WO2007083473A1 - Active ray-curable composition, active ray-curable ink, and image-forming method using same - Google Patents

Abstract

Disclosed is an active ray-curable composition which enables to form a strong image film having high sensitivity and high flexibility. Also disclosed are an active ray-curable ink using such an active ray-curable composition and an image-forming method. The active ray-curable composition contains a photopolymerization initiator and a photopolymerizable compound. This active ray-curable composition is characterized in that it further contains an acrylic polymer and the photopolymerizable compound is composed of a cationically polymerizable monomer.

Description

 Specification

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

 Technical field

 TECHNICAL FIELD [0001] The present invention relates to an actinic ray curable composition, and in particular, an actinic ray curable composition that cures with low viscosity and high sensitivity and further forms an image excellent in adhesion and flexibility. The present invention relates to an actinic ray curable ink and an image forming method using the composition.

 Background art

 [0002] Conventionally, curable compositions that are cured by active energy rays such as ultraviolet rays and electron beams or heat are paints such as plastic, paper, woodwork and inorganic materials, adhesives, printing inks, printed circuit boards, and electrical insulation relations. It has been put to practical use for various uses. In recent years, among them, printing inks, paints, adhesives, and the like have been desired to have higher curability and flexibility of formed images. As ink-jet inks using these, ultraviolet curable inks that are cured with ultraviolet rays are known. The ink jet method using this ultraviolet curable ink has been attracting attention in recent years because it has a relatively low odor, can be recorded on a recording material that does not dry quickly, and has no ink absorbability. Many inks have been disclosed (for example, see Patent Documents 1 and 2;).

 In this field, it is required that the formed image film is strong and flexible, has good adhesion to the recording material, and further has low odor.

 [0004] In addition, improvement in productivity, that is, improvement in printing speed is also demanded, and at the same time, improvement in curability is also demanded.

 Patent Document 1: JP-A-6-200204

 Patent Document 2: Japanese Translation of Special Publication 2000-504778

 Disclosure of the invention

 Problems to be solved by the invention

[0005] The present invention has been made in view of the above problems, and an object of the present invention is to use an actinic ray curable composition capable of forming a highly sensitive, flexible and strong image, and the same. An actinic ray curable ink and an image forming method are provided.

 Means for solving the problem

 [0006] The object of the present invention has been achieved by the following constitution.

 [0007] 1. In an actinic ray curable composition containing a photopolymerization initiator and a photopolymerizable compound, the photopolymerizable compound is a radical polymerizable monomer and contains an acrylic polymer. An actinic ray curable composition characterized.

[0008] 2. In the actinic ray curable composition containing a photopolymerization initiator and a photopolymerizable compound, the photopolymerizable ionic compound is a cationic polymerizable monomer and contains an acrylic polymer. An actinic ray curable composition characterized by the above.

[0009] 3. The actinic ray curable composition as described in 1 or 2 above, wherein the acrylic polymer has a molecular weight force of 100 or more and less than 10,000.

[0010] 4. The actinic ray curable composition according to any one of 1 to 3 above, wherein the viscosity of the acrylic polymer at 25 ° C is not less than lOmPa's and less than lOOOOmPa's. object.

 [0011] 5. The actinic ray curable composition as described in any one of 1 to 4 above, wherein the glass transition temperature of the acrylic polymer is 130 ° C or higher and 10 ° C or lower.

 [0012] 6. The photopolymerization initiator is an iodonium salt or a sodium salt having a sulfone salt power, and is a photoacid generator, and the photopolymerization initiator is contained in an amount of 1 to 10% by mass. 6. The actinic ray curable composition according to any one of 2 to 5, which is contained below.

 7. The actinic ray curable composition according to any one of 2 to 6, wherein the cation-polymerizable monomer is at least one alicyclic epoxy compound.

 [0014] 8. The actinic ray curable composition according to any one of 2 to 7 above, which is a compound having at least one oxetane ring of the cationic polymerizable monomer.

 [0015] 9. The actinic ray curable composition according to any one of 2 to 8 above, wherein the composition is at least one cyclic vinyl ether compound of the cationic polymerizable monomer.

[0016] 10. The actinic ray curable composition according to any one of 1 to 9 above, which has an additive weight capacity of the acrylic polymer of 0.1% by mass to 30% by mass. [0017] 11. The actinic ray curable composition as described in 7 above, wherein the addition power of the alicyclic epoxy compound is 10% by mass or more and 80% by mass or less.

[0018] 12. An actinic ray curable ink comprising the actinic ray curable composition according to any one of 1 to 11 above.

[0019] 13. The actinic ray curable ink as described in 12 above, which has a viscosity at 25 ° C. of ImPa ′s or more and less than 50 mPa ′s.

[0020] 14. An image forming method in which the actinic ray curable ink according to 12 or 13 is jetted onto a recording material from an inkjet recording head, and printing is performed on the recording material. An image forming method comprising irradiating actinic rays for 0.001 to 1.0 seconds after ink has landed.

[0021] 15. An image forming method in which the actinic ray curable ink according to 12 or 13 is sprayed onto a recording material from an ink jet recording head, and printing is performed on the recording material. An image forming method characterized in that the minimum ink droplet volume force ejected from each nozzle is 2 pl or more and 15 pl or less.

 The invention's effect

 [0022] According to the present invention, there is provided an actinic ray curable composition capable of forming a highly sensitive, flexible and strong image film, and an actinic ray curable ink and an image forming method using the same. Could be provided.

 Brief Description of Drawings

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

 Explanation of symbols

[0024] 1 Inkjet recording apparatus

 2 Head carriage

 3 Inkjet recording head

31 Ink outlet 5 Platen section

 6 Guide member

 7 Bellows structure

 P Recording material

 BEST MODE FOR CARRYING OUT THE INVENTION

[0025] The present invention will be described in more detail.

 [0026] The actinic ray curable composition of the present invention is characterized by containing an acrylic polymer together with a photopolymerization initiator and a photopolymerizable compound.

 [0027] The acrylic polymer according to the present invention means a polymer in which 10 mol% or more of the repeating units are acrylic acid and Z or methacrylic acid and derivatives thereof.

 [0028] Examples of the acrylic monomer that can be used in the acrylic polymer according to the present invention include ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and dimethylaminoethyl acrylate. Acrylic acid alkyl ester or derivatives thereof; methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, and methacrylic acid esters such as dimethylaminoethyl methacrylate or derivatives thereof It is done. These acrylic monomers may be used alone or in combination with a plurality of monomers.

 [0029] Examples of the acrylic polymer according to the present invention include an acrylic polymer having a functional group. The acrylic polymer having a functional group includes one or several monomers having a hydroxyl group, a tertiary amino group, a carboxyl group, an amide group, an N-substituted amide group, a nitrile group, etc., an alkyl (meth) acrylate, Copolymers with monomers such as butyl acetate, butyl propionate, butyl ether, and styrene.

[0030] Examples of the monomer having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth). There are atarylates, N-methylolacrylamide, allylic alcohols, etc. Monomers having a tertiary amino group include dimethylaminoethyl (meth) acrylate, jetylaminoethyl (meth) acrylate, dimethylaminopropyl (meth). Arc And rilamide. Examples of the monomer having a carboxyl group include acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, and citraconic acid. Examples of monomers having an amide group or N-substituted amide group include acrylic amide, methacrylamide, N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N —Ethoxymethyl (meth) acrylamide, N-propoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N-tert-butylacrylamide, N-octylacrylamide, diacetoneacrylamide, etc. Examples of the monomer having a nitrile group include acrylonitrile, methatalonitrile, crotono-tolyl, and fumaro-tolyl. Examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethyl hexyl (meth) acrylate and octyl (meth). It is an alkyl (meta) attalylate such as attalylate. In addition, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate and alkyl groups substituted with aromatic ring groups, heterocyclic groups, halogen atoms, etc. ) Monomers generally used in the synthesis of acrylic polymers such as attalylate can also be used in the synthesis of the polymers of the present invention.

 [0031] Examples of the ethylenic monomer containing a functional group to be copolymerized with the main monomer include a monomer having a carboxyl group such as acrylic acid, methacrylic acid, itaconic acid, fumaric acid, and 2-hydroxyethyl acrylate. , Monomers containing a hydroxyl group such as 2-hydroxyethyl methacrylate, monomers containing an epoxy group such as glycidyl methacrylate, acrylamide, methacrylamide, acrylonitrile, meta-tolyl, dimethylaminoethyl methacrylate Rate, dimethylaminopropyl acrylate, and the like. These are the cross-linking points of the polymer. In addition, if necessary, monomers such as vinyl acetate, styrene, and methylmethylene may be copolymerized.

