JP2014181074A - Packaging material - Google Patents

Abstract

The present invention provides a packaging material that is excellent in gas barrier properties and vapor barrier properties, and can be manufactured at a relatively low cost and efficiently.
A packaging material 10 includes a multilayer stretched film 41 including at least a first polyester resin layer 43 and a polyamide resin layer 44, and a barrier coat layer 42 laminated on the multilayer stretched film 41.
[Selection] Figure 1

Description

  The present invention relates to a packaging material, and more particularly, to a packaging material that has excellent vapor barrier properties and gas barrier properties, and can be manufactured relatively inexpensively and efficiently.

  For example, in packaging containers that contain foods such as confectionery and retort foods, steam that prevents the permeation of water vapor so that the contents can be preserved while preventing deterioration of the contents such as oxidation. A barrier property and a gas barrier property that prevents permeation of gas such as oxygen gas are required.

  Conventionally, in order to ensure the gas barrier property and vapor barrier property of the packaging container, a metal foil such as an aluminum thin film excellent in the function is laminated on the packaging material forming the packaging container. However, when a packaging container containing thin metal is incinerated, the thin metal contained in the packaging container remains as a residue in the incinerator. In addition, when passing through a security gate such as an airport, there is a problem that the metal detector of the security gate detects a thin metal in the packaging container.

  In consideration of this point, in recent years, an inorganic material is vapor-deposited on a base material made of a polymer resin in order to impart gas barrier properties and vapor barrier properties to a packaging container without using a metal foil such as thin aluminum. The vapor deposition film in which is formed is used. This vapor deposition film can solve the problems in the conventional packaging container containing a thin metal, and can impart excellent gas barrier properties and vapor barrier properties to the packaging container. As a method for vapor-depositing an inorganic material on a substrate, a vacuum vapor deposition method (PVD method) in which an inorganic material evaporated under reduced pressure is vapor-deposited on the substrate, or a deposition gas containing an inorganic material is irradiated with plasma under reduced pressure. A plasma chemical vapor deposition method (CVD method) in which the inorganic material is deposited on a substrate is used.

  If the deposited film on which this deposited film is formed is used as a packaging material as it is, the dimensional change of the multilayer stretched film 41 occurs due to moisture absorption, cracks (cracking) occur in the deposited film, or pinholes in the deposited film due to impact or bending. Will occur. In order to prevent this, a multilayer stretched film including a polyester resin layer and a polyamide resin layer excellent in dimensional stability and impact resistance is adopted as a base material, and an overcoat layer is formed on the base material on which a deposited film is formed. Are further laminated (for example, see Patent Document 1). This overcoat layer is formed by applying a coating agent to the deposited film and then performing an aging treatment for at least one week in order to crosslink the coating agent.

JP 2007-237588 A

  By the way, equipment for performing vapor deposition under reduced pressure such as a vacuum vapor deposition apparatus becomes large. For this reason, a great amount of time is required for the work of depressurizing from the atmospheric pressure or the work of returning from the depressurized state to the atmospheric pressure, resulting in low production efficiency. In particular, when plasma is used, it takes time until the plasma discharge is stabilized, and the production efficiency is further reduced.

  In addition, the equipment for performing the deposition under reduced pressure is large, and in order not to reduce the production efficiency as much as possible, usually using a wide roll-shaped raw material having a total length of tens of thousands of meters or more, Vapor deposition is performed on a substrate that is continuously unwound from the original fabric. However, since the roll-shaped original fabric having a total length of tens of thousands of meters or more is considerably large and heavy, depending on the original fabric, a plurality of roll-shaped original fabrics made of the same base material are prepared. The web is drawn from the webs by joining the webs and winding them. In such a roll-shaped original fabric having an overall length of tens of thousands of meters or more, the sections before and after the web-joined portion of the web cannot be used as a product. Therefore, the base material in this section and the vapor deposition material deposited on the base material in this section are largely lost.

  In particular, when a multilayer stretched film including a polyester resin layer and a polyamide resin layer having a high added value is used as a base material, cost loss due to the loss of the base material also increases. In addition, although the polyester-based resin layer and the polyamide-based resin layer have a certain degree of heat resistance, they may be deteriorated by heat applied during vapor deposition.

  Further, as described above, a coating agent is applied to the vapor deposition film in order to prevent the occurrence of defects such as cracks (cracks) and pinholes in the vapor deposition film. In order to crosslink this coating agent, it is necessary to carry out an aging treatment for at least one week, which is not preferable in terms of production efficiency.

  As described above, when a multilayer stretched film including a polyester-based resin layer and a polyamide-based resin layer is used as a base material and a deposited film is formed on the base material, it is not preferable in terms of cost, quality, and production efficiency.

  The present invention has been made in view of the above points, and provides a packaging material excellent in gas barrier properties and vapor barrier properties, which can be manufactured at a relatively low cost and efficiently. Objective.

A packaging material according to the present invention includes a multilayer stretched film including at least a first polyester resin layer and a polyamide resin layer;
A barrier coat layer laminated on the multilayer stretched film;
Is provided.

  In the packaging material according to the present invention, the first polyester resin layer of the multilayer stretched film and the multilayer stretch from the outer side to the inner side of the container when the bag is made into a container The polyamide resin layer of the film and the barrier coat layer may be laminated in this order.

  In the packaging material according to the present invention, the multilayer stretched film further includes a second polyester resin layer, and the polyamide resin layer is disposed between the first polyester resin layer and the second polyester resin layer. May be.

In the packaging material according to the present invention, the barrier coat layer may contain a barrier coat agent in a range of 0.1 g / m ^{2 to} 10 g / m ² .

