JP2024036095A - Packaging material and its manufacturing method - Google Patents

Abstract

[Problem] The present invention provides a packaging material that is less affected by elution to the contents when made into a packaging bag, has excellent lamination strength, and has good tearability even after time has passed after filling the contents. The task is to [Solution] A packaging material having a base material, a printed layer, an adhesive layer, and a sealant in this order, wherein the printed layer is a polyester-based urethane resin (A) having a molecular weight distribution (Mw/Mn) of 4 to 12. ), the adhesive layer is made of a cured product of a reactive adhesive containing a urethane polyol (B1) and an isocyanate compound (B2), and the isocyanate compound (B2) has a molecular weight distribution (Mw/Mn) of A packaging material having a rating of 5.5 to 18.5. [Selection diagram] None

Description

The present invention relates to a packaging material and a method for manufacturing the same.

Generally, packaging bags are provided with a printing layer made of ink in order to add patterns such as pictures and to make the contents invisible. These inks include offset inks, flexo inks, silk screen inks, gravure inks, and other printing inks. Among them, gravure ink is often used because it has high productivity due to its printing speed and ability to create high-definition patterns.

In food packaging and flexible packaging, a printed layer gravure printed on a base material is further laminated with an adhesive layer, a thermoplastic base material, etc. in this order to form a laminate. The laminate becomes a packaging bag by further heat-sealing the sealant, which is a thermoplastic base material, to each other. In such packaging bags, if the adhesion between the layers is low, the layers may peel off during filling or transportation, resulting in problems such as poor design and leakage of contents. In the body, good interlayer adhesion strength is required.

Further, in food packaging bags, liquid sachets and the like are often opened by tearing the packaging bag directly by hand in order to take out the contents. At that time, the ability to tear and open the packaging bag without using tools such as scissors is a great advantage in terms of convenience, giving it a higher market value. However, if the packaging bag has poor tearability, especially if the contents of the packaging bag are liquid, there may be problems such as excessive force being required when opening the bag, or the bag being torn in an unexpected direction and the contents spilling out. Therefore, good tearability is required for laminates used in the food packaging field (Patent Document 1). Incidentally, such easy tearability often gradually deteriorates over time after the packaging bag is manufactured, and there has been a need for something with improved tearability.

As a conventional technique, for example, Patent Document 1 describes a technique in which a curing agent is used in an ink containing a urethane resin to increase the strength of the laminate, thereby making it easy to tear. However, it may still be difficult to increase the laminate strength using only a curing agent. On the other hand, Patent Document 2 discloses a technique that uses a silane coupling agent in addition to a curing agent. However, the target is only white ink, and color ink is not described.

JP 2017-031298 Publication JP 2019-199509 Publication

An object of the present invention is to provide a packaging material that has little residual solvent, excellent lamination strength, and good tearability even after time has passed after filling the packaging material.

As a result of intensive studies, the inventors discovered that the above problems can be solved by using the packaging material of the present invention, and have completed the present invention.

That is, the present invention provides a packaging material having a base material, a printed layer, an adhesive layer, and a sealant in this order, wherein the printed layer is made of a polyester urethane resin (Mw/Mn) having a molecular weight distribution (Mw/Mn) of 4 to 12. A), the adhesive layer is made of a cured product of a reactive adhesive containing a urethane polyol (B1) and an isocyanate compound (B2), and the isocyanate compound (B2) has a molecular weight distribution (Mw/Mn) of , 5.5 to 18.5.

The present invention also relates to the above packaging material, wherein the urethane polyol (B1) is an ether-based urethane polyol (b1).

The present invention also relates to the above-mentioned packaging material, wherein the ether-based urethane polyol (b1) has a molecular weight distribution (Mw/Mn) of 2 to 17.

Further, the present invention provides that the polyester-based urethane resin (A) contains a structural unit derived from a polyester that is a condensation product of a dibasic acid and a diol, and the dibasic acid contains sebacic acid and/or succinic acid. Regarding the above packaging material.

The present invention also relates to the above packaging material, wherein the diol contains a branched diol and a linear diol.

The present invention also provides the above packaging material, wherein the printing layer further contains at least one resin selected from the group consisting of cellulose resin, vinyl chloride copolymer resin, rosin resin, acrylic resin, and polyvinyl acetal resin. Regarding.

The present invention also relates to the above packaging material, wherein the printing layer further contains a silane coupling agent.

The present invention also relates to the above-mentioned packaging material, wherein the ether-based urethane polyol (b1) contains a structural unit derived from polypropylene glycol.

The present invention also relates to the above packaging material, wherein the ether-based urethane polyol (b1) further contains a constituent unit derived from castor oil.

The present invention also relates to the above packaging material, wherein the printing layer has a crosslinked structure using an isocyanate curing agent (C) having a weight average molecular weight of 800 to 8,000.

The present invention also provides a method for manufacturing a packaging material having a base material, a printed layer, an adhesive layer, and a sealant in this order, in which the printed layer is formed by gravure printing with a gravure ink containing a polyester urethane resin (A). and a step of forming an adhesive layer by applying a reactive adhesive consisting of a urethane polyol (B1) and an isocyanate compound (B2), the molecular weight distribution (Mw /Mn) is 4 to 12, and the isocyanate compound (B2) has a molecular weight distribution (Mw/Mn) of 5.5 to 18.5.

The present invention also relates to a method for producing the above-mentioned packaging material, wherein the urethane polyol (B1) is an ether-based urethane polyol (b1).

The present invention also relates to a method for producing the above-mentioned packaging material, wherein the ether-based urethane polyol (b1) has a molecular weight distribution (Mw/Mn) of 2 to 17.

The present invention has made it possible to provide a packaging material that has little residual solvent, excellent lamination strength, and good tearability even after time has passed after filling the packaging material.

The embodiments of the present invention will be described in detail below, but the explanation of the constituent elements described below is an example (representative example) of the embodiments of the present invention, and the present invention does not exceed the gist thereof. Not limited to content.

In this specification, polyester-based urethane resin (A) may be simply referred to as "urethane resin (A)", but they have the same meaning. The printing layer may be simply referred to as a "printing layer" or "ink layer", but they have the same meaning.

In the following description, the polyester-based urethane resin (A) refers to a urethane resin containing structural units derived from polyester. Preferably, it is in a form further having a urea bond.

Hereinafter, the packaging material of the present invention will be explained in detail.
The present invention is a packaging material having a base material, a printed layer, an adhesive layer, and a sealant in this order, wherein the printed layer is a polyester urethane resin (A ), the adhesive layer is a cured layer of a reactive adhesive containing a urethane polyol (B1) and an isocyanate compound (B2), and the isocyanate compound (B2) has a molecular weight distribution (Mw/Mn) of 5. .5 to 18.5.
Since the packaging material has each layer containing a component having the above-mentioned specific molecular weight distribution, the isocyanate compound (B2) of the adhesive layer penetrates both the adhesive layer and the printing layer, and the adhesive layer and the printing layer are bonded together. It is thought that the coating film of the layer becomes tough as a whole and satisfies the laminated strength, low residual solvent property, and easy tearability as a packaging material. However, this function is based on consideration and does not particularly limit the present invention.

<Packaging material>
The packaging material of the present invention is a packaging material having a structure in which at least a base material, a printed layer, an adhesive layer, and a sealant are laminated in this order. Specifically, the laminated structure can be exemplified below in order from the outer layer side (left side). Note that in the configuration representations (1) to (3) below, "/" means the boundary between each layer.
(1) Base material/Print layer/Adhesive layer/Sealant (2) Base material/Print layer/Adhesive layer/Intermediate base material layer/Adhesive layer/Sealant (3) Base material/Print layer/Adhesive layer/ Intermediate base layer/adhesive layer/intermediate base layer/sealant Note that the layer configuration can be arbitrarily selected as long as the printed layer is visible from the outside (base material side).

<Print layer>
The printing layer contains at least one type of polyester urethane resin (A) within the above range as a binder resin. In 100% by mass of the printing layer, the binder resin is preferably contained in an amount of 10 to 90% by mass, more preferably 20 to 80% by mass.
In addition, it is preferable that the said printing layer is crosslinked with the isocyanate hardening agent (C) mentioned later.
The thickness of the printed layer is preferably 0.1 to 100 μm, more preferably 0.1 to 50 μm, and even more preferably 0.1 to 10 μm.

(Polyester urethane resin (A))
The polyester-based urethane resin (A) used in the present invention is a urethane resin that has a polyester-derived structural unit, and preferably further has a urea bond. The polyester urethane resin (A) is preferably contained in an amount of 50 to 100% by weight, more preferably 70 to 100% by weight, based on 100% by weight of the binder resin. It is preferable to have polyester-derived structural units in the total weight of the polyester urethane resin (A) at 40% by mass or more, more preferably at least 50% by mass, even more preferably at least 60% by mass, and even more preferably at least 65% by mass. It is particularly preferable to have

In the present invention, the polyester urethane resin (A) preferably contains a structural unit based on a biomass-derived raw material. Contains structural units based on biomass-derived raw materials, contributing to environmental conservation. In the polyester urethane resin (A), the degree of biomass described below is preferably from 40% by mass to 100% by mass, more preferably from 45% by mass to 100% by mass, from the concept of carbon neutrality. Further, the biomass degree of the printed layer in the present invention is preferably 5% by mass or more, preferably 7% by mass or more, and still more preferably 10% by mass.

The polyester-based urethane resin (A) is not limited to the following, but for example, a urethane prepolymer obtained by reacting a polyisocyanate with a polyol including a polyester polyol, and optionally a polyamine (chain extender). Examples include polyester urethane resins (A) obtained by reacting with a reaction terminator. A polyester-derived structural unit can be obtained by synthesizing a urethane resin using a polyester polyol as a polyol as described above.

The polyester urethane resin (A) and the printing ink for forming the printing layer can be prepared by any method described in, for example, JP-A No. 2022-056494, JP-A No. 2022-019058, and JP-A No. 2022-19058. It is possible to manufacture

The polyester urethane resin (A) preferably has active hydrogen groups such as hydroxyl groups and amino groups. This is to obtain reaction sites with the isocyanate curing agent (C) and isocyanate compound (B2) described later.

When the polyester urethane resin (A) has a hydroxyl group, the hydroxyl value is preferably 0.5 to 30 mgKOH/g, more preferably 1 to 20 mgKOH/g, and more preferably 2 to 15 mgKOH/g. More preferably.
When the polyester urethane resin (A) has an amino group, its amine value is preferably 0.1 to 15 mgKOH/g, more preferably 1 to 12 mgKOH/g.
On the other hand, the acid value of the polyester urethane resin (A) is preferably 5 mgKOH/g or less, more preferably 3 mgKOH/g or less. This is because the acid group has low reactivity with the isocyanate curing agent (C) and isocyanate compound (B2) described later.

The weight average molecular weight of the polyester urethane resin (A) is preferably 20,000 to 100,000, more preferably 25,000 to 90,000, and more preferably 30,000 to 80,000. is even more preferable. This is because the printed layer is made into a strong film that can withstand heating in a retort.