[0032] Commercially available acrylic polymers include, for example, Alfon UP-1010, UP-1021, UP-1041, UP1061, UH-2130, UH-2000, UHE-2012, UC-3010, manufactured by Toa Gosei Co., Ltd. UC-3900, Soken Chemical's Fact Flow UMB-1001, UT-2001, UMB-2005, AS-300, CB-3098, BGV-11, UTMM-LS2, Toagoi SALON TALLON S— 1511L, S— 151 IX, S— 1515, S— 1517, TOACRON AR—601, AR-602, AR—603, Toppe Corporation — Pole AR—3, manufactured by Zeon Corporation 1, AR—51, AR—54,

 Noxtite PA-301, PA-501, PA-502 manufactured by NOK, Tisan Resin WS-022, WS-023, SG-51, SG-80 manufactured by Nagase ChemteX, etc.

[0033] The molecular weight is preferably 100 or more and less than 10,000. If the molecular weight is less than 100, the desired effect cannot be obtained, and if the molecular weight is 10,000 or more, the ink ejection properties are adversely affected. The viscosity (25 ° C share 1000 lZs) is preferably lOmPa's or more and less than lOOOOmPa's. If the viscosity is less than lOmPa's or more than lOOOOPa's, it becomes difficult to maintain the ejection stability. The glass transition temperature is preferably −130 ° C. or higher and −10 ° C. or lower. When the glass transition temperature exceeds -10 ° C, the effect of the present invention becomes small.

 [0034] The addition amount of the acrylic polymer in the actinic ray curable composition of the present invention is 0.1% by mass or more and 30% by mass or less per 100% by mass of the actinic ray curable composition. If the addition amount is less than 0.1% by mass, the effect of the acrylic polymer cannot be expressed, and if it exceeds 30% by mass, there is a concern about the effect on curability and emission stability.

 [0035] The radical polymerizable monomer according to the present invention is a compound having an ethylenically unsaturated bond capable of radical polymerization and any compound having at least one ethylenically unsaturated bond capable of radical polymerization in the molecule. In other words, those having chemical forms such as monomers, oligomers and polymers may be included. Only one type of radically polymerizable monomer may be used, or two or more types may be used in combination at an arbitrary ratio in order to improve the desired properties.

[0036] Examples of compounds having an ethylenically unsaturated bond capable of radical polymerization include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, and salts and esters thereof. , Urethane, amide anhydride, acrylonitrile, styrene, and various radically polymerizable compounds such as various unsaturated polyesters, unsaturated polyethers, unsaturated polyamides, and unsaturated urethanes. Specifically, 2-ethylhexyl talylate, 2-hydroxyethyl talylate, butoxetyl talylate, carbitol Ruatalylate, cyclohexyl acrylate, tetrahydrofurfuryl acrylate, benzyl acrylate, bis (4-ataryloxypolyethoxyphenol) propane, neopentyl glycol diatalate, 1,6-hexanediol diatali Rate, ethylene glycol diatalylate, diethylene glycol diatalylate, triethylene glycol diatalylate, tetraethylene glycol diatalylate, polyethylene glycol diatalylate, polypropylene glycol diatalylate, pentaerythritol triatalylate, pentaerythritol teratrate Rate, dipentaerythritol tetraatarylate, trimethylol propanetritalylate, tetramethylol methanetetratalylate, ori Estenoacrylate, N-methylolacrylamide, diacetoneacrylamide, acrylic acid derivatives such as epoxytalylate, methylmethacrylate, n-butylmethacrylate, 2-ethylhexylmethacrylate, laurylmethacrylate, allylmeta Tallylate, Glycidinoremethacrylate, Benzylmethacrylate, Dimethylaminomethylmethacrylate, 1,6-Hexanedioldimethacrylate, Ethyleneglycolonemethacrylate, Triethyleneglycolonemethacrylate, Polyethylene glycol dimethacrylate, polypropylene glycol dimethacrylate, trimethylol ethane trimethacrylate, trimethylol propane trimethacrylate, 2,2-bis (4-methacryloxy polyethoxylate) (E) Methacryl derivatives such as propane, and other derivatives of aryl compounds such as allylic glycidyl ether, diallyl phthalate, and triallyl trimellitate. , "Crosslinking agent handbook" (1981 Taiseisha); Kato Kiyomi ed., "UV'EB curing handbook (raw material)" (1985, polymer publication society); Radtech study group, "UV'EB curing" Application and Market of Technology ”, 79 page, (1989, CMC 1); Eiichiro Takiyama,“ Polyester Liquor Handbook ”, (1 988, Nikkan Kogyo Shimbun), etc. These radically polymerizable or crosslinkable monomers, oligomers and polymers can be used. The addition amount of the radically polymerizable compound according to the present invention is preferably 1 to 97% by mass, more preferably 30 to 95% by mass.

Examples of the radical polymerization initiator include triazine derivatives described in JP-B-59-1281, JP-A-69-1621, and JP-A-60-60104, JP-A-59-1504 and JP-A-61-243807. Organic peracid compounds described in each of the above publications, JP-B 43-23684, 44 6413, 44-6413, 47-1604, etc. and U.S. Pat.No. 3,567,453 Organic azide compounds described in the respective specifications of 2,852,379 and 2,940,853, JP-B 36-22062, 37-13109, 38-18015, 45-9610 Ortho-quinonediazides described in each publication such as No. 55-39162, JP-A-59-14023, etc., and “Macromolecules (10th and 1307)”. Di- (1977), various azo compounds described in JP-A-59-142205, JP-A-1 54440, Cyono-Juno Patent No. 109,851, Nos. 126, 712, etc., “Journal 'Ob' Imaging 'Science'” (J. Imag. Sci.), Pp. 30 and 174 (1986); Four 21386 1 and 4-255347, (oxo) sulfo-um organoboron complexes, titanocenes described in JP-A-61-151197, “Coordinant Chemistry” 84), 85-277 (1988), and transition metal complexes containing transition metals such as ruthenium described in JP-A-2-182701, JP-A-3-209477 2, 4, 5 triaryl imidazole dimers, carbon tetrabromide, and organic halogen compounds described in JP-A-59-107344. These polymerization initiators are preferably contained in the range of 0.01 to 10 parts by mass with respect to 100 parts by mass of the compound having an ethylenically unsaturated bond capable of radical polymerization.

 [0038] In the actinic ray curable composition of the present invention, when a cationic polymerizable monomer is used as the photopolymerizable compound, the photopolymerization initiator is an onium salt that can also be an iodine salt or a sulfonium salt. A photoacid generator is preferred.

 [0039] The sulfonium salt used in the present invention is preferably a sulfo salt salt compound represented by the following general formulas [1] to [4].

[0040] [Chemical 1] -General formula [1]-General formula [2]

 -General formula C3]

General formula (4)

[0041] In the general formulas [1] to [4], R 1 to R 4 each represents a hydrogen atom or a substituent.

 31

 R to R can simultaneously represent hydrogen atoms, and R to R can simultaneously represent hydrogen atoms.

31 33 34 37

 R 〜R represents hydrogen atom at the same time R 〜R represents hydrogen at the same time

 38 41 42 47

 It does not represent an atom.

 [0042] The substituent represented by R 1 to R 5 is preferably a methyl group, an ethyl group, a propyl group,

 31 47

 Alkyl groups such as isopropyl group, butyl group, isobutyl group, t-butyl group, pentyl group, hexyl group, alkoxy groups such as methoxy group, ethoxy group, propyl group, butoxy group, hexyloxy group, decyloxy group, dodecyloxy group, Acetoxy group, propionyloxy group, decylcarboxoxy group, dodecylcarboxoxy group, methoxycarbon group, ethoxycarbol group, benzoyloxy group and other carbocyclic groups, phenolthio group, fluorine, chlorine, bromine And halogen atoms such as iodine, cyan groups, nitro groups, hydroxy groups and the like.

 [0043] X represents a non-nucleophilic cation residue, for example, a halogen atom such as F, Cl, Br, or I,

31 B (CF), R COO, R SO, SbF, AsF, PF, BF and the like can be mentioned. However

6 5 4 18 19 3 6 6 6 4

 R and R are alkyl groups such as methyl, ethyl, propyl, and butyl, respectively.

18 19

 An alkyl group or a phenyl group, which may be substituted with an alkyl group, a halogen atom such as fluorine, chlorine, bromine or iodine, an alkoxy group such as a nitro group, a cyano group, a methoxy group or an ethoxy group. Among these, B (C F) and PF are preferable from the viewpoint of safety.

