JP2022104135A - Flexible packaging material sheet, package - Google Patents

Abstract

To provide a flexible packaging material sheet that is unlikely to cause defect such as misalignment, blurring, and dropping in a printed image even when a force such as friction or impact is applied through a surface protective layer, or when it is greatly deformed in water, in a flexible packaging material sheet including at least the surface protective layer, a printing ink layer, a barrier layer made of a metal foil, and a sealant layer.SOLUTION: A printing anchor coat layer 12 containing a saturated copolymerized polyester resin having a glass transition temperature of -30 to 60°C is interposed between a printing ink layer 11 and a barrier layer 13.SELECTED DRAWING: Figure 1

Description

The present invention relates to a soft packaging material sheet and a package body in which a bag-shaped container made of the soft packaging material sheet is filled with contents.

Conventionally, products such as foods, pharmaceuticals, and chemicals that require long-term storage have been stored in a molded container with an upper opening and then heat-sealed with a lid material as a solid package, or in the form of a bag made of various flexible packaging material sheets. It is distributed in the market as a package sealed in a container (flexible packaging container).

As the flexible packaging material sheet, for example, Patent Document 1 describes a sheet including at least a surface protective layer, a barrier layer made of an aluminum foil, and a sealant layer made of a heat-sealing resin film. Also, in the same document, as a package, after processing this sheet into a rectangular shape, it is folded in half so that the sealant layer is on the inside, and the left and right edges are side-sealed to create a bag-shaped container with an upper opening. Therefore, an embodiment in which the contents are stored in this container and the opening is top-sealed is disclosed.

Japanese Unexamined Patent Publication No. 2019-199268

By the way, on the surface of the package, a printing ink layer may be provided on the upper surface side of the barrier layer of the flexible packaging material sheet for displaying information on the contents or decorating a design such as an advertisement. .. However, depending on the storage environment and usage conditions of the flexible packaging material sheet and the packaging material using the flexible packaging material sheet, defects such as misalignment, blurring, and dropping may occur in the printed image (hereinafter, may be simply abbreviated as printing defects). This printing defect is also caused by the moisture that comes into contact with the surface of the flexible packaging material sheet or the flexible packaging material.

For example, when the contents are foods, pharmaceuticals, chemicals, etc. that are easily deteriorated or deteriorated even at room temperature, the package is stored at a low temperature of about 10 ° C. or lower. At this time, if the humidity is high, dew condensation occurs on the surface of the package, and the dew condensation water permeates the inside of the flexible packaging material sheet over time and also penetrates into the interface between the printing ink layer and the barrier layer, so that both layers are formed. There may be a situation where the adhesion of the material is reduced. As a result, when the package is transported by a belt conveyor after storage, packed in a cardboard box, or displayed at the store after unpacking, the surface of the package is subject to strong friction, impact, or other external force. If the cardboard is significantly deformed, the printing defect may occur on the surface thereof, and the appearance is impaired. Therefore, in the flexible packaging material sheet constituting the flexible packaging body, it is ideal that the printing defects due to external force, deformation, etc. do not occur even in a stress or water.

Based on the above idea, the present inventor is a flexible packaging material sheet including at least a surface protective layer, a printing ink layer, a barrier layer made of a metal foil, and a sealant layer, and the surface protective layer is subjected to friction or impact. It is an object of the present invention to provide a printing ink layer that is less likely to have printing defects such as misalignment, blurring, and dropping even when an external force such as the above is applied or the printing ink layer is deformed while being immersed in water for a certain period of time. I set it as an assignment.

As a result of the study, the present inventor comprises forming the surface protective layer of the flexible packaging material sheet with an overprint coating agent, interposing a printing anchor coating layer between the printing ink layer and the barrier layer, and forming this layer. By using a saturated copolymerized polyester resin having a glass transition temperature in a predetermined range as an anchor coating agent for forming the above, it has been found that the printing defects are less likely to occur in this flexible packaging material sheet, and the present invention has been completed. That is, the present invention relates to the flexible packaging material sheet and the package shown below.

1) A soft packaging material sheet used to produce a package in which the contents are stored in a bag-shaped container. The soft packaging material sheet includes an overprint coat layer and a printing ink layer in this order from the outside. A printed anchor coat layer, a barrier layer made of a metal foil, and a sealant layer made of a heat-sealing resin are provided at least, and the anchor coating agent constituting the printed anchor coat layer is -30 ° C to 60 ° C. A flexible packaging material sheet comprising a saturated copolymerized polyester resin having a glass transition temperature of.

2) The soft packaging material sheet of 1), wherein the overcoat agent forming the overprint coat layer is made of a cellulosic overcoat agent.

3) The soft packaging material sheet of 1) or 2) in which a reinforcing layer made of a synthetic resin film is arranged between the barrier layer and the sealant layer.

4) A sealed package in which the contents are stored in a bag-shaped container made of the soft packaging material sheet according to any one of 1) to 3), and then the opening edge of the bag-shaped container is heat-sealed.

In the flexible packaging material sheet of 1), the surface protective layer is composed of an overprint coating agent, and the printing anchor coating layer interposed between the printing ink layer and the barrier layer has a glass transition temperature of -30 ° C to 60 ° C. It is characterized by being formed with an anchor coating agent made of a saturated copolymerized polyester resin, even when an external force such as friction or impact is applied to the surface protective layer or when it is deformed after being immersed in water for a certain period of time. , Printing defects such as misalignment, blurring, and dropping are unlikely to occur in the printing ink layer.

In the soft packaging material sheet of 2), the overprint coat layer is made of a cellulosic overcoat agent and has high water resistance. Therefore, printing defects are less likely to occur in the package made of this soft packaging material sheet.

In the soft packaging material sheet of 3), a reinforcing layer made of a synthetic resin film is arranged between the barrier layer and the sealant layer, and the overall strength is enhanced by this reinforcing layer, so that the soft packaging material is used. Printing defects are less likely to occur in a package made of a sheet. Further, the reinforcing layer enhances the so-called dead hold property of the flexible packaging material sheet, and there is almost no return even when folded for processing, so that it is easy to manufacture a bag-shaped container having a complicated shape.

