JP2002188025A - Actinic energy ray-curable ink-jet ink - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an actinic energy ray-curable ink-jet ink having low viscosity, excellent in photopolymerizability, having excellent curability in a thick coat, good at heat stability, and to provide the actinic energy ray-curable ink-jet ink good at issue stability with a nozzle, adhesion to printing medium, solvent resistance and water resistance. SOLUTION: This actinic energy ray-curable ink-jet ink is characterized by being obtained by compounding a liquid component comprising (1) 10-50 wt.% oxirane group-containing compound, (2) 50-90 wt.% oxetane ring-containing compound and (3) 0-40 wt.% vinyl ether compound with (4) a pigment, (5) a photo cationic polymerization initiator and (6) a pigment dispersant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention is excellent in photopolymerizability,
Active energy ray curing type with good curability, good stability as ink, strong strength of cured film, good ejection stability at nozzle, adhesion to recording medium, solvent resistance and water resistance Related to inkjet ink.

[0002]

2. Description of the Related Art Conventionally, ink jet inks having good water resistance include those in which an oil-soluble dye is dispersed or dissolved in a solvent having a high boiling point, and those in which an oil-soluble dye is dissolved in a volatile solvent. Inferior to pigments due to various resistances such as properties,
An ink using a pigment as a colorant is desired. However, it is difficult to stably disperse the pigment in the organic solvent, and it is also difficult to secure stable dispersibility and dischargeability. On the other hand, ink using a high-boiling solvent cannot print on a non-absorbing substrate because the solvent in the ink does not evaporate on the non-absorbing image receptor and drying by evaporation of the solvent is difficult. It is.

[0003] In an ink using a volatile organic solvent, good printing can be formed even on a non-absorbable substrate due to the adhesion of the resin used and the volatilization of the solvent. However, since a volatile solvent is a main component of the ink, drying by evaporation of the solvent on the nozzle surface of the head is very quick and requires frequent maintenance. In addition, since the ink essentially requires resolubility in a solvent, sufficient resistance to the solvent may not be obtained in some cases.

In order to satisfy such characteristics, non-volatile monomers are used to prevent the head from drying,
On the other hand, a type of ink that is cured by applying an active energy ray is also being used. Such inks are disclosed, for example, in JP-A-62-64874, JP-A-58-32674, and the like. These inks are mainly used in continuous type printers, and the viscosity of the ink is 3
About 5 mPa · s. Further, this printer can use a large amount of a volatile solvent in order to continuously discharge the ink, and can adjust the viscosity of the ink and impart the volatility relatively easily.

However, in an on-demand printer using a piezo element, the use of a large amount of a volatile solvent increases the frequency of maintenance, and
It facilitates the problem of dissolution and swelling of the ink contact material in the printer. In addition, volatile solvents are more restricted by dangerous substances in the Fire Defense Law. Therefore, in an on-demand type printer using a piezo element, it is necessary to use an ink containing a small amount of volatile solvent. However,
The material used for the active energy ray-curable ink is a material having a relatively high viscosity, and it is difficult to design an ink having good curability and good stability at a viscosity that can be ejected by a conventional printer. Was.

[0006]

SUMMARY OF THE INVENTION The present invention has a low viscosity,
Another object of the present invention is to provide an active energy ray-curable ink jet ink having excellent photopolymerizability, excellent curability in a thick film, and good thermal stability. Another object of the present invention is to provide an active energy ray-curable inkjet ink having good ejection stability at a nozzle, adhesion to a recording medium, solvent resistance and water resistance.

[0007]

That is, the present invention provides:
(1) 10 to 50% by weight of an oxirane group-containing compound, (2) 50 to 90% by weight of an oxetane ring-containing compound, and (3) 4) Pigment dispersed in a liquid component of 0 to 40% by weight of a vinyl ether compound. And an active energy ray-curable inkjet ink.

