JP6722092B2 - Composition for inkjet ink - Google Patents

Description

The present invention relates to a composition for inkjet ink. More specifically, it relates to a composition for an inkjet ink, in which a cured product has excellent transparency and high hardness.

The active energy ray-curable ink is characterized by being capable of reducing the environmental load because it does not use a solvent, and being capable of improving productivity because of its quick-drying property due to active energy ray curing, and is widely used for industrial applications. In recent years, among active energy ray curable inks, printing by an inkjet method, which enables high-definition and high-definition printing, has been attracting attention, and has begun to be widely used for printing for sign displays and packages.
The active energy ray-curable ink for inkjet printing must have a low viscosity in order to eject stably from an inkjet nozzle. Therefore, the main component is a low molecular weight monofunctional or bifunctional monomer, and the curing speed is slower than that of a general-purpose analog ink using a polyfunctional monomer, and the coating film hardness after curing is low. There is a demand for an ink having a lower viscosity, a faster curing speed, and a hard coating film hardness after curing.

As a method for achieving both low viscosity of the active energy ray-curable ink and coating hardness after curing, a method using a composition containing a caprolactone-modified dipentaerythritol hexaacrylate (for example, Patent Document 1), a polyfunctional monomer is used. A method using a compound to which an alkylene oxide is added (for example, Patent Document 2) has been proposed.

JP, 2013-256659, A JP, 2014-169360, A

However, in any of the methods of Patent Documents 1 and 2, although the polyfunctional monomer-modified composition can reduce the ink viscosity and is excellent in ejection stability, the cross-link density of the coating film after curing is lowered, and thus the coating film hardness is reduced. There is a problem of decrease.
An object of the present invention is to provide a composition for inkjet ink which gives a cured product having low viscosity, high hardness and high transparency.

The present inventors have arrived at the present invention as a result of studies to achieve the above object.
That is, the present invention provides a hydrolysis-condensation product (A) containing an inorganic alkoxide (a1) and a polyfunctional (meth)acrylate (B) as constituent monomers, the polyfunctional (meth)acrylate (B), a monofunctional An ink jet ink composition containing a functional unsaturated monomer (C) and a photopolymerization initiator (D), which comprises the above-mentioned (a1) and (B) constituting the hydrolysis-condensation product (A). The molar ratio [(a1)/(B)] is 67/33 to 87/13, and the content based on the total weight of (A) and (B) is 37 to 79 weight for (A). %, the (B) is 21 to 63% by weight, the (C) is 50 to 220% by weight, and the (D) is 2 to 3% by weight (X). Is.

The inkjet ink composition (X) of the present invention has the following effects.
(1) Excellent ejection stability (low viscosity) from an inkjet nozzle.
(2) The cured product has excellent scratch resistance (surface hardness).
(3) The cured product has excellent transparency.

<Inorganic alkoxide (a1)>
Examples of the inorganic alkoxide (a1) in the present invention include silane alkoxide, titanium alkoxide, zirconium alkoxide, hafnium alkoxide, zinc alkoxide, aluminum alkoxide, gallium alkoxide, indium alkoxide, germanium alkoxide, tin alkoxide.
Of these, silane alkoxide, titanium alkoxide, zirconium alkoxide, and aluminum alkoxide are preferable from the viewpoint of hardness, and silane alkoxide is more preferable.

<Polyfunctional (meth)acrylate (B)>
Examples of the polyfunctional (meth)acrylate (B) in the present invention include polyfunctional (meth)acrylates having at least 2, and preferably 3 to 6 (meth)acryloyl groups.

Specifically, the following di(meth)acrylate (B1), trivalent or higher valent (meth)acrylate (B2), polyester (meth)acrylate (B3), urethane (meth)acrylate (B4), epoxy (meth) Examples thereof include acrylate (B5), (meth)acryloyl group-modified butadiene polymer (B6), and (meth)acryloyl group-modified dimethylpolysiloxane polymer (B7).

