JP7459625B2 - Gravure ink for lamination or flexo ink for lamination and its use - Google Patents

Description

The present invention relates to gravure ink for lamination or flexographic ink for lamination, and printed matter and laminate thereof.

Gravure or flexographic inks are widely used for pattern printing to add beauty and functionality to printing materials, but in recent years, the variety of packaging materials, the sophistication of packaging technology, and the use of organic solvents have increased. Requirements for printing inks are diversifying year by year, including environmental efforts from the legal and regulatory aspects.

Among gravure or flexographic inks, laminating inks used for laminated laminates in particular often use polyurethane resins to maintain and improve laminate strength. This is because polyurethane resins allow for flexible coating film design, from hard and tough to soft and elastic, by selecting isocyanates, polyols, etc.
Furthermore, by using biomass-derived raw materials made from plants, the amount of carbon dioxide emitted during combustion is offset by the amount of carbon dioxide absorbed and fixed by the growth of plants, etc., so there is no effect on the increase or decrease of carbon dioxide in the air (also called carbon neutral). Therefore, it is urgent to use biomass-derived raw materials for polyurethane resins and other ink components used in gravure or flexo inks for packaging materials for films in order to avoid an increase in carbon dioxide, a greenhouse gas.

Even when biomass polyurethane resin is used, it is of course possible to maintain the same performance (lamination strength, printability, etc.) as conventional non-biomass polyurethane resins, and further performance improvements are required in the future. Therefore, various studies have been conducted on biomass-derived polyester polyols, which are the constituent raw materials of polyurethane resins (Patent Documents 1, 2, and 3). However, not all of the properties of biomass polyurethane resins used as ink raw materials have been clarified, and unexpected defects may occur.

Gravure or flexo ink has a relatively low ink viscosity and the printing press is large, so it is greatly affected by temperature and humidity factors in the printing environment. Among these, when the room temperature in the printing environment is low, problems such as plate fogging in gravure printing and plate entanglement in flexographic printing are likely to occur. Therefore, in order to improve printing suitability at low temperatures, studies are being conducted to apply polyurethane resins that use azelaic acid, which has a low melting point, as a dibasic acid to inks (Patent Document 4). However, there are concerns that the lowering of the melting point of polyurethane resin will affect evaluations related to heat resistance, particularly boiling and heat sealability.

JP 2018-95831 A JP2018-062642A WO2018/199085 pamphlet JP 2020-2185 A

The present invention aims to provide a gravure or flexographic ink that has good resolubility and also has good heat resistance, such as the lamination strength of the laminate and boiling and heat sealing suitability.

In light of the above problems, the inventors conducted intensive research and discovered that the problems could be solved by using the gravure or flexographic ink described below, which led to the creation of the present invention.

The present invention is a gravure or flexo ink for laminates containing a binder resin containing a polyurethane resin and an organic solvent, comprising:
The polyurethane resin contains a structural unit derived from a polyester polyol that is a condensation reaction product of a dibasic acid and a diol, and the dibasic acid is a dibasic acid with an odd number of carbon atoms and a dibasic acid with an even number of carbon atoms. This invention relates to a gravure or flexo ink for lamination containing.

The present invention also relates to a gravure or flexographic ink for the above laminate, in which the dibasic acid having an odd number of carbon atoms is azelaic acid.

The present invention also relates to a gravure or flexographic ink for the above-mentioned laminate, in which the dibasic acid having an even number of carbon atoms includes at least one selected from succinic acid, adipic acid, and sebacic acid.

The present invention also relates to a gravure or flexographic ink for the above-mentioned lamination, which contains 1 to 40% by mass of azelaic acid-derived structural units in the total solid content of the polyurethane resin.

Moreover, the present invention further relates to a gravure or flexographic ink for the above-mentioned laminate, which contains a vinyl chloride copolymer resin and/or a rosin resin.

The present invention also relates to a printed matter having a printed layer formed on a substrate 1 using gravure or flexographic ink for the above-mentioned lamination.

The present invention also relates to a laminate having, in this order, at least a substrate 1, a printing layer formed from a gravure or flexographic ink for the above-mentioned lamination, and a substrate 2.

The present invention makes it possible to provide gravure or flexographic inks that have good resolubility and also have good heat resistance, such as lamination strength of laminates and boil and heat seal suitability.

The following examples are provided to explain the embodiments of the present invention in detail, but the following examples are merely representative examples of the embodiments of the present invention, and the present invention is not limited to these details as long as they do not exceed the gist of the invention.

The present invention relates to a gravure or flexographic ink for lamination, which contains, for example, a pigment, a binder resin including a polyurethane resin, and an organic solvent,
The polyurethane resin contains a constituent unit derived from a polyester polyol, which is a condensation reaction product of a dibasic acid and a diol. The dibasic acid contains a dibasic acid having an odd number of carbon atoms and a dibasic acid having an even number of carbon atoms, and it is presumed that this gives the binder resin appropriate hardness and flexibility, and allows it to achieve both resolubility, lamination strength, and heat resistance.

Note that in this specification, "gravure or flexographic ink" may be simply referred to as "ink" or "printing ink", but they have the same meaning. A layer formed from gravure or flexo ink is referred to as a "print layer" or "ink film."

(binder resin)
The binder resin refers to a binding resin in the laminating gravure or flexographic ink of the present invention, and includes a polyurethane resin. Thermoplastic resins that are soluble in organic solvents are preferred. Although not limited to the following, the binder resin may include a resin containing a polyurethane resin with a glass transition temperature of -80°C or more and less than 20°C, and a resin with a glass transition temperature of 30°C or more and 200°C or less. is preferred. The latter resin preferably contains at least one resin selected from vinyl chloride copolymer resins, rosin resins, and cellulose resins. The glass transition temperature is preferably -60°C to 0°C for the former and 50°C to 190°C for the latter. Note that in this specification, the glass transition temperature is a measured value in dynamic viscoelasticity measurement, and refers to the maximum value at Tan δ. Further, the binder resin is preferably contained in an amount of 5 to 15% by weight, more preferably 7 to 13% by weight, based on the total weight of the ink.

