JP2023023016A - Gravure ink, printed matter, and laminate - Google Patents

Abstract

To provide a gravure ink having good printability and ink stability in addition to excellent physical properties and tearability of a laminate.SOLUTION: Provided is a gravure ink containing a polyester-based urethane resin for use in forming a printed layer of a laminated laminate having a printed layer, where the polyester-based urethane resin has a molecular weight distribution (Mw/Mn) of larger than 5 and 10 or less. Also provided are a gravure ink containing a hardening agent; and a gravure ink in which the hardening agent contains an isocyanate-based compound having a molecular weight distribution (Mw/Mn) of 1.5-5.SELECTED DRAWING: None

Description

The present invention relates to gravure ink. In particular, it relates to a gravure ink suitably used for forming a laminate exhibiting excellent lamination strength and tearability.

In general, a packaging bag may have a pattern such as a pattern, and is provided with a printed layer made of ink in order to make the contents invisible. These inks include offset inks, flexo inks, silk screen inks and gravure inks and other printing inks. Among them, gravure ink is often used in gravure printing because of its high printing speed and ability to produce high-definition patterns, and its productivity is high.

A printed layer made of gravure ink is laminated with an adhesive layer, a thermoplastic base material, and the like in order on the printed layer to form a laminate. The laminated body is formed into a packaging bag by thermally bonding (heat-sealing) the thermoplastic substrates of the outermost layers. Such packaging bags are often used in the food packaging field. In such packaging bags, if the adhesion between each layer is low, separation between layers may occur during filling and transportation of the contents, causing problems such as deterioration of design and leakage of contents. Good adhesion strength is required on the body.

Further, in the case of packaging bags for food packaging, for example, liquid pouches are often opened by directly tearing the packaging bag by hand in order to take out the contents. At that time, the fact that the packaging bag can be torn and opened without using a tool such as scissors is a great advantage in terms of convenience, and thus gives more market value. However, when the tearability of the packaging bag is poor, especially when the contents of the packaging bag are liquid, there is a problem that excessive force is required when opening the packaging bag, or the bag is torn in an unexpected direction and the contents spill out. Therefore, laminates in the food packaging field are required to have good tearability (Patent Document 1).

As a conventional technique, for example, Patent Literature 1 describes a technique in which a curing agent is used in an ink containing a polyurethane resin to increase lamination strength, thereby exhibiting easy tearability. However, it may still be difficult to increase the lamination strength simply by using the curing agent alone. On the other hand, Patent Document 2 describes a technique of using a silane coupling agent in combination with a curing agent. However, when a silane coupling agent is used in combination, there is a concern that the stability of the ink over time will deteriorate and the laminate strength will change.

Japanese Unexamined Patent Application Publication No. 2017-031298 JP 2019-199509 A

An object of the present invention is to provide a gravure ink having good printability and ink stability in addition to lamination physical properties and easy tearability.

As a result of diligent studies, the inventors have found that the above problems can be solved by using the gravure ink of the present invention, and have completed the present invention.

That is, the present invention provides a gravure ink containing a polyester-based urethane resin for use in forming the printed layer of a laminate having a printed layer,
The gravure ink, wherein the molecular weight distribution (Mw/Mn) of the polyester-based urethane resin is more than 5 and 10 or less.

The present invention also relates to the above gravure ink, which further contains a curing agent.

The present invention also relates to the above gravure ink, wherein the curing agent contains an isocyanate compound having a molecular weight distribution (Mw/Mn) of 1.5 to 5.

The present invention also relates to the above gravure ink, wherein the isocyanate compound has a weight average molecular weight of 800 to 8,000.

The present invention also relates to the above gravure ink, wherein the polyester-based urethane resin has a structure derived from at least one of sebacic acid, succinic acid and azelaic acid.

The present invention also relates to the above gravure ink, which further contains at least one resin selected from the group consisting of cellulose resins, vinyl chloride resins and rosin resins.

The present invention also relates to a printed material having a print layer formed from the gravure ink on the substrate 1 .

The present invention also relates to a laminated laminate having an adhesive layer and a substrate 2 in this order on the printed layer of the printed matter.

The present invention has made it possible to provide a gravure ink having good printability and ink stability in addition to laminate physical properties and easy tearability.

Embodiments of the present invention will be described in detail below, but the description of the constituent elements described below is an example (representative example) of embodiments of the present invention, and the present invention does not exceed the gist thereof. Content is not limited.

In the present invention, "gravure ink" may be abbreviated as "ink". Ink made of a mixture of "gravure ink" and "curing agent" is also "gravure ink", but hereinafter may be abbreviated as "curable gravure ink" or "curable ink". A printed layer formed by printing "gravure ink" or "curable gravure ink" may be simply referred to as "printed layer" or "ink layer", but they have the same meaning. Also, "○ to △" represents "○ or more and △ or less".

The present invention will be described in detail below.
The present invention provides a gravure ink containing a polyester-based urethane resin for use in forming the printed layer of a laminate having a printed layer,
The gravure ink, wherein the polyester-based urethane resin has a molecular weight distribution (Mw/Mn) of more than 5 and 10 or less. This is used to form a printing layer that sits as an intermediate layer in a laminate stack.
By using a polyester-based urethane resin having a molecular weight distribution (Mw/Mn) of more than 5 and not more than 10, adhesion to a substrate or the like is improved. By cross-linking and curing with a curing agent of ∼5, the printed layer containing the polyester-based urethane resin becomes strong, giving the entire laminate durability and easy tearability.

(Gravure ink containing polyester-based urethane resin)
The gravure ink contains a polyester urethane resin as a binder resin. The binder resin content is preferably 2 to 40% by mass, more preferably 3 to 30% by mass, based on 100% by mass of the gravure ink. The gravure ink is used by being mixed with a curing agent which will be described later.

(Polyester urethane resin)
The polyester-based urethane resin used in the present invention refers to a urethane resin having a constituent unit derived from polyester in the urethane resin. The polyester-based urethane resin preferably has 40% by mass or more of polyester-derived structural units in the total mass, more preferably 50% by mass or more, further preferably 60% by mass or more, and preferably 65% by mass or more. Especially preferred.
The polyester-based urethane resin is not limited to the following, but for example, a urethane prepolymer having an isocyanate group at the end obtained by reacting a polyisocyanate with a polyol containing a polyester polyol, and further with a polyamine (chain extender). A polyester-based urethane resin obtained by reacting with a reaction terminator, if necessary, may be mentioned. The urethane resin may be a resin having a urethane bond, and even if it has a urea bond or the like in addition to the urethane bond, it corresponds to the concept of the urethane resin. In order to obtain a polyester-derived structural unit, for example, a polyester polyol is used as the polyol as described above.