  The packaging material according to the present invention further comprises a sealant layer on the innermost side when the bag is made into a container, and the sealant layer includes an unstretched polypropylene layer or a linear low density polyethylene layer. May be.

  The packaging material according to the present invention further comprises a sealant layer on the innermost side of the container when the bag is made into a container, the sealant layer comprising a linear low density polyethylene layer and the bag made into the container. And a 6/12 nylon layer positioned outside the container from the linear low density polyethylene layer, and the packaging material may comply with FDA Regulation 21CFR1777.1390 (c) .

  The packaging material according to the present invention further comprises a sealant layer on the innermost side of the container when the bag is made into a container, the sealant layer comprising a linear low density polyethylene layer and the bag made into the container. And a 6/12 nylon layer located on the outside of the container with respect to the linear low density polyethylene layer, and the packaging material may comply with FDA Regulation 21CFR1777.1395 (b) .

  The packaging material according to the present invention further comprises a sealant layer on the innermost side of the container when the bag is made into a container, the sealant layer comprising a linear low density polyethylene layer and the bag made into the container. And a 6/69 nylon layer positioned outside the container from the linear low density polyethylene layer, and the packaging material may comply with FDA Regulation 21CFR1777.1395 (b) .

  The packaging material according to the present invention may further include a light shielding printing layer formed by printing ink.

  In the packaging material according to the present invention, the light-shielding print layer may include at least a white solid layer formed by solid printing and an achromatic layer formed by mixing white and black and printing solid.

  ADVANTAGE OF THE INVENTION According to this invention, it is a packaging material excellent in gas barrier property and vapor | steam barrier property, Comprising: The packaging material which can be manufactured comparatively cheaply and efficiently can be provided.

FIG. 1 is a cross-sectional view of the packaging material according to the first embodiment of the present invention along the stacking direction (normal direction), and is a view for explaining the layer structure 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 schematic view showing a method for producing the packaging material shown in FIG. 1 using a dry laminating method. FIG. 4 is a cross-section along the stacking direction of the packaging material according to the second embodiment of the present invention, and is a view for explaining the layer configuration of the packaging material. FIG. 5 is a view showing a state in which a light shielding layer is laminated on the packaging material shown in FIG.

<< First Embodiment >>
The first embodiment of the present invention will be described below 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 the packaging material according to the first embodiment of the present invention, taken along the stacking direction, for explaining the layer structure 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 container suitable for enclosing a foodstuff as a content. The packaging material 10 constituting the packaging container 1 includes a barrier layer 40 in order to ensure a vapor barrier property for preventing the permeation of water vapor and a gas barrier property for preventing the permeation of gas such as oxygen gas. Moreover, in this Embodiment, the light shielding layer 30 is laminated | stacked on the base material layer 20 in order to ensure light-shielding property and concealment property. In the example shown in the drawing, the packaging material 10 having such a layer structure is shielded from the base material layer 20 from the container outer side to the container inner side when the bag is made into the packaging container 1. The layer 30, the barrier layer 40, and the sealant layer 50 are included in this order. Hereinafter, each layer will be described in detail.

(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 an example, as the base material 22 having gas barrier properties, a film having high gas barrier properties, such as a saponified ethylene-vinyl acetate copolymer (EVOH), a polyvinylidene chloride resin (PVDC), or the like 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 layer)
The light shielding layer 30 has a function to prevent the quality of the content from being lowered by blocking the light from reaching the content contained in the packaged packaging container 1, that is, has a light shielding property. ing. The light to be shielded by the light shielding layer 30 is mainly visible light and ultraviolet light that are incident on the packaging material 10 under normal use conditions and are composed of external light having a wavelength range of 300 to 800 nm, for example. Further, it is preferable that infrared light having a wavelength exceeding 800 nm, for example, is also shielded by the light shielding layer 30 as much as possible. Further, the light shielding layer 30 is also provided to sufficiently enhance the concealing property so that the contents of the packaged packaging container 1 cannot be seen in order to increase consumers' willingness to purchase.

  The light shielding layer 30 is not particularly limited as long as it satisfies the above functions. As an example, the light shielding layer 30 may be a light shielding printing layer formed by printing ink, a resin layer colored in white or the like, or a resin layer to which an ultraviolet absorber is added. Among these, the light-shielding printing layer 31 formed by printing ink can be formed by printing ink on the base material 22 of the base material layer 20, thereby producing the light-shielding printing layer 31 efficiently at low cost. be able to.

  In addition, the light-shielding print layer 31 is formed by appropriately laminating at least one of the group consisting of a white ink layer, a black ink layer, an achromatic color layer, and a chromatic color layer. By appropriately combining these layers, the light shielding printing layer 31 can exhibit excellent light shielding properties and shielding properties. Here, white and black are called achromatic colors and are distinguished from chromatic colors. In addition, an achromatic color and a chromatic color are based on the definition in JIS-Z8102: 2001.

  The light-shielding print layer 31 is formed by printing one or more of the group consisting of a white ink layer, a black ink layer, an achromatic color layer, and a chromatic color layer on the substrate 22. The method for printing these inks on the substrate 22 may be either solid printing or halftone printing. Among these, in solid printing, since ink can be applied without a gap, the light-shielding printing layer 31 formed by solid printing is difficult to transmit light and further difficult to penetrate the contents.

  Specifically, the black ink layer is formed by printing black ink containing a black pigment on the base material 22 of the base material layer 20. In particular, the black pigment greatly contributes to improving the light shielding property and concealing property of the light shielding layer 30. The white ink layer is formed by printing white ink containing a white pigment on the base material 22 of the base material layer 20. The white ink layer greatly contributes to making the consumer 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 achromatic color layer is formed by 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 concealing property of the light shielding 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 layer 30 can be increased.