 6 5 4 6

 [0044] The above compounds are photoacids described in THE CHEMICAL SOCIETY OF JAPAN Voi. 71 No. 11, 1998, edited by Organic Electronics Materials Research Group, "Organic Materials for Imaging", Bunshin Publishing (1993). Similar to the generator, it can be easily synthesized by a known method.

 In the present invention, sulfonium salt power represented by the above general formulas [1] to [4] The following general formula [5] to [13] power is at least one selected from sulfonium salts. Power Especially preferred. X represents a non-nucleophilic key residue and is the same as described above.

 31

[0046] [Chemical 2]

[0047] In the present invention, the sulfone salt power represented by the general formulas [1] to [4] is at least one of the sulfone salts selected from the general formulas [5] to [13]. Particularly preferred. X represents a non-nucleophilic key residue, which is the same as described above.

 [0048] Examples of compounds including a ododonium salt include those represented by the formulas [5] to [13] wherein X = PF.

 6 Other examples include the following compounds.

[0049] [Chemical 3]

[0050] [Chemical 4]

[0051] Further, examples of the iodonium salt photoacid generator applicable in the present invention include the following compounds.

[0052] [Chemical 5] 1- 1

 1-4

PF ₆

[0053] In the actinic ray curable composition of the present invention, it is preferable that the cationic polymerizable monomer is a compound having at least one kind of oxetane ring.

[0054] The compound having an oxetane ring according to the present invention will be described below.

[0055] << Oxetane compound having a oxetane ring substituted at the 2-position >>

 In the actinic ray curable composition of the present invention, it is preferable to use an oxetane compound in which the 2-position represented by the following general formula (14) is substituted and has at least one oxetane ring in the molecule.

[0057] 上記一般式（14)において、 R〜Rは各々水素原子または置換基を表す。但し、 R [0056] [Chemical formula 6] General formula (14)

In the above general formula (14), R to R each represents a hydrogen atom or a substituent. However, R

 1 6

 At least one of the groups represented by -R is a substituent. In the general formula (14), R to R

Examples of the substituent represented by 3 6 1 6 include a fluorine atom, an alkyl group having 1 to 6 carbon atoms (for example, a methyl group, an ethyl group, a propyl group, or a butyl group), and 1 to 6 carbon atoms. Represents a fluoroalkyl group, an aryl group, an aryl group (for example, a full group, a naphthyl group, etc.), a furyl group, or a phenyl group. Moreover, these groups may further have a substituent.

 [0058] (Oxetane compound having one oxetane ring in the molecule)

 Furthermore, among the general formula (14), compounds having an oxetane ring represented by the following general formulas (15) to (18) are preferably used.

 [0059] [Chemical 7]

[0060] In the formula, R to R represent a hydrogen atom or a substituent, R and R each represents a substituent, and Z represents each

 1 6 7 8

 Each independently represents an oxygen or sulfur atom, or a divalent hydrocarbon group which may contain an oxygen or sulfur atom in the main chain. Substitution represented by R to R in the general formulas (15) to (18)

 1 6

The group is synonymous with the substituent represented by R to R in the general formula (14). [0061] In the general formulas (15) to (18), the substituents represented by R and R include 1 to 6 carbon atoms.

 7 8

 Alkyl group (for example, methyl group, ethyl group, propyl group or butyl group), alkenyl group having 1 to 6 carbon atoms (for example, 1 probe group, 2 probe group, 2— Methyl-1 propylene group, 2-methyl-2-propellyl group, 1-buturyl group, 2-buturyl group or 3-butenyl group), aryl group (for example, phenyl group, naphthyl group, etc.), Aralkyl groups (for example, benzyl group, fluorbenzyl group, methoxybenzyl group, etc.), C 1-6 acyl groups (for example, propyl carbo yl group, butyl carbo ol group, pentyl carbonyl group, etc.) , An alkoxycarbonyl group having 1 to 6 carbon atoms (for example, ethoxycarbol group, propoxycarbol group, butoxycarbol group, etc.), an alkyl group having 1 to 6 carbon atoms and a rubermoyl group (for example, propyl group) Rubamoyl group, butyl pliers A rucarbamoyl group, etc.) and an alkoxy group ruberamoyl group (for example, an ethoxycarbamoyl group).

 [0062] In the general formulas (15) to (18), an oxygen or sulfur atom represented by Z or an oxygen or sulfur atom in the main chain may be contained. The divalent hydrocarbon group may be an alkylene group. (For example, ethylene group, trimethylene group, tetramethylene group, propylene group, ethylethylene group

, Pentamethylene group, hexamethylene group, heptamethylene group, otatamethylene group, nonamethylene group, decamethylene group, etc.), alkylene group (for example, beylene group, probelene group, etc.), alkylene group ( For example, an ethylene group, a _3- pentylene group, etc.) may be mentioned, and the carbon atom of the alkylene group, alkenylene group, or alkynylene group may be replaced with an oxygen atom or a sulfur atom.

[0063] Among the above substituents, R is a lower alkyl group (for example, a methyl group, an ethyl group, a pro

 1

 Particularly preferred is a ethyl group. R and R

 7 8 is preferably a propyl group, a butyl group, a phenol group or a benzyl group.Z is a hydrocarbon group containing no oxygen or sulfur atom (an alkylene group, an alkylene group, an alkylene group, etc.). ) Is preferred.

 [0064] (compound having two or more oxetane rings in the molecule)

In the present invention, a compound having two or more oxetane rings in a molecule represented by the following general formulas (19) and (20) can be used. [0065] [8] General formula (19)

-General formula (20>

In the formula, Z has the same meaning as the group used in the general formulas (15) to (18), and m represents 2, 3 or 4. R to R are hydrogen atom, fluorine atom, alkyl group having 1 to 6 carbon atoms (example:

 1 6

 For example, it represents a methyl group, an ethyl group, a propyl group, a butyl group, etc.), a fluoroalkyl group having 1 to 6 carbon atoms, an aryl group, an aryl group (for example, a phenyl group, a naphthyl group, etc.) or a furyl group. However, in the general formula (19), at least one of R to R is a substituent.

 3 6

 [0067] In the formula, R represents a linear or branched alkylene group having 1 to 12 carbon atoms, a linear or branched poly (a

 9

 (Alkyleneoxy) group, or a divalent group selected from the following general formulas (22), (23) and (24).

 [0068] As an example of the branched alkylene group having 1 to 12 carbon atoms, an alkylene group represented by the following general formula (21) is preferably used.

[0069] [Chemical 9] General formula (21)

In the formula, R represents a lower alkyl group (for example, a methyl group, an ethyl group, a propyl group, etc.).

 Ten

[0071] [Chemical 10] General formula (22)

[0072] In the formula, n represents 0 or an integer of 1 to 2000, and R represents an alkyl group having 1 to 10 carbon atoms (eg,

 12

 For example, it represents a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, etc., and R represents an alkyl group having 1 to 10 carbon atoms (for example,

 11

 For example, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, or the like) or a group represented by the following general formula (25).

[0073] [Chem. 11] General formula (25)

— 0— (Si— 0) ”Si— (CH ₂ ) ₃ ——

[0074] In the formula, j represents 0 or an integer of 1 to 100, and R represents an alkyl group having 1 to 10 carbon atoms (for example,

 13

 For example, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, etc.).

[0075] [Chemical formula 12] General formula (23)

[0076] In the formula, R is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms (for example, a methyl group, ethyl

 14

Group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, etc.), carbon number 1 to: LO alkoxy group (for example, methoxy group, ethoxy group, propoxy group, Butoxy group, pentoxy group, etc.), halogen atom (for example, fluorine atom, chlorine atom, bromine atom, iodine atom, etc.), nitro group, cyano group, mercapto group, alkoxycarbonyl group (for example, methyloxycarbon group, Ethyloxycarbonyl group, butoxy force A sulfonyl group or the like,

 [0077] [Chem. 13] General formula (24)

[0078] In the formula, R represents an oxygen atom, a sulfur atom, —NH—, —SO—, —SO —CH C (

 15 2 2

 CH) or —C (CF) —.

 3 2 3 2

 [0079] Preferred embodiments of the partial structure of the compound having an oxetane ring applicable to the present invention include, for example, in the above general formulas (19) and (20), R is a lower alkyl group (for example,

 1

 Til group, ethyl group, propyl group, etc.) are preferred, and ethyl group is particularly preferred. R represents a hexamethylene group, or, in the above general formula (23), R represents water.