In the present invention, the weight average molecular weight and the molecular weight distribution (Mw/Mn) described below can be measured by gel permeation chromatography (GPC). As an example, Water 2690 (manufactured by Waters Corporation) is used as a GPC device, HLC-8220 (manufactured by Tosoh Corporation), PLgel, 5 μm, MIXED-D (manufactured by Polymer Laboratories Corporation), TSKgel Super AW series (manufactured by Tosoh Corporation), etc. are used as columns. I can do it. Tetrahydrofuran, 1,2,4-trichlorobenzene, N,N-dimethylformamide (0.01N-lithium bromide added), etc. can be used as the developing solvent, and the flow rate is 0.5 to 1.5 ml/min. It is preferable that An RI detector or the like can be used for detection, and measurement can be performed under conditions such as a sample injection concentration of 0.5 to 1.5 milligrams/ml and an injection volume of 0.1 to 1.0 microliter. The weight average molecular weight can be determined as a polystyrene equivalent value.

(Molecular weight distribution (Mw/Mn) of polyester urethane resin (A))
The molecular weight distribution (Mw/Mn) of the polyester urethane resin (A) needs to be 4 to 12, preferably 4.5 to 10, and more preferably 5 to 8. Mw represents weight average molecular weight, and Mn represents number average molecular weight. When the Mw/Mn of the polyester-based urethane resin (A) is within the above range, the cohesive force and adhesion force are strengthened by crosslinking with the isocyanate compound (B2) described below, and it exhibits sufficient resistance to boiling and retorting, and is easily processed. It is thought that it exhibits tearability.

In order to keep the molecular weight distribution (Mw/Mn) of the polyester urethane resin (A) within the above range, the selection of urethane synthesis raw materials, the solid content mass ratio, and the polyisocyanate in the synthesis reaction are necessary in the synthesis of the polyester urethane resin (A). There is a method of appropriately setting the dropping rate of reactive raw materials, stirring speed, shape of stirring blades, and reaction temperature.
For example, a urethane prepolymer having an isocyanate group at the end is manufactured using a polyol and a polyisocyanate as described below, and a chain extension reaction is controlled using this in combination with a polyamine and a polymerization terminator (also referred to as a reaction terminator). This makes it easy to set the molecular weight distribution within the range during synthesis of the polyester urethane resin (A).

Furthermore, when carrying out a chain extension reaction, it is effective to control the dropping rate and temperature range to a certain range, especially when reacting polyamine and urethane prepolymer, to keep the molecular weight distribution within a predetermined range. be. Controlling the reaction temperature is important; it is preferably controlled within the range of 50 to 130°C in the synthesis of urethane prepolymers, and preferably controlled within the range of 10 to 50°C when reacting polyamines and urethane prepolymers. is preferred.

Furthermore, in the synthesis process of the urethane prepolymer and the chain extension reaction described above, it is also effective to set the charging ratio of the reaction raw materials to an appropriate ratio to keep the molecular weight distribution within a predetermined range. The charging ratio includes, for example, the NCO/OH ratio, which is the equivalent ratio of the hydroxyl group of the polyol and hydroxy acid to the isocyanate group of the polyisocyanate, and the NCO/OH ratio is preferably 1.1 to 3. 1.2 to 3 are more preferred, and 1.3 to 2 are even more preferred. Further, the amino group/NCO ratio, which is the equivalent ratio between the amino group of the polyamine and the isocyanate group of the urethane prepolymer, is preferably 1.2 to 3. Furthermore, in order to control the molecular weight distribution, it is preferable to use a polymerization terminator for the purpose of preventing excessive polymerization reaction. Preferred examples of the polymerization terminator include monoalcohols and monoamines.

(polyol)
The polyol for synthesizing the polyester urethane resin (A) preferably contains a polyester polyol. Note that the polyol may include polyols other than polyester polyols, and for example, polyether polyols, polycarbonate polyols, polyolefin polyols, etc. can also be used. Furthermore, when introducing a polyester-derived structural unit into the urethane resin, the method of introducing the polyester structure is not particularly limited.

(Polyester polyol)
The number average molecular weight of the polyester polyol is preferably 500 to 10,000. Here, the number average molecular weight of the polyol is calculated from the hydroxyl value, and the hydroxyl value is calculated by esterifying or acetylating the hydroxyl groups in the resin and back titrating the remaining acid with an alkali. This is a value obtained by converting the amount of hydroxyl groups into mg of potassium hydroxide, and is a value calculated according to JIS K0070. When the number average molecular weight of the polyester polyol is 10,000 or less, the blocking resistance against plastic films is excellent. Moreover, when the number average molecular weight of the polyester polyol is 500 or more, the urethane resin coating has excellent flexibility and excellent adhesion to the plastic film. For the above reasons, the number average molecular weight of the polyester polyol is more preferably 1,000 to 5,000.

The polyester polyol is preferably a polyester diol, and the polyester diol is preferably a polyester diol that is a condensate of a diol and a dicarboxylic acid. In addition, a polyester diol obtained by subjecting a cyclic ester (lactone, etc.) to a ring-opening reaction may also be used.

The diols include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 1,6-hexanediol, 1,8-octane. Diol, 1,9-nonanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2-methyl-1,3-propanediol, 3,3,5-trimethylpentanediol, 2,4-diethyl -1,5-pentanediol, 1,12-octadecanediol, 1,2-alkanediol, 1,3-alkanediol, 1-monoglyceride, 2-monoglyceride, 1-monoglycerin ether, 2-monoglycerin ether, dimer Preferred examples include diols, hydrogenated dimer diols, and the like. Diols can be used alone or in combination of two or more. The diol is preferably a diol containing a branched diol, and part or all of the diol is preferably derived from biomass.

The dicarboxylic acids include adipic acid, phthalic anhydride, isophthalic acid, terephthalic acid, maleic acid, fumaric acid, succinic acid, oxalic acid, malonic acid, pimelic acid, azelaic acid, sebacic acid, suberic acid, glutaric acid, , 4-cyclohexyldicarboxylic acid, dimer acid, hydrogenated dimer acid, etc., and among them, adipic acid, succinic acid, and sebacic acid are preferably included in order to solve the problems of the present application. It is further preferred to contain succinic acid and/or sebacic acid. More preferably, it contains sebacic acid.
Note that part or all of the dibasic acid is preferably derived from biomass.
Furthermore, a polyol having three or more hydroxyl groups and a polycarboxylic acid having three or more carboxyl groups can be used in combination as raw materials for the polyester polyol.

Preferred specific examples include those containing structural units derived from polyesters consisting of dibasic acids selected from adipic acid, succinic acid, and sebacic acid and diols including branched diols and linear diols. This improves the laminate strength of the laminate. Here, the linear diol is a diol having two or more atoms, and refers to a diol in which the alkylene group does not have a substituent, such as alkylene glycol, dialkylene glycol, and trialkylene glycol. Further, the term "branched diol" refers to a diol in which at least one hydrogen atom of a hydrocarbon group of an alkylene glycol is substituted with a non-hydrogen atom.

Linear diols impart crystallinity and branched diols impart flexibility, so the balance between them makes the printing layer containing the polyester urethane resin (A) as the binder resin stronger and has high lamination strength. A packaging material is obtained.

Examples of branched diols include 2-butyl-2-ethyl-1,3-propanediol (hereinafter also referred to as BEPG), 2-methyl-1,3-propanediol (hereinafter also referred to as MPO), 3 Methyl-1,5-pentanediol (also referred to as MPD), neopentyl glycol (also referred to as NPG), 1,2-propylene glycol (hereinafter also referred to as PG), 2,4-diethyl-1,5- Examples include pentanediol, 1,3-butanediol, dipropylene glycol, and at least one branched diol selected from NPG and PG is particularly preferred.

The linear diol is preferably an alkylene glycol, and such compounds include ethylene glycol (also referred to as EG), diethylene glycol, 1,3-propanediol (also referred to as 1,3PD), 1,4- Butanediol (also described as 1,4BD), 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,4-butynediol, 1,4-butylene Examples include diol, diethylene glycol, triethylene glycol, and the like.
Among them, linear diols having 8 or less carbon atoms, preferably 6 or less carbon atoms are preferred, and include EG, 1,3PD, 1,4BD, 1,5-pentanediol, 1,6-hexanediol, and 1,8-octanediol. , etc. are preferable. Furthermore, from the viewpoint of physical properties and biomass degree, 1,3PD is particularly preferable.

When the diol contains a branched diol and a linear diol, the mass ratio of the branched diol and the linear diol in the total diol of the polyester polyol (branched diol: linear diol) is 10 from the viewpoint of lamination strength. :90 to 90:10, more preferably 20:80 to 80:20. More preferably, the ratio is 30:70 to 70:30.

The branched diol units and linear diol units may each be present in one polyester polyol, or a polyester polyol containing only branched diol units and a polyester polyol containing only linear diol units may be used. The polyester urethane resin (A) may be synthesized by using it as a mixture raw material. Approximately the same effect can be obtained.

(Polyisocyanate)
As the polyisocyanate for synthesizing the polyester urethane resin (A), diisocyanates are preferred, and as such compounds, various known aromatic, aliphatic or alicyclic diisocyanates can be used, for example, 1, 5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzylisocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,3-phenylene diisocyanate, 1 , 4-phenylene diisocyanate, tolylene diisocyanate, butane-1,4-diisocyanate, hexamethylene diisocyanate, isopropylene diisocyanate, methylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate , cyclohexane-1,4-diisocyanate, xylylene diisocyanate, isophorone diisocyanate, lysine diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, methylcyclohexane diisocyanate, m-tetramethylxylylene diisocyanate Examples include dimer diisocyanate, which is obtained by converting the carboxyl group of isocyanate and dimer acid into an isocyanate group. These can be used alone or in combination of two or more. Among them, isophorone diisocyanate, tolylene diisocyanate, and 4,4'-diphenylmethane diisocyanate are preferred, and from the viewpoint of solubility, isophorone diisocyanate is more preferred.

(Polyamine)
In the synthesis of the polyester urethane resin (A), the polyamine to be reacted with the urethane prepolymer is preferably an organic diamine, including, but not limited to, ethylene diamine, propylene diamine, hexamethylene diamine, isophorone diamine, dicyclohexylmethane-4, Examples include 4'-diamine. Also, 2-hydroxyethylethylenediamine, 2-hydroxyethylpropylenediamine, 2-hydroxyethylpropylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxyethylenediamine, di-2-hydroxyethylpropylenediamine, 2-hydroxypyro Amines having a hydroxyl group in the molecule, such as pyruethylenediamine and di-2-hydroxypropylethylenediamine, can also be used. These organic diamines can be used alone or in combination of two or more, but isophorone diamine is preferred. Furthermore, diethylenetriamine, iminobispropylamine: (IBPA, 3,3'-diaminodipropylamine), N-(3-aminopropyl)butane-1,4-diamine: (spermidine), 6,6-iminodihexylamine , 3,7-diazanonane-1,9-diamine, N,N'-bis(3-aminopropyl)ethylenediamine, and other polyfunctional amines having three or more amino groups can also be used in combination with the above organic diamine.

The reaction terminator used in the synthesis of the polyester urethane resin (A) is preferably a monoalcohol or a monoamine in the case of a polyester urethane resin (A) that can be produced only in the urethanization step, and in addition to the urethanization step. In the case of the polyester-based urethane resin (A) produced by performing the ureation reaction step, it is preferably a monoamine.
The monoalcohol is preferably a substituted or unsubstituted alcohol, and suitable examples include methanol, ethanol, n-propanol, isopropyl alcohol, and 1-butanol. The monoamine is preferably a substituted or unsubstituted monoamine, and suitable examples include n-butylamine, n-dibutylamine, octylamine, diethylamine, monoethanolamine, monopropanolamine, diethanolamine, and dipropanolamine. Further, as the reaction terminator, the compounds listed as the chain extender can also be used, and at least one kind may be used, or two or more kinds can be used in combination.

