JP6315358B2 - Packaging materials and packaging containers - Google Patents

Description

  The present invention relates to a packaging material, and more particularly, to a packaging material that has excellent concealability and light shielding properties, and can be manufactured efficiently at a relatively low cost. The present invention also relates to a packaging container using this packaging material.

  For products that use packaging containers that contain foods such as confectionery and retort foods, the light shielding properties of the packaging containers can be preserved so that the contents can be preserved while preventing deterioration of the contents such as oxidation. It is necessary to increase it sufficiently. Further, in order to increase consumers' willingness to purchase at the time of display of the above-mentioned various products, it is necessary to sufficiently improve the concealment of the packaging container so that the contents cannot be seen.

  Conventionally, in order to ensure the light shielding property and concealing property of the packaging container, a metal foil such as aluminum thin film excellent in the function is laminated on the packaging material forming the packaging container as a light shielding layer. However, when a packaging container containing thin metal is incinerated, there is a problem that the thin metal contained in the packaging container remains in the incinerator as a residue.

  In consideration of this point, in recent years, a light-shielding printing layer obtained by printing ink can be laminated on a packaging material in order to impart light-shielding properties and concealing properties to a packaging container without using a metal foil such as aluminum thin. It has been tried. Specifically, as a light-shielding print layer, a combination of a white ink layer and a chromatic color layer (Patent Document 1), a combination of a white ink layer and a black ink layer (Patent Document 2), a white ink layer and a black ink A combination comprising a layer and a white ink layer (Patent Document 2) and a combination comprising a white ink layer and a chromatic color layer containing a white or black pigment (Patent Document 3) have been proposed.

JP2003-144110A JP2005-8264 International Publication No. 2004-020303 Pamphlet

  When the light-shielding print layer includes a chromatic color layer, it is possible to select a chromatic color that is in harmony with the contents. This chromatic color is blended based on the color sample presented by the customer, but even if the chromatic color is blended with a theoretically accurate blending ratio, it is slightly affected by the surrounding environment such as humidity and temperature. Since the color changes, it is not easy to blend chromatic colors according to the color sample. For this reason, in order to reproduce the chromatic color according to the color sample, it is indispensable to perform the color matching work relying on the experience and intuition of the skilled worker, which takes a lot of time and effort. For this reason, when a combination including a chromatic color layer is employed as the light-shielding print layer, the production efficiency cannot be sufficiently increased, and the manufacturing cost is also increased.

  On the other hand, when the light-shielding printed layer includes a black ink layer, the black ink layer imparts excellent light-shielding properties and concealing properties to the packaging container. However, the black ink layer is directly visible on either the inner surface side or the outer surface side of the packaging container, which is a factor that reduces the consumer's willingness to purchase. In particular, in a food packaging container, when the black ink layer is directly visually recognized on the inner surface side, the contents are surrounded by the black surface, causing discomfort.

  In addition, in order to prevent the black ink layer from being directly recognized when observing the packaging container from the inner surface side or the outer surface side, a combination of a white ink layer, a black ink layer, and a white ink layer is used as a light-shielding printing layer. It can also be adopted. However, in order to form each ink layer in order on the packaging material, three roll-shaped plates are prepared. For this reason, the production of the light-shielding print layer is complicated and disadvantageous in terms of cost, and thus lacks practicality. Furthermore, it takes time to wash the plate after using the black ink.

  It is also possible to adopt a light-shielding printing layer consisting of only a white ink layer, but even if a plurality of white ink layers are laminated within the limit of thickness required for the packaging container, the light shielding and concealing properties of the packaging container are maintained. It cannot be secured sufficiently.

  In recent years, there has been a demand for packaging materials that can be manufactured more inexpensively and efficiently without impairing the functions described above. However, a conventional packaging material including a light-shielding printing layer has not obtained a light-shielding printing layer that sufficiently satisfies all of these requirements.

  The present invention has been made in consideration of such points, and an object of the present invention is to provide a packaging material and a packaging container that are excellent in light-shielding property and concealing property, and can be manufactured relatively inexpensively and efficiently.

The packaging material according to the present invention is a packaging material including a base material layer, a light-shielding printing layer, and a sealant layer from a container outer side to a container inner side when a bag is made into a container. ,
The light-shielding print layer is formed by laminating two white solid layers formed by solid printing and an achromatic layer formed by mixing white and black and printing solid in this order.

  The packaging material according to the present invention may include at least one barrier layer between the light-shielding print layer and the sealant layer.

  In the packaging material according to the present invention, the barrier layer may include an inorganic oxide vapor deposition film.

  In the packaging material according to the present invention, the sealant layer may be a single layer or a multilayer, and the thickness of the sealant layer may be in the range of 40 μm to 200 μm.

  The packaging container according to the present invention is manufactured using the packaging material having any one of the above characteristics.

  According to this invention, the packaging container excellent in light-shielding property and concealment property can be manufactured comparatively cheaply and efficiently.

FIG. 1 is a cross-sectional view along the stacking direction (normal direction) of packaging material according to an embodiment of the present invention, and is a view for explaining the layer configuration of the packaging material. FIG. 2 is a view showing an example of a packaging container produced using the packaging material of FIG. FIG. 3 is a diagram illustrating an example of a barrier layer in the packaging material of FIG. 1. FIG. 4 is a schematic view showing a method for producing the packaging material shown in FIG. 1 using a dry laminating method.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings attached to the present specification, for the sake of illustration and ease of understanding, the scale, the vertical / horizontal dimension ratio, and the like are appropriately changed and exaggerated from those of the actual product. FIG. 1 is a cross-sectional view of a packaging material according to an embodiment of the present invention along the stacking direction, and is a view for explaining a layer configuration of the packaging material. FIG. 2 is a view showing an example of a packaging container produced using the packaging material of FIG.

The packaging material 10 shown in FIG. 1 is used for the retort pouch type packaging container 1 shown in FIG. 2, for example. In the retort pouch type packaging container 1, the side portions are bonded together by heat-sealing the opposing side portions by overlapping the packaging materials 10. For this reason, the packaging material 10 is provided with a sealant layer 50 having a sealing property at a portion on the inner side of the container.
Moreover, the packaging container 1 demonstrated here is a packaging container suitable for enclosing a foodstuff as a content, Comprising: In order to ensure light-shielding property and concealment property in the packaging material 10 which comprises the packaging container 1, A light shielding printing layer 30 is laminated. That is, the packaging material 10 according to the present embodiment includes the base material layer 20, the light-shielding printing layer 30, and the sealant from the container outer side toward the container inner side when the bag is made into the packaging container 1. Layer 50. In the present embodiment, the barrier layer 40 is laminated between the light-shielding print layer 30 and the sealant layer 50 in order to ensure gas barrier properties.

