JP6745630B2 - (Meth)acrylate resin and printing ink - Google Patents

Description

The present invention relates to a (meth)acrylate resin that can be suitably used for printing ink applications, a curable composition containing the (meth)acrylate resin, a printing ink, and a printed material obtained by printing the printing ink.

Conventionally, diallyl phthalate resin has been widely used as a binder resin for UV-curable printing inks, but recently, the toxicity of diallyl phthalate, which is a raw material for the diallyl phthalate resin, has been pointed out, and there is no concern about toxicity as a substitute for this resin material. Development is required.

As a binder resin for UV-curable printing inks other than diallyl phthalate resin, for example, a polyfunctional isocyanate compound and 2-hydroxyethyl acrylate are reacted in a ratio such that the isocyanate group becomes excessive, and then the obtained reaction product A urethane acrylate resin obtained by reacting an acid diol and a polyol with a residual isocyanate group is known (see Patent Document 1). Such a urethane acrylate resin does not leave 2-hydroxyethyl acrylate, which has high skin irritation, in the resin, and is excellent in safety and hygiene when handling printing ink, but it has curability, fluidity, and Various performances such as misting resistance were not sufficient.

JP 2001-151848 A

Therefore, the problem to be solved by the present invention is to provide a (meth)acrylate resin having an excellent balance between fluidity and misting resistance when used in a printing ink and having high curability, and a curable composition containing the same. Another object of the present invention is to provide a printing ink and a printed matter obtained by printing the printing ink.

As a result of intensive studies to solve the above problems, the inventors have found that a (meth)acrylate resin containing a monohydroxy compound having an unsaturated aliphatic hydrocarbon group having 4 to 50 carbon atoms as an essential reaction raw material is It has been found that the curability is high and the balance between fluidity and misting resistance when used in printing ink is excellent, and the present invention has been completed.

That is, the present invention requires the monohydroxy compound (A), the monohydroxy(meth)acrylate compound (B), and the polyisocyanate compound (C) having an aliphatic unsaturated hydrocarbon group having 4 to 50 carbon atoms. It relates to a (meth)acrylate resin characterized by being used as a reaction raw material.

The present invention further relates to a curable composition containing the (meth)acrylate resin.

The present invention further relates to a printing ink using the curable composition.

The present invention further relates to a printed matter obtained by printing the printing ink.

According to the present invention, a (meth)acrylate resin having an excellent balance between fluidity and misting resistance when used in a printing ink and having high curability, a curable composition and a printing ink containing the same, and the above-mentioned printing A printed matter obtained by printing ink can be provided.

The (meth)acrylate resin of the present invention comprises a monohydroxy compound (A) having an aliphatic unsaturated hydrocarbon group having 4 to 50 carbon atoms, a monohydroxy (meth)acrylate compound (B), and a polyisocyanate compound (C). ) Is used as an essential reaction raw material.

The monohydroxy compound (A) having an aliphatic unsaturated hydrocarbon group having 4 to 50 carbon atoms may be any one as long as it has an aliphatic unsaturated hydrocarbon group having 4 to 50 carbon atoms in its molecular structure. Other specific structures are not limited, and various compounds can be used. Specific examples of the monohydroxy compound (A) include, for example, the following structural formulas (1) to (3).

［式（１）中のＲ^１は不飽和結合を一つ乃至複数有する炭素原子数３〜４９の直鎖型又は分岐型の脂肪族炭化水素基である。式（２）中のＲ^２はそれぞれ独立に炭素原子数１〜４８の直鎖型又は分岐型の脂肪族炭化水素基であり、二つのＲ^２のうち少なくとも一方は不飽和結合を一つ乃至複数有し、二つのＲ^２の炭素原子数の合計は３〜４９である。式（３）中のＲ^３はそれぞれ独立に炭素原子数１〜４７の直鎖型又は分岐型の脂肪族炭化水素基であり、三つのＲ^３のうち少なくとも一つは不飽和結合を一つ乃至複数有し、三つのＲ^３の炭素原子数の合計は４〜４９である。］
の何れかで表される分子構造を有するモノヒドロキシ化合物（Ａ１）や、下記構造式（４）〜（６）

[R ¹ in the formula (1) is a linear or branched aliphatic hydrocarbon group having ^{1 to} plural unsaturated bonds and 3 to 49 carbon atoms. R ^{2 s} in formula (2) are each independently a linear or branched aliphatic hydrocarbon group having 1 to 48 carbon atoms, and at least one of the two R ^{2 s} has one or more unsaturated bonds. The total number of carbon atoms of two R ² is 3 to 49. R ^{3 s} in formula (3) are each independently a linear or branched aliphatic hydrocarbon group having 1 to 47 carbon atoms, and at least one of the three R ^{3 s} has one unsaturated bond. To more than one, and the total number of carbon atoms of the three R ³ is 4 to 49. ]
Or a monohydroxy compound (A1) having a molecular structure represented by any of the following structural formulas (4) to (6)

［式（４）中のＲ^４は炭素原子数３〜４９の直鎖型又は分岐型の脂肪族炭化水素基である。式（５）中のＲ^５はそれぞれ独立に炭素原子数１〜４８の直鎖型又は分岐型の脂肪族炭化水素基であり、二つのＲ^５の炭素原子数の合計は３〜４９である。式（６）中のＲ^６はそれぞれ独立に炭素原子数１〜４７の直鎖型又は分岐型の脂肪族炭化水素基であり、三つのＲ^６の炭素原子数の合計は４〜４９である。］
の何れかで表されるカルボキシ化合物と、ポリオール化合物とのエステル化物であって、分子構造中に一つ乃至複数の不飽和結合を有するモノヒドロキシ化合物（Ａ２）、下記構造式（７）〜（９）

[R ⁴ in Formula (4) is a linear or branched aliphatic hydrocarbon group having 3 to 49 carbon atoms. R ^{5 s} in formula (5) are each independently a linear or branched aliphatic hydrocarbon group having 1 to 48 carbon atoms, and the total number of carbon atoms of two R ^{5 s} is 3 to 49. .. R ⁶ in formula (6) is each independently a linear or branched aliphatic hydrocarbon group having 1 to 47 carbon atoms, and the total number of carbon atoms of three R ⁶ is 4 to 49. .. ]
A monohydroxy compound (A2) having one or a plurality of unsaturated bonds in the molecular structure, which is an esterified product of a carboxy compound represented by any of the above and a polyol compound, and the following structural formulas (7) to ( 9)

