JP7277685B2 - Gravure ink for laminate laminate, printed matter using the same, laminate laminate - Google Patents

Description

The present invention relates to a gravure ink for laminate laminates, a printed matter having a printed layer formed by the gravure ink for laminate laminates, and a laminate laminate having an adhesive layer and a sealant base on the printed layer. .

In general, packaging bags may have a pattern such as a pattern, and a printed layer made of ink is provided to make the contents invisible. Often used as a layer. 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.

On the other hand, a printed layer made of gravure ink is laminated with an adhesive layer, a thermoplastic substrate, 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. 2. Description of the Related Art In the case of packaging bags for food packaging, for example, liquid pouches, the packaging bag is often manually torn open 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, good tearability is required for laminates in the food packaging field.

As a conventional technique, for example, there is a method of creating a trigger for tearing by making a notch on the end face of the film. It causes a situation where it gets caught / does not tear in a straight line. Further, for example, as described above, depending on the pattern of the packaging bag, there may be a portion having a pattern layer and a portion (blank portion) having no pattern layer. In this way, when the patterned portion and the plain portion are mixed in the same packaging bag, if the hardness of the adhesive layer is adjusted so that the patterned layer can be torn, the tearability cannot be balanced between the plain portion and the plain portion. It is known that when the hardness of the adhesive layer is matched to that of the plain portion, tearability is inferior in the pattern portion (Patent Document 1).

In order to improve tearability, for example, a printing ink using a combination of a polyurethane resin and a vinyl chloride-vinyl acetate copolymer resin has been proposed with a gravure ink using an isocyanate curing agent, but the ink film becomes too hard when cured. The lamination strength may deteriorate over time, and the amount of residual solvent increases. ・The presence of a large amount of isocyanate compound for the development of tearability may cause printability and physical property balance to collapse ( Patent document 2).

In order to solve these problems, a gravure ink for white laminates containing an isocyanate curing agent and an amino group-containing silane coupling agent has been proposed (Patent Document 3). However, it is desired to further improve the tearability of white ink. It was difficult to develop easy-tearability in the conventional technique of containing

JP 2008-274061 A Japanese Patent Application Laid-Open No. 2017-31298 JP 2019-199509 A

An object of the present invention is to provide a gravure ink for laminated laminates having good lamination strength and tearability.

As a result of earnest studies, the present inventors have found that the above problems can be solved by using the gravure ink for laminated laminates described below, and have completed the present invention.

That is, the present invention provides a gravure ink for laminates containing a pigment, a polyurethane resin, a vinyl chloride copolymer resin, a chelate cross-linking agent, an isocyanate curing agent, and an organic solvent,
Laminate in which the polyurethane resin and/or vinyl chloride copolymer resin has an active hydrogen group capable of reacting with the chelate cross-linking agent, and the mass ratio of the chelate cross-linking agent to the isocyanate curing agent is 1:2 to 1:25. It relates to a gravure ink for laminates.

Further, the present invention provides the above-mentioned laminate laminate, wherein the polyurethane resin has an amine value and/or a hydroxyl value, the amine value is 1 to 15 mgKOH/g, and the hydroxyl value is 1 to 20 mg/KOHg. It relates to gravure ink.

The present invention also relates to the gravure ink for laminate laminates, wherein the vinyl chloride copolymer resin has a hydroxyl group.

The present invention also relates to the gravure ink for laminate laminates, wherein the chelate cross-linking agent contains a titanium chelate.

The present invention also relates to the gravure ink for laminate laminates, wherein the isocyanate-based curing agent contains at least one selected from the group consisting of biuret-based isocyanate compounds, isocyanurate-based isocyanate compounds, and adduct-based isocyanate compounds.

The present invention also relates to the gravure ink for laminate laminates, wherein the pigment contains an organic pigment.

The present invention also relates to a printed material having a printed layer formed on the base material 1 with the gravure ink for a laminated laminate.

The present invention also relates to a laminate having a substrate 1, a print layer made of the gravure ink for laminate laminates according to any one of claims 1 to 6, an adhesive layer, and a substrate 2 in this order.

INDUSTRIAL APPLICABILITY The present invention has made it possible to provide a gravure ink for laminated laminates having good lamination strength and 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.

The gravure ink for laminated laminates of the present invention will be described. In the following, the gravure ink for laminate laminates may be abbreviated as "gravure ink" or "ink" in some cases, but has the same meaning as the gravure ink for laminate laminates. In addition, the printed layer formed by the gravure ink for laminate laminates may be referred to as "printed layer", "ink layer" or "ink film", but is synonymous with the printed layer formed by gravure ink for laminate laminates. is.