Examples of binder resins include, but are not limited to, polyurethane resins, cellulose resins, polyamide resins, vinyl chloride-vinyl acetate copolymer resins, vinyl chloride-acrylic copolymer resins, rosin resins, and ethylene. - Vinyl acetate copolymer resin, vinyl acetate resin, acrylic resin, styrene resin, Dammar resin, styrene-maleic acid copolymer resin, polyester resin, alkyd resin, terpene resin, phenol-modified terpene resin, ketone resin, cyclized rubber, Examples include chlorinated rubber, butyral, polyacetal resin, petroleum resin, and modified resins thereof. These resins can be used alone or in combination of two or more.

(Polyurethane resin)
The polyurethane resin in the present invention functions as a binder resin. The mass average molecular weight of the polyurethane resin is preferably 10,000 to 100,000. More preferably, it is 30,000 to 80,000. When the mass average molecular weight is within the range of 10,000 to 100,000, the laminate strength tends to be improved. In addition, the glass transition temperature is preferably -60°C to 0°C, and more preferably -50°C to -30°C.

The polyurethane resin in the present invention is preferably a polyurethane resin obtained by a condensation reaction between a polyol and a polyisocyanate, or a polyurethane resin obtained by a reaction (called chain extension) between a polyamine and a urethane prepolymer having an isocyanate group at the end, which is a condensation reaction product between a polyol and a polyisocyanate.

The polyol used in the polyurethane resin preferably contains a polyester polyol and has a number average molecular weight of 400 to 10,000. In addition, it is preferable to contain polyester polyol in 50 mass % or more in raw material polyol, and it is still more preferable to contain 70 mass % or more.
Furthermore, polyols other than the above-mentioned polyester polyols may be used in combination. Examples include polyether polyols, polylactone polyols, polycarbonate polyols, polyolefin polyols, castor oil polyols, hydrogenated castor oil polyols, dimer diols, hydrogenated dimer diols, and the like.

(Polyester polyol)
The above polyester polyol is a polyester polyol formed by condensation reaction of a dibasic acid and a diol, and the dibasic acid includes a dibasic acid having an odd number of carbon atoms and a dibasic acid having an even number of carbon atoms. Dibasic acids have an even or odd number of carbon atoms between carboxyl groups, and this appears in the melting point. Note that the number of carbon atoms does not include the carbon of the carboxyl group. Generally, dibasic acids with an odd number of carbon atoms have a lower melting point than dibasic acids with an even number of carbon atoms. Dibasic acids with an odd number of carbon atoms impart flexibility, and dibasic acids with an even number of carbon atoms impart toughness, so it consists of a dibasic acid with an odd number of carbon atoms and a dibasic acid with an even number of carbon atoms. Inks using polyurethane resins made from polyester polyols have a good balance of resolubility, lamination strength, and heat resistance.

Examples of dibasic acids having an odd number of carbon atoms include azelaic acid, pimelic acid, glutaric acid, malonic acid, undecanedioic acid, tridecanedioic acid, and the like. Among these, it is preferable to include azelaic acid, which is a biomass raw material. The dibasic acid having an odd number of carbon atoms is preferably contained in an amount of 1 to 70% by mass, more preferably 3 to 50% by mass, and more preferably 5 to 30% by mass in the total mass of dibasic acids constituting the raw materials for the polyester polyol. It is more preferable that the content is % by mass. Further, the total solid content of the urethane resin preferably contains 1 to 40% by mass, more preferably 1 to 20% by mass, and even more preferably 2 to 10% by mass.

Examples of dibasic acids having an even number of carbon atoms include sebacic acid, suberic acid, adipic acid, succinic acid, and dodecanedioic acid. Among these, it is preferable to contain sebacic acid and/or succinic acid, which are biomass raw materials. The dibasic acid having an even number of carbon atoms is preferably contained in an amount of 30 to 99% by mass, more preferably 50 to 97% by mass, and more preferably 70 to 95% by mass in the total mass of dibasic acids constituting the raw material of the polyester polyol. It is more preferable that the content is % by mass. Further, the total solid content of the urethane resin preferably contains 5 to 60% by mass, and more preferably 20 to 40% by mass.

The mass ratio of "dibasic acid with an odd number of carbon atoms" and "dibasic acid with an even number of carbon atoms" constituting the dibasic acid is preferably 5:95 to 95:5, and 10:90 to 60: More preferably, it is 40. This is because the balance between resolubilability, lamination strength, and heat resistance is improved.

In the polyester polyol, the diol preferably includes both a branched diol and a linear diol. This improves the laminate strength of the laminate. Here, the linear diol is a compound having two hydroxyl groups, and refers to alkylene glycol, dialkylene glycol, trialkylene glycol, and other diols.
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. The branched diol and linear diol each may optionally include a biomass-derived diol. The linear diol imparts crystallinity, and the branched diol imparts flexibility, so the balance between them allows the polyurethane resin used as the binder resin to provide a strong ink film and high laminate strength.

Suitable examples of the branched diol 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 (hereinafter also referred to as MPD), neopentyl glycol (hereinafter also referred to as NPG), 1,2-propylene glycol (hereinafter also referred to as PG), 2,4-diethyl-1,5-pentanediol, 1,3-butanediol, dipropylene glycol, and the like. Among these, at least one branched diol selected from MPO, MPD, BEPG, NPG, PG, and 2,4-diethyl-1,5-pentanediol is preferred, and it is more preferred to use NPG and/or BEPG. Among these, the branched diol may have a carbon number of 3 or more, preferably 4 to 12, and even more preferably 4 to 10.

