JP7796691B2 - Packaging materials and products - Google Patents

Description

The present invention relates to packaging materials containing biomass-derived components and packaging products equipped with the packaging materials.

A variety of packaging materials have been developed and proposed for use in packaging products filled with a variety of items, including food and beverages, pharmaceuticals, chemicals, cosmetics, hygiene products, daily necessities, and more. Packaging materials consist of a laminate comprising at least a base layer containing, for example, oriented plastic, and a sealant layer for welding together the packaging materials. Typically, the laminate further includes a printing layer for forming a printed pattern, and an adhesive layer for joining the layers of the laminate.

In recent years, with growing calls for the creation of a recycling-oriented society, there has been a desire to move away from fossil fuels in the field of laminates that make up packaging materials, just as there is in the field of energy, and the use of biomass has been attracting attention. Biomass is an organic compound created by photosynthesis from carbon dioxide and water, and by using it, it can be converted back into carbon dioxide and water, making it a so-called carbon-neutral renewable energy source. Recently, the practical application of biomass plastics made from these biomass raw materials has progressed rapidly, and attempts are also being made to produce various resins from biomass raw materials.

Polylactic acid (PLA), which is produced via lactic acid fermentation, was the first biomass-derived resin to be commercially produced. However, its biodegradability and other plastic properties differ significantly from those of current general-purpose plastics, limiting its product applications and manufacturing methods and preventing widespread adoption. Furthermore, a life cycle assessment (LCA) is being conducted on PLA, and discussions are underway regarding the energy consumed in manufacturing PLA and its equivalence as a replacement for general-purpose plastics.

Various types of general-purpose plastics are used, including polyethylene, polypropylene, polyvinyl chloride, polystyrene, and polyester. Polyethylene, in particular, is molded into films, sheets, bottles, and other forms for a variety of uses, including packaging, and is used in large quantities worldwide. Therefore, using conventional fossil fuel-derived polyethylene places a heavy burden on the environment. Therefore, there is a desire to reduce the amount of fossil fuel used by using biomass-derived raw materials in the production of polyethylene. For example, research has been conducted to date on the production of ethylene and butylene, the raw materials for polyolefin resins, from renewable natural raw materials (see Patent Document 1).

Polyesters are widely used in a variety of industrial applications due to their excellent mechanical properties, chemical stability, heat resistance, transparency, and low cost. Polyesters are obtained by polycondensation of diol units and dicarboxylic acid units. For example, polyethylene terephthalate (hereinafter sometimes abbreviated as PET) is produced by esterifying ethylene glycol and terephthalic acid as raw materials, followed by a polycondensation reaction. These raw materials are produced from petroleum, a fossil resource; for example, ethylene glycol is produced industrially from ethylene, and terephthalic acid is produced industrially from xylene.

Recently, attempts have been made to produce polyester from biomass raw materials. For example, polyesters using biomass-derived ethylene glycol as a monomer component have been put to practical use. It has been proposed to use polyester resins containing such biomass-derived raw materials in packaging materials (see Patent Document 2).

Special Publication No. 2011-506628 JP 2012-96410 A

In conventional packaging materials, the printed and adhesive layers of the laminate are formed from materials derived from fossil fuels, which reduces the biomass content of the entire packaging material. Therefore, there is a demand for packaging materials composed of a laminate including a base layer, printed layer, adhesive layer, and sealant layer, with an increased biomass content throughout the entire packaging material.

The present invention was made with these points in mind, and aims to provide packaging materials with an increased biomass content.

The present invention relates to a packaging material comprising at least a substrate layer, a printing layer, an adhesive layer, and a sealant layer, wherein the adhesive layer is in contact with the sealant layer, the adhesive layer comprises a cured product of a polyol and an isocyanate compound, the polyol in the adhesive layer is a polyether polyol that is a reaction product of a polyfunctional alcohol and a polyfunctional isocyanate, the polyfunctional alcohol comprises neopentyl glycol derived from biomass, and the adhesive layer has a biomass content of 5% or more and 50% or less.

The present invention also relates to a packaging material comprising at least a base layer, a printed layer, an adhesive layer, and a sealant layer, wherein the adhesive layer is in contact with the sealant layer, the adhesive layer comprises a cured product of a polyol and an isocyanate compound, and at least one of the polyol and the isocyanate compound comprises a biomass-derived component, the adhesive layer has a biomass content of 5% or more and 50% or less, the printed layer comprises a colorant and a cured product of a polyol and an isocyanate compound, and at least one of the polyol and the isocyanate compound comprises a biomass-derived component, and the polyol in the printed layer is a polyester polyol, which is a reaction product of a polyfunctional alcohol and a polyfunctional carboxylic acid.

In the packaging material according to the present invention, at least one of the polyfunctional alcohol and the polyfunctional carboxylic acid in the printed layer may contain a biomass-derived component.

The present invention also relates to a packaging material comprising at least a substrate layer, a printed layer, an adhesive layer, and a sealant layer, wherein the adhesive layer is in contact with the sealant layer, the adhesive layer comprises a cured product of a polyol and an isocyanate compound, and at least one of the polyol and the isocyanate compound comprises a biomass-derived component, the adhesive layer has a biomass content of 5% or more and 50% or less, the printed layer comprises a colorant and a cured product of a polyol and an isocyanate compound, and at least one of the polyol and the isocyanate compound comprises a biomass-derived component, and the polyol in the printed layer may be a polyether polyol, which is a reaction product of a polyfunctional alcohol and a polyfunctional isocyanate.

In the packaging material according to the present invention, at least one of the polyfunctional alcohol and the polyfunctional isocyanate in the printed layer may contain a biomass-derived component.

In the packaging material according to the present invention, the isocyanate compound in the adhesive layer may contain a biomass-derived component.

In the packaging material according to the present invention, the substrate layer may have a substrate film containing polyester, polyamide, or polyolefin.

In the packaging material according to the present invention, the base film may contain a biomass polyester in which the diol unit is ethylene glycol derived from biomass and the dicarboxylic acid unit is a dicarboxylic acid derived from a fossil fuel.

In the packaging material according to the present invention, the sealant layer may contain polyolefin, which is a polymer of a monomer containing an olefin.

In the packaging material according to the present invention, the sealant layer may contain biomass polyolefin, which is a polymer of monomers containing ethylene derived from biomass.

The present invention also relates to a packaging product comprising the packaging material described above.

This invention makes it possible to increase the biomass content of packaging materials.

1 is a schematic cross-sectional view showing an example of a packaging material according to the present invention. 1 is a schematic cross-sectional view showing an example of a packaging material according to the present invention. 1 is a schematic cross-sectional view showing an example of a packaging material according to the present invention. 1 is a schematic cross-sectional view showing an example of a packaging material according to the present invention. 1 is a schematic front view showing an example of a packaged product according to the present invention. 1 is a schematic front view showing an example of a packaged product according to the present invention. 1 is a schematic front view showing an example of a packaged product according to the present invention. 1 is a schematic front view showing an example of a packaged product according to the present invention. 1 is a schematic front view showing an example of a packaged product according to the present invention. FIG. 1 is a diagram showing the layer structure of the packaging materials of Examples 1A to 1L. FIG. 1 is a diagram showing the layer structure of the packaging materials of Examples 1A and 2A to 11.

<Packaging materials>
The laminate constituting the packaging material according to the present invention includes at least a substrate layer, a printing layer, an adhesive layer, and a sealant layer. In the present invention, by forming the adhesive layer from a material containing a biomass-derived component, it is possible to reduce the amount of fossil fuel used compared to conventional methods, thereby reducing the environmental load.

In the present invention, the biomass ratio, as explained below, of the entire laminate that constitutes the packaging material is preferably 3% or more, more preferably 5% to 60%, and even more preferably 10% to 60%. If the biomass ratio is within the above range, it is possible to reduce the amount of fossil fuel used and thereby reduce the environmental burden.

The laminate that constitutes the packaging material preferably has a thickness of 10 μm or more and 500 μm or less, more preferably 20 μm or more and 300 μm or less, and even more preferably 30 μm or more and 200 μm or less.

In addition to the layers described above, the packaging material according to the present invention may further comprise at least one other layer, such as a barrier layer, such as a metal foil, a vapor deposition layer, or a gas barrier coating film. When two or more other layers are present, they may each have the same composition or different compositions.

The laminate constituting the packaging material of the present invention will be described with reference to the drawings. Examples of schematic cross-sectional views of packaging material 10 of the present invention are shown in FIGS. 1 to 4. In FIGS. 1 to 4, reference numeral 10y denotes the outer surface of packaging material 10, and reference numeral 10x denotes the inner surface of packaging material 10. In a packaging product such as a bag formed from packaging material 10, inner surface 10x is the surface located on the side of the contents to be placed in the packaging product. Furthermore, outer surface 10y is the surface located opposite inner surface 10x. In this application, the term "in this order" in expressions such as "provided in this order" and "layered in this order" refers to the order in the direction from outer surface 10y to inner surface 10x, unless otherwise specified.

The packaging material 10 shown in Figure 1 comprises, in this order, a substrate layer 20, a printing layer 50, an adhesive layer 30, and a sealant layer 40. The substrate layer 20 includes a substrate film 22. The sealant layer 40 includes a sealant film 42.

The packaging material 10 shown in Figure 2 has a barrier layer 60 provided between the base film 22 and the printed layer 50 of the packaging material 10 in Figure 1.

The packaging material 10 shown in Figure 3 has a barrier layer 60 provided between the adhesive layer 30 and the sealant film 42 of the packaging material 10 in Figure 1.

The packaging material 10 shown in Figure 4 is similar to the packaging material 10 in Figure 1, except that a first barrier layer 61 is provided between the base film 22 and the printed layer 50, and a second barrier layer 62 is provided between the adhesive layer 30 and the sealant film 42.