The present invention is a gravure ink for a laminate containing a pigment, a polyurethane resin, a vinyl chloride copolymer resin, a chelate cross-linking agent, an isocyanate-based curing agent, and an organic solvent, the gravure ink comprising a polyurethane resin and/or a vinyl chloride copolymer resin. has an active hydrogen group capable of reacting with a chelate, and contains a chelate cross-linking agent and an isocyanate-based curing agent at a mass ratio of 1:5 to 1:25. The active hydrogen group includes, for example, a hydroxyl group, an amino group and other groups, but is not limited to these.

By using a chelate cross-linking agent in a gravure ink consisting of a pigment, a polyurethane resin, and a vinyl chloride copolymer resin, the interaction between the resin component and the chelate cross-linking agent occurs, and the ink layer becomes stronger. Even when it is used, the laminated laminate exhibits good tearability. In addition, the use of an isocyanate-based curing agent accelerates the effect and further improves the easy tearability.

<Pigment>
Pigments that can be used in the present invention may be inorganic pigments or organic pigments. When it is in the form containing an organic pigment, the remarkable effects of the present invention are exhibited. When the pigment contains an organic pigment, it is preferably at least 50% by mass, preferably at least 60% by mass, and more preferably at least 70% by mass of the total mass of the pigment.
As the organic pigment, C.I. I. Any pigment can be used. Among them, C.I. I. Pigment Red 57:1, C.I. I. Pigment Red 48:1, C.I. I. Pigment Red 48:2, C.I. I. Pigment Red 48:3, C.I. I. Pigment Red 146, C.I. I. Pigment Red 242, C.I. I. Pigment Yellow 83, C.I. I. Pigment Yellow 14, C.I. I. Pigment Orange 38, C.I. I. Pigment Orange 13, C.I. I. Pigment Yellow 180, C.I. I. Pigment Yellow 139, C.I. I. Pigment Red 185, C.I. I. Pigment Red 122, C.I. I. Pigment Red 178, C.I. I. Pigment Red 149, C.I. I. Pigment Red 144, C.I. I. Pigment Red 166, C.I. I. Pigment Violet 23, C.I. I. Pigment Violet 37, C.I. I. Pigment Blue 15, C.I. I. Pigment Blue 15:1, C.I. I. Pigment Blue 15:2, C.I. I. Pigment Blue 15:3, C.I. I. Pigment Blue 15:4, C.I. I. Pigment Blue 15:6, C.I. I. Pigment Green 7, C.I. I. Pigment Orange 34, C.I. I. Pigment Orange 64, C.I. I. Pigment Black 7 and the like. Pigments include azo pigments, phthalocyanine pigments, anthraquinone pigments, perylene pigments, perinone pigments, quinacridone pigments, thioindigo pigments, dioxazine pigments, isoindolinone pigments, quinophthalone pigments, and azomethine azo pigments. Pigments, ditopyrrolopyrrole-based pigments, isoindoline-based pigments, and the like are suitable. The pigment content is preferably 1 to 45% by mass based on the total mass of the ink. Moreover, you may use together a multiple types of organic pigment.

The hue of the organic pigment is at least one or two selected from the group consisting of a black organic pigment, a blue organic pigment, a green organic pigment, a red organic pigment, a purple organic pigment, a yellow organic pigment, an orange organic pigment, and a brown organic pigment. The above is preferable. Furthermore, at least one or two or more selected from the group consisting of black organic pigments, indigo organic pigments, red organic pigments, and yellow organic pigments are preferred. Those containing a blue organic pigment and/or a red organic pigment are particularly preferred. This is because the use of these organic pigments exhibits effects such as easy tearability.

The gravure ink of the present invention has a total of four process colors (basic colors) of yellow, red, indigo, and black, three external process colors of red (orange), grass (green), and purple, and transparent yellow. , peony, vermillion, and brown may be used singly or in combination.

The pigment used in the gravure ink of the present invention does not exclude the application of titanium oxide and other inorganic pigments. The titanium oxide 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 titanium oxide is preferably 10 to 60% by mass, more preferably 10 to 45% by mass, based on 100% by mass of the ink. Moreover, you may use together the titanium oxide of multiple types.
In the gravure ink of the present invention, in addition to titanium oxide, other inorganic pigments and organic pigments can also be used in combination.