  The chromatic color layer is formed by printing chromatic color ink formed by mixing one or more of a red pigment, a blue pigment, and a yellow pigment on the substrate 22 of the substrate layer 20. Moreover, in order to improve the light-shielding property and concealment property of the light shielding layer 30, you may include a black pigment in this chromatic color ink. The chromatic color ink is adjusted to predetermined brightness and saturation according to JIS-Z8102: 2001 by mixing these pigments at an appropriate blending ratio. In particular, when the chromatic color layer can be visually recognized from the inner side of the container, the chromatic ink of the chromatic color layer is preferably toned in the same color as the color of the contents contained in the container. Thereby, when the chromatic color layer is observed from the inner side of the container, the color of the contents and the color of the inner surface of the packaging container 1 are harmonized, and the consumer can feel clean.

  Specific examples of the layer structure of the light-shielding printing layer 31 include a combination of a white ink layer and a black ink layer, a combination of a white ink layer, a black ink layer and a white ink layer, a white ink layer and a chromatic color layer, And combinations consisting of a white ink layer and an achromatic layer. Of these, the combination of the white ink layer and the achromatic layer is excellent in light shielding and concealing properties, and can be manufactured relatively inexpensively and efficiently. Hereinafter, the example which employ | adopted the combination which consists of a white ink layer and an achromatic layer as the light-shielding printing layer 31 is demonstrated.

  As shown in FIG. 1, the light-shielding print layer 31 of the present embodiment includes at least a white solid layer 33 formed by solid white printing, and an achromatic layer 32 formed by solid printing of white and black mixed. Consists of. In the illustrated example, the white solid layer 33 and the achromatic color layer 32 are laminated adjacent to each other. The white solid layer 33 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.

  Specifically, the white solid layer 33 is formed by solid printing on the base material layer 20 with white ink containing a white pigment. As the thickness of the white solid layer 33 increases, the whiteness of the white solid layer 33 of the light shielding 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 21 and the consumer can feel clean. The thickness of such a white solid layer 33 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. 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 33 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 33 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 33 and the achromatic layer 32 printed on the base material 22 are dried in the manufacturing method described later, sufficient heat is applied to the white solid layer 33 and the achromatic layer 32. The packaging material 10 may be manufactured in a state where the white solid layer 33 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 33 and the achromatic color layer 32 that have not been sufficiently dried, which is a factor of remarkably reducing the merchantability.

  Moreover, the thickness of the white solid layer 33, the thickness of the achromatic layer 32, and the blending 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 33, 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 shown in FIG. 2, when the pattern layer 21 and the light shielding layer 30 are viewed from the outer side of the packaging material 10, the white solid layer 33 side of the light shielding layer 30 is observed as the background of the pattern layer 21. The On the other hand, when the light shielding layer 30 is viewed from the container inner side of the packaging material 10, the achromatic layer 32 side of the light shielding 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 33 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 layer 30 to the total incident light amount of light incident on the light shielding layer 30 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 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 contained in the packaging container 1 can be effectively suppressed. On the other hand, when the total light transmittance of the light shielding layer 30 is less than 0.1%, the thickness of the light shielding printing layer 31, that is, the thickness of the white solid layer 33 and the thickness of the achromatic layer 32 are greatly increased. In addition to the increase, the total thickness obtained by adding the thickness of the white solid layer 33 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 33 and the achromatic layer 32 that are not sufficiently dried, and the merchantability is remarkably lowered. A significant contribution to lowering the total light transmittance of the light shielding layer 30 is the blending ratio of the black ink contained in the achromatic layer 32, but by using the white solid layer 33 in combination. Further, the light shielding property can be further improved.

(Barrier layer)
Next, the barrier layer 40 laminated between the light shielding layer 30 and the sealant layer 50 will be described. As described above, the packaging container 1 has a vapor barrier property that prevents the permeation of water vapor and the permeation of gas such as oxygen gas so that the content can be stored while preventing the content from being deteriorated such as oxidation. The gas barrier property which prevents is required. In addition, the packaging container 1 is required to have resistance to impact and bending when dropped. In the present embodiment, the barrier layer 40 includes a multilayer stretched film 41 including at least the first polyester resin layer 43 and the polyamide resin layer 44, and a barrier coat layer 42 laminated on the multilayer stretched film 41. The combination of these layers imparts excellent barrier properties to the packaging material 10.

  The polyester-based resin and the polyamide-based resin contained in the multilayer stretched film 41 are aligned in the stretching direction by the stretching treatment, and exhibit excellent dimensional stability. By exhibiting excellent dimensional stability, the multilayer stretched film 41 is less likely to cause a dimensional change of the multilayer stretched film 41 due to moisture absorption, and effectively suppresses occurrence of cracks (cracking) in the barrier coat layer 42. Can do.

  Moreover, since the multilayer stretched film 41 contains a polyamide-type resin, it exhibits impact resistance. Since the multilayer stretched film 41 exhibits impact resistance, the impact when the packaging container 1 is dropped can be absorbed by the multilayer stretched film 41, thereby causing pinholes to the packaging container 1 due to the impact. Generation | occurrence | production can be prevented effectively.

