WO2007099753A1

WO2007099753A1 - Active ray-curable composition, active ray-curable inkjet ink using same, image-forming method and inkjet recording apparatus

Info

Publication number: WO2007099753A1
Application number: PCT/JP2007/052221
Authority: WO
Inventors: Toshiyuki Takabayashi
Original assignee: Konica Minolta Medical & Graphic, Inc.
Priority date: 2006-03-03
Filing date: 2007-02-08
Publication date: 2007-09-07
Also published as: JPWO2007099753A1

Abstract

Disclosed is an active ray-curable composition with good curability, which enables to form a flexible cured film without deteriorating the texture of a printed matter. Also disclosed are an active ray-curable inkjet ink which is capable of extremely stably reproducing a high-precision image on various recording materials, an image-forming method using such an ink, and an inkjet recording apparatus. The active ray-curable composition is characterized by containing a photoinitiator, a polymerizable compound, and a polyester polyol obtained by reacting a polyvalent carboxylic acid including terephthalic acid with a polyhydric alcohol.

Description

Specification

Actinic ray curable composition, actinic ray curable inkjet ink using the same, image forming method and inkjet recording apparatus

Technical field

The present invention relates to an actinic ray curable composition, an actinic ray curable ink jet ink using the same, an image forming method, and an ink jet recording apparatus.

Background art

[0002] Conventionally, actinic ray curable compositions that are cured by actinic rays such as ultraviolet rays and electron beams include paints such as plastic, paper, woodwork, and inorganic materials, adhesives, printing inks, printed circuit boards, and electrical insulation relations. Have been put to practical use in various applications. In recent years, printing inks, paints, adhesives, and the like are desired to have even greater adhesion and improved flexibility of the cured film after curing.

[0003] In addition, as an ink-jet ink system using these polymerizable compositions, there is an ultraviolet curable ink jet ink that cures with ultraviolet rays. An ink jet system using this ultraviolet curable ink is quick-drying, ink-absorbing. In recent years, it has been attracting attention because it can record on a recording medium having no property, and ultraviolet curable inkjet inks have been disclosed (for example, see Patent Documents 1 and 2). However, since the cured film to be formed is not flexible enough, there is a problem that the cured film is not able to follow the recording material and the cured film is broken, and printing can be performed only on a limited recording material (thickness, thing). There was a problem. It has been disclosed that plasticity can be imparted by adding a plasticizer to an ink jet ink (for example, see Patent Document 3). However, there is no mention of UV curable ink-jet ink using solvent-type ink, as it is in melt-type ink.

[0004] In addition, when ultraviolet curable ink is used, there is a problem that the hardness sensitivity is likely to vary depending on the type of recording material and the working environment.

[0005] Inks using radically polymerizable compounds are subject to an oxygen inhibiting action, so that when the ink film thickness is low, curing inhibition tends to occur. Also, inks using cationically polymerizable compounds (see, for example, Patent Documents 4 to 7) are not subject to oxygen inhibition, but are There is a problem that it is susceptible to the moisture (humidity) of the water.

Patent Document 1: JP-A-6-200204 (Claims, Examples)

Patent Document 2: JP 2000-504778 (Claims, Examples)

Patent Document 3: JP-A-8-3493 (Claims, Examples)

Patent Document 4: Japanese Patent Laid-Open No. 2001-220526 (Claims, Examples)

Patent Document 5: Japanese Unexamined Patent Application Publication No. 2002-188025 (Claims, Examples)

Patent Document 6: Japanese Patent Application Laid-Open No. 2002-317139 (Claims and Examples)

Patent Document 7: Japanese Patent Laid-Open No. 2003-55449 (Claims, Examples)

Disclosure of the invention

Problems to be solved by the invention

[0006] An object of the present invention is to provide an actinic ray curable composition having good curability and capable of forming a flexible cured film without impairing the texture of the printed matter, and further to high-definition in various recording materials. An object is to provide an actinic ray curable inkjet ink capable of reproducing an image very stably, an image forming method using the ink, and an inkjet recording apparatus.

Means for solving the problem

[0007] The above object of the present invention can be achieved by the following configurations.

[0008] 1. An activity characterized by comprising a polyester polyol obtained by reacting a polyvalent carboxylic acid containing a photoinitiator, a polymerizable compound and terephthalic acid with a polyvalent alcohol. A photocurable composition.

[0009] 2. The actinic ray curable composition as described in 1 above, wherein the polymerizable compound contains 10 to 30% by mass of a monofunctional monomer.

[0010] 3. The actinic ray curable composition as described in 1 or 2 above, comprising 2 to 20% by mass of the polyester polyol.

[0011] 4. The actinic ray curable composition according to any one of 1 to 3 above, wherein the polyester polyol has a viscosity at 25 ° C of 100 to 6000 mPa's.

[0012] 5. The actinic ray curable composition as described in any one of 1 to 4 above, wherein the polymerizable compound contains a compound having at least one oxosilane group.

[0013] 6. The above-mentioned 5 characterized by further containing an oxetane compound as the polymerizable compound. The actinic ray curable composition according to 1.

[0014] 7. The actinic ray curable composition according to any one of 1 to 6 above, which comprises a basic compound.

[0015] 8. The actinic ray curable composition according to any one of 1 to 7 above, which contains a pigment as a coloring material.

[0016] 9. Actinic ray curable ink jet ink characterized by being an actinic ray curable ink composition as described in 8 above.

[0017] 10. The active light curable inkjet ink as described in 9 above, wherein the viscosity at 25 ° C is from 7 to LOOmPa's.

[0018] 11. An image forming method in which the actinic ray curable ink jet ink described in 9 or 10 is jetted onto a recording material from an inkjet recording head, and printing is performed on the recording material. An image forming method, wherein the total ink-jet ink has a film thickness of 2 to 20 m after the curable ink-jet ink has landed and cured by irradiation with actinic rays.

[0019] 12. An image forming method in which the actinic ray curable ink jet ink described in 9 or 10 is jetted onto a recording material from an ink jet recording head, and printing is performed on the recording material. Forming an image by ejecting from the recording head.

[0020] 13. The ink jet recording apparatus used in the image forming method according to 11 or 12, wherein the actinic ray curable ink jet ink and the recording head are heated to 35 to 100 ° C and then discharged. An ink jet recording apparatus.

The invention's effect

[0021] According to the present invention, an actinic ray curable composition having good curability and capable of forming a flexible cured film without impairing the texture of printed matter is provided, and further, high-definition images can be obtained on various recording materials. It was possible to provide an actinic ray curable ink jet ink that can be reproduced very stably, an image forming method using the ink, and an ink jet recording apparatus.

