JPWO2019058990A1 - Ink composition, method for producing the same, and image forming method - Google Patents

Abstract

An ink containing water and particles containing a polymer having a gelling group, which is a urethane polymer, a urea polymer, or a (meth)acrylic polymer and is a reaction product of a gelling agent having an active hydrogen group and an isocyanate group. Composition, method for producing the same, and image forming method.

Description

The present disclosure relates to an ink composition, a method for producing the same, and an image forming method.

In the field of ink compositions, an aqueous dispersion of gel particles containing water as a liquid component may be used.
For example, Patent Document 1 discloses a three-dimensional crosslinked structure containing a thioether bond and an ethylenic double bond as an aqueous dispersion of gel particles that can form a film having both hardness and flexibility and is excellent in redispersibility. And an aqueous dispersion of gel particles in which the gel particles having a hydrophilic group and encapsulating a photopolymerization initiator are dispersed in water. Patent Document 1 also discloses that an aqueous dispersion of gel particles is used for inkjet recording.

Further, Patent Document 2 discloses a coating film-forming material, a polyether-modified silicone oil, and water as an ink composition for inkjet recording, which is excellent in solid fillability, storage stability, and abrasion resistance. And a polyether-modified silicone oil, which is soluble in a solvent having an SP value of 8.5 or less and an upper limit of 18.0 or more, is disclosed.

Patent Document 1: International Publication No. 2016/136113 Patent Document 2: Japanese Unexamined Patent Publication No. 2014-5421

By the way, generally, in an ink film formed using an ink containing water as a liquid component, as compared with an ink film formed using an ink containing a polymerizable monomer and/or an organic solvent as a liquid component, It tends to be difficult to remove the liquid component from the ink film. Therefore, an image formed using an ink containing water as a liquid component may have poor scratch resistance.
Therefore, it may be required to improve scratch resistance of an image formed using an ink containing water as a liquid component.

An object of the present disclosure is to provide an ink composition capable of forming an image having excellent scratch resistance, a method for producing the ink composition, and an image forming method using the ink composition.

Specific means for solving the above problems include the following aspects.
<1> With water,
Particles containing a polymer having a gelling group which is a urethane polymer, a urea polymer, or a (meth)acrylic polymer, and is a reaction product of a gelling agent having an active hydrogen group and an isocyanate group,
An ink composition containing:

<2> The ink composition according to <1>, wherein the gelling group is a group represented by the following formula (G).

In the formula (G), n ^G represents 1 or 2, R ^U represents a urethane group, a urea group, a thiourethane group, or a thiourea group, and L ^G represents a single bond or a divalent linking group. , * Represents the bonding position.
In formula (G), R ^G is a polysaccharide, protein, acrylic resin, vinyl resin, or hydrogelating agent which is a polyoxyalkylene compound represented by formula (1) when n ^G is 1. It represents a residue obtained by removing one hydrogen atom, or represents a monovalent hydrophobic group.
In the formula (G), R ^G , when n ^G is 2, represents a residue obtained by removing two hydrogen atoms from the above hydrogelating agent, or represents a divalent hydrophobic group.
In formula (1), n and m each independently represent an integer of 2 or more, p represents an integer of 0 or more, L represents an alkylene group having 3 or more carbon atoms, and R represents a hydrogen atom. Represents an alkyl group or an aryl group.

<3> The hydrogelator is a polysaccharide or a polyoxyalkylene compound represented by the formula (1),
The monovalent hydrophobic group is a linear alkyl group having 10 or more carbon atoms,
The ink composition according to <2>, wherein the divalent hydrophobic group is a linear alkylene group having 10 or more carbon atoms.
<4> The hydrogelator is a polysaccharide,
The monovalent hydrophobic group is a linear alkyl group having 16 or more carbon atoms,
The ink composition according to <2> or <3>, wherein the divalent hydrophobic group is a linear alkylene group having 16 or more carbon atoms.
<5> The ink composition according to any one of <2> to <4>, wherein R ^U in the formula (G) is a urea group.
<6> The ink composition according to any one of <1> to <5>, in which the gelling group is a monovalent group.
<7> The polymer is a chain polymer,
The ink composition according to <6>, wherein the gelling group is arranged at the end of the main chain of the chain polymer.
<8> The ink composition according to any one of <1> to <7>, in which the particles contain a polymerizable monomer.
<9> The ink composition according to any one of <1> to <8>, in which the polymer has a polymerizable group.
<10> The ink composition according to any one of <1> to <9>, which is used as an inkjet ink.
<11> A method for producing the ink composition according to any one of <1> to <10>,
A method for producing an ink composition, comprising a step of forming particles by mixing and emulsifying an oil phase component containing an organic solvent and a polymer and an aqueous phase component containing water.
<12> A step of forming an ink film on the substrate by applying the ink composition according to any one of <1> to <10>,
Heating the ink film,
An image forming method including.

According to the present disclosure, there are provided an ink composition capable of forming an image having excellent scratch resistance, a method for producing the same, and an image forming method using the ink composition.

It is a figure which shows the character image used for evaluation of the fineness of the image in an Example.

In the present specification, the numerical range indicated by using "to" means a range including the numerical values before and after "to" as the minimum value and the maximum value, respectively.
In the present specification, the amount of each component in the composition refers to the total amount of the plurality of substances present in the composition, unless a plurality of substances corresponding to each component are present in the composition. Means
In the numerical range described stepwise in the present specification, the upper limit value or the lower limit value described in a certain numerical range may be replaced with the upper limit value or the lower limit value of another stepwise described numerical range. Also, the values shown in the embodiments may be replaced.
In the present specification, the term “process” is included in this term as long as the intended purpose of the process is achieved not only as an independent process but also when it cannot be clearly distinguished from other processes. Be done.
In the present specification, “*” in the chemical formula represents a bonding position.

In the present specification, the concept of “image” includes not only a pattern image (for example, a character, a symbol, or a figure) but also a solid image.
In the present specification, “light” is a concept including active energy rays such as γ rays, β rays, electron rays, ultraviolet rays, and visible rays.
In the present specification, ultraviolet rays may be referred to as “UV (Ultra Violet) light”.
In this specification, light generated from an LED (Light Emitting Diode) light source may be referred to as “LED light”.
In the present specification, “(meth)acrylic polymer” is a concept that includes both an acrylic polymer and methacrylic polymer, and “(meth)acrylic acid” is a concept that includes both acrylic acid and methacrylic acid. , "(Meth)acrylate" is a concept including both acrylate and methacrylate, and "(meth)acryloyl group" is a concept including both acryloyl group and methacryloyl group.
In this specification, a polyoxyalkylene group, an amide group, a urea group, and a urethane group mean a polyoxyalkylene bond, an amide bond, a urea bond, and a urethane bond, respectively.

[Ink composition]
The ink composition of the present disclosure (hereinafter, also simply referred to as “ink”) is water, a urethane polymer, a urea polymer, or a (meth)acrylic polymer, and a reaction between a gelling agent having an active hydrogen group and an isocyanate group. Particles containing a polymer having a gelling group (hereinafter, also referred to as “specific particles”).

As described above, generally, an ink film formed by using an ink containing water as a liquid component is compared with an ink film formed by using an ink containing a polymerizable monomer and/or an organic solvent as a liquid component. Therefore, it tends to be difficult to remove the liquid component from the ink film. Therefore, an image formed using an ink containing water as a liquid component may have poor scratch resistance.

With respect to the above points, the ink of the present disclosure can form an image having excellent scratch resistance.
The reason why such an effect is exhibited is speculated as follows, but the ink of the present disclosure is not limited by the following reasons.

When the ink of the present disclosure is applied onto a substrate to form an ink film, the formed ink film contains specific particles that are a component of the ink. The specific particles include a polymer having a gelling group which is a reaction product of a gelling agent having an active hydrogen group and an isocyanate group.
It is considered that by heating the ink film, the gelling function of the gelling group is exerted and the ink film thickens (that is, gels).
Therefore, when the ink of the present disclosure is formed on a substrate to form an ink film and the ink film is heated (including the case of applying the ink of the present disclosure to a heated substrate to form the ink film) The same applies to the following.) It is considered that the strength of the ink film is effectively increased by the above-mentioned increase in viscosity of the ink film. As a result, it is considered that the scratch resistance of the ink film (that is, the image) is improved.

In addition, in general, in an image formed using an ink containing water as a liquid component, as compared with an image formed using an ink containing a polymerizable monomer and/or an organic solvent as a liquid component, The definition tends to be inferior. The reason for this is that ink droplets formed by using an ink containing water as a liquid component are difficult to remove the liquid component from the ink droplets, and thus unintended coalescence of ink droplets may occur on the substrate. It is thought to be because there is.
In this regard, the ink of the present disclosure can form an image with excellent fineness.
It is considered that the reason why such an effect is exhibited is that the unintended coalescence of ink droplets on the substrate is suppressed by the above-described thickening of the ink film (here, thickening of ink droplets).
The ink droplets mentioned here are one mode of the ink film.

In the present specification, the active hydrogen group means a hydroxy group, a primary amino group, a secondary amino group, or a thiol group.

It is considered that the above-described mechanism of thickening the ink film differs depending on the type of gelling agent having an active hydrogen group (hereinafter, also referred to as “specific gelling agent”) for forming a gelling group.
Specific gelling agents (that is, gelling agents having active hydrogen groups) include, for example, hydrogelating agents having active hydrogen groups and amphiphilic gelling agents having active hydrogen groups.

In the present specification, the hydrogelating agent means a compound having a function of forming a hydrogel by heating.
In the present specification, the hydrogelator having an active hydrogen group means a hydrogelator which is a compound having an active hydrogen group.
The hydrogelating agent has two or more kinds of sites having different degrees of hydrophilicity in the compound in order to exert the function of forming a hydrogel.
Therefore, the degree of hydrophilicity in the compound is almost uniform, polyethylene glycol (ie, ethylene glycol homopolymer), polypropylene glycol (ie, propylene glycol homopolymer), polyethylene glycol monomethyl ether (PEGME; Comparative examples 1) and the like do not correspond to hydrogelating agents. These are merely hydrophilic polymers and do not have the function of forming hydrogels.
On the other hand, a polyoxyalkylene compound represented by Formula (1) or Formula (1A) described later (for example, an ethylene glycol-propylene glycol copolymer) having two or more types of moieties having different degrees of hydrophilicity is It corresponds to a hydrogelating agent and also corresponds to a hydrogelating agent having an active hydrogen group.
As the hydrogelating agent having an active hydrogen group, in addition to the polyoxyalkylene compound represented by the formula (1) or the formula (1A) described below, a polysaccharide, a protein, an acrylic resin having an active hydrogen group, an active hydrogen group And a vinyl resin having

In the present specification, the amphipathic gelling agent having an active hydrogen group means a compound having an active hydrogen group and a hydrophobic group.
In the present specification, the hydrophobic group means a group that can aggregate to form a hydrophobic segment. This hydrophobic segment becomes a gel.
As the hydrophobic group in the present specification,
As the monovalent hydrophobic group, an alkyl group having 4 or more carbon atoms, an alkenyl group having 4 or more carbon atoms, an aryl group having 6 or more carbon atoms, an alkoxyalkyleneoxy group containing an alkylene group having 3 or more carbon atoms in the structure, a structure An alkoxypolyalkyleneoxy group containing an alkylene group having 3 or more carbon atoms, a hydroxyalkyleneoxy group containing an alkylene group having 3 or more carbon atoms in the structure, a hydroxypolyalkyleneoxy group containing an alkylene group having 3 or more carbon atoms in the structure Groups and the like,
Examples of the divalent hydrophobic group include an alkylene group having 4 or more carbon atoms, an alkenylene group having 4 or more carbon atoms, an arylene group having 6 or more carbon atoms, and a polyalkyleneoxy group containing an alkylene group having 3 or more carbon atoms in the structure. Can be mentioned.

When the gelling agent having an active hydrogen group is a hydrogelating agent having an active hydrogen group, by heating the ink film, a gel incorporating water (that is, a hydrogel) is formed in the ink film. The ink film is effectively thickened.
When the gelling agent having an active hydrogen group is an amphipathic gelling agent having an active hydrogen group, the ink film is heated to evaporate at least a part of water from the ink film. , The hydrophobic groups of a plurality of amphipathic gelling agents approach each other and aggregate. This allows hydrophobic segments (ie gels) to be formed, effectively thickening the ink film.
As described above, by heating the ink film, the gelling agent having an active hydrogen group is either a hydrogelating agent having an active hydrogen group or an amphiphilic gelling agent having an active hydrogen group. The ink film can be effectively thickened.
Therefore, when the gelling agent having an active hydrogen group is a hydrogelating agent having an active hydrogen group and/or an amphipathic gelling agent having an active hydrogen group, the effect of the ink of the present disclosure (scratching of an image) Durability and image fineness) are more effectively exhibited.

Hereinafter, each component that can be included in the ink of the present disclosure will be described.

<Specific particles>
The specific particles are a urethane polymer, a urea polymer, or a (meth)acrylic polymer, and a polymer having a gelling group which is a reaction product of a gelling agent having an active hydrogen group and an isocyanate group (hereinafter, also referred to as “specific polymer”). At least one).

(Specific polymer)
The specific polymer is a urethane polymer, a urea polymer, or a (meth)acrylic polymer. All of these polymers have a strong structure. These strong structures also contribute to the effects of improving scratch resistance of images and improving fineness of images.

In the present specification, the urethane polymer means a polymer containing a urethane group (excluding a polymer corresponding to the (meth)acrylic polymer described later).
In the present specification, the urea polymer means a polymer containing a urea group (excluding the above-mentioned urethane polymer or the polymer corresponding to the (meth)acrylic polymer described below).
In the present specification, the (meth)acrylic polymer is a homopolymer of one kind of (meth)acrylate, a copolymer of two or more kinds of (meth)acrylate, or one or more kinds of (meth)acrylate and one. It means a copolymer with one or more other monomers.
The concept of the urethane polymer also includes a polymer containing both a urethane group and a urea group (so-called urethane urea polymer).
The concept of a (meth)acrylic polymer also includes a (meth)acrylic polymer containing at least one of a urethane group and a urea group.

The specific polymer is preferably a urethane polymer or a urea polymer from the viewpoint of more effectively exerting the effects (the scratch resistance of the image and the fineness of the image) of the ink of the present disclosure.
When the specific polymer is a urethane polymer or a urea polymer, a pseudo-crosslinked structure due to hydrogen bond is easily formed between the urethane group or the urea group in the specific polymer and the gelling group. By forming this pseudo-crosslinked structure, the viscosity of the ink film can be more effectively increased, and as a result, the scratch resistance of the image and the fineness of the image can be further improved.

-Gelling group-
The specific polymer has at least one gelling group which is a reaction product of a specific gelling agent (that is, a gelling agent having an active hydrogen group) and an isocyanate group.

As the active hydrogen group in the specific gelling agent (that is, the gelling agent having an active hydrogen group), a hydroxy group, a primary amino group, or a secondary amino group is preferable from the viewpoint of reactivity with an isocyanate group, and a hydroxy group is preferable. A group or a primary amino group is more preferable, and a primary amino group is particularly preferable.

The valence of the gelling group (that is, the number of bonding positions in the gelling group) is not particularly limited.
That is, the gelling group may be a monovalent group or a divalent or higher valent group.
From the viewpoint of easy formation of the gelling group, a monovalent group or a divalent group is preferable.

Further, from the viewpoint of further improving the scratch resistance of the image and the fineness of the image, the gelling group is more preferably a monovalent group.
The reason for this is considered as follows.
When the gelling group is a monovalent group, the gelling group is a site of high thermal reactivity and high mobility of a specific polymer (for example, a specific chain polymer described below or a specific crosslinked polymer described below). It is likely to be located at the terminal portion of the specific polymer, not in the skeleton. Therefore, when the gelling group is a monovalent group, it is considered that the ink film can be more effectively thickened, and as a result, the scratch resistance of the image and the fineness of the image are further improved.

From the viewpoint of further improving the scratch resistance of images and the fineness of images, a more preferable embodiment of the specific polymer is that the gelling group is a monovalent group, and the specific polymer is a specific chain polymer described later. In this mode, the gelling group, which is a valent group, is arranged at the end of the main chain of the specific chain polymer.
The reason for this is considered to be that the end of the main chain of the specific chain polymer is a site having higher thermal reactivity and higher mobility than the end of the specific crosslinked polymer described later.

When the gelling group is a divalent group and the specific polymer is a specific chain polymer described later, the gelling group is arranged in the main chain of the specific chain polymer.

The gelling group is preferably a group represented by the following formula (G).
The group represented by the formula (G) is a specific gelling agent (that is, a gelling agent having an active hydrogen group), a hydrogelating agent having an active hydrogen group or an amphipathic gelling agent having an active hydrogen group. And an isocyanate group.

In the formula (G), n ^G represents 1 or 2, R ^U represents a urethane group, a urea group, a thiourethane group, or a thiourea group, and L ^G represents a single bond or a divalent linking group. , * Represents the bonding position.
In formula (G), R ^G is a polysaccharide, protein, acrylic resin, vinyl resin, or hydrogelating agent which is a polyoxyalkylene compound represented by formula (1) when n ^G is 1. It represents a residue obtained by removing one hydrogen atom, or represents a monovalent hydrophobic group.
In the formula (G), R ^G , when n ^G is 2, represents a residue obtained by removing two hydrogen atoms from the above hydrogelating agent, or represents a divalent hydrophobic group.
In formula (1), n and m each independently represent an integer of 2 or more, p represents an integer of 0 or more, L represents an alkylene group having 3 or more carbon atoms, and R represents a hydrogen atom. Represents an alkyl group or an aryl group.

In formula (G), n ^G represents 1 or 2.
From the viewpoint of further improving the scratch resistance of the image and the fineness of the image, n ^G is particularly preferably 1.
The fact that n ^G is 1 means that the group represented by formula (G) is a monovalent group. Therefore, when n ^G in the formula (G) is 1, the scratch resistance of the image and the fineness of the image are further improved due to the above-mentioned estimation reason.

In formula (G), R ^U represents a urethane group, a urea group, a thiourethane group, or a thiourea group. This R ^U is formed by a reaction between an active hydrogen group in a hydrogelling agent having an active hydrogen group or an active hydrogen group in an amphiphilic gelling agent having an active hydrogen group and an isocyanate group.

From the viewpoint of further improving the scratch resistance of images and the fineness of images, R ^U is preferably a urethane group or a urea group, and more preferably a urea group.
The reason for this is considered as follows.
As described above, the active hydrogen group is more preferably a hydroxy group or a primary amino group, and particularly preferably a primary amino group, from the viewpoint of reactivity with an isocyanate group.
The urethane group is a group formed by a reaction between a hydroxy group and an isocyanate group, and the urea group is a group formed by a reaction between a hydroxy group and a primary amino group.
Therefore, when R ^U is a urethane group or a urea group (particularly preferably a urea group), the stability of the group represented by the formula (G) is increased, so that the effect of the group represented by the formula (G) ( That is, the scratch resistance of the image and the improvement of the fineness of the image are more effectively achieved.

Wherein (G), ^{L G} represents a single bond or a divalent linking group.
As the divalent linking group, an alkylene group having 1 to 10 carbon atoms, a carbonyliminoalkylene group having 2 to 10 carbon atoms, an iminocarbonylalkylene group having 2 to 10 carbon atoms, and a number average molecular weight of 1,000 or less (preferably 500 or less). And a divalent residue obtained by removing a hydroxy group from both ends of the polyalkylene glycol.
Here, the carbonyliminoalkylene group means a divalent group in which a carbonyl group, an imino group and an alkylene group are linked in this order, and an iminocarbonylalkylene group means an imino group, a carbonyl group and an alkylene group. It means a divalent group linked in this order.

