JP6737131B2 - Active energy ray-curable resin composition for inkjet ink and active energy ray-curable inkjet ink composition - Google Patents

Description

The present invention relates to an active energy ray-curable resin composition for inkjet ink, and more specifically, it is possible to obtain a cured coating film having a low viscosity and excellent curability, and having a large elongation and a high Young's modulus. The present invention relates to an active energy ray-curable resin composition for inkjet ink.

Conventionally, UV curable ink is used to perform printing by an inkjet recording method or the like because of advantages such as reduction of environmental load due to low Voc (volatile organic compound) and improvement of productivity by not requiring a drying step. The technology is known. In recent years, particularly in fields where high definition and other types (multi-designs) are required, inkjet printing using an ultraviolet curable ink has been favorably used.

Such an ultraviolet curable ink composition is an ink composition containing a component that is polymerized by irradiation with ultraviolet rays, and after the ink composition is attached to a recording medium, the composition is irradiated with ultraviolet rays, The photopolymerization initiator in the ink composition produces radicals and the like, which causes the oligomers and monomers to polymerize and cure, so that the coloring material in the ink composition adheres to the recording medium.

Here, when an oligomer component is used as the UV-curable component, the viscosity of the ink composition tends to increase and the storage stability tends to decrease. It is difficult to make small droplets of the ink composition fly by filling the recording head of the recording device with stable ejection without causing clogging and the like, and an ultraviolet curable ink composition having a well-balanced viscosity and physical properties. Things are required.
As such an ink composition, for example, in Patent Document 1, a urethane (meth)acrylate compound containing a structural moiety derived from a polyol component as an oligomer component and a urethane (meth) having no structural moiety derived from a polyol component are described. It is described that the active energy ray-curable ink composition in which an acrylate compound is used in combination has low viscosity and excellent curability.

JP, 2010-1548, A

However, in recent years, inkjet printing has come to be applied to stretchable base materials (for example, cloth such as woven cloth and non-woven cloth, and leather), so that the printed coating film does not crack or peel off. Ink has been required to follow the movement of the base material such as expansion and contraction and bending, that is, have a high Young's modulus and a high elongation.
In the technique of Patent Document 1, since it is composed only of the oligomer, the elastic modulus of the obtained printed coating film is not sufficient, and cracks, peeling, and the like occur.

Under the circumstances, the present invention provides an active energy for an inkjet ink capable of obtaining a cured coating film having low viscosity and excellent curability as well as excellent elongation and Young's modulus. It is intended to provide a line-curable resin composition.

However, as a result of intensive studies conducted by the present inventors in view of such circumstances, as an oligomer component, a urethane (meth)acrylate compound containing a structural moiety derived from a polyol component and a structural moiety derived from a polyol component are not included. In addition to using the urethane (meth)acrylate compound in combination, by containing a monofunctional monomer containing a nitrogen atom as a monomer component, it has low viscosity and excellent curability, and further, has a large elongation, They have found that an active energy ray-curable resin composition capable of obtaining a cured coating film having a high Young's modulus can be obtained, and completed the present invention.

That is, the gist of the present invention is a urethane (meth)acrylate compound (A) obtained by reacting a hydroxyl group-containing (meth)acrylate compound (a1), a polyvalent isocyanate compound (a2) and a polyol compound (a3). , A urethane (meth)acrylate compound (B) obtained by reacting a hydroxyl group-containing (meth)acrylate compound (b1) and a polyvalent isocyanate compound (b2), and a nitrogen atom-containing monomer having one ethylenically unsaturated group The present invention relates to an active energy ray-curable resin composition for inkjet ink, which contains (C). It also provides an active energy ray-curable inkjet ink composition using the same.

The active energy ray-curable ink composition of the present invention has low viscosity and excellent curability, and further has excellent elongation and Young's modulus when formed into a cured coating film. Therefore, it is particularly useful as an ink composition, especially as an inkjet ink.

The present invention will be described in detail below.
In the present invention, (meth)acrylic means acryl or methacryl, (meth)acryloyl means acryloyl or methacryloyl, and (meth)acrylate means acrylate or methacrylate.

<Urethane (meth)acrylate compound (A)>
The urethane (meth)acrylate compound (A) in the present invention is obtained by reacting a hydroxyl group-containing (meth)acrylate compound (a1), a polyvalent isocyanate compound (a2) and a polyol compound (a3). And has a structural site derived from the polyol (a3) in its structure.

Examples of the hydroxyl group-containing (meth)acrylate compound (a1) include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth). Acrylate, hydroxyalkyl (meth)acrylate such as 6-hydroxyhexyl (meth)acrylate, 2-hydroxyethylacryloyl phosphate, 2-(meth)acryloyloxyethyl-2-hydroxypropyl phthalate, caprolactone-modified 2-hydroxyethyl (meth ) Acrylate, dipropylene glycol (meth)acrylate, fatty acid-modified-glycidyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, 2-hydroxy-3-(meth)acryloyloxypropyl( (Meth)acrylate, glycerin di(meth)acrylate, 2-hydroxy-3-acryloyl-oxypropyl methacrylate, pentaerythritol tri(meth)acrylate, caprolactone modified pentaerythritol tri(meth)acrylate, ethylene oxide modified pentaerythritol tri(meth) Acrylate, dipentaerythritol penta(meth)acrylate, caprolactone modified dipentaerythritol penta(meth)acrylate, ethylene oxide modified dipentaerythritol penta(meth)acrylate and the like can be mentioned. These can be used alone or in combination of two or more.
Among these, hydroxyalkyl (meth)acrylates are preferably used in terms of suppressing curing shrinkage and facilitating use as an ink composition, and more preferably hydroxyalkyl (meth) having an alkyl group having 1 to 4 carbon atoms. ) Acrylate, particularly preferably 2-hydroxyethyl acrylate.