Brief Description of Drawings

FIG. 1 is a front view showing an example of a configuration of a main part of an ink jet recording apparatus of the present invention. FIG. 2 is a top view showing another example of the configuration of the main part of the ink jet recording apparatus of the present invention.

[0023] 1 Recording device

2 Head carriage

3 Recording head

31 Ink outlet

4 Irradiation means

5 Platen section

6 Guide member

7 Bellows structure

8 Irradiation light source

P Recording material

BEST MODE FOR CARRYING OUT THE INVENTION

[0024] The present invention will be described in more detail. Among the polyester polyols, the present inventor has become a conventional problem by using a polyester polyol obtained by reacting a polyhydric carboxylic acid containing terephthalic acid with a polyhydric alcohol in an actinic ray curable composition. The present inventors have found that the problems of adhesion (adhesion to the recording medium) and flexibility of the cured film after curing are drastically improved. In order to improve the problem of the adhesion and the flexibility of the cured film after curing, it is preferable to use a monofunctional monomer in a large amount of 10 to 30% by mass as a polymerizable compound. In addition, there was a problem that the curability deteriorated and wrinkles were generated when the ink was cured. It has been found that this problem can be improved by using a polyester polyol obtained by reacting a polyhydric carboxylic acid containing terephthalic acid with a polyhydric alcohol.

[0025] In particular, when the polymerizable compound contains a compound having at least one oxosilane group, the problem of curing defects that easily occur under low humidity is remarkably improved. Furthermore, when an oxetane compound is contained, the improvement effect is greatly preferred.

[0026] Further, when used as an actinic ray curable inkjet ink, the ejection stability is further improved. It has been found that a high-definition image can be formed with extremely high reproducibility.

In the actinic ray curable composition of the present invention, a polyester polyol obtained by reacting a polyvalent carboxylic acid containing terephthalic acid with a polyhydric alcohol is used. The content in the actinic ray curable composition is preferably 2 to 20% by mass, more preferably 2 to 15% by mass. If the amount is less than 2% by mass, the effect is insufficient. If the amount exceeds 20% by mass, the scratch resistance of the cured film deteriorates.

[0028] As the polyvalent carboxylic acid that is a raw material for producing the polyester polyol used in the present invention, at least the ability to use terephthalic acid, and further use an aromatic dicarboxylic acid other than terephthalic acid or an aromatic tricarboxylic acid. can do. Suitable aromatic polyrubonic acid components include phthalic acid, trimellitic acid, and acid anhydrides thereof. Furthermore, what mixed aliphatic polycarboxylic acids, such as a succinic acid, maleic acid, and adipic acid, may be used. Of these carboxylic acid components other than terephthalic acid, phthalic acid, phthalic anhydride, and succinic acid are particularly preferable.

[0029] Examples of the polyhydric alcohol component which is a raw material for producing polyester polyol include ethylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, 1,2 butanediol, 1,4 butanediol, Examples include diols and triols such as 3-methyl-1,5-pentanediol, cyclohexanediol, glycerin, and trimethylolpropane. Of these, ethylene glycol, diethylene glycol, dipropylene glycol, 1,2-butanediol and 1,4 butanediol, 3-methyl-1,5-pentanediol, and the like are preferable.

[0030] The target polyester polyol can be produced by reacting the carboxylic acid component and the alcohol component usually in the presence of a catalyst at 150 to 230 ° C. The pressure at the time of reacting the above components may be normal pressure, but in order to remove the by-product water out of the system and complete the reaction quickly, the pressure may be gradually reduced as the reaction proceeds. preferable. In particular, at the start of the reaction, it is preferable to replace the space of the reaction vessel with nitrogen gas and further remove the dissolved oxygen in the reaction solution in order to prevent the resulting polyester polyol from being colored. As the catalyst, an acid catalyst is generally used. For example, Lewis acid The power of which tetraisopropyl titanate is suitable may be Bronsted acid such as para-toluenesulfonic acid.

[0031] The polyester polyol used in the present invention preferably has a viscosity of 100 to 6000 mPa's at 25 ° C. In particular, when used in an ink-jet ink composition, it is severe when the viscosity at 25 ° C exceeds 6000 mPa's from the viewpoint of ejection stability.

In the present invention, it is more preferable to use 10 to 30% by mass of a monofunctional monomer as the polymerizable compound. When the monofunctional monomer is less than 10% by mass, the effect is insufficient, and when it exceeds 30% by mass, the curability is remarkably inferior, resulting in a problem of image quality due to color bleeding. Specific examples of monofunctional monomers include, but are not limited to:

[0033] The oxetane compound as the cationically polymerizable compound used in the present invention is a compound having one or more oxetane rings in the molecule. Specifically, 3-ethyl-3-hydroxymethyloxetane (trade name OXT101 manufactured by Toa Gosei Co., Ltd.), 1,4-bis [(3 ethyl-3-oxeta-l) methoxymethyl] benzene (same as above) OXT121, etc.), 3 ethyl 3- (phenoxymethyl) oxetane (same as OXT211), di (1 ethyl 3 oxeta-l) methyl ether (same as OXT221), 3 ethyl 3- (2-ethylhexyloxymethyl) oxetane (same as above) OXT212, etc.) can be preferably used, and in particular, 3 ethyl 3 hydroxymethyloxetane, 3 ethyl-3 (phenoxymethyl) oxetane, di (1-ethyl-1-oxetanyl) methyl ether is preferably used. it can. These are independent, and can be used in combination of two or more.

[0034] The oxetane compound of the present invention is blended in an actinic ray curable ink composition in an amount of 30 to 95% by mass, preferably 50 to 80% by mass.

[0035] Examples of the radical polymerizable monofunctional monomer include isoamyl acrylate, stearyl acrylate, lauryl acrylate, octyl acrylate, decyl acrylate, isoamyl styrene acrylate, isostearyl acrylate, 2-ethylhexyl Lugoglycol acrylate, 2-hydroxybutyl acrylate, 2-atarylloy hexhydrohexyl hydrophthalic acid, butoxetyl acrylate, ethoxydiethylene glycol acrylate, methoxy diethylene glycol acrylate, methoxypolyethylene glycol acrylate, methoxy Cypropylene glycol acrylate, phenoloxyl acrylate, tetrahydrofurfuryl acrylate, isobornyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxy-3-phenoxypropyl Examples include attalylate, 2-acryloylchichetyl succinic acid, 2-atallyloylchichetyl phthalic acid, 2-atallyloyllo-chetyl 2-hydroxyethyl-phthalic acid, latathone-modified flexible acrylate, tert-butylcyclohexyl acrylate. It is done.