The packaging material 10 shown in Figures 2 to 4 includes a barrier layer 60, 61, or 62, but the barrier layer may be a single layer such as a metal foil or vapor deposition layer, or a laminated layer in which a gas barrier coating film is formed on a vapor deposition layer.

It is also possible to combine multiple layer structures of the packaging material 10 shown in Figures 1 to 4 above as appropriate.

The following describes each layer that makes up the packaging material 10.

(Base film)
The base film 22 of the base layer 20 is a plastic film. The base film 22 may or may not contain a biomass-derived component.

When the base film 22 contains biomass-derived components, the base film 22 can be formed using the biomass polyester or biomass polyethylene described below.

Biomass polyester has biomass-derived ethylene glycol as the diol unit and fossil fuel-derived dicarboxylic acid as the dicarboxylic acid unit. In addition to biomass polyester, the substrate layer may further contain a fossil fuel-derived polyester having fossil fuel-derived ethylene glycol as the diol unit and fossil fuel-derived dicarboxylic acid as the dicarboxylic acid unit. The substrate layer as a whole should be able to achieve the following biomass degree. In the present invention, by including biomass polyester in the substrate layer, the amount of fossil fuel-derived polyester can be reduced compared to conventional methods, thereby reducing the environmental impact.

In the present invention, "biomass content" may be expressed as a value measured by radiocarbon (C14) analysis to determine the content of carbon derived from biomass, or may be expressed as the weight ratio of biomass-derived components.

When the value measured for the content of biomass-derived carbon by radiocarbon (C14) measurement is expressed as the "biomass degree," the "biomass degree" can be calculated as follows. That is, atmospheric carbon dioxide contains a certain proportion of C14 (105.5 pMC), and it is known that the C14 content in plants that grow by absorbing atmospheric carbon dioxide, such as corn, is also about 105.5 pMC. It is also known that fossil fuels contain very little C14. Therefore, the proportion of biomass-derived carbon can be calculated by measuring the proportion of C14 in the total carbon atoms in the polyester. In the present invention, when the C14 content in the polyester is P _C14 , the biomass-derived carbon content P _bio can be calculated as follows.
P _bio (%) = P _C14 /105.5×100
It should be noted that pMC is an abbreviation for Percent Modern Carbon.

Taking polyethylene terephthalate, a typical polyester, as an example, polyethylene terephthalate is obtained by polymerizing ethylene glycol containing 2 carbon atoms and terephthalic acid containing 8 carbon atoms in a molar ratio of 1:1, so when only biomass-derived ethylene glycol is used, the biomass-derived carbon content P _bio in the polyethylene terephthalate is 20%. On the other hand, the biomass-derived carbon content in fossil fuel-derived polyethylene terephthalate produced using fossil fuel-derived ethylene glycol and fossil fuel-derived dicarboxylic acid is 0%, and the biomass degree of fossil fuel-derived polyethylene terephthalate is 0%.

Furthermore, when expressing the "biomass degree" as the weight ratio of biomass-derived components, it can be calculated as follows. Taking polyethylene terephthalate as an example, as mentioned above, polyethylene terephthalate is produced by polymerizing ethylene glycol containing two carbon atoms and terephthalic acid containing eight carbon atoms in a 1:1 molar ratio. Therefore, if only biomass-derived ethylene glycol is used, the weight ratio of biomass-derived components in the polyester is approximately 30%, resulting in a biomass degree of approximately 30%. Furthermore, the weight ratio of biomass-derived components in a fossil-fuel-derived polyester produced using fossil-fuel-derived ethylene glycol and fossil-fuel-derived dicarboxylic acid is 0%, resulting in a biomass degree of 0% for the fossil-fuel-derived polyester. Hereinafter, unless otherwise specified, "biomass degree" refers to the weight ratio of biomass-derived components.

When the base film 22 contains biomass-derived components, the biomass content in the base film 22 is 5% or more, preferably 10% to 30%, and more preferably 15% to 25%. If the biomass content in the base film 22 is 5% or more, the amount of fossil fuel-derived polyester can be reduced compared to conventional methods, thereby reducing the environmental burden.

Biomass-derived ethylene glycol is made from ethanol produced from biomass (biomass ethanol). For example, biomass-derived ethylene glycol can be obtained by converting biomass ethanol to ethylene oxide using a conventional method, thereby producing ethylene glycol. Alternatively, commercially available biomass ethylene glycol may be used; for example, biomass ethylene glycol available from India Glycoal Limited is suitable.

The dicarboxylic acid units of biomass polyester use dicarboxylic acids derived from fossil fuels. Dicarboxylic acids that can be used without limitation include aromatic dicarboxylic acids, aliphatic dicarboxylic acids, and their derivatives. Examples of aromatic dicarboxylic acids include terephthalic acid and isophthalic acid, and examples of aromatic dicarboxylic acid derivatives include lower alkyl esters of aromatic dicarboxylic acids, specifically methyl esters, ethyl esters, propyl esters, and butyl esters. Among these, terephthalic acid is preferred, and dimethyl terephthalate is preferred as a derivative of aromatic dicarboxylic acid.

Specific examples of aliphatic dicarboxylic acids include linear or alicyclic dicarboxylic acids typically having 2 to 40 carbon atoms, such as oxalic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, dodecanedioic acid, dimer acid, and cyclohexanedicarboxylic acid. Derivatives of aliphatic dicarboxylic acids include lower alkyl esters of the above aliphatic dicarboxylic acids, such as methyl esters, ethyl esters, propyl esters, and butyl esters, as well as cyclic acid anhydrides of the above aliphatic dicarboxylic acids, such as succinic anhydride. Among these, adipic acid, succinic acid, dimer acid, or mixtures thereof are preferred, with those containing succinic acid as the main component being particularly preferred. More preferred derivatives of aliphatic dicarboxylic acids include methyl esters of adipic acid and succinic acid, or mixtures thereof. These dicarboxylic acids can be used alone or in combination.

Biomass polyester may be a copolymerized polyester that contains, in addition to the diol and dicarboxylic acid components described above, a copolymerization component as a third component. Specific examples of copolymerization components include difunctional oxycarboxylic acids, and at least one polyfunctional compound selected from the group consisting of trifunctional or higher polyhydric alcohols, trifunctional or higher polycarboxylic acids and/or their anhydrides, and trifunctional or higher oxycarboxylic acids to form crosslinked structures. Among these copolymerization components, difunctional and/or trifunctional or higher oxycarboxylic acids are particularly preferred because they tend to facilitate the production of copolymerized polyesters with a high degree of polymerization. Among these, the use of trifunctional or higher oxycarboxylic acids is most preferred because they allow the easy production of polyesters with a high degree of polymerization in extremely small amounts without the need for chain extenders, as described below.

Biomass polyester can be obtained by a conventionally known method of polycondensing the above-mentioned diol units and dicarboxylic acid units. Specifically, it can be produced by a common melt polymerization method in which the above-mentioned dicarboxylic acid component and diol component are subjected to an esterification reaction and/or transesterification reaction, followed by a polycondensation reaction under reduced pressure, or by a known solution heating dehydration condensation method using an organic solvent. The amount of diol used in producing biomass polyester is substantially equimolar to 100 moles of dicarboxylic acid or its derivative. However, due to the distillation that occurs during the esterification and/or transesterification reaction and/or polycondensation reaction, it is generally preferable to use an excess of 0.1 mol % to 20 mol %.

The substrate film 22 can be formed by, for example, forming a film using a T-die method using a biomass polyester resin composition or a resin composition containing biomass polyester and a polyester derived from fossil fuels. Specifically, the resin composition described above is dried and then fed into a melt extruder heated to a temperature above the melting point Tm of the resin composition to a temperature of Tm + 70°C. The resin composition is melted and extruded into a sheet through a die such as a T-die. The extruded sheet is then quenched and solidified using a rotating cooling drum or the like to form the substrate film 22. As the melt extruder, a single-screw extruder, twin-screw extruder, vent extruder, tandem extruder, or other type of extruder can be used depending on the purpose.

Biomass polyethylene is a monomer polymer containing ethylene derived from biomass. Details about biomass polyethylene are explained in the section regarding the sealant layer 40.

When the base film 22 is formed from a material that does not contain biomass-derived components, the base film 22 can be made of a plastic film such as a polyester film such as polyethylene terephthalate film or polybutylene terephthalate, a polyolefin film such as polyethylene film or polypropylene film, a polyamide film such as nylon film or nylon 6/metaxylylenediamine nylon 6 co-extruded and co-stretched film, or a polypropylene/ethylene-vinyl alcohol copolymer co-extruded and co-stretched film, or a composite film made by laminating two or more of these films. The plastic film may also be coated with polyvinyl alcohol or the like.

The base film 22 may be a stretched plastic film that has been stretched in a predetermined direction. In this case, the base film 22 may be a uniaxially stretched film that has been stretched in one predetermined direction, or a biaxially stretched film that has been stretched in two predetermined directions. A stretched plastic film can be obtained, for example, by heating a plastic film extruded onto a cooling drum using roll heating, infrared heating, or the like, and stretching it in the longitudinal direction. This stretching is preferably carried out using the difference in peripheral speed between two or more rolls. Longitudinal stretching is usually carried out at a temperature ranging from 50°C to 100°C. The longitudinal stretching ratio is preferably 2.5 times to 4.2 times, although this depends on the required properties of the film's intended use. If the stretching ratio is less than 2.5 times, the film will have significant thickness unevenness, making it difficult to obtain a good film.

The longitudinally stretched film is then subjected to the subsequent processes of transverse stretching, heat setting, and heat relaxation to become a biaxially stretched film. Transverse stretching is typically carried out at a temperature between 50°C and 100°C. The transverse stretching ratio is preferably between 2.5 and 5.0 times, depending on the required properties of the application. If the ratio is less than 2.5 times, the film thickness will be uneven, making it difficult to obtain a good film, and if the ratio is more than 5.0 times, breakage will occur during film production.