Examples of the polyvalent isocyanate compound (a2) include aromatic compounds such as tolylene diisocyanate, diphenylmethane diisocyanate, polyphenylmethane polyisocyanate, modified diphenylmethane diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, phenylene diisocyanate, and naphthalene diisocyanate. Polyisocyanates; Aliphatic polyisocyanates such as hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, lysine diisocyanate, lysine triisocyanate, hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, isophorone diisocyanate, norbornene diisocyanate, 1,3-bis Examples thereof include polyisocyanates such as alicyclic polyisocyanates such as (isocyanatomethyl)cyclohexane, trimer compounds of the above polyisocyanates, and polymer compounds of the above polyisocyanates. Also, allophanate type polyisocyanates, burette type polyisocyanates, water-dispersible polyisocyanates such as "Aquanate 100", "Aquanate 110", "Aquanate 200", "Aquanate 210" manufactured by Nippon Polyurethane Industry Co., Ltd. , And so on. These can be used alone or in combination of two or more.

Among these, aliphatic polyisocyanates and alicyclic polyisocyanates are preferable from the viewpoint of less yellowing of the cured coating film, and isophorone diisocyanate, water-added diphenylmethane diisocyanate, water-added xylene diisocyanate, and hexa are more preferable because the curing shrinkage is small. Methylene diisocyanate is preferable, and isophorone diisocyanate is particularly preferable in terms of the balance between low viscosity and storage stability.

Examples of the polyol-based compound (a3) include polyether-based polyols, polyester-based polyols, polycarbonate-based polyols, polyolefin-based polyols, polybutadiene-based polyols, (meth)acrylic-based polyols, polysiloxane-based polyols, and the like. These can be used alone or in combination of two or more.
Among these, polyester-based polyols and polyether-based polyols are preferable because the viscosity of the urethane (meth)acrylate-based compound produced is low, and polyether-based polyols are particularly preferable.

Examples of the polyether polyol include alkylene structure-containing polyether polyols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polybutylene glycol, and polyhexamethylene glycol, and random or block copolymerization of these polyalkylene glycols. An example is coalescence.
Among them, polypropylene glycol is preferable from the viewpoint of lowering the viscosity.

Examples of the polyester-based polyol include (i) a condensation polymer of a polyhydric alcohol and a polycarboxylic acid, (ii) a ring-opening polymer of a cyclic ester (lactone), (iii) a polyhydric alcohol, a polycarboxylic acid. Examples include reaction products of three kinds of components, an acid and a cyclic ester.

Examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, trimethylene glycol, 1,4-tetramethylene diol, 1,3-tetramethylene diol, 2-methyl-1,3-trimethylene. Methylene diol, 1,5-pentamethylene diol, neopentyl glycol, 1,6-hexamethylene diol, 3-methyl-1,5-pentamethylene diol, 2,4-diethyl-1,5-pentamethylene diol, glycerin , Trimethylolpropane, trimethylolethane, cyclohexanediols (1,4-cyclohexanediol, etc.), bisphenols (bisphenol A, etc.), sugar alcohols (xylitol, sorbitol, etc.), and the like.

Examples of the polycarboxylic acid include aliphatic dicarboxylic acids such as malonic acid, maleic acid, fumaric acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid and dodecanedioic acid; 1,4 Alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid; aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, 2,6-naphthalenedicarboxylic acid, paraphenylenedicarboxylic acid and trimellitic acid.

Examples of the cyclic ester include propiolactone, β-methyl-δ-valerolactone, ε-caprolactone and the like.

Examples of the polycarbonate-based polyol include (i) a reaction product of a polyhydric alcohol and phosgene, and (ii) a ring-opening polymerization product of a cyclic carbonic acid ester such as an alkylene carbonate.
Examples of the polyhydric alcohol include polyhydric alcohols exemplified in the description of the polyester-based polyol, and examples of the alkylene carbonate include ethylene carbonate, trimethylene carbonate, tetramethylene carbonate, and hexamethylene carbonate. To be
The polycarbonate-based polyol may be a compound having a carbonate bond in the molecule and a terminal hydroxyl group, and may have an ester bond as well as the carbonate bond.

Examples of the polyolefin-based polyol include those having a homopolymer or copolymer of ethylene, propylene, butene or the like as a saturated hydrocarbon skeleton, and having a hydroxyl group at the molecular end thereof.

Examples of the polybutadiene-based polyol include those having a copolymer of butadiene as a hydrocarbon skeleton and having a hydroxyl group at its molecular end.
The polybutadiene-based polyol may be a hydrogenated polybutadiene polyol in which all or some of the ethylenically unsaturated groups contained in the structure are hydrogenated.

Examples of the (meth)acrylic polyol include those having at least two hydroxyl groups in the molecule of the polymer or copolymer of (meth)acrylic acid ester. Examples of such (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, hexyl (meth)acrylate, (meth) Examples thereof include alkyl (meth)acrylates such as octyl acrylate, 2-ethylhexyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, and octadecyl (meth)acrylate, and preferably alkyl. Examples thereof include alkyl (meth)acrylates having 1 to 20 carbon atoms, and particularly preferably 1 to 10 carbon atoms.

Examples of the polysiloxane-based polyol include dimethylpolysiloxane polyol and methylphenylpolysiloxane polyol.

The weight average molecular weight of the polyol compound (a3) is preferably 200 to 6000, more preferably 500 to 4000, and further preferably 1000 to 3000. If the weight average molecular weight of the polyol compound (a3) is too large, the viscosity tends to increase, and when it is used as an ink composition, it tends to cause clogging of the head and prevent stable ejection. If it is too small, the shrinkage during curing tends to increase, and the adhesion tends to decrease, or the printed surface tends to crack.

The urethane (meth)acrylate compound (A) may be produced according to a known general method, and usually, the above-mentioned hydroxyl group-containing (meth)acrylate compound (a1), polyvalent isocyanate compound (a2), polyol The system compound (a3) may be charged into the reactor all at once or separately for reaction.

In particular, a hydroxyl group-containing (meth)acrylate compound (a1) is reacted with a terminal isocyanate group-containing reaction product obtained by previously reacting the polyol compound (a3) and the polyvalent isocyanate compound (a2). However, it is useful and preferable in terms of reaction stability and reduction of by-products.

The reaction between the polyol compound (a3) and the polyvalent isocyanate compound (a2) can be carried out by using a known reaction means. At that time, for example, the molar ratio of the isocyanate group in the polyvalent isocyanate compound (a2) to the hydroxyl group in the polyol compound (a3) is usually about 2n:(2n-2) (n is an integer of 2 or more). By doing so, the isocyanate group remains, and the addition reaction with the hydroxyl group-containing (meth)acrylate compound (a1) becomes possible.

