WO2019054019A1

WO2019054019A1 - Ink composition and image forming method

Info

Publication number: WO2019054019A1
Application number: PCT/JP2018/025243
Authority: WO
Inventors: 一郎小山; 昭太鈴木; 憲晃佐藤
Original assignee: 富士フイルム株式会社
Priority date: 2017-09-14
Filing date: 2018-07-03
Publication date: 2019-03-21
Also published as: JPWO2019054019A1; JP7102420B2

Abstract

Provided are: an ink composition that comprises water and particles comprising an acid group neutralized by a volatile neutralizer having a boiling point of 25 to 250°C and a non-volatile neutralizer having a boiling point of over 250°C; and an image forming method.

Description

Ink composition and image forming method

The present disclosure relates to an ink composition and an image forming method.

Conventionally, in the field of ink compositions, techniques using volatile bases and non-volatile bases are known.
For example, in JP-A-2010-138297, as a method for producing a thermal ink jet aqueous dispersion having excellent ejection speed and ejection stability, step (1): pigment, polymer having an anionic group, volatile base A mixture containing a non-volatile base, an organic solvent, and water, and the total of the degree of neutralization of the anionic group by the volatile base and the degree of neutralization of the anionic group by the non-volatile base is 210% to 500% And dispersing the mixture having a molar ratio of (volatile base / non-volatile base) of more than 1 to obtain a dispersion, and step (2): the dispersion obtained in step (1) And the step of removing the volatile base and the organic solvent to obtain an aqueous dispersion of polymer particles containing the pigment, and a method of producing a thermal ink jet aqueous dispersion is disclosed.

By the way, in the water-based ink containing particles, the dispersion stability of the particles is required.
In general, in an ink film formed using an ink containing water as a liquid component, the liquid component in the ink film is removed as compared to an ink film formed using an ink containing an organic solvent as a liquid component It is hard to be done. Therefore, an image formed using an ink containing water as a liquid component tends to be inferior in definition.
Therefore, the water-based ink containing particles may be required to be able to form a precise image.

Regarding the above-mentioned point, although the technology described in JP-A-2010-138297 can improve the dispersion stability of particles, the composition of the water dispersion described in JP-A-2010-138297 can be improved by heating. It is a composition that is difficult to thicken quickly. Therefore, it is difficult to form a fine image with the aqueous dispersion described in JP-A-2010-138297.

A problem to be solved by an embodiment of the present invention is to provide an ink composition which is excellent in dispersion stability and can form a fine image.
Further, another problem to be solved by the other embodiments of the present invention is to provide an image forming method capable of forming a fine image.

Means for solving the above problems include the following aspects.
<1> An ink containing water, a volatile neutralizing agent having a boiling point of 25 ° C. or more and 250 ° C. or less, and particles containing an acid group neutralized by a non-volatile neutralizing agent having a boiling point exceeding 250 ° C. Composition.
<2> The particle contains a polymer, and the polymer has an acid group neutralized by a volatile neutralizing agent having a boiling point of 25 ° C. or more and 250 ° C. or less and a nonvolatile neutralizing agent having a boiling point of 250 ° C. or more The ink composition as described in <1>.
<3> The ink composition according to <1> or <2>, wherein the volatile neutralizing agent is at least one selected from the group consisting of an amine compound and a quaternary ammonium hydroxide.
The ink composition as described in <3> whose valences of <4> amine compounds are one.

<5> The amine compound is at least one selected from the group consisting of a compound represented by the following formula (1), a compound represented by the formula (2), and a compound represented by the formula (3) The ink composition as described in <3> or <4>.
Formula (1): NR ¹ R ² R ³
Formula (2): NR ⁴ R ⁵ H
Formula (3): NR ⁶ H ₂
In formula (1), R ¹ , R ² and R ³ each independently represent an alkyl group. Any ^{two of} R ¹ , R ² and R ³ may be bonded to each other to form a ring containing a nitrogen atom.
In formula (2), R ⁴ and R ⁵ each independently represent an alkyl group, and R ⁴ and R ⁵ may combine with each other to form a ring containing a nitrogen atom.
In formula (3), R ⁶ represents an alkyl group.

