JP7215082B2 - Packaging material, method for producing packaging material, packaging bag, method for producing package, and composition for forming medium layer - Google Patents

Description

TECHNICAL FIELD The present disclosure relates to a packaging material, a method for manufacturing a packaging material, a packaging bag, a method for manufacturing a package, and a composition for forming a medium layer.

BACKGROUND ART As a packaging bag for packaging food, for example, a packaging bag produced by heat-sealing a packaging material in which a base material, a barrier layer and a sealant layer are laminated is known. In general, such packaging bags are printed with characters for describing information about the contents, and decorations and the like for imparting a design to the packaging bag.

As an ink used for printing as described above, Patent Document 1 discloses a printing ink composition for lamination containing a pigment, a binder resin, a polyfunctional isocyanate compound as a curing agent, and an organic solvent, wherein the binder resin is , a polyurethane resin and a vinyl chloride vinyl acetate copolymer, wherein at least one of the polyurethane resin and the vinyl chloride vinyl acetate copolymer has a reactive group capable of reacting with the isocyanate group of the polyfunctional isocyanate compound, and the polyurethane resin and the solid content ratio of the vinyl chloride-vinyl acetate copolymer is polyurethane resin/vinyl chloride-vinyl acetate copolymer = 9/1 to 1/9, and the total of the polyurethane resin and the vinyl chloride-vinyl acetate copolymer and the solid content ratio of the curing agent is (polyurethane resin + vinyl chloride vinyl acetate copolymer): curing agent = 1: 0.2 to 0.9. It is

WO2017/022640

In the case where the packaging material filled in the packaging bag has fluidity such as a liquid seasoning, it is desirable to prevent the packaging material from scattering when the sealed package is opened. Therefore, it is desirable that the packaging bag has good tearability so that it can be torn with less force. In addition, it is conceivable to hot-pack the packing material into a packaging bag so as to make it suitable for long-term storage of the packing material. It is desirable that the change in tear strength is suppressed and maintained at a sufficiently low level.

The present disclosure is able to exhibit good tearability even when filled with a fluid package, and has sufficient tear strength even when the package is filled in a hot pack. To provide a packaging material, a method for manufacturing the packaging material, and a packaging bag capable of maintaining a low temperature. The present disclosure also provides the manufacture of a package that exhibits good tearability even when a fluid package is filled in a hot pack and that maintains a sufficiently low tear strength. The purpose is to provide a method. The present disclosure is able to exhibit good tearability even when filled with a fluid package, and has sufficient tear strength even when the package is filled in a hot pack. An object of the present invention is to provide a composition for forming a medium layer used for manufacturing a packaging material capable of maintaining a low temperature.

One aspect of the present disclosure is a packaging material comprising a substrate, a barrier layer, a medium layer, an anchor coat layer and a sealant layer in this order, the medium layer having a thickness of 2 μm or less, and the medium layer comprising: A cured product of a medium layer-forming composition containing a binder and a curing agent, wherein the binder contains polyurethane and a copolymer having a structural unit derived from vinyl chloride and a structural unit derived from vinyl acetate. , based on the total amount of the polyurethane and the copolymer, the content of the polyurethane is 60 to 70% by mass, the content of the copolymer is 30 to 40% by mass, and the curing agent is A packaging material containing an alicyclic isocyanate compound having at least two isocyanate groups in one molecule is provided.

In the packaging material, the medium layer contains a cured product of a medium layer-forming composition containing a specific binder and a specific curing agent in a specific ratio, thereby sufficiently bonding the barrier layer and the anchor coat layer. . Moreover, since the thickness of the medium layer in the packaging material is 2 μm or less, the reduction in tearability is sufficiently suppressed. Due to such action, the packaging material can exhibit good tearability even when filled with fluid packaging materials, and can exhibit good tearability even when the packaging materials are hot-packed. can also keep the tear strength sufficiently low. In the structure of a conventional packaging material, if the composition of the medium layer is adjusted to improve the tear strength, there is a concern that the medium layer will be softened and the tearability of the resulting packaging material will be reduced. However, in the packaging material described above, the decrease in tearability is sufficiently suppressed by setting the thickness of the medium layer to 2 μm or less.

In the medium layer-forming composition, the content of the curing agent may be 3 to 15% by mass based on the total amount of the binder. When the content of the curing agent is within the above range, the adhesiveness between the medium layer, the barrier layer and the anchor coat layer can be further improved, and a decrease in tearability can be suppressed.

The binder has a polyurethane having at least one functional group selected from the group consisting of a hydroxyl group, an amino group and a carboxy group, and at least one functional group selected from the group consisting of a hydroxyl group, an amino group and a carboxy group. It may contain at least one selected from the group consisting of the above copolymers. At least one of the polyurethane and the copolymer has at least one functional group selected from the group consisting of a hydroxyl group, an amino group and a carboxyl group, thereby further improving the adhesiveness between the medium layer and the anchor coat layer. can be done.

The adhesive strength of the packaging material may be 2 N/15 mm width or more. When the adhesive strength of the packaging material is within the above range, separation between the layers is less likely to occur, and the tearability when tearing the packaging material can be further improved.

The tear strength of the packaging material may be 1N or less. When the tear strength of the packaging material is within the above range, the packaging material can be torn with less force, and scattering of the packaged material when the package is opened can be more sufficiently suppressed.

The packaging material may further include an ink layer between the barrier layer and the medium layer. By providing the packaging material with an ink layer, it is possible to write information about the packaged item on the packaging material, and to impart information transmission properties, design properties, and the like to the packaging material.

One aspect of the present invention is a method for producing a packaging material comprising a substrate, a barrier layer, a medium layer, an anchor coat layer and a sealant layer in this order, wherein a medium is formed on the barrier layer of the substrate having the barrier layer. A step of contacting a layer-forming composition and a solution containing an organic solvent to form a coating film, a step of providing a composition layer by reducing the organic solvent in the coating film, heating and curing the composition layer to obtain a thickness forming a medium layer having a thickness of 2 μm or less; and providing an anchor coat layer and a sealant layer on the medium layer in this order, wherein the medium layer-forming composition contains a binder and a curing agent. , the binder contains polyurethane and a copolymer having a structural unit derived from vinyl chloride and a structural unit derived from vinyl acetate, and based on the total amount of the polyurethane and the copolymer, the content of the polyurethane The content is 60 to 70% by mass, the content of the copolymer is 30 to 40% by mass, and the curing agent contains an alicyclic isocyanate compound having at least two isocyanate groups in one molecule. To provide a method of manufacturing a packaging material.