(Base material layer)
As shown in FIG. 1, the base material layer 20 includes a base material 22 and a picture layer 21 including a picture that is laminated on the surface of the base material 22 on the container inner side. In the present embodiment, the base material 22 also functions as a layer of the packaging material 10 that is most outward from the container when the bag is made into the packaging container 1.

  As such a base material 22, for example, a uniaxial or biaxially stretched film of a thermoplastic resin film such as polyethylene terephthalate (PET), polypropylene (PP), or nylon (Ny) can be suitably used.

Furthermore, the base material 22 may have gas barrier properties. In this case, the gas barrier property of the packaging material 10 as a whole is improved, and in the packaging container 1 made from the packaging material 10, for example, permeation of oxygen from the outside can be suppressed and deterioration due to oxidation of the contents can be suppressed. .
As the base material 22 having gas barrier properties, a laminate obtained by coating a uniaxial or biaxially stretched film of the thermoplastic resin film with a gas barrier resin may be used, or as the base material 22 itself. A film having a high gas barrier property, such as a saponified ethylene-vinyl acetate copolymer (EVOH) or a polyvinylidene chloride resin (PVDC) may be used.

  As described above, the pattern layer 21 including the pattern is laminated on the surface of the base material 22 on the inner side of the container. Here, the pattern is a recording target of various modes that can be recorded or printed on the base material layer 20, and is not particularly limited, and includes a figure, a character, a pattern, a pattern, a symbol, a pattern, a mark, and the like. Including widely. In particular, in the packaging material 10 used for the retort pouch-type packaging container 1, characters indicating information such as a diagram of the content, a product name of the content, a shelf life, a production date, and a production number are used as a pattern. But the pattern layer 21 is laminated | stacked on the base material 22 according to the specification of goods, and the pattern layer 21 does not need to be provided in the base material layer 20. FIG.

  In this Embodiment, the pattern layer 21 is given to the inner surface of the base material 22 instead of the outer surface of the base material 22 used as the container outer side. In this case, since the pattern layer 21 is excellent in wear resistance, disappearance due to rubbing or the like can be effectively prevented, and alteration of the pattern can also be effectively prevented. In addition, the base material 22 has transparency so that the pattern layer 21 laminated on the inner surface of the base material 22 can be visually recognized through the base material 22 when the bag is made into the packaging container 1. Is preferred.

(Light-shielding printing layer)
The light-shielding print layer 30 includes at least a white solid layer 31 obtained by printing solid white, and an achromatic layer 32 obtained by mixing white and black and printing solid. Here, white and black are called achromatic colors and are distinguished from chromatic colors. That is, the achromatic color layer 32 obtained by solid printing by mixing white and black does not include a chromatic color. In addition, an achromatic color and a chromatic color are based on the definition in JIS-Z8102: 2001.

  The white solid layer 31 and the achromatic layer 32 constituting the light-shielding print layer 30 are laminated adjacent to each other. The white solid layer 31 and the achromatic color layer 32 are formed by solid printing in order on the surface of the base material layer 20 on the container inner side. Therefore, when the picture layer 21 and the light-shielding print layer 30 are viewed from the outer side of the packaging material 10 through the transparent base material 22, the light-shielding print layer 30 is observed as the background of the picture layer 21. For this reason, it is possible to display a pattern with a desired hue, to bring out brightness and to make the consumer feel clean.

  Specifically, the white solid layer 31 is formed by solid printing white ink containing a white pigment on the base material 22 of the base material layer 20. As the thickness of the white solid layer 31 increases, the whiteness of the white solid layer 31 of the light-shielding printed layer 30 observed as the background of the pattern layer 21 increases when the packaging material 10 is viewed from the outside of the container. Brightness is created in the background of the layer 21 and the consumer can feel clean. Moreover, although the light-shielding property and concealment property of the packaging material 10 can be improved, the contribution is small compared with black ink. The thickness of the white solid layer 31 is, for example, about 1 μm to 10 μm.

  On the other hand, the achromatic layer 32 is formed by solid-printing achromatic ink formed by mixing white ink containing a white pigment and black ink containing a black pigment on the substrate 22 of the substrate layer 20. This achromatic color ink is adjusted to a predetermined brightness according to JIS-Z8102: 2001 by mixing white ink and black ink at an appropriate blending ratio. As the blending ratio of the black ink contained in the achromatic color ink is increased, that is, as the brightness of the achromatic color ink is decreased, the light shielding property and the hiding property of the light shielding printing layer 30 can be increased. Further, as the thickness of the achromatic layer 32 made of achromatic ink is increased, the light shielding property and concealing property of the light shielding printing layer 30 can be increased. The thickness of such an achromatic layer 32 is, for example, about 1 μm to 10 μm.

  Here, the relationship between the white solid layer 31 and the achromatic layer 32 will be described in further detail. First, the total thickness obtained by adding the thickness of the white solid layer 31 and the thickness of the achromatic layer 32 is preferably 30 μm or less. When the total thickness exceeds 30 μm, when the white solid layer 31 and the achromatic layer 32 printed on the substrate 22 are dried in the manufacturing method described later, sufficient heat is applied to the white solid layer 31 and the achromatic layer 32. The packaging material 10 may be manufactured in a state where the white solid layer 31 and the achromatic layer 32 are not sufficiently dried. In this case, an unpleasant odor is generated from the pigment and binder contained in the white solid layer 31 and the achromatic color layer 32 that have not been sufficiently dried, which is a factor that significantly lowers the merchantability.

  Moreover, the thickness of the white solid layer 31, the thickness of the achromatic layer 32, and the mixing ratio of the white ink and the black ink in the achromatic color ink constituting the achromatic color layer 32 are obtained when the packaging material 10 is viewed from the outside of the container. This is determined on the basis of the appearance, the interior when the packaging material 10 is viewed from the inner side of the container, and the degree of light shielding and concealing required of the packaging material 10.

