JP2010106085A - Active energy ray-curing type ink-jet ink - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an active energy ray-curing type ink-jet ink which can form images excellent in smoothness and gloss and having high image qualities, and to provide a printed article using the ink. <P>SOLUTION: There is provided the active energy ray-curing type ink-jet ink composition characterized by containing a polymerizable monomer and inorganic oxide colloid. In more detail, there is provided the active energy ray-curing type ink-jet ink composition, wherein the inorganic oxide colloid is colloidal silica. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an active energy ray-curable inkjet ink capable of forming a high-quality image excellent in smoothness and glossiness, and a printed matter using the ink.

  Conventionally, active energy ray-curable inks have been used for offset printing and silk screen printing, but the cost per color can be reduced by ejecting the required amount of ink droplets when needed during printing. In recent years, demand for active energy ray-curable inks for ink jet printing has been increasing from the point that on-demand printing is possible without requiring a plate. Active energy ray curable inks for inkjet printing include ultraviolet curable ink jet inks that are cured with ultraviolet rays. Compared to conventional water-based or solvent-based non-curable inkjet inks, environmentally friendly by reducing volatile solvents. In recent years, a patent has been disclosed (see Patent Documents 1 and 2) in that it can be printed on a substrate having quick drying properties, odor reduction, and no ink absorbability, and has high substrate selectivity.

  However, printed materials printed using ultraviolet curable ink-jet inks often have inferior image quality as compared with printed materials using water-based or solvent-based ink-jet inks. For water-based or solvent-based inks, high-precision printing is possible because the ink penetrates the substrate and the printing surface becomes smooth after being printed on the substrate by an inkjet discharge device. Since the mold ink is cured by ultraviolet rays, the droplet shape causes unevenness on the printing surface, so the accuracy is poor. In addition, when unevenness occurs on the printed surface, irregular reflection of reflected light occurs, resulting in an adverse effect that the printed matter is not glossy and banding is conspicuous.

Although addition of silica fine particles to inkjet ink is disclosed, many are non-curing inks mainly composed of water, and many are intended to improve abrasion resistance (Patent Documents 3 and 4). reference). In addition, although ink that does not contain water is also disclosed (see Patent Document 5), the purpose is to improve wrinkles during thick film curing, and in both the substrate and the ink cured film as in the present invention. There is no description on improvement of wettability.
JP-A-6-200204 Special Table 2000-504778 JP 2000-53901 A (Claims, Examples) JP-A-10-287035 (Claims, Examples) JP 2006-152064 A (Claims, Examples)

An object of the present invention is to provide an active energy ray-curable inkjet ink that has good wettability to both a base material and an ink-cured film, and can produce a high-quality printed matter with excellent smoothness and gloss. It is to provide.

  In order to obtain a smooth and glossy high-quality printed matter, it is important that the ink spreads on the printing substrate. In the printing of the active energy ray-curable ink-jet ink, in order to improve the quality of the printed matter, the printing is generally divided into about 4 to 16 passes, but the ink is applied to the substrate in the first pass. Whereas wet dots are formed, after the second pass, ink wet dots are formed on the dots (= ink cured film) formed in the previous pass. Therefore, in order to obtain a high-quality printed matter, wetting and spreading of the ink with respect to both the base material and the ink cured film becomes important.

In order for the ink to wet the substrate, the surface tension of the ink needs to be smaller than the surface free energy of the substrate. Therefore, in general, as a method for improving the wettability of the ink, a method of reducing the surface tension by adding a surface tension adjusting agent to the ink is often used. Typical examples include silicon-based, acrylic-based, and fluorine-based additives, which can improve the wettability of dots with respect to the substrate. However, when the surface tension adjusting agent is contained in the ink, the surface free energy of the ink cured film made of the ink is lowered, so that the wettability of dots with respect to the ink cured film is deteriorated.
As a result of diligent research, the present inventors have used an active energy ray-curable inkjet ink containing an inorganic oxide colloid to wet both the substrate and the ink cured film regardless of the presence or absence of a surface tension modifier. It was found that the spreadability is good and it is possible to create a high-quality printed matter.

That is, the first invention relates to an active energy ray-curable ink-jet ink composition comprising a polymerizable monomer and an inorganic oxide colloid.
The second invention relates to the active energy ray-curable inkjet ink composition as described above, wherein the inorganic oxide colloid is colloidal silica.

The third invention relates to the active energy ray-curable inkjet ink composition described above, wherein the content of the inorganic oxide colloid is 0.5 to 5.0% by weight.
A fourth invention relates to the active energy ray-curable inkjet ink composition described above, characterized by comprising a radical photopolymerization initiator.

5th invention is related with the said active energy ray hardening-type inkjet ink composition characterized by including a pigment and a pigment dispersant.
A sixth invention relates to the active energy ray-curable inkjet ink composition described above, characterized by not containing 3% or more of water.
The seventh invention relates to a printed matter obtained by forming an image on a substrate with the active energy ray-curable inkjet ink described above and then curing the ink with an active energy ray.