In formula (G), R ^G is a polysaccharide, protein, acrylic resin, vinyl resin, or hydrogelating agent which is a polyoxyalkylene compound represented by formula (1) when n ^G is 1. It represents a residue obtained by removing one hydrogen atom, or represents a monovalent hydrophobic group.
In the formula (G), R ^G , when n ^G is 2, represents a residue obtained by removing two hydrogen atoms from the above hydrogelating agent, or represents a divalent hydrophobic group.
Here, the residue obtained by removing one hydrogen atom from the hydrogelator and the residue obtained by removing two hydrogen atoms from the hydrogelator are both partial structures in the hydrogelator having an active hydrogen group.
Both the monovalent hydrophobic group and the divalent hydrophobic group are partial structures in an amphiphilic gelling agent having an active hydrogen group (that is, a compound having an active hydrogen group and a hydrophobic group). Is.

Examples of the polysaccharide as the hydrogelating agent for forming R ^G (that is, the polysaccharide before the hydrogen atom is removed to form a residue) include agarose, agaropectin, amylose, amylopectin, gum arabic, sodium alginate, and alginic acid. Propylene glycol ester, methyl cellulose, ethyl cellulose, ethyl hydroxyethyl cellulose, curdlan, carrageenan, carboxymethyl cellulose, carboxymethyl starch, agar, xanthan gum, guar gum, quince seed, glucomannan, keratan sulfate, hydroxyethyl cellulose, hydroxypropyl cellulose, pectin, methyl starch , Locust bean gum, dextrin, cyclodextrin and the like.
On the other hand, from the viewpoint of ease of forming the group represented by the formula (G), the polysaccharide as the hydrogelating agent is preferably a disaccharide to a decasaccharide, more preferably a trisaccharide to a hexasaccharide, and a trisaccharide to a hexasaccharide. Particularly preferred are sugars to pentasaccharides.

There is no particular limitation on the weight average molecular weight (Mw) of the polysaccharide.
The weight average molecular weight (Mw) of the polysaccharide is, for example, 300 to 1,000,000, preferably 400 to 100,000, more preferably 400 to 10,000, and particularly preferably 400 to 2000.

In the present specification, the weight average molecular weight (Mw) and the number average molecular weight (Mn) both mean the values measured by gel permeation chromatography (GPC). However, for a compound whose accurate Mw cannot be measured by GPC due to its small molecular weight, the molecular weight obtained from the chemical structure of the compound is adopted as the Mw of the compound. The same applies to Mn.
In the present specification, the measurement by gel permeation chromatography (GPC) uses HLC (registered trademark)-8020GPC (Tosoh Corporation) as a measuring device, and TSKgel (registered trademark) Super Multipore HZ-H as a column. (4.6 mm ID×15 cm, Tosoh Corporation) can be used, and THF (tetrahydrofuran) can be used as an eluent. The measurement conditions are as follows: a sample concentration of 0.45% by mass, a flow rate of 0.35 ml/min, a sample injection amount of 10 μl, a measurement temperature of 40° C., and a differential refractive index (RI) detector. ..
The calibration curve is “standard sample TSK standard, polystyrene” of Tosoh Corporation: “F-40”, “F-20”, “F-4”, “F-1”, “A-5000”, “A”. -2500", "A-1000", and "n-propylbenzene".

When ^RG is a residue obtained by removing one or two hydrogen atoms from a polysaccharide as a hydrogelator, the group represented by the formula (G) is preferably a polysaccharide having a primary amino group. Formed by.
As the polysaccharide having a primary amino group, a polysaccharide which is an aminoethyl glycoside (for example, G0402, N0949 and S0946 in the examples described later) or a polysaccharide which is an aminopropyl glycoside is preferable.
As an example of the group represented by the formula (G) formed using a polysaccharide that is an aminoethyl glycoside (for example, G0402, N0949 and S0946 in the examples described below), n ^G in the formula (G) is is 1, ^{R U} is a urea group formed by reaction of an amino group and an isocyanate group, ^{L G} is an ethylene group - a _(-CH 2 CH ₂ group), ^{R G} is hydrogen polysaccharide An example is a residue obtained by removing one atom.
As an example of the group represented by the formula (G) formed by using a polysaccharide which is an aminopropyl glycoside, in the formula (G), n ^G is 1 and R ^U is an amino group and an isocyanate group. Is a urea group formed by the reaction of, L ^G is a propylene group (—CH ₂ CH ₂ CH ₂ — group), and R ^G is a residue obtained by removing one hydrogen atom from a polysaccharide. Can be mentioned.
The preferred range of Mw of the polysaccharide having a primary amino group for forming the group represented by the formula (G) is that of Mw of the above-mentioned polysaccharide (that is, the polysaccharide for forming R ^G ). It is similar to the preferred range.

There is no particular limitation on the protein as the hydrogelating agent for forming R ^G (that is, the protein before the hydrogen atom is removed to form a residue).
Examples of proteins include gelatin.
The weight average molecular weight (Mw) of the protein is, for example, 1,000 to 100,000,000, preferably 5,000 to 10,000,000, and more preferably 10,000 to 100,000.

There is no particular limitation on the acrylic resin as the hydrogelating agent for forming R ^G (that is, the acrylic resin before the hydrogen atom is removed to form a residue).
Examples of the acrylic resin include poly(N-isopropylacrylamide).
The weight average molecular weight (Mw) of the acrylic resin is, for example, 1,000 to 500,000, preferably 5,000 to 100,000, and more preferably 10,000 to 50,000.

There is no particular limitation on the vinyl resin as the hydrogelating agent for forming R ^G (that is, the vinyl resin before the hydrogen atom is removed to form a residue).
Examples of the vinyl resin include polyvinyl alcohol.
The weight average molecular weight (Mw) of the vinyl resin is, for example, 1,000 to 500,000, preferably 5,000 to 100,000, and more preferably 10,000 to 50,000.

A polyoxyalkylene compound represented by formula (1) as a hydrogelating agent for forming R ^G (that is, a polyoxyalkylene compound represented by formula (1) before a hydrogen atom is removed to form a residue) ) Is as follows.

In formula (1), n and m each independently represent an integer of 2 or more, p represents an integer of 0 or more, L represents an alkylene group having 3 or more carbon atoms, and R represents a hydrogen atom. Represents an alkyl group or an aryl group.

In formula (1), the alkylene group represented by L may be a linear alkylene group or a branched alkylene group.
The alkylene group represented by L has 3 or more carbon atoms, preferably 3 to 6, more preferably 3 to 4, and particularly preferably 3.

In the formula (1), the alkyl group represented by R may be a linear alkyl group or a branched alkyl group.
1-24 are preferable, as for carbon number of the alkyl group represented by R, 1-12 are more preferable, and 1-3 are especially preferable.

6-18 are preferable and, as for carbon number of the aryl group represented by R in Formula (1), 6-12 are more preferable.

In the formula (1), the alkyl group represented by R and the aryl group represented by R may each be substituted with a substituent.
Examples of the substituent include a halogen atom, an alkoxy group, a carboxy group and the like.

As the polyoxyalkylene compound represented by the formula (1), specifically,
Polyethylene glycol-polypropylene glycol block copolymer polyethylene glycol-polypropylene glycol-polyethylene glycol triblock copolymer,
Polypropylene glycol-polyethylene glycol-polypropylene glycol triblock copolymer,
Etc.

The number average molecular weight (Mn) of the polyoxyalkylene compound represented by the formula (1) is, for example, 500 to 500,000, preferably 1,000 to 100,000, more preferably 2,000 to 30,000. Yes, and more preferably 2,000 to 20,000.

When R ^G is a residue obtained by removing one hydrogen atom from the polyoxyalkylene compound represented by formula (1) as a hydrogelator, the group represented by formula (G) is preferably the following: It is formed by a polyoxyalkylene compound represented by the formula (1A).

In formula (1A), n, m, p, L, and R have the same meanings as n, m, p, L, and R in formula (1), respectively, and the preferred embodiments are also the same.
The polyoxyalkylene compound represented by the formula (1A) is a compound having one more oxyethylene unit than the polyoxyalkylene compound represented by the formula (1) (see “n+1” in the formula (1A)). ).

When the group represented by the formula (G) is formed by the polyoxyalkylene compound represented by the formula (1A), for example, a hydroxy group in the hydroxyethyl group at the terminal portion in the formula (1A) and an isocyanate group R ^U (urethane group) in the formula (G) is formed by the reaction of and, and the ethyl group part in the hydroxyethyl group becomes ^LG (ethylene group) in the formula (G), and the formula (1A) From which the hydroxyethyl group is removed becomes R ^G in the formula (G). This R ^G corresponds to a residue obtained by removing one hydrogen atom from the polyoxyalkylene compound represented by the formula (1). In the case of this example, n ^G in the formula (G) is 1.

A preferable range of Mn of the polyoxyalkylene compound represented by the formula (1A) for forming the group represented by the formula (G) is represented by the formula (1) for forming R ^G described above. It is the same as the preferable range of Mn of the polyoxyalkylene compound.

A commercially available product may be used as the polyoxyalkylene compound represented by the formula (1A).
Examples of commercially available products include Pluronic (registered trademark) F108 (Mn14600, melting point 62° C.), P85 (Mn4600, melting point 40° C.) and F87 (Mn7700, melting point 49° C.) manufactured by BASF.

The hydrogelating agent for forming R ^G in the formula (G) is a polysaccharide or a polyoxyalkylene compound represented by the formula (1) from the viewpoint of further improving the scratch resistance of the image and the fineness of the image. Preferably, it is a polysaccharide, and more preferably a polysaccharide.

In the formula (G), each of the monovalent hydrophobic group and the divalent hydrophobic group represented by R ^G is an amphiphilic gelling agent having an active hydrogen group (that is, an active hydrogen group and a hydrophobic group). A compound having a functional group).

As described above, the monovalent hydrophobic group represented by R ^G includes an alkyl group having 4 or more carbon atoms, an alkenyl group having 4 or more carbon atoms, an aryl group having 6 or more carbon atoms, and 3 or more carbon atoms in the structure. , An alkoxyalkyleneoxy group containing an alkylene group, an alkoxypolyalkyleneoxy group containing an alkylene group having 3 or more carbon atoms in the structure, a hydroxyalkyleneoxy group containing an alkylene group having 3 or more carbon atoms in the structure, a carbon number in the structure Examples thereof include a hydroxypolyalkyleneoxy group containing 3 or more alkylene groups.
The divalent hydrophobic group represented by R ^G includes, as described above, an alkylene group having 4 or more carbon atoms, an alkenylene group having 4 or more carbon atoms, an arylene group having 6 or more carbon atoms, and 3 or more carbon atoms in the structure. And a polyalkyleneoxy group containing the alkylene group.

The monovalent hydrophobic group represented by R ^G is preferably a linear alkyl group having 4 or more carbon atoms.
The carbon number of the straight-chain alkyl group having 4 or more carbon atoms is preferably 7 or more, more preferably 10 or more, and 16 or more from the viewpoint of further improving the scratch resistance of the image and the fineness of the image. It is particularly preferable that
The upper limit of the carbon number of the linear alkyl group having 4 or more carbon atoms is not particularly limited, but the upper limit is, for example, 30 and preferably 25.

The divalent hydrophobic group represented by R ^G is preferably a linear alkylene group having 4 or more carbon atoms.
The carbon number of the linear alkylene group having 4 or more carbon atoms is preferably 7 or more, more preferably 10 or more, and 16 or more from the viewpoint of further improving the scratch resistance of the image and the fineness of the image. It is particularly preferable that
The upper limit of the carbon number of the linear alkylene group having 4 or more carbon atoms is not particularly limited, but the upper limit is, for example, 30 and preferably 25.

The group represented by formula (G) in the embodiment in which R ^G is a monovalent hydrophobic group or a divalent hydrophobic group is a reaction of an amphiphilic gelling agent having an active hydrogen group with an isocyanate group. Formed by.

The amphipathic gelling agent having an active hydrogen group is preferably solid at room temperature (25° C.) from the viewpoint of more effectively exhibiting the gelling function in the ink film.
From this viewpoint, the melting point of the amphiphilic gelling agent having an active hydrogen group is preferably 40°C or higher, more preferably 60°C or higher, even more preferably 80°C or higher, and particularly preferably 100°C. That is all.
In addition, the upper limit of the melting point of the amphiphilic gelling agent having an active hydrogen group is preferably 200° C. or lower from the viewpoint of the suitability for producing the amphiphilic gelling agent.

The molecular weight of the amphipathic gelling agent having an active hydrogen group is not particularly limited.
The amphiphilic gelling agent having an active hydrogen group has a molecular weight of preferably 2000 or less, more preferably 1500 or less, and particularly preferably 1100 or less.
The molecular weight of the amphipathic gelling agent is preferably 300 or more, more preferably 400 or more, and particularly preferably 500 or more.

As the amphiphilic gelling agent having an active hydrogen group, preferably,
A linear alkylamine having 10 to 30 carbon atoms (more preferably 12 to 30 carbon atoms, further preferably 15 to 30 carbon atoms, and particularly preferably 15 to 15 carbon atoms),
A linear alkylenediamine having 10 to 30 carbon atoms (more preferably 12 to 30 carbon atoms, further preferably 15 to 30 carbon atoms, and particularly preferably 15 to 15 carbon atoms),
A monoalkyl polyethylene glycol having a linear alkyl group having 10 to 30 carbon atoms (more preferably 12 to 30 carbon atoms, further preferably 15 to 30 carbon atoms, particularly preferably 15 to 15 carbon atoms), or
It has 10 to 30 carbon atoms (more preferably 12 to 30 carbon atoms, further preferably 15 to 30 carbon atoms, and particularly preferably 15 to 15 carbon atoms), and a hydroxyalkyl group, an amide group, an alkylene group, an amide group, and a hydroxy group. Alkyl group is a compound bonded in this order,
Particularly preferably, it is a linear alkylamine having 10 to 30 carbon atoms (more preferably 12 to 30 carbon atoms, further preferably 15 to 30 carbon atoms, and particularly preferably 15 to 15 carbon atoms).

Specific examples of the amphiphilic gelling agent having an active hydrogen group include eicosylamine (C ₂₀ H ₄₁ NH ₂ ), octadecylamine (C ₁₈ H ₃₇ NH ₂ ), hexadecylamine (in the examples described later). C ₁₆ H ₃₃ NH _2), octylamine _{(C 8 H 17 NH 2)} , 1,12- dodecyl diamine _{(H 2 N (CH 2)} 12 NH 2), gel-01~gel-06, monoalkyl glycol , And the like.

As the amphiphilic gelling agent having an active hydrogen group, a compound having an active hydrogen group and a hydrophobic group may be selected and used from the gelling agents described in JP2013-7039A. ..

The molecular weight of the gelling group described above (for example, the group represented by the formula (G)) is preferably 2000 or less, more preferably 1500 or less, and particularly preferably 1100 or less.
The molecular weight of the gelling group is preferably 300 or more, more preferably 400 or more, and particularly preferably 500 or more.

-Preferred embodiment of specific polymer-
A preferred embodiment of the specific polymer is an embodiment (hereinafter, also referred to as “embodiment A”) which is a reaction product of a gelling agent having an active hydrogen group and a compound having an isocyanate group.
In Aspect A, the compound having an isocyanate group may be a raw material monomer for forming a polymer, or may be a polymer having an isocyanate group.
That is, in the embodiment A, the gelling agent may be incorporated into the structure of the specific polymer in the process of forming the specific polymer, or the gelling agent may be added to the polymer by a macromolecular addition reaction so that It may be incorporated in the structure.

Examples of the compound having an isocyanate group in the embodiment A include a bifunctional or higher functional isocyanate compound as a raw material monomer having an isocyanate group, and a (meth)acrylate having at least one isocyanate group.
As the compound having an isocyanate group in the embodiment A, as a polymer having an isocyanate group, a urethane polymer having at least one isocyanate group, a urea polymer having at least one isocyanate group, a (meth)acrylic polymer having at least one isocyanate group , And the like.

The specific polymer may be a chain polymer having no crosslinked structure (hereinafter, also referred to as “specific chain polymer”), or a polymer having a crosslinked structure (for example, a three-dimensional crosslinked structure) (hereinafter, “specific polymer”). Also referred to as a "crosslinked polymer").
The specific chain polymer may include a cyclic structure such as an aliphatic ring, an aromatic ring, or a heterocycle in the main chain.
Regarding the three-dimensional crosslinked structure that the specific crosslinked polymer may have, the three-dimensional crosslinked structure described in WO2016/052053 may be referred to.

-Specific chain polymer-
The specific chain polymer is
Reaction product A1 of at least one member selected from the group consisting of bifunctional isocyanate compounds and at least one member selected from the group consisting of compounds having two active hydrogen groups and water, and gel containing active hydrogen groups A reaction product A2 with an agent, or
Reaction product B1 of at least one selected from the group consisting of bifunctional isocyanate compounds, at least one selected from the group consisting of a compound having two active hydrogen groups and water, and another compound, and active hydrogen The reaction product B2 of the gelling agent having a group is preferable.

Examples of the compound having two active hydrogen groups include a diol compound, a diamine compound, and a dithiol compound.
For example, a urethane group is formed by the reaction of a bifunctional isocyanate compound and a diol compound.
Further, a urea group is formed by the reaction of the bifunctional isocyanate compound and the diamine compound.
Further, a urea group is formed by the reaction between the bifunctional isocyanate compound and water.

In addition, as the above-mentioned other compounds,
Of the compounds for introducing a polymerizable group described below, a compound containing only one active hydrogen group,
Of the isocyanate compounds introduced with a polymerizable group described below, a compound containing only one isocyanate group,
Of the compounds for introducing a hydrophilic group described below, a compound containing only one active hydrogen group,
Of the isocyanate compounds introduced with a hydrophilic group described below, a compound containing only one isocyanate group,
Etc.

Examples of the bifunctional isocyanate compound for forming the specific chain polymer include the following compounds (1-1) to (1-20).

Examples of the compound having two active hydrogen groups for forming the specific chain polymer include the following compounds (2-1) to (2-24).

Further, as the compound having two active hydrogen groups for forming the specific chain polymer, among the compounds for introducing a polymerizable group described below, a compound containing two active hydrogen groups, and a compound for introducing a hydrophilic group described below. Among the compounds, compounds containing two active hydrogen groups and the like are also included.

-Specific cross-linked polymer-
The specific crosslinked polymer is
Reaction product C1 of at least one selected from the group consisting of trifunctional or higher functional isocyanate compounds and at least one selected from the group consisting of compounds having two or more active hydrogen groups and water, and active hydrogen groups A reaction product C2 of a gelling agent having
A reaction product D1 of at least one selected from the group consisting of trifunctional or higher functional isocyanate compounds, at least one selected from the group consisting of compounds having two or more active hydrogen groups, and water, and other compounds. The reaction product D2 of the gelling agent having an active hydrogen group is preferable.

As the above-mentioned other compounds,
Of the compounds for introducing a polymerizable group described below, a compound containing only one active hydrogen group,
Of the isocyanate compounds introduced with a polymerizable group described below, a compound containing only one isocyanate group,
Of the compounds for introducing a hydrophilic group described below, a compound containing only one active hydrogen group,
Of the isocyanate compounds introduced with a hydrophilic group described below, a compound containing only one isocyanate group,
Etc.

When the specific particles include the specific crosslinked polymer, the specific particles preferably include microcapsules (hereinafter, “MC”) including a shell made of the specific crosslinked polymer and a core.

Examples of the compound having two or more active hydrogen groups for forming the specific crosslinked polymer include a diol compound and a diamine, similar to the compounds having two active hydrogen groups for forming the specific chain polymer described above. Compounds, and dithiol compounds.
Examples of the compound having two or more active hydrogen groups for forming the specific crosslinked polymer also include a trifunctional or higher functional polyol compound, a trifunctional or higher functional polyamine compound, and a trifunctional or higher functional polythiol compound.