［式（７）中のＲ^７は炭素原子数３〜４９の直鎖型又は分岐型の脂肪族炭化水素基である。式（８）中のＲ^８はそれぞれ独立に炭素原子数１〜４８の直鎖型又は分岐型の脂肪族炭化水素基であり、二つのＲ^８の炭素原子数の合計は３〜４９である。式（９）中のＲ^９はそれぞれ独立に炭素原子数１〜４７の直鎖型又は分岐型の脂肪族炭化水素基であり、三つのＲ^９の炭素原子数の合計は４〜４９である。］
の何れかで表されるモノヒドロキシ化合物と、モノヒドロキシカルボン酸化合物とのエステル化物であって、分子構造中に一つ乃至複数の不飽和結合を有するモノヒドロキシ化合物（Ａ３）等が挙げられる。

[R ⁷ in Formula (7) is a linear or branched aliphatic hydrocarbon group having 3 to 49 carbon atoms. R ⁸ in formula (8) is each independently a linear or branched aliphatic hydrocarbon group having 1 to 48 carbon atoms, and the total number of carbon atoms of two R ⁸ is 3 to 49. .. R ⁹ in formula (9) is independently a linear or branched aliphatic hydrocarbon group having 1 to 47 carbon atoms, and the total number of carbon atoms of three R ⁹ is 4 to 49. .. ]
And a monohydroxy compound represented by any of the above, and a monohydroxy compound (A3) having one or more unsaturated bonds in the molecular structure.

Regarding the monohydroxy compound (A1), among the compounds represented by the structural formula (1), a (meth)acrylate resin having an excellent balance between fluidity and misting resistance is obtained. Compounds in which R ^{1 of} is a linear aliphatic unsaturated hydrocarbon group are preferred. Moreover, the number of carbon atoms of R ¹ is more preferably in the range of 8 to 24, and particularly preferably in the range of 10 to 20. The unsaturated bond site is preferably an ethylenic double bond, and the number of unsaturated bonds in the molecule is preferably in the range of 1 to 3. Such a compound is, for example, a compound having one unsaturated bond site such as tetradecen-1-ol, pentadecen-1-ol, hexadecen-1-ol, octadecen-1-ol, and icocen-1-ol; tetra. Decadiene-1-ol, pentadecadiene-1-ol, hexadecadiene-1-ol, heptadecadiene-1-ol, octadecadiene-1-ol, nonadecadiene-1-ol, icosadien-1-ol, etc. Compounds having two unsaturated bond sites; tetradecatriene-1-ol, pentadecatriene-1-ol, hexadecatriene-1-ol, heptadecatrien-1-ol, octadecatriene-1-ol, Examples thereof include compounds having three unsaturated bond sites such as nonadecatrien-1-ol and icosatrien-1-ol; and the like.

Among the compounds represented by the structural formula (2), at least one of the two R ^{2 in} the structural formula (2), since it is a (meth)acrylate resin having an excellent balance between fluidity and misting resistance. Is preferably an aliphatic hydrocarbon group having 8 to 24 carbon atoms, and more preferably an aliphatic hydrocarbon group having 10 to 20 carbon atoms. Further, R ² is preferably a linear aliphatic hydrocarbon group. The unsaturated bond site is preferably an ethylenic double bond, and the number of unsaturated bonds in the molecule is preferably in the range of 1 to 3. Such compounds include, for example, hexadecen-4-ol, heptadecen-3-ol, octadecen-3-ol, octadecen-4-ol, octadecen-5-ol, nonadecen-2-ol, nonadecen-3-ol, Nonadecen-4-ol, icosen-3-ol, henicosen-3-ol, henicosen-4-ol, docosen-5-ol and the like can be mentioned.

Among the compounds represented by the structural formula (3), since it is a (meth)acrylate resin having an excellent balance between fluidity and misting resistance, at least one of the three R ^{3 in} the structural formula (3) is used. Is preferably an aliphatic hydrocarbon group having 8 to 24 carbon atoms, and more preferably an aliphatic hydrocarbon group having 10 to 20 carbon atoms. Further, R ² is preferably a linear aliphatic hydrocarbon group. Further, R ³ is preferably a linear aliphatic hydrocarbon group. The unsaturated bond site is preferably an ethylenic double bond, and the number of unsaturated bonds in the molecule is preferably in the range of 1 to 3.

The monohydroxy compound (A2) is an esterified product of a carboxy compound represented by any one of the structural formulas (4) to (6) and a polyol compound, and has one or more unsaturated groups in its molecular structure. It has a bond. R ⁴ , R ⁵ , and R ⁶ in the structural formulas (4) to (6) may be selected so that the monohydroxy compound (A2) contains one or more unsaturated bonds. Among them, at least one of R ⁴ , R ⁵ , and R ⁶ present in the monohydroxy compound (A2) has 8 to 24 carbon atoms because it is a (meth)acrylate resin having an excellent balance between fluidity and misting resistance. Is preferably an unsaturated aliphatic hydrocarbon group, and particularly preferably at least one is an unsaturated aliphatic hydrocarbon group having 10 to 20 carbon atoms. Further, it is more preferable that each of R ⁴ , R ⁵ and R ⁶ is a linear aliphatic hydrocarbon group.

Examples of the polyol compound which is a raw material of the compound (A2) include ethylene glycol, propanediol, 2-methylpropanediol, butanediol, neopentyl glycol, 3-methylpentanediol, hexanediol, glycerin, trimethylolethane and tri Aliphatic polyol compounds such as methylolpropane, pentaerythritol, ditrimethylolpropane and dipentaerythritol can be mentioned. These may be used alone or in combination of two or more.

When the polyol compound is a trifunctional or higher functional polyol compound, the carboxy compound to be reacted with the polyol compound is one of the carboxy compounds represented by any of the structural formulas (4) to (6). Or two or more types may be used in combination. Among them, those obtained by using the compound represented by the structural formula (4) are preferable because they are (meth)acrylate resins having an excellent balance between fluidity and misting resistance.