 Those which are 9 14 elemental atoms are preferably used.

 [0080] In the above general formula (21), R is an ethyl group, R and R acetyl groups, Z is oxygen or

 10 12 13

 Is preferably a hydrocarbon group that does not contain sulfur atoms.

Furthermore, an example of a preferred embodiment of the compound having an oxetane ring according to the present invention includes a compound represented by the following general formula (26).

[0082] [Chem. 14] General formula (26)

[0083] In the formula, r is an integer of 25 to 200, and R is an alkyl group having 1 to 4 carbon atoms (for example, methyl

 16

Group, ethyl group, propyl group, butyl group and the like) or a trialkylsilyl group. R, R, R and R are synonymous with the substituent represented by R to R in the general formula (14). However,

5 6 1 6

 At least one of R to R is a substituent.

 3 6

 [0084] Specific examples of the compound having a oxetane ring substituted at the 2-position according to the present invention are shown below as Exemplified Compounds 1 to 15, but the present invention is not limited thereto.

 [0085] 1: trans— 3— tert-Butyl 2-phenol-oxetane

 2: 3, 3, 4, 4-tetramethyl-2, 2 diphenyloxetane

 3: Di [3 ethyl (2-methoxy-3-oxetal)] methyl ether

 4: 1, 4 Bis (2, 3, 4, 4-tetramethyl-3 ethyloxeta-l) butane 5: 1, 4 bis (3-methyl-3 ethyloxeta-l) butane

 6: Di (3,4,4 trimethyl-3-ethyloxetanyl) methyl ether

 7: 3-((2-ethylhexyloxymethyl) -2,2,3,4-tetramethyloxetane 8: 2-(2-ethylhexyloxy) 2,3,3,4,4 pentamethylo Xetane 9: 4, 4 '—bis [(2,4 dimethyl-3 ethyl 3-oxeta) methoxy] bihue-nore

 10: 1, 7 bis (2, 3, 3, 4, 4 pentamethyloxetal) heptane)

11: Oxetanyl · Silsesquioxane

 12: 2-Methoxy 3, 3 dimethyloxetane

 13: 2, 2, 3, 3—tetramethyloxetane

 14: 2— (4-Methoxyphenol) 3, 3 Dimethyloxetane

 15: Di (2- (4-methoxyphenol) 3 methyloxetane 3yl) ether According to the present invention, the compound having an oxetane ring substituted at least at the 2-position is synthesized by referring to the following documents: be able to.

[0086] (l) Hu Xianming, Richard M. Kellogg, Synthesis, 533-538, May (19 95)

 (2) A. O. Fitton, J. Hill, D. Ejane, R. Miller, Synth., 12, 1140 (1987)

(3) Toshiro Imai and Shinya Nishida, Can.

 J. Chem. Vol. 59, 2503-2509 (1981)

(4) Nobujiro Shimizu, Shintaro Yamaoka, and Yuho Tsuno, Bull. Ch em. Soc. Jpn., 56, 3853-3854 (1983)

 (5) Walter Fisher and Cyril A. Grob, Helv. Chim. Acta., 61, 2336 (1 978)

 (6) Chem. Ber. 101, 1850 (1968)

 (7) "Heterocyclic Compounds with Three— and Four— membered Rings", Part Two, Chapter IX, Interscience Publishers, John Wiley & S ons, New York (1964)

 (8) Bull. Chem. Soc. Jpn., 61, 1653 (1988)

 (9) Pure Appl. Chem., A29 (10), 915 (1992)

 (10) Pure Appl. Chem., A30 (2 & 3), 189 (1993)

 (11) JP 6-16804 A

 (12) German Patent No. 1, 021, 858

 The content of the compound having an oxetane ring substituted at the 2-position according to the present invention in the actinic ray curable ink is preferably 1 to 97% by mass, more preferably 30 to 95% by mass.

 [0087] (Combination of oxetane compound and other monomer)

Further, the compound having an oxetane ring substituted at least at the 2-position according to the present invention may be used alone, or two kinds having different structures may be used in combination. Photopolymerizable compounds such as monomers and polymerizable monomers can be used in combination. When used in combination, it is preferable to adjust the mixing ratio so that the compound having an oxetane ring substituted at least at the 2-position is 10 to 98% by mass in the mixture, and other photopolymerizable monomers and polymerizable compounds. It preferred that the photopolymerizable I匕合of such monomers is adjusted to 2 to 90 weight ^_0/0.

 [0088] oxetane compound having a substituent only at the 3-position

 In the present invention, an oxetane compound having a substituent only at the 3-position can be preferably used in combination with the above-described oxetane compound having a substituent at the 2-position and a conventionally known oxetane compound.

Here, as an oxetane compound having a substituent only at the 3-position, for example, JP 2001 -Introduced in 220526, 2001-310937, the publicly known ones can be used.

 [0090] Examples of the compound having a substituent only at the 3-position include compounds represented by the following general formula (27).

[0091] [Chemical 15] General formula (27>

[0092] In the general formula (27), R ¹ is a hydrogen 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 aryl group, an aryl group, a furyl group, or a chael 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, a 1 probe group, a 2 probe group, a 2-methyl-1 probe group, 2 —Methyl-2-propellyl group, 1-butul group, 2-butul group, 3-butul group, etc., 2 to 6 carbon group, phenyl group, phenyl group, benzil group, fluoric benzyl group A group having an aromatic ring such as methoxybenzyl group and phenoxychetyl group, an alkylcarbol group having 2 to 6 carbon atoms such as an ethylcarbol group, a propylcarbol group, and a butylcarbol group, and an ethoxycarboro group Carbon number such as 2 to 6 carbon atoms such as propoxycarbol group, butoxycarbol group, etc., or carbon number such as ethylcarbamoyl group, propyl carbamoyl group, butylcarbamoyl group, pentylcarbamoyl group, etc. 2 to 6 N alkyl power Luba -Yl group. As the oxetane compound used in the present invention, it is particularly preferable to use a compound having one oxetane ring because it has excellent adhesiveness, low viscosity and excellent workability.

 [0093] An example of a compound having two oxetane rings includes a compound represented by the following general formula (28).

[0094] [Chemical 16] General formula (28>

In general formula (28), R ¹ is the same group as that in general formula (27). R ³ is, for example, a linear or branched poly (alkylene) such as a linear or branched alkylene group such as an ethylene group, a propylene group or a butylene group, a poly (ethyleneoxy) group or a poly (propyleneoxy) group. Oxy) group, probelene group, methyl probelene group, butylene group etc. linear or branched unsaturated hydrocarbon group, carbonyl group or carbonyl group containing alkylene group, carboxyl An alkylene group containing a group, an alkylene group containing a strong rubermoyl group, and the like.

[0096] Further, as R ³ , there can be mentioned a polyvalent group selected from the basic forces represented by the following general formulas (29), (30) and (31).

[0097] [Chemical Formula 17] General formula (29}

[0098] In the general formula (29), R ⁴ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a propyl group, or a butyl group, a methoxy group, an ethoxy group, or a propoxy group. An alkoxy group having 1 to 4 carbon atoms such as a butoxy group, a halogen atom such as a chlorine atom or a bromine atom, a nitro group, a cyano group, a mercapto group, a lower alkoxy carbo group, a carboxyl group, or a strong rubamoyl group. .

 [0099] [Chemical 18]

[0100] 一般式（30)にお!/、て、 R⁵は酸素原子、硫黄原子、メチレン基、 NH、 SO、 SO、 C 'General formula (30)

[0100] In general formula (30)! /, R ⁵ is oxygen atom, sulfur atom, methylene group, NH, SO, SO, C

 2

Represents (CF) or C (CH).

 3 2 3 2

[0101] [Chemical 19] General formula (31)

[0102] In the general formula (31), R ⁶ is an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a propyl group, or a butyl group, or an aryl group. n is an integer from 0 to 2000. R ⁷ is a methyl group, ethyl group, propyl group, butyl group alkyl group having 1 to 4 carbon atoms, or an aryl group. As R ⁷ , further, a group selected from the group represented by the following general formula (32) can be mentioned.

 [0103] [Chemical formula 20] General formula (32)

8 R ⁸

 ~ *** 0 ***** S '*** Q

 * I '}' * "m *** sj—f¾8

8 R ⁸

In the general formula (32), R ⁸ is an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a propyl group, or a butyl group, or an aryl group. m is an integer from 0 to 100.

[0105] Specific examples of the compound having two oxetane rings include the following compounds.