The package of 4) is a sealed product in which the contents are stored in a bag-shaped container made of the soft packaging material sheet according to any one of 1) to 3), and then the opening edge of the bag-shaped container is heat-sealed. Even if external force such as friction or impact force or large deformation is applied after water comes into contact with the surface, the printing defect is unlikely to occur, and the effect is particularly good in the soft packaging material sheet of 2). .. In addition, among the packages in 4), those using the soft packaging material sheet in 3) have the overall strength of the soft packaging material sheet enhanced by a predetermined reinforcing layer and are also excellent in dead hold. , The print defect prevention property is further improved, and the form retention property is also excellent.

It is sectional drawing of the flexible packaging material sheet of this invention. It is a perspective view of the bag-shaped container which concerns on this invention. It is a perspective view of the package body of this invention, and is the sectional view of the opening. It is a conceptual diagram of a print defect evaluation apparatus.

Hereinafter, the flexible packaging material sheet (1) according to the present invention, a bag-shaped container (2) made of the same, and a package (3) filled with the contents (C) thereof will be described through FIGS. It will be explained in detail. However, these drawings do not limit the scope of the present invention.

FIG. 1 is a cross-sectional view of the flexible packaging material sheet (1).
The embodiment of FIG. 1 (a) is an overprint coat layer (10) which is the outermost layer, a printing ink layer (11), a printing anchor coat layer (12), a barrier layer (13), and an adhesive layer (14). ), A reinforcing layer (15), an inner surface side anchor coat layer (16), and an innermost sealant layer (17). In this aspect, the printing ink layer (11) is an intermittent layer, and the overprint coat layer (10) is partially adhered to the print anchor coat layer (12). The adhesive layer (14), the reinforcing layer (15), and the inner surface side anchor coat layer (16) are optional and can be omitted.
The embodiment of FIG. 1 (b) is an embodiment in which the printing ink layer (11) is made into a continuous layer in the flexible packaging material sheet (1) of FIG. 1 (a).
The embodiment of FIG. 1 (c) is an embodiment in which the reinforcing layer (15) and the inner surface side anchor coat layer (16) are omitted in the flexible packaging material sheet (1) of FIG. 1 (b).

The overprint coat layer (10) is a protective layer and a water resistant layer of the flexible packaging material sheet (1). The overprint coat layer (10) makes it difficult for water in contact with the surface of the package (3) to reach the printing ink layer (12), and the surfaces of the flexible packaging material sheet (1) and the package (3). It is possible to prevent printing defects in the printing ink layer (12) due to external force or deformation applied to the printing ink layer, and it is also possible to prevent defects such as cracks and pinholes in the barrier layer (13) caused by them.
The overprint coat layer (10) is composed of various known overcoat agents. This overcoat agent is a composition obtained by dissolving various known binder resins in a solvent, and may include a curing agent (described later) and other functional additives (described later).
Examples of the binder resin include at least one selected from the group consisting of animal-based overcoating agents such as shellac resin, synthetic resin-based overcoating agents, and cellulose-based overcoating agents. Examples of the synthetic resin-based overcoat agent include epoxy resin, polyurethane resin, chlorinated polyolefin resin, acrylic resin, vinyl chloride-vinyl acetate copolymer, polyester resin (unsaturated copolymerized polyester resin, saturated copolymerized polyester resin, etc.). ) Etc. can be mentioned. Examples of the cellulosic overcoat agent include nitrocellulose, cellulose acetate, cellulose propionic acid, acetic acid / cellulose butyrate and the like. Among these, cellulosic overcoating agents are preferable, and nitrocellulose and / or cellulose acetate are particularly preferable, because they have good water resistance and are excellent in preventing printing defects.
Examples of the solvent include toluene, xylene, acetone, methyl ethyl ketone, ethyl acetate, butyl acetate, methanol, ethanol, isopropyl alcohol and the like (hereinafter, the same applies to the solvent).
Examples of the curing agent include polyisocyanate, polyepoxy compound, polyoxazoline compound, ketimine compound, melamine compound and the like (hereinafter, the same applies to the term curing agent).
The overprint coat layer (10) can be formed by applying an overcoat agent to the printing ink layer (11) and usually drying at 80 to 170 ° C. The amount of coating is not particularly limited, and may be, for example, usually 0.3 to 1 g / m ² , preferably 0.4 to 0.7 g / m ² .
The number of layers of the overprint coat layer (10) is not limited, and may be a single coat or a multi-coat having two or more layers. The multi-coat may be composed of the same type of overcoat agent, or may be composed of two or more types of overcoat agents.
The thickness of the overprint coat layer (10) is also not particularly limited, and is usually 0.3 to 2 μm, preferably 0.4 to 1.5 μm, considering the strength as a protective layer and the barrier function as a water resistant layer. Just do it.