The trifunctional or higher functional isocyanate compound for forming the specific crosslinked polymer is at least one compound selected from the group consisting of bifunctional isocyanate compounds and a compound having three or more active hydrogen groups (for example, a trifunctional or higher functional compound). It is preferably a reaction product of at least one selected from the group consisting of a polyol compound, a trifunctional or higher functional polyamine compound, and a trifunctional or higher functional polythiol compound.
The number of moles (number of molecules) of the bifunctional isocyanate compound to be reacted with the compound having three or more active hydrogen groups is the number of moles of active hydrogen groups in the compound having three or more active hydrogen groups (equivalent of active hydrogen group). 0.6 times or more, more preferably 0.6 times to 5 times, even more preferably 0.6 times to 3 times, still more preferably 0.8 times to 2 times the number.

Examples of the bifunctional isocyanate compound for forming the trifunctional or higher functional isocyanate compound include the same as the above-mentioned bifunctional isocyanate compound for forming the specific chain polymer.

Examples of the compound having three or more active hydrogen groups for forming a trifunctional or higher functional isocyanate compound include compounds having a structure represented by the following (H-1) to (H-13). In the structure below, n represents an integer selected from 1 to 100.

Examples of the trifunctional or higher functional isocyanate compound used for forming the specific crosslinked polymer include adduct type trifunctional or higher functional isocyanate compounds, isocyanurate type trifunctional or higher functional isocyanate compounds, biuret type trifunctional or higher functional isocyanate compounds, and the like. Can be mentioned.
Commercially available adduct-type trifunctional or higher functional isocyanate compounds include Takenate (registered trademark) D-102, D-103, D-103H, D-103M2, P49-75S, D-110N, D-120N and D-. 140N, D-160N (above, Mitsui Chemicals, Inc.), Desmodur (registered trademark) L75, UL57SP (Sumitomo Bayer Urethane Co., Ltd.), Coronate (registered trademark) HL, HX, L (Nippon Urethane Polymer Co., Ltd.) )), P301-75E (Asahi Kasei Co., Ltd.) and the like.
Commercially available isocyanurate-type trifunctional or higher isocyanate compounds include Takenate (registered trademark) D-127N, D-170N, D-170HN, D-172N, D-177N (above, Mitsui Chemicals, Inc.), Sumidur N3300, Desmodur (registered trademark) N3600, N3900, Z4470BA (above, Sumika Bayer Urethane Co., Ltd.), Coronate (registered trademark) HX, HK (above, Nippon Urethane Polymer Co., Ltd.), Duranate (registered trademark) ) TPA-100, TKA-100, TSA-100, TSS-100, TLA-100, TSE-100 (above Asahi Kasei Co., Ltd.), etc. are mentioned.
Commercially available biuret-type trifunctional or higher functional isocyanate compounds include Takenate (registered trademark) D-165N, NP1100 (above, Mitsui Chemicals, Inc.), Desmodur (registered trademark) N3200 (Sumitomo Bayer Urethane Co., Ltd.). ), Duranate (registered trademark) 24A-100 (Asahi Kasei Co., Ltd.) and the like.

When the specific particles include MC (that is, microcapsules) including a shell made of a specific crosslinked polymer and a core, the specific particles are hydrophilic as a dispersant for MC among the specific chain polymers described above. You may contain the specific chain polymer of the aspect which has a group. In the ink according to this aspect, at least a part of the periphery of the MC shell may be covered with the specific chain polymer as the dispersant. In this aspect, the interaction between the urethane group and/or urea group of the MC shell and the urethane group and/or urea group of the dispersant (specific chain polymer), and the hydrophilic group of the dispersant Combined with the dispersing action, the dispersion stability of the specific particles is further improved.
In this embodiment, the ratio of the amount of the dispersant to the total solid content of MC (hereinafter, also referred to as mass ratio [dispersant/MC solid content]) is preferably 0.005 to 1.000, and is preferably 0.005 to 1.000. More preferably, it is 05 to 0.7.
When the mass ratio [dispersant/MC solid content] is 0.005 or more, the dispersion stability of the specific particles is further improved.
When the mass ratio [dispersant/MC solid content] is 1.000 or less, the hardness of the image is further improved.

-Preferable weight average molecular weight (Mw) of specific polymer-
The weight average molecular weight (Mw) of the specific polymer is preferably 5,000 or more, more preferably 7,000 or more, and more preferably 8,000 or more from the viewpoint of the dispersion stability of the ink (that is, the dispersion stability of the specific particles). Is more preferable.
There is no particular upper limit to the Mw of the specific polymer. The upper limit of Mw of the specific polymer is, for example, 150,000, 100,000, 70,000 or 50,000.

The content of the specific polymer is preferably 10% by mass or more, and more preferably 20% by mass or more, based on the total solid content of the specific particles.
When the content of the specific polymer is 10% by mass or more based on the total solid content of the specific particles, the dispersion stability of the ink (that is, the dispersion stability of the specific particles) is further improved.
The content of the specific polymer may be 100% by mass with respect to the total solid content of the specific particles, but is preferably 80% by mass or less, more preferably 70% by mass or less, and 50% by mass or less. It is particularly preferable that

-Polymerizable group-
The specific polymer preferably has at least one polymerizable group.
When the specific polymer has a polymerizable group, the viscosity of the ink film can be increased by the action of the gelling group, and then the increased viscosity of the ink film can be cured by the action of the polymerizable group.
Thereby, the scratch resistance of the image is further improved.

As the polymerizable group, a photopolymerizable group or a thermopolymerizable group is preferable.
The photopolymerizable group is preferably a radical polymerizable group, more preferably a group containing an ethylenic double bond, and further preferably a (meth)acryloyl group, an allyl group, a styryl group, or a vinyl group. As the radically polymerizable group, a (meth)acryloyl group is particularly preferable from the viewpoint of radical polymerization reactivity and hardness of a film to be formed.
As the thermopolymerizable group, an epoxy group, an oxetanyl group, an aziridinyl group, an azetidinyl group, a ketone group, an aldehyde group, or a blocked isocyanate group is preferable.
The specific polymer may contain only one type of polymerizable group, or may contain two or more types thereof.
The fact that the specific polymer has a polymerizable group can be confirmed by, for example, Fourier transform infrared spectroscopy (FT-IR) analysis.

-Compound for introducing a polymerizable group-
When the specific polymer has a polymerizable group, the polymerizable group can be introduced into the specific polymer by using a compound for introducing a polymerizable group.
As the compound for introducing a polymerizable group, a compound having a polymerizable group and an active hydrogen group can be used.
As the compound for introducing a polymerizable group, it is preferable to use a compound having one or more polymerizable groups and two or more active hydrogen groups.

The method of introducing the polymerizable group into the specific polymer is not particularly limited, but at the time of synthesizing the specific polymer, at least one selected from the group consisting of bifunctional isocyanate compounds, water, a diol compound, and a diamine compound. And a method of reacting at least one selected from the group consisting of dithiol compounds, at least one compound for introducing a polymerizable group, and (at least one compound for introducing a hydrophilic group, if necessary) preferable.
The polymerizable group-introducing monomer may be used alone or in combination of two or more.

As the compound for introducing a polymerizable group, for example, the compounds described in paragraphs 0075 to 0089 of WO 2016/052053 can also be used.

As the compound for introducing a polymerizable group, a compound represented by the following formula (ma) is preferable.
L ¹ Lc _m Z _n (ma)

In formula (ma), L ¹ represents an m+n-valent linking group, m and n are each independently an integer selected from 1 to 100, and Lc represents a monovalent ethylenically unsaturated group, Z represents an active hydrogen group.
L ¹ is a divalent or higher valent aliphatic group, a divalent or higher valent aromatic group, a divalent or higher valent heterocyclic group, —O—, —S—, —NH—, —N<, —CO—, —SO. -, - SO ₂ - or preferably a combination thereof.
m and n are each independently preferably 1 to 50, more preferably 2 to 20, even more preferably 3 to 10, and particularly preferably 3 to 5.
Examples of the monovalent ethylenically unsaturated group represented by Lc include an allyl group, a vinyl group, an acryloyl group and a methacryloyl group.
The active hydrogen group represented by Z is more preferably a hydroxy group or a primary amino group, and further preferably a hydroxy group.

Hereinafter, examples of the compound for introducing a polymerizable group will be shown, but the compound for introducing a polymerizable group is not limited to the following examples. In addition, n in the compounds (a-3) and (a-14) represents, for example, an integer selected from 1 to 90.

-Isocyanate compound having a polymerizable group-
When the specific polymer has a polymerizable group, the introduction of the polymerizable group into the specific polymer can also be performed using an isocyanate compound having the polymerizable group introduced.
The isocyanate compound having a polymerizable group introduced,
A reaction product of at least one kind of the above-mentioned compound for introducing a polymerizable group and at least one kind of a bifunctional isocyanate compound;
A reaction product of at least one kind of the compound for introducing a polymerizable group described above and at least one kind of a trifunctional or higher functional isocyanate compound;
From the group consisting of at least one compound described above for introducing a polymerizable group, at least one difunctional isocyanate compound, a trifunctional or higher functional polyol compound, a trifunctional or higher functional polyamine compound, and a trifunctional or higher functional polythiol compound. A reaction product of at least one selected;
Etc.

-Hydrophilic group-
The specific polymer may have at least one hydrophilic group.
When the specific polymer has a hydrophilic group, the dispersion stability of the ink (for example, storage stability, ejection stability, etc.) is improved.
As the hydrophilic group, an anionic group or a nonionic group is preferable, and an anionic group is preferable from the viewpoint of excellent effect of improving dispersion stability.
For example, when comparing an anionic group and a nonionic group having the same molecular weight, the anionic group is more excellent in the effect of improving dispersion stability. That is, the anionic group (particularly preferably at least one selected from the group consisting of a carboxy group and a salt of a carboxy group) can sufficiently exert the effect of improving the dispersion stability even when the molecular weight thereof is small. ..

Examples of the nonionic group include groups having a polyether structure, and a monovalent group containing a polyalkyleneoxy group is preferable.

The anionic group may be a non-neutralized anionic group or a neutralized anionic group.
Examples of the non-neutralized anionic group include a carboxy group, a sulfo group, a sulfuric acid group, a phosphonic acid group, and a phosphoric acid group.
Examples of the neutralized anionic group include a carboxy group salt, a sulfo group salt, a sulfuric acid group salt, a phosphonic acid group salt, and a phosphoric acid group salt.

In the present specification, the phrase “carboxy group is neutralized” means that the carboxy group as an anionic group is in the form of “salt” (for example, “—COONa”). The same applies to the sulfo group, the sulfuric acid group, the phosphonic acid group, and the phosphoric acid group as the anionic group.
Neutralization can be performed using, for example, an alkali metal hydroxide (eg, sodium hydroxide, potassium hydroxide, etc.) and an organic amine (eg, triethylamine, etc.).

The anionic group that the specific polymer may have is, from the viewpoint of dispersion stability, a carboxy group, a salt of a carboxy group, a sulfo group, a salt of a sulfo group, a sulfuric acid group, a salt of a sulfuric acid group, a phosphonic acid group, a phosphonic acid group. At least one selected from the group consisting of salts, phosphoric acid groups, and salts of phosphoric acid groups, and more preferably at least one selected from the group consisting of carboxy groups and salts of carboxy groups.
As the “salt” in the above-mentioned salt of carboxy group, salt of sulfo group, salt of sulfuric acid group, salt of phosphonic acid group, and salt of phosphoric acid group, alkali metal salt or organic amine salt is preferable, and alkali metal salt is preferable. Is more preferable.
The alkali metal in the alkali metal salt is preferably K or Na.

When the specific polymer has a neutralized anionic group, the neutralization degree of the anionic group (eg, carboxy group) of the specific polymer is preferably 50% to 100%.
In the present specification, the “degree of neutralization of anionic groups” means the number of moles of neutralized anionic groups and the number of moles of non-neutralized anionic groups in the entire anionic groups of the specific polymer. The ratio of the number of moles of neutralized anionic groups to the total of [the number of moles of neutralized acid groups/(the number of moles of neutralized acid groups + the number of moles of non-neutralized acid groups)] means.
When the neutralization degree of the anionic group is 50% or more, the dispersion stability of the specific particles is further improved.
The degree of neutralization of the anionic group is preferably 50% to 95%, more preferably 80% to 95%, further preferably 90% to 95%.
The neutralized anionic group (that is, the anionic group in the form of a salt) exhibits basicity. When the degree of neutralization of the anionic group is 95% or less, hydrolysis of the urethane group and/or urea group that the specific polymer may have can be further suppressed.
The degree of neutralization can be determined by neutralization titration.

When the specific polymer contains an anionic group (for example, at least one selected from the group consisting of a carboxy group and a salt of a carboxy group) as a hydrophilic group, the number of millimoles of the anionic group in 1 g of the specific polymer ( For example, when the total number of millimoles of a carboxy group and a salt of a carboxy group is used as the acid value of the specific polymer, the acid value of the specific polymer is 0.10 mmol/g to 2. It is preferably 00 mmol/g, and more preferably 0.30 mmol/g to 1.50 mmol/g.

-Compound for introducing hydrophilic group-
When the specific polymer in the specific particles has a hydrophilic group, the hydrophilic group can be introduced into the specific polymer using a compound for introducing a hydrophilic group.
As the compound for introducing a hydrophilic group, a compound having a hydrophilic group and an active hydrogen group can be used.
As the compound for introducing a hydrophilic group, it is preferable to use a compound having one or more hydrophilic groups and two or more active hydrogen groups.

Among the compounds for introducing a hydrophilic group, as the compound for introducing an anionic group, α-amino acids (specifically, lysine, alanine, arginine, asparagine, aspartic acid, cysteine, glutamine, glutamic acid, glycine, histidine, isoleucine, Amino acids such as leucine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine and valine).
Examples of the compound for introducing an anionic group include the following specific examples in addition to the above α-amino acid.

As the compound for introducing an anionic group, an inorganic base such as sodium hydroxide or potassium hydroxide; an organic base such as triethylamine; or the like may be used after neutralizing at least a part of the anionic group.

Among the compounds for introducing a hydrophilic group, the compound for introducing a nonionic group is preferably a compound having a polyether structure, and more preferably a compound having a polyoxyalkylene group.

-Isocyanate compound having a hydrophilic group-
When the specific polymer in the specific particles has a hydrophilic group, the hydrophilic group can be introduced into the specific polymer using an isocyanate compound into which the hydrophilic group has been introduced.
As the isocyanate compound having a hydrophilic group introduced,
A reaction product of at least one kind of the above-mentioned compound for introducing a hydrophilic group and at least one kind of a bifunctional isocyanate compound;
A reaction product of at least one kind of the above-mentioned hydrophilic group-introducing compound and at least one kind of a trifunctional or higher functional isocyanate compound;
From the group consisting of at least one kind of the compound for introducing a hydrophilic group, at least one kind of a bifunctional isocyanate compound, a trifunctional or higher functional polyol compound, a trifunctional or higher functional polyamine compound, and a trifunctional or higher functional polythiol compound. A reaction product of at least one selected;
Etc.

Specific examples of the isocyanate compound having a hydrophilic group introduced therein include an adduct of trimethylolpropane (TMP), m-xylylene diisocyanate (XDI) and polyethylene glycol monomethyl ether (EO) (for example, manufactured by Mitsui Chemicals, Inc. Takenate (registered trademark) D-116N).

(Polymerizable monomer)
The specific particles preferably include a polymerizable monomer.
When the specific particles contain a polymerizable monomer, the viscosity of the ink film can be increased by the action of the gelling group, and then the increased viscosity of the ink film can be cured by the action of the polymerizable monomer.
Thereby, the scratch resistance of the image is further improved.
When the specific particles contain a polymerizable monomer, the polymerizable monomer contained in the specific particles may be only one kind or two or more kinds.

As the polymerizable monomer contained in the specific particles, compounds described in paragraphs 0097 to 0105 of International Publication No. 2016/052053 may be used.

The polymerizable monomer contained in the specific particles is preferably a photopolymerizable monomer or a thermopolymerizable monomer.
The photopolymerizable monomer has a property of being polymerized by irradiation with light (that is, active energy ray).
The thermopolymerizable monomer has a property of being polymerized by heating or irradiation with infrared rays.
The photopolymerizable monomer is preferably a radical polymerizable monomer having a radically polymerizable ethylenic double bond.

In the present specification, an ink in which the specific particles contain a photopolymerizable monomer and the specific polymer has at least one of a photopolymerizable group is referred to as a “photocurable ink”. In some cases, the ink in which the specific particles include a thermopolymerizable monomer and/or the specific polymer has a thermopolymerizable group is referred to as a “thermosetting ink”.
When the ink of the present disclosure is a photo-curable ink, curing of the ink film formed by the ink of the present disclosure can be performed by irradiating the ink film with light (curing step described below. When the ink of the present disclosure is a thermosetting ink, it can be performed by heating or irradiating infrared rays on the ink film (see heating step or curing step B described later).

A preferred embodiment of the photocurable ink is an embodiment in which the specific particles contain a photopolymerizable monomer and the specific polymer has a photopolymerizable group.
As a result, the curability of the image due to the irradiation of the active energy rays is further improved, and the scratch resistance of the image is further improved.

When the specific particles include a photopolymerizable monomer as the polymerizable monomer, it is preferable that the specific particles further include a photopolymerization initiator described below.
Moreover, when the specific particles contain a thermopolymerizable monomer as the polymerizable monomer, the specific particles may further contain a photothermal conversion agent, a thermal curing accelerator, or a photothermal conversion agent and a thermal curing accelerator described later.

From the viewpoint of improving the curing sensitivity of the film and the hardness of the film, the content of the polymerizable monomer contained in the specific particle (the total amount when two or more kinds are contained) is 10 mass with respect to the total solid content of the specific particle. % To 90 mass% is preferable, 20 mass% to 80 mass% is more preferable, and 30 mass% to 70 mass% is further preferable.

In the present specification, the total solid content of the specific particles means the total amount of the specific particles when the specific particles do not contain a solvent, and the solvent is removed from the specific particles when the specific particles contain a solvent. It means the whole quantity.

The molecular weight of the polymerizable monomer is preferably 100 to 4000, more preferably 100 to 2000, further preferably 100 to 1000, further preferably 100 to 900, and further preferably 100 to 800. Yes, and particularly preferably 150 to 750.

-Photopolymerizable monomer-
Examples of the photopolymerizable monomer include a polymerizable monomer having a radically polymerizable ethylenically unsaturated bond (that is, a radically polymerizable monomer) and a cationically polymerizable polymerizable monomer having a cationically polymerizable group (that is, a cationically polymerizable monomer). ) Can be selected.

Examples of radically polymerizable monomers include acrylate compounds, methacrylate compounds, styrene compounds, vinylnaphthalene compounds, N-vinyl heterocyclic compounds, unsaturated polyesters, unsaturated polyethers, unsaturated polyamides, and unsaturated urethanes.
The radically polymerizable monomer is preferably a compound having an ethylenically unsaturated group.
When the specific particles contain a radical-polymerizable monomer, the specific particles may contain only one type of radical-polymerizable monomer, or may contain two or more types thereof.