<6> The ink composition according to any one of <1> to <5>, wherein the boiling point of the volatile neutralizing agent is 25 ° C. or more and 100 ° C. or less.
<7> The ink composition according to any one of <1> to <6>, wherein the non-volatile neutralizing agent is an alkali metal hydroxide.
<8> The molar ratio of the acid group neutralized by the volatile neutralizing agent to the acid group neutralized by the nonvolatile neutralizing agent in the particle is in the range of 60/40 to 90/10. The ink composition according to any one of <1> to <7>.
<9> The ink composition according to any one of <1> to <8>, wherein the polymer is a linear polymer.
<10> The ink composition according to any one of <1> to <9>, wherein the polymer is a urethane polymer, a urea polymer, or a (meth) acrylic polymer.
<11> The ink composition according to any one of <1> to <10>, which is used as an inkjet ink.
<12> An image including a step of forming an ink film by applying the ink composition according to any one of <1> to <11> on a substrate, and a step of heating the ink film. Formation method.

According to one embodiment of the present invention, an ink composition that is excellent in dispersion stability and can form a fine image is provided.
Further, according to another embodiment of the present invention, an image forming method capable of forming a fine image is provided.

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

In the present disclosure, a numerical range indicated by using “to” means a range including numerical values described before and after “to” as the minimum value and the maximum value, respectively.
The upper limit value or the lower limit value described in a certain numerical value range may be replaced with the upper limit value or the lower limit value of the other stepwise description numerical value range in the numerical value range described stepwise in the present disclosure. Further, in the numerical range described in the present disclosure, the upper limit value or the lower limit value described in a certain numerical range may be replaced with the value shown in the example.
In the present disclosure, a combination of two or more preferred embodiments is a more preferred embodiment.
In the present disclosure, the amount of each component means the total amount of a plurality of types of substances unless a plurality of types of substances corresponding to each component are present.

In the present disclosure, the term "step" is included in the term if the intended purpose of the step is achieved, even if it can not be clearly distinguished from other steps, as well as independent steps.
In the present disclosure, "*" in a chemical formula represents a bonding position.

In the present disclosure, the concept of "image" encompasses not only pattern images (eg, characters, symbols, or figures) but also solid images.
In the present disclosure, “light” is a concept including active energy rays such as γ rays, β rays, electron beams, ultraviolet rays, visible rays and the like.
In the present disclosure, ultraviolet light may be referred to as "UV (Ultra Violet) light".
In the present disclosure, light generated from a light emitting diode (LED) light source may be referred to as “LED light”.
In the present disclosure, “(meth) acrylic acid” is a concept including both acrylic acid and methacrylic acid, and “(meth) acrylate” is a concept including both acrylate and methacrylate, “(meth) acrylic acid” ) An acryloyl group is a concept including both an acryloyl group and a methacryloyl group.
In the present disclosure, “(meth) acrylic polymer” is a concept including both acrylic polymer and methacrylic polymer.
In the present disclosure, the polyoxyalkylene group, the urea group and the urethane group mean a polyoxyalkylene bond, a urea bond and a urethane bond, respectively.

In the present disclosure, “dispersion stability” means the dispersion stability of the particles contained in the ink composition, and is evaluated using the storage stability of the ink and the dischargeability of the ink when applied as an inkjet ink as an index. Ru.

[Ink composition]
The ink composition of the present disclosure (hereinafter, also simply referred to as “ink”) is water, and a volatile neutralizing agent having a boiling point of 25 ° C. to 250 ° C. (hereinafter, also simply referred to as “volatile neutralization agent”) And particles containing an acid group neutralized by a non-volatile neutralizing agent having a boiling point exceeding 250 ° C. (hereinafter, also simply referred to as “non-volatile neutralizing agent” (hereinafter, also referred to as “specific particle”); Contains
According to the ink of the present disclosure, it is possible to form a fine image with excellent dispersion stability.
Although it is not clear why the ink of the present disclosure can exhibit such an effect, the present inventors speculate as follows.