The printing ink layer (11) is a layer that gives information on the contents (C) and a design to the surfaces of the flexible packaging material sheet (1), the bag-shaped container (2), and the package (3). It is composed of known printing inks.
The printing ink is a composition containing a coloring material and a binder resin, and examples thereof include an active energy ray non-curable type and a curable type.
Examples of the coloring material include pigments and / or dyes. Pigments include, for example, titanium dioxide, zinc flower, gloss white, parite, barium carbonate, calcium carbonate, precipitated silica, aerodyl, talc, alumina white, mica, synthetic calcium silicate, magnesium carbonate, barium carbonate, carbon black, magnesium and Examples thereof include organic or inorganic pigments such as red iron oxide. The size of the pigment is not particularly limited, and for example, the average primary particle size may be usually 0.1 to 5 μm, preferably 0.5 to 3 μm. On the other hand, examples of the dye include anthraquinone dyes, azo dyes, quinoline dyes and the like. The content of the coloring material is not particularly limited, and may be usually 0.5 to 40% by weight, preferably 2 to 10% by weight.
Examples of the binder resin include an active energy ray non-curable binder resin and / or an active energy ray curable binder resin. Examples of the former binder resin include shellac resin, nitrocellulose, cellulose acetate, cellulose propionate and acetic acid / butyrate cellulose, epoxy resin, polyurethane resin, chlorinated polyolefin resin, polyamide resin, acrylic resin, vinyl chloride-vinyl acetate copolymer. And polyester resin (unsaturated copolymerized polyester resin, saturated copolymerized polyester resin, etc.) and the like. On the other hand, examples of the latter binder resin include various known di (meth) acrylates, tri (meth) acrylates and tetra (meth) acrylates, and (meth) acrylates having 5 to 6 (meth) acryloyl groups in the molecule. Poly (meth) acrylates can be mentioned. The poly (meth) acrylates include various known modified poly (meth) acrylates such as urethane (meth) acrylate, epoxy (meth) acrylate and polyester (meth) acrylate. Examples of the active energy ray include ultraviolet rays and electron beams.
The printing ink may optionally include a solvent, a curing agent, a polymerization initiator, and other additives. When the binder resin is an active energy ray-curable type, various known (meth) acrylates can be included in the solvent as a reactive diluent. Examples of the polymerization initiator include photopolymerization initiators such as benzophenone-based initiators, acetophenone-based initiators and benzoin-based initiators. Examples of the additive include a surfactant, a plasticizer, a silane coupling agent, an antistatic agent and the like.
The printing ink layer (11) can be formed by a known printing method such as gravure printing, offset printing, flexographic printing, etc., and may be monochromatic printing or multicolor printing.
The thickness of the entire printing ink layer (11) is not particularly limited, and may be usually 0.5 to 4 μm, preferably 0.8 to 3 μm, for example, from the viewpoint of preventing printing defects.

The print anchor coat layer (12) is a layer for joining the printing ink layer (11) and the barrier layer (13), and the overprint coat layer (10) is formed by interposing the print anchor coat layer (12) between both layers. ), Even if the water in contact with the surface of the printing ink layer (11) reaches the printing ink layer (11), the adhesion between the printing ink layer (11) and the barrier layer (13) is unlikely to decrease. Therefore, when external forces such as friction and impact are applied to the surfaces of the flexible packaging material sheet (1), bag-shaped container (2), and package (3), or they are excessively deformed in water. However, it is considered that the printing defect is less likely to occur.
The anchor coating agent (hereinafter, also referred to as the outer surface side anchor coating agent) constituting the printed anchor coating layer (12) is a saturated copolymer polyester resin having a glass transition temperature (JIS K7121-2012) of -30 ° C or higher and 60 ° C or lower. Containing the solvent.
The saturated copolymerized polyester resin can be produced by various known methods. Examples of the constituent raw materials include polyols, polycarboxylic acids, hydroxycarboxylic acids, lactones and unsaturated monomers. Examples of the polyol include aliphatic, alicyclic to aromatic diols such as ethylene glycol, propylene glycol, butanediol, neopentyl glycol, diethylene glycol, polyethylene glycol, cyclohexanedimethanol, bisphenol A and bisphenol A-alkylene oxide adduct. Examples thereof include tri-tetraols such as glycerin, trimethylolpropane, trimethylolethane, pentaerythritol, diglycerin, trimethylolpropane and trimethylolethane. Examples of the polycarboxylic acid include aliphatic, alicyclic or aromatic polycarboxylic acids such as terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, cyclohexanedicarboxylic acid, adipic acid, azelaic acid, sebacic acid, maleic acid, maleic anhydride and fumaric acid. Examples thereof include group dicarboxylic acids, and tri-tetracarboxylic acids such as trimellitic acid, trimellitic anhydride, pyromellitic acid and pyromellitic anhydride, which may be alcohol esters. Examples of the alcohol include methanol, ethanol, butanol and the like. Examples of the hydroxycarboxylic acid include p-hydroxybenzoic acid, p-hydroxyethoxybenzoic acid, citric acid, isocitric acid, malic acid, tartaric acid and the like, and two or more of them can be used in combination. Examples of the lactone include β-butyrolactone, δ-valerolactone, ε-caprolactone and the like. Examples of unsaturated monomers (graft monomers) include acrylic acid, methacrylic acid, maleic acid, fumaric acid and the like.
When the glass transition temperature of the saturated copolymerized polyester resin is less than -30 ° C, the printed anchor coat layer (12) becomes too soft, and when it exceeds 60 ° C, the printed anchor coat layer (12) becomes too hard. However, printing defects in the printing ink layer (12) tend to occur strongly, especially when the flexible packaging material sheet (1) is treated in water. From this point of view, the glass transition temperature is preferably -20 ° C or higher and 40 ° C or lower.
The glass transition temperature of the saturated copolymerized polyester resin can be adjusted by various known means. For example, from the viewpoint of the constituent raw materials, if it is desired to lower the glass transition temperature, an aliphatic polyol and / or an aliphatic polycarboxylic acid may be selected. Further, when it is desired to raise the glass transition temperature, tri to tetraol and tri to tetracarboxylic acid can be selected. The glass transition temperature can also be adjusted by adjusting the molecular weight of the saturated copolymerized polyester resin. Specifically, the molecular weight may be a number average molecular weight (polystyrene conversion value in the gel permeation chromatography method) and is usually 8000 to 20000. Examples of the means for adjusting the molecular weight include a method in which the polycondensation reaction is carried out under reduced pressure.
The outer surface side anchor coating agent may be either a one-component curing type or a two-component curing type, and may include the curing agent.
The outer surface side anchor coating agent may contain a functional additive. For example, if a surfactant is included, the surface tension of the printing anchor coat layer (12) can be adjusted, and for example, printing omission (non-printing portion of printing ink) can be avoided. In addition, if a plasticizer is included, the hardness of the printing anchor coat layer (12) can be adjusted, and it is possible to prevent the printing from blurring and falling off. Further, when the silane coupling agent is included, the adhesion between the print anchor coat layer (12) and the barrier layer (13) is improved, and as a result, printing defects can be prevented. Examples of the surfactant include anionic surfactants, cationic surfactants, amphoteric surfactants and nonionic surfactants. Examples of the plasticizer include an adipic acid alkyl ester, a phosphoric acid alkyl ester, and a trimellitic acid ester alkyl as an aliphatic dicarboxylic acid alkyl ester. Examples of the silane coupling agent include γ-chloropropyltrimethoxysilane, vinyltrichlorosilane, vinyltriethoxysilane, vinyl-tris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, and β- (3, 4-Epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane and the like can be mentioned. The content of the additive is not particularly limited, and may be usually 0.1 to 4% by weight.
The printed anchor coat layer (12) can be formed by applying an outer surface side anchor coat agent to one side of the barrier layer (13) and drying it at, for example, 70 to 90 ° C. The amount of coating is not particularly limited, and may be, for example, usually 1 to 5 g / m ² , preferably 2 to 4 g / m ² .
The print anchor coat layer (12) can suitably prevent printing defects when the contact angle of water is usually 65 to 80 °, preferably 70 to 78 °. This contact angle is a measured value after 30 seconds have passed by dropping 1 μL of water on the surface of the printed anchor coat layer (12), and can be measured by various known water contact angle meters.
The thickness of the print anchor coat layer (12) is not particularly limited, and is usually 0.5 to 3 μm, preferably 0.5 to 3 μm in consideration of print defect prevention and adhesion between the print ink layer (11) and the print anchor coat layer (12). May be 0.8 to 2 μm.