(polyisocyanate)
The polyisocyanate preferably contains a diisocyanate. Examples of the diisocyanate include aliphatic diisocyanates such as tetramethylene diisocyanate, isopropylene diisocyanate, methylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, and 2,4,4-trimethylhexamethylene diisocyanate;
Cyclohexane-1,4-diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, lysine diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, methylcyclohexane diisocyanate, m-tetramethyl Alicyclic diisocyanates such as xylylene diisocyanate and dimer diisocyanate obtained by converting the carboxyl group of dimer acid to an isocyanate group;
α,α,α',α'-tetramethylxylylene diisocyanate, 1,5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzyl isocyanate , dimethyldiphenylmethane diisocyanate, tetramethyldiphenylmethane diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, o-xylylene diisocyanate and 2,4-tolylene diisocyanate, aromatic diisocyanates such as 2,6-tolylene diisocyanate; Among these, alicyclic or araliphatic diisocyanates are preferred from the viewpoint of easy control of the reaction and good balance of performance of the resulting urethane resin, and in particular, isophorone diisocyanate, α, α, α', α '-Tetramethylxylylene diisocyanate is preferred. At least one type of diisocyanate may be used, and two or more types may be used in combination.

(polyol)
Polyester polyols are often used as polyols, but polyether polyols, polycarbonate polyols, polyolefin polyols, and the like can also be used. However, when introducing a polyester-derived structural unit into a urethane resin, the method for introducing the polyester structure is not particularly limited.

(polyester polyol)
The polyester polyol preferably has a number average molecular weight of 500 to 10,000. Here, the number average molecular weight used in the polyol is calculated from the hydroxyl value. It is a value obtained by converting the amount of hydroxyl groups into the number of mg of potassium hydroxide, and is a value obtained according to JIS K0070. When the number average molecular weight of the polyol is 10,000 or less, the blocking resistance to plastic films is excellent. Further, when the number average molecular weight of the polyol is 500 or more, the flexibility of the urethane resin film is excellent and the adhesion to the plastic film is excellent. For the above reasons, the number average molecular weight is more preferably 1,000 to 5,000.

The polyester polyol is preferably a polyester diol. In addition, a diol means a compound having two hydroxyl groups in one molecule. In addition, even when other polyols are used in combination, diols are preferable, and examples thereof include polyether diols, polycarbonates, polybutadiene glycol, and the like. At least one type of diol may be used, and two or more types may be used in combination.

The polyester diol is preferably a polyester diol that is a condensate of a diol and a dicarboxylic acid.
Examples of the polyester diol include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 1,6-hexanediol, and 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-monoglycerol ether, 2-monoglycerol ether, dimer Diols, hydrogenated dimer diols, and the like are preferred. A polyester polyol can be used individually or in mixture of 2 or more types. A polyester diol that is a condensate of a diol containing a branched diol and a dicarboxylic acid is preferred. Polyester diols obtained by ring-opening reaction of cyclic esters (such as lactones) may also be used.
Such 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, 1 , 4-cyclohexyldicarboxylic acid, dimer acid, hydrogenated dimer acid, and the like, among which adipic acid, succinic acid, sebacic acid and azelaic acid are preferred.
Furthermore, polyols having 3 or more hydroxyl groups and polyvalent carboxylic acids having 3 or more carboxyl groups can be used in combination as raw materials for polyester polyols.

Preferred specific examples of these include those containing a polyester-derived structural unit composed of a dibasic acid such as adipic acid, succinic acid, sebacic acid, and a diol having a branched structure. This is because the adhesiveness to the plastic substrate and the solubility of the ink composition can be improved. The diol having a branched structure is preferably a diol having a structure in which at least one hydrogen of alkylene glycol is substituted with an alkyl group. Examples of diols having a branched structure include 1,2-propanediol, 1,3-butanediol, 2-methyl-1,3-propanediol, neopentyldiol, 1,4-pentanediol, 3-methyl-1,5-pentanediol, 2,5-hexanediol, 2-methyl -1,4-pentanediol, 2,4-diethyl-1,5-pentanediol, 2-butyl-2-ethyl-1,3-propanediol, 2-methyl-1,8-octanediol, 2,2 ,4-trimethyl-1,3-pentanediol and 2,2,4-trimethyl-1,6-hexanediol are preferred. Among them, at least one selected from 1,2-propanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, and 2-butyl-2-ethyl-1,3-propanediol is preferable. , 2-propanediol and/or 3-methyl-1,5-pentanediol are preferably used.

(polyamine)
Preferably, the chain extender is a polyamine. Examples of the polyamine include, but are not limited to, ethylenediamine, propylenediamine, hexamethylenediamine, isophoronediamine, dicyclohexylmethane-4,4'-diamine, and dimer diamine obtained by converting the carboxyl group of dimer acid into an amino group. Diamines are preferred. These can be used alone or in combination of two or more. A reaction terminator may be used to suppress excessive reaction due to chain elongation.
Amino acids can also be used for chain extension. Amino acid refers to a compound having both an amino group and an acidic functional group in one molecule, and preferably includes glutamine, asparagine, lysine, diaminopropionic acid, ornithine, diaminobenzoic acid, diaminobenzenesulfonic acid and the like. In the process of synthesizing the urethane resin, the acidic group is highly likely to remain unreacted with the isocyanate group, so that the acid value can be maintained in the urethane resin.

The reaction terminator is preferably a monoalcohol or monoamine in the case of a urethane resin that can be produced only in the urethanization step, and a monoamine in the case of a urethane resin that is produced by performing a urea reaction step in addition to the urethanization step. is preferred.
The monoalcohol is preferably a substituted or unsubstituted alcohol, such as methanol, ethanol, n-propanol, isopropyl alcohol, 1-butanol, and the like. The monoamine is preferably a substituted or unsubstituted monoamine, and preferred examples include n-butylamine, n-dibutylamine, octylamine, diethylamine, monoethanolamine, monopropanolamine, diethanolamine, and dipropanolamine. Moreover, as the reaction terminator, the compounds exemplified as the chain elongation agent can also be used, and at least one of them may be used, and two or more of them can be used in combination.