The ink of the present disclosure achieves excellent dispersion stability and formation of a fine image by containing an acid group neutralized by two types of neutralizing agents, a volatile neutralizing agent and a non-volatile neutralizing agent. It can.
In particular, the ink of the present disclosure contains particles that contain acid groups neutralized with neutralizing agents (i.e., volatile neutralizing agents and non-volatile neutralizing agents), so that charge repulsion between particles is achieved. As a result, aggregation of particles is suppressed, and as a result, it is considered that excellent dispersion stability can be realized.
When the particles contain only the acid group neutralized by the volatile neutralizing agent, the volatile neutralizing agent gradually volatilizes due to the dissociation equilibrium with the acid group during the storage of the ink. Stability may be reduced.

Generally, in an ink film formed using an ink containing water as a liquid component, the liquid component is difficult to remove as compared to an ink film formed using an ink containing an organic solvent as a liquid component. Therefore, an image formed using an ink containing water as a liquid component tends to be inferior in definition. The reason for this is considered to be that unintended ink droplet coalescence may occur on the substrate because the liquid component in the ink film is difficult to remove. Therefore, in order to form a fine image, it is desirable that the ink applied on the substrate be rapidly thickened.

The ink film formed by applying the ink of the present disclosure on a substrate is middle-sized by a volatile neutralizing agent having a boiling point of 25 ° C. or more and 250 ° C. or less and a non-volatile neutralizing agent having a boiling point exceeding 250 ° C. A particle is included that contains the mixed acid groups. When the formed ink film is heated, the volatile neutralizing agent neutralizing the acid groups contained in the particles is volatilized. It is considered that the ink thickens rapidly because the particles from which the volatile neutralizing agent that is neutralizing the acid group has volatilized coagulate by losing charge repulsion. For this reason, the ink of the present disclosure can form a fine image while including water as a liquid component.

With respect to the ink of the present disclosure, the aqueous dispersion described in JP-A-2010-138297 is a thermal ink jet aqueous dispersion for the purpose of excellent ejection speed and ejection stability. Therefore, it is considered that the problem of forming a fine image is not assumed. In addition, in JP 2010-138297 A, a volatile base and a non-volatile base are used in the production of the aqueous dispersion, but the volatile base is removed in the step (2). For this reason, the polymer particles contained in the aqueous dispersion described in JP-A-2010-138297 do not have a volatile base.
Therefore, it is difficult to form a fine image with the aqueous dispersion described in JP-A-2010-138297.

In addition, the ink of the present disclosure can form an image excellent in scratch resistance.
As described above, in the ink film formed using the ink of the present disclosure, the particles in the ink film are coagulated by heating, whereby the ink is thickened. This thickening of the ink is considered to increase the film strength of the formed image.

The above guess does not limit interpretation of the effect of the invention, but explains as an example.

Hereinafter, each component in the ink of the present disclosure will be described in detail.

[Specific particle]
The specific particles contain a volatile neutralizing agent having a boiling point of 25 ° C. to 250 ° C. and an acid group neutralized by a non-volatile neutralizing agent having a boiling point of 250 ° C. or higher.
The specific particles are not particularly limited as long as they contain an acid group neutralized with a volatile neutralizing agent and a non-volatile neutralizing agent.
In an aspect of the specific particle, the specific particle contains a polymer, and the polymer is neutralized by a volatile neutralizing agent having a boiling point of 25 ° C. to 250 ° C. and a non-volatile neutralizing agent having a boiling point of 250 ° C. Preferred is an embodiment having a substituted acid group.
Hereinafter, a polymer having an acid group neutralized with a volatile neutralizing agent having a boiling point of 25 ° C. or more and 250 ° C. or less and a non-volatile neutralizing agent having a boiling point of 250 ° C. or more is also referred to as “specific polymer”.

