TWI641662B - Water-based liquid ink, flexible ink, gravure ink and printed matter - Google Patents

Abstract

An object of the present invention is to provide an aqueous liquid printing ink adhesive that can be used for an aqueous liquid printing ink that has good adhesion to a substrate, anti-blocking properties, and good re-solubility of the printing ink; and an adhesive containing the same Water-based liquid ink composition.

As a solution, it can be an aqueous liquid printing ink adhesive, which is an aqueous liquid printing ink adhesive containing a urethane resin (A) and an aqueous medium (B), wherein the amino formic acid is The ester resin (A) is a polyalcohol (a1) containing a polyalcohol (a1-1) having an acid group, a polyether polyalcohol (a1-2) other than the polyalcohol (a1-1), and a polyisocyanate ( The reactant of a2), wherein the acid group of the urethane resin (A) can be neutralized by a metal salt, and the urethane resin (A) is relative to the urethane The resin (A) contains the entire alicyclic structure in the range of 1000 to 5000 mmol / kg.

Description

Water-based liquid ink, flexible ink, gravure ink and printed matter

The present invention relates to a resin adhesive for aqueous liquid printing inks and an aqueous liquid printing ink composition that can be used in aqueous gravure printing and aqueous flexogrophy.

Water-based gravure printing and water-based elastic printing are widely used for the purpose of imparting beauty and functionality to a printed object.

In recent years, in the printing ink industry, based on the sustainability perspective based on the global expansion of global pollution, such as deterioration of air pollution caused by VOCs contained in solvent-based printing inks, and global warming, coupled with occupations From the viewpoint of safety, health, and even flammability and explosiveness, and there are actions to convert to petroleum resources, the regulations on the use of organic solvents have become increasingly strict.

In addition, due to the increase in population, rising income levels, and changes in logistics systems, the global consumption of film packaging is increasing, and the output of packaging inks is increasing year by year.

For film packaging printing, solvent-based flexible printing inks and solvent-based gravure printing inks have been mainly used in the past. However, due to changes in environmental awareness shown above, in recent years, water-based printing inks that have replaced organic solvents in printing inks with water have been carried out. The development of high-quality liquid inks is underway.

However, when the aqueous liquid ink is compared with the solvent-based liquid ink, it has the advantages of adhesion to the film, anti-blocking with the overlapping transfer of the printed pattern, and long-term printing ( In long-run printing), the so-called "printing ink resolubility" that reduces the dirt caused by printing ink drying on the plate requires further improvement in function. The current status of water-based liquid printing ink is not correct. These have gained sufficient awareness and fail to anticipate faster penetration.

As an example of a surface printing water-based ink composition for packaging, the invention has been completed in which a polyhydrazine compound and a polyamine compound other than the polyhydrazine compound are reacted in an isocyanate group-containing polymer, and ammonia water is included. The deionized water is used to neutralize the organic solvent solution of the obtained polyurethane resin, and the water-soluble aqueous polyurethane resin is used as a binder. However, even if the adhesiveness and anti-caking property of the film can be maintained, it cannot be said that the re-solubility is sufficient. In particular, it cannot be called a so-called long-print-resistant printer (for example, Patent Document 1: JP-A-8) -053641).

In addition, although the invention has completed the invention of a water-based printing ink composition using a layer of a water-based aqueous polyurethane resin, the water-based polyurethane resin is an organic diisocyanate compound containing a specific Polycarbonate diol is obtained by reacting a high molecular weight diol compound and a chain extender, and then water and trimethylamine are added to form an aqueous solution. However, it is not an invention that takes into account anti-caking properties and redissolution ( For example, Patent Document 2: Japanese Patent Application Laid-Open No. 5-171091).

In order to make water-based liquid printing inks with a choice of global environment, operating environment, and cost more popular, it is desirable to maintain the adhesion to the substrate and overcome the trade-off relationship between the improvement of anti-caking properties and the improvement of resolubility. -off) Development of higher-quality adhesives for aqueous liquid printing inks.

Advance technical literature Patent literature

Patent Document 1 JP-A-8-053641

Patent Document 2 Japanese Unexamined Patent Publication No. 5-171091

The problem to be solved by the present invention is to provide an aqueous liquid printing ink adhesive which can be used for an aqueous liquid printing ink which has good adhesion to a substrate, anti-blocking property, and good re-solubility of the printing ink, and contains the same. The adhesive is an aqueous liquid ink composition.

As a result of intensive research by the present inventors in order to solve the above-mentioned problems, they have found that it is possible to use an aqueous liquid printing ink containing a urethane resin containing an acid group which has been neutralized by a metal salt with a urethane resin With the use of an adhesive, the foregoing problems are solved and the present invention has been completed.

That is, the present invention relates to an aqueous liquid printing ink adhesive, which is an aqueous liquid printing ink adhesive containing a urethane resin (A) and an aqueous medium (B), wherein the amino formic acid is The ester resin (A) belongs to: a polyalcohol (a1) containing a polyalcohol (a1-1) having an acid group, a polyether polyalcohol (a1-2) other than the aforementioned polyalcohol (a1-1); and a polyisocyanate ( The reactant of a2), wherein the acid group of the urethane resin (A) is neutralized by a metal salt, and the urethane resin (A) contains An alicyclic structure in which the resin (A) is all in a range of 1000 to 5000 mmol / kg; and an aqueous liquid ink composition containing the aforementioned binder.

The present invention relates to an adhesive for aqueous liquid printing inks, wherein the urethane resin (A) has an acid value in the range of 10 to 50.

In addition, the present invention relates to an adhesive for aqueous liquid printing inks, in which the aforementioned polyol (a1) further contains 0-20% by mass of a polyol (a1-3) having an alicyclic structure.