In the method for producing the packaging material, the medium layer is formed using a medium layer-forming composition containing a specific binder and a specific curing agent in a specific ratio, so that the barrier layer and the anchor coat layer are sufficiently formed. Can be glued. In the packaging material manufacturing method described above, the medium layer is further formed so that the thickness of the medium layer is 2 μm or less, so that the deterioration of the tearability of the formed packaging material can be sufficiently suppressed. The resulting packaging material can exhibit good tearability even when filled with a fluid packaging material, and has sufficient tear strength even when the packaging material is hot-packed. can be kept low to

One aspect of the present disclosure provides a packaging bag configured by laminating laminated films, wherein the laminated film is the packaging material described above.

Since the packaging bag uses the above-described packaging material, it can exhibit good tearability even when filled with a fluid package, and can be filled with a hot pack. The tear strength can be kept sufficiently low even in the case of

The above-mentioned packaging bag may be used for hot-pack filling of objects to be packaged.

One aspect of the present disclosure includes a step of filling the accommodation portion of the above-described packaging bag with an object to be packaged in a heated state, and a step of sealing the packaging bag to obtain a package. A manufacturing method is provided.

Since the above-described packaging bag is used in the above-described method for manufacturing a package, even when a fluid package is filled in a hot pack, it exhibits good tearability and has sufficient tear strength. A package can be produced that can be kept low.

One aspect of the present disclosure is a composition for forming a medium layer containing a binder and a curing agent, wherein the binder is a copolymer having a polyurethane, a structural unit derived from vinyl chloride, and a structural unit derived from vinyl acetate. Based on the total amount of the polyurethane and the copolymer, the content of the polyurethane is 60 to 70% by mass, and the content of the copolymer is 30 to 40% by mass, Provided is a composition for forming a medium layer, wherein the curing agent contains an alicyclic isocyanate compound having at least two isocyanate groups in one molecule.

Since the composition for forming a medium layer contains a specific binder and a specific curing agent in a specific ratio, it is possible to form a medium layer capable of sufficiently adhering the barrier layer and the anchor coat layer. .

The content of the curing agent may be 3 to 15% by mass based on the total amount of the binder. By using a medium layer-forming composition having a curing agent content within the above range, the adhesiveness between the formed medium layer, the barrier layer, and the anchor coat layer can be further improved.

The binder has a polyurethane having at least one functional group selected from the group consisting of a hydroxyl group, an amino group and a carboxy group, and at least one functional group selected from the group consisting of a hydroxyl group, an amino group and a carboxy group. It may contain at least one selected from the group consisting of the above copolymers. A medium layer formed by using a medium layer-forming composition in which at least one of a polyurethane and a copolymer has at least one functional group selected from the group consisting of a hydroxyl group, an amino group, and a carboxyl group; and an anchor. Adhesiveness with the coat layer can be further improved.

According to the present disclosure, it is possible to exhibit good tearability even when a fluid package is filled, and even when the package is hot-packed, tear strength can be kept sufficiently low, a method for manufacturing the packaging material, and a packaging bag. The present disclosure also provides the manufacture of a package that exhibits good tearability even when a fluid package is filled in a hot pack and that maintains a sufficiently low tear strength. can provide a method. The present disclosure is able to exhibit good tearability even when filled with a fluid package, and has sufficient tear strength even when the package is filled in a hot pack. It is possible to provide a composition for forming a medium layer used for manufacturing a packaging material that can be maintained at a low temperature.

FIG. 1 is a schematic cross-sectional view showing an example of a packaging material. FIG. 2 is a schematic cross-sectional view showing another example of the packaging material. FIG. 3 is a perspective view showing an example of a packaging bag. FIG. 4 is a diagram showing an example of tearability sensory test results.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings as the case may be. However, the following embodiments are examples for explaining the present disclosure, and are not intended to limit the present disclosure to the following contents. Also, in the description, the same reference numerals are used for elements having the same structure or the same function, and redundant description is omitted depending on the case. In addition, unless otherwise specified, positional relationships such as up, down, left, and right are based on the positional relationships shown in the drawings. Furthermore, the dimensional ratio of each element is not limited to the ratio illustrated in the drawings.

The present disclosure provides packaging. The packaging material of the present disclosure can be used, for example, to manufacture packaging bags for filling fluid foods such as seasonings, soups, and miso soups.

FIG. 1 is a schematic cross-sectional view showing an example of a packaging material. The packaging material 100 is a laminated film having a laminated structure in which a barrier layer 2, a medium layer 4, an anchor coat layer 6, and a sealant layer 8 are provided on a substrate 10 in this order from the substrate 10 side.

The base material 10 is composed of, for example, a resin film or the like. Examples of resin films include polyester films such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyolefin films such as polypropylene (PP), polyamide films such as 6,6-nylon, polystyrene films, polycarbonate films, poly Examples include acrylonitrile films and engineering plastic films such as polyimide films. These films may be used singly or in combination of two or more. The substrate 10 may be, for example, a laminate of a PET film and a nylon film.

The resin film preferably includes polyester films such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyamide films such as 6,6-nylon, and polyolefin films such as polypropylene (PP). When the resin film contains these films, the tearability of the packaging material is excellent.

The resin film may be a stretched film. The stretched film may be, for example, a uniaxially stretched film or a biaxially stretched film. The resin film preferably contains a biaxially stretched film. When the resin film contains a biaxially stretched film, the substrate 10 is superior in mechanical strength and dimensional stability.

The thickness of the substrate 10 may be, for example, 3-50 μm, or 6-30 μm. The substrate 10 may contain at least one additive selected from, for example, fillers, antistatic agents, plasticizers, lubricants, antioxidants, and the like. The surface of the substrate 10 may be subjected to at least one treatment selected from, for example, chemical treatment, solvent treatment, corona treatment, plasma treatment, ozone treatment, and the like.