The monohydroxy compound (A3) is an esterified product of the monohydroxy compound represented by any of the structural formulas (7) to (9) and a monohydroxycarboxylic acid compound, and has one of the molecular structures. It has the above unsaturated bonds. R ⁷ , R ⁸ and R ⁹ in the structural formulas (7) to (9) may be selected so that the monohydroxy compound (A3) contains at least one unsaturated bond. Among them, at least one of R ⁷ , R ⁸ and R ⁹ present in the monohydroxy compound (A3) has 8 to 24 carbon atoms because it is a (meth)acrylate resin having an excellent balance between fluidity and misting resistance. Is preferably an unsaturated aliphatic hydrocarbon group, and particularly preferably at least one is an unsaturated aliphatic hydrocarbon group having 10 to 20 carbon atoms. Further, it is more preferable that R ⁷ , R ⁸ and R ⁹ are all linear aliphatic hydrocarbon groups.

Examples of the monohydroxycarboxylic acid compound as a raw material of the monohydroxy compound (A3) include malic acid, itamaric acid, 3-methyl-3-hydroxyglutaric acid, 4-hydroxypimelic acid, and 2,4-dimethyl-3. -Hydroxyglutaric acid and the like can be mentioned. These may be used alone or in combination of two or more.

When the monohydroxycarboxylic acid compound is a bifunctional or higher functional carboxylic acid compound, the monohydroxy compound (A3) to be reacted therewith is one of the compounds represented by any one of the structural formulas (7) to (9). One kind may be used alone, or two or more kinds may be used in combination. Among them, those obtained by using the compound represented by the structural formula (7) are preferable because they are (meth)acrylate resins having a good balance between fluidity and misting resistance.

Among these monohydroxy compounds (A) having an aliphatic unsaturated hydrocarbon group having 4 to 50 carbon atoms, a (meth)acrylate resin having an excellent balance between fluidity and misting resistance is used, and therefore secondary or primary. A compound having a primary hydroxyl group is preferable, a compound represented by the structural formula (1) or (2) is more preferable, and a compound represented by the structural formula (1) is particularly preferable.

The monohydroxy (meth)acrylate compound (B) is a compound having one hydroxyl group and one or more (meth)acryloyl groups in the molecular structure, and examples thereof include hydroxyethyl (meth)acrylate and hydroxypropyl. Aliphatic monohydroxymono(meth)acrylate compounds such as (meth)acrylate and hydroxybutyl acrylate; glycerin di(meth)acrylate, trimethylolpropane di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol penta( Aliphatic monohydroxy poly(meth)acrylate compounds such as (meth)acrylate; 4-hydroxyphenyl acrylate, β-hydroxyphenethyl acrylate, 4-hydroxyphenethyl acrylate, 1-phenyl-2-hydroxyethyl acrylate, acrylic acid Aromatic monohydroxymono(meth)acrylate compounds such as 3-hydroxy-4-acetylphenyl, 2-hydroxy-3-phenoxypropyl acrylate; the above monohydroxy(meth)acrylate compounds, ethylene oxide, propylene oxide, tetrahydrofuran, ethylglycidyl Polyoxyalkylene-modified monohydroxy(meth)acrylate compound obtained by ring-opening polymerization with various cyclic ether compounds such as ether, propylglycidyl ether, butylglycidyl ether, phenylglycidyl ether, and allylglycidyl ether; said monohydroxy(meth)acrylate Examples thereof include a lactone-modified monohydroxy(meth)acrylate compound obtained by polycondensation of a compound and a lactone compound such as ε-caprolactone. These may be used alone or in combination of two or more.

Among them, the above-mentioned aliphatic monohydroxy mono(meth)acrylate compound, aliphatic monohydroxy poly(meth)acrylate compound, and polyoxy compounds thereof are obtained because the (meth)acrylate resin has an excellent balance between fluidity and misting resistance. An alkylene modified product or a lactone modified product is preferable, and an aliphatic monohydroxymono(meth)acrylate compound is more preferable.

Examples of the polyisocyanate compound (C) include aliphatic diisocyanate compounds such as hexamethylene diisocyanate; alicyclic diisocyanate compounds such as isophorone diisocyanate; tolylene diisocyanate, xylylene diisocyanate, diphenylmethane-4,4′-diisocyanate, 1, Aromatic diisocyanate compounds such as 5-naphthalene diisocyanate; the following structural formula (4)

［式中、Ｒ^４はそれぞれ独立に水素原子、炭素原子数１〜６の炭化水素基の何れかである。Ｒ^５はそれぞれ独立に水素原子、炭素原子数１〜４のアルキル基、又は構造式（４）で表される構造部位と＊印が付されたメチレン基を介して連結する結合点の何れかである。ｍは１〜３の整数であり、ｎは１以上の整数である。］
で表される繰り返し構造を有するポリメチレンポリフェニルポリイソシアネート；これらのイソシアヌレート変性体、アダクト変性体、ビウレット変性体、アロファネート変性体等が挙げられる。これらはそれぞれ単独で使用しても良いし、２種類以上を併用しても良い。

[In the formula, each R ⁴ is independently a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms. R ^{5 s} are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a bonding point connecting the structural site represented by the structural formula (4) and the methylene group marked with *. Is. m is an integer of 1 to 3, and n is an integer of 1 or more. ]
Polymethylene polyphenyl polyisocyanate having a repeating structure represented by the following; and isocyanurate modified products thereof, adduct modified products, biuret modified products, and allophanate modified products thereof. These may be used alone or in combination of two or more.

Among them, a polyisocyanate compound having a ring structure in the molecular structure, that is, a polyisocyanate compound having an isocyanurate ring structure, which is an alicyclic compound, since it is a (meth)acrylate resin having an excellent balance between fluidity and misting resistance. A diisocyanate compound, the aromatic diisocyanate compound, and polymethylene polyphenyl polyisocyanate having a molecular structure represented by the structural formula (4) are preferable. Furthermore, a polyisocyanate compound having an aromatic ring in the molecular structure, that is, the aromatic diisocyanate compound, a polymethylene polyphenyl polyisocyanate having a molecular structure represented by the structural formula (4), and their isocyanurate modified products Particularly preferred are adduct modified products, biuret modified products, and allophanate modified products.