As the acrylate compound, 2-hydroxyethyl acrylate, butoxyethyl acrylate, carbitol acrylate, cyclohexyl acrylate, tetrahydrofurfuryl acrylate, benzyl acrylate, tridecyl acrylate, 2-phenoxyethyl acrylate (PEA), bis(4-acryloxypolyacrylate). Ethoxyphenyl)propane, oligoester acrylate, epoxy acrylate, isobornyl acrylate (IBOA), dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, dicyclopentanyl acrylate, cyclic trimethylolpropane formal acrylate, 2-(2 -Ethoxyethoxy)ethyl acrylate, 2-(2-vinyloxyethoxy)ethyl acrylate, octyl acrylate, decyl acrylate, isodecyl acrylate, lauryl acrylate, 3,3,5-trimethylcyclohexyl acrylate, 4-t-butylcyclohexyl acrylate, Isoamyl acrylate, stearyl acrylate, isoamyl still acrylate, isostearyl acrylate, 2-ethylhexyl diglycol acrylate, 2-hydroxybutyl acrylate, 2-acryloyloxyethyl hydrophthalic acid, ethoxydiethylene glycol acrylate, methoxydiethylene glycol acrylate, methoxypolyethylene glycol acrylate, methoxy Propylene glycol acrylate, 2-hydroxy-3-phenoxypropyl acrylate, vinyl ether acrylate, 2-acryloyloxyethyl succinic acid, 2-acryloyloxyphthalic acid, 2-acryloxyethyl-2-hydroxyethylphthalic acid, lactone-modified acrylate, acryloyl Monofunctional acrylate compounds such as morpholine, acrylamide, substituted acrylamides (eg, N-methylol acrylamide, and diacetone acrylamide);

Polyethylene glycol diacrylate, polypropylene glycol diacrylate, polytetramethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate (HDDA), 1,9 -Nonanediol diacrylate (NDDA), 1,10-decanediol diacrylate (DDDA), 3-methylpentadiol diacrylate (3MPDDA), neopentyl glycol diacrylate, tricyclodecane dimethanol diacrylate, bisphenol A ethylene oxide ( EO) adduct diacrylate, bisphenol A propylene oxide (PO) adduct diacrylate, ethoxylated bisphenol A diacrylate, hydroxypineopentyl glycol diacrylate, propoxylated neopentyl glycol diacrylate, alkoxylated dimethylol tricyclodecane diacrylate Acrylate, polytetramethylene glycol diacrylate, alkoxylated cyclohexanone dimethanol diacrylate, alkoxylated hexanediol diacrylate, dioxane glycol diacrylate, cyclohexanone dimethanol diacrylate, diethylene glycol diacrylate, neopentyl glycol diacrylate, tetraethylene glycol diacrylate , Dipropylene glycol diacrylate, tripropylene glycol diacrylate (TPGDA), neopentyl glycol propylene oxide adduct diacrylate, and other bifunctional acrylate compounds;

Trimethylolpropane triacrylate, pentaerythritol triacrylate, dipentaerythritol tetraacrylate, ethoxylated isocyanuric acid triacrylate, ε-caprolactone modified tris-(2-acryloxyethyl)isocyanurate, ditrimethylolpropane tetraacrylate, dipentaerythritol penta Acrylate, dipentaerythritol hexaacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, caprolactone-modified trimethylolpropane triacrylate, pentaerythritol tetraacrylate, pentaerythritol ethoxytetraacrylate, glycerin propoxytriacrylate, ethoxylated Examples thereof include trifunctional or higher functional acrylate compounds such as dipentaerythritol hexaacrylate, caprolactam-modified dipentaerythritol hexaacrylate, propoxylated glycerin triacrylate, ethoxylated trimethylolpropane triacrylate, and propoxylated trimethylolpropane triacrylate.

Examples of the methacrylate compound include methyl methacrylate, n-butyl methacrylate, allyl methacrylate, glycidyl methacrylate, benzyl methacrylate, dimethylaminomethyl methacrylate, methoxy polyethylene glycol methacrylate, methoxytriethylene glycol methacrylate, hydroxyethyl methacrylate, phenoxyethyl methacrylate and cyclohexyl methacrylate. Monofunctional methacrylate compounds;

Examples thereof include bifunctional methacrylate compounds such as polyethylene glycol dimethacrylate, polypropylene glycol dimethacrylate, 2,2-bis(4-methacryloxypolyethoxyphenyl)propane, and tetraethylene glycol dimethacrylate.

Examples of the styrene compound include styrene, p-methylstyrene, p-methoxystyrene, β-methylstyrene, p-methyl-β-methylstyrene, α-methylstyrene, p-methoxy-β-methylstyrene and the like.

Examples of the vinylnaphthalene compound include 1-vinylnaphthalene, methyl-1-vinylnaphthalene, β-methyl-1-vinylnaphthalene, 4-methyl-1-vinylnaphthalene and 4-methoxy-1-vinylnaphthalene.

Examples of the N-vinyl heterocyclic compound include N-vinylcarbazole, N-vinylpyrrolidone, N-vinylethylacetamide, N-vinylpyrrole, N-vinylphenothiazine, N-vinylacetanilide, N-vinylethylacetamide and N-vinylsuccinic acid. Examples thereof include imide, N-vinylphthalimide, N-vinylcaprolactam, N-vinylimidazole and the like.

Other radically polymerizable monomers include N-vinyl amides such as allyl glycidyl ether, diallyl phthalate, triallyl trimellitate, and N-vinyl formamide.

Among these radically polymerizable monomers, as the bifunctional or less radically polymerizable monomer, 1,6-hexanediol diacrylate (HDDA), 1,9-nonanediol diacrylate (NDDA), 1,10-decanediol are used. Diacrylate (DDDA), 3-methylpentadiol diacrylate (3MPDDA), neopentyl glycol diacrylate, tricyclodecane dimethanol diacrylate, diethylene glycol diacrylate, tetraethylene glycol diacrylate, dipropylene glycol diacrylate, tripropylene glycol At least one selected from diacrylate (TPGDA), cyclohexanone dimethanol diacrylate, alkoxylated hexanediol diacrylate, polyethylene glycol diacrylate, and polypropylene glycol diacrylate is preferable.
Further, as the tri- or higher functional radically polymerizable monomer, trimethylolpropane triacrylate, pentaerythritol triacrylate, dipentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, ethoxylated Trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, caprolactone modified trimethylolpropane triacrylate, pentaerythritol tetraacrylate, pentaerythritol ethoxytetraacrylate, glycerin propoxytriacrylate, ethoxylated dipentaerythritol hexaacrylate, caprolactam modified dipenta At least one selected from erythritol hexaacrylate, propoxylated glycerin triacrylate, ethoxylated trimethylolpropane triacrylate, and propoxylated trimethylolpropane triacrylate is preferable.

The specific particles may include a combination of a bifunctional or less radical polymerizable monomer and a trifunctional or more functional radical polymerizable monomer. In this case, the bifunctional or less radically polymerizable monomer contributes to the adhesion between the image and the base material, and the trifunctional or more functional radical polymerizable monomer contributes to the improvement of the image hardness.
As a combination of a bifunctional or less radically polymerizable monomer and a trifunctional or more functional radically polymerizable monomer, a combination of a bifunctional acrylate compound and a trifunctional acrylate compound, a bifunctional acrylate compound and a pentafunctional acrylate compound And a combination of a monofunctional acrylate compound and a tetrafunctional acrylate compound.

From the viewpoint of further improving the adhesion between the image and the substrate, at least one of the radical polymerizable monomers that can be contained in the specific particles is a radical polymerizable monomer having a cyclic structure (hereinafter, also referred to as “cyclic radical polymerizable monomer”). It is preferable that
Examples of the cyclic radical polymerizable monomer include cyclohexyl acrylate, tetrahydrofurfuryl acrylate, benzyl acrylate, isobornyl acrylate, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, dicyclopentanyl acrylate, ethoxylated isocyanuric acid triacrylate, ε. -Caprolactone-modified tris-(2-acryloxyethyl) isocyanurate, and the like.
Further, bifunctional or higher functional cyclic radically polymerizable monomers described below are also included.

From the viewpoint of further improving the adhesion between the image and the substrate, at least one of the radically polymerizable monomers that can be contained in the specific particles contains at least one cyclic structure and at least two (meta- ) A polymerizable monomer containing an acryloyl group (hereinafter, also referred to as “bifunctional or higher functional cyclic radical polymerizable monomer”) is preferable.
As the bifunctional or higher functional cyclic radical polymerizable monomer,
Tricyclodecane dimethanol di(meth)acrylate,
Bisphenol A ethylene oxide (EO) adduct di(meth)acrylate,
Bisphenol A propylene oxide (PO) adduct di(meth)acrylate,
Ethoxylated bisphenol A di(meth)acrylate,
Alkoxylated dimethylol tricyclodecane di(meth)acrylate,
Alkoxylated cyclohexanone dimethanol di(meth)acrylate,
Examples thereof include cyclohexanone dimethanol di(meth)acrylate.

When the specific particles include a radically polymerizable monomer, the proportion of the bifunctional or higher functional cyclic radically polymerizable monomer in the entire polymerizable monomer is preferably 10% by mass to 100% by mass, more preferably 30% by mass to 100% by mass. 40 mass%-100 mass% are especially preferable.

In addition to the radical-polymerizable monomers listed above, edited by Shinzo Yamashita, “Crosslinking Agent Handbook” (Taiseisha, 1981); Kiyomi Kato, “UV/EB Curing Handbook (raw materials)” (1985, Polymer Society of Japan); RadTech Study Group, "Applications and Markets of UV/EB Curing Technology", page 79, (1989, CMC); Eiichiro Takiyama, "Polyester Resin Handbook", (1988, Nikkan Kogyo) Commercially available products described in newspapers, etc., and radically polymerizable and crosslinkable monomers known in the art can be used.

Examples of cationically polymerizable monomers include epoxy compounds, vinyl ether compounds, and oxetane compounds.
The cationically polymerizable monomer is a compound having at least one olefin, thioether, acetal, thioxane, thietane, aziridine, N heterocycle, O heterocycle, S heterocycle, P heterocycle, aldehyde, lactam, or cyclic ester group. preferable.

As cationically polymerizable monomers, JV Crivello et al. "Advances in Polymer Science", 62, pages 1 to 47 (1984), Lee et al. "Handbook of Epoxy Resins", McGraw Hill Book Company, New York (1967), and The compounds described in "Epoxy Resin Technology" of PF Bruins et al., (1968) may be used.

Further, as the photopolymerizable monomer, JP-A-7-159983, JP-B-7-31399, JP-A-8-242982, JP-A-10-863, JP-A-9-134011, Photocurable polymerizable monomers used in the photopolymerizable composition described in each publication such as Table 2004-514014 are known, and these may also be applied as the polymerizable monomer that can be contained in the specific particles. it can.

As the photopolymerizable monomer, a commercially available product on the market may be used.
Examples of commercially available photopolymerizable monomers include AH-600 (bifunctional), AT-600 (bifunctional), UA-306H (6functional), UA-306T (6functional), UA-306I (6functional). ), UA-510H (10 functional), UF-8001G (2 functional), DAUA-167 (2 functional), light acrylate NPA (2 functional), light acrylate 3EG-A (2 functional) (above, Kyoeisha Chemical Co., Ltd. )), SR339A (PEA, monofunctional), SR506 (IBOA, monofunctional), CD262 (bifunctional), SR238 (HDDA, bifunctional), SR341 (3MPDDA, bifunctional), SR508 (bifunctional), SR306H (2 functional). Functional), CD560 (bifunctional), SR833S (bifunctional), SR444 (trifunctional), SR454 (trifunctional), SR492 (trifunctional), SR499 (trifunctional), CD501 (trifunctional), SR502 (trifunctional). , SR9020 (trifunctional), CD9021 (trifunctional), SR9035 (trifunctional), SR494 (4-functional), SR399E (5-functional) (above, Sartomer), A-NOD-N (NDDA, bifunctional), A -DOD-N (DDDA, bifunctional), A-200 (bifunctional), APG-400 (bifunctional), A-BPE-10 (bifunctional), A-BPE-20 (bifunctional), A-9300. (Trifunctional), A-9300-1CL (trifunctional), A-TMPT (trifunctional), A-TMM-3L (trifunctional), A-TMMT (4-functional), AD-TMP (4-functional) (above) , Shin-Nakamura Chemical Co., Ltd., UV-7510B (trifunctional) (Nippon Gosei Kagaku KK), KAYARAD DPCA-30 (6-functional), KAYARAD DPEA-12 (6-functional) (above, Nippon Kayaku ( Ltd.) and the like.
Other polymerizable monomers include NPGPODA (neopentyl glycol propylene oxide adduct diacrylate), SR531, SR285, SR256 (above, Sartomer), A-DHP (dipentaerythritol hexaacrylate, Shin-Nakamura Chemical Co., Ltd.). ), Aronix (registered trademark) M-156 (Toagosei Co., Ltd.), V-CAP (BASF Corporation), Viscoat #192 (Osaka Organic Chemical Industry Co., Ltd.), and the like can be preferably used.
Among these commercially available products, SR506, SR833S, A-9300, or A-9300-CL, which are photopolymerizable monomers having a cyclic structure, are particularly preferable, and SR833S is particularly preferable.

-Thermopolymerizable monomer-
The thermopolymerizable monomer can be selected from the group of polymerizable monomers that can be polymerized by heating or irradiation with infrared rays. Examples of the heat-polymerizable monomer include epoxy compounds, oxetane compounds, aziridine compounds, azetidine compounds, ketone compounds, aldehyde compounds, blocked isocyanate compounds, and the like.

Examples of the epoxy compound include 1,4-butanediol diglycidyl ether, 3-(bis(glycidyloxymethyl)methoxy)-1,2-propanediol, limonene oxide, 2-biphenylglycidyl ether, 3,4-epoxycyclohexylmethyl. -3',4'-epoxycyclohexanecarboxylate, epoxide derived from epichlorohydrin-bisphenol S, epoxidized styrene, epoxide derived from epichlorohydrin-bisphenol F, epoxide derived from epichlorohydrin-bisphenol A, epoxy A bifunctional or lower epoxy compound such as a modified novolak or an alicyclic diepoxide;
Examples include polyglycidyl esters of polybasic acids, polyglycidyl ethers of polyols, polyglycidyl ethers of polyoxyalkylene glycols, polyglycidyl esters of aromatic polyols, urethane polyepoxy compounds, trifunctional or higher functional epoxy compounds such as polyepoxypolybutadiene. To be
As a commercial item of an epoxy compound, EPICLON (registered trademark) 840 (DIC Corporation) can be mentioned.

As the oxetane compound, 3-ethyl-3-hydroxymethyl-1-oxetane, 1,4bis[3-ethyl-3-oxetanylmethoxy)methyl]benzene, 3-ethyl-3-phenoxymethyl-oxetane, bis([ 1-ethyl(3-oxetanyl)]methyl)ether, 3-ethyl-3-[(2-ethylhexyloxy)methyl]oxetane, 3-ethyl-[(triethoxysilylpropoxy)methyl]oxetane, 3,3-dimethyl 2-(p-methoxyphenyl)-oxetane and the like can be mentioned.

Examples of the blocked isocyanate compound include compounds obtained by inactivating an isocyanate compound with a blocking agent (active hydrogen-containing compound).
Examples of the isocyanate compound include hexamethylene diisocyanate, isophorone diisocyanate, toluyl diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate trimer, trimethylhexylylene diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, hydrogenated xylylene diisocyanate, and takenate (registered). A commercially available isocyanate such as a trademark; Mitsui Chemicals, Inc., Duranate (registered trademark; Asahi Kasei), Bayhydur (registered trademark; Bayer AG), or a difunctional or higher functional isocyanate in combination thereof is preferable.

Examples of the blocking agent include lactam [eg, ε-caprolactam, δ-valerolactam, γ-butyrolactam, etc.], oxime [eg, acetoxime, methylethylketoxime (MEK oxime), methylisobutylketoxime (MIBK oxime), cyclohexanone oxime, etc.]. , Amine [eg, aliphatic amine (dimethylamine, diisopyramine, di-n-propylamine, diisobutylamine, etc.), alicyclic amine (methylhexylamine, dicyclohexylamine, etc.), aromatic amine (aniline, diphenylamine, etc.)], Aliphatic alcohols [eg methanol, ethanol, 2-propanol, n-butanol, etc.], phenols and alkylphenols [eg phenol, cresol, ethylphenol, n-propylphenol, isopropylphenol, n-butylphenol, octylphenol, nonylphenol, xylenol, diisopropyl] Phenol, di-t-butylphenol etc.], imidazole [eg imidazole, 2-methylimidazole etc.], pyrazole [eg pyrazole, 3-methylpyrazole, 3,5-dimethylpyrazole etc.], imine [eg ethyleneimine, polyethyleneimine etc.] ], active methylene [eg, dimethyl malonate, diethyl malonate, diisopropyl malonate, acetylacetone, methyl acetoacetate, ethyl acetoacetate, etc.], blocking described in JP-A-2002-309217 and 2008-239890. Agents, as well as mixtures of two or more of these. Among them, the oxime, lactam, pyrazole, active methylene, or amine is preferable as the blocking agent.

As the blocked isocyanate compound, a commercially available commercially available product may be used. Company) is preferably used. Moreover, the compound group described in paragraph 0064 of WO 2015/158654 is also preferably used.

The specific particles containing the specific polymer described above and the polymerizable monomer described above can be produced, for example, by emulsifying a mixture obtained by mixing an oil phase component containing the specific polymer and the polymerizable monomer, and an aqueous phase component. ..

(Photopolymerization initiator)
The specific particles may include at least one kind of photopolymerization initiator.
When the specific particles include a photopolymerizable monomer (for example, a radical polymerizable monomer), the specific particles preferably include at least one photopolymerization initiator.

When the specific particles contain a photopolymerization initiator, the sensitivity to light (that is, active energy rays) becomes high, and an image having excellent hardness and excellent adhesion to the substrate can be obtained.
Specifically, when the specific particles contain a photopolymerization initiator, one specific particle has both the photopolymerizable monomer and the photopolymerization initiator. Therefore, the distance between the photopolymerizable monomer and the photopolymerization initiator becomes short, so that the curing sensitivity of the film (hereinafter, also simply referred to as “sensitivity”) as compared with the case where a conventional photocurable composition is used. ) Is improved. As a result, a film that is more excellent in hardness and also more excellent in adhesion to the substrate is formed.

Further, when the specific particles include a photopolymerization initiator, a photopolymerization initiator that has been conventionally difficult to use because of high sensitivity but low dispersibility in water or low solubility (for example, solubility in water Is 1.0% by mass or less at 25° C.). As a result, the range of selection of the photopolymerization initiator to be used is expanded, and the range of selection of the light source used is also expanded. Therefore, the curing sensitivity can be improved as compared with the conventional case.
As the above-mentioned photopolymerization initiator, which has a high sensitivity but has low dispersibility in water or low solubility, it is difficult to use, specifically, a carbonyl compound and an acylphosphine oxide compound described later. , An acylphosphine oxide compound is preferable.
As described above, the ink of the present disclosure can be contained in the ink of the present disclosure, which is a water-based composition, by including a substance having low water solubility in the specific particles. This is also one of the advantages of the ink of the present disclosure.

In addition, the ink in which the specific particles contain a photopolymerization initiator has excellent storage stability as compared with the conventional photocurable composition. The reason for this is considered to be that the photopolymerization initiator contained in the specific particles suppresses aggregation or precipitation of the photopolymerization initiator.

As the photopolymerization initiator that can be contained in the specific particles, a known photopolymerization initiator can be appropriately selected and used.
The photopolymerization initiator is a compound that absorbs light (that is, active energy ray) to generate a radical that is a polymerization initiation species.

Although known compounds can be used as the photopolymerization initiator, preferred photopolymerization initiators include (a) carbonyl compounds such as aromatic ketones, (b) acylphosphine oxide compounds, (c) aromatic onium salt compounds, (D) organic peroxide, (e) thio compound, (f) hexaarylbiimidazole compound, (g) ketoxime ester compound, (h) borate compound, (i) azinium compound, (j) metallocene compound, ( Examples include k) active ester compounds, (l) compounds having a carbon-halogen bond, and (m) alkylamine compounds.