The addition reaction between the hydroxyl group-containing (meth)acrylate compound (a1) and the terminal isocyanate group-containing reaction product obtained by previously reacting the polyol compound (a3) and the polyvalent isocyanate compound (a2), The reaction may be performed using a known reaction means.

The reaction molar ratio of the terminal isocyanate group-containing reaction product and the hydroxyl group-containing (meth)acrylate compound (a1) is, for example, two isocyanate groups in the terminal isocyanate group-containing reaction product, and the hydroxyl group-containing (meth)acrylate compound. When the compound (a1) has one hydroxyl group, the reaction product containing the terminal isocyanate group-containing reaction product: the hydroxyl group-containing (meth)acrylate compound (a1) is usually about 1:2, and the terminal isocyanate group-containing reaction product. When the number of the isocyanate groups is 3 and the hydroxyl group-containing (meth)acrylate compound (a1) has one hydroxyl group, the reaction product containing the terminal isocyanate group is usually a hydroxyl group-containing (meth)acrylate compound (a1). Is about 1:3.
In the addition reaction of the reaction product containing the terminal isocyanate group with the hydroxyl group-containing (meth)acrylate compound (a1), the reaction is carried out when the residual isocyanate group content of the reaction system is usually 0.5% by weight or less. By completing the process, the urethane (meth)acrylate compound (A) can be obtained.

In the reaction between the polyol compound (a3) and the polyvalent isocyanate compound (a2), and further the reaction between the terminal isocyanate group-containing reaction product and the hydroxyl group-containing (meth)acrylate compound (a1), the reaction is promoted. It is also preferable to use a catalyst for the purpose.

Examples of such catalysts include organic metal compounds such as dibutyltin dilaurate, trimethyltin hydroxide, tetra-n-butyltin, zinc octoate, tin octoate, cobalt naphthenate, stannous chloride, stannic chloride and the like. Metal salts of triethylamine, benzyldiethylamine, 1,4-diazabicyclo[2,2,2]octane, 1,8-diazabicyclo[5,4,0]undecene, N,N,N',N'-tetramethyl- In addition to amine catalysts such as 1,3-butanediamine and N-ethylmorpholine, bismuth nitrate, bismuth bromide, bismuth iodide, bismuth sulfide, and the like, organic bismuth compounds such as dibutylbismuth dilaurate and dioctylbismuth dilaurate, and 2- Ethyl hexanoic acid bismuth salt, naphthenic acid bismuth salt, isodecanoic acid bismuth salt, neodecanoic acid bismuth salt, lauric acid bismuth salt, maleic acid bismuth salt, stearic acid bismuth salt, oleic acid bismuth salt, linoleic acid bismuth salt, bismuth acetate salt, Examples thereof include bismuth-based catalysts such as bismuth ribis neodecanoate, organic acid bismuth salts such as bismuth disalicylate and bismuth digallate. Among these, dibutyltin dilaurate and 1,8-diazabicyclo[5,4,0]undecene are preferable.

In addition, in the reaction between the polyol compound (a3) and the polyvalent isocyanate compound (a2), and the reaction between the terminal isocyanate group-containing reaction product and the hydroxyl group-containing (meth)acrylate compound (a1), an isocyanate group is added. It is possible to use an organic solvent having no functional group that reacts with each other, for example, esters such as ethyl acetate and butyl acetate, ketones such as methyl ethyl ketone and methyl isobutyl ketone, and organic solvents such as aromatic compounds such as toluene and xylene. it can.

The reaction temperature is generally 30 to 90° C., preferably 40 to 80° C., and the reaction time is generally 2 to 10 hours, preferably 3 to 8 hours.

The weight average molecular weight of the obtained urethane (meth)acrylate compound (A) is preferably 500 to 50,000, more preferably 1,000 to 30,000. If the weight average molecular weight is too small, the cured coating film becomes brittle and cracks tend to occur on the printed surface. If it is too large, the viscosity becomes high and stable ejection from the nozzle becomes difficult.

In addition, the weight average molecular weight is a weight average molecular weight in terms of standard polystyrene molecular weight, and in high performance liquid chromatography (manufactured by Japan Waters, "Waters 2695 (main body)" and "Waters 2414 (detector)"), Column: Shodex GPC KF-806L (exclusion limit molecular weight: 2×107, separation range: 100 to 2×107, theoretical plate number: 10,000 plates/piece, packing material: styrene-divinylbenzene copolymer, packing particles (Diameter: 10 μm) It is measured by using three series.

Further, the viscosity of the urethane (meth)acrylate compound (A) at 60° C. is preferably 100,000 mPa·s or less, particularly 70,000 mPa·s or less, and further 50,000 mPa·s or less. Is preferred. If the viscosity is out of the above range, the coatability may decrease, which is not preferable. The lower limit of the viscosity is usually 100 mPa·s.
Here, the above-mentioned viscosity measurement method is based on an E-type viscometer.

<Urethane (meth)acrylate compound (B)>
The urethane (meth)acrylate compound (B) in the present invention is obtained by reacting a hydroxyl group-containing (meth)acrylate compound (b1) and a polyvalent isocyanate compound (b2), and the urethane (meth) The acrylate compound (B) has no structural moiety derived from the polyol component.

Examples of the hydroxyl group-containing (meth)acrylate compound (b1) include the same as those exemplified for the hydroxyl group-containing (meth)acrylic acid compound (a1). For example, hydroxyalkyl such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and 6-hydroxyhexyl (meth)acrylate. (Meth)acrylate, 2-hydroxyethylacryloyl phosphate, 2-(meth)acryloyloxyethyl-2-hydroxypropyl phthalate, caprolactone-modified 2-hydroxyethyl (meth)acrylate, dipropylene glycol (meth)acrylate, fatty acid-modified Glycidyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, 2-hydroxy-3-(meth)acryloyloxypropyl (meth)acrylate, glycerin di(meth)acrylate, 2-hydroxy -3-acryloyl-oxypropyl methacrylate, pentaerythritol tri(meth)acrylate, caprolactone modified pentaerythritol tri(meth)acrylate, ethylene oxide modified pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, caprolactone modified diester Examples thereof include pentaerythritol penta(meth)acrylate and ethylene oxide-modified dipentaerythritol penta(meth)acrylate.
Among these, it is preferable to use a compound containing one ethylenically unsaturated group, because the viscosity of the urethane (meth)acrylate becomes low.

