JP2012077159A - Ink composition, printed matter and production method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink composition which is good in ink extrusion stability and blocking controllability and is cured to give an image good in punching characteristics.SOLUTION: The ink composition comprises at least one polymer of polythiourethanes, polyurethanes and polyureas, each having thiol structures at both the ends of a main chain, a polymerizable monomer and a polymerization initiator.

Description

  The present invention relates to an ink composition, a printed matter, and a method for producing the same.

  As an image recording method for forming an image on a recording medium such as paper based on an image data signal, there are an electrophotographic method, a sublimation type and a melt type thermal transfer method, an ink jet method and the like. Among these, the ink jet method can be implemented with an inexpensive apparatus, and the ink can be efficiently used because the image is directly formed on the recording medium by ejecting the ink only to the required image portion. Running cost is low.

  The ink jet method can print not only on plain paper but also on non-water-absorbing recording media such as plastic sheets and metal plates. In the ink jet method, the time required for drying and curing of the droplets after printing has an effect on speeding up and high image quality such as productivity of printed matter or sharpness of a printed image.

  As one of the ink jet methods, there is a recording method using an ink that can be cured by irradiation with an active energy ray such as UV light. According to this method, by irradiating energy rays immediately after ink ejection or after a certain period of time and curing the ink droplets, the productivity of printing can be improved and a sharp image can be formed. Can be improved.

  As such an active energy ray-curable ink, for example, Patent Document 1 discloses an acrylic polymer, a polymerizable compound, a photopolymerization initiator, and the like that include a thiol group and a partial structure such as a fluorine-substituted hydrocarbon in the side chain. Ink compositions containing the same have been proposed. The ink composition of Patent Document 1 has excellent ink ejection stability, and is also excellent in terms of suppressing set-off (blocking) that occurs when a plurality of recorded sheets are stacked.

JP 2010-14375 A

  By the way, when manufacturing a molded product of a plastic printed product typified by a dummy can or a blister pack, an image is printed on a recording medium such as plastic, and after molding, a part or all of the molded product is quickly A punching process may be performed. When the punching is performed, a crack (peripheral crack) of the image may occur in the cut surface or the periphery thereof. When such cracks occur, the product value is lowered, and therefore, a good punching characteristic that can withstand punching is also required.

Therefore, this invention makes it a subject to achieve the following objectives.
That is, the object of the present invention is good ink ejection stability and blocking suppression (particularly, blocking sensitivity, which is a sensitivity necessary for preventing blocking), and excellent punching characteristics of an image obtained by curing. An ink composition, a printed matter obtained using the ink composition, and a method for producing the same.

  The present inventor has intensively studied in view of the above problems. As a result, it has been found that the above-mentioned problems can be solved by using an ink composition containing a specific polymer or the like, and the present invention has been completed. That is, the present invention relates to the following ink composition, a printed matter obtained using the ink composition, and a method for producing the same.

Item 1. An ink composition comprising (i) at least one polymer of a polythiourethane having a thiol structure at both ends of the main chain, polyurethane and polyurea, (ii) a polymerizable monomer, and (iii) a polymerization initiator.
Item 2. Item 2. The ink composition according to Item 1, wherein the thiol structure is a secondary thiol.
Item 3. Item 3. The ink composition according to Item 1 or 2, wherein the main chain skeleton of the polymer has a ring structure.
Item 4. Item 4. The ink composition according to any one of Items 1 to 3, wherein the polymer has a weight average molecular weight of 2000 to 200,000.
Item 5. Item 5. The ink composition according to any one of Items 1 to 4, wherein the polymerizable monomer contains a monofunctional monomer, and the proportion of the monofunctional monomer contained in the polymerizable monomer is 80% by mass or more.
Item 6. Item 6. The ink composition according to any one of Items 1 to 5, wherein the content of the polymerizable monomer in the ink composition is 50% by mass or more.
Item 7. Item 7. The ink composition according to any one of Items 1 to 6, further comprising a colorant.
Item 8. Item 8. The ink composition according to any one of Items 1 to 7, which is for inkjet.
Item 9. A step of forming an image by ejecting the ink composition according to any one of Items 1 to 8 on a recording medium by an inkjet method, and irradiating the obtained image with active energy rays, whereby the recording is performed. Obtaining a printed matter having an image cured on the medium, and a method for producing the printed matter.
Item 10. Item 10. A print obtained by the production method according to Item 9.

  ADVANTAGE OF THE INVENTION According to this invention, the ink composition suitable for the inkjet recording use which is excellent in the discharge stability and blocking sensitivity of an ink, and is excellent in the punching characteristic of the image obtained can be provided.

It is the wooden type | mold used for the punching characteristic evaluation of the printed matter of this invention.

1. Ink composition The ink composition of the present invention comprises (i) at least one polymer of polythiourethane having a thiol structure at both ends of the main chain, polyurethane and polyurea, (ii) a polymerizable monomer, and (iii) polymerization. Contains an initiator. These will be described below.
<Polythiourethane, polyurethane or polyurea having a thiol structure at both ends of the main chain>
The polythiourethane, polyurethane or polyurea contained in the ink composition of the present invention has thiol structures at both ends of the main chain of the polymer (“thiol-terminated polythiourethane”, “thiol-terminated polyurethane”, “thiol”, respectively). Abbreviated as "terminal polyurea" and collectively referred to as "thiol-terminated polymer").
The thiol structure at both ends of the main chain of the thiol-terminated polymer in the present invention may be any one having functional groups represented by —SH groups.
The thiol structure in the present invention may be bonded to the terminal in a form having any structure of, for example, a primary thiol structure, a secondary thiol structure and a tertiary thiol structure. A tertiary thiol structure, more preferably a secondary thiol structure. Thereby, it is excellent in storage stability.
The primary thiol structure is represented by —R—CH ₂ —SH group or the like. For example, R is preferably a divalent hydrocarbon group having 1 to 10 carbon atoms. In particular, a linear, branched or cyclic alkylene group, an aralkylene group and the like can be mentioned. These alkylene groups and the like may have a substituent or may not have a substituent.
The secondary thiol structure is represented by —R—CHR ^* —SH group, — (cycloalkylene group) —SH group and the like. R is the same as R in the primary thiol structure. R ^* is preferably a monovalent hydrocarbon group having 1 to 10 carbon atoms. In particular, a linear, branched or cyclic alkyl group, an aralkyl group and the like can be mentioned.
The tertiary thiol structure is represented by —R—CR ^** ₂ —SH group and the like. R is the same as R in the primary thiol structure. R ^** is preferably a monovalent hydrocarbon group having 1 to 10 carbon atoms. In particular, a linear, branched or cyclic alkyl group, an aralkyl group and the like can be mentioned. These alkylene groups and the like may have a substituent or may not have a substituent, and two R ^{** s} may be bonded to each other to form a ring.
In addition, these thiol structures should just have -SH in a part of terminal, and may have the said 1-3 grade thiol structure through connecting groups, such as an ester bond.
The thiol-terminated polymer of the present invention has the thiol structure at both ends of the main chain, and further has a thiourethane structure (—NHCO—S—), urethane structure (—NHCO—O—) and urea as the main chain repeating unit. It has at least one structure of the structure (—HN—CO—NH—). Moreover, the copolymer containing 2 or more types may be sufficient.
The thiol-terminated polythiourethane used in the present invention is prepared by, for example, preparing a terminal isocyanate polythiourethane main chain by polymerizing diisocyanate and dithiol (bifunctional thiol), and then using a polyfunctional thiol ( Polythiol) and the like.
The thiol-terminated polyurethane used in the present invention can be obtained, for example, by preparing a polyurethane main chain by polymerizing diisocyanate and diol and then reacting with a polyfunctional thiol as a terminal terminator.
The thiol-terminated polyurea used in the present invention can be obtained, for example, by preparing a polyurea main chain by polymerizing diisocyanate and an amine such as diamine, and then reacting polyfunctional thiol or the like as a terminal terminator.
In addition, after preparing a polythiourethane main chain, polyurethane main chain or polyurea main chain, reacting with a monofunctional alcohol or monofunctional amine having a thiol group protected by a protecting group, and then removing the protecting group Can also be obtained.
These methods may be performed according to conventional methods, and can be obtained with reference to, for example, JP-A-2008-255353.
Examples of the polyfunctional thiol include compounds having two or more groups in which —SH (mercapto group) is bonded to the end of a hydrocarbon group. This hydrocarbon group may be either an aliphatic (including alicyclic) hydrocarbon group or an aromatic hydrocarbon group. The polyfunctional thiol of the present invention may have a substituent (alkyl group, nitro group, etc.) that does not participate in the urethanization reaction, and a hetero atom (oxygen atom, sulfur atom, nitrogen) in the carbon chain. Atom), an ester group, a thioester group, or other atoms or groups that do not participate in the urethanization reaction may be contained.

 Examples of the polyfunctional thiol in which the hydrocarbon group is an aliphatic hydrocarbon group include 1,2-ethanedithiol, 1,3-propanedithiol, 1,4-butanedithiol, 1,5-pentanedithiol, 1, 6-hexanedithiol, 1,7-heptanedithiol, 1,8-octanedithiol, 1,9-nonanedithiol, 1,10-decanedithiol, 1,12-dodecanedithiol, 2,2-dimethyl-1,3- Alkanedithiol such as propanedithiol, 3-methyl-1,5-pentanedithiol, 2-methyl-1,8-octanedithiol, cyclohexane such as 1,4-cyclohexanedithiol, 1,4-bis (mercaptomethyl) cyclohexane Alkanedithiol,

 Bis (2-mercaptoethyl) ether, 1,4-bis (3-mercaptobutyryloxy) butane, bis (2-mercaptoethyl) sulfide, bis (2-mercaptoethyl) disulfide, 2,2 ′-(ethylenedithio) ) Alkanedithiol having a hetero atom such as diethanethiol, 2-mercaptomethyl-1,3-propanedithiol, 2,5-bis (mercaptomethyl) -1,4-dioxane, 2,5-bis (mercaptomethyl) ) Cycloalkanedithiol having a hetero atom such as -1,4-dithiane,

Alkanetrithiol such as 1,1,1-tris (mercaptomethyl) ethane, 2-ethyl-2-mercaptomethyl-1,3-propanedithiol,
Alkanetetrathiols such as tetrakis (mercaptomethyl) methane, 3,3′-thiobis (propane-1,2-dithiol), 2,2′-thiobis (propane-1,3-dithiol), and pentaerythritol tetrakis (mercapto) Propionate), pentaerythritol tetrakis (3-mercaptobutyrate), alkanetetrakis (mercaptoalkylate) such as pentaerythritol tetrakis (mercaptoacetate), 1,3,5-tris (3-mercaptobutyloxyethyl)- 1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione and the like.