These photopolymerization initiators may be used alone or in combination of two or more of the compounds (a) to (m).

Preferable examples of the (a) carbonyl compound, (b) acylphosphine oxide compound, and (e) thio compound include "RADIATION CURING IN POLYMER SCIENCE AND TECHNOLOGY", J. P. FOUASSIER, J. F. RABEK (1993), pp. The compound etc. which have a benzophenone skeleton or a thioxanthone skeleton of 77-117 are mentioned.
More preferred examples include α-thiobenzophenone compounds described in JP-B-47-6416, benzoin ether compounds described in JP-B-47-3981, and α-substituted benzoin compounds described in JP-B-47-22326. Benzoin derivatives described in JP-A-47-23664, aroylphosphonates described in JP-A-57-30704, dialkoxybenzophenones described in JP-B-60-26483, JP-B-60-26403, and JP-A-60-26403. Benzoin ethers described in JP-A-62-81345, Japanese Patent Publication No. 1-34242, US Pat. No. 4,318,791, and α-aminobenzophenones described in European Patent No. 0284562A1, JP-A-2-211452. P-di(dimethylaminobenzoyl)benzene described in JP-A No. 61-194062, a thio-substituted aromatic ketone described in JP-A-61-194062, an acylphosphine sulfide described in JP-B-2-9597, and JP-B-2-9596. Examples thereof include the acylphosphines described, thioxanthones described in JP-B-63-61950, and coumarins described in JP-B-59-42864.
Further, the polymerization initiators described in JP2008-105379A or JP2009-114290A are also preferable.

Examples of commercially available photopolymerization initiators include IRGACURE (registered trademark) 184, 369, 500, 651, 819, 907, 1000, 1300, 1700, 1870, DAROCUR (registered trademark) 1173, 2959, 4265, ITX, LUCIRIN (registered trademark) TPO [all above manufactured by BASF], ESACURE (registered trademark) KTO37, KTO46, KIP150, EDB [all above manufactured by Lamberti], H-Nu (registered trademark) 470, 470X [all above all] Spectra Group Limited], Omnipol TX, 9210 [above, all IGM Resins B. V. Company], SPEEDCURE 7005, 7010, 7040 [above, manufactured by LAMBSON] and the like.

Among these photopolymerization initiators, (a) carbonyl compound or (b) acylphosphine oxide compound is more preferable, and specifically, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (for example, BASF IRGACURE (registered trademark) 819), 2-(dimethylamine)-1-(4-morpholinophenyl)-2-benzyl-1-butanone (for example, IRGACURE (registered trademark) 369 manufactured by BASF), 2 -Methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one (for example, IRGACURE (registered trademark) 907 manufactured by BASF), 1-hydroxy-cyclohexyl-phenyl-ketone (for example, BASF) Manufactured by IRGACURE (registered trademark) 184), 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (for example, DAROCUR (registered trademark) TPO, LUCIRIN (registered trademark) TPO (both manufactured by BASF)) and the like. Can be mentioned.
Among these, the encapsulated photopolymerization initiator is preferably (b) an acylphosphine oxide compound, and more preferably a monoacylphosphine oxide compound (particularly preferably 2, from the viewpoint of improving sensitivity and compatibility with LED light). 4,6-trimethylbenzoyl-diphenyl-phosphine oxide) or a bisacylphosphine oxide compound (particularly preferably bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide) is more preferable.
The wavelength of the LED light is preferably 355 nm, 365 nm, 385 nm, 395 nm, or 405 nm.

From the viewpoint of suppressing migration, a polymer photopolymerization initiator is also preferable as the photopolymerization initiator.
Examples of the high molecular weight photopolymerization initiator include Omnipol TX, 9210; SPEEDCURE 7005, 7010, 7040;

Specific particles containing a photopolymerization initiator can be produced by, for example, emulsifying a mixture obtained by mixing an oil phase component containing a specific polymer, a photopolymerizable monomer, and a photopolymerization initiator, and an aqueous phase component. it can.

The content of the photopolymerization initiator is preferably 0.1% by mass to 25% by mass, more preferably 0.5% by mass to 20% by mass, and further preferably 1% by mass with respect to the total solid content of the specific particles. Is about 15% by mass.

(Sensitizer)
The specific particles may contain at least one sensitizer.
When the specific particles include at least one photopolymerization initiator, the specific particles preferably include at least one sensitizer.
When the specific particles contain a sensitizer, the decomposition of the photopolymerization initiator by irradiation with light (that is, active energy rays) can be further promoted.
The sensitizer is a substance that absorbs a specific active energy ray to be in an electronically excited state. The sensitizer in the electronically excited state comes into contact with the photopolymerization initiator and causes the effects of electron transfer, energy transfer, heat generation and the like. As a result, chemical change of the photopolymerization initiator, that is, decomposition, generation of radicals, acids or bases, etc. is promoted.

Examples of the sensitizer include benzophenone, thioxanthone, isopropylthioxanthone, anthraquinone, 3-acylcoumarin derivative, terphenyl, styryl ketone, 3-(aroylmethylene)thiazoline, camphorquinone, eosin, rhodamine, and erythrosine. ..
Further, as the sensitizer, the compound represented by the general formula (i) described in JP-A-2010-24276 and the compound represented by the general formula (I) described in JP-A-6-107718. Can also be preferably used.
Among the above, the sensitizer is preferably at least one selected from thioxanthone, isopropylthioxanthone, and benzophenone, from the viewpoint of compatibility with LED light and reactivity with a photopolymerization initiator, and from thioxanthone and isopropylthioxanthone. At least one selected is more preferable, and isopropylthioxanthone is further preferable.
When the specific particles contain a sensitizer, one kind of the sensitizer may be contained alone, or two or more kinds thereof may be contained.

When the specific particles include a sensitizer, the content of the sensitizer is preferably 0.1% by mass to 20% by mass, and 0.2% by mass to 15% by mass, based on the total solid content of the specific particles. % Is more preferable, and 0.3% by mass to 10% by mass is still more preferable.

Specific particles containing a photopolymerization initiator and a sensitizer, for example, a mixture of an oil phase component containing a specific polymer, a photopolymerizable monomer, a photopolymerization initiator, and a sensitizer, and an aqueous phase component, It can be produced by emulsification.

(Photothermal conversion agent)
When the specific particles include a heat-polymerizable monomer as the polymerizable monomer, the specific particles may include at least one kind of photothermal conversion agent.
The photothermal conversion agent is a compound that absorbs infrared rays and generates heat to polymerize and cure the thermopolymerizable monomer. A known compound can be used as the photothermal conversion agent.

As the photothermal conversion agent, an infrared absorbing agent is preferable. Examples of the infrared absorbing agent include polymethylindolium, indocyanine green, polymethine dye, croconium dye, cyanine dye, merocyanine dye, squarylium dye, chalcogenopyrrillolidene dye, metal thiolate complex dye, bis(chalcogenopyrrillo)polymethine dye. , Oxyindolizine dye, bisaminoallyl polymethine dye, indolizine dye, pyrylium dye, quinoid dye, quinone dye, phthalocyanine dye, naphthalocyanine dye, azo dye, azomethine dye, carbon black and the like.

The specific particles containing a photothermal conversion agent can be produced, for example, by emulsifying a mixture obtained by mixing an oil phase component containing a specific polymer, a thermopolymerizable monomer, and a photothermal conversion agent, and an aqueous phase component.

The photothermal conversion agents may be used alone or in combination of two or more.
The content of the photothermal conversion agent is preferably 0.1% by mass to 25% by mass, more preferably 0.5% by mass to 20% by mass, based on the total solid content of the specific particles. More preferably, it is from 15% by mass to 15% by mass.

(Thermal curing accelerator)
When the specific particles include a heat-polymerizable monomer as the polymerizable monomer, the specific particles may include at least one type of thermosetting accelerator.
The thermosetting accelerator is a compound that catalytically promotes the thermosetting reaction of the thermopolymerizable monomer.

As the thermosetting accelerator, known compounds can be used. The thermosetting accelerator is preferably an acid or a base, or a compound which generates an acid or a base by heating, and examples thereof include carboxylic acid, sulfonic acid, phosphoric acid, aliphatic alcohol, phenol, aliphatic amine, aromatic amine, and imidazole. (For example, phenyl imidazole, 2-methyl imidazole), pyrazole, etc. are mentioned.

Specific particles containing a heat curing accelerator can be produced, for example, by emulsifying a mixture obtained by mixing an oil phase component containing a specific polymer, a heat-polymerizable monomer, and a heat curing accelerator, and an aqueous phase component. it can.

The thermosetting accelerators may be used alone or in combination of two or more.
The content of the thermosetting accelerator is preferably 0.1% by mass to 25% by mass, more preferably 0.5% by mass to 20% by mass, based on the total solid content of the specific particles. It is more preferably 1% by mass to 15% by mass.

In the ink of the present disclosure, the total solid content of the specific particles is preferably 50 mass% or more, more preferably 60 mass% or more, and more preferably 70 mass% or more with respect to the total solid content of the ink. Is more preferable, 80% by mass or more is further preferable, and 85% by mass or more is further preferable.
This further improves the dispersion stability and the adhesion between the image and the base material.

In the ink of the present disclosure, the total solid content of the specific particles is preferably 1% by mass to 50% by mass, more preferably 3% by mass to 40% by mass, and more preferably 5% by mass with respect to the total amount of the ink. % To 30% by mass is more preferable.
When the total solid content of the specific particles is 1% by mass or more with respect to the total amount of the ink, the adhesion between the image and the base material is further improved.
Further, when the total solid content of the specific particles is 50% by mass or less based on the total amount of the ink, the dispersion stability of the ink is further improved.

The volume average dispersed particle diameter of the specific particles is not particularly limited, but from the viewpoint of dispersion stability, it is preferably 0.01 μm to 10.0 μm, more preferably 0.01 μm to 5 μm, and 0.05 μm. ˜1 μm is more preferable, 0.05 μm to 0.5 μm is further preferable, and 0.05 μm to 0.3 μm is further preferable.
In the present specification, the “volume average dispersed particle diameter” refers to a value measured by a light scattering method. The volume average dispersed particle diameter of the specific particles by the light scattering method is measured using, for example, LA-960 (Horiba Ltd.).

<water>
The ink of the present disclosure contains water.
Water is a dispersion medium for specific particles (dispersoids).
The content of water in the ink of the present disclosure is not particularly limited, but the content of water is preferably 10% by mass to 99% by mass, more preferably 20% by mass to 95% by mass with respect to the total amount of the ink. %, more preferably 30% to 90% by mass, and particularly preferably 50% to 90% by mass.

<Color material>
The ink of the present disclosure may be an ink containing at least one kind of coloring material (so-called “colored ink”) or an ink containing no coloring material (so-called “clear ink”).
When the ink contains a coloring material, it is preferable that the coloring material is contained outside the specific particles (that is, the specific particles do not contain the coloring material).
The color material is not particularly limited and can be arbitrarily selected from known color materials such as pigments, water-soluble dyes and disperse dyes. Among these, it is more preferable to include a pigment because it has excellent weather resistance and rich color reproducibility.

The pigment is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include known organic pigments and inorganic pigments, and resin particles dyed with a dye, and commercially available pigment dispersions and surfaces. Examples also include treated pigments (for example, pigments dispersed in water, a liquid compound or an insoluble resin as a dispersion medium, and pigments whose surface is treated with a resin or a pigment derivative).
Examples of organic pigments and inorganic pigments include yellow pigments, red pigments, magenta pigments, blue pigments, cyan pigments, green pigments, orange pigments, purple pigments, brown pigments, black pigments, and white pigments.

When a pigment is used as the coloring material, a pigment dispersant may be used if necessary.
When a pigment is used as the coloring material, a self-dispersion pigment having a hydrophilic group on the pigment particle surface may be used as the pigment.
Regarding the color material and the pigment dispersant, paragraphs 0180 to 0200 of JP-A-2014-040529 and paragraphs 0122 to 0129 of International Publication No. 2016/052053 can be appropriately referred to.

When the ink of the present disclosure contains a coloring material, the content of the coloring material is preferably 0.1% by mass to 20% by mass, more preferably 0.5% by mass to 10% by mass, and 0% by mass based on the total amount of the ink. Particularly preferably, it is 0.5% by mass to 5% by mass.

<Other ingredients>
The ink of the present disclosure may contain other components than those described above, if necessary.
Other components may be contained in the specific particles or may not be contained in the specific particles.

(Organic solvent)
The ink of the present disclosure may contain an organic solvent.
When the ink of the present disclosure contains an organic solvent, the adhesion between the image and the substrate can be further improved.
When the ink of the present disclosure contains an organic solvent, the content of the organic solvent is preferably 0.1% by mass to 10% by mass, and 0.1% by mass to 5% by mass with respect to the total amount of the ink. Is more preferable.
Specific examples of the organic solvent are as follows.
Alcohols (for example, methanol, ethanol, propanol, isopropanol, butanol, isobutanol, secondary butanol, tertiary butanol, pentanol, hexanol, cyclohexanol, benzyl alcohol, etc.)
-Polyhydric alcohols (for example, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, butylene glycol, hexanediol, pentanediol, glycerin, hexanetriol, thiodiglycol, 2- Methyl propane diol, etc.)
Polyhydric alcohol ethers (for example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monobutyl ether, tripropylene) Glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether, ethylene glycol monomethyl ether acetate, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, ethylene glycol monophenyl ether, propylene glycol monophenyl ether Ether etc.)
-Amines (for example, ethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, morpholine, N-ethylmorpholine, ethylenediamine, diethylenediamine, triethylenetetramine, tetraethylenepentamine, polyethyleneimine, penta (Methyldiethylenetriamine, tetramethylpropylenediamine, etc.)
-Amids (eg, formamide, N,N-dimethylformamide, N,N-dimethylacetamide, etc.)
Heterocycles (for example, 2-pyrrolidone, N-methyl-2-pyrrolidone, cyclohexylpyrrolidone, 2-oxazolidone, 1,3-dimethyl-2-imidazolidinone, γ-butyrolactone, etc.)
・Sulfoxides (eg, dimethyl sulfoxide, etc.)
.Sulfones (eg, sulfolane)
・Others (urea, acetonitrile, acetone, etc.)

(Surfactant)
The ink of the present disclosure may contain at least one surfactant.
When the ink of the present disclosure contains a surfactant, the wettability of the ink to the base material is improved.
Examples of the surfactant include higher fatty acid salts, alkyl sulfates, alkyl ester sulfates, alkyl sulfonates, alkylbenzene sulfonates, sulfosuccinates, naphthalene sulfonates, alkyl phosphates, polyoxyalkylene alkyl ethers. Examples thereof include phosphate, polyoxyalkylene alkyl phenyl ether, polyoxyethylene polyoxypropylene glycol, glycerin ester, sorbitan ester, polyoxyethylene fatty acid amide, amine oxide and the like.
Among these, as the surfactant, at least one surfactant selected from alkyl sulfates, alkyl sulfonates, and alkyl benzene sulfonates is preferable, and alkyl sulfate is particularly preferable.
From the viewpoint of dispersibility of specific particles, the surfactant is preferably an alkyl sulfate having an alkyl chain length of 8 to 18, and sodium dodecyl sulfate (SDS, alkyl chain length: 12) and sodium cetyl sulfate (SCS). More preferably, it is at least one selected from alkyl chain length: 16).

Other surfactants besides the above-mentioned surfactants include those described in JP-A Nos. 62-173463 and 62-183457. For example, other surfactants include nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, acetylene glycols, polyoxyethylene/polyoxypropylene block copolymers, and siloxanes. Can be mentioned.
Moreover, an organic fluoro compound is also mentioned as a surfactant.
The organic fluoro compound is preferably hydrophobic. Examples of the organic fluoro compound include a fluorine-based surfactant, an oily fluorine-based compound (for example, fluorine oil), and a solid fluorine compound resin (for example, tetrafluoroethylene resin), and Japanese Patent Publication No. 57-9053 ( Columns 8 to 17) and those described in JP-A-62-135826.

It should be noted that the ink of the present disclosure may contain substantially no surfactant (for example, anionic surfactant).
Here, "not substantially contain" means that the content is less than 1% by mass (preferably less than 0.1% by mass) with respect to the total amount of the ink.
A mode in which the ink does not substantially contain an anionic surfactant has an advantage that foaming of the ink can be suppressed, an advantage that water resistance of an image can be improved, an advantage that whitening due to bleed-out after image formation can be suppressed, and the like. Have. In particular, when a pigment dispersion having an anionic dispersible group is used in the preparation of the ink, the anionic surfactant increases the ion concentration in the system, and the ionization degree of the anionic pigment dispersant decreases. Then, there is also an advantage that it is possible to suppress deterioration of the dispersibility of the pigment.

(Polymerization inhibitor)
The ink of the present disclosure may contain a polymerization inhibitor.
When the ink of the present disclosure contains a polymerization inhibitor, the storage stability of the ink can be further improved.
Examples of the polymerization inhibitor include p-methoxyphenol, quinones (eg, hydroquinone, benzoquinone, methoxybenzoquinone, etc.), phenothiazine, catechols, alkylphenols (eg, dibutylhydroxytoluene (BHT), etc.), alkylbisphenols, dimethyldithiocarbamine. Zinc acid, copper dimethyldithiocarbamate, copper dibutyldithiocarbamate, copper salicylate, thiodipropionates, mercaptobenzimidazoles, phosphites, 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), 2,2,6,6-tetramethyl-4-hydroxypiperidine-1-oxyl (TEMPOL), cuperone Al, tris(N-nitroso-N-phenylhydroxylamine) aluminum salt and the like can be mentioned.
Among these, at least one selected from p-methoxyphenol, catechols, quinones, alkylphenols, TEMPO, TEMPOL, cuperone Al, and tris(N-nitroso-N-phenylhydroxylamine) aluminum salt is preferable, and p -At least one selected from methoxyphenol, hydroquinone, benzoquinone, BHT, TEMPO, TEMPOL, cuperone Al, and tris(N-nitroso-N-phenylhydroxylamine) aluminum salt is more preferable.

(UV absorber)
The ink of the present disclosure may contain an ultraviolet absorber.
When the ink of the present disclosure contains an ultraviolet absorber, the weather resistance of an image can be further improved.
Examples of the ultraviolet absorber include known ultraviolet absorbers such as benzotriazole compounds, benzophenone compounds, triazine compounds and benzoxazole compounds.

In addition, the ink of the present disclosure may have a polymerizable monomer, a photopolymerization agent, or the like, outside the specific particles, if necessary, from the viewpoint of controlling the image hardness, the adhesion between the image and the substrate, and the ink ejection stability control. It may contain an initiator, a resin and the like.
These components preferably have water solubility or water dispersibility.
Here, "water-soluble" refers to the property that the amount of dissolution in 100 g of distilled water at 25°C exceeds 1 g when dried at 105°C for 2 hours.
Further, "water dispersibility" refers to the property of being insoluble in water and being dispersed in water. Here, "water-insoluble" refers to the property that the amount of dissolution in 100 g of distilled water at 25°C is 1 g or less when dried at 105°C for 2 hours.
In addition, “the ink contains a polymerizable monomer outside the specific particles” means that the ink contains a polymerizable monomer that is not included in the specific particles. The same applies when a photopolymerization initiator, a water-soluble resin, a water-dispersible resin, etc. are contained outside the specific particles.