The barrier layer 2 is a layer having gas barrier properties. The barrier layer 2 may be, for example, a metal foil, a deposited film made of an inorganic substance, or the like. More specifically, the barrier layer 2 includes an aluminum foil, an aluminum vapor deposition film, an inorganic vapor deposition film such as a silica vapor deposition film and an alumina vapor deposition film, and the like. As the barrier layer 2, a silica deposition film, an alumina deposition film, or the like is preferable.

As used herein, the term "gas barrier property" means that the oxygen permeability is 10 cc/m ² ·day·atm or less. The oxygen permeability of the barrier layer 2 may be, for example, 8 cc/m ² ·day·atm or less, or 6 cc/m ² ·day·atm or less. It is preferable that the barrier layer 2 also have excellent water vapor permeability. The water vapor permeability of the barrier layer 2 may be, for example, 10 g/m ² ·day or less, 8 g/m ² ·day or 6 g/m ² ·day. As used herein, "oxygen permeability" indicates a value measured under conditions of temperature of 30° C. and relative humidity (RH) of 70% according to ASTM F1927-98 (2004). As used herein, "water vapor transmission rate" refers to a value measured under conditions of a temperature of 40°C and a relative humidity of 90% according to ASTM F1249-01.

The thickness of the barrier layer 2 may be appropriately adjusted according to the material and the like. If the barrier layer 2 comprises a metal foil, the thickness of the barrier layer 2 may be, for example, 7-9 μm. If the barrier layer 2 comprises a vapour-deposited film, the thickness of the barrier layer 2 may be, for example, 5-100 nm. The barrier layer 2 can be formed by, for example, a dry lamination method, an extrusion lamination method, a vacuum deposition method, a sputtering method, an ion plating method, a plasma vapor deposition method (CVD), or the like.

The medium layer 4 contains a cured product of the medium layer-forming composition. The medium layer 4 preferably consists of a cured product of the medium layer-forming composition. The medium layer-forming composition contains a binder and a curing agent. In addition to the above, the medium layer-forming composition further contains at least one additive selected from the group consisting of a tackifier, a cross-linking agent, a lubricant, an anti-blocking agent, an antistatic agent, a surfactant, and the like. may contain.

The binder contains polyurethane and a copolymer having structural units derived from vinyl chloride and structural units derived from vinyl acetate. The binder may contain other binders in addition to the above. Other binders may further include, for example, at least one selected from the group consisting of cellulose, acrylic resins, polyamide resins, adhesive resins, and the like.

The binder is preferably a polyurethane having at least one functional group selected from the group consisting of hydroxyl groups, amino groups and carboxy groups, or at least one functional group selected from the group consisting of hydroxyl groups, amino groups and carboxy groups. including the above copolymers having At least one of the polyurethane and the copolymer has a hydroxyl group, an amino group, or a carboxyl group, so that the adhesiveness to the anchor coat layer 6 described later can be improved. contains an isocyanate resin, the adhesion between the medium layer 4 and the anchor coat layer 6 can be further improved. The binder more preferably contains at least one of a polyurethane having at least one functional group selected from the group consisting of a hydroxyl group and an amino group and a copolymer having a hydroxyl group, more preferably consisting of a hydroxyl group and an amino group. Polyurethane having at least one selected from the group and the copolymer having a hydroxyl group are included. When at least one of the polyurethane and the copolymer has a hydroxyl group, an amino group, or a carboxyl group, it is preferable because it can react with a curing agent (for example, a polyfunctional isocyanate compound) described below.

The binders are still more preferably composed of at least one amino-terminated and at least one hydroxyl-terminated polyurethane and at least one amino-terminated and at least one hydroxyl-terminated polyurethane. Contains a polymer. By including such polyurethane and copolymer in the binder, the tearability of the packaging material 100 and the like can be further improved. The amino group is preferably at least one amino group selected from the group consisting of primary amino groups and secondary amino groups.

Polyurethane may be prepared, for example, by reacting a polyamine compound with a polymer obtained by reacting a diisocyanate compound and a polymer diol, or by reacting a diisocyanate compound and a polymer diol. A polymer prepared by reacting an amine compound having a hydroxyl group with the resulting polymer may also be used. When preparing a polymer obtained by reacting a diisocyanate compound and a high-molecular-weight diol, a low-molecular-weight diol may be used in addition to the high-molecular-weight diol.

As a method of reacting a polyamine compound or an amine compound having a hydroxyl group with a polymer obtained by the reaction of a diisocyanate compound and a polymer diol, for example, (i) the polymer is reacted with a chain extender to extend the chain. and (ii) a method of simultaneously performing chain elongation by reacting the polymer with a chain extender and stopping the reaction by reacting the polymer with a reaction terminator. etc.

Diisocyanate compounds include, for example, aliphatic diisocyanates such as hexamethylene diisocyanate (HDI), as well as tolylene diisocyanate (TDI), xylylene diisocyanate (XDI), α,α,α',α'-tetramethylxylylene diisocyanate. , and aromatic diisocyanates such as diphenylmethane diisocyanate (MDI). The diisocyanate compound may be an adduct, isocyanurate or biuret. A diisocyanate compound may be used individually by 1 type or in combination of 2 or more types. The diisocyanate compound preferably contains an aliphatic diisocyanate.

Polymeric diols include, for example, polyalkylene glycols such as polyethylene glycol and polypropylene glycol; polyether diols such as alkylene oxide adducts of bisphenol A; dibasic acids such as adipic acid, sebacic acid and phthalic anhydride, and ethylene glycol. , propylene glycol, butanediol, neopentyl glycol, and polyols such as 3-methyl-1,5-pentanediol; and ester diols such as polycaprolactone diol. These polymeric diols may be used singly or in combination of two or more. Polymeric diols preferably contain polyether diols. When the polymer diol contains a polyether diol, the solubility of the resulting polyurethane in organic solvents can be further improved.

Low-molecular-weight diols are, for example, ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 1,4-pentanediol, 2,5-hexanediol, and 3-methyl-1,5- Examples include alkanediols such as pentanediol. These low-molecular-weight diols may be used alone or in combination of two or more.

