JP2013112789A - Ink composition, image forming method and printed matter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink composition which gives an image having excellent water resistance, solvent resistance and blocking resistance and is appropriate for image formation using an inkjet method, and also to provide an image forming method using the ink composition and printed matter.SOLUTION: The ink composition includes (a) a polymer compound having a repeating unit with a partial structure represented by formula (1) and at least one selected from a perfluoroalkyl group and a dialkylsiloxane structure and (b) water. In formula (1), Rand Reach independently represents a hydrogen atom or a 1-4C alkyl group and at least one of Rand Ris a 1-4C alkyl group, Rand Rmay be bonded with each other to form four- to six-membered ring, and * shows a binding site between the main chain and a side chain of the polymer compound.

Description

  The present invention relates to an ink composition that can be applied for ink jet recording, image formation using the ink composition, and a print formed by the ink composition.

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.
The electrophotographic system requires a process of forming an electrostatic latent image on a photosensitive drum by charging and exposure, and there is a problem that the system becomes complicated and consequently the manufacturing cost becomes high. In addition, although the thermal transfer system is inexpensive, there are problems such as high running costs and waste materials due to the use of ink ribbons.
On the other hand, the ink-jet method has an advantage that the ink can be used efficiently and the running cost is low because the ink is ejected only on the required image portion and the image is directly formed on the recording medium. In addition, it has less noise and is excellent as an image recording method.

  Among the ink compositions used for image recording by the inkjet method, the active energy ray-curable aqueous ink composition is used for image printing, pretreatment for imparting printability to the recording medium, and protection of the printed image. -It can be used suitably for decoration post-processing, etc., and since it has water as the main component, it has excellent safety, such as being able to be applied to high-density inkjet recording due to its low viscosity, It is a technology with potential.

  Examples of basic constituent materials of the active energy ray-curable water-based ink composition include water, a polymerizable substance, a polymerization initiator that generates radicals by active energy rays and starts polymerization, and a coloring material (pigment or dye). be able to. Among these, a polymerizable substance and a polymerization initiator may be prepared in an emulsion state, or may be present in a solution state given water solubility by an appropriate substituent.

Examples of the active energy ray-curable aqueous ink composition in which the polymerizable substance and the polymerization initiator are water-soluble include, for example, the ink composition described in Patent Document 1, and according to the ink composition, It is said that an ink composition for ink jet recording can be obtained in which a film having excellent adhesion and the like can be obtained by light irradiation.
Patent Documents 2 and 3 describe ink compositions containing an active energy ray polymerizable substance having a specific maleimide structure.

JP 2005-307199 A JP 2007-119449 A Japanese Patent Laid-Open No. 2000-160086

However, in the technique described in Patent Document 1 using a water-soluble polymerization initiator, the degradation of the added polymerization initiator and the unreacted residue remain in the cured film, which adversely affects the film properties and the printed matter. Therefore, there is room for further improvement in the blocking resistance and water resistance of the printed image.
In Patent Document 2, no study is made regarding solvent resistance, and there is room for improvement in solvent resistance. In Patent Document 3, use as water-based ink, blocking resistance, and water resistance are not studied.
Accordingly, a water-based ink composition that forms an image having good blocking resistance, water resistance, and solvent resistance has been eagerly desired, but has not yet been provided.

The present invention has been made in light of the above circumstances, and provides an ink composition that is excellent in water resistance, solvent resistance, and blocking resistance, and that is suitable for image formation using an inkjet method. Is an issue.
The present invention also provides an image recording method capable of forming an image excellent in water resistance, solvent resistance and blocking resistance, and a printed matter having an image excellent in water resistance, solvent resistance and blocking resistance. This is the issue.

Specific means for solving the above problems are as follows.
<1> (a) a polymer compound having a repeating unit having a partial structure represented by the following general formula (1), and at least one selected from a perfluoroalkyl group and a dialkylsiloxane structure, and (b) ) An ink composition containing water.

In General Formula (1), R ^a and R ^b each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and at least one of R ^a and R ^b represents an alkyl group having 1 to 4 carbon atoms. Represent. R ^a and R ^b may be bonded to each other to form a 4- to 6-membered alicyclic structure. * Indicates a binding site to the main chain or side chain in the polymer compound.

<2> The ink composition according to <1>, wherein the polymer compound (a) is a polymer compound having a hydrophilic group.
<3> The ink composition according to <1> or <2>, wherein the repeating unit having a partial structure represented by the general formula (1) is a repeating unit represented by the following general formula (2).

In General Formula (2), R ^a and R ^b each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and at least one of R ^a and R ^b represents an alkyl group having 1 to 4 carbon atoms. Represent. R ^a and R ^b may be bonded to each other to form a 4- to 6-membered alicyclic structure. R ^c represents a hydrogen atom or a methyl group. Z represents a single bond, —COO — ** or —CONR ^d — **, R ^d represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and ** represents a bonding position with X. X represents a divalent organic group.

<4><1> to <3>, wherein the polymer compound (a) has at least one hydrophilic group selected from alcoholic hydroxyl groups, alkyl-substituted carbamoyl groups, carboxyl groups, sulfo groups, and salts thereof. The ink composition according to any one of the above.
<5> The polymer compound (a) includes 10% by mass to 70% by mass of a repeating unit having a partial structure represented by the general formula (1), and is selected from a perfluoroalkyl group and a dialkylsiloxane structure. The ink composition according to any one of <1> to <4>, which is a polymer compound containing 5% by mass to 25% by mass of a repeating unit having at least one kind.

<6> The ink composition according to any one of <1> to <5>, further comprising (c) a water-soluble polymer compound having a structure different from that of the polymer compound (a).
<7> Further, (a) a water-soluble polymer compound having a structure different from that of the polymer compound (c) is contained, and (c) the water-soluble polymer compound is (c ′) a crosslinkable compound <1 The ink composition according to any one of> to <6>.

<8> The content according to any one of <1> to <7>, wherein the content of the polymer compound (a) is 0.1% by mass to 15% by mass with respect to the total mass of the ink composition. Ink composition.
<9> The content according to any one of <1> to <8>, wherein the content of the polymer compound (a) is 0.1% by mass to 2% by mass with respect to the total mass of the ink composition. Ink composition.

<10> The ink composition according to any one of <1> to <9>, further comprising (d) a colorant.
<11> The ink composition according to any one of <1> to <10>, further comprising (e) a water-soluble organic solvent.
<12> The ink composition according to any one of <1> to <11>, which is for inkjet recording.

<13> An ink application step of applying the ink composition according to any one of <1> to <12> onto a recording medium, and irradiating the ink composition applied onto the recording medium with active energy rays. An image forming method including an irradiation step.
<14> An ink application step of applying the ink composition according to any one of <1> to <12> onto a recording medium, and (b) water contained in the ink composition applied onto the recording medium And (e) an ink drying step for drying and removing at least a part of the water-soluble organic solvent, and an irradiation step for irradiating the dried ink composition with active energy rays applied on the recording medium. Forming method.
<15> Formed on the image recording medium by the ink composition according to any one of <1> to <12>, or recorded by the image forming method according to <13> or <14>. Printed image with an image.

According to the present invention, an image excellent in water resistance, solvent resistance and blocking resistance can be obtained, and an ink composition suitable for image formation using an inkjet method can be provided.
Further, according to the present invention, an image recording method capable of forming an image excellent in water resistance, solvent resistance and blocking resistance, and a printed matter having an image excellent in water resistance, solvent resistance and blocking resistance. Can be provided.

Hereinafter, the ink composition, the image forming method, and the printed material of the present invention will be described.
In addition, in this specification, when mentioning the amount of each component in the composition, when there are a plurality of substances corresponding to each component in the composition, the present in the composition unless otherwise specified. It means the total amount of multiple substances.
In the ink composition of the present invention, the solid content means the total mass of all components excluding the solvent among the components contained in the ink composition at 25 ° C. The solid content in the present specification includes liquid components such as low molecular weight components other than the solvent.
In the present specification, a numerical range indicated using “to” indicates a range including the numerical values described before and after “to” as the minimum value and the maximum value, respectively.
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 comprises (a) a repeating unit having a partial structure represented by the following general formula (1), and at least one repeating unit selected from a perfluoroalkyl structure and a dialkylsiloxane structure. And an ink composition containing (b) water.

In General Formula (1), R ^a and R ^b each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and at least one of R ^a and R ^b represents an alkyl group having 1 to 4 carbon atoms. Represent. R ^a and R ^b may be bonded to each other to form a 4- to 6-membered alicyclic structure. * Indicates a binding site to the main chain or side chain in the polymer compound.

  In the following, a polymer compound having a repeating unit having a partial structure represented by the general formula (1) and at least one selected from a perfluoroalkyl structure and a dialkylsiloxane structure is appropriately represented by “ Also referred to as (a) polymer compound ”.

  The ink composition of the present invention can form an image excellent in water resistance, solvent resistance, and blocking resistance by containing each of the above components. Here, in the present invention, the water resistance and solvent resistance of the image mean the durability of the formed image with respect to water and solvent. Further, the anti-blocking property of the image means that, when the printed material on which the image is formed is stored on the recording medium, the sticking or transfer of the undesired image to the adjacent printed material is suppressed. means.

Although the mechanism of the present invention is not yet clear, the present inventors presume as follows.
That is, (a) the polymer compound has a perfluoroalkyl group and / or a dialkylsiloxane structure having a low surface energy, so that ink is applied onto the recording medium by an inkjet nozzle or the like and dried at the stage where the ink droplet is dried. It is considered that (a) the polymer compound is unevenly distributed at the interface between the surface and air. Furthermore, since the polymer compound (a) has a partial structure represented by the general formula (1) that is not easily inhibited by polymerization by oxygen, the curing reaction proceeds well by irradiation with active energy rays. The cured film obtained by such an action exhibits (a) water and oil repellency characteristics due to the molecular structure of the polymer compound, water resistance and solvent resistance characteristics, and also has blocking resistance. It will be excellent.

  The ink composition of the present invention may contain various liquid or solid compounds as additives as required, as long as the effects of the present invention are not impaired, in addition to (a) the polymer compound and (b) water. Well, for example, it may suitably contain other components such as (a) a structure different from the polymer compound, (c) a water-soluble polymer compound, (d) a colorant, or (e) a water-soluble organic solvent. . For example, the curability of the image is further improved by including (c ′) a crosslinkable compound which is one embodiment of (c) a water-soluble polymer compound described later.

  Hereinafter, the ink composition of the present invention (hereinafter also simply referred to as “ink composition”) will be described in detail.

[(A) a polymer compound having a repeating unit having a partial structure represented by the general formula (1) and at least one selected from a perfluoroalkyl group and a dialkylsiloxane structure]
The ink composition of the present invention comprises a polymer compound (() having a repeating unit having a partial structure represented by the following general formula (1) and at least one selected from a perfluoroalkyl group and a dialkylsiloxane structure. a) a polymer compound).

  (A) The polymer compound is preferably a vinyl polymer, polyurethane, polyester, polyether, or polyamide, and more preferably a vinyl polymer or polyurethane.