The linear diol is preferably an alkylene glycol, and examples of such compounds include ethylene glycol (also described as EG), diethylene glycol, 1,3-propanediol (also described as 1,3-PD), 1,4-butanediol (also described as 1,4-BD), 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,4-butynediol, 1,4-butylenediol, diethylene glycol, and triethylene glycol.
Among these, the carbon number of the linear diol is preferably 3 to 8, and more preferably 3 to 6. 1,3-PD, 1,4-BD, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, and the like are preferred.

The branched diol units and the linear diol units may each be present in one type of polyester polyol, or a polyester polyol containing only branched diol units and a polyester polyol containing only linear diol units may be used. may be used as a mixture raw material to produce biomass polyurethane resin. Approximately the same effect can be obtained.
Further, in 100% by mass of the diol, the branched diol and the linear diol are preferably contained in a mass ratio (branched diol:linear diol) of 10:90 to 90:10, and preferably 30: It is more preferable that the ratio is 70 to 80:20, and even more preferably 40:60 to 70:30. This is because these compositions have the effect of improving resolubility, lamination strength, and residual solvent in multilayer printed matter or laminates.

The polyurethane resin in the present invention preferably has a biomass degree of 40 to 100% by mass, more preferably 55 to 100% by mass. Furthermore, the degree of biomass in the nonvolatile matter of the gravure or flexographic ink having a binder containing a polyurethane resin in the present invention, that is, the degree of biomass in the printing layer, is preferably 5% by mass or more, and preferably 7% by mass or more. , more preferably 10% by mass or more.

The biomass ratio refers to the ratio of plant-derived and other biomass-derived components contained in a compound. That is, the biomass ratio is a value expressed by the following formula (4).

Equation (4) Biomass degree = 100 × total mass of biomass-derived components in a compound / total mass of a compound

However, when the compound is a reaction product between a biomass-derived raw material and a non-biomass-derived raw material, the calculation is performed by converting the raw material before the reaction. For example, in the case of a polyester resin (polyester polyol) which is a reaction product between a dibasic acid and a diol,

Biomass degree = 100 x (biomass diacid + biomass-derived diol) / (total diacid + total diol)

"All diacids" refers to the sum of biomass-derived and non-biomass-derived diacids, and "all diols" refers to the sum of biomass-derived and non-biomass-derived diols.

As the polyisocyanate, a diisocyanate is preferred, and various known aromatic, aliphatic, or alicyclic diisocyanates can be used as such compounds. For example, 1,5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzyl isocyanate, 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-trimethylsilyl diisocyanate, tetra ... Representative examples include methylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, cyclohexane-1,4-diisocyanate, xylylene diisocyanate, isophorone diisocyanate, lysine diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 1,3-bis(isocyanatemethyl)cyclohexane, methylcyclohexane diisocyanate, m-tetramethylxylylene diisocyanate, and dimer diisocyanate in which the carboxyl group of a dimer acid is converted to 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 isophorone diisocyanate is more preferred from the viewpoint of solubility.

The above-mentioned polyamine is preferably a diamine, and examples of such diamine include ethylene diamine, propylene diamine, hexamethylene diamine, isophorone diamine, and dicyclohexylmethane-4,4'-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 diamine.

In the present invention, the polyurethane resin preferably has an amine value. The amine value of the polyurethane urea resin is preferably 0.5 to 15 mgKOH/g, more preferably 1 to 13 mgKOH/g. Within this range, the laminate strength with respect to the base material tends to improve.

For chain extension reactions using polyamines, monoamines may be used as reaction terminators. Examples of reaction terminators include dialkylamines such as dibutylamine, diethylamine, and dipropylamine, as well as monoethanolamine, diethanolamine, 2-amino-2-methyl-1-propanol, tri(hydroxymethyl)aminomethane, Amines having a hydroxyl group such as amines having a hydroxyl group can also be used.

As described above, it is also preferable that the binder resin contains at least two kinds of resins. Among them, it is preferable to use a polyurethane resin in combination with a vinyl chloride copolymer resin and/or a rosin-based resin. The content of the vinyl chloride copolymer resin and/or the rosin-based resin is preferably 1 to 6 mass % of the total mass of the ink. As the vinyl chloride copolymer resin, it is preferable to use a vinyl chloride-vinyl acetate-acrylic copolymer resin. As the rosin-based resin, it is preferable to use a rosin ester or a rosin-modified maleic acid resin. However, the combined resin is not limited to these. The mass ratio of the polyurethane resin to the vinyl chloride copolymer resin and/or the rosin-based resin is preferably 95:5 to 30:70, more preferably 95:5 to 50:50, and even more preferably 90:10 to 65:35.
The total content of the polyurethane resin, the vinyl chloride copolymer resin and/or the rosin-based resin is preferably 60 mass % or more, more preferably 70 mass % or more, and even more preferably 80 mass % or more, of the total mass of the binder resin.

(Vinyl chloride-vinyl acetate copolymer resin)
The vinyl chloride-vinyl acetate copolymer resin is a copolymer of vinyl chloride and vinyl acetate, and the molecular weight is preferably 5,000 to 100,000 in weight average molecular weight, more preferably 20,000 to 70,000. The vinyl acetate monomer-derived structure is preferably 1 to 30 mass% and the vinyl chloride monomer-derived structure is preferably 70 to 95 mass% in 100 mass% of the solid content of the vinyl chloride-vinyl acetate copolymer resin. In this case, the solubility in organic solvents is improved, and further, the adhesion to the substrate, the film properties, the laminate strength, etc. are improved.
In order to improve the solubility in organic solvents, it is more preferable that the polyvinyl alcohol contains a hydroxyl group derived from a saponification reaction or copolymerization, and the hydroxyl value is preferably 20 to 200 mgKOH/g. The glass transition temperature is preferably 50°C to 90°C.