Chain extenders include, for example, aliphatic diamines such as ethylenediamine, propylenediamine, tetramethylenediamine and hexamethylenediamine, alicyclic diamines such as isophoronediamine and 4,4'-dicyclohexylmethanediamine, diethylenetriamine and triethylenetetratriamine. polyamines, aromatic diamines such as toluylenediamine and xylylenediamine, N-(2-hydroxyethyl)ethylenediamine, N-(2-hydroxyethyl)propylenediamine, and N,N'-di(2-hydroxyethyl) Diamines having a hydroxyl group such as ethylenediamine, ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 1,4-pentanediol, 2,5-hexanediol, and 3-methyl-1,5 - low-molecular-weight diols such as pentanediol; These chain extenders may be used singly or in combination of two or more.

The reaction terminator includes, for example, diamine compounds having primary amino groups at both ends, monoalkylamines such as n-propylamine and n-butylamine, dialkylamines such as N,N'-di-n-butylamine, mono Alkanolamines such as ethanolamine and diethanolamine, and monoalcohols such as ethanol are included. These reaction terminating agents may be used alone or in combination of two or more.

The compounding ratio of the diisocyanate compound and the polymeric diol may be adjusted based on the isocyanate index. The isocyanate index can be, for example, 1.2-3.0, or 1.3-2.0. When the isocyanate index is within the above range, the flexibility of the resulting polyurethane can be further improved, and the medium layer 4 can more sufficiently bond the barrier layer 2 and the anchor coat layer 6 together. As used herein, the isocyanate index is a value indicating the equivalent ratio of the concentration of isocyanate groups in a diisocyanate compound to the concentration of all active hydrogen groups (here, the concentration of hydroxyl groups) in the polymer diol.

The weight average molecular weight of the polyurethane can be, for example, 10,000-70,000, 15,000-60,000, 20,000-40,000, or 20,000-30,000. By using a polyurethane having a weight-average molecular weight within the above range, the film forming property when forming the medium layer 4 can be improved, a thinner layer can be formed, and the tearability of the resulting packaging material can be improved. can be improved. As used herein, the weight-average molecular weight means a value measured by gel permeation chromatography and expressed in terms of polystyrene.

The copolymer having structural units derived from vinyl chloride and structural units derived from vinyl acetate may further have structural units derived from other monomers. Other monomers include monomers copolymerizable with vinyl chloride and vinyl acetate. Examples of the copolymerizable monomer include vinyl alcohol, acrylates having a hydroxyl group such as hydroxyalkyl (meth)acrylate, and monomers having a carboxyl group such as acrylic acid, maleic acid and itaconic acid. These monomers may be used singly or in combination of two or more.

A copolymer having a structural unit derived from vinyl chloride and a structural unit derived from vinyl acetate preferably has a hydroxyl group. The copolymer having a hydroxyl group may be prepared, for example, by hydrolyzing (saponifying) at least a portion of the structural units derived from vinyl acetate in the copolymer, or a hydroxyalkyl (meth) ) may be prepared by copolymerization with other monomers such as acrylates.

Commercially available copolymers having structural units derived from vinyl chloride and structural units derived from vinyl acetate may be used, or those prepared separately may be used. Examples of the copolymer include Solbin series manufactured by Nissin Chemical Industry Co., Ltd. SOLBIN TAO, SOLBIN TA5R, SOLBIN M, SOLBIN ME, and SOLBIN MFK (SOLBIN and SOLBIN are registered trademarks), and the VINNOL series manufactured by Wacker Chemie AG (e.g., VINNOL E15/48A, VINNOL E22/48A, VINNOL E14 /45, VINNOL H14/36, VINNOL H40/55, and VINNOL E15/45M, etc.) may also be used.

The content of the polyurethane is 60 to 70% by mass, for example, 65 to 70% by mass, or 60 to 65% by mass, based on the total amount of the polyurethane and the copolymer. The content of the copolymer is 30 to 40% by mass, for example, 30 to 35% by mass, or 35 to 40% by mass, based on the total amount of the polyurethane and the copolymer. When the contents of the polyurethane and the copolymer are within the above ranges, the barrier layer 2 and the anchor coat layer 6 can be more sufficiently adhered by the medium layer 4 .

The curing agent cures the medium layer-forming composition to form the medium layer. The curing agent contains an alicyclic isocyanate compound having at least two isocyanate groups in one molecule, preferably an alicyclic isocyanate compound having two isocyanate groups in one molecule. An alicyclic isocyanate compound having at least two isocyanate groups in one molecule may be an adduct added to a polyhydric alcohol, an isocyanurate, or a biuret. Alicyclic isocyanate compounds having at least two isocyanate groups in one molecule include, for example, isophorone diisocyanate (IPDI) and 1,4-cyclohexane diisocyanate. Alicyclic isocyanate compounds having at least two isocyanate groups in one molecule preferably include isophorone diisocyanate (IPDI).

The curing agent may further contain other polyfunctional isocyanate compounds in addition to the alicyclic isocyanate compound having at least two isocyanate groups in one molecule. Other polyfunctional isocyanate compounds include, for example, aliphatic polyfunctional isocyanates such as hexamethylene diisocyanate (HDI), tolylene diisocyanate (TDI), xylylene diisocyanate (XDI), α, α, α', α' -Aromatic polyfunctional isocyanates such as tetramethylxylylene diisocyanate and diphenylmethane diisocyanate (MDI). Other polyfunctional isocyanate compounds may be adducts, isocyanurates or biurets. Other polyfunctional isocyanate compounds may be used singly or in combination of two or more. As used herein, polyfunctional means having at least two functional groups.

Examples of polyfunctional isocyanate compounds include 24A-100, 22A-75, TPA-100, TSA-100, TSS-100, TAE-100, TKA-100, P301-75E, E402-808, E405-70B, and AE700. -100, D101, D201, A201H (manufactured by Asahi Kasei Corporation), Mitec Y260A (manufactured by Mitsubishi Chemical Corporation), Coronate CORONATE HX, Coronate CORONATE HL, Coronate CORONATE L (manufactured by Tosoh Corporation), Desmodur N75MPA / X ( manufactured by Bayer) or the like may be used.

