JP5591768B2 - INK COMPOSITION, PRINTED MATERIAL, PRINTED MATERIAL, AND METHOD FOR PRODUCING PRINTED MATERIAL - Google Patents

Description

  The present invention relates to an ink composition, a printed material, a printed material molded body, and a method for producing the printed material.

  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.

  As an ink composition used in such a recording method, an ink composition for ink jet printing containing a ketone resin having a hydroxyl group and an acrylate compound having a specific structure has been proposed from the viewpoint of adhesion to a polycarbonate plate (for example, Patent Document 1).

JP 2011-52107 A

By the way, when printing a plastic printed matter (for example, a dummy can, a blister pack, etc.) when printing by an ink jet method, sufficient adhesion to a recording medium such as a plastic substrate of the obtained image is required. ing. There is also a demand for improving the surface hardness of the cured product.
However, in the technique of Patent Document 1, there is still room for improvement with respect to the adhesion of the ink composition to the recording medium and the surface hardness of the cured product.

Therefore, this invention makes it a subject to achieve the following objectives.
That is, an object of the present invention is to provide an ink composition having excellent adhesion to a recording medium and having a high surface hardness of an image obtained by curing. Another object of the present invention is to provide a printed matter and a printed matter molded article having high surface hardness and excellent heat and moisture resistance. Furthermore, it is providing the method of manufacturing printed matter.

Specific means for achieving the above object are as follows.
<1> Contains a ketone resin containing at least one structural unit selected from the group consisting of the following general formula (1) and the following general formula (2) , a polymerizable compound containing a compound having an acrylamide group, and a polymerization initiator. Ink composition .

(In the general formula ^(1), R 1 ~R ³ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms, ^{R 1} and linked having 10 or less carbon ring with ^{R 2} (In formula (2), R ⁴ represents a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 6 carbon atoms, and m represents an integer of 0 to 5).
<2> Sutaira average molecular weight of the ketone resin is 3,000 to 100,000 ink composition according to <1>.
< 3> The ink composition according to <1> or <2>, wherein the content of the ketone resin with respect to the ink composition is 0.5% by mass to 15% by mass.
< 4> The ink composition according to any one of <1> to < 3> , wherein the content of the compound having an acrylamide group with respect to the total amount of the polymerizable compound is 5% by mass to 80% by mass.
< 5> The ink composition according to any one of <1> to < 4> , wherein the content of the monofunctional monomer with respect to the total amount of the polymerizable compound is 80% by mass to 100% by mass.
< 6> The ink composition according to < 5> , wherein the content of the compound having an acrylamide group with respect to the total amount of the monofunctional monomer is 1% by mass to 30% by mass.
< 7> The ink composition according to any one of <1> to < 6> , wherein the polymerizable compound further contains an N-vinyl compound.
< 8> The ink composition according to < 7> , wherein the N-vinyl compound is represented by the following general formula (3).

(In general formula (3), p represents an integer of 1 to 5.)
< 9> The ink composition according to any one of <1> to < 8> , further containing a urethane resin.
< 10> The ink composition according to any one of <1> to < 9> , which is for inkjet.
< 11> A printed matter having an image formed on the recording medium by the ink composition according to any one of <1> to < 10> .
< 12> A printed matter formed by molding the printed matter according to < 11> .
< 13> A step of ejecting the ink composition according to any one of <1> to < 10> onto a recording medium by an ink jet method to form an ink image, and irradiating the obtained ink image with active energy rays And a step of curing the ink image to form an image.

  According to the present invention, it is possible to provide an ink composition having excellent adhesion to a recording medium and having a high surface hardness of an image obtained by curing. Another object of the present invention is to provide a printed matter and a printed matter molded article having high surface hardness and excellent heat and moisture resistance. Furthermore, a method for producing a printed matter can be provided.

Hereinafter, the ink composition, the printed matter, the printed matter molded article, and the method for producing the printed matter of the present invention will be described in detail. The description of the constituent elements described below may be made based on typical embodiments of the present invention, but the present invention is not limited to such embodiments.
In the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.
In the present specification, “(meth) acryl” represents both or one of acrylic and methacrylic.
In the present specification, “monomer” and “monomer” are synonymous. The monomer in this specification is distinguished from an oligomer and a polymer, and refers to a compound having a weight average molecular weight of 2,000 or less. In the present specification, the polymerizable compound refers to a compound having a polymerizable functional group, and may be a monomer, an oligomer, or a polymer. The polymerizable functional group refers to a group that participates in a polymerization reaction.
In this specification, the term “process” is not limited to an independent process, and is included in the term if the intended action of the process is achieved even when it cannot be clearly distinguished from other processes. .

<Ink composition>
The ink composition of the present invention contains a ketone resin, a polymerizable compound containing a compound having an acrylamide group, and a polymerization initiator.

Although the operation of the present invention is not clear, it is estimated as follows.
That is, the ink composition of the present invention, which combines a ketone resin, a polymerizable compound containing a compound having an acrylamide group, and a polymerization initiator, as compared with an ink composition that combines a ketone resin and another polymerizable compound, It is derived from the relative polarity of the ketone resin and the acrylamide monomer, and is considered to be a composition in which a cured film can be easily obtained in a state where a high Tg ketone resin is segregated at the base material interface and the air interface during curing. Therefore, it is presumed that an ink composition having excellent adhesion to a recording medium and having a high surface hardness of an image obtained by curing can be provided.
In addition, the polymerizable compound having an acrylamide group has a problem that it has high sensitivity and is highly compatible with other coexisting polymerizable compounds, but has poor wet heat properties. Surprisingly, however, when used in combination with a ketone resin, the physical properties of the formed film are improved, the wet heat property is improved, and the formed image is not only improved in adhesion but also in heat and heat resistance. Presumed to be excellent.
Hereinafter, each component will be described.