[0036] As the polymerizable compound used in the actinic ray curable composition of the present invention, a compound having an oxysilane group is preferred in that the shrinkage upon curing is small. Any known alicyclic epoxy compound can be used as the compound having an oxysilane group.

[0037] Further, in the present invention, it is preferable to contain a compound having at least one oxosilane group.

[0038] Examples of the compound having an oxysilane group include epoxy compounds, and examples thereof include the following aromatic epoxides, alicyclic epoxides, and aliphatic epoxides.

[0039] A preferable aromatic epoxide is a di- or di- or olefin produced by the reaction of a polyhydric phenol having at least one aromatic nucleus or an alkylene oxide-attached cage thereof with epichlorohydrin. Polyglycidyl ethers, such as di- or polyglycidyl ethers of bisphenol A or alkylene oxide-attached cages, hydrogenated bisphenol A or! Examples include ethers and novolac type epoxy resins. Here, examples of the alkylene oxide include ethylene oxide and propylene oxide.

[0040] As the alicyclic epoxide, a compound having at least one cycloalkane ring such as cyclohexene or cyclopentene ring is epoxidized with an appropriate oxidizing agent such as hydrogen peroxide or peracid. The resulting cyclohexene oxide or cyclopentene oxide-containing compound is preferred.

[0041] Preferable aliphatic epoxides include aliphatic polyhydric alcohols or di- or polyglycidyl ethers of adducts thereof, and typical examples thereof include diglycidyl ether of ethylene glycol, propylene Alkylene glycol such as diglycidyl ether of glycol or diglycidyl ether of 1,6-hexanediol Polyglycidyl ether of polyhydric alcohols such as diglycidyl ether, glycerin or alkylene oxides thereof or triglycidyl ethers, diglycidyl ethers of polyethylene glycol or alkylene oxides thereof, polypropylene Examples thereof include diglycidyl ethers of polyalkylene glycols such as glycol or alkylene oxide-attached diglycidyl ether. Here, examples of the alkylene oxide include ethylene oxide and propylene oxide.

[0042] Of these epoxides, aromatic epoxides and alicyclic epoxides are preferred, and alicyclic epoxides are particularly preferred in view of fast curability.

In the present invention, the most preferred alicyclic epoxide is, for example, JP 2004

315778, JP 2005 28632, and the following force S.

[0044] Examples of other polymerizable compounds used in the actinic ray curable composition of the present invention include all known radically polymerizable compounds. For example, in addition to the monofunctional radical monomers described above, 1,4 butanediol ditalylate, 1,6 hexanediol ditalylate, 1,9-nonanediol ditalylate, neopentyl glycol diacrylate, dimethylol Monotricyclodecane ditalylate, Bisphenol A EO-containing ditalylate, Bisphenol A PO-enriched diatalylate, hydroxybivalate neopentyl tildaricol ditalylate, polytetramethylene glycol ditalylate Bifunctional monomers such as trimethylolpropane tritalylate, EO-modified trimethylolpropane triacrylate, pentaerythritol tritalylate, pentaerythritol tetratalylate, dipentaerythritol hexaatalylate, ditrimethylol Examples thereof include polyfunctional monomers having three or more functional groups such as propanetetraatalylate, glycerin propoxytriatalylate, force-prolatatatone-modified trimethylolpropane triacrylate, pentaerythritol ethoxytetraatalylate, force-prolatatum-modified dipentaerythritol hexaatalylate.

In addition, polymerizable oligomers can be blended in the same manner as the monomer. Examples of the polymerizable oligomer include epoxy acrylate, aliphatic urethane acrylate, aromatic urethane acrylate, polyester acrylate, and linear acrylic oligomer.

[0046] In the present invention, as the photoinitiator, "application and application of UV'EB curing technology" (CM) Any publicly-known photoinitiator published in See Publishing, edited by Yoneho Tabata, edited by Z Rad Tech Study Group) can be used. Examples of the photoinitiator include a photoacid generator and a photoradical generator.

[0047] As the photoacid generator, for example, a chemical amplification type photoresist and a compound used for photopower thione polymerization are used (Organic Materials Research Group, “Organic Materials for Imaging”, Bunshin Publishing ( 1993), pages 187-192). Specific examples include an onium compound, a sulfonate compound that generates sulfonic acid, a halogen compound that generates halogen hydrogen, and an iron allene complex. Detailed descriptions of these compounds are described in paragraphs 0030 to 0038 of JP-A No. 20 03 327875.

[0048] As the photo radical generator, conventionally known initiators such as arylalkyl ketones, oxime ketones, thiobenzoic acid S phenol, titanocene, aromatic ketones, thioxanthone, benzyl and quinone derivatives, and ketocoumarins are used. I can do it. Among these, acylphosphine phosphatyl phosphate is particularly effective for internal curing with a thick curable composition because absorption is reduced by photocleavage of a highly sensitive initiator. Specifically, bis (2,4,6 trimethylbenzoyl) monophenylphosphine oxide, bis (2,6 dimethoxybenzoyl) -1,2,4,4 trimethyl monopentylphosphine oxide and the like are preferable.

[0049] In addition, in consideration of safety, 1-hydroxy-cyclohexyl roofing luketone, 2 methyl 1 [4 (methylthio) phenol] 2 morpholinopropane 1-on, bis (2, 6 dimethoxy Benzyl) -2,4,4 trimethyl-pentylphosphine oxide, 2-hydroxy 2-methyl 1-phenol-propan 1-one (Darocur (registered trademark) 1173) is preferably used.

[0050] A preferred amount of addition of the photoinitiator is 1 to 6% by mass, preferably 2 to 5% by mass, based on the entire ink composition.

[0051] In the present invention, it is preferable to use a basic compound in combination for further improving the ejection stability.

[0052] As the basic compound, any known compound can be used. Representative examples include basic alkali metal compounds, basic alkaline earth metal compounds, and amines. And basic organic compounds.

[0053] Examples of the basic alkali metal compound include alkali metal hydroxides (lithium hydroxide, sodium hydroxide, potassium hydroxide, etc.), alkali metal carbonates (lithium carbonate, sodium carbonate, carbonate carbonate). Potassium) and alkali metal alcoholates (sodium methoxide, sodium ethoxide, potassium methoxide, potassium ethoxide, etc.).