Examples of the polyvalent isocyanate compound (b2) include the same as those exemplified for the polyvalent isocyanate compound (a2), and examples thereof include aromatic polyisocyanates, aliphatic polyisocyanates, and alicyclic compounds. Examples thereof include polyisocyanates such as polyisocyanate. Specifically, tolylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, polyphenylmethane polyisocyanate, modified diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, tetramethyl Polyisocyanates such as xylylene diisocyanate, isophorone diisocyanate, norbornene diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, phenylene diisocyanate, lysine diisocyanate, lysine triisocyanate, naphthalene diisocyanate, trimer compounds of the above polyisocyanates, and the above poly Examples include multimeric compounds of isocyanate.
Also, allophanate type polyisocyanates, burette type polyisocyanates, water-dispersible polyisocyanates such as "Aquanate 100", "Aquanate 110", "Aquanate 200", "Aquanate 210" manufactured by Nippon Polyurethane Industry Co., Ltd. And so on.

Among these, aliphatic polyisocyanate compounds are preferable, and more preferably, in that yellowing of the cured coating film is small and curing shrinkage is small, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate. Isocyanate.

In addition, in order to adjust the number of ethylenically unsaturated groups, the hydroxyl group-containing (meth)acrylate compound (b1) and the polyvalent isocyanate compound (b2) may be appropriately selected and used.
For example, when a compound having one ethylenically unsaturated group is used as the hydroxyl group-containing (meth)acrylate compound (b1) and a triisocyanate compound is used as the polyvalent isocyanate compound (b2), urethane (meth ) The number of ethylenically unsaturated groups in the acrylate compound (B) is 3.

The method for producing the urethane (meth)acrylate compound (B) is not particularly limited, and it may be produced according to the method for producing the urethane (meth)acrylate compound (A).

The reaction molar ratio between the polyvalent isocyanate compound (b2) and the hydroxyl group-containing (meth)acrylate compound (b1) is, for example, two isocyanate groups in the polyvalent isocyanate compound (b2) and a hydroxyl group-containing ( When the (meth)acrylate compound (b1) has one hydroxyl group, the reaction product:hydroxyl group-containing (meth)acrylate compound (b1) is usually about 1:2, and the polyvalent isocyanate compound (b2) 2) has 3 isocyanate groups and the hydroxyl group-containing (meth)acrylate compound (b1) has 1 hydroxyl group, the reaction product: hydroxyl group-containing (meth)acrylate compound (b1) is usually 1: It is about 3.
In the addition reaction between the reaction product and the hydroxyl group-containing (meth)acrylate compound (b1), the reaction is terminated when the residual isocyanate group content in the reaction system is usually 0.5% by weight or less, The urethane (meth)acrylate compound (B) can be obtained.

The weight average molecular weight of the obtained urethane (meth)acrylate compound (B) is preferably 3000 or less, and more preferably 1500 or less. If the weight average molecular weight is too large, the resin viscosity tends to increase. The lower limit of the weight average molecular weight is usually 150, preferably 200.

Here, the weight average molecular weight is measured in the same manner as the method for measuring urethane (meth)acrylate (A).

The viscosity of the urethane (meth)acrylate compound (B) at 60° C. is preferably 10,000 mPa·s or less, particularly 7,000 Pa·s or less, and further 5,000 mPa·s or less. Is preferred.
If the viscosity is out of the above range, the coatability may be deteriorated, which is not preferable, and the lower limit of the viscosity is usually 100 mPa·s.
Here, the above-mentioned viscosity measurement method is based on an E-type viscometer.

The active energy ray-curable ink composition of the present invention contains a urethane (meth)acrylate compound (A) and a urethane (meth)acrylate compound (B). In this case, the urethane (meth)acrylate is used. The compound (A) and the urethane (meth)acrylate compound (B) may be separately prepared and then mixed, or the urethane (meth)acrylate compound (A) and the urethane (meth)acrylate may be mixed. A mixture of the urethane (meth)acrylate compound (A) and the urethane (meth)acrylate compound (B) may be prepared by simultaneously charging the raw materials of the compound (B) and reacting them at the same time.

Further, regarding the polyvalent isocyanate-based compound and the hydroxyl group-containing (meth)acrylate-based compound constituting the urethane (meth)acrylate-based compound (A) and the urethane (meth)acrylate-based compound (B) in the present invention, urethane (meth) The same acrylate compound (A) and urethane (meth)acrylate compound (B) may be used, or different compounds may be used. Particularly, the production efficiency is good when the urethane (meth)acrylate compound (A) and the urethane (meth)acrylate compound (B) are composed of the same polyvalent isocyanate compound and hydroxyl group-containing (meth)acrylate compound. It is preferable in terms.

Specifically, in the case where the raw materials of the urethane (meth)acrylate compound (A) and the urethane (meth)acrylate compound (B) are collectively charged and reacted to produce a mixture of (A) and (B). The reaction molar ratio of the raw materials is preferably a hydroxyl group-containing (meth)acrylate compound:polyvalent isocyanate compound:polyol compound=1 to 1.5:1:0.2 to 0.5.

The content of the urethane (meth)acrylate compound (A) and the urethane (meth)acrylate compound (B) (the sum of (A) and (B)) in the active energy ray-curable ink composition will be described later. In the case of containing a nitrogen atom-containing monomer (C) having one ethylenically unsaturated group, a polymerizable monomer (D) and a coloring material (E), the total amount of the components (A) to (E) is 100 parts by weight. 0.1 to 20 parts by weight, particularly preferably 1 to 17 parts by weight, particularly preferably 3 to 15 parts by weight.
If the content of the urethane (meth)acrylate compound (A) and the urethane (meth)acrylate compound (B) is too small, the curability tends to decrease and the strength tends to decrease. The workability tends to decrease.