  The polyester-based resin layers 43 and 45 are excellent to some extent in vapor barrier properties that prevent permeation of water vapor. On the other hand, the polyamide-based resin layer 44 is easy to absorb moisture and may be curled. Therefore, the multilayer stretched film 41 of the present embodiment further includes a second polyester resin layer 45, and the polyamide resin layer 44 is interposed between the first polyester resin layer 43 and the second polyester resin layer 45. It is arranged. According to such a configuration, the vapor reaches the polyamide resin layer 44 by disposing the polyamide resin layer 44 between the first polyester resin layer 43 and the second polyester resin layer 45. Can be disturbed. In addition, the multilayer stretched film 41 is generally symmetric with respect to the polyamide-based resin layer 44. Further, the polyamide resin layer 44 is held in a well-balanced manner between the first polyester resin layer 43 and the second polyester resin layer 45, so that curling of the polyamide resin layer 44 can be further effectively suppressed. Can do. As a result, the multilayer stretched film 41 is formed as a smooth surface, and a uniform barrier coat layer 42 can be formed on the multilayer stretched film 41.

  Further, the polyester resin and polyamide resin exhibit a certain degree of vapor barrier property that prevents the permeation of water vapor, and also exhibits some gas barrier property that prevents the permeation of gas such as oxygen gas. However, the high level of vapor barrier properties and gas barrier properties required for recent packaging materials 10 cannot be sufficiently satisfied. As a result of extensive research conducted by the present inventors, the multilayer stretched film 41 is used as a means for imparting excellent vapor barrier properties and gas barrier properties to the packaging material 10 in place of an expensive vapor deposited film obtained by depositing an inorganic material on a base material. Thus, the means for coating the barrier coat layer 42 was reached. By adopting the coating process, it is possible to impart a high vapor barrier property and a high gas barrier property to the packaging material 10 relatively inexpensively and efficiently without requiring a long period of production.

  The barrier coat layer 42 is formed by using a barrier coat agent used for imparting a barrier property to the packaging material 10 forming the packaging container 1 for enclosing food. The barrier coating agent also exhibits vapor barrier properties, but is particularly excellent in gas barrier properties. That is, the barrier coat layer 42 greatly imparts to the packaging material 10 a gas barrier property that prevents permeation of gas such as oxygen gas.

  That is, by laminating the barrier coat layer 42 on the multilayer stretched film 41 that exhibits a certain degree of vapor barrier properties, both excellent gas barrier properties and excellent vapor barrier properties can be imparted to the packaging material 10.

  Hereinafter, the configuration of each layer of the multilayer stretched film 41 and the configuration of the barrier coat layer 42 will be described in detail. In the following description, the first polyester resin layer 43 and the second polyester resin layer 45 may be simply abbreviated as polyester resin layers 43 and 45.

(1) Polyester-based resin layer The polyester-based resin layers 43 and 45 provide the multilayer stretched film 41 with functions such as dimensional stability and heat resistance. In particular, by providing dimensional stability, it is possible to suppress a decrease in gas barrier properties when wet. In the present embodiment, two or more polyester resin layers 43 and 45 are provided, and the first polyester resin layer 43, the polyamide resin layer 44, and the second polyester resin layer 45 are formed in this order.

  The polyester resin layers 43 and 45 preferably each contain a crystalline polyester as a main component. The crystalline polyester greatly contributes to imparting functions such as dimensional stability and heat resistance to the multilayer stretched film 41. Examples of the crystalline polyester include a resin obtained by polycondensation of a dicarboxylic acid and a diol.

  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 to form the polyester resin layers 43 and 45. It can be used as polyester.

  In addition, the crystalline polyester used for the polyester-type resin layers 43 and 45 may be only 1 type, and may blend and use 2 or more types as needed.

  The polyester resin layers 43 and 45 may contain a resin compatible with the crystalline polyester if necessary, but the crystalline polyester with respect to the total weight of the components constituting the polyester resin layers 43 and 45. The content of 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 polyester-type resin layers 43 and 45 as needed in the range which does not impair the effect of the barrier layer 40. 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) Polyamide-based resin layer The polyamide-based resin layer 44 imparts functions such as flex resistance and impact resistance to the multilayer stretched film 41. In particular, the provision of bending resistance can suppress a decrease in gas barrier properties after bending.

  The polyamide-based resin layer 44 contains 70 to 99% by weight of aliphatic polyamide and 1 to 30% by weight of 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 (manufactured by Mitsui DuPont Polychemical Co., Ltd.) and the like.

  As the polyamide-based resin layer 44, 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 polyamide resin layer 44 in the multilayer stretched film 41, 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 a ratio of 1 to 30% by weight, preferably 3 to 15% by 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.

  The polyamide-based resin layer 44 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. The second polyester resin layer 45 can be provided not only in one layer but also in two or more layers.

(3) Adhesive layer An adhesive layer may be formed for the purpose of improving the interlayer strength between the polyester resin layers 43 and 45 and the polyamide resin layer 44. 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 for example, an acid-modified resin graft-modified with an unsaturated carboxylic acid or a derivative thereof can be used.

  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 (linear low density polyethylene), etc.), polypropylene, polybutene, their intercopolymers, ionomer resin, ethylene- Examples include acrylic acid copolymers and ethylene-vinyl acetate copolymers.

  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 Configuration The multilayer stretched film 41 according to this embodiment is a biaxial multilayer laminate having three layers of a first polyester resin layer 43, a polyamide resin layer 44, and a second polyester resin layer 45 in this order. It is a biaxially stretched multilayer film obtained by stretching. Here, the polyester resin layers 43 and 45 can be provided not only in two layers but also in three or more layers. Further, the polyamide resin layer 44 can be provided not only in one layer but also in two or more layers. The plurality of polyester resin layers 43 and 45 may be the same or different in resin and thickness. Similarly, when there are a plurality of polyamide-based resin layers 44, the resin and thickness to be used may be the same or different. In addition, an adhesive layer, a gas barrier layer, a seal layer, and the like can be provided as necessary.