(A) The polymer compound preferably further contains a hydrophilic group in the molecule, and the repeating unit having a partial structure represented by the general formula (1) is represented by the general formula (2) described later. An embodiment that is a unit and further contains a repeating unit having a hydrophilic group as a copolymerization component is particularly preferable.
Hereinafter, (a) the polymer compound will be described in detail.

(Repeating unit having a partial structure represented by the general formula (1))
(A) The polymer compound includes a repeating unit having a partial structure represented by the following general formula (1).

In General Formula (1), R ^a and R ^b each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and at least one of R ^a and R ^b represents an alkyl group having 1 to 4 carbon atoms. Represent. R ^a and R ^b may be bonded to each other to form a 4- to 6-membered alicyclic structure. * Indicates a binding site to the main chain or side chain in the polymer compound.

In the general formula (1), the alkyl group having 1 to 4 carbon atoms represented by R ^a or R ^b may have a straight chain structure or a branched structure. Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, and a t-butyl group. Among these alkyl groups, an alkyl group having 1 to 2 carbon atoms (methyl group and ethyl group) is preferable, and an alkyl group having 1 carbon atom (methyl group) is particularly preferable.

In general formula (1), the alkyl group represented by R ^a or R ^b may or may not have a substituent, but preferably does not have a substituent.

R ^a and R ^b may be bonded to each other to form a 4- to 6-membered alicyclic structure.

As R ^a and R ^b , an aspect in which both are alkyl groups having 1 to 4 carbon atoms, or R ^a and R ^b are bonded to each other to form a 4- to 6-membered alicyclic structure. It is more preferable that both R ^a and R ^b are alkyl groups having 1 to 2 carbon atoms, and it is still more preferable that both R ^a and R ^b are alkyl groups having 1 carbon atom.

  Specific examples of the partial structure represented by the general formula (1) are shown below, but the present invention is not limited to these.

  (A) It is preferable that a high molecular compound is an aspect which has multiple partial structures represented by General formula (1) in a side chain.

  The repeating unit having a partial structure represented by the general formula (1) is preferably a repeating unit represented by the following general formula (2).

In General Formula (2), R ^a and R ^b each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and at least one of R ^a and R ^b represents an alkyl group having 1 to 4 carbon atoms. Represent. R ^a and R ^b may be bonded to each other to form a 4- to 6-membered alicyclic structure. R ^c represents a hydrogen atom or a methyl group. Z represents a single bond, —COO — **, or —CONR ^d — **, R ^d represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and ** represents a bonding position with X. X represents a divalent organic group.

In General Formula (2), R ^a and R ^b each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and at least one of R ^a and R ^b represents an alkyl group having 1 to 4 carbon atoms. Represent. R ^a and R ^b may combine with each other to form a 4- to 6-membered ring structure.

^{R a} and ^{R b} in the general formula (2) has the same meaning as ^{R a} and ^{R b} in the general formula (1), and preferred ranges are also the same.

In the general formula (2), R ^c represents a hydrogen atom or a methyl group. R ^c is preferably a methyl group.

In General Formula (2), Z represents a single bond, —COO — **, or —CONR ^d — **, R ^d represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and ** represents X Represents the binding position. Z is preferably -COO-**.

Further, R ^d in the —CONR ^d — * represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. The alkyl group having 1 to 4 carbon atoms represented by R ^d may have a linear structure or a branched structure. Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, and a t-butyl group. R ^d is preferably a hydrogen atom or an alkyl group having 1 to 2 carbon atoms, that is, a methyl group or an ethyl group, and particularly preferably a hydrogen atom. If R ^d represents an alkyl group, the alkyl group may have a substituent, may not have a substituent, but preferably does not have a substituent.

  In the general formula (2), X represents a divalent organic group. Examples of the divalent organic group include an alkylene group or an aralkylene group, and an alkylene group having 2 to 20 carbon atoms or an aralkylene group having 6 to 12 carbon atoms is preferable. X is more preferably an alkylene group.

  When X represents an alkylene group, the alkylene group preferably has 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, and still more preferably 2 to 8 carbon atoms. When the carbon number of the alkylene group represented by X is within this range, (a) the mobility of the partial structure represented by the general formula (1) existing at the end of the side chain in the polymer compound is improved. The effect of the invention is further improved.

  The alkylene group represented by X may have a linear structure, a branched chain in the alkylene chain, or a cyclic structure. In addition, the alkylene group may contain a bond selected from —O—, —COO—, —OC (═O) —, and —CONH— in the alkylene chain. The alkylene group may be substituted with an alkyl group having 4 or less carbon atoms, a hydroxyl group, or a chlorine atom.

As the repeating unit represented by the general formula (2), R ^a and R ^b are each independently an alkyl group having 1 to 2 carbon atoms, R ^c is a methyl group, and Z is —COO — **. And X is preferably an alkylene group having 2 to 12 carbon atoms.

(A) The content of the repeating unit having a partial structure represented by the general formula (1) contained in the polymer compound (preferably the repeating unit represented by the general formula (2)) is formed by the ink composition. The cured film (image) to be selected is appropriately selected according to the intended properties. That is, the content of the repeating unit represented by the general formula (1) tends to be increased if a strong ink image is obtained and decreased if a flexible cured film is obtained.
In consideration of these, the content of the repeating unit represented by the general formula (1) is preferably 5% by mass to 95% by mass and 15% by mass to 95% by mass with respect to the mass of the polymer compound (a). %, More preferably 30% by mass to 95% by mass.

The repeating unit having a partial structure represented by the general formula (1) is copolymerized using a monomer having a partial structure represented by the general formula (1) as one of the copolymerization components ( a) It can be introduced into a polymer compound. When the repeating unit represented by the general formula (1) is a repeating unit represented by the general formula (2), a monomer represented by the following general formula (2 ′) can be used.
The partial structure represented by the general formula (1) can also be introduced by a method using a polymer reaction. Examples of such a method include a method obtained by reacting a prepolymer having a primary amino group with a corresponding anhydride, a functional group that reacts with a functional group in the prepolymer to form a bond and a general formula ( Examples thereof include a method of reacting a compound having a partial structure represented by 1) with a prepolymer.

In the general formula ^{(2 '), R a,} R b, R c, Z and X, ^R a in the formula ^{(2), R b, R} c, are respectively the Z and X synonymous, preferable ranges It is the same.

  Preferable examples of the monomer represented by the general formula (2 ′) include monomers (2′-1) to (2′-11) shown below. It is not limited.

  Monomers containing a partial structure represented by the general formula (1) represented by the monomers (2′-1) to (2′-11) include, for example, JP-A-52-988, It can be produced with reference to the method described in JP-A-4-251258.

(Perfluoroalkyl group and dialkylsiloxane structure)
The polymer compound (a) in the present invention has at least one selected from a perfluoroalkyl group and a dialkylsiloxane structure at the side chain or main chain terminal.

  (A) The polymer compound may have only one of a perfluoroalkyl group and a dialkylsiloxane structure, or may have both, but either a perfluoroalkyl group or a dialkylsiloxane structure. An embodiment having one is more preferable.

~ Perfluoroalkyl group ~
(A) As a perfluoroalkyl group which a high molecular compound has, a C1-C16 or more perfluoroalkyl group is preferable and a C1-C16 perfluoroalkyl group is more preferable.
(A) 1 type may be sufficient as the perfluoroalkyl group which a high molecular compound has, and 2 or more types may be sufficient as it.

  A perfluoroalkyl group can be introduced into the polymer compound (a) by copolymerizing a monomer containing a perfluoroalkyl group as one of the copolymerization components.

  As the monomer containing a perfluoroalkyl group, only one kind may be used, or two or more kinds may be used.

  Preferred examples of the monomer containing a perfluoroalkyl group include monomers represented by the following general formula (I). That is, one of the preferred embodiments of the polymer compound (a) in the present invention is a monomer having a partial structure represented by the general formula (1) and a single compound represented by the following general formula (I). And a polymer compound obtained by copolymerization using a polymer.

In general formula (I), R ¹ represents a hydrogen atom, a halogen atom, a methyl group which may have a substituent, or an ethyl group which may have a substituent. R ² and R ³ each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and X ¹ represents a single bond or a divalent linking group. m represents an integer of 0 or more, and n represents an integer of 1 or more.

In the general formula (I), examples of the halogen atom represented by R ¹ include a fluorine atom, a chlorine atom, and a bromine atom.

In the general formula (I), the alkyl group having 1 to 4 carbon atoms represented by ^{R 2} or ^{R 3,} methyl, ethyl, propyl, isopropyl, n- butyl group, isobutyl group, tert- butyl Groups and the like. R ² and R ³ are preferably each independently a hydrogen atom or a methyl group, and more preferably a hydrogen atom.

In the general formula (I), examples of the divalent linking group represented by X ¹ include —O—, —S—, —N (R ⁴ ) —, —CO—, and the like.
R ⁴ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a tert-butyl group. Can be mentioned. R ⁴ is preferably a hydrogen atom, a methyl group or a butyl group.
The divalent linking group represented by X ¹ is more preferably —O—.

m represents an integer of 0 or more, an integer of 2 to 8 is preferable, and m = 2 is particularly preferable. In addition, when m is an integer of 2 or more, functional groups on adjacent carbons (that is, R ² and R ³ bonded to adjacent carbons) are bonded to form an aliphatic ring. May be.

  n represents an integer of 1 or more, preferably an integer of 1 to 16, more preferably 1 to 8, and further preferably 1, 6 or 8.

  Although the specific example of the monomer containing a perfluoroalkyl group is shown below, this invention is not limited to these.

~ Dialkylsiloxane structure ~
The dialkylsiloxane structure in the present invention means a structure having at least one siloxane bond (Si—O) and having a silicon atom in the siloxane bond bonded to two alkyl groups. The dialkylsiloxane structure may have at least one siloxane bond, but (a) from the viewpoint of surface segregation of the polymer compound, it is more preferable to have three or more siloxane bonds.
(A) The dialkylsiloxane structure of the polymer compound may be one type or two or more types.

  For example, the dialkylsiloxane structure is introduced into the polymer compound by copolymerization using a monomer having an ethylenically unsaturated double bond and a dialkylsiloxane structure as one of the copolymerization components. be able to.

  An example of a monomer having an ethylenically unsaturated double bond and a dialkylsiloxane structure is preferably a compound represented by the following general formula (A).

In the general formula (A), R ¹¹ represents a linear or branched alkylene group having 2 to 6 carbon atoms, or a divalent linking group represented by the following general formula (B).

In the general formula ^{(B), R 12} represents a hydrogen atom or a methyl group, n represents an integer of 1 to 50. Formula (B) * in a bonding position to ^{X 2.} A plurality of R ¹² may be the same or different from each other.

In the general formula ^(A), x 1, ^{x 2} and ^{x 3 are} each an integer sum of x 1, ^{x 2} and ^{x 3} is 1 to 100. y ¹ is an integer of 1 to 150.

In General Formula (A), X ² represents a single bond, an oxygen atom, or a divalent linking group represented by the following General Formula (C).