 Examples of the polyfunctional thiol in which the hydrocarbon group is an aromatic hydrocarbon group include 1,2-benzenedithiol, 1,3-benzenedithiol, 1,4-benzenedithiol, 1,2-bis (mercapto). Arenedithiols (aromatic dithiols) such as methyl) benzene, 1,3-bis (mercaptomethyl) benzene, 1,4-bis (mercaptomethyl) benzene, toluene-3,4-dithiol, 1,3,5- Examples thereof include arenetrithiol (aromatic trithiol) such as benzenetrithiol and 1,3,5-tris (mercaptomethyl) benzene.

  Examples of the monofunctional alcohol or amine having a thiol group protected by a protecting group include 2- (acetylthio) ethanol.

As the diisocyanate, dithiol, diol, amine, and the like, which are monomers used for the polymerization of the thiol-terminated polymer of the present invention, known or commercially available monomers can be used.
Examples of the dithiol include diols (alkanedithiol, cycloalkanedithiol) among the polyfunctional polyols described above.
Specific examples of the diisocyanate include the following monomers.

  As the diol, a diol generally used for synthesizing polyurethane such as alkylene diol, polyether diol, polyester diol, polycarbonate diol and the like may be used.

  Examples of the polyether diol include random copolymers of ethylene oxide and propylene oxide represented by the following formulas (1), (2), (3), (4), and (5), and having a hydroxyl group at the terminal. .

In formulas (1) to (5), R ¹⁴ represents a hydrogen atom or a methyl group, and X ¹ represents the following group. Moreover, a, b, c, d, e, f, and g each represent an integer of 2 or more, and preferably an integer of 2 to 100.

  Specific examples of the polyether diol represented by the above formulas (1) and (2) include the following. That is, diethylene glycol, triethylene glycol, tetraethylene glycol, pentaethylene glycol, hexaethylene glycol, heptaethylene glycol, octaethylene glycol, di-1,2-propylene glycol, tri-1,2-propylene glycol, tetra-1, 2-propylene glycol, hexa-1,2-propylene glycol, di-1,3-propylene glycol, tri-1,3-propylene glycol, tetra-1,3-propylene glycol, di-1,3-butylene glycol, Tri-1,3-butylene glycol, hexa-1,3-butylene glycol, polyethylene glycol having a number average molecular weight of preferably 300 to 10,000 (more preferably 300 to 5,000), polyethylene glycol Polyethylene glycol, polyethylene glycol, polyethylene glycol, polypropylene glycol, polypropylene glycol, polypropylene glycol, polypropylene glycol, polypropylene glycol, polypropylene glycol. (The above number average molecular weight is a commercially available catalog value.)

  Specific examples of the polyether diol represented by the above formula (3) include the following. That is, Sanyo Chemical Industries, Ltd. (trade name) PTMG650, PTMG1000, PTMG2000, PTMG3000, and the like.

Specific examples of the polyether diol represented by the above formula (4) include the following. That is, Sanyo Chemical Industries, Ltd. (trade name) New Pole PE-61, New Pole PE-62, New Pole PE-64, New Pole PE-68, New Pole PE-71, New Pole PE-74, New Pole PE-75, New Pole PE-78, New Pole PE-108, New Pole PE-128, and the like.

  Specific examples of the polyether diol represented by the above formula (5) include the following. That is, Sanyo Chemical Industries, Ltd. (trade name) New Pole BPE-20, New Pole BPE-20F, New Pole BPE-20NK, New Pole BPE-20T, New Pole BPE-20G, New Pole BPE-40, New Pole BPE-60, New Pole BPE-100, New Pole BPE-180, New Pole BPE-2P, New Pole BPE-23P, New Pole BPE-3P, New Pole BPE-5P, and the like.

  Specific examples of the random copolymer of ethylene oxide and propylene oxide having a hydroxyl group at the terminal include the following. That is, Sanyo Chemical Industries, Ltd. (trade name) New Pole 50HB-100, New Pole 50HB-260, New Pole 50HB-400, New Pole 50HB-660, New Pole 50HB-2000, New Pole 50HB-5100, etc. It is.

  Examples of the polyester diol include compounds represented by formulas (6) and (7).

In formulas (6) and (7), L ² , L ³ and L ⁴ may be the same or different and each represents a divalent aliphatic or aromatic hydrocarbon group, and L ⁵ represents a divalent aliphatic. Represents a hydrocarbon group. Preferably, L ² , L ³ , and L ⁴ each represent an alkylene group, an alkenylene group, an alkynylene group, or an arylene group, and L ⁵ represents an alkylene group. In addition, other functional groups that do not react with the isocyanate group, such as ether, carbonyl, ester, cyano, olefin, urethane, amide, ureido group or halogen atom may be present in L ^{2 to} L ⁵ . n1 and n2 are each an integer of 2 or more, preferably an integer of 2 to 100.
As the polycarbonate diol, there is a compound represented by the formula (8).

In formula (8), L ⁶ may be the same or different and represents a divalent aliphatic or aromatic hydrocarbon group. Preferably, L ⁶ represents an alkylene group, an alkenylene group, an alkynylene group or an arylene group. Further, L ⁶ may contain other functional groups that do not react with the isocyanate group, such as ether, carbonyl, ester, cyano, olefin, urethane, amide, ureido group or halogen atom. n3 is an integer of 2 or more, and preferably represents an integer of 2 to 100.

  Examples of the diols represented by the above formulas (6), (7), and (8) include, for example, Plaxel series (Placcel 205, Plaxel 220 (polycaprolactone diol), Plaxel CD (polycarbonate diol)) manufactured by Daicel Chemical Industries, Ltd. DURANOL series (T3000 series T4000 series, T5000 series, T6000 series) manufactured by Asahi Kasei Chemical Co., Ltd., ETERNACOLL (UH, UHC, UC, UM series) manufactured by Ube Industries, Ltd. Specifically, (Exemplary Compound No. 1) to (Exemplary Compound No. 18) shown below are included. N in the specific examples represents an integer of 2 or more. Preferably it is an integer of 2-100.

  In addition to the above diols, the following diols can be used in combination.

^{HO-L 7 -O-CO-} L 8 -CO-O-L 7 -OH (9)
^{HO-L 8 -CO-O-} L 7 -OH (10)

In the formulas (9) and (10), L ⁷ and L ⁸ may be the same or different, and each may have a substituent (for example, an alkyl group, an aralkyl group, an aryl group, an alkoxy group, an aryloxy group, —F, —Cl , -Br, -I, and other groups such as halogen atoms are included.) A divalent aliphatic hydrocarbon group, an aromatic hydrocarbon group or a heterocyclic group which may have a hydrogen atom. If necessary, L ⁷ and L ⁸ may have another functional group that does not react with an isocyanate group, such as a carbonyl group, an ester group, a urethane group, an amide group, or a ureido group. Note that L ⁷ and L ⁸ may form a ring.

  As the amine, amines generally used for synthesizing polyurea may be used. For example, the following monomers are preferably exemplified.

In the formula, R ¹⁶ and R ¹⁸ may be the same or different from each other, such as a hydrogen atom, a substituent (for example, alkoxy, halogen atom (—F, —Cl, —Br, —I), ester, carboxyl group, etc. Each group is included) may be an alkyl, aralkyl or aryl group which may have a hydrogen atom, preferably an alkyl or carbon having 1 to 8 carbon atoms which may have a carboxyl group as a substituent. 6 to 15 aryl groups are shown. L ¹⁷ has a substituent (for example, each group such as alkyl, aralkyl, aryl, alkoxy, aryloxy, halogen atom (—F, —Cl, —Br, —I), carboxyl group and the like is included). And a divalent aliphatic hydrocarbon group, aromatic hydrocarbon group or heterocyclic group. If necessary, L ¹⁷ may have another functional group that does not react with an isocyanate group, such as a carbonyl group, an ester group, a urethane group or an amide group. Two of R ¹⁶ , L ¹⁷ and R ¹⁸ may form a ring.

Specific examples of the compounds represented by formulas (11) and (12) include those shown below. That is, ethylenediamine, propylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, dodecamethylenediamine, propane-1,2-diamine, bis (3-aminopropyl) methylamine, 1 , 3-bis (3-aminopropyl) tetramethylsiloxane, piperazine, 2,5-dimethylpiperazine, N- (2-aminoethyl) piperazine, 4-amino-2,2-6,6-tetramethylpiperidine, N , N-dimethylethylenediamine, lysine, L-cystine, isophoronediamine, and the like; o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 2,4-tolylenediamine, benzidine, o- Toluidine, o-dianisidine, 4-nitro-m-phenylenediamine, 2,5-dimethoxy-p-phenylenediamine, bis- (4-aminophenyl) sulfone, 4-carboxy-o-phenylenediamine, 3-carboxy-m -Aromatic diamine compounds such as phenylenediamine, 4,4'-diaminophenyl ether, 1,8-naphthalenediamine, etc .; 2-aminoimidazole, 3-aminotriazole, 5-amino-1H-tetrazole, 4-aminopyrazole 2-aminobenzimidazole, 2-amino-5-carboxy-triazole, 2,4-diamino-6-methyl-S-triazine, 2,6-diaminopyridine, L-histidine, DL-tryptophan, adenine, etc. Heterocyclic amine compounds; ethanolamine, N Methylethanolamine, N-ethylethanolamine, 1-amino-2-propanol, 1-amino-3-propanol, 2-aminoethoxyethanol, 2-aminothioethoxyethanol, 2-amino-2-methyl-1-propanol P-aminophenol, m-aminophenol, o-aminophenol, 4-methyl-2-aminophenol, 2-chloro-4-aminophenol, 4-methoxy-3-aminophenol, 4-hydroxybenzylamine, 4 -Amino-1-naphthol, 4-aminosalicylic acid, 4-hydroxy-N-phenylglycine, 2-aminobenzyl alcohol, 4-aminophenethyl alcohol, 2-carboxy-5-amino-1-naphthol, L-tyrosine, etc. Such as amino alcohol or amino Examples thereof include a nor compound.

The main chain portion of the thiol-terminated polymer of the present invention may have a branched structure. In order to introduce a branched structure into the polymer, the polymer may be used using a polyfunctional alcohol or the like. Examples of the polyfunctional alcohol include 1,2,6-trihydroxyhexane, 1,2,3-heptanetriol, pentaerythritol, D-threitol L-xylose and the like.
Preferable examples of the thiol-terminated polymer used in the present invention include polymers obtained by combinations of monomers shown in the following table.