  As an example, the thickness of the white solid layer 31, the thickness of the achromatic color layer 32, and the blending ratio in the achromatic color ink are determined as follows. As described above, in the example illustrated in FIG. 2, when the pattern layer 21 and the light shielding print layer 30 are viewed from the container outer side of the packaging material 10, the white solid layer 31 side of the light shielding print layer 30 is the background of the pattern layer 21. Observed. On the other hand, when the light shielding printing layer 30 is viewed from the container inner side of the packaging material 10, the achromatic layer 32 side of the light shielding printing layer 30 is observed. First, in order to adjust the inside appearance when the packaging material 10 is viewed from the inner side of the container, the brightness of the achromatic ink forming the achromatic layer 32 described above is in harmony with the contents contained in the packaging container 1. Determined by brightness. Next, the blending ratio of the white ink and the black ink in the achromatic ink is determined based on the determined lightness, and the non-colored ink made of the achromatic ink is selected according to the light shielding property and the concealment required for the packaging material 10. The thickness of the coloring layer 32 is determined. And the thickness of the white solid layer 31 is determined in order to adjust the external appearance when the packaging material 10 is viewed from the inner side of the container.

  Further, the total light transmittance can be used as an index for evaluating the light transmittance of the packaging material 10. Here, the total light transmittance refers to the ratio of the total transmitted light amount that has passed through the light-shielding print layer 30 to the total incident light amount of light incident on the light-shielding print layer 30 serving as a sample. Since most samples have light diffusivity, the total light transmittance is the sum of the parallel light transmittance and the diffuse transmittance, which is an optical characteristic test method using an integrating sphere defined by JIS JIS-K7361-1. Measured in compliance.

  As an example, the total light transmittance of the light-shielding printed layer 30 is preferably 0.1% or more and 20% or less. When the total light transmittance is 20% or less, visible light and ultraviolet rays composed of external light having a wavelength range of 300 to 800 nm incident on the packaging material 10 under normal use conditions can be effectively blocked. Deterioration of the contents accommodated in the packaging container 1 can be effectively suppressed. On the other hand, when the total light transmittance of the light-shielding printing layer 30 is less than 0.1%, the thickness of the white solid layer 31 and the thickness of the achromatic layer 32 are greatly increased to increase the cost as a film. The total thickness obtained by adding the thickness of the white solid layer 31 and the thickness of the achromatic color layer 32 may exceed 30 μm. In this case, as described above, an unpleasant odor is generated from the pigment and binder contained in the white solid layer 31 and the achromatic layer 32 that are not sufficiently dried, and the merchantability is remarkably lowered. In addition, it is the compounding ratio of the black ink contained in the achromatic layer 32 that greatly contributes to lowering the total light transmittance of the light-shielding printing layer 30, but the white solid layer 31 is also used in combination. Therefore, the light shielding property can be further improved.

(Sealant layer)
As described above, the sealant layer 50 is provided in order to bond and seal the side portions by heat-sealing the side portions facing each other by overlapping the two packaging materials 10. Moreover, in this Embodiment, the sealant layer 50 functions also as a layer which becomes the container innermost part when making a bag and making it into the packaging container 1 among the packaging materials 10.

  As such a sealant layer 50, a heat-resistant film made of a polyolefin resin such as polyethylene, polypropylene, an ethylene-vinyl acetate copolymer, an ethylene-propylene block copolymer, an easy peel film, or the like can be employed. Furthermore, the sealant layer 50 may be configured as a single layer by a film made of these materials, or the sealant layer 50 may be configured as a multilayer by films made of a plurality of the above materials. In addition, when forming the packaging material 10 in the packaging container 1 in which heat resistance is requested | required, such as a container for boil and a retort, it is preferable to use an unstretched polypropylene film (CPP) as the sealant layer 50. FIG.

The thickness of the sealant layer 50 is preferably in the range of 40 μm to 200 μm.
In this case, the impact resistance against dropping that may occur in the distribution process of the packaging container 1 is excellent, and handling properties such as easy filling of contents and easy refilling of contents are also excellent.

(Barrier layer)
Next, the barrier layer 40 laminated between the light shielding printing layer 30 and the sealant layer 50 will be described. The barrier layer 40 is provided mainly for improving the barrier property that prevents the permeation of water vapor and oxygen gas. Various materials used as the barrier layer 40 in the general packaging material 10 can be applied as the barrier layer 40. In the present embodiment, the barrier layer 40 in which the vapor deposition film 41 is formed by vapor-depositing an inorganic substance on a polyester-based material or a polyamide-based material is used. Specifically, examples of the method for forming the vapor deposition film 41 include a vacuum vapor deposition method, a sputtering method, an ion plating method, a plasma vapor deposition method (CVD), and the like. Among these, the vacuum evaporation method is preferable because of excellent productivity.

  By including the vapor deposition film 41 of the inorganic oxide in the barrier layer 40, the barrier property that prevents the permeation of water vapor and oxygen gas can be remarkably improved. In addition, even if the packaging container 1 containing an inorganic oxide is incinerated, the inorganic oxide does not remain as a residue in the incinerator. As the inorganic material used to form such a vapor deposition film 41, generally, a metal oxide is used. For example, a metal oxide such as silicon oxide, aluminum oxide, or magnesium oxide, or a metal such as aluminum. Etc.

  In particular, the vapor deposition film 41 is preferably formed on the side of the barrier layer 40 that is most outward from the container, that is, adjacent to the light-shielding print layer 30. In this case, water vapor and oxygen gas incident on the packaging material 10 from the outside can be blocked on the outside of the container. For this reason, deterioration of the polyester-type material or polyamide-type material by which the inorganic substance was vapor-deposited by water vapor | steam or oxygen gas can be suppressed effectively.

  In addition, in order to improve resistance to impact when the packaging container 1 made of the packaging material 10 is dropped, the barrier layer 40 may be provided with a function of absorbing the impact. In this case, the impact when the packaging container 1 falls can be absorbed by the barrier 40 layer, thereby effectively preventing the occurrence of pinholes in the packaging container 1 due to the impact. As an example of a form for imparting a shock absorbing function to the barrier layer 40 as described above, a form in which a uniaxial or biaxially stretched nylon film is further laminated on the barrier layer can be mentioned.

  Alternatively, as the barrier layer 40, a barrier multilayer stretched film 43 having the following configuration may be used. This barrier multilayer stretched film 43 is excellent in barrier properties and resistance to impact of dropping, and does not deteriorate the barrier properties and impact resistance even when the dimensions change due to bending or moisture absorption. When the barrier multilayer stretched film 43 is used as the barrier layer 40, the barrier layer 40 can be formed extremely thin.