(pigment)
The printing layer in the present invention preferably contains a pigment as a colorant, and preferably contains an inorganic pigment or an organic pigment. As the pigment, C.I. listed in the color index is used. I. Pigments can be used as appropriate.

Examples of inorganic pigments include titanium oxide, zinc oxide, zinc sulfide, barium sulfate, calcium carbonate, aluminum hydroxide, chromium oxide, silica, carbon black, aluminum, mica, and the like. From the viewpoints of coloring power, hiding power, chemical resistance, and weather resistance, titanium oxide is preferable as the white pigment, and titanium oxide whose pigment surface is basic is more preferable. Aluminum is in the form of powder or paste, but from the viewpoint of ease of handling and safety, it is preferable to use it in paste form, and it may be either leafing or non-leafing. Barium sulfate, calcium carbonate, and aluminum hydroxide are called extender pigments and are used as fillers to improve fluidity, strength, and optical properties.

Examples of organic pigments include, but are not limited to, soluble azo, insoluble azo, azo, phthalocyanine, halogenated phthalocyanine, anthraquinone, anthurone, dianthraquinone, anthrapyrimidine, and perylene. pigments such as perinone series, quinacridone series, thioindigo series, dioxazine series, isoindolinone series, quinophthalone series, azomethine azo series, flavanthrone series, diketopyrrolopyrrole series, isoindoline series, indanthrone series, carbon black series, etc. , and those listed in the color index can be used in combination at any time.

In order to ensure the density and coloring power of the printing layer, the pigment is preferably contained in an amount of 5 to 90% by mass, more preferably 10 to 80% by mass, based on the total mass of the printing layer. More preferably, it is contained in an amount of 20 to 80% by mass.

(Isocyanate curing agent (C))
In the packaging material of the present invention, in order to improve the laminate physical properties, retort resistance, and subsequent tearability, it is preferable that the printed layer has a crosslinked structure using an isocyanate curing agent (C). When the polyester urethane resin (A) has a hydroxyl group, an amino group, or other active hydrogen group, it is crosslinked with the active hydrogen group, and when the polyester urethane resin (A) does not have the active hydrogen group, it is cured with isocyanate. By self-crosslinking with only the agent, the laminate strength, tearability, etc. are improved.

Preferred embodiments of the isocyanate curing agent (C) are shown below. The weight average molecular weight of the isocyanate curing agent (C) is preferably from 800 to 8,000, more preferably from 1,000 to 4,500, even more preferably from 1,500 to 4,000. Further, the molecular weight distribution (Mw/Mn) of the isocyanate curing agent (C) is preferably from 2 to 5, more preferably from 2.2 to 4.5, and more preferably from 2.5 to 4. is even more preferable. When the weight average molecular weight and/or Mw/Mn of the isocyanate curing agent (C) is within the above range, the printing layer and the adhesive layer containing the cured product of the urethane polyol (B1) and the isocyanate compound (B2). It is thought that the cohesive force and adhesion of the laminate are strengthened, resulting in good laminate strength, sufficient resistance in boiling and retorting, and easy tearability.

The isocyanate curing agent (C) includes polyisocyanates including adduct type polyisocyanate (adduct type), biuret type polyisocyanate (biuret type), isocyanurate type polyisocyanate (isocyanurate type), bifunctional type polyisocyanate, etc. is suitable, and the adduct, biuret and isocyanurate are, for example, adducts obtained from the reaction of trimethylolpropane and other polyols with diisocyanates, biurets in which diisocyanates are dimerized and connected by biuret bonds, and diisocyanates. Examples include isocyanurates obtained from a cyclic trimerization reaction. As the diisocyanate, the diisocyanates mentioned above may be arbitrarily selected and used, and among them, tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), hydrogenated diphenylmethane diisocyanate (hydrogenated MDI), and hexamethylene diisocyanate (HDI). , isophorone diisocyanate, xylylene diisocyanate (XDI), hydrogenated xylylene diisocyanate (hydrogenated XDI), and the like. Adduct type polyisocyanates, biuret type polyisocyanates, and isocyanurate type polyisocyanates may be used in combination, and furthermore, they may be used in combination with other polyisocyanates.

In order to make the weight average molecular weight and molecular weight distribution (Mw/Mn) of the isocyanate curing agent (C) within the above range, it is possible to manufacture it by the method described in JP-A No. 2022-056494, for example. .

Furthermore, the mass ratio of the polyester urethane resin (A) and the isocyanate curing agent (C) (polyester urethane resin (A):isocyanate curing agent (C)) should be 99:1 to 60:40. The ratio is preferably 98:2 to 65:35, and even more preferably 95:5 to 70:30. When the printing layer contains a combination resin described below in addition to the polyester urethane resin (A), the mass ratio of the total of the polyester urethane resin (A) and the combination resin to the isocyanate curing agent is 99:1. The ratio is preferably from 95:5 to 70:30, more preferably from 95:5 to 70:30. This is because it is believed that within this range, the effects of crosslinking and adhesion to the base material will be good, and sufficient resistance will be exhibited in terms of boiling retort and laminate strength after aging, as well as easy tearability.

(Used resin)
The ink forming the printing layer is selected from the group consisting of a cellulose resin, a vinyl chloride copolymer resin, a rosin resin, an acrylic resin, and a polyvinyl acetal resin, along with a polyester urethane resin (A) as a binder resin. It is preferable to contain at least one type of resin. Among these, it is preferable to contain a vinyl chloride copolymer resin. Preferred embodiments of each resin used in combination are shown below.

(vinyl chloride resin)
The vinyl chloride copolymer resin is not particularly limited as long as it contains structural units derived from vinyl chloride and structural units derived from other monomers, but vinyl chloride-vinyl acetate copolymer resins, vinyl chloride-acrylic copolymer resins, etc. preferable.
The weight average molecular weight of the vinyl chloride copolymer resin is preferably 5,000 to 100,000, more preferably 5,000 to 50,000. The content of the structural unit derived from the vinyl acetate monomer in 100% by mass of the solid content of the vinyl chloride copolymer resin is preferably 70 to 95% by mass. Further, the glass transition temperature is preferably 50°C to 90°C.
The vinyl chloride copolymer resin preferably has a hydroxyl group, and the hydroxyl value thereof is preferably 10 to 200 mgKOH/g. This is because the reactivity with the isocyanate curing agent (C) and the isocyanate compound (B2) is improved. The hydroxyl group is preferably derived from a vinyl alcohol unit or an acrylic monomer having a hydroxyl group.

(cellulose resin)
Cellulose-based resin refers to a fibrous carbon-based resin that is soluble in organic solvents.
The weight average molecular weight of the cellulose resin is preferably 5,000 to 100,000, more preferably 10,000 to 70,000. Further, those having a glass transition temperature of 100°C to 160°C are preferable.
Examples of the cellulose resin include nitrocellulose, cellulose acetate alkylates such as cellulose acetate propionate and cellulose acetate butyrate, or alkyl celluloses such as hydroxyalkylcellulose and carboxyalkylcellulose, and the alkyl group is Examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a pentyl group, a hexyl group, and the alkyl group may further have a substituent. Among these, cellulose acetate propionate, cellulose acetate butyrate, and nitrocellulose are preferred.

(rosin resin)
Rosin resin refers to a resin having as a main component (50% by mass or more) a structural unit derived from rosin acid (abietic acid, neoabietic acid, parastric acid, pimaric acid, isopimaric acid, dehydroabietic acid, etc.). The rosin acid or rosin resin may be hydrogenated. The acid value of the rosin resin is preferably 150 mgKOH/g or less, more preferably 100 mgKOH/g or less, even more preferably 50 mgKOH/g or less. The softening point is preferably 60 to 180°C, more preferably 70 to 150°C. Note that the softening point refers to a value measured by the ring and ball method, and can be measured by the measuring method described in JIS K2207.
Examples of the type of rosin resin include rosin-modified phenol resin, rosin ester, rosin-modified maleic acid resin, and polymerized rosin resin, and at least one rosin resin selected from these is preferred. The weight average molecular weight of the rosin ester is preferably 500 to 3,000, more preferably 1,000 to 2,000.

(acrylic resin)
The acrylic resin refers to one having a structural unit derived from an acrylic monomer, and is preferably an acrylic resin having a weight average molecular weight of 10,000 to 160,000, and does not include the above-mentioned vinyl chloride copolymer resin. Moreover, it is preferable that the acrylic resin contains a structural unit derived from an acrylic monomer in an amount of 50% by mass or more based on the entire acrylic resin.
The glass transition temperature of the acrylic resin is preferably 30 to 120°C, more preferably 40 to 100°C. The acid value is preferably 25 mgKOH/g or less, more preferably 20 mgKOH/g or less.

(Polyvinyl acetal resin)
The polyvinyl acetal resin is obtained by reacting polyvinyl alcohol with an aldehyde such as butyraldehyde and/or formaldehyde to form an acetal cyclizer, and preferably contains a vinyl alcohol unit, a vinyl acetate unit, and an acetal ring group.
The polyvinyl acetal resin preferably contains 60 to 90% by mass of acetal rings, 5 to 30% by mass of vinyl alcohol units, and 0.5 to 10% by mass of vinyl acetate units, and is a polyvinyl butyral resin having a butyral ring as the acetal ring. It is more preferable.
The weight average molecular weight of the polyvinyl acetal resin is preferably 10,000 to 100,000, more preferably 10,000 to 80,000. The glass transition point of the polyvinyl acetal resin is preferably 50 to 80°C, more preferably 60 to 75°C.

The mass ratio of the polyester urethane resin (A) and the combined resin (urethane resin (A): combined resin) is preferably 95:5 to 30:70, and preferably 90:10 to 40:60. is more preferable. This is because the adhesion to the base material, the physical properties of the coating, the lamination strength, etc. are improved.

(Other resins)
The printing layer can further contain a resin component other than the above-mentioned resin component (referred to as "other resin") within a range that does not interfere with the effects of the invention. Other resins include, for example, polyolefin resins such as polyethylene resins and chlorinated polypropylene resins, polyvinyl acetate resins, polystyrene resins, styrene-butadiene copolymers, styrene-maleic acid copolymers, and vinylidene fluoride resins. Resin, polyvinyl alcohol resin, polybutadiene resin, polyester resin, polyamide resin, alkyd resin, epoxy resin, unsaturated polyester resin, thermosetting poly(meth)acrylic resin, melamine resin, urea resin Examples include resins, phenolic resins, xylene resins, maleic acid resins, rubber resins such as chlorinated rubber and cyclized rubber, petroleum resins, and natural resins such as casein.

(Additive)
The printing layer can contain additives, if necessary. Examples of additives include silane coupling agents, fillers, stabilizers, plasticizers, antioxidants, light stabilizers such as ultraviolet absorbers, dispersants, thickeners, desiccants, lubricants, antistatic agents, Examples include crosslinking agents.