The polymethylene polyphenyl polyisocyanate having the molecular structure represented by the structural formula (4) preferably contains 30% by mass or more of the component in the structural formula (4) in which n is 2 or more. Further, it is preferable that the viscosity measured by an E-type viscometer (25° C.) is in the range of 100 to 700 mPa·s.

The (meth)acrylate resin of the present invention is a monohydroxy compound (A) having an aliphatic unsaturated hydrocarbon group having 4 to 50 carbon atoms, a monohydroxy (meth)acrylate compound (B), and a polyisocyanate compound ( In addition to C), other reaction raw materials may be used together. Examples of the other reaction raw material include a polyol compound (D).

The polyol compound (D) may be a compound having a plurality of hydroxyl groups in the molecular structure, and examples thereof include ethylene glycol, propanediol, 2-methylpropanediol, butanediol, neopentyl glycol, 3-methylpentanediol, Aliphatic polyol compounds such as hexanediol, glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, ditrimethylolpropane, dipentaerythritol; the aliphatic polyol compounds and ethylene oxide, propylene oxide, tetrahydrofuran, ethylglycidyl ether, propylglycidyl Polyoxyalkylene-modified polyol compound obtained by ring-opening polymerization with various cyclic ether compounds such as ether, butyl glycidyl ether, phenyl glycidyl ether, and allyl glycidyl ether; of the aliphatic polyol compound and a lactone compound such as ε-caprolactone Lactone-modified polyol compound obtained by polycondensation; the above-mentioned aliphatic polyol compound, and dicarboxylic acid such as succinic acid, adipic acid, sebacic acid, (anhydrous)phthalic acid, maleic acid, fumaric acid, and 1,4-cyclohexanedicarboxylic acid Examples thereof include polyester polyols obtained by co-condensation of These may be used alone or in combination of two or more.

Among them, the aliphatic polyol compound is preferable, since it is a (meth)acrylate resin having excellent balance between fluidity and misting resistance when used in a printing ink, and having high curability, glycerin, trimethylolethane, A trifunctional aliphatic polyol compound such as trimethylolpropane is more preferable.

In the (meth)acrylate resin of the present invention, the ratio of each component in the reaction raw material is appropriately adjusted according to desired resin properties such as molecular weight and (meth)acryloyl group equivalent, and is not particularly limited. is not. For example, when the (meth)acrylate resin of the present invention uses the components (A) to (C) and the component (D) used as necessary as a reaction raw material, generally 1 mol of the isocyanate group in the reaction raw material is used. On the other hand, it is preferable to react the hydroxyl groups in the reaction raw material at a ratio of 0.9 to 1.1 mol.

A more preferable resin design of the (meth)acrylate resin is 0.1 to 30 parts by mass in 100 parts by mass of the total amount of the reaction raw materials, because the (meth)acrylate resin has an excellent balance between fluidity and misting resistance. Is preferably a monohydroxy compound (A) having an aliphatic unsaturated hydrocarbon group having 4 to 50 carbon atoms, and 0.3 to 15 parts by mass of 4 to 4 carbon atoms having the unsaturated bond site. Particularly preferred are 50 aliphatic monohydroxy compounds (A).

When the (meth)acrylate resin uses the polyol compound (D) as a reaction raw material, a (meth)acrylate resin having an excellent balance between fluidity and misting resistance when used in a printing ink and having high curability Therefore, the total number of moles of the hydroxyl group of the monohydroxy compound (A) having an aliphatic unsaturated hydrocarbon group having 4 to 50 carbon atoms and the hydroxyl group of the monohydroxy (meth)acrylate compound (B). And the ratio [(A _OH +B _OH )/(D _OH )] of the polyol compound (D) to the number of moles of hydroxyl groups are preferably in the range of 8/2 to 5/5.

The method for producing the (meth)acrylate resin of the present invention is not particularly limited, and for example, it can be produced by a general method for producing a urethane acrylate resin. As an example of the production method, for example, the monohydroxy compound (A) having an aliphatic unsaturated hydrocarbon group having 4 to 50 carbon atoms, the monohydroxy (meth)acrylate compound (B), and the polyisocyanate compound ( Examples include a method of reacting C) to obtain an isocyanate group-containing intermediate, and then reacting the intermediate with the above-mentioned polyol compound (D) used as necessary.

Specifically, first, the polyisocyanate compound (C) is charged into a reaction vessel, heated to 20 to 120° C., and the monohydroxy compound (A having an aliphatic unsaturated hydrocarbon group having 4 to 50 carbon atoms). ) And the monohydroxy (meth)acrylate compound (B) are continuously or intermittently added to the reaction system to react them. In the reaction, a well-known and commonly used urethanization catalyst such as zinc octylate, various antioxidants, polymerization inhibitors and the like may be used, if desired. Then, the above-mentioned polyol compound (D), which is used if necessary, is added to the reaction system to further react in the temperature range of 20 to 120° C., and the end point of the reaction is determined by the infrared absorption spectrum of 2250 cm ⁻¹ showing an isocyanate group. After confirmation, the desired (meth)acrylate resin is obtained.

The weight average molecular weight (Mw) of the (meth)acrylate resin of the present invention is in the range of 1,000 to 30,000 because it is excellent in fluidity and misting resistance when used in printing ink applications. It is preferably in the range of 3,000 to 20,000.

In the present invention, the weight average molecular weight (Mw) is a value measured by gel permeation chromatography (GPC) under the following conditions.

Measuring device: HLC-8220GPC manufactured by Tosoh Corporation
Column; Tosoh Corporation TSK-GUARDCOLUMN SuperHZ-L
+ Tosoh Corporation TSK-GEL SuperHZM-M×4
Detector; RI (differential refractometer)
Data processing: Multi-station GPC-8020 modelII manufactured by Tosoh Corporation
Measurement conditions; Column temperature 40°C
Solvent tetrahydrofuran
Flow rate 0.35 ml/min Standard; Monodisperse polystyrene sample; 0.2% by mass of tetrahydrofuran solution in terms of resin solid content filtered with a microfilter (100 μl)

Further, the (meth)acryloyl group content of the (meth)acrylate resin of the present invention has high curability and is excellent in gloss of the printing surface when used for printing ink applications, so that it is 1.5 to 4.0 mmol/ The range of g is preferable, the range of 2.0 to 3.5 mmol/g is more preferable, and the range of 2.5 to 3.5 mmol/g is particularly preferable. The (meth)acryloyl group content of the (meth)acrylate resin in the present invention is a theoretical value calculated from the reaction raw materials used.