[Ketone resin]
Examples of the ketone resin in the present invention, obtained by condensation of a ketone compound and formaldehyde, if Sutaira average molecular weight of 3000 or more polymeric compounds is not particularly limited. These may be chemically modified, such as subsequent hydrogenation or end group modification. Even a commercial product can be used as the ketone resin in the present invention. Examples of commercially available products include Synthetic resin SK, Synthetic resin AP (manufactured by Evonik Degussa), and ketone resin K-90 (manufactured by Arakawa Chemical Co., Ltd.).
Ketone resin in the present invention, from the viewpoint of high solubility in a solution containing A acrylic-based compound, at least one structural unit selected from the group consisting of the following general formula (1) and the following general formula (2) including.

In the general formula (1), R ^{1 to} R ³ each independently represents a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms, and R ¹ and R ² are linked to form a ring having 10 or less carbon atoms. A structure may be formed.
In the general formula (2), R ⁴ represents a hydrogen atom, a halogen atom (F, Cl, Br, I, etc.) or a hydrocarbon group having 1 to 6 carbon atoms. m shows the integer of 0-5.

In addition, as a ketone resin in this invention, 1 type, or 2 or more types of structural units can be used combining among the structural units represented by the said General formula (1) and the said General formula (2).
Especially, as a ketone resin in this invention, the ketone resin which consists only of each structural unit represented by the said General formula (1) and the said General formula (2) is preferable, and is represented by the said General formula (1). A ketone resin consisting only of structural units is more preferred.

Hereinafter, the formula (1) will be described in detail.
In the formula ^(1), R 1 to R ³ are each independently a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms, ^{R 1} and carbon atoms linked to the ^{R 2} 10 following ring structures May be formed.
In the formula (1), R ^{1 to} R ³ preferably represent a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, and more preferably a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. Indicates.
In the present specification, the hydrocarbon group may be either a saturated hydrocarbon group or an unsaturated hydrocarbon group, and may be either linear or branched. Moreover, it includes not only an unsubstituted hydrocarbon group having no substituent but also a hydrocarbon group having a substituent.

As the substituent when the hydrocarbon group having 1 to 6 carbon atoms represented by R ^{1 to} R ³ has a substituent, a substituent such as a hydroxyl group, a halogen atom (F, Cl, Br, I, etc.), a thiol group, etc. It may have a group, and preferably has a hydroxyl group, a bromine atom, or a chlorine atom from the viewpoint of solubility.

In the formula (1), R ¹ _and R ² represent a hydrogen atom, R ³ preferably represents an alkyl group having 6 or less carbon atoms, R ¹ _and R ² represent a hydrogen atom, and R ³ represents a carbon number. More preferably, it represents 3 or less alkyl groups.

In the formula (1), R ¹ and R ² may be linked to form a ring structure having 10 or less carbon atoms, preferably a ring structure having 8 or less carbon atoms, more preferably 5 carbon atoms. Or form a 6 ring structure.
In the formula (1), R ¹ and R ² are linked to form a cycloalkyl structure having 8 or less carbon atoms, and R ³ preferably represents a hydrogen atom or a methylol group, and R ¹ and R 2 ² is linked to form a cycloalkyl structure having 6 or less carbon atoms, and R ³ is preferably a hydrogen atom or a methylol group.

Hereinafter, the formula (2) will be described in detail.
In the above formula (2), ^{R 4} represents a hydrogen atom, a halogen atom (F, Cl, Br, I, etc.) or a hydrocarbon group having 1 to 6 carbon atoms. More preferably, R ⁴ represents a hydrogen atom, a chlorine atom, a bromine atom, a fluorine atom or a hydrocarbon group having 1 to 6 carbon atoms. More preferably, R ⁴ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

  In said formula (2), m shows the integer of 0-5, Preferably the integer of 0-4 is shown, More preferably, the integer of 0-2 is shown.

  Specific examples of the ketone resin in the present invention are shown below. However, it is not necessarily limited to these. In the following specific examples, n represents 5 to 100.

Of the above formula (1) and formula (2), formula (1) is preferable from the viewpoint of solubility in ink and small increase in viscosity.
Further, among the specific examples a-1 to a-14 of the structural units of the ketone resin, a-1, a-2, a-3, a-8, a, from the viewpoint of improving inkjet discharge stability and adhesion. -9, a-10 or a-11 is preferable, and a-2 or a-11 is more preferable.

  Specific examples a-1 to a-14 of the structural units of the ketone resin can be synthesized by a known method. The terminal group can also be synthesized by a known method. As a known method, for example, it can be synthesized according to Journal of applied Polymer Science (1993) 50, 577-584, Japanese Patent Application Laid-Open No. 2009-249611, and the like.

The weight average molecular weight (Mw) of the ketone resin in the present invention is 3000 to 100,000, preferably 3000 to 50000. From the viewpoint of solubility in a solvent containing an acrylic compound, the weight average molecular weight of the ketone resin is More preferably, it is 3000-20000.
When the weight average molecular weight of the ketone resin is 3000 to 100,000, it is preferable because the ejection stability in ink jet is good.

