JP2021008578A - Liquid printing ink and printed matter - Google Patents

Abstract

To provide a liquid printing ink which uses a biomass-derived raw material and is excellent in scratch resistance, oil resistance and printability.SOLUTION: The liquid printing ink contains a polyurethane resin (A) using a polyester polyol as a reaction raw material and a chlorinated polyolefin (B). The polyester polyol is a polyester polyol (A1) using a polycarboxylic acid containing sebacic acid and an aromatic polycarboxylic acid, and a polyol as reaction raw materials. A printed matter has a printed layer printed with the liquid printing ink on a substrate.SELECTED DRAWING: None

Description

The present invention relates to organic solvent type liquid printing inks such as gravure inks and flexographic inks.

Gravure inks and flexographic inks are widely used for the purpose of imparting cosmeticity and functionality to an object to be printed such as a flexible packaging film. In particular, gravure inks and flexo inks using polyurethane resin using polymer diol and diisocyanate as a binder have appropriate polarity and cohesive power, and have solubility in ester / alcohol solvents that affect printability. It is widely used because it can achieve both film properties such as blocking resistance.

When a gravure- or flexographic-printed object is used as a packaging material, especially for foods and sanitary goods, it is printed on the back side that touches the contents to prevent contact with the contents. It is common to use front printing, which prints the design only on the outside of the packaging material, or laminated printing, which is laminated.

In front printing, in which the design is printed only on the outside of the flexible packaging film, the ink film printed on the outside of the flexible packaging film is rubbed directly by an external force or comes into contact with other substances, so the film strength and resistance of the ink itself. Is required. For example, it does not cause scratches even when it comes into contact with other substances (scratch resistance), and even if organic solvents or oils adhere to it or oils in food adhere to it at the packaging stage, the pattern melts or peels off. Oil resistance, etc. is required.
Further, in laminating printing, since the guide roll and the ink film come into direct contact with each other during the laminating process, abrasion resistance at that time is required.

On the other hand, in recent years, with the growing demand for the construction of a recycling-oriented society, it is desired to break away from fossil fuels in the material field as well as energy, and the use of biomass is drawing attention. Biomass is an organic compound photosynthesized from carbon dioxide and water, and by using it, it becomes carbon dioxide and water again, so-called carbon-neutral renewable energy. In recent years, the practical application of biomass plastics made from these biomasses is rapidly progressing.

Sebacic acid is known as a biomass raw material. Examples of the gravure printing ink using sebacic acid include a biomass-derived polyurethane urea resin made from at least one biomass-derived polycarboxylic acid selected from the group consisting of succinic acid, sebacic acid, and dimer acid. , A solvent-type gravure printing ink composition for back printing that mixes and disperses a solution, a coloring material, and a solvent (see, for example, Patent Document 1), and a terminal OH group formed by reacting sebacic acid and a polyol as a polyol component. There is known a gravure printing ink composition for surface printing, which has a polyester polyol having a above-mentioned content and contains a polyurethane resin composed of the polyol component and a polyisocyanate component. (See, for example, Patent Document 2)
However, liquid printing inks using a urethane resin using sebacic acid as a reaction raw material are sometimes inferior in scratch resistance and oil resistance.

JP-A-2018-62642 JP-A-2018-188558

An object to be solved by the present invention is to provide a liquid printing ink which uses a biomass-derived raw material and has excellent scratch resistance, oil resistance, and printability.

The present inventors have developed a scratch-resistant liquid printing ink in which a polyester polyol containing sebacic acid and an aromatic polycarboxylic acid, which are raw materials for biomass, and a polyurethane resin and chlorinated polypropylene using the polyether polyol as a reaction raw material are used in combination. We found that it has an excellent balance of properties, oil resistance, and printability.

In general, urethane resins made from sebacic acid tend to reduce printability. For example, the urethane resin used in the examples of Patent Document 3 may not be an ink that satisfies all of printability, scratch resistance, and oil resistance.

The present inventors use an aromatic polycarboxylic acid as a raw material for a urethane resin in addition to sebacic acid, that is, by containing sebacic acid and an aromatic polycarboxylic acid, desired oil resistance is exhibited, and at the same time, the urethane resin. It has been found that by containing a certain amount of a flexible component such as a polyether polyol as a raw material of the above, it is possible to impart a certain degree of elasticity to the ink film while maintaining oil resistance. Furthermore, by using chlorinated polypropylene in combination, we have found an ink that has an excellent balance of scratch resistance, oil resistance, and printability, which are desired for front printing inks and (back printing) laminate inks.

That is, the present invention is a liquid printing ink containing a polyurethane resin (A) using a polyester polyol as a reaction raw material and a chlorinated polyolefin (B).
Provided is a liquid printing ink in which the polyester polyol is a polyester polyol (A1) containing a polycarboxylic acid containing sebacic acid and an aromatic polycarboxylic acid and a polyol as reaction raw materials.

The present invention also provides a printed matter having a printed layer on which the above-mentioned liquid printing ink is printed on a substrate.

According to the present invention, it is possible to obtain a liquid printing ink having excellent scratch resistance, oil resistance, and printability by using a biomass-derived raw material.

(Definition of words)
In the present invention, the liquid printing ink refers to a liquid ink applied to a printing method using a printing plate, such as a gravure ink or a flexo ink, and is preferably a gravure ink or a flexo ink. Further, the liquid printing ink of the present invention does not contain an active energy curable component, that is, is a liquid ink that is non-reactive with active energy rays.
The "inks" used in the following description all refer to "printing inks". Moreover, all "parts" indicate "mass parts".

(Polyurethane resin (A) using polyester polyol as a reaction raw material)
The polyurethane resin (A) using the polyester polyol used in the present invention as a reaction raw material is a polyurethane resin obtained by reacting a polyol containing at least a polyester polyol with a polyisocyanate.

(Polyester polyol)
The polyester polyol used in the present invention contains a polyester polyol (A1) containing sebacic acid, an aromatic polycarboxylic acid-containing polycarboxylic acid, and a polyol as reaction raw materials as essential components.
The aromatic polycarboxylic acid that is the raw material of the polyester polyol (A1) is not particularly limited, and is, for example, terephthalic acid, isophthalic acid, phthalic acid, naphthalene-2,6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid. , Diphenyl-4,4'-dicarboxylic acid, diphenoxyetanedicarboxylic acid, inden-4,7-dicarboxylic acid, naphthalene-2,5-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, azulene-2,5- Dicarboxylic acid, heptalene-1,7-dicarboxylic acid, biphenylene-1,5-dicarboxylic acid, as-indacene-2,6-dicarboxylic acid, s-indacene-1,7-dicarboxylic acid, acenaphthylene-3,8-dicarboxylic acid Acid, fluorene-1,8-dicarboxylic acid, phenalene-4,8-dicarboxylic acid, phenanthrene-1,6-dicarboxylic acid, anthracene-1,8-dicarboxylic acid, fluoranten-6,7-dicarboxylic acid, acephenant Lilen-3,8-dicarboxylic acid, acetylene-3,7-dicarboxylic acid, triphenylene-2,10-dicarboxylic acid, pyrene-1,6-dicarboxylic acid, chrysen 1,7-dicarboxylic acid, naphthacene-1, 5-dicarboxylic acid, prairanden 2,5-dicarboxylic acid, picene-2,8-dicarboxylic acid, perylene-2,8-dicarboxylic acid, pentaphen-5,11-dicarboxylic acid, pentacene 2,6-dicarboxylic acid, these Examples thereof include alkyl nuclear-substituted carboxylic acids, and aromatic dicarboxylic acids such as these halogen nuclear-substituted carboxylic acids. These may be used alone or in combination.
Among these, phthalic acids, particularly terephthalic acid or isophthalic acid are preferable.

In the polyester polyol (A1), the amount of the aromatic polycarboxylic acid used is preferably 5 to 80% in terms of molar ratio with respect to the total amount of the polycarboxylic acid, more preferably 10 to 70%, and most preferably. Is 10 to 60%. The aromatic ring group concentration (mol / g) with respect to the total amount of the polyester polyol is preferably 0.01 to 0.22 mol / g.
The aromatic ring group concentration is calculated from the following formula.

In the present invention, carboxylic acids other than sebacic acid and aromatic polycarboxylic acids may be used alone or in combination of two or more as long as the effects of the present invention are not impaired. Examples of such a carboxylic acid include adipic acid, maleic acid, fumaric acid, succinic acid, oxalic acid, malonic acid, glutaric acid, dimer acid, and the like.

When a raw material is selected from the viewpoint of biomass, examples of the plant-derived polycarboxylic acid include sebacic acid, succinic acid, succinic acid anhydride, and dimer acid among the above carboxylic acids.

(Polyprethane)
The polyol which is the raw material of the polyester polyol (A1) is not particularly limited, but is limited to ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexane. Diol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol and other glycols; 2-methyl-1,5-pentanediol, 3 -Methyl-1,5-pentanediol, 1,2-butanediol, 1,3-butanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,2-propanediol, 2-methyl- 1,3-Propanediol, neopentyl glycol, 2-isopropyl-1,4-butanediol, 2,4-dimethyl-1,5-pentanediol 2,4-diethyl-1,5-pentanediol, 2-ethyl Glycols having a branched structure such as -1,3-hexanediol, 2-ethyl-1,6-hexanediol, 3,5-heptandiol, 2-methyl-1,8-octanediol; glycerin, trimethylpropane, Examples thereof include trimethylol ethane, pentaerythritol, and sorbitol. These compounds may be used alone or in combination of two or more.
When selecting a raw material from the viewpoint of biomass, the plant-derived polyols include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, diethylene glycol, and glycerin among the above carboxylic acids. Can be mentioned.
And so on.

The dicarboxylic acid and the polyol are obtained, for example, by heating and stirring at 100 to 300 ° C. under reduced pressure in the presence of various esterification catalysts.

Among them, the polyester polyol (A1) is a polyester polyol (A1) using the plant-derived polycarboxylic acid containing sebacic acid and aromatic polycarboxylic acid and a short-chain diol having 2 to 10 carbon atoms as reaction raw materials. It is preferably A1-1).
Examples of the short chain diol having 2 to 10 carbon atoms include 3-methyl-1,5-pentanediol, propylene glycol, neopentyl glycol, and 2-methyl-1,3-propanediol.

The number average molecular weight of the polyester polyol (A1) is preferably 370 to 7,000, more preferably 500 to 5,000. The hydroxyl value is preferably 16 to 300 mgKOH / g, more preferably 20 to 200 mgKOH / g.

In the present invention, the weight average molecular weight and the number average molecular weight indicate values measured under the following conditions by a gel permeation chromatography (GPC) method.

Measuring device: High-speed GPC device ("HLC-8220GPC" manufactured by Tosoh Corporation)
Column: The following columns manufactured by Tosoh Corporation were connected in series and used.
"TSKgel G5000" (7.8 mm I.D. x 30 cm) x 1 "TSKgel G4000" (7.8 mm I.D. x 30 cm) x 1 "TSKgel G3000" (7.8 mm ID x 30 cm) x 1 This "TSKgel G2000" (7.8 mm ID x 30 cm) x 1 Detector: RI (Differential Refractometer)
Column temperature: 40 ° C
Eluent: tetrahydrofuran (THF)
Flow velocity: 1.0 mL / min Injection volume: 100 μL (tetrahydrofuran solution with a sample concentration of 0.4% by mass)
Standard sample: A calibration curve was prepared using the following standard polystyrene.

[Standard polystyrene]
"TSKgel Standard Polystyrene A-500" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene A-1000" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene A-2500" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene A-5000" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-1" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-2" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-4" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-10" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-20" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-40" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-80" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-128" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-288" manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-550" manufactured by Tosoh Corporation

In the present invention, the hydroxyl value is the amount of hydroxyl groups in 1 g of the resin calculated by back-titrating the remaining acid with an alkali when the hydroxyl groups in the polyurethane resin are acetylated with an excess acetyl reagent, and potassium hydroxide. It is shown by the mg number of (KOH), and is based on JIS K0070.