  According to the present invention, there is provided an active energy ray-curable inkjet ink that has good wettability to both a substrate and an ink-cured film, and that can produce a high-quality printed matter with excellent smoothness and gloss. I was able to.

Hereinafter, the present invention will be described in detail.

[Inorganic oxide colloid]
The active energy ray-curable inkjet ink used in the present invention contains an inorganic oxide colloid. Examples of the inorganic oxide colloid include colloidal silica and alumina colloid, and colloidal silica is preferably used.
The colloidal silica in the present invention is a colloidal solution in which fine particles of SiO ₂ are dispersed in water or an organic solvent. Commercially available colloidal silica can be dispersed in water-insoluble organic solvents such as ketones, esters, and toluene by modifying the surface of fine particles from water-soluble ones such as water, alcohol, and ether. There is something like that. It has been confirmed that the wettability of the dots varies depending on the degree of surface modification of the silica fine particles. When the silica surface is not treated, the wettability of the dots is better and the dot diameter is larger than the modified surface.

In the present invention, colloidal silica in which the dispersion medium is alcohol or ether having a boiling point of 140 ° C. or higher is particularly preferable because of low volatility as an ink jet ink and wettability of dots. From the viewpoint of compatibility with the monomer and ink stability, it is preferable that the amount of water contained in the ink is less than 3%, and therefore the colloidal silica dispersion medium is not preferably water.
The average particle size of the inorganic oxide colloid is preferably 1 to 200 nm, more preferably 2 to 100 nm, and most preferably 5 to 50 nm. If the average particle size is too small, the colloid becomes unstable, and if fine particles with an average particle size exceeding 200 nm are used, not only the ejection stability is lowered, but also appearance defects such as a decrease in brightness of the image and poor gloss are caused. Sometimes.

The content of the inorganic oxide colloid is preferably 0.5 to 5.0% by weight, more preferably 0.7 to 4.0% by weight, and 1.0 to 3.0% by weight. It is particularly preferred. If the amount of the inorganic oxide colloid is too small, the effect of improving the wettability is lowered, and if it is too large, the stability and curability of the ink may be impaired.
Said inorganic oxide colloid can be used individually or in combination of 2 or more types, respectively.

[Polymerizable monomer]
The polymerizable monomer in the present invention is an active energy ray curing reaction component, and specifically represents a molecule having an ethylenically unsaturated double bond.

  Specific examples of the monofunctional polymerizable monomer used in the present invention include cyclohexyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, benzyl (meth) acrylate, methylphenoxyethyl (meth) acrylate, and 4-t-butyl. Cyclohexyl (meth) acrylate, caprolactone-modified tetrahydrofurfuryl (meth) acrylate, tribromophenyl (meth) acrylate, ethoxylated tribromophenyl (meth) acrylate, 2-phenoxyethyl (meth) acrylate (or ethylene oxide array / Or propylene oxide addition monomer), acryloylmorpholine, isobornyl (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, N-vinyl capro Cutam, N-vinylpyrrolidone, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 1,4-cyclohexanedimethanol mono (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate 4-hydroxybutyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, isooctyl (meth) acrylate, 2 -Methoxyethyl (meth) acrylate, methoxytriethylene glycol (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, ethoxyethoxyethyl ( Acrylate), butoxyethyl (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, methoxydipropylene glycol (meth) acrylate, dipropylene glycol (meth) acrylate, β-carboxylethyl (meth) acrylate, ethyl diglycol (meth) Acrylate, trimethylolpropane formal mono (meth) acrylate, imide (meth) acrylate, isoamyl (meth) acrylate, ethoxylated succinic acid (meth) acrylate, trifluoroethyl (meth) acrylate, ω-carboxypolycaprolactone mono (meth) Examples thereof include, but are not limited to, acrylate and N-vinylformamide.

Further, among these polymerizable monomers having high ink jet suitability, cyclohexyl acrylate, methylphenoxyethyl acrylate, 2-phenoxyethyl acrylate (or its ethylene oxide / or propylene oxide addition monomer), acryloylmorpholine, isobornyl acrylate, N- Vinyl caprolactam, N-vinyl pyrrolidone, 2-hydroxy-3-phenoxypropyl acrylate, 1,4-cyclohexanedimethanol monoacrylate, isooctyl acrylate, and lauryl acrylate can be more preferably used.
Ink jet aptitude is aptitude as an active energy ray-curable ink jet ink, and specifically means discharge stability in an ink jet discharge device and curability when irradiated with active energy rays. Rheological properties such as the viscosity and surface tension of the monomer affect the ejection stability, and structural properties such as the number of functional groups and molecular weight of the monomer affect the curability.

  Furthermore, from the viewpoint of safety and coating film performance, methylphenoxyethyl acrylate, 2-phenoxyethyl acrylate (or its ethylene oxide / or propylene oxide addition monomer), acryloylmorpholine, isobornyl acrylate, N-vinylcaprolactam 2-hydroxy-3-phenoxypropyl acrylate, 1,4-cyclohexanedimethanol monoacrylate, and lauryl acrylate can be more preferably used.