(vinyl chloride-acrylic copolymer resin)
Vinyl chloride-acrylic copolymer resin is mainly composed of a copolymer resin of vinyl chloride monomer and acrylic monomer, and the acrylic monomer is used because it improves adhesiveness to the substrate and solubility in organic solvents (meth). ) It is preferable to include acrylic acid hydroxyalkyl ester. The acrylic monomer may be incorporated into the main chain of polyvinyl chloride in a block or random manner, or may be graft-polymerized onto the side chain of polyvinyl chloride. The vinyl chloride-acrylic copolymer resin preferably has a weight average molecular weight of 10,000 to 100,000, more preferably 30,000 to 70,000. Further, the hydroxyl value is preferably 20 to 200 mgKOH/g, and the glass transition temperature is preferably 50°C to 90°C.

The vinyl chloride monomer-derived structure in the vinyl chloride-acrylic copolymer resin is preferably 70 to 95% by mass out of 100% by mass of the vinyl chloride-acrylic copolymer resin solids. In this case, the solubility in organic solvents is improved, and the adhesion to the substrate, film properties, laminate strength, etc. are also improved.

(Vinyl chloride-vinyl acetate-acrylic copolymer resin)
The vinyl chloride-vinyl acetate-acrylic copolymer resin is mainly composed of a copolymer resin of vinyl chloride monomer, vinyl acetate monomer, and acrylic monomer, and the molecular weight is preferably 5,000 to 100,000 in weight average molecular weight, more preferably 20,000 to 70,000. The vinyl chloride monomer-derived structure in 100% by mass of the solid content of the vinyl chloride-vinyl acetate-acrylic copolymer resin is preferably 70 to 95% by mass, the vinyl acetate monomer-derived structure is preferably 1 to 30% by mass, and the acrylic monomer-derived structure is preferably 1 to 30% by mass. In this case, the solubility in organic solvents is improved, and further the adhesion to the substrate, film properties, laminate strength, etc. are improved. In addition, the hydroxyl value is preferably 20 to 200 mgKOH/g, and the glass transition temperature is preferably 50°C to 90°C.

In the following description, (meth)acrylic and (meth)acrylate refer to methacrylic and acrylic, methacrylate and acrylate, respectively.

The acrylic monomer preferably contains one having a hydroxyl group, and examples thereof include hydroxyalkyl esters of (meth)acrylic acid such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, and 8-hydroxyoctyl (meth)acrylate, as well as glycol mono(meth)acrylates such as polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, and 1,4-cyclohexanedimethanol mono(meth)acrylate, caprolactone-modified (meth)acrylate, and hydroxyethylacrylamide. Among these, 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and 2-hydroxypropyl acrylate are more preferable because they improve solubility in solvents. These can be used alone or in combination of two or more. Acrylic monomers other than those mentioned above may be included at any time.

(rosin resin)
The rosin-based resin used in the present invention refers to a resin having a structural unit derived from rosin acid (abietic acid, neoabietic acid, palustric acid, pimaric acid, isopimaric acid, dehydroabietic acid, etc.). The rosin acid or rosin-based resin may be hydrogenated. The acid value of the rosin-based resin is 100 mgKOH/g or less, and the softening point is 60 to 150°C. The rosin-based resin is a biomass raw material derived from pine resin, and contributes to improving the biomass content in the ink solids and improving the laminate strength, etc. Suitable types of rosin-based resin include rosin-modified phenolic resin, rosin ester, rosin-modified maleic acid resin, and polymerized rosin-based resin. Among them, the combined use of polyurethane resin with rosin ester or rosin-modified maleic acid resin is preferable.

(rosin ester)
The rosin-based resin is preferably a rosin ester, which is an ester condensation resin of rosin acid and a low molecular weight polyol having a molecular weight of less than 1000. The low molecular weight polyol preferably has 2 to 4 hydroxyl groups. The molecular weight of the low molecular weight polyol is more preferably 50 to 500.
Suitable low molecular weight polyols include bifunctional low molecular weight polyols such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, and 1,10-decanediol, trifunctional low molecular weight polyols such as glycerin and trimethylolpropane, and tetrafunctional low molecular weight polyols such as erythritol and pentaerythritol. Of these, trifunctional low molecular weight polyols are preferred. The weight average molecular weight of the rosin ester is preferably 500 to 2,000. More preferably, it is 500 to 1,500.

(rosin modified maleic acid resin)
The rosin-modified maleic acid resin is a resin having a structure derived from rosin and a structure derived from maleic acid and/or maleic anhydride, and may contain a component derived from a polyhydric alcohol as necessary. Examples of the rosin include gum rosin, tall oil rosin, wood rosin, and polymerized rosin. Examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, neopentyl glycol, glycerin, trimethylolethane, trimethylolpropane, 1,2,6-hexanetriol, 1,2,4-butanetriol, pentaerythritol, sorbitol, and tertiary alkanolamines. The resin may contain other compounds such as fumaric acid, itaconic acid, itaconic anhydride, citraconic acid, acrylic acid, methacrylic acid, saturated acids and fatty acids, long-chain alkyl compounds having polar groups, and surfactants.

(Organic solvent)
The ink of the present invention preferably contains an organic solvent as a liquid medium. The organic solvent used is preferably used as a mixed solvent, and known organic solvents such as aromatic organic solvents such as toluene and xylene, ketone organic solvents such as methyl ethyl ketone and methyl isobutyl ketone, ethyl acetate, n-propyl acetate, isopropyl acetate, isobutyl acetate, ester organic solvents, and alcohol organic solvents such as methanol, ethanol, n-propanol, isopropanol, and n-butanol can be used. Among them, organic solvents that do not contain aromatic organic solvents such as toluene and xylene (non-toluene organic solvents) are more preferred. More preferred are organic solvents that do not contain aromatic organic solvents and/or ketone organic solvents such as methyl ethyl ketone (hereinafter referred to as "MEK"), and preferably contain an ester organic solvent as the main component (50% by mass or more of the total organic solvent). In particular, those containing an ester organic solvent and an alcohol organic solvent are preferred.