The content ratio (weight ratio) of the urethane (meth)acrylate compound (A) and the urethane (meth)acrylate compound (B) is (A):(B)=99:1 to 60:40. It is preferable that (A):(B)=95:5 to 70:30, particularly preferably (A):(B)=90:10 to 75:25.
If the content of the urethane (meth)acrylate compound (A) is too high, the viscosity tends to be high and the coatability tends to be low.

<Nitrogen atom-containing monomer (C) having one ethylenically unsaturated group>
Examples of the nitrogen atom-containing monomer (C) having one ethylenically unsaturated group (hereinafter referred to as the nitrogen atom-containing monomer (C)) include:
For example, a nitrogen atom-containing monomer having a cyclic structure such as acryloylmorpholine (Tg: 145° C.), (meth)acryloylpyrrolidone, (meth)acryloylpiperidine, (meth)acryloylpyrrolidine, (meth)acryloylaziridine, or acrylamide (Tg: 153° C.), N-methyl acrylamide (Tg:171° C.), diethyl acrylamide (Tg:81° C.), dimethyl acrylamide (Tg:119° C.), isopropyl acrylamide (Tg:134° C.), t-butyl acrylamide (Tg:135). ℃), phenyl acrylamide (Tg: 160 ℃), hydroxyethyl acrylamide (Tg: 98 ℃), dimethylaminopropyl acrylamide (Tg: 134 ℃), diacetone acrylamide (Tg: 86 ℃), acrylonitrile (Tg: 104 ℃) , And so on.

Among them, a nitrogen atom-containing monomer having a cyclic structure is preferable, and acryloylmorpholine is particularly preferable, from the viewpoint of low skin irritation and a balance between Young's modulus and elongation of the cured coating film.

Further, in the present invention, it is preferable to use a nitrogen atom-containing monomer (C) having a glass transition temperature of 20° C. or higher when formed into a homopolymer from the viewpoint of the balance between Young's modulus and elongation of the cured coating film, In particular, the temperature is preferably 40°C or higher, more preferably 60°C or higher.
The glass transition temperature of the homopolymer of the monomer is usually measured by a differential scanning calorimeter (DSC).

The content of the nitrogen atom-containing monomer (C) is preferably 1 to 99 parts by weight, and particularly preferably, 100 parts by weight of the urethane (meth)acrylate compound (A) and (B). The amount is 5 to 90 parts by weight, more preferably 10 to 80 parts by weight, and particularly preferably 15 to 70 parts by weight.
If the content is too small, the viscosity of the resin composition becomes high, making it unsuitable for ink jet applications, and the Young's modulus of the cured coating film tends to be small. If the oil content is too large, the curability will decrease, and the desired extensibility will not be obtained, and the effect coating film will tend to crack.

In addition, in the present invention, in addition to the nitrogen atom-containing monomer (C), other monomer (D) having one other ethylenically unsaturated group (hereinafter referred to as other monofunctional monomer (D)). May be used). The content of the other monofunctional monomer (D) is preferably 0 to 50% by weight, particularly preferably 5 to 40% by weight, based on the whole monomer having one ethylenically unsaturated group. It is preferably 10 to 30% by weight. If the content of the other monofunctional monomer (D) is too high, the cured coating film tends to be too flexible and a high Young's modulus cannot be obtained.

The other monofunctional monomer (D) may be a monomer containing one ethylenically unsaturated group, and examples thereof include styrene, vinyltoluene, chlorostyrene, α-methylstyrene, methyl (meth)acrylate, ethyl ( (Meth)acrylate, acrylonitrile, vinyl acetate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, phenoxyethyl (meth)acrylate, 2-phenoxy-2-hydroxy Propyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate, glycerin mono (meth)acrylate, glycidyl (meth)acrylate, lauryl (meth)acrylate , Cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, tricyclodecanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, n-butyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, Octyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, dodecyl (meth)acrylate, n-stearyl (meth)acrylate, benzyl (meth)acrylate, phenol ethylene oxide modified (meth ) Acrylate, nonylphenol propylene oxide modified (meth)acrylate, half ester (meth)acrylate of phthalic acid derivative such as 2-(meth)acryloyloxy-2-hydroxypropyl phthalate, furfuryl (meth)acrylate, carbitol (meth)acrylate , Benzyl (meth)acrylate, butoxyethyl (meth)acrylate, allyl (meth)acrylate, 2-hydroxyethylacrylamide and the like.

In addition to the above-mentioned other monofunctional monomers (D), acrylic acid Michael adducts or 2-acryloyloxyethyldicarboxylic acid monoesters are also mentioned, and acrylic acid Michael adducts include acrylic acid dimers and methacrylic acid. Examples thereof include dimers, acrylic acid trimers, methacrylic acid trimers, acrylic acid tetramers, and methacrylic acid tetramers. Examples of 2-acryloyloxyethyl dicarboxylic acid monoester, which is a carboxylic acid having a specific substituent, include 2-acryloyloxyethyl succinic acid monoester, 2-methacryloyloxyethyl succinic acid monoester, and 2-acryloyloxyethyl. Examples thereof include phthalic acid monoester, 2-methacryloyloxyethyl phthalic acid monoester, 2-acryloyloxyethyl hexahydrophthalic acid monoester, and 2-methacryloyloxyethyl hexahydrophthalic acid monoester. Furthermore, oligoester acrylates are also included.

Further, in the present invention, a polyfunctional monomer (E) having two or more ethylenically unsaturated groups can be contained in order to increase the curing speed of the inkjet ink.
Examples of the polyfunctional monomer (E) include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate. , Dipropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, ethylene oxide modified bisphenol A type di(meth)acrylate, propylene oxide modified Bisphenol A type di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,6-hexanediol ethylene oxide-modified di(meth)acrylate, glycerin di(meth)acrylate, pentaerythritol di(meth)acrylate , Ethylene glycol diglycidyl ether di(meth)acrylate, diethylene glycol diglycidyl ether di(meth)acrylate, phthalic acid diglycidyl ester di(meth)acrylate, hydroxypivalic acid modified neopentyl glycol di(meth)acrylate, isocyanuric acid ethylene oxide Monomers having two ethylenically unsaturated groups such as modified diacrylate and 2-(meth)acryloyloxyethyl acid phosphate diester; trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth) ) Acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tri(meth)acryloyloxyethoxy trimethylolpropane, glycerin polyglycidyl ether poly(meth)acrylate, isocyanuric acid ethylene oxide modified triacrylate, Ethylene oxide modified dipentaerythritol penta(meth)acrylate, ethylene oxide modified dipentaerythritol hexa(meth)acrylate, ethylene oxide modified pentaerythritol tri(meth)acrylate, ethylene oxide modified pentaerythritol tetra(meth)acrylate, caprolactone modified dipenta Erythritol penta(meth)acrylate, caprolactone-modified dipentaerythritol hexa(meth) Examples thereof include monomers having three or more ethylenically unsaturated groups such as acrylate, caprolactone-modified pentaerythritol tri(meth)acrylate, caprolactone-modified pentaerythritol tetra(meth)acrylate, and succinic acid-modified pentaerythritol tri(meth)acrylate.