In the production of a urethane prepolymer having terminal isocyanate groups obtained by reacting a polyisocyanate and a polyol, the molar equivalent ratio of the NCO of the polyisocyanate to the OH of the polyol (molar equivalent of the NCO of the polyisocyanate/mole of the OH of the polyol compound equivalent) is preferably 1.3 to 3, more preferably 1.5 to 2.

The polyester-based urethane resin preferably has active hydrogen groups such as a hydroxyl value and/or an amine value. This is for obtaining a reaction site with a curing agent, which will be described later. The hydroxyl value is preferably 0.5 to 30 mgKOH/g, more preferably 1 to 20 mgKOH/g, even more preferably 2 to 15 mgKOH/g. When it has an amine value, it 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-based urethane resin is preferably 5 mgKOH/g or less, more preferably 3 mgKOH/g or less. This is because the acid value is difficult to react with the curing agent described below.

The weight average molecular weight of the polyester-based urethane resin is preferably 20,000 to 100,000, more preferably 25,000 to 90,000, further preferably 30,000 to 80,000. . This is because the printed layer is formed into a strong film by cross-linking with a curing agent, which will be described later, and good lamination strength is exhibited.
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, Water2690 (manufactured by Waters Co., Ltd.) and HLC-8220 (manufactured by Tosoh Corporation) are used as the GPC apparatus, PLgel, 5 μm, MIXED-D (manufactured by Polymer Laboratories), TSKgelSuperAW series (manufactured by Tosoh Corporation), etc. as the column. can be done. Tetrahydrofuran, 1,2,4-trichlorobenzene, N,N-dimethylformamide (0.01N-lithium bromide added) and the like can be used as a developing solvent at a flow rate of 0.5 to 1.5 ml/min. Preferably. 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 mg/ml and an injection amount of 0.1 to 1.0 microliter. A weight average molecular weight can be calculated|required as a polystyrene conversion value.

The molecular weight distribution (Mw/Mn) of the polyester-based urethane resin is more than 5 and 10 or less, preferably more than 5 and 9 or less, more preferably 5.2 to 8.5. Mw represents weight average molecular weight and Mn represents number average molecular weight. When Mw/Mn is within the above range, it is believed that the cohesive force and adhesive force are strengthened by crosslinking with the curing agent described below, exhibiting sufficient resistance to boiling and retorting, and exhibiting easy tearability. . Mw, Mn and Mw/Mn can be determined by gel permeation chromatography (GPC) as described above.

In order to make the molecular weight distribution (Mw/Mn) of the polyester-based urethane resin within the above range, the selection of the urethane synthetic raw materials and the solid content mass ratio in the synthesis of the urethane resin, the dropping rate of the reactive raw material such as polyisocyanate in the synthesis reaction, The molecular weight distribution (Mw/Mn) can be set within the range by appropriately setting the stirring speed, the shape of the stirring blade, and the reaction temperature. In the case of further chain extension reaction, it is effective to set the molecular weight distribution within a predetermined range by controlling the dropping rate and the temperature range in particular when the polyamine and the urethane prepolymer are reacted. It is important to control the reaction temperature. It is preferable to control the reaction temperature in the range of 50 to 130°C in the synthesis of the urethane prepolymer, and to control it in the range of 10 to 50°C in the reaction of the polyamine and the urethane prepolymer. preferable.
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 feed ratio includes, for example, the ratio of the hydroxyl groups of the polyol and the hydroxy acid, and the ratio of the isocyanate groups of the polyisocyanate, and the NCO/OH ratio, which is the ratio of the amino groups of the polyamine and the isocyanate groups of the urethane prepolymer. , amino group/NCO ratio, and the like. In order to control the molecular weight distribution, it is preferable to use a polymerization terminator (also referred to as a reaction terminator) for the purpose of preventing excessive polymerization reaction. Preferred examples of the polymerization terminator include monoalcohols and monoamines.
Also, the molecular weight distribution of the polyester polyol has an effect. By selecting a polyester polyol having a molecular weight distribution of about 2 to 10, the molecular weight distribution (Mw/Mn) of the polyester-based urethane resin can be easily controlled within the above range.
Among polyols, the amount of polyols having a relatively small molecular weight, for example, a weight average molecular weight of 800 or less, is preferably 30% by mass or less, more preferably 20% by mass or less, in the total mass of the polyester-based urethane resin. , 10% by mass or less.

<Combined resin>
The gravure ink used in the present invention is suitable even if it has a combined resin together with the urethane resin. Preferred embodiments of the combined resin are shown below.
For example, polyolefin resins such as polyethylene resins and chlorinated polypropylene resins, poly(meth)acrylic resins, vinyl chloride copolymer resins, polyvinyl acetate resins, vinyl chloride-vinyl acetate copolymers, polystyrene resins, Styrene-butadiene copolymer resin, styrene-maleic acid copolymer, vinylidene fluoride resin, polyvinyl alcohol resin, polyvinyl acetal resin, polyvinyl butyral resin, polybutadiene resin, polyester resin, polyamide resin, alkyd resin Resins, epoxy resins, polyester resins, thermosetting poly(meth)acrylic resins, melamine resins, urea resins, polyurethane resins, phenolic resins, xylene resins, maleic acid resins, nitrocellulose, ethyl cellulose, Examples include cellulose resins such as acetylbutyl cellulose and ethyloxyethyl cellulose, rubber resins such as chlorinated rubber and cyclized rubber, petroleum resins, and natural resins such as rosin and casein.
Among them, at least one selected from vinyl chloride copolymer resins, cellulose resins, poly(meth)acrylic resins, styrene-maleic acid copolymers and rosin resins is preferable. A vinyl chloride copolymer resin is more preferable.