<Specific polymer>
The specific polymer has an acid group neutralized by a volatile neutralizing agent having a boiling point of 25 ° C. or more and 250 ° C. or less and a non-volatile neutralizing agent having a boiling point of 250 ° C. or more.
The specific polymer may have only one acid group neutralized by the volatile neutralizing agent and one acid group neutralized by the non-volatile neutralizing agent. The acid group may have two or more types of mixed acid groups and acid groups neutralized by the non-volatile neutralizing agent, and one type of acid group neutralized by the volatile neutralizing agent and the non-volatile group The acid group may have two or more kinds of acid groups neutralized by the neutral neutralizing agent, and the acid groups neutralized by the volatile neutralizing agent may be neutralized by the two or more kinds and the non-volatile neutralizing agent You may have 1 type of acid group.

(Volatile neutralizer)
The volatile neutralizing agent is a neutralizing agent having a boiling point of 25 ° C. or more and 250 ° C. or less.
In the present disclosure, “boiling point” refers to a boiling point at normal pressure (101.325 kPa).
When the boiling point of the volatile neutralizing agent is 25 ° C. or more, the dispersion stability of the specific particles may be improved.
When the boiling point of the volatile neutralizing agent is 250 ° C. or less, the definition of the image may be improved. In addition, scratch resistance of the image may also be improved.
The boiling point of the volatile neutralizing agent is preferably 150 ° C. or less, more preferably 100 ° C. or less, from the viewpoint that the definition of the image and the scratch resistance of the image can be further improved.
That is, the boiling point of the volatile neutralizing agent is preferably 25 ° C. or more and 150 ° C. or less, and more preferably 25 ° C. or more and 100 ° C. or less, from the viewpoint of ink dispersion stability, image definition, and image scratch resistance. It is more preferable that

The volatile neutralizing agent is not particularly limited.
The volatile neutralizing agent includes at least one selected from the group consisting of an amine compound and a quaternary ammonium hydroxide.
Among these, as the volatile neutralizing agent, an amine compound is preferable from the viewpoint of volatility at the time of heating.

The amine compound is not particularly limited.
The molecular weight of the amine compound is not particularly limited.
The molecular weight of the amine compound is preferably 20 to 1000, more preferably 30 to 750, and still more preferably 50 to 500, from the viewpoint of handleability.

The valence of the amine compound is not particularly limited, but is preferably 1 from the viewpoint of the dispersion stability of the specific particles.
In the present disclosure, the “valence of amine compound” means the number of nitrogen atoms contained in the amine compound.
When the amine compound has a valence of 1, aggregation of specific particles due to crosslinking of neutralized acid groups, which may occur during storage of the ink, does not occur, so that the dispersion stability of the specific particles is unlikely to be impaired.

The amine compound is selected from the group consisting of a compound represented by the following formula (1), a compound represented by the formula (2), and a compound represented by the formula (3) from the viewpoint of dispersion stability of specific particles: It is preferable that it is at least one selected.

Formula (1): NR ¹ R ² R ³
Formula (2): NR ⁴ R ⁵ H
Formula (3): NR ⁶ H ₂

In formula (1), R ¹ , R ² and R ³ each independently represent an alkyl group. Any ^{two of} R ¹ , R ² and R ³ may be bonded to each other to form a ring containing a nitrogen atom.
In formula (2), R ⁴ and R ⁵ each independently represent an alkyl group, and R ⁴ and R ⁵ may combine with each other to form a ring containing a nitrogen atom.
In formula (3), R ⁶ represents an alkyl group.

In formulas (1) to (3), the alkyl group represented by R ¹ , R ² , R ³ , R ⁴ , R ⁵ , and R ⁶ may be a linear alkyl group, or a branched alkyl group. It may be a group.
The carbon number of the alkyl group represented by R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ is preferably independently 1 to 12, more preferably 1 to 6 Preferably, it is more preferably 1 to 3.