The barrier layer (13) is a layer for protecting the content (C) of the package (3) from gas, water vapor, light, etc., and is composed of a metal foil.
Examples of the metal foil include aluminum foil, iron foil, stainless steel foil, copper foil, nickel foil and the like, and aluminum foil is suitable in consideration of barrier function, moldability, cost and the like. Examples of the aluminum foil include pure aluminum foil and aluminum alloy foil, and soft material (O material) is preferable, and in particular, O material of 1000 series aluminum alloy foil or O material of 8000 series aluminum alloy foil specified by JIS H 4160. Is preferable.
When the metal foil has an appropriate surface roughness, the adhesion between the print anchor coat layer (12) and the barrier layer (13) is improved, and printing defects are less likely to occur. The surface roughness may be, for example, an arithmetic average roughness Ra (JIS B0601-2013) of 0.05 μm to 1 μm.
An underlayer (not shown) made of a predetermined chemical conversion treatment liquid can be formed on the outer surface and / or the inner surface of the metal foil. Examples of the chemical conversion treatment liquid include a water-alcohol solution containing phosphoric acid, a chromium-based compound, a fluorine-based compound and / or a binder resin. Chromic acid and / or chromium (III) salt as the chromium-based compound, metal salt of fluoride and / or non-metal salt of fluoride as the fluorine-based compound, acrylic resin, chitosan derivative resin and chitosan derivative resin as the binder resin. Examples thereof include at least one kind of resin selected from the group consisting of phenolic resins. The amount of the chemical conversion treatment liquid used is not particularly limited, and usually, the amount of chromium adhered to one side of the metal foil may be in the range of 0.1 to 50 mg / m ² .
The thickness of the barrier layer (13) is not particularly limited, but is usually 6 to 50 μm, preferably 10 to 10 in consideration of the balance between the strength of the entire flexible packaging material sheet (1) and the print defect prevention property and the dead hold property. It may be 35 μm.

The adhesive layer (14) is any layer used to prevent delamination between the barrier layer (13) and the sealant layer (17). For example, when the reinforcing layer (15) is provided on the flexible packaging material sheet (1), the reinforcing layer (15) is bonded to the barrier layer (13) via the adhesive layer (14), so that the flexible packaging material sheet (15) is provided. 1) The overall strength is increased, which in turn leads to the prevention of printing defects.
The adhesive layer (14) is composed of various known adhesives. Specific examples thereof include vinyl chloride-vinyl acetate copolymer adhesives, polyester resin adhesives (unsaturated copolymerized polyester resins, saturated copolymerized polyester resins, etc.), polyurethane resin adhesives, and the like. Among them, a polyurethane resin-based adhesive, particularly a two-component curable polyurethane resin-based adhesive, is preferable in terms of adhesion between the barrier layer (13) and the adhesive layer (14).
As the two-component curable polyurethane resin-based adhesive, a two-component curable polyether-urethane resin-based adhesive and / or a two-component curable polyester-urethane resin-based adhesive are particularly suitable. All of these are composed of a main agent and a curing agent, and examples thereof include various known polyether polyols and / or polyester polyols, and various known polyisocyanates can be used as the curing agent. Examples of the polyisocyanate include hexamethylene diisocyanate, isophorone diisocyanate, rearranged isocyanate and diphenylmethane diisocyanate, and derivatives thereof (isocyanurate form, biuret form, adduct form, etc.).
The thickness of the adhesive layer (14) is not particularly limited, but is usually 1 to 5 μm, preferably 2 to 3.5 μm in consideration of the preventive effect of delamination and the like.

The reinforcing layer (15) is an arbitrary layer for improving the print defect prevention property and the dead hold property by increasing the overall strength of the flexible packaging material sheet (1), and is composed of various known synthetic resin films. do.
The synthetic resin film may be either a stretched type or a non-stretched type, and examples thereof include a polyamide film, a polyolefin film and a polyester film. Examples of the polyamide film include a 6-nylon film and the like. Examples of the polyolefin film include high-density polyethylene film, medium-density polyethylene film, linear low-density polyethylene film, homopolypropylene film, poly (ethylene-propylene) random copolymer film, polyethylene-polypropylene block copolymer film, and the like. These may be acid-modified with maleic anhydride, vinyl acetate or the like. Examples of the polyester film include polyethylene terephthalate film, polybutylene terephthalate film, polyethylene naphthalate film, and polybutylene naphthalate film.
Of the synthetic resin films, the polyester film increases the overall strength of the flexible packaging material sheet (1), so when the flexible packaging material sheet (1), bag-shaped container (2), and package (3) are significantly deformed. In addition, printing defects are less likely to occur, and the dead hold property of the flexible packaging material sheet (1) is also improved. From this point of view, the stretched polyester film is particularly preferable as the polyester film.
The thickness of the reinforcing layer (15) is not particularly limited, but may be usually 10 to 50 μm, preferably 10 to 35 μm from the viewpoint of prevention of printing defects and dead hold.