[0106] [Chemical 21]

Illustrative compound 1

例示化合物 2

Exemplary Compound 2

[0107] Exemplary compound 1 is a compound in which R ¹ is an ethyl group and R ³ is a carboxyl group in the general formula (28). Exemplified Compound 2 is a compound in which R ¹ is an ethyl group, R ³ is R ⁶ and R ⁷ carbyl groups in the general formula (31), and n is 1 in the general formula (28).

[0108] Among the compounds having two oxetane rings, preferred examples other than the above compounds include compounds represented by the following general formula (33). In the general formula (33), R ¹ has the same meaning as R ¹ in the general formula (27).

 [0109] [Chemical 22]

—Formula 3>

[0110] Further, an example of the compound having 3 to 4 oxetane rings includes a compound represented by the following general formula (34).

[0111] [Chemical formula 23] General formula (34)

[0112] In the general formula (34), R ¹ has the same meaning as R ¹ in the general formula (27). As R ⁹ For example, a branched alkylene group having 1 to 12 carbon atoms such as a group represented by the following AC, a branched poly (alkyleneoxy) group such as a group represented by the following D, or a group represented by the following E or the like Examples thereof include a branched polyoxy group. j is 3 or 4.

[0113] [Chemical 24]

A

 C

— CH ₂ — CH ₂ — CH— CH ₂ — CH— CH, — CH,-

D

"† CH ₂ CH ₂ 0 CH ₂ — C-CH ₂ CH ₃

CH ₂ OCH ₂ CH, H ~

[0114] In A, R ^1U represents a lower alkyl group such as a methyl group, an ethyl group, or a propyl group. In D above, p is an integer of 1 10.

[0115] As an example of a compound having 4 oxetane rings, Exemplified Compound 3 may be mentioned.

[0116] [Chemical Formula 25] Exemplified Compound 3

0 ノ Si-Oj— Si [0117] Further, examples of the compound having 1 to 4 oxetane rings other than those described above include compounds represented by the following general formula (35).

[0118] [Chemical formula 26] General formula (35}

In the general formula (35), R ° has the same meaning as R ° in the general formula (32). R ¹¹ is an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a propyl group or a butyl group, or a trialkylsilyl group, and r is 1 to 4.

 [0120] Preferable specific examples of the oxetane compound according to the present invention include exemplified compounds 4, 5, and 6 shown below.

[0121] [Chemical 27] Exemplified Compound 4

Exemplary Compound 5

上述したォキセタン環を有する各化合物の製造方法は、特に限定されず、従来知 られた方法に従えばよぐ例えば、パティソン（D. B. Pattison, J. Am. Chem. Soc . , 3455, 79 (1957) )が開示している、ジオールからのォキセタン環合成法等があ る。また、これら以外にも、分子量 1000〜5000程度の高分子量を有する 1〜4個の ォキセタン環を有する化合物も挙げられる。これらの具体的化合物例としては、以下 の例示化合物 7、 8、 9が挙げられる。 Exemplary Compound 6

The method for producing each compound having an oxetane ring described above is not particularly limited, and may be performed according to a conventionally known method. For example, Pattyson (DB Pattison, J. Am. Chem. Soc , 3455, 79 (1957)), etc., for the synthesis of oxetane rings from diols. Besides these, compounds having 1 to 4 oxetane rings having a high molecular weight of about 1000 to 5000 are also exemplified. Specific examples of these compounds include the following exemplified compounds 7, 8, and 9.

[0123] [Chemical 28] Exemplified Compound 7

 : 20 ~ 200

[0124] In the actinic ray curable composition of the present invention, an epoxy compound can be used as the cationic polymerizable monomer.

 [0125] As an epoxy compound applicable to the present invention, both a monomer of an epoxy group-containing compound and an oligomer thereof can be used. Specific examples include conventionally known aromatic epoxy compounds, alicyclic epoxy compounds, and aliphatic epoxy compounds. Hereinafter, the epoxy compound means a monomer or an oligomer thereof. As the oligomer in the present invention, an oligomer having a molecular weight of less than 1000, which is preferably a low molecular weight compound, is more preferable.

[0126] A preferable aromatic epoxy compound is a di- or polyglycidyl produced by the reaction of a polyhydric phenol having at least one aromatic nucleus or an alkylene oxide adduct thereof with epichlorohydrin. Ether, for example, bisphenol Alternatively, di- or polyglycidyl ethers of the alkylene oxide adducts, di- or polyglycidyl ethers of hydrogenated bisphenol A or alkylene oxide adducts, and novolak-type epoxy resins. Here, examples of the alkylene oxide include ethylene oxide and propylene oxide.

 [0127] In the actinic ray curable composition of the present invention, at least one of the cationically polymerizable monomers is particularly preferably an alicyclic epoxy compound.

 [0128] As the alicyclic epoxy compound, at least one compound having a cycloalkane ring such as cyclohexene or cyclopentene ring is epoxidized with an appropriate oxidizing agent such as hydrogen peroxide or peracid. Specific examples of preferred cyclohexene oxide or cyclopentene oxide-containing compounds obtained by the above include the following compounds.

 [0129] Preferred examples of the aliphatic epoxy compound include dihydric polyglycidyl ethers of aliphatic polyhydric alcohols or alkylene oxide adducts, and typical examples thereof include diglycidyl ether of ethylene glycol, Polyglycerides such as diglycidyl ether of propylene glycol or diglycidyl ether of alkylene glycol such as diglycidyl ether of 1,6-hexanediol, di- or triglycidyl ether of glycerin or its alkylene oxide cage Polyglycidyl ether of alcohol, diglycidyl ether of polyethylene glycol or its alkylene oxide-attached case, polypropylene glycol or diglycidyl ether of its case containing alkylene oxide Diglycidyl ethers of sharpness glycol or the like can be mentioned, et al are. Here, examples of the alkylene oxide include ethylene oxide and propylene oxide.

[0130] Furthermore, in addition to these compounds, monoglycidyl ethers of higher aliphatic alcohols and phenols, monoglycidyl ethers of cresol, etc., which are monomers having one oxosilane ring in the molecule, may be used. it can. Of these epoxy compounds, aromatic epoxy compounds and alicyclic epoxy compounds are preferred in view of fast curing properties. Particularly preferred are alicyclic epoxy compounds. In the present invention, one of the above epoxy compounds may be used alone, or two or more may be used in appropriate combination. [0131] Specific examples of alicyclic epoxy compounds that can be preferably used in the present invention are listed below.

[0132] [Chemical 29]

[0133] [Chemical 30]

[τε ^] ίηι

99CSZC / 900Zdf / X3d 1-8 £ L £ 80 / L00Z OAV

[0135] The addition amount of the alicyclic epoxy compound is preferably 10 to 80% by mass. If the amount added is less than 10% by mass, the curability will change significantly depending on the curing environment (temperature, humidity). On the other hand, if it exceeds 80% by mass, the film properties after curing are weak and unusable. In the present invention, one type of alicyclic epoxy compound may be used alone, or two or more types may be used in appropriate combination!

[0136] These alicyclic epoxy compounds may be produced by any method. For example, Maruzen KK Published, Fourth Edition Laboratory Chemistry Course 20 Organic Synthesis II, 213-, 1992, Ed. By Alfred

Hasfner, The cnemistry oi cyclic compounds-Small Ring Heterocycles part 3 Oxiranes, John & Wiley and Sons, An Interscience Publication, New York, 1985, Yoshimura, Adhesion, 29-12, 32, 1985, Yoshimura, Adhesion卷 5, 42, 1986, Yoshimura, Adhesion, 30-7, 42, 1986, JP-A-11-100378, Patent 2906245, Patent 2926262, etc.

 [0137] The actinic ray curable composition of the present invention may contain an epoxy fatty acid ester or an epoxy fatty acid glyceride as an epoxy compound.

 [0138] Safety of AMES and sensitization, skin irritation, odor, etc. by using epoxy fatty acid ester or epoxy fatty acid glyceride in combination with oxetane compound Z cycloaliphatic epoxy compound system The curing environment (temperature, humidity) which is preferable from the viewpoint of environment can solve the problems of conventional strength such as generation of wrinkles due to curing shrinkage and poor curability / discharge properties.

 [0139] The epoxy fatty acid ester and epoxidized fatty acid glyceride that can be used in the present invention are not particularly limited as long as an epoxy group is introduced into the fatty acid ester or fatty acid dalyceride.