  Specific examples of the polyfunctional polymerizable monomer include dimethylol-tricyclodecane di (meth) acrylate, propoxylated bisphenol A di (meth) acrylate, ethoxylated bisphenol A di (meth) acrylate, and cyclohexanedimethanol. Di (meth) acrylate, dimethylol dicyclopentane di (meth) acrylate, ethoxylated isocyanuric acid tri (meth) acrylate, tri (2-hydroxyethyl isocyanurate) tri (meth) acrylate, tri (meth) allyl isocyanurate , Ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, ethoxylated 1,6-hex Diol di (meth) acrylate, neopentyl glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, tetraethylene glycol Di (meth) acrylate, 2-n-butyl-2-ethyl-1,3-propanediol di (meth) acrylate, hydroxypivalate neopentyl glycol di (meth) acrylate, caprolactone-modified hydroxypivalate ester neopentyl glycol di (Meth) acrylate, 1,3-butylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, hydroxypivalate trimethylolpropane tri (meth) acrylate , Ethoxylated phosphate tri (meth) acrylate, ethoxylated tripropylene glycol di (meth) acrylate, neopentyl glycol modified trimethylolpropane di (meth) acrylate, stearic acid modified pentaerythritol di (meth) acrylate, pentaerythritol tri ( (Meth) acrylate, tetramethylolpropane tri (meth) acrylate, tetramethylolmethane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, caprolactone-modified trimethylolpropane tri (meth) acrylate, propoxylate glyceryl tri (meth) acrylate, Tetramethylol methane tetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, ditrimethylolpropane Tetra (meth) acrylate, ethoxylated pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, caprolactone modified dipentaerythritol hexa (meth) acrylate, dipentaerythritol hydroxypenta (meth) acrylate, neopentyl glycol oligo (Meth) acrylate, 1,4-butanediol oligo (meth) acrylate, 1,6-hexanediol oligo (meth) acrylate, trimethylolpropane oligo (meth) acrylate, pentaerythritol oligo (meth) acrylate, ethoxylated neopentyl Glycol di (meth) acrylate, propoxylated neopentyl glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate , Ethoxylated trimethylolpropane tri (meth) acrylate, there may be mentioned propoxylated trimethylolpropane tri (meth) acrylate, but is not limited thereto.

  Among these, dimethylol-tricyclodecane diacrylate, hydroxypivalic acid neopentyl glycol di (meth) acrylate, propoxylated bisphenol A di (meth) acrylate, ethoxylated bisphenol A di (meta) ) Acrylate can be used more suitably. These monofunctional and polyfunctional monomers may be used alone or in combination of two or more as required.

  Although the composition ratio of the polymerizable monomer is not particularly limited, it is preferable to contain 30 to 60% by weight of the monofunctional monomer and 70 to 40% by weight of the polyfunctional monomer from the viewpoint of curability and adhesion.

  In addition to the above, what is called an oligomer or a prepolymer can be used for the inkjet ink of the present invention. Specifically, “Ebecryl 230, 244, 245, 270, 280 / 15IB, 284, 285, 4830, 4835, 4858, 4883, 8402, 8803, 8800, 254, 264, 265, 294 / 35HD, manufactured by Daicel UCB, 1259, 1264, 4866, 9260, 8210, 1290.1290K, 5129, 2000, 2001, 2002, 2100, KRM7222, KRM7735, 4842, 210, 215, 4827, 4849, 6700, 6700-20T, 204, 205, 6602, 220, 4450, 770, IRR567, 81, 84, 83, 80, 657, 800, 805, 808, 810, 812, 1657, 1810, IRR302, 450, 670, 830, 835, 870, 1 30, 1870, 2870, IRR267, 813, IRR483, 811, 436, 438, 446, 505, 524, 525, 554W, 584, 586, 745, 767, 1701, 1755, 740 / 40TP, 600, 601, 604, 605, 607, 608, 609, 600 / 25TO, 616, 645, 648, 860, 1606, 1608, 1629, 1940, 2958, 2959, 3200, 3201, 3404, 3411, 3412, 3415, 3500, 3502, 3600, 3603, 3604, 3605, 3608, 3700, 3700-20H, 3700-20T, 3700-25R, 3701, 3701-20T, 3703, 3702, RDX63182, 6040, IRR419 ", manufactured by Sartomer CN104, CN120, CN124, CN136, CN151, CN2270, CN2271E, CN435, CN454, CN970, CN971, CN972, CN9782, CN981, CN9873, CN991, "Laromar EA81L, F87" manufactured by BASF LR8800, PE46T, LR8907, PO43F, PO77F, PE55F, LR8967, LR8981, LR8982, LR8992, LR9004, LR8956, LR8985, LR8987, UP35D, UA19T, LR9005, PO83F, PO33F, L8489, L9489 LR8996, LR9013 LR9019, PO9026V, PE9027V "manufactured by Cognis" Photomer 3005, 3015, 3016, 3072, 3982, 3215, 5010, 5429, 5430, 5432, 5662, 5806, 5930, 6008, 6010, 6019, 6184, 6210, 6217, 6230, 6891, 6892, 6893-20R, 6363, 6572, 3660 "," Art Resin UN-9000HP, 9000PEP, 9200A, 7600, 5200, 1003, 1255, 3320HA, 3320HB, 3320HC, 3320HS, 901T, manufactured by Negami Kogyo Co., Ltd. 1200TPK, 6060PTM, 6060P "," Nippon Gosei Chemical Co., Ltd. "" purple light UV-6630B, 7000B, 7510B, 7461TE, 3000B, 320 " 0B, 3210EA, 3310B, 3500BA, 3520TL, 3700B, 6100B, 6640B, 1400B, 1700B, 6300B, 7550B, 7605B, 7610B, 7620EA, 7630B, 7640B, 2000B, 2010B, 2250EA, 2750B, “Kayarad” R-280, R-146, R131, R-205, EX2320, R190, R130, R-300, C-0011, TCR-1234, ZFR-1122, UX-2201, UX-2301, UX3204, UX-3301, UX-4101, UX-6101, UX-7101, MAX-5101, MAX-5100, MAX-3510, UX-4101 "and the like.