Di(meth)acrylate (B1):
Polyoxyalkylene (the carbon number of alkylene is 2 to 4) [molecular weight 106 or more and number average molecular weight (hereinafter, number average molecular weight by gel permeation chromatography (GPC) method is abbreviated as Mn.) 3,000 or less] Di(meth)acrylate (B11)
Each di(meth)acrylate of polyethylene glycol (Mn400), polypropylene glycol (Mn200) and polytetramethylene glycol (Mn650);

Di(meth)acrylate (B12) of alkylene oxide of dihydric phenol compound (hereinafter, “alkylene oxide” is abbreviated as AO) (2 to 30 mol) adduct:
AO adduct of dihydric phenol compound [monocyclic phenol (catechol, resorcinol, hydroquinone, etc.), condensed polycyclic phenol (dihydroxynaphthalene, etc.), bisphenol compound (bisphenol A, -F, -S, etc.] [EO 4 mol of resorcinol Di(meth)acrylate of adduct, PO4 mol of PO of dihydroxynaphthalene, di(meth)acrylate of adduct of bisphenol A, -F and -S, EO2 mol, and PO4 mol, etc.] Acrylate, etc.;

Di(meth)acrylate of aliphatic dihydric alcohol having 2 to 30 carbon atoms (B13):
Neopentyl glycol and 1,6-hexanediol di(meth)acrylates and the like;

Di(meth)acrylate (B14) of an alicyclic divalent alcohol having 6 to 30 carbon atoms:
Di(meth)acrylate of dimethyloltricyclodecane, di(meth)acrylate of cyclohexanedimethanol, di(meth)acrylate of hydrogenated bisphenol A, etc.

Trivalent or higher valent (meth)acrylate (B2):
A poly(meth)acrylate of a polyhydric alcohol having 3 to 40 carbon atoms and its AO adduct,
Trimethylolpropane tri(meth)acrylate, tri(meth)acrylate of glycerin, EO3 moles of trimethylolpropane and PO3 mole adduct tri(meth)acrylates, EO3 moles of glycerine and PO3 mole adduct tri(meth) ) Acrylate, tri(meth)acrylate of pentaerythritol, tetra(meth)acrylate of pentaerythritol, tetra(meth)acrylate of EO 4 mol adduct of pentaerythritol, penta(meth)acrylate of dipentaerythritol, hexa of dipentaerythritol (Meth)acrylate and the like;

Polyester (meth)acrylate (B3):
A polyester acrylate having a molecular weight of 150 or more and Mn of 4,000 or less and having a plurality of ester bonds and 5 or more acryloyl groups, which is obtained by esterification of a polyvalent carboxylic acid, a polyhydric alcohol, and an ester-forming acryloyl group-containing compound.

Examples of the above-mentioned polyvalent carboxylic acid include aliphatic [eg, malonic acid, maleic acid (anhydride), adipic acid, sebacic acid, succinic acid, acid anhydride reaction product (reaction product of dipentaerythritol and maleic anhydride Etc.)], alicyclic [eg cyclohexanedicarboxylic acid, tetrahydro(anhydrous)phthalic acid, methyltetrahydro(anhydrous)phthalic acid] and aromatic polycarboxylic acids [eg isophthalic acid, terephthalic acid, phthalic acid (anhydride), Trimellitic acid (anhydride), pyromellitic acid (anhydride)].

Urethane (meth)acrylate (B4):
Urethane (meth)acrylates having a molecular weight of 400 or more and Mn of 5,000 or less having a plurality of urethane bonds and two or more acryloyl groups obtained by a urethane-forming reaction with a polyisocyanate, a polyol, and a hydroxyl group-containing (meth)acrylate;

Examples of corresponding polyisocyanates include aliphatic polyisocyanates [hexamethylene diisocyanate and the like], aromatic (aliphatic) polyisocyanates [2,4- and/or 2,6-tolylene diisocyanate, 1,5-naphthalene diisocyanate, xylylene Diisocyanate and the like] and alicyclic polyisocyanate [isophorone diisocyanate, 4,4′-methylenebis(cyclohexyl isocyanate) and the like].
Examples of the polyol include ethylene glycol, 1,4-butanediol, neopentyl glycol, polyether polyol, polycaprolactone polyol, polyester polyol, polycarbonate polyol, polytetramethylene glycol and the like.
Examples of the hydroxyl group-containing (meth)acrylate include hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, pentaerythritol tri(meth)acrylate, and dipentaerythritol penta(meth)acrylate.