[0054] Examples of the basic alkaline earth metal compound include alkaline earth metal hydroxides (hydroxymagnesium hydroxide, calcium hydroxide, etc.), alkali metal carbonates (magnesium carbonate, carbonate carbonate). Calcium) and alkali metal alcoholates (magnesium methoxide, etc.).

[0055] Examples of basic organic compounds include amines and nitrogen-containing bicyclic compounds such as quinoline and quinolidine. Among these, amines are preferred because of their compatibility with photopolymerization monomers. Octylamine, naphthylamine, xylenediamine, dibenzylamine, diphenylamine, dibutylamine, dioctylamine, dimethylaniline, quinuclidine, tributylamine, trioctylamine, tetramethylethylenediamine, tetramethyl-1,6-hexamethylenediamine, Examples include hexamethylenetetramine and triethanolamine.

[0056] The concentration of the basic compound in the presence of the compound is preferably in the range of 10 to 50,000 mass ppm, particularly 100 to 5,000 mass ppm with respect to the total amount of the photopolymerizable monomer. Basic compounds may be used alone or in combination.

[0057] The actinic ray curable inkjet ink of the present invention (hereinafter also simply referred to as ink) contains 1S, preferably a pigment, containing various known dyes and Z or pigments together with the actinic ray curable composition described above. contains.

[0058] Pigments that can be preferably used in the present invention are listed below.

C. I. Pigment Yellow

1, 2, 3, 12, 13, 14, 16, 17, 73, 74, 75, 81, 83, 87, 93, 95, 97, 98, 109, 114, 120, 128, 129, 138, 150, 151, 154, 180, 185

C. I. Pigment Red

5, 7, 12, 22, 38, 48: 1, 48: 2, 48: 4, 49: 1, 53: 1, 57: 1, 63: 1, 101, 112, 122, 123, 144, 146, 168, 184, 185, 202

C. I. Pigment Violet

19, 23

C. I. Pigment Blue

1, 2, 3, 15: 1, 15: 2, 15: 3, 15: 4, 18, 22, 27, 29, 60 C. I. Pigment Green 7, 36

C. I. Pigment White

6, 18, 21

C. I. Pigment Black

7

In the present invention, it is preferable to use a white ink in order to improve the color concealment property on a transparent substrate such as a plastic film. In particular, white ink is preferably used in soft packaging printing and label printing.

[0059] For the dispersion of the pigment, for example, a ball mill, sand mill, attritor, roll mill, agitator, Henschel mixer, colloid mill, ultrasonic homogenizer, pearl mill, wet jet mill, paint shaker, or the like can be used. Further, a dispersing agent can be added when dispersing the pigment. As the dispersant, it is preferable to use a polymer dispersant. Examples of the polymer dispersant include Avecia Solsperse series and Ajinomoto Fine Techno Co. PB series. Further, a synergist corresponding to various pigments can be used as a dispersion aid. These dispersants and dispersion aids are preferably added in an amount of 1 to 50 parts by mass with respect to 100 parts by mass of the pigment. The dispersion medium is a solvent or a polymer compound. The ink used in the present invention is preferably solvent-free because it reacts and hardens immediately after ink landing. If the solvent remains in the cured image, the solvent resistance deteriorates and the VOC problem of the remaining solvent occurs. Therefore, it is preferable in view of dispersibility that the dispersion medium is not a solvent but a polymerizable compound, and among them, a monomer having the lowest viscosity is selected.

[0060] The pigment dispersion is preferably such that the average particle size of the pigment particles is 0.08 to 0.2 μm, and the maximum particle size is 0.3 to: LO / zm, preferably 0.3. Pigment, dispersant, dispersion medium to be ~ 3 m The body selection, dispersion conditions, and filtration conditions are set appropriately. By controlling the particle size, clogging of the head nozzle can be suppressed, and ink storage stability, ink transparency, and curing sensitivity can be maintained.

In the ink according to the present invention, the color material concentration is preferably 1% by mass to 10% by mass of the whole ink! /.

[0062] In the ink of the present invention, the viscosity at 25 ° C is preferably 7 to 100 mPa's in order to obtain good curability. The viscosity in the present invention is a value of a shear rate of 1000 (lZs) measured with a viscoelasticity measuring device MCR300 manufactured by Physica.

[0063] In the present invention, in the case of coating paints and adhesives such as printing inks, cans, plastics, paper, and wood, inorganic fillers, softeners, antioxidants, antioxidants, stabilizers are used. Inactive ingredients such as tackifiers, leveling agents, antifoaming agents, plasticizers, dyes, treating agents, viscosity modifiers, organic solvents, lubricity-imparting agents and UV blockers it can. Examples of inorganic fillers include, for example, zinc oxide, acid aluminum, acid antimony, calcium oxide, chromium oxide, tin oxide, titanium oxide, iron oxide, copper oxide, lead oxide, bismuth oxide, and acid oxide. Metals such as magnesium and acid and manganese, non-metal oxides, hydroxides such as aluminum hydroxide, ferrous hydroxide and calcium hydroxide, salts such as calcium carbonate and calcium sulfate, Key compounds such as diacid key, natural pigments such as kaolin, bentonite, clay and talc, minerals such as natural zeolite, Oya stone, natural mica and ionite, synthetic inorganic materials such as artificial mica and synthetic zeolite, And aluminum

And various metals such as iron and zinc. Some of these may overlap with the pigment, but these may be added to the composition as a filler, if necessary, in addition to the essential pigment. The lubricity-imparting agent is blended for the purpose of improving the lubricity of the resulting coating film. For example, a fatty acid ester wax, a silicon-based wax, which is an ester mixture of a polyol and a fatty acid, Mention may be made of waxes such as fluorine waxes, polyolefin waxes, animal waxes and plant waxes. Examples of adhesive resins include rosins such as rosin acid, polymerized rosin acid and rosin ester, terpene resin, terpene phenol resin, aromatic hydrocarbon resin, aliphatic saturated hydrocarbon resin, and Petroleum oil is included. [0064] In the case of optical three-dimensional molding, a thermoplastic polymer compound can be further added. The thermoplastic polymer compound is a polymer compound that is liquid or solid at room temperature and is homogeneously mixed with the resin composition at room temperature. Typical examples of such thermoplastic polymer compounds include polyester, poly (vinyl acetate), poly (vinyl chloride), poly (butadiene), polycarbonate, polystyrene, poly (butyl ether), poly (butyral), poly (aryl acrylate), poly (methyl methacrylate), Examples include polybutene and hydrogenated styrene butadiene block copolymer. Further, those obtained by introducing a functional group such as a hydroxyl group, a carboxyl group, a vinyl group, or an epoxy group into these thermoplastic polymer compounds can also be used. For a strong thermoplastic polymer compound, a number average molecular weight of 1,000 to 500,000 is desirable for the present invention, and a more preferred number / molecular weight average molecular weight of 5,000 to 100,000 is preferred. If it is outside this range, it cannot be used, but if the molecular weight is too low, the effect of improving the strength cannot be obtained sufficiently, and if the molecular weight is too high, the viscosity of the resin composition becomes high. It cannot be said that it is preferable as a resin composition for optical three-dimensional modeling.