In addition, the present invention relates to an aqueous liquid printing ink, which contains the binder for aqueous liquid printing ink, pigment, and aqueous liquid printing ink containing water, and is characterized in that the surface tension at 25 ° C is 25 to 50 mN / m .

The present invention relates to a printed matter, which is characterized in that elastic printing can be performed by using the above-mentioned aqueous liquid printing ink.

The present invention also relates to a printed matter, which is characterized in that gravure printing can be performed with the aqueous liquid printing ink.

According to the adhesive for aqueous liquid printing inks of the present invention, it is possible to obtain an aqueous liquid printing ink with good adhesion to a substrate, anti-blocking properties, and re-solubility of the printing ink.

The adhesive for aqueous liquid printing inks of the present invention is characterized by containing a urethane resin (A) and an aqueous medium (B).

As the urethane resin (A), for example, a polyether polyol (a1-2) containing a polyalcohol (a1-1) having an acid group and a polyether polyalcohol (a1-2) other than the polyalcohol (a1-1) can be used. Polyol (a1) and polyisocyanate (a2) are obtained by reaction.

Examples of the polyalcohol (a1-1) having an acid group include a polyalcohol having a carboxyl group and a polyalcohol having a sulfonic acid group.

Examples of the polyol having a carboxyl group include 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, and 2,2-dimethylolvaleric acid. Among these, 2,2-dimethylolpropionic acid and 2,2-dimethylolbutyric acid which are excellent in dispersion stability are particularly preferable. In addition, a polyester polyol having a carboxyl group obtained by reacting the polyol having a carboxyl group with various polycarboxylic acids can also be used. These polyalcohols having a carboxyl group can be used alone or in combination of two or more kinds.

Examples of the polyhydric alcohol having a sulfonic acid group include 5-sulfonic acid isophthalic acid, sulfonic acid terephthalic acid, 4-sulfonic acid phthalic acid, and 5- (4-sulfonic acid group). (Phenoxy) isophthalic acid and other dicarboxylic acids or their salts, and ethylene glycol and propylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, neopentyl glycol, etc. A polyester polyol obtained by reacting a low molecular weight polyol. These polysulfonic alcohols can be used alone or in combination of two or more.

The polyhydric alcohol (a1-1) having an acid group is preferably used in a range of 10 to 50, and more preferably in a range of 10 to 35. . In addition, the so-called acid value in the present invention is calculated based on the amount of acid group-containing compounds such as the polyhydric alcohol (a1-1) having an acid group used in the production of the urethane resin (A). Theoretical value.

The aforementioned acid group is capable of neutralizing a part or all of them by metal ions such as sodium, potassium, calcium, copper, lithium and the like to form a metal salt, and is preferable because it exhibits good water dispersibility. The neutralization ratio is preferably in the range of 30 to 130%, and more preferably in the range of 50 to 100%.

Metal ions such as sodium, potassium, calcium, copper, and lithium that can be used to neutralize the aforementioned acid groups can be obtained from metal hydroxides such as sodium hydroxide, potassium hydroxide, lithium hydroxide, and chlorinated Metal chlorides such as sodium and potassium chloride, and metal sulfides such as copper sulfate.

Examples of the polyether polyol (a1-2) include a product obtained by addition polymerization of an alkylene oxide using one or two or more compounds having two or more active hydrogen atoms as a starter.

Examples of the initiator include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, trimethylene glycol, 1,3-butanediol, 1,4-butanediol, and 1,6 -Hexanediol, bisphenol A, glycerol, trimethylolethane, trimethylolpropane and the like.

Examples of the alkylene oxide include ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, and tetrahydrofuran.

As the aforementioned polyetherpolyol, it is preferable to use a substance having a number average molecular weight of 500 to 3,000 because it has good compatibility with pigments and the like used in printing inks.

In addition, as the polyalcohol (a1), in addition to the polyalcohol, a polyalcohol (a1-3) having an alicyclic structure can be used.

Examples of the polyalcohol (a1-3) having an alicyclic structure include cyclobutanediol, cyclopentanediol, 1,4-cyclohexanediol, cycloheptanediol, cyclooctanediol, and cyclohexane. Alkylenedimethanol, hydroxypropylcyclohexanol, dicyclohexanediol, butylcyclohexanediol, 1,1'-bicyclohexylene glycol, cyclohexanetriol, hydrogenated bisphenol A, 1,3- Low molecular weight alicyclic structure polyalcohols, such as adamantanediol, with about 100 ~ 500. These polyols having an alicyclic structure can also be used alone or in combination of two or more.

Moreover, since the said polyhydric alcohol (a1-3) is used in the range of 0-20 mass% of the whole amount of the said polyhydric alcohol (a1), it is preferable that the agglomeration of a printed matter can be suppressed.

Examples of the polyisocyanate (a2) capable of reacting with the aforementioned polyol (a1) include 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, and carbodiimide modification. Diphenylmethane diisocyanate, crude diphenylmethane diisocyanate, crude diphenylmethane diisocyanate, phenylene diisocyanate, tolyl diisocyanate, naphthyl diisocyanate, xylylene diisocyanate, tetramethylxylylene Aromatic polyisocyanates such as diisocyanates; aliphatic polyisocyanates such as hexamethylene diisocyanates and lysine diisocyanates; cyclohexane diisocyanates, hydrogenated xylylene diisocyanates, isophorone diisocyanates, Polyisocyanate having an alicyclic structure, such as dicyclohexylmethane diisocyanate. These polyisocyanates (a2) can also be used individually or in combination of 2 or more types.