The content of the curing agent may be, for example, 3-15% by mass based on the total amount of the binder. The content of the curing agent may be, for example, 14% by mass or less, or 13% by mass or less based on the total amount of the binder. The content of the curing agent may be, for example, 5% by mass or more, or 8% by mass or more based on the total amount of the binder. The content of the curing agent can be appropriately adjusted within the range described above, and may be, for example, 5 to 15% by mass, 8 to 15% by mass, or 8 to 13% by mass. When the content of the curing agent is within the above range, even if the medium layer 4 to be obtained is relatively thin, it can exhibit a sufficient adhesive strength, and the barrier layer 2 and the anchor coat layer 6 can be more sufficiently bonded. It can be adhered, and the pressure resistance of the package can be further improved. Moreover, when the content of the curing agent is within the above range, the pot life of the composition for forming a medium layer can be made longer.

The thickness of the medium layer 4 may be 2 μm or less, for example, 1 μm or less, or 0.5 μm or less. The thickness of the medium layer 4 may be, for example, 0.1 μm or more, 0.2 μm or more, or 0.3 μm or more. When the thickness of the medium layer 4 is within the above range, both the adhesiveness between the medium layer 4 and the barrier layer 2 and the anchor coat layer 6 and the tearability of the packaging material can be achieved at a higher level.

The medium layer 4 is formed, for example, by applying a solution containing the above medium layer forming composition and an organic solvent onto the barrier layer 2 and drying it to provide a layer composed of the medium layer forming composition. It may be formed by heating and curing. In the above solution for forming the medium layer 4, the amount of the binder compounded in terms of solid content in the solution is 5% by mass or more, 10% by mass or more, 15% by mass or more, 18% by mass or more, or 20% by mass or more. you can In the solution for forming the medium layer 4, the amount of the binder compounded may be 40% by mass or less, or 30% by mass or less in terms of solid content in the solution. The amount of the binder to be blended can be appropriately adjusted within the range described above, and may be, for example, 5 to 40% by mass, 10 to 30% by mass, or 20 to 30% by mass. When the blending amount of the binder is within the above range, the tearability of the obtained packaging material is more excellent.

Examples of coating methods include coating methods using a gravure coater, a dip coater, a reverse coater, a wire bar coater, a die coater, and the like. The heating temperature for curing the layer composed of the medium layer-forming composition can be appropriately adjusted according to the types of the binder and curing agent, the composition ratio, etc. For example, it is 70 to 80°C. good.

The anchor coat layer 6 has a function of bonding the medium layer 4 and the sealant layer 8 together. The anchor coat layer 6 may contain, for example, an isocyanate-based resin. Examples of isocyanate-based resins include two-component reactive polyurethane adhesives manufactured by Mitsui Chemicals, Inc. (e.g., A3210/A3070, A3210/A-3072, and A3210/A-3075, etc.). name), and two-liquid reactive polyurethane adhesives manufactured by Toyo-Morton Co., Ltd. (eg, EL-540/CAT-RT86L, etc. The above are product names). These isocyanate-based resins may be used alone or in combination of two or more.

The thickness of the anchor coat layer 6 may be, for example, 2 μm or less, 1 μm or less, or 0.5 μm or less. The thickness of the anchor coat layer 6 may be, for example, 0.3 μm or more, or 0.4 μm or more.

The anchor coat layer 6 may be formed, for example, by applying a solution containing the above-described isocyanate-based resin onto the medium layer 4, drying it, and curing it by heating. As the coating method, for example, the method exemplified as the coating method for forming the medium layer 4 may be used.

The sealant layer 8 is, for example, a layer that can be melted by heating. For example, the sealant layer 8 exhibits a function when sealing a packaging bag formed by bonding a pair of packaging materials together, and the opposing sealant layers can be fused by being heated. can be sealed in the containing portion of the packaging bag.

The sealant layer 8 may contain, for example, a thermoplastic resin. Thermoplastic resins include, for example, low density polyethylene (low density PE), medium density polyethylene (medium density PE), high density polyethylene (high density PE), linear (linear) low density polyethylene (linear low density PE), polypropylene, ethylene-vinyl acetate copolymer, ionomer resin, ethylene-acrylic acid copolymer, ethylene-methyl acrylate copolymer, ethylene-methacrylic acid copolymer, ethylene-propylene copolymer, etc. mentioned. These thermoplastic resins may be used singly or in combination of two or more.

The thickness of the sealant layer 8 may be, for example, 10-100 μm, 15-50 μm, or 20-50 μm. When the thickness of the sealant layer 8 is within the above range, it is possible to further improve the adhesive strength when the packaging bag is filled with the items to be packaged and sealed.

For example, the sealant layer 8 may be laminated on the anchor coat layer 6 while forming a film from the thermoplastic resin by extrusion lamination, or may be laminated on the anchor coat layer 6 by forming a separate film sheet.

The packaging material 100 may comprise one or more additional intermediate layers between each layer described above. Examples of the intermediate layer include films of nylon, polyethylene terephthalate, polyamide, polyethylene, polypropylene, polyvinyl chloride, polycarbonate, polyvinyl alcohol, ethylene-propylene copolymers, saponified ethylene-vinyl acetate copolymers, and the like.

FIG. 2 is a schematic cross-sectional view showing another example of the packaging material. The packaging material 102 is a laminated film having a laminated structure in which a barrier layer 2, an ink layer 3, a medium layer 4, an anchor coat layer 6 and a sealant layer 8 are provided on the substrate 10 in this order from the substrate 10 side. The ink layer 3 and the medium layer 4 are different layers. The example shown in FIG. 2 shows an example in which the ink layer 3 is provided in a pattern on the barrier layer 2 (an embodiment in which printing or decoration is provided). A region provided with the ink layer 3 on the barrier layer 2 is called a printed portion, and a region not provided with the ink layer 3 on the barrier layer 2 is also called a blank portion.

The packaging material 102 differs from the packaging material 100 described above in that it includes the ink layer 3, but has other configurations in common. Therefore, for each layer other than the ink layer 3 that constitutes the packaging material 102, the description of each layer that constitutes the packaging material 100 described above can be applied.