(Silane coupling agent)
Examples of the silane coupling agent include those having a functional group such as a vinyl group, an epoxy group, an amino group, an imino group, a mercapto group, and a functional group such as a methoxy group or an ethoxy group. Specifically, vinyl group-containing trialkoxysilanes such as vinyltrimethoxysilane and vinyltriethoxysilane; amino acids such as 3-aminopropyltriethoxysilane and N-(2-aminoethyl)3-aminopropyltrimethoxysilane; trialkoxysilane having a glycidyl group; trialkoxysilane having a glycidyl group such as 3-glycidoxypropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane can be mentioned. The amount of the silane coupling agent added is preferably 0.1 to 7% by mass, more preferably 0.5 to 3% by mass, based on 100% of the total ink composition.

(Method for forming printed layer)
Although the printing layer can be formed by any method, gravure printing or flexographic printing is particularly preferable, and gravure printing using a gravure plate is more preferable.

(Gravure version)
The gravure plate is a cylindrical piece made of metal, and recesses for each color are created by engraving, etching, or laser. There are no restrictions on the use of engraving and lasers, and settings can be made to suit the pattern. A line number of 100 to 300 lines is appropriately used, and the larger the number of lines, the finer the print. The depth of the printing plate is preferably 0.1 μm to 100 μm.

(gravure printing machine)
In a gravure printing machine, one printing unit is equipped with the above-mentioned gravure plate and a doctor blade. There are a large number of printing units, and printing units corresponding to organic solvent-based printing inks and pattern inks can be set up, and each unit has an oven drying unit. Printing is done using a rotary press and is a roll printing method. The type of plate and the type of doctor blade can be selected as appropriate, and one can be selected according to the specifications.

<Base material>
The base material is preferably a plastic film. The base material corresponds to the outer layer side of the packaging material, and is made of a light-transmitting material so that the printed layer can be visually recognized from the outside.
Specifically, polyolefin resins such as polyethylene (PE) and polypropylene (PP), cyclic polyolefin resins, polystyrene resins, acrylonitrile-styrene copolymer (AS) resins, acrylonitrile-butadiene-styrene copolymers (ABS) ) resin, poly(meth)acrylic resin, polycarbonate resin, polyvinyl alcohol resin, ethylene-vinyl alcohol copolymer (EVOH), saponified ethylene-vinyl ester copolymer, polyethylene terephthalate (PET) and polybutylene terephthalate (PBT), polyester resins such as polyethylene naphthalate (PEN), polyamide resins such as various nylons (Ny), polyurethane resins, acetal resins, cellulose resins, polyvinylidene chloride resins (PVDC), etc. It will be done. The base material may be uniaxially stretched or biaxially stretched. Alternatively, it may be a composite film in which two or more of the above resin films are laminated. Alternatively, a metal oxide such as silica or alumina may be deposited.

The base material preferably has excellent heat resistance from the viewpoint of boiling and retort processing. As the resin constituting the base material having excellent heat resistance, polyester resins and/or polyamide resins are suitable.
Specific examples of the base material having excellent heat resistance include a single polyester film, a single polyamide film such as nylon, and a composite film containing at least one of a polyester film and a polyamide film. Examples of the composite film include a coextruded stretched film having a structure of PET/Ny/PET and PET/Ny from the outer layer side. It is also preferable to combine one or more selected from polyester films and polyamide films with one or more selected from ethylene-vinyl alcohol copolymer films and polyvinylidene chloride films.

The thickness of the base material is not particularly limited and can be set appropriately depending on the use of the packaging material, but it is usually preferably about 5 to 50 μm, more preferably 10 to 30 μm.

The total light transmittance of the base material according to JIS K7361-1:1997 is preferably 85% or more, more preferably 90% or more. Further, the haze of the base material according to JIS K7136:2000 is preferably 1.5% or less, more preferably 1.0% or less, and even more preferably 0.5% or less.

<Gas barrier layer>
A gas barrier layer can be provided anywhere between the base material and the sealant, if necessary. The gas barrier layer plays a role in blocking the permeation of oxygen, water vapor, etc. between the object to be packaged by the packaging material and the external environment of the packaging material. Furthermore, it may also provide light-shielding properties that block transmission of visible light, ultraviolet rays, and the like. The gas barrier layer may be composed of only one layer, or may be composed of two or more layers.

An example of a gas barrier layer is a vapor deposited film, such as silicon (Si), aluminum (Al), magnesium (Mg), calcium (Ca), potassium (K), tin (Sn), sodium (Na), boron ( B), a vapor-deposited film formed of an inorganic substance such as titanium (Ti), lead (Pb), zirconium (Zr), or yttrium (Y) or an oxide thereof is suitable. Among these, when the packaging material is for use in a microwave oven, inorganic oxides such as silicon oxide, aluminum oxide, and magnesium oxide are preferred.
Methods for forming the deposited film include, for example, physical vapor deposition (PVD) methods such as vacuum evaporation, sputtering, and ion plating, and chemical vapor deposition (CVD) methods such as plasma chemical vapor deposition, thermal chemical vapor deposition, and photochemical vapor deposition. Laws etc.

The thickness of the deposited film varies depending on the forming material, required gas barrier performance, etc., but is usually preferably about 5 to 200 nm, more preferably 5 to 150 nm, and even more preferably 10 to 100 nm. In the case of inorganic oxides such as silicon oxide and aluminum oxide, the thickness is preferably about 5 to 100 nm, more preferably 5 to 50 nm, and still more preferably 10 to 30 nm.

<Intermediate base material layer>
The packaging material used in the present invention may have an intermediate base material layer between the printing layer and the sealant. The intermediate base material layer is a layer provided as necessary for the purpose of improving the strength and processing suitability of the packaging material. Examples of the constituent material of the intermediate base layer include a base material in the form of a plastic film. As the base material, the same base material as described above can be used. In order to increase the heat resistance of the packaging material in consideration of heating in a microwave oven and retort treatment, it is preferable that the intermediate base material layer has excellent heat resistance. Polyester base materials, polyamide base materials, and the like are preferably used.

<Adhesive layer>
The adhesive layer is made of a cured product of a reactive adhesive containing a urethane polyol (B1) and an isocyanate compound (B2), and the isocyanate compound (B2) has a molecular weight distribution (Mw/Mn) of 5.5 to 18. It is .5. The molecular weight distribution (Mw/Mn) of the isocyanate compound (B2) is preferably 6.5 to 17.5. This is because it acts integrally with the printing layer to obtain effects such as laminate strength and easy tearability (over time).
In addition, the blending ratio of the urethane polyol (B1) and the isocyanate compound (B2) is such that the molar equivalent ratio (NCO/OH) of all the isocyanate groups in the isocyanate compound (B2) to all the hydroxyl groups in the urethane polyol (B1) is 1 to 1. The range is preferably 5, more preferably 2-4.

[Urethane polyol (B1)]
The urethane polyol (B1) refers to a compound having a urethane bond derived from polyisocyanate and a hydroxyl group. The molecular weight distribution (Mw/Mn) of the urethane polyol (B1) is preferably from 2 to 17, more preferably from 3 to 16. Further, the urethane polyols may be used alone or in combination of two or more.
Urethane polyols (B1) include ester-based urethane polyols, ether-based urethane polyols, and the like, depending on their constituent units, and in the present invention, it is preferable to use ether-based urethane polyols (b1).

[Ether urethane polyol (b1)]
The ether-based urethane polyol (b1) refers to a urethane polyol having a structural unit derived from polyether. The polyether-derived structural unit is obtained by using the following polyether polyol as a reaction raw material, and is preferably a reaction product of a polyol containing a polyether polyol and a polyisocyanate. The polyol can include polyols other than polyether polyols.

(Polyether polyol)
The polyether polyol for synthesizing the ether-based urethane polyol (b1) is a compound having a plurality of hydroxyl groups and a plurality of ether bonds in its molecule.
Examples of polyether polyols include polyalkylene glycols such as polyethylene glycol, polytrimethylene glycol, polypropylene glycol, polytetramethylene glycol, and polybutylene glycol; polyethylene glycol/polypropylene glycol block copolymers; propylene oxide/ethylene oxide random Preferred examples include polyether. From the viewpoint of coating properties due to the influence of viscosity during adhesive coating, polyether polyols containing structural units derived from polypropylene glycol are particularly preferred. The number average molecular weight of the polyether glycol is preferably 400 to 10,000, more preferably 400 to 5,000.

In addition, addition polymers are obtained by addition-polymerizing oxirane compounds such as ethylene oxide, propylene oxide, butylene oxide, and tetrahydrofuran to low-molecular-weight polyol initiators such as water, ethylene glycol, propylene glycol, trimethylolpropane, glycerin, sorbitol, and sucrose. may be used as the polyether polyol.
Examples of the addition polymer include propylene glycol propylene oxide adducts, glycerin propylene oxide adducts, sorbitol-based propylene oxide adducts, and sucrose-based propylene oxide adducts.

(Castor oil polyol)
The urethane polyol (B1) preferably has a constitutional unit derived from castor oil, and more preferably has a constitutional unit derived from the ether-based urethane polyol (b1) and castor oil. The castor oils are not particularly limited, and known castor oil, castor oil derivatives, ricinoleic acid, ricinoleic acid polyols, etc. can be used, and one type may be used alone or two or more types may be used in combination.
Examples of castor oil derivatives include dehydrated castor oil, hydrogenated castor oil which is a hydrogenated product of castor oil, castor oil fatty acids, dehydrated castor oil fatty acids, castor oil fatty acid condensates, castor oil adducts of 5 to 50 moles of ethylene oxide, ricinoleic acid polyols, and castor oil. Examples include polyols.
Among them, from the viewpoint of production quality stability of urethane polyol (B1), the acid value of castor oil is preferably in the range of 0.1 to 5.0 mgKOH/g, more preferably 0.1 to 2.0 mgKOH/g. g, more preferably 0.1 to 1.0 mgKOH/g. The content of the constituent units derived from castor oil is preferably 5 to 33% by mass based on the total mass of the urethane polyol (B1) from the viewpoint of decomposition properties.

(reaction accelerator)
The above-mentioned reactive adhesive may further contain a reaction accelerator in order to accelerate the curing reaction. Examples of the reaction accelerator include metal catalysts such as dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate, and dibutyltin dimalate; 1,8-diaza-bicyclo(5,4,0)undecene-7,1 Tertiary amines such as ,5-diazabicyclo(4,3,0)nonene-5,6-dibutylamino-1,8-diazabicyclo(5,4,0)undecene-7; reactive such as triethanolamine Examples include tertiary amines.

(Polyisocyanate)
As the polyisocyanate for synthesizing the urethane polyol (B1), those similar to the polyisocyanate explained for the polyester urethane resin (A) can be suitably used.

(Method for producing urethane polyol (B1))
There are no particular restrictions on the method for producing the urethane polyol (B1), and it can be produced by a general urethanization reaction. For example, in the absence of a solvent or in an organic solvent having no hydroxyl groups, a polyol and a polyisocyanate are reacted at an equivalent ratio in which the hydroxyl groups are in excess of the isocyanate groups, and the urethane polyol (B1) with terminal hydroxyl groups is do.
Urethane polyol (B1) has a hydroxyl value in the resin of 5 to 40 mgKOH/g, a urethane group content of 0.5 to 4 mmol/g, and a weight average molecular weight of 5,000 to 100,000 from the viewpoint of lamination strength and coatability. It is preferable that

(Other additives)
The above-mentioned reactive adhesive may contain various additives as long as the effects of the present invention are not impaired. Examples of additives include inorganic fillers such as silica, alumina, mica, talc, aluminum flakes, and glass flakes, layered inorganic compounds, and stabilizers (antioxidants, heat stabilizers, ultraviolet absorbers, hydrolysis inhibitors, etc.) ), rust inhibitors, thickeners, plasticizers, antistatic agents, lubricants, antiblocking agents, colorants, fillers, crystal nucleating agents, and catalysts for adjusting the curing reaction.