Examples of the polymerizable monomer that can be contained outside the specific particles include the polymerizable monomers described in paragraphs 0148 to 0156 of WO 2016/052053.
The polymerizable monomer that can be contained outside the specific particles, a compound having an ethylenically unsaturated group, acrylonitrile, styrene, unsaturated polyester, unsaturated polyether, unsaturated polyamide, a radical polymerizable monomer such as unsaturated urethane Can be mentioned.
Among these, as the polymerizable monomer that can be contained outside the specific particles, a compound having an ethylenically unsaturated group is preferable, and a compound having a (meth)acryloyl group is particularly preferable.

From the viewpoint of water solubility or water dispersibility, the polymerizable monomer that can be contained outside the specific particles is selected from the group consisting of an amide structure, a polyethylene glycol structure, a polypropylene glycol structure, a carboxyl group, and a salt of a carboxy group. Compounds having at least one are preferred.

From the viewpoint of water solubility or water dispersibility, examples of the polymerizable monomer that can be contained outside the specific particles include (meth)acrylic acid, sodium (meth)acrylate, potassium (meth)acrylate, and N,N-. Dimethyl acrylamide, N,N-diethyl acrylamide, morpholine acrylamide, N-2-hydroxyethyl (meth)acrylamide, N-vinylpyrrolidone, N-vinylcaprolactam, 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth) Acrylate, 2-hydroxypropyl (meth)acrylate, glycerin monomethacrylate, N-[tris(3-acryloylaminopropyloxymethylene)methyl]acrylamide, diethylene glycol bis(3-acryloylaminoproyl) ether, polyethylene glycol di(meth) At least one selected from acrylates, polypropylene glycol di(meth)acrylates, compounds represented by the following general formulas (a) to (d), and ethoxylated trimethylolpropane triacrylate (for example, SR9035 manufactured by Sartomer). Preferred are (meth)acrylic acid, N,N-dimethylacrylamide, N-2-hydroxyethyl(meth)acrylamide, 2-hydroxyethyl(meth)acrylate, glycerin monomethacrylate, N-[tris(3-acryloylamino). Propyloxymethylene)methyl]acrylamide, diethylene glycol bis(3-acryloylaminoproyl) ether, polyethylene glycol di(meth)acrylate, and polypropylene glycol di(meth)acrylate, represented by the following general formulas (a) to (d): At least one selected from the compound represented and ethoxylated trimethylolpropane triacrylate (for example, SR9035 manufactured by Sartomer) is more preferable.

In the general formula (a), a plurality of R ^1's each independently represent a hydrogen atom, an alkyl group, an aryl group or a heterocyclic group, and a plurality of R ^2's each independently represent a hydrogen atom or a methyl group. L ^1's each independently represent a single bond or a divalent linking group.
In the general formula (b), a plurality of R ^3's each independently represent a hydrogen atom or a methyl group, a plurality of L ^2's each independently represent an alkylene group having 1 to 8 carbon atoms, and a plurality of k's and p's. Each independently represent 0 or 1, and plural m's each independently represent an integer of 0 to 8, provided that at least one of k and p is 1.
In general formula (c), a plurality of R ^4's each independently represent a hydrogen atom or a methyl group, a plurality of n's each independently represent an integer of 1 to 8, and l represents an integer of 0 or 1.
In general formula (d), Z ¹ represents a residue obtained by removing q hydrogen atoms from the hydroxyl group of the polyol, q represents an integer of 3 to 6, and a plurality of R ^5's each independently represent a hydrogen atom or a methyl atom. And a plurality of L ^3's each independently represent an alkylene group having 1 to 8 carbon atoms.

Specific examples of the compounds represented by the general formulas (a) to (d) include compounds represented by the following AM-1 to AM-4.

The above AM-1 to AM-4 can be synthesized by the method described in Japanese Patent No. 5591858.

Regarding the photopolymerization initiator and the resin that may be contained outside the specific particles, paragraphs 0139 to 0147 and 0157 of International Publication WO2016/052053 can be appropriately referred to.

<Preferable physical properties of ink>
The ink of the present disclosure preferably has a viscosity of 3 mPa·s to 15 mPa·s, and more preferably 3 mPa·s to 13 mPa·s, when the temperature of the ink is 25° C. to 50° C. In particular, the ink of the present disclosure preferably has a viscosity of 50 mPa·s or less when the ink is at 25°C. When the viscosity of the ink is in the above range, higher ejection stability can be realized.
The viscosity of the ink is a value measured using a viscometer (VISCOMTER TV-22, Toki Sangyo Co., Ltd.).

The ink of the present disclosure can be used for image formation by a coating method, a dipping method, a gravure method, a flexo method, an inkjet method, or the like.
The ink of the present disclosure is particularly preferably used for image formation by an inkjet method (that is, used as an inkjet ink).

When the ink of the present disclosure is a photocurable ink or a thermosetting ink, the following modes 1 to 4 are mentioned as particularly preferable modes.

<Form 1>
Form 1 is a photocurable ink in which the specific particles contain a photopolymerizable monomer and the specific polymer is a specific chain polymer.
In the form 1, the Mw of the specific chain polymer is preferably 5000 or more. For the more preferable range of Mw of the specific chain polymer, the preferable range of the molecular weight of the specific polymer can be referred to.
In form 1, the molecular weight of the photopolymerizable monomer is preferably 100 to 4000. For the more preferable range of the molecular weight of the photopolymerizable monomer, the above-mentioned more preferable range of the molecular weight of the polymerizable monomer can be referred to.

<Form 2>
Form 2 is a photocurable ink in which the specific particles contain a photopolymerizable monomer and the specific polymer is a specific crosslinked polymer.
In form 2, it is preferable that the specific particles are microcapsules including a shell made of a specific crosslinked polymer having a three-dimensional crosslinked structure and a core containing a photopolymerizable monomer.
In form 2, the molecular weight of the photopolymerizable monomer is preferably 100 to 4000. For the more preferable range of the molecular weight of the photopolymerizable monomer, the above-mentioned more preferable range of the molecular weight of the polymerizable monomer can be referred to.

<Form 3>
Form 3 is a thermosetting ink, in which the specific particles contain a thermopolymerizable monomer and the specific polymer is a specific chain polymer.
In the form 3, the Mw of the specific chain polymer is preferably 5000 or more. For the more preferable range of Mw of the specific chain polymer, the preferable range of the molecular weight of the specific polymer can be referred to.
In the form 3, the molecular weight of the heat-polymerizable monomer is preferably 100 to 4000. Regarding the more preferable range of the molecular weight of the heat-polymerizable monomer, the above-mentioned more preferable range of the molecular weight of the polymerizable monomer can be referred to.

<Form 4>
Form 4 is a thermosetting ink in which the specific particles contain a thermopolymerizable monomer and the specific polymer is a specific crosslinked polymer.
As Form 4, it is preferable that the specific particles are microcapsules including a shell made of a specific crosslinked polymer having a three-dimensional crosslinked structure and a core containing a thermopolymerizable monomer.
In the form 4, the molecular weight of the thermopolymerizable monomer is preferably 100 to 4000. Regarding the more preferable range of the molecular weight of the heat-polymerizable monomer, the above-mentioned more preferable range of the molecular weight of the polymerizable monomer can be referred to.

[One Example of Ink Manufacturing Method (Manufacturing Method A)]
The method for producing the ink of the present disclosure is not particularly limited, but the following example (Production method A) can be mentioned.
The production method A has a step of forming specific particles by mixing an oil phase component containing an organic solvent and a specific polymer and an aqueous phase component containing water and emulsifying the mixture.

In the step of forming the specific particles, the specific particles are formed by mixing the oil phase component and the aqueous phase component described above and emulsifying the obtained mixture. The formed specific particles function as a dispersoid in the manufactured ink.
The water in the water phase component functions as a dispersion medium in the manufactured ink.

Examples of the organic solvent contained in the oil phase component include ethyl acetate and methyl ethyl ketone.
At least a part of the organic solvent is preferably removed during the formation process of the specific particles and after the formation of the specific particles.

The oil phase component may be, for example, a polymerizable monomer, a photopolymerization initiator, a sensitizer, a compound for introducing a polymerizable group (preferably a compound having a polymerizable group and an active hydrogen group), a polymer, in addition to the above components. It may include an isocyanate compound having a hydrophilic group introduced, an isocyanate compound having a hydrophilic group introduced, and the like.

The water phase component is not particularly limited except that it contains water, and may be water alone.
The water phase component may include components other than water.
For example, the aqueous phase component may contain a compound for introducing a hydrophilic group (preferably a compound having a hydrophilic group and an active hydrogen group).
Further, the aqueous phase component may contain a basic compound as a neutralizing agent for unneutralized anionic groups (carboxy group, sulfo group, phosphoric acid group, phosphonic acid group, sulfuric acid group, etc.). .. As a result, in the process of forming the specific particles, a neutralized anionic group (that is, an anionic group in the form of a salt; for example, a salt of carboxy group, a salt of sulfo group, a salt of phosphoric acid group, a phosphonic acid group). Salt, a sulfate group salt, etc.) can be formed.
When the basic compound (neutralizing agent) is used, it is preferable that the basic compound (neutralizing agent) is contained in at least the aqueous phase component.
Examples of the basic compound include inorganic bases such as sodium hydroxide and potassium hydroxide, organic bases such as triethylamine, and the like. Among these, the basic compound is preferably an inorganic base such as sodium hydroxide or potassium hydroxide.
Examples of the salt in the anionic group in the form of salt include alkali metal salts such as sodium salt and potassium salt; organic amine salts such as triethylamine salt; and the like. Among these, as the salt in the anionic group in the form of salt, alkali metal salts such as sodium salt and potassium salt are preferable.

The total amount obtained by removing the organic solvent and water from the oil phase component and the water phase component in the production method A corresponds to the total solid content of the specific particles in the produced ink.
For the preferable range of the amount of each component used in the production method A, the above-mentioned “ink” can be referred to. At the time of this reference, in the above-mentioned "ink", "content" and "total solid content of specific particles" refer to "usage" and "oil phase component and water phase component from organic solvent and water, respectively". Read the whole quantity.

In the step of forming the specific particles, the method of mixing the oil phase component and the aqueous phase component is not particularly limited, and examples thereof include mixing by stirring.

In the step of forming the specific particles, the emulsification method is not particularly limited, and examples thereof include emulsification with an emulsification device such as a homogenizer (for example, a disperser).
The number of revolutions of the disperser in the emulsification is, for example, 5000 rpm (round per minute) to 20000 rpm, and preferably 10,000 rpm to 15000 rpm.
The rotation time in the emulsification is, for example, 1 minute to 120 minutes, preferably 3 minutes to 60 minutes, more preferably 3 minutes to 30 minutes, and further preferably 5 minutes to 15 minutes.

The emulsification in the step of forming the specific particles may be performed under heating.
By performing the emulsification under heating, the specific particles can be formed more efficiently.
Further, by performing the emulsification under heating, it is easy to remove at least a part of the organic solvent in the oil phase component from the mixture.
When the emulsification is performed under heating, the heating temperature is preferably 35°C to 70°C, more preferably 40°C to 60°C.

Further, the step of forming the specific particles includes an emulsification step of emulsifying the mixture (for example, at a temperature lower than 35° C.), and a heating step of heating the emulsion obtained by the emulsification step (for example, at a temperature higher than 35° C.). , May be included.
In the embodiment including the emulsification step and the heating step, the specific particles can be formed more efficiently, particularly in the heating step.
Further, in the embodiment including the emulsification step and the heating step, particularly in the heating step, at least a part of the organic solvent in the oil phase component can be easily removed from the mixture.
The heating temperature in the heating step is preferably 35°C to 70°C, more preferably 40°C to 60°C.
The heating time in the heating stage is preferably 6 hours to 50 hours, more preferably 12 hours to 40 hours, and even more preferably 15 hours to 35 hours.

In addition, the production method A may have other steps than the step of forming the specific particles, if necessary.
Examples of the other step include a step of adding other components (such as a pigment) after the step of forming the specific particles.
The other components (pigments, etc.) to be added are as already described as the other components that can be contained in the ink.

[Another example of ink production method (production method B)]
As a method of producing an ink containing specific particles containing a specific crosslinked polymer, the following production method B is also suitable.
In the production method B, an oil phase component containing an organic solvent and a trifunctional or higher functional isocyanate compound is mixed with an aqueous phase component containing water, and a specific gelling agent (that is, a gelling agent having an active hydrogen group) is present. It has a process of forming specific particles by emulsifying below.
A preferred embodiment of the production method B is that a trifunctional or higher functional isocyanate compound is used as an oil phase component instead of a specific polymer, and that a mixture of an oil phase component and an aqueous phase component is emulsified in the presence of a specific gelling agent. It is the same as the preferred embodiment of the production method A except for.
In a more preferred embodiment of the production method B, a water phase component containing water and a specific gelling agent is used as the water phase component, and the mixture of the oil phase component and the water phase component is converted into the specific gelation contained in the water phase component. This is an embodiment of emulsifying in the presence of an agent.

[Image forming method]
The image forming method of the present disclosure includes a step of forming an ink film on a substrate by applying the above-described ink of the present disclosure (hereinafter, also referred to as “applying step”), and a step of heating the ink film ( Hereinafter, also referred to as "heating step").
The image forming method of the present disclosure may include other steps as necessary.
According to the image forming method of the present disclosure, an image having excellent scratch resistance is formed on a base material.

(Applying process)
The applying step is a step of forming an ink film by applying the ink of the present disclosure on the base material.
As a mode of applying the ink on the base material, any of modes using a known method such as a coating method, a dipping method, and an inkjet method may be adopted. Among them, the inkjet method is preferable because a film (for example, an image) can be formed on various base materials (including a recording medium).

The base material is not particularly limited, and for example, known base materials provided as a support and a recording medium can be appropriately selected and used.
Examples of the substrate include paper, paper laminated with plastic (eg, polyethylene, polypropylene, polystyrene, etc.), metal plate (eg, metal plate of aluminum, zinc, copper, etc.), plastic film (eg, polychlorinated material). Polyvinyl Chloride (PVC) resin, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate (PET), polyethylene (PE:polyethylene), polystyrene (PS) : Polystyrene), polypropylene (PP: Polypropylene), polycarbonate (PC: Polycarbonate), polyvinyl acetal, acrylic resin and other films), the above-mentioned metal laminated or vapor-deposited paper, the above-mentioned metal laminated or vapor-deposited Examples include plastic films.

Further, as the base material, a textile base material can also be mentioned.
Examples of the material for the textile substrate include natural fibers such as cotton, silk, hemp and wool; chemical fibers such as viscose rayon and rheocell; synthetic fibers such as polyester, polyamide and acrylic; natural fibers, chemical fibers and synthetic fibers. A mixture of at least two kinds selected from the group consisting of fibers; and the like. As the textile base material, the textile base material described in paragraphs 0039 to 0042 of WO 2015/158592 may be used.

As the base material, a plastic such as a polyvinyl chloride (PVC) base material, a polystyrene (PS) base material, a polycarbonate (PC) base material, a polyethylene terephthalate (PET) base material, a polypropylene (PP) base material, or an acrylic resin base material. Substrates are preferred.

The ink can be applied by the inkjet method using a known inkjet recording device.
The inkjet recording device is not particularly limited, and a known inkjet recording device that can achieve a desired resolution can be arbitrarily selected and used.
Examples of the inkjet recording device include a device including an ink supply system, a temperature sensor, and a heating unit.
The ink supply system includes, for example, a main tank containing the ink of the present disclosure, 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 (dot per inch) x 320 dpi to 4000 dpi x 4000 dpi, more preferably 400 dpi x 400 dpi to 1600 dpi x 1600 dpi. More preferably, it can be driven so as to eject at a resolution of 720 dpi×720 dpi. In addition, dpi represents the number of dots per 2.54 cm (1 inch).

In addition, in the applying step, the ink may be applied to the preheated base material.
In the applying step, when the ink is applied to the preheated base material, the following heating step can be performed by the heated base material (that is, the ink film is formed by the heated base material). Can be heated).
The heating of the base material before applying the ink can be performed, for example, by the heating means exemplified in the heating step described later.

(Heating process)
The heating step is a step of heating the ink film formed on the base material.
By heating the ink film in the heating step, the viscosity of the ink film increases as described above, and as a result, an image having excellent scratch resistance is obtained.
In the image forming method of the present disclosure, when the above-described thermosetting ink is used as the ink of the present disclosure, the ink film is cured (that is, thermal polymerization by the heat-polymerizable monomer) by heating in the heating step. May be. In other words, when the thermosetting ink described above is used as the ink of the present disclosure, the heating step may also serve as the curing step B described below.

Examples of the heating mode in the heating step include a mode in which the ink applied on the base material is heated by a heating means.
Further, as described above, when the ink is applied to the substrate that has been heated in advance in the applying step, the aspect of heating in the heating step also includes an aspect in which the ink is heated by the heated substrate.

The heating means is not particularly limited, and examples thereof include a heat drum, warm air, infrared lamp, infrared LED, infrared heater, heat oven, heat plate, infrared laser, and infrared dryer. Among them, a light emitting diode having a maximum absorption wavelength at a wavelength of 0.8 μm to 1.5 μm or a wavelength of 0.8 μm to 3.5 μm, and a light emitting diode having an emission wavelength from near infrared to far infrared ( (LED), a heater emitting near infrared rays to far infrared rays, a laser having an oscillation wavelength in the near infrared rays to far infrared rays, or a dryer emitting the near infrared rays to far infrared rays is preferable.

From the viewpoint of more effectively increasing the viscosity of the ink film, the heating temperature during heating is preferably 40° C. or higher, more preferably 40° C. to 200° C., further preferably 45° C. to 100° C., and 50° C. to 80° C. More preferably, 55° C. to 70° C. is further preferable.
The heating temperature refers to the temperature of the ink on the substrate, and can be measured by a thermograph using an infrared thermography device H2640 (manufactured by Japan Avionics Co., Ltd.).
The heating time can be appropriately set in consideration of the heating temperature, the composition of the ink, the printing speed, and the like. The heating time is preferably 5 seconds or longer, more preferably 5 seconds to 5 minutes, even more preferably 10 seconds to 1 minute, still more preferably 20 seconds to 1 minute.

(Curing process)
The image forming method of the present disclosure can include a curing step of curing the ink film heated by the heating step.
By this curing step, a polymerization reaction (that is, a crosslinking reaction) by the polymerizable monomer proceeds in the ink film. Therefore, when the image forming method of the present disclosure has a curing step, the hardness of the image can be further improved, and the scratch resistance of the image can be further improved.

In the image forming method of the present disclosure, when a photocurable ink is used, as a curing step, the ink film heated by the heating step is irradiated with light (that is, active energy rays) to expose the ink film to light. A curing step for curing (hereinafter, “curing step A”) can be provided.

In the image forming method of the present disclosure, when a thermosetting ink is used, as a curing step, a curing step of thermally curing the ink film by heating or irradiating infrared rays to the ink film heated by the heating step ( Hereinafter, "curing step B") can be provided.
However, when a thermosetting ink is used, the curing step B (that is, a curing step B different from the heating step described above) is not provided, and the thickening and the thermal curing of the ink film are performed by the heating step described above. May be.
That is, in the image forming method of the present disclosure, when a thermosetting ink is used, a heating step for thickening the ink film and a curing step B for thermally curing the ink film may be separately provided. However, a single heating step may be provided to both increase the viscosity and heat cure the ink film.

-Curing step A-
The curing step A is a step of curing the ink film by irradiating the ink film heated by the heating process with active energy rays.
In the curing step A, by irradiating the ink film heated in the heating step with an active energy ray, a photocrosslinking reaction (that is, a photopolymerization reaction) of specific particles in the ink film progresses, whereby an ink film is formed. The strength of is increased.

Examples of the active energy ray that can be used in the curing step A include ultraviolet rays (UV light), visible rays, and electron rays, and among these, UV light is preferable.