The number average molecular weight (Mn) of the ketone resin in the present invention is preferably 700 or more, more preferably 1000 or more, more preferably 3000 to 100,000, further preferably 3000 to 50000, to a solvent containing an acrylic compound. From the viewpoint of solubility of the ketone resin, the number average molecular weight of the ketone resin is most preferably 3000 to 20000.
When the number average molecular weight of the ketone resin is 700 or more, it is preferable because the ejection stability in ink jet is good.
In addition, the value measured in terms of styrene by GPC method is used for a weight average molecular weight and a number average molecular weight.

  The content of the ketone resin is preferably 0.5% by mass to 15.0% by mass, more preferably 1.0% by mass to 10.0% by mass with respect to the ink composition. From the viewpoint of improving the viscosity at which stable discharge is possible when using acrylamide and improving the adhesion to the substrate, the content is more preferably 1.0% by mass to 5.0% by mass.

[Polymerizable compound]
The ink composition of the present invention contains a polymerizable compound, and the polymerizable compound contains a compound having an acrylamide group. Moreover, you may contain the monofunctional monomer or polyfunctional monomer other than the compound which has an acrylamide group as needed.

(Compound having acrylamide group)
The compound having an acrylamide group is not particularly limited as long as it is a polymerizable compound having one or more acrylamide groups or methacrylamide groups. Of these, compounds having 1 to 2 acrylamide groups are preferred, and compounds having 1 are most preferred. For example, acrylamide, N-methylol acrylamide, diacetone acrylamide, N, N-dimethyl acrylamide, N, N-diethyl acrylamide, N-isopropyl acrylamide, acryloylmorpholine, methacrylamide, N-methylol methacrylamide, diacetone methacrylamide, N , N-dimethylmethacrylamide, N, N-diethylmethacrylamide or N-isopropylmethacrylamide, methylenebisacrylamide.
Among these, N-isopropylacrylamide, acryloylmorpholine or dimethylacrylamide is particularly preferable from the viewpoints of film curability and viscosity.

The content of the compound having an acrylamide group is preferably 5% by mass to 90% by mass, more preferably 10% by mass to 80% by mass, and more preferably 10% by mass to 10% by mass with respect to the total amount of the polymerizable compound. More preferably, it is 70 mass%.
The content of the compound having an acrylamide group is preferably 5% by mass to 90% by mass because it has high curing sensitivity and pigment dispersion stability.

(Polymerizable compounds other than compounds having an acrylamide group)
The polymerizable compound other than the compound having an acrylamide group preferably contains a monofunctional monomer such as an N-vinyl compound, an acrylate compound, a methacrylate compound, or a vinyl ether compound from the viewpoint of curing sensitivity. It is also useful to include a polyfunctional monomer from the viewpoint of improving the strength of the printed matter and durability at high temperatures.

-N-vinyl compound-
Examples of the N-vinyl compound include N-vinylformamide (NVF), N-vinylcaprolactam (NVC), N-vinylpyrrolidone, N-vinylcarbazole and the like.
Among these, an N-vinyl compound represented by the following general formula (3) is preferable from the viewpoint of ink exposure sensitivity and safety.

  In formula (3), p represents an integer of 1 to 5. More preferably, it represents an integer of 2 to 5, more preferably N-vinylcaprolactam.

The content of the N-vinyl compound is preferably 1% by mass to 60% by mass, more preferably 1% by mass to 50% by mass with respect to the total amount of the polymerizable compound, and 1% by mass to 40%. More preferably, it is mass%.
When the content of the N-vinyl compound is 1% by mass to 60% by mass, it is preferable because adhesion to a substrate such as vinyl chloride and sensitivity are improved.

-Acrylic compounds-
As acrylic compounds, 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-acryloyloxyethylphthalic acid, methoxy-polyethylene glycol acrylate, 2-acryloyloxyethyl-2-hydroxyethylphthalic acid, cycle Trimethylolpropane formal acrylate, 2- (2-ethoxyethoxy) ethyl acrylate, 2-methoxyethyl acrylate, 3-methoxybutyl acrylate, ethoxylated phenyl acrylate, 2-acryloyloxyethyl succinic acid, nonylphenol EO adduct acrylate Acrylate compounds such as phenoxydiethylene glycol 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, grease Jill methacrylate, benzyl methacrylate, methacrylate compounds such as dimethylaminoethyl methacrylate are preferred.

The content of the acrylic compound is preferably 1% by mass to 90% by mass, more preferably 1% by mass to 80% by mass, and more preferably 5% by mass to 60% by mass with respect to the total amount of the polymerizable compound. More preferably.
When the content of the acrylic compound is 1% by mass to 90% by mass, it is preferable because the dispersion stability of the pigment and the ink sensitivity are increased.

-Other monofunctional monomers-
Allyl compounds such as allyl glycidyl ether;

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-methyl cyclohexyl methyl vinyl ether, benzyl vinyl ether, dicyclopentenyl vinyl ether, 2-dicyclopentenoxyethyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, butoxyethyl vinyl 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 monovinyl 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-propylene carbon Vinyl ether compounds such as preparative;
Etc.

  In the ink composition of the present invention, the content of the monofunctional monomer is preferably 80% by mass to 100% by mass and more preferably 85% by mass to 100% by mass with respect to the total amount of the polymerizable compound. Preferably, it is 90 mass%-100 mass%.