[0065] The preparation of the actinic ray curable composition is not particularly limited as long as these materials can be sufficiently mixed. Specific examples of the mixing method include a stirring method using a stirring force accompanying the rotation of the propeller, a roll kneading method, and a normal disperser such as a sand mill.

[0066] Further, an outline of the method of use depending on the application is described below.

[0067] In the case of printing ink use, the actinic ray curable composition is prepared by various printing methods such as lithographic printing such as offset printing, letterpress printing, silk screen printing or the like using paper, film or sheet as a base material. It can be used in gravure printing. The actinic ray curable composition is cured by irradiation with actinic rays after printing. Examples of actinic rays include ultraviolet rays, X-rays, and electron beams. Various light sources that can be used for curing by ultraviolet rays can be used, such as pressurized or high-pressure mercury lamps, metal halide lamps, xenon lamps, electrodeless discharge lamps, or carbon arc lamps. . When curing with an electron beam, various irradiation devices can be used, such as a cock loftwaldsin type, a bandegraph type, or a resonant transformer type. As an electron beam, one having an energy of 50 to: LOOOeV More preferably 100-300eV is there. In the present invention, since an inexpensive apparatus can be used, it is preferable to use ultraviolet rays for curing the actinic ray curable composition.

[0068] In the case of coating paint applications such as cans, plastics, paper, and wood, the actinic ray curable composition can be applied to various metal materials, plastic materials, paper, wood, and other coatings. Examples of plastic materials such as electro-plated steel plate, chin-free steel, aluminum, etc. include polycarbonate, polymethylmethallate, polyethylene terephthalate, salty bulb resin, ABS resin, etc. In addition to ordinary paper, the paper whose surface is treated with polyethylene, polyvinyl chloride, polypropylene, polyester, polycarbonate, polyimide, etc., such as cherry, sardine, rose, quince, mahogany, lawan, kaku, gege , Cypress, yellowfin, hoe, wig, zelkova, walnut, tas, oak, chi Processed wood such as plywood, laminated board, partition board and printed plywood, as well as natural wood such as cucumbers, oysters, jindai wigs, jinshiro cedar, blackwood, kokutan, shimakoktan, tochi, rikide, yanagi and ash Alternatively, floor materials, furniture, and wall materials that are produced by processing wood force may be mentioned, and these may be plate-like or fame-like.

[0069] The film thickness on the surface of the substrate of the actinic ray curable composition may be appropriately selected depending on the use to be used, but the preferred film thickness is 1 to 50 µm, more preferably 3 to 20 μm.

[0070] The method of using the actinic ray curable composition is not particularly limited, and may be performed according to a conventionally known method. For example, dating, flow coat, spray, bar coat, gravure coat, roll coat, blade There is a method in which an actinic ray curable composition is applied on the surface of a substrate using a coating machine by a method such as coating or air knife coating, and then cured by irradiation with actinic rays. Examples of the actinic rays include ultraviolet rays, X-rays and electron beams. As the light source that can be used for curing with ultraviolet rays, various light sources can be used, and examples thereof include a pressurized or high-pressure mercury lamp, a metal nitride lamp, a xenon lamp, an electrodeless discharge lamp, or a carbon arc lamp. In the case of curing with an electron beam, various irradiation devices can be used, such as a cockroft walthsin type, a bandegraph type, or a resonant transformer type. As an electron beam, 50 to: LOOOeV Those having energy are more preferably 100 to 300 eV. In the present invention, since an inexpensive apparatus can be used, it is preferable to use ultraviolet rays for curing the actinic ray curable composition. After applying the actinic ray curable composition to the plastic material, it may be subjected to processing such as molding, printing, or transfer, as necessary. In the case of molding, for example, a substrate having an actinic ray curable composition coating film is heated to an appropriate temperature and then used by a method such as vacuum forming, vacuum / pressure forming, pressure forming or mat forming. And a method of forming only a coating layer as in the case of embossing an actinic ray curable composition coating film such as a CD or a record, such as an interference fringe. When printing, use a normal printing machine on the coating and print in the usual way. When transferring, for example, an actinic ray curable composition is applied to a substrate such as a polyethylene terephthalate film, and if necessary, the above-described printing or embossing is performed, and after applying an adhesive layer, the other layers are applied. Transfer to substrate.

In the case of an adhesive, the method for using the actinic ray curable composition is not particularly limited, and may be a method that is usually performed in the production of a laminate. For example, the actinic ray curable composition is applied to the first thin-layer adherend and dried as necessary, and then the second thin-layer adherend is bonded thereto and irradiated with actinic rays. The method of performing etc. is mentioned. Here, at least one of the thin layer adherends needs to be a plastic film. Examples of the thin layer adherend include a plastic film, paper, and metal foil. Here, the plastic film means one that can transmit actinic rays, and the film thickness may be selected according to the thin layer adherend to be used and the application, but preferably the thickness is 0.2 mm or less. is there. Examples of plastic films include polysalt vinyl resin, polysalt vinylidene, cellulosic resin, polyethylene, polypropylene, polystyrene, ABS resin, polyamide, polyester, polyurethane, polybutyl alcohol, and ethylene. Examples include butyl acetate copolymer and chlorinated polypropylene. Examples of the paper include imitation paper, high-quality paper, craft paper, art-coated paper, caster-coated paper, pure white roll paper, parchment paper, water-resistant paper, dalasin paper, and corrugated paper. Examples of the metal foil include aluminum foil. For coating on thin-layer adherends, Nachi Yurano coater, knife benor coater, floating knife. , Knife on blanket, spray, dip, kiss slew, squeeze roll, river roll, air blade, curtain flow coater and gravure coater. The application thickness of the actinic ray curable composition may be selected according to the thin-layer adherend to be used and the application, but is preferably 0.1 to: LOOO / zm, more preferably 1. ~ 50 m. Examples of the actinic rays include ultraviolet rays, X-rays, and electron beams. A variety of light sources can be used as the light source that can be cured by ultraviolet rays, such as a pressurized or high-pressure mercury lamp, a metal nitride lamp, a xenon lamp, an electrodeless discharge lamp, or a carbon arc lamp. . When curing with an electron beam, a known EB irradiation apparatus can be used. In the case of curing with an electron beam, various irradiation devices can be used, for example, a cockroft waltsin type, a bande graph type, or a resonance transformer type. As an electron beam, an energy of 50 to: LOOOeV is used. It is more preferably 100 to 300 eV. In the present invention, since an inexpensive apparatus can be used, it is preferable to use ultraviolet rays for curing the composition.