The peak wavelength of the active energy ray (light) is preferably 200 nm to 405 nm, more preferably 220 nm to 390 nm, further preferably 220 nm to 385 nm.
It is also preferably 200 nm to 310 nm, and more preferably 200 nm to 280 nm.

Exposure surface illuminance when the active energy ray (light) is irradiated, for example, ^{10mW / cm 2 ~2000mW / cm 2} , preferably ^{20mW / cm 2 ~1000mW / cm 2} .
Exposure energy at the time of an active energy ray (light) is irradiated, for example, ^{10mJ / cm 2 ~2000mJ / cm 2} , preferably ^{20mJ / cm 2 ~1000mJ / cm 2} .

As a source for generating active energy rays (light), mercury lamps, metal halide lamps, UV fluorescent lamps, gas lasers, solid-state lasers, etc. are widely known.
Further, the replacement of the light source exemplified above with a semiconductor ultraviolet light emitting device is very useful industrially and environmentally.
Among semiconductor ultraviolet light emitting devices, LEDs (Light Emitting Diodes) and LDs (Laser Diodes) are small, have a long life, have high efficiency, and are low in cost, and are expected as light sources.
As the light source, a metal halide lamp, an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a medium pressure mercury lamp, a low pressure mercury lamp, an LED, or a blue-violet laser is preferable.
Among these, when a sensitizer and a photopolymerization initiator are used in combination, an ultrahigh pressure mercury lamp capable of light irradiation with a wavelength of 365 nm, 405 nm, or 436 nm, and light irradiation with a wavelength of 365 nm, 405 nm, or 436 nm is possible. A high-pressure mercury lamp or an LED capable of irradiating light with a wavelength of 355 nm, 365 nm, 385 nm, 395 nm, or 405 nm is more preferable, and an LED capable of irradiating light with a wavelength of 355 nm, 365 nm, 385 nm, 395 nm, or 405 nm is most preferable.

In the curing step A, the irradiation time of the active energy ray to the ink applied on the substrate is, for example, 0.01 seconds to 120 seconds, preferably 0.1 seconds to 90 seconds.
As the irradiation conditions and the basic irradiation method, the irradiation conditions and the irradiation method disclosed in JP-A-60-132767 can be similarly applied.
As a method of irradiating the active energy ray, specifically, a light source is provided on both sides of a head unit including an ink ejecting 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 is used. A method of irradiating with active energy rays is preferable.
Irradiation with active energy rays is preferably carried out after a fixed time (for example, 0.01 seconds to 120 seconds, preferably 0.01 seconds to 60 seconds) after the ink is landed and heated and dried.

-Curing step B-
The curing step B is a step of thermally curing the ink film by heating or irradiating infrared rays to the ink film heated in the heating process.
In the curing step B, the ink film heated in the heating step is heated or irradiated with infrared rays, whereby a thermal crosslinking reaction (that is, a thermal polymerization reaction) of specific particles in the ink progresses, whereby an ink film is formed. The strength of is increased.
The preferred embodiment of the curing step B is the same as the preferred embodiment of the heating step.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to the following Examples.
In the following, "parts" means parts by mass unless otherwise specified.
Further, “*” in the chemical formula represents a bonding position.

<Synthesis of specific chain polymer>
(Synthesis of Polymer 1 (with a terminal and a photopolymerizable group))
According to the following reaction scheme, the following polymer 1 (having a terminal and a photopolymerizable group) was synthesized as a specific chain polymer.
Here, the term “terminal” means that the polymer has a monovalent gelling group at the terminal of the main chain, and “having a photopolymerizable group” means that the polymer has a photopolymerizable group. Meaning (hereinafter the same).

In a three-necked flask, dicyclohexylmethane-4,4'-diisocyanate (HMDI) (82.5 g), dimethylolpropionic acid (DMPA) (16.9 g), tricyclodecane dimethanol (compound (2-5)) (2 .9 g), bisphenol A epoxy diacrylate (compound (a-21)) (77.0 g), and ethyl acetate (102.3 g) were charged and heated to 70°C. Then, 0.2 g of Neostan U-600 (manufactured by Nitto Kasei Co., Ltd., inorganic bismuth catalyst; hereinafter also referred to as "U-600") was added, and the mixture was stirred at 70°C for 5 hours.
Then, there, eicosylamine (C ₂₀ H ₄₁ NH ₂ ) (0.3 g as a specific gelling agent (specifically, an amphipathic gelling agent having an active hydrogen group), which is an end-capping agent, is added thereto. ) And ethyl acetate (190 g) were added, and the mixture was stirred at 70° C. for 3 hours. After stirring for 3 hours, the reaction solution was allowed to cool to room temperature and then the concentration was adjusted with ethyl acetate to obtain a 30 mass% solution of polymer 1 (solvent: ethyl acetate).
The weight average molecular weight (Mw) of Polymer 1 was 8000, and the acid value was 0.70 mmol/g.

Polymer 1 has an acryloyl group as a photopolymerizable group.
Polymer 1 is a chain urethane polymer having a gelling group at the end of the main chain.
Specifically, the polymer 1 contains the following group (G-1), which is an example of the group represented by the formula (G) (when n ^G is 1), at the end of the main chain.
Following groups (G-1) includes a eicosyl amine amphiphilic gelling agent having an active hydrogen group _{(C 20 H 41 NH 2)} , and an isocyanate group in the HMDI, which is a reaction product of.

(Synthesis of Polymers 2 to 9 (with a terminal and a photopolymerizable group))
Except that the type of the specific gelling agent that is an end-capping agent was changed as shown in Table 1, all were chain polymers such as polymers 2 to 9 (terminal, photopolymerizable). (With group) was synthesized.
All of the polymers 2 to 9 had a weight average molecular weight (Mw) of 8000 and an acid value of 0.70 mmol/g.

In the classification of raw materials in Table 1 and Table 2, HG means a hydrogelating agent, and AMG means an amphipathic gelling agent.
The specific gelling agents in Table 1 and Table 2 are as follows.
C20H41NH2, C18H37NH2, C16H33NH2, and C8H17NH2, respectively, eicosyl amine _{(C 20 H 41 NH 2)} , octadecylamine _{(C 18 H 37 NH 2)} , hexadecylamine _{(C 16 H 33 NH 2)} , and octylamine (C ₈ H ₁₇ NH ₂ ) is meant. All of these compounds are amphiphilic gelling agents having active hydrogen groups.

G0402, N0949, and S0946 are all polysaccharides, which are aminoethyl glycosides manufactured by Tokyo Chemical Industry Co., Ltd., and their structures are as follows. All of these compounds are hydrogelators having an active hydrogen group.
In each of these examples using the aminoethylglycoside polysaccharide, the primary amino group in the aminoethylglycoside polysaccharide reacts with the isocyanate group of HMDI to give R in the formula (G). ^{As U} , a urea group is formed. In these examples, both, n ^G becomes 1 in the formula (G), L ^G in formula (G) becomes an ethylene group, R ^G in the formula (G) is a hydrogen atom polysaccharides 1 The residue is the one removed.

E707 is an amphipathic gelling agent having an active hydrogen group, specifically Emulgen (registered trademark) E707 manufactured by Kao Corporation, and more specifically, a linear alkyl group having 11 to 15 carbon atoms. Is a monoalkyl polyethylene glycol (number average molecular weight 508).
In the example using E707, the hydroxy group in E707 and the isocyanate group of HMDI react with each other to form a urethane group as R ^U in the formula (G). In this example, n ^G becomes 1 in the formula (G), L ^G in formula (G) becomes an ethylene group, R ^G in the formula (G) is, as a monovalent hydrophobic group, the number of carbon atoms It becomes a straight chain alkyl group of 11 to 15.

F108 is a hydrogelating agent having an active hydrogen group, specifically, Pluronic (registered trademark) F108 manufactured by BASF, and more specifically, polyethylene glycol/polypropylene glycol/polyethylene glycol triblock copolymer ( The number average molecular weight is 14600). F108 is an example of the polyoxyalkylene compound represented by the above formula (1A). In F108, R in the formula (1A) is a hydrogen atom.
In this example using F108, R ^U (urethane group) is formed by the reaction between the hydroxy group in the hydroxyethyl group at the terminal portion in F108 and the isocyanate group, and the ethyl group portion in the hydroxyethyl group is L ^It becomes ^G (ethylene group), and the part of F108 excluding the hydroxyethyl group becomes R ^G. R ^G corresponds to a residue obtained by removing one hydrogen atom from the polyoxyalkylene compound represented by the formula (1) as a hydrogelating agent.

(Synthesis of Comparative Polymers A and B)
Comparative polymers A and B, each of which is a chain polymer, were synthesized in the same manner as in the synthesis of polymer 1 except that the specific gelling agent as the terminal blocking agent was changed to the comparative compound shown in Table 1.
The comparative polymers A and B each had a weight average molecular weight (Mw) of 8000 and an acid value of 0.70 mmol/g.

In Tables 1 and 2, PEGME is polyethylene glycol monomethyl ether (number average molecular weight (Mn)=4000), and IPA is isopropyl alcohol.

(Synthesis of Polymer 10 (with a photopolymerizable group in the main chain))
Polymer 10 (having a photopolymerizable group in the main chain) was synthesized as a specific chain polymer according to the following reaction scheme.
Here, “in the main chain” means that the polymer has a divalent gelling group in the main chain, and “with a photopolymerizable group” means that the polymer has a photopolymerizable group. Means

In a three-necked flask, dicyclohexylmethane-4,4'-diisocyanate (HMDI) (82.5 g), dimethylolpropionic acid (DMPA) (16.9 g), tricyclodecane dimethanol (compound (2-5)) (2 1.9 g), bisphenol A epoxy diacrylate (compound (a-21)) (77.0 g), 1,12- as a specific gelling agent (specifically, an amphiphilic gelling agent having an active hydrogen group). dodecyl diamine _{(H 2 N (CH 2)} 12 NH 2) (0.3g), and it was charged ethyl acetate (102.3 g), heated to 70 ° C.. U-600 0.2g was added there and it stirred at 70 degreeC for 5 hours.
Next, isopropyl alcohol (IPA) (80 g) as an end-capping agent and ethyl acetate (110 g) were added thereto, and the mixture was stirred at 70° C. for 3 hours. After stirring for 3 hours, the reaction solution was allowed to cool to room temperature, and then the concentration was adjusted with ethyl acetate to obtain a 30 mass% solution of polymer 9 (the solvent is ethyl acetate).
Polymer 9 had a weight average molecular weight (Mw) of 8,000 and an acid value of 0.70 mmol/g.

In Table 1 and Table 2, H2N- (CH2) 12- NH2 is a 1,12-dodecyl diamine _{(H 2 N (CH 2)} 12 NH 2).

The polymer 10 contains the following group (G-10), which is an example of the group represented by the formula (G).
Following groups (G-10) is to be amphiphilic gelling agent having an active hydrogen group 1,12 dodecyl diamine _{(H 2 N (CH 2)} 12 NH 2), and an isocyanate group in the HMDI, the It is a reaction product.

(Synthesis of Polymers 11 to 16 (with a photopolymerizable group in the main chain))
Polymers 11 to 16 which were all chain polymers were synthesized in the same manner as the synthesis of polymer 10, except that the type of the specific gelling agent was changed as shown in Table 1.
All of the polymers 11 to 16 had a weight average molecular weight (Mw) of 8000 and an acid value of 0.70 mmol/g.

In Table 1, the structures of gel-01 to gel-06 are as follows, and melting points and molecular weights are as shown in Table 1.

gel-01 to gel-06 were respectively synthesized as follows.
-Synthesis of gel-01: 20 g of 3-amino-1-propanol was dissolved in 300 mL of acetonitrile, and the mixture was stirred at 0°C. 26.8 g of dodecanedioic acid dichloride was added dropwise thereto, and the mixture was stirred at 0° C. for 1 hour. The obtained reaction liquid was poured into 300 mL of water, hydrochloric acid was added thereto to adjust the pH to 3 or less, and the precipitated solid was collected by filtration. The solid was washed with 300 mL of water and dried at 60°C for 6 hours. As a result, the target product gel-01 was obtained.
-Synthesis of gel-02: Gel-02 was obtained in the same manner except that 3-amino-1-propanol was changed to DL-1-amino-2-propanol in the synthesis example of gel-01.
-Synthesis of gel-03: 23 g of hexamethylenediamine and 11.4 g of ε-caprolactone were dissolved in 200 mL of THF, and they were reacted for 2 hours under heating and refluxing conditions. The obtained reaction liquid was poured into 300 mL of water, hydrochloric acid was added thereto to adjust the pH to 3 or less, and the precipitated solid was collected by filtration. The solid was washed with 100 mL of water and dried at 60° C. for 6 hours. As a result, the target product, gel-03, was obtained.
Synthesis of gel-04: Gel-04 was obtained in the same manner as in the synthesis example of gel-03, except that 40 g of 1,12-dodecanediamine was used instead of hexamethylenediamine.
Synthesis of gel-05: In the same manner as in the synthesis example of gel-03, except that hexamethylenediamine was replaced with 40 g of 1,12-dodecanediamine and ε-caprolactone was replaced with 8.4 g of γ-butyrolactone, gel-05 was prepared in the same manner. Obtained.
-Synthesis of gel-06: In the same manner as in the synthesis example of gel-03, hexamethylenediamine was changed to 40 g of 1,12-dodecanediamine and ε-caprolactone was changed to 8.4 g of β-butyrolactone, respectively. -06 was obtained.

(Polymer 17)
As the polymer 17, a methacrylic polymer having a monovalent gelling group in its side chain was synthesized. The details will be described below.
1-Methoxy-2-propanol (11.3 g) was charged into a three-necked flask, and the mixture was stirred at 75° C. for 30 minutes under a nitrogen stream of 10 mL/min. Here, Karens (registered trademark) MOI (Showa Denko, 2-methacryloyloxyethyl isocyanate) (1.13 g), methyl methacrylate (10.67 g), methacrylic acid (0.90 g), V-601 (Wako Pure) A liquid mixture of dimethyl 2,2′-azobis(2-methylpropionic acid) (0.14 g) and 1-methoxy-2-propanol (11.3 g) manufactured by Yakuhin Kogyo was added dropwise over 2 hours. After completion of the dropping, eicosylamine (2.29 g), which is an amphiphilic gelling agent having an active hydrogen group, was added, and the mixture was further stirred at 75°C for 2 hours. The obtained reaction solution was allowed to cool to room temperature and then poured into a mixed solution of 200 mL of water/20 mL of acetone. The precipitated powder was collected by filtration and dried in an oven at 60°C for 6 hours. Ethyl acetate was added to the obtained powder to adjust the concentration to obtain a 30 mass% solution of polymer 17 (the solvent is ethyl acetate).
Polymer 17 had a weight average molecular weight (Mw) of 20,000 and an acid value of 0.70 mmol/g.

(Synthesis of Polymer 101 (Terminal, No Photopolymerizable Group))
According to the following reaction scheme, the following polymer 101 (terminal, no photopolymerizable group) was synthesized as a specific chain polymer.
Here, the term "terminal" means that the polymer has a monovalent gelling group at the terminal of the main chain, and "no photopolymerizable group" means that the polymer has no photopolymerizable group. Means

In a three-necked flask, dicyclohexylmethane-4,4'-diisocyanate (HMDI) (41.2 g), dimethylolpropionic acid (DMPA) (6.4 g), tricyclodecane dimethanol (compound (2-5)) (20 .2 g) and ethyl acetate (67.7 g) were charged and heated to 70°C. 0.14g of U-600 was added there and it stirred at 70 degreeC for 5 hours.
Then, thereto was added a eicosyl amine as the specific gelling agent is a terminal blocking agent _{(C 20 H 41 NH 2)} (0.2g), and ethyl acetate (42.9 g), a 70 The mixture was stirred at °C for 3 hours. After stirring for 3 hours, the reaction solution was allowed to cool to room temperature and then the concentration was adjusted with ethyl acetate to obtain a 30 mass% solution of polymer 101 (the solvent is ethyl acetate).
The weight average molecular weight (Mw) of the polymer 101 was 8000, and the acid value was 0.70 mmol/g.
The polymer 101 contains the group (G-1) similarly to the polymer 1.

(Synthesis of Polymer 102 to Polymer 104 (Terminal, No Photopolymerizable Group))
Polymers 102 to 104, which are all chain polymers, were synthesized in the same manner as the synthesis of the polymer 101 except that the type of the specific gelling agent that was the end capping agent was changed as shown in Table 2.
All of the polymers 102 to 104 had a weight average molecular weight (Mw) of 8000 and an acid value of 0.70 mmol/g.

(Synthesis of Comparative Polymers C and D)
Comparative polymers C and D, each of which is a chain polymer, were synthesized in the same manner as in the synthesis of the polymer 101 except that the specific gelling agent as the end cap was changed to the comparative compound shown in Table 2.
The comparative polymers C and D both had a weight average molecular weight (Mw) of 8000 and an acid value of 0.70 mmol/g.

(Synthesis of Polymer 105 (without photopolymerizable group in main chain))
According to the following reaction scheme, polymer 105 (with no photopolymerizable group in the main chain) was synthesized as a specific chain polymer.

In a three-necked flask, dicyclohexylmethane-4,4'-diisocyanate (HMDI) (41.2 g), dimethylolpropionic acid (DMPA) (6.4 g), tricyclodecane dimethanol (compound (2-5)) (20 .2 g), eicosylamine (C ₂₀ H ₄₁ NH ₂ ) (0.2 g) as a specific gelling agent, and ethyl acetate (67.7 g) were charged, and the mixture was heated to 70°C. 0.14g of U-600 was added there and it stirred at 70 degreeC for 5 hours.
Next, isopropyl alcohol (IPA) (10 g) as an end-capping agent and ethyl acetate (32.9 g) were added thereto, and the mixture was stirred at 70° C. for 3 hours. After stirring for 3 hours, the reaction solution was allowed to cool to room temperature, and then the concentration was adjusted with ethyl acetate to obtain a 30 mass% solution of polymer 105 (the solvent is ethyl acetate).
The weight average molecular weight (Mw) of the polymer 105 was 8000, and the acid value was 0.70 mmol/g.
The polymer 105 contains the group (G-10) similarly to the polymer 10.

(Synthesis of Polymer 106 (without photopolymerizable group in main chain))
Polymer 106 was synthesized in the same manner as polymer 105 except that the type of the specific gelling agent was changed as shown in Table 2.
The polymer 106 had a weight average molecular weight (Mw) of 8000 and an acid value of 0.70 mmol/g.

[Example 1] (photocurable ink)
<Preparation of water dispersion>
-Preparation of oil phase component-
A mixed solution of ethyl acetate and ethanol (ethyl acetate:ethanol (mass ratio)=10:1),
A 30% by weight solution of polymer 1 (53 parts by weight of polymer 1),
Photopolymerizable compound SR833S (22 parts; hereinafter also referred to as "S833") manufactured by Sartomer Co., Ltd.,
Photopolymerizable compound SR399E (22 parts; hereinafter also referred to as "S399") manufactured by Sartomer Co., Ltd.,
A photopolymerization initiator IRGACURE (registered trademark) 819 (2.5 parts; hereinafter also referred to as “IRG819”) manufactured by BASF,
2-isopropyl thioxanthone (0.5 part; hereinafter also referred to as "ITX") manufactured by Tokyo Kasei Kogyo Co., Ltd. as a sensitizer,
Were mixed and stirred for 15 minutes to obtain 44 g of an oil phase component having a solid content of 36 mass %.

S833 is a bifunctional photopolymerizable monomer having a cyclic structure, and specifically is tricyclodecane dimethanol diacrylate (molecular weight 304).
S399 is a pentafunctional photopolymerizable monomer having no cyclic structure, and is specifically dipentaerythritol pentaacrylate (molecular weight 525).
IRG819 is an acylphosphine oxide-based photopolymerization initiator, and is specifically bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide.