As a method for producing the urethane resin (A) obtained by reacting the above-mentioned polyol (a1) and the above-mentioned polyisocyanate (a2), for example, the above-mentioned polyol can be mixed without a solvent or in the presence of an organic solvent. (a1) and the above-mentioned polyisocyanate (a2), and a method of performing a reaction in a range of a reaction temperature of about 50 ° C to 150 ° C.

The reaction between the polyalcohol (a1) and the polyisocyanate (a2) is preferably, for example, in a range of 0.8 to 2.5 based on the equivalent ratio of isocyanate groups of the polyisocyanate (a2) to the hydroxyl group of the polyalcohol (a1). It is more preferable to perform it in the range of 0.9 to 1.5.

Moreover, as said urethane resin (A), since the blocking of a printed matter can be suppressed, it is preferable to use the thing which has an alicyclic structure.

Examples of the alicyclic structure include a cyclobutyl ring, a cyclopentyl ring, a cyclohexyl ring, a cycloheptyl ring, a cyclooctyl ring, a propylcyclohexyl ring, and a tricyclo [5.2.1.0.2.6] decane Base skeleton, bicyclo [4.3.0] -nonyl skeleton, tricyclic [5.3.1.1] dodecyl skeleton, propyltricyclo [5.3.1.1] dodecyl skeleton, Ene skeleton, isofluorenyl skeleton, dicyclopentyl skeleton, adamantyl skeleton, and the like. Among these, a cyclohexyl ring structure is particularly preferable.

Since the alicyclic structure has a range of 1000 mmol / kg to 5000 mmol / kg with respect to all of the urethane resin (A), it is preferable that agglomeration of printed matter can be suppressed.

Among these, a range of 1000 mmol / kg to 4000 mmol / kg is particularly preferable. Furthermore, it is more preferably in a range of 1000 mmol / kg to 3000 mmol / kg, and a printing ink having very good resolubility and blocking resistance can be obtained.

In addition, the calculation method refers to the total mol of the alicyclic structure bound to the solid content of 1 kg of the urethane resin.

The alicyclic structure is preferably an alicyclic structure containing a polyol derived from an alicyclic structure that can be used as the polyalcohol (a1) that can be used in the production of the urethane resin (A). It is not necessary that all of them are derived from a polyalcohol having an alicyclic structure, and a part of them may be derived from a polyisocyanate containing an alicyclic structure such as isophorone diisocyanate.

The ratio of the alicyclic structure contained in the urethane resin (A) to the entire urethane resin (A) according to the present invention is based on the urethane resin. The total mass of all raw materials such as the polyol (a1) and polyisocyanate (a2) used in the production of (A), and the alicyclic structure-containing compound used in the production of the aforementioned urethane resin (A) Calculated value of the amount of alicyclic structure.

Moreover, when manufacturing the said urethane resin (A), a chain extender can be used as needed.

Examples of the chain extender include polyamines, hydrazine compounds, and other compounds having an active hydrogen atom. These chain extenders can also be used alone or in combination of two or more.

Examples of the polyamine include ethylenediamine, 1,2-propanediamine, 1,6-hexamethylenediamine, and piperazine. 2,5-dimethylpiperazine , Isophorone diamine, 4,4'-dicyclohexylmethanediamine, 3,3'-dimethyl-4,4'-dicyclohexylmethanediamine, 1,4-cyclohexanediamine And other diamines; N-hydroxymethylaminoethylamine, N-hydroxyethylaminoethylamine, N-hydroxypropylaminopropylamine, N-ethylaminoethylamine, N-methylaminopropylamine, diethylenetriamine, Dipropylene triamine, triethylenetetramine, etc. Among these, ethylenediamine is particularly preferable.

Examples of the hydrazine compound include hydrazine, N, N'-dimethylhydrazine, 1,6-hexamethylenebishydrazine, succinic acid dihydrazine, adipic acid dihydrazine, and glutaric acid dihydrazine. Hydrazine, hydrazine sebacate, hydrazine isophthalate, β-aminoureapropionate hydrazine, 3-aminourea-propyl-hydrazine formate, aminourea-3-aminourea Methyl-3,5,5-trimethylcyclohexane and the like.

Examples of the other compounds having active hydrogen include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, Diols such as hexamethylene glycol, sucrose, methylene glycol, glycerol, sorbitol, etc .; bisphenol A, 4,4'-dihydroxydiphenyl, 4,4'-dihydroxydiphenyl Ether, 4,4'-dihydroxydiphenylhydrazone, hydrogenated bisphenol A, phenol such as hydroquinone, water and the like.

When a polyamine is used as the aforementioned chain extender, the equivalent ratio of the amine group and the isocyanate group of the polyamine [amine group / isocyanate group] is preferably 1.2 or less, and more preferably in the range of 0.3 to 1.

Examples of the organic solvent that can be used in the production of the urethane resin (A) include ketone solvents such as acetone and methyl ethyl ketone; ether solvents such as tetrahydrofuran and dioxane; ethyl acetate, Acetate solvents such as butyl acetate; nitrile solvents such as acetonitrile; acetamide solvents such as dimethylformamide and N-methylpyrrolidone. These organic solvents can be used alone or in combination of two or more.

In addition, in order to reduce the burden on safety and the environment, the organic solvent may be partially or completely removed by, for example, reduced pressure distillation during or after the production of the urethane resin (A). Organic solvents.

For the urethane resin (A) obtained by the aforementioned method, in order to exhibit the durability of the printed matter, it is preferable to use a substance having a weight average molecular weight in the range of 5,000 to 500,000, and more preferably to use a resin having a weight average molecular weight in the range of 5,000 to 200,000. The weight average molecular weight is more preferably a weight average molecular weight in the range of 20,000 to 100,000.