(Polyether polyol (A2))
In the present invention, for example, a polyester polyol other than the polyester polyol (A1), a polyether polyol, a polyol containing no ester group or an ether group, or the like can be used as long as the effects of the present invention are not impaired. In particular, it is preferable to use a polyether polyol containing an ether group in combination (hereinafter, in the present invention, the polyether polyol used as a reaction raw material of the polyurethane resin (A) in combination with the polyester polyol (A1) is referred to as "polyether polyol (hereinafter). A2) ")

The polyether polyol (A2) used in the present invention is not particularly limited, and examples thereof include polyether polyols of polymers such as methylene oxide, ethylene oxide, and tetrahydrofuran, or copolymers.
Preferred polyether polyols (A2) include polyethylene glycol and polypropylene glycol.

When the polyether polyol (A2) is used in combination, it is preferable to use it in the range of 10 to 80% by weight based on the total amount of the polyol which is the reaction raw material of the polyurethane resin. Among them, it is preferably 20 to 70% by weight, and most preferably 30 to 60% by weight.

The number average molecular weight of the polyether polyol (A2) is preferably 300 to 6,000, more preferably 400 to 4000.

The hydroxyl value of the polyether polyol (A2) is preferably 18.5 to 300 mgKOH / g, more preferably in the range of 30 to 280.

As the other polyol, for example, various known polyols generally used in the production of polyurethane resin can be used, and one kind or two or more kinds may be used in combination. For example, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2-ethyl-2butyl-1,3-propanediol, 1,3-butanediol. , 1,4-Butanediol, Neopentyl glycol, Pentandiol, 3-Methyl-1,5 Pentandiol, Hexadiol, Octanediol, 1,4-Butindiol, 1,4-Butylenediol, Diethylene glycol, Triethylene glycol , Dipropylene glycol, glycerin, trimethylolpropane, trimethylolethane, 1,2,6-hexanetriol, 1,2,4-butanetriol, sorbitol, pentaeslitol and other saturated or unsaturated low molecular weight polyols. And / or low molecular weight polyols (1) derived from biomass resources, these low molecular weight polyols (1), and adipic acid, phthalic acid, isophthalic acid (excluding combinations of sebacic acid, sebacic acid and aromatic polycarboxylic acid). , Telephthalic acid, maleic acid, fumaric acid, oxalic acid, oxalic acid, malonic acid, glutaric acid, pimelli acid, speric acid, azelaic acid, trimellitic acid, pyromellitic acid and other polyvalent carboxylic acids or anhydrides thereof / Or polyester polyols (2) obtained by dehydration condensation or polymerization with polyvalent carboxylic acids derived from biomass resources; cyclic ester compounds such as polycaprolactone, polyvalerolactone, poly (β-methyl-γ-valerolactone). Polyol polyols (3) obtained by ring-opening polymerization of lactones such as the above; polycarbonate obtained by reacting the low molecular weight polyols (1) with, for example, dimethyl carbonate, diphenyl carbonate, ethylene carbonate, phosgen, etc. Polyols (4); polybutadiene glycols (5); glycols obtained by adding ethylene oxide or propylene oxide to bisphenol A; glycols (6); one or more hydroxyethyls in one molecule, hydroxypropul acrylate, Examples thereof include acrylic polyol (7) obtained by copolymerizing acrylic hydroxybutyl or the like, or these corresponding methacrylic acid derivatives, and acrylic acid, methacrylic acid or an ester thereof.

(Polyisocyanate)
Examples of the polyisocyanate used as the reaction raw material of the polyurethane resin (A) in the present invention include various known aromatic diisocyanates, aliphatic diisocyanates, and alicyclic diisocyanates generally used in the production of polyurethane resins. For example, 1,3-phenylenediisocyanate, 1,4-phenylenediocyanate, 1-methyl-2,4-phenylenediocyanate, 1-methyl-2,6-phenylenediisocyanate, 1-methyl-2,5-phenylenediisocyanate, 1 -Methyl-2,6-phenylenediisocyanate, 1-methyl-3,5-phenylenediocyanate, 1-ethyl-2,4-phenylenediisocyanate, 1-isopropyl-2,4-phenylenediocyanate, 1,3-dimethyl-2 , 4-phenylenediisocyanate, 1,3-dimethyl-4,6-phenylenediocyanate, 1,4-dimethyl-2,5-phenylenediocyanate, diethylbenzene diisocyanate, diisopropylbenzene diisocyanate, 1-methyl-3,5-diethylbenzene diisocyanate, 3-Methyl-1,5-diethylbenzene-2,4-diisocyanate, 1,3,5-triethylbenzene-2,4-diisocyanate, naphthalene-1,4-diisocyanate, naphthalene-1,5-diisocyanate, 1-methyl -Naphthalene-1,5-diisocyanate, naphthalene-2,6-diisocyanate, naphthalene-2,7-diisocyanate, 1,1-dinaphthyl-2,2'-diisocyanate, biphenyl-2,4'-diisocyanate, biphenyl-4 , 4'-diisocyanate, 3-3'-dimethylbiphenyl-4,4'-diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, diphenylmethane-2,4-diisocyanate and other aromatic polyisocyanates Tetramethylene diisocyanate, hexamethylene diisocyanate, dodecamethylene diisocyanate, trimethylhexamethylene diisocyanate, 1,3-cyclopentylene diisocyanate, 1,3-cyclohexylene diisocyanate, 1,4-cyclohexylene diisocyanate, 1,3-di (isocyanate) Methyl) cyclohexane, 1,4-di (isocyanatemethyl) cyclohexane, lysine diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 2,4'-dicyclohexylmethane diisocyanate, 2,2'-dicyclohexylmethane diisocyanate, 3, 3'-dimethyl-4,4'-dicyclohexylmethane Aliphatic compounds such as diisocyanates or alicyclic polyisocyanates can be used. These polyisocyanates may be used alone or in combination of two or more. Among these, an aliphatic polyisocyanate and / or an alicyclic polyisocyanate is preferably used from the viewpoint of obtaining appropriate flexibility, and isophorone diisocyanate or hexamethylene diisocyanate is used from the viewpoint of further improving the adhesive strength. Is more preferable.
These diisocyanate compounds can be used alone or in combination of two or more.

Further, a chain extender may be used in the synthesis of the polyurethane resin (A). Examples of the chain extender include ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, isophoronediamine, dicyclohexylmethane-4,4'-diamine, as well as 2-hydroxyethylethylenediamine and 2-hydroxyethylpropyldiamine. , 2-Hydroxyethyl propylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxyethylenediamine, di-2-hydroxyethylpropylenediamine, 2-hydroxypyropylethylenediamine, di-2-hydroxypyropylethylenediamine, di- Amines having a hydroxyl group in the molecule such as 2-hydroxypropylethylenediamine can also be used. These chain extenders can be used alone or in admixture of two or more.
In addition, a monovalent active hydrogen compound can also be used as an end-blocking agent for the purpose of stopping the reaction. Examples of such a compound include dialkylamines such as di-n-butylamine and alcohols such as ethanol and isopropyl alcohol. Further, especially when it is desired to introduce a carboxyl group into a polyurethane resin, amino acids such as glycine and L-alanine can be used as a reaction terminator. These terminal blockers can be used alone or in admixture of two or more.

The polyurethane resin (A) used in the liquid ink composition of the present invention is obtained by reacting a polyol, a polyisocyanate, a chain extender, and if necessary, a monovalent active hydrogen compound. For example, a polyester polyol, a combined polyol, and a diisocyanate compound are reacted in an excess ratio of isocyanate groups to obtain a prepolymer having terminal isocyanate groups, and the obtained prepolymer is placed in a suitable solvent, that is, a solvent for liquid ink. Ester solvents such as ethyl acetate, propyl acetate and butyl acetate; ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone; alcohol solvents such as methanol, ethanol, isopropyl alcohol and n-butanol; toluene, A hydrocarbon solvent such as xylene, methylcyclohexane, ethylcyclohexane; or a two-step method of reacting with a chain extender and / or terminal blocker in a mixed solvent thereof, or a polyester polyol and a combined polyol, a diisocyanate compound, It is produced by a one-step method in which a chain extender and / or a terminal blocker are reacted at once in a suitable solvent among the above. Among these methods, in order to obtain a uniform polyurethane resin (A), the two-step method is preferable. Further, when the polyurethane resin (A) is produced by the two-step method, the total (equivalent ratio) of the amino groups of the chain extender and / or the terminal blocker is 1 / 0.9 to 1.3. It is preferable to react with. When the equivalent ratio of the isocyanate group to the amino group is less than 1 / 1.3, the chain extender and / or the terminal sequestering agent remain unreacted, the polyurethane resin turns yellow, and the odor after printing is generated. It may occur.

The number average molecular weight of the polyurethane resin (A) thus obtained is preferably in the range of 5,000 to 70,000, more preferably in the range of 7,000 to 50,000. When the number average molecular weight of the polyurethane resin is less than 5,000, the blocking resistance of the obtained ink, the strength of the printing film, the oil resistance, etc. tend to be low, and when it exceeds 70,000, it is obtained. The viscosity of the ink tends to increase, and the gloss of the print film tends to decrease.

The polyurethane resin (A) is a polyurethane resin obtained by reacting the polyester polyol (A1) and the polyether polyol (A2) with an isocyanate component, and the polyether polyol is 10 to 80% by weight based on the total amount of the polyol. Is preferable. Within this range, improvements in scratch resistance and printability can be expected.

Further, among the polyurethane resins (A), the polyester polyol (A1) is a polyester polyol having a hydroxyl value of 16 to 300 mgKOH / g, and the polyether polyol (A2) has a hydroxyl value of 18.5 to 300 mgKOH / g. It is preferably a polyether polyol. Within this range, oil resistance, scratch resistance, and printability can be maintained.

The polyurethane resin (A) is preferably contained in an amount of 2 to 15% by mass, more preferably 3 to 12% by mass, based on the total amount of the ink.

(Chlorinated polyolefin (B))
The chlorinated polyolefin (B) used in the present invention is not particularly limited, and chlorinated polyolefins usually used in the ink field can be used. For example, polyolefins in which at least a part of hydrogen atoms are replaced by chlorine atoms can be mentioned.
Since the chlorinated polyolefin (B) has a flexible alkyl group as a branched structure, it is a resin that is flexible even at low temperatures, and the substrate adhesiveness is improved by the above amount. The structure of the polyolefin in the chlorinated polyolefin is not particularly limited. For example, resins containing homopolymers or copolymers of α-olefin unsaturated hydrocarbons such as polypropylene, poly-1-butene, and poly-4-methyl-1-pentene are preferable. Of these, chlorinated polypropylene containing a polypropylene structure (that is, a chlorinated polypropylene structure) is particularly preferable.

When the weight average molecular weight of the chlorinated polyolefin (B) is 5,000 to 100,000, the compatibility with the polyurethane resin (A) is good, which is preferable. Among them, 5,000 to 70,000 is preferable, and 7,000 to 50,000 is the most preferable. Further, since the chlorinated polyolefin (B) improves the adhesiveness to the base material, the chlorine content thereof is preferably 25 to 45% by mass. From the viewpoint of solubility in a non-aromatic organic solvent, the chlorine content is more preferably 26 to 43% by mass. Here, the chlorine content means the content mass% of chlorine atoms in 100% by mass of the chlorinated polyolefin resin. Further, from the viewpoint of the balance with the blocking resistance, the chlorinated polyolefin (B) is contained in an amount of 0.1 to 2.5% by mass, preferably 0.2 to 2.3% by mass, in the total amount of the ink solids. ..

(Other resins)
In the present invention, a resin other than the polyurethane resin (A) and the chlorinated polyolefin (B) may be contained. In printing inks, the resin mainly plays a role as a binder resin that imparts adhesion to the object to be printed, and from this viewpoint, the resin is preferably a thermoplastic resin that is soluble in an organic solvent. Examples of such a binder resin are not particularly limited as long as they are known as binder resins for gravure ink and flexo ink, but for example, cellulose-based resin, polyamide resin, vinyl chloride-vinyl acetate copolymer resin. , Vinyl chloride-acrylic copolymer resin, rosin resin, ethylene-vinyl acetate copolymer resin, vinyl acetate resin, acrylic resin, styrene resin, dammar resin, styrene-maleic acid copolymer resin, polyester resin, alkyd resin, Examples thereof include terpene resin, phenol-modified terpene resin, ketone resin, cyclized rubber, chloride rubber, butyral, polyacetal resin, petroleum resin, and modified resins thereof. These resins can be used alone or in admixture of two or more. It is assumed that the binder resin does not contain the chlorinated polyolefin resin.

