer, an intermediate substrate layer, an adhesive layer and a sealant layer. have.

<Glitter printing layer forming ink 1>
・9 parts by mass of a composition containing metal flakes and mineral spirits (the content of metal flakes is 85% by mass)
(Metal scale: non-leafing type aluminum scale, aspect ratio 45, average thickness 0.07 μm)
・ Inorganic fine particles 2 parts by mass (silica, average primary particle size: 20 nm)
・Binder resin 20 parts by mass (polyurethane resin, melting point 140°C)
・Solvent 1 (propylene glycol monomethyl ether, normal propyl acetate, ethyl acetate, mixed solvent of isopropanol) 70 parts by mass ・Solvent 2 (mineral spirit) 6 parts by mass

[Examples 2-3]
Packaging materials of Examples 2 and 3 were obtained in the same manner as in Example 1, except that the aspect ratio and average thickness of the metal flakes in the ink for forming a glittering print layer 1 were changed as follows.
(Example 2: aspect ratio 33, average thickness 0.15 μm)
(Example 3: aspect ratio 72, average thickness 0.05 μm)

[Comparative Example 1]
A packaging material of Comparative Example 1 was obtained in the same manner as in Example 1, except that 3 parts by mass of an organic yellow pigment (average particle size: 0.6 μm) was added to the ink for forming a glittering print layer 1. .

2. Evaluation 2-1. Aesthetic appearance with metallic luster Using a light source equipped with one three-wavelength fluorescent tube, the curtain is closed to block the incidence of external light, and under the illumination of the light source, the packaging materials of Examples and Comparative Examples are tilted in various directions and plastic Observation was made from the film side, and aesthetic appearance due to metallic luster was evaluated.
The evaluation points are the strength of the reflection intensity and the angle distribution of the reflected light (the narrower the angle distribution, the better). Evaluation was made by 20 subjects, with 1 point indicating insufficient aesthetic appearance based on metallic luster. The average score of 20 evaluations was calculated and ranked according to the following criteria. Table 1 shows the results.
<Evaluation Criteria>
A: average score of 2.5 or more B: average score of 1.5 or more and less than 2.5 C: average score of less than 1.5

2-2. Microwave Resistance Using the packaging materials of Examples and Comparative Examples, 20 pouches having the structure shown in FIG. 6 were produced and sealed. Twenty pouches were high-retorted at 135° C. for 30 minutes using a batch-type spray (hot water shower) retort apparatus, and then heated at 600 W for 2 minutes in a microwave oven. After heating in a microwave oven, all the samples were evaluated as "A" when no holes were formed, and as "C" when even one hole was formed. Table 1 shows the results.

From the results in Table 1, the packaging materials of Examples 1 to 3 concentrated the angular distribution of the reflected light in a narrow range near the direction of specular reflection, while the chromatic underlayer (yellow layer) on the inner layer side gave a metallic luster. It can be confirmed that it has a high level of designability based on metallic luster by making the color golden. Moreover, it can be confirmed that the packaging materials of Examples 1 to 3 can suppress deterioration due to microwave heating after high retort processing.
On the other hand, since the packaging material of Comparative Example 1 contains large colored particles in the glitter printed layer, it can be confirmed that a high level of metallic luster cannot be imparted due to the influence of diffusion of the colored particles.

REFERENCE SIGNS LIST 1 packaging material 2 plastic film 3 picture layer 3a glitter print layer 3b chromatic underlayer 3c non-glitter print layer 3d achromatic solid print layer 4 sealant layer 5 intermediate substrate layer 6 adhesive layer 7 thermosoftening resin layer 10 Packaging container 11 body 12 bottom 13 main sheet 14 side edge 15 lower edge 16 bottom sheet 17 accommodation space 18 upper edge 19 opening 20 automatic steaming mechanism 21 first unsealed area 22 opening 23 second unsealed area 24 notch 25 Heat-sealed portion 25a Overhanging portion 30 Container with lid 31 Accommodating portion 32 Container main body 33 Lid 34 Flange 35 Joining line

Claims (10)

A packaging material having a configuration in which a plastic film, a pattern layer and a sealant layer are laminated in this order from the outer layer side, wherein at least a partial region of the pattern layer is a glittering print containing a binder resin and metal flakes. A layer and a chromatic underlayer are laminated in this order from the outer layer side,
The metal scale is a scale made of at least one selected from aluminum, silver, titanium, nickel, stainless steel, and alloys thereof, and the chromatic underlayer is a yellow layer,
The content of particles with a size of 380 nm or more other than the metal scales in the glitter print layer is 1% by mass or less of the total solid content of the glitter print layer, and the glitter print layer has an average A packaging material containing inorganic particles having a primary particle size of 1 nm or more and less than 100 nm . The packaging material according to claim 1, wherein the metal flakes are non-leafing type metal flakes. The packaging material according to claim 1 or 2, wherein the metal flakes are flakes made of aluminum or an alloy containing aluminum. The packaging material according to any one of claims 1 to 3, which is for a microwave oven. A packaging container at least partly formed of the packaging material according to any one of claims 1 to 3. 6. The packaging container according to claim 5, wherein said packaging container is a pouch. A lidded container comprising a container body having an accommodating portion and a lid joined to the container body so as to seal the accommodating portion, wherein the lid is formed of the packaging material. 6. The packaging container according to item 5. The packaging container according to any one of claims 5 to 7, which is for a microwave oven. The packaging container according to any one of claims 5 to 8, which is a retort container. A lid made of the packaging material according to any one of claims 1 to 3.

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