At least one amine compound selected from the group consisting of a compound represented by Formula (1), a compound represented by Formula (2), and a compound represented by Formula (3) has high basicity. , The neutralized acid group is stabilized. This can further improve the dispersion stability of the specific particles.
Among these, as an amine compound, it is especially preferable that it is a compound represented by Formula (1) from a viewpoint similar to the above.

Examples of amine compounds which are volatile neutralizing agents are shown in Tables 1 and 2. However, the amine compound which is a volatile neutralizing agent is not limited to these examples.

The quaternary ammonium hydroxide is not particularly limited.
Examples of quaternary ammonium hydroxide which is a volatile neutralizing agent include tetramethyl ammonium hydroxide, tetraethyl ammonium hydroxide, tetrapropyl ammonium hydroxide, tetrabutyl ammonium hydroxide, benzyltrimethyl ammonium hydroxide and the like. .

(Non-volatile neutralizer)
A non-volatile neutralizing agent is one having a boiling point above 250 ° C.
The boiling point of the non-volatile neutralizing agent exceeding 250 ° C. is a rule to distinguish it from the volatile neutralizing agent.
The boiling point of the non-volatile neutralizing agent can be more effectively improved in the dispersion stability of the specific particle, the definition of the image, and the scratch resistance of the image by the combination with the above-mentioned volatile neutralizing agent. From the viewpoint, the temperature is preferably 1000 ° C. or more, and more preferably 1250 ° C. or more.
Further, the upper limit of the boiling point of the non-volatile neutralizing agent is not particularly limited, and can be, for example, 1500 ° C. or less.

The non-volatile neutralizing agent is not particularly limited.
Non-volatile neutralizing agents include, for example, metal hydroxides.
Among these, alkali metal hydroxides are preferable as the non-volatile neutralizing agent from the viewpoint of easy availability.
In addition, since alkali metal hydroxides have high basicity, the neutralized acid groups can be easily stabilized, and the dispersion stability of the specific particles can be further improved.
Furthermore, since the alkali metal hydroxide has a valence of 1, in the ink using the alkali metal hydroxide as the non-volatile neutralizing agent, neutralized acid groups which can be generated during storage The aggregation of specific particles does not occur due to the cross-linking, and the dispersion stability of the specific particles is less likely to be impaired.

Specific examples of the alkali metal hydroxide include sodium hydroxide (boiling point: 1388 ° C.), potassium hydroxide (boiling point: 1327 ° C.) and the like.

-Neutralized acid group-
In the present disclosure, "neutralized acid group" refers to an acid group in the form of a salt. The "neutralized acid group" may be present in the ink in the form of ions.
Examples of the neutralized acid group include salts of carboxy group, salts of sulfo group, salts of phosphoric acid group, salts of sulfuric acid group, salts of phosphonic acid group and the like.
Among these, as a neutralized acid group, a salt of a carboxy group is preferable from the viewpoint of dispersion stability of a specific particle.

“Salts” in salts of carboxy group, salts of sulfo group, salts of phosphoric acid group, salts of sulfuric acid group, salts of phosphonic acid group etc. are neutralizing agents (ie volatile neutralizing agents and non-volatile neutralizing agents Depends on the type of agent).
For example, in the case of an acid group neutralized by an amine compound as a volatile neutralizing agent, the aforementioned "salt" is an amine salt.
For example, in the case of an acid group neutralized with an alkali metal hydroxide as a non-volatile neutralizing agent, the aforementioned "salt" is an alkali metal salt.

-Degree of neutralization of acid groups-
The degree of neutralization of the acid groups contained in the specific particles is preferably 50% to 100%.
In the present disclosure, the “degree of neutralization of acid groups” means the total of the number of moles of neutralized acid groups and the number of moles of non-neutralized acid groups in the entire acid groups contained in a specific particle. The ratio of the number of moles of the acid group [mole number of neutralized acid group / (mole number of neutralized acid group + mole number of non-neutralized acid group)] is meant.
When the degree of neutralization of the acid groups is 50% or more, the dispersion stability of the specific particles is further improved.
The neutralization degree of the acid group is preferably 50% to 95%, more preferably 80% to 95%, and still more preferably 90% to 95%.
A neutralized acid group (ie, an acid group in the form of a salt) exhibits basicity. When the degree of neutralization of the acid group is 95% or less, the hydrolysis of the urethane group and / or the urea group which can be possessed by the specific polymer contained in the specific particle can be further suppressed.