  In Table 1 and Table 2, Karenz MT-BD1, MT-NR1, MT-PE1, DPMP, TMMP and PEMP are compounds having the following structural formulas, respectively.

  The thiol-terminated polymer of the present invention preferably has a ring structure in its main chain structure (particularly the isocyanate component). The ring structure may be either an alicyclic structure or an aromatic ring structure. Thereby, a punching characteristic etc. become more favorable.

  Although the weight average molecular weight of the thiol terminal polymer of this invention is not restrict | limited in particular, For example, it is 2000-200000, Preferably it is 5000-150,000, More preferably, it is 8000-100,000. In addition, the polymerization average molecular weight of this invention is measured by polystyrene conversion using N methylpyrrolidone for a solvent using a gel permeation chromatograph (GPC).

  The ratio of the thiol-terminated polymer in the ink composition of the present invention may be, for example, 0.1 to 20% by mass, preferably 0.5 to 15% by mass, and more preferably 1 to 8% by mass.

Since the ink composition of the present invention has the thiol-terminated polymer, the ink ejection stability and blocking sensitivity are good, and the ink image punching characteristics are excellent. Although this mechanism is not clear, it is estimated as follows.
Since the thiol structure portion of the thiol-terminated polymer structure serves as a chain transfer agent for the polymerizable monomer (described later), a polymer (cured film constituting a recorded image) is formed together with the polymerizable monomer by irradiation with active energy rays. Form. Moreover, the thiourethane structure, the urethane structure, or the urea structure has higher impact resistance than the acrylic structure. For these reasons, when the thiol-terminated polymer-containing ink composition of the present invention is discharged and polymerized into a cured film (recorded image) by irradiation with active energy rays, the structure having impact resistance is cured film (polymer). ) In the main chain skeleton. Therefore, it is considered that it has a shock absorbing ability even for a quick impact and can improve cracks in a recorded image.
In addition, since the high molecular weight thiol-terminated polymer also acts as a chain transfer agent for the polymerizable monomer, it is possible to suppress the adverse effect of the decrease in the molecular weight of the cured film upon irradiation with active energy rays, and more efficiently to the high molecular weight cured film. can do. For this reason, it is considered that the ink composition of the present invention also has good blocking sensitivity.
The present invention is not limited to the above estimation mechanism.

<Polymerizable monomer>
The ink composition of the present invention contains a polymerizable monomer. The polymerizable monomer of the present invention may be either a radical polymerizable monomer or a cationic polymerizable monomer, but in the present invention, a radical polymerizable monomer is preferable.

-Radically polymerizable monomer-
Examples of the radical polymerizable monomer applicable to the present invention include compounds having an ethylenically unsaturated bond capable of radical polymerization. More specifically, any monomer having at least one ethylenically unsaturated bond capable of radical polymerization in the molecule may be used.

  Examples of polymerizable monomers 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, unsaturated carboxylic acid esters, and the like. A salt having an ethylenically unsaturated group; acrylonitrile; styrene and the like. Further, various macromonomers such as various unsaturated polyesters, unsaturated polyethers, unsaturated polyamides and unsaturated polyurethanes are also included.

Examples of the radical polymerizable monomer include monofunctional monomers and polyfunctional monomers.
As such a monofunctional monomer, for example, 2-hydroxyethyl acrylate, butoxyethyl acrylate, carbitol acrylate, cyclohexyl acrylate, tetrahydrofurfuryl acrylate, benzyl acrylate, tridecyl acrylate, 2-phenoxyethyl acrylate, N- Methylol acrylamide, diacetone acrylamide, epoxy acrylate, isobornyl acrylate, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, dicyclopentanyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 2-acryloyloxyethyl phthalate Acid, methoxy-polyethylene glycol acrylate, 2-acryloyloxyethyl-2-hydride Xylethylphthalic acid, cyclic trimethylolpropane formal acrylate, 2- (2-ethoxyethoxy) ethyl acrylate, 2-methoxyethyl acrylate, 3-methoxybutyl acrylate, ethoxylated phenyl acrylate, 2-acryloyloxyethyl succinic acid Acrylate compounds such as nonylphenol EO adduct acrylate, phenoxy-polyethylene glycol acrylate, 2-acryloyloxyethyl hexahydrophthalic acid, lactone-modified acrylate, stearyl acrylate, isoamyl acrylate, isomyristyl acrylate, isostearyl acrylate, lactone-modified acrylate; Methyl methacrylate, n-butyl methacrylate, allyl methacrylate, glycidyl methacrylate DOO, benzyl methacrylate, methacrylate compounds such as dimethylaminoethyl methacrylate; allyl compounds such as allyl glycidyl ether.

  Among these, acrylate compounds are preferable. Of these, acrylates having a cyclic structure in the molecule are preferred. Specifically, from the viewpoints of viscosity, curability, and the like, acrylates such as alcohols having ether oxygen atoms such as tetrahydrofurfuryl acrylate and 2-phenoxyethyl acrylate, and alcohols having an aromatic ring are preferable. For the same reason, acrylates having a bicyclo ring structure or a tricyclo ring structure such as isobornyl acrylate, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, dicyclopentanyl acrylate, etc. are preferable. Dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate and the like having a double bond are preferred. Furthermore, in addition to the acrylate having a cyclic structure, an acrylate having a chain ether bond is also preferred, and specifically, ethoxyethoxyethyl acrylate, 2-methoxyethyl acrylate, 3-methoxybutyl acrylate, butoxyethyl acrylate Etc.

  Also suitable are monofunctional vinyl ether compounds. Specific examples of the monofunctional vinyl ether compound include, for example, methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, t-butyl vinyl ether, n-octadecyl vinyl ether, 2-ethylhexyl vinyl ether, n -Nonyl vinyl ether, dodecyl vinyl ether, octadecyl vinyl ether, cyclohexyl vinyl ether, cyclohexyl methyl vinyl ether, 4-methylcyclohexyl methyl vinyl ether, benzyl vinyl ether, dicyclopentenyl vinyl ether, 2-dicyclopentenoxyethyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, Butoxyethylbi Ether, methoxyethoxyethyl vinyl ether, ethoxyethoxyethyl vinyl ether, methoxypolyethylene glycol vinyl ether, tetrahydrofurfuryl vinyl ether, 2-hydroxyethyl vinyl ether, 2-hydroxypropyl vinyl ether, 4-hydroxybutyl vinyl ether, 4-hydroxymethylcyclohexyl methyl vinyl ether, diethylene glycol mono Vinyl ether, polyethylene glycol vinyl ether, chloroethyl vinyl ether, chlorobutyl vinyl ether, chloroethoxyethyl vinyl ether, phenylethyl vinyl ether, phenoxy polyethylene glycol vinyl ether, cyclohexanedimethanol monovinyl ether, isopropenyl ether-O-pro Ren carbonate, and the like.

  In addition, N-vinyl compounds such as N-vinyl lactams and N-vinylformamide are also preferable. Preferred examples of N-vinyl lactams are represented by the following formula.

  In the above, m represents an integer of 1 to 5, and m is preferably an integer of 2 to 4 from the viewpoint of flexibility after the ink composition is cured and availability of raw materials, and m is 2 or 4. It is more preferable that m is 4, that is, N-vinylcaprolactam is particularly preferable. N-vinylcaprolactam is preferably used because it is excellent in safety, and particularly good ink curability and adhesion of the image film to the support can be obtained.

  Bifunctional or higher polyfunctional monomers include bis (4-acryloxypolyethoxyphenyl) propane, tripropylene glycol diacrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, dipentaerythritol tetraacrylate, trimethylolpropane (PO modified) ) Triacrylate, oligoester acrylate, hydroxypivalate neopentyl glycol diacrylate, tetramethylol methane triacrylate, dimethylol tricyclodecane diacrylate, modified glycerin triacrylate, bisphenol A diglycidyl ether acrylic acid adduct, modified bisphenol A di Acrylate, bisphenol A PO adduct diacrylate, bisphenol A EO adduct di Acrylate compounds such as acrylate, dipentaerythritol hexaacrylate, propylene glycol diglycidyl ether acrylic acid adduct, ditrimethylolpropane tetraacrylate; polyethylene glycol dimethacrylate, polypropylene glycol dimethacrylate 2,2-bis (4-methacryloxypolyethoxy) And methacrylate compounds such as phenyl) propane. Other examples include allyl compounds such as diallyl phthalate and triallyl trimellitate. PO represents propylene oxide, and EO represents ethylene oxide. More specifically, Shinzo Yamashita, “Crosslinker Handbook”, (1981 Taiseisha); Kato Kiyosumi, “UV / EB Curing Handbook (Materials)” (1985, Polymer Publications); Radtech Study Group, “Application and Market of UV / EB Curing Technology”, p. 79, (1989, CMC); Eiichiro Takiyama, “Polyester Resin Handbook”, (1988, Nikkan Kogyo Shimbun) Commercially available products or radically polymerizable or crosslinkable monomers known in the industry can be used.

  Moreover, polyfunctional vinyl ether is also mentioned. Examples of the polyfunctional vinyl ether include ethylene glycol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, polyethylene glycol divinyl ether, propylene glycol divinyl ether, dipropylene glycol divinyl ether, butylene glycol divinyl ether, butanediol divinyl ether, hexane. Divinyl ethers such as diol divinyl ether, cyclohexane dimethanol divinyl ether, bisphenol A alkylene oxide divinyl ether, bisphenol F alkylene oxide divinyl ether; trimethylolethane trivinyl ether, trimethylolpropane trivinyl ether, ditrimethylolpropane tetravinyl Ether, glycerin trivinyl ether, pentaerythritol tetravinyl ether, dipentaerythritol pentavinyl ether, dipentaerythritol hexavinyl ether, ethylene oxide-added trimethylolpropane trivinyl ether, propylene oxide-added trimethylolpropane trivinyl ether, ethylene oxide-added ditrimethylolpropane tetravinyl ether, Propylene oxide addition ditrimethylolpropane tetravinyl ether, ethylene oxide addition pentaerythritol tetravinyl ether, propylene oxide addition pentaerythritol tetravinyl ether, ethylene oxide addition dipentaerythritol hexavinyl ether, propylene oxide addition dipenta Risuri tall polyfunctional vinyl ethers such as hexa vinyl ether. Among these polyfunctional vinyl ether compounds, di- or trivinyl ether compounds are preferable from the viewpoints of curability, adhesion to a recording medium, surface hardness of the formed image, and the like, and divinyl ether compounds are particularly preferable.