The curable composition of the present invention contains, in addition to the (meth)acrylate resin, other (meth)acrylate compound (X), a polymerization initiator (Y), various additives, and the like, if desired. ..

Examples of the other (meth)acrylate compounds (X) include various (meth)acrylate monomers (X1), urethane (meth)acrylates (X2) other than the (meth)acrylate resin of the present invention, and epoxy (meth). ) Acrylate (X3) and the like.

The (meth)acrylate monomer (X1) is, for example, an aliphatic mono(meth)acrylate compound such as methyl(meth)acrylate, ethyl(meth)acrylate, propyl(meth)acrylate, butyl(meth)acrylate; cyclohexyl(meth). A) alicyclic mono(meth)acrylate compounds such as acrylate, isobornyl(meth)acrylate, adamantyl mono(meth)acrylate; heterocyclic mono(meth)acrylate compounds such as glycidyl(meth)acrylate, tetrahydrofurfuryl acrylate; benzyl Aromatic mono(meth)acrylate compounds such as (meth)acrylate and phenoxy(meth)acrylate; Hydroxyl group-containing mono(meth)acrylate compounds such as hydroxyethyl(meth)acrylate and hydroxypropyl(meth)acrylate; A polyoxyalkylene-modified mono(meth)acrylate compound having a polyoxyethylene chain such as a polyoxyethylene chain, a polyoxypropylene chain, or a polyoxytetramethylene chain introduced into the molecular structure of the (meth)acrylate compound; A lactone-modified mono(meth)acrylate compound in which a (poly)lactone structure is introduced into the molecular structure of the (meth)acrylate compound;

Aliphatic di(meth)acrylate compounds such as ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, butanediol di(meth)acrylate, hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate Alicyclic di(meth)acrylate compounds such as norbornane di(meth)acrylate, norbornane dimethanol di(meth)acrylate, dicyclopentanyl di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate; biphenols Aromatic di(meth)acrylate compounds such as di(meth)acrylate and bisphenol di(meth)acrylate; polyoxyethylene chains, polyoxypropylene chains, polyoxytetra in the molecular structures of the various di(meth)acrylate compounds. A polyoxyalkylene-modified di(meth)acrylate compound having a polyoxyalkylene chain such as a methylene chain introduced therein; a lactone-modified di(meth) having a (poly)lactone structure introduced into the molecular structure of each of the various di(meth)acrylate compounds Acrylate compound;

Aliphatic tri(meth)acrylate compounds such as trimethylolpropane tri(meth)acrylate and glycerin tri(meth)acrylate; pentaerythritol tri(meth)acrylate, ditrimethylolpropane tri(meth)acrylate, dipentaerythritol tri(meth) Hydroxy group-containing tri(meth)acrylate compounds such as acrylates; polyoxyalkylene chains such as polyoxyethylene chains, polyoxypropylene chains, and polyoxytetramethylene chains were introduced into the molecular structures of the various tri(meth)acrylate compounds. A polyoxyalkylene-modified tri(meth)acrylate compound; a lactone-modified tri(meth)acrylate compound in which a (poly)lactone structure is introduced into the molecular structure of each of the various tri(meth)acrylate compounds;

4-functional or higher-functional aliphatic poly(meth)acrylate compounds such as pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate; dipentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate Tetraerythritol penta(meth)acrylate and other tetrafunctional or higher functional hydroxyl group-containing poly(meth)acrylate compounds; polyoxyethylene chains, polyoxypropylene chains, polyoxytetramethylene in the molecular structures of the various poly(meth)acrylate compounds. Tetra- or higher-functional polyoxyalkylene-modified poly(meth)acrylate compound having a polyoxyalkylene chain introduced therein; tetra- or higher functional having a (poly)lactone structure introduced into the molecular structure of each of the various poly(meth)acrylate compounds And the lactone-modified poly(meth)acrylate compound.

Examples of the urethane (meth)acrylate compound (X2) include those obtained by reacting various polyisocyanate compounds, hydroxyl group-containing (meth)acrylate compounds, and, if necessary, various polyol compounds. Examples of the polyisocyanate compound include diisocyanate compounds such as hexamethylene diisocyanate, isophorone diisocyanate, tolylene diisocyanate, xylylene diisocyanate, and 4,4′-diphenylmethane diisocyanate, or nurate modified products, adduct modified products, and biuret modified products thereof. .. Examples of the hydroxyl group-containing (meth)acrylate compound include hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, trimethylolpropane diacrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, and Examples thereof include modified polyoxyalkylenes and modified polylactones. Examples of the polyol compound include ethylene glycol, propylene glycol, butanediol, hexanediol, polyoxyethylene glycol, polyoxypropylene glycol, glycerin, trimethylolpropane and pentaerythritol.

Examples of the epoxy (meth)acrylate compound (X3) include bisphenol type epoxy resins and (meth)acrylic acid esters of epoxy group-containing compounds such as trimethylolpropane triglycidyl ether.

These other (meth)acrylate compounds (X) may be used alone or in combination of two or more kinds. Among them, the (meth)acrylate monomer (X1) is preferable, and the tri- or more-functional (meth)acrylate compound is more preferable, because the curability is high and the coating strength on the printed surface when used for printing ink is excellent. .. Furthermore, aliphatic tri(meth)acrylate compounds such as trimethylolpropane tri(meth)acrylate and glycerin tri(meth)acrylate; polyoxyethylene chain, polyoxypropylene in the molecular structure of the aliphatic tri(meth)acrylate compound. Chain, polyoxyalkylene-modified tri(meth)acrylate compound introduced with polyoxyalkylene chain such as polyoxytetramethylene chain; pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, dipentaerythritol hexa(meta) ) Tetrafunctional or higher-functional aliphatic poly(meth)acrylate compounds such as acrylates; polyoxyethylene chains, polyoxypropylene chains, polyoxytetramethylene chains in the molecular structure of the tetrafunctional or higher-functional aliphatic poly(meth)acrylate compounds Particularly preferred are polyoxyalkylene-modified poly(meth)acrylate compounds having 4 or more functional groups introduced with a polyoxyalkylene chain.