(pigment)
The gravure or flexographic ink in the present invention preferably contains a pigment as a coloring agent, and it is preferable to use an inorganic pigment or an organic pigment. C. as described in the color index. I. Pigments can be used as appropriate.

(Inorganic pigments)
Examples of the inorganic pigment include titanium oxide, zinc oxide, zinc sulfide, barium sulfate, calcium carbonate, chromium oxide, silica, aluminum particles, mica, bronze powder, chrome vermilion, yellow lead, cadmium yellow, cadmium red, ultramarine, Prussian blue, red iron oxide, yellow iron oxide, iron black, titanium oxide, and zinc oxide. Aluminum can be either leafing or non-leafing type, with the non-leafing type being preferred.

(Titanium oxide)
In the present invention, titanium oxide having an anatase type, rutile type, or brookite type crystal structure may be used as titanium oxide. Among them, it is preferable to use rutile-type titanium oxide because it has good pigment dispersibility. In industrial production of titanium oxide, rutile ore or ilmenite ore (FeTiO3) is used as a raw material. There are two main manufacturing methods: the chlorine method and the sulfuric acid method, and either method may be used.
In addition, it is preferable that the titanium oxide be surface-treated so that printability in gravure printing is improved. Particularly preferred are those whose surface has been treated with at least one metal selected from Si, Al, Zn, Zr, and their oxides. Note that it is more preferable that the surface be treated with silica and/or alumina. Note that "surface-treated" refers to a state in which the surface of titanium oxide is coated with a compound to be treated.

The oil absorption amount measured by the method specified in JIS K5101 is preferably 14 to 35 ml/100 g, and more preferably 17 to 32 ml/100 g. The average particle size (median particle size) measured by a transmission electron microscope is preferably 0.2 to 0.3 μm. The total content of titanium oxide is preferably 10 to 60% by weight, and more preferably 10 to 45% by weight, based on 100% by weight of the ink. Multiple types of titanium oxide may be used in combination. In the present invention, the mass ratio of titanium oxide to binder resin (titanium oxide/binder resin) is preferably 2.8 to 5, and more preferably 3.2 to 4.5. In addition to the titanium oxide pigment, other inorganic pigments and organic pigments may also be used in combination.

(organic pigment)
Examples of the above-mentioned organic pigments include, but are not limited to, soluble azo, insoluble azo, azo, phthalocyanine, halogenated phthalocyanine, anthraquinone, anthurone, dianthraquinonyl, and anthrapyrimidine. , perylene series, 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. Pigments include:
In terms of product names, for example, Carmine 6B, Lake Red C, Permanent Red 2B, Disazo Yellow, Pyrazolone Orange, Carmine FB, Cromophthal Yellow, Cromophthal Red, Phthalocyanine Blue, Phthalocyanine Green, Dioxazine Violet, Quinacridone Magenta, Quinacridone. Examples include red, indanthrone blue, pyrimidine yellow, thioindigo bordeaux, thioindigo magenta, perylene red, perinone orange, isoindolinone yellow, aniline black, diketopyrrolopyrrole red, and daylight fluorescent pigments.

The pigment is preferably present in an amount sufficient to ensure the density and coloring power of the ink, i.e., 1 to 50% by weight of the total weight of the printing ink. It is even more preferable that the pigment is present in an amount of 3 to 25% by weight.

(Other additives)
The ink of the present invention may contain additives such as a leveling agent, an antifoaming agent, a wax, a silane coupling agent, a plasticizer, a light stabilizer, silica particles, an infrared absorbing agent, an ultraviolet absorbing agent, a fragrance, a flame retardant, and a curing agent, as necessary.

(Ink manufacturing method)
In the gravure or flexo ink of the present invention, for example, titanium oxide, a binder resin containing a biomass polyurethane resin, an organic solvent, etc. are mixed in advance using a stirring mixer, and the mixture is further added to a pigment dispersion process using a dispersion machine such as a bead mill. The ink of the present invention can be produced by adding a binder resin, various additives, organic solvents, etc. to the obtained dispersion.
As the dispersing machine, commonly used ones such as a roller mill, ball mill, pebble mill, attritor, and sand mill can be used. The particle size distribution of the pigment in the pigment dispersion is adjusted by appropriately adjusting the size of the crushing media of the dispersion machine, the filling rate of the crushing media, the dispersion processing time, the discharge speed of the pigment dispersion, the viscosity of the pigment dispersion, etc. be able to. Furthermore, the present invention can also be applied to mediums that do not contain pigments.

The viscosity of gravure or flexographic ink is in the range of 10 mPa・s or more at 25°C from the viewpoint of preventing pigment sedimentation and moderate dispersion, and 1000 mPa・s or less from the viewpoint of workability efficiency during ink production and printing. It is preferable. More preferably, it is 20 to 500 mPa·s. For the above-mentioned viscosity, a viscosity value measured at 25° C. using a B-type viscometer manufactured by Tokimec Corporation can be used.

(Gravure or flexographic ink printing)
The ink of the present invention can also be used in gravure printing and flexographic printing. In gravure printing, the ink is diluted with a diluting solvent to a viscosity and concentration suitable for printing, and is supplied to each printing unit either alone or in a mixture.

(gravure printing)
When the gravure or flexographic ink of the present invention is gravure printed to form a printing layer, a gravure plate is used for printing. In the present invention, the gravure plate is a cylindrical metal plate, and recesses of each color are created by engraving or etching/laser. There are no restrictions on the use of engraving and laser, and they can be set arbitrarily according to the pattern. A line count of 100 to 300 lines/inch is appropriately used, and the higher the line count, the more precise the printing.
(Gravure printing machine)
A printing machine equipped with the above-mentioned gravure plate can be suitably used as the gravure printing machine. Usually, a printing unit is provided for each color, and each unit is provided with a doctor blade that scrapes off the ink as the gravure plate rotates, and the substrate 1 passes through each printing unit and is intaglio printed, and then becomes a film roll. Depending on the circumstances, a furnisher roll can be used for the gravure plate. Also, each unit is provided with a drying oven, and the printed substrate is passed through the oven to dry. The drying temperature is usually about 40 to 60°C.