In General Formula (C), Z ¹ represents a single bond, an oxygen atom, a sulfur atom, or NR ¹⁴ , and R ¹⁴ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. In General Formula (C), R ¹³ represents a divalent linking group selected from an alkylene group having 6 to 10 carbon atoms, a cyclic alkylene group, an arylene group, and a xylylene group. * In the general formula (C) is a bonding position with Y.

  In General Formula (A), Y represents a monovalent group represented by an acryloyl group, a methacryloyl group, the following General Formula (D), the following General Formula (E), or the following General Formula (F).

In the general formulas (D) to (F), R ¹⁶ represents a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms, and R ¹⁷ is linear or branched. 2 represents an alkylene group having 2 to 10 carbon atoms, and R ¹⁸ represents a linear or branched alkylene group having 1 to 6 carbon atoms. * In the general formulas (D) to (F) is a bonding position with X.

  In general formula (A), Z represents a monovalent group represented by the following general formula (G). When a plurality of Z are present in the general formula (A), these may be the same or different from each other.

In General Formula (G), z ¹ represents an integer of 0 to 100, preferably an integer of 0 to 50, and more preferably an integer of 0 to 10. * In General Formula (G) is a bonding position with X.

  In general formula (A), R represents an alkyl group having 1 to 4 carbon atoms, and is preferably a methyl group, an n-butyl group, a sec-butyl group, or a tert-butyl group. In the general formula (A), three Rs may be the same or different from each other. As R, an embodiment in which all three Rs are methyl groups and an embodiment in which two of the three Rs are methyl groups and one is an n-butyl group are preferable.

  Specific examples of the monomer having an ethylenically unsaturated double bond and a dialkylsiloxane structure are shown below, but the present invention is not limited thereto.

  In addition, in the polymer compound (a), the repeating unit having at least one selected from a perfluoroalkyl group and a dialkylsiloxane structure has a total of each in the copolymer from the viewpoint of surface orientation and solubility. It is preferably contained in the range of 1.0% by mass to 20% by mass, more preferably 2.0% by mass to 15% by mass, and most preferably in the range of 3.0% by mass to 10% by mass.

  (A) As a high molecular compound, 10 mass%-70 mass% of repeating units which have the partial structure represented by General formula (1) are included, At least 1 sort (s) selected from the perfluoroalkyl group and the dialkylsiloxane structure is included. It is particularly preferable that the repeating unit has 5 to 25% by mass.

  (A) The polymer compound is preferably a polymer compound further containing a hydrophilic group in the molecule.

  Here, the hydrophilic group is not particularly limited as long as it is a group having a function of enhancing the hydrophilicity of the polymer compound (a), and may be a nonionic hydrophilic group or an ionic hydrophilic group. It may be an ionic group (for example, an anionic hydrophilic group or a cationic hydrophilic group).

  (A) The number of hydrophilic groups contained in the polymer compound is not limited, and the number is appropriately selected according to the type of the hydrophilic group, (a) the molecular weight of the polymer compound, and the like.

  The content of the hydrophilic group in the polymer compound (a) is preferably included in such a number that the polymer compound is water-soluble. Here, (a) that the polymer compound is water-soluble means that (a) the polymer compound can be dissolved by 3% by mass or more in water at 25 ° C.

(Hydrophilic group)
(A) The hydrophilic group that can be introduced into the polymer compound will be described.
(A) Nonionic hydrophilic group and ionic hydrophilicity are preferably exemplified as the hydrophilic group that can be introduced into the polymer compound.

  Nonionic hydrophilic groups include, but are not particularly limited to, for example, residues obtained by removing one hydrogen atom from a heterocyclic structure containing a nitrogen atom or oxygen atom, an amide group, a carbamoyl group, an alkyl-substituted carbamoyl group, an alcohol Nonionic hydrophilic groups such as a functional hydroxyl group or a group having a polyalkyleneoxy structure.

    Examples of the heterocyclic structure in the residue obtained by removing one hydrogen atom from a heterocyclic structure containing a nitrogen atom or an oxygen atom include lactones such as γ-butyrolactone; cyclic ureas such as 2-pyrrolidone and ethylene urea; ethylene carbonate, And cyclic carbonates such as propylene carbonate, and cyclic ethers such as tetrahydrofuran and 1,4-dioxane;

  As the amide group, an amide group having 2 to 10 carbon atoms is preferable, and a hydrogen atom is preferably bonded to a nitrogen atom in the amide group.

  The alkyl-substituted carbamoyl group is a monoalkylcarbamoyl group in which a hydrogen atom bonded to a nitrogen atom of a carbamoyl group is substituted with an alkyl group, or two hydrogen atoms bonded to a nitrogen atom of a carbamoyl group are substituted with an alkyl group And a dialkylcarbamoyl group formed. The alkyl group may further have a substituent such as a hydroxyl group. Among these alkyl-substituted carbamoyl groups, a monoalkylcarbamoyl group substituted with an alkyl group having 1 to 8 carbon atoms or an alkyl group having 1 to 4 carbon atoms substituted with a hydroxyl group is preferable.

  Although it does not specifically limit as group which has a polyalkyleneoxy structure, The polyalkyleneoxy structure which has a C1-C4 alkyleneoxy group in a repeating unit is preferable. One type of alkyleneoxy group in the polyalkyleneoxy structure may be used, or a plurality of types of alkyleneoxy groups may be combined. The terminal group of the polyalkyleneoxy structure is preferably a hydroxyl group or an alkoxy group, more preferably a hydroxyl group or a methoxy group.

  Although it does not specifically limit as an ionic hydrophilic group, For example, ionic hydrophilic groups, such as a carboxyl group, a sulfo group, a phosphoric acid group, a phosphonic acid group, a phenolic hydroxyl group, or a quaternary ammonium group, are mentioned. The ionic hydrophilic group may form a salt.

  When the ionic hydrophilic group forms a salt, examples of the counter salt include onium salts such as alkali metal salts (Li, Na, K, etc.), ammonium salts, pyridinium salts, and phosphonium salts. Among these, alkali metal salts (Li, Na, K, etc.) or ammonium salts are preferable.

  Among these hydrophilic groups, an amide group, a carbamoyl group, an alkyl-substituted carbamoyl group, an alcoholic hydroxyl group, a group having a polyalkyleneoxy structure, a carboxyl group, a sulfo group, and a salt thereof are preferable. A carbamoyl group, a carboxyl group, a sulfo group, and salts thereof are more preferable.

  (A) The polymer compound includes a repeating unit having a partial structure represented by the general formula (1), and at least one repeating unit selected from a perfluoroalkyl structure and a dialkylsiloxane structure, The embodiment preferably has a repeating unit having a hydrophilic group. (A) In a more preferred embodiment of the polymer compound, the repeating unit having a partial structure represented by the general formula (1) is a repeating unit represented by the general formula (2), and a perfluoroalkyl structure and It is an embodiment that includes at least one repeating unit selected from dialkylsiloxane structures and further includes a repeating unit having a hydrophilic group.

  When the polymer compound (a) in the present invention further contains a repeating unit having a hydrophilic group, the repeating unit having a hydrophilic group may be a repeating unit represented by the following general formula (3). preferable.

In general formula (3), R ^cy represents a hydrogen atom or a methyl group. Z ^y represents —COO — ***, —CONR ^dy — ***, or a single bond, and R ^dy represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. R ^y represents a group selected from the group consisting of a single bond, an alkylene group, an arylene group, and an aralkylene group. A represents a hydrophilic group. *** represents a position where Z ^y is bonded to R ^y .

The general formula (3) will be described in detail.
In general formula (3), R ^cy represents a hydrogen atom or a methyl group.

In the general formula ^{(3), Z} y ^{is, -COO - ***, - CONR dy} - ***, or a single bond, -COO - is preferably ***. Incidentally, *** is a position ^{where Z y} is bonded to ^{R y.}

R ^dy represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. The alkyl group having 1 to 4 carbon atoms may have a linear structure or a branched structure. Specifically, it represents a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, or a t-butyl group. R ^dy is preferably a hydrogen atom or an alkyl group having 1 to 2 carbon atoms (that is, a methyl group or an ethyl group), and particularly preferably a hydrogen atom.

R ^dy may or may not have a substituent, but preferably does not have a substituent. Examples of the substituent that R ^dy may have include an aryl group having 6 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, a hydroxyl group, a carboxyl group, and a halogen atom (F, Cl, Br, I, etc.). Etc.

In General Formula (3), R ^y represents a single bond or a group selected from the group consisting of an alkylene group, an arylene group, and an aralkylene group, an alkylene group having 1 to 20 carbon atoms, and an arylene having 6 to 20 carbon atoms. It is preferably a group or an aralkylene group having 7 to 20 carbon atoms.
When ^Ry is a group selected from the group consisting of an alkylene group, an arylene group, and an aralkylene group, these groups may or may not have a substituent. The alkylene group, arylene group, and aralkylene group represented by R ^y may have an ether bond, an ester bond, an amide bond, or a urethane bond in the structure.
In the general formula (3), R ^y is preferably a single bond.

When ^Ry is a group selected from the group consisting of an alkylene group, an arylene group, and an aralkylene group, these groups may further have a substituent. Examples of the substituent include an aryl group having 6 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, a hydroxyl group, a carboxyl group, a halogen atom (F, Cl, Br, I, etc.) and the like.

When ^Ry is an alkylene group having 1 to 20 carbon atoms, the alkylene group may have a linear structure, a branched structure, or a cyclic structure. When ^Ry is an alkylene group, the number of carbon atoms is more preferably 2 to 12, and further preferably 2 to 8. Specific examples of the alkylene group for R ^y include —CH ₂ —, —C ₂ H ₄ —, —C (CH ₃ ) ₂ —CH ₂ —, —CH ₂ C (CH ₃ ) ₂ CH ₂ —, —C. _{6 H 12 -, - C 4} H 7 (C 4 H 9) C 4 H 8 -, C 18 H 36 -, 1,4-trans- cyclohexylene _{group, -C 2 H 4 -OCO-C} 2 H 4 _{-, - C 2 H 4 -OCO} -, - C 2 H 4 -O-C 5 H 10 -, - CH 2 -O-C 5 H 9 (C 5 H 11) -, - C 2 H 4 -CONH _{-C 2 H 4 -, - C} 4 H 8 -OCONH-C 6 H 12 -, - CH 2 -OCONHC 10 H 20 -, - CH 2 CH (OH) CH 2 -, and the like.

When ^Ry is an arylene group having 6 to 20 carbon atoms, the arylene group preferably has 6 to 18 carbon atoms, more preferably 6 to 14 carbon atoms, and particularly preferably 6 to 10 carbon atoms. . Specific examples of the arylene group represented by R ^y include a phenylene group, a biphenylene group, —C ₆ H ₄ —CO—C ₆ H ₄ —, a naphthylene group, and the like.

When ^Ry is an aralkylene group having 7 to 20 carbon atoms, the aralkylene group preferably has 7 to 18 carbon atoms, more preferably 7 to 14 carbon atoms, and particularly preferably 7 to 10 carbon atoms. . Specific examples of the aralkylene group represented by R ^y _{is, -C 3 H 6 -C 6 H} 4 -, - C 2 H 4 -C 6 H 4 -C 6 H 4 -, - CH 2 -C 6 H _{4 -C 6 H 4 -C 2 H} 4 -, - C 2 H 4 -OCO-C 6 H 4 - , and the like.

  Examples of the hydrophilic group represented by A in the general formula (3) include the hydrophilic groups described above, and preferred ranges thereof are also the same.

(A) When the polymer compound has a repeating unit represented by the general formula (3), the content of the repeating unit represented by the general formula (3) in the polymer compound (a) is as follows. .
When the hydrophilic group A in General formula (3) is an ionic hydrophilic group, content of the repeating unit represented by General formula (3) is 5 mass%-50 mass in (a) polymer compound. %, Preferably 5% to 40% by weight, more preferably 1% to 20% by weight.
When the hydrophilic group A in General formula (3) is a nonionic hydrophilic group, it is preferable that it is 20 mass%-95 mass% in (a) polymer compound, and 30 mass%-80 mass% are further. Preferably, 30 mass%-70 mass% is especially preferable.

  The repeating unit represented by the general formula (3) can be obtained by polymerizing a monomer represented by the following general formula (3 ').

In the general formula ^{(3 '), R cy,} Z y, R y, and A, ^R cy in Formula ^{(3), Z y, R} y, and A and have the same meanings, the preferred range is also the same is there.

  Preferable examples of the monomer represented by the general formula (3 ′) include the following monomer compounds, but the present invention is not limited thereto.

Methoxypolyethylene glycol (meth) acrylate, polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, poly (ethylene glycol-co-propylene glycol) (meth) acrylate, 2-hydroxyethyl (meth) acrylate, glycerol (meth) Acrylate (meth) acryloyloxyethyl ethylene urea, vinyl pyrrolidone, 3- (meth) acryloyloxy-γ-butyrolactone, acrylamide, tert-butyl acrylamide, N, N-dimethyl (meth) acrylamide, diacetone acrylamide, (meth) Sodium acrylate, potassium (meth) acrylate, tetrabutylammonium (meth) acrylate, mono (meth) acryloyloxyethyl succinic acid, Sodium (meth) acryloyloxyethyl succinate, sodium mono (meth) acryloyloxyethyl phthalate, (meth) acryloyloxyethyl acid phosphate, sodium 2-acrylamido-2-methylpropanesulfonate, 2-acrylamide- Examples include 2-methylpropane sulfonic acid, styrene sulfonic acid, sodium styrene sulfonate, and vinyl benzoic acid.

  As the monomer represented by the general formula (3 ′), a commercially available compound can be used, and it can be produced by a generally known and commonly used method.

  In the present invention, in addition to the monomer represented by the general formula (3 ′), unsaturated dicarboxylic acids such as maleic acid, maleic anhydride, and fumaric acid, and anhydrides thereof, and further derived therefrom. Dicarboxylic acid salts can also be preferably used.

  (A) The content of the repeating unit having a hydrophilic group in the polymer compound varies depending on the type of the hydrophilic group, but (a) the polymer compound is preferably a water-soluble content. .

  The polymer compound (a) according to the present invention includes a repeating unit having a partial structure represented by the general formula (1), at least one repeating unit selected from a perfluoroalkyl structure and a dialkylsiloxane structure, and A copolymer containing a repeating unit other than the repeating unit having a hydrophilic group may also be used.

Other monomers that form the repeating unit include styrenes such as styrene and p-methoxystyrene, methyl (meth) acrylate, ethyl (meth) acrylate, allyl (meth) acrylate, butyl (meth) acrylate, hexyl ( Meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, decyl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, bornyl (meth) acrylate, isobornyl (meth) acrylate, benzyl (Meth) acrylate, 2-ethylhexyl diglycol (meth) acrylate, butoxyethyl (meth) acrylate, butoxymethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, 2- (2-me Xyloxy) ethyl (meth) acrylate, 2- (2-butoxyethoxy) ethyl (meth) acrylate, 4-butylphenyl (meth) acrylate, phenyl (meth) acrylate, 2,4,5-tetramethylphenyl (meth) acrylate 4-chlorophenyl (meth) acrylate, phenoxymethyl (meth) acrylate, phenoxyethyl (meth) acrylate, glycidyl (meth) acrylate, glycidyloxybutyl (meth) acrylate, glycidyloxyethyl (meth) acrylate, glycidyloxy Examples include (meth) acrylates such as propyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, butoxydiethylene glycol (meth) acrylate, methyl (meth) acrylate, ethyl ( Data) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) alkyl (meth) acrylates having 1 to 8 carbon atoms such as acrylate preferred.
In addition, as a monomer which forms another repeating unit, well-known monomers other than the above can also be used as needed.

  (A) As content of the other repeating unit in a high molecular compound, it is preferable that it is 0-60 mass%, 0-40 mass% is still more preferable, and 0-30 mass% is especially preferable.

  (A) The polymer compound is, for example, (i) a single unit for forming a repeating unit having a partial structure represented by the general formula (1) such as a monomer represented by the general formula (2 ′). A monomer, a monomer having a perfluoroalkyl group, a monomer having an ethylenically unsaturated double bond and a dialkylsiloxane structure, and at least one selected from a perfluoroalkyl group and a dialkylsiloxane structure And (iii) a monomer for forming a repeating unit represented by the general formula (3), which is optionally used, is polymerized by a known polymerization method, If necessary, the acid group can be obtained by neutralizing with an alkali metal hydroxide or the like. Specifically, for example, a method according to the polymerization method described in JP-A-52-988, JP-A-55-154970, Langmuir Vol. 18, No. 14, pages 5414-5421 (2002), etc. a) A polymer compound can be produced.

  (A) The weight average molecular weight of the polymer compound is preferably 2,000 to 100,000, more preferably 2,000 to 80,000, and still more preferably 2,000 to 60,000.

  The weight average molecular weight is measured by gel permeation chromatography (GPC). GPC uses HLC-8020GPC (manufactured by Tosoh Corporation), TSKgel SuperHZM-H, TSKgel SuperHZ4000, TSKgel SuperHZ200 (4.6 mm ID × 15 cm, Tosoh Corporation) as columns and THF (tetrahydrofuran) as an eluent. Is used.

Hereinafter, as specific examples of the polymer compound (a), exemplary compound (A-1) to exemplary compound (A-9) are shown together with their weight average molecular weights, but the present invention is not limited thereto. In the following exemplary compounds, the copolymerization ratios indicated using a, b, c and d are based on mass.

[(B) Water]
The ink composition of the present invention contains water.
(B) As water, it is preferable to use ion-exchanged water, distilled water or the like that does not contain impurities.
The water content in the ink composition of the present invention is preferably 10 to 97% by mass, more preferably 30 to 95% by mass, and even more preferably 50 to 85% by mass.

[Other additives]
In the ink composition of the present invention, in addition to the essential components (a) polymer compound and (b) water, known additives can be used in combination as long as the effects of the present invention are not impaired. Hereinafter, additives that can be used in the ink composition will be described.

<< (a) Structure different from polymer compound (c) Water-soluble polymer compound >>
The ink composition of the present invention may contain (a) a water-soluble polymer compound having a structure different from that of the polymer compound (c). Hereinafter, (a) a water-soluble polymer compound having a structure different from that of the polymer compound is also simply referred to as (c) a water-soluble polymer compound.

  (C) The water-soluble polymer compound can be used without particular limitation as long as it is water-soluble and has a structure different from that of the polymer compound (a). In view of the degree, it is preferably a water-soluble vinyl polymer.

(C) The water-soluble polymer compound preferably contains a repeating unit having a hydrophilic group, and the repeating unit having a hydrophilic group contains a repeating unit represented by the general formula (3). Is preferred. (C) The preferable content of the repeating unit represented by the general formula (3) in the water-soluble polymer compound is in the same range as in the polymer compound (a).
(C) The water-soluble polymer compound may further contain a copolymer component. Examples of the copolymer component include a repeating unit obtained from a radical polymerizable monomer having no hydrophilic group. As an example of the radically polymerizable monomer having no hydrophilic group, among the radically polymerizable monomers included in the curable compound having a molecular weight of 100 or more and less than 100,000, which will be described later, as the combination component, it does not have a hydrophilic group. Things.

  When the ink composition of the present invention contains (c) a water-soluble polymer compound, (a) even when the content of the polymer compound is small, when the ink composition is applied to the recording medium, The surface portion of the ink droplet in contact with air tends to cover (a) the polymer compound, and good blocking resistance, water resistance, and solvent resistance can be exhibited. Furthermore, a cured film (image) excellent in film strength can be obtained by the crosslinking effect of (c ′) the crosslinkable compound.

(C) It is also a preferred embodiment that the water-soluble polymer compound is (c ′) a crosslinkable compound.
(C ′) The crosslinkable compound includes a repeating unit including the partial structure represented by the general formula (1) and does not include at least one repeating unit selected from a perfluoroalkyl structure and a dialkylsiloxane structure. It is preferably a water-soluble polymer compound. Particularly preferably, the repeating unit represented by the general formula (2) and the repeating unit represented by the general formula (3) are at least one selected from a perfluoroalkyl structure and a dialkylsiloxane structure. It is a water-soluble polymer compound that does not contain units.

  (C) Content of the repeating unit having a partial structure represented by the general formula (1) and the repeating unit having a hydrophilic group in the case where the water-soluble polymer compound is (c ′) a crosslinkable compound (preferably Is the content of the repeating unit represented by the general formula (2) and the repeating unit represented by the general formula (3) is in the same range as in the polymer compound (a). .

  (C) Other examples of the crosslinkable compound (c ′) which is an embodiment of the water-soluble polymer compound include (meth) acryloyl group, (meth) acrylamide group, maleimidyl group, styryl group, vinyl ether group, allyl group Or a water-soluble polymer compound having a partial structure represented by the general formula (1). In the present invention, the water-soluble polymer contains a repeating unit containing the partial structure represented by the general formula (1) and does not contain at least one repeating unit selected from a perfluoroalkyl structure and a dialkylsiloxane structure. Particularly preferred are compounds.

  The molecular weight of the water-soluble polymer compound is preferably in the range of 3,000 to 20,000, more preferably in the range of 5,000 to 150,000, and in the range of 10,000 to 100,000 in terms of weight average molecular weight. Further preferred.

  As the (c) water-soluble polymer compound, either a non-crosslinkable compound or (c ′) a crosslinkable compound may be used, or both may be used in combination.

The total content of the water-soluble polymer compound (c) in the ink composition is preferably 2 to 30% by mass, more preferably 2 to 20% by mass, and still more preferably 2 to 10% by mass.
(C) By making content of a water-soluble high molecular compound into the said range, it becomes a tendency for sclerosis | hardenability, discharge property, and the smoothness of an ink cured film to be good.

<< Curable compound with molecular weight of 100 or more and less than 100,000 >>
The ink composition of the present invention may be used in combination with a curable compound having a molecular weight of 100 or more and less than 100,000 (hereinafter sometimes simply referred to as “curable compound”). The curable compound does not include (a) a polymer compound and (c ′) a crosslinkable compound.

  Examples of the curable compound include a water-soluble curable compound having an ethylenically unsaturated bond capable of radical polymerization in the molecule, or a water-soluble compound having at least one partial structure represented by the general formula (1). A curable compound is preferable, and in the present invention, any of a curable low molecular compound having a molecular weight of 100 or more and less than 1,000 and a curable polymer compound having a molecular weight of 1,000 or more and less than 100,000. Can also be used. In addition, molecular weight is a weight average molecular weight about what has molecular weight distribution here.

  As the curable compound, only one kind each of the curable low molecular compound and the curable polymer compound may be used, or two or more kinds may be used in combination at an arbitrary ratio in order to improve the target property. Both a polymerizable low molecular compound and a polymerizable polymer compound may be used. Two or more curable compounds are preferably used in combination.

  The curable compound used in the present invention is required to be a water-soluble compound or a water-dispersible compound. In the present invention, the water-soluble or water-dispersible compound refers to a compound that dissolves or disperses in 2% by mass in distilled water at room temperature. Those that are mixed in are particularly preferred.

  Examples of curable compounds having a molecular weight of 100 or more and less than 100,000 include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, maleic acid, unsaturated carboxylic acid esters, and salts thereof; Examples include anhydrides having an ethylenically unsaturated group; (meth) acrylamide; styrene derivatives; radical polymerizable monomers such as vinyl ethers and N-vinyl compounds.

  Examples of the radical polymerizable monomer include a radical polymerizable monofunctional monomer and a radical polymerizable polyfunctional monomer.

  Examples of the radical polymerizable monofunctional monomer include acrylamide, 2-hydroxyethyl acrylamide, 2-hydroxymethyl acrylamide, t-butyl acrylamide, 3-dimethylaminopropyl acrylamide, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, methoxy oligoethylene. Examples include glycol (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, polyethylene glycol (meth) acrylate, tetrahydrofurfuryl acrylate, 2-hydroxyethyl (meth) acrylate, and 2-hydroxypropyl (meth) acrylate.

  Examples of the radical polymerizable polyfunctional monomer include oligoethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, bis [2- (methacryloyloxy) ethyl] phosphate, methylene bisacrylate, 4,7,10-trioxa Examples include -1,13-tridecanbisacrylamide and triethylene glycol divinyl ether.

  As the radical polymerizable oligomer, polyester oligomer, urethane oligomer, modified polyether oligomer, acrylic oligomer, epoxy oligomer, and the like can be used. Among these, from the viewpoint of hydrolysis stability, an oligomer having an acrylamide group as a polymerizable group and a water-dispersible urethane oligomer are more preferable.

  Moreover, you may use the low molecular compound which has the partial structure represented by the said General formula (1) as a sclerosing | hardenable low molecular compound of molecular weight 100-1,000.

Such a polymerizable low molecular weight compound is preferably a compound having 2 to 6 partial structures represented by the general formula (1) in one molecule, more preferably 2 to 4 compounds, and 2 to 3 More preferably, it is a compound, and 2 is particularly preferable.
More specifically, a compound represented by the following general formula (1-L) can be given.

In General Formula (1-L), R ^a and R ^b each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and at least one of R ^a and R ^b is alkyl having 1 to 4 carbon atoms. Represents a group. R ^a and R ^b may combine with each other to form a 4- to 6-membered ring structure. Q represents a g-valent linking group. g represents an integer of 2 or more.

^{R a} and ^{R b} in the general formula (1-L) are each and ^{R a} and ^{R b} synonymous in the general formula described above (1), and preferred examples are also the same.

  In the general formula (1-L), Q represents a g-valent linking group. Q is preferably a residue obtained by removing g hydrogen atoms from a hydrocarbon group. When Q is a hydrocarbon group, an ether group, an ester group, an amino group, an amide bond, a silyl ether group, a thiol group, or the like may be present in the hydrocarbon group. When Q is a hydrocarbon group, it is preferably a hydrocarbon group having 1 to 30 carbon atoms, and more preferably a hydrocarbon group having 1 to 20 carbon atoms.

  In the general formula (1-L), g represents an integer of 2 or more, preferably 2 to 6, more preferably 2 to 4, still more preferably 2 to 3, and is 2. It is particularly preferred.

  Specific examples of the compound represented by the general formula (1-L) include, but are not limited to, the following compounds (4-1) to (4-6).

In addition, a monofunctional compound having one partial structure represented by the general formula (1) in one molecule may be used as a curable low molecular compound having a molecular weight of 100 or more and less than 1,000.
Examples of the monofunctional compound having one partial structure represented by the general formula (1) include (4-7) to (4-9) below, but are not limited thereto.

  When the ink composition of the present invention contains a curable compound having a molecular weight of 100 or more and less than 100,000, the content is preferably 2% by mass to 20% by mass with respect to the total mass of the ink composition. More preferably, 15% by mass to 15% by mass is more preferable, and 2% by mass to 12% by mass is even more preferable.

<< (d) Colorant >>
The ink composition of the present invention preferably contains a colorant.
Examples of the colorant include dyes and pigments, and pigments are preferable from the viewpoint of durability such as heat resistance, light resistance, and water resistance.

  When a pigment is used as the colorant, the pigment can be contained in the ink composition as a pigment dispersion. Use of a pigment dispersion as a colorant is preferable from the viewpoint of improving solvent resistance. As the pigment dispersion, a self-dispersed pigment can be used in addition to a pigment dispersed with a pigment dispersant.

(Pigment)
As the pigment used as the colorant, generally used organic pigments, inorganic pigments, and those obtained by dyeing resin particles with a dye can be used. Usually, any commercially available pigment can be used, and further, a pigment pretreated with a commercially available pigment dispersion or surface treatment agent, for example, a pigment dispersed in an insoluble resin or the like as a dispersion medium, Or what grafted resin to the pigment surface etc. can be used unless the effect of this invention is impaired.
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.

  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, etc.), C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 3, C.I. I. Pigment yellow 16, C.I. I. Pigment yellow 83, C.I. I. Pigment yellow 155, C.I. I. Disazo pigments such as C.I. Pigment Yellow 219; I. Azo lake pigments such as C.I. Pigment Yellow 100 (eg Tartrazine Yellow Lake); I. Pigment yellow 95 (condensed azo yellow, etc.), C.I. I. Pigment yellow 93, C.I. I. Pigment yellow 94, C.I. I. Pigment yellow 128, C.I. I. Condensed azo pigments such as C.I. Pigment Yellow 166; 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. Metal complex salt azomethine pigments such as C.I. Pigment Yellow 117 (copper azomethine yellow, etc.); I. Pigment yellow 120 (benzimidazolone yellow) C.I. I. Pigment yellow 151, C.I. I. Pigment yellow 175, C.I. I. Pigment yellow 180, C.I. I. Pigment yellow 181, C.I. I. And acetolone pigments such as CI Pigment Yellow 194.

  Examples of those exhibiting red or magenta color include C.I. I. Monoazo pigments such as CI Pigment Red 3 (Toluidine Red, etc.); I. Pigment red 1, C.I. I. Pigment red 4, C.I. I. B-naphthol pigments such as C.I. Pigment Red 6; 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. Pigment Red 57: 1 (Brilliant Carmine 6B etc.), C.I. I. Pigment red 52: 1, C.I. I. Azo lake pigments such as C.I. Pigment Red 48 (B-oxynaphthoic acid lake, etc.); I. Pigment red 144 (condensed azo red, etc.), C.I. I. Pigment red 166, C.I. I. Pigment red 220, C.I. I. Pigment red 214, C.I. I. Pigment red 221, C.I. I. Condensed azo pigments such as C.I. Pigment Red 242, C.I. I. Pigment Red 174 (Phloxine B lake, etc.), C.I. I. Acidic dye lake pigments such as C.I. Pigment Red 172 (Erythrosin 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 CI Pigment Red 194 (perinone red, etc.)

C. I. Pigment red 149 (perylene scarlet, etc.), C.I. I. Pigment red 179, C.I. I. Pigment red 178, C.I. I. Pigment red 190, C.I. I. Pigment red 224, C.I. I. Pigment red 123, C.I. I. Perylene pigments such as C.I. Pigment Red 224; I. Pigment violet 19 (unsubstituted quinacridone), C.I. I. Pigment red 122 (quinacridone magenta, etc.), C.I. I. Pigment red 262, C.I. I. Pigment red 207, C.I. I. Quinacridone pigments such as C.I. Pigment Red 209; I. Isoindolinone pigments such as CI Pigment Red 180 (isoindolinone red 2BLT, etc.); I. Alizarin lake pigments such as C.I. Pigment Red 83 (Madalake, etc.); I. Pigment red 171, C.I. I. Pigment red 175, C.I. I. Pigment red 176, C.I. I. Pigment red 185, C.I. I. Naphtholone pigments such as C.I. Pigment Red 208; I. Naphthol AS lake pigments such as C.I. Pigment Red 247; I. Pigment red 2, C.I. I. Pigment red 5, C.I. I. Pigment red 21, C.I. I. Pigment red 170, C.I. I. Pigment red 187, C.I. I. Pigment red 256, C.I. I. Pigment red 268, C.I. I. Naphthol AS pigments such as C.I. Pigment Red 269; I. Pigment red 254, C.I. I. Pigment red 255, C.I. I. Pigment red 264, C.I. I. And diketopyrrolopyrrole pigments such as CI Pigment Red 27.

  Examples of pigments exhibiting blue or cyan colors include C.I. I. Disazo pigments such as C.I. Pigment Blue 25 (Dianisidine Blue, etc.); I. Pigment blue 15, C.I. I. Pigment blue 15: 1, C.I. I. Pigment blue 15: 2, C.I. I. Pigment blue 15: 3, C.I. I. Pigment blue 15: 4, C.I. I. Pigment blue 15: 6, C.I. I. Phthalocyanine pigments such as C.I. Pigment Blue 16 (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).

Examples of the pigment exhibiting green include C.I. I. Pigment green 7 (phthalocyanine green), C.I. I. Phthalocyanine pigments such as C.I. Pigment Green 36 (phthalocyanine green); I. Pigment green 8 (nitroso green), C.I. I. And azo metal complex pigments such as CI Pigment Green 10.
Examples of orange pigments include C.I. I. An isoindoline pigment such as C.I. Pigment Orange 66 (isoindoline orange); I. Anthraquinone pigments such as C.I. Pigment Orange 51 (dichloropyrantron orange); I. Pigment orange 2, C.I. I. Pigment orange 3, C.I. I. Β-naphthol pigments such as C.I. Pigment Orange 5; I. Pigment orange 4, C.I. I. Pigment orange 22, C.I. I. Pigment orange 24, C.I. I. Pigment orange 38, C.I. I. Naphthol AS pigments such as CI Pigment Orange 74; I. Isoindolinone pigments such as CI Pigment Orange 61; I. Perinone pigments such as C.I. Pigment Orange 43; I. Pigment orange 15, C.I. I. Disazo pigments such as CI Pigment Orange 16; I. Pigment orange 48, C.I. I. Quinacridone pigments such as CI Pigment Orange 49; I. Pigment orange 36, C.I. I. Pigment orange 62, C.I. I. Pigment orange 60, C.I. I. Pigment orange 64, C.I. I. An acetolone pigment such as C.I. Pigment Orange 72; I. Pigment orange 13, C.I. I. And pyrazolone pigments such as CI Pigment Orange 34.
Examples of the pigment exhibiting brown include C.I. I. Pigment brown 25, C.I. I. And naphthron pigments such as CI Pigment Brown 32.

Examples of pigments exhibiting black color include carbon black, titanium black, C.I. I. Indazine pigments such as CI Pigment Black 1 (aniline black); I. Pigment black 31, C.I. I. And perylene pigments such as CI Pigment Black 32.
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), and titanium. Strontium acid (SrTiO ₃ , so-called titanium strontium white) can be used. The inorganic particles used for the white pigment may be a simple substance or, for example, oxides such as silicon, aluminum, zirconium, and titanium, organometallic compounds, and composite particles with an organic compound.

  Here, titanium oxide has a smaller specific gravity than other white pigments, a large refractive index, and is chemically and physically stable, so that it has a large 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.

Since the non-white pigment has a better color developability as the average particle size is smaller, if the pigment dispersion is applied to a pigment dispersion other than white, the average particle size of the pigment contained in the pigment dispersion is: The thickness is preferably about 0.01 μm to 0.4 μm, more preferably 0.02 μm to 0.3 μm.
The maximum particle diameter of the pigment is 3 μm or less, preferably 1 μm or less. The particle size of the pigment can be adjusted by selecting a pigment, a dispersant, a dispersion medium, setting dispersion conditions, and filtering conditions. Further, when the ink composition of the present invention is prepared as a white ink composition, the average particle size of the pigment contained in the pigment dispersion is 0.05 μm to The thickness is preferably about 1.0 μm, more preferably about 0.1 μm to 0.4 μm. Also when it is set as a white pigment dispersion, it is preferable that the maximum particle diameter of a pigment is 3 micrometers or less, Preferably it is 1 micrometer or less.

(Dispersant)
When a pigment is used as the colorant, a pigment dispersant may be used as necessary when preparing the pigment particles. Examples of the pigment dispersant that can be used include higher fatty acid salts and alkyl sulfates. , Alkyl ester sulfate, alkyl sulfonate, sulfosuccinate, naphthalene sulfonate, alkyl phosphate, polyoxyalkylene alkyl ether phosphate, polyoxyalkylene alkyl phenyl ether, polyoxyethylene polyoxypropylene glycol, glycerin Activators such as esters, sorbitan esters, polyoxyethylene fatty acid amides, amine oxides, or styrene, styrene derivatives, vinyl naphthalene derivatives, acrylic acid, acrylic acid derivatives, maleic acid, maleic acid derivatives, itaconic acid, itaconic acid derivatives, Mar acids, block copolymers of two or more monomers selected from fumaric acid derivatives, random copolymers and can be exemplified salts thereof.

  A self-dispersing pigment can also be used in the ink composition of the present invention. The self-dispersing pigment as used in the present invention refers to a pigment that can be dispersed without a dispersant, and particularly preferably pigment particles having a polar group on the surface.

The pigment particles having a polar group on the surface as used in the present invention are a pigment whose surface is directly modified with a polar group, or an organic substance having an organic pigment mother nucleus, which is bonded directly or via a joint. (Hereinafter referred to as pigment derivative).
Examples of the polar group include a sulfonic acid group, a carboxylic acid group, a phosphoric acid group, a boric acid group, and a hydroxyl group, preferably a sulfonic acid group and a carboxylic acid group, and more preferably a sulfonic acid group.

  Examples of a method for obtaining pigment particles having a polar group on the surface include, for example, WO 97/48769, JP-A-10-110129, JP-A-11-246807, JP-A-11-57458, 11-189739, JP-A-11-323232, JP-A-2000-265094, etc., oxidize the pigment particle surface with an appropriate oxidizing agent, so that at least a part of the pigment surface has a sulfonic acid group or The method of introduce | transducing polar groups, such as the salt, is mentioned. Specifically, it is prepared by oxidizing carbon black with concentrated nitric acid or, in the case of color pigments, by oxidizing with sulfamic acid, sulfonated pyridine salt, amidosulfuric acid, etc. in sulfolane or N-methyl-2-pyrrolidone. can do. In these reactions, the pigment dispersion can be obtained by removing and purifying the substance that has been excessively oxidized and becomes water-soluble. Moreover, when a sulfonic acid group is introduced onto the surface by oxidation, the acidic group may be neutralized with a basic compound as necessary.

  As other methods for obtaining pigment particles having polar groups on the surface, the pigment particles described in JP-A-11-49974, JP-A-2000-273383, JP-A-2000-303014, etc. are treated with a treatment such as milling. Examples include a method of adsorbing to the surface, a method described in Japanese Patent Application Nos. 2000-377068, 2001-1495, and 2001-234966, and a method of crystallizing in a poor solvent after dissolving the pigment derivative together with a solvent. In any method, pigment particles having a polar group on the surface can be easily obtained.

  The polar group on the surface of the pigment may be free or in a salt state, or may have a counter salt. Examples of the counter salt include inorganic salts (lithium, sodium, potassium, magnesium, calcium, aluminum, nickel, ammonium) and organic salts (triethylammonium, diethylammonium, pyridinium, triethanolammonium, etc.), preferably 1 A counter salt having a valence.

  The content of the colorant with respect to the total amount of the ink composition in the invention is preferably 0.5% by mass to 10% by mass, and more preferably 0.5% by mass to 5% by mass.

<< (e) Water-soluble organic solvent >>
The ink composition of the present invention contains water as a main solvent, but it is preferable to further use a water-soluble organic solvent in the solvent depending on the purpose.
Here, the water-soluble organic solvent means an organic solvent having a solubility in water at 25 ° C. of 10% by mass or more.

Examples of water-soluble organic solvents that can be used in the present invention include the following.
Alcohols (eg, methanol, ethanol, propanol, isopropanol, butanol, isobutanol, secondary butanol, tertiary butanol, pentanol, hexanol, cyclohexanol, benzyl alcohol, etc.),
Polyhydric alcohols (for example, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, butylene glycol, hexanediol, pentanediol, glycerin, hexanetriol, thiodiglycol, 2- Methylpropanediol, etc.)
Polyhydric alcohol ethers (for example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, tripropylene Glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether, ethylene glycol monomethyl ether acetate, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, ethylene glycol Monophenyl ether, propylene glycol monophenyl ether, etc.),

-Amines (eg, ethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, morpholine, N-ethylmorpholine, ethylenediamine, diethylenediamine, triethylenetetramine, tetraethylenepentamine, polyethyleneimine, pentane Methyldiethylenetriamine, tetramethylpropylenediamine, etc.),
Amides (eg, formamide, N, N-dimethylformamide, N, N-dimethylacetamide, etc.),
Heterocycles (for example, 2-pyrrolidone, N-methyl-2-pyrrolidone, cyclohexyl pyrrolidone, 2-oxazolidone, 1,3-dimethyl-2-imidazolidinone, γ-butyrolactone, propylene carbonate, ethylene carbonate, ethylene urea etc),
・ Sulphoxides (for example, dimethyl sulfoxide),
-Sulfones (for example, sulfolane),
・ Others (urea, acetonitrile, acetone, etc.)

  Preferable water-soluble organic solvents include polyhydric alcohol ethers and heterocyclic rings, and these are preferably used in combination.

Among the polyhydric alcohol ethers, so-called glycol ethers are preferable, specifically, tripropylene glycol monomethyl ether, dipropylene glycol monomethyl ether, and dipropylene glycol dimethyl ether are preferable, and 2-dipropylene glycol monomethyl ether is more preferable.
As the heterocyclic ring, 2-pyrrolidone, γ-butyrolactone, propylene carbonate, ethylene urea and the like are preferable, and 2-pyrrolidone and γ-butyrolactone are particularly preferable.
In particular, a solvent having a high boiling point can be preferably used, and the boiling point at normal pressure is preferably 120 ° C. or higher, more preferably 150 ° C. or higher.

  One or more water-soluble organic solvents may be used in combination. The total amount of the water-soluble organic solvent added to the ink composition is preferably 1% by mass to 60% by mass, and more preferably 2% by mass to 35% by mass.

<< Surfactant >>
A surfactant can be added to the ink composition of the present invention.
As surfactants preferably used, anionic surfactants such as dialkylsulfosuccinates, alkylnaphthalenesulfonates, fatty acid salts, polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, acetylene glycols, Nonionic surfactants such as polyoxyethylene / polyoxypropylene block copolymers, and cationic surfactants such as alkylamine salts and quaternary ammonium salts. In particular, an anionic surfactant and a nonionic surfactant can be preferably used.

In the present invention, a polymer surfactant can also be used, and the following water-soluble resins are mentioned as preferred polymer surfactants. As the water-soluble resin, styrene-acrylic acid-acrylic acid alkyl ester copolymer, styrene-acrylic acid copolymer, styrene-maleic acid-acrylic acid alkyl ester copolymer, styrene-maleic acid copolymer are preferably used. Polymer, styrene-methacrylic acid-acrylic acid alkyl ester copolymer, styrene-methacrylic acid copolymer, styrene-maleic acid half ester copolymer, vinyl naphthalene-acrylic acid copolymer, vinyl naphthalene-maleic acid copolymer Etc.
In the present invention, a silicone surfactant having a polyalkylsiloxane and a fluorine surfactant having a fluorinated alkyl group can also be preferably used.

  In the ink composition of the present invention, when a surfactant is used, the addition amount is preferably 0.1% by mass or more and 5% by mass or less in terms of solid content. It is particularly preferable that the solid content addition amount be 0.5 mass% or more and 2 mass% or less.

<< sensitizing dye >>
In the present invention, a known sensitizing dye can be used in combination, and a sensitizing dye is preferably used in combination. The solubility is preferably 0.5% by mass or more, more preferably 1% by mass or more, at room temperature in distilled water. Those that dissolve 3% by mass or more are particularly preferable. Further, as the sensitizing dye, a photopolymerization initiator in which a water-insoluble polymerization initiator is dispersed can also be used.

  Examples of known sensitizing dyes that can be used in combination include N- [2-hydroxy-3- (3,4-dimethyl-9-oxo-9H-thioxanthen-2-yloxy) propyl] -N, N, N. -Trimethylaluminum chloride, benzophenone, thioxanthone, anthraquinone derivatives and 3-acylcoumarin derivatives, terphenyl, styryl ketone and 3- (aroylmethylene) thiazoline, camphorquinone, eosin, rhodamine and erythrosine, and their modified forms And dispersions thereof. Moreover, the compound represented by the general formula (i) described in JP-A 2010-24276 and the compound represented by the general formula (I) described in JP-A-6-107718 can also be suitably used. .

  In addition to the above-described components, the ink according to the present invention is used for the purpose of improving ejection stability, print head and ink cartridge compatibility, storage stability, image storage stability, and other various performances as necessary. According to various known additives, for example, viscosity modifiers, surface tension modifiers, specific resistance modifiers, film forming agents, dispersants, surfactants, ultraviolet absorbers, antioxidants, antifading agents, anticorrosives Agents, rust preventives, solid wetting agents, silica fine particles and the like can be appropriately selected and used. For example, oil droplet fine particles such as liquid paraffin, dioctyl phthalate, tricresyl phosphate, silicone oil, Nos. 57-87988 and 62-261476, JP-A 57-74192, 57-87989, 60-72785, 61- No. 46591, JP-A-1-95091 and JP-A-3-13376, etc., and JP-A-59-42993, 59-52689, 62-280069, 61-242871 Examples thereof include fluorescent brighteners and pH adjusters such as sulfuric acid, phosphoric acid, citric acid, sodium hydroxide, potassium hydroxide, and potassium carbonate described in JP-A-4-219266.

<Method for Preparing Ink Composition>
The method for preparing the ink composition according to the present invention is not particularly limited, and each component may be a medium such as a ball driving machine mill such as a ball mill, a centrifugal mill or a planetary ball mill, a high speed rotating mill such as a sand mill, or a stirring tank mill. It can be prepared by stirring, mixing, and dispersing with a simple dispersing machine such as a stirring mill or a disper. About the addition order of each component, it is arbitrary. Preferably, the azo pigment, the polymer dispersant and the organic solvent are premixed and then subjected to a dispersion treatment, and the obtained dispersion is mixed with the resin and the organic solvent. In this case, at the time of addition or after addition, the mixture is uniformly mixed with a simple stirrer such as a three-one motor, a magnetic stirrer, a disper, or a homogenizer. You may mix using mixers, such as a line mixer. Further, in order to make the dispersed particles finer, they may be mixed using a dispersing machine such as a bead mill or a high-pressure jet mill. Depending on the type of pigment or polymer dispersant, a resin may be added during premixing before pigment dispersion.

  The ink composition of the present invention preferably has a surface tension at 25 ° C. of 200 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).

<Image forming method>
The image forming method of the present invention includes an ink applying step of applying the ink composition onto a recording medium, and an irradiation step of irradiating the applied ink composition with active energy rays. By performing these steps, an image of the ink composition fixed on the recording medium is formed.

(Ink application process)
Hereinafter, the ink application process in the image forming method of the present invention will be described.
The ink application process in the present invention is not limited as long as it is a process of applying the ink composition onto a recording medium.

  As an embodiment of applying the ink composition of the present invention on a recording medium, an embodiment of applying an ink composition by an inkjet method onto a recording medium is particularly preferable.

  In the image forming method of the present invention, the ink jet recording apparatus used when the ink applying process ink jet method is applied is not particularly limited, and a known ink jet recording apparatus capable of achieving a target resolution is arbitrarily selected. Can be used. That is, any known inkjet recording apparatus including a commercially available product can discharge the ink composition onto the recording medium in the image forming method of the present invention.

Examples of the ink jet recording apparatus that can be used in the present invention include an apparatus including an ink supply system, a temperature sensor, and a heating unit.
The ink supply system includes, for example, an original tank containing the ink composition of the present invention, a supply pipe, an ink supply tank immediately before the inkjet head, a filter, and a piezo-type inkjet head. The piezo-type inkjet head preferably has a multi-size dot of 1 to 100 pl, more preferably 8 to 30 pl, preferably 320 × 320 to 4,000 × 4,000 dpi (dot per inch), more preferably 400 × 400. ˜1,600 × 1,600 dpi, more preferably 720 × 720 dpi. The dpi referred to in the present invention represents the number of dots per 2.54 cm (1 inch).

In the ink application step, it is desirable that the discharged ink composition has a constant temperature. Therefore, the ink jet recording apparatus preferably includes a means for stabilizing the ink composition temperature. The parts to be kept at a constant temperature are all the piping systems and members from the ink tank (intermediate tank if there is an intermediate tank) to the nozzle ejection surface. That is, heat insulation and heating can be performed from the ink supply tank to the inkjet head portion.
The temperature control method is not particularly limited, but for example, it is preferable to provide a plurality of temperature sensors in each piping portion and perform heating control according to the flow rate of the ink composition and the environmental temperature. The temperature sensor can be provided near the ink supply tank and the nozzle of the inkjet head. Moreover, it is preferable that the head unit to be heated is thermally shielded or insulated so that the apparatus main body is not affected by the temperature from the outside air. In order to shorten the printer start-up time required for heating or to reduce the loss of thermal energy, it is preferable to insulate from other parts and reduce the heat capacity of the entire heating unit.

  The ink composition is discharged using the ink jet recording apparatus, and the ink composition is preferably heated to 25 to 80 ° C., more preferably 25 to 50 ° C., and the viscosity of the ink composition is preferably 3 mPa · s to It is preferable to carry out after lowering to 15 mPa · s, more preferably 3 mPa · s to 13 mPa · s. In particular, it is preferable to use an ink composition having a viscosity of 50 mPa · s or less at 25 ° C. as the ink composition of the present invention, since it can be discharged satisfactorily. By using this method, high ejection stability can be realized.

  The temperature of the ink composition during ejection is preferably constant, and the control range of the temperature of the ink composition is more preferably ± 5 ° C. of the set temperature, more preferably ± 2 ° C. of the set temperature, and most preferably set. A temperature of ± 1 ° C. is appropriate.

In the present invention, the recording medium is not particularly limited, and a known recording medium can be used as a support or a recording material. Examples of the recording medium include paper, paper laminated with plastic (eg, polyethylene, polypropylene, polystyrene, etc.), metal plate (eg, aluminum, zinc, copper, etc.), plastic film (eg, polyvinyl chloride resin, two Cellulose acetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate, polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, etc.), paper or plastic on which the above metals are laminated or deposited A film etc. are mentioned.
Among them, since the ink composition of the present invention is excellent in adhesion, it can be suitably used for a non-absorbent recording medium as a recording medium, and a plastic substrate such as polyvinyl chloride, polyethylene terephthalate, polyethylene is preferable, A polyvinyl chloride resin base material is more preferable, and a polyvinyl chloride resin sheet or film is more preferable.

(Irradiation process)
Hereinafter, the irradiation step in the image forming method of the present invention will be described.
The irradiation step in the present invention is not limited as long as it is a step of irradiating the ink composition applied on the recording medium with active energy rays.
By irradiating the ink composition of the present invention with active energy rays, the crosslinking reaction of the compound in the ink composition proceeds to fix the image and to improve the solvent resistance of the printed matter. By this irradiation step, a cross-linking reaction is caused by the partial structure represented by the general formula (1) which is a reactive group of the polymer compound (a), and a cross-linked structure of the following general formula (5) is formed in the ink composition. Is done. This reaction also occurs between adjacent polymer compound particles, or between (a) a specific polymer and a polymerizable compound having a partial structure represented by the general formula (1), which is optionally contained. Since this crosslinking reaction is a reaction that does not involve radicals, it has a feature that there is no concern that the crosslinking reaction is inhibited by oxygen.

In General Formula (5), R ^a , R ^b , R ^{a ′} and R ^{b ′} each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and at least one of R ^a and R ^b , and , R ^{a ′} and R ^{b ′} each represents an alkyl group having 1 to 4 carbon atoms. R ^a and R ^b may combine with each other to form a 4- to 6-membered ring structure. R ^{a ′} and R ^{b ′} may combine with each other to form a 4- to 6-membered ring structure. R ^a and R ^b are the same as those described in the general formula (1), including a preferred range. R a ^'is the same as R ^a described in general formula (1), including the preferred ranges. R b ^'are the same as R ^b which has been described in general formula (1), including the preferred ranges.

  Examples of active energy rays that can be used in the irradiation step include ultraviolet rays (hereinafter also referred to as UV light), visible light glands, electron beams, and the like, and UV light is preferably used.

  Although the peak wavelength of UV light depends on the absorption characteristics of the sensitizing dye used as necessary, it is preferably, for example, 200 nm to 405 nm, more preferably 220 nm to 390 nm, and 220 nm to 350 nm. More preferably. In this invention, when not using a sensitizing dye and a photoinitiator together, it is preferable that it is 200 nm-310 nm, and 200 nm-280 nm are more preferable.

UV light is the illumination intensity on the exposed surface is, for ^{example, 10mW / cm 2 ~2,000mW / cm} 2, ^is preferably a suitably be irradiated with ^{20mW / cm 2 ~1,000mW / cm 2} .

  As the UV light source, a mercury lamp, a gas / solid laser or the like is mainly used, and a mercury lamp, a metal halide lamp and a UV fluorescent lamp are widely known. In addition, replacement with GaN-based semiconductor ultraviolet light-emitting devices is very useful industrially and environmentally. LED (UV-LED) and LD (UV-LD) are small, have long life, high efficiency, and low cost. Yes, it is expected as a UV light source. In the present invention, when a sensitizing dye and a photopolymerization initiator are used in combination, a metal halide lamp, a high pressure mercury lamp, a medium pressure mercury lamp, a low pressure mercury lamp, and a UV-LED are preferable, and a sensitizing dye and a photopolymerization initiator are used in combination. If not, a medium pressure mercury lamp or a low pressure mercury lamp is preferred.

In the irradiation step, the ink composition of the present invention applied on the recording medium is irradiated with such UV light, for example, for 0.01 seconds to 120 seconds, preferably 0.1 seconds to 90 seconds. It is appropriate.
As the irradiation conditions and the basic irradiation method, the irradiation conditions and the irradiation method disclosed in JP-A-60-132767 can be similarly applied to the present invention. Specifically, a light source is provided on both sides of the head unit including the ink ejection device, and the head unit and the light source are scanned by a so-called shuttle method, or another light source that is not driven and driven is used. Is preferred. The irradiation with the active energy ray is performed after a certain period of time (for example, 0.01 seconds to 120 seconds, preferably 0.01 seconds to 60 seconds) after ink landing and heat drying.

(Heat drying process)
The image forming method of the present invention preferably further includes a heat drying step after the ink application step and before the irradiation step.
In the heat drying step, the ink composition discharged onto the recording medium is preferably fixed by evaporating (b) water and a water-soluble organic solvent used in combination as necessary.

A process of heating and drying and fixing the discharged ink composition of the present invention (heat drying process) will be described.
The heating means is not limited as long as (b) water and a water-soluble organic solvent used in combination can be dried, if necessary. Heat drum, hot air, infrared lamp, heat oven, heat plate heating, etc. Can be used.
The heating temperature is preferably 40 ° C or higher, more preferably about 40 ° C to 150 ° C, and still more preferably about 40 ° C to 80 ° C. The drying / heating time can be appropriately set in consideration of the composition and printing speed of the ink composition to be used.

  The ink composition fixed by heating is irradiated with an active energy ray in an irradiation step as necessary, and further photofixed. As described above, in the irradiation step, fixing with UV light is preferable.

[Printed matter]
The printed matter of the present invention is characterized by having an image formed with the ink composition of the present invention or an image recorded by the image forming method of the present invention. The printed matter of the present invention is a printed matter excellent in water resistance, solvent resistance and blocking resistance of a recorded image.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, “part” and “%” are based on mass.

  The pigment dispersions and ink composition materials used in the examples and comparative examples are shown below.

(Preparation of pigment dispersion)
<Synthesis of Polymer Dispersant E-1>
To a 500 ml three-necked flask equipped with a stirrer and a condenser tube, 44 g of methyl ethyl ketone was added and heated to 72 ° C. in a nitrogen atmosphere. Here, 25 g of methyl ethyl ketone was mixed with 0.43 g of dimethyl 2,2′-azobisisobutyrate and benzyl methacrylate. A solution in which 30 g, 5 g of methacrylic acid and 15 g of methyl methacrylate were dissolved was dropped over 3 hours. After completion of the dropwise addition, the reaction was further continued for 1 hour, and then a solution of 0.21 g of dimethyl 2,2′-azobisisobutyrate dissolved in 1 g of methyl ethyl ketone was added, heated to 78 ° C. and heated for 4 hours. The obtained reaction solution was reprecipitated twice in a large excess amount of hexane, and the precipitated resin was dried to obtain 43 g of polymer dispersant E-1.
The composition of the obtained polymer dispersant E-1 was confirmed by ¹ H-NMR, and the weight average molecular weight (Mw) determined by GPC was 42,000. Furthermore, when the acid value was calculated | required by the method as described in JIS specification (JISK0070: 1992), it was 65.4 mgKOH / g.

<Preparation of resin-coated pigment dispersion>
(Dispersion of resin-coated cyan pigment (C))
Pigment Blue 15: 3 (phthalocyanine blue A220, manufactured by Dainichi Seika Co., Ltd.), 5 parts of the above polymer dispersant E-1, 42 parts of methyl ethyl ketone, 5.5 parts of 1 mol / L NaOH aqueous solution, Then, 87.2 parts of ion-exchanged water was mixed and dispersed with a bead mill using 0.1 mmφ zirconia beads for 2 to 6 hours.
Methyl ethyl ketone was removed from the obtained dispersion at 55 ° C. under reduced pressure, and a part of water was further removed to obtain a dispersion (C) of a resin-coated cyan pigment having a pigment concentration of 10.2% by mass. .

(A) Compounds A-1 to A-4 which are polymer compounds used in Examples, Compound C-1 ((c) Water-soluble polymer compound which is a non-crosslinkable compound), and Compound D-1 ( The crosslinkable compound (c) water-soluble polymer compound) was synthesized with reference to JP-A-52-988. Each polymer compound synthesized was re-precipitated in a large amount of hexane, and then dissolved in an aqueous solution of sodium hydrogen carbonate (Wako Pure Chemical Industries, Ltd.).
The structure of each compound used in this example and comparative example is shown below.
In addition, in compound A-1 to A-4, compound C-1, and compound D-1, the copolymerization ratio shown using a, b, c, and d is a mass reference | standard.

<(A) polymer compound>

<(C) Water-soluble polymer compound>

<Water-soluble organic solvent>
・ 2-Pyrrolidone (manufactured by Sigma-Aldrich Japan)

<Surfactant>
・ Fluorine-based surfactant (trade name: ZONYL FSN, manufactured by Aldrich)

[Examples 1 to 6, Comparative Example 1]
[Preparation of ink composition]
The obtained pigment dispersion [dispersion (C)] and the above (a) polymer compound, (c) water-soluble polymer compound, water-soluble organic solvent, surfactant and water are shown in Table 1 below. Using a mixer (L4R manufactured by Silverson Co., Ltd.) so as to have the composition shown, the mixture was stirred at 2,500 rpm to prepare a crude ink composition. Each obtained crude ink composition is packed into a plastic disposable syringe and filtered through a polyvinylidene fluoride (PVDF) pore size 5 μm filter (Millex-SV, Millipore, diameter 25 mm) to obtain a finished product. Ink compositions of Examples 1 to 6 and Comparative Example 1 were obtained.

<Evaluation>
The obtained ink compositions of Examples and Comparative Examples were used as No. of K hand coater manufactured by RK PRINT COAT INSTRUMENTS. Using 2 bars, it was applied to an 8 cm square vinyl chloride sheet (Avery 400 GLOSS WHITE PERMANENT, manufactured by Avery Dennison Co., Ltd.) with a thickness of 12 μm. Further, after moisture was dried at 60 ° C. for 3 minutes, exposure was performed with a low-pressure mercury lamp under the condition of an energy of 1000 mJ / cm ² to obtain a printed matter having a cured film (solid image) on the vinyl chloride sheet.
The following evaluation was performed using the obtained printed matter. The evaluation results are shown in Table 1.

<Blocking resistance evaluation>
The printed products are overlapped with each other so that the surfaces of the two printed products having the cured film face each other, and using an iron plate of the same size as the printed material, the pressure is further 1 kg / cm ² at 30 ° C. Pressurized for 1 hour. Then, the state at the time of peeling off two coating-film surfaces was observed visually, and the following evaluation criteria evaluated. The evaluation results are shown in Table 1. In addition, A and B are levels with no practical problem.
-Evaluation criteria-
A: There is no peeling in the coating film, and no sound is produced when peeling off.
B: Although there is no peeling in a coating film, a sound is produced when peeling off.
C: Although there is no peeling in the coating film, some transfer is seen in the coating film.
D: Peeling occurs in the coating film.

<Water resistance evaluation>
The surface on the side having the cured film in the obtained printed matter was rubbed with a cotton swab impregnated with ion-exchanged water and evaluated according to the following evaluation criteria. The evaluation results are shown in Table 1. In addition, A and B are levels with no practical problem.
-Evaluation criteria-
A: Even after rubbing 10 times or more, no change was observed in the image.
B: Image density decreased after 5 to 9 rubbing.
C: Image density decreased after 2-4 rubbing.
D: Image density was significantly reduced by just rubbing once.

<Solvent resistance evaluation>
The surface on the side having the cured film in the obtained printed material was rubbed with a cotton swab impregnated with isopropyl alcohol and evaluated according to the following evaluation criteria. The evaluation results are shown in Table 1. In addition, A and B are levels with no practical problem.
-Evaluation criteria-
A: Even after rubbing 10 times or more, no change was observed in the image.
B: Image density decreased after 5 to 9 rubbing.
C: Image density decreased after 2-4 rubbing.
D: Image density was significantly reduced by just rubbing once.

<Ejection evaluation>
A commercially available inkjet printer (SP-300V manufactured by Roland DG Inc.) was prepared as an inkjet recording apparatus. Each obtained ink composition was loaded into the above-mentioned ink jet printer, and ejected from a head for 3 minutes onto a vinyl chloride sheet (Avery 400 GLOSS WHITE PERMANENT, manufactured by Avery Dennison) to record a solid image and fine lines. After stopping the discharge, the obtained image was left for 3 minutes. Thereafter, the solid image and the image (5 cm × 5 cm) obtained by recording the thin line were observed again. The observed images were visually evaluated according to the following evaluation criteria. The evaluation results are shown in Table 1.
-Evaluation criteria-
A: The occurrence of missing dots due to the occurrence of missing or the like was not recognized, and a good image was obtained.
B: Although the occurrence of missing dots due to the occurrence of omission was slightly observed, it was of a level that would not cause any practical problems.
C: The image lacked practical use due to the occurrence of missing dots due to the occurrence of omission.
Note that the evaluation ranks A and B are levels that have no practical problem.

"-" In the following Table 1 represents not containing.

  As shown in Table 1, (a) the ink compositions of the respective examples containing the polymer compound were all resistant to blocking, water, and solvent in comparison with the ink compositions of the comparative examples. It can be seen that an excellent effect can be obtained.

Claims (15)

(A) a polymer compound having a repeating unit having a partial structure represented by the following general formula (1), and at least one selected from a perfluoroalkyl group and a dialkylsiloxane structure, and (b) water. An ink composition to contain.


[In General Formula (1), R ^a and R ^b each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and at least one of R ^a and R ^b is an alkyl group having 1 to 4 carbon atoms. Represents. R ^a and R ^b may be bonded to each other to form a 4- to 6-membered alicyclic structure. * Indicates a binding site to the main chain or side chain in the polymer compound. ]   The ink composition according to claim 1, wherein the polymer compound (a) is a polymer compound having a hydrophilic group. The ink composition according to claim 1, wherein the repeating unit having a partial structure represented by the general formula (1) is a repeating unit represented by the following general formula (2).


[In General Formula (2), R ^a and R ^b each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and at least one of R ^a and R ^b is an alkyl group having 1 to 4 carbon atoms. Represents. R ^a and R ^b may be bonded to each other to form a 4- to 6-membered alicyclic structure. R ^c represents a hydrogen atom or a methyl group. Z represents a single bond, —COO — ** or —CONR ^d — **, R ^d represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and ** represents a bonding position with X. X represents a divalent organic group. ]   The said (a) polymer compound has at least 1 sort (s) of hydrophilic group chosen from alcoholic hydroxyl group, an alkyl substituted carbamoyl group, a carboxyl group, a sulfo group, and these salts. Item 4. The ink composition according to item.   The (a) polymer compound contains 10% by mass to 70% by mass of a repeating unit having a partial structure represented by the general formula (1), and is at least one selected from a perfluoroalkyl group and a dialkylsiloxane structure The ink composition according to any one of claims 1 to 4, which is a polymer compound containing 5% by mass to 25% by mass of a repeating unit having a water content.   The ink composition according to any one of claims 1 to 5, further comprising (c) a water-soluble polymer compound having a structure different from that of the polymer compound (a).   Further, (a) a water-soluble polymer compound having a structure different from that of the polymer compound (c) is contained, and the (c) water-soluble polymer compound is (c ′) a crosslinkable compound. Item 7. The ink composition according to any one of items 6.   The ink composition according to any one of claims 1 to 7, wherein the content of the polymer compound (a) is 0.1% by mass to 15% by mass with respect to the total mass of the ink composition. .   The ink composition according to any one of claims 1 to 8, wherein the content of the polymer compound (a) is 0.1% by mass to 2% by mass with respect to the total mass of the ink composition. .   The ink composition according to any one of claims 1 to 9, further comprising (d) a colorant.   The ink composition according to any one of claims 1 to 10, further comprising (e) a water-soluble organic solvent.   The ink composition according to claim 1, wherein the ink composition is for inkjet recording.   An ink application step of applying the ink composition according to any one of claims 1 to 12 onto a recording medium, and an irradiation step of irradiating the ink composition applied onto the recording medium with active energy rays. And an image forming method.   An ink application step of applying the ink composition according to any one of claims 1 to 12 onto a recording medium, and (b) water and (e) contained in the ink composition applied onto the recording medium ) An image forming method comprising: an ink drying step of drying and removing at least a part of the water-soluble organic solvent; and an irradiation step of irradiating the ink composition applied and dried on the recording medium with active energy rays.   An image formed on the image recording medium by the ink composition according to any one of claims 1 to 12 or recorded by the image forming method according to claim 13 or 14. Prints that have.