In the case of using these and other other (meth)acrylate compounds (X), the curability is high, and the coating film strength of the printing surface when used in printing ink applications is excellent. The other (meth)acrylate compound (X) is preferably used in the range of 5 to 300 parts by mass, and more preferably in the range of 50 to 200 parts by mass with respect to 100 parts by mass of the acrylate resin.

Examples of the polymerization initiator (Y) include an intramolecular cleavage type photopolymerization initiator and a hydrogen abstraction type photopolymerization initiator, and any of them may be used. The intramolecular cleavage type photopolymerization initiator is, for example, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethylketal, 1-(4-isopropylphenyl)-2-hydroxy. 2-methylpropan-1-one, 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl)ketone, 1-hydroxycyclohexyl-phenylketone, 2-hydroxy-1-{4-[4 -(2-Hydroxy-2-methyl-propionyl)-benzyl]-phenyl}-2-methyl-propan-1-one, 2,2-dimethoxy-1,2-diphenylethan-1-one, 2,2- Acetophenone compounds such as diethoxy-1,2-diphenylethan-1-one; 1-[4-(phenylthio)-,2-(O-benzoyloxime)], 1-[9-ethyl-6-(2- Methylbenzoyl)-9H-carbazol-3-yl]-, 1-(O-acetyloxime) and other oxime compounds, 3,6-bis(2-methyl-2-morpholinopropanonyl)-9-butylcarbazole Carbazole compounds such as benzoin, benzoin methyl ether, benzoin isopropyl ether and other benzoin compounds;

2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butan-1-one, 2-(dimethylamino)-2-(4-methylbenzyl)-1-(4-morpholinophenyl)butane Aminoalkylphenones such as -1-one, 2-methyl-2-morpholino((4-methylthio)phenyl)propan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone Compounds: bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl -Acylphosphine oxide compounds such as pentylphosphine oxide; benzyl, methylphenylglyoxy ester and the like.

Examples of the hydrogen abstraction-type photopolymerization initiator include benzophenone, methyl-4-phenylbenzophenone o-benzoylbenzoate, 4,4′-dichlorobenzophenone, hydroxybenzophenone, 4-benzoyl-4′-methyl-diphenylsulfide, and acrylic. Benzophenone, 3,3′,4,4′-tetra(t-butylperoxycarbonyl)benzophenone, 3,3′-dimethyl-4-methoxybenzophenone and other benzophenone compounds; 2-isopropylthioxanthone, 2,4-dimethyl Thioxanthone compounds such as thioxanthone, 2,4-diethylthioxanthone, and 2,4-dichlorothioxanthone; aminobenzophenone compounds such as 4,4′-bisdimethylaminobenzophenone and 4,4′-bisdiethylaminobenzophenone; other 10-butyl 2-chloroacridone, 2-ethylanthraquinone, 9,10-phenanthrenequinone, camphorquinone and the like can be mentioned.

These polymerization initiators (Y) may be used alone or in combination of two or more. Among these, aminoalkylphenone compounds are preferable from the viewpoint of excellent curability, and particularly when a UV-LED light source that emits ultraviolet rays having an emission peak wavelength in the range of 350 to 420 nm is used as an active energy ray source. Are preferably used in combination with an aminoalkylphenone compound, an acylphosphine oxide compound, and an aminobenzophenone compound, from the viewpoint of excellent curability.

The addition amount of the polymerization initiator (Y) is preferably in the range of 0.1 to 10 parts by mass based on 100 parts by mass of the curable composition.

The curable composition of the present invention may contain a photosensitizer in addition to the polymerization initiator (Y). Examples of the photosensitizer include amine compounds such as aliphatic amines, ureas such as o-tolylthiourea, sodium diethyldithiophosphate, sulfur compounds such as s-benzylisothiuronium-p-toluenesulfonate, and the like. .. The addition amount of these photosensitizers is preferably in the range of 0.1 to 10 parts by mass based on 100 parts by mass of the curable composition.

The curable composition of the present invention is further a pigment, dye, extender pigment, organic or inorganic filler, organic solvent, antistatic agent, defoaming agent, viscosity modifier, polymerization inhibitor, light stabilizer, weathering stabilizer, Additives such as a heat resistance stabilizer, a UV absorber, an antioxidant, a leveling agent, a pigment dispersant, and a wax may be contained.

Examples of the pigment include publicly known and commonly used organic pigments for coloring, and examples thereof include organic pigments for printing inks described in "Organic Pigment Handbook (Author: Isao Hashimoto, Publisher: Color Office, 2006 First Edition)". Examples include soluble azo pigments, insoluble azo pigments, condensed azo pigments, metal phthalocyanine pigments, metal-free phthalocyanine pigments, quinacridone pigments, perylene pigments, perinone pigments, isoindolinone pigments, isoindoline pigments, dioxazine pigments, thioindigo pigments, anthraquinone. A system pigment, a quinophthalone pigment, a metal complex pigment, a diketopyrrolopyrrole pigment, a carbon black pigment, and other polycyclic pigments can be used. The optimum amount of these pigments to be added varies depending on the type of pigment and the like, but is preferably in the range of 5 to 30 parts by mass with respect to 100 parts by mass of the curable composition.

The extender pigment is, for example, titanium oxide, claphite, zinc, lime carbonate powder, precipitated calcium carbonate, gypsum, clay, silica powder, diatomaceous earth, talc, kaolin, alumina white, barium sulfate, aluminum stearate, magnesium carbonate, Barite powder, glass beads, etc. are raised. The optimum amount of these extender pigments varies depending on the type of pigment and the like, but it is preferably in the range of 0.1 to 20 parts by mass based on 100 parts by mass of the curable composition.

The printing ink of the present invention is not particularly limited in its composition and the like as long as it uses the (meth)acrylate resin of the present invention, and the composition and the composition ratio are appropriately adjusted depending on the intended printing application, performance and the like. can do. Examples of the manufacturing method include a method in which a mixture of each component is stirred and mixed with a mixer or the like, and kneaded using a disperser such as a three-roll mill or a bead mill.