 [0140] The epoxy fatty acid ester is produced by epoxidizing an oleic acid ester, and therefore, methyl epoxy stearate, ptyl epoxy stearate, octyl epoxy stearate and the like are used. Similarly, epoxy fatty acid glyceride is produced by epoxidizing soybean oil, linseed oil, castor oil, etc., and epoxidized soybean oil, epoxidized linseed oil, epoxidized castor oil, etc. Used.

 [0141] Furthermore, in the present invention, a bull etheric compound can be used as the cationic polymerizable monomer, and a cyclic bull etheric compound is preferable.

[0142] Examples of the burether compound include ethylene glycol dibule ether, diethyleneglycolinoresininoreatenore, triethyleneglycolinoresininoreatenore, propylene glycol divininoleether, dipropyleneglycol divininoleether. , Butanolinoresininoreethenole, hexanediol divinyl ether, cyclohexane Di- or tri-butyl ether compounds such as dimethanol divinyl ether and trimethylolpropane trivinyl ether, ethyl vinyl ether, _n -butyl vinyl ether, isobutyl vinyl ether, octadecyl vinyl ether, cyclohexyl vinyl ether, hydroxybutynole vinylino Tenoré, 2-Ethinorehexinolevinoleateol, Cyclohexanedimethanol monovinyl ether, n-Propyl vinyl ether, Isopropyl vinyl ether, Isopropyl ether o Propylene carbonate, Dodecyl vinyl ether, Diethylene glycol monobutyl ether, Octadecyl vinyl ether And monobuyl ether compounds such as

 [0143] Among these vinyl ether compounds, in consideration of curability, adhesion, and surface hardness, di- or trivinyl ether compounds are preferred, and dibuty ether compounds are particularly preferred. In the present invention, one of the above vinyl ether compounds may be used alone, or two or more may be used in appropriate combination.

 [0144] The actinic ray curable ink of the present invention (hereinafter also simply referred to as ink) preferably contains a pigment as a coloring material together with the actinic ray curable composition of the present invention. The pigments that can be preferably used in the present invention are listed below.

 [0145] C. I Pigment Yellow—1, 3, 12, 13, 14, 17, 42, 74, 81, 83, 87, 93, 95, 109, 120, 128, 138, 139, 151, 166, 180 , 185,

 C. I Pigment Orange— 16, 36, 38,

 C. I Pigment Red—5, 22, 38, 48: 1, 48: 2, 48: 4, 49: 1, 53: 1, 57: 1, 63: 1, 101, 122, 144, 146, 177 , 185,

 c. I Pigment Violet—19, 23,

 c. I Pigment Blue—15: 1, 15: 3, 15: 4, 18, 60, 27, 29,

 c. I Pigment Green—7, 36,

 c. I Pigment White—6, 18, 21,

 c. I Pigment Black—7,

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. As a dispersion medium, light From the viewpoint of dispersion suitability, it is preferable to select a polymerizable compound, and among them, a monomer having the lowest viscosity.

 [0146] For the dispersion of the pigment, it is preferable that the average particle diameter of the pigment particles is 0.08 to 0.5 μm. The maximum particle diameter is 0.3 to: LO / zm, preferably 0.3. It is preferable that the selection of the pigment, the dispersant and the dispersion medium, the dispersion conditions and the filtration conditions are appropriately set so as to be ˜3 m. By managing the particle size in a predetermined range as described above, clogging of the head nozzle can be suppressed, and ink storage stability, ink transparency, and curing sensitivity can be maintained.

 [0147] In the actinic ray curable ink of the present invention, the colorant concentration is preferably 1% by mass to 10% by mass of the whole ink.

 [0148] As the pigment dispersant, one having a basic anchor portion is preferably used, and a polymer dispersant having a comb structure is more preferably used.

 [0149] Specific examples of the pigment dispersant that can be used in the present invention include Solus Nose 9000, 17000, 18000, 19000, 20000, 24000SC, 2400 0GR, 28000 manufactured by Avecia. 32000, Ajinomoto Fine Technone made by Ajisuno PB821, PB 822, Enomoto Kasei's PLAAD ED214, ED251, DISPARLON DA-325, DA-234, EFKA EFKA-5207, 5244, 6220, 6225, etc. In addition, pigment derivatives (synergists) can be used in combination with pigment dispersants. Specific examples of pigment derivatives include Solvex 5000, 12000, 22 000 from Avecia, EFKA-6746 from EFKA, 6750 etc. are mentioned.

 [0150] As the recording material that can be used in the present invention, in addition to ordinary uncoated paper, coated paper, and the like, various non-absorbable plastics used in so-called flexible packaging and films thereof can be used. Examples of films include polyethylene terephthalate (PET) film, stretched polystyrene (OPS) film, stretched polypropylene (OPP) film, stretched nylon (ONy) film, polychlorinated butyl (PVC) film, polyethylene (PE). Examples thereof include a film and a triacetyl cellulose (TAC) film. Other plastics that can be used include polycarbonate, acrylic resin, ABS, polyacetal, PV A, and rubbers. Moreover, it is applicable also to metals and glass.

[0151] In the present invention, the cost of recording materials such as packaging costs and production costs, and the production of prints It is more advantageous to use a long (web) recording material in terms of efficiency and compatibility with various size prints.

 [0152] Next, the image forming method of the present invention will be described.

 In the image forming method of the present invention, the actinic ray curable ink of the present invention is ejected and drawn on a recording material by an inkjet recording method, and then the ink is cured by irradiating active rays such as ultraviolet rays. U, which is the preferred method.

 [0154] (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 25 μm. In the actinic ray curable ink jet recording in the screen printing field, the total ink film thickness is currently over 25 m. The force recording material is thin and is often a plastic material. In addition to curling of the recorded material, it is not only a problem of wrinkles, but also the strain of the entire printed matter. V If there is a problem with the texture, it is preferable to eject ink with an excessive film thickness.

 [0155] Here, "total ink film thickness" means the maximum value of the film thickness of ink drawn on the recording material, and even for a single color, other two color layers (secondary colors) or 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.

 [0156] (Ink ejection conditions)

 As the ink discharge conditions, it is preferable from the viewpoint of discharge stability that the ink jet recording head and the actinic ray curable 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. It is necessary to keep it constant. The control range of the ink temperature is set temperature ± 5 ° C, preferably set temperature ± 2 ° C, more preferably set temperature ± 1 ° C. In the present invention, the amount of liquid droplets discharged from each nozzle is preferably 2 to 15 pl.

 [0157] (Light irradiation condition after ink landing)

In the image forming method of the present invention, it is preferable that the actinic ray is applied for a period of 0.001 seconds to 1.0 seconds after the ink landing as the actinic ray 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.

[0158] In the image forming method of the present invention, light irradiation is performed after the ink composition is adhered to the recording material. The light irradiation may be visible light irradiation or ultraviolet irradiation, and ultraviolet irradiation is particularly preferable. In the case of ultraviolet irradiation, the ultraviolet irradiation amount is lOOmjZcm ² or more, preferably 500 miZcm ² or more, and is 10, OOOiujZcm ² or less, preferably <5, OOOmj / cm ² or less. If the irradiation amount of ultraviolet rays is within an effective range, the curing reaction can be sufficiently carried out, and the colorant can be prevented from fading due to the irradiation of ultraviolet rays, which is advantageous. Examples of the ultraviolet irradiation include metal lamps, xenon lamps, carbon arc lamps, chemical lamps, low pressure mercury lamps, and high pressure mercury lamps. For example, it is possible to use a commercially available H lamp, D lamp, V lamp, etc. manufactured by Fusion System.

 [0159] Metal halide lamps have a continuous spectrum compared to high-pressure mercury lamps (main wavelength is 365 nm), have high luminous efficiency in the range of 200 to 450 nm and abundant in the long wavelength range. Therefore, use a pigment like the actinic ray curable composition of the present invention! If you want to speak, use a metal ride lamp.

 [0160] 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 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. In US Pat. No. 6,145,979, there is a method using an optical fiber as an irradiation method, or a method in which a collimated light source is applied to a mirror surface provided on the side of a head unit to irradiate a recording unit with UV light. It is disclosed. Any of these irradiation methods can be used in the image forming method of the present invention.

[0161] In addition, irradiation with actinic rays is divided into two stages. First, actinic rays are irradiated in the above-described manner within 0.001 to 2 seconds after ink landing, and after all printing is completed, actinic rays are further irradiated. The method is also a preferred embodiment. By dividing the irradiation with actinic rays into two stages, it is possible to further suppress the shrinkage of the recording material that occurs during ink hardening. [0162] Conventionally, in an ultraviolet curable ink jet method, a light source with high illuminance in which the total power consumption of the light source exceeds lkW'hr is usually used to suppress dot spread and bleeding after ink landing. It was. However, when these light sources are used, the shrinkage of the recording material is so large that it cannot be used practically, especially for printing on shrink labels.