[0008] The present invention further relates to the above active energy ray-curable ink-jet ink, which is a solventless ink. The present invention further relates to the above active energy ray-curable inkjet ink, which further comprises 5) a cationic photopolymerization initiator. Further, the present invention further provides:
6) The present invention relates to the above active energy ray-curable inkjet ink, which contains a pigment dispersant. The present invention further relates to the active energy ray-curable ink jet ink, wherein the pigment is a fine pigment having an average particle diameter of 10 to 150 nm. In addition, the present invention
The present invention relates to the above ink jet ink, which has a viscosity at 5 ° C. of 5 to 50 mPa · s. Also, the present invention
The present invention relates to a printed material obtained by printing the above active energy ray-curable inkjet ink on a substrate.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The pigment contained in the ink-jet ink of the present invention can be an achromatic inorganic pigment such as carbon black, titanium oxide, calcium carbonate or the like, or a chromatic organic pigment. As organic pigments, toluidine red,
Insoluble azo pigments such as Toluidine Maroon, Hansa Yellow, Benzidine Yellow, and Pyrazolone Red; soluble azo pigments such as Litol Red, Helio Bordeaux, Pigment Scarlet, and Permanent Red 2B; Derivatives, phthalocyanine blue, phthalocyanine-based organic pigments such as phthalocyanine green, quinacridone red, quinacridone-based organic pigments such as quinacridone magenta, perylene red, perylene-based organic pigments such as perylene scarlet, isoindolinone yellow,
Isoindolinone-based organic pigments such as isoindolinone orange, pyranthrone-based organic pigments such as pyranthrone red and pyranthrone orange, thioindigo-based organic pigments, condensed azo-based organic pigments, benzimidazolone-based organic pigments, and quinophthalones such as quinophthalone yellow Organic pigments, isoindoline organic pigments such as isoindoline yellow, and other pigments such as flavanthrone yellow, acylamide yellow, nickel azo yellow, copper azomethine yellow, perinone orange, anthrone orange, dianthraquinonyl red, and dianthraquinonyl red Oxazine violet and the like.

When an organic pigment is exemplified by a color index (CI) number, CI pigment yellow 12, 13,
14, 17, 20, 24, 74, 83, 86 93, 1
09, 110, 117, 125, 128, 129, 13
7, 138, 139, 147, 148, 150, 15
1,153,154,155,166,168,18
0, 185, CI Pigment Orange 16, 36, 4
3, 51, 55, 59, 61, CI Pigment Red 9, 48, 49, 52, 53, 57, 97, 122, 1
23, 149, 168, 177, 180, 192, 20
2,206,215,216,217,220,22
3, 224, 226, 227, 228, 238, 24
0, CI Pigment Violet 19, 23, 29, 3
0, 37, 40, 50, CI Pigment Blue 15, 1
5: 1, 15: 3, 15: 4, 15: 6, 22, 60,
64, CI Pigment Green 7, 36, CI Pigment Brown 23, 25, 26 and the like.

Among the above pigments, quinacridone organic pigments, phthalocyanine organic pigments, benzimidazolone organic pigments, isoindolinone organic pigments, condensed azo organic pigments, quinophthalone organic pigments, isoindoline organic pigments, etc. Is preferred because of its excellent light resistance. The organic pigment has an average particle size of 10 to 150 n as measured by laser scattering.
It is preferably a fine pigment having a particle size of m. When the average particle size of the pigment is less than 10 nm, the light resistance is reduced due to the decrease in the particle size. When the average particle size is more than 150 nm, it is difficult to maintain a stable dispersion, and the pigment tends to precipitate.

The organic pigment can be refined by the following method. That is, at least 3 parts by weight of an organic pigment, a water-soluble inorganic salt at least 3 times the weight of the organic pigment and a water-soluble solvent.
The mixture composed of the two components is made into a clay-like mixture, kneaded strongly with a kneader or the like, pulverized and then poured into water, and stirred with a high-speed mixer or the like to form a slurry. Next, filtration and washing of the slurry are repeated to remove the water-soluble inorganic salt and the water-soluble solvent. In the miniaturization step, a resin, a pigment dispersant and the like may be added. Examples of the water-soluble inorganic salt include sodium chloride and potassium chloride. These inorganic salts are at least 3 times the weight of the organic pigment,
Preferably, it is used in a range of 20 weight times or less. When the amount of the inorganic salt is less than 3 times by weight, a treated pigment having a desired size cannot be obtained. On the other hand, when the amount is more than 20 times by weight, the washing process in the subsequent step is large, and the substantial processing amount of the organic pigment decreases.