In addition, the measurement of the weight average molecular weight (polystyrene equivalent) by GPC (colloidal permeation chromatography) of the present invention was performed using the HLC8220 system manufactured by Tosoh Corporation under the following conditions.

Separation column: Four TSKgelGMHHR-N manufactured by Tosoh Corporation. Column temperature: 40 ° C. Moving layer: Tetrahydrofuran manufactured by Wako Pure Chemical Industries, Ltd. Flow rate: 1.0 ml / min. Sample concentration: 0.4% by mass. Sample injection volume: 100 microliters. Detector: Differential refractometer.

When the aforementioned weight-average molecular weight is less than 5,000, not only the durability of the printed matter is reduced, but various problems such as agglomeration due to poor drying may occur, and when the molecular weight is greater than 500,000, poor transfer and reprinting of the printing ink may easily occur. Problems such as a decrease in solubility.

Moreover, the hydration of the urethane resin (A) manufactured by the said method can be performed by the following method, for example.

[Method 1] After neutralizing a part or all of the acid groups of the aqueous urethane resin obtained by reacting the polyol (a1) and the polyisocyanate (a2), the aqueous medium (B) is charged and dispersed in water, and then borrowed A method of dispersing the urethane resin (A) in water by performing chain extension using the aforementioned chain extender.

[Method 2] The water-based urethane resin obtained by reacting the polyalcohol (a1) and the polyisocyanate (a2), and the same chain extender as described above, are placed in a reaction vessel together or in batches, and the chain The reaction is prolonged to produce a urethane resin (A), and then a part or all of the acid groups in the obtained urethane resin (A) are neutralized, and then the aqueous medium (B) is charged and a water dispersion method is performed. .

In the aforementioned [Method 1] to [Method 2], an emulsifier may be used as necessary. When water is dissolved or dispersed, a machine such as a homogenizer may be used as necessary.

Examples of the aqueous medium (B) include water, organic solvents mixed with water, and mixtures thereof. Examples of the organic solvent mixed with water include alcohol solvents such as methanol, ethanol, n-propanol, and isopropanol; ketone solvents such as acetone and methyl ethyl ketone; ethylene glycol, diethylene glycol, and propylene glycol. Polyalkylene glycols; alkyl ethers of polyalkylene glycols; L-amine solvents such as N-methyl-2-pyrrolidone. In the present invention, only water may be used, or a mixture of water and an organic solvent mixed with water may be used, or only an organic solvent mixed with water may be used.

In addition, as the aqueous medium (B), from the viewpoints of safety and environmental burden, it is preferable to use only water or a mixture of water and an organic solvent mixed with water, and particularly preferably only water.

Examples of the emulsifier include polyoxyethyl nonyl ether, polyoxy ethyl lauryl ether, polyoxy ethyl styryl phenyl ether, and polyoxy ethyl sorbitol tetraoleate. And non-ionic emulsifiers such as polyoxyethylene and polyoxypropylene copolymers; fatty acid salts such as sodium oleate, alkyl sulfate salts, alkyl benzene sulfonates, alkyl sulfosuccinates, and naphthalene sulfonates Anionic emulsifiers such as acid salts, polyoxyethylene alkyl sulfates, sodium alkane sulfonates, sodium diphenyl ether sulfonates; alkyl amine salts, alkyl trimethyl ammonium salts, alkyl di Cationic emulsifiers such as methyl benzyl ammonium salts. Among these, an anionic or nonionic emulsifier is preferable from the viewpoint of maintaining good storage stability of the aqueous elastic printing ink of the present invention.

The aqueous liquid printing ink adhesive of the present invention, in which the urethane resin (A) obtained in the foregoing method has been dispersed in an aqueous medium (B), contains 20 to 30% of the solid content of the entire aqueous liquid printing ink. The aforementioned urethane resin (A) in a range of 75% by mass preferably contains a range of 10 to 50% by mass with respect to the entire aqueous liquid ink. In addition to containing the aforementioned urethane resin (A) in a range of 20 to 75% by mass with respect to the solid content of all aqueous liquid inks, the adhesiveness to the substrate is improved, and relative to all aqueous liquid inks. The printing ink contains a range of 10 to 50% by mass, which is beneficial to the resolubility of the water-based printing ink during printing, the suppression of agglomeration of printed matter, and the improvement of printing density.

As the other resin that can be blended with the aqueous liquid ink binder of the present invention, an aqueous or water-dispersible resin is preferable, and an acid value of 5 to 150 mgKOH / g is particularly preferable. Examples include acrylic resin, Styrene-acrylic resin, maleic acid resin, styrene-maleic acid resin, α-olefin-maleic acid resin, ester resin, sulfonic acid resin, phosphoric acid resin, and the like. Among these, a styrene-maleic acid copolymer is preferable. In addition, if the styrene-maleic acid copolymer is exemplified, the addition amount thereof is preferably 1 to 10% by mass of the entire liquid printing ink. In addition, some of the resins described above may function as a pigment dispersant.

Examples of the pigment used in the aqueous liquid printing ink using the aqueous liquid printing ink binder according to the present invention include organic and inorganic pigments and dyes currently used in printing inks, coatings, and recording agents.

Examples of the organic pigment include azo-based, phthalocyanine-based, anthraquinone-based, fluorene-based, violone-based, quinacridone-based, thioindigo-based, and Based, isoindolinone based, quinoline yellow based, azomethine azo based, diketopyrrolopyrrole based, isoindoleline based pigments and the like. From the viewpoint of cost and light resistance, it is preferable to use copper phthalocyanine for blue printing ink and CIPigment No Yellow83 for transparent yellow printing ink.