This barrier multilayer stretched film 43 includes a multilayer laminate (two (2) layers having at least three layers of a polyester resin layer (A layer), a polyamide resin layer (B layer), and a polyester resin layer (A layer) in this order. A) The layers may be the same or different), and a deposited layer (C layer) is provided on at least one side of a biaxially stretched multilayer film obtained by biaxial stretching. . this house,
(A) Each of the layers 44 contains crystalline polyester,
(B) The layer 45 contains 70 to 99% by weight of aliphatic polyamide and 1 to 30% by weight of aromatic polyamide,
(C) The layer 46 contains an inorganic substance.

  Hereinafter, each configuration of the barrier multilayer stretched film 43 will be described in detail. Hereinafter, the barrier multilayer stretched film 43 may be simply referred to as a multilayer stretched film.

(1) (A) Layer 44
The (A) layer 44 imparts functions such as dimensional stability and heat resistance to the multilayer stretched film 43. In particular, by providing dimensional stability, it is possible to suppress a decrease in gas barrier properties when wet. In this embodiment, two or more (A) layers 44 are provided, and the (A) layer 44, the (B) layer 45, and the (A) layer 44 are formed in this order.

  (A) The layer 44 contains crystalline polyester as a main component. The crystalline polyester is not particularly limited as long as it can impart functions such as dimensional stability and heat resistance to the multilayer stretched film 43, and examples thereof include resins obtained by polycondensation of dicarboxylic acid and diol. Can be mentioned.

  Examples of the dicarboxylic acid include o-phthalic acid, terephthalic acid, isophthalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, octyl succinic acid, cyclohexanedicarboxylic acid, naphthalenedicarboxylic acid, fumaric acid, maleic acid, and itaconic acid. , Decamethylene carboxylic acid, anhydrides and lower alkyl esters thereof, 5-sulfoisophthalic acid, 2-sulfoisophthalic acid, 4-sulfoisophthalic acid, 3-sulfophthalic acid, dialkyl 5-sulfoisophthalate, 2-sulfoisophthalate Examples include dialkyl acid, dialkyl 4-sulfoisophthalate, dialkyl 3-sulfoisophthalate, and sulfo group-containing dicarboxylic acids such as sodium salts and potassium salts thereof.

  Examples of the diol include ethylene glycol, 1,3-propanediol, 1,4-butanediol, diethylene glycol, 1,5-pentanediol, 1,6-hexanediol, dipropylene glycol, triethylene glycol, and tetraethylene glycol. 1,2-propanediol, 1,3-butanediol, 2,3-butanediol, neopentyl glycol (2,2-dimethylpropane-1,3-diol), 1,2-hexanediol, 2,5 -Aliphatic diols such as hexanediol, 2-methyl-2,4-pentanediol, 3-methyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol; 2,2-bis (4 -Hydroxycyclohexyl) propane, 2,2-bis (4-hydroxycyclohex) E) Alkylene oxide adducts such as propane, alicyclic diols such as 1,4-cyclohexanediol and 1,4-cyclohexanedimethanol, 1,3-dihydroxybutanesulfonic acid, 1,4-dihydroxybutanesulfonic acid, etc. And a sulfone group-containing diol.

  Among these, in particular, polyethylene terephthalate (PET) in which the component derived from dicarboxylic acid is terephthalic acid and the component derived from diol is ethylene glycol; the components derived from dicarboxylic acid are terephthalic acid (99 to 80 mol%) and isophthalic acid ( 1-20 mol%), isophthalic acid copolymerized polyethylene terephthalate whose component derived from diol is ethylene glycol; polybutylene whose component derived from dicarboxylic acid is terephthalic acid and component derived from diol is 1,4-butanediol Terephthalate (PBT); the component derived from dicarboxylic acid is terephthalic acid (99.5 to 90 mol%) and 5-sodium sulfoisophthalic acid (0.5 to 10 mol%), and the component derived from diol is ethylene glycol Sulfoisophthalic acid copolymer poly Chi terephthalate or the like dimensional stability, is suitable from the viewpoint of heat resistance and the like, more preferably a polyethylene terephthalate composed of terephthalic acid and ethylene glycol (PET).

  Such crystalline polyester is commercially available. For example, Belpet-EFG6C, Belpet PIFG5 (both manufactured by Bell Polyester Products Co., Ltd.) and the like are used as the crystalline polyester constituting the (A) layer 44. Can be used.

  In addition, the crystalline polyester used for (A) layer 44 may be only 1 type, and may mix and use 2 or more types as needed.

  In addition, the (A) layer 44 may contain a resin compatible with the crystalline polyester as required, but the content of the crystalline polyester with respect to the total weight of the components constituting the (A) layer 44 is , 50% by weight or more, preferably 70% by weight or more.

Non-crystalline polyester etc. can be illustrated as resin compatible with crystalline polyester.
Amorphous polyester is polyester in which the heat of fusion is not observed in differential scanning calorimetry based on JIS-K7121. Although it will not specifically limit if it is polyester which has such a characteristic, As a specific example, the component derived from dicarboxylic acid is terephthalic acid, the component derived from diol is ethylene glycol (20-80 mol%) and cyclohexane dimethanol (80 Polyester having a component derived from dicarboxylic acid is preferably terephthalic acid (20 to 80 mol%) and isophthalic acid (80 to 20 mol%), and a polyester having a component derived from diol is ethylene glycol. is there. Such an amorphous polyester is commercially available. For example, Eastar Copolyester 6763 (manufactured by Eastman Chemical) or the like can be used as the amorphous polyester.

  Moreover, a well-known inorganic or organic additive etc. can be suitably mix | blended with the (A) layer 44 as needed as long as the effect of the barrier layer 40 is not impaired. As an inorganic or organic additive, an antiblocking agent, a nucleating agent, a water repellent, an antioxidant, a heat stabilizer, a lubricant, an antistatic agent, a colorant, a pigment, a dye, and the like can be appropriately blended.

(2) (B) Layer 45
The (B) layer 45 gives the multilayer stretched film 43 functions such as flex resistance and impact resistance. In particular, the provision of bending resistance can suppress a decrease in gas barrier properties after bending.

  (B) The layer 45 contains an aliphatic polyamide and an aromatic polyamide.