The ink layer 3 contains a cured product of the composition for forming an ink layer. The ink layer 3 preferably consists of a cured product of the composition for forming an ink layer. The ink layer-forming composition contains a binder, a curing agent, and a pigment. As for the binder and the curing agent, the description of the binder and the curing agent in the medium layer-forming composition can be applied. In addition to the above, the ink layer-forming composition further contains at least one additive selected from the group consisting of a tackifier, a cross-linking agent, a lubricant, an anti-blocking agent, an antistatic agent, a surfactant, and the like. You may

The pigment contains at least one selected from the group consisting of inorganic pigments and organic pigments. Inorganic pigments include colored pigments such as titanium oxide, red iron oxide, antimony red, cadmium yellow, cobalt blue, Prussian blue, ultramarine blue, carbon black, and graphite, and silica, calcium carbonate, kaolin, clay, barium sulfate, and aluminum hydroxide. , and extender pigments such as talc. Examples of organic pigments include soluble azo pigments, insoluble azo pigments, azo lake pigments, condensed azo pigments, copper phthalocyanine pigments, and condensed polycyclic pigments. These contents may be used singly or in combination of two or more.

The thickness Hb of the ink layer 3 may be, for example, 0.5-4 μm, 0.5-2 μm (thin film), or 2-4 μm (thick film). The thickness Hb of the ink layer 3 is preferably smaller than the thickness Ha of the medium layer 4, as shown in FIG. When the thickness Hb of the ink layer 3 is within the above range, the uniformity of the surface of the medium layer 4 opposite to the barrier layer 2 side is excellent, and the adhesion between the medium layer 4 and the anchor coat layer 6 is improved. can be improved. The ink layer 3 may be formed by, for example, printing a solution containing the composition for forming an ink layer in a pattern on the barrier layer 2 by a method such as inkjet. The amount of pigment compounded may be 5 to 60% by mass in terms of solid content in the above solution. When the blending amount of the pigment is within the above range, the coating liquid has more sufficient coloring power, and the increase in the viscosity of the coating liquid can be suppressed, resulting in more excellent handleability.

In the packaging material 102, the barrier layer 2 has a printed portion provided with the ink layer 3 and a plain portion not provided with the ink layer 3, and the surface 2a of the barrier layer 2 (the base material 10 of the barrier layer 2 side) and a surface 3a of the ink layer 3 (the surface of the ink layer 3 opposite to the barrier layer 2 side). When an adhesive layer is provided on the barrier layer 2 having the surface as described above, the surface 2a and the surface 3a may have different adhesion to the adhesive layer, and good tearability may not be obtained. However, since the packaging material 102 is provided with the medium layer 4 containing a cured product of a specific medium layer-forming composition, the packaging material 102 is superior in adhesiveness to the anchor coat layer 6 and can have good tearability. .

The thickness of each layer forming the packaging materials 100 and 102 can be measured by the following procedure. First, the packaging materials 100 and 102 are cut by a diamond cutter to obtain cut surfaces. An observation image of the cross section is obtained using a microscopic Fourier transform infrared spectrophotometer (microscopic FT-IR spectrophotometer), and the thickness of each layer can be measured from the observation image. The thickness is preferably measured at 10 or more arbitrary points in the observation screen, and the average value is taken as the thickness of each layer.

The adhesive strength of the packaging materials 100 and 102 may be, for example, 2 N/15 mm width or more, 4 N/15 mm width or more, 6 N/15 mm width or more, or 8 N/15 mm width or more. When the adhesive strength of the packaging material is within the above range, separation between the layers is less likely to occur, and the tearability when tearing the packaging material can be further improved. Adhesive strength as used herein means a value measured according to JIS-K6854.

The tear strength of the wrapping materials 100 and 102 may be, for example, 1 N or less, 0.7 N or less, 0.5 N or less, or 0.3 N or less. When the tear strength of the packaging material is within the above range, the packaging material can be torn with less force, and scattering of the packaged material when the package is opened can be more sufficiently suppressed. As used herein, tear strength means a value measured according to JIS K7128.

The packaging materials 100 and 102 described above can be manufactured, for example, by the following packaging material manufacturing method. An embodiment of a method for producing a packaging material is a method for producing a packaging material comprising a base material, a barrier layer, a medium layer, an anchor coat layer and a sealant layer in this order, wherein the barrier layer of the base material having the barrier layer. a step of contacting a medium layer-forming composition and a solution containing an organic solvent to form a coating film, a step of reducing the organic solvent in the coating film to form a composition layer, and a step of heating the composition layer. A step of curing to form a medium layer having a thickness of 12 μm or less, and a step of providing an anchor coat layer and a sealant layer on the medium layer in this order. The composition for forming a medium layer can use the composition for forming a medium layer described above, and contains a binder and a curing agent. Examples of the organic solvent that can be used include isopropyl alcohol (IPA), methyl ethyl ketone (MEK), ethyl acetate, and toluene.

One embodiment of the packaging bag is a packaging bag formed by laminating laminated films, and the laminated film is the packaging material described above. FIG. 3 is a perspective view showing an example of a packaging bag. The packaging bag 200 is configured by pasting together a pair of laminated films, and shows an example using the packaging material 100 described above as the laminated film. The packaging bag 200 includes a sealing portion 202 formed by pasting together the peripheral edges of a pair of film-like substantially rectangular packaging materials 100 , and an accommodating portion 204 formed between the pair of packaging materials 100 by the sealing portion 202 . That is, the packaging bag 200 is sealed by the sealing portions 202 at the side ends, the lower end and the upper end. The packaging bag 200 includes an accommodating portion 204 in which an object to be packaged is accommodated in a non-sealed portion (sheet portion) surrounded by a sealed portion 202 . Note that the sealing portion 202 at the lower end may be sealed after the storage portion 204 is filled with the package items. In this example, the packaging material 100 described above is used as the laminated film, but in a modified example, the packaging material 102 described above may be used instead of the packaging material 100 described above.

A pair of packaging materials 100 are overlaid so that the surfaces of the sealant layers 8 shown in FIG. 1 face each other. The pair of film-like packaging materials 100 may be adhered together at the seal portion 202 with an adhesive. The pair of packaging materials 100 forming the packaging bag 200 does not necessarily have the same layer structure. For example, the pair of packaging materials 100 may have barrier layers 2 made of different materials.

Since the packaging bag 200 is configured by pasting together the packaging materials 100 described above, it can be used for hot-pack filling of objects to be packaged.

An embodiment of a method for manufacturing a package includes the steps of: filling a storage portion of the above-described packaging bag with a heated object to be packaged; and sealing the above-described packaging bag.