  When the polyester-based resin layers 43 and 45 are expressed as A layer, the polyamide-based resin layer 44 as B-layer, and the adhesive layer as D-layer, as a specific layer structure, (A) layer / (B) layer / (A) Layer, (A) layer / (A) layer / (B) layer / (A) layer, (A) layer / (A) layer / (B) layer / (A) layer / (A) layer, (A) Layer / (B) layer / (A) layer / (A) layer, (A) layer / (A) layer / (B) layer / (B) layer / (A) layer / (A) layer, (A) Layer / (D) layer / (B) layer / (D) layer / (A) layer, (A) layer / (B) layer / (B) layer / (A) layer, (A) layer / (B) Layer / (A) layer and the like.

  The total thickness of the multilayer stretched film 41 having the above-described layer configuration 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 about 1-20 micrometers normally about the polyester-type resin layers 43 and 45, Preferably it is about 1-15 micrometers. When the thickness of the polyester resin layers 43 and 45 is 1 μm or more, excellent functions such as dimensional stability and heat resistance can be imparted to the multilayer stretched film 41. Moreover, the film excellent in bending resistance can be obtained because it is 20 micrometers or less. When the polyester resin layers 43 and 45 are composed of a plurality of layers, the thickness of the polyester resin layers 43 and 45 is the total thickness of the plurality of polyester resin layers 43 and 45.

  The polyamide resin layer 44 has a thickness of about 5 to 49 μm, preferably about 8 to 23 μm. When the thickness of the polyamide-based resin layer 44 is 5 μm or more, excellent functions such as flex resistance and impact resistance are imparted, and when it is 49 μm or less, sufficient impact strength is imparted and the product cost is suppressed. Can do. When a plurality of polyamide resin layers 44 are formed, the thickness of the polyamide resin layer 44 is the total thickness of the plurality of polyamide resin layers 44.

  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.

(6) Barrier Coat Layer Next, the barrier coat layer 42 laminated on the multilayer stretched film 41 will be described. As described above, the barrier coat layer 42 is formed using the barrier coat agent that has been used to impart barrier properties to the packaging material 10 that forms the packaging container 1 for enclosing food. This barrier coating agent contains a barrier component having a gas barrier property and a vapor barrier property, and a solvent in which the barrier component is dispersed.

  Examples of the barrier component contained in the barrier coating agent include organic substances such as polyvinyl alcohol (PVA), ethylene-vinyl alcohol copolymer (EVOH), polyacrylonitrile (PAN), and polyvinylidene chloride (PVDC). Among these, ethylene-vinyl alcohol copolymer (EVOH) is extremely excellent in gas barrier properties, and is not inferior in gas barrier properties even when compared with a deposited film in which a deposited film made of an inorganic material is formed.

  Further, in order to improve the barrier property in a high temperature or high humidity state, a layered or plate-like fine inorganic substance is also added as a barrier component. That is, the barrier coating agent of the present embodiment includes a barrier component containing an organic substance and a layered or plate-like inorganic substance, and a solvent for dispersing the barrier component. In particular, when an ethylene-vinyl alcohol copolymer (EVOH) is employed as a barrier component made of an organic material, the gas barrier property is extremely excellent under normal temperature and normal humidity, but the gas barrier property is greatly reduced in a high temperature or high humidity state. In this regard, when a layered or plate-like fine inorganic substance is added as a barrier component, gas barrier properties at high temperature or high humidity can be improved.

  As a solvent for dispersing the barrier component, water and / or a water-soluble organic solvent is used. Examples of the water-soluble organic solvent include alcohols such as methanol, ethanol, and isopropanol, ketones such as acetone, and ethers. The solvent is determined according to the barrier component, but it is preferable to use a mixture of water and a water-soluble organic solvent from the viewpoint of stably dispersing the layered or plate-like fine inorganic substance.

As an example, the barrier coat layer 42 may contain a barrier coat agent in a range of 0.1 g / m ^{2 to} 10 g / m ² . By containing 0.1 g / m ² or more of the barrier coating agent, gas barrier properties and vapor barrier properties can be sufficiently obtained. On the other hand, even if the barrier coating agent is contained in excess of 10 g / m ² , not only the gas barrier property and vapor barrier property corresponding to the added amount cannot be obtained, but also the thickness of the barrier coat layer 42 becomes considerably thick. It is not preferable.

  In order to improve the adhesion between the multilayer stretched film 41 and the barrier coat layer 42, an anchor layer (not shown) may be interposed between the multilayer stretched film 41 and the barrier coat layer 42. As such an anchor layer, a urethane resin or a polyester resin dispersed in a solvent can be used.

  Moreover, when forming the packaging container 1 for boil or retort with the packaging material 10 by this Embodiment, since the packaging container 1 is heated to high temperature for sterilization etc., heat resistance is requested | required of the packaging container 1. The In this case, since the packaging container 1 is heated from the outer side, the heat load on the outer side of the packaging container 1 is greater than that on the inner side. In this regard, in the present embodiment, the first polyester-based resin layer 43 of the multilayer stretched film 41 and the multilayer are formed from the container outer side to the container inner side when the bag is made into a container. The polyamide resin layer 44 of the stretched film 41 and the barrier coat layer 42 are laminated in this order. According to this arrangement, the layers are arranged from the inner side toward the outer side of the container so that the resistance to heat increases in order. Therefore, when the packaging container 1 is heated from the outer side, the heat load on the polyamide resin layer 44 which is less resistant to heat than the first polyester resin layer 43 is increased. The heat load on the barrier coat layer 42 that is less resistant to heat than the polyamide-based resin layer 44 can be suppressed more than the polyamide-based resin layer 44. For this reason, even when the packaging material 10 forming the packaging container 1 is required to have heat resistance, the packaging container 1 can sufficiently exhibit the heat resistance.