In addition, the content of the compound having an acrylamide group is preferably 5% by mass to 100% by mass, more preferably 10% by mass to 100% by mass, and more preferably 15% by mass with respect to the total amount of the monofunctional monomer. More preferably, it is -100 mass%.
When the content of the compound having an acrylamide group is 5% by mass to 100% by mass with respect to the total amount of the monofunctional monomer, it is preferable because the balance between stretchability and sensitivity of the film is good.

  The molecular weight of the monofunctional monomer is preferably from 150 to 100, more preferably from 150 to 800, and even more preferably from 200 to 500.

-Multifunctional monomer-
Examples of the polyfunctional monomer include polyfunctional radical polymerizable compounds having two or more ethylenically unsaturated bonds capable of radical polymerization.

  Examples of the polyfunctional monomer include bis (4-acryloxypolyethoxyphenyl) propane, 1,6-hexanediol diacrylate, tripropylene glycol diacrylate, polyethylene glycol diacrylate, polypropylene glycol diacrylate, and dipentaerythritol tetra. Acrylate, 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 diacrylate, PO adduct diacrylate of bisphenol A, EO adduct diacrylate of bisphenol A, dipentaerythritol hexaacrylate, propylene glycol diglycidyl ether Acrylate compounds such as acrylic acid adducts and ditrimethylolpropane tetraacrylate; and methacrylate compounds such as polyethylene glycol dimethacrylate and polypropylene glycol dimethacrylate 2,2-bis (4-methacryloxypolyethoxyphenyl) propane. Other examples include allyl compounds such as diallyl phthalate and triallyl trimellitate. PO represents propylene oxide, and EO represents ethylene oxide.

  Polyfunctional vinyl ethers are also preferably used as the polyfunctional radical polymerizable monomer. 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,

Divinyl ethers such as butanediol divinyl ether, hexanediol divinyl ether, cyclohexane dimethanol divinyl ether, bisphenol A alkylene oxide divinyl ether, bisphenol F alkylene oxide divinyl ether; trimethylol ethane trivinyl ether, trimethylol propane trivinyl ether, ditrimethylol propane 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-added ditrimethylolpropane tetravinyl ether, ethylene oxide-added pentaerythritol tetravinyl ether, propylene oxide-added pentaerythritol tetravinyl ether, ethylene oxide-added dipentaerythritol hexavinyl ether, propylene oxide-added dipentaerythritol hexavinyl ether And polyfunctional vinyl ethers. 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.

  In addition to the above, examples of the polyfunctional radical polymerizable compound include, for example, JP-A-7-159983, JP-B-7-31399, JP-A-8-224982, JP-A-10-863, Photo-curable polymerizable compounds used in photopolymerizable compositions described in various publications such as Kaihei 9-134011 and JP-T-2004-514014 are known, and these are also inks of the present invention. It can be applied to the composition.

  In the present invention, the molecular weight of the polyfunctional monomer is preferably 200 to 1500, more preferably 250 to 1500, and still more preferably 250 to 1200.

  Content of a polyfunctional monomer is 20 mass% or less with respect to the total amount of a polymeric compound, Preferably it is 0 mass%-15 mass%, More preferably, it is 0 mass%-10 mass%.

[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 a photopolymerization initiator is preferably mentioned.
As the polymerization initiator, a known polymerization 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 polymerization 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 polymerization initiator, the light for initiating polymerization indicates active energy rays, that is, γ rays, β rays, electron beams, ultraviolet rays, visible rays, infrared rays, and the like, and preferably ultraviolet rays.

  As the polymerization initiator, known compounds can be used. Preferred polymerization initiators that can be used in the present invention include (a) aromatic ketones, (b) acylphosphine oxide compounds, and (c) aromatic onium salts. Compound, (d) organic peroxide, (e) thio compound, (f) hexaarylbiimidazole compound, (g) ketoxime ester compound, (h) borate compound, (i) azinium compound, (j) metallocene compound , (K) active ester compounds, (l) compounds having a carbon halogen bond, and (m) alkylamine compounds, and more preferably (a) aromatic ketones and (b) acylphosphine oxide compounds. Can be mentioned.

  These polymerization initiators may use the above compounds (a) to (m) alone or in combination. The polymerization initiator in the present invention is suitably 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 polymerization 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) is 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 3% by mass to 20% by mass, more preferably 3% by mass to 18% by mass, and further preferably 3% by mass to 15% by mass with respect to the ink composition. It is.

[Urethane resin]
The ink composition of the present invention may contain a urethane resin. Since the strength of the ink film is improved by containing a urethane resin, it is preferable.
The urethane resin is not particularly limited as long as it includes a urethane structural unit (—NH—CO—O—). Examples thereof include polycarbonate polyurethane, polyester polyurethane, polyalkylene oxide polyurethane, and polycaprolactone polyurethane.
The content of the urethane resin in the ink composition is preferably 0.1% by mass to 20.0% by mass with respect to the ink composition, more preferably 0.5% by mass to 15.0% by mass, and still more preferably. 1.0% by mass to 10.0% by mass.
The weight average molecular weight of the urethane resin is preferably 3000 to 60000, more preferably 5000 to 50000, and still more preferably 8000 to 30000.