The object to be packaged may be, for example, fluid and may be food. The foods may be, for example, seasonings, soups, miso soup, and the like. Seasonings include, for example, soy sauce and miso.

The heating temperature in the step of filling the package may be, for example, 70° C. or higher, 75° C. or higher, 80° C. or higher, 85° C. or higher, 90° C. or higher, or 95° C. or higher.

Although several embodiments have been described above, the mutual descriptions can be applied to common configurations. Moreover, the present disclosure is not limited to the above embodiments.

Hereinafter, the contents of the present disclosure will be described in more detail with reference to examples and comparative examples. However, the present disclosure is not limited to the following examples.

The following materials were used in the following examples and comparative examples.
[binder]
Binder A: manufactured by Sakata Inx Co., Ltd., containing polyurethane and a copolymer of a composition containing vinyl chloride and vinyl acetate. % by mass and the content of the above copolymer is 30 to 40% by mass [Other binders]
Binder B: manufactured by Sakata Inx Co., Ltd., a binder that is a copolymer that does not have a structural unit derived from polyurethane and a structural unit derived from vinyl chloride and vinyl acetate

<Preparation of coating solution of composition for forming ink layer>
As the ink, gravure ink (ink manufactured by Toyo Ink Co., Ltd., Sakata Inks Co., Ltd., etc.), hexamethylene diisocyanate (HDI) as a curing agent, and isopropyl alcohol (IPA), methyl ethyl ketone (MEK), and toluene as organic solvents. was used to prepare an ink layer-forming composition.

<Preparation of Coating Liquid for Medium Layer Forming Composition>
(Preparation of coating liquid 1)
Binder A (manufactured by Sakata Inx Co., Ltd.) was prepared as a binder, isophorone diisocyanate (IPDI) as a curing agent, and IPA, MEK, and ethyl acetate as organic solvents. A binder, a curing agent, and an organic solvent (IPA, MEK, and ethyl acetate) are added so that the amount of the binder is 25% by mass in terms of solid content and the content of the curing agent is 15% by mass based on the total amount of the binder. A mixed solvent mixed in a volume ratio of 6:47:47 was mixed to prepare a coating liquid 1.

(Preparation of coating liquid 2)
Binder B (manufactured by Sakata Inx Co., Ltd.) was prepared as a binder, hexamethylene diisocyanate (HDI) as a curing agent, and IPA, MEK, and ethyl acetate as organic solvents. A binder, a curing agent, and an organic solvent (IPA, MEK, and ethyl acetate) are added so that the amount of the binder is 25% by mass in terms of solid content and the content of the curing agent is 3% by mass based on the total amount of the binder. A mixed solvent mixed in a volume ratio of 6:47:47 was mixed to prepare a coating liquid 2.

(Preparation of coating liquid 3)
Binder B (manufactured by Sakata Inx Co., Ltd.) was prepared as a binder, isophorone diisocyanate (IPDI) as a curing agent, and IPA, MEK, and ethyl acetate as organic solvents. A binder, a curing agent, and an organic solvent (IPA, MEK, and ethyl acetate) are added so that the amount of the binder is 25% by mass in terms of solid content and the content of the curing agent is 15% by mass based on the total amount of the binder. A mixed solvent mixed so that the volume ratio was 6:47:47) was mixed to prepare a coating liquid 3.

(Example 1)
A nylon (NY) film (manufactured by Toppan Printing Co., Ltd., trade name: GLEY #15, thickness: 15 μm) having a substrate and a barrier layer made of silica deposited on the substrate was prepared. An ink layer was provided in a pattern on the barrier layer by printing. Next, the coating solution 1 prepared as described above was applied to the surface of the barrier layer on which the ink layer was provided so that the film thickness after drying was 0.5 μm, and dried to form a composition for forming a medium layer. A layer of material was provided. A medium layer was provided by heating a layer made of the medium layer-forming composition to 70°C.

A solution of an anchor coating agent containing an isocyanate resin was applied to the surface of the medium layer opposite to the barrier layer, dried, and then heated and cured to form an anchor coat layer. Furthermore, a sealant layer was provided by laminating linear low-density polyethylene (LLDPE) as a thermoplastic resin on the anchor coat layer while forming a film by extrusion lamination. Thus, a nylon film (thickness: 15 μm), a barrier layer (thickness: 0.5 μm), an ink layer (thickness: 2 μm), a medium layer (thickness: 0.5 μm), an anchor coat layer (thickness: thickness: 0.5 μm) and a sealant layer (thickness: 50 μm) in this order.

Next, two sheets of the packaging material obtained as described above were prepared, arranged so that the sealant layers faced each other, and heat-sealed to prepare a packaging bag. Adhesion strength, tear strength and tearability of the obtained packaging bag were evaluated according to the evaluation methods described later. Moreover, the packaging body was produced by filling the said packaging bag with miso at normal temperature, and sealing it. After 48 hours from the filling of miso, the adhesive strength, tear strength and tearability of the package were evaluated in the same manner. Table 1 shows the results.

The thickness of each layer was measured by the following procedure. First, the packaging material was cut with a diamond cutter to obtain a cut surface. An observation image of the cross section was obtained using a microscopic Fourier transform infrared spectrophotometer (microscopic FT-IR spectrophotometer), and the thickness of each layer was measured from the observation image. For the measurement, the thickness was measured at arbitrary 10 points in the observation screen, and the average value was taken as the thickness of each layer.

<Evaluation of adhesive strength of packaging bag and package>
Using a commercially available tensile tester (manufactured by Shimadzu Corporation, trade name: Shimadzu Autograph AGS-X), the adhesive strength of the produced packaging bag and package was evaluated according to JIS-K6854. At this time, the speed was 300 mm/min.

<Evaluation of tear strength of packaging bag and package>
Using a commercially available tear tester (manufactured by Shimadzu Corporation, trade name: Shimadzu Autograph AGS-X), the tear strength of the prepared packaging bag and package was evaluated according to JIS K 7128-1. At this time, the tearing speed was 200 mm/min.