[0072] In the case of an optical three-dimensional molding application, an arbitrary surface of the actinic ray curable composition is irradiated with an energy line, and the energy ray irradiated surface of the actinic ray curable composition is cured to obtain a desired thickness. Then, an actinic ray curable composition is further supplied onto the cured layer, and this is cured in the same manner to obtain a cured layer continuous with the aforementioned cured layer. By repeating the operation, a three-dimensional object is obtained.

Next, the inkjet image forming method of the present invention will be described.

In the image forming method of the present invention, a method is preferred in which the ink described above is ejected and drawn on a recording material by an ink jet recording method, and then the ink is cured by irradiation with actinic rays such as ultraviolet rays.

[0075] (Total ink film thickness after ink landing)

In the present invention, the total ink film thickness after the ink has landed on the recording material and cured by irradiation with actinic rays is preferably 2 to 20 m. Actinic ray curable inkjet recording in the field of screen printing currently has a total ink film thickness of over 20 m. The force recording material is thin and is often a plastic material. The curl of the recorded material · Not only because of wrinkles, but also the entire printed material · If the texture changes However, since there is a problem, it is preferable to discharge ink with an excessive film thickness.

[0076] Here, "total ink film thickness" means the maximum value of the ink film thickness drawn on the recording material, and even for a single color, other two color layers (secondary colors), three color layers Even when recording is performed with the four-color superposition (white ink base) inkjet recording method, the meaning of the total ink film thickness is the same.

[0077] (Ink ejection conditions)

In the case of forming an image using the ink of the present invention, as the ink discharge conditions, it is preferable from the viewpoint of discharge stability that the recording head and the ink are heated to 35 to: LOO ° C. and discharged. Actinic light curable ink has a large viscosity fluctuation range due to temperature fluctuations. Viscosity fluctuations directly affect the droplet size and droplet ejection speed, causing image quality degradation, so the temperature is kept constant while raising the ink temperature. It is necessary to keep on. The control range of the ink temperature is set temperature ± 5 ° C, preferably set temperature ± 2 ° C, more preferably set temperature ± 1 ° C.

[0078] (Light irradiation conditions after ink landing)

In the image forming method of the present invention, it is preferable that the active light is irradiated for 0.001 seconds to 1.0 seconds after the landing of the ink as the active light irradiation condition, more preferably 0.001 seconds to 0. 5 seconds. In order to form a high-definition image, it is particularly important that the irradiation timing is as early as possible.

[0079] A basic method of actinic ray irradiation is disclosed in JP-A-60-132767. According to this, a light source is provided on both sides of the head unit, and the head and the light source are scanned by the shuttle method. Irradiation is performed after a certain period of time after ink landing. Further, the curing is completed by another light source that is not driven. U.S. Pat.No. 6,145,979 discloses a method using an optical fiber as an irradiation method and a method of irradiating a recording unit with UV light by applying a collimated light source to a mirror surface provided on the side surface of the head unit. Has been. Any of these irradiation methods can be used in the image forming method of the present invention.

Next, an ink jet recording apparatus (hereinafter simply referred to as a recording apparatus) of the present invention will be described. Hereinafter, the recording apparatus of the present invention will be described with reference to the drawings as appropriate. Note that the recording apparatus in the drawings is merely one aspect of the recording apparatus of the present invention, and the recording apparatus of the present invention is not limited to this drawing.

FIG. 1 is a front view showing the configuration of the main part of the recording apparatus of the present invention. The recording apparatus 1 includes a head carriage 2, a recording head 3, an irradiation unit 4, a platen unit 5, and the like. In this recording apparatus 1, a platen unit 5 is installed under the recording material P. The platen section 5 has a function of absorbing ultraviolet rays and absorbs excess ultraviolet rays that have passed through the recording material P. As a result, a high-definition image can be reproduced very stably.

The recording material P is guided by the guide member 6 and moves from the front side to the back side in FIG. 1 by the operation of the conveying means (not shown). Head scanning means (not shown) scans the recording head 3 held by the head carriage 2 by reciprocating the head carriage 2 in the Y direction in FIG.

The head carriage 2 is installed on the upper side of the recording material P, and a plurality of recording heads 3 to be described later are arranged in accordance with the number of colors used for image printing on the recording material P, and the discharge ports are arranged on the lower side. Store. The head carriage 2 is installed on the main body of the recording apparatus 1 in such a manner that it can reciprocate in the Y direction in FIG. 1, and reciprocates in the Y direction in FIG. 1 by driving the head scanning means.

In FIG. 1, the head carriage 2 is white (W), yellow (Y), magenta (M), cyan (C), black (K), light yellow (Ly), light magenta (Lm), and light cyan. (Lc), light black (Lk), and white (W) should be drawn as containing the recording head 3! /, And the color of the recording head 3 stored in the head carriage 2 when performing 1S. The number is determined as appropriate.

[0086] The recording head 3 operates an ejection means (not shown) provided with a plurality of actinic ray curable inks (for example, UV curable ink) supplied by an ink supply means (not shown). As a result, the discharge roller is also discharged toward the recording material P. The UV ink discharged from the recording head 3 is composed of a coloring material, a polymerizable monomer, an initiator, etc., and the monomer crosslinks when the initiator acts as a catalyst when irradiated with ultraviolet rays. It has the property of being cured by a polymerization reaction. [0087] During the scanning in which the recording head 3 moves from one end of the recording material P to the other end of the recording material P in the Y direction in FIG. UV ink is ejected as ink droplets onto the possible area), and ink droplets are landed on the landable area.

[0088] After the above scanning is performed as many times as necessary, and UV ink is ejected toward one landable area, the recording material P is appropriately moved in the front direction in FIG. While performing scanning by means, the recording head 3 discharges UV ink to the next landable area adjacent in the rear direction in FIG.