Examples of the inorganic pigment include carbon black, titanium oxide, zinc oxide, zinc sulfide, barium sulfate, calcium carbonate, chromium oxide, silicon oxide, iron oxide red, aluminum, and mica. When a glass flake or a bulk flake is used as a base material, a glittering pigment (Metashine; Nihon Itachi Glass Co., Ltd.) coated with a metal or a metal oxide can be used. From the viewpoint of cost and tinting power, it is preferable to use titanium oxide for white printing inks, carbon black for black printing inks, aluminum for gold, silver printing inks, and mica for pearl printing inks. Although aluminum is powder or paste, it is preferably used in paste form from the viewpoint of handleability and safety. Using floating or non-leafing, it can be considered from the viewpoint of brightness and concentration. Appropriately selected.

The sum of the aforementioned pigments is in order to ensure a sufficient amount of the concentration and coloring power of the printing ink, that is, it is preferably a ratio of 1 to 50% by mass relative to the total weight of the printing ink. Moreover, a coloring agent can also be used individually or in combination of 2 or more types.

The aqueous liquid printing ink using the aqueous liquid printing ink binder of the present invention can further use a solvent and an auxiliary agent according to other purposes.

As the solvent, only water or an organic solvent mixed with water can be used. Examples of the organic solvent include alcohols such as methanol, ethanol, isopropanol, and n-propanol; polyols such as propylene glycol and glycerol; propylene glycol monomethyl ether, propylene glycol monoethyl ether, and propylene glycol mono-n-butyl alcohol. Ethers such as propyl ether and ethyl carbitol.

In addition, as other auxiliary components, waxes such as linear paraffin waxes, polyethylene waxes, carnauba waxes, ammonium oleate, and stearic acid for the purpose of imparting friction resistance and slip resistance can also be suitably used. Fatty acid amines such as fluoramine and erucamide, silicon-based, non-silica-based defoamers to suppress foaming during printing, and various dispersants to increase the wetting of pigments.

The water-based printing ink composition related to the present invention is an Eiger Mill, a sand mill, a Gamma Mill, and a mill which are generally used in the manufacture of gravure and elastic printing inks. Machine (attritor).

The water-based liquid printing ink obtained by using the water-based liquid printing ink adhesive of the present invention, when used as a water-based elastic printing ink, has a viscosity of 7 to 25 at 25 ° C using a Zahn cup # 4 manufactured by Clutch Corporation. Seconds, more preferably 10-20 seconds. The surface tension of the obtained water-based elastic printing ink at 25 ° C. is preferably 25 to 50 mN / m, and more preferably 33 to 43 mN / m. Although the lower the surface tension of the ink, the better the ink wettability of the film and other substrates. However, if the surface tension is less than 25mN / m, the ink wetting expands, and the dots in the middle color area have dots. The tendency to connect with each other easily causes the cause of contamination of the printing surface called a dot bridge. In addition, if the surface tension is more than 50 mN / m, the wettability of the printing ink to a substrate such as a film is reduced, and a cause of shrinkage cracking (cissing) is likely to occur.

In addition, when used as a water-based gravure printing ink, the viscosity is 7-25 seconds, more preferably 10-20 seconds at 25 ° C using a viscosity cup Zahn cup # 3 manufactured by Clutch Corporation. The surface tension of the obtained water-based gravure printing ink at 25 ° C. is the same as that of the water-based elastic printing ink, and is preferably 25 to 50 mN / m, and more preferably 33 to 43 mN / m. Although the lower the surface tension of the ink, the better the ink wettability of the film and other substrates. However, if the surface tension is less than 25mN / m, the ink wetting expands, and the dots in the middle color area have dots. The tendency to connect with each other easily causes the cause of contamination of the printing surface called a dot bridge. In addition, if the surface tension is more than 50 mN / m, the wettability of the printing ink to a substrate such as a film is reduced, and a cause of shrinkage cracking is likely to be formed.

The aqueous liquid printing ink obtained by using the aqueous liquid printing ink adhesive of the present invention has good adhesion to various substrates and can be used for printing on paper, synthetic paper, thermoplastic resin films, plastic products, steel plates, and the like.

Examples of the base film include polyamide resins such as Ny6, nylon 66, and nylon 46, PET, polyethylene naphthalate, polytrimethylene terephthalate, and polynaphthalene dicarboxylic acid. Polyester resins such as trimethylene ester, polybutylene terephthalate, polybutylene naphthalate, polyhydroxycarboxylic acids such as polylactic acid, poly (butylene succinate), poly ( Butyl succinate) and other aliphatic polyester resins are representative of biodegradable resins, polyolefin resins such as PP, polyethylene, polyimide resins, polyacrylate resins, or mixtures thereof. Among the films made of thermoplastic resins and such laminates, films made of polyester, polyamide, polyethylene, and polypropylene are preferably used. These substrate films may be unstretched films or stretched films, and the manufacturing method is not limited. In addition, although the thickness of the base film is not particularly limited, it may generally be in the range of 1 to 500 μm.

The printed surface of the base film is preferably subjected to a corona discharge treatment. Alternatively, silicon oxide, aluminum oxide, or the like may be deposited.

Hereinafter, the present invention will be specifically described by way of examples and comparative examples.

[Synthesis Example 1: Preparation of Aqueous Liquid Printing Ink Adhesive (1)]

191 parts by mass of polyoxytetramethylene glycol (molecular weight 2000), 141 parts by mass of isophorone diisocyanate, and 26 parts of a container having a thermometer, a nitrogen introduction tube, and a stirrer which have been replaced by nitrogen. A mass of 2,2-dimethylolpropionic acid and 28 parts by mass of 1,4-cyclohexanedimethanol and 200 parts by mass of methyl ethyl ketone were reacted in a mixed solvent to obtain an amine having an isocyanate group at a molecular terminal. Organic solvent solution of urethane prepolymer.