The printing ink of the present invention can be cured by irradiating with active energy rays. Examples of the active energy rays include ionizing radiation such as ultraviolet rays, electron rays, α rays, β rays, and γ rays. Examples of light sources include germicidal lamps, fluorescent lamps for ultraviolet rays, UV-LEDs, carbon arcs, xenon lamps, high-pressure mercury lamps for copying, medium-pressure or high-pressure mercury lamps, ultra-high pressure mercury lamps, electrodeless lamps, metal halide lamps, and natural light. And an electron beam from a scanning or curtain type electron beam accelerator.

The printing ink of the present invention can be printed on various base materials such as paper and various plastic films. Specifically, catalogs, posters, leaflets, CD jackets, direct mails, brochures, paper base materials used for packaging cosmetics and beverages, pharmaceuticals, toys, equipment, etc.; polypropylene film, polyethylene terephthalate film, foods and beverages, Plastic film base materials for packaging materials such as cosmetics; aluminum foil, synthetic paper, and various other base materials conventionally used as print base materials can be used as print targets.

The printing method of the printing ink of the present invention is not particularly limited, and for example, lithographic offset printing, letterpress printing, gravure printing, gravure offset printing, flexographic printing, screen printing and the like can be used. Among them, it can be particularly suitably used in planographic offset printing in which water is continuously supplied to the plate surface. Offset printers that continuously supply water are manufactured and sold by a number of printer manufacturers, and examples include Heidelberg, Komori Corporation, Ryobi MHI Graphic Technology, Man Roland, KBA, etc. The present invention can be preferably used in any sheet feeding system, such as a sheet-fed offset printing machine using sheet-shaped printing paper and an offset rotary printing machine using reel-shaped printing paper. More specifically, offset printing machines such as the Speedmaster series manufactured by Heidelberg, the Lithrone series manufactured by Komori Corporation, and the diamond series manufactured by Ryobi MHI Graphic Technology can be mentioned.

Hereinafter, the present invention will be described in more detail with reference to examples. The present invention is not limited to these examples.

Infrared absorption spectrum measurement conditions [model] FT/IR-4100 manufactured by JASCO Corporation
[Measurement conditions] The completion of the reaction was confirmed by confirming the infrared absorption spectrum at 2250 cm ^-1 showing an isocyanate group.

Measurement conditions for weight average molecular weight (Mw) The weight average molecular weight (Mw) was measured by gel permeation chromatography (GPC) under the following conditions.
Measuring device: HLC-8220GPC manufactured by Tosoh Corporation
Column; Tosoh Corporation TSK-GUARDCOLUMN SuperHZ-L
+ Tosoh Corporation TSK-GEL SuperHZM-M×4
Detector; RI (differential refractometer)
Data processing: Multi-station GPC-8020 modelII manufactured by Tosoh Corporation
Measurement conditions; Column temperature 40°C
Solvent tetrahydrofuran
Flow rate 0.35 ml/min Standard; Monodisperse polystyrene sample; 0.2% by mass of tetrahydrofuran solution in terms of resin solid content filtered with a microfilter (100 μl)

Example 1 Production of (meth)acrylate resin (1) A four-necked flask equipped with a stirrer, a gas introduction tube, a condenser, and a thermometer has a repeating structure represented by the following structural formula (4-1). Polymethylene polyphenyl polyisocyanate (BASF INOAC Polyurethane Co., Ltd. "Luplanate M20S": Isocyanate group content 31% by mass) 58.9 parts by mass, tertiary butyl hydroxytoluene 0.5 parts by mass, methoxyhydroquinone 0.05 parts by mass , 0.02 parts by mass of zinc octylate were added, and the temperature was raised to 50°C. While stirring the reaction system, 35.2 parts by mass of 2-hydroxyethyl acrylate and 2 parts by mass of oleyl alcohol [(9Z)-9-octadecen-1-ol] were added dropwise over 1 hour. After reacting at 90° C. for 3 hours, 4 parts by mass of glycerin was added. The reaction was continued at 90° C., and it was confirmed that the infrared absorption spectrum at 2250 cm ⁻¹ showing an isocyanate group disappeared, and (meth)acrylate resin (1) was obtained. The weight average molecular weight (Mw) of the (meth)acrylate resin (1) was 5,492, and the theoretical value of the (meth)acryloyl group content calculated from the reaction raw materials was 3.03 mmol/g.

［式中、Ｒ^５はそれぞれ独立に水素原子又は構造式（４−１）で表される構造部位と＊印が付されたメチレン基を介して連結する結合点の何れかである。ｍは１〜３の整数であり、ｎは１以上の整数である。］

[In the formula, R ^{5 s} are each independently a hydrogen atom or a bonding point connecting to the structural moiety represented by the structural formula (4-1) and the methylene group marked with *. m is an integer of 1 to 3, and n is an integer of 1 or more. ]

Examples 2 to 9 Production of (meth)acrylate resins (2) to (9) (meth)acrylate was carried out in the same manner as in Example 1 except that the type and the amount of each raw material component were changed as shown in Table 1 below. Resins (2) to (9) were obtained.

(*) Isocyanurate modified hexamethylene diisocyanate: "Sumijour N3300" manufactured by Sumika Bayer Urethane Co., Ltd. 22% by mass in isocyanate group content

Comparative Production Example 1 Production of (meth)acrylate resin (1′) In a four-necked flask equipped with a stirrer, a gas introduction tube, a condenser, and a thermometer, 16.3 parts by mass of tolylene diisocyanate and tert-butyl hydroxytoluene were used. 0.1 parts by mass, 0.02 parts by mass of methoxyhydroquinone, and 0.02 parts by mass of zinc octylate are added, the temperature is raised to 75° C., and 3.7 parts by mass of 2-hydroxyethyl acrylate is added dropwise under stirring for 1 hour. did. After dropping, after reacting at 75° C. for 3 hours, as a second step, 80.0 parts by mass of polypropylene glycol (“Actcole D-3000” number average molecular weight 3000 manufactured by Mitsui Chemicals, Inc.) was added, and further reacted at 75° C. Then, the reaction was carried out until the infrared absorption spectrum at 2250 cm −1 indicating an isocyanate group disappeared to obtain a (meth)acrylate resin (1′). The weight average molecular weight (Mw) of the (meth)acrylate resin (1′) was 5,680, and the theoretical value of the (meth)acryloyl group content calculated from the reaction raw materials was 0.32 mmol/g.