(Cellulose resin)
Examples of the cellulosic resin include cellulose acetate propionate, cellulose acetate butyrate and other cellulosic ester resins, nitrocellulose, hydroxyalkyl cellulose, and carboxyalkyl cellulose. The cellulose ester resin preferably has an alkyl group, and examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a pentyl group, a hexyl group and the like, and further, an alkyl group. May have a substituent.
Of the above, cellulose acetate propionate, cellulose acetate butyrate, and nitrocellulose are preferable as the cellulosic resin. Particularly preferred is nitrocellulose. The molecular weight preferably has a weight average molecular weight of 5,000 to 200,000, and more preferably 10,000 to 50,000. Further, it is preferable that the glass transition temperature is 120 ° C to 180 ° C. The combined use of the polyurethane resin (A) of the present invention is expected to improve blocking resistance, scratch resistance and other ink film physical characteristics.
Nitrocellulose (also referred to as nitric acid cotton) is obtained as a nitrate ester in which three hydroxyl groups in the 6-membered ring of anhydrous glucopyranose groups in natural cellulose are replaced with nitric acid groups by reacting natural cellulose with nitric acid. Those having an average degree of polymerization of 20 to 200, more preferably those in the range of 30 to 150 are preferable. The nitrogen content is preferably 10.5 to 12.5% by mass. Nitrocellulose can also be expected to improve blocking resistance, scratch resistance and other ink film physical properties when used in combination with the polyurethane resin (A) of the present invention.
From the viewpoint of biomass, it is also preferable to use a cellulosic resin which is a plant-derived raw material in combination.

(Polyamide resin)
The polyamide resin is, for example, a thermoplastic polyamide that is soluble in an organic solvent and can be obtained by polycondensing a polybasic acid and a polyvalent amine. In particular, a polyamide resin containing a reaction product of an acid component containing a polymerized fatty acid and / or dimer acid and an aliphatic and / or aromatic polyamine, and further containing a part of primary and secondary monoamines. Is preferable.

The polybasic acid used as a raw material for the polyamide resin is not limited to the following, but is limited to adipic acid, sebacic acid, azelaic acid, phthalic anhydride, isophthalic acid, suberic acid, glutaric acid, fumaric acid, and pimelic acid. Acids, glutaric acid, malonic acid, succinic acid, maleic acid, terephthalic acid, 1,4-cyclohexyldicarboxylic acid, pimelic acid, dimeric acid, hydrogenated dimeric acid, polymerized fatty acids, etc., among which dimeric acid or polymerized A polyamide resin containing a structure derived from a fatty acid as a main component (50% by mass or more in the polyamide resin) is preferable. Here, the polymerized fatty acid is obtained by a cyclization reaction of an unsaturated fatty acid fatty acid or the like, and includes a monobasic fatty acid, a dimerized fatty acid (dimeric acid), a trimerized polymerized fatty acid and the like. As the fatty acid constituting dimer acid or polymerized fatty acid, those derived from natural oil such as soybean oil, palm oil and rice bran oil can be preferably mentioned, and those obtained from oleic acid and linoleic acid are preferable.
A monocarboxylic acid can also be used in combination with the polybasic acid. Examples of the monocarboxylic acid used in combination include acetic acid, propionic acid, lauric acid, palmitic acid, benzoic acid, cyclohexanecarboxylic acid and the like.

Examples of the polyamine include polyamines, primary or secondary monoamines, and the like. Examples of the polyamine used in the polyamide resin include aliphatic diamines such as ethylenediamine, propylenediamine, hexamethylenediamine and methylaminopropylamine, and aliphatic polyamines such as diethylenetriamine and triethylenetetramine. Examples of the alicyclic polyamines include aliphatic polyamines. , Cyclohexylene diamine, isophorone diamine and the like. Further, examples of the aromatic aliphatic polyamine include xylylenediamine, and examples of the aromatic polyamine include phenylenediamine and diaminodiphenylmethane. Further, examples of the primary and secondary monoamines include n-butylamine, octylamine, diethylamine, monoethanolamine, monopropanolamine, diethanolamine, and dipropanolamine.

(Vinyl chloride-vinyl acetate copolymer resin)
The vinyl chloride-vinyl acetate copolymer resin is not particularly limited as long as it is a copolymer of vinyl chloride and vinyl acetate. The molecular weight preferably has a weight average molecular weight of 5,000 to 100,000, and more preferably 10,000 to 70,000. The structure derived from the vinyl acetate monomer is preferably 1 to 30% by mass, and the structure derived from the vinyl chloride monomer is preferably 70 to 95% by mass in the solid content of the vinyl chloride-vinyl acetate copolymer resin. In this case, the solubility in an organic solvent is improved, and the adhesion to the base material, the physical characteristics of the film, the scratch resistance and the like are improved.
Further, from the viewpoint of solubility in an organic solvent, those containing a hydroxyl group derived from a vinyl alcohol structure are also preferable. The hydroxyl value is preferably 20 to 200 mgKOH / g. The glass transition temperature is preferably 50 ° C to 90 ° C.

(Rosin resin)
The rosin-based resin is not particularly limited as long as it has a rosin skeleton, but rosin-modified maleic acid resin, rosin ester, rosin phenol, polymerized rosin and the like are preferable. The softening point (according to the ring-and-ball method) is preferably 90 to 200 ° C.
From the viewpoint of biomass, it is also preferable to use a rosin-based resin, which is a plant-derived raw material, in combination.

(Organic solvent)
The liquid printing ink of the present invention is an ink whose main medium is an organic solvent. In the present invention, the organic solvent is an organic compound having a property of being able to dissolve a binder resin which is one of the main raw materials of a liquid printing ink. The organic solvent (C) that can be used in the liquid ink composition of the present invention is not particularly limited, but for example, aromatic hydrocarbons such as toluene, xylene, Solbesso # 100 and Solbesso # 150, hexane, methylcyclohexane, etc. Examples thereof include aliphatic hydrocarbon-based solvents such as heptane, octane and decane, and various ester-based organic solvents such as methyl acetate, ethyl acetate, isopropyl acetate, normal propyl acetate, butyl acetate, amyl acetate, ethyl formate and butyl propionate. Also, as water-mixable organic solvents, alcohol-based solvents such as methanol, ethanol, propanol, butanol, and isopropyl alcohol, ketone-based solvents such as acetone, methyl ethyl ketone, and cyclohaxanone, ethylene glycol (mono, di) methyl ether, and ethylene glycol (mono, di) ethyl. Ether, ethylene glycol monopropyl ether, ethylene glycol monoisopropyl ether, monobutyl ether, diethylene glycol (mono, di) methyl ether, diethylene glycol (mono, di) ethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monobutyl ether, triethylene glycol (mono, di) Examples thereof include various glycol ether-based organic solvents such as di) methyl ether, propylene glycol (mono, di) methyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, and dipropylene glycol (mono, di) methyl ether. It is more preferable not to use an aromatic solvent such as toluene or a ketone solvent such as methyl ethyl ketone from the viewpoints of both work hygiene during printing and harmfulness of the packaging material. Above all, a mixed solution of isopropyl alcohol / ethyl acetate / normal propyl acetate / methylcyclohexane is more preferable from the viewpoint of solubility in polyamide resin and nitrocellulose. Further, glycol ethers can be added as long as it is less than 10% by mass of the total amount of the composition for drying adjustment.
In the present invention, the total amount of the organic solvent is the mass obtained by taking 1 gram of the ink on a metallic tray and drying it in an explosion-proof oven dryer at 120 ° C. for 60 minutes, minus the mass of the solid content.

(Plasticizer)
The liquid printing ink of the present invention may contain a plasticizer in order to enhance ink fluidity, adhesiveness, and abrasion resistance. By adding a plasticizer, the flexibility and flexibility of the ink drying film after printing can be maintained.
Plasticizing agents include fatty oils such as castor oil, phthalates such as dioctyl phthalate, phosphate esters, fatty acid esters such as adipate and sebacic acid esters, polyesters, and epoxidized vegetable oils. Such epoxy-based, citrate ester such as tributyl acetyl citrate, sulfonic acid amide system such as N-butylbenzene sulphonamide and N-ethyltoluene sulphonamide can be mentioned. Of these, citric acid esters, epoxidized vegetable oils, phosphoric acid esters and sulfonic acid amides are preferable.
The blending amount of the plasticizer is preferably 0.01 to 10.0% by mass, more preferably 0.1 to 5.0% by mass, and 0.5 to 3.0% by mass with respect to the total amount of the ink. More preferred. Each of these plasticizers may be used alone, or a plurality of these plasticizers may be used in combination.

(wax)
The liquid printing ink of the present invention may be waxed in order to further enhance scratch resistance. The wax is not particularly limited as long as it is used for ordinary gravure inks such as hydrocarbon waxes and amido waxes and flexographic inks. Assuming that it is not added, the wax is contained in an amount of 0 to 5.0% by mass based on the total amount of the ink.

Examples of the hydrocarbon wax include polyethylene wax and hydrocarbon wax such as Fisher Tropsch wax, paraffin wax, microstalin wax, and polypropylene wax. Among them, polyethylene wax and / or hydrocarbon wax containing Fischer-Tropsch wax and the like can be mentioned, and these may be used alone or in combination of two or more.
When a hydrocarbon wax is added, it is preferably contained in an amount of 0.1 to 5% by mass based on the total amount of the ink. Above all, it is preferably contained in an amount of 0.1 to 4% by mass, preferably 0.3 to 2.5% by mass in order to achieve both adhesiveness to a substrate, scratch resistance and stability of the ink with time. ..

Examples of the amido wax include palmitic acid amide, stearic acid amide, ethylene bisoleic acid amide, hexamethylene bisoleic acid amide and the like, and these may be used alone or in combination of two or more. May be good.
When amide wax is added, it is preferably contained in an amount of 0.1 to 5% by mass based on the total amount of the ink. Above all, it is preferably contained in an amount of 0.1 to 4% by mass, preferably in an amount of 0.3 to 2.5% by mass, in order to achieve both scratch resistance, adhesiveness to a substrate, scratch resistance and stability of the ink over time. It is preferable to do so.

(silica)
In the liquid printing ink of the present invention, silica may be added in order to further enhance scratch resistance. Assuming that it is not added, silica is contained in an amount of 0 to 5.0% by mass based on the total amount of the ink.
The silica is not particularly limited as long as it is usually used for gravure ink or flexographic ink, but usually silica having an average particle size of 6 μm or less is used.
When silica is added, it is preferably contained in an amount of 0.1 to 5% by mass based on the total amount of the ink. Above all, from the viewpoint of excellent printability of the obtained ink, it is preferably contained in an amount of 0.1 to 4% by mass, preferably 0.3 to 2.5% by mass.

(Chelate cross-linking agent)
The liquid printing ink of the present invention may contain a chelate cross-linking agent. Assuming that it is not added, the chelate cross-linking agent is contained in an amount of 0 to 5.0% by mass based on the total amount of the ink.
The chelate cross-linking agent is intended to improve the cohesive force, and a chelate-type metal organic compound is preferable. As the metal chelate compound, an organic titanium type, an organic zirconium type, or an organic aluminum type can be used. If a chelate-type metal-organic compound is used, the cross-linking reaction is completed without heating, but hydrolysis at room temperature is unlikely to occur and a stable cross-linking reaction can be obtained, especially when amine is present in the molecule. The effect is great.
The titanium chelate has a Ti—OC bond in one molecule, and by having this alkoxy group, it has a role of strengthening the intermolecular or intramolecular cross-linking bond of the resin. Examples of the titanium chelate include titanium alkoxide and titanium acylate. Examples of the titanium alkoxide include tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, tetramethyl titanate, and tetrastearyl titanate, as well as triethanolamine titanate, titanium acetyl acetate, and titanium ethyl acet acetate. , Titanium lactate, octylene glycol titanate, titanium tetraacetyl acetate, titanium phosphate compound and the like. Among the organic titanium compounds, titanium phosphate compounds and titanium acetyl acetate are preferable.
When a chelate cross-linking agent is added, it is preferably contained in an amount of 0.1 to 5% by mass based on the total amount of the ink. Above all, it is preferably contained in an amount of 0.1 to 4% by mass, preferably 0.5 to 3.0% by mass.