Next, some or all of the carboxyl groups of the urethane prepolymer were neutralized by adding 20 parts by mass of a 50% potassium hydroxide aqueous solution, and then 700 parts by mass of water and 9.0 parts by mass of 80% were added. The hydrazine aqueous solution was sufficiently stirred to obtain an aqueous dispersion of a urethane resin, and then, aging and solvent removal were performed to obtain a 40% by mass non-volatile component aqueous liquid ink binder (1).

The ratio of the alicyclic structure in the urethane resin of the aqueous liquid ink binder (1) was 2067 mmol / kg, and the acid value was 28.

In addition, the calculation method refers to the total mol of the alicyclic structure placed with respect to the solid content of 1 kg of the urethane resin.

[Synthesis Example 2: Preparation of Adhesive (2) for Aqueous Liquid Printing Ink]

In a container having a thermometer, a nitrogen introduction tube, and a stirrer that has been replaced by nitrogen, 256 parts by mass of polyoxytetramethylene glycol (molecular weight 2000), 102 parts by mass of isophorone diisocyanate, 23 The reaction was performed in a mixed solvent of 2,2-dimethylolpropionic acid, 6.5 parts by mass of neopentyl glycol, and 200 parts by mass of methyl ethyl ketone to obtain an urethane prepolymer having an isocyanate group at a molecular terminal. Polymer in organic solvent solution.

Next, some or all of the carboxyl groups of the urethane prepolymer were neutralized by adding 18 parts by mass of a 50% potassium hydroxide aqueous solution, and then 700 parts by mass of water and 6.5 parts by mass of 80% were added. The hydrazine aqueous solution was sufficiently stirred to obtain an aqueous dispersion of a urethane resin, and then aging and solvent removal were performed to obtain a 40% by mass non-volatile component aqueous liquid ink binder (2).

The ratio of the alicyclic structure in the urethane resin of the aqueous liquid ink binder (2) was 1150 mmol / kg, and the acid value was 25.

[Synthesis Example 3: Preparation of Aqueous Liquid Printing Ink Adhesive (3)]

In a container having a thermometer, a nitrogen introduction tube, and a stirrer that has been replaced by nitrogen, 263 parts by mass of polyoxytetramethylene glycol (molecular weight 2000), 98 parts by mass of isophorone diisocyanate, 22 Part of the reaction was performed in a mixed solvent of 2,2-dimethylolpropionic acid and 5.6 parts by mass of 1,4-cyclohexanedimethanol and 200 parts by mass of methyl ethyl ketone to obtain an amine having an isocyanate group at a molecular terminal. Organic solvent solution of urethane prepolymer.

Next, some or all of the carboxyl groups of the urethane prepolymer were neutralized by adding 17 parts by mass of a 50% potassium hydroxide aqueous solution, and then 700 parts by mass of water and 6.2 parts by mass of 80% were added. The hydrazine aqueous solution was sufficiently stirred to obtain an aqueous dispersion of a urethane resin, and then aging and solvent removal were performed to obtain a 40% by mass non-volatile component aqueous liquid ink binder (3).

The ratio of the alicyclic structure in the urethane resin of the aqueous liquid ink binder (3) was 1198 mmol / kg, and the acid value was 23.

[Synthesis Example 4: Preparation of Aqueous Liquid Printing Ink Adhesive (4)]

In a container having a thermometer, a nitrogen introduction tube, and a stirrer that has been replaced by nitrogen, 250 parts by mass of polyoxytetramethylene glycol (molecular weight 2000), 109 parts by mass of isophorone diisocyanate, 8.6 Part of the reaction was performed in a mixed solvent of 2,2-dimethylolpropionic acid and 26 parts by mass of 1,4-cyclohexanedimethanol and 200 parts by mass of methyl ethyl ketone to obtain an amine having an isocyanate group at the molecular terminal. Organic solvent solution of urethane prepolymer.

Next, 6.8 parts by mass of a 50% potassium hydroxide aqueous solution was added to neutralize some or all of the carboxyl groups of the urethane prepolymer, and then 700 parts by mass of water and 6.9 parts by mass of 80% were added. The hydrazine aqueous solution was sufficiently stirred to obtain an aqueous dispersion of a urethane resin, and then, aging and solvent removal were performed to obtain a 40% by mass non-volatile component aqueous liquid ink binder (4).

The ratio of the alicyclic structure in the urethane resin of the aqueous liquid ink binder (4) was 1671 mmol / kg, and the acid value was 9.

[Synthesis Example 5: Preparation of Aqueous Liquid Printing Ink Adhesive (5)]

In a container having a thermometer, a nitrogen introduction tube, and a stirrer that has been replaced with nitrogen, 113 parts by mass of polyoxytetramethylene glycol (molecular weight 2000), 178 parts by mass of isophorone diisocyanate, 17 A mass of 2,2-dimethylolpropionic acid and 84 parts by mass of 1,4-cyclohexanedimethanol and 200 parts by mass of methyl ethyl ketone were reacted in a mixed solvent to obtain an amine having an isocyanate group at a molecular terminal. Organic solvent solution of urethane prepolymer.

Next, some or all of the carboxyl groups of the urethane prepolymer were neutralized by adding 13 parts by mass of a 50% potassium hydroxide aqueous solution, and then 700 parts by mass of water and 2.2 parts by mass of 80% were added. The hydrazine aqueous solution was sufficiently stirred to obtain an aqueous dispersion of a urethane resin, and then, aging and solvent removal were performed to obtain a 40% by mass non-volatile component aqueous liquid ink binder (5).