[0013] The water-soluble solvent is used for forming an appropriate clay state of an organic pigment and a water-soluble inorganic salt used as a crushing aid, and for efficiently performing sufficient crushing. Although there is no particular limitation, a high boiling solvent having a boiling point of 120 to 250 ° C. is preferred from the viewpoint of safety because the temperature rises during kneading and the solvent is easily evaporated. Examples of the water-soluble solvent include 2- (methoxymethoxy) ethanol, 2-butoxyethanol, 2- (isopentyloxy) ethanol, 2- (hexyloxy) ethanol, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and diethylene glycol monobutyl ether. , Triethylene glycol, triethylene glycol monomethyl ether, liquid polyethylene glycol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, low molecular weight Polypropylene glycol and the like.

In the present invention, in order to obtain a sufficient concentration and a sufficient light fastness, the pigment is used in the ink-jet ink.
Preferably, it is contained in the range of 15 to 15% by weight.

The oxirane group-containing compound contained in the ink-jet ink of the present invention has at least one oxirane ring represented by the following formula in the molecule.

Embedded image Any of monomers, oligomers and polymers which are usually used as epoxy resins can be used. Specific examples include conventionally known aromatic epoxides, alicyclic epoxides, and aliphatic epoxides. Here, epoxide means a monomer or an oligomer thereof. One or more of these compounds may be used as needed.

Preferred as aromatic epoxides are:
Di- or polyglycidyl ethers produced by the reaction of a polyhydric phenol having at least one aromatic nucleus or an alkylene oxide adduct thereof with epichlorohydrin, such as bisphenol A or a di- or polyglycidyl ether of the alkylene oxide adduct thereof And di- or polyglycidyl ethers of hydrogenated bisphenol A or an alkylene oxide adduct thereof, and novolak epoxy resins. Here, examples of the alkylene oxide include ethylene oxide and propylene oxide.

As the alicyclic epoxide, at least one
Compounds having a cycloalkane ring such as a cyclohexene or cyclopentene ring obtained by epoxidation with a suitable oxidizing agent such as hydrogen peroxide or peracid are preferably cyclohexene oxide or cyclopentene oxide-containing compounds. Examples include, for example, Daicel Chemical Industries, Ltd., Celloxide 2021, Celloxide 2021A, Celloxide 2021P, Celloxide 2080, Celloxide 3000, Celloxide 2
000, EPOLID GT301, EPOLID GT302, EPOLID GT401, EPOLID GT403, EHPE-3
150, EHPEL3150CE, manufactured by Union Carbide,
UVR-6105, UVR-6110, UVR-612
8, UVR-6100, UVR-6216, UVR-6
000 etc.).

Preferred examples of the aliphatic epoxide include di- or polyglycidyl ethers of aliphatic polyhydric alcohols or alkylene oxide adducts thereof. Representative examples thereof include diglycidyl ether of ethylene glycol and diglycidyl ether of propylene glycol. Diglycidyl ether of alkylene glycol such as glycidyl ether or diglycidyl ether of 1,6-hexanediol, polyglycidyl ether of polyhydric alcohol such as di- or triglycidyl ether of glycerin or its alkylene oxide adduct, polyethylene glycol or alkylene thereof Polyalkylenes such as diglycidyl ether of oxide adduct and polypropylene glycol or diglycidyl ether of alkylene oxide thereof Diglycidyl ethers of recall and the like. Here, examples of the alkylene oxide include ethylene oxide and propylene oxide.

In addition to these compounds, monoglycidyl ethers of higher aliphatic alcohols and monoglycidyl ethers of phenol and cresol can also be used. Of these epoxides, aromatic epoxides and alicyclic epoxides are preferred, and alicyclic epoxides are particularly preferred, in view of rapid curing properties.

The oxirane group-containing compound is compounded in an amount of 10 to 50% by weight, preferably 30 to 50% by weight, based on the liquid component comprising the oxetane ring-containing compound and the vinyl ether compound optionally added. When the oxirane group-containing compound is less than the above value, the strength of the cured film is weakened and the resistance as a printed matter is not obtained. It is not preferable because it cannot be applied as an ink.