Epoxy (meth)acrylate (B5):
Epoxy (meth)acrylate having a molecular weight of 400 or more and Mn of 5,000 or less, which is obtained by the reaction of a polyvalent (2 to 4 valent) epoxide and (meth)acrylic acid;

(Meth)acryloyl group-modified butadiene polymer (B6):
Polybutadiene poly(meth)acrylate (Mn 500 to 500,000) having a (meth)acryloyl group in the main chain and/or side chain;

(Meth)acryloyl group-modified dimethylpolysiloxane polymer (B7):
Mn 300 to 20,000 dimethylpolysiloxane poly(meth)acrylate having a (meth)acryloyl group in the main chain and/or side chain].

The above (B1) to (B7) may be used alone or in combination of two or more kinds. Among these (B1) to (B7), from the viewpoint of the hardness of the cured product, (B2) to (B7) are preferable, and (B2) and (B4) are more preferable.

The hydrolysis-condensation product (A) in the present invention contains the inorganic alkoxide (a1) and the polyfunctional (meth)acrylate (B) as constituent monomers [hereinafter, sometimes referred to as constituent units]. ..
From the viewpoint of the hardness of the cured product, the hydrolysis-condensation product (A) preferably has a (meth)acryloyl group, and more preferably has a (meth)acryloyl group derived from (B).
The concentration of the (meth)acryloyl group possessed by (A) is preferably 2.0 to 8.0 mmol/g, more preferably 2.5 to 7.5 mmol/g, and particularly preferably 3.0 to 7.0 mmol. /G.
The (meth)acryloyl group can be quantified by the method described below.

The (meth)acryloyl group preferably has a structure represented by the following general formula (1).

[Wherein R ¹ is H or an alkyl group having 1 to 3 carbon atoms; R ² is a residue obtained by removing one (meth)acryloyloxy group from the polyfunctional (meth)acrylate (B); X is Si , Zr, Ti, or Sn. ]

The molar ratio [(a1)/(B)] of (a1) and (B) constituting (A) is preferably 50/50 to 95/5, more preferably 50/50 to 95/5, from the viewpoint of transparency and hardness of the cured product. It is preferably 55/45 to 90/10, particularly preferably 60/40 to 85/15.

(A) in the present invention is preferably a hydrolytic condensate (A1) and/or a particulate hydrolyzate (A2) having a weight average molecular weight (Mw) of 500 to 20,000.

The weight average molecular weight [hereinafter abbreviated as Mw] of the hydrolysis-condensation product (A1) is preferably 20,000 or less, more preferably 15,000 or less, and particularly preferably 10,000 or less. The Mw is preferably 500 or more, more preferably 700 or more, and particularly preferably 1,000 or more. The weight average molecular weight is measured by GPC, and the following measurement conditions are used.

<GPC measurement conditions>
GPC model: Waters Alliance 2695, Waters column: TSKgel Super H4000+
TSKgel Super H3000+
TSKgel Super H2000+
Guardcolumn Super HL, Tosoh Co., Ltd. solvent: Tetrahydrofuran (THF)
Detection device: Refractive index detector Reference substance: Standard polystyrene (TSKstandard)
POLYSTYRENE), manufactured by Tosoh Corporation

The volume average particle diameter (Dv) of the particulate hydrolyzed condensate (A2) is preferably 1 μm or less, more preferably 0.7 μm or less, and particularly preferably 0.4 μm from the viewpoint of ejection stability of the inkjet ink. It is as follows.
Further, (Dv) is preferably 0.005 μm or more, more preferably 0.01 μm or more, and particularly preferably 0.02 μm, from the viewpoint of the thixotropic property of the inkjet ink. The volume average particle diameter (Dv) is measured by a light scattering particle size distribution measuring device.

The hydrolysis-condensation product (A) in the present invention is preferably a polyfunctional (meth)acrylate (B) in which the inorganic alkoxide (a1) and water are mixed in a molar ratio of [a1] and (water). (A1)/(water)] is preferably 2 to 200, more preferably 5 to 150, and particularly preferably 10 to 100, from the viewpoint of transparency and hardness, by performing a hydrolysis reaction and a condensation reaction. Can be manufactured.
Further, in the manufacturing method, in the above reaction, (A) which is (A1) may be obtained by first producing the above-mentioned (A1). Further, (A) which is (A2) may be obtained by further reaction (sol-gel reaction).
In the above-mentioned production method, it can be estimated that it is obtained as a solution of (A) and (B), and is mainly a solution in the case of (A1) and a (dispersed) solution in the case of (A2).