(Pigment)
The liquid printing ink of the present invention can be used without containing a pigment, but a pigment is used for the purpose of printing a character pattern or the like. Examples of the pigments used include inorganic pigments and organic pigments used in general inks, paints, recording agents and the like. Organic pigments include soluble azo-based, insoluble azo-based, azo-based, phthalocyanine-based, halogenated phthalocyanine-based, anthraquinone-based, anthraslon-based, dianthraquinone-based, anthrapyrimidine-based, perylene-based, perinone-based, quinacridone-based, Pigments such as thioindigo-based, dioxazine-based, isoindolinone-based, quinophthalone-based, azomethine-azo-based, flavanthlon-based, diketopyrrolopyrrole-based, isoindoline-based, indanslon-based, and carbon black-based pigments can be mentioned. Also, for example, Carmin 6B, Lake Red C, Permanent Red 2B, Disazo Yellow, Pyrazolone Orange, Carmin FB, Chromophthal Yellow, Chromophthal Red, Phthalocyanine Blue, Phthalocyanine Green, Dioxazine Violet, Kinakridon Magenta, Kinakridon Red, Indance Examples include lonblue, pyrimidine yellow, thioindigo bordeaux, thioindigo magenta, perylene red, perinone orange, isoindolinone yellow, aniline black, diketopyrrolopyrrole red, daylight fluorescent pigment and the like. Further, both unacidified treated pigments and acidic treated pigments can be used. Specific examples of preferable organic pigments are given below.

Examples of the black pigment include C.I. I. Pigment Black 1, C.I. I. Pigment Black 6, C.I. I. Pigment Black 7, C.I. I. Pigment Black 9, C.I. I. Pigment Black 20 and the like.

Examples of the indigo pigment include 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: 5, C.I. I. Pigment Blue 15: 6, C.I. I. Pigment Blue 16, C.I. I. Pigment Blue 17: 1, C.I. I. Pigment Blue 22, C.I. I. Pigment Blue 24: 1, C.I. I. Pigment Blue 25, C.I. I. Pigment Blue 26, C.I. I. Pigment Blue 60, C.I. I. Pigment Blue 61, C.I. I. Pigment Blue 62, C.I. I. Pigment Blue 63, C.I. I. Pigment Blue 64, C.I. I. Pigment Blue 75, C.I. I. Pigment Blue 79, C.I. I. Pigment Blue 80 and the like.

Examples of the green pigment include C.I. I. Pigment Green 1, C.I. I. Pigment Green 4, C.I. I. Pigment Green 7, C.I. I. Pigment Green 8, C.I. I. Pigment Green 10, C.I. I. Pigment Green 36 and the like.

Examples of the red pigment include C.I. I. Pigment Red 1, C.I. I. Pigment Red 2, C.I. I. Pigment Red 3, C.I. I. Pigment Red 4, C.I. I. Pigment Red 5, C.I. I. Pigment Red 6, C.I. I. Pigment Red 7, C.I. I. Pigment Red 8, C.I. I. Pigment Red 9, C.I. I. Pigment Red 10, C.I. I. Pigment Red 11, C.I. I. Pigment Red 12, C.I. I. Pigment Red 15, C.I. I. Pigment Red 16, C.I. I. Pigment Red 17, C.I. I. Pigment Red 18, C.I. I. Pigment Red 19, C.I. I. Pigment Red 20, C.I. I. Pigment Red 21, C.I. I. Pigment Red 22, C.I. I. Pigment Red 23, C.I. I. Pigment Red 31, C.I. I. Pigment Red 32, C.I. I. Pigment Red 38, C.I. I. Pigment Red 41, C.I. I. Pigment Red 43, C.I. I. Pigment Red 46, C.I. I. Pigment Red 48, 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 48: 4, C.I. I. Pigment Red 48: 5, C.I. I. Pigment Red 48: 6, C.I. I. Pigment Red 49, C.I. I. Pigment Red 49: 1, C.I. I. Pigment Red 49: 2, C.I. I. Pigment Red 49: 3, C.I. I. Pigment Red 52, C.I. I. Pigment Red 52: 1, C.I. I. Pigment Red 52: 2, C.I. I. Pigment Red 53, C.I. I. Pigment Red 53: 1, C.I. I. Pigment Red 53: 2, C.I. I. Pigment Red 53: 3, C.I. I. Pigment Red 54, C.I. I. Pigment Red 57, C.I. I. Pigment Red 57: 1, C.I. I. Pigment Red 58, C.I. I. Pigment Red 58: 1, C.I. I. Pigment Red 58: 2, C.I. I. Pigment Red 58: 3, C.I. I. Pigment Red 58: 4, C.I. I. Pigment Red 60: 1, C.I. I. Pigment Red 63, C.I. I. Pigment Red 63: 1, C.I. I. Pigment Red 63: 2, C.I. I. Pigment Red 63: 3, C.I. I. Pigment Red 64: 1, C.I. I. Pigment Red 68, C.I. I. Pigment Red 68, C.I. I. Pigment Red 81: 1, C.I. I. Pigment Red 83, C.I. I. Pigment Red 88, C.I. I. Pigment Red 89, C.I. I. Pigment Red 95, C.I. I. Pigment Red 112, C.I. I. Pigment Red 114, C.I. I. Pigment Red 119, C.I. I. Pigment Red 122, C.I. I. Pigment Red 123, C.I. I. Pigment Red 136, C.I. I. Pigment Red 144, C.I. I. Pigment Red 146, C.I. I. Pigment Red 147, C.I. I. Pigment Red 149, C.I. I. Pigment Red 150, C.I. I. Pigment Red 164, C.I. I. Pigment Red 166, C.I. I. Pigment Red 168, C.I. I. Pigment Red 169, C.I. I. Pigment Red 170, C.I. I. Pigment Red 171 and C.I. I. Pigment Red 172, C.I. I. Pigment Red 175, C.I. I. Pigment Red 176, C.I. I. Pigment Red 177, C.I. I. Pigment Red 178, C.I. I. Pigment Red 179, C.I. I. Pigment Red 180, C.I. I. Pigment Red 181 and C.I. I. Pigment Red 182, C.I. I. Pigment Red 183, C.I. I. Pigment Red 184, C.I. I. Pigment Red 185, C.I. I. Pigment Red 187, C.I. I. Pigment Red 188, C.I. I. Pigment Red 190, C.I. I. Pigment Red 192, C.I. I. Pigment Red 193, C.I. I. Pigment Red 194, C.I. I. Pigment Red 200, C.I. I. Pigment Red 202, C.I. I. Pigment Red 206, C.I. I. Pigment Red 207, C.I. I. Pigment Red 208, C.I. I. Pigment Red 209, C.I. I. Pigment Red 210, C.I. I. Pigment Red 211, C.I. I. Pigment Red 213, C.I. I. Pigment Red 214, C.I. I. Pigment Red 216, C.I. I. Pigment Red 215, C.I. I. Pigment Red 216, C.I. I. Pigment Red 220, C.I. I. Pigment Red 221 and C.I. I. Pigment Red 223, C.I. I. Pigment Red 224, C.I. I. Pigment Red 226, C.I. I. Pigment Red 237, C.I. I. Pigment Red 238, C.I. I. Pigment Red 239, C.I. I. Pigment Red 240, C.I. I. Pigment Red 242, C.I. I. Pigment Red 245, C.I. I. Pigment Red 247, C.I. I. Pigment Red 248, C.I. I. Pigment Red 251 and C.I. I. Pigment Red 253, C.I. I. Pigment Red 254, C.I. I. Pigment Red 255, C.I. I. Pigment Red 256, C.I. I. Pigment Red 257, C.I. I. Pigment Red 258, C.I. I. Pigment Red 260, C.I. I. Pigment Red 262, C.I. I. Pigment Red 263, C.I. I. Pigment Red 264, C.I. I. Pigment Red 266, C.I. I. Pigment Red 268, C.I. I. Pigment Red 269, C.I. I. Pigment Red 270, C.I. I. Pigment Red 271, C.I. I. Pigment Red 272, C.I. I. Pigment Red 279, and the like.

Examples of the purple pigment include C.I. I. Pigment Violet 1, C.I. I. Pigment Violet 2, C.I. I. Pigment Violet 3, C.I. I. Pigment Violet 3: 1, C.I. I. Pigment Violet 3: 3, C.I. I. Pigment Violet 5: 1, C.I. I. Pigment Violet 13, C.I. I. Pigment Violet 19 (γ type, β type), C.I. I. Pigment Violet 23, C.I. I. Pigment Violet 25, C.I. I. Pigment Violet 27, C.I. I. Pigment Violet 29, C.I. I. Pigment Violet 31, C.I. I. Pigment Violet 32, C.I. I. Pigment Violet 36, C.I. I. Pigment Violet 37, C.I. I. Pigment Violet 38, C.I. I. Pigment Violet 42, C.I. I. Pigment Violet 50, and the like.

Examples of the yellow pigment include C.I. I. Pigment Yellow 1, C.I. I. Pigment Yellow 3, C.I. I. Pigment Yellow 12, C.I. I. Pigment Yellow 13, C.I. I. Pigment Yellow 14, Pigment Yellow 17, C.I. I. Pigment Yellow 24, C.I. I. Pigment Yellow 42, C.I. I. Pigment Yellow 55, C.I. I. Pigment Yellow 62, C.I. I. Pigment Yellow 65, C.I. I. Pigment Yellow 74, C.I. I. Pigment Yellow 83, C.I. I. Pigment Yellow 86, C.I. I. Pigment Yellow 93, C.I. I. Pigment Yellow 94, C.I. I. Pigment Yellow 95, C.I. I. Pigment Yellow 109, C.I. I. Pigment Yellow 110, C.I. I. Pigment Yellow 117, C.I. I. Pigment Yellow 120, Pigment Yellow 125, C.I. I. Pigment Yellow 128, C.I. I. Pigment Yellow 129, C.I. I. Pigment Yellow 137, C.I. I. Pigment, Yellow 138, C.I. I. Pigment Yellow 139, C.I. I. Pigment Yellow 147, C.I. I. Pigment Yellow 148, C.I. I. Pigment Yellow 150, C.I. I. Pigment Yellow 151, C.I. I. Pigment Yellow 153, C.I. I. Pigment Yellow 154, C.I. I. Pigment Yellow 155, C.I. I. Pigment Yellow 166, C.I. I. Pigment Yellow 168, C.I. I. Pigment Yellow 174, C.I. I. Pigment Yellow 180, C.I. I. Pigment Yellow 185 and C.I. I. Pigment Yellow 213 and the like.

Examples of the orange pigment include C.I. I. Pigment Orange 5, C.I. I. Pigment Orange 13, C.I. I. Pigment Orange 16, C.I. I. Pigment Orange 34, C.I. I. Pigment Orange 36, C.I. I. Pigment Orange 37, C.I. I. Pigment O Orange 38, C.I. I. Pigment Orange 43, C.I. I. Pigment Orange 51, C.I. I. Pigment range 55, C.I. I. Pigment Orange 59, C.I. I. Pigment Orange 61, C.I. I. Pigment Orange 64, C.I. I. Pigment Orange 71, or C.I. I. Pigment Orange 74 and the like.

Examples of the brown pigment include C.I. I. Pigment Brown 23, C.I. I. Pigment Brown 25, or C.I. I. Pigment Brown 26 and the like.

Among them, as a preferable pigment, as a black pigment, C.I. I. Pigment Black 7,
As an indigo pigment, 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,
As a green pigment, C.I. I. Pigment Green 7,
As a red pigment, 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 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,
As a purple pigment, C.I. I. Pigment Violet 23, C.I. I. Pigment Violet 37,
As a yellow pigment, C.I. I. Pigment Yellow 83, C.I. I. Pigment Yellow 14, C.I. I. Pigment Yellow 180, C.I. I. Pigment Yellow 139,
As an orange pigment, C.I. I. Pigment Orange 38, C.I. I. Pigment Orange 13, C.I. I. Pigment Orange 34, C.I. I. Pigment Orange 64,
Etc., and it is preferable to use at least one or two or more selected from these groups.