When the above organic pigment is contained, the solid content mass ratio of the organic pigment and the binder resin is preferably 5:10 to 30:10, more preferably 5:10 to 20:10. When the inorganic pigment is contained, the solid content mass ratio of the inorganic pigment and the binder resin is preferably 15:10 to 50:10, more preferably 15:10 to 40:10. Here, the binder resin means a binder resin in the ink, and is a resin including polyurethane resin and vinyl chloride-vinyl acetate copolymer resin.

<Polyurethane resin>
The polyurethane resin used in the present invention refers to a polyurethane resin intended to act as a binder resin. The polyurethane resin preferably has an active hydrogen group capable of reacting with the chelate cross-linking agent, and in many embodiments has a hydroxyl group or an amino group, and thus has an amine value and/or a hydroxyl value. The amine value is preferably 1-15 mgKOH/g, more preferably 1-10 mgKOH/g. Also, the hydroxyl value is preferably 1 to 20 mgKOH/g, more preferably 1 to 10 mgKOH/g. It is also preferred in one embodiment to have an amine value and a hydroxyl value of zero. This is because it reacts with the chelate cross-linking agent and/or the isocyanate curing agent to improve tearability.
Further, the polyurethane resin is preferably a polyurethane resin containing structural units derived from polyester polyol.

The polyurethane resin is preferably a polyurethane resin that is a reaction product of a polyisocyanate and a polyol containing the polyester polyol, and the polyisocyanate and the polyol form a urethane prepolymer, and the polyurethane is chain-extended using a polyamine. Resin is more preferred.
The structural unit derived from the polyester polyol is preferably contained in an amount of 20 to 75% by mass, more preferably 40 to 75% by mass, in the total mass of the polyurethane resin. Moreover, it is preferably contained in an amount of 50% by mass or more, more preferably 70% by mass or more, in the total mass of the polyol. This is because the tearability of the laminate is improved, and the amount of residual solvent in the printed matter can be reduced. The content of structural units derived from the polyester polyol can be calculated from the compounding amount during synthesis.

The polyol preferably contains the above polyester polyol, and is preferably used in combination with polyether polyol, polycaprolactone polyol, polycarbonate polyol, or the like.

<Polyester polyol>
The polyester polyol preferably has a structure represented by the following general formulas (1) and/or (2). A structure represented by the following general formula (1) is more preferable.
General formula (1)
-OCO-R1-COO-
general formula (2)
-COO-R2-COO-
(In the formula, R1 and R2 each independently represent a substituted or unsubstituted alkylene group having 2 to 20 carbon atoms or a substituted or unsubstituted alkenylene group having 2 to 20 carbon atoms, provided that the above 2 to 20 does not include the number of carbon atoms in the alkyl group of the substituent when the substituent is an alkyl group.)
The polyester polyol preferably has a number average molecular weight of 500 to 10,000. The number average molecular weight is obtained by the following formula (1), and the valence is the average number of hydroxyl groups possessed by one polyol molecule. Refers to mg of potassium hydroxide required for neutralization. The same applies to the number average molecular weight of polyols other than polyester polyols.
Formula (1) number average molecular weight = 1000 × 56.1 × valence of hydroxyl group / hydroxyl value

In the general formula (1), -OCO-R1-COO- is a diester structural unit of a dibasic acid, and is obtained by dehydration condensation of a dibasic acid represented by HOCO-R1-COOH and a diol. Such dibasic acids include adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, thapsic acid, 1,12-dodecanedicarboxylic acid, 1, 3-adamantanedicarboxylic acid, hexadecafluorosebacic acid and the like can be mentioned, and adipic acid and/or sebacic acid are preferred because of their well-balanced physical properties. Diols include ethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 1,6-hexanediol, 1,8-octanediol, 1 ,9-nonanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2-methyl-1,3-propanediol, 3,3,5-trimethylpentanediol, 1,12-octadecanediol, 1 , 2-alkanediols, 1,3-alkanediols, dimer diols, hydrogenated dimer diols, etc., and propylene glycol, 1,3-propanediol, 1,4-butanediol, and neopentyl whose physical properties are easily balanced. Glycol, 3-methyl-1,5-pentanediol is preferred.

In the general formula (2), -COO-R2-COO- is a structural unit obtained as a condensate of hydroxycarboxylic acid, and hydroxycarboxylic acids include 15-hydroxypentadecanic acid, 16-hydroxyhexadecanoic acid, ricinoleic acid, Hydrogenated ricinoleic acid, trans-hydroxy-2-decenoic acid and the like can be mentioned, and ricinoleic acid or hydrogenated ricinoleic acid is preferable from the balance of physical properties. In order to obtain a polyester polyol, it is preferable to use a diol as an initiator.