A catalyst (b) may be used in the above reaction for the purpose of accelerating the reaction, and examples of the acid catalyst include inorganic acids such as hydrochloric acid, sulfuric acid and phosphoric acid, maleic acid, acetic acid, methanesulfonic acid and paratoluenesulfonic acid. Examples of the organic acid and alkali catalyst include aliphatic amines such as hexylamine and octylamine, alicyclic amines such as cyclohexylamine and cyclopentylamine, aromatic amines such as aniline and diphenylamine, and heterocyclic amines such as morpholine.

Examples of the organic solvent used in the sol-gel method include alcohol solvents such as methanol, ethanol and 2-propanol, ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, and ester solvents such as ethyl acetate and isobutyl acetate. Of these, alcohol solvents are preferable, and ethanol is more preferable.

The (meth)acryloyl group concentration (mmol/g) of the above (A) is measured by the following method.
(1) Separation and purification of hydrolysis condensate (A) <Hydrolysis condensate (A1)>
The preparative GPC is used to separate and purify the hydrolysis condensate (A1). The preparative GPC is performed under the following conditions.
<GPC measurement conditions>
-GPC model: Waters Alliance 2695, manufactured by Waters-Column: GPC K-2001+GPC K2002+
GPC K2002.5+ GPC K-2003+
GPCK-2004+GPC K-LG, Showa Denko KK Solvent: Chloroform Detection device: Refractive index detector Reference substance: Standard polystyrene (TSKstandard)
POLYSTYRENE), manufactured by Tosoh Corporation

<Particulate hydrolyzate (A2)>
A 0.5 g sample is precisely weighed and added to a 1 ml centrifuge tube, and a tabletop ultracentrifuge [model "Optima MAX-XP", manufactured by Beckman Coulter, Inc., the same applies hereinafter. ] For 30 minutes at 150,000 rpm. After centrifugation, the supernatant is removed, 0.5 ml of acetone is added, and centrifugation is performed again under the same conditions. After repeating the above operation 5 times, the precipitate is taken out and dispersed in 20 ml of acetone to prepare (A) dispersed acetone solution. The solid content in the acetone solution is calculated from the following formula, with about 1.0 g of the sample being weighed (W1) in a petri dish and the residual weight after drying at room temperature for 90 minutes (W2).

Solid content (% by weight)=(W2)×100/(W1)

(2) Calculation of (meth)acryloyl group concentration (mmol/g) The (meth)acryloyl group concentration (mmol/g) is calculated from the iodine value measured by the following method.
<Iodination measurement method>
The hydrolysis-condensation product (A) purified by the above method was precisely weighed so that the solid content was 0.3 g, put in a 500 mL iodine flask, and 10 mL of chloroform and Wyeth reagent (7.9 g of iodine trichloride and 8.7 g of iodine). Glacial acetic acid is added to the mixture to make 1 L), and the mixture is left to react in the dark for 1 hour. To the above solution, 20 mL of 10% potassium iodide solution and 100 g of water are added, and the solution is titrated with 0.1N sodium thiosulfate standard solution using 1% starch solution as an indicator. At the same time, a blank test is also performed, the iodine value Y is calculated from the following formula, and the (meth)acryloyl group concentration (mmol/g) can be calculated from the iodine value.
Iodine value: Y=(B−A)×f×1.269/S
A: ml number of 0.1 mol/l sodium thiosulfate standard solution required for this test B: ml number of 0.1 mol/l sodium thiosulfate standard solution required for blank test f: 0.1 mol/l sodium thiosulfate Standard solution titer.
S: Sampling amount (g)

(Meth)acryloyl group concentration (mmol/g)=Y/25.38

<Composition for inkjet ink (X)>
The inkjet composition (X) of the present invention comprises the hydrolysis-condensation product (A), a polyfunctional (meth)acrylate (B), a monofunctional unsaturated monomer (C) described below, and a photopolymerization initiator (described below). D).