By repeating the above-described operation and discharging the UV ink from the recording head 3 in conjunction with the head scanning unit and the conveying unit, an image having the collective force of UV ink droplets is formed on the recording material P.

The irradiation means 4 includes an ultraviolet lamp that emits ultraviolet light in a specific wavelength region with stable exposure energy, and a filter that transmits ultraviolet light of a specific wavelength. Here, mercury lamps, metal halide lamps, electrodeless lamps, excimer lasers, ultraviolet lasers, cold cathode tubes, hot cathode tubes, black lights, LEDs (light emitting diodes), etc. are applicable as the ultraviolet lamps. .

[0091] The irradiation means 4 is the largest one that can be set by the recording apparatus (UV inkjet printer) 1 among the landable areas in which the recording head 3 ejects UV ink by a single scan driven by the head scanning means. The shape is almost the same or larger than the landable area.

The irradiation means 4 is installed on both sides of the head carriage 2 so as to be substantially parallel to the recording material P.

[0093] As described above, as a means for adjusting the illuminance of the ink discharge portion, not only the entire recording head 3 is shielded, but in addition, the recording head is determined by the distance hi between the irradiation means 4 and the recording material P. 3 Increase the distance h2 between the ink ejection part 31 and the recording material P (hl <h2), or increase the distance d between the head carriage 2 (recording head 3) and the irradiation means 4 (d is increased). Is effective. Further, it is more preferable that a bellows structure 7 is provided between the head carriage 2 (recording head 3) and the irradiation means 4. Here, the wavelength of the ultraviolet rays irradiated by the irradiation means 4 can be appropriately changed by replacing the ultraviolet lamp or filter provided in the irradiation means 4.

The ink of the present invention has very excellent ejection stability, and is particularly effective when an image is formed using a line head type recording apparatus.

FIG. 2 is a top view showing another example of the configuration of the main part of the ink jet recording apparatus.

The ink jet recording apparatus shown in FIG. 2 is called a line head system, and a plurality of recording heads 3 of each color are covered with the head carriage 2 so as to cover the entire width of the recording material P.

, Fixedly arranged.

On the other hand, on the downstream side of the head carriage 2, an irradiating means 4 is provided so as to cover the entire width of the recording material P.

In this line head system, the head carriage 2 and the irradiation means 4 are fixed, and the recording material

Only P is transported to perform image formation by performing ink ejection and curing.

Example

[0100] The present invention will be specifically described below with reference to examples, but the embodiments of the present invention are not limited to these examples.

[0101] Example 1

<< Preparation of actinic ray curable composition >>

The compositions shown in Tables 1 to 3 were mixed and dissolved to prepare actinic ray curable compositions 1 to 9 (hereinafter simply referred to as cured products).

[0102] [Table 1]

Content Hardened product 1 (Comparison)

(Powder%)

Cured product 4 (Invention) Content

(mass%)

Cured product 7 (Invention)

EP-1

[0106] The actinic ray curable compositions 1-9 thus obtained were applied to a 80 µm-thick PET film with a wire bar so that the film thickness was 6 µm, and then a high humidity condition of 27 ° C 80% RH Below, exposure was performed with an A bulb, 80 W / cm output, using a light source VZero085 manufactured by INTEGRA TIONTECHNOLOGY. A curing sample was obtained by passing 2 cm under a light source through the coating film at a speed of 600 mmZs. Get the sample! Finally, the following (1) and (2) were evaluated.

[0107] A cured sample having a total thickness of about 60 µm was prepared by repeating the above operation 10 times, and the following evaluation (3) was performed.

[0108] <Evaluation method of cured product>

(1) Pencil attraction test: According to JIS K 5400, the pencil hardness of each cured product was measured.

[0109] The pencil hardness rank is (soft) 6B to B, HB, F, H to 9H (hard) in the order 6B is the softest

9H is the hardest and most preferable.

(2) Residual adhesion rate test by peeling the substrate tape: Adhesive tape (Scotch # 250, manufactured by Sumitomo 3M) is pasted on the cured composition sample obtained in the cross-cut test of JIS K 5400, and 1 reciprocating with a 2 kg roller After that, it was peeled off at once and the number of remaining grid-like samples was investigated. The larger the residual ratio, the better.

(3) Cured film flexibility test:

The evaluation was based on the degree of occurrence of bending cracks when the sample was placed on a 3 mm diameter stainless steel rod.

[0110] Evaluation was performed according to the following evaluation criteria.

[0111] ○: No cracks caused by bending (wrapping)

Δ: Cracking is observed when bending (winding) multiple times

X: Cracks occur when bent (wrapped).

[0112] [Table 4] Actinic ray curable composition Pencil hardness Flexibility

(%)

1 2H 60 X

2 B 30 X

3 4H 65 ○

4 2H 60 △

5 3H 70 ○

6 4H 75 ○

7 4H 80 ○

8 2H 60 Δ

9 3H 65 ○

[0113] From Table 4, it is evident that the actinic ray curable composition of the present invention has good curability and excellent physical properties of the cured product.

[0114] Example 2

The pigment was dispersed with the following composition.

[0115] [Cationic polymerization system]

The following two compounds were placed in a stainless beaker and dissolved by stirring and heating for 1 hour while heating on a 65 ° C hot plate.

9 parts of PB822 (Ajinomoto Fine Technone Earth Dispersant)

71 parts made by OXT-22K manufactured by Toagosei Co., Ltd.

After cooling to room temperature, 20 parts of the following pigment was added thereto, sealed in a glass bottle with 200 g of Zirco-Abyss having a diameter of 0.5 mm, and sealed with a paint shaker for the following time, and then the Zirco-Urea beads were removed.

Pigment 1: Pigment Black 7 (Mitsubishi Chemical Corporation, # 52) 10 hours

Pigment 2: Pigment Blue 15: 4

(Daiichi Seika, Blue No.32) 9 hours

Pigment 3: Pigment Yellow 150

(LANXESS, E4GN—GT CH20015) 8 hours

Pigment 4: Pigment Red 122 (Daiichi Seiki Co., Ltd., CFR-321) 10 hours

Pigment 5: Titanium oxide (anatase type: particle size 0.2 m) 10 hours

[Radical polymerization system]

The following two compounds were placed in a stainless beaker and dissolved with stirring and heating for 1 hour while heating on a 65 ° C hot plate.