[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. I. Pigment yellow 120 (monoazobenzimidazolone), C.I. I. Pigment yellow 155 (diazo), C.I. I. Pigment Yellow 151 (monoazobenzimidazolone), C.I. I. Pigment yellow 185 (isoindoline), C.I. I. Please add Pigment Yellow 213 (monoazo, quinoxaline).

  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.

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 to the ink composition in an amount of 0.05% to 20.00% by weight, and more preferably 0.2% to 10.0% by weight. When an oil-soluble dye is used as the colorant, the content is particularly preferably 0.2% by mass to 6.0% 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; ethanethiol, butanethiol, dodecanethiol, mercaptoethanol, mercaptopropanol, methyl mercaptopropionate, ethyl mercaptopropionate, mercaptopropionic acid, thioglycolic acid, ethyl disulfide , Sec-butyl disulfide, 2-hydroxyethyl disulfide, thiosalicylic acid, thiophenol, thiocresol, benzyl mercaptan, phenethyl mercaptan, thiocarbonate, 1,4-bis (3-mercaptobuty Ruoxy) butane, 1,3,5-tris (3-mercaptobutyloxyethyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione, pentaerythritol tetrakis (3-mercaptobuty Sulfur-containing compounds such as (Rate); and the like, but are not limited thereto.

Among these, the chain transfer agent is preferably a thiol compound from the viewpoints of storage stability and sensitivity improvement of the ink composition. Furthermore, the chain transfer agent is more preferably a secondary or tertiary thiol polyfunctional thiol compound.
Is preferred.

  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 still more preferably 3,000 or more and 80,000 or less.

  As a commercial item, Karenz MT series (made by Showa Denko KK) is used suitably.

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.
In the present specification, the total solid mass means the total content of all components excluding the solvent constituting the ink composition.

(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 polymerization initiator used in the ink composition may be used, but it is used for a curing reaction of a general ink composition. Considering 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.

  The addition amount of the sensitizing dye to the ink composition of the present invention is preferably 0.1% by mass to 10% by mass, and 0.5% by mass to 6% by mass with respect to the total solid content mass of the ink composition. More preferably, it is more preferably 1% by mass to 5% by mass.

(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.

  The amount of the co-sensitizer added to the ink composition of the present invention is preferably 0.1% by mass to 10% by mass, and preferably 0.5% by mass to 0.5% by mass relative to the total solid mass of the ink composition. It is more preferable that it is 6 mass%, and it is further more preferable that it is 0.5 mass%-5 mass%.

(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 with respect to the total solid content mass of the ink composition.

(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.
The addition amount is appropriately selected according to the purpose, but is preferably 0.1% by mass to 8% by mass with respect to the total solid mass of the ink composition.

(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. .
The addition amount is appropriately selected according to the purpose, but is preferably 0.1% by mass to 8% by mass with respect to the total solid mass of the ink composition.

(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. Although content of electroconductive salt is not limited, 0.1 mass%-8 mass% are preferable with respect to the whole ink composition, and 0.5 mass%-5 mass% are more preferable.

(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 thereof is preferably from 0.1% by mass to 5% by mass, more preferably from 0. It is in the range of 1% by mass to 3% by mass.

(Polymer compound)
In the ink composition of the present invention, various oil-soluble polymer compounds can be used in combination 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 copolymers obtained by copolymerization of acrylic monomers are 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.
Although content of a high molecular compound is not limited, 0.1 mass%-10 mass% are preferable with respect to the whole ink composition, and 0.5 mass%-4.0 mass% are more preferable.

(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). Examples described in Japanese Patent Publication (columns 8 to 17) and JP-A No. 62-135826.
The content of the surfactant in the composition is appropriately selected depending on the purpose of use, but is preferably 0.0001% by mass to 1% by mass, and 0.001% by mass to 0.1% by mass with respect to the entire ink composition. Is more preferable.

In addition, in order to improve the adhesion to recording media such as polymerization inhibitors, leveling additives, matting agents, waxes for adjusting film physical properties, polyolefins, PET, etc. A tack fire (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, thiodipropionic acid esters, 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 mass%-5 mass% are preferable with respect to the whole ink composition, and 0.02 mass%-1 mass% are 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. Therefore, in consideration of dischargeability, it is preferable that the viscosity is 7 mPa · s to 30 mPa · s at the temperature during discharge (for example, 40 ° C. to 80 ° C., preferably 25 ° C. to 30 ° C.). More preferably, it is 7 mPa · s to 20 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.
The ink composition of the present invention preferably has a surface tension at 25 ° C. of 20 mN / m to 40 mN / m. The surface tension is measured under the condition of 25 ° C. using an Automatic Surface Tensiometer CBVP-Z (manufactured by Kyowa Interface Science Co., Ltd.). The viscosity is preferably 1 mPa · s to 40 mPa · s, and more preferably 3 mPa · s to 30 mPa · s. The viscosity of the ink composition is measured under conditions of 25 ° C. using VISCOMETER TV-22 (manufactured by TOKI SANGYOCO. LTD).

  The ink composition of the present invention is suitably used for ink jet recording. When the ink composition of the present invention is 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 energy rays and cured. To record.

The ink composition of the present invention can also be used for image formation of general printed materials other than inkjet recording.
In addition, the ink composition of the present invention can also be suitably used in an embodiment in which processing is performed after an image is formed on a recording medium such as a support.