<Evaluation of tearability of packaging bag and package: sensory evaluation>
The prepared packaging bag and package were manually torn, and a sensitivity test of tearability was performed, and evaluation was made according to the following criteria. FIG. 4 is a diagram showing an example of tearability sensory test results. FIG. 4(a) shows the result of a package having good tearability without peeling or elongation of the PE constituting the sealant layer. FIG. 4(b) shows the result of peeling of the PE constituting the sealant layer, the stretching of the PE portion, and poor tearability of the package.
A: Elongation of PE was not observed.
B: Elongation of PE was partially observed.
C: Elongation of PE was observed.

(Comparative example 1)
A packaging bag was produced in the same manner as in Example 1, except that the coating liquid 2 was used instead of the coating liquid 1, and the thickness of the layer composed of the composition for forming the medium layer was changed from 0.5 μm to 1 μm. . Using the obtained packaging bag, miso was filled under the same conditions as in Example 1, and the adhesive strength, tear strength and tearability of the package were evaluated in the same manner. Table 1 shows the results.

(Comparative example 2)
A packaging bag was produced in the same manner as in Example 1, except that the coating liquid 3 was used instead of the coating liquid 1, and the thickness of the layer composed of the medium layer-forming composition was changed from 0.5 μm to 1 μm. . Using the obtained packaging bag, miso was filled under the same conditions as in Example 1, and the adhesive strength, tear strength and tearability of the package were evaluated in the same manner. Table 1 shows the results.

(Comparative Example 3)
A packaging bag was prepared in the same manner as in Example 1, except that coating liquid 3 was used instead of coating liquid 1 and the thickness of the layer composed of the medium layer forming composition was changed from 0.5 μm to 0.8 μm. made. Using the obtained packaging bag, miso was filled under the same conditions as in Example 1, and the adhesive strength, tear strength and tearability of the package were evaluated in the same manner. Table 1 shows the results.

(Comparative Example 4)
A packaging bag was produced in the same manner as in Example 1 except that the coating liquid 3 was used instead of the coating liquid 1. Using the obtained packaging bag, miso was filled under the same conditions as in Example 1, and the adhesive strength, tear strength and tearability of the package were evaluated in the same manner. Table 1 shows the results.

(Example 2)
A PET film (manufactured by Toppan Printing Co., Ltd., trade name: GLAECF #12, thickness: 12 μm) having a substrate and a barrier layer made of alumina deposited on the above substrate is used, and a polyethylene film (Toppan Printing A packaging bag was produced in the same manner as in Example 1, except that the product name: NewLD, thickness: 50 μm) was used.

Adhesion strength, tear strength and tearability were evaluated for the obtained packaging bag. Also, a packaging body was produced by filling a packaging bag with hot water heated to 95° C. and sealing the bag. After 48 hours from filling with hot water, the adhesive strength, tear strength and tear resistance of the package were evaluated. Table 2 shows the results.

(Comparative Example 5)
A packaging bag was produced in the same manner as in Example 2, except that the coating liquid 2 was used instead of the coating liquid 1. Using the resulting packaging bag, hot water was filled under the same conditions as in Example 1, and the adhesive strength, tear strength and tear resistance of the package were evaluated in the same manner. Table 2 shows the results.

According to the present disclosure, it is possible to exhibit good tearability even when a fluid package is filled, and even when the package is hot-packed, tear strength can be kept sufficiently low.

DESCRIPTION OF SYMBOLS 2 Barrier layer 3 Ink layer 4 Medium layer 6 Anchor coat layer 8 Sealant layer 10 Base material 100, 102 Packaging material 200 Packaging bag 202 Seal portion 204 Containment department.

Claims (9)

A packaging material comprising a substrate, a barrier layer, a medium layer, an anchor coat layer and a sealant layer in this order,
The medium layer has a thickness of 2 μm or less,
The medium layer comprises a cured product of a medium layer-forming composition containing a binder and a curing agent,
In the medium layer-forming composition, the content of the curing agent is 3 to 15% by mass based on the total amount of the binder,
The binder contains polyurethane and a copolymer having structural units derived from vinyl chloride and structural units derived from vinyl acetate,
Based on the total amount of the polyurethane and the copolymer, the content of the polyurethane is 60 to 70% by mass, and the content of the copolymer is 30 to 40% by mass,
The curing agent contains an alicyclic isocyanate compound having at least two isocyanate groups in one molecule,
The packaging material, wherein the anchor coat layer has a thickness of 0.5 μm or less . The binder has a polyurethane having at least one functional group selected from the group consisting of a hydroxyl group, an amino group and a carboxy group, and at least one functional group selected from the group consisting of a hydroxyl group, an amino group and a carboxy group. The packaging material according to claim 1 , containing at least one selected from the group consisting of said copolymers. 3. The packaging material according to claim 1, wherein the adhesive strength is 2 N/15 mm width or more. The packaging material according to any one of claims 1 to 3 , which has a tear strength of 1N or less. The packaging material according to any one of claims 1 to 4 , further comprising an ink layer between the barrier layer and the medium layer. A method for producing a packaging material comprising a substrate, a barrier layer, a medium layer, an anchor coat layer and a sealant layer in this order,
A step of contacting a solution containing a composition for forming a medium layer and an organic solvent to form a coating film on the barrier layer of a substrate having a barrier layer;
A step of providing a composition layer by reducing the organic solvent in the coating film;
a step of heating and curing the composition layer to form a medium layer having a thickness of 2 μm or less;
providing an anchor coat layer having a thickness of 0.5 μm or less and a sealant layer in this order on the medium layer;
The medium layer-forming composition contains a binder and a curing agent,
In the medium layer-forming composition, the content of the curing agent is 3 to 15% by mass based on the total amount of the binder,
The binder contains polyurethane and a copolymer having structural units derived from vinyl chloride and structural units derived from vinyl acetate,
Based on the total amount of the polyurethane and the copolymer, the content of the polyurethane is 60 to 70% by mass, and the content of the copolymer is 30 to 40% by mass,
A method for producing a packaging material, wherein the curing agent contains an alicyclic isocyanate compound having at least two isocyanate groups in one molecule. A packaging bag made by laminating laminated films,
A packaging bag, wherein the laminated film is the packaging material according to any one of claims 1 to 5 . 8. The packaging bag according to claim 7 , which is used for hot-pack filling of objects to be packaged. A step of filling the storage portion of the packaging bag according to claim 7 or 8 with an object to be packaged in a heated state;
and a step of sealing the packaging bag to obtain a package.

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