[Isocyanate compound (B2)]
The above-mentioned isocyanate compound (B2) refers to a compound having a plurality of isocyanate groups. Examples of the isocyanate compound (B2) include, but are not limited to, urethane prepolymers having terminal isocyanate groups obtained from polyisocyanate and polyol.

(polyol)
As the polyol used in the synthesis of the isocyanate compound (B2), the same polyols as those explained for the urethane polyol (B1) can be suitably used. Among these, ether-based urethane polyols are preferred, and specifically polypropylene glycol and polytetramethylene glycol are preferred. The polyol may be difunctional or trifunctional or more functional. Moreover, it is also possible to use a combination of a plurality of materials having different numbers of functional groups. The polyol preferably has a number average molecular weight of 400 to 5,000. Moreover, a combination of a plurality of materials having different molecular weights can also be used.

(Polyisocyanate)
Examples of the polyisocyanate used in the synthesis of the isocyanate compound (B2) include the polyisocyanates and polyisocyanate derivatives (polyisocyanate adducts, allophanate bodies, burette bodies, uretidine dione bodies, and isocyanurates) mentioned in the description of the polyester urethane resin (A). body), etc. are preferably mentioned.
The polyisocyanate used for the isocyanate compound (B2) preferably contains an aromatic or araliphatic polyisocyanate with trifunctional or higher functionality, and since the viscosity during coating can be lowered, the appearance does not change even when coated at high speed. A good laminate can be obtained. Furthermore, by requiring an aliphatic or alicyclic isocyanate with trifunctional or higher functionality, a branched structure can be introduced, so that a flexible adhesive layer with high elasticity at high temperatures can be formed.

The molecular weight distribution (Mw/Mn) of the isocyanate compound (B2) needs to be 5.5 to 18.5 from the viewpoint of acting integrally with the printing layer and exhibiting the effect of tearing over time. It is preferably 6.5 to 17.5 from the viewpoint of adhesive solution, laminate physical properties, heat resistance, and tearability. In order to adjust the molecular weight distribution (Mw/Mn) of the isocyanate compound (B2) to 5.5 to 18.5, for example, methods such as urethanization of polyfunctional polypropylene glycol and polyisocyanate and its derivatives can be mentioned. Furthermore, methods for mixing them may also be mentioned.

Examples of the aromatic polyisocyanate include aromatic diisocyanates such as diphenylmethane diisocyanate, carbodiimide-modified diphenylmethane diisocyanate, phenylene diisocyanate, tolylene diisocyanate, and naphthalene diisocyanate; aromatic polyisocyanates such as polymethylene polyphenyl polyisocyanate; .
Examples of the araliphatic polyisocyanate include 1,3- or 1,4-xylylene diisocyanate or a mixture thereof, ω,ω'-diisocyanate-1,4-diethylbenzene, 1,3- or 1,4-bis( Aroaliphatic diisocyanates such as 1-isocyanate-1-methylethyl)benzene or mixtures thereof;

Examples of modified polyisocyanates include allophanate-type modified products, isocyanurate-type modified products, biuret-type modified products, and adduct-type modified products.

(Method for producing isocyanate compound (B2))
The isocyanate compound (B2) is, for example, in the form of a urethane prepolymer having isocyanate groups, and the urethane prepolymer can be obtained by reacting an isocyanate component and a polyol under conditions in which isocyanate groups are excessive.

<Sealant>
The inner surface of the sealant comes into direct contact with the packaged item and plays a role in protecting the packaged item. In order to make the laminate into a bag shape, it is preferable that the innermost layer of the sealant has heat-sealing properties. Examples of materials constituting the sealant include low density polyethylene (LDPE), linear low density polyethylene (LLDPE), medium density polyethylene (MDPE), high density polyethylene (HDPE), ethylene-vinyl acetate copolymer, and propylene. Examples include polyolefin resins such as homopolymers and ethylene-propylene copolymers, and one or more types of resins can be used. The sealant may be composed of a single layer or multiple layers of two or more layers. Note that the sealant is preferably an unstretched film made of the above resin in order to suppress shrinkage during heat sealing.

In order to improve heat resistance from the viewpoint of heating during boiling and retort processing, it is preferable that the sealant is made of a resin with excellent heat resistance. Specifically, the sealant is made of a resin based on a propylene resin such as polypropylene or ethylene-propylene copolymer. and HDPE are preferred.

The thickness of the sealant is not particularly limited, and is appropriately set depending on the use of the laminate and the type and properties of the packaged product, but it is usually preferably 10 to 200 μm. Further, in the case of a pouch (particularly a retort pouch), the thickness of the sealant is preferably 20 to 150 μm, more preferably 30 to 100 μm.

(Manufacturing method of packaging material)
The packaging material of the present invention includes a step of gravure printing a gravure ink containing a polyester urethane resin (A) to form a printed layer, and a reactive adhesive consisting of a urethane polyol (B1) and an isocyanate compound (B2). The polyester urethane resin (A) has a molecular weight distribution (Mw/Mn) of 4 to 12, and the isocyanate compound (B2) has a molecular weight distribution (Mw/Mn) of 4 to 12. Mn) is 5.5 to 18.5.
The adhesive layer may be formed by coating on the printing layer, or may be formed by coating on a sealant.
A preferred embodiment is, for example, a mode in which an adhesive is coated on the printing layer, and then a sealant is attached. In addition, when the packaging material further has an intermediate base material layer, an embodiment including a step of once pasting together the printed layer and the intermediate base material layer with an adhesive, and then pasting the intermediate base material layer and a sealant together is possible. preferable. Note that the configuration is arbitrary and not particularly limited.

The packaging material thus obtained can be cut into a predetermined size and heat-sealed at the edges with the sealants placed together to form a bag. The heat sealing temperature is preferably 50 to 250°C, more preferably 80 to 180°C. The heat sealing pressure may be 1 to 5 kg/cm ² or the like. One packaging material may be folded and the edges heat-sealed, or two or more packaging materials may be heat-sealed. Furthermore, the bag made of packaging material may be one in which the contents are packaged and then all openings are heat-sealed.

Hereinafter, the present invention will be explained in detail with reference to Examples, but the following embodiments are merely examples of the present invention, and the present invention is not limited to these Examples. Note that parts and % in the present invention represent parts by mass and % by mass unless otherwise noted.

<Method for measuring amine value>
The amine value was determined according to the following method according to JIS K0070 using the equivalent amount of hydrochloric acid in mg of potassium hydroxide required to neutralize the amino groups contained in 1 g of the resin.
0.5 to 2 g of the sample was accurately weighed (sample solid content: Sg). 50 mL of a mixed solution of methanol/methyl ethyl ketone = 60/40 (mass ratio) was added to the accurately weighed sample and dissolved. Bromophenol blue was added to the obtained solution as an indicator, and the obtained solution was titrated with a 0.2 mol/L ethanolic hydrochloric acid solution (potency: f). The end point was the point at which the color of the solution changed from green to yellow, and the amine value was determined by the following (Formula 1) using the titration amount (AmL) at this time.
(Formula 1) Amine value = (A x f x 0.2 x 56.108)/S [mgKOH/g]

(Weight average molecular weight Mw, number average molecular weight Mn and molecular weight distribution Mw/Mn)
The weight average molecular weight Mw, number average molecular weight Mn, and molecular weight distribution Mw/Mn were determined by measuring the molecular weight distribution using a GPC (gel permeation chromatography) device (HLC-8220, manufactured by Tosoh Corporation), and using polystyrene as a standard substance. It was calculated as the equivalent molecular weight. The measurement conditions are shown below.
Column: The following columns were connected in series and used.
TSKgelSuperAW2500 manufactured by Tosoh Corporation
TSKgelSuperAW3000 manufactured by Tosoh Corporation
TSKgelSuperAW4000 manufactured by Tosoh Corporation
TSKgelguardcolumnSuperAWH manufactured by Tosoh Corporation
Detector: RI (differential refractometer)
Measurement conditions: Column temperature 40℃
Eluent: Tetrahydrofuran Flow rate: 1.0 mL/min

<Method for measuring hydroxyl value>
It was determined according to the method described in JIS K0070.

<Method for measuring acid value>
It was determined according to the method described in JIS K0070.

[Synthesis Example 1-1] (Synthesis of polyester polyol A1)
In a round bottom flask equipped with a stirrer, a thermometer, a water separator, and a nitrogen gas inlet tube, 26 parts of 1,3-propanediol (hereinafter also abbreviated as 1,3-PD) and 26 parts of neopentyl glycol (hereinafter also abbreviated as NPG) were placed. 1 part, 48 parts of sebacic acid, and 0.002 part of tetrabutyl titanate were charged, and esterification was carried out for 8 hours at 230° C. under a nitrogen stream while removing water produced by condensation. After confirming that the acid value of the polyester was 15 or less, the degree of vacuum was gradually increased using a vacuum pump to complete the reaction. As a result, a polyester polyol (A1) having a number average molecular weight of 2000, a hydroxyl value of 56.1 mgKOH/g, an acid value of 0.3 mgKOH/g, and a biomass degree of 84.4% was obtained.

[Synthesis Examples 1-2 to 1-6] (Synthesis of polyester polyols A2 to A6)
Polyester polyols A2 to A6 were obtained in the same manner as in Synthesis Example 1-1, except that the raw materials and charging ratios listed in Table 1 were changed. In addition, the abbreviations described in the table represent the following.
NPG: Neopentyl glycol (plant-based, biomass content 40%)
PG: 1,2-propylene glycol (plant-based, 100% biomass)
1,3-PD: 1,3-propanediol (plant-based, 100% biomass)
In the above, the biomass degree of NPG is derived from the Perstorp catalog value.
・The dibasic acids in the table have the following biomass degrees.
Succinic acid: (derived from biomass, 100% biomass)
Adipic acid: (petroleum derived, biomass content 0%)
Sebacic acid: (derived from biomass, 100% biomass)

Note that the biomass level refers to the proportion of plant-derived and other biomass-derived components contained in a compound.
Biomass degree=100×mass of biomass-derived components of the compound/total mass of the compound.
However, if the relevant compound is a reaction product of a biomass-derived raw material and a non-biomass-derived raw material, the calculation is performed by converting it to the raw material before the reaction. For example, in the case of polyester resin (polyester polyol), which is a reaction product of dibasic acid and diol,
Biomass degree = 100 x (biomass dibasic acids + biomass-derived diols) / (all dibasic acids + all diols)
"All dibasic acids + all diols" refers to the sum of biomass-derived and non-biomass-derived dibasic acids, and biomass-derived and non-biomass-derived diols.