The method of measuring the degree of neutralization of the acid group contained in the specific particles is not particularly limited, and can be measured by a known method such as neutralization titration or structural analysis. Below, an example of a measuring method is shown.

<< Method of measuring neutralization degree >>
In the present disclosure, the degree of neutralization (%) of the acid group contained in the specific particle can be measured, for example, by the potentiometric titration method shown below. The measuring apparatus is not particularly limited, and, for example, a potentiometric automatic titrator (model number: AT-510) manufactured by Kyoto Denshi Kogyo Co., Ltd. can be suitably used.
Hereinafter, the case where the acid group is a carboxy group (—COOH) will be described as an example. When the acid group is a group other than a carboxy group (such as a sulfo group or a phosphate group), in the following description, the degree of neutralization may be measured by replacing the carboxy group with a group other than a carboxy group. Can.

First, an aqueous dispersion of specific particles having a neutralized carboxy group is prepared by removing specific particles having a neutralized carboxy group and components other than water from the ink for which the degree of neutralization of the acid group is to be measured. Do.
For 50 g of the prepared aqueous dispersion, centrifugation at 80,000 rpm (revolutions per minute; the same applies hereinafter) for 40 minutes is applied. The supernatant produced by centrifugation is removed, and the precipitate (ie, specific particles) is recovered.
About 0.5 g of the specific particles recovered is weighed into a container 1 and a weighing value W1 (g) is recorded. Next, a mixture of 54 mL of tetrahydrofuran (THF) and 6 mL of distilled water is added, and the weighed specific particles are diluted to obtain a sample for neutralization degree measurement 1.
The obtained sample for neutralization degree measurement 1 was titrated with a 0.1 N (= 0.1 mol / L) sodium hydroxide aqueous solution as a titrant, and the amount of the titrant required until the equivalent point was F1 ( Record as mL). If multiple equivalence points are obtained in titration, use the value of the equivalence point at the maximum titer. Here, the “maximum titer F1 (mL)” corresponds to the amount of non-neutralized acid groups (ie, —COOH) among the acid groups contained in the specific particles.
In addition, about 0.5 g of the collected specific particles is weighed into the container 2 and the weighing value W2 (g) is recorded. Next, 60 mL of acetic acid is added, and the weighed specific particles are diluted to obtain a sample for neutralization degree measurement 2.
The obtained sample 2 for neutralization degree measurement was titrated using a 0.1 N (= 0.1 mol / L) perchloric acid acetic acid solution as a titrant, and the amount of the titrant required until the equivalent point was F2 Record as (mL). If multiple equivalence points are obtained in titration, use the value of the equivalence point at the maximum titer. Here, the “maximum titer F2 (mL)” corresponds to the amount of acid groups that are neutralized (ie, —COONa) among the acid groups contained in the specific particles.
Based on the measured values of "F1 (mL)" and "F2 (mL)", the degree of neutralization (%) of the carboxy group which is an acid group is determined according to the following formula.
F1 (mL) × normality of aqueous sodium hydroxide solution (0.1 mol / L) / W1 (g) + F2 (mL) × normality of perchloric acid solution (0.1 mol / L) / W2 (g) = Total amount (mmol / g) of non-neutralized carboxy group and neutralized carboxy group contained per 1 g of the specific particle (1)
F2 (mL) × normality of perchloric acid acetic acid solution (0.1 mol / L) / W 2 (g) = amount of carboxy group neutralized (mmol / g) among carboxy groups contained per 1 g of specific particles ) ... (2)
Neutralization degree (%) = (2) / (1) x 100

When the millimole number of the acid group in 1 g of the specific particle (for example, the total mmol number of the carboxy group and the salt of the carboxy group) is the acid value of the specific particle, the acid value of the specific particle is the dispersion stability of the specific particle From the viewpoint, it is preferably 0.10 mmol / g to 2.00 mmol / g, and more preferably 0.30 mmol / g to 1.50 mmol / g.