The base film 22 has a breaking strength of, for example, 5 kg/ ^mm2 to 40 kg/ ^mm2 in the MD direction and 5 kg/ ^mm2 to 35 kg/ ^mm2 in the TD direction, and a breaking elongation of, for example, 50% to 350% in the MD direction and 50% to 300% in the TD direction. The shrinkage when left in a 150°C temperature environment for 30 minutes is, for example, 0.1% to 5%.

When the base film 22 is a biomass polyester film or a polyester film, the thickness of the base film 22 is preferably 6 μm or more and 20 μm or less, and more preferably 12 μm or more and 16 μm or less.
When the base film 22 is a polyamide film, the thickness of the base film 22 is preferably 10 μm or more and 30 μm or less, and more preferably 15 μm or more and 25 μm or less.
When the base film 22 is a polypropylene film, the thickness of the base film 22 is preferably 15 μm or more and 50 μm or less, and more preferably 20 μm or more and 30 μm or less.
When the base film 22 is a biomass polyethylene film or a polyethylene film, the thickness of the base film 22 is preferably 10 μm or more and 80 μm or less, and more preferably 30 μm or more and 60 μm or less.

The base film 22 may be a single-layer film or a co-extruded film of two or more layers.

(Printing layer)
The printed layer 50 is a layer formed by printing for decoration, indication of contents, expiration date, manufacturer, seller, and other indications or aesthetic purposes. The printed layer 50 includes a pattern layer that forms any desired pattern, such as a picture, photograph, letter, number, figure, symbol, or pattern. The printed layer may further include a background color layer formed by printing to highlight the pattern of the pattern layer. The printed layer 50 includes a colorant and a cured product of a polyol and an isocyanate compound. The printed layer 50 may or may not contain a biomass-derived component. When the printed layer 50 is formed from a material containing a biomass-derived component, the printed layer 50 can be formed using a cured product in which at least one of the polyol as the base agent and the isocyanate compound as the curing agent contains a biomass-derived component. When the printed layer 50 is formed from a material that does not contain a biomass-derived component, the printed layer 50 can be formed using a conventionally known polyol composed of a fossil fuel-derived component and an isocyanate compound composed of a fossil fuel-derived component. As the polyol, a polyester polyol, which is a reaction product of a polyfunctional alcohol and a polyfunctional carboxylic acid, or a polyether polyol, which is a reaction product of a polyfunctional alcohol and a polyfunctional isocyanate, can be used.

[Polyester polyol]
When the polyester polyol contains a biomass-derived component, at least one of the polyfunctional alcohol and the polyfunctional carboxylic acid contains a biomass-derived component. Examples of polyester polyols containing a biomass-derived component include the following.
・Reaction products of biomass-derived polyfunctional alcohols and biomass-derived polyfunctional carboxylic acids ・Reaction products of fossil fuel-derived polyfunctional alcohols and biomass-derived polyfunctional carboxylic acids ・Reaction products of biomass-derived polyfunctional alcohols and fossil fuel-derived polyfunctional carboxylic acids

As biomass-derived polyfunctional alcohols, aliphatic polyfunctional alcohols obtained from plant materials such as corn, sugarcane, cassava, and sago palm can be used. Examples of biomass-derived aliphatic polyfunctional alcohols include polypropylene glycol (PPG), neopentyl glycol (NPG), ethylene glycol (EG), diethylene glycol (DEG), butylene glycol (BG), and hexamethylene glycol, all of which can be obtained from plant materials by the methods described below. These may be used alone or in combination.

Biomass-derived polypropylene glycol is produced by a fermentation method in which glucose is obtained by decomposing plant raw materials, via 3-hydroxypropylaldehyde (HPA) from glycerol. Compared to polypropylene glycol produced by the EO production method, polypropylene glycol produced by a biomethod such as the fermentation method is preferable in terms of safety, as useful by-products such as lactic acid can be obtained, and production costs can be kept low.
Biomass-derived butylene glycol can be produced by producing glycol from plant raw materials, fermenting the glycol, obtaining succinic acid, and then hydrogenating the resulting succinic acid.
Biomass-derived ethylene glycol can be produced, for example, from bioethanol obtained by a conventional method via ethylene.

The fossil fuel-derived polyfunctional alcohol can be a compound having two or more hydroxyl groups, preferably two to eight hydroxyl groups, per molecule. Specifically, the fossil fuel-derived polyfunctional alcohol is not particularly limited and conventionally known substances can be used. Examples include polypropylene glycol (PPG), neopentyl glycol (NPG), ethylene glycol (EG), diethylene glycol (DEG), butylene glycol (BG), hexamethylene glycol, as well as triethylene glycol, dipropylene glycol, 1,4-cyclohexanedimethanol, trimethylolpropane, glycerin, 1,9-nonanediol, 3-methyl-1,5-pentanediol, polyether polyol, polycarbonate polyol, polyolefin polyol, and acrylic polyol. These may be used alone or in combination of two or more.

As biomass-derived polyfunctional carboxylic acids, aliphatic polyfunctional carboxylic acids obtained from plant materials such as renewable plant-derived oils such as soybean oil, linseed oil, tung oil, coconut oil, palm oil, and castor oil, as well as regenerated oils made from recycled waste cooking oils containing these oils as a primary component, can be used. Examples of biomass-derived aliphatic polyfunctional carboxylic acids include sebacic acid, succinic acid, phthalic acid, adipic acid, glutaric acid, and dimer acid. For example, sebacic acid is produced by alkaline pyrolysis of ricinoleic acid obtained from castor oil, with heptyl alcohol as a by-product. In the present invention, it is particularly preferable to use biomass-derived succinic acid or biomass-derived sebacic acid. These may be used alone or in combination of two or more types.

The fossil fuel-derived polyfunctional carboxylic acid may be an aliphatic polyfunctional carboxylic acid or an aromatic polyfunctional carboxylic acid. The fossil fuel-derived aliphatic polyfunctional carboxylic acid is not particularly limited and may be any conventionally known substance, such as adipic acid, dodecanedioic acid, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, maleic anhydride, itaconic anhydride, sebacic acid, succinic acid, glutaric acid, dimer acid, and their ester compounds. The fossil fuel-derived aromatic polyfunctional carboxylic acid is not particularly limited and may be any conventionally known substance, such as isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, phthalic anhydride, trimellitic acid, pyromellitic acid, and their ester compounds. These may be used alone or in combination of two or more.

[Polyether polyol]
When the polyether polyol contains a biomass-derived component, at least one of the polyfunctional alcohol and the polyfunctional isocyanate contains a biomass-derived component. Examples of polyether polyols containing a biomass-derived component include the following.
・Reaction products of biomass-derived polyfunctional alcohols and biomass-derived polyfunctional isocyanates ・Reaction products of fossil fuel-derived polyfunctional alcohols and biomass-derived polyfunctional isocyanates ・Reaction products of biomass-derived polyfunctional alcohols and fossil fuel-derived polyfunctional isocyanates

As the biomass-derived polyfunctional alcohol and the fossil fuel-derived polyfunctional alcohol, the biomass-derived polyfunctional alcohol and the fossil fuel-derived polyfunctional alcohol described above for the polyester polyol can be used.

Biomass-derived polyfunctional isocyanates can be obtained by converting plant-derived dicarboxylic acids into terminal amino groups through acid amidation and reduction, and then reacting with phosgene to convert the amino groups into isocyanate groups. Examples of biomass-derived polyfunctional isocyanates include biomass-derived diisocyanates. Examples of biomass-derived diisocyanates include dimer acid diisocyanate (DDI), octamethylene diisocyanate, and decamethylene diisocyanate. Plant-derived diisocyanates can also be obtained by using plant-derived amino acids as raw materials and converting their amino groups into isocyanate groups. For example, lysine diisocyanate (LDI) can be obtained by methyl esterifying the carboxyl groups of lysine and then converting the amino groups to isocyanate groups. 1,5-pentamethylene diisocyanate can be obtained by decarboxylating the carboxyl groups of lysine and then converting the amino groups to isocyanate groups.

Other methods for synthesizing 1,5-pentamethylene diisocyanate include the phosgenation method and the carbamate method. More specifically, the phosgenation method involves directly reacting 1,5-pentamethylene diamine or its salt with phosgene, or suspending pentamethylene diamine hydrochloride in an inert solvent and reacting it with phosgene to synthesize 1,5-pentamethylene diisocyanate. The carbamate method involves first carbamatizing 1,5-pentamethylene diamine or its salt to produce pentamethylene dicarbamate (PDC), which is then thermally decomposed to synthesize 1,5-pentamethylene diisocyanate. A suitable polyisocyanate for use in the present invention is 1,5-pentamethylene diisocyanate-based polyisocyanate (product name: STABIO (registered trademark)) manufactured by Mitsui Chemicals, Inc.

The fossil fuel-derived polyfunctional isocyanate is not particularly limited and conventionally known isocyanates can be used, such as aromatic diisocyanates such as toluene-2,4-diisocyanate, 4-methoxy-1,3-phenylene diisocyanate, 4-isopropyl-1,3-phenylene diisocyanate, 4-chloro-1,3-phenylene diisocyanate, 4-butoxy-1,3-phenylene diisocyanate, 2,4-diisocyanate diphenyl ether, 4,4'-methylenebis(phenylene isocyanate) (MDI), durylene diisocyanate, tolidine diisocyanate, xylylene diisocyanate (XDI), 1,5-naphthalene diisocyanate, benzidine diisocyanate, o-nitrobenzidine diisocyanate, and 4,4'-diisocyanate dibenzyl. Other examples include aliphatic diisocyanates such as methylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, and 1,10-decamethylene diisocyanate; and alicyclic diisocyanates such as 1,4-cyclohexylene diisocyanate, 4,4-methylenebis(cyclohexyl isocyanate), 1,5-tetrahydronaphthalene diisocyanate, isophorone diisocyanate, hydrogenated MDI, and hydrogenated XDI. These may be used alone or in combination of two or more.