(2-1) Aliphatic polyamide Examples of the aliphatic polyamide include aliphatic nylon and copolymers thereof. Specifically, polycapramide (nylon-6), poly-ω-aminoheptanoic acid (nylon-7), poly-ω-aminononanoic acid (nylon-9), polyundecanamide (nylon-11), polylauryllactam ( Nylon-12), polyethylenediamine adipamide (nylon-2,6), polytetramethylene adipamide (nylon-4,6), polyhexamethylene adipamide (nylon-6,6), polyhexamethylene Bacamide (nylon-6,10), polyhexamethylene dodecamide (nylon-6,12), polyoctamethylene adipamide (nylon-8,6), polydecamethylene adipamide (nylon-10,8) , Caprolactam / lauryl lactam copolymer (nylon-6 / 12), caprolactam / ω-aminononanoic acid copolymer Body (nylon-6 / 9), caprolactam / hexamethylenediammonium adipate copolymer (nylon-6 / 6,6), lauryllactam / hexamethylenediammonium adipate copolymer (nylon-12 / 6,6), Ethylenediamine adipamide / hexamethylene diammonium adipate copolymer (nylon-2,6 / 6,6), caprolactam / hexamethylene diammonium adipate / hexamethylene diammonium sebacate copolymer (nylon-6 / 6,6) / 6,10), ethyleneammonium adipate / hexamethylenediammonium adipate / hexamethylenediammonium sebacate copolymer (nylon-6 / 6,6 / 6,10), etc. Even if you mix the aliphatic polyamide There.

  Preferred aliphatic polyamides include nylon-6, nylon-6,6, nylon-6 / 6,6 (copolymer of nylon 6 and nylon 6,6), more preferably nylon-6, nylon. -6/6, 6 and more preferably nylon-6. As the two or more kinds of aliphatic polyamides, a combination of nylon-6 and nylon-6 / 6,6 (weight ratio of about 50:50 to 95: 5) is preferable.

(2-2) Aromatic polyamide Examples of aromatic polyamides include aromatic diamines such as metaxylenediamine and paraxylenediamine, and adipic acid, suberic acid, sebacic acid, cyclohexanedicarboxylic acid, terephthalic acid, and isophthalic acid. Examples thereof include crystalline aromatic polyamides obtained by polycondensation reaction with dicarboxylic acid or a derivative thereof. A crystalline aromatic polyamide such as polymetaxylene adipamide (MXD-nylon) is preferable. Specific examples include S-6007 and S-6011 (both manufactured by Mitsubishi Gas Chemical Co., Inc.).

  Alternatively, an amorphous aromatic polyamide (amorphous nylon) obtained by a polycondensation reaction between an aliphatic diamine such as hexamethylenediamine and a dicarboxylic acid such as terephthalic acid or isophthalic acid or a derivative thereof can be used. Preferred is a copolymer of hexamethylenediamine-terephthalic acid-hexamethylenediamine-isophthalic acid. Specific examples include Sealer PA (Mitsui / DuPont Polychemical Co., Ltd.) and the like.

  (B) As the layer 45, preferable combinations of aliphatic polyamide and aromatic polyamide include a combination of nylon-6 and MXD-nylon, and a combination of nylon-6 and amorphous aromatic polyamide (amorphous nylon).

(2-3) Content In the (B) layer 45 in the multilayer stretched film 43, the content of the aliphatic polyamide and the aromatic polyamide is 70 to 99% by weight, preferably 85 to 97% by weight for the aliphatic polyamide. It adjusts so that a group polyamide may be contained in the ratio of 1-30 weight%, preferably 3-15 weight%. When the amount of the aliphatic polyamide is more than 99% by weight, when the amount of the aromatic polyamide is less than 1% by weight, the biaxial stretchability is lowered, and it becomes difficult to form a film. On the other hand, when the aliphatic polyamide is less than 70% by weight and when the aromatic polyamide is more than 30% by weight, the bending resistance is lowered.

  (B) The layer 45 may be made of the above-mentioned polyamide-based resin. However, a known flex resistance improver, an inorganic or organic additive, or the like is necessary as long as the effect of the barrier layer 40 is not impaired. Can be blended. Examples of the bending resistance improver include polyolefins, polyester elastomers, polyamide elastomers, and the like, and can be appropriately blended in the range of about 0.5 to 10% by weight. Examples of inorganic or organic additives include antiblocking agents, nucleating agents, water repellents, antioxidants, thermal stabilizers, lubricants, antistatic agents, and the like. For example, if it is an antiblocking agent, a silica, a talc, a kaolin etc. can be mix | blended suitably in the range of about 100-5000 ppm. Note that the (B) layer 45 can be provided not only in one layer but also in two or more layers.

(3) (C) Layer 46
The (C) layer 46 provides the multilayer stretched film 43 with functions such as gas barrier properties, moisture resistance, and fragrance retention.

  (C) The layer 46 contains an inorganic substance. The inorganic substance is not particularly limited as long as it can form a layer having a gas barrier property against oxygen, water vapor, and the like by vapor deposition on the (A) layer 44 and the (B) layer 45. For example, silicon oxide, aluminum oxide, Examples thereof include metal oxides such as magnesium oxide and metals such as aluminum. Of these, metal oxides are preferable and silicon oxide is more preferable from the viewpoints of transparency and inspection of metal foreign matter.

  There are various methods for forming the (C) layer 46, and examples thereof include a vacuum deposition method, a sputtering method, an ion plating method, and a plasma vapor deposition method (CVD). Especially, since it is excellent in productivity, a vacuum evaporation method is preferable.

  Examples of the heating means in the vacuum deposition method include an electron beam heating method, a resistance heating method, an induction heating method, and the like, but the electron beam heating method is preferable in consideration of the wide selection of the evaporation material. In order to improve the density of the (C) layer 46, a plasma assist method or an ion beam assist method may be employed. Moreover, in order to improve the transparency of the (C) layer 46, reactive vapor deposition in which various gases such as oxygen are blown during vapor deposition may be used.

(4) Adhesive layer An adhesive layer may be formed for the purpose of improving the interlayer strength between the (A) layer 44 and the (B) layer 45 described above. By interposing the adhesive layer, it is possible to dramatically improve the interlayer strength after bonding the two. The adhesive layer is not particularly limited, and an acid-modified resin formed between (A) layer 44 and (B) layer 45 in multilayer stretched film 43 and graft-modified with, for example, unsaturated carboxylic acid or a derivative thereof is used. be able to.

  Examples of the acid-modified resin graft-modified with unsaturated carboxylic acid or a derivative thereof include modified polyolefin and modified styrene elastomer.

  The modified polyolefin is obtained by a known production method, for example, obtained by heating and mixing an unsaturated carboxylic acid or a derivative thereof and a polyolefin in the presence of a radical generator.

  Examples of unsaturated carboxylic acids or derivatives thereof include unsaturated carboxylic acids such as maleic acid and fumaric acid, acid anhydrides, esters or metal salts thereof (for example, sodium salts, potassium salts, calcium salts). .