[Synthesis Example 2-1] (Synthesis of polyester urethane resin (A) B1)
In a four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen gas inlet tube, 23.6 parts of polyester polyol A1, 4.68 parts of isophorone diisocyanate (hereinafter also abbreviated as IPDI), and 7.0 parts of ethyl acetate were added. 5 parts and 0.003 part of tin 2-ethylhexanoate were charged, and the mixture was reacted at 120°C for 6 hours under a nitrogen stream. 7.5 parts of propyl acetate was added and cooled to obtain a solution of terminal isocyanate prepolymer. Next, 1.60 parts of isophorone diamine (hereinafter also abbreviated as IPDA), 0.12 parts of dibutylamine (hereinafter also abbreviated as DBA), 34 parts of ethyl acetate, and 21 parts of isopropyl alcohol (hereinafter also abbreviated as IPA) were added. A solution of the terminal isocyanate prepolymer obtained was gradually added at room temperature, and then reacted at 50°C for 1 hour to obtain a solid content of 30%, a mass average molecular weight of 70,000, an amine value of 4 mgKOH/g, and a molecular weight distribution (Mw/Mn) of 5. 5. A polyester urethane resin (A) B1 solution with a biomass degree of 66% by mass was obtained.

[Synthesis Examples 2-2 to 2-9] (Synthesis of polyester urethane resin (A) B2 to B9)
Polyester urethane resins (A) B2 to B9 were obtained in the same manner as in Synthesis Example 2-1 except that the raw materials and charging ratios listed in Table 2 were changed. The properties of the resin are shown in the same table.
In addition, the abbreviations described in the table represent the following.
IBPA: iminobispropylamine

[Comparative synthesis examples 2-A to 2-C]
Urethane resins C1 to C3 were obtained in the same manner as in Synthesis Example 2-1, except that the raw materials and charging ratios listed in Table 2 were changed. The properties of the resin are shown in the same table.

[Ink Preparation Example 3-1] (Preparation of gravure ink D1)
10 parts of phthalocyanine pigment (copper phthalocyanine blue, LIONOL BLUE FG-7330 manufactured by Toyocolor Co., Ltd.), 10 parts of urethane resin B1 solution, vinyl chloride-vinyl acetate resin solution (chloride with a hydroxyl value of 140 mgKOH/g and a mass average molecular weight of 50,000) After stirring and mixing 10 parts of vinyl-vinyl acetate copolymer resin (solid content 30% solution) and 10 parts of a mixed solvent (propyl acetate/IPA = 70/30 (mass ratio)) and dispersing with a sand mill, 30 parts of urethane resin (B1) and 30 parts of a mixed solvent (normal propyl acetate/isopropyl alcohol = 70/30 (mass ratio)) were stirred and mixed to obtain a blue printing ink D1.

[Ink Preparation Examples 3-2 to 3-17] (Preparation of gravure inks D2 to D17)
Inks D2 to D17 were obtained in the same manner as in Synthesis Example 3-1, except that the raw materials and charging ratios listed in Table 3 were changed. The abbreviations in the table are as follows.
・CAP-504-0.2: Manufactured by EASTMAN CHEMICAL, cellulose acetate propionate, number average molecular weight 15,000, glass transition temperature 159°C (ethyl acetate, isopropanol solution with solid content of 19.2%)
・Hariestar P: manufactured by Harima Kasei Co., Ltd. Rosin-modified pentaerythritol ester 30% solids ethyl acetate solution ・BR-105: manufactured by Mitsubishi Chemical Company, acrylic resin, weight average molecular weight 60,000, glass transition point 50°C, acid value 3 .5mgKOH/g 30% solids ethyl acetate solution/Mowital B30H: Kuraray Co., Ltd. Polyvinyl butyral resin having vinyl alcohol units, vinyl acetate units, and vinyl butyral units, and containing 73% by mass of butyral ring groups (glass transition point 70 ℃, weight average molecular weight 50,000, chlorine content 0% by mass, degree of nitrification 0% by mass) 30% solid solution in ethyl acetate/isopropanol = 1/1 mixed solvent Titanium oxide: CR-90 manufactured by Ishihara Sangyo Co., Ltd. Titanium oxide coated with silica and alumina, average particle size (median particle size) measured by transmission electron microscope is 0.25 μm

[Comparative Preparation Examples 3-A to 3-C] (Preparation of gravure inks E1 to E3)
Inks E1 to E3 were obtained in the same manner as in Preparation Example 3-1, except that the raw materials and charging ratios listed in Table 3 were changed.
Polyether polyol: bifunctional polypropylene glycol with a number average molecular weight of approximately 2000

[Curing agent synthesis example] (Synthesis of curing agent F1)
In a nitrogen gas atmosphere, in a reaction vessel with stirring blades, 15 parts of trimethylolpropane, 60.3 parts of toluene-2,4-diisocyanate, and 32.3 parts of ethyl acetate, which had been dehydrated in advance, were stirred at 50°C and 150 rpm. The reaction was carried out at high speed for 3 hours to obtain curing agent F1. Weight average molecular weight: 1200 Mw/Mn: 2.5 Solid content 70% by mass

In the Examples described below, the following isocyanate compound (isocyanate-based curing agent) was also used in addition to the above-mentioned curing agent.
・Curing agent F2
TLA-100: Manufactured by Asahi Kasei Corporation Isocyanurate type isocyanate curing agent Weight average molecular weight: 1300 Mw/Mn: 2.4 Solid content 70% by mass
・Curing agent F3
24A-100: Asahi Kasei Co., Ltd. Biuret type isocyanate curing agent Weight average molecular weight: 1600 Mw/Mn: 3.2 Solid content 70% by mass
・Curing agent F4
E402-80B: Asahi Kasei Co., Ltd. Adduct type isocyanate curing agent Weight average molecular weight: 4100 Mw/Mn: 3.4 Solid content 70% by mass

[Synthesis Example 4-1] (Synthesis of ether-based urethane polyol (B1) G1)
In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping tank, and a nitrogen gas inlet tube, 99 parts of bifunctional polytetramethylene glycol (PTMG) with a number average molecular weight of about 2,000 and 1 part of trimethylolpropane (TMP) were placed. 15 parts of tolylene diisocyanate (TDI) were placed in a reaction vessel, and heated at 70 to 80° C. for 5 hours with stirring under a nitrogen gas stream to perform a urethane reaction. During the urethanization reaction, 0.2% of ORGATIX TC-100 was added as a reaction catalyst to promote the reaction, and a polyether urethane polyol was obtained. 0.02 part of DYNASYLAN GLYMO was added to the obtained polyether urethane polyol, and the solid content concentration was adjusted to 60% with ethyl acetate to obtain a polyol resin G1 solution. The weight average molecular weight of the polyol resin G1 was 25,000, and the molecular weight distribution (Mw/Mn) was 2.4.

[Synthesis Example 4-2] (Synthesis of ether-based urethane polyol (B1) G2)
In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping tank, and a nitrogen gas inlet tube, 25 parts of a bifunctional polypropylene glycol with a number average molecular weight of about 2,000 and 75 parts of a bifunctional polypropylene glycol with a number average molecular weight of about 400 were added. , 36 parts of tolylene diisocyanate were charged into a reaction vessel, and the mixture was heated at 70 to 80° C. for 5 hours with stirring under a nitrogen gas stream to carry out a urethanization reaction. During the urethanization reaction, 0.2% of ORGATIX TC-100 was added as a reaction catalyst to accelerate the reaction, and a polyether urethane polyol was obtained. 0.02 part of DYNASYLAN GLYMO was added to the obtained polyether urethane polyol, and the solid content concentration was adjusted to 60% with ethyl acetate to obtain a polyol resin G2 solution. The weight average molecular weight of polyol resin G2 was 12,000, and the molecular weight distribution (Mw/Mn) was 3.0.

[Synthesis Example 4-3] (Synthesis of ether-based urethane polyol (B1) G3)
40 parts of bifunctional polypropylene glycol with a number average molecular weight of about 2,000 and 50 parts of bifunctional polypropylene glycol with a number average molecular weight of about 400 are placed in a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping tank, and a nitrogen gas introduction tube. , 10 parts of trifunctional polypropylene glycol having a number average molecular weight of about 400, and 26 parts of tolylene diisocyanate were charged into a reaction vessel, and heated at 70 to 80° C. for 5 hours with stirring under a nitrogen gas stream to perform a urethanization reaction. During the urethanization reaction, 0.2% of ORGATIX TC-100 was added as a reaction catalyst to accelerate the reaction, and a polyether urethane polyol was obtained. 0.02 part of DYNASYLAN GLYMO was added to the obtained polyether urethane polyol, and the solid content concentration was adjusted to 60% with ethyl acetate to obtain a polyol resin G3 solution. The weight average molecular weight of polyol resin G3 was 35,000, and the molecular weight distribution (Mw/Mn) was 8.0.

[Synthesis Example 4-4] (Synthesis of ether-based urethane polyol (B1) G4)
In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping tank, and a nitrogen gas inlet tube, 13 parts of a bifunctional polypropylene glycol with a number average molecular weight of about 2,000 and 70 parts of a bifunctional polypropylene glycol with a number average molecular weight of about 400 were added. , 18 parts of trifunctional polypropylene glycol having a number average molecular weight of about 400, and 33 parts of tolylene diisocyanate were charged into a reaction vessel, and the mixture was heated at 70 to 80° C. for 5 hours with stirring under a nitrogen gas stream to perform a urethanization reaction. During the urethanization reaction, 0.2% of ORGATIX TC-100 was added as a reaction catalyst to accelerate the reaction, and a polyether urethane polyol was obtained. 0.02 part of DYNASYLAN GLYMO was added to the obtained polyether urethane polyol, and the solid content concentration was adjusted to 60% with ethyl acetate to obtain a polyol resin G4 solution. The weight average molecular weight of polyol resin G4 was 54,000, and the molecular weight distribution (Mw/Mn) was 16.0.

[Synthesis Example 4-5] (Synthesis of ether-based urethane polyol (B1) G5)
In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping tank, and a nitrogen gas inlet tube, 20 parts of a bifunctional polypropylene glycol with a number average molecular weight of about 2,000 and 60 parts of a bifunctional polypropylene glycol with a number average molecular weight of about 400 are added. , 20 parts of castor oil-based polyol, and 28 parts of tolylene diisocyanate were placed in a reaction vessel, and the mixture was heated at 70 to 80°C for 5 hours with stirring under a nitrogen gas stream to perform a urethanization reaction. During the urethanization reaction, 0.2% of ORGATIX TC-100 was added as a reaction catalyst to accelerate the reaction, and a polyether urethane polyol was obtained. 0.02 part of DYNASYLAN GLYMO was added to the obtained polyether urethane polyol, and the solid content concentration was adjusted to 60% with ethyl acetate to obtain a polyol resin G5 solution. The weight average molecular weight of polyol resin G5 was 56,000, and the molecular weight distribution (Mw/Mn) was 14.0.

[Synthesis Example 4-6] (Synthesis of ether-based urethane polyol (B1) G6)
In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping tank, and a nitrogen gas inlet tube, 45 parts of a bifunctional polypropylene glycol having a number average molecular weight of about 2,000 and 15 parts of a bifunctional polypropylene glycol having a number average molecular weight of about 400 were added. , 40 parts of trifunctional polypropylene glycol having a number average molecular weight of about 400, and 12 parts of diphenylmethane diisocyanate were charged into a reaction vessel, and heated at 70°C to 80°C for 5 hours with stirring under a nitrogen gas stream to perform a urethanization reaction. An ether urethane polyol was obtained. 0.02 part of DYNASYLAN GLYMO was added to the obtained polyether urethane polyol to obtain a polyol resin G6 solution. The weight average molecular weight of polyol resin G6 was 3000, and the molecular weight distribution (Mw/Mn) was 3.4.