(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 is arrange | positioned among the packaging materials 10 at the side which becomes the container innermost when bag-making and it is set as the packaging container 1. FIG.

  As such a sealant layer 50, a heat-resistant film made of a polyolefin resin such as polyethylene, polypropylene, ethylene-vinyl acetate copolymer, and ethylene-propylene block copolymer, an easy peel film, and 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 particular, when the packaging material 10 is formed in a packaging container 1 that requires heat resistance, such as a container for boil or retort, the sealant layer 50 includes an unstretched polypropylene layer (CPP) mainly containing unstretched polypropylene (CPP). Layer) or a linear low-density polyethylene layer (LLDPE layer) mainly containing linear low-density polyethylene (LLDPE). When the sealant layer 50 includes an unstretched polypropylene layer (CPP layer) or a linear low-density polyethylene layer (LLDPE layer), the vapor barrier property of the packaging material 10 can be further enhanced.

  As an example of the packaging material 10 constituting the packaging container 1 requiring such heat resistance, the sealant layer 50 includes a linear low density polyethylene layer (LLDPE layer) and a linear chain when a bag is made into a container. And a 6/12 nylon layer positioned outside the container with respect to the low-density polyethylene layer (LLDPE layer), and the packaging material 10 may be made in accordance with FDA regulations 21CFR1777.1390 (c). According to such a form, it can apply suitably to the packaging container 1 for enclosing a foodstuff which requires heat resistance on the conditions of 121 degreeC (250 degreeF) or more.

  Alternatively, as another example, the sealant layer 50 includes a linear low density polyethylene layer (LLDPE layer) and a container outside the linear low density polyethylene layer (LLDPE layer) when the bag is made into a container. 6/12 nylon layer, and the packaging material 10 may be made in accordance with FDA Regulation 21CFR1777.1395 (b). According to such a form, it applies suitably to the packaging container 1 for enclosing a foodstuff in which heat resistance is requested | required on the conditions of 48.9 degreeC (120 degreeF)-121 degreeC (250 degreeF). be able to.

  Alternatively, as still another example, the sealant layer 50 includes a linear low density polyethylene layer (LLDPE layer) and a linear low density polyethylene layer (LLDPE layer) when the bag is made into a container. 6/69 nylon layer located outside the container, and the packaging material 10 may be made in accordance with FDA regulations 21CFR1777.1395 (b). According to such a form, it is suitably applied to the packaging container 1 for enclosing food, which requires heat resistance under conditions of 48.9 ° C. (120 ° F.) to 121 ° C. (250 ° F.) or higher. can do.

  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.

(Bonding layer)
A bonding layer 60 may be interposed between the light shielding 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 Examples include packaging containers in the form of laminated tubes. 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 packaging material 10 includes the multilayer stretched film 41 including at least the first polyester resin layer 43 and the polyamide resin layer 44, and the barrier coat laminated on the multilayer stretched film 41. And a layer 42. The multilayer stretched film 41 including the first polyester-based resin layer 43 and the polyamide-based resin layer 44 is excellent in impact resistance and dimensional stability, and is packaged due to the occurrence of cracks (cracks) in the barrier coat layer 42 or impact. Generation | occurrence | production of the pinhole to the container 1 can be prevented effectively. On the other hand, the barrier coat layer 42 contributes to greatly improving the vapor barrier property and gas barrier property of the packaging material 10. That is, as a result of the combination of the multilayer stretched film 41 including the first polyester resin layer 43 and the polyamide resin layer 44, and the barrier coat layer 42, both the vapor barrier property and the gas barrier property required for the packaging container 1 are achieved. It can be exhibited sufficiently stably.

  Moreover, according to such a form, since the barrier layer 40 can be formed by coating the barrier coating layer 42 on the multilayer stretched film 41 as will be described later, comparison is made without requiring a long period of manufacturing. Therefore, the packaging material 10 can be manufactured efficiently and inexpensively.

  In addition, according to the present embodiment, the sealant layer 50 is further provided on the innermost side when the bag is made into a container, and the sealant layer 50 is an unstretched polypropylene layer or a linear low density polyethylene. Contains layers. According to such a form, it becomes possible to heat-seal the side part which opposes two packaging materials 10 on each other, and can further improve the vapor barrier property of the packaging material 10.

  Further, according to the present embodiment, the light shielding layer 30 includes the white solid layer 33 formed by solid printing and the achromatic layer 32 formed by mixing white and black and printing solid. In the solid printing, the ink can be applied without any gap, so that the white solid layer 33 formed by solid printing and the achromatic layer 32 formed by solid printing are difficult to transmit light and further difficult to permeate the contents. For this reason, the solid white layer 33 formed by solid printing and the achromatic color layer 32 formed by solid printing are excellent in light shielding properties and concealing properties. Furthermore, since the achromatic color layer 32 contains black ink at a predetermined blending ratio, the light shielding property and concealing property of the light shielding layer 30 can be further improved. That is, the light shielding layer 30 is composed of a solid white layer 33 formed by solid printing and an achromatic color layer 32 printed by solid printing, and the light shielding layer 30 is a packaging container. 1 can sufficiently exhibit the light-shielding property and concealment required.

  Further, according to the present embodiment, the light shielding layer 30 includes the white solid layer 33 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 layer 30 includes the white solid layer 33 and the achromatic 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. 3 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 33, 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 layer 30 is obtained. The obtained laminated web is wound into a roll to form a roll-shaped original fabric 105 (see FIG. 3). 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. 3, a laminated web 101 including a base material layer 20 including a pattern layer 21 and a light shielding layer 30 including a white solid layer 33 and an achromatic layer 32 from a roll-shaped raw fabric 105. Is fed out, and an adhesive 102 for dry laminating 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.