  Examples of the radical polymerizable monomer include, for example, JP-A-7-159983, JP-B-7-31399, JP-A-8-224982, JP-A-10-863, JP-A-9-134011, and JP-T-2004. Photo-curable polymerizable compounds used in the photopolymerizable compositions described in each publication such as JP-A-514014 are known, and these can also be applied to the ink composition of the present invention.

-Cationically polymerizable monomer-
Examples of the polymerizable monomer that can be used in the present invention also include a cationic polymerizable monomer. There is no particular limitation as long as it is a compound that causes a polymerization reaction with an acid generated from a photoacid generator and cures, and various known cationically polymerizable monomers known as photocationically polymerizable compounds can be used. Examples of the cationic polymerizable compound include an epoxy compound and an oxetane compound.

Examples of the epoxy compound include aromatic epoxides, alicyclic epoxides, and aromatic epoxides.
Aromatic epoxides include di- or polyglycidyl ethers obtained by the reaction of polyphenols having at least one aromatic nucleus or their alkylene oxide adducts with epichlorohydrin. Examples thereof include di- or polyglycidyl ether of bisphenol A or its alkylene oxide adduct, di- or polyglycidyl ether of hydrogenated bisphenol A or its alkylene oxide adduct, and novolak-type epoxy resin. Here, examples of the alkylene oxide include ethylene oxide and propylene oxide.

  As the alicyclic epoxide, cyclohexene oxide obtained by epoxidizing a compound having at least one cycloalkane ring such as cyclohexene or cyclopentene ring with a suitable oxidizing agent such as hydrogen peroxide or peracid. Or a cyclopentene oxide containing compound is mentioned preferably.

  Examples of the aliphatic epoxide include an aliphatic polyhydric alcohol or a di- or polyglycidyl ether of an alkylene oxide adduct thereof. Typical examples include diglycidyl ether of ethylene glycol, diglycidyl ether of propylene glycol or diglycidyl ether of 1,6-hexanediol, diglycidyl ether of alkylene glycol, glycerin or its alkylene oxide adduct di- or tri- Polyglycidyl ethers of polyhydric alcohols such as glycidyl ether, diglycidyl ethers of polyethylene glycol or alkylene oxide adducts thereof, diglycidyl ethers of polyalkylene glycols typified by diglycidyl ethers of polypropylene glycol or alkylene oxide adducts thereof, etc. Can be mentioned. Here, examples of the alkylene oxide include ethylene oxide and propylene oxide.

Epoxy compounds include monofunctional epoxy compounds and polyfunctional epoxy compounds.
Examples of monofunctional epoxy compounds that can be used in the present invention include, for example, phenyl glycidyl ether, p-tert-butylphenyl glycidyl ether, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, allyl glycidyl ether, 1,2-butylene oxide, 1,3-butadiene monooxide, 1,2-epoxydodecane, epichlorohydrin, 1,2-epoxydecane, styrene oxide, cyclohexene oxide, 3-methacryloyloxymethylcyclohexene oxide, 3-acryloyloxymethylcyclohexene oxide, 3 -Vinylcyclohexene oxide etc. are mentioned.

  Examples of polyfunctional epoxy compounds include, for example, bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, brominated bisphenol A diglycidyl ether, brominated bisphenol F diglycidyl ether, and brominated bisphenol. S diglycidyl ether, epoxy novolac resin, hydrogenated bisphenol A diglycidyl ether, hydrogenated bisphenol F diglycidyl ether, hydrogenated bisphenol S diglycidyl ether, 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxy 2- (3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy) cyclohexane-meta-dioxane, bis (3,4-epoxy Hexylmethyl) adipate, vinylcyclohexene oxide, 4-vinylepoxycyclohexane, bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate, 3,4-epoxy-6-methylcyclohexyl-3 ', 4'-epoxy- 6'-methylcyclohexanecarboxylate, methylenebis (3,4-epoxycyclohexane), dicyclopentadiene diepoxide, ethylene glycol di (3,4-epoxycyclohexylmethyl) ether, ethylenebis (3,4-epoxycyclohexanecarboxylate) ), Dioctyl epoxyhexahydrophthalate, di-2-ethylhexyl epoxyhexahydrophthalate, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl Ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ethers, 1,1,3-tetradecadiene dioxide, limonene dioxide, 1,2,7,8 -Diepoxyoctane, 1,2,5,6-diepoxycyclooctane and the like.

  Among these epoxy compounds, alicyclic epoxides are preferable from the viewpoint of excellent curing speed.

  In the present invention, the molecular weight of the polymerizable monomer is preferably 130 to 3000, and more preferably 130 to 500, as the molecular weight.

The content of the polymerizable monomer is preferably 50% by mass or more, more preferably 60% by mass to 90% by mass, and still more preferably 70% by mass to 90% by mass with respect to the total amount of the ink composition. It is. By setting it within the above range, a highly sensitive ink composition can be obtained.
In particular, in the present invention, the content of the monofunctional monomer is preferably 80% by mass or more, more preferably from 80% by mass to 100% by mass, and still more preferably from 90% by mass to the total amount of the polymerizable monomers. It is 100 mass%, Most preferably, it is 95-100 mass%. By setting it as the above range, it is excellent in stretch moldability and the like.

  In addition to the polymerizable monomer, the ink composition of the present invention may contain an oligomer, a prepolymer or a polymer made of the polymerizable monomer as necessary. Specifically, for example, the above (meth) acrylic, epoxy or urethane oligomers, prepolymers, polymers and the like can be mentioned.

<Polymerization initiator>
The ink composition of the present invention contains a polymerization initiator.
The polymerization initiator of the present invention may be either a thermal polymerization initiator or a photopolymerization initiator, but in the present invention, a photopolymerization initiator is preferably mentioned. As the photopolymerization initiator, a known photopolymerization initiator can be appropriately selected and used according to the kind of the polymerizable compound and the purpose of use of the ink composition.

The photopolymerization initiator used in the ink composition of the present invention is a compound that absorbs external energy (light) and generates radicals that are polymerization initiation species. In the photopolymerization initiator, the light for initiating polymerization indicates active illumination energy rays, that is, γ rays, β rays, electron beams, ultraviolet rays, visible rays, infrared rays, etc., and preferably ultraviolet rays.

  As the photopolymerization initiator, known compounds can be used. Preferred photopolymerization initiators that can be used in the present invention include (a) aromatic ketones, (b) acylphosphine oxide compounds, and (c) aromatics. Onium salt compound, (d) organic peroxide, (e) thio compound, (f) hexaarylbiimidazole compound, (g) ketoxime ester compound, (h) borate compound, (i) azinium compound, (j) Examples thereof include metallocene compounds, (k) active ester compounds, (l) compounds having a carbon halogen bond, and (m) alkylamine compounds.

  These photopolymerization initiators may use the above compounds (a) to (m) alone or in combination. The photopolymerization initiator in the present invention is preferably used alone or in combination of two or more.

  Preferable examples of (a) aromatic ketones, (b) acylphosphine oxide compounds, and (e) thio compounds include “RADIATION CURING IN POLYMER SCIENCE AND TECHNOLOGY”, J. MoI. P. FOUASSIER, J.A. F. RABEK (1993), pp. Examples include compounds having a benzophenone skeleton or a thioxanthone skeleton described in 77-117. More preferable examples include α-thiobenzophenone compounds described in JP-B-47-6416, benzoin ether compounds described in JP-B-47-3981, α-substituted benzoin compounds described in JP-B-47-22326, Benzoin derivatives described in JP-B-47-23664, aroylphosphonic acid esters described in JP-A-57-30704, dialkoxybenzophenones described in JP-B-60-26483, JP-B-60-26403, JP-A Benzoin ethers described in JP-A-62-81345, JP-B-1-34242, US Pat. No. 4,318,791, α-aminobenzophenones described in European Patent 0284561A1, JP-A-2-21152 P-Di (dimethylaminobenzoyl) benze Thio-substituted aromatic ketones described in JP-A-61-194062, acylphosphine sulfides described in JP-B-2-9597, acylphosphines described in JP-B-2-9596, and JP-B-63-61950 Thioxanthones, and coumarins described in JP-B-59-42864. Moreover, the polymerization initiators described in JP 2008-105379 A and JP 2009-114290 A are also preferable.

  Among these, in the present invention, it is preferable to use an aromatic ketone or an acylphosphine oxide compound as a photopolymerization initiator, and p-phenylbenzophenone (manufactured by Wako Pure Chemical Industries, Ltd.), bis (2, 4, 6 -Trimethylbenzoyl) -phenylphosphine oxide (Irgacure 819: manufactured by BASF), bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenyl -Phosphine oxide (Darocur TPO: manufactured by BASF, Lucirin TPO: manufactured by BASF) and the like are preferable.

A polymerization initiator can be used individually by 1 type or in combination of 2 or more types.
The content of the polymerization initiator in the ink composition is preferably 0.1 to 20% by mass, more preferably 0.5 to 15% by mass, and further preferably 1 to 10% by mass with respect to the ink composition. .

<Colorant>
The ink composition of the present invention may contain a colorant. By adding a colorant to the ink composition, the ink composition can form a visible image (colored image).
The colorant that can be used in the ink composition of the present invention is not particularly limited, and various known color materials (pigments, dyes) can be appropriately selected and used depending on the application. For example, when forming an image excellent in weather resistance, a pigment is preferable. As the dye, both water-soluble dyes and oil-soluble dyes can be used, but oil-soluble dyes are preferred.

(Pigment)
First, a pigment that is preferably used as a colorant in the ink composition of the present invention will be described. When a pigment is used as the colorant, a colored image formed using the ink composition has excellent light resistance.
The pigment is not particularly limited, and all commercially available organic pigments and inorganic pigments or pigments dispersed in an insoluble resin or the like as a dispersion medium, or a resin is grafted on the pigment surface. Can be used. Moreover, what dye | stained the resin particle with dye can be used.
Examples of these pigments include, for example, “Pigment Dictionary” (2000), edited by Seijiro Ito. Herbst, K.M. Hunger “Industrial Organic Pigments”, JP 2002-12607 A, JP 2002-188025 A, JP 2003-26978 A, and JP 2003-342503 A3.