Examples of the inorganic pigment include white inorganic pigments such as titanium oxide, zinc oxide, zinc sulfide, barium sulfate, calcium carbonate, chromium oxide, silica, lithobon, antimony white, and gypsum. Among the inorganic pigments, the use of titanium oxide is particularly preferable. Titanium oxide has a white color and is preferable from the viewpoints of coloring power, hiding power, chemical resistance and weather resistance, and from the viewpoint of printing performance, the titanium oxide is preferably treated with silica and / or alumina.

Examples of non-white inorganic pigments include aluminum particles, mica (mica), bronze powder, chrome vermilion, chrome yellow, cadmium yellow, cadmium red, ultramarine, dark blue, red iron oxide, yellow iron oxide, iron black, and zircon. Although aluminum is in the form of powder or paste, it is preferably used in the form of paste from the viewpoint of handleability and safety, and whether chrome yellow or non-leafing is used is appropriately selected from the viewpoint of brightness and density.

The average particle size of the pigment (A) is preferably in the range of 10 to 200 nm, more preferably about 50 to 150 nm.
The pigment (A) is in an amount sufficient to secure the concentration and coloring power of the liquid printing ink, that is, 1 to 60% by weight based on the total weight of the ink composition, in terms of the solid content weight ratio in the ink composition. It is preferably contained in a proportion of 10 to 90% by weight. In addition, these pigments can be used alone or in combination of two or more.

(Other)
The liquid printing ink of the present invention may also contain extender pigments, pigment dispersants, leveling agents, defoamers, infrared absorbers, ultraviolet absorbers, fragrances, flame retardants and the like, if necessary.

(Production method)
The liquid printing ink of the present invention can be produced by dissolving and / or dispersing a binder resin, a pigment, or the like in an organic solvent. Specifically, a pigment dispersion in which a pigment is dispersed in an organic solvent with a polyurethane resin (A) is produced, and an ink is produced by blending the obtained pigment dispersion with another compound or the like as necessary. can do.

The particle size distribution of the pigment in the pigment dispersion is adjusted by appropriately adjusting the size of the pulverized media of the disperser, the filling rate of the pulverized media, the dispersion treatment time, the discharge rate of the pigment dispersion, the viscosity of the pigment dispersion, and the like. can do. As the disperser, generally used, for example, a roller mill, a ball mill, a pebble mill, an attritor, a sand mill and the like can be used.
If the ink contains air bubbles or unexpectedly coarse particles, it is preferable to remove them by filtration or the like in order to deteriorate the quality of the printed matter. As the filter, a conventionally known one can be used.

The viscosity of the ink produced by the above method is in the range of 10 mPa · s or more from the viewpoint of preventing the pigment from settling and appropriately dispersing the pigment, and 1000 mPa · s or less from the viewpoint of workability efficiency during ink production or printing. preferable. The viscosity is the viscosity measured at 25 ° C. with a B-type viscometer manufactured by Tokimec.
The viscosity of the ink can be adjusted by appropriately selecting the type and amount of raw materials used, such as resin, pigment, and organic solvent. Further, the viscosity of the ink can be adjusted by adjusting the particle size and the particle size distribution of the pigment in the ink.

The liquid printing ink of the present invention has excellent adhesion to various base materials and can be used for printing on paper, synthetic paper, thermoplastic resin film, plastic products, steel plates, etc. It is useful as an ink for gravure printing using a gravure printing plate, or for flexographic printing using a flexographic printing plate such as a resin plate, but for an inkjet method in which ink is ejected from an inkjet nozzle without using a plate. It excludes ink.
That is, in the case of an inkjet ink, the ink droplets ejected from the nozzle directly adhere to the substrate to form a printed matter, whereas in the liquid printing ink of the present invention, the printing ink is once adhered and transferred to the printing plate or the printing pattern. After that, only the ink is brought into close contact with the base material again, and if necessary, it is dried to obtain a printed matter.
The film thickness of the printing ink formed by the gravure printing method or the flexographic printing method using the liquid printing ink of the present invention is, for example, 10 μm or less, preferably 5 μm or less.

The base material is a polyamide resin such as nylon 6, nylon 66, nylon 46, polyethylene terephthalate (hereinafter sometimes referred to as PET), polyethylene naphthalate, polytrimethylene terephthalate, polytrimethylene naphthalate, polybutylene terephthalate, polybutylene. Polyester resins such as naphthalate, polyhydroxycarboxylic acids such as polylactic acid, biodegradable resins such as aliphatic polyester resins such as poly (ethylene succinate) and poly (butylene succinate), and polyolefins such as polypropylene and polyethylene. Examples thereof include a film made of a thermoplastic resin such as a resin, a polyimide resin, a polyarylate resin or a mixture thereof, and a laminate thereof. Among them, a film made of polyester, polyamide, polyethylene and polypropylene can be preferably used. These base films may be unstretched films or stretched films, and the production method thereof is not limited. Further, the thickness of the base film is not particularly limited, but usually it may be in the range of 1 to 500 μm.
The printed surface of the base film is preferably corona discharge treated, and silica, alumina, or the like may be vapor-deposited.

The present invention will be described in more detail with reference to Examples. Hereinafter, "parts" and "%" are both based on mass.
The weight average molecular weight (in terms of polystyrene) measured by GPC (gel permeation chromatography) in the present invention was measured using the HLC8220 system manufactured by Toso Co., Ltd. under the following conditions.
Separation column: Uses 4 TSKgelGMHR-N manufactured by Tosoh Corporation. Column temperature: 40 ° C. Moving layer: Tetrahydrofuran manufactured by Wako Pure Chemical Industries, Ltd. Flow velocity: 1.0 ml / min. Sample concentration: 0.4% by mass. Sample injection volume: 100 microliters. Detector: Differential refractometer.
The viscosity was measured at 25 ° C. with a Tokimec B-type viscometer.
The hydroxyl value is the amount of hydroxyl groups in 1 g of resin calculated by back titrating the remaining acid with alkali when the hydroxyl groups in the polyurethane resin are acetylated with an excess acetyl reagent, and potassium hydroxide (KOH) is used. It is shown by the number of mg of, and is based on JIS K0070.

Synthesis Example 1 (A1)
3-Methyl-1,5-pentanediol, terephthalic acid, sebacic acid (terephthalic acid / sebacic acid = 5/95 molar ratio) in a four-necked flask equipped with a stirrer, thermometer, recirculation cooler and nitrogen gas introduction tube. 68.3 parts of polyester polyol (hydroxyl value: 20 mgKOH / g), 159.3 parts of polypropylene glycol (hydroxyl value: 280.5 mgKOH / g), 59.0 parts of isophorone diisocyanate, and 59.0 parts of toluene diisocyanate were charged. After reacting at 90 ° C. for 10 hours under a nitrogen stream to produce a urethane prepolymer having an isocyanate group content of 4.70%, the reaction solution was cooled to 70 ° C. or lower, and then 380.1 parts of ethyl acetate and 118 parts of isopropyl alcohol 118. .9 parts were added. The reaction mixture was kept at about 35 to 40 ° C., 23.72 parts of isophorone diamine was dissolved in 71.2 parts of isopropyl alcohol and added dropwise, and the mixture was reacted at 50 ° C. for 3 hours under a stirring frame. Then, 10.77 parts of cyclohexylamine was added and reacted at 50 ° C. for 30 minutes under a stirring frame to obtain a polyurethane resin solution A1.
The obtained polyurethane resin solution (A1) had a resin solid content concentration of 40.1% by mass, a weight average molecular weight of 20,100, and an amine value (solid) of 0.

Synthesis Example 2 (A2)
Neopentyl glycol, isophthalic acid, sebacic acid, adipic acid (isophthalic acid / sebacic acid / adipic acid = 1/8/1 mol) in a four-necked flask equipped with a stirrer, thermometer, recirculation cooler and nitrogen gas introduction tube. 136.6 parts of polyester polyol (hydroxyl value: 300 mgKOH / g), 91.0 parts of polypropylene glycol (hydroxyl value: 300 mgKOH / g) and 136.68 parts of toluenediisocyanate are charged and prepared at 90 ° C. under a nitrogen stream. After reacting for 10 hours to prepare a urethane prepolymer having an isocyanate group content of 4.05%, the reaction solution was cooled to 70 ° C. or lower, and then 395.1 parts of ethyl acetate and 121.9 parts of isopropyl alcohol were added. The reaction mixture was kept at about 35 to 40 ° C., 25.21 parts of isophorone diamine was dissolved in 75.6 parts of isopropyl alcohol and added dropwise, and the mixture was reacted at 50 ° C. for 3 hours under a stirring frame. Then, 5.60 parts of cyclohexylamine was added and reacted at 50 ° C. for 30 minutes under a stirring frame to obtain a polyurethane resin solution A2.
The obtained polyurethane resin solution (A2) had a resin solid content concentration of 39.9% by mass, a weight average molecular weight of 41,300, and an amine value (solid) of 0.

Synthesis Example 3 (A3)
Neopentyl glycol, isophthalic acid, sebacic acid, dimer acid (isocyanate / sebacic acid / dimer acid = 1/3/1 mol) in a four-necked flask equipped with a stirrer, thermometer, recirculation cooler and nitrogen gas introduction tube. 202.6 parts (hydroxyl value: 20.4 mgKOH / g) of polyester polyol consisting of (ratio), 22.8 parts (hydroxyl value: 22.4 mgKOH / g) of polypropylene glycol, and 2.3 3-methyl-1,5-pentanediol. Parts and 23.55 parts of hexamethylene diisocyanate were charged and reacted at 90 ° C. for 10 hours under a nitrogen stream to produce a urethane prepolymer having an isocyanate group content of 2.65% by mass, which was then subjected to ethyl acetate 167.4. Parts were added to prepare a uniform solution of urethane prepolymer. Next, the urethane prepolymer solution was added to a mixture consisting of 12.62 parts of isophoronediamine, 1.42 parts of cyclohexylamine, 274.1 parts of ethyl acetate and 176.6 parts of isopropyl alcohol, and the reaction was stirred at 45 ° C. for 5 hours. To obtain a polyurethane resin solution A3. The obtained polyurethane resin solution A3 had a resin solid content concentration of 30.0% by mass, an amine value (solid) of 0.75, and a weight average molecular weight of 67,000.

Synthesis Example 4 (A4)
2-Methyl-1,3-propanediol, isophthalic acid, sebacic acid (isocyanate / sebacic acid = 1/5 molar ratio) in a four-necked flask equipped with a stirrer, thermometer, recirculation cooler and nitrogen gas introduction tube. 88.8 parts of polyester polyol (hydroxyl value: 74.8 mgKOH / g), 134.3 parts of polypropylene glycol (hydroxyl value: 56.1 mgKOH / g), and 4.5 parts of 2-methyl-1,3-propanediol. , And 30.0 parts of toluene diisocyanate and 30.0 parts of hexamethylene diisocyanate were charged and reacted at 90 ° C. for 10 hours under a nitrogen stream to produce a urethane prepolymer having an isocyanate group content of 5.08% by mass. 191.7 parts of ethyl acetate was added to a uniform solution of urethane prepolymer. Next, the urethane prepolymer solution was added to a mixture consisting of 25.32 parts of isophorone diamine, 5.44 parts of cyclohexylamine, 339.0 parts of ethyl acetate and 212.3 parts of isopropyl alcohol, and the reaction was stirred at 45 ° C. for 5 hours. To obtain a polyurethane resin solution A4. The obtained polyurethane resin solution A4 had a resin solid content concentration of 29.9% by mass, an amine value (solid) of 0.7, and a weight average molecular weight of 37,600.