The vinyl chloride copolymer resin is preferably a vinyl chloride-vinyl acetate copolymer resin, a vinyl chloride-acrylic copolymer resin, or the like. The vinyl chloride copolymer resin preferably has a weight average molecular weight of 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. Also, the glass transition temperature is preferably 50°C to 90°C. Also, the vinyl chloride copolymer resin preferably has a hydroxyl group, and preferably has a hydroxyl value of 10 to 200 mgKOH/g. This is because the reactivity with the curing agent is improved, and the hydroxyl group is preferably derived from a vinyl alcohol unit-derived hydroxyl group or from an acrylic monomer having a hydroxyl group.

The mass ratio of the urethane resin and at least one resin (combined resin) selected from the group consisting of cellulose resin, vinyl chloride resin and rosin resin (urethane resin:combined resin) is 95:5 to 30:70. preferably 90:10 to 40:60. This is because the adhesion to the base material, film physical properties, lamination strength, etc. are improved.

(coloring agent)
The gravure ink used in the present invention may contain a coloring agent. The colorant preferably contains a pigment, preferably in an amount of 0.2 to 38% by mass based on 100% by mass of the gravure ink. Any of organic pigments, inorganic pigments, and extender pigments can be used as the pigment. Examples of inorganic pigments include titanium oxide, and extender pigments include silica, barium sulfate, kaolin, clay, calcium carbonate, and carbonate. Magnesium and the like are preferred. Among organic pigments, it is preferable to use those composed of organic compounds and organometallic complexes.
Either an organic pigment or an inorganic pigment can be used as the pigment. Examples of inorganic pigments include yellow lead, titanium yellow, red iron oxide, cadmium red, ultramarine blue, cobalt blue, and the like. azo, insoluble azo, azo, phthalocyanine, halogenated phthalocyanine, anthraquinone, anthanthrone, dianthraquinonyl, anthrapyrimidine, perylene, perinone, quinacridone, thioindigo, dioxazine, Examples include isoindolinone, quinophthalone, azomethineazo, flavanthrone, diketopyrrolopyrrole, isoindoline, indanthrone, and carbon black pigments. Also, the C.I. I. Any pigment indicated by the pigment number can be used.

(titanium oxide)
It is also preferable that the gravure ink used in the present invention contains titanium oxide. For example, in the case of printing on the reverse side of a laminate for lamination, white gravure ink is finally applied to the entire surface to promote cross-linking and curing of the entire surface including other printed layers. In the present invention, the titanium oxide pigment may have any of anatase, rutile, and brookite crystal structures. Among them, the use of rutile-type titanium oxide is preferable because of its excellent cross-linking and curing. In the industrial production of titanium oxide, rutile ore or ilmenite ore (FeTiO3) is used as a raw material. There are two main production methods, the chlorine method and the sulfuric acid method, and either method may be used.
Moreover, since the cross-linking and curing of the printed layer are improved, the titanium oxide pigment is preferably surface-treated. In particular, those surface-treated with at least one metal selected from Si, Al, Zn, Zr and their oxides are preferred.

In addition, it preferably has an oil absorption of 14 to 35 ml/100 g, more preferably 17 to 32 ml/100 g, as measured by the method specified in JIS K5101. Also, the average particle size (median particle size) measured by a transmission electron microscope is preferably 0.2 to 0.3 μm. Also, the total content of the titanium oxide pigment is preferably 10 to 60% by weight, more preferably 10 to 45% by weight, based on 100% by weight of the ink. Also, a plurality of types of titanium oxide pigments may be used in combination.

(medium)
The gravure ink used in the present invention may contain organic solvents, water and other media. The medium is not limited, but if it is an organic solvent, toluene and other aromatic organic solvents, methyl ethyl ketone and other ketone organic solvents, ethyl acetate, normal propyl acetate and other ester organic solvents, ethanol, isopropanol, normal Suitable examples include propanol and other alcoholic organic solvents. It may contain water, and when an organic solvent is used as a main medium, it is preferably contained in an amount of 10% by mass or less.

(Additive)
The gravure ink used in the present invention may further contain, if necessary, fillers, stabilizers, plasticizers, antioxidants, light stabilizers such as UV absorbers, dispersants, thickeners, and drying agents. , lubricants, antistatic agents, cross-linking agents and the like can be added.

<Curing agent>
In the present invention, the curing agent is mixed with the gravure ink and used for printing as a curable gravure ink. Curing agents include isocyanate compounds, carbodiimide compounds, epoxy compounds, etc., but those containing isocyanate compounds are preferred. It crosslinks with hydrogen groups, and when the polyester-based urethane resin does not have the active hydrogen group, self-crosslinking with only the isocyanate-based compound improves lamination strength, easy tearability, and the like. In the gravure ink used in combination with the curing agent, the polyester-based urethane resin preferably has a hydroxyl group, an amino group, or other active hydrogen groups.

Preferred embodiments of the isocyanate compound are shown below. The weight average molecular weight of the isocyanate compound is preferably 800-8000, more preferably 900-6000, and still more preferably 1000-4000. The molecular weight distribution (Mw/Mn) of the isocyanate compound is preferably 1.5-5, more preferably 2-4.5, and still more preferably 2-4.
It is believed that within the above range, cohesion and adhesion are strengthened by the action of the polyester-based urethane resin, resulting in good lamination strength and easy tearability.

As the isocyanate-based compound, adduct-type polyisocyanate (adduct), biuret-type polyisocyanate (biuret), isocyanurate-type polyisocyanate (isocyanurate), polyisocyanate containing bifunctional polyisocyanate, etc. are suitable. , adducts, biurets and isocyanurates are, for example, adducts obtained from the reaction of trimethylolpropane or other polyols with diisocyanates, biurets obtained by dimerizing diisocyanates and linked by biuret bonds, and cyclotrimerization of diisocyanates. An isocyanurate obtained from the reaction and the like can be mentioned. As the diisocyanate, the diisocyanate described above may be arbitrarily selected and used, among which tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), hydrogenated diphenylmethane diisocyanate (hydrogenated MDI), and hexamethylene diisocyanate (HDI). , isophorone diisocyanate, xylylene diisocyanate (XDI), and hydrogenated xylylene diisocyanate (hydrogenated XDI). The adduct-type polyisocyanate, biuret-type polyisocyanate, and isocyanurate-type polyisocyanate may be used in combination, and may also 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 compound within the above range, it is necessary to select diisocyanate, polyol, etc. in the synthesis of the isocyanate compound, the solid content mass ratio, and the reaction such as polyisocyanate in the synthesis reaction. The reaction temperature can be set within the range by appropriately setting the dropping speed of the raw material, the stirring speed, the shape of the stirring blade, and the reaction temperature. It is effective to set the molecular weight distribution within a predetermined range by controlling the dropping rate and the temperature range when reacting the polyamine and the polyisocyanate within a predetermined range.
Moreover, it is effective to set the molecular weight distribution within a predetermined range by setting the charging ratio of the reaction raw materials to an appropriate ratio. The feed ratio includes, for example, the NCO/OH ratio, which is the ratio of the isocyanate groups of the polyol and the polyisocyanate, and the amino group/NCO ratio, which is the ratio of the amino groups of the polyamine and the isocyanate groups of the polyisocyanate. is mentioned. Reaction temperature control is important, and in synthesis using polyol and polyisocyanate, it is preferable to control within the range of 50 to 130 ° C. When reacting polyamine and polyisocyanate, it is controlled within the range of 10 to 50 ° C. is preferred. The solid content is also important, and the solid content during the reaction is preferably 40 to 80% by mass. The reaction solvent is also important, and it is preferable to use ethyl acetate, n-propyl acetate and other ester-based organic solvents.