The inner surface side anchor coat layer (16) is an arbitrary layer used for the purpose of adhering the reinforcing layer (15) and the sealant layer (17), and an anchor coat agent (hereinafter, inner surface side anchor coat agent) that achieves this purpose. Also referred to as), various known substances can be used without particular limitation.
As the inner surface side anchor coating agent, specifically, a polyester resin-based anchor coating agent and / or an adhesive can be used. The former anchor coating agent may be either a one-component curing type or a two-component curing type, and is useful when the sealant layer (17) is composed of a hot melt adhesive described later, for example, a printed anchor coating layer. The same as the outer surface side anchor coating agent forming (12) can be used. Further, the latter adhesive is useful when the sealant layer (17) is composed of a heat-sealing resin film described later, and for example, the same adhesive as the adhesive forming the adhesive layer (14) is particularly cured by two liquids. A type polyether-urethane resin adhesive and / or a two-component curable polyester-urethane resin adhesive can be preferably used.
The thickness of the inner surface side anchor coat layer (16) is not particularly limited, but is usually 1 to 5 μm, preferably 2 to 3.5 μm from the viewpoint of adhesion to the sealant layer (17).

The sealant layer (17) is a layer that constitutes the innermost surface of the flexible packaging material sheet (1) and also constitutes the inner surface of the package (3), and is a layer that constitutes various known hot melt adhesives and / or heat. It is made of a fusion resin film.

Examples of the hot melt adhesive include a composition containing a base resin, a wax and a tackifier resin. Examples of the base resin include a polyolefin resin and an ethylene vinyl acetate copolymer, and examples of the polyolefin resin include high-density polyethylene, medium-density polyethylene, linear low-density polyethylene, homopolypropylene, and poly (ethylene-propylene) random copolymer. And polyethylene-polypropylene block copolymer and the like. Examples of the vinyl acetate copolymer include ethylene, ethyl acrylate, and vinyl acetate copolymer. Examples of the tackifier resin include rosins such as rosin, disproportionated rosin, hydrocarbon rosin and polymerized rosin, esters of rosins with polyhydric alcohols such as glycol, glycerin and pentaerythritol, and terpenes and /. Alternatively, a hydrocarbon resin or the like having styrene or the like as a constituent monomer can be mentioned. Examples of the wax include polyethylene wax, polypropylene wax, silicon-based wax (silicone wax), fluorine-based wax, and amide-based wax.
Examples of the means for forming the sealant layer (17) with the hot melt adhesive include a hot applicator and a gravure coater.

The heat-fusing resin film may be either a non-stretchable type or a stretched type, and examples of the heat-fusing resin forming this film include polyolefin resin, polyester resin, polyvinyl resin, polysulfone resin and the like. .. Examples of the polyolefin resin include polypropylenes such as homopolypropylene, block polypropylene, random polypropylene and acid-modified polypropylene, polyethylenes such as low-density polyethylene, linear low-density polyethylene and high-density polyethylene, and poly (ethylene-propylene). Examples thereof include polyethylene and propylenes such as random copolymers and polyethylene-polypropylene block copolymers. Examples of the polyester resin include polyethylene terephthalate resin and polybutylene terephthalate resin. Examples of the polyvinyl resin include polystyrene resin and the like.
The heat-sealing resin film may be a single layer or a multilayer. The multilayer heat-sealing resin film may be a combination of two or more single-layer heat-sealing resin films of the same resin type, and two or more single-layer heat-sealing resin films of different resin types are combined. It may be a plastic one. Specifically, a multilayer film formed by co-extruding one or more of the heat-sealing resins, or a multilayer film made of, for example, polypropylenes and a polyvinyl resin, in any order. Sealant film can be mentioned.
The heat-bondable resin film preferably has a mode in which it can be aggregated and peeled off when the package (3) is opened (see FIG. 3 (c)). As such, for example, a low-density polyethylene resin film is preferable, and an additive-free one is particularly preferable.

The thickness of the sealant layer (17) is not particularly limited, but is usually 10 to 60 μm, preferably 24 to 45 μm in consideration of sealing accuracy and sealing strength.

The flexible packaging material sheet (1) can be produced by various known methods such as a dry laminating method, a melt extrusion laminating method, a heat laminating method, and a gravure coating method. These methods may be combined.

The package (3) of the present invention is obtained by storing the content (C) in a bag-shaped container (2) processed from a flexible packaging material sheet (1) and then sealing it with a heat seal.

The bag-shaped container (2) has an opening (21), an opening edge (22) and a body (23). The body portion (23) constitutes a storage portion by sealing the peripheral edge thereof with at least one linear sealing portion (24).

FIG. 2 is a perspective view of the bag-shaped container (2).
The bag-shaped container (2) of FIG. 2 (a) is obtained by folding a rectangular flexible packaging material sheet (1) in the horizontal direction so that the sealant layer (17) is on the inside. This is an embodiment in which a total of two linear seal portions (24) are provided on the side and the bottom.
The bag-shaped container (2) in FIG. 2 (b) is obtained by folding a rectangular flexible packaging material sheet (1) in the vertical direction so that the sealant layer (17) is on the inside. This is an embodiment in which a total of two linear seal portions (24) are provided on both sides.
In the bag-shaped container (2) of FIG. 2 (c), two rectangular soft packaging material sheets (1) having the same dimensions are laminated so that the sealant layers (17) face each other. This is an embodiment in which a total of three linear seal portions (24) are provided on the side and the bottom.
The bag-shaped container (2) in FIG. 2 (d) has two air chambers by providing a linear seal portion (24) in the center of the width of the bag-shaped container (2) in FIG. 2 (c). It is an aspect.
The bag-shaped container (2) in FIG. 2 (e) is an aspect of a gusset bag, in which both sides are folded inward and a gasp-shaped linear seal portion (gassho-type linear seal portion) is attached to the body portion (23) on the back side. 24) is provided.
The bag-shaped container (2) in FIG. 2 (f) is an aspect of a standing pouch, and a bottom portion (25) that enables self-reliance is formed at the bottom portion.
The above are all examples, and in each embodiment, the shape of the entire container and the number and shape of the storage portions are not limited.