[Active energy rays]
The active energy ray described in the present invention affects an electron orbit of an irradiated object such as an electron beam, an ultraviolet ray, and an infrared ray, and indicates an energy ray that can trigger a polymerization reaction such as a radical, a cation, and an anion. The energy ray is not limited to this as long as it induces a polymerization reaction.

  In the present invention, when ultraviolet rays are used as active energy rays, a radical photopolymerization initiator is blended in the ink. As the radical photopolymerization initiator, those of molecular cleavage type or hydrogen abstraction type are suitable for the present invention. Specific examples include benzoin isobutyl ether, 2,4-diethylthioxanthone, 2-isopropylthioxanthone, benzyl, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2-benzyl-2-dimethylamino-1- (4- Morpholinophenyl) -butan-1-one, bis (2,4,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, 1,2-octanedione, 1- (4- (phenylthio) -2,2- (O-benzoyloxime)) and the like are preferably used, and other molecular cleavage types include 1-hydroxycyclohexyl phenyl ketone, benzoin ethyl ether, benzyldimethyl ketal, 2-hydroxy-2 -Methyl-1-phenylpropane-1-o 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one and 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one Moreover, benzophenone, 4-phenylbenzophenone, isophthalphenone, 4-benzoyl-4′-methyl-diphenyl sulfide, etc., which are hydrogen abstraction type photopolymerization initiators, can also be used in combination.

For the photo radical polymerization initiator, as sensitizers, for example, trimethylamine, methyldimethanolamine, triethanolamine, p-diethylaminoacetophenone, ethyl p-dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate, N, An amine that does not cause an addition reaction with the polymerizable component, such as N-dimethylbenzylamine and 4,4′-bis (diethylamino) benzophenone, can also be used in combination. Of course, it is preferable to select and use the radical photopolymerization initiator and the sensitizer, which are excellent in solubility in the ultraviolet curable compound and do not inhibit the ultraviolet transmittance.
The radical photopolymerization initiator and the sensitizer are used in the range of 1 to 20% by weight, preferably 5 to 18% by weight, more preferably 10 to 16% by weight, based on the total amount of the ultraviolet curable composition.

[Pigment]
The ink shown by this invention shows the liquid printed or applied to the base-material surface. This ink can be used as a coating application when it does not contain a coloring component, and can be used as a material for displaying graphics, characters, photographs, etc. when it contains a coloring component. Conventionally, dyes and pigments are widely used as the coloring component, but pigments are often used particularly from the viewpoint of weather resistance. As a pigment component,
Specific examples of carbon black include “Special Black 350, 250, 100, 550, 5, 4, 4A, 6” “Printex U, V, 140 U, 140 V, 95, 90, 85, 80, 75, 55, manufactured by Degussa. 45, 40, P, 60, L6, L, 300, 30, 3, 35, 25, A, G ", Cabot's" REGAL 400R, 660R, 330R, 250R "," MOGUL E, L ", Mitsubishi Chemical “MA7, 8, 11, 77, 100, 100R, 100S, 220, 230” “# 2700, # 2650, # 2600, # 200, # 2350, # 2300, # 2200, # 1000, # 990, # 980, # 970, # 960, # 950, # 900, # 850, # 750, # 650, # 52, # 50, # 47, # 45, # 4 L, # 44, # 40, # 33, # 332, # 30, # 25, # 20, # 10, # 5, CF9, # 95, # 260 "
And so on. Further, in the present invention, yellow, magenta, cyan ink, or other colors such as white can be used, and pigments used in inks generally used in printing applications and paint applications can be used, such as color developability and light resistance. Can be selected according to the required use.