<Printed matter, printed matter molded body, and method for producing printed matter>
The printed matter of the present invention has an image formed with the ink composition of the present invention on a recording medium.
Since the printed material of the present invention uses the ink composition of the present invention, a high-hardness image is formed and the printed material has an image with excellent moldability.
Moreover, the printed matter of the present invention can be suitably used in a method for processing after forming an image on a recording medium such as a support, in addition to being suitably used in a general method for producing a printed matter.

  The production method of the printed material of the present invention is not particularly limited, and can be produced by a known method. For example, it can also manufacture according to the manufacturing method explained in full detail below.

  The method for producing a printed material of the present invention includes a step of forming an ink 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 device including a commercially available device. Irradiating the obtained ink image with active energy rays to cure the ink image and form a cured image on the recording medium.

The recording medium (base material) that can be applied to the present invention is not particularly limited, and various non-absorbent resin materials used for ordinary non-coated paper and coated paper, so-called soft packaging, or films thereof. A resin film molded into a shape can be used, and examples of various plastic films include PET film, OPS film, OPP film, ONy film, PVC film, PE film, and TAC film. 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.
In the ink composition of the present invention, acrylic resin, polycarbonate resin, polyethylene terephthalate resin, ABS resin, polystyrene, and polyvinyl chloride are preferable as plastics that can be used as a recording medium material. Moldability, durability, and scratch resistance are preferred. From the viewpoint of properties, acrylic resin and acrylic resin / polycarbonate resin plywood are more preferable.

Examples of the active energy rays applied to 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 print production process of the present invention, the energy beam irradiation, emission wavelength peak is 350Nm～420nm, and maximum illuminance of the recording medium surface is 10mW ^/ cm ² ~2,000mW ^/ cm 2 The light is preferably emitted from a light emitting diode that generates ultraviolet rays. 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.

  The printed matter molded article obtained by the present invention is obtained by molding the printed matter of the present invention. It does not restrict | limit especially as a manufacturing method of a printed matter molded object, A well-known method can be used. For example, a step of forming an ink image by ejecting the above-described active energy ray-curable inkjet ink composition of the present invention on a recording medium by an inkjet method, and irradiating the obtained ink image with active energy rays. A printed matter molded body according to 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 obtaining the printed matter by molding the printed matter. It can manufacture with the manufacturing method of this.

  A recording medium made of a moldable resin material is used as a recording medium used for manufacturing a printed product, and examples thereof include PET, polycarbonate, polystyrene, and acrylic resin.

  As a processing method for producing the above-described printed product, 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.

  Among the compounds used in Examples and Comparative Examples, compounds not described by the manufacturer were synthesized by applying known methods or known methods.

IBOA (Isobornyl acrylate, Aronix M-156, manufactured by Toagosei Co., Ltd.)
Ebecryl 110: Phenoxydiethylene glycol acrylate (Daicel Cytec)
ACMO (compound name acryloylmorpholine, manufactured by Kojin Co., Ltd.)
・ NIPAM (Compound name: N-isopropylacrylamide, manufactured by Kojinsha)
・ DMAA (dimethylacrylamide, manufactured by Kojinsha)
-PEA (2-phenoxyethyl acrylate, biscoat # 192, manufactured by Osaka Organic Chemical Co., Ltd.)
・ NVF (N-vinylformamide, manufactured by Arakawa Chemical)
NVC (compound name N-vinylcaprolactam, manufactured by BASF)
HDDA: hexanediol diacrylate, bifunctional radical polymerizable monomer, SR238, Sartomer)

Synthetic resin SK (polyol resin, manufactured by Evonik Degussa) Mn = 800
・ Synthetic resin AP (Mn = 780)

Synthesis example of ketone resin (synthesis of a-1)
To a three-necked flask, 98 g of cyclohexanone, 20 g of cyclohexane, and 20 g of formalin were added and heated to 60 degrees with stirring. 0.36 ml of 20% NaOH aqueous solution was added dropwise and refluxed at 75 degrees for 1 hour. Further, 100 g of formalin and 3.64 ml of 20% NaOH aqueous solution were added, and the reflux was continued for 2 hours. After cooling, the oil phase was taken out by decantation, washed with warm water three times, and then dried under reduced pressure to obtain a-1. The obtained a-1 was identified by NMR and GPC measurements.

(Synthesis of a-2)
The resulting a-1 (5 g) was dissolved in dry pyridine (20 ml) and chloroform (20 ml). While vigorously stirring and ice-cooling, 20 g of benzoyl chloride was added dropwise, followed by reaction at room temperature for 24 hours. After completion of the reaction, 80 ml of chloroform was added, washed with dilute sulfuric acid aqueous solution and sodium hydrogen carbonate aqueous solution, poured into hexane solution, and the precipitate was vacuum dried at 100 ° C. to obtain a-2. The obtained a-2 was identified by NMR and GPC measurements.

(Synthesis of a-3 to a-5)
a-3 to a-5 were obtained under the same conditions as a-1, except that the cyclohexanone used in the synthesis of a-1 was changed to the raw materials shown in Table 1. The obtained a-3 to a-5 were identified by NMR and GPC measurements.

(Synthesis of a-6 and a-7)
While 5 g of the obtained a-4 was dissolved in 20 ml of dry pyridine and 20 ml of chloroform, 20 g of benzoyl chloride was added dropwise with vigorous stirring and ice cooling, and reacted for 24 hours. After completion of the reaction, the mixture was washed with dilute sulfuric acid aqueous solution and sodium hydrogen carbonate aqueous solution, poured into a hexane solution, and the precipitate was vacuum dried at 100 ° C. to obtain a-6. Further, 2 g of a-5 was added to 20 ml of a 3: 1 mixture of pyridine and acetic anhydride, and a-7 was obtained by refluxing at 120 ° C. for 3 hours. The obtained a-6 and a-7 were identified by NMR and GPC measurement.