From the viewpoint of hardness and transparency, the composition (X) for inkjet ink has a content based on the total weight of (A) and (B), (A) is preferably 10 to 80% by weight, and (B). Is 20 to 90% by weight, (C) is 40 to 200% by weight, (D) is 0.1 to 10% by weight, and more preferably (A) is 20 to 70% by weight and (B) is 30 to 30% by weight. 80% by weight, (C) is 50 to 160% by weight, and (D) is 0.2 to 8% by weight.

The (B) contained in the (X) is the above (B), and from the viewpoint of the hardness of the cured product, (B2) to (B7) are preferable, and (B2) and (B4) are more preferable. is there.

<Monofunctional unsaturated monomer (C)>
Examples of the monofunctional unsaturated monomer (C) in the present invention include monofunctional (meth)acrylates (C1) having 3 to 35 carbon atoms and nitrogen atom-containing monofunctional unsaturated monomers (C2).

(C1) C3-C35 monofunctional (meth)acrylate:
(Meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, tert-butyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 4-n- Butylcyclohexyl (meth)acrylate, bornyl (meth)acrylate, isobornyl (meth)acrylate, benzyl (meth)acrylate, 2-ethylhexyl diglycol (meth)acrylate, butoxyethyl (meth)acrylate, 2-chloroethyl (meth)acrylate , 4-bromobutyl(meth)acrylate, butoxymethyl(meth)acrylate, methoxypropylene mono(meth)acrylate, 3-methoxybutyl(meth)acrylate, 2-ethylhexylcarbitol(meth)acrylate, 2-(2- Methoxyethoxy)ethyl(meth)acrylate, 2-(2-butoxyethoxy)ethyl(meth)acrylate, phenyl(meth)acrylate, phenoxymethyl(meth)acrylate, phenoxyethyl(meth)acrylate, glycidyl(meth)acrylate, tetrahydro. Furfuryl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, polyethylene oxide monomethyl ether (meth) Acrylate;

(C2) Nitrogen atom-containing monofunctional unsaturated monomer:
Vinylamine, N-methylvinylamine, N-ethylvinylamine, N-propylvinylamine, Nn-butylvinylamine, Nt-butylvinylamine, N-butoxymethylvinylamine, N-isopropylvinylamine, N -Methylol vinyl amine, N,N-dimethyl vinyl amine, N,N-diethyl vinyl amine, N-vinyl morpholine, allyl amine, N-methyl allyl amine, N-ethyl allyl amine, N-propyl allyl amine, Nn-butyl allyl amine, N-t-butylallylamine, N-butoxymethylallylamine, N-isopropylallylamine, N-methylolallylamine, N,N-dimethylallylamine, N,N-diethylallylamine, N-allylmorpholine, N-vinylpyrrolidone, vinylformamide, N,N-dimethylacrylamide, diacetone acrylamide, acryloylmorpholine;

Among these monofunctional unsaturated monomers (C), from the viewpoint of hardness, (C2) is preferable, and N,N-dimethylacrylamide, diacetone acrylamide, and acryloylmorpholine are more preferable.

<Photopolymerization initiator (D)>
Examples of the photopolymerization initiator (D) in the present invention include phosphine oxide compounds (D1), benzoyl formate compounds (D2), thioxanthone compounds (D3), oxime ester compounds (D4), hydroxybenzoyl compounds. (D5), benzophenone compounds (D6), ketal compounds (D7), 1,3α aminoalkylphenone compounds (D8) and the like.

Examples of the phosphine oxide compound (D1) include bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide and 2,4,6-trimethylbenzoyldiphenylphosphine oxide.

Examples of the benzoyl formate compound (D2) include methylbenzoyl formate and the like.

Examples of the thioxanthone compound (D3) include isopropylthioxanthone.

Examples of the oxime ester compound (D4) include 1,2-octanedione, 1-[4-(phenylthio)-,2-(O-benzoyloxime)], ethanone, 1-[9-ethyl-6-(2. -Methylbenzoyl)-9H-carbazol-3-yl]-, 1(O-acetyloxime)) and the like.