Examples 10 to 18 and Comparative Example 1
The respective components were blended in the proportions shown in Tables 2 and 3 below, and the mixture was stirred using a mixer (single screw dissolver), and then the blended product was kneaded using a three-roll mill to prepare a printing ink. Various evaluations were performed on the obtained printing ink under the following conditions. The results are shown in Tables 2 and 3.

Details of each component used for preparing the printing ink are as follows: Other (meth)acrylate compound (X-1): ethylene oxide-modified trimethylolpropane triacrylate (“MIRAMER M3130” manufactured by MIWON, viscosity: 50-70 mPa· s (25°C), average number of ethylene oxide added per molecule: 3)
Pigment: "SYMULER FAST YELLOW 4342" manufactured by DIC Corporation
Extender pigment: hydrous magnesium silicate (extender pigment "High Filler #5000PJ" manufactured by Matsumura Sangyo Co., Ltd.)
Wax: Polyolefin wax (Shamrock Wax "S-381-N1")
Polymerization inhibitor: N-nitrosophenylhydroxylamcy aluminum salt ("Q-1301" manufactured by Wako Pure Chemical Industries, Ltd.)
Polymerization initiator (Y-1): α-aminoalkylphenone (“Irgacure907” manufactured by BASF)
Polymerization initiator (Y-2): 4,4′-bisdimethylaminobenzophenone (“EAB-SS” manufactured by Daido Kasei)

Evaluation of fluidity 1 Measurement of diameter value Measurement was carried out by a method according to JIS K5101, 5701 by a spread meter method (parallel plate viscometer). The printing ink sandwiched between two horizontally placed parallel plates was observed over time for the characteristics of concentric spreading due to the weight of the load plate (115 grams), and the spreading diameter of the ink after 60 seconds (mm) Was evaluated as the diameter value. The evaluation criteria are as follows.
A: Diameter value is 37 mm or more B: Diameter value is 34 mm or more and less than 37 mm C: Diameter value is less than 34 mm

Evaluation of fluidity 2 Measurement of fluidity of glass plate In a room air-conditioned at 25°C, 1.0 ml of printing ink was placed on the upper end of the glass plate forming an angle of 70° with the ground plane, and the distance of fluidization was measured after 1 day. .. The larger the value, the better the fluidity.

Evaluation of misting 1.31 ml of printing ink was placed on an incomer type misting tester, and rotated at a machine temperature of 32° C. and 1200 rpm for 3 minutes. The misting was compared with the change in the mass increase of the printing paper which was sprinkled with the rotation and arranged along the rotating body. When misting resistance is poor, the amount of printing ink flying increases and the mass of paper increases.
(Evaluation criteria)
A: less than 0.050 g B: 0.050 g or more less than 0.075 g C: 0.075 g or more

Evaluation of curability Using a simple color developing machine (RI tester, manufactured by Hoei Seiko Co., Ltd.), 0.10 ml of the above printing ink was used to uniformly stretch the rubber roll and the metal roll of the RI tester to obtain transparent PET tuck paper (DIC). and color exhibition as uniformly applied to an area ranging from about 220 cm ² on the surface of the manufactured "Daitakku UVPET transparent 25EMH-S"), the exhibition colored article was produced.
The developed material after applying the printing ink was irradiated with ultraviolet rays (UV) to cure the printing ink to obtain a printed material. Specifically, using a water-cooled metal halide lamp (output 100 W/cm 1 lamp) and a UV irradiator equipped with a belt conveyor (made by Eye Graphics Co., with a cold mirror), the developed product is placed on the conveyor and the lamp is An area directly below (irradiation distance: 11 cm) was passed under the predetermined conditions described below. The ultraviolet irradiation amount under each condition was measured by using an ultraviolet integrated light amount system (UNIMETER UIT-150-A manufactured by Ushio Inc./light receiver UVD-C365).
For curability, the presence or absence of scratches on the surface of the printed material was confirmed by the nail scratch method immediately after irradiation. The fastest conveyor speed (m/min) at which there is no scratch even when the developed product is irradiated with ultraviolet rays while the conveyor speed (m/min) of the UV irradiation device is changed and is strongly rubbed with a nail after curing is described. The larger the value of the conveyor speed, the better the curability of the printing ink.

Gloss evaluation Using a simple color developing machine (RI tester, manufactured by Hoei Seiko Co., Ltd.), a UV-curable overprint varnish with wet-on was applied on the color-developed material used for curability evaluation ("UV carton ACT OP varnish" manufactured by DIC) ) 0.15 ml was overprinted. Using a UV irradiation device under the same conditions as in the curability evaluation, the conveyor speed was set to 30 m/min, and the printing ink and overprint varnish were cured. The gloss of the printed surface of the obtained printed matter was measured and evaluated. The higher the gloss value, the better the ink acceptability for overprint varnish.
(Evaluation criteria)
A: Gloss 55 or more B: Gloss 45 or more and less than 55 C: Gloss less than 45

Claims (6)

Monohydroxy compound having an aliphatic unsaturated hydrocarbon group having a carbon number of 4 to 50 (A), monohydroxy (meth) acrylate compound (B), Po polyisocyanate compound (C) and the essential reaction of an aliphatic polyol compound (Meth)acrylate resin as a raw material ,
A curable composition containing other (meth)acrylate compound (X),
The (meth)acrylate compound (X) is
A curable composition comprising a polyoxyalkylene-modified tri(meth)acrylate compound . The curable composition according to claim 1, wherein 0.1 to 30 parts by mass is a monohydroxy compound (A) having an aliphatic unsaturated hydrocarbon group having 4 to 50 carbon atoms in a total of 100 parts by mass of the reaction raw material. Thing . The curable composition according to claim 1, wherein the polyisocyanate compound (C) is a polyisocyanate compound having an aromatic ring in its molecular structure. The curable composition according to claim 1, having a weight average molecular weight (Mw) of 1,000 to 30,000. A printing ink comprising the curable composition according to any one of claims 1 to 4 . A printed matter obtained by printing the printing ink according to claim 5 .