(Synthesis of a-8)
To a three-necked flask, 67 g of acetophenone, 30 g of formalin, and 10 g of 40% KOH aqueous solution were added and refluxed at 90 degrees for 8 hours. Furthermore, 6.5 g of 40% KOH aqueous solution was added and refluxed for 8 hours. After cooling, the oil phase was taken out by decantation, washed with warm water three times, and then dried under reduced pressure to obtain a-8. The obtained a-8 was identified by NMR and GPC measurements.

(Synthesis of a-9 to a-13)
a-9 to a-13 were obtained under the same conditions as a-8, except that the acetophenone used in the synthesis of a-8 was changed to the raw materials shown in Table 1. The obtained a-9 to a-13 were identified by NMR and GPC measurements.

(Synthesis of a-14)
5 g of the obtained a-8 was dissolved in 20 ml of isopropyl alcohol, 2 g of sodium borohydride was added and reacted at 40 ° C. for 6 hours, then poured into ice water, and the precipitate was vacuum-dried at 100 ° C. -14 was obtained. The obtained a-14 was identified by NMR and GPC measurements.

  The structures of ketone resins (a-1) to (a-14) used in the following examples are shown below.

(Preparation of pigment dispersion)
The following pigment, dispersant, and solvent were mixed and stirred for 10 minutes at 2500 rpm using a mixer (L4R manufactured by Silverson). Then, it is placed in a bead mill disperser DISPERMAT LS (manufactured by VMA) and dispersed for 6 hours at 2,500 rpm with a YTZ ball (manufactured by Nikkato Co., Ltd.) having a diameter of 0.65 mm. (Y1, M1, C1, K1, and W1) were prepared.

Yellow pigment dispersion (Y1)
Pigment: C.I. I. Pigment Yellow 12 10 parts ・ Dispersant: Polymer dispersant (manufactured by Nippon Lubrizol Co., Ltd., Solsperse 32000) ・ Monofunctional polymerizable compound: 2-phenoxyethyl acrylate [PEA, Biscote # 192, Osaka Organic Chemical Co., Ltd. Made] 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) ・ Monofunctional polymerizable compound: 2-phenoxyethyl acrylate 80 parts

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 parts Monofunctional polymerizable compound: 75 parts of 2-phenoxyethyl acrylate

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

White pigment dispersion (W1)
Pigment: MICROLITH WHITE RA (BASF) 20 parts Dispersant: Polymer dispersing agent [Nippon Lubrizol Corporation, Solsperse 32000] 5 parts Monofunctional polymerizable compound: 2-phenoxyethyl acrylate 75 Part

Example 1
-Preparation of color ink composition-
The following components were mixed with the components shown in Table 2 and stirred for 15 minutes at 2500 rpm using a mixer (Silverson L4R). Thereafter, the mixture was filtered using a cartridge filter (product name: Profile II AB01A01014J) manufactured by Nippon Pole Co., Ltd., and the ink composition of Example 1 was prepared.

・ Genorad 16 [manufactured by Rahn, polymerization inhibitor] 0.05 parts ・ Lucirin TPO [manufactured by BASF, polymerization initiator] 6.0 parts ・ p-phenylbenzophenone [manufactured by Wako Pure Chemical Industries, polymerization initiator] 4 0.0 part. Karenz MT-PE1 [polyfunctional thiol compound, pentaerythritol tetrakis (3-mercaptobutyrate), Showa Denko KK, chain transfer agent] 2.0 parts. Byk 307 [manufactured by BYK Chemie, surface activity Agent] 0.05 parts

  The obtained ink composition of Example 1 was evaluated for adhesion as follows. The results are shown in Table 3.

-Adhesion evaluation-
Using a polycarbonate sheet (PC, manufactured by Teijin Kasei Co., Ltd.) and an acrylic sheet (Acryl, manufactured by Nihon Acryase Co., Ltd.) as a recording medium, the ink composition of Example A1 obtained on each surface was coated with a K hand coater (bar No. .2) was applied to a wet film thickness of 12 μm. Next, energy ray curing is carried out by an experimental UV mini conveyor device CSOT (manufactured by GS Yuasa Power Supply Co., Ltd.) equipped with an ozone-less metal halide lamp MAN250L and set to a conveyor speed of 9.0 m / min and an exposure intensity of 2.0 W / cm ^2. I let you. The adhesion to the recording medium was evaluated according to the following criteria by ISO 2409 (cross-cut method) using this cured coating film. The results are shown in Table 3.

0: The edge of the cut is completely smooth and there is no peeling to the eyes of any lattice.
1: Small peeling of the coating film occurs at the intersection of cuts. The cross cut is not affected by more than 5%.
2: Peel along the edge of the cut of the coating and / or at the intersection. The cross-cut portion is affected by more than 5% but not more than 15%.
3: The coating film is partially or completely peeled along the edge of the cut, and / or various parts of the eye are partially or completely peeled off. The cross-cut part is affected by more than 15% but not more than 35%.
4: The coating film is partially or completely peeled along the edge of the cut, and / or some eyes are partially or completely peeled off. The cross-cut portion is affected by more than 35% but not more than 65%.
5: The degree of peeling exceeds 65%.
Based on the evaluation of ISO, 0-1 was evaluated as A, 2-4 as B, and 5 as C.