-Preparation of water phase components-
Distilled water (45 g) was mixed with sodium hydroxide as a neutralizing agent and stirred for 15 minutes to prepare an aqueous phase component.
The amount of sodium hydroxide used as a neutralizing agent was adjusted so that the degree of neutralization of carboxy groups in the produced particles was 90%.
The specific amount of sodium hydroxide was calculated by the following calculation formula.
Amount of sodium hydroxide (g)=total amount of oil phase component (g)×(solid content concentration of oil phase component (mass %)/100)×(content of polymer 1 relative to total solid content of oil phase component (mass) %)/100)×acid value of polymer 1 (mmol/g)×0.9×molecular weight of sodium hydroxide (g/mol)/1000

The above oil phase component and the above water phase component were mixed, and the obtained mixture was emulsified at 18000 rpm for 10 minutes using a homogenizer at 25° C. to obtain an emulsion. The obtained emulsion was added to distilled water (25 g), and the obtained liquid was stirred at room temperature for 30 minutes. Next, this liquid was heated to 50° C. and stirred at 50° C. for 6 hours to distill off ethyl acetate and ethanol from the liquid.
The liquid from which the ethyl acetate and ethanol had been distilled off was further stirred at 50° C. for 24 hours to form specific particles in the liquid.
Next, the liquid containing the specific particles was diluted with distilled water so that the solid content was 20% by mass to obtain an aqueous dispersion of the specific particles.

<Preparation of photocurable ink>
The components having the following compositions were mixed to prepare a photocurable ink.
-Composition of photocurable ink-
-The above water dispersion ... 82 parts-Pigment dispersion liquid (Pro-jet Cyan APD1000 (manufactured by FUJIFILM Imaging Colorants), pigment concentration 14 mass%) ... 13 parts-Fluorosurfactant (manufactured by DuPont, Capstone FS-31) , Solid content 25% by mass) 0.3 part 2-methylpropanediol 4.7 parts

<Evaluation>
The following evaluation was performed using the photocurable ink obtained above.
The results are shown in Table 1.

(Scratch resistance of cured film)
The photocurable ink stored at room temperature for less than 1 day after preparation was applied onto a substrate to form a coating film having a thickness of 12 μm on the substrate.
As the base material, COREX, which is a polypropylene (PP) substrate manufactured by DUR Plastic, was used.
In addition, the above-mentioned coating is performed by RK PRINT COAT INSTRUMENTS K hand coater No. Performed using 2 bars.

Next, the coating film was heated at 60° C. for 3 minutes to be dried.
The dried coating film was irradiated with ultraviolet rays (UV) to cure the coating film to obtain a cured film.
Ultraviolet (UV) irradiation is equipped with an ozone-less metal halide lamp MAN250L as an exposure light source, and the experimental UV mini-conveyor device CSOT (GS Co., Ltd.) is set to conveyer speed 35 m/min and exposure intensity 1.0 W/cm ^2. Yuasa Power Supply) was used. This UV irradiation was performed at an exposure energy of 1000 mJ/cm ² .

A scratch test under the following conditions was performed on the cured film formed above.

-Scratch test conditions-
・Equipment... Reciprocating abrasion tester "TYPE30S" made by Haydn
Scratch needle: SUS (stainless steel) scratch needle with a tip radius of curvature of 1.0 mm-Weighted load: 100 g and 200 g, two conditions-Scratch speed: 3000 mm/min.
・Number of scratches: 5 round trips

After the execution of the scratch test, the surface of the cured film was visually observed, and the scratch resistance of the cured film was evaluated according to the following evaluation criteria.
In the following evaluation criteria, A has the highest scratch resistance of the cured film.

-Evaluation criteria for scratch resistance of cured film-
A: After 5 reciprocations, no scratch marks were observed on the cured film under both conditions of load 100 g and load 200 g.
B: After 5 reciprocations, no scratch mark was observed on the cured film under the condition of a load of 100 g, but a slight scratch mark was observed on the cured film under the condition of a load of 200 g.
C: After 5 reciprocations, a slight scratch mark was observed on the cured film under the condition of a load of 100 g.
D: After 5 reciprocations, a scratch mark was clearly seen on the cured film under the condition of a load of 100 g.

(Image fineness)
The base material is heated to 60° C. by a print heater, and the photocurable ink is discharged from the head of the inkjet printer onto the heated base material, and the character image shown in FIG. , 7 points, and 10 points.

The formed character image shown in FIG. 1 of each size was observed with a craft magnifier (manufactured by Etsumi Co., Ltd.) at a magnification of 10 times. Based on the observation result, the fineness of the image was evaluated according to the following evaluation criteria. In the following evaluation criteria, A has the highest image definition.

− Evaluation criteria for image fineness −
A: The character image shown in FIG. 1 having a size of 5 points was formed without being crushed or bleeding.
B: The character image shown in FIG. 1 having a size of 7 points was formed without crushing and bleeding (except for the case corresponding to A).
C: The character image shown in FIG. 1 having a size of 10 points was formed without crushing and bleeding (except for the case corresponding to A or B).
D: The character image shown in FIG. 1 having a size of 10 points was crushed or smeared.

[Examples 2 to 17] (photocurable ink)
The same operation as in Example 1 was performed except that the polymer 1 was changed to the polymers shown in Table 1.
The results are shown in Table 1.

[Comparative Examples 1 and 2] (photocurable ink)
The same operation as in Example 1 was performed except that the comparative polymer shown in Table 1 was used instead of the polymer 1.
The results are shown in Table 1.

As shown in Table 1, in Examples 1 to 17 using the photocurable ink containing water and particles containing a polymer having a gelling group (that is, specific particles), the polymer in the particles was The scratch resistance of the image and the fineness of the image were excellent as compared with Comparative Examples 1 and 2 having the comparative group instead of the gelling group.

From the comparison of Examples 1 to 3 and 5 to 9 and Examples 10 to 16, the gelling group is a monovalent group (that is, n ^G in the formula (G) is 1). In Examples 1 to 3 and 5 to 9, it can be seen that the scratch resistance of the image and the fineness of the image are further improved.

From the comparison between Examples 1 to 3 and 5 to 9 and Example 17, when the gelling group is arranged at the end of the main chain of the polymer (Examples 1 to 3 and 5 to 9), It can be seen that the scratch resistance of the image and the fineness of the image are further improved.

From the results of Examples 5 to 8, when a hydrogelating agent (HG) having an active hydrogen group was used to form a gelling group, the group corresponding to R ^G in formula (G) remained as a polysaccharide residue. It can be seen that in the case of the base (Examples 5 to 7), the scratch resistance of the image and the definition of the image are further improved.

From the results of Examples 1 to 4 and 9, when the amphiphilic gelling agent having an active hydrogen group (AMG) was used for forming the gelling group, the hydrophobicity corresponding to R ^G in the formula (G) was obtained. It can be seen that when the number of carbon atoms in the functional group is 10 or more (Examples 1 to 3 and 9), scratch resistance of the image and fineness of the image are further improved.
Especially, when the number of carbon atoms of the hydrophobic group corresponding to R ^G in the formula (G) is 16 or more (Examples 1 to 3), the scratch resistance of the image and the fineness of the image are particularly improved. Recognize.

The volume average dispersed particle diameter of the specific particles was measured using the aqueous dispersion of the specific particles in each of Examples 1 to 17 described above.
As a result, in any of the examples, the volume average dispersed particle diameter of the specific particles was in the range of 0.15 μm to 0.25 μm.

[Example 101] (thermosetting ink)
<Preparation of thermosetting ink>
In the ink preparation, S833, S399, IRG819, and ITX were distilled off under reduced pressure from propylene glycol monomethyl ether under the conditions of 60° C. and 2.67 kPa (20 torr), Trixene ^™ BI7982 (thermopolymerizable monomer; blocked isocyanate; Baxenden Chemicals). Company) (hereinafter also referred to as “BI7982”; the amount is as shown in Table 2; molecular weight 793) and in the same manner as in Example 1 except that the polymer 1 was changed to the same amount of the polymer 101. A thermosetting ink was prepared.

<Evaluation>
The following evaluations were performed using the thermosetting ink obtained above.
The results are shown in Table 2.

(Scratch resistance of cured film)
Regarding the evaluation of scratch resistance of the cured film, the coating film was heated at 60° C. for 3 minutes to be dried, and the dried coating film was irradiated with ultraviolet rays (UV). The evaluation was performed in the same manner as the evaluation of scratch resistance of the cured film in Example 1 except that the heating operation was changed.

(Image fineness)
The image fineness was evaluated in the same manner as the image fineness evaluation in Example 1.

[Examples 102, 104, 105 and 106] (thermosetting ink)
The same operation as in Example 101 was performed, except that the polymer shown in Table 2 was used instead of the polymer 101.
The results are shown in Table 2.

[Example 103] (thermosetting ink)
BI7982 is a thermally polymerizable monomer having an epoxy group, EPICLON ^™ 840 (DIC; hereinafter also referred to as “EP840”; the amount is as shown in Table 2; molecular weight 340) and a thermosetting accelerator, 2-methylimidazole. (Hereinafter, also referred to as “2MI”; the amount is as shown in Table 2), except that the same operation as in Example 102 was performed.
The results are shown in Table 2.

[Comparative Examples 101 and 102] (thermosetting ink)
The same operation as in Example 101 was performed, except that the comparative polymer shown in Table 2 was used instead of the polymer 101.
The results are shown in Table 2.

As shown in Table 2, also in Examples 101 to 106 relating to the thermosetting ink, the same results as in Examples 1 to 17 relating to the photocurable ink were obtained.

The volume average dispersed particle diameter of the specific particles was measured using the aqueous dispersion of the specific particles in each of Examples 101 to 106 described above.
As a result, in any of the examples, the volume average dispersed particle diameter of the specific particles was in the range of 0.15 μm to 0.25 μm.

[Example 201] (Photocurable ink containing MC)
<Preparation of aqueous dispersion of microcapsules (MC)>
A microcapsule (MC) including a shell made of a urethane polymer, which is a specific crosslinked polymer having a three-dimensional crosslinked structure, and a core containing a photopolymerizable monomer, a photopolymerization initiator, and a sensitizer as described below. An aqueous dispersion of was prepared.
In this example, the microcapsules (MC) correspond to the specific particles.

-Preparation of oil phase component-
Ethyl acetate,
Takenate (registered trademark) D-110N manufactured by Mitsui Chemicals, Inc. (43 parts as the amount of the trifunctional isocyanate compound as the solid content; hereinafter, this solid content is also referred to as "D110"),
The following NCO1 solution (10 parts as the amount of NCO1 which is a solid content),
The above-mentioned S833 (20.5 parts) which is a photopolymerizable monomer,
The above-mentioned S399 (22 parts) which is a photopolymerizable monomer,
IRG819 (2.5 parts), which is a photopolymerization initiator,
The above-mentioned ITX (0.5 part) which is a sensitizer,
Were mixed and stirred for 15 minutes to obtain 45.7 g of an oil phase component having a solid content of 30% by mass.

Takenate D-110N is a 75 mass% ethyl acetate solution of an adduct of trimethylolpropane (TMP) and m-xylylene diisocyanate (XDI) (trifunctional isocyanate compound "D110").

NCO1 is an isocyanate compound having a carboxy group introduced therein, and specifically, an adduct of 2,2-bis(hydroxymethyl)butyric acid (DMBA) and IPDI (DMBA/IPDI=1/3 (molar ratio)). Is. The acid value of NCO1 is 1.2 mmol/g.
The above-mentioned solution of NCO1 is a 35 mass% ethyl acetate solution of NCO1.
A solution of NCO1 was charged with 18 g of 2,2-bis(hydroxymethyl)butyric acid (DMBA), 82 g of isophorone diisocyanate (IPDI), and 186 g of ethyl acetate (AcOEt) in a three-necked flask and heated to 50° C., and neostann was added thereto. It was prepared by adding 0.3 g of U-600 and reacting for 3 hours.

-Preparation of water phase components-
Distilled water (43.1 g), sodium hydroxide as a neutralizing agent, and eicosylamine (C ₂₀ H ₄₁ NH ₂ ) as a specific gelling agent were mixed and stirred for 15 minutes to give water. The phase components were prepared.
Here, the amount of eicosylamine (C ₂₀ H ₄₁ NH ₂ ) was 1.5 parts with respect to 43 parts of D110 described above.
The amount of sodium hydroxide used as the neutralizing agent was adjusted so that the degree of neutralization of carboxy groups in the manufactured MC was 90%.
The specific amount of sodium hydroxide was calculated by the following calculation formula.
Amount of sodium hydroxide (g)=total amount of oil phase component (g)×(solid content concentration of oil phase component (mass %)/100)×(content of NCO1 relative to total solid content of oil phase component (mass %) )/100)×acid value of NCO1 (mmol/g)×0.9×molecular weight of sodium hydroxide (g/mol)/1000

The oil phase component and the aqueous phase component were mixed, and the obtained mixture was emulsified at room temperature for 10 minutes at 12000 rpm using a homogenizer to obtain an emulsion. The obtained emulsion was added to distilled water (15.3 g), and the obtained liquid was heated to 50° C. and stirred at 50° C. for 5 hours to distill off ethyl acetate from the liquid. The remaining liquid was diluted with distilled water so that the solid content was 20% by mass to obtain an aqueous dispersion of microcapsules.

The polymer, which is the shell of the microcapsules, is a urethane polymer having a three-dimensional crosslinked structure formed by the reaction of D110, which is a trifunctional isocyanate compound, and NCO1, which is an isocyanate compound having a carboxy group introduced. The ends of this urethane polymer are blocked by the reaction between eicosylamine, which is a specific gelling agent as a terminal blocking agent, and an isocyanate group.
The polymer that is the shell of this microcapsule is
Urethane group originally included in NCO1,
The urethane group originally included in D110, and
It has a urea group formed by the reaction of the isocyanate group in D110 or NCO1, the isocyanate group in D110 or NCO1, and water.

<Preparation of photocurable ink>
The components having the following compositions were mixed to prepare a photocurable ink.
-Composition of photocurable ink-
-The above water dispersion ... 82 parts-Pigment dispersion liquid (Pro-jet Cyan APD1000 (manufactured by FUJIFILM Imaging Colorants), pigment concentration 14 mass%) ... 13 parts-Fluorosurfactant (manufactured by DuPont, Capstone FS-31) , Solid content 25% by mass) 0.3 part 2-methylpropanediol 4.7 parts

<Evaluation>
Using the obtained photocurable ink, the same evaluation as that performed in Example 1 was performed.
The results are shown in Table 3.

As shown in Table 3, it was confirmed that the example 201 relating to the photocurable ink containing MC as the specific particles also has an effect of excellent scratch resistance of an image and fineness of the image.

From the comparison between this Example 201 (Table 3) and the above-mentioned Example 1 (Table 1), in Example 1 containing the chain polymer (polymer 1) as the specific polymer, the tertiary polymer which was the shell of MC as the specific polymer was used. It can be seen that the scratch resistance of the image and the fineness of the image are excellent as compared with Example 201 containing the original crosslinked polymer.

When the volume average dispersed particle diameter of MC was measured using the aqueous dispersion of MC in Example 201 described above, the volume average dispersed particle diameter of MC was in the range of 0.15 μm to 0.25 μm.

[Example 301] (thermosetting ink containing MC)
<Preparation of thermosetting ink>
In the following manner, an aqueous dispersion of microcapsules (MC) including a shell made of a urethane polymer, which is a specific crosslinked polymer having a three-dimensional crosslinked structure, and a core containing a thermopolymerizable monomer was prepared.
In this example, the microcapsules (MC) correspond to the specific particles.

Specifically, in the same manner as in the preparation of the photocurable ink in Example 201, except that S833, S399, IRG819, and ITX were changed to BI7982 (the amounts are as shown in Table 4), the thermosetting ink An ink was prepared.
In the thermosetting ink, the structure of the polymer forming the MC shell is similar to that of the polymer forming the MC shell in Example 201.

<Evaluation>
Using the thermosetting ink obtained above, the same evaluation as in Example 101 regarding the thermosetting ink was performed.
The results are shown in Table 4.

As shown in Table 4, also in Example 301 relating to the thermosetting ink containing MC, the same results as in Example 201 relating to the photocurable ink containing MC were obtained.

From the comparison between this Example 301 (Table 4) and the above-mentioned Example 101 (Table 2), in Example 101 containing the chain polymer (polymer 101) as the specific polymer, the tertiary polymer which is the shell of MC as the specific polymer was used. It can be seen that the scratch resistance of the image and the fineness of the image are excellent as compared with Example 301 containing the original crosslinked polymer.

When the volume average dispersed particle diameter of MC was measured using the aqueous dispersion of MC in Example 301 described above, the volume average dispersed particle diameter of MC was in the range of 0.15 μm to 0.25 μm.

The disclosure of Japanese Patent Application No. 2017-183868 filed on Sep. 25, 2017 is incorporated herein by reference in its entirety.
All documents, patent applications, and technical standards mentioned herein are to the same extent as if each individual document, patent application, and technical standard was specifically and individually noted to be incorporated by reference. Incorporated herein by reference.

Claims (12)

water and,
Particles containing a polymer having a gelling group which is a urethane polymer, a urea polymer, or a (meth)acrylic polymer, and is a reaction product of a gelling agent having an active hydrogen group and an isocyanate group,
An ink composition containing: The ink composition according to claim 1, wherein the gelling group is a group represented by the following formula (G).

In the formula (G), n ^G represents 1 or 2, R ^U represents a urethane group, a urea group, a thiourethane group, or a thiourea group, and L ^G represents a single bond or a divalent linking group. , * Represents the bonding position.
In formula (G), R ^G is a polysaccharide, protein, acrylic resin, vinyl resin, or hydrogelating agent which is a polyoxyalkylene compound represented by formula (1) when n ^G is 1. It represents a residue obtained by removing one hydrogen atom, or represents a monovalent hydrophobic group.
In the formula (G), R ^G , when n ^G is 2, represents a residue obtained by removing two hydrogen atoms from the hydrogelating agent or represents a divalent hydrophobic group.
In formula (1), n and m each independently represent an integer of 2 or more, p represents an integer of 0 or more, L represents an alkylene group having 3 or more carbon atoms, and R represents a hydrogen atom. Represents an alkyl group or an aryl group. The hydrogelator is the polysaccharide or the polyoxyalkylene compound represented by the formula (1),
The monovalent hydrophobic group is a linear alkyl group having 10 or more carbon atoms,
The ink composition according to claim 2, wherein the divalent hydrophobic group is a linear alkylene group having 10 or more carbon atoms. The hydrogelator is the polysaccharide,
The monovalent hydrophobic group is a linear alkyl group having 16 or more carbon atoms,
The ink composition according to claim 2 or 3, wherein the divalent hydrophobic group is a linear alkylene group having 16 or more carbon atoms. The ink composition according to any one of claims 2 to 4, wherein the R ^U in the formula (G) is a urea group. The ink composition according to any one of claims 1 to 5, wherein the gelling group is a monovalent group. The polymer is a chain polymer,
The ink composition according to claim 6, wherein the gelling group is arranged at an end of a main chain of the chain polymer. The ink composition according to claim 1, wherein the particles contain a polymerizable monomer. The ink composition according to any one of claims 1 to 8, wherein the polymer has a polymerizable group. The ink composition according to claim 1, which is used as an inkjet ink. A method for producing the ink composition according to any one of claims 1 to 10, comprising:
A method for producing an ink composition, comprising a step of forming the particles by mixing an oil phase component containing an organic solvent and the polymer with an aqueous phase component containing water and emulsifying the mixture. Forming an ink film by applying the ink composition according to any one of claims 1 to 10 on a substrate;
Heating the ink film,
An image forming method including.