Synthesis Example 5 (A5)
2-Methyl-1,3-propanediol, isophthalic acid, sebacic acid, succinic acid (isocyanate / sebacic acid / succinic acid =) in a four-necked flask equipped with a stirrer, thermometer, recirculation cooler and nitrogen gas introduction tube. 113.8 parts (hydroxyl value: 56.1 mgKOH / g) of polyester polyol composed of 2/7/1), 113.8 parts (hydroxyl value: 112.2 mgKOH / g) of polypropylene glycol, and 74.48 parts of isophorone diisocyanate were charged. , The reaction was carried out at 90 ° C. for 10 hours under a nitrogen stream to produce a urethane prepolymer having an isocyanate group content of 4.57% by mass, and then 201.4 parts of ethyl acetate was added thereto to prepare a uniform solution of the urethane prepolymer. .. Next, the urethane prepolymer solution was added to a mixture consisting of 25.71 parts of isophorone diamine, 3.56 parts of cyclohexylamine, 351.6 parts of ethyl acetate and 221.1 parts of isopropyl alcohol, and the reaction was stirred at 45 ° C. for 5 hours. To obtain a polyurethane resin solution A5. The obtained polyurethane resin solution A5 had a resin solid content concentration of 30.2% by mass, an amine value (solid) of 1.5, and a weight average molecular weight of 52,000.

Synthesis Example 6 (A6)
68.3 parts of polyester polyol consisting of 3-methyl-1,5-pentanediol and sebacic acid in a four-necked flask equipped with a stirrer, thermometer, recirculation cooler and nitrogen gas introduction tube (hydroxyl value: 112.2) 68.3 parts of polyester polyol (hydroxyl value: 112.2 mgKOH / g) and polypropylene glycol 91. Consists of 3-methyl-1,5-pentanediol, isocyanic acid, and sebacic acid (isophthalic acid / sebacic acid = 1/2). 0 part (hydroxyl value: 28.1 mgKOH / g) and 72.97 parts of isophorone diisocyanate were charged and reacted at 90 ° C. for 10 hours under a nitrogen stream to produce a urethane prepolymer having an isocyanate group content of 5.09%. Then, the reaction solution was cooled to 70 ° C. or lower, and then 332.4 parts of ethyl acetate and 87.2 parts of isopropyl alcohol were added. The reaction solution was kept at about 35 to 40 ° C., 26.32 parts of isophorone diamine was dissolved in 79.0 parts of isopropyl alcohol and added dropwise, and the mixture was reacted at 50 ° C. for 3 hours under a stirring frame. Then, 5.50 parts of cyclohexylamine was added and reacted at 50 ° C. for 30 minutes under a stirring frame to obtain a polyurethane resin solution A6.
The obtained polyurethane resin solution (A6) had a resin solid content concentration of 40.2% by mass, a weight average molecular weight of 38,600, and an amine value (solid) of 0.

Synthesis Example 7 (A7)
3-Methyl-1,5-pentanediol, isophthalic acid, sebacic acid (isocyanate / sebacic acid = 3/7 molar ratio) in a four-necked flask equipped with a stirrer, thermometer, recirculation cooler and nitrogen gas introduction tube. 134.4 parts of polyester polyol (hydroxyl value: 56.1 mgKOH / g), 91.0 parts of polypropylene glycol (hydroxyl value: 112 mgKOH / g), 2.3 parts of 1,4-butanediol, and isophorone diisocyanate 90. 64 parts were charged and reacted at 90 ° C. for 10 hours under a nitrogen stream to produce a urethane prepolymer having an isocyanate group content of 5.69%, and then the reaction solution was cooled to 70 ° C. or lower and then ethyl acetate 355.9. And 82.9 parts of isopropyl alcohol were added. The reaction mixture was kept at about 35 to 40 ° C., 31.70 parts of isophorone diamine was dissolved in 95.1 parts of isopropyl alcohol and added dropwise, and the mixture was reacted at 50 ° C. for 3 hours under a stirring frame. Then, 5.88 parts of cyclohexylamine was added and reacted at 50 ° C. for 30 minutes under a stirring frame to obtain a polyurethane resin solution A7.
The obtained polyurethane resin solution (A7) had a resin solid content concentration of 39.9% by mass, a weight average molecular weight of 31,500, and an amine value (solid) of 0.

Synthesis Example 8 (A8)
2-Methyl-1,3-propanediol, propylene glycol, isocyanate, sebacic acid (2-methyl-1,3-propanediol) in a four-necked flask equipped with a stirrer, thermometer, recirculation cooler and nitrogen gas introduction tube. 113.8 parts of polyester polyol (hydroxyl value: 37.4 mgKOH / g) and 113.8 parts of polypropylene glycol (hydroxyl value: 56) consisting of / propylene glycol = 1/1, isocyanate / sebacic acid = 3/7 molar ratio) .1 mgKOH / g) and 60.27 parts of isophorone diisocyanate were charged and reacted at 90 ° C. for 10 hours under a nitrogen stream to produce a urethane prepolymer having an isocyanate group content of 5.14%, and then the reaction solution was charged at 70 ° C. After cooling, 318.7 parts of ethyl acetate and 84.0 parts of isopropyl alcohol were added. The reaction mixture was kept at about 35 to 40 ° C., 25.11 parts of isophorone diamine was dissolved in 75.3 parts of isopropyl alcohol and added dropwise, and the mixture was reacted at 50 ° C. for 3 hours under a stirring frame. Then, 5.74 parts of cyclohexylamine was added and reacted at 50 ° C. for 30 minutes under a stirring frame to obtain a polyurethane resin solution A8.
The obtained polyurethane resin solution (A8) had a resin solid content concentration of 40.3% by mass, a weight average molecular weight of 36,400, and an amine value (solid) of 0.

Synthesis Example 9 (A9)
3-Methyl-1,5-pentanediol, isophthalic acid, sebacic acid, dimer acid (isophthalic acid / sebacic acid / dimer acid =) in a four-necked flask equipped with a stirrer, thermometer, recirculation cooler and nitrogen gas introduction tube. 159.3 parts of polyester polyol (hydroxyl value: 37.4 mgKOH / g), 68.3 parts of polypropylene glycol (hydroxyl value: 28.1 mgKOH / g), and 57.6 parts of isophorone diisocyanate consisting of (4/4/2 molar ratio). Was charged and reacted at 90 ° C. for 10 hours under a nitrogen stream to produce a urethane prepolymer having an isocyanate group content of 5.57%, and then the reaction solution was cooled to 70 ° C. or lower and then charged with 318.2 parts of ethyl acetate. 74.9 parts of isopropyl alcohol was added. The reaction solution was kept at about 35 to 40 ° C., 28.06 parts of isophorone diamine was dissolved in 84.2 parts of isopropyl alcohol and added dropwise, and the mixture was reacted at 50 ° C. for 3 hours under a stirring frame. Then, 4.86 parts of cyclohexylamine was added and reacted at 50 ° C. for 30 minutes under a stirring frame to obtain a polyurethane resin solution A9.
The obtained polyurethane resin solution (A9) had a resin solid content concentration of 40.1% by mass, a weight average molecular weight of 39,200, and an amine value (solid) of 0.

Synthesis Example 10 (A10)
A polyester polyol 91.1 consisting of propylene glycol, isophthalic acid, and sebacic acid (isocyanate / sebacic acid = 1/1 molar ratio) in a four-necked flask equipped with a stirrer, a thermometer, a recirculation cooler, and a nitrogen gas introduction tube. Parts (hydroxyl value: 37.4 mgKOH / g), polypropylene glycol 134.3 parts (hydroxyl value: 37.4 mgKOH / g), ethylene glycol 2.27 parts, and isophorone diisocyanate 68.91 parts were charged and placed under a nitrogen stream. After reacting at 90 ° C. for 10 hours to produce a urethane prepolymer having an isocyanate group content of 5.62%, the reaction solution was cooled to 70 ° C. or lower, and then 331.2 parts of ethyl acetate and 81.2 parts of isopropyl alcohol were added. added. The reaction mixture was kept at about 35-40 ° C., 28.16 parts of isophorone diamine was dissolved in 84.5 parts of isopropyl alcohol and added dropwise, and the mixture was reacted at 50 ° C. for 3 hours under a stirring frame. Then, 6.57 parts of cyclohexylamine was added and reacted at 50 ° C. for 30 minutes under a stirring frame to obtain a polyurethane resin solution A10.
The obtained polyurethane resin solution (A10) had a resin solid content concentration of 40.2% by mass, a weight average molecular weight of 29,400, and an amine value (solid) of 0.

Synthesis Example 11 (A11)
2-Methyl-1,3-propanediol, isophthalic acid, sebacic acid, dimer acid (isocyanate / sebacic acid / dimer acid =) in a four-necked flask equipped with a stirrer, thermometer, recirculation cooler and nitrogen gas introduction tube. 179.8 parts (hydroxyl value: 27.4 mgKOH / g) of polyester polyol composed of 6/3/1), 45.5 parts (hydroxyl value: 18.5 mgKOH / g) of polypropylene glycol, and 40.53 parts of isophorone diisocyanate were charged. , The reaction was carried out at 90 ° C. for 10 hours under a nitrogen stream to produce a urethane prepolymer having an isocyanate group content of 3.31% by mass, and then 178.8 parts of ethyl acetate was added thereto to prepare a uniform solution of the urethane prepolymer. .. Next, the urethane prepolymer solution was added to a mixture consisting of 16.92 parts of isophoronediamine, 1.78 parts of cyclohexylamine, 299.5 parts of ethyl acetate and 191.3 parts of isopropyl alcohol, and the reaction was stirred at 45 ° C. for 5 hours. To obtain a polyurethane resin solution A11. The obtained polyurethane resin solution A11 had a resin solid content concentration of 30.2% by mass, an amine value (solid) of 1, and a weight average molecular weight of 62,100.

Synthesis Example 12 (A12)
3-Methyl-1,5-pentanediol, isophthalic acid, sebacic acid, dimer acid (isophthalic acid / sebacic acid / dimer acid =) in a four-necked flask equipped with a stirrer, thermometer, recirculation cooler and nitrogen gas introduction tube. 200.3 parts (hydroxyl value: 37.4 mgKOH / g) of polyester polyol consisting of 7/2/1 molar ratio), 22.76 parts of polypropylene glycol (hydroxyl value: 18.5 mgKOH / g), and 2-methyl-1,3 -4.54 parts of propanediol and 49.85 parts of isophorone diisocyanate are charged and reacted at 90 ° C. for 10 hours under a nitrogen stream to produce a urethane prepolymer having an isocyanate group content of 3.13%, and then a reaction solution. Was cooled to 70 ° C. or lower, and then 296.0 parts of ethyl acetate and 112.0 parts of isopropyl alcohol were added. The reaction mixture was kept at about 35 to 40 ° C., 12.01 parts of isophorone diamine was dissolved in 36.0 parts of isopropyl alcohol and added dropwise, and the mixture was reacted at 50 ° C. for 3 hours under a stirring frame. Then, 6.5 parts of cyclohexylamine was added and reacted at 50 ° C. for 30 minutes under a stirring frame to obtain a polyurethane resin solution A12.
The obtained polyurethane resin solution (A12) had a resin solid content concentration of 40.1% by mass, a weight average molecular weight of 23,500, and an amine value (solid) of 0.

Synthesis Example 13 (A13)
3-Methyl-1,5-pentanediol, isophthalic acid, sebacic acid, dimer acid (isophthalic acid / sebacic acid / dimer acid =) in a four-necked flask equipped with a stirrer, thermometer, recirculation cooler and nitrogen gas introduction tube. 204.8 parts (hydroxyl value: 37.4 mgKOH / g) of polyester polyol consisting of 8/1 / 1 molar ratio), 22.8 parts of polypropylene glycol (hydroxyl value: 18.5 mgKOH / g), and 42.4 parts of isophorone diisocyanate. Was charged and reacted at 90 ° C. for 10 hours under a nitrogen stream to produce a urethane prepolymer having an isocyanate group content of 3.69% by mass, and then 180.0 parts of ethyl acetate was added thereto to form a uniform solution of the urethane prepolymer. And said. Next, the urethane prepolymer solution was added to a mixture consisting of 17.26 parts of isophorone diamine, 0.85 parts of cyclohexylamine, 304.7 parts of ethyl acetate and 193.9 parts of isopropyl alcohol, and the reaction was stirred at 45 ° C. for 5 hours. To obtain a polyurethane resin solution A13. The obtained polyurethane resin solution A13 had a resin solid content concentration of 30.0% by mass, an amine value (solid) of 0.6, and a weight average molecular weight of 42,000.