Moreover, the printed matter was produced by the following method, and pencil hardness evaluation and wet heat resistance evaluation were performed. The results are shown in Table 3.
-Production of printed matter-
The ink composition prepared in Example 1 was filtered with a filter having an absolute filtration accuracy of 2 μm.
Next, using a commercially available inkjet recording apparatus having a piezo-type inkjet nozzle (trade name LuxJet UV350GTW, manufactured by FUJIFILM Corporation), the recording medium [(polycarbonate resin (Panlite PC-1151) with fine mode, lamp 5) , Thickness 500 μm, manufactured by Teijin Chemicals Ltd.), or (acrylic resin (acrylic E), thickness 30 mm, manufactured by Mitsubishi Rayon Co., Ltd.)]. The ink supply system consists of an original tank, supply piping, an ink supply tank immediately before the inkjet head, a filter, and a piezo-type inkjet head. The ink supply tank is insulated and heated from the inkjet head part, and the nozzle part is always 45 ° C. The temperature was controlled so as to be ± 2 ° C. The piezo-type inkjet head was driven so that multi-size dots of 8 pl to 30 pl could be ejected at a resolution of 600 × 450 dpi to form a solid image. Note that dpi (dot per inch) in the present invention 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} . Note that the ultraviolet irradiation time was set until the sticky feeling disappeared on the image surface after the ultraviolet irradiation.

-Pencil hardness evaluation-
About the obtained printed matter, the pencil hardness test was done based on JIS K5600-4. The results are shown in Table 3.
In the ink of the present invention having stretchability, the allowable range of hardness is HB or more, and preferably H or more. A printed material having an evaluation result of B is not preferable because scratches may occur when the printed material is handled.
The pencil used was UNI (registered trademark) manufactured by Mitsubishi Pencil Co., Ltd.

―Heat and heat resistance evaluation―
The above printed coating film of 3 cm × 3 cm was placed in a thermostat bath of 70 degrees and 90 RH% so that the coating film would become a table, and after 192 hours, the shape change of the film was observed visually and with a 50-fold optical microscope.
The results are shown in Table 3.
A evaluation: No change in coating film B evaluation: Although it is difficult to see visually, the coating film is peeled off and distorted with an optical microscope. C evaluation: The coating film is peeled off and visibly visible.

(Examples 2-19, Comparative Examples 1-3)
Ink compositions of Examples 2 to 19 and Comparative Examples 1 to 3 were the same as Example 1 except that the types and addition amounts of the pigment dispersion, polymerizable compound and ketone resin were changed as shown in Table 2. Was prepared and the adhesion was evaluated. Moreover, the printed matter was produced similarly to Example 1, and pencil hardness and wet heat resistance were evaluated. The results are shown in Table 3.

  As is clear from the results in Table 3, it was found that Examples 1 to 19 using the ink composition of the present invention were excellent in adhesion as compared with the ink compositions of Comparative Examples 1 to 3. It has also been clarified that the printed matter produced using the ink composition of the present invention has high hardness and excellent heat and humidity resistance. Furthermore, among the ink compositions of Examples 1 to 19, it was revealed that the ink composition using a ketone resin having a number average molecular weight of 700 or more exhibits an excellent effect.

Claims (13)

Containing a ketone resin containing at least one structural unit selected from the group consisting of the following general formula (1) and the following general formula (2) , a polymerizable compound containing a compound having a (meth) acrylamide group, and a polymerization initiator Ink composition.


(In the general formula ^(1), R 1 ~R ³ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms, ^{R 1} and linked having 10 or less carbon ring with ^{R 2} (In formula (2), R ⁴ represents a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 6 carbon atoms, and m represents an integer of 0 to 5). The ink composition of claim 1 Sutaira average molecular weight of the ketone resin is 3,000 to 100,000. The ink composition according to claim 1 or 2, wherein a content of the ketone resin with respect to the ink composition is 0.5% by mass to 15% by mass. The ink composition according to any one of claims 1 to 3, wherein a content of the compound having an acrylamide group with respect to a total amount of the polymerizable compound is 4% by mass to 90% by mass. The ink composition according to any one of claims 1 to 4, wherein the content of the monofunctional monomer with respect to the total amount of the polymerizable compound is 80% by mass to 100% by mass. The ink composition according to claim 5, wherein the content of the compound having an acrylamide group with respect to the total amount of the monofunctional monomer is 5% by mass to 90% by mass. The polymerizable compound is further ink composition according to any one of claims 1 to 6 containing N- vinyl compound. The ink composition according to claim 7, wherein the N-vinyl compound is represented by the following general formula (3).


(In general formula (3), p represents an integer of 1 to 5.) Furthermore, the ink composition of any one of Claims 1-8 containing a urethane resin. The ink composition according to any one of claims 1 to 9, which is for inkjet. Printed matter having an image formed by the ink composition according to any one of claims 1 to 10 on a recording medium. A printed matter formed by molding the printed matter according to claim 11 . A step of ejecting the ink composition according to any one of claims 1 to 10 on a recording medium by an ink jet method to form an ink image;
Irradiating the obtained ink image with active energy rays, curing the ink image, and forming an image;
A method for producing printed matter including