The ratio of the alicyclic structure in the urethane resin of the aqueous liquid ink binder (5) was 3459 mmol / kg, and the acid value was 18.

[Comparative Synthesis Example 1: Preparation of Aqueous Liquid Printing Ink Adhesive (6)]

196 parts by mass of polyoxytetramethylene glycol (molecular weight 2000), 145 parts by mass of isophorone diisocyanate, and 26 parts of a container having a thermometer, a nitrogen introduction tube, and a stirrer which have been replaced by nitrogen. Part of the reaction was performed in a mixed solvent of 2,2-dimethylolpropionic acid and 28 parts by mass of 1,4-cyclohexanedimethanol and 200 parts by mass of methyl ethyl ketone to obtain an amine having an isocyanate group at the molecular terminal. Organic solvent solution of urethane prepolymer.

Next, some or all of the carboxyl groups of the urethane prepolymer were neutralized by adding 19 parts by mass of triethylamine, and then 700 parts by mass of water and 9.2 parts by mass of an 80% hydrazine aqueous solution were added and Stir well to obtain an aqueous dispersion of a urethane resin, and then perform curing and solvent removal to obtain a 40% by mass non-volatile component aqueous liquid ink binder (6).

The ratio of the alicyclic structure in the urethane resin of the aqueous liquid ink binder (6) was 2120 mmol / kg, and the acid value was 28.

[Comparative Synthesis Example 2: Preparation of Aqueous Liquid Printing Ink Adhesive (7)]

In a container having a thermometer, a nitrogen introduction tube, and a stirrer that has been replaced by nitrogen, 291 parts by mass of polyoxytetramethylene glycol (molecular weight 2000), 80 parts by mass of isophorone diisocyanate, 16 The reaction was performed in a mixed solvent of 2,2-dimethylolpropionic acid, 4.9 parts by mass of neopentyl glycol, and 200 parts by mass of methyl ethyl ketone to obtain an urethane prepolymer having an isocyanate group at a molecular terminal. Polymer in organic solvent solution.

Next, some or all of the carboxyl groups of the urethane prepolymer were neutralized by adding 13 parts by mass of a 50% potassium hydroxide aqueous solution, and then 700 parts by mass of water and 3.4 parts by mass of 80% were added. The hydrazine aqueous solution was sufficiently stirred to obtain an aqueous dispersion of a urethane resin, and then aging and solvent removal were performed to obtain a 40% by mass non-volatile component aqueous liquid ink binder (7).

The ratio of the alicyclic structure in the urethane resin of the aqueous liquid ink binder (7) was 901 mmol / kg, and the acid value was 17.

[Comparative Synthesis Example 3: Preparation of Aqueous Liquid Printing Ink Adhesive (8)]

196 parts by mass of polyoxytetramethylene glycol (molecular weight 2000), 145 parts by mass of isophorone diisocyanate, and 26 parts of a container having a thermometer, a nitrogen introduction tube, and a stirrer which have been replaced by nitrogen. Part of the reaction was performed in a mixed solvent of 2,2-dimethylolpropionic acid and 28 parts by mass of 1,4-cyclohexanedimethanol and 200 parts by mass of methyl ethyl ketone to obtain an amine having an isocyanate group at the molecular terminal. Organic solvent solution of urethane prepolymer.

Next, some or all of the carboxyl groups of the urethane prepolymer were neutralized by adding 13 parts by mass of a 25% aqueous ammonia solution, and then 700 parts by mass of water and 9.2 parts by mass of an 80% aqueous solution of hydrazine were added. The mixture was sufficiently stirred to obtain an aqueous dispersion of a urethane resin, and then aging and solvent removal were performed to obtain a 40% by mass non-volatile component aqueous liquid ink binder (8).

The ratio of the alicyclic structure in the urethane resin of the aqueous liquid ink binder (8) was 2120 mmol / kg, and the acid value was 28.

[Production of water-based elastic printing ink]

Using each of the adhesives for aqueous liquid printing inks obtained in Synthesis Examples 1 to 5 and Comparative Synthesis Examples 1 to 3, each of the elastic printing inks was thoroughly stirred and mixed with the following composition, and then kneaded with a bead mill to produce kneading. For printing inks, add 10 parts of "Aqueous Liquid Printing Ink Adhesive" and 4 parts of water to the kneading printing inks to make water-based blue elastic printing inks. It was adjusted with water (+ α) so that the viscosity of the obtained elastic printing ink was 16 seconds (25 ° C) when measured with a viscosity cup Zahn cup # 4 (manufactured by Clutch).

In order to determine the surface tension of the obtained elastic printing ink, the surface tension at 25 ° C was measured.

The measurement method of the surface tension was carried out by the Whihelmy method using an automatic surface tension meter DY-300 manufactured by Kyowa Interface Science Co., Ltd.

[Kneading ink blending]

[The total amount of the final water-based blue elastic printing ink (excluding water for viscosity adjustment)]

Using Flexoproof 100 test printing machine (Testing Machines, Inc., anilox 200 lines / inch), Examples 1 to 5 and Comparative Examples 1 to 14 of the above-mentioned adjusted blue elastic printing ink with viscosity adjustment 3 Corona-treated polyethylene terephthalate (PET) film (ESTER E5102 manufactured by Toyobo Co., Ltd., thickness 12 μm) and corona-treated polypropylene (OPP) biaxially stretched film (Toyobo PYLEN P2161 (manufactured by Co., Ltd., thickness 20 μm), a solid line pattern of 240 mm in length × 80 mm in width was printed, and then dried with a dryer to obtain a printed matter.