  Specific examples of organic pigments and inorganic pigments that can be used in the present invention include C.I. I. Pigment Yellow 1 (Fast Yellow G etc.), C.I. I. A monoazo pigment such as C.I. Pigment Yellow 74; I. Pigment Yellow 12 (disaji yellow AAA, etc.), C.I. I. Disazo pigments such as C.I. Pigment Yellow 17; I. Non-benzidine type azo pigments such as CI Pigment Yellow 180; I. Azo lake pigments such as C.I. Pigment Yellow 100 (eg Tartrazine Yellow Lake); I. Condensed azo pigments such as CI Pigment Yellow 95 (Condensed Azo Yellow GR, etc.); I. Acidic dye lake pigments such as C.I. Pigment Yellow 115 (such as quinoline yellow lake); I. Basic dye lake pigments such as CI Pigment Yellow 18 (Thioflavin Lake, etc.), anthraquinone pigments such as Flavantron Yellow (Y-24), isoindolinone pigments such as Isoindolinone Yellow 3RLT (Y-110), and quinophthalone yellow Quinophthalone pigments such as (Y-138), isoindoline pigments such as isoindoline yellow (Y-139), C.I. I. Nitroso pigments such as C.I. Pigment Yellow 153 (nickel nitroso yellow, etc.); I. And metal complex salt azomethine pigments such as CI Pigment Yellow 117 (copper azomethine yellow, etc.).

  C. As a thing which exhibits red or magenta color, C.I. I. Monoazo pigments such as CI Pigment Red 3 (Toluidine Red, etc.); I. Disazo pigments such as C.I. Pigment Red 38 (Pyrazolone Red B, etc.); I. Pigment Red 53: 1 (Lake Red C, etc.) and C.I. I. Azo lake pigments such as C.I. Pigment Red 57: 1 (Brilliant Carmine 6B); I. Condensed azo pigments such as C.I. Pigment Red 144 (condensed azo red BR, etc.); I. Acidic dye lake pigments such as C.I. Pigment Red 174 (Phloxine B Lake, etc.); I. Basic dye lake pigments such as C.I. Pigment Red 81 (Rhodamine 6G 'lake, etc.); I. Anthraquinone pigments such as C.I. Pigment Red 177 (eg, dianthraquinonyl red); I. Thioindigo pigments such as C.I. Pigment Red 88 (Thioindigo Bordeaux, etc.); I. Perinone pigments such as C.I. Pigment Red 194 (perinone red, etc.); I. Perylene pigments such as C.I. Pigment Red 149 (perylene scarlet, etc.); I. Pigment violet 19 (unsubstituted quinacridone), C.I. I. Quinacridone pigments such as CI Pigment Red 122 (quinacridone magenta, etc.); I. Isoindolinone pigments such as CI Pigment Red 180 (isoindolinone red 2BLT, etc.); I. And alizarin lake pigments such as CI Pigment Red 83 (Mada Lake, etc.).

  As a pigment exhibiting blue or cyan, C.I. I. Disazo pigments such as C.I. Pigment Blue 25 (Dianisidine Blue, etc.); I. Phthalocyanine pigments such as C.I. Pigment Blue 15 (phthalocyanine blue, etc.); I. Acidic dye lake pigments such as C.I. Pigment Blue 24 (Peacock Blue Lake, etc.); I. Basic dye lake pigments such as C.I. Pigment Blue 1 (Viclotia Pure Blue BO Lake, etc.); I. Anthraquinone pigments such as C.I. Pigment Blue 60 (Indantron Blue, etc.); I. And alkali blue pigments such as CI Pigment Blue 18 (Alkali Blue V-5: 1).

  As a pigment exhibiting green, C.I. I. Pigment green 7 (phthalocyanine green), C.I. I. Phthalocyanine pigments such as C.I. Pigment Green 36 (phthalocyanine green); I. And azo metal complex pigments such as CI Pigment Green 8 (Nitroso Green).

  As a pigment exhibiting an orange color, C.I. I. An isoindoline pigment such as C.I. Pigment Orange 66 (isoindoline orange); I. And anthraquinone pigments such as CI Pigment Orange 51 (dichloropyrantron orange).

  Examples of the black pigment include carbon black, titanium black, and aniline black.

Specific examples of the white pigment include basic lead carbonate (2PbCO ₃ Pb (OH) ₂ , so-called silver white), zinc oxide (ZnO, so-called zinc white), titanium oxide (TiO ₂ , so-called titanium white), Strontium titanate (SrTiO ₃ , so-called titanium strontium white) or the like can be used.

  Here, titanium oxide has a smaller specific gravity than other white pigments, a large refractive index, and is chemically and physically stable, and thus has a high hiding power and coloring power as a pigment. Excellent durability against other environments. Therefore, it is preferable to use titanium oxide as the white pigment. Of course, other white pigments (may be other than the listed white pigments) may be used as necessary.

  For dispersion of the pigment, for example, a dispersion device such as a ball mill, a sand mill, an attritor, a roll mill, a jet mill, a homogenizer, a paint shaker, a kneader, an agitator, a Henschel mixer, a colloid mill, an ultrasonic homogenizer, a pearl mill, or a wet jet mill is used. Can do.

It is also possible to add a dispersant when dispersing the pigment. Examples of the dispersant include a hydroxyl group-containing carboxylic acid ester, a salt of a long-chain polyaminoamide and a high molecular weight acid ester, a salt of a high molecular weight polycarboxylic acid, a high molecular weight unsaturated acid ester, a high molecular weight copolymer, a modified polyacrylate, an aliphatic polyacrylate. Carboxylic acid, naphthalenesulfonic acid formalin condensate, polyoxyethylene alkyl phosphate ester, pigment derivative and the like. It is also preferable to use a commercially available polymer dispersant such as Solsperse series manufactured by Lubrizol.
Moreover, it is also possible to use a synergist according to various pigments 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.

  In the ink composition, as a dispersion medium for various components such as pigments, a solvent may be added, and the polymerizable compound which is a low molecular weight component without a solvent may be used as a dispersion medium. The ink composition of the invention is an energy ray curable ink, and is preferably solvent-free in order to be cured after the ink is applied onto a recording medium. This is because if the solvent remains in the cured ink image, the solvent resistance is deteriorated or a problem of VOC (Volatile Organic Compound) of the remaining solvent occurs. From such a viewpoint, a polymerizable compound is used as the dispersion medium, and among them, it is preferable to select a cationically polymerizable monomer having the lowest viscosity from the viewpoint of improving dispersibility and handling properties of the ink composition.

  The volume average particle size of the pigment particles in the ink composition is preferably 0.02 μm to 0.60 μm, more preferably 0.02 μm to 0.10 μm. Further, the maximum particle size is preferably 3 μm or less, more preferably 1 μm or less, and the selection of the pigment, dispersant, dispersion medium, dispersion conditions, and filtration conditions are set so as to be in such a range. By controlling the particle size, clogging of the head nozzle can be suppressed, and ink storage stability, ink transparency, and blocking sensitivity can be maintained. The volume average particle diameter is measured using a laser diffraction / scattering particle size distribution analyzer (LA920, manufactured by Horiba, Ltd.) using tripropylene glycol methyl ether as a measurement solvent.

(dye)
Next, the dyes preferably used as the colorant in the present invention will be described.
The dye can be appropriately selected from conventionally known compounds (dyes). Specific examples include compounds described in paragraph numbers [0023] to [0089] of JP-A No. 2002-114930 and paragraph numbers [0136] to [0140] of JP-A No. 2008-13646. These can also be applied to the present invention.

  The colorant is preferably added in an amount of 0.05% by mass to 20% by mass with respect to the total mass of the ink composition, and more preferably 0.2% by mass to 10% by mass. When an oil-soluble dye is used as the colorant, the content is particularly preferably 0.2% by mass to 6% by mass with respect to the total mass (including the solvent) of the ink composition.

<Water>
The ink composition of the present invention is preferably a non-aqueous ink composition containing substantially no water. Specifically, it is preferably 3% by mass or less, more preferably 2% by mass or less, and most preferably 1% by mass or less with respect to the total amount of the ink composition. This is excellent in terms of storage stability.
<Other ingredients>
Furthermore, components other than those described above can be added to the ink composition of the present invention. This will be sequentially described below.

(Chain transfer agent)
The ink composition of the present invention may further contain a chain transfer agent.
The chain transfer agent can be used without particular limitation as long as it is a substance that moves the active site of the reaction by a chain transfer reaction in the polymerization reaction.

  Specific examples of the chain transfer agent that can be used in the present invention include, for example, halogen compounds such as carbon tetrachloride and carbon tetrabromide; alcohols such as isopropyl alcohol and isobutyl alcohol; 2-methyl-1-butene, 2,4 -Olefins such as diphenyl-4-methyl-1-pentene; sulfur-containing compounds; and the like, but are not limited thereto.

  The molecular weight of the chain transfer agent is preferably 250 or more, particularly preferably 250 or more and 100,000 or less, more preferably 500 or more and 80,000 or less, and most preferably 3,000 or more and 80,000 or less.

Only 1 type may be used for a chain transfer agent and it may use 2 or more types together.
The addition amount of the chain transfer agent to the ink composition of the present invention is preferably 0.1% by mass to 15% by mass, and preferably 0.5% by mass to 10% by mass with respect to the total solid mass of the ink composition. More preferably, it is more preferably 1% by mass to 10% by mass.

(Sensitizing dye)
A sensitizing dye can be added to the ink composition of the present invention in order to accelerate the decomposition of the polymerization initiator by irradiation with actinic rays. A sensitizing dye absorbs specific active energy rays and enters an electronically excited state. The sensitizing dye in an electronically excited state is brought into contact with the polymerization initiator to cause actions such as electron transfer, energy transfer, and heat generation, thereby causing a chemical change of the polymerization initiator, that is, decomposition, radical, acid or base. It promotes the generation of.

As the sensitizing dye, a compound corresponding to the wavelength of the active energy ray that generates an initiation species in the photopolymerization initiator used in the ink composition may be used, but it is used for a curing reaction of a general ink composition. In view of this, examples of preferable sensitizing dyes include those belonging to the following compounds and having an absorption wavelength in the 350 nm to 450 nm region.
Polynuclear aromatics (for example, anthracene, pyrene, perylene, triphenylene), thioxanthones (for example, isopropylthioxanthone), xanthenes (for example, fluorescein, eosin, erythrosine, rhodamine B, rose bengal), cyanines (for example, thiaxene) Carbocyanine, oxacarbocyanine), merocyanines (eg, merocyanine, carbomerocyanine), thiazines (eg, thionine, methylene blue, toluidine blue), acridines (eg, acridine orange, chloroflavin, acriflavine), anthraquinones ( For example, anthraquinone), squalium (for example, squalium), coumarins (for example, 7-diethylamino-4-methylcoumarin), and the like can be mentioned. Xanthones may be mentioned as preferred class.
Further, sensitizing dyes described in JP-A-2008-95086 are also suitable.

(Co-sensitizer)
The ink composition of the present invention can also contain a co-sensitizer. In the present invention, the co-sensitizer has functions such as further improving the sensitivity of the sensitizing dye to the active energy ray or suppressing inhibition of polymerization of the polymerizable compound by oxygen.