In the present invention, the mass ratio of the urethane resin (including polyester-based urethane resin) contained in the gravure ink to the isocyanate-based compound contained in the curing agent, that is, the urethane resin:isocyanate-based compound is 99:1 to 60: 40 is preferred, 98:2 to 65:35 is preferred, and 95:5 to 70:30 is more preferred.
When the combination resin described below is contained in addition to the urethane resin, the mass ratio of the total amount of the urethane resin and the combination resin (binder resin total mass) to the isocyanate compound is 99:1 to 60:40. is preferably 98:2 to 65:35, more preferably 95:5 to 70:30. This is because it is believed that within this range, the effect of cross-linking and adhesion to the substrate will be good, and good laminate physical properties and easy tearability will be exhibited.

(Curable gravure ink)
The gravure ink of the present invention can be made into a curable gravure ink by mixing a curing agent. A curable gravure ink obtained by mixing 0.3 to 10% by mass of a curing agent with respect to 100% by mass of the gravure ink is preferred. The amount of the curing agent is more preferably 0.5 to 7% by mass, more preferably 0.8 to 5% by mass or 1 to 4% by mass, based on 100% by mass of the gravure ink. preferable.
Furthermore, it is also possible to adjust the viscosity to be suitable for printing with an organic solvent or the like, and as the organic solvent, the same organic solvent as described above is preferably used.

(Printed layer formed by printing "curable gravure ink")
A printed layer means a printed layer formed from a curable gravure ink, and is formed by gravure printing. The printed layer after printing is gradually cross-linked and cured by a curing agent. It is preferable to leave it still for about 1 to 24 hours after printing. The film thickness of the printed layer is preferably 0.5 to 10 μm, more preferably 0.8 to 8 μm.

<Gravure printing>
(gravure version)
A gravure plate is a metal cylindrical plate, in which depressions are made for each color by engraving or etching/laser. There are no restrictions on the use of engraving and laser, and settings can be made arbitrarily according to the pattern. A line number of 100 to 300 lines is appropriately used, and the larger the number of lines, the finer the printing is possible. The thickness of the printed layer is preferably 0.1 μm to 100 μm.
(gravure printing machine)
In a gravure printing press, one printing unit includes the gravure plate and the doctor blade. There are many printing units, and printing units corresponding to organic solvent-based printing inks and graphic inks can be set, and each unit has an oven drying unit. Printing is carried out by rotary printing, which is a web printing method. The type of plate and the type of doctor blade can be selected as appropriate, and can be selected according to the specifications.

<Laminate>
The laminate of the present invention comprises the printed layer as an intermediate layer of the laminated laminate. A laminate having a configuration in which at least a base material 1, a printed layer and a base material 2 (sealant) are laminated in this order is preferable. The base material 1 and the base material 2 may be the same or different, but it is preferable that the base material 2 is an unstretched polyolefin base material (sealant) having heat sealability (see below). Specifically, the laminate structure of the laminate can be exemplified as follows. In addition, in the structural representations (1) to (4) below, "/" means the boundary of each layer.
(1) Substrate 1/printing layer/adhesive layer/sealant (2) Substrate 1/printing layer/adhesive layer/intermediate substrate layer/adhesive layer/sealant (3) Substrate 1/printing layer/ink Layer/Adhesive Layer/Sealant (4) Substrate 1/Printing Layer/Ink Layer/Adhesive Layer/Intermediate Substrate Layer/Adhesive Layer/Sealant A layer configuration that allows the printed layer to be visible from the substrate side. can be arbitrarily selected.

<Base material 1>
The base material 1 is preferably a plastic film, plays a role as a base material on the outer layer side of the laminate, 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), ethylene-vinyl ester copolymer saponified product, polyethylene terephthalate (PET) and poly Polyester resins such as butylene terephthalate (PBT) and polyethylene naphthalate (PEN), polyamide resins such as various nylons (Ny), polyurethane resins, acetal resins, cellulose resins, polyvinylidene chloride resins (PVDC), etc. is mentioned. The substrate 1 may be uniaxially stretched or biaxially stretched. Also, a composite film in which two or more of the above resin films are laminated may be used. Moreover, the form in which metal oxides, such as silica and an alumina, were vapor-deposited may be sufficient.

The substrate 1 preferably has excellent heat resistance from the viewpoint of boiling and retorting. Polyester-based resins and/or polyamide-based resins are suitable as resins constituting the substrate having excellent heat resistance.
Specific examples of the substrate 1 having excellent heat resistance include a single polyester film, a single polyamide film such as nylon, and a composite film containing one or more of a polyester film and a polyamide film. Examples of the composite film include a coextruded stretched film composed of PET/Ny/PET and PET/Ny from the outer layer side. As the composite film, it is also preferable to combine one or more of polyester film and polyamide film with one or more of ethylene-vinyl alcohol copolymer film and polyvinylidene chloride film.

The thickness of the base material 1 is not particularly limited, and can be appropriately set according to the use of the laminate. .

The substrate 1 preferably has a total light transmittance of 85% or more, more preferably 90% or more, according to JIS K7361-1:1997. The haze of the base material is preferably 1.5% or less, more preferably 1.0% or less, and even more preferably 0.5% or less, according to JISK7136:2000.