[Comparative Synthesis Example 4-7] (Synthesis of ester-based urethane polyol (B1) H1)
12 parts of ethylene glycol (EG), 12 parts of 1,6-hexanediol (1,6-HD), and neopentyl were placed in a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping tank, and a nitrogen gas introduction tube. 20 parts of glycol (NPG), 0.5 parts of trimethylolpropane (TMP), 35 parts of isophthalic acid, and 16.5 parts of succinic acid were charged, and an esterification reaction was carried out at 240°C. After distilling off a predetermined amount of water, the pressure was gradually reduced and a deglycol reaction was carried out at 250° C. for 4.5 hours at 1 mmHg or less to obtain a polyester polyol. Thereafter, 3 parts of isophorone diisocyanate (IPDI) was added, and the reaction was carried out at 150° C. for 2 hours to obtain a polyester urethane polyol. One part of trimellitic anhydride (TMA) was added to this polyester urethane polyol and reacted at 180° C. for 2 hours, and then diluted with ethyl acetate to a non-volatile content of 60% to obtain a polyol resin H1 solution. The weight average molecular weight of the polyol resin H1 was 22,000, and the molecular weight distribution (Mw/Mn) was 4.5.

[Synthesis Example 5-1] (Synthesis of isocyanate compound (B2) I1)
80 parts of bifunctional polypropylene glycol (PPG) with a number average molecular weight of about 2,000 and bifunctional polypropylene with a number average molecular weight of about 400 are placed in a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping tank, and a nitrogen gas introduction tube. 15 parts of glycol, 5 parts of trimethylolpropane, and 55 parts of diphenylmethane diisocyanate were placed in a reaction vessel and heated at 70 to 80°C for 5 hours with stirring under a nitrogen gas stream to perform a urethane reaction. During the urethanization reaction, 0.2% of ORGATIX TC-100 was added as a reaction catalyst to accelerate the reaction and obtain an isocyanate compound. 55 parts of a TDI-TMP adduct composition was added to the obtained isocyanate processed product, and the solid content concentration was adjusted to 60% with ethyl acetate to obtain an isocyanate compound I1 solution. The weight average molecular weight of the isocyanate compound I1 was 8400, and the molecular weight distribution (Mw/Mn) was 11.8.

[Synthesis Example 5-2] (Synthesis of isocyanate compound (B2) I2)
In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping tank, and a nitrogen gas inlet tube, 73 parts of a bifunctional polypropylene glycol having a number average molecular weight of about 2,000 and 17 parts of a bifunctional polypropylene glycol having a number average molecular weight of about 400 were added. , 10 parts of trifunctional polypropylene glycol having a number average molecular weight of about 400, and 42 parts of diphenylmethane diisocyanate were charged into a reaction vessel, and heated at 70 to 80°C for 5 hours with stirring under a nitrogen gas stream to perform a urethanization reaction. During the urethanization reaction, 0.2% of ORGATIX TC-100 was added as a reaction catalyst to accelerate the reaction, and a polyether urethane composition was obtained. 20 parts of a TDI-TMP adduct composition was added to the obtained isocyanate compound, and the solid content concentration was adjusted to 60% with ethyl acetate to obtain an isocyanate compound I2 solution. The weight average molecular weight of the isocyanate compound I2 was 17,000, and the molecular weight distribution (Mw/Mn) was 17.8.

[Synthesis Example 5-3] (Synthesis of isocyanate compound (B2) I3)
In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping tank, and a nitrogen gas inlet tube, 55 parts of a bifunctional polypropylene glycol having a number average molecular weight of about 2,000 and 43 parts of a bifunctional polypropylene glycol having a number average molecular weight of about 400 were added. , 2 parts of trifunctional polypropylene glycol having a number average molecular weight of about 400, and 75 parts of diphenylmethane diisocyanate were charged into a reaction vessel, and heated at 70 to 80°C for 5 hours with stirring under a nitrogen gas stream to perform a urethanization reaction. During the urethanization reaction, 0.2% of ORGATIX TC-100 was added as a reaction catalyst to accelerate the reaction and obtain an isocyanate compound. 25 parts of a TDI-TMP adduct composition was added to the obtained isocyanate compound, and the solid content concentration was adjusted to 60% with ethyl acetate to obtain an isocyanate compound I3 solution. The weight average molecular weight of isocyanate compound I3 was 5000, and the molecular weight distribution (Mw/Mn) was 6.2.

[Synthesis Example 5-4] (Synthesis of isocyanate compound (B2) I4)
In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping tank, and a nitrogen gas inlet tube, 80 parts of a bifunctional polypropylene glycol with a number average molecular weight of about 2,000 and 15 parts of a bifunctional polypropylene glycol with a number average molecular weight of about 400 were added. , 5 parts of trimethylolpropane, and 55 parts of diphenylmethane diisocyanate were charged into a reaction vessel, and the mixture was heated at 70 to 80° C. for 5 hours with stirring under a nitrogen gas stream to perform a urethanization reaction. During the urethanization reaction, 0.2% of ORGATIX TC-100 was added as a reaction catalyst to accelerate the reaction and obtain an isocyanate compound. 55 parts of the XDI-TMP adduct composition was added to the obtained isocyanate processed product, and the solid content concentration was adjusted to 60% with ethyl acetate to obtain an isocyanate compound I4 solution. The weight average molecular weight of isocyanate compound I4 was 9000, and the molecular weight distribution (Mw/Mn) was 12.2.

[Synthesis Example 5-5] (Synthesis of isocyanate compound (B2) I5)
In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping tank, and a nitrogen gas inlet tube, 78 parts of a bifunctional polypropylene glycol with a number average molecular weight of about 2,000 and 10 parts of a bifunctional polypropylene glycol with a number average molecular weight of about 400 were added. , 12 parts of bifunctional polypropylene glycol having a number average molecular weight of about 400, 63 parts of diphenylmethane diisocyanate, and 18 parts of a buret of hexamethylene diisocyanate were placed in a reaction vessel and heated at 70 to 80°C for 5 hours while stirring under a nitrogen gas flow. A urethanization reaction was performed to obtain an isocyanate compound I5 solution. The weight average molecular weight of isocyanate compound I5 was 4500, and the molecular weight distribution (Mw/Mn) was 13.0.

[Synthesis Example 5-6] (Synthesis of isocyanate compound (B2) I6)
In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping tank, and a nitrogen gas inlet tube, 80 parts of a bifunctional polypropylene glycol with a number average molecular weight of about 2,000 and 20 parts of a bifunctional polypropylene glycol with a number average molecular weight of about 400 were added. , 250 parts of diphenylmethane diisocyanate, and 140 parts of a burette of hexamethylene diisocyanate were charged into a reaction vessel, and heated at 70 to 80°C for 5 hours with stirring under a nitrogen gas stream to perform a urethanization reaction to obtain an isocyanate compound I6 solution. Ta. 260 parts of a TDI-TMP adduct composition was added to the obtained isocyanate compound I6, and the solid content concentration was adjusted to 75% with ethyl acetate to obtain an isocyanate compound I6 solution. The weight average molecular weight of isocyanate compound I6 was 2500, and the molecular weight distribution (Mw/Mn) was 5.8.

[Comparative Synthesis Example 5-A] (Synthesis of isocyanate compound J1)
In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping tank, and a nitrogen gas inlet tube, 73 parts of a bifunctional polypropylene glycol having a number average molecular weight of about 2,000 and 17 parts of a bifunctional polypropylene glycol having a number average molecular weight of about 400 were added. , 10 parts of trifunctional polypropylene glycol having a number average molecular weight of about 400, and 39 parts of diphenylmethane diisocyanate were charged into a reaction vessel, and heated at 70 to 80°C for 5 hours with stirring under a nitrogen gas stream to perform a urethanization reaction. During the urethanization reaction, 0.2% of ORGATIX TC-100 was added as a reaction catalyst to accelerate the reaction and obtain an isocyanate compound. 20 parts of a TDI-TMP adduct composition was added to the obtained isocyanate compound, and the solid content concentration was adjusted to 60% with ethyl acetate to obtain an isocyanate compound J1 solution. The weight average molecular weight of isocyanate compound J1 was 25,000, and the molecular weight distribution (Mw/Mn) was 19.2.

[Comparative Synthesis Example 5-B] (Synthesis of isocyanate compound J2)
In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping tank, and a nitrogen gas inlet tube, 86 parts of a bifunctional polypropylene glycol with a number average molecular weight of about 2,000 and 14 parts of a bifunctional polypropylene glycol with a number average molecular weight of about 400 were added. , 38 parts of diphenylmethane diisocyanate were charged into a reaction vessel and heated at 70 to 80° C. for 5 hours with stirring under a nitrogen gas stream to carry out a urethane reaction. During the urethanization reaction, 0.2% of ORGATIX TC-100 was added as a reaction catalyst to accelerate the reaction and obtain an isocyanate compound. 25 parts of a TDI-TMP adduct composition was added to the obtained isocyanate compound, and the solid content concentration was adjusted to 60% with ethyl acetate to obtain an isocyanate compound J2 solution. The weight average molecular weight of isocyanate compound J2 was 5200, and the molecular weight distribution (Mw/Mn) was 5.0.

[Example 1]
(Manufacture of printed matter) The viscosity of printing ink D1 of gravure ink D1 is adjusted to a viscosity of 15 seconds (25°C) in Zahn cup #3 (manufactured by Rigosha) using an ethyl acetate/IPA mixed solvent (mass ratio 80/20). After adjusting the dilution and printing on stretched polypropylene (OPP) film (thickness 20 μm) using a gravure proofing machine equipped with a gravure plate with a plate depth of 20 μm, it was dried at 40 to 50°C to obtain printed matter (OPP). . The base material was changed to a nylon (Ny) film (thickness: 15 μm) and a single-sided corona-treated polyethylene terephthalate (PET) film (thickness: 12 μm), and prints with different base materials were created in the same manner as above.