(Flexographic printing)
When the gravure or flexographic ink of the present invention is flexographically printed to form a printing layer, the plate used for flexographic printing in the present invention may be a photosensitive resin plate that utilizes ultraviolet curing with a UV light source or an elastomer material plate that uses a direct laser engraving method. Regardless of the method for forming the image part of the flexographic plate, a plate with a screening line count of 75 lpi or more is used. Any sleeve or cushion tape for attaching the plate may be used.
(Flexographic printing machine)
The flexographic printing press includes a CI type multi-color flexographic printing press and a unit type multi-color flexographic printing press, and the ink supply system includes a chamber system and a two-roll system, and an appropriate printing press can be used.

(Base material 1)
The gravure or flexo ink of the present invention is printed on the base material 1 to form a printed matter.
Examples of the substrate 1 to which the gravure or flexo ink of the present invention can be applied include polyethylene, polypropylene, and other polyolefin substrates, polycarbonate substrates, polyester substrates (such as polyethylene terephthalate and polylactic acid), polystyrene substrates, AS resins, and ABS resins. Polystyrene base materials such as polyamide base materials, polyvinyl chloride base materials, various polyvinylidene chloride base materials, cellophane base materials, paper base materials, aluminum foil base materials, etc., or film-like materials made of composite materials thereof, or There are sheet-like ones. Among these, polyester base materials and polyamide base materials having a high glass transition temperature are preferably used.

The substrate 1 may have a surface that has been subjected to deposition coating treatment with metal oxide or the like and/or coating treatment with polyvinyl alcohol or the like, for example, GL-AE manufactured by Toppan Printing Co., Ltd., in which aluminum oxide is deposited on the substrate surface, or IB-PET-PXB manufactured by Dai Nippon Printing Co., Ltd., etc. Furthermore, if necessary, a substrate treated with additives such as an antistatic agent or an ultraviolet ray inhibitor, or a substrate whose surface has been subjected to corona treatment or low-temperature plasma treatment, etc. may also be used.

(laminate)
The laminate of the present invention is obtained by further preferably providing an adhesive layer on the printed layer on the base material 1 formed by gravure or flexographic ink, and laminating it with the base material 2. Preferred examples of lamination include extrusion lamination, dry lamination, non-sol lamination, and the like. Extrusion lamination is a method in which an anchor coating agent is applied onto the printing layer of a printed matter, molten polyethylene resin, molten polypropylene resin, etc. is extruded thereon, and the material is laminated by simultaneously bonding it to a base material. The dry lamination method and the non-sol lamination method are methods in which an adhesive is applied onto the printed layer of a printed matter, dried, and then bonded with a sealant under heat and pressure to laminate the adhesive. The difference between the dry lamination method and the non-sol lamination method is whether or not an organic solvent or other volatile medium is contained.

(Adhesive Layer)
The adhesive layer refers to a composition that can bond the ink to the substrate, and examples of the adhesive layer include a layer formed from a molten polyethylene resin, a molten polypropylene resin, a urethane adhesive, a layer formed from an acrylic adhesive, and an anchor coat layer. For example, the adhesive layer can be obtained by applying a urethane adhesive and drying it. The urethane adhesive is preferably a two-liquid adhesive made of a mixture of a polyol and an isocyanate curing agent, and examples of the polyol include polyester-based and polyether-based adhesives. Specific examples include TM-250HV/CAT-RT86L-60, TM-550/CAT-RT37, and TM-314/CAT-14B manufactured by Toyo-Morton Co., Ltd.

(Substrate 2)
The substrate 2 may be the same as or different from the substrate 1. A thermoplastic substrate (sometimes called a sealant) is preferable, and a non-oriented polyethylene substrate, a non-oriented polypropylene substrate, a non-oriented polyester substrate, or the like is preferable.

The gravure or flexographic ink of the present invention is preferably used for lamination. "For lamination" means a usage form in which the base material 1, the printing layer formed from the ink of the present invention, and the base material 2 are laminated in this order, and the base material 1, the printing layer, and the adhesive layer are A laminate having the base material 2 and the base material 2 in this order is more preferable.

Hereinafter, the present invention will be described in detail with reference to examples, but the following embodiments are just 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.
Note that Examples 3, 4, 15, 18, 19, and 30 are reference examples.

<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]

<Method of measuring number average molecular weight (Mn) and mass average molecular weight (Mw)>
The number average molecular weight (Mn) and the mass average molecular weight (Mw) were measured using a GPC (gel permeation chromatography) "Shodex GPC System-21" manufactured by Showa Denko K.K. GPC is a liquid chromatography that separates and quantifies substances dissolved in a solvent based on the difference in their molecular size. Tetrahydrofuran was used as the solvent, and the molecular weight was determined in terms of polystyrene.

<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)
A round-bottom flask equipped with a stirrer, a thermometer, a water divider, and a nitrogen gas inlet tube was charged with 18 parts of neopentyl glycol (hereinafter also abbreviated as NPG), 13 parts of 1,3-propanediol (derived from plants, biomass degree 100%, hereinafter also abbreviated as "1,3-PD"), 11 parts of azelaic acid, 58 parts of sebacic acid, and 0.002 parts of tetrabutyl titanate, and esterification was carried out for 8 hours at 230°C under a nitrogen stream while removing water generated by condensation. After confirming that the acid value of the polyester was 15 or less, the degree of vacuum was gradually increased by a vacuum pump to terminate 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 100% was obtained.