The oxetane ring-containing compound in the present invention includes compounds having one or more oxetane rings in the molecule.

The compound having one oxetane ring in the molecule includes a compound represented by the following formula (1).

[0023]

Embedded image

(In the formula (1), Z is an oxygen atom or a sulfur atom, R ¹ is a hydrogen atom, a fluorine atom, an alkyl group having 1 to 6 carbon atoms such as a methyl group, an ethyl group, a propyl group or a butyl group, A fluoroalkyl group having 1 to 6 carbon atoms, an allyl group, an aryl group, a furyl group or a thienyl group, R ² is an alkyl group having 1 to 6 carbon atoms such as a methyl group, an ethyl group, a propyl group or a butyl group; 1-propenyl group, 2-propenyl group, 2-methyl-1-propenyl group, 2-methyl-
An alkenyl group having 1 to 6 carbon atoms such as a 2-propenyl group, a 1-butenyl group, a 2-butenyl group or a 3-butenyl group;
Phenyl group, benzyl group, fluorobenzyl group, methoxybenzyl group or aryl group such as phenoxyethyl group,
C1-C6 alkylcarbonyl group such as propylcarbonyl group, butylcarbonyl group or pentylcarbonyl group, C1-C6 alkoxycarbonyl group such as ethoxycarbonyl group, propoxycarbonyl group or butoxycarbonyl group, ethoxycarbamoyl Represents an alkoxycarbamoyl group having 1 to 6 carbon atoms, such as a propylcarbamoyl group or a butylpentylcarbamoyl group. )

As the oxetane ring-containing compound used in the present invention, in the above formula (1), R ¹ is a lower alkyl group, especially an ethyl group, R ² is a butyl group, a phenyl group or a benzyl group, and Z is an oxygen atom. Some are preferred.

The compound having two or more oxetane rings in the molecule includes a compound represented by the following formula (2).

[0027]

Embedded image

(In the formula (2), m is 2, 3 or 4, Z is an oxygen atom or a sulfur atom, R ³ is a hydrogen atom, a fluorine atom, a carbon number such as a methyl group, an ethyl group, a propyl group or a butyl group. An alkyl group having 1 to 6 carbon atoms, a phenyl group, a fluoroalkyl group having 1 to 6 carbon atoms, an allyl group, an aryl group or a furyl group, and R ⁴ are, for example, having 1 to 1 carbon atoms represented by the following formula (3).
2 linear or branched alkylene groups, linear or branched poly (alkyleneoxy) groups,

[0029]

Embedded image

(In the formula (3), R ⁵ represents a lower alkyl group such as a methyl group, an ethyl group or a propyl group.)

Alternatively, it represents a polyvalent group selected from the group consisting of the following formulas (4), (5) and (6).

[0032]

Embedded image

(In the formula (4), n is 0 or an integer of 1 to 2000, R ⁶ is an alkyl group having 1 to 10 carbon atoms such as a methyl group, an ethyl group, a propyl group or a butyl group, and the following formula (7) Represents a group selected from the group consisting of:

[0034]

Embedded image

(In the formula (7), j is 0 or an integer of 1 to 100, R ⁸ is alkyl having 1 to 10 carbon atoms, R
⁷ represents an alkyl group having 1 to 10 carbon atoms such as a methyl group, an ethyl group, a propyl group or a butyl group. )

[0036]

Embedded image

(In the formula (5), R ⁹ represents a hydrogen atom, a methyl group, an ethyl group, a propyl group or a butyl group having 1 to 1 carbon atoms.
It represents 10 alkyl groups, an alkoxy group having 1 to 10 carbon atoms, a halogen atom, a nitro group, a cyano group, a mercapto group, a lower alkyl carboxylate group or a carboxyl group. )

[0038]

Embedded image

(In the formula (6), R ¹⁰ represents an oxygen atom, a sulfur atom, NH, SO, SO ₂ , CH ₂ , C (CH ₃ ) ₂ or C (CF ₃ ) _2. )

Oxetane ring-containing compound used in the present invention
In the above formula (2), R^ThreeIs lower alkyl
Group, especially an ethyl group, R^FourIs R in formula (5)⁹But water
A group which is an elemental atom, a hexamethylene group, in the formula (3)
R^FiveIs an ethyl group, R⁷And R ⁸Is a methyl group, Z is an oxygen atom
Those that are children are preferred.