The content of the polyfunctional monomer (E) is preferably 5 to 50 parts by weight, more preferably 10 to 40 parts by weight, based on 100 parts by weight of the total of the components (A) to (D). .. If the amount of the polyfunctional monomer (E) is too large, the cured coating film becomes hard, and high elongation tends not to be obtained.

The active energy ray-curable resin composition of the present invention preferably further contains a photopolymerization initiator (F) in order to impart curability.

The photopolymerization initiator (F) is not particularly limited, and examples thereof include diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethylketal, 4-(2). -Hydroxyethoxy)phenyl-(2-hydroxy-2-propyl)ketone, 1-hydroxycyclohexylphenyl ketone, 2-methyl-2-morpholino(4-thiomethylphenyl)propan-1-one, 2-benzyl-2- Acetophenones such as dimethylamino-1-(4-morpholinophenyl)butanone and 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone oligomer; benzoin, benzoin methyl ether, benzoin ethyl Benzoins such as ether, benzoin isopropyl ether, benzoin isobutyl ether; benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4'-methyl-diphenyl sulfide, 3,3',4,4'- Tetra(t-butylperoxycarbonyl)benzophenone, 2,4,6-trimethylbenzophenone, 4-benzoyl-N,N-dimethyl-N-[2-(1-oxo-2-propenyloxy)ethyl]benzenemethanamine Nitrogen bromide, benzophenones such as (4-benzoylbenzyl)trimethylammonium chloride; 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone, 1-chloro-4-propoxythioxanthone, Thioxanthones such as 2-(3-dimethylamino-2-hydroxy)-3,4-dimethyl-9H-thioxanthone-9-one mesochloride; 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, bis(2 , 6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, and other acylphosphine oxides; and the like. In addition, as for these photoinitiators (E), only 1 type may be used independently and 2 or more types may be used together.

Among these, α-aminoketone-based photopolymerization initiators such as α-aminoalkylphenone, α-hydroxyketone-based photopolymerization initiators such as α-hydroxyalkylphenone, monoacylphosphine oxide, and acyl such as bisacylphosphine oxide. A phosphine oxide-based photopolymerization initiator is preferably used, and in particular, α-hydroxyalkylphenone and bisacylphosphine oxide are radicals by absorbing light having a wavelength irradiated to the ink composition for the purpose of photocuring. It is preferable in that it is generated and the curing reaction can be efficiently performed.

Further, as these auxiliary agents, triethanolamine, triisopropanolamine, 4,4'-dimethylaminobenzophenone (Michler's ketone), 4,4'-diethylaminobenzophenone, 2-dimethylaminoethylbenzoic acid, 4-dimethylaminobenzoic acid Ethyl, 4-dimethylaminobenzoic acid (n-butoxy)ethyl, 4-dimethylaminobenzoic acid isoamyl, 4-dimethylaminobenzoic acid 2-ethylhexyl, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone It is also possible to use the above together.

The content of the photopolymerization initiator (F) is preferably 0.1 to 30 parts by weight based on 100 parts by weight of the total of the components (A) to (E). If the content of the photopolymerization initiator (F) is too small, the influence of oxygen inhibition will be large, and curing will tend to be insufficient, and if it is too large, the durability will tend to be reduced.

Thus, the activity for inkjet ink containing the urethane (meth)acrylate compound (A), the urethane (meth)acrylate compound (B), and the nitrogen atom-containing monomer (C) having one ethylenically unsaturated group of the present invention An energy ray curable resin composition can be obtained.

The active energy ray-curable resin composition of the present invention has a low viscosity, excellent curability, and a cured coating film excellent in both elongation and Young's modulus. It is useful as a composition, and can be used as an inkjet ink composition by blending a coloring material (G) and other components.

The coloring material (G) in the present invention may be either a dye or a pigment, but the pigment is preferable in terms of durability of the printed matter.

Examples of the dye include direct dyes, acid dyes, food dyes, basic dyes, reactive dyes, disperse dyes, vat dyes, soluble vat dyes, reactive disperse dyes, and various dyes usually used in inkjet recording. Can be used.

The pigment is not particularly limited, and either an inorganic pigment or an organic pigment may be used.

As such an inorganic pigment, for example, titanium oxide, iron oxide, carbon black produced by a known method such as a contact method, a furnace method, a thermal method, or the like can be used.

Examples of such organic pigments include azo lake pigments, insoluble azo pigments, condensed azo pigments, azo pigments such as chelate azo pigments, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, thioindigo pigments, isoindo pigments. It is possible to use polycyclic pigments such as linone pigments and quinofuraron pigments, dye chelates such as basic dye chelates and acid dye chelates, nitro pigments, nitroso pigments and aniline black.

Specific examples of the pigment include carbon black such as C.I. I. Pigment Black 7; No. manufactured by Mitsubishi Chemical Corporation. 2300, No. 900, MCF88, No. 33, No. 40, No. 45, No. 52, MA7, MA8, MA100, No. 52. 2200B, etc.; Raven 5750, 5250, 5000, 3500, 1255, 700, etc., manufactured by Colombia; Regal 400R, 330R, 660R, Mogul L, 700, Monarch 800, 880 manufactured by Cabot. , 900, 1000, 1100, 1300, 1400, etc.; Color Black FW1, FW2, FW2V, FW2, FW18, FW200, Color Black S150, S160, S170, Printex 35, manufactured by Degussa. The same U, the same V, the same 140 U, Special Black 6, the same 5, the same 4A, the same 4 and the like;

Examples of pigments used in yellow ink include C.I. I. Pigment Yellow 1, 2, 3, 12, 13, 14, 16, 17, 73, 74, 75, 83, 93, 95, 97, 98, 109, 110, 114, 120, 128, 129, 138, 150, 151, 154, 155, 180, 185, 213 and the like.