The ratio of the pigment to the total ink is 1 to 15 parts by weight for organic pigments such as yellow, magenta, cyan and black with respect to 100 parts by weight of ink. It is preferable to mix | blend in arbitrary ratios of 5 weight part-40 weight part.
When a pigment is contained, it is preferable to add a pigment dispersant in order to improve the dispersibility of the pigment and the storage stability of the ink. There are various types of pigment dispersants such as a high molecular type dispersant and a low molecular type dispersant. These can be selected according to dispersibility, for example, hydroxyl group-containing carboxylic acid ester, salt of long chain polyaminoamide and high molecular weight acid ester, salt of high molecular weight polycarboxylic acid, long chain polyaminoamide and polar acid ester. Salt, high molecular weight unsaturated acid ester, polymer copolymer, modified polyurethane, modified polyacrylate, polyether ester type anionic activator, naphthalenesulfonic acid formalin condensate salt, aromatic sulfonic acid formalin condensate salt, polyoxy Ethylene alkyl phosphate ester, polyoxyethylene nonylphenyl ether, stearylamine acetate and the like can be used.

  Specific examples of the pigment dispersant include "Anti-Terra-U (polyaminoamide phosphate)", "Anti-Terra-203 / 204 (high molecular weight polycarboxylate)" manufactured by BYK Chemie, "Disperbyk-101 ( (Polyaminoamide phosphate and acid ester), 107 (hydroxyl group-containing carboxylic acid ester), 110, 111 (copolymer containing an acid group), 130 (polyamide), 161, 162, 163, 164, 165, 166, 170 ( Polymer copolymer) ”,“ 400 ”,“ Bykumen ”(high molecular weight unsaturated acid ester),“ BYK-P104, P105 (high molecular weight unsaturated acid polycarboxylic acid) ”,“ P104S, 240S (high molecular weight unsaturated) Saturated acid polycarboxylic acid and silicon system "," Lactimon (long chain amine and unsaturated acid poly) Recarboxylic acid and silicon) ”.

Also, “Efka CHEMICALS” “Efka 44, 46, 47, 48, 49, 54, 63, 64, 65, 66, 71, 701, 764, 766”, “Efka Polymer 100 (modified polyacrylate), 150 (aliphatic) System modified polymer), 400, 401, 402, 403, 450, 451, 452, 453 (modified polyacrylate), 745 (copper phthalocyanine system) "," Floren TG-710 (urethane oligomer) "," Flownon "manufactured by Kyoeisha Chemical Co., Ltd. “SH-290, SP-1000”, “Polyflow No. 50E, No. 300 (acrylic copolymer)”, “Disparon KS-860, 873SN, 874 (polymer dispersing agent), # 2150 (manufactured by Enomoto Kasei Co., Ltd.) Aliphatic polyvalent carboxylic acid), # 7004 (polyether ester type) ” That.
Further, “Demol RN, N (Naphthalenesulfonic acid formalin condensate sodium salt), MS, C, SN-B (aromatic sulfonic acid formalin condensate sodium salt), EP”, “Homogenol L-18 (poly) Carboxylic acid type polymer), “Emulgen 920, 930, 931, 935, 950, 985 (polyoxyethylene nonylphenyl ether)”, “Acetamine 24 (coconut amine acetate), 86 (stearyl amine acetate)”, “Abisia” Solspers 5000 (phthalocyanine ammonium salt type), 13940 (polyesteramine type), 17000 (fatty acid amine type), 24000GR, 32000, 33000, 39000, 41000, 53000, “Nikkor T106 (polyoxy) manufactured by Nikko Chemical Co., Ltd. Ethylene sorbitan monooleate), MYS-IEX (polyoxyethylene monostearate), Hexagline 4-0 (hexaglyceryl tetraoleate), “Ajisper PB821, 822, 824” manufactured by Ajinomoto Fine Techno Co., etc.

  The pigment dispersant is preferably contained in the composition in an amount of 0.1 to 10% by weight. Further, in order to further improve the dispersibility of the pigment and the storage stability of the ink, it is preferable to add an acidic derivative of an organic pigment to the composition of the present invention when the pigment is dispersed.

[Additive]
In the ink-jet ink of the present invention, various additives such as a plasticizer, a surface tension adjuster, an ultraviolet ray inhibitor, a slipping agent, an antiblocking agent, a light stabilizer, and an antioxidant can be used.

  As a surface tension adjusting agent for improving the wettability to the substrate, the slipperiness of the printed film, and the blocking property, “BYK-300, 302, 306, 307, 310, 315, 320, 322, 323, 325, 330, 331, 333, 337, 340, 344, 370, 375, 377, 350, 352, 354, 355, 356, 358N, 361N, 357, 390, 392, UV3500, UV3510, UV3570 “Tegorad-2100, 2200, 2250, 2500, 2700” and the like manufactured by the company are listed. These surface conditioners are preferably contained in the composition in an amount of 0.001 to 1% by weight, and may be used alone or in combination of two or more as required.

[ink]
The ink-jet ink of the present invention is produced by well dispersing a pigment together with a polymerizable monomer and a pigment dispersant using an ordinary dispersing machine such as a sand mill. It is preferable to prepare a concentrated solution having a high pigment concentration in advance and dilute with a monomer. Sufficient dispersion is possible even with dispersion by a normal disperser. Therefore, excessive dispersion energy is not required, and a large amount of dispersion time is not required. An ink having excellent properties is prepared. The ink is preferably filtered through a filter having a pore size of 3 μm or less, and more preferably 1 μm or less.