In the formula (8), r is an integer of 25 to 200, and R ¹¹ is an alkyl group having 1 to 4 carbon atoms or a trialkylsilyl group.

In the present invention, the composition may be a combination of two or more of the above compounds having one or more oxetane rings in the molecule.

The oxetane ring-containing compound is compounded in an amount of 50 to 90% by weight, preferably 50 to 70% by weight, of the liquid component comprising the oxirane group-containing compound and the vinyl ether compound to be added as required. If the amount of the oxetane ring-containing compound is less than the above value, the curability is deteriorated. If the value is greater than the above value, the curability is improved. However, the strength of the cured film is weak, and the resistance as a printed material is lost, which is not preferable.

The vinyl ether compound contained in the ink-jet ink of the present invention includes, for example, ethylene glycol divinyl ether, ethylene glycol monovinyl ether, diethylene glycol divinyl ether, triethylene glycol monovinyl ether, triethylene glycol divinyl ether, propylene glycol divinyl ether, dipropylene glycol. Divinyl ether, butanediol divinyl ether, hexanediol divinyl ether, cyclohexane dimethanol divinyl ether, hydroxyethyl monovinyl ether,
Hydroxynonyl monovinyl ether, di- or trivinyl ether compounds such as trimethylolpropane trivinyl ether, ethyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, octadecyl vinyl ether, cyclohexyl vinyl ether, hydroxybutyl vinyl ether, 2-ethylhexyl vinyl ether, cyclohexane dimethanol monovinyl ether, Monovinyl ether compounds such as n-propyl vinyl ether, isopropyl vinyl ether, isopropenyl ether-O-propylene carbonate, dodecyl vinyl ether, diethylene glycol monovinyl ether, and octadecyl vinyl ether are exemplified.

Among these vinyl ether compounds, di- or trivinyl ether compounds are preferable, and divinyl ether compounds are particularly preferable in consideration of curability, adhesion and surface hardness. In the present invention, one of the above vinyl ether compounds may be used alone, or two or more thereof may be used in appropriate combination.

The vinyl ether compound is an optional compounding component, and by mixing the compound, a low viscosity required for an ink jet ink can be realized. Further, the curing speed can be improved. The vinyl ether compound is blended in an amount of 0 to 40% by weight, preferably 0 to 20% by weight, in a liquid component comprising an oxirane group-containing compound and an oxetane ring-containing compound.

As the cationic photopolymerization initiator used in the present invention, an arylsulfonium salt derivative (for example, Cyracure UVI-699 manufactured by Union Carbide Co., Ltd.)
0, Cyracure UVI-6974, Adeka Optomer SP-150, Adeka Optomer SP manufactured by Asahi Denka Kogyo Co., Ltd.
-152, Adeka optomer SP-170, Adeka optomer SP-172), allyl iodonium salt derivative (for example, RP-2074 manufactured by Rhodia), Allen-
Examples include an ion complex derivative (for example, Irgacure 261 manufactured by Ciba Geigy), a diazonium salt derivative, a triazine initiator, and an acid generator such as another halide. The cationic polymerization initiator is preferably contained at a ratio of 0.2 to 20 parts by weight based on 100 parts by weight of the compound having an alicyclic epoxy group. If the content of the polymerization initiator is less than 0.2 parts by weight, it is difficult to obtain a cured product,
If the content exceeds 20 parts by weight, there is no further effect of improving curability. These cationic photopolymerization initiators may be used alone or in combination.
More than one species can be selected and used.

Examples of the photopolymerization accelerator include anthracene and anthracene derivatives (for example, Adeka Optomer SP-100 manufactured by Asahi Denka Kogyo KK). These photopolymerization accelerators can be used alone or in combination of two or more.