  Examples of co-sensitizers include amines such as M.I. R. Sander et al., “Journal of Polymer Science”, Vol. 10, page 3173 (1972), Japanese Patent Publication No. 44-20189, Japanese Patent Publication No. 51-82102, Japanese Patent Publication No. 52-134692, Japanese Patent Publication No. 59-138205. No. 60-84305, JP-A 62-18537, JP-A 64-33104, Research Disclosure 33825, and the like. Specific examples include triethanolamine. P-dimethylaminobenzoic acid ethyl ester, p-formyldimethylaniline, p-methylthiodimethylaniline and the like.

  Other examples of co-sensitizers include thiols and sulfides such as thiol compounds described in JP-A-53-702, JP-B-55-500806, JP-A-5-142772, No. 56-75643, such as 2-mercaptobenzothiazole, 2-mercaptobenzoxazole, 2-mercaptobenzimidazole, 2-mercapto-4 (3H) -quinazoline, β-mercapto. And naphthalene.

  Other examples of the co-sensitizer include amino acid compounds (eg, N-phenylglycine), organometallic compounds described in JP-B-48-42965 (eg, tributyltin acetate), JP-B 55- No. 34414, a hydrogen donor described in JP-A-6-308727 (eg, trithiane), a phosphorus compound described in JP-A-6-250387 (eg diethylphosphite), JP-A-8-65779 Si-H and Ge-H compounds described in the above No.

(UV absorber)
In the ink composition of the present invention, an ultraviolet absorber can be used from the viewpoint of improving the weather resistance of the obtained image and preventing fading.
Examples of the ultraviolet absorber are described in JP-A-58-185679, JP-A-61-190537, JP-A-2-782, JP-A-5-97075, JP-A-9-34057, and the like. Benzotriazole compounds, benzophenone compounds described in JP-A No. 46-2784, JP-A No. 5-194843, US Pat. No. 3,214,463, etc., JP-B Nos. 48-30492 and 56-21141 Cinnamic acid compounds described in JP-A-10-88106, JP-A-4-298503, JP-A-8-53427, JP-A-8-239368, JP-A-10-182621, JP The triazine compounds described in JP-A-8-501291, Research Disclosure No. Examples thereof include compounds described in No. 24239, compounds that emit ultraviolet light by absorbing ultraviolet rays typified by stilbene and benzoxazole compounds, so-called fluorescent brighteners, and the like.
The addition amount is appropriately selected according to the purpose, but generally it is preferably 0.5% by mass to 15% by mass in terms of solid content.

(Antioxidant)
An antioxidant can be added to improve the stability of the ink composition of the present invention.
Examples of the antioxidant include European published patents, 223739, 309401, 309402, 310551, 310552, 359416, and 3435443. JP, 54-85535, 62-262417, 63-113536, 63-163351, JP-A-2-262654, JP-A-2-71262, Examples thereof include those described in Kaihei 3-121449, JP-A-5-61166, JP-A-5-119449, US Pat. No. 4,814,262, US Pat. No. 4,980,275, and the like.
Although the addition amount is appropriately selected according to the purpose, it is preferably 0.1% by mass to 8% by mass in terms of solid content.

(Anti-fading agent)
In the ink composition of the present invention, various organic and metal complex anti-fading agents can be used. Examples of organic anti-fading agents include hydroquinones, alkoxyphenols, dialkoxyphenols, phenols, anilines, amines, indanes, chromans, alkoxyanilines, heterocycles, and the like.
In addition, examples of the metal complex anti-fading agent include nickel complexes and zinc complexes. No. 17643, No. VII, I to J, ibid. 15162, ibid. No. 18716, page 650, left column, ibid. No. 36544, page 527, ibid. No. 307105, page 872, ibid. The compounds described in the patent cited in No. 15162 and the compounds included in the general formulas and compound examples of representative compounds described in JP-A-62-215272, pages 127 to 137 can be used. .
Although the addition amount is appropriately selected according to the purpose, it is preferably 0.1% by mass to 8% by mass in terms of solid content.

(Conductive salts)
Conductive salts such as potassium thiocyanate, lithium nitrate, ammonium thiocyanate, and dimethylamine hydrochloride can be added to the ink composition of the present invention for the purpose of controlling ejection properties.

(solvent)
In order to improve the adhesion to the recording medium (base material), an extremely small amount of a non-curable organic solvent may be added to the ink composition of the present invention.
Examples of the solvent include ketone solvents such as acetone, methyl ethyl ketone, and diethyl ketone, alcohol solvents such as methanol, ethanol, 2-propanol, 1-propanol, 1-butanol, and tert-butanol, and chlorine such as chloroform and methylene chloride. Solvents, aromatic solvents such as benzene and toluene, ester solvents such as ethyl acetate, butyl acetate and isopropyl acetate, ether solvents such as diethyl ether, tetrahydrofuran and dioxane, glycols such as ethylene glycol monomethyl ether and ethylene glycol dimethyl ether And ether solvents.
In this case, it is effective to add the solvent within a range that does not cause the problem of solvent resistance or VOC, and the amount is preferably 0.1% by mass to 5% by mass, more preferably 0.1% by mass with respect to the entire ink composition. % To 3% by mass.

(Polymer compound)
Various oil-soluble polymer compounds can be added to the ink composition of the present invention in order to adjust film physical properties.
Examples of oil-soluble polymer compounds include acrylic polymers, polyvinyl butyral resins, polyurethane resins, polyamide resins, polyester resins, epoxy resins, phenol resins, polycarbonate resins, polyvinyl butyral resins, polyvinyl formal resins, shellacs, vinyl resins, acrylics. Resins, rubber resins, waxes, and other natural resins can be used. Two or more of these may be used in combination. Of these, vinyl copolymer obtained by copolymerization of acrylic monomers is preferred. Furthermore, a copolymer containing “carboxyl group-containing monomer”, “methacrylic acid alkyl ester” or “acrylic acid alkyl ester” as a structural unit is also preferably used as the copolymer composition of the polymer compound.
In addition, when the ink composition of the present invention is used as a film, a polymer compound that easily segregates on the surface for the purpose of improving tackiness or the like is also suitable. These polymer compounds contain Si and F atoms described in paragraph numbers [0017] to [0037] of JP-A-2008-248119, paragraph numbers [0015] to [0034] of JP-A-2005-250890, and the like. A polymer, a polymer having a long-chain alkyl group in the side chain, and the like can be used.

(Surfactant)
A surfactant may be added to the ink composition of the present invention.
Examples of the surfactant include those described in JP-A Nos. 62-173463 and 62-183457. For example, anionic surfactants such as dialkylsulfosuccinates, alkylnaphthalenesulfonates, fatty acid salts, polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, acetylene glycols, polyoxyethylene / polyoxypropylene blocks Nonionic surfactants such as copolymers, and cationic surfactants such as alkylamine salts and quaternary ammonium salts.
An organic fluoro compound may be used in place of the surfactant.
The organic fluoro compound is preferably hydrophobic. Examples of the organic fluoro compound include fluorine surfactants, oily fluorine compounds (eg, fluorine oil) and solid fluorine compound resins (eg, tetrafluoroethylene resin). (Columns 8 to 17) and those described in JP-A Nos. 62-135826.
The content of the surfactant in the composition is appropriately selected depending on the purpose of use, but is preferably 0.0001 to 1% by mass and more preferably 0.001 to 0.1% by mass with respect to the entire ink composition.

In addition to this, for example, a polymerization inhibitor, a leveling additive, a matting agent, a wax for adjusting film properties, a polyolefin, a PET, etc. Further, a tackifier (tackifier) that does not inhibit the polymerization can be contained.
Examples of the polymerization inhibitor include hydroquinone, methoxybenzoquinone, methoxyphenol, phenothiazine, t-butylcatechol, mercaptobenzimidazole, alkyldithiocarbamates, alkylphenols, alkylbisphenols, salicylates, thiodipropionates, phosphines Phytes, nitroxide aluminum complexes and the like. Specific examples include Gerrad 16, 18, 20, 21, 22, (Rahn). Although content of a polymerization inhibitor is not limited, 0.01-5 mass% is preferable with respect to an ink composition, and 0.02-1 mass% is more preferable.
As the tackifier, specifically, a high molecular weight adhesive polymer described in JP-A-2001-49200, 5-6p (for example, (meth) acrylic acid and an alkyl group having 1 to 20 carbon atoms). An ester with an alcohol having, an ester of (meth) acrylic acid with an alicyclic alcohol having 3 to 14 carbon atoms, a copolymer comprising an ester of (meth) acrylic acid with an aromatic alcohol having 6 to 14 carbon atoms) And a low molecular weight tackifying resin having a polymerizable unsaturated bond.

(Preferred physical properties of ink composition)
The ink composition of the present invention is suitably used for inkjet applications. For this reason, in consideration of ejection properties, the viscosity is at a temperature during ejection (for example, 40 ° C. to 80 ° C., preferably 25 ° C. to 30 ° C.). 7 mPa · s to 30 mPa · s is preferable. More preferably, it is 7 mPa · s to 20 mPa · s. For example, the viscosity of the ink composition of the present invention at room temperature (25 ° C. to 30 ° C.) is preferably 35 to 500 mPa · s, more preferably 35 mPa · s to 200 mPa · s.
It is preferable that the composition ratio of the ink composition of the present invention is appropriately adjusted so that the viscosity is in the above range. By setting the viscosity at room temperature high, even when a porous recording medium is used, ink permeation into the recording medium can be avoided, and uncured monomers can be reduced and odors can be reduced. Further, it is preferable because ink bleeding at the time of ink droplet landing can be suppressed, and as a result, the image quality is improved.
In the ink composition of the present invention, the ratio of the mass of the ink composition before being cured with active energy rays to the mass of the image obtained by curing and drying the ink composition with active energy rays is the former: the latter (Mass of ink composition: mass of image obtained by curing ink composition) = (100: 95) to (100: 100), more preferably (100: 97) to (100: 100). Thereby, it is excellent in suppression of a time-dependent change of film | membrane performance.
The said mass ratio can be adjusted by setting suitably the quantity of water, a solvent, etc. which can be contained in an ink composition.

  The ink composition of the present invention is suitably used for ink jet recording. When applied to ink jet recording, the ink composition of the present invention is ejected onto a recording medium by an ink jet recording apparatus, and then the ejected ink composition is irradiated with an energy ray and cured to perform recording.