[Coloring Agent]
The colorant is not particularly limited, and any conventionally known pigment or dye can be used.

When the printed layer 50 contains biomass-derived components, the printed layer 50 preferably has a biomass ratio of 5% or more, more preferably 5% to 50%, and even more preferably 10% to 50%. A biomass ratio within the above range can reduce the amount of fossil fuel used and lessen the environmental burden.

The weight of the printed layer 50 after drying is preferably 0.1 g/m ² or more and 10 g/m ² or less, more preferably 1 g/m ² or more and 5 g/m ² or less, and even more preferably 1 g/m ² or more and 3 g/m ² or less.

The printing layer 50 preferably has a thickness of 0.1 μm or more and 10 μm or less, more preferably 1 μm or more and 5 μm or less, and even more preferably 1 μm or more and 3 μm or less.

(adhesive layer)
The adhesive layer 30 is a layer that functions to bond the printed layer 50 and the sealant layer 40 that constitute the packaging material 10. Furthermore, when a barrier layer 60 such as a vapor deposition layer is included between the adhesive layer 30 and the sealant layer 40, it goes without saying that the adhesive layer 30 also functions to bond the printed layer 50 and the barrier layer 60. The adhesive layer 30 contains a cured product of a polyol and an isocyanate compound, and at least one of the polyol and the isocyanate compound contains a biomass-derived component.

In the adhesive layer 30, the isocyanate compound containing a biomass-derived component can be the same isocyanate compound containing a biomass-derived component as in the printed layer 50 described above. In addition, in the adhesive layer 30, the polyol containing a biomass-derived component can be the same polyol as in the printed layer 50 described above. When both the printed layer 50 and the adhesive layer 30 are formed using a cured product containing a biomass-derived component, the cured product in the printed layer 50 and the cured product in the adhesive layer 30 may have the same composition or different compositions.

The adhesive layer preferably has a biomass content of 5% or more, more preferably 5% to 50%, and even more preferably 30% to 50%. A biomass content within this range can reduce the amount of fossil fuel used and the environmental impact.

The weight of the adhesive layer after drying is preferably 0.1 g/m ² or more and 10 g/m ² or less, more preferably 1 g/m ² or more and 6 g/m ² or less, and even more preferably 2 g/m ² or more and 5 g/m ² or less.

The adhesive layer preferably has a thickness of 0.1 μm or more and 10 μm or less, more preferably 1 μm or more and 6 μm or less, and even more preferably 2 μm or more and 5 μm or less.

(Sealant layer)
The sealant film 42 of the sealant layer 40 constitutes the inner surface 10x of the packaging material 10. The sealant film 42 of the sealant layer 40 may or may not contain a biomass-derived component. When the sealant layer 40 is formed from a material containing a biomass-derived component, the sealant layer 40 can be formed using the biomass polyolefin described below. When the sealant layer 40 is formed from a material not containing a biomass-derived component, the sealant layer 40 can be formed using a conventionally known thermoplastic resin derived from fossil fuels.

Biomass polyolefins are polymers of monomers containing olefins such as ethylene derived from biomass. Because biomass-derived olefins are used as the raw material monomers, the resulting polymerized polyolefins are biomass-derived. Note that the raw material monomers for polyolefins do not have to contain 100% biomass-derived olefins by mass.

For example, biomass-derived ethylene can be produced using biomass-derived ethanol as a raw material. In particular, it is preferable to use biomass-derived fermented ethanol obtained from plant raw materials. There are no particular limitations on the plant raw material, and conventionally known plants can be used. Examples include corn, sugarcane, beet, and manioc.

Biomass-derived fermented ethanol refers to ethanol produced by contacting a culture medium containing a carbon source obtained from plant raw materials with an ethanol-producing microorganism or a product derived from its disrupted material, and then purifying the ethanol. Conventional methods such as distillation, membrane separation, and extraction can be used to purify ethanol from the culture medium. Examples include adding benzene, cyclohexane, etc., and then azeotroping, or removing water by membrane separation, etc.

The monomers used as raw materials for biomass polyolefins may further include fossil fuel-derived ethylene monomers and/or fossil fuel-derived α-olefin monomers, or may further include biomass-derived α-olefin monomers.

The above-mentioned α-olefins are not particularly limited in terms of the number of carbon atoms, but those with 3 to 20 carbon atoms can typically be used, with butylene, hexene, or octene being preferred. This is because butylene, hexene, or octene can be produced by polymerizing ethylene, a biomass-derived raw material. Furthermore, by including such α-olefins, the resulting polymerized polyolefin has a branched alkyl group structure, making it more flexible than simple linear polyolefins.

As biomass polyolefins, polyethylene or copolymers of ethylene and α-olefins may be used alone or in combination. It is particularly preferable that the biomass polyolefin be polyethylene. This is because, by using ethylene, a biomass-derived raw material, it is theoretically possible to produce polyolefins from 100% biomass-derived components.

The biomass polyolefin may contain two or more biomass polyolefins with different biomass degrees, as long as the biomass degree of the entire polyolefin resin layer is within the range described below.

The biomass polyolefin preferably has a density of 0.91 g/cm or ^more and 0.93 g/cm ^or less, more preferably 0.912 g/cm ^{or more} and 0.928 g/cm or less, and even more preferably 0.915 g/cm ^or more and ^0.925 g/cm or less. The density of the biomass polyolefin is a value measured according to the method specified in Method A of JIS K7112-1980 after annealing as described in JIS K6760-1995. If the density of the biomass polyolefin is 0.91 g/cm ^or more, the rigidity of the polyolefin resin layer containing the biomass polyolefin can be increased, making it suitable for use as an inner layer of a packaging product. Furthermore, if the density of the biomass polyolefin is 0.93 g/cm ^or less, the transparency and mechanical strength of the polyolefin resin layer containing the biomass polyolefin can be increased, making it suitable for use as an inner layer of a packaging product.

The biomass polyolefin has a melt flow rate (MFR) of 0.1 g/10 min or more and 10 g/10 min or less, preferably 0.2 g/10 min or more and 9 g/10 min or less, and more preferably 1 g/10 min or more and 8.5 g/10 min or less. The melt flow rate is a value measured by Method A under conditions of a temperature of 190°C and a load of 21.18 N, as specified in JIS K7210-1995. If the MFR of the biomass polyolefin is 0.1 g/10 min or more, the extrusion load during molding can be reduced. Furthermore, if the MFR of the biomass polyolefin is 10 g/10 min or less, the mechanical strength of the polyolefin resin layer containing the biomass polyolefin can be increased.

Suitable biomass polyolefins include biomass-derived low-density polyethylene manufactured by Braskem (trade name: SBC818, density: 0.918 g/cm ³ , MFR: 8.1 g/10 min, biomass content: 95%), biomass-derived low-density polyethylene manufactured by Braskem (trade name: SPB681, density: 0.922 g/cm ³ , MFR: 3.8 g/10 min, biomass content: 95%), and biomass-derived linear low-density polyethylene manufactured by Braskem (trade name: SLL118, density: 0.916 g/cm ³ , MFR: 1.0 g/10 min, biomass content: 87%).

Examples of the above-mentioned fossil fuel-derived thermoplastic resins include low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, high-density polyethylene, polypropylene, propylene-ethylene copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl methacrylate copolymer, and ionomers.

The sealant layer may be formed by dry laminating a sealant film onto the printed layer on the substrate layer side via an adhesive layer. Alternatively, the sealant layer may be formed by extruding the above-mentioned thermoplastic resin onto the adhesive layer side using a melt extrusion lamination method. When using the melt extrusion lamination method, the anchor coat layer may be formed by applying an anchor coat agent to the surface of the adhesive layer and drying it. Examples of anchor coat agents include any resin with a heat resistance temperature of 135°C or higher, such as vinyl-modified resins, epoxy resins, urethane resins, polyester resins, and polyethyleneimine. However, anchor coat agents that are cured products of polyacrylic or polymethacrylic resins (polyols) containing two or more hydroxyl groups in their structure and an isocyanate compound as a curing agent are particularly preferred. A silane coupling agent may also be used as an additive, and soluble nitrocellulose may also be used to enhance heat resistance.

After drying, the anchor coat layer has a thickness of 0.1 μm or more and 1 μm or less, preferably 0.3 μm or more and 0.5 μm or less. After drying, the adhesive layer has a thickness of 1 μm or more and 10 μm or less, preferably 2 μm or more and 5 μm or less. The adhesive resin layer preferably has a thickness of 5 μm or more and 50 μm or less, preferably 10 μm or more and 30 μm or less.

The sealant layer 40 preferably has a biomass ratio of 5% or more, more preferably 5% to 60%, and even more preferably 10% to 60%. A biomass ratio within the above range can reduce the amount of fossil fuel used and the environmental impact. While the biomass ratio is expressed as a weight ratio, it can also be expressed as a value measured by measuring the content of biomass-derived carbon by radiocarbon (C14) analysis. That is, the percentage of biomass-derived carbon can be calculated by measuring the percentage of C14 contained in the total carbon atoms in the sealant layer. When the C14 content in the sealant layer is P _C14 , the content of biomass-derived carbon, P _bio , can be calculated, as above, by the following formula: P _bio (%) = P _C14 /105.5 × 100
The biomass content of polyethylene produced using ethylene, a biomass-derived raw material, is the same whether expressed as a weight ratio or as a value measured by radiocarbon (C14) measurement of the content of biomass-derived carbon.

The sealant layer 40 may be a single layer or multiple layers. When using a biomass polyolefin as described above for the sealant layer, the sealant layer may have three layers: an inner layer, an intermediate layer, and an outer layer. In this case, it is preferable that the intermediate layer be made of a biomass polyolefin or a biomass polyolefin and a conventionally known fossil fuel-derived polyolefin, and that the inner and outer layers be made of conventionally known fossil fuel-derived polyolefins.