Examples of the hydroxybenzoyl compound (D5) include 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexylphenylketone, and benzoin alkyl ether.

Examples of the benzophenone compound (D6) include benzophenone.

Examples of the ketal compound (D7) include benzyl dimethyl ketal.

Examples of the 1,3α aminoalkylphenone compound (D8) include 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one.

Among these photopolymerization initiators (D), from the viewpoint of hardness, (D1), (D5) and (D8) are preferable, and more preferably bis(2,4,6-trimethylbenzoyl)- Phenylphosphine oxide, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one.

Further, the composition (X) for inkjet ink of the present invention may contain various additives, if necessary, within a range that does not impair the effects of the present invention.
Examples of the additives include pigments, plasticizers, organic solvents, dispersants, defoamers, thixotropic agents (thickeners), slip agents, antioxidants, hindered amine light stabilizers, and ultraviolet absorbers.

<Printed matter>
The printed matter of the present invention is a printed matter on which a cured product of the composition (X) for inkjet ink is printed. That is, the (X) can be obtained as a printed matter by printing with an inkjet printing machine and then irradiating with active energy rays (ultraviolet rays, electron rays, X-rays, etc.) to cure.
The film thickness after curing and drying is preferably 0.5 to 300 μm. The more preferable upper limit is 250 μm from the viewpoint of curability, and the more preferable lower limit is 1 μm from the viewpoint of hardness.

Examples of the base material include those made of resins such as vinyl chloride, methyl methacrylate (co)polymer, polyethylene terephthalate, polycarbonate, polytriacetyl cellulose and polycycloolefin.

The active energy rays in the present invention include ultraviolet rays, electron rays, X-rays, infrared rays and visible rays. Among these active energy rays, ultraviolet rays and electron rays are preferable from the viewpoint of curability and resin deterioration.

When the composition for inkjet ink of the present invention is cured by ultraviolet rays, various ultraviolet irradiation devices [for example, ultraviolet irradiation device [model number "VPS/I600", manufactured by Fusion UV Systems Co., Ltd.]] can be used.
Examples of lamps used include UV-LED lamps and metal halide lamps. The irradiation amount of ultraviolet rays is preferably 10 to 10,000 mJ/cm ² , and more preferably 100 to 5,000 mJ/cm ² from the viewpoint of curability of the composition and flexibility of the cured product.

Hereinafter, the present invention will be further described with reference to Examples and Comparative Examples, but the present invention is not limited thereto. Hereinafter, unless otherwise specified,% means% by weight and part means part by weight.

<Production Example 1>
In a reaction vessel equipped with a stirrer, a cooling tube, and a thermometer, dipentaerythritol pentaacrylate (B-1) [trade name: Neomer DA-600, manufactured by Sanyo Chemical Industry Co., Ltd.] 65.0 parts, water 0. After charging 01 parts and 0.01 parts of hydrochloric acid [reagent, the same below] for 30 minutes and stirring, silicate tetra-n-ethoxide (a1-1) [trade name: TEOS, manufactured by Tokyo Chemical Industry Co., Ltd.] 35.0 After the reaction was carried out at 65° C. for 2 hours, water and ethanol produced by the reaction were distilled off under reduced pressure to give a solution of the hydrolyzed condensate (A-1) (B-1) [( The content of A-1) was 79% by weight].
The (meth)acryloyl group concentration of (A-1) was 6.0 mmol/g, and the weight average molecular weight (Mw) was 3310.
The molar ratio [(a1)/(B)] constituting (A) was 67/33.

<Production Examples 2-5>
Inorganic alkoxide (a1) shown in Table 1 and hydrochloric acid and water in respective parts are obtained in the same manner as in Production Example 1 to obtain a solution of hydrolysis-condensation products (A-2) to (A-5) (B). It was
The results are shown in Table 1.