Comparative Synthesis Example 1 (H1)
45.5 parts of polyester polyol consisting of 3-methyl-1,5-pentanediol and sebacic acid (hydroxyl value: 16.0 mgKOH /) in a four-necked flask equipped with a stirrer, thermometer, recirculation cooler and nitrogen gas introduction tube. g), 182.1 parts of polypropylene glycol (hydroxyl value: 37.0 mgKOH / g) and 26.66 parts of isophorone diisocyanate were charged and reacted at 90 ° C. for 10 hours under a nitrogen stream to have an isocyanate group content of 1.76% by mass. After producing the urethane prepolymer of the above, 169.5 parts of ethyl acetate was added thereto to prepare a uniform solution of the urethane prepolymer. Next, the urethane prepolymer solution was added to a mixture consisting of 8.77 parts of isophorone diamine, 0.85 parts of cyclohexylamine, 270.0 parts of ethyl acetate and 175.8 parts of isopropyl alcohol, and the reaction was stirred at 45 ° C. for 5 hours. To obtain a polyurethane resin solution H1. The obtained polyurethane resin solution H1 had a resin solid content concentration of 29.8% by mass, an amine value (solid) of 0.4, and a weight average molecular weight of 70,400.

Comparative Synthesis Example 2 (H2)
113.8 parts of polyester polyol consisting of 3-methyl-1,5-pentanediol and sebacic acid (hydroxyl value: 112.2 mgKOH /) in a four-necked flask equipped with a stirrer, thermometer, recirculation cooler and nitrogen gas introduction tube. g), 113.8 parts of polypropylene glycol (hydroxyl value: 15.0 mgKOH / g), and 56.25 parts of isophorone diisocyanate were charged and reacted at 90 ° C. for 10 hours under a nitrogen stream to have an isocyanate group content mass of 3.67. After producing% urethane prepolymer, the reaction solution was cooled to 70 ° C. or lower, and then 305.7 parts of ethyl acetate and 102.5 parts of isopropyl alcohol were added. The reaction mixture was kept at about 35 to 40 ° C., 16.80 parts of isophorone diamine was dissolved in 50.40 parts of isopropyl alcohol and added dropwise, and the mixture was reacted at 50 ° C. for 3 hours under a stirring frame. Then, 5.05 parts of cyclohexylamine was added and reacted at 50 ° C. for 30 minutes under a stirring frame to obtain a polyurethane resin solution H2.
The obtained polyurethane resin solution (H2) had a resin solid content concentration of 40.3% by mass, a weight average molecular weight of 30,200, and an amine value (solid) of 0.

Comparative Synthesis Example 3 (H3)
It consists of 3-methyl-1,5-pentanediol, terephthalic acid, and sebacic acid (terephthalic acid / sebacic acid = 1/99) in a four-necked flask equipped with a stirrer, a thermometer, a recirculation cooler, and a nitrogen gas introduction tube. 113.8 parts of polyester polyol (hydroxyl value: 56.1 mgKOH / g), 113.8 parts of polypropylene glycol (hydroxyl value: 37.0 mgKOH / g), and 55.67 parts of isophorone diisocyanate were charged and 90 ° C. under a nitrogen stream. To produce a urethane prepolymer having an isocyanate group content of 4.63%, the reaction solution was cooled to 70 ° C. or lower, and then 310.7 parts of ethyl acetate and 91.5 parts of isopropyl alcohol were added. .. The reaction solution was kept at about 35 to 40 ° C., 21.30 parts of isophorone diamine was dissolved in 63.9 parts of isopropyl alcohol and added dropwise, and the mixture was reacted at 50 ° C. for 3 hours under a stirring frame. Then, 6.17 parts of cyclohexylamine was added and reacted at 50 ° C. for 30 minutes under a stirring frame to obtain a polyurethane resin solution H3.
The obtained polyurethane resin solution (H3) had a resin solid content concentration of 40.1% by mass, a weight average molecular weight of 18,600, and an amine value (solid) of 0.

Comparative Synthesis Example 4 (H4)
A four-necked flask equipped with a stirrer, a thermometer, a recirculation cooler and a nitrogen gas introduction tube is composed of 3-methyl-1,5-pentanediol, isophthalic acid, and sebacic acid (isocyanate / sebacic acid = 99/1). 91.0 parts of polyester polyol (hydroxyl value: 112.0 mgKOH / g), 136.6 parts of polypropylene glycol (hydroxyl value: 56.0 mgKOH / g), and 76.39 parts of isophorone diisocyanate were charged and 90 ° C. under a nitrogen stream. To produce a urethane prepolymer having an isocyanate group content of 5.10%, the reaction solution was cooled to 70 ° C. or lower, and then 336.6 parts of ethyl acetate and 95.4 parts of isopropyl alcohol were added. .. The reaction solution was kept at about 35 to 40 ° C., 24.30 parts of isophorone diamine was dissolved in 72.9 parts of isopropyl alcohol and added dropwise, and the mixture was reacted at 50 ° C. for 3 hours under a stirring frame. Then, 8.34 parts of cyclohexylamine was added and reacted at 50 ° C. for 30 minutes under a stirring frame to obtain a polyurethane resin solution H4.
The obtained polyurethane resin solution (H4) had a resin solid content concentration of 40.2% by mass, a weight average molecular weight of 22,400, and an amine value (solid) of 0.

Comparative Synthesis Example 5 (H5)
A four-necked flask equipped with a stirrer, a thermometer, a recirculation cooler and a nitrogen gas introduction tube is composed of 2-methyl-1,3-propanediol, isophthalic acid, and sebacic acid (isocyanate / sebacic acid = 1/5). 220.8 parts of polyester polyol (hydroxyl value: 74.8 mgKOH / g), 6.8 parts of polypropylene glycol (hydroxyl value: 112.0 mgKOH / g) and 51.16 parts of isophorone diisocyanate were charged, and at 90 ° C. under a nitrogen stream. After reacting for 10 hours to produce a urethane prepolymer having an isocyanate group content of 2.29% by mass, 185.8 parts of ethyl acetate was added thereto to prepare a uniform solution of the urethane prepolymer. Next, the urethane prepolymer solution was added to a mixture consisting of 12.63 parts of isophorone diamine, 0.94 parts of cyclohexylamine, 301.6 parts of ethyl acetate and 195.0 parts of isopropyl alcohol, and the reaction was stirred at 45 ° C. for 5 hours. To obtain a polyurethane resin solution H6. The obtained polyurethane resin solution H6 had a resin solid content concentration of 30.2% by mass, an amine value (solid) of 1, and a weight average molecular weight of Mn of 72,300.

Comparative Synthesis Example 6 (H6)
A four-necked flask equipped with a stirrer, a thermometer, a recirculation cooler and a nitrogen gas introduction tube is composed of 3-methyl-1,5-pentanediol, terephthalic acid, and sebacic acid (terephthalic acid / sebacic acid = 5/95). 11.4 parts of polyester polyol (hydroxyl value: 20.0 mgKOH / g), 216.2 parts of polypropylene glycol (hydroxyl value: 37.0 mgKOH / g) and 28.37 parts of isophorone diisocyanate were charged, and at 90 ° C. under a nitrogen stream. After reacting for 10 hours to produce a urethane prepolymer having an isocyanate group content of 1.78% by mass, 170.6 parts of ethyl acetate was added thereto to prepare a uniform solution of the urethane prepolymer. Next, the urethane prepolymer solution was added to a mixture consisting of 9.15 parts of isophorone diamine, 0.59 parts of cyclohexylamine, 272.4 parts of ethyl acetate and 177.2 parts of isopropyl alcohol, and the mixture was stirred at 45 ° C. for 5 hours. To obtain a polyurethane resin solution H5. The obtained polyurethane resin solution H5 had a resin solid content concentration of 29.9% by mass, an amine value (solid) of 1.0, and a weight average molecular weight of 74,200.

Comparative Synthesis Example 7 (H7)
A four-necked flask equipped with a stirrer, a thermometer, a recirculation cooler, and a nitrogen gas introduction tube is composed of 2-methyl-1,3-propanediol, isophthalic acid, and sebacic acid (isocyanate / sebacic acid = 1/5). 182.1 parts of polyester polyol (hydroxyl value: 15.0 mgKOH / g), 45.5 parts of polypropylene glycol (hydroxyl value: 374.0 mgKOH / g), and 87.15 parts of isophorone diisocyanate were charged, and 90 ° C. was charged under a nitrogen stream. To produce a urethane prepolymer having an isocyanate group content of 5.76%, the reaction solution was cooled to 70 ° C. or lower, and then 352.4 parts of ethyl acetate and 80.6 parts of isopropyl alcohol were added. .. The reaction solution was kept at about 35 to 40 ° C., 31.86 parts of isophorone diamine was dissolved in 95.6 parts of isopropyl alcohol and added dropwise, and the mixture was reacted at 50 ° C. for 3 hours under a stirring frame. Then, 5.77 parts of cyclohexylamine was added and reacted at 50 ° C. for 30 minutes under a stirring frame to obtain a polyurethane resin solution H7.
The obtained polyurethane resin solution (H7) had a resin solid content concentration of 40.1% by mass, a weight average molecular weight of 31,200, and an amine value (solid) of 0.

Comparative Synthesis Example 8 (H8)
A four-necked flask equipped with a stirrer, a thermometer, a recirculation cooler and a nitrogen gas introduction tube is composed of 3-methyl-1,5-pentanediol, isophthalic acid, and sebacic acid (isocyanate / sebacic acid = 3/7). 113.8 parts of polyester polyol (hydroxyl value: 374.0 mgKOH / g), 113.8 parts of polypropylene glycol (hydroxyl value: 22.4 mgKOH / g) and 105.88 parts of isophorone diisocyanate were charged, and at 90 ° C. under a nitrogen stream. After reacting for 10 hours to prepare a urethane prepolymer having an isocyanate group content of 1.87% by mass, 222.3 parts of ethyl acetate was added thereto to prepare a uniform solution of the urethane prepolymer. Next, the urethane prepolymer solution was added to a mixture consisting of 13.06 parts of isophorone diamine, 0.46 parts of cyclohexylamine, 356.5 parts of ethyl acetate and 231.5 parts of isopropyl alcohol, and the reaction was stirred at 45 ° C. for 5 hours. To obtain a polyurethane resin solution H8. The obtained polyurethane resin solution H8 had a resin solid content concentration of 30.0% by mass, an amine value (solid) of 1.5, and a weight average molecular weight of the resin solid content of 80,300.

Comparative Synthesis Example 9 (H9)
3-Methyl-1,5-pentanediol, neopentyl glycol, sebacic acid, adipic acid (3-methyl-1,5-pentane) in a four-necked flask equipped with a stirrer, thermometer, recirculation cooler and nitrogen gas introduction tube. 182.1 parts (hydroxyl value: 56.1 mgKOH / g) of polyester polyol consisting of diol / neopentanediol = 4/1, sebacic acid / adipic acid = 1/1) and 45.5 parts of polypropylene glycol (hydroxyl value: 56) .1 mgKOH / g) and 52.52 parts of isophorone diisocyanate were charged and reacted at 90 ° C. for 10 hours under a nitrogen stream to produce a urethane prepolymer having an isocyanate group content of 3.67% by mass, and then ethyl acetate 186 was added thereto. .8 parts were added to make a uniform solution of urethane prepolymer. Next, the urethane prepolymer solution was added to a mixture consisting of 22.37 parts of isophorone diamine, 0.33 parts of cyclohexylamine, 318.0 parts of ethyl acetate and 201.9 parts of isopropyl alcohol, and the reaction was stirred at 45 ° C. for 5 hours. To obtain a polyurethane resin solution H9. The obtained polyurethane resin solution H9 had a resin solid content concentration of 30.0% by mass, an amine value (solid) of 3.9, and a weight average molecular weight of 61,700.