  On the other hand, a barrier web 104 composed of a multilayer stretched film 41 including a first polyester resin layer 43 and a polyamide resin layer 44 is fed out from a separate roll-shaped raw fabric 109. A coating agent 112 for coating is applied by the gravure roller 111. Thereafter, the barrier web 104 is conveyed to a drying furnace 113, and after the solvent contained in the coating agent 112 is removed in the drying furnace 113, the barrier web 104 is guided to the nip roller 107.

  In the nip roller 107, the laminated web 101 and the barrier web 104 are overlaid, and the laminated web 101 and the barrier web 104 are pressure-bonded while being heated. Thereby, the intermediate laminated body 108 which consists of the laminated web 101 and the barrier web 104 is produced, and this intermediate laminated body 108 is wound up by 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.

<< Second Embodiment >>
Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 4 is a cross-section along the stacking direction of the packaging material according to the second embodiment of the present invention, and is a view for explaining the layer configuration of the packaging material. The second embodiment described with reference to FIG. 4 is different from the first embodiment in that the base material layer 20 and the light shielding layer 30 are not provided. It can be configured similarly to the embodiment. In the following description of the second embodiment and the drawings used in the following description, the parts that can be configured in the same manner as in the first embodiment described above are the same as the corresponding parts in the first embodiment described above. The same reference numerals as those used above will be used, and redundant explanation will be omitted.

  A packaging material 200 shown in FIG. 4 includes a barrier layer 40 having a vapor barrier property and a gas barrier property, and a sealant layer 50 laminated on a surface of the barrier layer 40 on the container inner side. Among these, the barrier layer 40 includes a multilayer stretched film 41 including at least a first polyester resin layer 43 and a polyamide resin layer 44, and a barrier coat layer 42 laminated on the multilayer stretched film 41. An excellent barrier property is imparted to the packaging material 10 by the combination of these layers. In the illustrated example, the multilayer stretched film 41 further includes a second polyester resin layer 45, and the polyamide resin layer 44 is disposed between the first polyester resin layer 43 and the second polyester resin layer 45. ing.

  Since the multilayer stretched film 41, the barrier coat layer 42, and the sealant layer 50 can be configured in substantially the same manner as in the first embodiment described above, further detailed description is omitted here.

  As described above, according to the present embodiment, the packaging material 200 includes the multilayer stretched film 41 including at least the first polyester resin layer 43 and the polyamide resin layer 44, and the barrier coat laminated on the multilayer stretched film 41. And a layer 42. The multilayer stretched film 41 including the first polyester-based resin layer 43 and the polyamide-based resin layer 44 is excellent in impact resistance and dimensional stability, and is packaged due to the occurrence of cracks (cracks) in the barrier coat layer 42 or impact. Generation | occurrence | production of the pinhole to the container 1 can be prevented effectively. On the other hand, the barrier coat layer 42 contributes to greatly improving the vapor barrier property and gas barrier property of the packaging material 200. That is, as a result of the combination of the multilayer stretched film 41 including the first polyester resin layer 43 and the polyamide resin layer 44, and the barrier coat layer 42, both the vapor barrier property and the gas barrier property required for the packaging container 1 are achieved. It can be exhibited sufficiently stably.

  Moreover, according to such a form, since the barrier layer 40 can be formed by coating the barrier coating layer 42 on the multilayer stretched film 41 as will be described later, comparison is made without requiring a long period of manufacturing. Therefore, the packaging material 200 can be manufactured efficiently and inexpensively.

  In addition, the packaging material in 2nd Embodiment mentioned above may further be provided with the light shielding layer 30, and may further be provided with the pattern layer 21. FIG. FIG. 5 shows an example in which the packaging material shown in FIG. In the packaging material 300 shown in FIG. 5, the light shielding layer 30 is laminated between the multilayer stretched film 41 and the barrier coat layer 42 shown in FIG. 4. That is, the light shielding layer 30 is printed on the inner surface of the multilayer stretched film 41, and the barrier coat layer 42 is formed on the light shielding layer 30. In the illustrated example, the light shielding layer 30 is configured as a light shielding printing layer 31 formed by printing ink. By printing the light-shielding print layer 31 on the inner surface of the multilayer stretched film 41 on the inner side of the container, the wear resistance of the light-shielding print layer 31 is improved, and the disappearance of the light-shielding print layer 31 due to rubbing or the like is effectively prevented. can do. Since this light shielding layer 30 can be configured in substantially the same manner as in the first embodiment described above, further detailed description is omitted here.

  In addition, the example of arrangement | positioning of the light shielding layer 30 is not limited to the example shown in FIG. As another example, the light shielding layer 30 may be laminated on the surface of the multilayer stretched film 41 on the outer side of the container. Alternatively, the barrier coat layer 42 may be formed on the multilayer stretched film 41, and the light shielding layer 30 may be formed on the barrier coat layer 42.

  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 according to Examples and Comparative Examples were produced, and gas barrier properties and vapor barrier properties were evaluated for each packaging material.

  Example 1 and Example 2 correspond to the packaging material shown in FIG. 4, and Example 3 corresponds to the packaging material shown in FIG.