-Molar ratio of the acid group neutralized by the volatile neutralizing agent to the acid group neutralized by the non-volatile neutralizing agent contained in the specific particle-
Molar ratio of the acid group neutralized by the volatile neutralizing agent to the acid group neutralized by the non-volatile neutralizing agent contained in the specific particle (mol of the acid group neutralized by the volatile neutralizing agent The number / number of moles of acid group neutralized by the non-volatile neutralizing agent is not particularly limited.
The molar ratio of the acid group neutralized by the volatile neutralizing agent to the acid group neutralized by the nonvolatile neutralizing agent contained in the specific particle is, for example, in the range of 40/60 to 95/5. From the viewpoint of further improving the image definition and the image scratch resistance, it is more preferably in the range of 60/40 to 95/5, and in addition to the image definition and the image scratch resistance, From the viewpoint of further improving the dispersion stability of the specific particles, the range of 60/40 to 90/10 is more preferable.

The molar ratio of the acid group neutralized by the volatile neutralizing agent to the acid group neutralized by the non-volatile neutralizing agent contained in the specific particle (hereinafter, also simply referred to as “molar ratio of acid group”) The measuring method is not particularly limited, and can be measured by known methods such as neutralization titration and structural analysis. Below, an example of a measuring method is shown.

<< Method of measuring the molar ratio of neutralized acid groups >>
In the present disclosure, the molar ratio of the acid group neutralized by the volatile neutralizing agent to the acid group neutralized by the non-volatile neutralizing agent contained in the specific particle is, for example, the potentiometric titration method described below. It can be measured. The measuring apparatus is not particularly limited, and, for example, a potentiometric automatic titrator (model number: AT-510) manufactured by Kyoto Denshi Kogyo Co., Ltd. can be suitably used.

First, specific particles and components other than water are removed from the ink to be measured to prepare an aqueous dispersion of the specific particles.
Centrifugation under conditions of 80,000 rpm for 40 minutes is applied to 50 g of the prepared aqueous dispersion. The supernatant produced by centrifugation is removed, and the precipitate (specific particles) is recovered.
About 0.5 g of the specific particles recovered is weighed into a container 1 and a weighing value W1 (g) is recorded. Next, 60 mL of acetic acid is added, and the weighed specific particles are diluted to obtain a sample for neutralization degree measurement 1.
The obtained sample for neutralization degree measurement 1 was titrated using a 0.1 N (= 0.1 mol / L) perchloric acid acetic acid solution as a titrant, and the amount of the titrant required until the equivalent point was F1. Record as (mL). Further continue the titration and record the volume of titrant required to the second equivalence point as F2 (mL).
Here, "F1 (mL)" is the number of moles of the acid group neutralized by the non-volatile neutralizing agent which is a strong base, and "(F2-F1) (mL)" is a volatile base which is a weak base It corresponds to the number of moles of acid groups neutralized by the neutralizing agent.

Confirming that the ink contains particles containing an acid group neutralized by a volatile neutralizing agent and a non-volatile neutralizing agent by combining the above-mentioned neutralization titration, gas chromatography analysis, elemental analysis and the like. Can.

(Type of specific polymer)
There is no particular limitation on the type of the specific polymer.
The specific polymer is preferably a urethane polymer, a urea polymer, or a (meth) acrylic polymer.

In the present disclosure, the urethane polymer means a polymer containing a urethane group (except for the polymer corresponding to the (meth) acrylic polymer described later).
In the present disclosure, the urea polymer means a polymer containing a urea group (except a polymer corresponding to the above-mentioned urethane polymer and a polymer corresponding to the below-mentioned (meth) acrylic polymer).
In the present disclosure, a (meth) acrylic polymer refers to a homopolymer of one (meth) acrylate, a copolymer of two or more (meth) acrylates, or one or more (meth) acrylates It means a copolymer with the above other monomers.
The concept of urethane polymer also includes polymers containing both urethane groups and urea groups (so-called urethane urea polymers).
The term "(meth) acrylic polymer" also encompasses (meth) acrylic polymers containing at least one of a urethane group and a urea group.