(Preparation of packaging material K1 with laminate configuration A) For laminate strength/residual solvent test A laminate prepared by adding ethyl acetate to a mixture of 1 part of polyol resin G3 and 1 part of isocyanate compound I1 to adjust the non-volatile content to 30%. An adhesive solution was applied onto the printing layer of the printed matter (OPP) of the above ink D1, dried, and laminated with an unstretched polypropylene (CPP) film (thickness 25 μm, surface corona discharge treatment) using a laminating machine. It was kept warm at ℃ for 1 day to create a packaging material K1.
Laminated configuration A: Stretched polypropylene (OPP) film (thickness 20 μm)/printed layer/unstretched polypropylene (CPP) film (thickness 25 μm, surface corona discharge treatment)

(Preparation of packaging material M1 with laminated structure B) For tearability/temporal tearability test Ethyl acetate was added to a mixture of 1 part of polyol resin G3 and 1 part of isocyanate compound I1 to adjust the nonvolatile content to 30%. A laminating adhesive solution was applied onto the printed layer of the printed matter (Ny) of the ink D1, dried, and then laminated with a linear low-density polyethylene (LLDPE) film (thickness 50 μm, surface corona discharge treatment) using a laminating machine. They were pasted together and kept warm at 40° C. for 1 day to create packaging material M1.
Laminated structure B: Nylon (Ny) film (thickness 15 μm)/printed layer/linear low density polyethylene (thickness 50 μm, surface corona discharge treatment)

(Preparation of packaging material O1 with laminated configuration C) For tearability test A laminating adhesive solution prepared by adding ethyl acetate to a mixture of 1 part of polyol resin G3 and 1 part of isocyanate compound I1 to adjust the non-volatile content to 30%. was coated on the print layer of the printed matter (PET) of the above ink D1, dried, and the coated surface was bonded to an aluminum vapor-deposited film. Next, a laminating adhesive solution prepared by adding ethyl acetate to a mixture of 1 part of polyol resin G3 and 1 part of isocyanate compound I1 and adjusting the non-volatile content to 30% was applied onto the aluminum vapor-deposited film. , it was dried, bonded to an unstretched polypropylene film, and kept warm at 40° C. for 1 day to create a packaging material O1.
Laminated structure C: polyethylene terephthalate (PET) film (thickness 12 μm) / printed layer / aluminum vapor deposited film (thickness 25 μm) / unstretched polypropylene (CPP) film (thickness 25 μm, surface corona discharge treatment)

[Example 2-24] (Production of packaging materials K2 to K24, M2 to M24, O2 to O24)
Packaging materials having laminate configuration A, laminate configuration B, and laminate configuration C were obtained in the same manner as in Example 1 except that the inks, polyol resins, and isocyanate compounds shown in Tables 4 and 5 were used, respectively.

[Example 25] (Preparation of packaging materials K25, M25, O25)
Printed matter for each base material was created in the same manner as in Example 1 using a stirred mixture of 100 parts of ink D1 and 3 parts of hardening agent F1.
Packaging materials having laminate configuration A, laminate configuration B, and laminate configuration C were obtained in the same manner as in Example 1 except that the above printed matter, the polyol resin shown in Table 5, and the isocyanate compound were used.

[Example 26-28] (Preparation of packaging materials K26 to K28, M26 to M28, O26 to O28)
Using the curing agents shown in Table 5, prints of each base material were created in the same manner as in Example 25.
Packaging materials having laminate configuration A, laminate configuration B, and laminate configuration C were obtained in the same manner as in Example 1, except that the above printed matter, the polyol resin, and the isocyanate compound shown in Table 5 were used, respectively.

[Example 29] (Preparation of packaging materials K29, M29, O29)
Printed matter for each base material was created in the same manner as in Example 1 using a mixture of 100 parts of ink D1, 3 parts of curing agent F1, and 2 parts of the following silane coupling agent.
- Silane coupling agent: Solid content of KBM-903 (manufactured by Shin-Etsu Silicone Co., Ltd., 3-aminopropyltrimethoxysilane) dissolved in a mixed solvent of normal propyl acetate (NPAC)/isopropyl alcohol (IPA) = 70:30 5% solution Packaging materials of laminate configuration A, laminate configuration B, and laminate configuration C were obtained in the same manner as in Example 1 except that the above printed matter, the polyol resin, and the isocyanate compound shown in Table 5 were used. .

[Example 30] (Preparation of packaging materials K30, M30, O30)
Packaging materials having laminate configuration A, laminate configuration B, and laminate configuration C were obtained in the same manner as in Example 1 except that ink D1, 100 parts of polyol resin H1, and 12 parts of isocyanate compound I6 were used.

[Example 31] (Preparation of packaging materials K31, M31, O31)
(Preparation of packaging material K31 with lamination configuration A) For lamination strength/residual solvent test: 1 part of polyol resin G6 and 1 part of isocyanate compound I5 were added to the surface of the printed layer of the printed matter of ink D1 prepared in the same manner as in Example 1. The blended material was applied and dried using a solvent-free laminating machine, laminated with an unstretched polypropylene (CPP) film (thickness 25 μm, surface corona discharge treated), and kept at 40°C for 1 day to form packaging material K31. Created.
Laminated configuration A: Stretched polypropylene (OPP) film (thickness 20 μm)/printed layer/unstretched polypropylene (CPP) film (thickness 25 μm, surface corona discharge treatment)

(Preparation of packaging material M31 with laminated structure B) For tearability/temporal tearability test 1 part of polyol resin G6 and 1 part of isocyanate compound I5 were added to the surface of the printed layer of the printed matter of ink D1 prepared in the same manner as in Example 1. The mixture was applied and dried using a solvent-free laminating machine, laminated with a linear low-density polyethylene (LLDPE) film (thickness 50 μm, surface corona discharge treated), and kept at 40°C for 1 day. Packaging material M31 was created.
Laminated structure B: Nylon (Ny) film (thickness 15 μm)/printed layer/linear low density polyethylene (thickness 50 μm, surface corona discharge treatment)

(Preparation of packaging material O31 with laminated structure C) For tearability test: 1 part of polyol resin G6 and 1 part of isocyanate compound I5 were added to the surface of the printed layer of the printed matter of ink D1 prepared in the same manner as in Example 1. was coated and dried using a solvent-free laminating machine, and the coated surface was bonded to an aluminum vapor-deposited film. Next, a mixture of 1 part of polyol resin G6 and curing agent I5 was similarly applied to the aluminum vapor-deposited film using a solvent-free laminating machine, dried, and laminated with an unstretched polypropylene film. It was kept warm for 1 day to create packaging material O31.
Laminated structure C: polyethylene terephthalate (PET) film (thickness 12 μm) / printed layer / aluminum vapor deposited film (thickness 25 μm) / unstretched polypropylene (CPP) film (thickness 25 μm, surface corona discharge treatment)

[Comparative Example 1-5] (Creation of packaging materials L1 to L5, N1 to N5, P1 to P5)
Packaging materials having laminate configuration A, laminate configuration B, and laminate configuration C were obtained in the same manner as in Example 1 except that the ink, polyol resin, and isocyanate compound shown in Table 6 were used.

The following characteristics were evaluated using the above packaging material. The results are shown in Tables 4-6.

(laminate strength)
The packaging material with lamination configuration A obtained in the above Examples and Comparative Examples was cut out to a length of 150 mm and width of 15 mm, opened at the ink/OPP film interface, and the laminate strength was measured by T-peel using a tensile tester.
(Evaluation criteria)
5: 1.5N/15mm or more (excellent)
4: 1.0N/15mm or more but less than 1.5N/15mm (good)
3: 0.7N/15mm or more but less than 1.0N/15mm (acceptable)
2: 0.5N/15mm or more but less than 0.7N/15mm (not allowed)
1: Less than 0.5N/15mm (poor)
The practical level is 3 to 5.

(Residual solvent in packaging materials)
After laminating the packaging materials with laminated configuration A obtained in the above Examples and Comparative Examples, the laminated laminate was cut into a size of 20 cm in width and 25 cm in length, and 20 pieces were placed in an eggplant flask, sealed, and heated. (Temperature: 80° C., 30 minutes) Then, 0.4 ml of air in the flask was extracted and analyzed by gas chromatography (GC) to confirm the amount of solvent components.
(Evaluation criteria)
5: The total amount of residual solvent was less than 1 mg/m ² . (Excellent)
4: The total amount of residual solvent was 1 mg/m ² or more and less than 3 mg/m ² . (good)
3: The total amount of residual solvent was 3 mg/m ² or more and less than 5 mg/m ² . (possible)
2: The total amount of residual solvent was 5 mg/m ² or more and less than 10 mg/m ² . (Not allowed)
1: The total amount of residual solvent was 10 mg/m ² or more. (poor)
Note that the practical level is 3 to 5.

(Easy tearability)
Samples were prepared in accordance with JIS K7128-1:1998 for the packaging materials of laminated configuration B and laminated configuration C obtained in the above Examples and Comparative Examples, and evaluated by the resistance when torn using a 201 universal tensile tester manufactured by Intesco. .
[Evaluation criteria]
5: Less than 0.5N (good)
4: 0.5N or more and less than 1.0N (slightly good)
3: 1.0N or more and less than 1.5N (practical)
2: 1.5N or more but less than 2.0N (slightly poor)
1: 2.0N or more (defective)
The practical evaluation is 3 to 5.

(Easy tearability over time)
For the packaging materials with laminated structure B obtained in the above examples and comparative examples, the contents were made into a 1:1:1 soup (ketchup: vinegar: oil = 1:1:1 in mass ratio) and retorted at 98°C for 30 minutes. The sample was treated and left flat in an oven at 40°C for 2 weeks. Thereafter, samples were prepared according to JISK7128-1:1998, and evaluated by tearing resistance using a 201 universal tensile tester manufactured by Intesco.
[Evaluation criteria]
5: Less than 0.5N (good)
4: 0.5N or more and less than 1.0N (slightly good)
3: 1.0N or more and less than 1.5N (practical)
2: 1.5N or more and less than 2.0N (slightly poor)
1: 2.0N or more (defective)
The practical evaluation is 3 to 5.

Claims (13)

A packaging material comprising a base material, a printing layer, an adhesive layer, and a sealant in this order,
The printing layer contains a polyester urethane resin (A) having a molecular weight distribution (Mw/Mn) of 4 to 12,
The adhesive layer is made of a cured product of a reactive adhesive containing a urethane polyol (B1) and an isocyanate compound (B2), and the isocyanate compound (B2) has a molecular weight distribution (Mw/Mn) of 5.5 to 18.5, packaging material. The packaging material according to claim 1, wherein the urethane polyol (B1) is an ether-based urethane polyol (b1). The packaging material according to claim 2, wherein the ether-based urethane polyol (b1) has a molecular weight distribution (Mw/Mn) of 2 to 17. 2. The polyester urethane resin (A) contains a structural unit derived from a polyester that is a condensation product of a dibasic acid and a diol, and the dibasic acid contains sebacic acid and/or succinic acid. Packaging materials listed in . The packaging material according to claim 4, wherein the diol contains a branched diol and a linear diol. The packaging according to claim 1 or 2, wherein the printing layer further contains at least one resin selected from the group consisting of cellulose resin, vinyl chloride copolymer resin, rosin resin, acrylic resin, and polyvinyl acetal resin. Material. The packaging material according to claim 1 or 2, wherein the printing layer further contains a silane coupling agent. The packaging material according to claim 2 or 3, wherein the ether-based urethane polyol (b1) contains a structural unit derived from polypropylene glycol. The packaging material according to claim 2 or 3, wherein the ether-based urethane polyol (b1) further contains a constituent unit derived from castor oil. The packaging material according to claim 1 or 2, wherein the printing layer has a crosslinked structure with an isocyanate curing agent (C) having a weight average molecular weight of 800 to 8,000. A method for producing a packaging material comprising a base material, a printed layer, an adhesive layer, and a sealant in this order,
A step of gravure printing a gravure ink containing a polyester-based urethane resin (A) to form a printed layer, and a step of applying a reactive adhesive consisting of a urethane polyol (B1) and an isocyanate compound (B2) to form an adhesive layer. including the step of forming
The polyester urethane resin (A) has a molecular weight distribution (Mw/Mn) of 4 to 12, and the isocyanate compound (B2) has a molecular weight distribution (Mw/Mn) of 5.5 to 18.5. Method of manufacturing packaging materials. The method for manufacturing a packaging material according to claim 11, wherein the urethane polyol (B1) is an ether-based urethane polyol (b1). The method for producing a packaging material according to claim 12, wherein the ether-based urethane polyol (b1) has a molecular weight distribution (Mw/Mn) of 2 to 17.