Examples of the pigment dispersant of the present invention include a carboxylic acid ester having a hydroxyl group, a salt of a long-chain polyaminoamide and a high-molecular-weight acid ester, a salt of a high-molecular-weight polycarboxylic acid, a salt of a long-chain polyaminoamide and a polar acid ester, Molecular weight unsaturated acid ester, high molecular weight copolymer, modified polyurethane,
Modified polyacrylate, polyetherester type anionic surfactant, naphthalenesulfonic acid formalin condensate, aromatic sulfonic acid formalin condensate, polyoxyethylene alkyl phosphate, polyoxyethylene nonylphenyl ether, stearylamine acetate, pigment Derivatives and the like can be mentioned.

Specific examples of the pigment dispersant include BYK C
"Anti-Terra-U (polyaminoamide phosphate)", "Anti-Terra-20" manufactured by Hemie
3/204 (high molecular weight polycarboxylate) "," Dis
perbyk-101 (polyaminoamide phosphate and acid ester), 107 (hydroxyl-containing carboxylate), 110 (copolymer containing 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 acid polycarboxylic acid and silicon type)", "Lacti
mon (long-chain amine, unsaturated acid polycarboxylic acid, and silicon) ".

Further, "Efka 44, 46, 47, 48, 49, 54, 63," manufactured by Efka Chemicals, Inc.
64, 65, 66, 71, 701, 764, 766 ",
"Efka polymer 100 (modified polyacrylate), 1
50 (aliphatic modified polymer), 400, 401, 40
2, 403, 450, 451, 452, 453 (modified polyacrylate), 745 (copper phthalocyanine) ",
Kyoeisha Chemical Co., Ltd. "Floren TG-710 (urethane oligomer)", "Flonon SH-290, SP-10"
00, "Polyflow No. 50E, No. 300 (acrylic copolymer)", "DISPARON" manufactured by Kusumoto Kasei Co., Ltd.
KS-860, 873SN, 874 (polymer dispersant),
# 2150 (aliphatic polycarboxylic acid), # 7004 (polyetherester type) ".

Further, “Demol RN, N (sodium salt of naphthalenesulfonic acid formalin condensate)” manufactured by Kao Corporation,
MS, C, SN-B (sodium salt of aromatic sulfonic acid formalin condensate), EP "," Homogenol L-18
(Polycarboxylic acid type polymer), "Emulgen 920, 9
30, 931, 935, 950, 985 (polyoxyethylene nonyl phenyl ether), "Acetamine 24
(Coconut amine acetate), 86 (stearylamine acetate) ", manufactured by Zeneca Corporation
0 (phthalocyanine ammonium salt), 13240,
13940 (polyesteramine type), 17000 (fatty acid amine type), 24000, 32000 ", Nikko Chemical Co., Ltd." Nikkor T106 (polyoxyethylene sorbitan monooleate), MYS-IEX (polyoxyethylene monostearate), Hexagline
4-0 (hexaglyceryltetraolate) "and the like.

The pigment dispersant of the present invention may contain 0.1 to
It is preferable to contain a dispersant in the range of 10% by weight.

The ink-jet ink of the present invention is produced by well dispersing a pigment together with an active energy ray-curable compound and a pigment dispersant using a conventional disperser such as a sand mill. It is preferable that a concentrated solution having a high pigment concentration is prepared in advance and then diluted with an active energy ray-curable compound. Sufficient dispersion is possible even with a normal dispersing machine, so that excessive dispersing energy is not required and a large dispersing time is not required. An ink with excellent properties is prepared. The ink has a pore size of 3 μm or less and 1 μm or less.
It is preferable to filter with the following filters.

The inkjet ink of the present invention has a temperature of 25 ° C.
It is preferable to adjust the viscosity at 5 to 50 mPa · s. Inks having a viscosity of 5 to 50 mPa · s at 25 ° C. exhibit stable ejection characteristics, especially from a normal head having a frequency of 4 to 10 KHz to a high frequency head of 10 to 50 KHz. When the viscosity is less than 5 mPa · s, a decrease in the followability of discharge is observed in a high-frequency head, and when the viscosity exceeds 50 mPa · s, even if a mechanism for lowering the viscosity by heating is incorporated in the head, the discharge itself is not improved. As a result, the stability of the ejection becomes poor and the ejection becomes impossible.