In formulas (1) and/or (2), the substituents for R1 and R2 are preferably alkyl groups. The alkyl group for the substituent preferably has 1 to 20 carbon atoms, more preferably 4 to 10 carbon atoms.

The polyisocyanate preferably contains at least one diisocyanate selected from aromatic diisocyanates, aliphatic diisocyanates, and alicyclic diisocyanates. Such diisocyanates are, 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, xylylene diisocyanate, m-tetramethylxylylene diisocyanate butane-1,4-diisocyanate, hexamethylene diisocyanate, isopropylene diisocyanate, methylene diisocyanate, 2,2 ,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, lysine diisocyanate,
Cyclohexane-1,4-diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, methylcyclohexane diisocyanate and dimer diisocyanate obtained by converting the carboxyl group of dimer acid into isocyanate group and the like are typical examples. These may be trimers to form an isocyanurate ring structure. These polyisocyanate species can be used alone or in combination of two or more.

Polyamines form urea bonds by reaction with isocyanate groups, and preferred examples include ethylenediamine, propylenediamine, hexamethylenediamine, isophoronediamine, and dicyclohexylmethane-4,4'-diamine. In addition, 2-hydroxyethylethylenediamine, 2-hydroxyethylpropyldiamine, 2-hydroxyethylpropylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxyethylenediamine, di-2-hydroxyethylpropylenediamine, 2-hydroxypyro It is also preferable to use amines having a hydroxyl group in the molecule, such as pyrethylenediamine, di-2-hydroxypypropylethylenediamine, and di-2-hydroxypropylethylenediamine. Although these organic diamines can be used alone or in combination of two or more, isophoronediamine and 2-hydroxyethylethylenediamine are preferred. In addition, 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 3 or more amino groups can be used in combination with the above organic diamines.

<Polyether polyol>
The polyurethane resin preferably contains structural units derived from polyether polyol, and the polyether polyol includes, for example, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polytrimethylene glycol, and copolymers thereof. mentioned. The number average molecular weight is preferably 500-10,000.

The production of the polyurethane resin used in the present invention is not particularly limited. can be used as appropriate.

<Vinyl chloride copolymer resin>
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. When the vinyl chloride copolymer resin is a vinyl chloride-vinyl acetate copolymer resin, the structure derived from the vinyl acetate monomer in 100 mass% of the solid content is preferably 1 to 30 mass%, and the structure derived from the vinyl chloride monomer is preferably 70 mass%. It is preferably ~95% by mass. Also, the glass transition temperature is preferably 50°C to 90°C.
The vinyl chloride copolymer resin preferably has an active hydrogen group capable of reacting with the chelate crosslinking agent, preferably has a hydroxyl group, and preferably has a hydroxyl value of 10 to 200 mgKOH/g. This is because the reactivity with chelate cross-linking agents and polyisocyanate curing agents and pigment dispersibility are improved, and the hydroxyl groups are derived from vinyl alcohol-derived hydroxyl groups or acrylic monomers having hydroxyl groups through saponification reaction or copolymerization. is preferred. When the vinyl chloride copolymer resin has a hydroxyl group, its effect is remarkable with the chelate cross-linking agent described later.

The mass ratio of the polyurethane resin to the vinyl chloride copolymer resin (polyurethane resin: vinyl chloride copolymer resin) is preferably 95:5 to 30:70, more preferably 90:10 to 40:60. This is because the solubility in an organic solvent is improved, and the adhesion to the substrate, film physical properties, laminate strength, etc. are also improved.

<Chelate cross-linking agent>
The chelate crosslinking agent used in the present invention is preferably at least one selected from aluminum chelates, zirconium chelates and titanium chelates. Among them, it is more preferable to contain a titanium chelate. By using these chelate cross-linking agents, if the vinyl chloride copolymer resin has a hydroxyl group, it is possible to cross-link the inside of the printed layer, which increases the adhesion to the substrate and strengthens the printed layer. Good lamination strength and easy tearability are obtained in the body. In addition, the two-liquid stability is improved, and deterioration over time can be suppressed.
(titanium chelate)
Examples of the titanium chelate include titanium alkoxides such as tetraisopropyl titanate, tetra-normal butyl titanate, butyl titanate dimer, tetra(2-ethylhexyl) titanate, tetramethyl titanate, and tetrastearyl titanate, triethanolamine titanate, and titanium acetylacetonate. titanium tetraacetylacetonate, tetraisopropoxytitanium, titanium ethylacetoacetate, titanium lactate, octylene glycol titanate, titanium n-butyl phosphate, propanediox titanium bis(ethylacetylacetate), and the like. can. The titanium chelate preferably contains at least one ligand selected from phosphoric acid, phosphate and acetylacetonate. This is because the action is homogeneous.
The content of the chelate cross-linking agent in the gravure ink is preferably 0.1 to 5% by mass, more preferably 0.1 to 1% by mass, because it reacts with the active hydrogen of the binder resin.