An aspect of the manufacturing method is shown by taking the bag-shaped container (2) of FIG. 2 (f) as an example. First, one bellows folding portion in the horizontal direction is formed in the central portion of the vertical length of the rectangular flexible packaging material sheet (1) cut to a predetermined size. A central valley fold is formed in this bellows fold, and one mountain fold and one valley fold are formed on the upper side of this central valley fold with the same width, and below this central valley fold. On the side, one mountain fold and one valley fold are formed with the same width. Next, the soft packaging material sheet (1) is split in half at the central valley fold line so that the sealant layer (17) is on the inside. Next, the linear seal portion (24) is formed by heat-sealing both sides of the soft packaging material sheet (1) folded in half in this way. Then, by opening the middle split portion to the left and right, a three-way bag-shaped container (2) as shown in FIG. 2 (f) can be obtained.

The package (3) is a sealed body formed by filling the storage portion of the bag-shaped container (2) with the contents (C) and then heat-sealing (linearly sealing) the opening edges (23) to each other. ..

The content (C) is not particularly limited, and examples thereof include foods and non-foods. Examples of foods include cream cheese, butter, jelly, sheep can, pudding, miso, curry and pasta sauce, juice, dressing and the like. Examples of non-food products include industrial products such as glues, sealants, and clays, pharmaceuticals, and chemicals. In addition, sanitary goods such as napkins, gauze, and cotton can be sufficient for the contents (C). The content (C) is suitable for a soft material, a fluid material, or a liquid material, but is not limited to these forms.

FIG. 3 is a perspective view of the package (3) and a partial cross-sectional view of the opened portion (26) thereof.
The package (3) of FIG. 3 (a) has the bag-shaped container (2) of FIG. 2 (f) as the main body, is filled with the contents (C), and then heats the opening edges (23). It is fused. The content (C) has a flat block shape, and examples of such foods include cream cheese, butter, and jelly. This package (3) is sealed by a total of three linear sealing portions (24) on both sides and the top, and it is possible to maintain the quality of the contents (C) for a long period of time. Further, the opened portion (26) of the package (3) functions as a knob portion by bending both of the two opening edges (22) forming the package (3) inward. This picking portion may be formed after the bag-shaped container (2) is manufactured, or may be formed in advance on the flexible packaging material sheet (1).
FIG. 3 (b) is a partial cross-sectional view of the opened portion (26) of the package (3) of FIG. 3 (a) before opening. As shown in this figure, the opened portion (26) constitutes a heat fusion zone by heat-sealing the sealant layers (17) with each other. In this figure, the printing ink layer (11) is omitted for convenience.
FIG. 3 (c) shows the destruction mode of the sealant layer (17) in the process of opening the package (3) of FIG. 3 (a). This fracture mode is cohesive fracture, and easy opening is made possible by the progress of this fracture inside the layer with opening. The easy opening may be realized by the interface fracture at the heat-sealing interface between the sealant layers (17) (not shown). Further, in this figure as well, the printing ink layer (11) is omitted for convenience.
After opening, take out the contents (C) and use it for the purpose of use.

The package (3) of FIG. 3 (a) is stored in an outer box with the top seal portion and both side seal portions folded, and then refrigerated. At this time, dew condensation may occur on the surface of the package (3), but as already described, the soft packaging material sheet (1) forming the package (3) has a predetermined layer structure, and such dew water is generated. Even if the printing ink layer (11) is reached after penetrating into the inside of the overprint coating layer (10), the printing ink layer (11) is bonded to the barrier layer (13) via the printing anchor coat layer (12). Therefore, it is made more difficult to peel off or fall off than this barrier layer (13). Therefore, when the package (3) is transported or packed after refrigerated storage, even if some external force is applied to the surface, it is unlikely that defects such as blurring, misalignment, and dropping will occur in the printed image. Be done.

Hereinafter, the present invention will be described in more detail through Examples and Comparative Examples, but the technical scope of the present invention is not limited by these specific examples.

<Preparation of flexible packaging material sheet (1)>
Example 1
A one-component curable outer surface side anchor coating agent consisting of a solution of saturated copolymerized polyester resin with a glass transition temperature of -28 ° C is applied to one side of a 12 μm thick aluminum foil (A8021H-O), and the thickness after curing is approximately 1.0. A printed anchor coat layer was formed by applying with a roll coater to a thickness of μm and drying at 70 ° C. for 30 seconds. Next, a white printing ink (pigment: titanium dioxide, binder resin: vinyl chloride-vinyl acetate copolymer, hereinafter common) is applied to this printing anchor coat layer with a roll coater so that the thickness after drying is about 2.0 μm. It was applied to form a printing ink layer. Next, a nitrified cotton solution was applied to this printing ink layer with a roll coater so that the thickness after drying was about 1.0 μm, and dried at 80 ° C. for 1 minute to form an overprint coat layer.
Subsequently, a two-component curable polyester-urethane resin adhesive (hereinafter, also referred to as two-component PU) was applied to the other surface of the aluminum foil with a roll coater so that the cured thickness would be 3.0 μm. An adhesive layer was formed by drying at 100 ° C. for 1 minute. Next, a stretched polyester film having a thickness of about 12 μm (hereinafter, also referred to as PET film) was attached to this adhesive layer, and then an aging treatment was performed at 40 ° C. for 72 hours to form a reinforcing layer. Next, on this PET film, a commercially available one-component curable polyester resin-based anchor coating agent (hereinafter, also referred to as one-component AC) as an inner surface side anchor coating agent is rolled so that the film thickness after drying becomes about 3.0 μm. The inner surface side anchor coat layer was formed by applying with a coater and drying at 80 ° C. for 1 minute. Next, a hot melt adhesive (base resin: ethylene vinyl acetate copolymer, tackifier resin: rosins) (hereinafter, also referred to as HM adhesive) is applied to this anchor coat layer to a thickness of about 30 μm after cooling. The flexible packaging material sheet A1 was prepared by coating with a roll coater as described above to form a sealant layer.