Further, the ink-jet ink of the present invention comprises:
In the case of a piezo head, it is preferable to use an ink having an electric conductivity of 10 μS / cm or less and having no electrical corrosion inside the head. 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.

As the synthetic resin substrate used in the present invention, a wide range of synthetic resins conventionally used in various applications are all targets. Specifically, for example, polyester, polyvinyl chloride, polyethylene, polyurethane, polypropylene , Acrylic resin, polycarbonate, polystyrene,
Examples thereof include acrylonitrile-butadiene-styrene copolymer, polyethylene terephthalate, and polybutadiene terephthalate, and the thickness and shape of these synthetic resin substrates are not limited at all.

In order to use the ink-jet ink of the present invention, the ink-jet ink is first supplied to a printer head of a printer for an ink-jet recording system, discharged from the printer head onto a substrate, and then activated by ultraviolet rays or electron beams. Irradiate energy rays. Thereby, the composition on the print medium is quickly cured.

The light source of the active energy ray is as follows.
When irradiating ultraviolet rays, for example, a mercury arc lamp,
Xenon arc lamps, fluorescent lamps, carbon arc lamps, tungsten-halogen copying lamps and sunlight can be used. In the case of curing with an electron beam, it is usually cured with an electron beam having an energy of 300 eV or less, but it is also possible to cure instantaneously with an irradiation amount of 1 to 5 Mrad.

[0060]

Embodiments will be described below with reference to embodiments. Parts and% in the examples indicate parts by weight and% by weight, respectively. Examples 1 to 8 Pigments, dispersants and oxirane group-containing compounds shown in Table 1,
Both the oxetane ring-containing compound and the vinyl ether compound were placed in a sand mill and dispersed for 4 hours to obtain an active energy ray-curable ink stock solution. Next, the photoinitiator was added to the ink stock solution, mixed gently until the photoinitiator was dissolved, and then filtered under pressure through a membrane filter to obtain an active energy ray-curable IJ ink. This ink is printed on various substrates (polycarbonate, polystyrene, ABS (acetonitrile-styrene-butadiene copolymer), polyvinyl chloride, polyethylene terephthalate, polybutylene terephthalate) by an IJ printer having a piezo head, and thereafter Curing was performed with a UV irradiation device (one metal halide lamp: output 120 W) under the condition of a conveyance speed of the printing medium of 10 m / min.

[0061]

[Table 1]

The following compounds are shown in the table. The numbers indicate the number of copies. Pigment ・ P1 Crude copper phthalocyanine (“Copper phthalocyanine” manufactured by Toyo Ink Mfg.): 250 parts, sodium chloride: 25
00 parts and polyethylene glycol (“Polyethylene glycol 300” manufactured by Tokyo Kasei Co., Ltd.): 160 parts were charged into a styrene 1 gallon kneader (manufactured by Inoue Seisakusho),
Kneaded for 3 hours. Next, the mixture was poured into 2.5 liters of warm water, stirred for about 1 hour with a high-speed mixer while heating to about 80 ° C. to form a slurry, and then filtered and washed with water five times to repeat sodium chloride and solvent. Except for
Subsequently, the treated pigment was spray-dried to obtain a dried treated pigment. P2 quinacridone red pigment ("Cincacia Magenta RT-355-D" manufactured by Ciba Geigy): 250 parts,
2500 parts of sodium chloride and 160 parts of “polyethylene glycol 300” were charged into a 1-gallon kneader made of styrene, and a treated pigment was obtained in the same manner as in P1.・ P3 Benzimidazolone-based yellow pigment (“Hostapalm Yellow H3G” manufactured by Hoechst): 250 parts, sodium chloride: 2500 parts, and “polyethylene glycol 300”: 160 parts are charged into a 1-gallon kneader made of styrene, in the same manner as P1. Thus, a treated pigment was obtained.・ P4 Carbon black pigment “Printex 15
0T "(made by Degussa)