<Isocyanate curing agent>
In the gravure ink of the present invention, an isocyanate curing agent is used to improve tearability. This is because it crosslinks with the hydroxyl group amino group and other active hydrogen groups of the polyurethane resin and/or the vinyl chloride copolymer resin to improve lamination strength, easy tearability, and the like.
Preferred embodiments of the isocyanate curing agent are shown below. As the isocyanate curing agent, polyisocyanates containing adduct isocyanates (adducts), biuret isocyanates (biurets), isocyanurate isocyanates (isocyanurates) and the like are suitable.
Examples of adduct-based polyisocyanates include adducts obtained from the reaction of 1 mol of trimethylolpropane and 3 mols of diisocyanate, adducts obtained from the reaction of 1 mol of ethylene glycol and 2 mols of diisocyanate, and 1 mol of ditrimethylolpropane and 4 diisocyanates. Molar adducts, etc.
Biuret-based polyisocyanates include, for example, a biuret obtained from the reaction of 1 mol of water and 3 mol of diisocyanate, a biuret obtained from the reaction of 0.5 mol of water and 3 mol of diisocyanate, and a mixture of 1 mol of water and 5 mol of diisocyanate. Biuret obtained from the reaction, etc.
Examples of isocyanurate-based polyisocyanates include isocyanurates obtained from cyclotrimerization reaction of diisocyanates and derivatives thereof.
The amount of the polyisocyanate curing agent to be added is preferably 0.5 to 5% by mass based on the total mass of the ink.
Further, the isocyanate curing agent preferably has a molecular weight of 100 to 2,000. 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.

The weight ratio of the chelate cross-linking agent and the isocyanate curing agent is preferably 1:2 to 1:25, more preferably 1:2 to 1:15. The total mass of the chelate crosslinking agent and the isocyanate curing agent is preferably 3 to 40% by mass, preferably 5 to 30%, based on the total mass of 100 of the polyurethane resin and the vinyl chloride copolymer resin in the ink. % by mass is more preferred, and 5 to 20% by mass is more preferred. This is to improve the easy tearability.

<Organic solvent>
The gravure ink of the present invention contains an organic solvent as a liquid medium. As the organic solvent to be used, it is preferable to use a mixed solvent consisting of two or more organic solvents, and aromatic organic solvents such as toluene and xylene; ketone organic solvents such as methyl ethyl ketone and methyl isobutyl ketone; Known organic solvents such as -propyl, isopropyl acetate, isobutyl acetate, ester-based organic solvents, and alcohol-based organic solvents such as methanol, ethanol, n-propanol, isopropanol, and n-butanol can be used. Among them, organic solvents such as toluene and xylene that do not contain aromatic organic solvents (non-toluene organic solvents) are more preferable. More preferably, the organic solvent does not contain an aromatic organic solvent and/or a ketone organic solvent such as methyl ethyl ketone (hereinafter referred to as "MEK"). A mixed solvent of an ester-based organic solvent and an alcohol-based organic solvent is preferable because printability is improved. A preferred mass ratio of the ester-based organic solvent to the alcohol-based organic solvent (ester-based organic solvent/alcohol-based organic solvent) is 40/60 to 90/10.

<Other additives>
In addition, additives such as leveling agents, antifoaming agents, waxes, plasticizers, light stabilizers, infrared absorbers, ultraviolet absorbers, fragrances, and flame retardants may be added as necessary.

<Other resins>
Other resins may be used in combination with the gravure ink of the present invention as long as the effect of the present invention is not impaired. Examples of resins used include chlorinated polypropylene resins, ethylene-vinyl acetate copolymer resins, vinyl acetate resins, polyamide resins, acrylic resins, polyester resins, alkyd resins, polyvinyl chloride resins, and rosin resins other than those described above. , rosin-modified maleic acid resin, terpene resin, phenol-modified terpene resin, ketone resin, cyclized rubber, chlorinated rubber, butyral, petroleum resin, and modified resins thereof. These resins can be used alone or in combination of two or more.