  Examples of the polyolefin include olefin homopolymers, mutual copolymers, and copolymers with other copolymerizable monomers (for example, other vinyl monomers). Specifically, for example, polyethylene (for example, low density polyethylene (LDPE), linear low density polyethylene (LLDPE), etc.), polypropylene, polybutene, their intercopolymer, ionomer resin, ethylene-acrylic acid copolymer And ethylene-vinyl acetate copolymer.

  As the modified polyolefin, maleic anhydride-modified polyolefin is preferable. Specific examples include maleic anhydride-modified polyolefin resins (for example, ADMER SF731, SE800 manufactured by Mitsui Chemicals, Inc., modic manufactured by Mitsubishi Chemical Corporation, etc.).

  The modified styrene elastomer can be obtained by a known production method, for example, by heating and mixing an unsaturated carboxylic acid or a derivative thereof and a styrene elastomer in the presence of a radical polymerization agent.

  Examples of the styrene elastomer include a hydrogenated product of a styrene-butadiene copolymer and a hydrogenated product of a styrene-isoprene copolymer.

  Examples of unsaturated carboxylic acids or derivatives thereof include unsaturated carboxylic acids such as maleic acid and fumaric acid, acid anhydrides, esters or metal salts thereof (for example, sodium salts, potassium salts, calcium salts). .

  The modified styrene elastomer is preferably a hydrogenated styrene-butadiene copolymer modified with maleic anhydride. Specific examples include hydrogenated styrene-butadiene copolymers modified with maleic anhydride (for example, Kraton FG1901 manufactured by Kraton Polymer, Tuftec M1913 manufactured by Asahi Kasei Chemicals Corporation), and the like.

(5) Layer structure The multilayer stretched film 43 is a multilayer laminate having at least three layers of (A) layer 44, (B) layer 45, and (A) layer 44 in this order (the two (A) layers 44 are the same). A biaxially stretched multilayer film obtained by biaxially stretching a film (which may be different or different), and having a (C) layer 46 on at least one surface. Here, the (A) layer 44 can be provided not only in two layers but also in three or more layers. In addition, the (B) layer 45 can be provided not only in one layer but also in two or more layers. The plurality of (A) layers 44 may be the same or different in resin and thickness used. Similarly, when there are a plurality of (B) layers 45, the resin and thickness to be used may be the same or different. In addition, an adhesive layer (D layer), a gas barrier layer (E layer), a seal layer (F layer), and the like can be provided as necessary.

  Specific layer structures include (A) layer / (B) layer / (A) layer / (C) layer, (A) layer / (A) layer / (B) layer / (A) layer / (C) Layer, (A) layer / (A) layer / (B) layer / (A) layer / (A) layer / (C) layer, (A) layer / (B) layer / (A) layer / (A) Layer / (C) layer, (A) layer / (A) layer / (B) layer / (B) layer / (A) layer / (A) layer / (C) layer, (A) layer / (D) Layer / (B) layer / (D) layer / (A) layer / (C) layer, (A) layer / (B) layer / (E) layer / (B) layer / (A) layer / (C) Layer, (A) layer / (B) layer / (A) layer / (C) layer / (F) layer, and the like. These layer structures can suppress a decrease in gas barrier properties when wet.

Here, the gas barrier layer is a layer having a low gas permeability such as oxygen, nitrogen, and carbon dioxide.
Specific examples include ethylene-vinyl alcohol copolymers and aromatic polyamides.

  The ethylene-vinyl alcohol copolymer is obtained by saponification of an ethylene-vinyl acetate copolymer. The ethylene content of the ethylene-vinyl alcohol copolymer is 20 to 70 mol%, preferably 25 to 50 mol%. If the ethylene content is less than 20 mol%, the thermal stability is poor and the moldability is poor, and foreign matters such as gels are likely to be generated in extrusion melt molding, and the film tends to be easily broken in stretch molding. When the ethylene content exceeds 70 mol%, sufficient barrier properties cannot be obtained. In addition, in the ethylene-vinyl alcohol copolymer, other known components that do not significantly reduce the gas barrier property may be copolymerized or blended. The ethylene-vinyl alcohol copolymer may be a blend of ethylene-vinyl alcohol copolymers having different compositions. Examples of commercially available ethylene-vinyl alcohol copolymers include “EVAL” (manufactured by Kuraray Co., Ltd.), “Soarnol” (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), and the like.

  As the aromatic polyamide, for example, an aromatic diamine such as metaxylenediamine and paraxylenediamine and a dicarboxylic acid such as adipic acid, suberic acid, sebacic acid, cyclohexanedicarboxylic acid, terephthalic acid, and isophthalic acid, or a derivative thereof can be used. Examples thereof include crystalline aromatic polyamides obtained by a condensation reaction. A crystalline aromatic polyamide such as polymetaxylene adipamide (MXD-nylon) is preferable. Specific examples include S6007 and S6011 (both manufactured by Mitsubishi Gas Chemical Co., Inc.).

  The sealing layer may be a resin film having sealing properties, for example, polyethylene such as LLDPE (linear low density polyethylene), LDPE (low density polyethylene), HDPE (high density polyethylene); Polypropylene (stretched polypropylene) and the like; EVA (ethylene-vinyl acetate copolymer), EAA (ethylene-acrylic acid copolymer), EMAA (ethylene-methacrylic acid copolymer), EMA (ethylene-methyl acrylate copolymer) A layer composed of polyolefin such as EEA (ethylene-ethyl acrylate copolymer), EMMA (ethylene-methyl methacrylate copolymer), or ionomer can be employed. These resins may be used alone or in combination of two or more.

  As a method for forming the seal layer, a laminating method can be employed, and examples thereof include a dry laminating method and an extrusion laminating method. The dry laminating method is a method in which an adhesive is applied to the multilayer stretched film 43, a seal layer film is laminated on the adhesive, and the multilayer stretched film 43 and the seal layer are laminated. The extrusion laminating method is a method in which the resin constituting the sealing layer is eluted from the extruder and laminated as a sealing layer on the multilayer stretched film 43, or from the extruder between the multilayer stretched film 43 and the seal layer film. In this method, a resin such as polyethylene is eluted and the multilayer stretched film 43 and the seal layer are laminated and laminated. When the sealing layer is laminated by the extrusion laminating method, the multilayer stretched film 43 is preferably subjected to anchor coating treatment in advance.

  The total film thickness of the multilayer stretched film 43 having the above layer structure can be appropriately set according to the application, and is not particularly limited, but is usually about 10 to 50 μm, preferably about 12 to 25 μm.