[Synthesis Examples 1-2 to 1-13, Comparative Synthesis Examples 1-1 to 1-2] (Synthesis of Polyester Polyols A2 to A13, B1 to B2)
Polyester polyols A2 to A13 and B1 to B2 were obtained in the same manner as in Synthesis Example 1-1, except that the raw materials and charging ratios shown in Table 1 were used. The abbreviations shown in the table are as follows.
・BEPG: 2-butyl-2-ethyl-1,3-propanediol (petroleum-derived, biomass content 0%)
NPG: Neopentyl glycol (plant-derived, 100% biomass)
・1,4-BD: 1,4-butanediol (derived from plants, 100% biomass)

[Synthesis Example 2-1] (Synthesis of polyurethane resin P1)
A four-neck flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen gas inlet tube was charged with 24.2 parts of Polyester Polyol A1, 4 parts of isophorone diisocyanate (hereinafter also abbreviated as IPDI), 10 parts of ethyl acetate (hereinafter also abbreviated as EA), and 0.003 parts of tin 2-ethylhexanoate, and reacted for 6 hours at 120° C. under a nitrogen stream, and 14 parts of propyl acetate (hereinafter also abbreviated as NPA) was added and cooled to obtain a solution of a terminal isocyanate prepolymer. Next, the obtained solution of isocyanate-terminated prepolymer was gradually added at room temperature to a mixture of 1.7 parts of isophorone diamine (hereinafter also abbreviated as IPDA), 0.2 parts of dibutylamine (hereinafter also abbreviated as DBA), 18 parts of EA, and 28 parts of isopropyl alcohol (hereinafter also abbreviated as IPA), and then the mixture was reacted at 50° C. for 1 hour to obtain a polyurethane resin P1 solution having a solid content of 30%, a mass average molecular weight of 73,000, an amine value of 3 mg KOH/g, and a biomass degree of 80.5 mass%.

[Synthesis Examples 2-2 to 2-13, Comparative Synthesis Examples 2-1 to 2-2] (Synthesis of Polyurethane Resins P2 to P13, PP1 to PP2)
Polyurethane resins P2 to P13 and PP1 to PP2 were obtained in the same manner as in Synthesis Example 2-1, except that the raw materials and the charging ratios thereof shown in Table 2 were used. The biomass degree and other properties are shown in the same table.

[Example 1] (Manufacture of white ink W1)
35 parts of titanium oxide pigment (JR806 manufactured by Teika, rutile type titanium oxide surface treated with silica and alumina, oil absorption 21g/100g), 31 parts of polyurethane resin P1 solution, vinyl chloride resin solution (T5HX, manufactured by Kaneka) Vinyl chloride component: Vinyl acetate component: Acrylic component = 83:9:8 Solid content 24% solution, biomass degree 0%) 4 parts and mixed solvent (EA/IPA = 75/25 (mass ratio)) 13 parts were mixed with stirring and dispersed with a sand mill. After that, 17 parts of a mixed solvent (EA/IPA=75/25 (mass ratio)) was stirred and mixed to obtain ink W1. (Table 3-1 shows the total of each component.)

[Examples 2 to 15, Comparative Examples 1 to 2] (Production of white inks W2 to W15, WW1 to WW2)
Inks W2 to W15 and WW1 to WW2 were obtained in the same manner as in Example 1, except that the raw materials and charging ratios listed in Table 3-1 were used. Note that the descriptions in the table represent the following.
Rosin resin: Harima Kasei Co., Ltd. Rosin ester Softening point: 125℃℃ Solid content: 24% solution

[Example 16] (Preparation of indigo ink C1)
12 parts of copper phthalocyanine indigo pigment (phthalocyanine LIONOL BLUE FG-7358-G manufactured by Toyocolor Co., Ltd.), 40 parts of polyurethane resin P1 solution, 8 parts of vinyl chloride resin solution, and 15 parts of mixed solvent (EA/IPA=75/25 (mass ratio)) were stirred and mixed and dispersed in a sand mill, and then 25 parts of mixed solvent (EA/IPA=75/25 (mass ratio)) was stirred and mixed to obtain ink C1. (Table 3-1 shows the total of each component.)

[Examples 17 to 30, Comparative Examples 3 to 4] (Manufacture of white inks C2 to C15, CC1 to CC2)
Inks C2 to C15 and CC1 to CC2 were obtained in the same manner as in Example 1, except that the raw materials and charging ratios listed in Table 3-2 were used.

[Production of printed matter using ink W1]
The viscosity of ink W1 was diluted with an EA/IPA mixed solvent (mass ratio 75/25) to a viscosity of 15 seconds (at 25°C) in Zahn cup #3 (manufactured by Rigosha), and a gravure plate with a plate depth of 30 μm was prepared. Printing was performed using a gravure proofing machine on the corona-treated side of a single-sided corona-treated polypropylene (OPP) film (Pylene P2161, manufactured by Toyobo Co., Ltd.) and dried at 40 to 50°C to obtain a printed matter using ink W1. In addition, printed materials using ink W1 were obtained by printing on the corona-treated side of a single-sided corona-treated nylon (NY) film (Emblem ON-RT, manufactured by Unitika Co., Ltd.) and drying at 40 to 50°C.

[Production of printed matter using inks W2 to W15, WW1 to WW2, C1 to C13, CC1 to CC2]
Ink W2-W15, WW1-WW2, C1-C15, CC1-W15, WW1-WW2, C1-C15, CC1- Printed materials (OPP and NY) using CC2 were obtained.

[evaluation]
Using the inks and printed matter thereof obtained in the above Examples and Comparative Examples, resolubility, lamination strength, heat seal strength, and heat resistance (boiling resistance) were evaluated by the methods described below.

[Redissolvability]
10 ml of an EA/IPA mixed solvent (mass ratio 75/25) was poured onto the printed matter (OPP) of the ink obtained in the above Examples and Comparative Examples, and the degree of solubility of the ink was visually evaluated.
5: The ink film completely dissolves, leaving no traces (Excellent)
4: 75% or more but less than 100% of the ink film has dissolved, leaving only slight dissolved traces (good)
3: 50% to less than 75% of the ink film has dissolved, leaving traces of dissolved ink (OK)
2: 25% to less than 50% of the ink film has dissolved, leaving traces of dissolved ink (not acceptable)
1: The ink film dissolves by 5% or more but less than 25%, leaving traces of dissolution (poor)
The practical level is 3 to 5.
The better the resolubility, the better the printability tends to be.