<Production of gravure ink>
The gravure ink of the present invention is produced by dispersing a pigment in an organic solvent with a polyurethane resin, a vinyl chloride copolymer resin, or the like using a dispersing machine, and then mixing the resulting pigment dispersion with other resins, various additives, an organic solvent, and the like. can be manufactured by Commonly used dispersing machines, such as roller mills, ball mills, pebble mills, attritors and sand mills, can be used. The particle size distribution of the pigment in the pigment dispersion is adjusted by appropriately adjusting the size of the grinding media of the disperser, the filling rate of the grinding media, the dispersion processing time, the ejection speed of the pigment dispersion, the viscosity of the pigment dispersion, and the like. be able to. A sand mill is preferably used as the disperser. Further, the gravure ink of the present invention preferably has a viscosity of 40 to 400 mPa·s.

The gravure ink is preferably used in such a manner that the chelate cross-linking agent is included in the ink when the ink is manufactured, and the isocyanate curing agent is included in the ink when printing. In this form of use, since the isocyanate curing agent has an isocyanate group, it gradually reacts, so the ink stability (also referred to as two-component stability) between the gravure ink including the chelate crosslinking agent and the isocyanate curing agent is reduced. Although necessary, the stability of the gravure ink in the present invention is good.

<Printing of gravure ink, printed layer made of gravure ink, printed matter>
The printed matter in the present invention is obtained by printing gravure ink on the base material 1 with a gravure printing machine to form a printed layer, drying it in an oven, and fixing it. The drying temperature is usually about 40-60°C.

<Base material 1>
Substrates to which the gravure ink of the present invention can be applied include polyethylene, polypropylene and other polyolefin substrates, polycarbonate substrates, polyethylene terephthalate, polylactic acid and other polyester substrates, polystyrene substrates, and polystyrene-based materials such as AS resins and ABS resins. Resin, polyamide base material, polyvinyl chloride base material, polyvinylidene chloride base material, cellophane base material, paper base material, aluminum foil base material, etc., or film-like or sheet-like materials made of these composite materials be. Among them, a polyester base material and a polyamide base material having a high glass transition temperature are preferably used. This is for facilitating the development of tearability.

The base material may be subjected to vapor deposition coating treatment such as metal oxide on the surface and/or coating treatment such as polyvinyl alcohol. For example, GL- Examples include AE and IB-PET-PXB manufactured by Dai Nippon Printing Co., Ltd. Further, if necessary, those treated with additives such as antistatic agents and ultraviolet inhibitors, and those treated with corona treatment or low-temperature plasma on the surface of the base material can also be used.

<Base material 2>
Substrate 2 may be the same as substrate 1 and may be the same or different. A thermoplastic substrate (sometimes referred to as a sealant) is preferable, and an unstretched polyethylene substrate, an unstretched polypropylene substrate, an unstretched polyester substrate, or the like is preferable.

<Laminate>
The laminate in the present invention refers to a laminate having at least base material 1, printed layer and base material 2 in this order and having easy tearability. It is preferable to use a laminate having at least a base material 1, a printed layer, an adhesive layer, and a base material 2 in this order.
The laminate of the present invention is obtained by providing an adhesive layer on a printed layer of a printed material printed with gravure ink, and bonding (laminating) the base material 2 together. A typical example of lamination processing is a dry lamination method or the like. The dry lamination method is a method in which an adhesive is applied onto a printed layer of a printed matter, dried, and pressed against a sealant for lamination.

<Adhesive layer>
The adhesive layer is obtained by applying an adhesive and drying it. As the adhesive, a two-liquid type adhesive comprising a mixture of a polyol and an isocyanate curing agent is suitable, and examples of the polyol include polyester-based and polyether-based adhesives. Specific examples include TM-250HV/CAT-RT86L-60, TM-550/CAT-RT37, TM-314/CAT-14B manufactured by Toyo-Morton Co., Ltd.

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 % in the present invention represent parts by mass and % by mass unless otherwise specified.

(hydroxyl value)
It was obtained according to JISK0070.
(acid number)
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)
The weight-average molecular weight was obtained by measuring the molecular weight distribution using a GPC (gel permeation chromatography) device (HLC-8220 manufactured by Tosoh Corporation) and obtaining the converted molecular weight using polystyrene as a standard substance. 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) [Polyurethane resin PU1]
90.0 parts of polyester polyol (hereinafter "MPD/SA"), which is a condensate of methylpentanediol (MPD) and sebacic acid (SA) having a number average molecular weight of 2000, polypropylene glycol having a number average molecular weight of 1000 (hereinafter "PPG" ), 1.0 parts of 1,4-butanediol (hereinafter “1,4-BD”), and 30.9 parts of isophorone diisocyanate (hereinafter “IPDI”) are reacted at 110° C. for 4 hours in a nitrogen atmosphere. , to obtain an isocyanate-terminated urethane prepolymer. Then, to 14.5 parts of isophoronediamine (hereinafter "IPDA") and 1.0 part of dibutylamine (hereinafter "DBA"), the resulting isocyanate-terminated urethane prepolymer was gradually added at 40°C, and then at 80°C. After reacting for 1 hour, a polyurethane resin solution PU1 having a solid content of 30%, an amine value of 4.0 mgKOH/g, a hydroxyl value of 0 mgKOH/g and a weight average molecular weight of 48,000 was obtained.