9 parts of PB822 (Ajinomoto Fine Technone Dispersant)

Tetraethylene glycol ditalylate (bifunctional) 71 parts

After cooling to room temperature, add 20 parts of the following pigment to this, put it in a glass jar with 200 g of Zirco-Abes with a diameter of 0.5 mm, seal it with a paint shaker for the following time, and then remove the Zirco-Urea beads. .

Pigment 6: Pigment Black 7 (Mitsubishi Chemical Corporation, MA7) 8 hours

Pigment 7: Pigment Blue 15: 4

(Sanyo Dye, Shean Blue 4044) 8 hours

Pigment 8: Pigment Yellow 180

(Daiichi Seiki Co., Ltd., CFY-313-2) 10 hours

Pigment 9: Pigment Red 122

(Daiichi Seiki Co., Ltd., CFR—338—3) 10 hours

Pigment 10: Titanium acid (anatase type: particle size 0.2 μ, 8 hours

<< Preparation of actinic ray curable ink jet ink >>

Prepare ink sets 1 to 8 of actinic ray curable inkjet ink (hereinafter referred to simply as ink) with the composition shown in Tables 5 to 8, and filter with an ADVATEC Teflon (registered trademark) 3 μm membrane filter. went. Each ink viscosity is as shown in the table.

[Table 5] Ink 1 (comparison) Viscosity of each color 18 21mPa.s (Z5'C)

[0117

Ink 2 (comparison) Viscosity of each color 25 28-32mf * a

Ink 3 (Invention) Viscosity of each color 3l to 33 Pa · s (25 "C)

[¾ S] 0117

Ink 5 (Invention) Viscosity of each color 31-33mPa · s {25'C)

[] Sfif

Society December 1995)). The ink supply system consisted of an ink tank, a supply pipe, a front chamber ink tank just before the head, a pipe with a filter and a piezo head. The piezo head was driven to eject 2 to 15 pl multi-size dots at a resolution of 720 x 720 dpi, and each ink was ejected continuously. After landing, it is cured instantly (less than 2 seconds after landing) by the lamp units on both sides of the carriage. After recording, the total ink film thickness was measured and found to be in the range of 2.3 to 20 m. The dpi referred to in the present invention represents 2.5 dots per 54 cm. Inkjet images were formed according to the above method in an environment of 10 ° C. and 20% RH, an environment of 25 ° C., 50% RH, and an environment of 27 ° C. and 80% RH, respectively.

[0121] In addition, the line head recording type ink jet recording apparatus shown in Fig. 2 is used in exactly the same manner, and the conveyance guide plate (platen part) is heated to 40 ° C, so that the recording material can be used. After landing, the ink was kept at approximately 40 ° C., and an image was formed using ink composition sets 6-8.

[0122] << Evaluation of Inkjet Recorded Image >>

For each image recorded by the above image forming method, the following evaluations were performed at the time of lm and 100 m output, and it was evaluated whether images could be stably formed.

[0123] (Curl of recording material)

The curl of the recording material after image formation (after curing) was visually evaluated.

[0124] ○: No car nore

Δ: られる, Μ, C3 The power at which a slight curl (wave of recording material) can be seen in the overlapping part (thick film part) of C3 color

X: A level where curls are not very useful.

[0125] (mixed colors (bleeding, wrinkles))

At 720dpi, Y, M, C, and K colors are printed so that one dot is adjacent to each other, each adjacent color dot is enlarged with a ruler, the degree of bleeding is visually observed, and color mixing is evaluated according to the following criteria. went.

[0126] ◎: Adjacent dot shape keeps perfect circle and no blur

◯: Adjacent dot shape keeps almost perfect circle and almost no bleeding

Δ: Adjacent dots are slightly blurred and the dot shape is slightly deformed. Lebenore

X: Adjacent dots are blurred and mixed, and wrinkles are generated in the overlapping area, which is unusable.

[0127] Table 9 shows the actinic ray irradiation conditions of each sample obtained as described above, and Table 10 shows the evaluation results.

[0128] [Table 9]

S¾S0121

From Table 10, it can be seen that the sample of the present invention can reproduce a high-definition image without curling problems very stably on a PET (polyethylene terephthalate) film that does not absorb ink. The recording material is PET film, OPS (oriented polystyrene) film Similar results were obtained when switching to OPP (oriented polypropylene), ONy (oriented nyron), and PVC (polyvinyl chloride) films.

Claims

The scope of the claims

[I] An active light curable composition comprising a polyester polyol obtained by reacting a polyhydric carboxylic acid containing a photoinitiator, a polymerizable compound and terephthalic acid with a polyhydric alcohol.

[2] The actinic ray curable composition according to claim 1, wherein the polymerizable compound contains 10 to 30% by mass of a monofunctional monomer.

[3] The polyester polyol contains 2 to 20% by mass of the polyester polyol.

3. The actinic ray curable composition according to item 1 or 2.

[4] The actinic ray curable composition according to any one of claims 1 to 3, wherein the polyester polyol has a viscosity at 25 ° C of 100 to 6000 mPa's.

[5] The actinic ray curable type according to any one of claims 1 to 4, wherein the polymerizable compound contains at least one compound having an oxosilane group. Composition.

[6] The actinic ray curable composition according to claim 5, further comprising an oxetane compound as the polymerizable compound.

[7] The actinic ray curable composition according to any one of [1] to [6], which contains a basic compound.

[8] The actinic ray curable composition according to any one of [1] to [7], which contains a pigment as a coloring material.

[9] The actinic ray curable inkjet ink, wherein the actinic ray curable inkjet ink is the actinic ray curable composition described in claim 8.

[10] The actinic ray-curable inkjet ink according to item 9, wherein the viscosity at 25 ° C is 7 to: LOOmPa's.

[II] An image forming method in which the actinic ray curable inkjet ink according to claim 9 or 10 is jetted onto a recording material from an inkjet recording head to perform printing on the recording material. Thus, the image forming method is characterized in that the actinic ray curable ink jet ink is landed and has a total inkjet ink film thickness of 2 to 20 m after being cured by irradiation with actinic rays.

[12] An image forming method for performing printing on a recording material by ejecting the actinic ray curable inkjet ink according to claim 9 or 10 onto the recording material from an ink jet recording head. An image forming method characterized in that an image is formed by jetting from a line head type recording head.

[13] An ink jet recording apparatus for use in the image forming method according to claim 11 or 12, wherein the actinic ray curable ink jet ink and the recording head are heated to 35 to: L 00 ° C. An ink jet recording apparatus that discharges the ink.