[Lamination strength]
A methanol solution containing 1% by mass of an imine-based anchor coating agent (EL420, manufactured by Toyo-Morton) was applied onto the printed layer of the OPP film print of the ink obtained in the above Examples and Comparative Examples, and molten polyethylene (LC600A, manufactured by Japan Polyethylene Corporation) was extruded at 320°C at a line speed of 100 m/min using an extrusion laminator (manufactured by Musashino Kikai Co., Ltd.) to laminate at a thickness of 18 μm. At the same time, CPP (FCMN, 20 μm thick, manufactured by Futamura Chemical Co., Ltd.) was similarly bonded to obtain a laminated body.
The laminate was cut into a piece having a length of 150 mm and a width of 15 mm, opened at the ink/OPP film interface, and the laminate strength in the 90° direction was measured using a tensile tester.
(Evaluation criteria)
5: 1.5N/15mm or more (Excellent)
4: 1.0N/15mm or more, less than 1.5N/15mm (good)
3: 0.8N/15mm or more, less than 1.0N/15mm (acceptable)
2: 0.5N/15mm or more, less than 0.8N/15mm (not acceptable)
1: Less than 0.5N/15mm (poor)
The practical level is 3 to 5.

[Heat seal strength]
The laminate was heat-sealed at 160° C. with the polyethylene film side facing inward, cut into a piece 150 mm long and 15 mm wide, and the heat seal strength in the 90° direction was measured using a tensile tester.
(Evaluation criteria)
5: 40N/15mm or more (Excellent)
4: 30N/15mm or more, less than 40N/15mm (good)
3: 20N/15mm or more, less than 30N/15mm (acceptable)
2: 10N/15mm or more, less than 20N/15mm (not acceptable)
1: Less than 10N/15mm (inferior)
The practical level is 3 to 5.

[Heat resistance] (boil resistance)
A polyurethane anchor coating agent (EL510, CAT-RT80, manufactured by Toyo-Morton) was applied onto the printed layer of the NY film printed matter obtained in the above Examples and Comparative Examples, and molten polyethylene (LC600A, manufactured by Japan Polyethylene Co., Ltd.) was extruded at 320°C at a line speed of 100 m/min using an extrusion laminator (manufactured by Musashino Kikai Co., Ltd.) to laminate at 18 μm, and LLDPE (LL-XMTN, film thickness 25 μm, manufactured by Futamura Chemical Co., Ltd.) was similarly laminated at the same time to obtain a laminated body. The resulting nylon film laminated body was heat-sealed at 160°C with the polyethylene film side facing inward, and the resulting bag was filled with water as the content and boiled at 90°C for 30 minutes, after which the appearance was visually evaluated.
(Evaluation criteria)
5: No delamination or unevenness (very good)
4: There are 1 to 3 floating areas with a diameter of less than 2 mm (good)
3: There are 4 to 10 floating areas with a diameter of less than 2 mm (usable)
2: Streaky or widespread lifting is observed (poor)
1: Peeling over 50% of the surface area (very poor)
The practical level is 3 to 5.

From the above results, the problems of the present application could be achieved by using the gravure or flexographic ink of the present invention. In addition, when using polyurethane resins that use polyester polyols containing dibasic acids with an odd number of carbon atoms and dibasic acids with an even number of carbon atoms, they are particularly advantageous in terms of lamination strength, heat seal strength, and heat resistance (boil resistance). The results were obtained. In addition, in the comparative example, any one of resolubilability, gloss, density, stability over time, lamination strength, heat seal strength, and heat resistance deteriorated, and the properties were inferior.

Claims (7)

A gravure or flexographic ink for lamination, comprising a polyurethane resin, a binder resin containing a vinyl chloride copolymer resin and/or a rosin-based resin, and an organic solvent,
the polyurethane resin contains a structural unit derived from a polyester polyol which is a condensation reaction product of a dibasic acid and a diol, the dibasic acid contains a dibasic acid having an odd number of carbon atoms and a dibasic acid having an even number of carbon atoms ,
the dibasic acid having an odd carbon number is contained in an amount of 1 to 70 mass % in the total mass of the dibasic acids constituting the raw material of the polyester polyol,
A gravure or flexographic ink for lamination , wherein the dibasic acid having an even number of carbon atoms comprises succinic acid and/or sebacic acid .
(However, in the above polyurethane resin, the dibasic acid having an even number of carbon atoms is succinic acid and sebacic acid,
the dibasic acid having an odd carbon number is azelaic acid;
Furthermore, polyurethane resins containing structural units derived from isocyanates, the structural units derived from isocyanates being composed of isophorone diisocyanate and methylene bis (cyclohexane-4,1-diyl) bis isocyanate, are excluded. The gravure or flexographic ink for lamination according to claim 1, wherein the dibasic acid having an odd number of carbon atoms is azelaic acid. A gravure or flexographic ink for lamination according to claim 1 or 2, wherein the diol comprises a branched diol and a linear diol. The gravure or flexographic ink for lamination according to any one of claims 1 to 3, which contains 1 to 40 mass% of azelaic acid-derived structural units in the total solid content of the polyurethane resin. 5. The gravure or flexographic ink for lamination according to claim 1, wherein a ratio of the mass of the polyurethane resin to the total mass of the vinyl chloride copolymer resin and the rosin-based resin is from 95:5 to 30:70. A printed matter having, on a substrate 1, a printing layer formed by gravure or flexo ink for lamination according to any one of claims 1 to 5. A laminate having, in this order, at least a substrate 1, a printed layer formed from a gravure or flexographic ink for lamination according to any one of claims 1 to 5, and a substrate 2.