(Synthesis Examples 2-4) [Polyurethane Resins PU2-PU4]
Polyurethane resin solutions PU2 to PU4 were obtained in the same manner as in Synthesis Example 1 using the raw materials shown in Table 1. Abbreviations in Table 1 are as follows.
・MPD/AA: polyester polyol which is a condensation product of methylpentanediol and adipic acid, number average molecular weight 2000
・AEA: 2-(2-aminoethylamino) ethanol

(Comparative Synthesis Example 1) [Polyurethane Resin PU5]
A polyurethane resin solution PU5 was obtained in the same manner as in Synthesis Example 1 using the raw materials shown in Table 1.

(Example 1) [Preparation of gravure ink S1]
20 parts by mass of polyurethane resin solution PU1 (solid content 30%), vinyl chloride copolymer resin (Solbin TA5R: manufactured by Nissin Chemical Industry Co., Ltd., vinyl chloride: vinyl acetate: vinyl alcohol = 88: 1: 11 (solid content 30% acetic acid Ethyl solution)) 20 parts by mass, C.I. I. Pigment Blue 15:3 (product name: LIONOL BLUE FG-7330 manufactured by Toyocolor Co., Ltd.) 10 parts by weight, chelate cross-linking agent (titanium acetylacetonate, solid content 40% by weight ethyl acetate solution) 0.5 parts by weight, n- 48.5 parts by mass of a mixed solvent of propyl acetate (NPAC)/isopropanol (IPA) = 70/30 was mixed and dispersed for 20 minutes with an Eiger mill. Compound (trifunctional isocyanate group, solid content: 65% by mass) was mixed to obtain gravure ink S1. In addition, 5 parts by mass of the adduct isocyanate compound was added and used immediately before printing.

(Examples 2 to 15) [Preparation of gravure inks S2 to S15]
Gravure inks S2 to S15 were obtained in the same manner as in Example 1, except that the raw materials shown in Table 2 were used. In addition, the abbreviations in Table 2 represent the following.
Solbin CL: vinyl chloride: vinyl acetate = 86:14 (manufactured by Nisshin Chemical Co., Ltd.) solid content 30% ethyl acetate solution Aluminum acetylacetonate (solid content 40% by mass ethyl acetate solution)
・ Biuret-based isocyanate compound (biuret body obtained from the reaction of 1 mol of water and 3 mol of diisocyanate, isocyanate group bifunctional, solid content 65% by mass, manufactured by Asahi Kasei Co., Ltd. Duranate 24A-100)
- Isocyanurate-based isocyanate compound (isocyanurate compound obtained by cyclization of 3 moles of diisocyanate, isocyanate group trifunctional, solid content 65% by mass, manufactured by Asahi Kasei Corporation Duranate TPA-100)
・IPDI: isophorone diisocyanate

(Comparative Examples 1 to 7) [Preparation of gravure inks T1 to T7]
Gravure inks T1 to T7 were obtained in the same manner as described in Examples 1 to 15 above, except that the raw materials shown in Table 3 were used.

<Printing with gravure ink>
The gravure inks S1-15 and T1-7 obtained above were mixed with a mixed solvent (methyl ethyl ketone “MEK”: N propyl acetate “NPAC”: isopropanol “IPA” = 30:40:30) to reduce the viscosity to 16 seconds (25 ° C., Zahn Cup No. 3), and a polyester base material (Tech Barrier VX, Mitsubishi Chemical Co., Ltd. 12 μm in thickness) was printed at a printing speed of 100 m/min to obtain prints SS1 to SS15 and TT1 to TT7.