Comparative Synthesis Example 10 (H10)
3-Methyl-1,5-pentanediol, 2-methyl-1,3-propanediol, sebacic acid, adipic acid (3-methyl-1,5-pentanediol, 3-methyl-1,3-propanediol) in a four-necked flask equipped with a stirrer, thermometer, recirculation cooler and nitrogen gas introduction tube 159.3 parts of polyester polyol consisting of methyl-1,5-pentanediol / 2-methyl-1,3-propanediol = 4/1, sebacic acid / adipic acid = 3/7) (hydroxyl value: 56.1 mgKOH / g) , 68.3 parts of polypropylene glycol (hydroxyl value: 56.1 mgKOH / g) and 50.55 parts of isophorone diisocyanate were charged and reacted at 90 ° C. for 10 hours under a nitrogen stream to urethane having an isocyanate group content of 3.43% by mass. After producing the prepolymer, 185.4 parts of ethyl acetate was added thereto to prepare a uniform solution of urethane prepolymer. Next, the urethane prepolymer solution was added to a mixture consisting of 20.77 parts of isophorone diamine, 0.42 parts of cyclohexylamine, 313.5 parts of ethyl acetate and 199.6 parts of isopropyl alcohol, and the reaction was stirred at 45 ° C. for 5 hours. To obtain a polyurethane resin solution H10. The obtained polyurethane resin solution H10 had a resin solid content concentration of 30.1% by mass, an amine value (solid) of 4.1, and a weight average molecular weight of 60,200.

Comparative Synthesis Example 11 (H11)
3-Methyl-1,5-pentanediol, propylene glycol, sebacic acid, adipic acid (3-methyl-1,5-pentanediol) in a four-necked flask equipped with a stirrer, thermometer, recirculation cooler and nitrogen gas introduction tube. 159.3 parts of polyester polyol (hydroxyl value: 56.1 mgKOH / g) and 68.3 parts of polypropylene glycol (hydroxyl value: 56.1 mgKOH) consisting of / propylene glycol = 4/1, sebacic acid / adipic acid = 1/1) / G) and 50.55 parts of isophorone diisocyanate were charged and reacted at 90 ° C. for 10 hours under a nitrogen stream to produce a urethane prepolymer having an isocyanate group content of 3.43% by mass, and then ethyl acetate 185.4 was added thereto. The parts were added to prepare a uniform solution of urethane prepolymer. Next, the urethane prepolymer solution was added to a mixture consisting of 20.81 parts of isophorone diamine, 0.43 parts of cyclohexylamine, 313.6 parts of ethyl acetate and 199.6 parts of isopropyl alcohol, and the reaction was stirred at 45 ° C. for 5 hours. To obtain a polyurethane resin solution H12. The obtained polyurethane resin solution H12 had a resin solid content concentration of 30.0% by mass, an amine value (solid) of 3.7, and a weight average molecular weight of Mn of 58,400.

The compositions are shown in Tables 1 to 4. The blanks indicate that they are not mixed.

The abbreviations in the table are listed below.
3MPD: 3-Methyl 1,5-pentanediol SeA: Sebacic acid TPA: Terephthalic acid NPG: Neopentyl glycol IPA: Isophthalic acid AdA: Adipate DA: Diamine 2MPD: 2-Methyl-1,3-propanediol PG: Propylene glycol 1,4BG: 1,4-butanediol EG: Ethylene glycol IPDI: Isophorone diisocyanate TDI: Toluene diisocyanate HDI: Hexamethylene diisocyanate PPG: Polypropylene glycol IPDA: Isophorone diamine CHA: Cyclohexylamine (A1): Polyester polyol (A1)
(A2): Polyether polyol (A2)

(Example 1) Example of adjusting white liquid printing ink 20 parts of titanium oxide, 8 parts of nitrocellulose solution, 15 parts of ethyl acetate, 20 parts of polyurethane resin solution A1 obtained in Synthesis Example 1, 1 part of wax, plasticizer A white liquid printing ink was prepared by blending 0.5 parts of the agent, 2 parts of chlorinated polypropylene, 2 parts of the metal chelate cross-linking agent, and 100 parts of isopropyl alcohol in total.

(Examples 2 to 10, Comparative Examples 1 to 7)
A white liquid printing ink was prepared in the same manner as in Example 1 according to the formulations shown in Tables 5 to 9.

Details of the raw materials used are as follows.
Nitrocellulose solution: Nobel nitrocellulose DLX 5-8 / ethyl acetate / IPA = 44.1 / 28 / 27.9
Rosin resin solution: Made by Arakawa Chemical Co., Ltd. Malkid # 31 / IPA = 50/50
Vinyl Chloride Vinyl Acetate Copolymer Solution: Solverine A / NPAc = 15/85 manufactured by Nissin Chemical Co., Ltd.
Titanium oxide: TAYCA Corporation JR-600E
Plasticizer (epoxy soybean oil): DIC Corporation Eposizer W-100EL
Metal chelate cross-linking agent: Matsumoto Chemical Co., Ltd. Olga Chikus TC-100
Chlorinated polypropylene: Nippon Paper Industries Co., Ltd. Supercron 360T
Silica: Fuji Silysia Chemical Ltd. Silicia 350
Wax: Mitsui Chemicals, Inc. Mitsui High Wax 220MP

(Example 11) Example of adjusting blue liquid printing ink 10 parts of DIC Corporation FASTOGEN BLUE FA5380, 20 parts of vinyl chloride vinyl acetate copolymer solution, 30 parts of polyurethane resin solution A3 obtained in Synthesis Example 3, isopropyl alcohol 8 18 parts of ethyl acetate were mixed and kneaded. Further, 2 parts of a chlorinated polypropylene solution, 10 parts of normal propyl acetate, and 2 parts of water were mixed to prepare a blue liquid printing ink.

(Examples 12 to 15, Comparative Examples 8 to 14)
A blue liquid printing ink was prepared in the same manner as in Example 11 according to the formulations shown in Tables 5 to 9.

Details of the raw materials used are as follows.
Vinyl Chloride Vinyl Acetate Copolymer Solution: Solverine A / NPAc = 15/85 manufactured by Nissin Chemical Co., Ltd.
Indigo pigment: DIC Corporation FASTOGEN BLUE FA5380
Chlorinated polypropylene: Nippon Paper Industries Co., Ltd. Supercron 360T

[Manufacturing method of film printed matter]
The obtained white liquid printing ink was printed on a biaxially stretched polypropylene film (hereinafter referred to as OPP film) by a gravure proofing machine equipped with a plate depth of 35 μm gravure plate and dried at 45 ° C. to obtain a printed matter.
The obtained printed matter was evaluated for oil resistance, scratch resistance, and printability of the printed matter according to the following test method.

The obtained blue liquid printing ink was printed on a biaxially stretched polyethylene terephthalate film (hereinafter referred to as PET film) by a gravure proofing machine equipped with a plate depth of 35 μm gravure plate and dried at 45 ° C. to obtain a printed matter.
The obtained printed matter was evaluated for scratch resistance, retort resistance and printability of the printed matter according to the following test method.

(Evaluation item: Oil resistance)
The printed surface of the OPP film printed matter is rubbed 100 times under a load of 200 g with a cloth impregnated with edible salad oil: butter at a ratio of 1: 1 using a Gakushin type friction resistance tester, and oil resistance due to changes in the printed surface. Was evaluated. Evaluation 4 or higher is the practical range.
(Evaluation criteria)
5: No change on the printed surface or the cover cloth.
4: There is no change on the printed surface, but the cover cloth is colored.
3: Streaky scratches are observed on the printed surface.
2: Thick and streaky scratches are observed on the printed surface.
1: Surface scratches are observed on the printed surface.

(Evaluation item: Scratch resistance)
The state of appearance when the printed matter of the OPP film or the printed matter of the PET film was rubbed with a nail was visually evaluated in the following five stages.
(Evaluation criteria)
The film does not come off even after rubbing 5:10 times or more.
The film peels off slightly after 4:10 rubbing.
3: The film peels off by rubbing 4 to 5 times.
The film is peeled off by rubbing 2: 2 to 3 times.
The film can be easily peeled off by rubbing 1: 1.

(Evaluation item: Printability cassoulet test)
The liquid printing inks of Examples and Comparative Examples were diluted with a mixed organic solvent having the same ratio as that used for ink production, and diluted with Zahn Cup No. 3 manufactured by Rigosha for 16 seconds. A biaxially stretched polypropylene film (Futamura Chemical Co., Ltd. FOR) that was subjected to corona discharge treatment on one side using an MD type gravure printing machine (manufactured by Fuji Machinery Co., Ltd.) equipped with a laser gravure plate having a plate depth of 25 μm. Printing was performed on the treated surface having a thickness of 20 μm).
In the blur test, the ratio of the blur area in the highlight printed portion (halftone dot area less than 10%) and the degree of stain on the non-printed portion when the printing speed was 200 m / min at a circumference of 600 mmφ of the gravure plate were visually evaluated. .. Evaluation 4 or higher is the practical range.
(Evaluation criteria)
5: There is no blurring and no stains on the non-printed part.
4: Some blurring is seen, or some stains are seen on the non-printed part.
3: A little blurring is seen, and a little stain is seen on the non-printed part.
2: Blurring is seen, and stains are seen on the non-printed part.
1: A lot of blurring is seen, and a lot of stains are also seen in the non-printed part.

(Evaluation item: Retort resistance)
A urethane-based dry laminating adhesive Dick Dry LX-500 / KW-75 (manufactured by DIC) is applied to the PET film printed matter so that the coating film amount is 3.5 g / m ^2, and after drying, a dry laminating machine (DIC) is applied. Aluminum foil (hereinafter referred to as AL: aluminum foil C manufactured by Toyo Aluminum Kogyo Co., Ltd., 15 μm) was laminated by (manufactured by Engineering) to obtain a two-layer laminate 1. Next, an adhesive was similarly applied onto the AL of the laminate 1, a non-stretched polypropylene film (hereinafter, R-CPP: ZK-75 50 μm manufactured by Toray Synthetic Film Co., Ltd.) was laminated, and aged at 40 ° C. for 5 days. A three-layer composite laminate 2 was obtained.
The obtained laminate 2 was made into a bag in a pouch having a size of 120 mm × 120 mm, and 70 g of a simulated food containing vinegar, salad oil, and meat sauce in a weight ratio of 1: 1: 1 was filled and sealed as the contents. The prepared pouch was subjected to steam retort sterilization treatment at 135 ° C. for 30 minutes, and then the degree of peeling was evaluated in three stages.
◯: There is no peeling.
Δ: There is a small blister-like peeling.
X: There is peeling on the entire surface regardless of size.

The results are shown in Tables 5-9. The blanks indicate that they are not mixed.

As a result, in Examples 1 to 10, excellent results were obtained in oil resistance, scratch resistance, and printability. Further, in Examples 11 to 15, the results were excellent in retort resistance (hot water) resistance, scratch resistance, and printability.

Claims (7)

A liquid printing ink containing a polyurethane resin (A) and a chlorinated polyolefin (B) using a polyester polyol as a reaction raw material.
A liquid printing ink, wherein the polyester polyol is a polyester polyol (A1) containing a polycarboxylic acid containing sebacic acid and an aromatic polycarboxylic acid and a polyol as reaction raw materials. The polyurethane resin (A) is a polyurethane resin obtained by reacting the polyester polyol (A1) with the polyether polyol (A2) with an isocyanate component, and the polyether polyol is 10 to 80% by weight based on the total amount of the polyol. Item 1. The liquid printing ink according to Item 1. The invention according to claim 1 or 2, wherein the polyester polyol (A1) is a polyester polyol having a hydroxyl value of 16 to 300 mgKOH / g, and the polyether polyol (A2) is a polyether polyol having a hydroxyl value of 18.5 to 300 mgKOH / g. Liquid printing ink. The liquid printing ink according to any one of claims 1 to 3, wherein the aromatic polycarboxylic acid in the polyester polyol (A1) is 5 to 80% in molar ratio with respect to the total amount of the polycarboxylic acid. The polyester polyol (A1) is a polyester polyol (A1-1) using a plant-derived polycarboxylic acid containing sebacic acid and an aromatic polycarboxylic acid and a short-chain diol having 2 to 10 carbon atoms as reaction raw materials. The liquid printing ink according to any one of claims 1 to 4. The liquid printing ink according to any one of claims 1 to 5, which contains 0 to 5.0% by mass of silica and 0 to 5.0% by mass of wax with respect to the total amount of ink. A printed matter having a printed layer on which the liquid printing ink according to any one of claims 1 to 6 is printed on a substrate.