Example 2
In the flexible packaging material sheet A1, the inner surface side anchor coat layer is composed of an adhesive made of two-component PU (the film thickness after curing is about 3.0 μm. The same applies hereinafter), and the sealant layer is absent with a thickness of about 30 μm. A flexible packaging material sheet A2 was produced in the same manner except that it was formed by laminating an added low-density polyethylene film (hereinafter, also referred to as LDPE film).

Example 3
The flexible packaging material sheet B was prepared in the same manner except that the printed anchor coat layer of the flexible packaging material sheet A1 was composed of a solution of a saturated copolymerized polyester resin having a glass transition temperature of 35 ° C.

Example 4
A flexible packaging material sheet C was prepared in the same manner except that the printed anchor coat layer of the flexible packaging material sheet A1 was composed of a solution of a saturated copolymerized polyester resin having a glass transition temperature of 58 ° C.

Example 5
In the flexible packaging material sheet A1, a cellulose acetate solution was used as an overcoat agent, and the outer anchor coat layer was composed of a saturated copolymerized polyester resin solution having a glass transition temperature of -28 ° C. , A flexible packaging material sheet D1 was prepared.

Example 6
In the soft packaging material sheet D1, the soft packaging material sheet D2 was produced in the same manner except that the inner surface side anchor coat layer was composed of an adhesive made of two-component PU and the sealant layer was composed of an LDPE film.

Example 7
The flexible packaging material sheet E1 was prepared in the same manner except that the printed anchor coat layer of the flexible packaging material sheet D1 was composed of a solution of a saturated copolymerized polyester resin having a glass transition temperature of -17 ° C.

Example 8
In the soft packaging material sheet E1, the soft packaging material sheet E2 was produced in the same manner except that the inner surface side anchor coat layer was composed of an adhesive made of two-component PU and the sealant layer was composed of an LDPE film.

Example 9
A flexible packaging material sheet F1 was produced in the same manner as in the flexible packaging material sheet D1 except that the printing anchor coat layer was composed of a solution of a saturated copolymerized polyester resin having a glass transition temperature of 3 ° C.

Example 10
In the soft packaging material sheet F1, the soft packaging material sheet F2 was produced in the same manner except that the inner surface side anchor coat layer was composed of an adhesive made of two-component PU and the sealant layer was composed of an LDPE film.

Example 11
A flexible packaging material sheet G1 was produced in the same manner as in the flexible packaging material sheet D1 except that the printing anchor coat layer was composed of a solution of a saturated copolymerized polyester resin having a glass transition temperature of 8 ° C.

Example 12
In the soft packaging material sheet G1 of Example 11, the soft packaging material sheet G2 is similarly formed except that the inner surface side anchor coat layer is composed of an adhesive made of two-component PU and the sealant layer is composed of an LDPE film. Was produced.

Example 13
A flexible packaging material sheet H was produced in the same manner as in the flexible packaging material sheet D1 except that the printing anchor coat layer was composed of a solution of a saturated copolymerized polyester resin having a glass transition temperature of 35 ° C.

Example 14
The flexible packaging material sheet I was prepared in the same manner except that the printed anchor coat layer of the flexible packaging material sheet D1 was composed of a solution of a saturated copolymerized polyester resin having a glass transition temperature of 57 ° C.

Comparative example 1
A flexible packaging material sheet J was prepared in the same manner except that the printed anchor coat layer of the flexible packaging material sheet A1 was composed of a solution of a saturated copolymerized polyester resin having a glass transition temperature of −34 ° C.

Comparative example 2
A flexible packaging material sheet K1 was produced in the same manner as in the flexible packaging material sheet A1 except that the printing anchor coat layer was composed of a solution of a saturated copolymerized polyester resin having a glass transition temperature of 67 ° C.

Comparative example 3
In the soft packaging material sheet K1, the soft packaging material sheet K2 was produced in the same manner except that the inner surface side anchor coat layer was composed of an adhesive made of two-component PU and the sealant layer was composed of an LDPE film.

Comparative example 4
A flexible packaging material sheet L1 was prepared in the same manner except that the printed anchor coat layer of the flexible packaging material sheet J was composed of a solution of a vinyl chloride-vinyl acetate copolymer having a glass transition temperature of 70 ° C.

Comparative example 5
In the soft packaging material sheet L1, the soft packaging material sheet L2 was produced in the same manner except that the inner surface side anchor coat layer was composed of an adhesive made of two-component PU and the sealant layer was composed of an LDPE film.

Comparative Example 6
A flexible packaging material sheet M was prepared in the same manner except that the printed anchor coat layer of the flexible packaging material sheet D1 was composed of a solution of a saturated copolymerized polyester resin having a glass transition temperature of −34 ° C.

Comparative example 7
The flexible packaging material sheet N1 was prepared in the same manner except that the printed anchor coat layer of the flexible packaging material sheet M was composed of a solution of a saturated copolymerized polyester resin having a glass transition temperature of 67 ° C.

Comparative Example 8
In the soft packaging material sheet N1, the soft packaging material sheet N2 was produced in the same manner except that the inner surface side anchor coat layer was composed of an adhesive made of two-component PU and the sealant layer was composed of an LDPE film.

Comparative Example 9
A flexible packaging material sheet O1 was prepared in the same manner except that the printed anchor coat layer of the flexible packaging material sheet M was composed of a solution of a vinyl chloride-vinyl acetate copolymer having a glass transition temperature of 5 ° C.

Comparative Example 10
In the soft packaging material sheet O1, the soft packaging material sheet O2 was produced in the same manner except that the inner surface side anchor coat layer was composed of an adhesive made of two-component PU and the sealant layer was composed of an LDPE film.

Comparative Example 11
A flexible packaging material sheet P1 was prepared in the same manner except that the printed anchor coat layer of the flexible packaging material sheet M was composed of a solution of a vinyl chloride-vinyl acetate copolymer having a glass transition temperature of 30 ° C.

Comparative Example 12
In the soft packaging material sheet P1, the soft packaging material sheet P2 was produced in the same manner except that the inner surface side anchor coat layer was composed of an adhesive made of two-component PU and the sealant layer was composed of an LDPE film.