Oxirane group-containing compound ・ Celoxide 3000 alicyclic epoxy (manufactured by Daicel) ・ UVR6110 alicyclic epoxy (manufactured by Union Carbide) Oxetane ring-containing compound ・ XDO 1,4-bis [[(3-ethyl-3 -Oxetanyl) methoxy] methyl} benzene (manufactured by Toagosei Co., Ltd.) -POX 3-ethyl-3- (phenoxymethyl) oxetane (manufactured by Toagosei Co., Ltd.) -OXA 3-ethyl-3-hiroshiki methyloxetane
(Toagosei Co., Ltd.) Vinyl ether compoundDVE-3 Triethylene glycol divinyl ether (IS
(Company P)

Dispersant 32000 Aliphatic modified dispersant (“SOLSPERS 32000”)
(Zeneca)

Initiator: SP-150 Triphenylsulfonium salt (“ADEKA OPTOMER SP-150” manufactured by Asahi Denka) • SP-170 Triphenylsulfonium salt (“ADEKA OPTOMER SP-170” manufactured by Asahi Denka). UVI6990 Triphenylsulfonium salt (`` Cyracure U
VI6990 '' manufactured by Union Carbide)

Comparative Examples 1 to 4 The pigments, dispersants and monomers shown in Table 2 were both placed in a sand mill and dispersed for 4 hours.
A J ink stock solution was obtained. The photoinitiator was then added to the stock ink solution and mixed gently until the photoinitiator dissolved,
This was filtered under pressure through a membrane filter to obtain an active energy ray-curable IJ ink. This ink prints on the above-mentioned base material with an IJ printer having a piezo head, and then a UV irradiation device (one metal halide lamp:
With the output of 120 W), curing was performed under the condition of a conveyance speed of the printing medium of 10 m / min.

[0067]

[Table 2]

The compounds in the table were the same as those used in Examples 1 to 8. The numbers indicate the number of copies.

The inks and printed materials obtained in Examples 1 to 8 and Comparative Examples 1 to 4 were evaluated as follows. Table 3 shows the results.

[0070]

[Table 3]

Evaluation methods in the table [Viscosity] The value obtained when the viscosity of the ink was measured at 25 ° C. using a B-type viscometer. The unit is mPa · s [curable] The number of passes of the co-conveyor UV lamp until the tack disappears due to the touch. [Stability over time] The state of dispersion of the ink after storage at 25 ° C. for one month was evaluated visually and by a change in viscosity. ：: No precipitate was observed and no change in viscosity was observed. Δ: No precipitate was observed and the viscosity increased. X: A precipitate was observed. [Film Strength] The strength of the cured film was measured by a nail scratch test. ：: Not at all even when scratched △: Slightly removed when strongly scratched ×: Easily removed when scratched

According to the present invention, in an ink jet in which a pigment is dispersed in an active energy ray-curable compound, low viscosity, strong strength of a cured film, good curability, good stability, and discharge stability at a nozzle. A good inkjet ink was obtained. Further, the recorded matter recorded by the inkjet ink of the present invention has high transparency, excellent durability of the recorded matter, and excellent gloss.

Continued on the front page F term (reference) 2C056 EA13 FC01 FC02 2H086 BA55 BA59 BA60 BA61 4J005 AA04 AA07 AA11 BA00 4J039 AD21 AE07 BD02 BE01 BE22 BE27 EA04 EA38 EA39 EA43 EA44 EA46 EA48 GA24

Claims (7)

[Claims] 1) 10 to 50% by weight of an oxirane group-containing compound, 2) 50 to 90% by weight of an oxetane ring-containing compound,
And 3) an active energy ray-curable ink jet ink comprising 4) a pigment dispersed in a liquid component comprising 0 to 40% by weight of a vinyl ether compound. 2. The active energy ray-curable ink jet ink according to claim 1, which is a solventless ink. 3. The active energy ray-curable inkjet ink according to claim 1, further comprising 5) a cationic photopolymerization initiator. 4. The active energy ray-curable inkjet ink according to claim 1, further comprising 6) a pigment dispersant. 5. The active energy ray-curable ink-jet ink according to claim 1, wherein the pigment is a fine pigment having an average particle diameter of 10 to 150 nm. 6. The active energy ray-curable inkjet ink according to claim 1, which has a viscosity at 25 ° C. of 5 to 50 mPa · s. 7. A printed matter obtained by printing the active energy ray-curable ink jet ink according to claim 1 on a substrate.