(Gas barrier layer)
A gas barrier layer can be provided anywhere between the substrate and the sealant, if desired. The gas barrier layer plays a role of blocking permeation of oxygen, water vapor, and the like between the object to be packaged by the laminate and the environment outside the laminate. In addition, it may also have a light-shielding property that blocks the 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.

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

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

<Intermediate base material layer>
The laminate of the present invention may have an intermediate substrate layer between the print 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 laminate. Examples of the constituent material of the intermediate base material layer include a plastic film-like base material. As the base material, the same base material as described above can be used. In consideration of heating in a microwave oven and retort treatment, the intermediate substrate layer preferably has excellent heat resistance in order to increase the heat resistance of the laminate. A polyester base material, a polyamide base material, or the like is preferably used.

<Adhesive layer>
In the laminate, each component layer is laminated via an adhesive layer from the viewpoint of improving the bonding strength between the layers. The adhesive layer can be formed by a method using a known adhesive for dry lamination.
Examples of dry laminate adhesives include polyvinyl acetate adhesives, polyacrylate adhesives, cyanoacrylate adhesives, ethylene copolymer adhesives, cellulose adhesives, polyester adhesives, and polyamide adhesives. Adhesives, polyimide adhesives, amino resin adhesives such as urea resins and melamine resins, phenol resin adhesives, epoxy adhesives, polyurethane adhesives (for example, cured products of polyols and isocyanate compounds), reactions Examples include (meth)acrylic acid-based adhesives, rubber-based adhesives such as chloroprene rubber, nitrile rubber, and styrene-butadiene rubber, silicone-based adhesives, and inorganic adhesives such as alkali metal silicate and low-melting glass.
The adhesive is formed by applying it to the printed layer, sealant or intermediate substrate layer and then laminating each layer, substrate or sealant. The coating film thickness is preferably 0.5 to 5 μm, and more preferably 1 to 4 μm.

<Base material 2 (sealant)>
The sealant has a surface on the inner layer side that comes into direct contact with the object to be packaged and plays a role of protecting the object to be packaged. It is preferable that the innermost layer of the sealant has a heat-sealing property in order to make the laminate bag-like. Materials constituting the sealant include, for example, 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 of these resins can be used. The sealant may be composed of a single layer or multiple layers of two or more layers. It should be noted that the sealant is preferably a non-stretched film made of the resin described above in order to suppress shrinkage during heat sealing.

From the viewpoint of heating during boiling and retorting, the sealant is preferably composed of a resin with excellent heat resistance in order to increase heat resistance. Specifically, propylene-based resins such as polypropylene and ethylene-propylene copolymers are used. and HDPE are preferred.

The thickness of the sealant is not particularly limited, and is appropriately set according to the use of the laminate and the type and properties of the object to be packaged, but it is usually preferably 10 to 200 μm. In the case of pouches (especially retort pouches), the thickness of the sealant is preferably 20-150 μm, more preferably 30-100 μm.

(Laminate manufacturing method)
The laminate of the present invention is a method for producing a laminate having at least a substrate, a printing layer, an adhesive layer and a sealant in this order, wherein the printing layer comprises a gravure ink containing a pigment, a polyester-based urethane resin, and an isocyanate-based compound. A curable ink mixed with a curing agent containing is formed by gravure printing on the substrate. The adhesive layer may be formed by applying it on the printed layer, or may be formed by applying it to the sealant.
A preferred mode is, for example, a mode in which an adhesive is applied on the printed layer, and then a sealant is attached. In addition, when the laminate further has an intermediate base material layer, there is an aspect including a step of bonding the printed layer and the intermediate base material layer together with an adhesive, and further bonding the intermediate base material layer and the sealant. preferable. Note that the configuration is arbitrary and not particularly limited.
The thus-obtained laminate is cut to a predetermined size and heat-sealed at the edges to form a bag, with the sealants aligned with each other. 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. A single laminate may be folded and the edges heat-sealed, or two or more laminates may be heat-sealed. Moreover, the bag made of the laminate may be one in which all the openings are heat-sealed after the contents are packed.

EXAMPLES The present invention will be described in detail below with reference to Examples, but the present invention is not limited to these Examples. Parts, % and ratios in the present invention represent parts by mass, % by mass and mass ratios unless otherwise specified.

(hydroxyl value)
It was obtained according to JISK0070.
(acid value)
It was obtained according to JISK0070.
(amine value)
The amine value was obtained in mg of potassium hydroxide equivalent to the equivalent of hydrochloric acid required to neutralize the amino groups contained in 1 g of the resin according to JIS K0070 according to the following method.
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 to dissolve the sample. Bromophenol blue was added to the resulting solution as an indicator, and the resulting solution was titrated with a 0.2 mol/L ethanolic hydrochloric acid solution (potency: f). The point at which the color of the solution changed from green to yellow was defined as the end point, and the titration amount (AmL) at this time was used to determine the amine value by the following (formula 2).
(Formula 2) 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, the number average molecular weight Mn and the molecular weight distribution Mw/Mn are measured using a GPC (gel permeation chromatography) device (HLC-8220 manufactured by Tosoh Corporation), and polystyrene is used as a standard substance. It was obtained as a converted molecular weight. 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
TSK gelguard column Super AWH manufactured by Tosoh Corporation
Detector: RI (differential refractometer)
Measurement conditions: Column temperature 40°C
Eluent: Tetrahydrofuran Flow rate: 1.0 mL/min

[Synthesis Example 1] (Synthesis of polyester urethane resin PU1)
Neopentyl glycol (hereinafter “NPG”), 1,3-propanediol (hereinafter “1,3-PD”), sebacic acid and adipic acid having a number average molecular weight of 2000 are placed in a reaction vessel equipped with stirring blades under a nitrogen gas atmosphere. Polyester polyol (NPG: 1,3-PD = 60: 40, sebacic acid: adipic acid = 50: 50) which is a condensate of 100 parts, 1,4-butanediol (hereinafter "1,4-BD") 1.0 part, 28.5 parts of isophorone diisocyanate (hereinafter “IPDI”), and 32.1 parts of ethyl acetate were reacted under a nitrogen stream at 80° C. and a stirring speed of 150 rpm for 5 hours to obtain a solvent solution of a terminal isocyanate urethane prepolymer. got Next, in another reactor equipped with stirring blades, 11 parts of isophoronediamine (hereinafter "IPDA"), 1.0 parts of N-(2-aminoethyl)ethanolamine (hereinafter "AEA"), dibutylamine (hereinafter "DBA") ) and 300.4 parts of a mixed solvent of ethyl acetate/isopropanol (hereinafter “IPA”) = 60/40 were rapidly stirred at a stirring speed of 180 rpm and kept at 40 ° C., and the resulting terminal The isocyanate prepolymer solution was added dropwise at 40°C over 60 minutes and then reacted at 80°C for 1 hour. After completion of the reaction, the solid content was adjusted to 30% by mass with an ethyl acetate/IPA mixed solvent to obtain a polyester urethane resin PU1 solution.