2. Printed matter and method for producing the same,
The method for producing a printed material of the present invention comprises a step of forming an image on a recording medium by ejecting the ink composition of the present invention by an ink jet method using a known ink jet recording apparatus including a commercially available apparatus. Irradiating the obtained image with active energy rays to cure the ink composition to obtain a print having a cured image on the recording medium. The printed matter of the present invention is produced by the above-described method for producing a printed matter.

  The recording medium (base material) that can be applied to the production method of the present invention is not particularly limited, and various non-absorbent resin materials used for ordinary uncoated paper, paper such as coated paper, so-called soft packaging, or The resin film which shape | molded it in the film form can be used, and as a various plastic film, PET film, OPS film, OPP film, ONy film, PVC film, PE film, TAC film etc. can be mentioned, for example. In addition, examples of the plastic that can be used as the recording medium material include polycarbonate, acrylic resin, ABS, polyacetal, PVA, and rubbers. Metals and glasses can also be used as a recording medium. Furthermore, examples of the recording material applicable to the present invention include a support for a lithographic printing plate.

Examples of active energy rays applied to the production method of the present invention include α rays, γ rays, X rays, ultraviolet rays, visible rays, infrared rays, and electron beams. The peak wavelength of the active energy ray is preferably 200 nm to 600 nm, more preferably 300 nm to 450 nm, and still more preferably 350 nm to 420 nm. The output of the active energy rays, is preferably 2,000 mW / cm ² or less, more ^preferably at ^{10mW / cm 2 ~2,000mW / cm 2} , more preferably, 20 mW / ^cm 2 to 1 a 000mW / cm ^2, particularly ^{preferably 50mW / cm 2 ~800mW / cm 2} .

In particular, in the manufacturing method of the present invention, the energy beam irradiation, emission wavelength peak is 350Nm～420nm, and the ultraviolet maximum illuminance of the recording medium surface is 10mW ^/ cm ² ~2,000mW ^/ cm 2 Irradiation is preferably from a generated light emitting diode. The ink composition of the present invention can be cured with high sensitivity even with low exposure light such as light emitted from a light emitting diode.

  In the production method of the present invention, since the ink composition of the present invention described above is used and the ink composition is cured by irradiating active energy rays, the hardness is high, and the moldability and punching characteristics are improved. An excellent image can be formed. In addition, although irradiation of an active energy ray can expose collectively after discharging all the colors, it is more preferable from a viewpoint of hardening acceleration to expose for every color.

The printed material of the present invention is an image in which an image is formed by the ink composition of the present invention by the above-described production method. Therefore, an image is formed with high hardness, and a printed matter having an image excellent in moldability and punching characteristics is obtained.
Further, as described above, the ink composition of the present invention is suitably used for image formation of general printed matter, and also suitable for a mode in which an image is formed on a recording medium such as a support and then processed. Can be used.

The printed product molded body of the present invention is obtained by molding the printed product of the present invention. That is, a step of ejecting the above-described active energy ray-curable inkjet ink composition of the present invention on a recording medium by an inkjet method to form an image, and irradiating the obtained image with active energy rays, The printed matter of the present invention, comprising: a step of curing the ink composition to obtain a printed matter having a cured image on the recording medium; and a step of forming the printed matter to obtain a printed matter molded body. It is manufactured by a method for manufacturing a molded body.
As the recording medium used for the production of the printed matter molded body, a recording medium made of a moldable resin material is used, and examples thereof include PET, polycarbonate, polystyrene and the like.

  As a processing method for producing the printed product molded article of the present invention, vacuum forming, pressure forming, or vacuum / pressure forming is most preferable. In principle, vacuum forming pre-heats a flat support to a temperature at which it can be thermally deformed, sucks it into the mold by decompression, and cools it by crimping to the mold. Pressure is applied from the opposite side to the mold and cooled by pressure. In vacuum / pressure forming, the pressure reduction and pressurization are performed simultaneously.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist thereof. Unless otherwise specified, “%” and “parts” are based on mass.

<Synthesis of thiol-terminated polymer>
(Synthesis of P-1)
34 g of dimethylacetamide, dithiol (1,4-bis (3-mercaptobutyryloxy) butane, “Karenz MT-BD1”, secondary thiol made by Showa Denko KK) and 8.83 g of xylylene diisocyanate (XDI, Tokyo Chemical Industry) (Comparative bifunctional isocyanate) 5.83 g was put into a 200 ml three-necked flask and reacted at 80 ° C. for 8 hours. Thereafter, 0.44 g of the above dithiol (Karenz MT-BD1) was added, and the reaction was further performed for 4 hours. Purification by pouring into a large amount of methanol and reprecipitation, dissolving in acetone and then pouring into methanol was repeated three times. Thereby, thiol terminal polythiourethane (P-1) was obtained. The weight average molecular weight (Mw) was calculated in terms of polystyrene using a gel permeation chromatograph (GPC) manufactured by Tosoh Corporation using a solvent as N-methylpyrrolidone. The structure of both ends was confirmed by 1H-NMR and thiol titration.
(Synthesis of P-2)
68.0 g of dimethylacetamide, 10.0 g of diol (“Placcel 205” (number average molecular weight 500), manufactured by Daicel Chemical Industries), 7.8 g of xylylene diisocyanate, trimethylhexamethylene diisocyanate (2,2,4- 2,4,4-isomer mixture) (TMDI, manufactured by Tokyo Chemical Industry Co., Ltd.) 2.1 g was placed in a 200 ml three-necked flask and reacted at 80 ° C. for 8 hours. Thereafter, 3 g of dithiol (Karenz MT-BD1) was added, and the mixture was further reacted for 4 hours. Purification by pouring into a large amount of methanol and reprecipitation, dissolving in acetone and then pouring into methanol was repeated three times. This obtained the thiol terminal polyurethane (P-2).
(Synthesis of P-3 to P-11)
A thiol-terminated polymer and thiol-terminated polyureas (P-3) to (P-11) were synthesized in the same manner as (P-2) except that the raw materials and blending ratios were as shown in Table 3.

<Synthesis of comparative polymer>
Comparative polymer 1 and comparative polymer 2 were synthesized in the same manner as (P-2) using the compounds described in Table 3.

In addition, the raw material used for the name or abbreviation in Table 3 was as follows. The following number average molecular weight is a value described in the catalog.
XDI: (Xylylene Diisocyanate, Mitsui Chemicals, Takenate 500)
BDI: (1,4-butane diisocyanate, manufactured by Aldrich)
MDI: (4,4′-diphenylmethane diisocyanate, manufactured by Aldrich)
NDI: (1,5-nephthalene diisocyanate, manufactured by Aldrich)
TDI: (Tolylene-2,6-diisocyanate)
TMDI: Trimethylhexamethylene diisocyanate (2,2,4-2,2,4,4-isomer mixture) (TMDI, manufactured by Tokyo Chemical Industry Co., Ltd.)
HMDI: (Hexamethylene diisocyanate, manufactured by Aldrich)
IPDI: (Isophorone diisocyanate, manufactured by Aldrich)
IPCI: (isopropylidenebis-4-cyclohexyl diisocyanate, manufactured by Aldrich)
PXDI: (p-xylene diisocyanate, manufactured by Aldrich)
H12XDI: (Dicyclohexylmethane diisocyanate, manufactured by Aldrich)
PLACCEL 205: (polycaprolactone diol, number average molecular weight 500, manufactured by Daicel Chemical Industries)
PLACCEL 220EB: (polycaprolactone diol, number average molecular weight 2000, manufactured by Daicel Chemical Industries)
PLACCEL CD205: (polycarbonate diol, number average molecular weight 500, manufactured by Daicel Chemical Industries)
PLACCEL CD210: (polycarbonate diol, number average molecular weight 1000, manufactured by Daicel Chemical Industries)
PPG300: (polypropylene glycol diol, number average molecular weight 300, manufactured by Wako Pure Chemical Industries, Ltd.)
PPG700: (polypropylene glycol diol, number average molecular weight 700, manufactured by Wako Pure Chemical Industries, Ltd.)
PPG1000: (polypropylene glycol diol, number average molecular weight 1000, manufactured by Wako Pure Chemical Industries, Ltd.)
N-methyldiethanolamine: (Aldrich)
Diethylene glycol: (Aldrich)
Catechol ethylene glycol ether: (Ube Industries)
1,6-hexanediol: (Ube Industries)
Karenz MT-NR1: (1,3,5-tris (3-mercaptobutyloxyethyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione, trifunctional thiol, Showa (Electric Industries, secondary thiol)
Karenz MT-PE1: (pentaerythritol tetrakis (3-mercaptobutyrate), tetrafunctional thiol, made by Showa Denko KK, secondary thiol)
DPMP: (dipentaerythritol hexakis (3-mercaptopropionate), hexafunctional thiol, manufactured by Sakai Chemical Industry Co., Ltd., primary thiol)
2-hydroxyethyl acrylate: (Wako Pure Chemical Industries, Ltd.)
Hexamethylenediamine: (Wako Pure Chemical Industries, Ltd.)
1,2-bis (2-aminoethoxy) ethane: (manufactured by Tokyo Chemical Industry Co., Ltd.)

<Preparation of pigment dispersion>
The following pigments, dispersant, and solvent were mixed to prepare pigment dispersions (Y1, M1, C1, K1, and W1) for each color.

Yellow pigment dispersion (Y1)
Pigment: C.I. I. Pigment Yellow 12 10 parts Dispersant: Polymer dispersant [manufactured by Nippon Lubrizol Co., Ltd., Solsperse 32000] 5 parts Monofunctional radical polymerizable monomer: 2-phenoxyethyl acrylate [PEA, Biscoat # 192, Osaka Organic Chemical Co., Ltd. Made by company] 85 parts

Magenta pigment dispersion (M1)
Pigment: C.I. I. Pigment Red 57: 1 15 parts Dispersant: Polymer dispersant [manufactured by Nippon Lubrizol Co., Ltd., Solsperse 32000] 5 parts Monofunctional radical polymerizable monomer: 80 parts of 2-phenoxyethyl acrylate

Cyan pigment dispersion (C1)
Pigment: C.I. I. Pigment Blue 15: 3 20 parts Dispersant: Polymer dispersant [manufactured by Nippon Lubrizol Co., Ltd., Solsperse 32000] 5 partsMonofunctional radically polymerizable monomer: 75 parts of 2-phenoxyethyl acrylate

Black pigment dispersion (K1)
Pigment: C.I. I. 20 parts of Pigment Black 7 / Dispersant: Polymer dispersant [manufactured by Nippon Lubrizol Co., Ltd., Solsperse 32000] 5 parts / Monofunctional radical polymerizable monomer: 75 parts of 2-phenoxyethyl acrylate

White pigment dispersion (W1)
-Pigment: MICROLITH WHITE RA (BASF) 20 parts-Dispersant: Polymer dispersant [Nippon Lubrizol Corp., Solsperse 32000] 5 parts-Monofunctional radical polymerizable monomer: 2-phenoxyethyl acrylate 75 copies

<Preparation of ink composition>
Example 1
The ink composition of Example 1 was prepared by mixing the following components, the polymerizable compound described in Table 4, and the thiol-terminated polymer.