  Moreover, the film thickness of each layer is (A) layer 44 normally about 1-20 micrometers, Preferably it is about 2-15 micrometers. (A) When the thickness of the layer 44 is 1 μm or more, excellent functions such as dimensional stability and heat resistance can be imparted to the multilayer stretched film 43. Moreover, the film excellent in bending resistance can be obtained because it is 20 micrometers or less. A plurality of (A) layers 44 are formed. The thickness of the (A) layer 44 is the total thickness of the plurality of (A) layers 44.

  (B) The thickness of the layer 45 is about 5-49 micrometers, Preferably it is about 8-23 micrometers. (B) When the thickness of the layer 45 is 5 μm or more, excellent functions such as bending resistance and impact resistance are imparted, and if it is 49 μm or less, sufficient impact strength is imparted and the product cost is suppressed. Can do. When a plurality of (B) layers 45 are formed, the thickness of (B) layer 45 is the total thickness of the plurality of (B) layers 45.

  Furthermore, the thickness of the (C) layer 46 is about 10 to 200 nm, preferably about 20 to 150 nm. (C) When the thickness of the layer 46 is 10 nm or more, gas barrier properties, moisture resistance, and aroma retention can be imparted, and when it is 200 nm or less, excellent gas barrier properties, moisture resistance, and aroma retention properties are achieved. While being applied, it is possible to obtain a vapor deposition layer having excellent crack resistance.

  In addition, when providing an adhesive layer, the thickness of an adhesive layer is about 0.5-5 micrometers, Preferably it is about 0.5-2.5 micrometers. If the thickness of the adhesive layer is 0.5 μm or more, it is easy to control the film thickness, and if it is 5 μm or less, the production cost can be suppressed while providing sufficient adhesive strength.

  In particular, it is preferable that the (C) layer 46 containing an inorganic substance is formed in the barrier layer 40 so as to be closest to the outer side of the container, that is, adjacent to the light-shielding printing layer 30. In this case, water vapor and oxygen gas incident on the packaging material 10 from the outside can be blocked on the outside of the container, so that the deterioration of the (A) layer 44 and the (B) layer 45 due to water vapor and oxygen gas is effective. Can be suppressed.

(Bonding layer)
A bonding layer 60 may be interposed between the light shielding printing layer 30 and the barrier layer 40 and / or between the barrier layer 40 and the sealant layer 50. As the bonding layer 60, for example, an adhesive generally used in a known laminating method can be used. For example, a polyvinyl acetate adhesive, a polyacrylate adhesive, a cyanoacrylate adhesive, An ethylene copolymer adhesive, a cellulose adhesive, a polyester adhesive, a polyamide adhesive, an amino resin adhesive, an epoxy adhesive, a polyurethane adhesive, and the like can be used.

(Packaging container)
The form of the packaging container 1 obtained from the packaging material 10 described above is not particularly limited. The packaging container in the form of a standing pouch, the packaging container in the gusset packaging form, the packaging container in the pillow packaging form, and the packaging container in the three-way pouch packaging form A form is mentioned. Furthermore, it is also possible to employ the packaging material 10 as a lid material covering the container opening.

  As shown in FIG. 2, in the packaging container 1 of the present embodiment, the packaging materials 10 are overlapped, the opening 2 is provided on the upper side, and the other opposing side is heat-sealed. Sides are pasted together. And after filling the content from the opening 2 provided in the upper side, the side part in which the said opening 2 was provided is sealed by heat-sealing, and the packaging container 1 is obtained. In addition, as a method of heat-sealing a side part, it can carry out by methods, such as a bar seal, a rotary roll seal, a belt seal, an impulse seal, a high frequency seal, an ultrasonic seal, for example.

  As described above, according to the present embodiment, the light-shielding print layer 30 includes the white solid layer 31 that is solid-printed and the achromatic layer 32 that is solid-printed by mixing white and black. In the solid printing, the ink can be applied without any gap, so that the white solid layer 31 formed by solid printing and the achromatic color layer 32 formed by solid printing are difficult to transmit light and further difficult to penetrate the contents. For this reason, the solid white layer 31 obtained by solid printing and the achromatic color layer 32 obtained by solid printing are excellent in light shielding properties and concealing properties. Further, since the achromatic color layer 32 contains black ink at a predetermined blending ratio, the light shielding property and the concealing property of the light shielding printing layer 30 can be further improved. That is, the light shielding print layer 30 is composed of a solid white layer 31 obtained by solid printing and an achromatic color layer 32 obtained by solid printing. As a result of the combination that the achromatic color layer 32 contains black ink, The light shielding and concealing properties required for the packaging container 1 can be sufficiently exhibited.

  Further, according to the present embodiment, the light-shielding print layer 30 includes the white solid layer 31 and the achromatic color layer 32 formed by mixing white and black, and does not include the black ink layer. For this reason, even if the packaging container 1 made of the packaging material 10 is observed from the inner surface side or the outer surface side, the consumer is not uncomfortable and the consumer's willingness to purchase is not reduced. Moreover, the packaging container 1 which consists of this packaging material 10 can be used suitably also for the use which accommodates a foodstuff as a content.

  Further, according to the present embodiment, the light-shielding print layer 30 includes the white solid layer 31 and the achromatic color layer 32 formed by mixing white and black, and does not include chromatic colors. In this case, the packaging material can be manufactured relatively inexpensively and efficiently because it does not require a great deal of time and effort due to the toning operation and it is not necessary to use many types of ink.

(Production method)
Next, an example of a method for manufacturing the packaging material 10 described above will be described with reference to FIG. FIG. 4 is a schematic view showing a method for producing the packaging material 10 shown in FIG. 1 using a dry laminating method.

  First, the pattern layer 21, the white solid layer 31, and the achromatic layer 32 are printed on a base sheet (not shown) that forms the base 22 of the base layer 20, and the printed base sheet is heated by hot air. Dried. In this way, a laminated web including the base material layer 20 and the light-shielding print layer 30 is obtained. The obtained laminated web is wound into a roll to form a roll-shaped original fabric 105 (see FIG. 4). As this printing method, gravure printing, offset printing, letterpress printing, screen printing, transfer printing, flexographic printing, and the like can be used.