 [0163] In the present invention, it is preferable to use an actinic ray having the highest illuminance in the wavelength region of 254 nm. Even when a light source having a total power consumption of lkW'hr or more is used, a high-definition image can be formed and recorded. The shrinkage of the material is also within a practically acceptable level.

[0164] In the present invention, it is preferable that the total power consumption of the light source for irradiating active light is less than lkW'hr. Examples of light sources with a total power consumption of less than lkW'hr include, but are not limited to, fluorescent tubes, cold cathode tubes, hot cathode tubes, and LEDs.

Next, an ink jet recording apparatus (hereinafter simply referred to as a recording apparatus) applicable to the image forming method of the present invention will be described.

Hereinafter, the recording apparatus will be described with reference to the drawings as appropriate. Note that the recording apparatus in the drawing 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 an example of a main part configuration of an ink jet recording apparatus applicable to the present invention. The ink jet recording apparatus 1 includes a head carriage 2, a recording head 3, an irradiation unit 4, a platen unit 5, and the like. In the ink jet recording apparatus 1, a platen unit 5 is installed under a recording material P. The platen unit 5 has a function of absorbing ultraviolet rays, and absorbs excess ultraviolet rays that have passed through the recording material P. As a result, high-definition images can be reproduced very stably.

 [0168] 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). A 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.

[0169] The head carriage 2 is installed on the upper side of the recording material P, and a plurality of inkjet recording heads 3 to be described later are arranged on the recording material P according to the number of colors used for image printing, and the discharge ports are arranged on the lower side. Place and store. The head carriage 2 is installed in 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) ink jet recording heads 3 are drawn. However, in practice, the ink jet recording heads 3 stored in the head carriage 2 are used. The number of colors is determined as appropriate.

 [0171] The recording head 3 is operated by an ejection unit (not shown) provided with a plurality of actinic ray curable inks (for example, UV ink) supplied by an ink supply unit (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 is a monomer that acts as a catalyst when the initiator is irradiated with ultraviolet rays. It has the property of being cured by crosslinking and polymerization reactions.

 [0172] 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. 1 by driving the head scanning means. UV ink is ejected as ink droplets onto the possible area), and ink droplets are landed on the landable area.

 [0173] The above scanning is performed as many times as necessary, and after UV ink is discharged toward one landable area, the recording material P is appropriately moved in the forward direction in FIG. 1 by the transport means, and head scanning is performed again. While performing scanning by means, the recording head 3 discharges UV ink to the next landable area adjacent in the rear direction in FIG.

 An image is formed on the recording material P by repeating the above-described operation and discharging UV ink from the recording head 3 in conjunction with the head scanning unit and the conveying unit.

The irradiating 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, as an ultraviolet lamp, a mercury lamp, a metal nitride lamp, an excimer laser, UV laser, cold cathode tube, hot cathode tube, black light, LED (Light Emitting Diode), etc. can be applied, and strip metal halide lamp, cold cathode tube, hot cathode tube, mercury lamp or black light are preferred. In particular, a low-pressure mercury lamp, a hot cathode tube, a cold cathode tube, and a germicidal lamp that emit ultraviolet light having a wavelength of 254 nm are preferable because they can prevent bleeding and control the dot diameter efficiently. By using black light as the radiation source of the irradiation means 4, the irradiation means 4 for curing the UV ink can be produced at low cost.

 [0176] 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 one scan by driving 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 fixed substantially parallel to the recording material P.

 [0178] 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. It is effective to increase the distance h2 between the ink ejection part 31 and the recording material P in Fig. 3 (hl <h2), or to increase the distance d between the recording head 3 and the irradiation means 4 (d is increased). is there. Further, it is more preferable that the space between the recording head 3 and the irradiation means 4 is a bellows structure 7.

 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.

 [0180] The actinic ray curable ink of the present invention can also form an image using a line head type recording apparatus.

 FIG. 2 is a top view showing another example of the main configuration 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 ink jet recording heads 3 of each color are fixedly arranged on the head carriage 2 so as to cover the entire width of the recording material P. ing.

[0182] On the other hand, on the downstream side of the head carriage 2, there is provided an irradiating means 4 arranged so as to cover the entire width of the recording material P and to cover the entire area of the ink printing surface. . The ultraviolet lamp used for the illumination means 4 can be the same as described in FIG. In this line head system, the head carriage 2 and the irradiating means 4 are fixed, and only the recording material P is transported, and ink ejection and curing are performed to form an image. In the present invention, the recording material P is preferably heated to 35 to 60 ° C.

 Example

 Examples of the present invention will be specifically described below, but the embodiments of the present invention are not limited to these examples.

[0185] Example 1

 << Production of actinic ray curable composition >>

 [Preparation of each pigment dispersion]

 5 parts by weight of a dispersant (PB822 Ajinomoto Fine Technone Earth) and each photopolymerizable compound listed in Table 1 and Table 2 are placed in a stainless steel beaker and heated on a hot plate at 65 ° C. Stir and mix for 1 hour to dissolve. Next, after adding the following color pigments to this solution, place it in a plastic bottle with 200 g of 1 mm diameter zirconia beads, seal tightly, disperse with a paint shaker for 2 hours, remove the zirconia beads, and disperse the black pigment. Liquid, cyan pigment dispersion, magenta pigment dispersion and yellow pigment dispersion were prepared.

 [0186] Black pigment: C. I. Pigment Black 7 (Mitsubishi Chemical Corporation, # 52)

 Cyan Pigment: C. I. Pigment Blue 15: 4 (Sanyo Dye, Shean Blue 4044) Magenta Pigment: C. I. Pigment Red 122 (Dai-Ni Seika, Custom)

 Yellow pigment: C. I. Pigment Yellow 150 (LANXESS¾: ¾, E4GN-GTCH 20003)

 [Preparation of each ink composition set]

Next, each pigment dispersion prepared above and various additives such as each photopolymerization initiator, acid proliferating agent, basic compound, and surfactant are added in the combinations shown in Tables 1 and 2, and this is added. In order to prevent printer clogging, it is filtered with a 0.8 μm membrane filter, and K, C, M, Y (more dark ink), and Lk, Lc, Lm, Ly (more light color ink) forces are also configured. Ink composition sets 1-19 were prepared. The pigment concentration of light color (Lk, Lc, Lm, Ly) was 1Z5. [0187] Table 1 shows the compositions of ink composition sets 1 to 3, which are radical polymerization type actinic radiation curable compositions (hereinafter also referred to as curable compositions), and Table 2 shows cationic polymerization types. The compositions of ink composition sets 4 to 19, which are curing compositions of Table 3 shows the characteristics of the acrylic polymer used. The viscosity of the acrylic polymer was measured as a viscosity at 25 ° C and a shear rate of lOOOOlZs. In addition, the numerical values described in Table 1 and Table 2 represent parts by mass of each additive.

[0188] Details of items described in symbols in Tables 1 and 2 are as follows.

[0189] * 1: Tetraethylene glycol ditalylate

 * 2: ε-force prolatatam modified dipentaerythritol hexaatalylate

 * 3: Fuenoki Shechinoretale Metalate

 * 4: Compound with oxetane ring

 * 5: Bull ether compound

 * 6: Triisopropanolamine

[0190] [Table 1]

^

s] ^ [2w019

Acrylic polymer Viscosity (25 ° C) Tg

 Molecular weight

 (mPa-s) (° c)

 UP -1010 1600 400 One 71

 UP -1021 1700 4500 -31

 UP -1041 1800 30000 -25

 UH-2130 5000 35000 -40

 UMB-1001 1500 300 ―

 UC-3000 8000 Solid 25

[0193] Details of the additives described in abbreviations in Tables 1 and 2 are as follows.

[0194] OXT101: Toagosei, monofunctional

 OXT212: Toagosei Co., Ltd., monofunctional

 OXT213: Toagosei Co., Ltd., monofunctional

 OXT221: Toagosei Co., Ltd., bifunctional

 DVE-3: Triethylene glycol dibulle ether (ISP)

 S2021P: Celoxide 2021P, manufactured by Daicel Chemical Industries, bifunctional

 S3000: Celoxide 3000, manufactured by Daicel Chemical Industries, bifunctional

 EP-2: Exemplary compound EP-2

 UVI6992: Dow Chemical Company Propion Carbonate 50% solution

 1-184: Irgacure 184, Ciba Specialty Chemicals

 1-250: Inore Gacure 250, Ciba Special Society, Chemicals

 CI5102: Made by Nippon Soda Co., Ltd.