A barrier coat agent was formed by coating a multilayer stretched film employing a polyethylene terephthalate layer as the first polyester-based resin layer, a nylon layer as the polyamide-based resin layer, and a polyethylene terephthalate layer as the second polyester-based resin layer. . The thickness of this multilayer stretched film was 15 μm. Moreover, Tokyo Ink Co., Ltd. product name "LG-OX barrier agent E" was used as a barrier coating agent, and it coated so that the quantity of a barrier coating agent might be 1.0 g / m < ² >. Further, the sealant layer was bonded to the multilayer stretched film using the dry lamination method shown in FIG. As this sealant layer, unstretched polypropylene (product name “Torphan ZK99S” manufactured by Toray Industries, Inc.) having a thickness of 30 μm was used. For this reason, between the multilayer stretched film and the sealant layer, a two-component curable adhesive (manufactured by Rock Paint Co., Ltd., product names “RU004” and “H-1”) was used as a bonding layer.

The packaging material according to Example 2 used a barrier coating agent different from the packaging material according to Example 1, and was otherwise the same as the packaging material according to Example 1. In the packaging material according to Example 2, the product name “Unilex BHC-70” manufactured by Brenz Corporation is used as the barrier coating agent, and the amount of the barrier coating agent is 2.5 g / m ^2. did.

  The packaging material according to Example 3 is obtained by further forming a light-shielding printing layer on the packaging material according to Example 1. Specifically, an achromatic layer and a white solid layer were sequentially formed on the multilayer stretched film by solid printing. 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 a solid ink on a white solid layer that is a mixture of white ink (Toyo Ink, product name “R631AT”) and black ink (Toyo Ink, product name “N800LPGT Sumi”). It was formed by printing. The white solid layer was formed by printing solid white ink twice on a multilayer stretched film by gravure printing. For the formation of the white solid layer, a plate cylinder having a plate depth of 28 μm and a plate cylinder line number of 175 was used. The achromatic layer was formed by printing solid achromatic ink once on a multilayer stretched film 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.

[Comparative Example 1]
The packaging material according to Comparative Example 1 corresponds to the form in which the barrier coating layer is not provided with respect to the packaging material according to Example 1. That is, the packaging material according to Comparative Example 1 is obtained by joining a multilayer stretched film not formed with a barrier coat layer and a sealant layer using a dry laminating method shown in FIG. The multilayer stretched film and the sealant layer of the packaging material according to Comparative Example 1 were the same as the multilayer stretched film and the sealant layer of the packaging material according to Example 1 in the materials and the forming method.

(Evaluation results of gas barrier properties and vapor barrier properties)
Table 1 shows the evaluation results of gas barrier properties and vapor barrier properties of the packaging materials according to Examples 1, 2, 3 and Comparative Example 1 obtained above. Among these, the gas barrier property was measured with a measuring instrument for measuring oxygen permeability [model name, OXTRAN] manufactured by MOCON, USA under the conditions of a temperature of 23 ° C. and a humidity of 90% RH. On the other hand, with regard to the vapor barrier property, a measuring device for measuring water vapor transmission rate (model name, PERMATRAN) manufactured by MOCON, USA, under the conditions of a temperature of 40 ° C. and a humidity of 90% RH. It was measured.

  As understood from Table 1, the packaging materials according to Examples 1 to 3 were able to sufficiently obtain gas barrier properties and vapor barrier properties. On the other hand, the packaging material according to Comparative Example 1 could hardly obtain the gas barrier property, but could obtain the vapor barrier property to some extent.

DESCRIPTION OF SYMBOLS 1 Packaging container 2 Opening 10 Packaging material 20 Base material layer 21 Picture layer 22 Base material 30 Light shielding layer 31 Light shielding printing layer
32 Achromatic layer 33 White solid layer 40 Barrier layer 41 Multilayer stretched film 42 Barrier coat layer 43 First polyester resin layer 44 Polyamide resin layer 45 Second polyester resin layer 50 Sealant layer 60 Bonding layer

Claims (9)

A multilayer stretched film including at least a first polyester resin layer and a polyamide resin layer;
A barrier coat layer laminated on the multilayer stretched film;
A packaging material comprising:   The first polyester-based resin layer of the multilayer stretched film and the polyamide-based resin layer of the multilayer stretched film from the outer side to the inner side of the container when the bag is made into a container The packaging material according to claim 1, wherein the barrier coat layer is laminated in this order. The multilayer stretched film further includes a second polyester resin layer,
The packaging material according to claim 1 or 2, wherein the polyamide-based resin layer is disposed between the first polyester-based resin layer and the second polyester-based resin layer. The packaging material according to any one of claims 1 to 3, wherein the barrier coat layer contains a barrier coat agent in a range of 0.1 g / m ^{2 to} 10 g / m ² . A sealant layer is further provided on the innermost side when making a bag into a container,
The packaging material according to any one of claims 1 to 4, wherein the sealant layer includes an unstretched polypropylene layer or a linear low-density polyethylene layer. A sealant layer is further provided on the innermost side when making a bag into a container,
The sealant layer includes a linear low density polyethylene layer, and a 6/12 nylon layer located outside the linear low density polyethylene layer when the bag is made into a container,
The said packaging material is a packaging material as described in any one of Claims 1 thru | or 4 based on FDA regulation 21CFR1777.1390 (c). A sealant layer is further provided on the innermost side when making a bag into a container,
The sealant layer includes a linear low density polyethylene layer, and a 6/12 nylon layer located outside the linear low density polyethylene layer when the bag is made into a container,
The said packaging material is a packaging material as described in any one of Claims 1 thru | or 4 based on FDA regulation 21CFR1777.1395 (b). A sealant layer is further provided on the innermost side when making a bag into a container,
The sealant layer includes a linear low density polyethylene layer, and a 6/69 nylon layer positioned outside the linear low density polyethylene layer when the bag is made into a container,
The said packaging material is a packaging material as described in any one of Claims 1 thru | or 4 based on FDA regulation 21CFR1777.1395 (b).   The packaging material according to any one of claims 1 to 8, further comprising a light-shielding printing layer formed by printing ink.

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