  Next, as shown in FIG. 4, a laminated web including a base material layer 20 including a picture layer 21 and a light-shielding printing layer 30 including a white solid layer 31 and an achromatic layer 32 from a roll-shaped raw fabric 105. 101 is fed out, and an adhesive 102 for dry lamination is applied to the laminated web 101 by, for example, a gravure roller 106. Thereafter, the laminated web 101 is conveyed to the drying furnace 103, and after the solvent contained in the adhesive 102 is removed in the drying furnace 103, the laminated web 101 is guided to the nip roller 107. At the same time, the barrier sheet 104 that forms the barrier layer 40 is fed out from the separate roll-shaped original fabric 109 and guided to the nip roller 107. In the nip roller 107, the laminated web 101 and the barrier sheet 104 are overlaid, and the overlaid laminated web 101 and the barrier sheet 104 are pressed while being heated. Thereby, the intermediate laminated body 108 which consists of the laminated web 101 and the barrier sheet 104 is produced, and this intermediate laminated body 108 is wound up in roll shape.

  Next, the intermediate laminate 108 and the sealant sheet composed of the sealant layer 50 are pressure-bonded using the same dry lamination method. Thereby, the packaging material 10 is manufactured.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail using an Example, this invention is not limited to this Example. As described below, packaging materials and packaging containers according to Examples and Comparative Examples were prepared, and light shielding properties and concealing properties were evaluated for each packaging material and packaging container. Moreover, the packaging container which concerns on an Example and a comparative example is a retort pouch type packaging container, and encloses curry as a content.

  Example 1 corresponds to the packaging material shown in FIG. 1, and a packaging container shown in FIG. 2 was produced from this packaging material.

  As a base material, a pattern layer, a white solid layer and an achromatic layer were sequentially formed on a polyethylene terephthalate (PET) base material having a thickness of 12 μm by solid printing. Next, a barrier layer and a sealant layer were laminated in order on the achromatic layer to produce a packaging material according to Example 1.

  The white solid layer was formed by solid printing white ink (manufactured by Toyo Ink Co., Ltd., product name “Fine Star 681AT”). The achromatic layer is made of achromatic ink containing white ink (product name “R631AT” manufactured by Toyo Ink Co., Ltd.) and black ink (product name “N800LPGT Sumi” manufactured by Toyo Ink Co., Ltd.) in a mixing ratio of 6: 4. It was formed by solid printing on a white solid layer. The white solid layer was formed by printing solid white ink twice on the substrate by gravure printing. For the formation of the white solid layer 31, a plate cylinder having a plate depth of 28 μm and a plate cylinder line number of 175 was used. The achromatic color layer was formed by printing solid achromatic ink once on the substrate by gravure printing. For forming the achromatic layer, a plate cylinder having a plate depth of 22 μm and a plate cylinder line number of 175 was used.

  A silica-deposited nylon stretched film having a thickness of 15 μm was used as the barrier layer. As the sealant layer, unstretched polypropylene (product name “ZK99S” manufactured by Toray Industries, Inc.) having a thickness of 60 μm was used. Further, the barrier layer 40 was bonded to the light-shielding printing layer 30 by using the dry laminating method shown in FIG. Similarly, the sealant layer 50 was bonded to the barrier layer using the dry lamination method shown in FIG. For this reason, a two-part curable adhesive having a thickness of 2 μm (product of Rock Paint Co., Ltd., product between the light-shielding printed layer and the barrier layer, and between the barrier layer and the sealant layer) The name “RU77TH7”) was used.

[Comparative Example 1]
The packaging material according to Comparative Example 1 was produced by forming a white solid layer on the base material. That is, the packaging material according to Comparative Example 1 was composed of a base material and a white solid layer. The base material and the white solid layer of the packaging material according to Comparative Example 1 were the same as the base material and the white solid layer of the packaging material according to Example 1 in the materials and the forming method.

[Comparative Example 2]
The packaging material according to Comparative Example 2 differs from the packaging material according to Example 1 in that a chromatic color layer formed by printing chromatic color ink is formed instead of the achromatic color layer formed by printing achromatic color ink. The other points are the same. As a chromatic layer, white ink (manufactured by DIC Graphics Corporation, trade name “CLIOS 950 Shiro”, yellow ink (manufactured by DIC Graphics Corporation, trade name “CLIOS 423 ki”, red ink DIC graphics) A chromatic color layer in which a product name “CLIOS 212 Beni” manufactured by Co., Ltd. was blended at 1: 1: 1 was employed.

(Evaluation results of shading and hiding properties)
Table 1 shows the evaluation results of the light shielding properties and concealing properties of the packaging materials and packaging containers according to Example 1, Comparative Example 1 and Comparative Example 2 obtained above. Among these, the total light transmittance is used as an index for evaluating the light shielding property, and this total light transmittance is measured by a total light transmittance measuring device (trade name “Haze Meter HM-150” manufactured by Murakami Color Research Laboratory Co., Ltd.). Was measured according to JIS-K7361-1. On the other hand, the concealment property was evaluated by visually wrapping curry as a content in a packaging container made of a packaging material. Note that cumin contained in the curry is excellent as an index for evaluating concealment because it easily penetrates into the packaging container.

  As understood from Table 1, Comparative Example 1 did not exhibit sufficient light shielding properties. Moreover, the light-shielding property and concealing property of Example 1 were comparable to the light-shielding property and concealing property of Comparative Example 2 including the chromatic color layer. That is, since the packaging material of Example 1 does not include a chromatic color layer, it can be manufactured at a much lower cost and efficiency than the packaging material of Comparative Example 2, and in addition, the packaging material of Comparative Example 2 is of the same level. It has been found that light-shielding properties and concealing properties can be ensured.

DESCRIPTION OF SYMBOLS 1 Packaging container 2 Opening 10 Packaging material 20 Base material layer 21 Picture layer 22 Base material 30 Light-shielding printing layer 50 Sealant layer 60 Joining layer 31 White solid layer 32 Achromatic layer 40 Barrier layer 41 Deposition film 43 Barrier multilayer stretched film

Claims (5)

A packaging material including a base material layer, a light-shielding print layer, and a sealant layer from the side that is the outer side of the container when the bag is made into a container toward the inner side of the container,
The light-shielding print layer is formed by laminating two white solid layers obtained by solid printing and an achromatic layer obtained by mixing white and black and printing solid in this order. Packaging material characterized by.   The wrapping material according to claim 1, further comprising at least one barrier layer between the light-shielding print layer and the sealant layer.   The wrapping material according to claim 2, wherein the barrier layer includes an inorganic oxide vapor deposition film.   The packaging material according to any one of claims 1 to 3, wherein the sealant layer is a single layer or a multilayer, and the thickness of the sealant layer is in a range of 40 µm to 200 µm.   A packaging container produced using the packaging material according to claim 1.

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