The sealant layer 40 preferably has a thickness of 10 μm or more and 300 μm or less, more preferably 20 μm or more and 200 μm or less, and even more preferably 30 μm or more and 150 μm or less.

(Barrier layer)
A layer other than those described above, such as a barrier layer, may be provided between the substrate layer and the printing layer and/or between the adhesive layer and the sealant layer. As the barrier layer, a metal foil or a vapor-deposited layer of an inorganic material or an inorganic oxide can be suitably used.

(metal foil)
Conventionally known metal foils can be used as the metal foil constituting the barrier layer. Aluminum foil is preferred from the viewpoints of gas barrier properties that prevent the transmission of oxygen gas, water vapor, etc., and light blocking properties that prevent the transmission of visible light, ultraviolet light, etc. Furthermore, it can impart metallic luster to the packaging bag, thereby improving the design. The thickness of the metal foil is, for example, 5 μm or more and 15 μm or less.

(vapor deposited layer)
The vapor-deposited layer 60 is a vapor-deposited film made of an inorganic substance and/or an inorganic oxide. The vapor-deposited film can be formed by a conventionally known method using a conventionally known inorganic substance or inorganic oxide, and the composition and method of formation are not particularly limited. The packaging material 10 may have two or more vapor-deposited layers 60. When the packaging material 10 has two or more vapor-deposited layers 60, the layers may have the same composition or different compositions.

The vapor deposition layer 60 can be, for example, a vapor deposition film of an inorganic substance or inorganic oxide such as silicon (Si), aluminum (Al), magnesium (Mg), calcium (Ca), potassium (K), tin (Sn), sodium (Na), boron (B), titanium (Ti), lead (Pb), zirconium (Zr), or yttrium (Y).

Vapor-deposited films of inorganic oxides such as silicon oxide and aluminum oxide are transparent. When the vapor-deposited layer 60 is located closer to the outer surface 10y than the printed layer 50, a vapor-deposited film of a transparent inorganic oxide is used as the vapor-deposited layer 60.

Inorganic oxides are expressed as _MOx (where M represents an inorganic element, and the value of X varies depending on the inorganic element), such as _SiOx , _AlOx , etc. The range of X is as follows: silicon (Si) is 0 to 2, aluminum (Al) is 0 to 1.5, magnesium (Mg) is 0 to 1, calcium (Ca) is 0 to 1, potassium (K) is 0 to 0.5, tin (Sn) is 0 to 2, sodium (Na) is 0 to 0.5, boron (B) is 0 to 1.5, titanium (Ti) is 0 to 2, lead (Pb) is 0 to 1, zirconium (Zr) is 0 to 2, and yttrium (Y) is 0 to 1.5. In the above, when X = 0, it is a completely inorganic element (pure substance) and is not transparent, and the upper limit of the range of X is the value when it is completely oxidized. Silicon (Si) and aluminum (Al) are preferably used for the vapor deposition layer 60 of the packaging material 10, and silicon (Si) having a value in the range of 1.0 to 2.0 and aluminum (Al) having a value in the range of 0.5 to 1.5 can be used.

The thickness of the above-mentioned inorganic or inorganic oxide vapor deposition film varies depending on the type of inorganic or inorganic oxide used, but it is desirable to select any thickness within the range of, for example, 50 Å to 2000 Å, preferably 100 Å to 1000 Å. More specifically, in the case of an aluminum vapor deposition film, the thickness is desirably 50 Å to 600 Å, more preferably 100 Å to 450 Å. Furthermore, in the case of an aluminum oxide or silicon oxide vapor deposition film, the thickness is desirably 50 Å to 500 Å, more preferably 100 Å to 300 Å.

The vapor deposition layer 60 can be formed on the base layer 20, sealant layer 40, etc. using the following methods. Examples of methods for forming the vapor deposition layer 60 include physical vapor deposition (PVD) methods such as vacuum deposition, sputtering, and ion plating, as well as chemical vapor deposition (CVD) methods such as plasma-enhanced chemical vapor deposition, thermal chemical vapor deposition, and photochemical vapor deposition.

(Gas barrier coating film)
The gas barrier coating film is a film that is provided on a vapor-deposited layer as needed. The gas barrier coating film functions as a layer that suppresses the permeation of oxygen gas, water vapor, and the like. The gas barrier coating film is obtained from a gas barrier composition that contains at least one alkoxide represented by the general formula R ¹ _n M(OR ² ) _m (wherein R ¹ and R ² represent organic groups having 1 to 8 carbon atoms, M represents a metal atom, n represents an integer of 0 or greater, m represents an integer of 1 or greater, and n + m represents the atomic valence of M) and the above-mentioned polyvinyl alcohol resin and/or ethylene-vinyl alcohol copolymer, and further, is polycondensed by a sol-gel process in the presence of a sol-gel catalyst, an acid, water, and an organic solvent.

As the alkoxide represented by the general formula R ¹ _n M(OR ² ) _m , at least one of a partial hydrolyzate of an alkoxide and a condensate of the hydrolysis of an alkoxide can be used. Furthermore, the partial hydrolyzate of the alkoxide does not necessarily have to have all of the alkoxy groups hydrolyzed, and may be one in which one or more alkoxy groups are hydrolyzed, or a mixture thereof. As the condensate of the hydrolysis of an alkoxide, a dimer or higher of a partially hydrolyzed alkoxide, specifically a dimer to a hexamer, is used.

In the alkoxide represented by the general formula R ¹ _n M(OR ² ) _m , silicon, zirconium, titanium, aluminum, and the like can be used as the metal atom represented by M. In this embodiment, preferred metals include silicon and titanium. In addition, in the present invention, the alkoxide can be used alone or by mixing two or more alkoxides of different metal atoms in the same solution.

In the alkoxides represented by the general formula R ¹ _n M(OR ² ) _m , specific examples of the organic group represented by R ¹ include alkyl groups such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, t-butyl, n-hexyl, n-octyl, and the like. In the alkoxides represented by the general formula R ¹ _n M(OR ² ) _m , specific examples of the organic group represented by R ² include methyl, ethyl, n-propyl, i-propyl, n-butyl, sec-butyl, and the like. These alkyl groups may be the same or different within the same molecule.

When preparing the gas barrier composition, for example, a silane coupling agent may be added. Known organoalkoxysilanes containing organic reactive groups can be used as the silane coupling agent. In this embodiment, organoalkoxysilanes containing epoxy groups are particularly preferred. Specific examples include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane. The above-mentioned silane coupling agents may be used alone or in combination of two or more.

<Method of manufacturing packaging material>
Next, an example of a method for manufacturing the laminate that constitutes the packaging material 10 will be described.

First, the above-mentioned base layer 20 and are prepared. The base layer 20 has a printed layer 50 already formed on it. If necessary, the base layer 20 may also include a barrier layer 60 such as a vapor deposition layer or a gas barrier coating film.

Next, the printed layer 50 side of the base layer 20 is laminated to the sealant layer 40 via the adhesive layer 30 using a dry lamination method. This allows for the production of a packaging material 10 comprising the base layer 20, printed layer 50, adhesive layer 30, and sealant layer 40.

In the dry lamination method, an adhesive composition is first applied to one of the two films to be laminated. The applied adhesive composition is then dried to volatilize the solvent. The two films are then laminated together via the dried adhesive composition. The two laminated films are then rolled up and aged, for example, in an environment of 20°C or higher for 24 hours or more.

The packaging material 10 can also be subjected to secondary processing to impart surface functions such as chemical functions, electrical functions, magnetic functions, mechanical functions, friction/wear/lubrication functions, optical functions, thermal functions, and biocompatibility. Examples of secondary processing include embossing, painting, adhesives, printing, metallizing (plating, etc.), machining, and surface treatments (antistatic treatment, corona discharge treatment, plasma treatment, photochromism treatment, physical vapor deposition, chemical vapor deposition, coating, etc.). Additionally, the packaging material of the present invention can be subjected to lamination (dry lamination or extrusion lamination), bag making, and other post-processing processes to produce molded products.

<Packaged products>
Examples of packaging products formed using the packaging material include packaging bags, laminated tubes, lid materials, sheet molded products, label materials, and the like.

Packaged products equipped with the packaging material can be suitably used to package various types of food and beverages, such as food and beverages, fruit juices, juices, drinking water, alcohol, prepared foods, fish paste products, frozen foods, meat products, simmered dishes, rice cakes, liquid soups such as hot pot soup, seasonings, cosmetics such as liquid detergent, shampoo, rinse, and conditioner, hygiene products, daily necessities, and chemical products. Specific examples of food and beverages include coffee, coffee beans, coffee powder, ice cream, gummies, prepared dishes, pasta sauce, curry, jelly, bacon, chocolate, and chocolate paste. Specific examples of daily necessities include absorbent cotton, masks, bath salts, and powdered milk. Furthermore, as illustrated in the examples described below, packaged products equipped with packaging material 10 configured to be heat-resistant can be used to contain contents that undergo heat sterilization treatments such as retort and boiling. Retort treatment is a process in which the contents are filled into a package, the package is sealed, and then the package is heated under pressure using steam or heated hot water. The temperature for retort processing is, for example, 120°C or higher. Boiling processing is a process in which the contents are filled into a packaged product, the packaged product is sealed, and then the packaged product is heated in a water bath under atmospheric pressure. The temperature for boiling processing is, for example, 90°C or higher and 100°C or lower.

Packaging bags for packaged products can be produced by folding the packaging material 10 in half, or by preparing two sheets of packaging material 10 and overlapping them with the sealant layer 40 of the front packaging material 10 facing the sealant layer 40 of the back packaging material 10. The peripheral edges are then heat-sealed using a heat seal technique, such as a side seal, two-sided seal, three-sided seal, four-sided seal, envelope seal, hem seal (pillow seal), pleated seal, flat bottom seal, or square bottom seal. A gusset-type packaging bag can also be produced by inserting a folded-over packaging material 10 between the front and back packaging materials 10 and heat sealing the materials. It is not necessary for all of the packaging material 10 making up the packaging bag to be the packaging material 10 of the present invention. In other words, it is sufficient that at least a portion of the packaging material 10 that constitutes the packaging bag has an adhesive layer containing a biomass-derived component, and the other portion of the packaging material 10 that constitutes the packaging bag may be packaging material 10 that has an adhesive layer derived from fossil fuels.