 S— 2: Exemplary compound S— 2

 KF—351: Silicone oil, manufactured by Shin-Etsu Chemical Co., Ltd.

 DBA: 9, 10, dibutoxyanthracene

 << Inkjet image forming method >>

The ink jet recording apparatus provided with the piezo-type ink jet nozzle and having the constitutional power shown in FIG. 1 is loaded with each color ink of each of the ink composition sets prepared above, to a long recording material having a width of 600 mm and a length of 20 m. Images were recorded continuously. The ink supply system consists of an ink tank, supply pipe, front chamber ink tank just before the head, pipe with filter, and piezo head. The front chamber tank force was also insulated to the head and heated to 50 ° C. In addition, the head part is heated according to the viscosity of each ink composition set, and multi-size dots with a drop volume of 2 to 15 pl are set to 720 X 720 dpi (1 dpi, that is, 2.5 dots per dot). The ink of each color composing each ink composition set described above was continuously ejected. The recording material was heated to 40 ° C with a surface heater. After landing, a hot-cathode tube on both sides of the carriage (custom-made by Toppo) with a 200W power source, irradiating 180mWZcm ² and curing instantly (less than 0.5 seconds after landing) It was. When the total ink film thickness was measured after image recording, it was in the range of 2 to 60 / ζ πι. The ink jet image was formed by printing on a synthetic paper “UPO FGS” manufactured by UPPO CORPORATION as a recording material in an environment of 30 ° C. and 80% RH according to the above method.

 [0195] The illuminance of each irradiation light source was measured by using UVPF-A1 manufactured by Iwasaki Electric Co., Ltd., and the integrated illuminance at 254 nm was measured.

 [0196] <Evaluation of formed image>

 The physical properties of the obtained cured product (formed image) were evaluated according to the methods shown below. Each evaluation was determined by an average value of each characteristic of an image formed with each color ink.

 [0197] [Measurement of curing sensitivity]

After applying each color ink constituting each ink composition set to a synthetic paper to a film thickness of 3 m, irradiating with ultraviolet rays with varying light quantity, and after irradiation, rubbing the cured film with a nail to remove the film. The minimum irradiation energy (mjZcm ² ) that causes this was measured, the average value of each color ink was determined, and this was used as a measure of curing sensitivity. The smaller the value, the higher the curing sensitivity.

 [0198] [Evaluation of flexibility]

Each color ink is printed on synthetic paper (Synthetic paper YUPO FGS made by YUPO Corporation) so that the film thickness is 40 μm, and hot cathode tube (custom product made by NIPPO) 200W power supply, 180m A light amount of WZcm ² was irradiated 0.1 seconds after landing to obtain a cured image. The obtained cured image was wound around a rod of each size of 1 to 10πιπιφ according to the method of JIS K 5600 flexural evaluation, and the occurrence of cracks was visually observed. Flexibility was determined using the smallest diameter that would not cause cracking, and this was used as a measure of flexibility. The smaller the value, the better the flexibility. [0199] [Evaluation of adhesion]

 The cross-cut tape peel residual adhesion amount test was performed on the image created by the above image forming method according to a method in accordance with JIS K 5400.

[0200] In each image film, 11 blades with a single-blade force razor were cut at an angle of 90 ° with respect to the surface at intervals of lmm vertically and horizontally, and 100 lmm square grids were produced. Next, after sticking adhesive tape (Scotch # 250, manufactured by Sumitomo SLEM) on the cured film surface with a grid pattern, it was pressed once with a 2kg mouth roller, and then peeled off at once. The peeled state was visually observed, and adhesion was evaluated according to the following criteria.

[0201] 5: No peeling of film is observed

 4: Slight peeling is observed, but almost good adhesion

 3: Force at which peeling is observed in some films Practically acceptable range

 2: Clear film peeling has occurred, and this is a quality that is a practical problem.

 1: All the film is peeled off, it can not be put into practical use!

 [Evaluation of odor resistance]

 Images cured in accordance with the above image forming method are allowed to stand in an environment of 23 ° C and 55% RH for 1 hour after curing. Was evaluated.

[0202] 5: No odor is observed

 4: The ability to feel a slight odor Almost good odor resistance

 3: Slight odor is observed, but within the practically acceptable range

 2: Obvious odor is recognized, and this is a practical problem.

 1: Strong, odor is recognized, is a characteristic that can not withstand practical use

 [Evaluation of ejection stability]

 In accordance with the above image forming method, after 30 minutes of continuous ejection, the ink ejection state and the presence or absence of ink shortage were visually observed, and ejection stability was evaluated according to the following criteria.

[0203] 5: Good output without nozzle missing

 4: Force at which nozzle missing occurs in a small part

3: The power with which the occurrence of missing nozzles is recognized in some areas It is not a level that affects image quality! / ヽ 2: For many nozzles, nozzle missing and oblique emission are observed, and this is a level effect that affects image quality.

 1 No more than 50% of nozzles are missing, which is not practical! Table 4 shows the results obtained as above.

[Table 4]

表 4に記載の結果より明らかなように、本発明で規定する構成力もなる活性光線硬 化型組成物を用いたインクにより構成したインク組成物セットは、比較例に対し、硬化 感度が高ぐ吐出安定性に優れ、形成した画像の臭気耐性、密着性、柔軟性に優れ ていることが分かる。

As is clear from the results shown in Table 4, the ink composition set composed of the ink using the actinic ray curable composition having the constitutional power defined in the present invention has higher curing sensitivity than the comparative example. It can be seen that the discharge stability is excellent, and the formed image is excellent in odor resistance, adhesion, and flexibility.

Claims

The scope of the claims  [1] In an actinic ray curable composition containing a photopolymerization initiator and a photopolymerizable compound, the photopolymerizable compound is a radical polymerizable monomer and contains an acrylic polymer. An actinic ray curable composition characterized by the above.  [2] In an actinic ray curable composition containing a photopolymerization initiator and a photopolymerizable compound, the photopolymerizable polymer is a cationic polymerizable monomer and contains an acrylic polymer. An actinic ray curable composition characterized by the above. [3] The actinic ray curable composition according to [1] or [2], wherein the acrylic polymer has a molecular weight force of 100 or more and less than 10,000. [4] The activity according to any one of claims 1 to 3, wherein the viscosity of the acrylic polymer at 25 ° C is not less than lOmPa's and less than lOOOOmPa's. A light curable composition.  [5] The active ray curable type according to any one of claims 1 to 4, wherein the acrylic polymer has a glass transition temperature of 130 ° C or higher and 10 ° C or lower. Composition.  [6] The photopolymerization initiator is an iodine salt photoacid generator having an iodonium salt or sulfo-um salt power, and contains 1 to 10% by mass of the photopolymerization initiator. 6. The actinic ray curable composition according to any one of claims 2 to 5, wherein the composition is an actinic ray curable composition.  [7] The actinic ray curable composition according to any one of claims 2 to 6, wherein the composition is an alicyclic epoxy compound of at least one kind of the cationic polymerizable monomer object.  [8] The actinic ray curable composition according to any one of claims 2 to 7, wherein the cation polymerizable monomer is a compound having at least one kind of oxetane ring. . [9] The actinic ray curable composition according to any one of claims 2 to 8, wherein the cationic polymerizable monomer is at least one kind of cyclic vinyl ether compound. object. [10] The actinic ray curable composition according to any one of claims 1 to 9, wherein the addition power of the acrylic polymer is 0.1% by mass or more and 30% by mass or less. object.  [11] The actinic ray curable composition according to claim 7, wherein an addition amount of the alicyclic epoxy compound is 10% by mass or more and 80% by mass or less.  [12] An actinic ray curable ink comprising the actinic ray curable composition according to any one of [1] to [11].  [13] The actinic ray curable ink according to item 12, wherein the viscosity at 25 ° C is not less than ImPa's and less than 50 mPa's.  [14] An image forming method in which the actinic ray curable ink according to claim 12 or 13 is jetted onto a recording material from an ink jet recording head, and printing is performed on the recording material. An image forming method comprising irradiating actinic rays for 0.001 to 1.0 seconds after landing of the actinic ray curable ink.  [15] An image forming method in which the actinic ray curable ink according to claim 12 or 13 is jetted onto a recording material from an inkjet recording head, and printing is performed on the recording material. An image forming method, wherein a minimum ink droplet volume force ejected from each nozzle of the ink jet recording head is 2 pl or more and 15 pl or less.