Comparative Example 13
A flexible packaging material sheet Q1 was prepared in the same manner except that the printed anchor coat layer of the flexible packaging material sheet M was composed of a solution of a vinyl chloride-vinyl acetate copolymer having a glass transition temperature of 70 ° C.

Comparative Example 14
In the soft packaging material sheet Q1, the soft packaging material sheet Q2 was produced in the same manner except that the inner surface side anchor coat layer was composed of an adhesive made of two-component PU and the sealant layer was composed of an LDPE film.

Comparative Example 15
The flexible packaging material sheet R was produced in the same manner as in the soft packaging material sheet A1 except that the printing anchor coat layer was omitted.

The layer structure of the soft packaging material sheet of the example is shown in Table 1, and those of the soft packaging material sheet of the comparative example are shown in Table 2.

1. Evaluation of printing defects: Underwater kneading test This test is performed as follows.

(Normal temperature water treatment)
Cut out three 10 cm square test pieces from one soft packaging material sheet, and place one of them on the center of the palm of one hand. At this time, the overprint coat layer is on the upper surface. Then, put the palm of the other hand on this test piece and immerse it in water at 24 ° C while holding it between both hands. Then, in water, roll the test piece into the inside of the palm of one hand, squeeze it tightly once, deform it strongly, and then pull the fist out of the water. Then open your fingers and spread the wet test piece A1 to smooth out the wrinkles. Then, the presence or absence of peeling of the printing ink layer was visually observed mainly in the wrinkled portion. The above evaluation is also performed on the other two test pieces. The evaluation by this test is performed according to the following criteria.

○: Ratio of (number of test pieces without peeling of printing ink layer / number of soaked test pieces) = 3/3
×: Same ratio = 2/3, 1/3 or 0/3

(High temperature water treatment)
Cut out three 10 cm square test pieces from one soft packaging material sheet, immerse one of them in high temperature water at 80 ° C for 3 days, take it out at room temperature, and lightly wipe off the water adhering to the surface with a non-woven fabric. Subsequently, the same operation as the above-mentioned room temperature water treatment was performed on the test piece, and the presence or absence of peeling of the printing ink layer was visually observed mainly in the wrinkled portion. The above evaluation is also performed on the other two test pieces. The evaluation by this test is performed according to the following criteria.

⊚: Ratio of (number of test pieces without peeling of printing ink layer / number of soaked test pieces) = 3/3
○: Same ratio = 2/3
×: Same ratio = 1/3 or 0/3

The high temperature water treatment is a compulsory operation for promoting the permeation of water into the test piece.

2. Evaluation of print defects: Friction test This test is performed using the sliding test device conceptually shown in Fig. 4. This device is composed of at least a stainless steel support column 41, a stainless steel spherical member 42 (diameter 10 mm) connected to the tip thereof, and a stainless steel support base 43. Further, the spherical member 42 is covered with cotton gauze (not shown).

In this test, first, two 10 cm square test pieces are prepared from one flexible packaging material sheet. Next, one of the test pieces is placed on the support base 43, and the four sides are fixed with adhesive tape. Next, 0.5 cc of water is dropped on the surface of the overprint coat layer, and then the spherical member 42 is lightly pressed by lowering the support column 41. In that state, move the support column 41 in the left-right direction so that the reciprocating distance is 2 cm / sec, and count the number of reciprocating times when the appearance changes such as blurring on the printed surface. However, the upper limit is 30 times. Then, the print defect prevention property against the frictional force is evaluated according to the following criteria.

◯: The appearance does not change on the printed surface even if it is reciprocated 28 times or more.
Δ: The appearance changes after 25 or more and 27 or less round trips.
×: The appearance changes after 24 round trips or less.

3. Dead hold property test This test is conducted as follows. First, make a 10 cm square test piece from one soft packaging material sheet, place it side by side on a support base, fix the four sides with adhesive tape, and then cover it with a stainless steel plate (760 g) whose temperature has been adjusted to 24 ° C. Then leave it for 1 minute. Next, except for this flat plate, the degree of opening and closing of each folded sample is visually observed over 1 minute. Then, the dead hold property is evaluated based on the following criteria.

○: The folded sample does not open at all.
×: The folded sample opens even slightly.

The evaluation results of Tests 1 to 3 are shown in Table 1 for the flexible packaging material sheet of the example, and in Table 2 of the comparative example.

The soft packaging material sheet of the present invention is used as a bag-shaped container for storing foods such as cream cheese, jelly and sheep can, industrial products such as glue, sealant and clay, and other contents such as pharmaceuticals and chemicals. can.

(1) Flexible packaging material sheet: (10) Overprint coat layer, (11) Printing ink layer, (12) Printing anchor coat layer, (13) Barrier layer, (14) Adhesive layer, (15) Reinforcing layer, (16) Inner surface side anchor coat layer, (17) Sealant layer
(2) Bag-shaped container: (21) opening, (22) opening edge, (23) body, (24) linear seal, (25) bottom
(3) Package: (26) Opening part
(C) Contents

Claims (4)

A flexible packaging material sheet used to produce a package in which the contents are stored in a bag-shaped container.
The flexible packaging material sheets are placed in order from the outside.
Overprint coat layer and
With the printing ink layer,
Print anchor coat layer and
A barrier layer made of metal leaf and
A sealant layer made of heat-sealing resin and
At least have
The anchor coating agent constituting the printed anchor coating layer is characterized by containing a saturated copolymerized polyester resin having a glass transition temperature of -30 ° C to 60 ° C.
Flexible packaging material sheet. The soft packaging material sheet according to claim 1, wherein the overcoating agent forming the overprint coating layer is made of a cellulosic overcoating agent. The flexible packaging material sheet according to claim 1 or 2, wherein a reinforcing layer made of a synthetic resin film is arranged between the barrier layer and the sealant layer. A sealed package in which the contents are stored in a bag-shaped container made of the flexible packaging material sheet according to any one of claims 1 to 3, and then the opening edge of the bag-shaped container is heat-sealed.

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