The raw materials used in Table 1 are as follows.
(A1-1):
Silicate tetra-n-ethoxide [trade name "TEOS", manufactured by Tokyo Chemical Industry Co., Ltd.]
(A1-2):
Titanium tetra-n-ethoxide [Brand name: B-1, manufactured by Nippon Soda Co., Ltd.]
(B-1):
Dipentaerythritol pentaacrylate [Product name: Neomer DA-600, manufactured by Sanyo Chemical Industry Co., Ltd.]
(B-2):
Pentaerythritol triacrylate [trade name: Neomer EA-300, manufactured by Sanyo Chemical Industry Co., Ltd.]
(B-3):
Trimethylolpropane EO 3 mol adduct triacrylate [trade name: Neomer TA-401, manufactured by Sanyo Chemical Industry Co., Ltd.]
(B-4):
Dipentaerythritol EO adduct hexaacrylate [trade name: New Frontier MF-001, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.]

<Production Example 6>
A reaction vessel equipped with a stirrer, a condenser and a thermometer was charged with 85.6 parts of ethanol, 0.6 part of water and 0.1 part of triethylamine, and heated to 65° C. while stirring for 30 minutes. After reaching 65° C., 13.6 parts of the solution of the hydrolysis-condensation product (A-1) obtained in Production Example 1 (B-1) prepared in Preparation Example 1 in advance was charged over 60 minutes. After completion of the addition, stirring was continued for 180 minutes at 65° C. to perform a sol-gel reaction.
After the reaction, the pressure in the reaction vessel was reduced and ethanol and water were distilled off to obtain a solution (B) solution of the hydrolyzed condensate (A-6) [content of (A-6) 75% by weight].
The (meth)acryloyl group concentration of (A-6) was 7.4 mmol/g, and the volume average particle diameter was 0.2 μm.
The molar ratio [(a1)/(B)] constituting (A) was 67/33.

<Production Example 7>
A solution of the hydrolysis-condensation product (A-7) (B) was obtained in the same manner as in Production Example 6 except that the preparation (parts by weight) shown in Table 2 was followed.
The results of Production Examples 6 and 7 are shown in Table 2.

<Comparative Production Example 1>
Dipentaerythritol pentaacrylate (B-1) 60 in 100 parts of commercially available inorganic oxide fine particles [trade name "Colloidal silica MEK-ST" particle size 10-15 nm MEK (methyl ethyl ketone) 40% solution, Nissan Chemical Industries, Ltd.] Parts were mixed and MEK was distilled off by an evaporator to obtain a solution of the hydrolysis-condensation product (ratio A-1) by (B-1) [content of (ratio A-1) 40% by weight]. ..
The volume average particle diameter of (ratio A-1) was 0.1 μm.

<Example 1>
In a reaction vessel equipped with a stirrer, a cooling tube and a thermometer, 100 parts of a polyfunctional (meth)acrylate (B-1) solution of the hydrolysis-condensation product (A-1) obtained in Production Example 1 and acryloylmorpholine. 150 parts, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one (D-2) [trade name "Irgacure 907", manufactured by BASF] 2.0 parts In addition, the mixture was mixed and stirred at 65° C. until it became uniform to obtain a composition (X-1) for inkjet ink.

<Examples 2 to 7, Comparative Example 1>
Compositions (X-2) to (X-7) for inkjet ink, (ratio X-1) were prepared in the same manner as in Example 1 except that the charged amount (parts by weight) in Example 1 was in accordance with Table 3. ) Got. The performance of each composition for inkjet ink was evaluated by the method described below. The results are shown in Table 3.

The raw materials used in Table 3 are as follows.
(C-1):
Acryloylmorpholine [Product name "ACMO", KJ Chemicals Co., Ltd.]
(C-2):
Isobornyl acrylate [Product name "IBXA", manufactured by Osaka Organic Chemical Industry Co., Ltd.]
(D-1):
2,4,6-Trimethylbenzoyldiphenylphosphine oxide [trade name "Lucirin TPO", manufactured by BASF Ltd.]
(D-2):
2-Methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one [trade name "Irgacure 907", manufactured by BASF Ltd.]
(D-3):
1-Hydroxycyclohexyl phenyl ketone [trade name "Irgacure 184", manufactured by BASF Corporation]

<1> Preparation of cured film A composition for inkjet ink was prepared by using a PET film having a thickness of 100 μm [trade name “COSMOSHINE A4300”, manufactured by Toyobo Co., Ltd.]. Of 5 μm and dried at 60° C. for 3 minutes, and then an ultraviolet irradiation device [model number “VPS/I600”, manufactured by Fusion UV Systems Co., Ltd. same as below. ], 300 mJ/cm ^{2 of} ultraviolet rays were irradiated to prepare a film having a cured film on the surface of the base film.
The performance of the obtained film was evaluated by the following methods. The evaluation results are shown in Table 3.