Heat sealing can be performed using known methods such as bar sealing, rotary roll sealing, belt sealing, impulse sealing, high frequency sealing, and ultrasonic sealing.

Figure 5 shows an example of a packaging bag 70 containing packaging material 10. The bag 70 includes a surface film 74 that forms the surface, a back film 75 that forms the back, and a lower film 76 that forms the lower portion 72. The lower film 76 is folded back at a fold portion 76f and is positioned between the surface film 74 and the back film 75. In this way, the packaging bag 70 shown in Figure 5 is a self-standing pouch with a gusseted lower portion.

The inner surfaces of the surface film 74, back film 75, and bottom film 76 are joined together by a seal. In front views of the packaging bag 70, such as Figure 5, the seal is hatched. As shown in Figure 5, the seal has an outer edge seal that extends along the outer edge of the packaging bag 70. The outer edge seal includes a lower seal 72a that extends to the bottom 72, and a pair of side seals 73a that extend along a pair of side portions 73. Note that, before the contents are filled into the packaging bag 70 (when no contents are filled), the top 71 of the bag 70 forms an opening 71b, as shown in Figure 5. After the contents are placed in the packaging bag 70, the inner surfaces of the surface film 74 and back film 75 are joined at the top 71 to form an upper seal, sealing the packaging bag 70.

The terms "surface film," "back film," and "bottom film" mentioned above merely distinguish between the films according to their positional relationships, and the method of providing packaging material 10 when manufacturing packaging bag 70 is not limited by the terms mentioned above. For example, packaging bag 70 may be manufactured using one sheet of packaging material 10 in which surface film 74, back film 75, and bottom film 76 are connected together; it may be manufactured using two sheets of packaging material 10, one sheet of packaging material 10 in which surface film 74 and bottom film 76 are connected together and one back film 75; or it may be manufactured using three sheets of packaging material 10, one sheet of surface film 74, one sheet of back film 75, and one bottom film 76.

At least one of the front film 74, back film 75, and bottom film 76 is made of packaging material 10 having an adhesive layer containing biomass-derived components. This allows for a reduction in the amount of fossil fuel used compared to conventional methods, thereby reducing the environmental impact.

Figure 6 is a diagram showing another example of a packaging bag 70 including packaging material 10. The packaging bag 70 shown in Figure 6 is substantially identical to the packaging bag 70 shown in Figure 5 in other respects, except that it further includes a steam vent mechanism 80. In the packaging bag 70 shown in Figure 6, the same parts as those in the packaging bag 70 shown in Figure 5 are designated by the same reference numerals and detailed descriptions thereof will be omitted.

As shown in Figure 6, the packaging bag 70 is equipped with a steam vent mechanism 80 for releasing steam generated when the contents stored in the storage section 77 are heated to the outside. The steam vent mechanism 80 is configured to communicate between the inside and outside of the packaging bag 70 to release steam when the steam pressure reaches a predetermined value or higher, and to prevent steam from escaping from locations other than the steam vent mechanism 80.

In the example shown in Figure 6, the steam release mechanism 80 has a steam release seal portion 81 that protrudes from the side seal portion 73a toward the inside of the packaging bag 70, and an unsealed portion 82 that is isolated from the storage portion 77 by the steam release seal portion 81. The unsealed portion 82 is in communication with the outside of the packaging bag 70. When the pressure in the storage portion 77 increases due to heating in a microwave oven or the like, the steam release seal portion 81 peels off. Steam in the storage portion 77 can escape to the outside of the packaging bag 70 through the peeled portion of the steam release seal portion 81 and the unsealed portion 82.

The configuration of the steam release mechanism 80 is not limited to the configuration shown in Figure 6. The steam release mechanism 80 may have any configuration as long as it can connect the storage section 77 to the outside of the packaging bag 70 when the steam pressure reaches or exceeds a predetermined value.

In the packaging bag 70 shown in Figure 6, at least one of the surface film 74, back film 75, and bottom film 76 is made of packaging material 10 having an adhesive layer containing biomass-derived components. This allows for a reduction in the amount of fossil fuel used compared to conventional methods, thereby reducing the environmental impact.

Figure 7 is a diagram showing another example of a packaging bag 70 including packaging material 10. The packaging bag 70 shown in Figure 7 is substantially identical to the packaging bag 70 shown in Figure 5 in other respects, except that it further includes a spout 85. In the packaging bag 70 shown in Figure 7, the same parts as those in the packaging bag 70 shown in Figure 5 are designated by the same reference numerals and detailed descriptions thereof will be omitted.

As shown in FIG. 7 , the packaging bag 70 is the portion through which the contents stored in the storage section 77 pass when being removed. In this case, the contents are a fluid liquid or the like. The width of the spout section 85 is narrower than the width of the storage section 77. This allows the user to accurately determine the pouring direction of the contents as they are poured from the packaging bag 70 through the spout section 85.

In the example shown in Figure 7, the spout section 85 is made up of a portion of the front film 74 and the back film 75. For example, the spout section 85 includes a spout seal section 86 that joins the front film 74 and the back film 75 to define the spout section 85, which has a width narrower than the storage section 77. A packaging bag 70 equipped with such a spout section 85 is suitable for use as a refill pouch for storing contents such as detergent, shampoo, and conditioner that can be refilled into a bottle.

Note that the configuration of the spout portion 85 is not limited to the configuration shown in Figure 7, as long as the contents can be properly poured. For example, the spout portion 85 may be a separate member from the front film 74 and back film 75, such as a spout.

In the packaging bag 70 shown in Figure 7, at least one of the surface film 74, back film 75, and bottom film 76 is made of packaging material 10 having an adhesive layer containing biomass-derived components. This allows for a reduction in the amount of fossil fuel used compared to conventional methods, thereby reducing the environmental impact.

Figure 8 shows another example of a packaging bag 70 including packaging material 10. The packaging bag 70 shown in Figure 8 is a four-sided sealed pouch formed by joining a front film 74 and a back film 75 on four sides along the outer edge. Note that, as with the examples shown in Figures 5 to 7, the top seal is formed on the top 71 after the contents are placed in the packaging bag 70 through the opening 71b.

In the packaging bag 70 shown in Figure 8, at least one of the front film 74 and back film 75 is made of packaging material 10 having an adhesive layer containing biomass-derived components. This allows for a reduction in the amount of fossil fuel used compared to conventional methods, thereby reducing the environmental impact.

Although not shown, the packaging bag 70 may be a three-sided sealed pouch formed by joining the front film 74 and the back film 75 on three sides along the outer edge. Also, although not shown, the packaging bag 70 may be a pillow pouch joined at the top 71, bottom 72, and seam.

Figure 9 shows an example of a lidded container 90 equipped with packaging material 10. The lidded container 90 comprises a container body 92 produced by sheet molding such as drawing, and a lid portion 94 joined to the container body 92.

In the example shown in Figure 9, the container body 92 is produced by extrusion molding a packaging material 10 having an adhesive layer containing biomass-derived components. This allows for a reduction in the amount of fossil fuel used compared to conventional methods, thereby reducing the environmental impact.

Furthermore, in the example shown in Figure 9, the lid portion 94 may be formed from a packaging material 10 having an adhesive layer containing biomass-derived components. This allows for a reduction in the amount of fossil fuel used compared to conventional methods, thereby reducing the environmental burden.

<Other Aspects>
According to another aspect of the present invention, there is provided a packaging material including at least a base layer, a printing layer, an adhesive layer, and a sealant layer, wherein the adhesive layer is in contact with the sealant layer, the adhesive layer includes a cured product of a polyol and an isocyanate compound, and at least one of the polyol and the isocyanate compound includes a biomass-derived component.
In the packaging material according to another aspect of the present invention, the polyol of the adhesive layer may be a polyester polyol which is a reaction product of a polyfunctional alcohol and a polyfunctional carboxylic acid.
In the packaging material according to another aspect of the present invention, at least one of the polyfunctional alcohol and the polyfunctional carboxylic acid in the adhesive layer may contain a biomass-derived component.
In the packaging material according to another aspect of the present invention, the polyol in the adhesive layer may be a polyether polyol that is a reaction product of a polyfunctional alcohol and a polyfunctional isocyanate.
In the packaging material according to another aspect of the present invention, at least one of the polyfunctional alcohol and the polyfunctional isocyanate in the adhesive layer may contain a biomass-derived component.
In the packaging material according to another aspect of the present invention, the isocyanate compound of the adhesive layer may contain a biomass-derived component.
In another aspect of the packaging material of the present invention, the printed layer contains a colorant and a cured product of a polyol and an isocyanate compound, and at least one of the polyol or the isocyanate compound may contain a biomass-derived component.
In the packaging material according to another aspect of the present invention, the polyol in the printed layer may be a polyester polyol that is a reaction product of a polyfunctional alcohol and a polyfunctional carboxylic acid.
In the packaging material according to another aspect of the present invention, at least one of the polyfunctional alcohol and the polyfunctional carboxylic acid in the printed layer may contain a biomass-derived component.
In the packaging material according to another aspect of the present invention, the polyol in the printed layer may be a polyether polyol that is a reaction product of a polyfunctional alcohol and a polyfunctional isocyanate.
In the packaging material according to another aspect of the present invention, at least one of the polyfunctional alcohol and the polyfunctional isocyanate in the printed layer may contain a biomass-derived component.
In the packaging material according to another aspect of the present invention, the substrate layer may have a substrate film containing polyester, polyamide, or polyolefin.
In the packaging material according to another aspect of the present invention, the base film may contain a biomass polyester having biomass-derived ethylene glycol as the diol unit and a fossil fuel-derived dicarboxylic acid as the dicarboxylic acid unit.
In the packaging material according to another aspect of the present invention, the sealant layer may contain polyolefin, which is a polymer of a monomer containing olefin.
In the packaging material according to another aspect of the present invention, the sealant layer may contain biomass polyolefin, which is a polymer of a monomer containing ethylene derived from biomass.
According to another aspect of the present invention, there is provided a packaging product comprising the packaging material described above.