Further, as a pigment used for magenta ink, C.I. I. Pigment Red 5, 7, 12, 48 (Ca), 48 (Mn), 57 (Ca), 57:1, 112, 122, 123, 168, 184, 202, 209, C.I. I. Pigment Violet 19 and the like.

Furthermore, examples of pigments used for cyan ink include C.I. I. Pigment Blue 1, 2, 3, 15:3, 15:4, 60, 16, 22.

The average particle size of the pigment is preferably 10 to 200 nm, more preferably 50 to 150 nm.

Further, it is also possible to use a metal pigment such as a simple metal such as gold, silver, copper, aluminum, brass, or titanium and/or an alloy thereof or a hollow white resin emulsion pigment as a coloring material. The diameter is preferably in the range of 100 nm to 5 μm, more preferably about 300 nm to 3 μm.

The content of the coloring material (G) in the ink composition is preferably 0.1 to 25 parts by weight, and more preferably 0.5 to 100 parts by weight of the total of the components (A) to (E). ~15 parts by weight.

According to a preferred embodiment of the present invention, these pigments can be used as an ink composition as a pigment dispersion liquid obtained by dispersing them in a monomer medium with a dispersant or a surfactant. As a preferable dispersant, a dispersant which is commonly used for preparing a pigment dispersion, for example, a polymer dispersant (polyoxyalkylene polyalkylene polyamine etc.) can be used.

When the ink composition contains a coloring material, the ink composition containing the coloring material may have a plurality of ink compositions for each color. For example, in addition to the basic four colors of yellow, magenta, cyan, and black, when adding the same series of dark and light colors for each color, in addition to magenta, in addition to light light magenta, dark red, and cyan In addition to light-colored light cyan, dark-colored blue, and black, light-colored gray, light black, and dark-colored matte black are listed.

Further, the ink composition of the present invention may contain insoluble fluorescent coloring material, fluorescent whitening agent, and fine particles containing the fluorescent coloring material. By containing these fine particles, these coloring materials have the property of absorbing light of a certain wavelength and emitting blue visible light on the longer wavelength side, thus masking the complementary yellow color and making it whiter. Is preferred because it has the effect of making the

Further, as other publicly known other components that can be used in the active energy ray-curable ink, a wetting agent, a penetrating solvent, a pH adjusting agent, an antiseptic agent, an antifungal agent and the like may be added.
In addition to these, it is possible to use a leveling additive, a matting agent, a polyester resin, a polyurethane resin, a vinyl resin, an acrylic resin, a rubber resin, and waxes for adjusting the physical properties of the film, if necessary. it can.

The active energy ray-curable resin composition and the ink composition of the present invention are cured by irradiation with active energy rays.

In irradiating with active energy rays, as active energy rays, light rays such as far-ultraviolet rays, ultraviolet rays, near-ultraviolet rays, infrared rays, etc., electromagnetic waves such as X-rays, γ-rays, electron rays, proton rays, neutron rays, etc. can be used. However, curing by UV irradiation is advantageous in terms of curing speed, availability of irradiation equipment, price, and the like.

For the ultraviolet irradiation, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, a chemical lamp, an electrodeless discharge lamp or the like which emits light in the wavelength range of 150 to 450 nm can be used.
Further, ultraviolet irradiation can be performed by an ultraviolet light emitting semiconductor element such as an ultraviolet light emitting diode (ultraviolet LED) or an ultraviolet light emitting semiconductor laser.

In the present invention, the dose of the active energy ray, usually 10~20,000mJ / cm ^2, preferably 50~15000mJ / cm ^2, particularly preferably from 100~10000mJ / cm ^2.

Suitable examples of the method for recording the ink composition according to the present invention include inkjet printing, UV flexographic printing, UV gravure printing, etc., which are particularly suitable for inkjet printing and have excellent film strength and curability. An excellent and clear image can be formed.

When the ink composition of the present invention is used in an ink jet recording system, the viscosity of the ink composition at 25° C. is preferably 15 mPa·s or less, particularly preferably 10 mPa·s or less, further preferably 5 mPa·s. s or less.

The ink composition of the present invention may be used as a one-component ink composition or a two-component ink composition.
When it is used as a two-component ink composition, it can be divided into a composition containing a coloring material and a composition containing a photopolymerization initiator in order to obtain excellent ink composition curing performance, abrasion resistance and printing reliability. It is preferable in terms of excellent properties.
When used as a two-component ink composition, the two liquids may be mixed in advance and then deposited on the recording medium, or the two liquids may be recorded simultaneously or in a plurality of times without mixing. It may be used in the form of being attached to the same position on the medium.

Thus, the urethane (meth)acrylate compound (A), the urethane (meth)acrylate compound (B), the nitrogen atom-containing monomer (C) having one ethylenically unsaturated group, and the coloring material (G) of the present invention are prepared. An ink composition for ink jet containing can be obtained.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded. In the examples, "part" and "%" mean weight basis unless otherwise specified.

Urethane (meth)acrylate compounds (A) and (B) were produced according to the following production examples.

<Production Example 1>
In a reaction vessel equipped with a stirrer, 67.1 parts of polyoxypropylene glycol (manufactured by Sanyo Chemical Industry Co., Ltd., "Sannicx PP-2000") and 19.8 parts of isophorone diisocyanate were put, and stirred at a temperature of 80°C for 6 hours. .. After adding 40 ppm of dibutyltin dilaurate and further stirring for 2 hours, the temperature was lowered to 60° C., 13.1 parts of 2-hydroxyethyl acrylate and 400 ppm of BHT (dibutylhydroxytoluene) were added, and the mixture was further stirred at 60° C. to obtain isocyanate. The reaction was stopped when the residue was below 0.3% to obtain 100 parts of a mixture [UA-1] of urethane (meth)acrylate compounds (A-1) and (B-1).
The fact that the urethane (meth)acrylate-based compound [UA-1] is a mixture of urethane (meth)acrylate-based compounds (A-1) and (B-1) means that the above-mentioned weight average molecular weight is measured. It was judged from the fact that two peaks having different molecular weights were obtained when GPC was measured by the same measuring method. The theoretical contents of the urethane (meth)acrylate compound (A-1) and the urethane (meth)acrylate compound (B-1) are (A-1)=81.92 parts, (B-1)=17. 63 copies.