<Dry lamination processing>
A polyester urethane laminate adhesive (TM-550/CAT-RT37 manufactured by Toyo-Morton Co., Ltd.) was applied to the printed surface of printed materials SS1 to 15 and TT1 to 7 with an ethyl acetate solution having a solid content of 30%, and the adhesive layer after drying was applied. After coating and drying to 3.0 g/m ² , unstretched polyethylene (PE) with a thickness of 50 μm is attached to the adhesive layer and dry lamination is performed to obtain laminates SL1 to 15 and TL1 to 7. got

<Evaluation>
The gravure inks, prints and laminates of Examples and Comparative Examples were used for the following evaluations. Tables 2 and 3 show the results.

<Tearability>
Samples were prepared according to JISK7128-1:1998 for laminates SL1 to 15 and TL1 to TL7, 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)
In addition, the evaluations that are practically possible are A, B, and C.

<Laminate strength>
After 48 hours at 40° C. for the laminates SL1-15 and TL1-7, the printed portion was cut to a width of 15 mm, the ink surface and the substrate surface were peeled off, and the peel strength (laminate strength) was measured by Intesco. It was measured with a 201 Universal Tensile Tester manufactured by Co., Ltd.
[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)
In addition, the evaluations that are practically possible are A, B, and C.

<Blocking resistance>
For printed materials SS1 to 15 and TT1 to TT7, the corona discharge treated surface and the printed layer surface of a polyester base material (Techbarrier VX, manufactured by Mitsubishi Chemical Corporation, thickness 12 μm) provided with a transparent deposition layer were heated at 40° C. and 5 kg/ The behavior of the surface of the printed layer was evaluated when it was pressed for 24 hours under the conditions of cm2 and then peeled off.
[Evaluation criteria]
A: No peeling and no resistance felt (good)
B: Although there is no peeling, resistance is felt (slightly good)
C: Thin peeling of less than 20% (practical)
D: 20% or more thin peeling and/or thick peeling (slightly poor)
E: 50% or more peeling (defective)
In addition, the evaluations that are practically possible are A, B, and C.

<Two liquid stability>
Gravure inks S1 to 15 and T1 to 7 were allowed to stand at 25°C for 1 day, and the viscosity measurement data was measured according to the elapsed time using a Zahn cup manufactured by Rigosha. was evaluated for storage stability.
[Evaluation criteria]
A: The change in viscosity over time is less than 1.2 times that immediately after finishing. (Good)
B: The change in viscosity over time is 1.2 to less than 1.5 times that immediately after finishing. (somewhat good)
C: The change in viscosity over time is 1.5 times to less than 2 times that immediately after finishing. (Practical)
D: The change in viscosity over time is at least twice that immediately after finishing. (somewhat bad)
E: Separation/precipitation/separation occurs. (defective)
In addition, the evaluations that are practically possible are A, B, and C.

The gravure ink for easily tearable laminates of the present invention can be applied to packaging bags that require easy tearability, such as liquid sachets and boil/retort packaging materials.

Claims (9)

A gravure ink for a laminate containing a pigment, a polyurethane resin, a vinyl chloride copolymer resin, a chelate cross-linking agent, an isocyanate curing agent, and an organic solvent,
Laminate in which the polyurethane resin and/or vinyl chloride copolymer resin has an active hydrogen group capable of reacting with the chelate cross-linking agent, and the mass ratio of the chelate cross-linking agent to the isocyanate curing agent is 1:2 to 1:25. Gravure ink for laminates. 2. The gravure ink for laminate according to claim 1, wherein the polyurethane resin has an amine value and/or a hydroxyl value, the amine value being 1 to 15 mgKOH/g, and the hydroxyl value being 1 to 20 mg/KOHg. . 3. The gravure ink for laminate laminates according to claim 1, wherein the vinyl chloride copolymer resin has a hydroxyl group. The gravure ink for laminate laminates according to any one of claims 1 to 3, wherein the chelate cross-linking agent contains a titanium chelate. The gravure ink for a laminated laminate according to any one of claims 1 to 4, wherein the isocyanate curing agent contains at least one selected from the group consisting of a biuret isocyanate compound, an isocyanurate isocyanate compound and an adduct isocyanate compound. The laminate according to any one of claims 1 to 5, wherein the total mass of the chelate cross-linking agent and the isocyanate curing agent is 3 to 40 mass% with respect to the total 100 mass% of the polyurethane resin and the vinyl chloride copolymer resin. Gravure ink for laminates. The gravure ink for laminate laminates according to any one of claims 1 to 6 , wherein the pigment contains an organic pigment. A printed matter having a print layer formed on a base material 1 with the gravure ink for a laminated laminate according to any one of claims 1 to 7 . A laminated laminate comprising a base material 1, a print layer made of the gravure ink for laminate laminate according to any one of claims 1 to 7 , an adhesive layer, and a base material 2 in this order.