・ Genorad 16 [manufactured by Rahn, polymerization inhibitor] 0.05 parts ・ Lucirin TPO [manufactured by BASF, photopolymerization initiator] 6.0 parts ・ IRGACURE907 [manufactured by BASF, photopolymerization initiator] 4.0 parts Kayacure ITX [manufactured by Nippon Kayaku Co., Ltd., sensitizer] 2.0 parts / Byk 307 [manufactured by BYK Chemie, surfactant] 0.05 parts / pigment dispersion (K1 above) 13.6 parts / polymerizable compound (Listed in Table 4)
-Thiol-terminated polymers (described in Table 4)

-Examples 2 to 18 and Comparative Examples 1 to 3
Examples 2 to 18 and Comparative Examples 1 to 3 were prepared in the same manner as in Example 1 except that the types of pigment dispersion, polymerizable compound, and thiol-terminated polymer, and addition amounts thereof were changed as shown in Table 4. did.

Abbreviations in Table 4 indicate the following.
PEA: 2-phenoxyethyl acrylate
[Monofunctional radical polymerizable monomer, Biscote # 192, manufactured by Osaka Organic Chemical Co., Ltd.]
IBOA: Isobornyl acrylate [Monofunctional radical polymerizable monomer, Aronix M-156, manufactured by Toagosei Co., Ltd.]
ACMO: acryloylmorpholine [Monofunctional radical polymerizable monomer, manufactured by Kojin Co., Ltd.]
IDA: Isodecyl acrylate [Monofunctional radical polymerizable monomer, SR-395, Sartomer Co.]
DVE: triethylene glycol divinyl ether,
[Bifunctional radical polymerizable monomer, Rapi-Cure DVE-3, manufactured by ISP Europe]
TPGDA: Tripropylene glycol diacrylate:
[Bifunctional radical polymerizable monomer, NK ester APG-200, manufactured by Shin-Nakamura Chemical Co., Ltd.]
HDDA: hexanediol diacrylate [bifunctional radical polymerizable monomer, KS-HDDA, Sartomer]
TMP (PO) TA: trimethylolpropane PO-modified triacrylate [Trifunctional radical polymerizable monomer, Aronix M-310, manufactured by Toagosei Co., Ltd.]

[Evaluation]
<Inkjet image recording (printing)>
First, the prepared ink composition was filtered with a filter having an absolute filtration accuracy of 2 μm.
Next, recording on a recording medium (soft vinyl chloride sheet) was performed using a commercially available inkjet recording apparatus having a piezoelectric inkjet nozzle. The ink supply system was composed of an original tank, a supply pipe, an ink supply tank immediately before the inkjet head, a filter, and a piezo-type inkjet head, and heat insulation and heating were performed from the ink supply tank to the inkjet head portion. Temperature sensors are provided near the ink supply tank and the nozzle of the inkjet head, respectively, and the temperature is controlled by controlling the heating device according to the temperature measured by the temperature sensor so that the nozzle part is always 70 ° C ± 2 ° C. It was. The piezo-type inkjet head was driven so that multi-size dots of 8 pl to 30 pl could be ejected with a resolution of 720 × 720 dpi. In the present invention, dpi represents the number of dots per 2.54 cm.

After landing, the image was cured by ultraviolet irradiation (exposure) using a proximity type exposure machine (manufactured by Hitachi High-Tech Electronics Engineering Co., Ltd.) having a high-pressure mercury lamp to obtain a printed matter. Specifically, the exposure system, the main scanning speed, and the emission frequency were adjusted so that irradiation was started 0.1 seconds after the ultraviolet rays were condensed to an exposure surface illuminance of 100 mW / cm ² and landed on the recording medium. Further, the exposure time was variable, and exposure energy was irradiated.

Depending on the setting of the distance from the medium and the transport speed, and adjusting the exposure energy on the medium between ^{0.01J / cm 2 ~15J / cm 2} . The ultraviolet irradiation time was set until there was no sticky feeling on the image surface after ultraviolet irradiation.

(Weight loss due to curing of ink composition)
Here, in the ink compositions of Examples 1 to 18 and Comparative Examples 1 to 3, the mass of the ink composition before being cured by ultraviolet irradiation, and the ink composition is obtained by curing and drying by ultraviolet irradiation. When the mass ratio with respect to the mass of the image was measured, the mass ratio of the image obtained from the ink composition with respect to the ink composition (before curing) 100 was in the range of 97 to 100 for all the ink compositions. Met.

  Under the above conditions, ejection stability and storage stability of the ink composition, blocking sensitivity when forming an image using the ink composition, punching of the image (cured film of the ink composition) obtained by the formation Suitability and stretch rate (formability) were evaluated. The results are shown in Table 4. In addition, the measurement / evaluation method of each evaluation item in Table 4 is as follows.

(Evaluation of storage stability)
After the prepared ink composition was stored at 75% RH and 60 ° C. for 3 days, the ink viscosity at the discharge temperature was measured, and the increase in the ink viscosity was calculated by the viscosity ratio after storage / before storage. Those having a viscosity change of 1.3 or less had good storage stability and were evaluated as ◯. When this value exceeded 1.3 and was 1.5 or less, Δ, and when the value exceeded 1.5, clogging may occur at the time of discharge, and it was evaluated as x.

(Evaluation of ejection stability)
In order to evaluate the ejection stability of the ink head nozzles, the number of nozzle losses in continuous ejection for 60 minutes was evaluated using a commercially available inkjet recording apparatus having a piezo-type inkjet nozzle under the following conditions.
In the experiment, the number of nozzle losses (nozzle when the ink compositions of Examples 1 to 18 and Comparative Examples 1 to 3 were ejected on the PET substrate under the following conditions to perform exposure (exposure amount: 1000 mW / cm ² ). Count the number of

-Condition-
Number of channels: 318 / head drive frequency: 4.8 kHz / dot
Ink drops: 7 drops, 42 pl
Temperature: 45 ° C

-Evaluation criteria-
○: Nozzle loss is 0 or more and less than 5 △: Nozzle loss is 5 or more and less than 10 ×: Nozzle loss is 10 or more

(Blocking sensitivity evaluation)
Overlay 500 images of PET (size: same size as soft vinyl chloride sheet imaged both vertically and horizontally, weight: 2 g / sheet) on the image formed after UV irradiation and leave it for a day to transfer to PET. Visual evaluation was made. The case where transfer could not be confirmed easily was regarded as a pass line, the case where transfer could be confirmed for use was regarded as a fail line, and the exposure energy amount [mJ / cm ² ] required to reach the pass line was defined as blocking sensitivity.
The allowable range of blocking sensitivity is 10,000 mJ / cm ² or less, and preferably 6,000 mJ / cm ² or less.

(Elongation rate evaluation)
In the production of the prints of Examples 1 to 18 and Comparative Examples 1 to 3, the recording medium (soft vinyl chloride sheet) was replaced with a polycarbonate sheet (manufactured by Teijin Chemicals Ltd., film thickness 500 μm), and the high pressure after ink jet image recording was Printed matter for evaluation of stretch ratio (average of cured film of ink), except that ultraviolet irradiation with a mercury lamp was changed to an integrated exposure of 12,000 mJ / cm ² and illuminance: 2,140 mW / cm ^2. A film thickness of about 12 μm) was obtained.
The obtained printed material for evaluation of the stretching ratio is cut into an axial length of 5 cm and a width of 2.5 cm, and stretched at a speed of 30 cm / min using a tensile tester (manufactured by Shimadzu Corporation), whereby the cured film breaks. The rate was measured. The state of elongation from the initial length to twice the length was defined as 100% elongation. The allowable range of the stretching ratio is 200% or more, and preferably 300% or more.

(Punching process aptitude evaluation)
A printed material for evaluation of punching process suitability was formed by the following method, and the obtained printed product was observed to evaluate the workability.

The printed material for evaluation of the stretching ratio was used as a printed material for evaluation of punching process suitability. 1 is placed in the center of the vacuum table of a vacuum forming apparatus (Forming 300X, manufactured by Seiko Sangyo Co., Ltd.) so that the temperature of the recording medium as a support becomes 170 ° C. The heater temperature was set. After the recording medium temperature was heated to 170 ° C., the vacuum table on which the wooden mold was installed was slowly raised while being operated with the table lifting lever to perform vacuum forming. Using the printed product (sample), the sample was punched by hitting a hammer into a punch (φ = 10 mm) and evaluated according to the following evaluation criteria.
-Evaluation criteria-
○: Cracks were hardly generated around the hole even when confirmed with an optical microscope.
(Triangle | delta): The fine crack of the grade which cannot be confirmed visually around a hole generate | occur | produced.
X: The crack which can be confirmed visually generate | occur | produced around the hole.

  As can be seen from Table 4, the ink composition of the present invention has good ink ejection stability and blocking sensitivity, and images obtained using the ink composition have excellent punching characteristics. Further, the ink storage stability and the stretchability of the image are also good.

Claims (10)

  An ink composition comprising (i) at least one polymer of a polythiourethane having a thiol structure at both ends of the main chain, polyurethane and polyurea, (ii) a polymerizable monomer, and (iii) a polymerization initiator.   The ink composition according to claim 1, wherein the thiol structure is a secondary thiol.   The ink composition according to claim 1, wherein the main chain skeleton of the polymer has a ring structure.   The ink composition according to any one of claims 1 to 3, wherein the polymer has a weight average molecular weight of 2000 to 200,000.   The ink composition according to any one of claims 1 to 4, wherein the polymerizable monomer contains a monofunctional monomer, and the proportion of the monofunctional monomer contained in the polymerizable monomer is 80% by mass or more.   The ink composition according to any one of claims 1 to 5, wherein the content of the polymerizable monomer in the ink composition is 50% by mass or more.   The ink composition according to any one of claims 1 to 6, further comprising a colorant.   The ink composition according to any one of claims 1 to 7, which is used for inkjet. A step of forming an image on a recording medium by ejecting the ink composition according to any one of claims 1 to 8 by an inkjet method;
Irradiating the obtained image with active energy rays to obtain a print having a cured image on the recording medium;
A method for producing a printed matter comprising:   A printed matter obtained by the production method according to claim 9.