Using the urethane (meth)acrylate compound produced in Production Example 1 above, active energy ray-curable resin compositions of Examples 1-2 and Comparative Examples 1-2 below were produced.

<Example 1>
70 parts of [UA-1] obtained in Production Example 1 as the urethane (meth)acrylate compound (A) and the urethane (meth)acrylate compound (B), and acryloylmorpholine (C-1) as the component (C). ) 30 parts, and 4 parts of "IRGACURE 184" manufactured by Ciba Japan Co., Ltd. as a photopolymerization initiator (F) were mixed and mixed with glass beads using a disper to obtain an active energy ray-curable resin composition.
<Example 2>
An active energy ray-curable ink composition was obtained in the same manner as in Example 1 except that dimethylacrylamide (C-2) was used instead of acryloylmorpholine as the component (C).

<Comparative Example 1>
An active energy ray-curable ink composition was obtained in the same manner as in Example 1 except that isobornyl acrylate (C′-1) was used instead of acryloylmorpholine as the component (C). ..

<Comparative example 2>
An active energy ray-curable ink composition was obtained in the same manner as in Example 1 except that isodecyl acrylate (C′-2) was used instead of acryloylmorpholine as the component (C).

Using the active energy ray-curable resin compositions obtained in Examples 1 and 2 and Comparative Examples 1 and 2, Young's modulus, strength and elongation of the obtained cured coating film were measured and evaluated as follows. .. The results are shown in Table 2 below.

<Creation of cured coating>
The active energy ray-curable composition is applied to a releasable polyethylene terephthalate (PET) film (thickness 25 μm) by an applicator so that the cured coating film has a thickness of 100 μm, and an ultraviolet ray having a wavelength of 365 nm is irradiated at an irradiation intensity of 200 mW/cm. ^2. Irradiation was carried out under conditions such that the integrated light quantity was 800 mJ/cm ² , and a cured coating film was obtained. Then, the cured coating film was punched out with a dumbbell to prepare a strip sample having a width of 15 cm and a length of 75 mm, and then the cured coating film was peeled from the PET film to obtain a measurement sample piece.

<Young's modulus>
The measurement sample piece (cured coating film) obtained above was used at a temperature of 23° C. and a humidity of 50% under a tensile tester “AG-X” (manufactured by Shimadzu Corporation) in accordance with JIS K 7127. A tensile test was conducted. The pulling speed was 10 mm/min, and the Young's modulus was measured from the slope to the yield point.

<Elongation>
The measurement sample piece (cured coating film) obtained above was used at a temperature of 23° C. and a humidity of 50% under a tensile tester “AG-X” (manufactured by Shimadzu Corporation) in accordance with JIS K 7127. A tensile test was conducted. The tensile speed was 10 mm/min, and the elongation at the breaking point of the coating film was measured.

<Strength>
The measurement sample piece (cured coating film) obtained above was used at a temperature of 23° C. and a humidity of 50% under a tensile tester “AG-X” (manufactured by Shimadzu Corporation) in accordance with JIS K 7127. A tensile test was conducted. The tensile speed was 10 mm/min, the strength at the breaking point of the coating film was measured, and evaluated according to the following criteria.

From the above results, as an oligomer component, a urethane (meth)acrylate compound containing a structural moiety derived from a polyol component and a urethane (meth)acrylate compound having no structural moiety derived from a polyol component were used in combination, It is understood that in the examples using the active energy ray-curable resin composition containing a monofunctional monomer containing a nitrogen atom, both Young's modulus and elongation are high and strength is excellent.

On the other hand, in Comparative Examples 1 and 2 which use the active energy ray-curable resin composition containing no monofunctional monomer containing a nitrogen atom and containing a monofunctional monomer other than the monofunctional monomer containing a nitrogen atom, It can be seen that the Young's modulus is extremely low.

The active energy ray-curable resin composition for an inkjet ink of the present invention has a low viscosity and is excellent in curability, and further, a cured coating film having high elongation and Young's modulus can be obtained. It is useful as a line-curable inkjet ink.

Claims (4)

A urethane (meth)acrylate compound (A) obtained by reacting a hydroxyl group-containing (meth)acrylate compound (a1), a polyvalent isocyanate compound (a2) and a polyol compound (a3),
A urethane (meth)acrylate compound (B) obtained by reacting a hydroxyl group-containing (meth)acrylate compound (b1) and a polyvalent isocyanate compound (b2), and
A nitrogen atom-containing monomer (C) having one ethylenically unsaturated group,
An active energy ray-curable resin composition for inkjet ink, which comprises: The content of the nitrogen atom-containing monomer (C) having one ethylenically unsaturated group is 100 parts by weight based on the total amount of the urethane (meth)acrylate compound (A) and the urethane (meth)acrylate compound (B). 1 to 99 parts by weight, the active energy ray-curable resin composition for inkjet ink according to claim 1. The active energy ray curing for inkjet ink according to claim 1 or 2, wherein the nitrogen atom-containing monomer (C) having one ethylenically unsaturated group is a nitrogen atom-containing ethylenically unsaturated compound having a cyclic structure. Type resin composition. A urethane (meth)acrylate compound (A) obtained by reacting a hydroxyl group-containing (meth)acrylate compound (a1), a polyvalent isocyanate compound (a2) and a polyol compound (a3),
A urethane (meth)acrylate compound (B) obtained by reacting a hydroxyl group-containing (meth)acrylate compound (b1) and a polyvalent isocyanate compound (b2), and
A nitrogen atom-containing ethylenically unsaturated compound (C) having one ethylenically unsaturated group,
Color material (G)
An active energy ray-curable inkjet ink composition comprising: