JP2014070184A - Ink composition, image forming method, and printed matter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink composition which can form an image superior in stretchability, anti-blocking performance and solvent resistance.SOLUTION: An ink composition includes: a polyurethane resin particle having at least one kind partial structure selected from the group consisting of a polysiloxane group and a fluorinated alkyl group, an ethylenically unsaturated bond group, and a hydrophilic functional group; water; a polymerization initiator; and a coloring agent.

Description

  The present invention relates to an ink composition, an image forming method, and a printed matter.

As an image forming 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, there is little noise and it is excellent as an image forming method.

Among the ink compositions used for image formation by the inkjet method, the active energy ray-curable water-based ink is used for image formation, pretreatment for imparting ink application suitability to a recording medium, and protection of the formed image. It can be used suitably for decorative post-processing, etc., and has many excellent features, such as being excellent in safety because it contains water as the main component, and being able to be applied to high-density inkjet recording due to low viscosity. It is an ink having properties.
Examples of basic constituent materials of the active energy ray-curable water-based ink 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). it can.

  In relation to the above, Patent Document 1 discloses an aqueous curable resin composition including a composite resin in which a hydrophilic group-containing polyurethane and a vinyl polymer are bonded via a polysiloxane, and has excellent substrate followability. It is said that. Patent Document 2 describes a water-based inkjet recording liquid containing a fluorodiol-modified polyurethane binder, which is excellent in scratch resistance of the formed image. Further, Patent Documents 3 and 4 disclose non-aqueous ink jet ink compositions containing a polyurethane having a fluorinated alkyl group or a siloxane skeleton and a polymerizable group.

JP 2011-111491 A Special table 2010-516868 gazette JP 2010-018728 A JP2012-092330A

  However, with the compositions described in Patent Documents 1 and 2, it was difficult to say that the stretchability, blocking resistance, and solvent resistance of the formed image were sufficient. The ink compositions described in Patent Documents 3 and 4 are non-aqueous ink compositions, and it is difficult to divert these techniques to aqueous ink compositions with lower environmental impact from the viewpoints of solubility and ink viscosity. Met.

  The present invention has been made in view of the above, and it is an object to provide an ink composition capable of forming an image excellent in stretchability, blocking resistance and solvent resistance, and an image forming method using the ink composition. To do.

Specific means for solving the above problems are as follows.
<1> Polyurethane resin particles having at least one partial structure selected from the group consisting of a polysiloxane group and a fluorinated alkyl group, an ethylenically unsaturated bond group, and a hydrophilic functional group, water, a polymerization initiator, And an ink composition containing a colorant.

<2> The ink composition according to <1>, wherein the hydrophilic functional group is an anionic hydrophilic group.

<3> The ink composition according to <1> or <2>, wherein the hydrophilic functional group is at least one selected from the group consisting of a carboxyl group, a sulfo group, and a salt thereof.

<4> The ink composition according to any one of <1> to <3>, further including a water-soluble polymerizable compound.

<5> The ink composition according to <4>, wherein the water-soluble polymerizable compound has a (meth) acrylamide group.

<6> The ink composition according to <4> or <5>, wherein the water-soluble polymerizable compound includes a radical polymerizable monofunctional monomer.

<7> The ink composition according to any one of <1> to <6>, further containing a water-soluble organic solvent.

<8> The ink composition according to any one of <1> to <7>, wherein the polyurethane resin particles include a polyurethane resin having a weight average molecular weight of 15,000 to 200,000.

<9> The ink composition according to any one of <1> to <8>, wherein the polyurethane resin particles have a volume average particle diameter of 10 nm to 200 nm.

<10> The ink composition according to any one of <1> to <9>, wherein the content of the polyurethane resin particles is 0.1% by mass to 5% by mass.

<11> An ink application step of applying the ink composition according to any one of <1> to <10> on a recording medium; and an irradiation step of irradiating the applied ink composition with actinic radiation. And an image forming method.

<12> A recording medium and an image formed with the ink composition according to any one of <1> to <10> on the recording medium, or an image formation according to <11> on the recording medium A printed matter having an image formed by the method.

  According to the present invention, it is possible to provide an ink composition capable of forming an image excellent in stretchability, blocking resistance and solvent resistance, and an image forming method using the ink composition.

Hereinafter, the ink composition, the image forming method, and the printed material of the present invention will be described.
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. The term “process” is not only an independent process, but is included in this term if the intended purpose of the process is achieved even when it cannot be clearly distinguished from other processes. Further, the amount of each component in the composition means the total amount of the plurality of substances present in the composition unless there is a specific notice when there are a plurality of substances corresponding to each component in the composition.
The solid content in the ink composition of the present invention means the total mass of all the non-volatile components excluding water and 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.
Furthermore, “(meth) acryl” means at least one of “acryl” and “methacryl”.

<Ink composition>
The ink composition of the present invention comprises polyurethane resin particles having at least one partial structure selected from the group consisting of a polysiloxane group and a fluorinated alkyl group, an ethylenically unsaturated bond group, and a hydrophilic functional group (hereinafter referred to as “ At least one of specific polyurethane resin particles), water, at least one polymerization initiator, and at least one colorant. The ink composition may further contain other components as necessary.

  By including the specific polyurethane resin particles, the ink composition of the present invention can form an image excellent in stretchability, blocking resistance and solvent resistance. This can be considered as follows, for example. After the ink composition is applied onto the recording medium by including specific polyurethane resin particles having at least one partial structure selected from the group consisting of a polysiloxane group and a fluorinated alkyl group in the ink composition, The particles are oriented on the surface of the formed image. This is because when the water content is reduced by drying from the applied ink composition, the specific polyurethane resin particles are partially dissolved in the non-volatile components in the ink composition, thereby forming a polymerizable ethylenically unsaturated bond group. It is considered that the specific polyurethane resin particles having a urethane structure having a high cohesive force are unevenly distributed on the surface. As described above, only the surface of the formed image (coating film) becomes a thin film having a high crosslinking density, and the image formed due to this is considered to have excellent stretchability and excellent workability. Further, the surface hardness is improved, and it is considered that an image excellent in blocking resistance and solvent resistance can be formed. In addition, since it is configured as a water-based ink, it can be made thinner than a solvent-based ink that is 100% cured, and it is advantageous for the substrate followability of the formed image (coating film). It is thought that there is.

[Specific polyurethane resin particles]
The ink composition of the present invention comprises at least one partial structure selected from the group consisting of a polysiloxane group and a fluorinated alkyl group (hereinafter also referred to as “specific partial structure”), an ethylenically unsaturated bond group, and hydrophilicity. At least 1 type of the polyurethane resin particle (specific polyurethane resin particle) which has a functional group is included. The specific polyurethane resin particle is a polyurethane resin having at least one partial structure selected from the group consisting of a polysiloxane group and a fluorinated alkyl group, an ethylenically unsaturated bond group, and a hydrophilic functional group (hereinafter referred to as “specific polyurethane”). As long as it contains a resin, it may further contain a resin other than a polyurethane resin. Here, the polyurethane resin refers to a resin composed of a compound having an isocyanate and active hydrogen, and a bond between the isocyanate and a functional group other than a hydroxyl group (urea group, allophanate group, burette group, uretdione group, An isocyanurate group, etc.) may be contained in a proportion of 50 mol% or less based on the urethane group.

  The specific polyurethane resin includes a urethane bond in the main chain structure, includes a specific partial structure in the main chain structure part, main chain terminal part or side chain part, and has an ethylenically unsaturated bond group and a hydrophilic functional group at the main chain terminal. If it has in a part or a side chain part, it will not restrict | limit in particular. Among them, the specific polyurethane resin includes a urethane bond in the main chain structure, includes a specific partial structure in the main chain terminal part or side chain part, and has an ethylenically unsaturated bond group and a hydrophilic functional group in the side chain part. It is preferable. The specific polyurethane resin is, for example, a polyisocyanate compound having two or more isocyanate groups, a polyol compound having two or more hydroxy groups, and a monoisocyanate compound and a monoalcohol compound that are used as necessary in a commonly used method. It can be obtained by condensation polymerization. Further, the specific partial structure, the ethylenically unsaturated bond group and the hydrophilic functional group may be contained in any of the polyisocyanate compound, monoisocyanate compound, polyol compound and monoalcohol compound, respectively. Especially, it is preferable that the specific partial structure, the ethylenically unsaturated bond group, and the hydrophilic functional group are respectively contained in the polyol compound or the monoalcohol compound.

(Specific partial structure)
In the specific polyurethane resin, the specific partial structure may be included in any part of the main chain structure part, the main chain terminal part, and the side chain part, and may be included in two or more parts. In the present invention, the specific partial structure is preferably contained in either the main chain terminal part or the side chain part.

-Polysiloxane group-
The polysiloxane group in the specific partial structure is not particularly limited as long as it has a “—Si—O—Si—” structure which is a siloxane structure. Specifically, a group represented by the following general formula (1) or a divalent group represented by the following general formula (10) is preferable.

In the general formula (1), R ¹¹ represents an alkyl group or an aryl group, and Z ¹¹ each independently represents a group represented by the following general formula (1a). ^{Further, x 1, x 2, x} 3 represents an integer which these sum satisfies 1-100. y ¹¹ represents an integer of 1 to 100. * Represents a position where the specific polyurethane resin is connected.
In the general formula (10), Z ¹¹ each independently represents a group represented by the following general formula (1a). Further, ^{also, x 1, x 2, x} 3 represents an integer which these sum satisfies 1-100. y ¹¹ represents an integer of 1 to 50. * Represents a position where the specific polyurethane resin is connected.
In general formulas (1) and (10), structural units of the number contained in x ^1, and a structural unit number contained in the number contained in x ² may be bonded randomly each structural unit x ³ They may be combined in a block shape.

In the general formula (1a), R ¹² represents an unsubstituted alkyl group having 1 to 4 carbon atoms, and y ¹² represents an integer of 1 to 100. In addition, ** represents a position bonded to Si in the general formula (1).

The alkyl group for R ¹¹ preferably has 1 to 12 carbon atoms, and may have a linear structure or a branched structure. Specific examples 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. Moreover, it is more preferable that it is a C1-C6 alkyl group, and it is still more preferable that it is a C1-C4 linear alkyl group.

The aryl group for R ¹¹ preferably has 6 to 20 carbon atoms, and more preferably 6 to 14 carbon atoms. Specific examples of the aryl group for R ¹¹ include a phenyl group, a biphenyl group, and a naphthyl group, and a phenyl group is more preferable.

x ¹ , x ² and x ³ are preferably an integer of 5 to 100, more preferably an integer of 5 to 50. The ^{y 11} is preferably an integer of 5-50, more preferably 5-30 integer.

In the general formula (1a), R ¹² is more preferably a methyl group, and y ¹² is preferably an integer of 1 to 50, more preferably an integer of 1 to 20.

The method for introducing the group represented by the general formula (1) into the specific polyurethane resin is not particularly limited. For example, if the monomer having the group represented by the general formula (1) is appropriately selected and applied during the synthesis of the specific polyurethane resin, the monomer represented by the general formula (1) is included in the repeating unit of the specific polyurethane resin to be obtained. Groups can be introduced.
Further, the group represented by the general formula (1) is added to the specific polyurethane resin by a polymer reaction in which a functional group of the polyurethane resin has a bond formed by reacting a compound having the group represented by the general formula (1). It can also be introduced.

  As the monomer having the group represented by the general formula (1), a commercially available compound can be used. However, the monomer represented by the general formula (1) has no group represented by the general formula (1). A desired structure containing a group represented by) may be appropriately introduced and used. There is no limitation on the method for introducing the group represented by the general formula (1) into a commercially available monomer, and a known method may be applied as appropriate.

  As the monomer having a group represented by the general formula (1), a monoalcohol compound having a group represented by the general formula (1), a polyol compound having a group represented by the general formula (1), a general formula ( 1) a monoamine compound having a group represented by formula (1), a polyamine compound having a group represented by formula (1), an isocyanate compound having a group represented by formula (1) and at least one isocyanate group, etc. be able to. Among them, a monoalcohol compound having a group represented by the general formula (1), a polyol compound having a group represented by the general formula (1), a monoamine compound having a group represented by the general formula (1), and a general formula It is preferable to use at least one compound selected from the group consisting of polyamine compounds having a group represented by (1), and at least one selected from the group consisting of compounds represented by the following general formula (1-1). More preferably, seeds are used.

In the above general formula, X ¹¹ represents a divalent linking group. R ¹³ represents a single bond or a divalent linking group containing an alkylene group. R ¹⁴ represents a p + 1 valent linking group. p represents an integer of 1 to 3. W ¹¹ each independently represents a hydroxy group or an amino group (—NH ₂ ), and is preferably a hydroxy group. Z ¹¹ , R ¹¹ , x ¹ , x ² , x ³ and y ¹¹ are synonymous with the above-mentioned general formula (1), including the preferred range.

In the general formula (1-1), examples of the divalent linking group represented by X ¹¹ include an ether bond (—O—), a sulfide bond (—S—), and an imino bond (—N (R ¹⁵ ) —). Etc. Among these, -O- is preferable. Here, R ¹⁵ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. The alkyl group may be a linear structure or a branched structure, and examples thereof 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. R ¹⁵ is preferably a hydrogen atom or a methyl group.

As the alkylene group for divalent linking group containing an alkylene group of R ^13, is preferably 1 to 20 carbon atoms. The alkylene group may have a linear structure or a branched structure. Moreover, even if it has a substituent, it may be unsubstituted. Examples of the substituent that may have include a halogen atom.

Among these, R ¹³ is preferably an unsubstituted alkylene group having 1 to 20 carbon atoms, more preferably an unsubstituted alkylene group having 1 to 10 carbon atoms, and further preferably 2 to 2 carbon atoms. 6 unsubstituted linear alkylene groups. Specific examples of the alkylene group include a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, an octylene group, and a decylene group.

In the divalent linking group containing an alkylene group represented by R ¹³ , an ether bond (—O—), an imino bond (—NH—), an amide bond (—CONH—), an ester bond is sandwiched between the alkylene groups. (-COO- or -OCO-), a sulfonamide bond (-NHSO ₂ - or _-SO 2 NH-), a urethane bond (-NHCOO- or -OCONH-), ureylene bond (-NHCONH-) or a carbonate bond (- OCOO-) may be present as a linking group.

R ¹³ is preferably an unsubstituted linear alkylene group having 2 to 6 carbon atoms, and more preferably an unsubstituted linear alkylene group having 2 to 4 carbon atoms.

The p + 1 valent linking group represented by R ¹⁴ may be a p + 1 valent linking group derived from an aliphatic hydrocarbon or a p + 1 valent linking group derived from an aromatic hydrocarbon. Here, the “p + 1 valent linking group derived from an aliphatic hydrocarbon” is a p + 1 valent linking group formed by removing p + 1 hydrogen atoms from an aliphatic hydrocarbon. The position where the hydrogen atom is removed from the aliphatic hydrocarbon is not particularly limited. Further, the “p + 1 valent linking group derived from an aromatic hydrocarbon” has the same meaning.
Although p is an integer of 1-3, it is more preferable that it is an integer of 1-2.

The aliphatic hydrocarbon forming the p + 1 valent linking group represented by R ¹⁴ may be a linear aliphatic hydrocarbon, a branched aliphatic hydrocarbon, or a cyclic structure. It may be an aliphatic hydrocarbon. The aliphatic hydrocarbon may be a saturated aliphatic hydrocarbon or an unsaturated aliphatic hydrocarbon. Furthermore, the number of carbon atoms of the aliphatic hydrocarbon is preferably 1-20, more preferably 1-16, and even more preferably 1-10.
The aromatic hydrocarbon forming the p + 1 valent linking group represented by R ¹⁴ preferably has 6 to 24 carbon atoms, more preferably 6 to 20 carbon atoms, and still more preferably 6 to 16 carbon atoms. .

The p + 1 valent linking group represented by R ¹⁴ may further have a substituent. As a substituent, a C1-C12 alkyl group, a halogen atom, etc. can be mentioned.

The p + 1 valent linking group represented by R ¹⁴ is preferably a p + 1 valent linking group derived from a linear or branched aliphatic hydrocarbon, and is a linear or branched group having 1 to 20 carbon atoms. More preferably, it is a divalent or tetravalent linking group derived from a chain aliphatic hydrocarbon, and a divalent or trivalent valent group derived from a linear or branched aliphatic hydrocarbon having 1 to 20 carbon atoms. More preferably, it is a linking group.

  Specific examples of the compound represented by the general formula (1-1) are shown below, but the present invention is not limited thereto. In the following exemplary compounds, m represents an integer of 5 to 150, and x represents an integer of 5 to 150.

  As the compound represented by the general formula (1-1), a commercially available compound can be appropriately selected and used as it is. For example, X-22-176DX, X-22-176F (both Shin-Etsu Chemical ( One-end reactive silicones such as FM-DA11, FM-DA21, FM-DA26 (all manufactured by JNC Corporation), and the like.

  The method for introducing the group represented by the general formula (10) into the specific polyurethane resin is not particularly limited. For example, when the monomer having the group represented by the general formula (1) is appropriately selected and applied during the synthesis of the specific polyurethane resin, the monomer represented by the general formula (10) is included in the repeating unit of the specific polyurethane resin to be obtained. Groups can be introduced.

  As the monomer having the group represented by the general formula (10), a commercially available compound can be used. However, the commercially available monomer having no group represented by the general formula (10) has a general formula (10 A desired structure containing a group represented by) may be appropriately introduced and used. There is no limitation on the method of introducing the group represented by the general formula (10) into a commercially available monomer, and a known method may be applied as appropriate.

  As the monomer having a group represented by the general formula (10), it is preferable to use at least one selected from the group consisting of compounds represented by the following general formula (1-2).

In the general formula (1-2), X ¹² each independently represents a divalent linking group. R ¹⁶ independently represents a single bond or a divalent linking group containing an alkylene group. R ¹⁷ each independently represents an alkylene group. W ¹² each independently represents a hydroxy group or an amino group (—NH ₂ ), and is preferably a hydroxy group. Z ¹¹ , x ¹ , x ² , x ³ and y ¹¹ are synonymous with the above general formula (1), including the preferred range.

In the general formula (1-2), examples of the divalent linking group represented by X ¹² include a single bond, an ether bond (—O—), a sulfide bond (—S—), and an imino bond (—N (R ¹⁸ )-) And the like. Among these, -O- is preferable. Here, R ¹⁸ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. The alkyl group may be a linear structure or a branched structure, and examples thereof 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. R ¹⁸ is preferably a hydrogen atom or a methyl group.

As the alkylene group for divalent linking group containing an alkylene group of R ^16, is preferably 1 to 20 carbon atoms. The alkylene group may have a linear structure or a branched structure. Moreover, even if it has a substituent, it may be unsubstituted. Examples of the substituent that may have include a halogen atom.

Among these, R ¹⁶ is preferably an unsubstituted alkylene group having 1 to 20 carbon atoms, more preferably an unsubstituted alkylene group having 1 to 10 carbon atoms, and further preferably 2 to 2 carbon atoms. 6 unsubstituted linear alkylene groups. Specific examples of the alkylene group include a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, an octylene group, and a decylene group.

In the divalent linking group containing an alkylene group represented by R ¹⁶ , an ether bond (—O—), an imino bond (—NH—), an amide bond (—CONH—), an ester bond is sandwiched between the alkylene groups. (-COO- or -OCO-), a sulfonamide bond (-NHSO ₂ - or _-SO 2 NH-), a urethane bond (-NHCOO- or -OCONH-), ureylene bond (-NHCONH-) or a carbonate bond (- OCOO-) may be present as a linking group.

R ¹⁶ is preferably an unsubstituted linear alkylene group having 2 to 6 carbon atoms, and more preferably an unsubstituted linear alkylene group having 2 to 4 carbon atoms.

Further, the alkylene group for R ¹⁷ preferably has 1 to 20 carbon atoms. The alkylene group may have a linear structure or a branched structure. Moreover, even if it has a substituent, it may be unsubstituted. Examples of the substituent that may have include a halogen atom.
R ¹⁷ is preferably an unsubstituted linear alkylene group having 2 to 6 carbon atoms, and more preferably an unsubstituted linear alkylene group having 2 to 4 carbon atoms.

  Specific examples of the compound represented by the general formula (1-2) are shown below, but the present invention is not limited thereto. In the following exemplary compounds, m represents an integer of 5 to 150.

As the compound represented by the general formula (1-2), a commercially available compound can be appropriately selected and used as it is. For example, as a compound having W ¹² as a hydroxy group, Silaplane FM-4411, FM-4421, FM -4425 (both manufactured by JNC Corporation) and the like are mentioned. Further, examples of the compound in which W ¹² is an amino group include FM-3331, FM-3321, and FM-3325 (manufactured by JNC Corporation).

-Fluorinated alkyl group-
The fluorinated alkyl group in the specific partial structure may be an alkyl group or an alkylene group substituted with at least one fluorine atom, and a perfluoroalkyl group or a perfluoroalkylene in which all hydrogen atoms of the alkyl group are substituted with fluorine atoms More preferably, it is a group.

  The alkyl group or alkylene group in the fluorinated alkyl group is preferably an alkyl group or alkylene group having 3 to 12 carbon atoms, more preferably an alkyl group or alkylene group having 4 to 10 carbon atoms, and an alkyl group having 6 to 8 carbon atoms. Or an alkylene group is still more preferable.

  A specific embodiment of the fluorinated alkyl group in the present invention will be described. Preferred examples of the fluorinated alkyl group include a group represented by the following general formula (2) and a group represented by the general formula (20).

In the general formula (2), n represents an integer of 0 or more, and Y ²¹ is any one group selected from the following Y ²¹ group. Moreover, * represents the position connected with a specific polyurethane resin.
In the general formula (20), n2 represents an integer of 1 or more. Moreover, * represents the position connected with a specific polyurethane resin.

Among the groups represented by the general formula (2), those in which “n” in the general formula (2) is 0 to 20 are preferable, 0 to 7 are more preferable, and 3 or 5 are preferable. Particularly preferred.
Among the groups represented by the general formula (20), those in which “n2” in the general formula (20) is 1 to 20 are preferable, 3 to 12 are more preferable, and 3 to 8 are preferable. Particularly preferred.

The method for introducing the group represented by the general formula (2) into the specific polyurethane resin is not particularly limited. For example, when a monomer having a group represented by the general formula (2) is appropriately selected and applied during the synthesis of the specific polyurethane resin, the monomer represented by the general formula (2) is included in the repeating unit of the specific polyurethane resin to be obtained. Groups can be introduced.
In addition, the group represented by the general formula (2) is added to the specific polyurethane resin by a polymer reaction that forms a bond by reacting the functional group of the polyurethane resin with a compound having the group represented by the general formula (2). It can also be introduced.

  As the monomer having the group represented by the general formula (2), a commercially available compound can be used. However, the monomer represented by the general formula (2) has no group represented by the general formula (2). A desired structure containing a group represented by) may be appropriately introduced and used. There is no limitation on the method for introducing the group represented by the general formula (2) into a commercially available monomer, and a known method may be applied as appropriate.

  As the monomer having a group represented by the general formula (2), a monoalcohol compound having a group represented by the general formula (2), a polyol compound having a group represented by the general formula (2), a general formula ( An isocyanate compound having a group represented by 2) and at least one isocyanate group can be exemplified. Among them, it is preferable to use at least one alcohol compound selected from the group consisting of a monoalcohol compound having a group represented by the general formula (2) and a polyol compound having a group represented by the general formula (2). It is more preferable to use at least one selected from the group consisting of compounds represented by the following general formula (2-1).

In the general formula (2-1), X ²¹ represents a single bond or a divalent linking group. R ²³ represents a single bond or a divalent linking group containing an alkylene group. R ²⁴ represents a q + 1 valent linking group. q represents an integer of 1 to 3. W ²¹ each independently represents a hydroxy group or an amino group (—NH ₂ ), and is preferably a hydroxy group. Y ²¹ and n are synonymous with the above general formula (2), including the preferred range.

In the general formula (2-1), examples of the divalent linking group represented by X ²¹ include a single bond, an ether bond (—O—), a sulfide bond (—S—), and an imino bond (—N (R ²⁵ )-) And the like. Among these, -O- is preferable. Here, R ²⁵ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. The alkyl group may be a linear structure or a branched structure, and examples thereof 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. R ²⁵ is preferably a hydrogen atom or a methyl group.

As the alkylene group for divalent linking group containing an alkylene group of R ^23, is preferably 1 to 20 carbon atoms. The alkylene group may have a linear structure or a branched structure. Moreover, even if it has a substituent, it may be unsubstituted. Examples of the substituent that may have include a halogen atom.

Among these, it is preferred that R ²³ is an unsubstituted alkylene group having 1 to 20 carbon atoms, more preferably an unsubstituted alkylene group having 1 to 10 carbon atoms, more preferably 2 to carbon atoms 6 unsubstituted linear alkylene groups. Specific examples of the alkylene group include a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, an octylene group, and a decylene group.

In addition, in the divalent linking group containing an alkylene group of R ²³ , an ether bond (—O—), an imino bond (—NH—), an amide bond (—CONH—), an ester bond is sandwiched between alkylene groups. (-COO- or -OCO-), a sulfonamide bond (-NHSO ₂ - or _-SO 2 NH-), a urethane bond (-NHCOO- or -OCONH-), ureylene bond (-NHCONH-) or a carbonate bond (- OCOO-) may be present as a linking group.

R ²³ is preferably an unsubstituted linear alkylene group having 2 to 6 carbon atoms, and more preferably an unsubstituted linear alkylene group having 2 to 4 carbon atoms.

The q + 1 valent linking group represented by R ²⁴ may be a q + 1 valent linking group derived from an aliphatic hydrocarbon or a q + 1 valent linking group derived from an aromatic hydrocarbon. Here, the “q + 1 valent linking group derived from an aliphatic hydrocarbon” is a q + 1 valent linking group formed by removing q + 1 hydrogen atoms from an aliphatic hydrocarbon. The position where the hydrogen atom is removed from the aliphatic hydrocarbon is not particularly limited. In addition, “q + 1 valent linking group derived from an aromatic hydrocarbon” has the same meaning.
Although q is an integer of 1-3, it is more preferable that it is an integer of 1-2.

The aliphatic hydrocarbon forming the q + 1 valent linking group represented by R ²⁴ may be a linear aliphatic hydrocarbon, a branched aliphatic hydrocarbon, or a cyclic structure. It may be an aliphatic hydrocarbon. The aliphatic hydrocarbon may be a saturated aliphatic hydrocarbon or an unsaturated aliphatic hydrocarbon. Furthermore, the number of carbon atoms of the aliphatic hydrocarbon is preferably 1-20, more preferably 1-16, and even more preferably 1-10.
The aromatic hydrocarbon forming the q + 1 valent linking group represented by R ²⁴ preferably has 6 to 24 carbon atoms, more preferably 6 to 20 carbon atoms, and still more preferably 6 to 16 carbon atoms. .

The q + 1 valent linking group represented by R ²⁴ may further have a substituent. Examples of the substituent include an alkyl group having 1 to 20 carbon atoms and a halogen atom.

The q + 1 valent linking group represented by R ²⁴ is preferably a q + 1 valent linking group derived from a linear or branched aliphatic hydrocarbon, and is a linear or branched group having 1 to 20 carbon atoms. More preferably, it is a divalent or tetravalent linking group derived from a chain aliphatic hydrocarbon, and a divalent or trivalent valent group derived from a linear or branched aliphatic hydrocarbon having 1 to 20 carbon atoms. More preferably, it is a linking group.

  Specific examples of the compound represented by the general formula (2-1) are shown below, but the present invention is not limited thereto.

  As the compound represented by the general formula (2-1), a commercially available compound can be appropriately selected and used as it is. Further, if a compound containing an epoxy group at the terminal and having a fluoroalkyl group is treated with an acid catalyst based on, for example, the method described in JP-A-2005-126357, a diol compound having a fluorinated alkyl group is increased. The yield can be obtained. The compound containing an epoxy group at the terminal and having a fluorinated alkyl group is available as a commercially available product. For example, E-1430, E-1630, E-5244, E-5444, E-5 manufactured by Daikin -5644, E-7432, etc. are mentioned.

  As the monomer having a group represented by the general formula (20), it is preferable to use at least one selected from the group consisting of compounds represented by the following general formula (2-2).

In the general formula (2-2), X ²² each independently represents a single bond or a divalent linking group. R ²⁶ each independently represents a single bond or a divalent linking group containing an alkylene group. R ²⁷ each independently represents an alkylene group. W ²² each independently represents a hydroxy group or an amino group (—NH ₂ ), and is preferably a hydroxy group. Moreover, n2 is synonymous also including the above-mentioned general formula (20) including a preferable range.

In the general formula (1-2), examples of the divalent linking group represented by X ²² include a single bond, an ether bond (—O—), a sulfide bond (—S—), and an imino bond (—N (R ²⁸ )-) And the like. Among these, -O- is preferable. Here, R ²⁸ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. The alkyl group may be a linear structure or a branched structure, and examples thereof 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. R ²⁵ is preferably a hydrogen atom or a methyl group.

As the alkylene group for divalent linking group containing an alkylene group of R ^26, is preferably 1 to 20 carbon atoms. The alkylene group may have a linear structure or a branched structure. Moreover, even if it has a substituent, it may be unsubstituted. Examples of the substituent that may have include a halogen atom.

Among these, it is preferred that R ²⁶ is an unsubstituted alkylene group having 1 to 20 carbon atoms, more preferably an unsubstituted alkylene group having 1 to 10 carbon atoms, more preferably 2 to carbon atoms 6 unsubstituted linear alkylene groups. Specific examples of the alkylene group include a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, an octylene group, and a decylene group.

In the divalent linking group containing an alkylene group represented by R ²⁶ , an ether bond (—O—), an imino bond (—NH—), an amide bond (—CONH—), an ester bond is sandwiched between the alkylene groups. (-COO- or -OCO-), a sulfonamide bond (-NHSO ₂ - or _-SO 2 NH-), a urethane bond (-NHCOO- or -OCONH-), ureylene bond (-NHCONH-) or a carbonate bond (- OCOO-) may be present as a linking group.

R ²⁶ is preferably an unsubstituted linear alkylene group having 2 to 6 carbon atoms, and more preferably an unsubstituted linear alkylene group having 2 to 4 carbon atoms.

In addition, the alkylene group for R ²⁷ preferably has 1 to 20 carbon atoms. The alkylene group may have a linear structure or a branched structure. Moreover, even if it has a substituent, it may be unsubstituted. Examples of the substituent that may have include a halogen atom.
R ²⁷ is preferably an unsubstituted linear alkylene group having 1 to 6 carbon atoms, and more preferably an unsubstituted linear alkylene group having 1 to 3 carbon atoms.

  As the compound represented by the general formula (2-2), a commercially available compound can be appropriately selected and used as it is. Moreover, you may use the compound synthesize | combined by the conventional method.

The content of the specific partial structure which is at least one selected from the group consisting of a polysiloxane group and a fluorinated alkyl group contained in the specific polyurethane resin includes the specific partial structure from the viewpoint of easy formation of fine particles and blocking resistance. The content of the structural unit derived from the monomer is preferably 0.1% by mass to 30% by mass, more preferably 1% by mass to 20% by mass, and 2% by mass to 15% by mass. Is more preferable.
Furthermore, content of the specific partial structure contained in specific polyurethane resin is 0.5 mass%-30 mass as content rate of the structural unit derived from the monomer containing a polysiloxane group, when a specific partial structure is a polysiloxane group. %, More preferably 2% by mass to 15% by mass, and still more preferably 3% by mass to 12% by mass. When the specific partial structure is a fluorinated alkyl group, the content of the structural unit derived from the monomer containing the fluorinated alkyl group is preferably 1% by mass to 30% by mass, and preferably 2% by mass to 25% by mass. It is more preferable that it is 2 mass%-10 mass%.

(Ethylenically unsaturated bond group)
In the specific polyurethane resin, the ethylenically unsaturated bond group only needs to be contained in any one of the main chain terminal part and the side chain part, and may be contained in both parts. In this invention, it is preferable that the ethylenically unsaturated bond group is contained in the side chain part.
Examples of ethylenically unsaturated bond groups include vinyl groups, allyl groups, acrylic ester groups, methacrylic ester groups, itaconic ester groups, crotonic ester groups, isocrotonic ester groups, maleic ester groups, etc. Examples thereof include a radical polymerizable group such as a carboxylic acid ester group and a styrene group. Among these, a methacrylic acid ester group and an acrylic acid ester group (that is, a (meth) acrylic acid ester group) are preferable.

  The content of the ethylenically unsaturated bond group is preferably 0.3 mmol / g or more in the specific polyurethane resin, more preferably 0.5 mmol / g to 6 mmol / g, and still more preferably 1 mmol / g. ~ 3 mmol / g.

The method for introducing the ethylenically unsaturated bond group into the specific polyurethane resin is not particularly limited. For example, if a monomer having an ethylenically unsaturated bond group is appropriately selected and applied during the synthesis of the specific polyurethane resin, the ethylenically unsaturated bond group can be introduced into the repeating unit of the specific polyurethane resin to be obtained.
Moreover, an ethylenically unsaturated bond group can also be introduce | transduced into specific polyurethane resin by the polymer reaction which makes the compound which has an ethylenically unsaturated bond group react with the functional group which a polyurethane resin has, and forms a bond.

  A commercially available compound can be used as the monomer having an ethylenically unsaturated bond group, but a desired structure containing an ethylenically unsaturated bond group can be used with respect to a commercially available monomer having no ethylenically unsaturated bond group. You may introduce and use suitably. There is no limitation on the method of introducing an ethylenically unsaturated bond group into a commercially available monomer, and a known method may be applied as appropriate.

  Examples of the monomer having an ethylenically unsaturated bond group include a monoalcohol compound having an ethylenically unsaturated bond group, a polyol compound having an ethylenically unsaturated bond group, and an isocyanate compound having an ethylenically unsaturated bond group. it can. Among them, it is preferable to use at least one alcohol compound selected from the group consisting of a monoalcohol compound having an ethylenically unsaturated bond group and a polyol compound having an ethylenically unsaturated bond group, and having an ethylenically unsaturated bond group It is more preferable to use a polyol compound, and it is even more preferable to use at least one selected from the group consisting of compounds represented by the following general formula (3-1).

In the general formula (3-1), X ³¹ each independently represents a divalent linking group. R ³³ represents a divalent linking group containing a single bond or an alkylene group. R ³⁴ represents an r + 1 valent linking group. r represents an integer of 1 to 3. R ³¹ each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. W ³¹ each independently represents a hydroxy group or an amino group (—NH ₂ ), and is preferably a hydroxy group.

R ³¹ is preferably each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and more preferably a hydrogen atom or a methyl group.

In the general formula (3-1), examples of the divalent linking group represented by X ³¹ include an ether bond (—O—), a sulfide bond (—S—), and an imino bond (—N (R ³⁵ ) —). Amide bond (—CONH— or —NHCO—), ester bond (—COO— or —OCO—), and the like. Among these, an ether bond, an ester bond or an amide bond is preferable, and an ether bond or an ester bond is more preferable. Here, R ³⁵ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. The alkyl group may be a linear structure or a branched structure, and examples thereof 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. R ³⁵ is preferably a hydrogen atom or a methyl group.

As the alkylene group for divalent linking group containing an alkylene group of R ^33, is preferably 1 to 20 carbon atoms. The alkylene group may have a linear structure or a branched structure. Moreover, even if it has a substituent, it may be unsubstituted. Examples of the substituent that may have include a halogen atom.

Among these, it is preferred that R ³³ is an unsubstituted alkylene group having 1 to 20 carbon atoms, more preferably an unsubstituted alkylene group having 1 to 10 carbon atoms, more preferably 2 to carbon atoms 6 unsubstituted linear alkylene groups. Specific examples of the alkylene group include a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, an octylene group, and a decylene group.

In the divalent linking group containing an alkylene group represented by R ³³ , an ether bond (—O—), an imino bond (—NH—), an amide bond (—CONH—), an ester bond is sandwiched between the alkylene groups. (-COO- or -OCO-), a sulfonamide bond (-NHSO ₂ - or _-SO 2 NH-), a urethane bond (-NHCOO- or -OCONH-), ureylene bond (-NHCONH-) or a carbonate bond (- OCOO-) may be present as a linking group.

R ³³ is preferably a single bond or an unsubstituted linear alkylene group having 2 to 6 carbon atoms, and more preferably a single bond or an unsubstituted linear alkylene group having 2 to 4 carbon atoms.

The r + 1 valent linking group represented by R ³⁴ may be an r + 1 valent linking group derived from an aliphatic hydrocarbon or an r + 1 valent linking group derived from an aromatic hydrocarbon. Here, the “r + 1 valent linking group derived from an aliphatic hydrocarbon” is an r + 1 valent linking group formed by removing r + 1 hydrogen atoms from an aliphatic hydrocarbon. The position where the hydrogen atom is removed from the aliphatic hydrocarbon is not particularly limited. In addition, “r + 1 valent linking group derived from aromatic hydrocarbon” has the same meaning.
Although r is an integer of 1-3, it is more preferable that it is an integer of 1-2, and it is still more preferable that it is 2.

The aliphatic hydrocarbon forming the r + 1 valent linking group represented by R ³⁴ may be a linear aliphatic hydrocarbon, a branched aliphatic hydrocarbon, or a cyclic structure. It may be an aliphatic hydrocarbon. The aliphatic hydrocarbon may be a saturated aliphatic hydrocarbon or an unsaturated aliphatic hydrocarbon. Furthermore, the number of carbon atoms of the aliphatic hydrocarbon is preferably 1-20, more preferably 1-16, and even more preferably 1-12.
The aromatic hydrocarbon forming the r + 1 valent linking group represented by R ³⁴ preferably has 6 to 24 carbon atoms, more preferably 6 to 20 carbon atoms, and still more preferably 1 to 16 carbon atoms. .

The r + 1 valent linking group represented by R ³⁴ may further have a substituent. Examples of the substituent include an alkyl group having 1 to 12 carbon atoms and a halogen atom.

The r + 1 valent linking group represented by R ³⁴ is preferably an r + 1 valent linking group derived from a linear or branched aliphatic hydrocarbon, and is a linear or branched group having 1 to 20 carbon atoms. It is more preferably a divalent to tetravalent linking group derived from a chain aliphatic hydrocarbon, and a trivalent linking group derived from a linear or branched aliphatic hydrocarbon having 1 to 12 carbon atoms. More preferably.

  Specific examples of the compound represented by the general formula (3-1) are shown below, but the present invention is not limited thereto.

  In the specific polyurethane resin, the content of the structural unit derived from the monomer having an ethylenically unsaturated bond group is preferably 15 to 50% from the viewpoint of solvent resistance and stretchability, and is preferably 20 to 50%. It is more preferable that it is 25 to 50%.

  In the specific polyurethane resin, the ratio of the content of the structural unit (a-1) derived from the monomer having a specific partial structure to the content of the structural unit (a-2) derived from the monomer having an ethylenically unsaturated bond group (A-1): (a-2) is preferably from 1: 100 to 1: 1 on a mass basis, and preferably from 1:60 to 1: 2 from the viewpoint of achieving both blocking resistance and stretching ratio. More preferably, it is more preferably 1:40 to 1: 3.

(Hydrophilic functional group)
In the specific polyurethane resin, the hydrophilic functional group only needs to be included in any one of the main chain terminal portion and the side chain portion, and may be included in both portions. In the present invention, the hydrophilic functional group is preferably contained in the side chain portion.
The hydrophilic functional group may be a nonionic hydrophilic group or an anionic or cationic ionic hydrophilic group as long as the functional group has a function of enhancing the hydrophilicity of the specific polyurethane resin. Can and is not limited.

  Nonionic hydrophilic groups include, but are not limited to, for example, residues obtained by removing one hydrogen atom from a heterocyclic compound containing a nitrogen atom or oxygen atom, an amide group, a carbamoyl group, an alkyl-substituted carbamoyl group, an alcoholic group. It is preferably at least one group selected from the group consisting of a hydroxyl group and a group having a polyalkyleneoxy structure, and is selected from the group consisting of a group having a carbamoyl group, an alkyl-substituted carbamoyl group, an alcoholic hydroxyl group, and a polyalkyleneoxy structure. More preferably, it is at least one group selected, and particularly preferably at least one group selected from the group consisting of an alcoholic hydroxyl group and a group having a polyalkyleneoxy structure.

  Examples of the heterocyclic compound containing a nitrogen atom or an oxygen atom include lactones such as γ-butyrolactone, cyclic ureas such as 2-pyrrolidone and ethylene urea, cyclic carbonates such as ethylene carbonate and propylene carbonate, tetrahydrofuran, 1,4 -Cyclic ethers, such as dioxane, and crown ethers, such as 12-crown-4.

  Although it does not limit as said amide group, For example, group represented by a following formula (4a) is mentioned preferably.

In formula (4a), R ^1a and R ^1b each independently represent a hydrogen atom or an alkyl group. R ^1a and R ^1b may be bonded to each other to form a 4- to 6-membered ring. * Represents a bonding position.

R ^1a and R ^1b in the formula (4a) each independently represent a hydrogen atom or an alkyl group. The alkyl group in R ^1a and R ^1b represents a linear or branched alkyl group, and may include a —COO— bond, —O— bond, or —NH— bond. The alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, and particularly preferably 1 to 3 carbon atoms. R ^1a and R ^1b may be bonded to each other to form a 4- to 6-membered ring. These groups may or may not have a substituent, but preferably do not have a substituent. Specific examples of the alkyl group represented by R ^1a and R ^1b include a methyl group and a t-butyl group.

In the formula (4a), the substituent that R ^1a and R ^1b may have is preferably a hydroxyl group or the like.

  The alkyl-substituted carbamoyl group includes a monoalkylcarbamoyl group in which the hydrogen atom bonded to N of the carbamoyl group is substituted with an alkyl group, or a dialkyl in which two hydrogen atoms bonded to N of the carbamoyl group are substituted with an alkyl group A carbamoyl group may be mentioned. Specifically, a group represented by the following formula (4b) is preferable.

In formula (4b), R ^2a and R ^2b each independently represent a hydrogen atom or an alkyl group. R ^2a and R ^2b may be bonded to each other to form a 4- to 6-membered ring. * Represents a bonding position.

R ^2a and R ^2b in the formula (4b) each independently represent a hydrogen atom or an alkyl group. The alkyl group in R ^2a and R ^2b represents a linear or branched alkyl group, and may include an —O— bond, —COO— bond, and —C (═O) — bond. The alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, and particularly preferably 1 to 3 carbon atoms. R ^2a and R ^2b may be bonded to each other to form a 4- to 6-membered ring. Specific examples of the alkyl group represented by R ^2a and R ^2b include, but are not limited to, a methylene group, an ethylene group, and the like. These groups may or may not have a substituent, but preferably do not have a substituent.

In the formula (4b), the substituent that R ^2a and R ^2b may have is preferably an alkoxy group having 1 to 2 carbon atoms, a hydroxyl group, or the like.

  Although it does not limit as group which has the said polyalkyleneoxy structure, For example, group represented by following formula (4c) is mentioned preferably.

In formula (4c), R ^3a represents an alkylene group, and R ^3b represents a hydrogen atom or an alkyl group. n3 represents an integer of 4 to 50. A plurality of R ^3a may be the same or different. * Represents a bonding position.

R ^3a in the formula (4c) represents an alkylene group. The alkylene group represented by R ^3a represents a linear, branched or cyclic alkylene group, and may include an —O— bond or a —COO— bond. The alkylene group preferably has 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms, and particularly preferably 1 to 3 carbon atoms. A plurality of R ^3a present in the group of the formula (4c) may be the same or different and are preferably the same. These groups may or may not have a substituent, but preferably do not have a substituent. Specific examples of the alkylene group represented by R ^3a include an ethylene group.

The substituent that R ^3a in formula (4c) may have is preferably an alkoxy group having 1 to 2 carbon atoms, a hydroxyl group, or the like.

R ^3b in the formula (4c) represents a hydrogen atom or an alkyl group. The alkyl group represented by R ^3b represents a linear, branched or cyclic alkyl group, preferably has 1 to 10 carbon atoms, more preferably has 1 to 6 carbon atoms, and particularly preferably has 1 to 3 carbon atoms. Specific examples of the alkyl group represented by R ^3b include a methyl group and an ethyl group.

  N3 in the formula (4c) represents an integer of 4 to 50, more preferably 4 to 40, and still more preferably 5 to 30.

Examples of the ionic hydrophilic group include a carboxyl group, a sulfo group, a phosphoric acid group, a phosphonic acid group, a phenolic hydroxyl group and an anionic hydrophilic group that is a salt thereof, an amino group, a nitrogen-containing heterocyclic group, and a quaternary ammonium. It is preferably at least one group selected from the group consisting of a cationic hydrophilic group as a group. Examples of the salt include metal salts and onium salts.
The ionic hydrophilic group is an anionic hydrophilic group selected from the group consisting of a carboxyl group, a sulfo group, a phosphoric acid group, a phosphonic acid group, and salts thereof from the viewpoint of stretchability and storage stability. A group selected from the group consisting of a carboxyl group, a sulfo group and a salt thereof is more preferable, and a group selected from the group consisting of a carboxyl group and a salt thereof is more preferable.

  The carboxyl group metal salt is preferably an alkali metal salt of a carboxyl group. Specific examples include -COOLi, -COONa, -COOK, and the like, and preferably -COONa, -COOK, and the like.

  Examples of carboxyl group onium salts include carboxyl group ammonium salts, pyridinium salts, phosphonium salts, and the like, with ammonium salts being preferred. Specific examples include a tetraalkylammonium salt of a carboxyl group and a trialkylarylammonium salt of a carboxyl group, and a tetraalkylammonium salt of a carboxyl group is preferable. The alkyl group forming an ammonium salt is preferably an alkyl group having 1 to 4 carbon atoms, and the aryl group is preferably a phenyl group.

The metal salt of the sulfo group is preferably an alkali metal salt of the sulfo group. Specific examples include —SO ₃ Li, —SO ₃ Na, —SO ₃ K, and the like, and —SO ₃ Na and —SO ₃ K are preferable.

  Examples of the onium salt of a sulfo group include an ammonium salt of a sulfo group, a pyridinium salt, a phosphonium salt, and the like, and an ammonium salt is preferable. Specific examples include a tetraalkylammonium salt of a sulfo group and a trialkylarylammonium salt of a sulfo group, and a tetraalkylammonium salt of a sulfo group is preferable. The alkyl group forming an ammonium salt is preferably an alkyl group having 1 to 4 carbon atoms, and the aryl group is preferably a phenyl group.

  The metal salt of a phosphate group is preferably an alkali metal salt of a phosphate group. Specific examples include phosphoric acid group sodium salt and potassium salt, and phosphoric acid group sodium salt is preferable.

  Examples of the onium salt of a phosphate group include an ammonium salt of a phosphate group, a pyridinium salt, a phosphonium salt, and the like, and an ammonium salt is preferable. Specific examples include a tetraalkylammonium salt of a phosphate group, a trialkylarylammonium salt of a phosphate group, and the like, and a tetraalkylammonium salt of a phosphate group is preferable. The alkyl group forming an ammonium salt is preferably an alkyl group having 1 to 4 carbon atoms, and the aryl group is preferably a phenyl group.

  The metal salt of a phosphonic acid group is preferably an alkali metal salt of a phosphonic acid group. Specific examples include sodium salts and potassium salts of phosphonic acid groups, and sodium salts of phosphonic acid groups are preferred.

  Examples of the onium salt of a phosphonic acid group include an ammonium salt of a phosphonic acid group, a pyridinium salt, a phosphonium salt, and the like, and an ammonium salt is preferable. Specific examples include tetraalkylammonium salts of phosphonic acid groups, trialkylarylammonium salts of phosphonic acids, and the like, and tetraalkylammonium salts of phosphonic acid groups are preferred. The alkyl group forming an ammonium salt is preferably an alkyl group having 1 to 4 carbon atoms, and the aryl group is preferably a phenyl group.

  The metal salt of a phenolic hydroxyl group is preferably an alkali metal salt of a phenolic hydroxyl group. Specific examples include sodium salts and potassium salts of phenolic hydroxyl groups, and sodium salts of phenolic hydroxyl groups are preferred.

  Examples of the onium salt of a phenolic hydroxyl group include an ammonium salt of a phenolic hydroxyl group, a pyridinium salt, a phosphonium salt, and the like, and an ammonium salt is preferable. Specific examples include a tetraalkylammonium salt of a phenolic hydroxyl group, a trialkylarylammonium salt of a phenolic hydroxyl group, and the like, and a tetraalkylammonium salt of a phenolic hydroxyl group is preferable. The alkyl group forming an ammonium salt is preferably an alkyl group having 1 to 4 carbon atoms, and the aryl group is preferably a phenyl group.

  The amino group may have a substituent on the nitrogen atom. Examples of the substituent include an alkyl group having 1 to 6 carbon atoms and an aryl group such as a phenyl group.

  Examples of the nitrogen-containing heterocyclic group include a piperidyl group, a morpholino group, a pyridyl group, and an oxazoline group. Among these, at least one selected from the group consisting of a piperidyl group, a morpholino group, a pyridyl group, and an oxazoline group is preferable. The nitrogen-containing heterocyclic group may have a substituent. Examples of the substituent include an alkyl group having 1 to 4 carbon atoms and a hydroxyl group.

The method for introducing the hydrophilic functional group into the specific polyurethane resin is not particularly limited. For example, if a monomer having a hydrophilic functional group is appropriately selected and applied during the synthesis of the specific polyurethane resin, the hydrophilic functional group can be introduced into the repeating unit of the specific polyurethane resin to be obtained.
Moreover, a hydrophilic functional group can also be introduce | transduced into specific polyurethane resin by the polymer reaction which makes the functional group which a polyurethane resin has react with the compound which has a hydrophilic functional group, and forms a bond.

  A commercially available compound can be used as the monomer having a hydrophilic functional group, but a desired structure containing a hydrophilic functional group is appropriately introduced and used with respect to a commercially available monomer having no hydrophilic functional group. Also good. There is no limitation on the method of introducing a hydrophilic functional group into a commercially available monomer, and a known method may be applied as appropriate.

  Examples of the monomer having a hydrophilic functional group include a monoalcohol compound having a hydrophilic functional group, a polyol compound having a hydrophilic functional group, and an isocyanate compound having a hydrophilic functional group. Of these, at least one alcohol compound selected from the group consisting of a monoalcohol compound having a hydrophilic functional group and a polyol compound having a hydrophilic functional group is preferably used, and a polyol compound having a hydrophilic functional group is preferably used. It is more preferable to use at least one selected from the group consisting of a compound represented by the following general formula (4-1) and a compound represented by the following general formula (4-2).

In the general formula ^{(4-1), X 41} represents a single bond or a divalent linking group. R ⁴³ represents a divalent linking group containing a single bond or an alkylene group. R ⁴⁴ represents an s + 1 valent linking group. s represents an integer of 1 to 3. A ⁴¹ represents a hydrophilic functional group. W ⁴¹ each independently represents a hydroxy group or an amino group (—NH ₂ ), and is preferably a hydroxy group.
In the general formula ^{(4-2), R 46} are each independently a single bond, an alkylene group, an alkenylene group. R ⁴⁷ represents a group containing a lone pair, a hydrogen atom or an alkyl group. Two R ⁴⁶ may be bonded to each other to form a nitrogen-containing heterocycle together with the nitrogen atom to which they are bonded. W ⁴² each independently represents a hydroxy group or an amino group (—NH ₂ ), and is preferably a hydroxy group.

In the general formula (4-1), a hydrophilic functional group represented by A ⁴¹ is a nonionic hydrophilic group or ionic hydrophilic group represented by any one of the above general formula (4a) ~ (4c) It is preferably an ionic hydrophilic group, more preferably a group selected from the group consisting of a carboxyl group, a sulfo group, a phosphoric acid group, a phosphonic acid group and salts thereof, Further, a group selected from the group consisting of a sulfo group and a salt thereof is more preferable, and a group selected from the group consisting of a carboxyl group and a salt thereof is particularly preferable.

In the general formula (4-1), the divalent linking group represented by X ⁴¹ includes a single bond, an ether bond (—O—), a sulfide bond (—S—), an imino bond (—N (R ³⁵ )-), An amide bond (—CONH—), an ester bond (—COO— or —OC (═O) —), and the like. Among these, an ether bond, an imino bond, an ester bond or an amide bond is preferable, and an ether bond or an ester bond is more preferable. Here, R ³⁵ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. The alkyl group may be a linear structure or a branched structure, and examples thereof 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. R ³⁵ is preferably a hydrogen atom or a methyl group.

As the alkylene group for divalent linking group containing an alkylene group of R ^43, is preferably 1 to 20 carbon atoms. The alkylene group may have a linear structure or a branched structure. Moreover, even if it has a substituent, it may be unsubstituted. Examples of the substituent that may have include a halogen atom.

Among these, R ⁴³ is preferably an unsubstituted alkylene group having 1 to 20 carbon atoms, more preferably an unsubstituted alkylene group having 1 to 10 carbon atoms, and still more preferably 2 carbon atoms. -6 unsubstituted linear alkylene groups. Specific examples of the alkylene group include a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, an octylene group, and a decylene group.

In the divalent linking group containing an alkylene group represented by R ⁴³ , an ether bond (—O—), an imino bond (—NH—), an amide bond (—CONH—), an ester bond is sandwiched between the alkylene groups. (-COO- or -OCO-), a sulfonamide bond (-NHSO ₂ - or _-SO 2 NH-), a urethane bond (-NHCOO- or -OCONH-), ureylene bond (-NHCONH-) or a carbonate bond (- OCOO-) may be present as a linking group.

R ⁴³ is preferably a single bond or an unsubstituted linear alkylene group having 2 to 6 carbon atoms, more preferably a single bond or an unsubstituted linear alkylene group having 2 to 4 carbon atoms, More preferably, it is a single bond.

The s + 1 valent linking group represented by R ⁴⁴ may be an s + 1 valent linking group derived from an aliphatic hydrocarbon or an s + 1 valent linking group derived from an aromatic hydrocarbon. Here, the “s + 1 valent linking group derived from an aliphatic hydrocarbon” is an s + 1 valent linking group formed by removing s + 1 hydrogen atoms from an aliphatic hydrocarbon. The position where the hydrogen atom is removed from the aliphatic hydrocarbon is not particularly limited. Further, “s + 1 valent connecting group derived from aromatic hydrocarbon” has the same meaning.
Although s is an integer of 1-3, it is more preferable that it is an integer of 1-2, and it is still more preferable that it is 2.

The aliphatic hydrocarbon forming the s + 1 valent linking group represented by R ⁴⁴ may be a linear aliphatic hydrocarbon or a branched aliphatic hydrocarbon, and may have a cyclic structure. It may be an aliphatic hydrocarbon. The aliphatic hydrocarbon may be a saturated aliphatic hydrocarbon or an unsaturated aliphatic hydrocarbon. Furthermore, the number of carbon atoms of the aliphatic hydrocarbon is preferably 1-20, more preferably 1-16, and even more preferably 1-12.
The aromatic hydrocarbon forming the s + 1 valent linking group represented by R ⁴⁴ preferably has 6 to 24 carbon atoms, more preferably 6 to 20 carbon atoms, and still more preferably 1 to 16 carbon atoms. .

The s + 1 valent linking group represented by R ⁴⁴ may further have a substituent. Examples of the substituent include an alkyl group having 1 to 12 carbon atoms and a halogen atom.

The s + 1 valent linking group represented by R ⁴⁴ is preferably an s + 1 valent linking group derived from a linear or branched aliphatic hydrocarbon, and is a linear or branched group having 1 to 20 carbon atoms. It is more preferably a divalent to tetravalent linking group derived from a chain aliphatic hydrocarbon, and a trivalent linking group derived from a linear or branched aliphatic hydrocarbon having 1 to 12 carbon atoms. More preferably.

In general formula (4-2), the alkylene group or alkenylene group represented by R ⁴⁶ preferably has 1 to 20 carbon atoms. The alkylene group or alkenylene group may have a linear structure or a branched structure. Moreover, even if it has a substituent, it may be unsubstituted. Examples of the substituent that may have include a halogen atom.

Among these, when R ⁴⁶ represents an alkylene group, it is preferably an unsubstituted alkylene group having 1 to 20 carbon atoms, more preferably an unsubstituted alkylene group having 1 to 10 carbon atoms, still more preferably. Is an unsubstituted linear alkylene group having 2 to 6 carbon atoms. Specific examples of the alkylene group include a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, an octylene group, and a decylene group.

Two R ⁴⁶ may be bonded to each other to form a nitrogen-containing heterocycle together with the nitrogen atom to which they are bonded. Examples of nitrogen-containing heterocycles include piperidine rings, pyridine rings, morpholino groups, and the like.

R ⁴⁷ represents a group containing a lone pair, a hydrogen atom or an alkyl group. The alkyl group for R ⁴⁷ preferably has 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and still more preferably 1 to 12 carbon atoms. The alkyl group may have a linear structure, a branched structure, or a cyclic structure. Moreover, even if it has a substituent, it may be unsubstituted. Examples of the substituent that may have include the above-mentioned hydrophilic functional groups and halogen atoms.

In the group containing an alkyl group in R ⁴⁷ , an ether bond (—O—), an imino bond (—NH—), a sulfide group (—S—), an amide bond (—CONH—), an ester bond ( -COO- or -OCO-), a sulfonamide bond (-NHSO ₂ - or _-SO 2 NH-), a urethane bond (-NHCOO- or -OCONH-), ureylene bond (-NHCONH-), carbonate bond (-OCOO -) May be present as a linking group.

  Specific examples of the compound represented by the general formula (4-1) or the general formula (4-2) are shown below, but the present invention is not limited thereto.

  In the specific polyurethane resin, the content of the structural unit derived from the monomer having a hydrophilic functional group is preferably 1% by mass to 30% by mass from the viewpoint of dispersion stability and solvent resistance, and 2% by mass to More preferably, it is 25 mass%, and it is still more preferable that it is 3 mass%-15 mass%.

  In the specific polyurethane resin, the ratio of the content of the structural unit (a-1) derived from the monomer having a specific partial structure to the content of the structural unit (a-3) derived from the monomer having a hydrophilic functional group (a -1): (a-3) is preferably from 1:50 to 50: 1, more preferably from 1:30 to 30: 1, from the viewpoints of dispersion stability and blocking resistance. : More preferably, it is 20-20: 1.

(Other diol compounds)
The specific polyurethane resin may contain a structural unit derived from another diol compound other than the polyol compound and the monoalcohol compound. Other diol compounds include ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, 1,4-butanediol, 2,3-butanediol, 1,3-butanediol, neopentyl glycol, methylpentanediol, 1, 6-hexanediol, trimethylhexamethylenediol, 2-methyloctanediol, 1,9-nonanediol, 1,4-cyclohexanedimethanol, tricyclodecane dimethanol, polycaprolactone diol, polycarbonate diol, glycerin, trimethylolpropane, Examples include trimethylol octane, pentaerythritol, polytetramethylene glycol and the like. Among these, a diol compound having a molecular weight of 4000 or less is preferable.

(Polyisocyanate compound)
The polyisocyanate compound capable of forming the specific polyurethane resin is not particularly limited as long as it is a compound having two or more isocyanate groups and a linking group for linking them. Among these, a diisocyanate compound having two isocyanate groups and a linking group for linking them is preferable. Examples of the diisocyanate compound include compounds represented by the following general formula (5).

In the general formula (5), X ⁰ represents a divalent organic group. Examples of the divalent organic group for X ⁰ include a divalent organic group composed of at least one selected from the group consisting of an alkylene group, an arylene group, an oxygen atom, an imino group, and a carbonyl group. The alkylene group preferably has 1 to 20 carbon atoms, and more preferably 1 to 16 carbon atoms. The alkylene group may have a linear structure, a branched structure, or a cyclic structure. The arylene group preferably has 6 to 10 carbon atoms, and more preferably a phenylene group. The divalent organic group for X ⁰ may have a substituent. As a substituent, a C1-C12 alkyl group, a halogen atom, etc. can be mentioned.

  Specific examples of the diisocyanate compound represented by the general formula (5) include tolylene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, norbornene diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, diphenylmethane-4, 4'-diisocyanate, dimer acid diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, hydrogenated m-xylylene diisocyanate, hydrogenated p-xylylene diisocyanate, tetramethyl-m-xylylene diisocyanate, hydrogen Diphenylmethane-4,4′-diisocyanate, 1,2-bis (isocyanatoethoxy) ethane and the like. Among these, from the viewpoint of storage stability, from the group consisting of tolylene diisocyanate, diphenylmethane-4,4′-diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, dimer acid diisocyanate, m-xylylene diisocyanate and p-xylylene diisocyanate. It is preferably at least one selected.

The specific polyurethane resin preferably has a weight average molecular weight of 15,000 to 200,000, more preferably 20,000 to 150,000, and still more preferably 30,000 to 100,000.
When the weight average molecular weight of the specific polyurethane resin is 15000 or more, an effect of suppressing tackiness after drying can be obtained. Moreover, the effect of improving discharge stability is acquired because the weight average molecular weight of specific polyurethane resin resin is 200000 or less.

  The weight average molecular weight of the specific polyurethane resin 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.

  Although the specific example of specific polyurethane resin is illustrated below, this invention is not limited to these.

The specific polyurethane resin includes, for example, a polyisocyanate compound having two or more isocyanate groups, a polyol compound having two or more hydroxy groups, and having a specific partial structure, an ethylenically unsaturated bond group, or a hydrophilic functional group, If necessary, it can be obtained by condensation polymerization with a monoalcohol compound having a specific partial structure, an ethylenically unsaturated bond group or a hydrophilic functional group by a commonly used method.
The reaction conditions for the condensation polymerization are not particularly limited, and can be appropriately selected from the reaction conditions usually used according to the type of monomer used.

The specific polyurethane resin is preferably used as a dispersion in which specific polyurethane resin particles are dispersed in a dispersion medium. Examples of the dispersion medium include water and a mixed solvent of a water-soluble solvent and water, and a dispersion medium containing at least water is preferable.
The aqueous dispersion of the specific polyurethane resin can be obtained by phase inversion from the polymer solution by, for example, a phase inversion emulsification method.

The volume average particle diameter of the specific polyurethane resin particles is preferably 10 nm to 400 nm, more preferably 10 nm to 300 nm, and still more preferably 10 nm to 200 nm.
When the volume average particle diameter of the specific polyurethane resin particles is 10 nm or more, an effect of reducing the viscosity is obtained. In addition, when the volume average particle diameter of the specific polyurethane resin particles is 400 nm or less, the effect of good dischargeability and printer maintenance is obtained.

  The content of the specific polyurethane resin particles in the ink composition of the present invention is preferably 0.1% by mass to 10% by mass, and preferably 0.1% by mass to 8% by mass based on the total mass of the ink composition. It is more preferable that it is 0.1 mass%-5 mass%. The effect of improving blocking resistance is obtained when the content of the specific polyurethane resin particles is 0.1% by mass or more. Moreover, when the content of the specific polyurethane resin particles is 10% by mass or less, the effect of good stretchability and good maintainability can be obtained.

[water]
The ink composition of the present invention contains water. As water, it is preferable to use ion-exchanged water, distilled water or the like.
The water content in the ink composition of the present invention is preferably 10% by mass to 97% by mass, more preferably 30% by mass to 90% by mass, based on the total mass of the ink composition. More preferably, it is 40 mass%-85 mass%.
When the water content is in the above range, the effects of low viscosity and good dischargeability can be obtained.

[Polymerization initiator]
The ink composition of the present invention contains at least one polymerization initiator.
A known polymerization initiator can be used as the polymerization initiator. Among these, a radical polymerization initiator is preferable.
Examples of the radical polymerization initiator include (a) aromatic ketones, (b) acylphosphine compounds, (c) aromatic onium salt compounds, (d) organic oxides, (e) thio compounds, (f) hexa An arylbiimidazole compound, (g) a ketoxime ester compound, (h) a borate compound, (i) an azinium compound, (j) a metallocene compound, (k) an active ester compound, (l) a compound having a carbon halogen bond, and ( m) alkylamine compounds and the like.
Specific examples of the polymerization initiator include, for example, polymerization initiators described on pages 65 to 148 of “Ultraviolet curing system” written by Kiyosuke Kato (published by General Technology Center Co., Ltd .: 1989). Can do.

  As the polymerization initiator in the present invention, a water-soluble polymerization initiator or the like can be used. In addition, water solubility here means melt | dissolving 0.5 mass% or more in distilled water at 25 degreeC. The water-soluble polymerization initiator is preferably dissolved at 1% by mass or more in distilled water at 25 ° C., more preferably at least 3% by mass.

Examples of the water-soluble polymerization initiator include compounds represented by the following general formula (A), compounds described in JP-A-2005-307198, and the like.
Especially, it is preferable that it is a water-soluble polymerization initiator represented with the following general formula (A) from a viewpoint which shows the effect of this invention more effectively.

In general formula (A), m and n each independently represent an integer of 0 or more, and m + n represents an integer of 0 to 3.
In the general formula (A), m is preferably 0 to 3 and n is preferably 0 or 1, more preferably m is 0 or 1 and n is 0.
Specific examples of the compound represented by the general formula (A) are shown below, but the present invention is not limited thereto.

  The compound represented by the general formula (A) may be a compound synthesized according to the description in JP-A-2005-307198 or a commercially available compound. Examples of commercially available compounds represented by the general formula (A) include Irgacure 2959 (m = 0, n = 0).

In the ink composition of the present invention, the polymerization initiator may be used alone or in combination of two or more.
The content of the polymerization initiator in the ink composition of the present invention is preferably in the range of 0.1% by mass to 30% by mass in terms of solid content, and is in the range of 0.5% by mass to 20% by mass. Is more preferable, and it is still more preferable that it is the range of 1.0 mass%-15 mass%.
The content of the polymerization initiator is preferably 0.1% by mass to 20% by mass, more preferably 0.1% by mass to 15% by mass, based on the total mass of the ink composition, and 1% by mass to 10% by mass. Mass% is particularly preferred.

[Colorant]
The ink composition of the present invention contains at least one colorant.
There is no restriction | limiting in particular as a coloring agent which can be used for this invention, It can select and use arbitrarily from well-known coloring agents, such as a pigment, a water-soluble dye, and a disperse dye. Among these, as a coloring agent, it is more preferable that a pigment is included.

(Pigment)
The pigment is not particularly limited and may be appropriately selected depending on the purpose. Examples thereof include known organic pigments and inorganic pigments. Resin particles dyed with dyes, commercially available pigment dispersions and surfaces Treated pigments (for example, pigments dispersed in water, liquid organic compounds or insoluble resins, and pigment surfaces treated with resins, pigment derivatives, etc.) are also included. Examples of the pigment include, for example, “The Pigment Dictionary” edited by Seijiro Ito (2000, published by Asakura Shoten), Isao Hashimoto “Organic Pigment Handbook” (2006, published by Color Office), Herbst, K.M. Hunger, “Industrial Organic Pigments” (published by Wiley-VHC in 1992), JP 2002-12607, JP 2002-188025, JP 2003-26978, JP 2003-342503, JP Examples described in Japanese Unexamined Patent Publication No. 2009-235370.

Examples of the organic pigment and the inorganic pigment include a yellow pigment, a red pigment, a magenta pigment, a blue pigment, a cyan pigment, a green pigment, an orange pigment, a purple pigment, a brown pigment, a black pigment, and a white pigment.
Examples of the yellow pigment include C.I. I. Pigment Yellow 1, 2, 3, 4, 5, 10, 65, 73, 74, 75, 97, 98, 111, 116, 130, 167, 205, monoazo pigments, 61, 62, 100, 168, 169 , 183, 191, 206, 209, 212, etc., 12, 13, 14, 16, 17, 55, 63, 77, 81, 83, 106, 124, 126, 127, 152, 155, 170, 172 Disazo pigments such as 174, 176, 214 and 219, anthraquinone pigments such as 24, 99, 108, 193 and 199, monoazopyrazolone pigments such as 60, condensed azo pigments such as 93, 95, 128 and 166, 109 and 110 139, 173, 185, etc. isoindoline pigments, 120, 151, 154, 175, 180, 181, 194, etc. Zymimidazolone pigments, azomethine metal complex pigments such as 117, 129, 150, and 153, quinophthalone pigments such as 138, and quinoxaline pigments such as 213 are preferable.

  Examples of the red or magenta pigment include C.I. I. Pigment Red 193 and other monoazo lake pigments, 38 and other disazo pigments, 2, 5, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18, 22, 23, 31, 32, 112, 114 146, 147, 150, 170, 184, 187, 188, 210, 213, 238, 245, 253, 256, 258, 266, 268, 269, etc. Naphthol AS pigments, 3, 4, 6, etc., β-naphthol Pigments, β-naphthol lake pigments such as 49, 53, and 68, naphthol AS lake pigments such as 237, 239, and 247, pyrazolone pigments such as 41, 48, 52, 57, 58, 63, 64: 1, and 200 BONA lake pigments, xanthene lake pigments such as 81: 1, 169, 172, thioindigo pigments such as 88, 181, 279, 123, 149, 78, 179, 190, 224 etc. perylene pigment, 144, 166, 214, 220, 221, 242, 262 etc. condensed azo pigment, 168, 177, 182, 226, 263 etc. anthraquinone pigment, 83 etc. anthraquinone lake Pigments, benzimidazolone pigments such as 171, 175, 176, 185, 208, quinacridone pigments such as 122, 202 (including mixtures with CI Pigment Violet 19), 207, 209, 254, 255, 264 Diketopyrrolopyrrole pigments such as 270 and 272 are preferred, and azomethine metal complex pigments such as 257 and 271 are preferred.

Examples of the blue or cyan pigment include C.I. I. Naphthol AS pigments such as CI Pigment Blue 25 and 26, phthalocyanine pigments such as 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 16, 17: 1, 75 and 79, Dye lake pigments such as 24: 1, 56, 61, and 62, anthraquinone pigments such as 60, indigo pigments such as 63, and dioxazine pigments such as 80 are preferable.
Examples of the green pigment include C.I. I. Dye lake pigments such as CI Pigment Green 1 and 4, phthalocyanine pigments such as 7 and 36, and azomethine metal complex pigments such as 8 are preferable.
Examples of the orange pigment include C.I. I. Monoazo pigments such as CI Pigment Orange 1, β-naphthol pigments such as 2, 3, 5 and the like, naphthol AS pigments such as 4, 24, 38 and 74, pyrazolone pigments such as 13, 34, 36, 60, 62, 64 and 72 Benzimidazolone pigments such as 15 and 16, disazo pigments such as 15 and 16, β-naphthol lake pigments such as 17 and 46, naphthalene sulfonic acid lake pigments such as 19; perinone pigments such as 43, quinacridone pigments such as 48 and 49, 51 Anthraquinone pigments such as 61, isoindolinone pigments such as 61, isoindoline pigments such as 66, azomethine metal complex pigments such as 68, and diketopyrrolopyrrole pigments such as 71, 73 and 81 are preferred.

Examples of the brown pigment include C.I. I. BONA lake pigments such as CI Pigment Brown 5; condensed azo pigments such as 23, 41 and 42; and benzimidazolone pigments such as 25 and 32 are preferred.
Examples of the purple pigment include C.I. I. Pigment violet 1, 2, 3, 27, etc. dyed lake pigments, 13, 17, 25, 50 naphthol AS pigments, 5: 1 etc. anthraquinone lake pigments, 19 etc. quinacridone pigments, 23, 37 etc. dioxazines A pigment, a perylene pigment such as 29, a benzimidazolone pigment such as 32, and a thioindigo pigment such as 38 are preferred.
Examples of the black pigment include C.I. I. Preferred are indazine pigments such as CI Pigment Black 1; carbon black as 7; graphite as 10; magnetite as 11; anthraquinone pigments as 20; and perylene pigments as 31 and 32.
Examples of the white pigment include C.I. I. Pigment White 4 Zinc Oxide, 6 Titanium Oxide, 7 Zinc Sulfide, 12 Zirconium Oxide (Zirconium White), 18 Calcium Carbonate, 19 Aluminum Oxide / Silicon Oxide (Kaolin clay), Preferred are barium sulfate 21 or 22, aluminum hydroxide (alumina white) 23, silicon oxide 27, and calcium silicate 28.
The inorganic particles used in the white pigment may be simple substances, or may be oxides such as silicon, aluminum, zirconium, and titanium, organometallic compounds, and composite particles with organic compounds.
Of these, the titanium oxide is preferably used. In addition to the titanium oxide, another white pigment (may be other than the above-described white pigment) may be used in combination.

  Pigment particles, dispersants, and media so that the volume average particle diameter of the pigment particles is preferably 0.005 μm to 0.5 μm, more preferably 0.01 μm to 0.45 μm, and still more preferably 0.015 μm to 0.4 μm. Selection, dispersion conditions, and filtration conditions are preferably set. In the present invention, the average particle size and particle size distribution of the particles are determined by dynamic light scattering using a commercially available particle size measuring device such as Nanotrack particle size distribution measuring device UPA-EX150 (manufactured by Nikkiso Co., Ltd.). It is obtained by measuring the volume average particle diameter by the method.

(Water-soluble dye)
Examples of water-soluble dyes that can be used in the present invention include acid dyes and direct dyes. Acid dyes and direct dyes have a structure having an acid group as a solubilizing group. Examples of acidic groups include sulfonic acid groups and salts thereof, carboxylic acid groups and salts thereof, phosphoric acid groups and salts thereof. The number of acidic groups may be one, multiple, or a combination. The chemical structure of the chromophore contained in the water-soluble dye includes azo, phthalocyanine, triphenylmethane, xanthene, pyrazolone, nitro, stilbene, quinoline, methine, thiazole, quinoneimine, and indigoid. Type, rhodamine type, anthraquinone type, anthraquinone type and the like.

(Disperse dye)
In the present invention, a disperse dye can also be used.

  The colorant that can be used in the present invention may be used alone or in combination of two or more.

  The content of the colorant in the ink composition can be appropriately selected depending on the physical properties of the colorant (specific gravity, coloring power, color, etc.), and how many colors of the ink composition are combined to produce a printed matter. However, it is preferably 0.1% by mass to 30% by mass and more preferably 0.5% by mass to 20% by mass based on the total mass of the entire ink composition.

(Pigment 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 include random copolymers and salts thereof.

  A self-dispersing pigment can also be used in the ink composition of the present invention. The self-dispersing pigment referred to in the present invention refers to a pigment that can be dispersed without a pigment 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.

  In order to obtain such pigment particles having a polar group on the surface, known methods can be used as appropriate.

  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.

  As a method for dispersing the pigment, for example, various dispersing machines such as a ball mill, a sand mill, an attritor, a roll mill, an agitator, a Henschel mixer, a colloid mill, an ultrasonic homogenizer, a pearl mill, a wet jet mill, and a paint shaker can be used. It is also preferable to use a centrifugal separator or a filter for the purpose of removing the coarse particles of the pigment dispersion.

  The preferred addition amount of the dispersant in the ink composition is such that the mass ratio (D / P) is P, where P is the mass of the pigment in the ink composition, and D is the mass of the polymer dispersant in the ink composition. 0.01 ≦ D / P ≦ 2.0 is preferable, 0.03 ≦ D / P ≦ 1.5 is more preferable, and 0.05 ≦ D / P ≦ 0.6 is satisfied. Is more preferable.

  Further, at the time of dispersion, in addition to the dispersant, a dispersion aid generally called synergist (for example, SOLPERSE series 5000, 12000, 22000, commercially available from Lubrizol, EFKA6745, commercially available from BASF Japan), etc. It is also preferred to improve the dispersibility and wettability of the pigment by adding various surfactants and antifoaming agents.

In the present invention, when the pigment is dispersed, the pigment and the dispersant are mixed and then added to the polar organic solvent and dispersed, or the polar organic solvent and the dispersant are mixed and then the pigment is added. And dispersing. For the dispersion, for example, various dispersion devices such as a ball mill, a bead mill, a sand mill, a salt mill, an attritor, a roll mill, an agitator, a Henschel mixer, a colloid mill, an ultrasonic homogenizer, a pearl mill, a wet jet mill, and a paint shaker can be used. Among these, a bead mill dispersing device is preferable because of its excellent dispersibility.
The beads used when performing bead mill dispersion are preferably those having a volume average diameter of 0.01 mm to 3.0 mm, more preferably 0.05 mm to 1.5 mm, and still more preferably 0.1 mm to 1.0 mm. By using it, a pigment dispersion excellent in stability can be obtained.

[Polymerizable compound]
The ink composition preferably further contains at least one water-soluble polymerizable compound. Examples of the water-soluble polymerizable compound include a water-soluble radical polymerizable monofunctional monomer and a water-soluble radical polymerizable polyfunctional monomer.
Here, water-soluble means to dissolve 5% by mass or more in distilled water at 25 ° C. The water-soluble polymerizable compound is preferably dissolved in distilled water at 25 ° C. by 10% by mass or more.

  Water-soluble radically polymerizable monofunctional monomers include 2-hydroxyethyl acrylamide, hydroxymethyl acrylamide, 3-dimethylaminopropyl acrylamide, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, methoxy oligoethylene glycol (meth) acrylate , Methoxypolyethylene glycol (meth) acrylate, polyethylene glycol (meth) acrylate, tetrahydrofurfuryl acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and other polymerizable compounds exemplified below (2-1-1) to (2-1-27) may be mentioned, but the present invention is not limited to these.

Water-soluble radically polymerizable polyfunctional monomers include oligoethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, bis [2- (methacryloyloxy) ethyl] phosphate, methylene bisacrylate, 4,7, Examples include 10-trioxa-1,13-tridecanbisacrylamide and triethylene glycol divinyl ether.
In addition to the above, examples of the water-soluble radical polymerizable polyfunctional monomer include the following compounds, but the present invention is not limited thereto.

  The water-soluble polymerizable compound may be a radical polymerizable oligomer. As the radical polymerizable oligomer, it is preferable to use at least one selected from the group consisting of polyester oligomers, urethane oligomers, modified polyether oligomers, acrylic oligomers and epoxy oligomers.

  The water-soluble polymerizable compound preferably has a (meth) acryloyloxy group or a (meth) acrylamide group, and more preferably has a plurality of (meth) acryloyloxy groups or (meth) acrylamide groups. Here, the (meth) acryloyloxy group represents at least one of an acryloyloxy group and a methacryloyloxy group, and the (meth) acrylamide group represents at least one of an acrylamide group and a methacrylamide group.

  The polymerizable compound having a (meth) acryloyloxy group preferably used in the present invention is preferably a compound represented by the general formula (6m-1).

In the general formula ^{(6m-1), Q} 1 represents a ^{n 1} valent connecting ^{group, R 1 m} is a hydrogen atom or a methyl group. N ¹ represents an integer of 1 or more.

Compounds of general formula (6 m-1) are unsaturated monomers are those bound to the linking group Q ¹ by an ester bond. R ^1m represents a hydrogen atom or a methyl group, preferably a hydrogen atom. The valence n ¹ of the linking group Q ¹ is preferably 2 or more, more preferably 2 or more and 6 or less, and still more preferably 2 or more and 4 or less.

Furthermore, the linking group Q ¹ is not particularly limited as long as it is capable of linking groups and (meth) acryloyloxy structure. Specifically, a residue obtained by removing n ¹ hydrogen atoms or hydroxyl groups from the following compound group X can be preferably exemplified.

-Compound group X-
Ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4 -Butanediol, 2,3-butanediol, 1,5-pentanediol, 1,4-pentanediol, 1,3-pentanediol, 2,4-pentanediol, 3-methyl-1,5-pentanediol, 2-methyl-2,4-pentanediol, 1,6-hexanediol, 1,5-hexanediol, 2,5-hexanediol, glycerin, 1,2,4-butanediol, 1,2,5-pentane Triol, 1,2,6-hexanetrio Le, trimethylolpropane, trimethylolethane, ditrimethylolpropane, di-trimethylol ethane, thiodiglycol, neopentylglycol, pentaerythritol, dipentaerythritol, and condensates thereof, polyols such as sugars.
Polyamines such as ethylenediamine, diethylenetriamine, triethylenetetramine, polyethyleneimine, and polypropylenediamine.

Moreover The linking group Q ^1, methylene, ethylene, propylene, 4 or less of the substituted or unsubstituted alkylene chain of carbon atoms such as butylene group, more pyridine ring, an imidazole ring, a pyrazine ring, piperidine ring, piperazine ring, morpholine ring Examples thereof include a functional group having a saturated or unsaturated heterocyclic ring.

Among these, the linking group Q ¹ is preferably a residue of a polyol containing an oxyalkylene group (preferably an oxyethylene group), and contains three or more oxyalkylene groups (preferably an oxyethylene group). A residue of a polyol is particularly preferable.

  The radically polymerizable compound having a (meth) acrylamide group preferably used in the present invention is more preferably a compound represented by the general formula (6m-2).

In the general formula ^{(6m-2), Q} 2 represents a ^{n 2} divalent linking ^{group, R 2m} represents a hydrogen atom or a methyl group. N ² represents an integer of 1 or more.

Compounds of formula (6 m-2) are those unsaturated monomers, bonded to the linking group Q ² by an amide bond. R ^2m represents a hydrogen atom or a methyl group, and preferably a hydrogen atom. The valence n ² of the linking group Q ² is preferably 2 or more, more preferably 2 or more and 6 or less, and still more preferably 2 or more and 4 or less.

The connecting group Q ² is not particularly limited as long as it is capable of linking groups and (meth) acrylamide structure. Specifically, a residue in which n ² hydrogen atoms or hydroxyl groups have been removed from the above compound group X can be preferably exemplified.

Among these, the linking group Q ² is preferably a residue of a polyol containing an oxyalkylene group (preferably an oxyethylene group), and contains 3 or more oxyalkylene groups (preferably an oxyethylene group). A residue of a polyol is particularly preferable.

When the ink composition contains a water-soluble polymerizable compound, it is preferable to contain at least one compound having a (meth) acrylamide group from the viewpoint of storage stability and curing sensitivity.
The water-soluble polymerizable compound preferably contains at least one radical polymerizable monofunctional monomer, and contains at least one radical polymerizable polyfunctional monomer and at least one radical polymerizable monofunctional monomer. Is more preferable, and it is more preferable that at least one radical polymerizable bifunctional monomer and at least one radical polymerizable monofunctional monomer are included.

Further, when the ink composition contains a water-soluble polymerizable compound, at least one radical polymerizable polyfunctional selected from the group consisting of compounds represented by formula (6m-1) or formula (6m-1). Monomer, acrylamide, 2-hydroxyethyl acrylamide, hydroxymethyl acrylamide, t-butyl acrylamide, 3-dimethylaminopropyl acrylamide, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, methoxy oligoethylene glycol (meth) acrylate, methoxy Polyethylene glycol (meth) acrylate, polyethylene glycol (meth) acrylate, tetrahydrofurfuryl acrylate, 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate Preferably contains at least a radical-polymerizable monofunctional monomer selected from the group consisting of relations, is represented by the general formula (6 m-1) or general formula ^(6m-1), n 1 and n ² is 2 At least one radical polymerizable bifunctional monomer selected from the group consisting of compounds, acrylamide, 2-hydroxyethyl acrylamide, hydroxymethyl acrylamide, t-butyl acrylamide, 3-dimethylaminopropyl acrylamide, 2-hydroxyethyl vinyl ether, 4 -Hydroxybutyl vinyl ether, methoxy oligoethylene glycol (meth) acrylate, methoxy polyethylene glycol (meth) acrylate, polyethylene glycol (meth) acrylate, tetrahydrofurfuryl acrylate, 2-hydride More preferably, it contains at least a radical polymerizable monofunctional monomer selected from the group consisting of roxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate.

When the ink composition contains a water-soluble polymerizable compound, the content of the water-soluble polymerizable compound is 0.1% by mass to 30% by mass based on the total mass of the ink composition from the viewpoint of curability. Is more preferable, and more preferably 1% by mass to 20% by mass.
The water-soluble polymerizable compound does not include a specific polyurethane resin.

When the ink composition contains a radical polymerizable monofunctional monomer as a water-soluble polymerizable compound, the content of the radical polymerizable monofunctional monomer is 5% by mass to 90% by mass based on the total content of the polymerizable compound. %, More preferably 10% by mass to 80% by mass, and still more preferably 15% by mass to 70% by mass.

  When the ink composition contains a radical polymerizable polyfunctional monomer and a radical polymerizable monofunctional monomer as a water-soluble polymerizable compound, the content ratio of the radical polymerizable polyfunctional monomer and the radical polymerizable monofunctional monomer (radical polymerization) Functional polyfunctional monomer: radically polymerizable monofunctional monomer) is preferably 10:90 to 90:10, more preferably 20:80 to 90:10, and 40:60 to 90 on a mass basis. : 10 is more preferable.

  The ratio of the specific polyethylene resin particles to the polymerizable compound in the ink composition is preferably 1:99 to 60:40 in terms of mass ratio, and is preferably 2:99 to 50:40. 50 is more preferable, and 5:95 to 40:60 is particularly preferable. In this range, the ink viscosity and the discharge recovery property tend to be balanced.

[Water-soluble organic solvent]
The ink composition may contain at least one water-soluble organic solvent as necessary. Water-soluble here means that the solubility in water at 25 ° C. is 1% by mass or more.
Examples of water-soluble organic solvents include alkane polyols (polyhydric alcohols) such as glycerin, ethylene glycol, and propylene glycol; sugar alcohols; alkyl alcohols having 1 to 4 carbon atoms such as ethanol, methanol, butanol, propanol, and isopropanol. Class: Ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, ethylene glycol monoisopropyl ether, diethylene glycol monoisopropyl ether, ethylene Glycol monobutyl ether, ethylene Recall mono-t-butyl ether, diethylene glycol mono-t-butyl ether, triethylene glycol monoethyl ether, 1-methyl-1-methoxybutanol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-t-butyl ether, propylene Glycol mono-n-propyl ether, propylene glycol monoisopropyl ether, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol monoisopropyl ether, tripropylene Glycol ethers such as glycol monomethyl ether, ethylene car Nate, propylene carbonate, 3-methyl-2-oxazolidinone, 3-ethyl-2-oxazolidinone, 3-propyl-2-oxazolidinone, 1,3-dimethyl-2-imidazolidinone, 2-pyrrolidone, 1-methyl-2 And heterocyclic solvents such as -pyrrolidone and γ-butyrolactone. These can be used individually by 1 type or in combination of 2 or more types.

As the water-soluble organic solvent, for example, known water-soluble organic solvents described in paragraphs 0124 to 0135 of JP2011-074150, paragraphs 0104 to 0119 of JP2011-079901A, and the like can be used. .
When the ink composition in the invention contains a water-soluble organic solvent, the content is preferably 60% by mass or less, more preferably 40% by mass or less, based on the total amount of the ink composition.

[Other additives]
In the ink composition of the present invention, in addition to the above components, other known additives can be used in combination as necessary as long as the effects of the present invention are not impaired. Hereinafter, other additives that can be used in the ink composition will be described.

(Surfactant)
The ink composition may contain a surfactant. As the surfactant 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 fluorine-based nonionic surfactants (for example, ZONYL FSN, manufactured by DuPont); cationic interfaces such as alkylamine salts and quaternary ammonium salts An activator is mentioned. In particular, an anionic surfactant or a nonionic surfactant can be preferably used.

  Moreover, a polymeric surfactant can also be used, and the following water-soluble resins are mentioned as preferred polymeric 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.

(latex)
The ink composition may contain a latex. Examples of the latex include styrene-butadiene copolymer, polystyrene, acrylonitrile-butadiene copolymer, acrylate copolymer, polyurethane, silicon-acrylic copolymer, and acrylic-modified fluororesin. The latex may be a polymer particle dispersed using an emulsifier, or a so-called soap-free latex dispersed without using an emulsifier. A surfactant is often used as an emulsifier, but a polymer having a water-soluble group such as a sulfonic acid group or a carboxylic acid group (for example, a polymer in which a solubilizing group is graft-bonded, a single group having a solubilizing group) It is also preferable to use a polymer obtained from a monomer and a monomer having an insoluble part.

(Aqueous polymer)
The ink composition may contain an aqueous polymer other than the specific polyurethane resin.
Preferable examples of the aqueous polymer include natural polymers. Specific examples of the aqueous polymer include proteins such as glue, gelatin, casein, and albumin; natural rubbers such as gum arabic and tragacanth; glucosides such as saponin; alginic acid and propylene glycol alginate, triethanolamine alginate, ammonium alginate And alginic acid derivatives such as methyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, and ethyl hydroxyl cellulose.

  Another preferred example of the aqueous polymer is a synthetic polymer. Synthetic polymers include polyvinyl alcohols; polyvinylpyrrolidones; polyacrylic acid, acrylic acid-acrylonitrile copolymer, potassium acrylate-acrylonitrile copolymer, vinyl acetate-acrylic ester copolymer, acrylic acid- Acrylic resin such as acrylic ester copolymer; styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer, styrene-methacrylic acid-acrylic ester copolymer, styrene-α-methylstyrene-acrylic acid copolymer Styrene acrylic resin such as polymer, styrene-α-methylstyrene-acrylic acid-acrylic acid ester copolymer; styrene-maleic acid copolymer, styrene-maleic anhydride copolymer, vinylnaphthalene-acrylic acid copolymer Coalesce, vinyl naphthalene-maleic acid copolymer, etc. Styrene copolymer: vinyl acetate-ethylene copolymer, vinyl acetate-fatty acid vinyl ethylene copolymer, vinyl acetate-maleic acid ester copolymer, vinyl acetate-crotonic acid copolymer, vinyl acetate-acrylic acid copolymer Examples thereof include vinyl acetate copolymers such as coalescence and salts thereof. Of these, nonionic aqueous polymers are preferred, and particularly preferred examples include polyvinylpyrrolidones.

  The molecular weight of the aqueous polymer is preferably 1,000 or more and 200,000 or less. Furthermore, 3,000 or more and 20,000 or less are more preferable.

  When the ink composition contains an aqueous polymer, the content of the aqueous polymer is preferably 10% by mass or more and 1,000% by mass or less with respect to the colorant. Furthermore, 50 mass% or more and 200 mass% or less are more preferable.

(Sensitizing dye)
The ink composition may contain a sensitizing dye. The ink composition preferably uses a sensitizing dye in combination with the polymerization initiator. The sensitizing dye is preferably water-soluble. The solubility of the sensitizing dye is preferably 0.5% by mass or more, more preferably 1% by mass or more, and particularly preferably 3% by mass or more, in distilled water at 25 ° C. . As the sensitizing dye, a sensitizing dye dispersion in which a water-insoluble sensitizing dye 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. Further, sensitizing dyes described in JP2010-24276A and sensitizing dyes described in JP-A-6-107718 can be suitably used.

  In addition to the above-described components, the ink composition may be used according to the purpose of improving ejection stability, print head and ink cartridge compatibility, storage stability, image storage stability, and other various performances as necessary. Various known additives such as viscosity modifiers, surface tension modifiers, specific resistance modifiers, film forming agents, ultraviolet absorbers, antioxidants, anti-fading agents, antifungal agents, rust preventives, solid wetting agents In addition, silica fine particles and the like can be appropriately selected and used. Various additives include oil droplets such as liquid paraffin, dioctyl phthalate, tricresyl phosphate, silicone oil, and ultraviolet absorbers described in JP-A-57-74193, 57-87988 and 62-261476. , And JP-A-57-74192, 57-87989, 60-72785, 61-14659, JP-A-1-95091, and JP-A-3-13376. Agents, optical brighteners described in JP-A-59-42993, JP-A-59-52689, JP-A-62-280069, JP-A-61-228771, JP-A-4-219266, and the like, sulfuric acid, Examples thereof include pH adjusters such as phosphoric acid, citric acid, sodium hydroxide, potassium hydroxide, and potassium carbonate.

[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. During and after addition, mix evenly with a simple stirrer such as a three-one motor, magnetic stirrer, disper, or 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 20 mN / m to 40 mN / m. The surface tension is measured under the condition of 25 ° C. using an Automatic Surface Tensiometer CBVP-Z (manufactured by Kyowa Interface Science Co., Ltd.). The viscosity is preferably 1 mPa · s to 40 mPa · s, and more preferably 3 mPa · s to 30 mPa · s. The viscosity of the ink composition is measured under conditions of 25 ° C. using VISCOMETER TV-22 (manufactured by TOKI SANGYOCO. LTD).

<Image forming method>
The image forming method of the present invention includes an ink application 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 image formation by an image forming method including these steps, an image is formed from the ink composition fixed on the recording medium.

(Ink application process)
Hereinafter, the ink application process in the image forming method of the present invention will be described. The ink application process is not particularly limited as long as the ink composition can be applied to a desired region on the recording medium. Among these, an application method by an ink jet method using an ink jet recording apparatus is preferable.

  There is no restriction | limiting in particular as an inkjet recording device used for an image forming method, The well-known inkjet recording device which can achieve the target resolution can be selected arbitrarily and can be used. That is, any known ink jet recording apparatus including a commercially available product can perform the step of applying the ink composition to 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 pl to 100 pl, more preferably 8 pl to 30 pl, preferably 320 dpi × 320 dpi to 4,000 dpi × 4,000 dpi, more preferably 400 dpi × 400 dpi to 1,600 dpi. It can be driven so as to discharge at a resolution of 1,600 dpi, more preferably 720 dpi × 720 dpi. In the present invention, dpi represents the number of dots per 2.54 cm.

Since it is desirable for the ink composition to have a constant temperature, 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.

  Using the ink jet recording apparatus, the ink composition is ejected by heating the ink composition to preferably 25 ° C. to 80 ° C., more preferably 25 ° C. to 50 ° C., so that the viscosity of the ink composition is preferably 3 mPa. It is preferable to carry out after lowering to s 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 particularly preferably the set temperature. A temperature of ± 1 ° C. is appropriate.

  The recording medium in the present invention 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 substrate is more preferable, and a sheet or film of polyvinyl chloride resin is still 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 particularly 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 with active energy rays, radical polymerization of the specific polyurethane resin in the ink composition and the water-soluble polymerizable compound contained as necessary proceeds, and the image is fixed on the recording medium. It is possible to improve the solvent resistance of the printed material.

  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.

  The peak wavelength of UV light depends on the absorption characteristics of the sensitizing dye used as necessary, but is preferably 200 nm to 405 nm, more preferably 250 nm to 405 nm, and 250 nm to 390 nm, for example. More preferably.

Irradiation amount of UV light is preferably at 2,000 mJ / cm ² or less, more ^preferably from ^{10mJ / cm 2 ~2,000mJ / cm 2} , more ^preferably, 20 mJ / cm 2 to 1,000 / Cm ² , particularly preferably 50 mJ / cm ^{2 to} 800 mJ / cm ² .
Further UV light exposure surface illuminance, for example, ^{10mW / cm 2 ~2,000mW / cm 2} , ^preferably, it is appropriate to be irradiated with ^{20mW / cm 2 ~1,000mW / cm 2} .

  As the UV light source, mercury lamps, gas / solid lasers, and the like are mainly used, and mercury lamps and metal halide lamps 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.

The ink composition of the present invention is suitably irradiated with such UV light, for example, for 0.01 seconds to 120 seconds, preferably 0.1 seconds to 90 seconds.
Irradiation conditions and basic irradiation methods are disclosed in JP-A-60-132767. 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. Irradiation with active energy rays is performed for a certain period of time after ink landing and thermal fixing (for example, 0.01 seconds to 60 seconds, preferably 0.01 seconds to 30 seconds, more preferably 0.01 seconds to 15 seconds). It will be done after.

(Heat drying process)
The ink composition ejected onto the recording medium is left as an ink residue by removing at least a part of water and the water-soluble organic solvent used together as necessary by the heating means before the irradiation step. Is preferred. That is, it is preferable that the image forming method includes a heating and drying step in which the ink composition applied on the recording medium is heated to form a remaining ink after the ink application step and before the irradiation step.
Hereinafter, the heating and drying process in which heat is applied to the applied ink composition to form the remaining ink will be described.

  The heating means is not limited as long as it can dry water and a water-soluble organic solvent used in combination as necessary. Examples of the heating means include a heating means such as a heat drum, hot air, an infrared lamp, a heat oven, and a heat plate.

The heating temperature is not particularly limited as long as at least a part of the water present in the ink composition and the water-soluble organic solvent used together as necessary can be removed and a film of the specific polyurethane resin can be formed. The effect is acquired if heating temperature is 40 degreeC or more, About 40 to 150 degreeC is preferable, More preferably, it is about 40 to 80 degreeC.
The drying / heating time is not particularly limited as long as water present in the ink composition and the water-soluble organic solvent used in combination as needed can be evaporated and a film of the resin agent can be formed. It can be appropriately set in consideration of the composition of the composition and the image forming speed.

<Printed matter>
The printed matter of the present invention has a recording medium and an image formed by the ink composition on the recording medium or an image formed by the image forming method on the recording medium. The printed matter of the present invention is a printed matter excellent in stretchability, blocking resistance and solvent resistance of the formed 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.

[Synthesis of Polymer Dispersant D-1]
To a 500 ml three-necked flask equipped with a stirrer and a condenser, 44 g of methyl ethyl ketone was added and heated to 72 ° C. in a nitrogen atmosphere. Then, a solution in which 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 deposited resin was dried to obtain 43 g of polymer dispersant D-1.
The composition of the obtained resin 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 dispersion of resin-coated pigment]
(Resin-coated cyan pigment dispersion (C))
Pigment Blue 15: 3 (phthalocyanine blue A220, manufactured by Dainichi Seika Co., Ltd.), 5 parts of the above polymer dispersant D-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 resin-coated cyan pigment dispersion (C) having a pigment concentration of 10.2% by mass.

(Resin-coated magenta pigment dispersion (M))
In the preparation of the resin-coated cyan pigment dispersion, the resin coating was carried out in the same manner as above except that Chromathal Jet Magenta DMQ (Pigment Red 122, manufactured by BASF Japan Ltd.) was used instead of phthalocyanine blue A220 used as the pigment. A magenta pigment dispersion (M) was obtained.

(Resin-coated yellow pigment dispersion (Y))
Resin-coated yellow was prepared in the same manner as described above except that Irgalite Yellow GS (Pigment Yellow 74, manufactured by BASF Japan Ltd.) was used instead of phthalocyanine blue A220 used as a pigment in the preparation of the resin-coated cyan pigment dispersion. A pigment dispersion (Y) was obtained.

(Resin-coated black pigment dispersion (K))
In the preparation of the resin-coated cyan pigment dispersion, a pigment dispersion CAB-O-JET ^™ 200 (carbon black, manufactured by CABOT) was used instead of phthalocyanine blue A220 used as a pigment in the same manner as described above. A resin-coated black pigment dispersion (K) was obtained.

(Polyurethane resin dispersion)
To 100 g of methyl ethyl ketone (MEK), 25.2 g of xylylene diisocyanate, 12.33 g of Bremer GLM, 5.72 g of Silaplane FM-DA11, 7.70 g of 2,2-bis (hydroxymethyl) lacric acid, 0.1 g of neostan U600 The mixture was added and reacted at 60 ° C. for 24 hours. After adding 50 g of isopropyl alcohol, 150 g of distilled water, and 0.1 mol / L sodium hydroxide aqueous solution in such an amount that the acid in the polyurethane solution is neutralized by 50%, the mixture is stirred at a reduced pressure of 100 mmHg and 50 ° C. for 5 hours. The solvent was removed. After confirming that the content of MEK and isopropyl alcohol was 1% or less, an aqueous dispersion of polyurethane resin (A-1) was obtained. Drying was performed at 150 ° C. for 5 hours in a vacuum oven, the solid content of the polyurethane dispersion was measured, and water was added to adjust the solid content to 20%.
It was confirmed by GPC that the polystyrene equivalent weight average molecular weight was 45,000. Moreover, it was confirmed by NMR measurement that the composition was as described.

  Polyurethane resins (A-2) to (A-7), (B-1) and (B-2) showing the composition and weight average molecular weight are synthesized according to the above-described methods, and each of the polyurethane resins is water-based. A dispersion was obtained. In addition, Table 1 shows monomer types when each polyurethane resin was synthesized.

Abbreviations in Table 1 are as follows.
XDI: m-xylylene diisocyanate H12MDI: 4,4′-dicyclohexylmethane diisocyanate IPDI: isophorone diisocyanate HMDI: 1,6-hexamethylene diisocyanate Silaplane FM-DA11: manufactured by JNC Corporation Silaplane FM-4411 manufactured by Co., Ltd. A-1620 manufactured by JNC Co., Ltd .: 2-perfluorohexyl ethanol (manufactured by Daikin Industries, Ltd.)
2-1-1: The following diol compound 2-1-2: The following diol compound Blemmer GLM: NOF Corporation PPG400: Polypropylene glycol, weight average molecular weight 400, diol type (Wako Pure Chemical Industries, Ltd.)
A-7612: 2,2,3,3,4,4,5,5,6,6,7,7-decafluoro-1,8-octanediol (manufactured by Daikin Industries)

(Polyfunctional polymerizable compound)
The polyfunctional polymerizable compound used in the examples is shown below.

  A-400: NK ester A-400, poly (ethylene glycol) diacrylate, number average molecular weight 400, manufactured by Shin-Nakamura Chemical Co., Ltd.

M-1 was synthesized as follows.
-Synthesis of M-1-
To a 1 L three-necked flask equipped with a stirrer was added 4,7,10-trioxa-1,13-tridecanediamine 40.0 g (182 mmol), sodium bicarbonate 37.8 g (450 mmol), water 100 g, tetrahydrofuran 300 mL, In an ice bath, 35.2 g (389 mmol) of acrylic acid chloride was added dropwise over 20 minutes. After dropping, the mixture was stirred at room temperature for 5 hours, and then tetrahydrofuran was distilled off from the obtained reaction mixture under reduced pressure. Next, the aqueous layer was extracted four times with 200 ml of ethyl acetate, and the resulting organic layer was dried over magnesium sulfate, filtered, and the solvent was distilled off under reduced pressure to obtain the polymerizable compound which is the desired polyfunctional polymerizable compound. 35.0 g (107 mmol, yield 59%) of M-1 white solid was obtained.

(Monofunctional polymerizable compound)
Hydroxyethylacrylamide: manufactured by Kojin Co., Ltd.

(Water-soluble organic solvent)
2-pyrrolidone: Sigma-Aldrich Japan Co., Ltd.

(Polymerization initiator)
Irgacure 2959: Irgacure 2959 (trade name, manufactured by BASF Japan)

(Surfactant)
Zonyl FSN: Made by DuPont

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

<Examples 1-19, Comparative Examples 1-3>
[Preparation of ink composition]
The dispersions obtained above (C dispersion, M dispersion, Y dispersion, K dispersion) and the materials shown above are shown in Table 2 below for the compositions of Examples 1-18 and Comparative Examples 1-3. An ink composition was prepared. Specifically, each material shown in Table 2 was weighed with the addition amount (parts by mass) shown in Table 2, and ion-exchanged water was added so that the total amount was 100 parts by mass. L4R) was stirred at 2,500 rpm for 10 minutes, and then packed in a plastic disposable syringe, and a 5 μm pore size filter made of polyvinylidene fluoride (PVDF) (Millipore Millex-SV, diameter 25 mm) The ink composition was prepared by filtration.
Moreover, when the viscosity of the obtained ink composition was measured using a VISCOMETER TV-22 (manufactured by TOKI SANGYOCO. LTD) under the condition of 25 ° C., all of them were 30 mPa · s or less, and inkjet discharge was possible. It was in range.

<Evaluation>
Each ink composition obtained above was evaluated as follows.

[Dischargeability]
A commercially available inkjet printer (Mimaki Engineering Co., Ltd., JV400-130SUV) 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. When the observed image was evaluated visually according to the following evaluation criteria, it was confirmed that none of the ink compositions of the examples showed the occurrence of missing dots due to the occurrence of missing or the like, and showed good dischargeability. It was.

[Extensible]
On a polycarbonate plate having a thickness of 500 μm as a base material, a solid image is formed by applying an ink composition in the same manner as in the inkjet image recording. Integrated exposure amount: 12,000 mJ / cm ² , illuminance: 2140 mW / cm ² was exposed and cured to prepare a cured film having a thickness of about 4 μm. The base material on which the cured film is formed is cut together with the cured film into an axial length of 5 cm and a width of 2.5 cm, and 180 ° C. and a speed of 30 cm / min using a tensile tester (manufactured by Shimadzu Corporation, Autograph AGS-J). The elongation until the cured film was broken was measured, and the stretchability was evaluated according to the following evaluation criteria. Note that the elongation percentage of 100% means that the film has been stretched to twice the initial length. The evaluation results are shown in Table 2.
-Evaluation criteria-
A: The elongation was 200% or more (stretched to 3 times or more of the initial length).
B: The elongation was 100% or more and less than 200% (stretched to 2 to 3 times the initial length).
C: The elongation was less than 100% (it was stretched only less than twice the initial length).

[Blocking resistance and solvent resistance]
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). Furthermore, after moisture was dried at 60 ° C. for 3 minutes, exposure was performed with a low-pressure mercury lamp under the condition of energy of 1000 mJ / cm ² to obtain a print having a cured film (solid image) on a 500 μm thick polycarbonate plate. .
The following evaluation was performed using the obtained printed matter. The evaluation results are shown in Table 2.

<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 an iron plate having the same size as the printed material is used, and further at a pressure of 1 kg / cm ² , 30 ° C. For 1 hour. Thereafter, the two printed materials were peeled off, and the state of the cured film was visually observed and evaluated according to the following evaluation criteria. The evaluation results are shown in Table 2.
-Evaluation criteria-
A: There was no peeling in the coating film, and no sound was produced when it was peeled off.
B: Although there was no peeling in a coating film, the sound produced when peeling.
C: Although there was no peeling in the coating film, some transfer was seen in the coating film.
D: Peeling occurred in the coating film.
Note that the evaluation ranks A and B are levels that have no practical problem.

<Solvent resistance evaluation>
The surface on the side having the cured film in the printed matter obtained above 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 2.
-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.
Note that the evaluation ranks A and B are levels that have no practical problem.

From Table 2, it can be seen that the ink composition of the present invention can form an image excellent in stretchability, blocking resistance and solvent resistance.

Claims (12)

Polyurethane resin particles having at least one partial structure selected from the group consisting of a polysiloxane group and a fluorinated alkyl group, an ethylenically unsaturated bond group, and a hydrophilic functional group;
water and,
A polymerization initiator;
A colorant;
An ink composition comprising:   The ink composition according to claim 1, wherein the hydrophilic functional group is an anionic hydrophilic group.   The ink composition according to claim 1, wherein the hydrophilic functional group is at least one selected from the group consisting of a carboxyl group, a sulfo group, and a salt thereof.   The ink composition according to claim 1, further comprising a water-soluble polymerizable compound.   The ink composition according to claim 4, wherein the water-soluble polymerizable compound has a (meth) acrylamide group.   The ink composition according to claim 4 or 5, wherein the water-soluble polymerizable compound contains a radical polymerizable monofunctional monomer.   The ink composition according to any one of claims 1 to 6, further comprising a water-soluble organic solvent.   The ink composition according to claim 1, wherein the polyurethane resin particles include a polyurethane resin having a weight average molecular weight of 15,000 to 200,000.   The ink composition according to claim 1, wherein the polyurethane resin particles have a volume average particle diameter of 10 nm to 200 nm.   The ink composition according to any one of claims 1 to 9, wherein a content of the polyurethane resin particles is 0.1% by mass to 5% by mass.   An ink application process for applying the ink composition according to any one of claims 1 to 10 and an irradiation process for irradiating the applied ink composition with actinic radiation on a recording medium. Image forming method. A recording medium and an image formed with the ink composition according to any one of claims 1 to 10 on the recording medium, or an image forming method according to claim 11 formed on the recording medium. Printed matter having a printed image.