Next, the present invention will be explained in more detail using examples, but the present invention is not limited to the description of the following examples as long as it does not depart from the gist of the invention.

[Example 1A]
A fossil fuel-derived biaxially stretched PET film (thickness: 12 μm) was prepared as the base film 22 of the base layer 20. Subsequently, a printed layer 50 was formed on the inner surface of the PET film using a fossil fuel-derived ink containing a cured product of a base agent containing a fossil fuel-derived polyester polyol and a curing agent containing a fossil fuel-derived isocyanate compound, with a colorant further added.

The sealant film 42 of the sealant layer 40 was a polyethylene film 1 prepared as follows. First, 90 parts by mass of a fossil fuel-derived linear low-density polyethylene (density: 0.918 g/cm ³ , MFR: 3.8 g/10 min, biomass content: 0%) and 10 parts by mass of a fossil fuel-derived low-density polyethylene (density: 0.924 g/cm ³ , MFR: 2.0 g/10 min, biomass content: 0%) were melt-kneaded to obtain a resin composition. The resulting resin composition was then formed into a film using a top-blown, air-cooled inflation co-extrusion film-forming machine to obtain a single-layer polyethylene film (biomass content: 0%) for the sealant layer. The polyethylene film prepared in this manner is also referred to as polyethylene film 1. The thickness of polyethylene film 1 was 30 μm. Next, the base film 22 on which the printed layer 50 was formed and the sealant film 42 were bonded together by dry lamination using an adhesive layer 30 containing a biomass-derived component to obtain the packaging material 10. The adhesive layer 30 has a cured product of a polyether polyol (base material) obtained by reacting a polyfunctional alcohol containing a biomass-derived component with a fossil fuel-derived polyfunctional isocyanate, and a fossil fuel-derived isocyanate compound (curing agent).

The layer structure of the packaging material 10 of this embodiment is expressed as follows.
PET12/Seal/Bio-bonded/PE(1)30
The "/" indicates the boundary between layers. The leftmost layer is the layer that forms the outer surface of the packaging material 10, and the rightmost layer is the layer that forms the inner surface of the packaging material 10.
"PET" means fossil-derived biaxially oriented PET film.
"Mark" refers to a printing layer derived from fossil fuels.
"Bio-adhesive" refers to an adhesive layer derived from biomass.
"PE(1)" refers to polyethylene film 1 as described above.
The numbers indicate the layer thickness (unit: μm).

[Example 1B]
The packaging material 10 was produced in the same manner as in Example 1A, except that the polyether polyol, which is the main component of the adhesive layer 30, was a reaction product of a fossil fuel-derived polyfunctional alcohol and a polyfunctional isocyanate containing a biomass-derived component.

[Example 1C]
The packaging material 10 was produced in the same manner as in Example 1A, except that a reaction product of a fossil fuel-derived polyfunctional alcohol and a fossil fuel-derived polyfunctional isocyanate was used as the polyether polyol, which was the main component of the adhesive layer 30, and an isocyanate compound containing a biomass-derived component was used as the isocyanate compound, which was the curing agent.

In Examples 1A to 1C, one of the three components of the adhesive layer - the polyfunctional alcohol or polyfunctional isocyanate used in the main polyether polyol, or the isocyanate compound used in the curing agent - is a biomass-derived component, but this is not limited to this. For example, two of the three components may contain biomass-derived components, or all three components may contain biomass-derived components.

[Example 1D]
A packaging material 10 was produced in the same manner as in Example 1A, except that a material containing a biomass-derived component was used for the printed layer 50. Specifically, a reaction product of a polyfunctional alcohol containing a biomass-derived component and a fossil fuel-derived polyfunctional isocyanate was used as the polyether polyol, the main component of the printed layer 50. In addition, a fossil fuel-derived isocyanate compound was used as the curing agent for the printed layer 50.

The layer structure of the packaging material 10 of this embodiment is expressed as follows.
PET12/Bio-marked/Bio-bonded/PE(1)30
"Bio-mark" means a printed layer derived from biomass.

[Example 1E]
The packaging material 10 was prepared in the same manner as in Example 1D, except that the polyether polyol, which is the main component of the printed layer 50, was a reaction product of a fossil fuel-derived polyfunctional alcohol and a polyfunctional isocyanate containing a biomass-derived component.

[Example 1F]
The packaging material 10 was produced in the same manner as in Example 1D, except that the polyether polyol, which is the main component of the printed layer 50, was a reaction product of a fossil fuel-derived polyfunctional alcohol and a fossil fuel-derived polyfunctional isocyanate, and the isocyanate compound, which is the curing agent of the printed layer 50, was an isocyanate compound containing a biomass-derived component.

[Example 1G]
A packaging material 10 was produced in the same manner as in Example 1A, except that a material containing a biomass-derived component was used as the printed layer 50. Specifically, a polyester polyol, which is a reaction product of a polyfunctional alcohol containing a biomass-derived component and a fossil fuel-derived polyfunctional carboxylic acid, was used as the base material for the printed layer 50. In addition, a fossil fuel-derived isocyanate compound was used as the curing agent for the printed layer 50.

[Example 1H]
The packaging material 10 was prepared in the same manner as in Example 1G, except that the polyester polyol, which is the main component of the printed layer 50, was a reaction product of a fossil fuel-derived polyfunctional alcohol and a polyfunctional carboxylic acid containing a biomass-derived component.

[Example 1I]
The packaging material 10 was produced in the same manner as in Example 1G, except that the polyester polyol, which is the main component of the printed layer 50, was a reaction product of a fossil fuel-derived polyfunctional alcohol and a fossil fuel-derived polyfunctional carboxylic acid, and the isocyanate compound, which is the curing agent of the printed layer 50, was an isocyanate compound containing a biomass-derived component.

In Examples 1G to 1I, one of the three components of the printed layer - the polyfunctional alcohol or polyfunctional carboxylic acid used in the polyester polyol base, or the isocyanate compound used in the curing agent - is a biomass-derived component, but this is not limited to this. For example, two of the three components may contain biomass-derived components, or all three components may contain biomass-derived components.

In addition, in Examples 1D to 1I, the adhesive layer shown in Examples 1B to 1C may be used as the adhesive layer in addition to the adhesive layer shown in Example 1A.

[Example 1J]
A packaging material 10 was produced in the same manner as in Example 1G, except that a biaxially stretched PET film (thickness 12 μm) containing a biomass-derived component was used as the base film 22.

The layer structure of the packaging material 10 of this embodiment is expressed as follows.
Bio PET12 / Bio mark / Bio adhesive / PE(1)30
"BioPET" refers to a PET film derived from biomass.

[Example 1K]
A packaging material 10 was produced in the same manner as in Example 1G, except that a polyethylene film 2 produced as described below was used as the sealant film 42 of the sealant layer 40.
The method for producing the polyethylene film 2 will be described. First, 60 parts by mass of fossil fuel-derived linear low-density polyethylene (density: 0.918 g/cm ³ , MFR: 3.8 g/10 min, biomass content: 0%), 20 parts by mass of fossil fuel-derived low-density polyethylene (density: 0.924 g/cm ³ , MFR: 2.0 g/10 min, biomass content: 0%), and 20 parts by mass of biomass-derived linear low-density polyethylene (LLDPE, manufactured by Braskem, trade name: SLL118, density: 0.916 g/cm ³ , MFR: 1.0 g/10 min, biomass content: 87%) were melt-kneaded to obtain a resin composition. Next, the obtained resin composition was formed into a film using a top-blown, air-cooled inflation co-extrusion film-forming machine to obtain a single-layer polyethylene film 2 (biomass content: 16%) for the sealant layer. The thickness of the polyethylene film 2 was set to 30 μm, the same as that of the polyethylene film 1 in Example 1A.

The layer structure of the packaging material 10 of this embodiment is expressed as follows.
PET12/Bio-marked/Bio-bonded/PE(2)30
"PE(2)" refers to the polyethylene film 2 described above.

[Example 1L]
The packaging material 10 was produced in the same manner as in Example 1G, except that a biaxially stretched PET film (thickness 12 μm) containing a biomass-derived component was used as the base film 22, and a polyethylene film containing a biomass-derived component was used as the sealant film 42 of the sealant layer 40.

The layer structure of the packaging material 10 of this embodiment is expressed as follows.
Bio PET12 / Bio mark / Bio adhesive / PE(2)30

In addition, in Examples 1J to 1L, the adhesive layer may be the adhesive layer shown in Examples 1B to 1C in addition to the adhesive layer shown in Example 1A. Furthermore, the printed layer may be the printed layer shown in Examples 1A to 1I in addition to the printed layer shown in Example 1G.

The layer structures of the packaging materials 10 of Examples 1A to 1L are shown together in Figure 10. In the "Type of adhesive layer" column of Figure 10, the term "ether-based" means that the main agent used in the adhesive layer is polyether polyol.
In the column "Biomass-derived components in adhesive layer," the term "polyfunctional alcohol" means that at least the polyfunctional alcohol of the main agent, among the main agent and curing agent components used in the adhesive layer, is derived from biomass. Similarly, the term "isocyanate compound" means that at least the isocyanate compound of the curing agent, among the main agent and curing agent components used in the adhesive layer, is derived from biomass.