The inkjet ink of the present invention is preferably adjusted to have a high viscosity at 25 ° C. of 5 to 50 mPa · s. An ink having a viscosity of 5 to 50 mPa · s at 25 ° C. exhibits stable ejection characteristics, particularly from a head having a normal frequency of 4 to 10 KHz to a head having a high frequency of 10 to 50 KHz.
When the viscosity is less than 5 mPa · s, a decrease in the follow-up property of the discharge is recognized in the high-frequency head. When the viscosity exceeds 50 mPa · s, even if a mechanism for reducing the viscosity by heating is incorporated in the head, the discharge itself A drop occurs, the ejection stability becomes poor, and the ejection cannot be performed at all.

  The ink-jet ink of the present invention preferably has an electric conductivity of 10 μS / cm or less in the piezo head and does not cause electrical corrosion inside the head. Further, in the continuous type, it is necessary to adjust the electric conductivity by the electrolyte. In this case, it is necessary to adjust the electric conductivity to 0.5 mS / cm or more.

  In order to form an image with the inkjet ink of the present invention, a method is preferred in which the ink is ejected and drawn on a substrate by an inkjet recording method and then the ink is cured by irradiation with an active energy ray such as ultraviolet rays. It is not limited to.

  In addition, when irradiating an ultraviolet-ray as a light source of an active energy ray, a high pressure mercury lamp, a metal halide lamp, a low pressure mercury lamp, an ultrahigh pressure mercury lamp, an ultraviolet laser, and sunlight can be used, for example. When cured with an electron beam, it is usually cured with an electron beam having an energy of 300 eV or less, but it can also be cured instantaneously with an irradiation dose of 1 to 5 Mrad.

[Base material]
The ink of the present invention is printed on a printing substrate by an inkjet discharge device. The printing substrate used in the present invention is not particularly limited, but a plastic substrate such as polycarbonate, polyvinyl chloride, polystyrene, foamed polystyrene, PMMA, polypropylene, polyethylene, PET, ABS, or a metal substrate such as stainless steel. , Glass base materials, wood base materials, paper base materials, and mixtures or modified products thereof. The substrate may be a film, sheet, or flat plate, or may be molded, but a film, sheet, or flat plate is preferably used.
Moreover, when processing after printing on the said base material, processing conditions, such as processing temperature, can be set as needed.

  EXAMPLES Hereinafter, although this invention is demonstrated further more concretely based on an Example, this invention is not limited to these. In the examples, “parts” represents “parts by weight” and “%” represents “% by weight”.

<Dot diameter>
The wettability of the ink was evaluated by the dot diameter. The dot diameter was measured by observing the printed surface using a digital microscope VHX-900 manufactured by KEYENCE.
<Glossy>
The gloss of the printed surface was measured at 60 ° using a BYK Big Gardner micro-Tri-gloss.
<Appearance>
The appearance of the printed surface was visually evaluated.
◎: Smooth and glossy without streaks or mats ○: No streaks or mats △: Slight streaks or mats ×: Streaks or mats

First, Pigment Dispersion A was prepared with the following composition. Hereinafter, a dispersion was prepared by adding a pigment and a dispersant to a monomer, stirring the mixture with a high-speed mixer or the like until uniform, and then dispersing the obtained mill base with a horizontal sand mill for about 1 hour.
・ Solsperse 32000 (pigment dispersant manufactured by Avicia) 9.0 parts ・ 2-phenoxyethyl acrylate 61.0 parts

[Example 1]
The pigment dispersion was converted into an ink with the following formulation to obtain an inkjet ink.
-Pigment dispersion A 10.0 parts-2-phenoxyethyl acrylate 10.0 parts-N-vinylcaprolactam 25.0 parts-Isooctyl acrylate 9.0 parts-Hydroxypivalic acid neopentyl glycol diacrylate 25.0 parts- EO-modified bisphenol A diacrylate 8.0 parts, Irgacure 907 (manufactured by Ciba Specialty Chemicals) 4.0 parts, Irgacure 819 (manufactured by Ciba Specialty Chemicals) 4.0 parts, IPA-ST (manufactured by Nissan Chemical Industries, Ltd.) Colloidal silica Average particle size 10-20 nm, solid content 30%) 5.0 parts of this ink Inkjet discharge device (PatterningJET, manufactured by Tritec Co., Ltd.) Head: KM512MH manufactured by Konica, UV lamp: 100 W / c manufactured by Integration Technology The second high pressure mercury lamp 1 lamp) to obtain discharge in the print rate of 5% on the polyvinyl chloride resin sheet (Metamaku manufactured MD-5), ultraviolet cured cured film (1). The dot diameter (1) was measured about the obtained cured film (1).