[Synthesis Examples 2 to 5] (Synthesis of polyester-based urethane resins PU2 to PU5)
Polyester-based urethane resins PU2 to PU5 were synthesized in the same manner as in Synthesis Example 1 except that the raw materials and blending ratios shown in Table 1 were used. Table 1 shows Mw/Mn, hydroxyl value, amine value and weight average molecular weight. Abbreviations in the table represent the following.
NPG, 1,3-PD/sebacic acid, succinic acid: a condensate of neopentyl glycol (hereinafter "NPG"), 1,3-propanediol (hereinafter "1,3-PD") and sebacic acid, succinic acid A polyester polyol (NPG: 1,3-PD = 60:40, sebacic acid: succinic acid = 50:50)
MPD/sebacic acid: polyester polyol which is a condensate of 3-methyl-1,5-pentanediol (hereinafter “MPD”) and sebacic acid (hereinafter “SA”) PEG: polyethylene glycol PPG with a number average molecular weight of 1000: Polypropylene glycol with a number average molecular weight of 2000

[Comparative Synthesis Examples 1, 2 and 3] (Synthesis of urethane resins P1, P2 and P3)
A urethane resin P1 was synthesized in the same manner as in Synthesis Example 1, except that the raw materials and blending ratios shown in Table 1 were used.

[Synthesis Example 6] (Synthesis of Curing Agent 1)
In a nitrogen gas atmosphere, 15 parts of trimethylolpropane, 60.3 parts of toluene-2,4-diisocyanate, and 32.3 parts of previously dehydrated ethyl acetate were stirred at 50° C. and 150 rpm in a reactor equipped with stirring blades. A curing agent 1 having a solid content of 70% by mass was obtained by reacting at a high speed for 3 hours.
(Curing agent 1 (adduct type))
Weight average molecular weight: 1200
Mw/Mn: 2.5

[Synthesis Example 7] (Synthesis of Curing Agent 2)
In a nitrogen gas atmosphere, 15 parts of trimethylolpropane, 29.8 parts of toluene-2,4-diisocyanate, and 99.3 parts of previously dehydrated ethyl acetate were stirred at 50° C. and 150 rpm in a reactor equipped with stirring blades. A curing agent 2 having a solid content of 70% by mass was obtained by reacting at a high speed for 3 hours.
(Curing agent 2 (adduct type))
Weight average molecular weight: 2500
Mw/Mn: 3.3

[Synthesis Example 8] (Synthesis of Curing Agent 3)
15 parts of ditrimethylolpropane, 39.7 parts of toluene-2,4-diisocyanate and 23.4 parts of ethyl acetate were reacted at 80° C. for 3 hours at a stirring speed of 150 rpm in a reactor equipped with stirring blades under a nitrogen gas atmosphere. A curing agent 3 having a solid content of 70% by mass was obtained.
(Curing agent 3 (adduct type))
Weight average molecular weight: 3500
Mw/Mn: 4.2

In addition to the above curing agents, the following curing agents were also used in the examples described below.
・ TLA-100: Asahi Kasei isocyanurate type isocyanate curing agent Weight average molecular weight: 1300 Mw / Mn: 2.4 Solid content 70% by mass
・ 24A-100: Biuret type isocyanate curing agent manufactured by Asahi Kasei Weight average molecular weight: 1600 Mw / Mn: 3.2 Solid content 70% by mass
・ E402-80B: Asahi Kasei isocyanate curing agent Weight average molecular weight: 4100 Mw / Mn: 3.4 Solid content 70% by mass

[Example 1] (Production of laminate S1)
<Preparation of gravure ink S1>
Using the polyester-based urethane resin PU1 obtained in Synthesis Example 1, the following gravure ink S1 was prepared.
・Polyester-based urethane resin 40 parts by mass ・Vinyl chloride copolymer resin solution 10 parts by mass (Vinyl chloride-vinyl acetate copolymer resin Solbin TA5R manufactured by Nisshin Chemical Co., Ltd. Solid content 30% by mass ethyl acetate solution)
- Phthalocyanine pigment 10 parts by mass (CI Pigment Blue 15:4))
・ Organic solvent 40 parts by mass (n-propyl acetate/isopropanol = 70/30 mixed solvent)

<Print>
For 100 parts by mass of the gravure ink S1 obtained above, a mixed solvent (methyl ethyl ketone “MEK”: N-propyl acetate “NPAC”: isopropanol “IPA” = 30:40:30) was used to increase the viscosity to 16 seconds (25 ℃, Zahn Cup No. 3) to obtain a curable gravure ink S1. After that, the ink is applied to the corona discharge treated surface of a biaxially stretched NY (polyamide) substrate (N1102, manufactured by Toyobo Co., Ltd., film thickness 15 μm) using a Helio 175 line solid plate (plate type compressed, 100% solid pattern) at a printing speed of Printing was performed at 100 m/min to obtain a printed matter S1.

<Extrusion lamination processing (EL method, imine)>
A methanol solution of an imine-based anchor coating agent (EL420 manufactured by Toyo-Morton Co., Ltd.) was applied to the above-mentioned printed matter in a solid content conversion of 0.03 g/m ² , and an extrusion laminator (manufactured by Musashino Kikai Co., Ltd.) was used at a line speed of 100 m/min. At 320° C., melted polyethylene (LC600A manufactured by Nippon Polyethylene Co., Ltd.) was melted at 320° C., laminated to a thickness of 18 μm, and laminated with CPP (FCMN#20 manufactured by Futamura Chemical Co., Ltd.) to obtain a laminate.