Similarly, in the "Type of Printed Layer" column, "Ether-based" means that the base agent used in the printed layer is polyether polyol. Furthermore, "Ester-based" means that the base agent used in the printed layer is polyester polyol. Furthermore, in the "Biomass-derived Components in Printed Layer" column, "Multifunctional Alcohol" means that, of the base agent and curing agent components used in the printed layer, at least the multifunctional alcohol of the base agent is derived from biomass. Similarly, "Multifunctional Carboxylic Acid" means that, of the base agent and curing agent components used in the printed layer, at least the multifunctional carboxylic acid of the base agent is derived from biomass. Similarly, "Isocyanate Compound" means that, of the base agent and curing agent components used in the printed layer, at least the isocyanate compound of the curing agent is derived from biomass. Furthermore, in the "Biomass-derived Components in Printed Layer" column, "-" means that the printed layer does not contain biomass-derived components.

[Example 2A]
A fossil fuel-derived biaxially stretched polypropylene film (thickness: 20 μm) was prepared as the base film 22 of the base layer 20. Subsequently, a printed layer 50 was formed on the inner surface of the polypropylene film using the same ink as used in Example 1A.

A polyethylene film 1 with a thickness of 25 μm was prepared as the sealant film 42 of the sealant layer 40. Next, the base film 22 on which the printing layer 50 was formed and the sealant film 42 were bonded together by dry lamination using the same adhesive as used in Example 1A to obtain the packaging material 10.

The layer structure of the packaging material 10 of this embodiment is expressed as follows.
OPP20/Seal/Bio-connector/PE(1)25
"OPP" means fossil fuel derived biaxially oriented polypropylene film.

[Example 2B]
A packaging material 10 was produced in the same manner as in Example 2A, except that the base film 22 was a polypropylene film in which a vapor-deposited layer of an inorganic oxide and a gas barrier coating film located on the vapor-deposited layer were provided on the surface of a fossil fuel-derived biaxially oriented polypropylene film (thickness: 20 μm).

The layer structure of the packaging material 10 of this embodiment is expressed as follows.
Barrier OPP20/Seal/Bio-bonding/PE(1)25
"Barrier OPP" refers to a polypropylene film in which a vapor-deposited layer of inorganic oxide and a gas barrier coating film are provided on a biaxially stretched polypropylene film derived from fossil fuels.

[Example 3]
A packaging material 10 was produced in the same manner as in Example 1A, except that a polypropylene film (thickness 20 μm) derived from fossil fuels with a metal vapor deposition layer was used as the sealant film 42.

The layer structure of the packaging material 10 of this embodiment is expressed as follows.
PET12/Seal/Bio-sealed/VMCPP20
"VMCPP" means a fossil fuel-derived biaxially oriented polypropylene film provided with a metallized layer.

[Example 4]
A packaging material 10 was produced in the same manner as in Example 2A, except that a polypropylene film (thickness 25 μm) derived from fossil fuels with a metal vapor deposition layer was used as the sealant film 42.

The layer structure of the packaging material 10 of this embodiment is expressed as follows.
OPP20/Seal/Bio-seal/VMCPP25

[Example 5]
A packaging material 10 was produced in the same manner as in Example 1A, except that a fossil fuel-derived polypropylene film (thickness: 20 μm) was used as the sealant film 42.

The layer structure of the packaging material 10 of this embodiment is expressed as follows.
PET12/Seal/Bio-sealed/CPP20

[Example 6A]
A packaging material 10 was produced in the same manner as in Example 2A, except that a fossil fuel-derived polypropylene film (thickness: 20 μm) was used as the sealant film 42.

The layer structure of the packaging material 10 of this embodiment is expressed as follows.
OPP20/Seal/Bio-seal/CPP20

[Example 6A]
A packaging material 10 was produced in the same manner as in Example 2B, except that a fossil fuel-derived polypropylene film (thickness: 20 μm) was used as the sealant film 42.

The layer structure of the packaging material 10 of this embodiment is expressed as follows.
Barrier OPP20/Seal/Bio-seal/CPP20

[Example 7]
A packaging material 10 was produced in the same manner as in Example 1A, except that a fossil fuel-derived nylon film (thickness: 60 μm) was used as the sealant film 42.

The layer structure of the packaging material 10 of this embodiment is expressed as follows.
PET20/Seal/Bio-bonded/CNY60
"CNY" stands for fossil fuel-derived nylon film.

[Example 8]
A packaging material 10 was produced in the same manner as in Example 1A, except that the base film 22 was a fossil fuel-derived biaxially stretched PET film (thickness 12 μm) provided with a vapor deposition layer of an inorganic oxide and a gas barrier coating film located on the vapor deposition layer, and the sealant film 42 was a fossil fuel-derived polypropylene film (thickness 25 μm).

The layer structure of the packaging material 10 of this embodiment is expressed as follows.
IB-PET12/Print/Bio-seal/CPP25
"IB-PET" refers to a PET film provided with a vapor-deposited layer of an inorganic oxide and a gas barrier coating film located on the vapor-deposited layer.

[Example 9]
A packaging material 10 was produced in the same manner as in Example 8, except that a polyethylene film 1 having a thickness of 40 μm was used as the sealant film 42.

The layer structure of the packaging material 10 of this embodiment is expressed as follows.
IB-PET12/Seal/Bio-bonded/PE(1)40

In the packaging materials of Examples 2A to 9 described above, the adhesive layer may be different from that used in Example 1A, and may be the adhesive layers shown in Examples 1B to 1C. Furthermore, the printed layer may be different from that used in Example 1A, and may have variations similar to those used in Examples 1B to 1L.

[Example 10]
A packaging material 10 was produced in the same manner as in Example 1A, except that a fossil fuel-derived biaxially stretched nylon film (thickness: 15 μm) was used as the base film 22, a 50 μm-thick polyethylene film 1 was used as the sealant film 42, a polyester polyol, which is a reaction product of a polyfunctional alcohol containing a biomass-derived component and a fossil fuel-derived polyfunctional carboxylic acid, was used as the main agent for the adhesive layer 30, and an isocyanate compound derived from a fossil fuel was used as the curing agent.

The layer structure of the packaging material 10 of this embodiment is expressed as follows.
ONY15/Seal/Bio-connector/PE(1)50
"ONY" means fossil fuel derived biaxially oriented nylon film.

[Example 11]
A packaging material 10 was produced in the same manner as in Example 10, except that a fossil fuel-derived biaxially stretched nylon film (thickness 15 μm) was used as the base film 22, which was a nylon film provided with a vapor-deposited layer of an inorganic oxide and a gas barrier coating film located on the vapor-deposited layer.

The layer structure of the packaging material 10 of this embodiment is expressed as follows.
IB-ONY15/Seal/Bio-connector/PE(1)50
"IB-ONY" refers to a fossil fuel-derived biaxially oriented nylon film having a vapor-deposited inorganic oxide layer and a gas barrier coating film positioned on the vapor-deposited layer.

In addition to the adhesive layer described above, in Examples 10 and 11, the adhesive layer may be an adhesive layer using, as the main agent, a polyester polyol, which is a reaction product of a fossil fuel-derived polyfunctional alcohol and a polyfunctional carboxylic acid containing a biomass-derived component, and an isocyanate compound derived from a fossil fuel, as the curing agent. Alternatively, the adhesive layer may be an adhesive layer using, as the main agent, a polyester polyol, which is a reaction product of a fossil fuel-derived polyfunctional alcohol and a fossil fuel-derived polyfunctional carboxylic acid, and an isocyanate compound containing a biomass-derived component, as the curing agent.

In addition, the printed layer may be other than that used in Example 1A, and variations similar to those in Examples 1B to 1L may be used.

Figure 11 shows examples of the layer structure and packaging container types of the packaging material 10 for Examples 1A, 2A to 11.

10 Packaging material 20 Base layer 22 Base film 30 Adhesive layer 40 Sealant layer 42 Sealant film 50 Printed layer 60 Barrier layer

Claims (11)

A packaging material comprising at least a substrate layer, a printing layer, an adhesive layer, a barrier layer, and a sealant layer in this order,
the adhesive layer contains a cured product of a polyol and an isocyanate compound,
the polyol of the adhesive layer is a polyether polyol, which is a reaction product of a polyfunctional alcohol and a polyfunctional isocyanate;
the polyfunctional alcohol of the adhesive layer is derived from a fossil fuel;
the polyfunctional isocyanate of the adhesive layer contains a biomass-derived component ,
A packaging material, wherein the isocyanate compound of the adhesive layer is derived from a fossil fuel. The packaging material according to claim 1, wherein the barrier layer is a vapor-deposited film of an inorganic substance or an inorganic oxide. The packaging material according to claim 1 or 2, consisting only of the substrate layer, the printing layer, the adhesive layer, the barrier layer, and the sealant layer. the printed layer contains a colorant and a cured product of a polyol and an isocyanate compound, and at least one of the polyol and the isocyanate compound contains a biomass-derived component;
The packaging material according to claim 1 , wherein the polyol in the printed layer is a polyester polyol that is a reaction product of a polyfunctional alcohol and a polyfunctional carboxylic acid. The packaging material according to claim 4, wherein at least one of the polyfunctional alcohol and the polyfunctional carboxylic acid in the printed layer contains a biomass-derived component. the printed layer contains a colorant and a cured product of a polyol and an isocyanate compound, and at least one of the polyol and the isocyanate compound contains a biomass-derived component;
The packaging material according to claim 1 , wherein the polyol in the printed layer is a polyether polyol that is a reaction product of a polyfunctional alcohol and a polyfunctional isocyanate. The packaging material according to claim 6, wherein at least one of the polyfunctional alcohol and the polyfunctional isocyanate in the printed layer contains a biomass-derived component. The packaging material according to any one of claims 1 to 7, wherein the substrate layer has a substrate film containing polyethylene terephthalate or polypropylene. The packaging material according to any one of claims 1 to 8, wherein the sealant layer comprises polypropylene. The packaging material according to any one of claims 1 to 8, wherein the sealant layer contains a biomass polyolefin, which is a polymer of a monomer containing ethylene derived from biomass. A packaging product comprising the packaging material of any one of claims 1 to 10.