[Production of water-based gravure printing ink]

Using each of the adhesives for aqueous liquid printing inks obtained in Synthesis Examples 1 to 5 and Comparative Synthesis Examples 1 to 3, each of the gravure printing inks was sufficiently stirred and mixed with the following composition, and then kneaded with a bead mill to prepare a kneading system. For the printing ink, 10 parts of "aqueous liquid printing ink adhesive" and 9 parts of water were further mixed with the kneading printing ink to prepare a water-based blue gravure printing printing ink. It was adjusted with water (+ α) so that the viscosity of the obtained gravure printing ink was 16 seconds (25 ° C) when measured with a viscosity cup Zahn cup # 3 (manufactured by Clutch).

In order to determine the surface tension of the obtained gravure printing ink, the surface tension at 25 ° C was measured.

The measurement method of the surface tension was performed by the Whihelmy method using an automatic surface tension meter DY-300 manufactured by Kyowa Interface Science Co., Ltd.

[Kneading ink blending]

[Total blending amount of final water-based blue gravure printing ink (excluding water for viscosity adjustment)]

Using a gravure correction machine equipped with a gravure having a plate depth of 25 μm, the viscosity-adjusted blue gravure printing inks of Examples 6 to 10 and Comparative Examples 4 to 6 shown in Table 2 were subjected to the same corona as Table 1 Treated polyethylene terephthalate (PET) film (ESTER E5102 manufactured by Toyobo Co., Ltd., 12 μm thick), corona treated polypropylene (OPP) biaxially stretched film (PYLEN P2161 manufactured by Toyobo Co., Ltd., 20μm thick) After printing a solid line pattern of 240 mm in length × 80 mm in width, it was dried with a dryer to obtain a printed matter.

With respect to the obtained elastic printed matter and gravure printed matter, the re-solubility, blocking resistance, and substrate adhesion of each film were evaluated, and the ink transferability was determined by the printing density.

[Assessment item 1: resolubility]

One drop of distilled water was dropped on the ink-film coating surface of the printed matter with a dropper, and wiped with gauze quickly.

After wiping, the time until the coating film was dissolved to disappear was measured and evaluated.

：: After dripping, the coating film was dissolved in less than 3 seconds.

(Circle): After dripping, it melt | dissolved for 3 to 5 seconds.

(Triangle | delta): After dripping, it melt | dissolved for 5 second or more and less than 7 second.

×: It takes 7 seconds or more to dissolve the coating film.

[Evaluation item 2: Anti-caking properties]

Cut a 4cm × 4cm size film, then make the printed surface and non-printed surface of the printed material contact and overlap, apply a load of 5Kgf / cm ² , and leave it at 40 ° C for 12 hours to overlap the transfer area (% ) As a reference, and the state of ink transfer (overlay transfer) to the non-printing surface when the film is peeled off is visually judged.

：: No transfer to non-printed surface was seen at all.

○: Transfer caused by overlapping transfer of less than 5% was seen.

(Triangle | delta): The transfer by overlapping transfer of 5% or more and less than 20% was seen.

×: Migration caused by overlapping transfer of 20% or more was seen.

[Evaluation item 3: Adhesiveness of substrate]

After the printed matter was left for one day, a cellophane tape (12 mm width made by NICHIBAN) was attached to the printing surface, and the remaining ratio of the printing film when the one end of the cellophane tape was quickly peeled off at right angles to the printing surface was expressed in terms of area ratio. Visually judge the appearance by reference.

：: The printing film was not peeled at all.

○: 80% or more to less than 90% of the printed film remained on the film.

△: More than 50% to less than 80% of the printed film remains in the film.

×: Less than 50% of the printed film remained on the film.

[Evaluation item 4: Printing ink transferability]

The solid line density of the printed matter was measured using a SpectroEye densitometer manufactured by X-Rite to evaluate the ink transferability.

○: The blue density of the printed matter is 1.9 or more, and the printability is good.

Δ: The blue density of the printed matter is 1.6 or more and less than 1.9, and the printability is moderate.

×: The blue density of the printed matter was less than 1.6, and the printability was poor.

Table 1 shows the evaluation results of the water-based blue elastic ink.

Table 2 shows the evaluation results of the water-based blue gravure ink.

By adjusting the viscosity of the viscosity cup (Zahn cup), the aqueous liquid printing ink using the water-based liquid printing ink adhesive of the present invention can maintain the adhesion to the substrate even in any of the elastic and gravure printing methods. Printing ink transferability, and can also have anti-caking resistance and printing ink redissolution.

Claims (7)

An aqueous liquid printing ink, which is an aqueous liquid printing ink containing a urethane resin (A) and an aqueous medium (B), wherein the urethane resin (A) belongs to: a polymer containing an acid group An alcohol (a1-1), a polyalcohol (a1) other than the polyalcohol (a1-1), a polyalcohol (a1), and a reactant of a polyisocyanate (a2), characterized in that the amine group The formate resin (A) has an acid group that can be neutralized by a metal salt. The urethane resin (A) contains 1000 to 5000 mmol / kg with respect to the entire urethane resin (A). The alicyclic structure has a surface tension of 25 to 50 mN / m at 25 ° C. For example, the aqueous liquid printing ink of claim 1, wherein the urethane resin (A) has an acid value in the range of 10-50. For example, the aqueous liquid printing ink of claim 1 or 2, wherein the polyol (a1) further contains 0-20% by mass of the polyol (a1-3) having an alicyclic structure. An elastic printing ink, characterized in that it contains an aqueous liquid printing ink according to any one of claims 1 to 3. A gravure printing ink, characterized in that it contains an aqueous liquid printing ink according to any one of claims 1 to 3. A printed matter characterized by being capable of performing flexogrophy using a flexible printing ink as claimed in claim 4. A printed matter characterized by being capable of performing gravure printing by using the gravure printing ink of claim 5.