Moreover, after coating using this ink on the said polyvinyl chloride resin sheet using a bar coater (No. 8), 120 W / cm <2> by integration technology company, 1 high pressure mercury lamp, conveyor speed 20m / min UV cured at 3 Pass to obtain a cured film (2). Next, the ink was discharged onto the cured film (2) at a printing rate of 5% by the above-described inkjet discharge device, and cured with ultraviolet rays to obtain a cured film (3). The dot diameter (3) was measured about the obtained cured film (3).
Moreover, this ink was ejected onto the polyvinyl chloride resin sheet at a printing rate of 100% by the ink jet ejection device, and cured with ultraviolet rays to obtain a cured film (4). The obtained cured film (4) was subjected to gloss measurement and appearance evaluation on the printed surface. The obtained results are shown in Table 1.

[Example 2]
The cured films (1), (3), (4) were the same as in Example 1 except that 14.0 parts of 2-phenoxyethyl acrylate and 1.0 part of inorganic oxide colloid (IPA-ST) were used. Got. Table 1 shows the dot diameters (1) and (3), gloss, and appearance of the obtained cured film.
[Example 3]
The cured films (1), (3), (4) were the same as in Example 1 except that 12.7 parts of 2-phenoxyethyl acrylate and 2.3 parts of inorganic oxide colloid (IPA-ST) were used. Got. Table 1 shows the dot diameters (1) and (3), gloss, and appearance of the obtained cured film.

[Example 4]
Cured films (1), (3), (4) were the same as in Example 1 except that 5.0 parts of 2-phenoxyethyl acrylate and 10.0 parts of inorganic oxide colloid (IPA-ST) were used. Got. Table 1 shows the dot diameters (1) and (3), gloss, and appearance of the obtained cured film.
[Example 5]
Cured films (1), (3), (4) were the same as in Example 1 except that 0.0 part of 2-phenoxyethyl acrylate and 15.0 parts of inorganic oxide colloid (IPA-ST) were used. Got. Table 1 shows the dot diameters (1) and (3), gloss, and appearance of the obtained cured film.
[Example 6]
A cured film (1) was prepared in the same manner as in Example 1 except that 0.0 part of 2-phenoxyethyl acrylate, 0.7 part of isooctyl acrylate, and 23.3 parts of inorganic oxide colloid (IPA-ST) were used. ), (3) and (4) were obtained. Table 1 shows the dot diameters (1) and (3), gloss, and appearance of the obtained cured film.

[Example 7]
The pigment dispersion was converted into an ink with the following formulation to obtain an inkjet ink.
-Pigment dispersion A 10.0 parts-2-phenoxyethyl acrylate 10.0 parts-Isobornyl acrylate 10.0 parts-Tripropylene glycol diacrylate 25.0 parts-Neopentyl glycol-modified trimethylolpropane diacrylate 30. 0 parts ・ Ethoxylated trimethylolpropane triacrylate 2.0 parts ・ Irgacure 907 (Ciba Specialty Chemicals) 4.0 parts ・ Irgacure 819 (Ciba Specialty Chemicals) 4.0 parts ・ IPA-ST (Nissan Chemical) Industrial Co., Ltd. colloidal silica, solid content 30%) 5.0 parts Cured films (1), (3) and (4) were obtained in the same manner as in Example 1 except that the above ink was used. Table 1 shows the dot diameters (1) and (3), gloss, and appearance of the obtained cured film.

[Example 8]
The pigment dispersion was converted into an ink with the following formulation to obtain an inkjet ink.
-Pigment dispersion A 10.0 parts-2-phenoxyethyl acrylate 10.0 parts-N-vinylcaprolactam 2.0 parts-Tripropylene glycol diacrylate 50.0 parts-Ethoxylated trimethylolpropane triacrylate 15.0 parts・ Irgacure 907 (Ciba Specialty Chemicals Co., Ltd.) 4.0 parts ・ Irgacure 819 (Ciba Specialty Chemicals Co., Ltd.) 4.0 parts ・ IPA-ST (Nissan Chemical Industry Co., Ltd. Colloidal Silica 30% solid content) 5.0 Parts Cured films (1), (3) and (4) were obtained in the same manner as in Example 1 except that the above ink was used. Table 1 shows the dot diameters (1) and (3), gloss, and appearance of the obtained cured film.

[Example 9]
Ink jet inks and cured films (1), (3), and (4) were obtained in the same manner as in Example 1 except that the inorganic oxide colloids were those shown in Table 1 (all solid content was 30%). Table 1 shows the dot diameters (1) and (3), gloss, and appearance of the obtained cured film.

[Example 10]
The pigment dispersion was converted into an ink with the following formulation to obtain an inkjet ink.
-Pigment dispersion A 10.0 parts-2-phenoxyethyl acrylate 9.85 parts-N-vinylcaprolactam 25.0 parts-Isooctyl acrylate 9.0 parts-Hydroxypivalic acid neopentyl glycol diacrylate 25.0 parts- EO-modified bisphenol A diacrylate 8.0 parts, Irgacure 907 (manufactured by Ciba Specialty Chemicals) 4.0 parts, Irgacure 819 (manufactured by Ciba Specialty Chemicals) 4.0 parts, IPA-ST (manufactured by Nissan Chemical Industries, Ltd.) Colloidal silica, solid content 30%) 5.0 parts BYK-UV3510 (Surface Tension Adjuster manufactured by Big Chemie) 0.15 parts A cured film (1), except that the above ink was used in the same manner as in Example 1. (3) and (4) were obtained. Table 1 shows the dot diameters (1) and (3), gloss, and appearance of the obtained cured film.