<1-1> [Evaluation of haze (transparency of film)]
In accordance with JIS-K7105, a total light transmittance measuring device [trade name "haze-gard
dual” BYK Gardner Co., Ltd.] was used to measure the haze.

<1-2> [Evaluation of total light transmittance (transparency of film)]
The total light transmittance (%) of the test piece was measured according to JIS-K7105 using a total light transmittance measuring device [trade name "haze-gardual", manufactured by BYK gardner Co., Ltd.].

<1-3> [Evaluation of Pencil Hardness (Film Hardness)]
The pencil hardness was measured according to JIS K-5400. The pencil hardness was evaluated according to the following criteria.
<Evaluation criteria>
◎: 3H or more ○: 2H
△: H
X: F or less

<2> [Evaluation of ejection stability]
An inkjet printer device [trade name "Material Printer DMP-2831", manufactured by FUJIFILM Global Graphic Systems Co., Ltd.] was used, and applied voltage so that the amount of one droplet was 10 pl and the droplet velocity was 6 m/sec. Was adjusted and continuously discharged. The head temperature was adjusted to 60°C. Ten minutes after the start of ejection, the number of nozzles in which ejection failure occurred out of 16 mounted nozzles was counted and the ejection stability was evaluated.
<Evaluation criteria>
◯: 0 nozzles with ejection failure Δ: 1 nozzle with ejection failure X: 2 or more nozzles with ejection failure

From the results of Tables 1 to 3, the inkjet ink composition (X) of the present invention imparted excellent ejection stability as compared with the comparative composition, and the cured product of the inkjet ink composition had excellent surface hardness. It can be seen that it imparts transparency.

INDUSTRIAL APPLICABILITY The composition for inkjet ink of the present invention is excellent in ejection stability and imparts excellent scratch resistance and transparency to a cured product, and thus can be widely used in various inkjet ink applications and is extremely useful. ..

Claims (7)

Hydrolysis condensate (A) containing an inorganic alkoxide (a1) and a polyfunctional (meth)acrylate (B) as constituent monomers, the polyfunctional (meth)acrylate (B), and a monofunctional unsaturated monomer (C). ), and a photopolymerization initiator (D), the composition for an inkjet ink, wherein the molar ratio [(a1) of (a1) and (B) that constitutes the hydrolysis-condensation product (A)]. /(B)] is 67/33 to 87/13, and the content based on the total weight of the (A) and the (B) is 37 to 79% by weight of the (A). The composition (X) for inkjet ink , wherein B) is 21 to 63% by weight, (C) is 50 to 220% by weight, and (D) is 2 to 3% by weight . Wherein (A) of a (meth) acryloyl group concentration inkjet ink composition of claim 1 Symbol placement is 2.0~8.0mmol / g. The inkjet ink according to claim 1 or 2 , wherein the (A) is a hydrolysis-condensation product (A1) and/or a particulate hydrolysis-condensation product (A2) having a weight average molecular weight (Mw) of 500 to 20,000. Composition. The inorganic alkoxide (a1) is at least one selected from the group consisting of silane alkoxide, zirconium alkoxide, titanium alkoxide, hafnium alkoxide, zinc alkoxide, aluminum alkoxide, gallium alkoxide, indium alkoxide, germanium alkoxide and tin alkoxide. The composition for inkjet ink according to any one of 3 to 5 . Prints cured product of claim 1-4 inkjet ink composition according to any one (X) is printed. Among the polyfunctional (meth) acrylate (B), in the presence of a catalyst (b), by reacting with an inorganic alkoxide (a1) water, according to claim 1-4 comprising the step of generating a hydrolysis-condensation product (A1) 5. The method for producing the inkjet ink composition (X) according to any one of items 1. The method for producing an inkjet ink composition (X) according to claim 6 , further comprising a step of subjecting the hydrolysis-condensation product (A1) to a sol-gel reaction to obtain a particulate hydrolysis-condensation product (A2).