<Extrusion lamination processing (EL method, Isosia)>
A methanol solution of an isocyanate-based ^anchor coating agent (EL530 manufactured by Toyo-Morton Co., Ltd.) was applied to the above printed matter at a line speed of 100 m/min with an extrusion laminator (manufactured by Musashino Kikai Co., Ltd.) at a line speed of 100 m/min. At 320° C., melted polyethylene (LC600A manufactured by Japan Polyethylene Co., Ltd.) was melted at 320° C., laminated at 18 μm, and laminated with LLDPE (TUX-FCD #40 manufactured by Mitsui Chemicals Tohcello Co., Ltd.) to obtain a laminate.

[Examples 2 to 22] (Production of laminates S2 to 22)
The curable inks, prints, and laminates S2-22 of Examples 2-22 were obtained in the same manner as in Example 1, except that the raw materials and blending ratios shown in Table 2 were used and the curing agent was added and mixed with stirring. rice field.
Abbreviations in the table indicate the following.
DLX5-8: ICI Novel enterprises nitrocellulose weight average molecular weight 50000 nitrogen content 12.0% glass transition temperature 150 ° C. (solid content 30% isopropanol solution)
· Harrier P: Ethyl acetate solution with rosin-modified pentaerythritol ester solid content of 30% manufactured by Harima Chemicals Co., Ltd. BR-105: Mitsubishi Chemical Corporation acrylic resin, weight average molecular weight 60,000, glass transition point 50 ° C., acid value 3. 5 mg KOH / g 30% solid content ethyl acetate solution 7018: polyester resin solid content 30% solution manufactured by Arakawa Chemical Co., Ltd. Titanium oxide: titanium oxide coated with CR-90 silica and alumina manufactured by Ishihara Sangyo Co., Ltd., transmission electron microscope The average particle size (median particle size) measured by 0.25 μm

[Comparative Examples 1-6] (Production of laminates H1-6)
Laminates H1-6 of Comparative Examples 1-6 were obtained in the same manner as in Example 1, except that the raw materials and the blending ratios of the urethane resin and ink shown in Table 3 were used.

(measurement and evaluation)
The following measurements and evaluations were performed on the laminates of Examples and Comparative Examples. The results are shown in Tables 2-3.

<Ink stability>
100 g of the inks obtained in the above examples and comparative examples were filled in a glass bottle, sealed, and aged at 40° C. for 7 days, and the presence or absence of separation/precipitation and the degree of change (increase) in ink viscosity were evaluated.
[Evaluation criteria]
A: No separation or sedimentation, and no change in viscosity. (Good)
B: Occurrence of separation/precipitation of less than 5 mm, or increase in ink viscosity of less than 10% is observed. (somewhat good)
C: Occurrence of separation/precipitation of less than 1 cm, or increase in ink viscosity of less than 30% is observed. (Practical)
D: Separation of less than 3 cm, generation of hard precipitates, or increase in ink viscosity of less than 50% is observed. (somewhat bad)
E: Defects such as separation of a transparent liquid phase of 3 cm or more, generation of irreversible precipitates, or an increase in ink viscosity of 50% or more are observed. (defective)
Evaluations of A, B and C are practicable.

<Printability>
The printing inks of Examples and Comparative Examples were evaluated for plate fogging. The diluting solvent was NC201 solvent:ethyl acetate:IPA=80:20, the viscosity was 16 seconds (25° C.) with a Zahn cup #3, and the area of the plate fogging portion after 90 minutes of idling of the plate in the printing machine was Evaluation was carried out by visual determination.
Criteria A (Excellent): Plate fogging area is 0% or more and less than 5% B (Good): Plate fogging area is 5% or more and less than 10% C (Fair): Plate fogging area is 10% or more and 15% Less than D (improper): Plate fogging area is 15% or more and less than 30% E (Poor): Plate fogging area is 30% or more, still practical evaluation is A, B and C.

<Laminate strength>
For the laminates obtained in the above Examples and Comparative Examples, after 48 hours at 40° C., the printed portion was cut to a width of 15 mm, and the ink surface and the substrate surface were peeled off, and the peel strength (laminate strength) was measured. It was measured with a 201 universal tensile tester manufactured by Intesco.
[Evaluation criteria]
A: 1.6 N or more (good)
B: 1.2 N or more and less than 1.6 N (slightly good)
C: 0.8N or more and less than 1.2N (practical)
D: 0.4 N or more and less than 0.8 N (slightly poor)
E: less than 0.4N (defective)
Evaluations of A, B and C are practicable.

<Easy tearability>
Samples were prepared according to JISK7128-1:1998 for the laminates obtained in the above examples and comparative examples, and evaluated by resistance when torn with a 201 universal tensile tester manufactured by Intesco.
[Evaluation criteria]
A: less than 0.5N (good)
B: 0.5 N or more and less than 1.0 N (slightly good)
C: 1.0 N or more and less than 1.5 N (practical)
D: 1.5 N or more and less than 2.0 N (slightly poor)
E: 2.0 N or more (defective)
Evaluations of A, B and C are practicable.

Claims (8)

A gravure ink containing a polyester-based urethane resin for use in forming the printed layer of a laminate having a printed layer,
A gravure ink, wherein the polyester-based urethane resin has a molecular weight distribution (Mw/Mn) of more than 5 and 10 or less. The gravure ink of Claim 1, further comprising a curing agent. The gravure ink according to claim 2, wherein the curing agent contains an isocyanate compound having a molecular weight distribution (Mw/Mn) of 1.5-5. 4. The gravure ink according to claim 3, wherein the isocyanate compound has a weight average molecular weight of 800 to 8,000. 5. The gravure ink according to claim 1, wherein the polyester urethane resin has a structure derived from at least one of sebacic acid, succinic acid and azelaic acid. The gravure ink according to any one of claims 1 to 5, further comprising at least one resin selected from the group consisting of cellulose resins, vinyl chloride resins and rosin resins. A printed matter having a printing layer formed from the gravure ink according to any one of claims 1 to 6 on a substrate 1. A laminated laminate having an adhesive layer and a base material 2 in this order on the printed layer of the printed material according to claim 7 .