[Example 11]
An inkjet ink and cured films (1), (3), and (4) were obtained in the same manner as in Example 14 except that the surface tension adjusting agent was changed to that shown in Table 1. Table 1 shows the dot diameters (1) and (3), gloss, and appearance of the obtained cured film.

[Comparative Example 1]
The pigment dispersion was converted into an ink with the following formulation to obtain an inkjet ink.
-Pigment dispersion A 10.0 parts-2-phenoxyethyl acrylate 10.85 parts-N-vinylcaprolactam 26.5 parts-Isooctyl acrylate 9.5 parts-Hydroxypivalate neopentyl glycol diacrylate 26.5 parts- EO-modified bisphenol A diacrylate 8.5 parts, Irgacure 907 (Ciba Specialty Chemicals) 4.0 parts, Irgacure 819 (Ciba Specialty Chemicals) 4.0 parts, BYK-310 (BIC Chemie surface tension modifier ) 0.15 parts Cured films (1), (3) and (4) were obtained in the same manner as in Example 1 except that the above ink was used. Table 1 shows the dot diameters (1) and (3), gloss, and appearance of the obtained cured film.

[Comparative Examples 2 to 11]
An inkjet ink and cured films (1), (3), and (4) were obtained in the same manner as in Example 1 except that the surface tension adjusting agent was changed to that shown in Table 1. Table 1 shows the dot diameters (1) and (3), gloss, and appearance of the obtained cured film.

[Comparative Example 12]
The pigment dispersion was converted into an ink with the following formulation to obtain an inkjet ink.
-Pigment dispersion A 10.0 parts-2-phenoxyethyl acrylate 11.0 parts-N-vinylcaprolactam 26.5 parts-Isooctyl acrylate 9.5 parts-Hydroxypivalate neopentyl glycol diacrylate 26.5 parts- EO-modified bisphenol A diacrylate 8.5 parts, Irgacure 907 (manufactured by Ciba Specialty Chemicals) 4.0 parts, Irgacure 819 (manufactured by Ciba Specialty Chemicals) 4.0 parts Same as Example 1 except using the above ink Thus, cured films (1), (3) and (4) were obtained. Table 1 shows the dot diameters (1) and (3), gloss, and appearance of the obtained cured film.

[Comparative Example 13]
The pigment dispersion was converted into an ink with the following formulation to obtain an inkjet ink.
Pigment dispersion A 10.0 parts 2-phenoxyethyl acrylate 11.0 parts Isobornyl acrylate 11.0 parts Tripropylene glycol diacrylate 26.5 parts Neopentyl glycol-modified trimethylolpropane diacrylate 31. 5 parts, ethoxylated trimethylolpropane triacrylate 2.0 parts, Irgacure 907 (Ciba Specialty Chemicals) 4.0 parts, Irgacure 819 (Ciba Specialty Chemicals) 4.0 parts except using the above ink In the same manner as in Example 1, cured films (1), (3), and (4) were obtained. Table 1 shows the dot diameters (1) and (3), gloss, and appearance of the obtained cured film.

[Comparative Example 14]
The pigment dispersion was converted into an ink with the following formulation to obtain an inkjet ink.
-Pigment dispersion A 10.0 parts-2-phenoxyethyl acrylate 11.0 parts-N-vinylcaprolactam 2.0 parts-Tripropylene glycol diacrylate 53.0 parts-Ethoxylated trimethylolpropane triacrylate 16.0 parts・ Irgacure 907 (Ciba Specialty Chemicals Co., Ltd.) 4.0 parts ・ Irgacure 819 (Ciba Specialty Chemicals Co., Ltd.) 4.0 parts Except using the above ink, cured film (1), ( 3) and (4) were obtained. Table 1 shows the dot diameters (1) and (3), gloss, and appearance of the obtained cured film.

Claims (7)

  An active energy ray-curable inkjet ink composition comprising a polymerizable monomer and an inorganic oxide colloid.   The active energy ray-curable inkjet ink composition according to claim 1, wherein the inorganic oxide colloid is colloidal silica.   The active energy ray-curable inkjet ink composition according to claim 1 or 2, wherein the content of the inorganic oxide colloid is 0.5 to 5.0% by weight.   The active energy ray-curable inkjet ink composition according to any one of claims 1 to 3, comprising a photo radical polymerization initiator.   The active energy ray-curable inkjet ink composition according to claim 1, further comprising a pigment and a pigment dispersant.   The active energy ray-curable inkjet ink composition according to claim 1, which does not contain 3% or more of water. A printed matter obtained by forming an image on the substrate with the active energy ray-curable inkjet ink according to claim 1 and then curing the ink with the active energy ray.