The specific polymer may be a chain-like polymer having no crosslinked structure (hereinafter, also referred to as “specific chain-like polymer”), or a polymer having a crosslinked structure (for example, a three-dimensional crosslinked structure) It may also be referred to as “specifically crosslinked polymer”, and is preferably a specific linear polymer.
The specific chain polymer may contain cyclic structures such as aliphatic rings, aromatic rings, and heterocyclic rings in the main chain.
For the three-dimensional crosslinked structure that the specific crosslinked polymer may have, reference may be made to the three-dimensional crosslinked structure described in WO 2016/052052.

-Specific linear polymer-
The specific chain polymer is a neutralized product of the reaction product of (1) a bifunctional isocyanate compound and a compound having an acid group and two active hydrogen groups, or (2) a bifunctional isocyanate compound Or a neutralized product of a reaction product of a compound having an acid group and two active hydrogen groups and another compound, or (3) a bifunctional isocyanate compound, an acid group and two active hydrogen groups Or a compound having two active hydrogen groups and a compound having no acid group, which is a neutralized product of a reaction product of (4) a bifunctional isocyanate compound, an acid group, It is preferable to be a neutralized product of a reaction product of a compound having two active hydrogen groups, a compound having two active hydrogen groups and no acid group, and another compound.
The "neutralized substance" in the present disclosure also includes partially neutralized substances.

As a compound which has two active hydrogen groups, a diol compound, a diamine compound, and a dithiol compound are mentioned.
For example, a urethane group is formed by the reaction of a difunctional isocyanate compound and a diol compound.
Further, a urea group is formed by the reaction of a bifunctional isocyanate compound and a diamine compound.

In addition, among the above-mentioned compounds for introducing a polymerizable group, compounds containing only one active hydrogen group among the compounds for introducing a polymerizable group described later, among isocyanate compounds having introduced a polymerizable group described later, contain only an isocyanate group. Among the compounds and compounds for introducing an acid group described later, compounds containing only one active hydrogen group, compounds containing only one isocyanate group among isocyanate compounds having a hydrophilic group described later, and the like can be mentioned.

The following compounds (1-1) to (1-20) may be mentioned as the bifunctional isocyanate compound for forming the specific chain polymer.

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

Moreover, as a compound which has two active hydrogen groups for forming a specific chain | strand-shaped polymer, the compound which contains two active hydrogen groups among the compounds for polymeric group introduction | transduction mentioned later, and the compound for acid group introduction mentioned later And compounds containing two active hydrogen groups.

There is no particular limitation on the compound having an acid group and an active hydrogen group to form a specific chain polymer.
As the acid group, carboxy group, salt of carboxy group, sulfo group, salt of sulfo group, phosphoric acid group, salt of phosphoric acid group, phosphonic acid group, salt of phosphonic acid group, sulfuric acid group, salt of sulfuric acid group, etc. It can be mentioned. As the "salt", an alkali metal salt is preferable, and a sodium salt or a potassium salt is more preferable.
Among these, from the viewpoint of dispersion stability of the ink, the acid group is selected from the group consisting of a carboxy group, a salt of a carboxy group, a sulfo group, a salt of a sulfo group, a phosphate group, and a salt of a phosphate group. At least one is preferable, and at least one selected from carboxy group and salts of carboxy group is more preferable.

As an active hydrogen group, a hydroxyl group, an amino group (a primary amino group and a secondary amino group), a mercapto group etc. are mentioned.
The compound having an acid group and an active hydrogen group may have only one kind of acid group and one active hydrogen group, and has one of either an acid group or an active hydrogen group, and two or more of the other. And may have two or more of both an acid group and an active hydrogen group.

As a compound having an acid group and an active hydrogen group, α-amino acids (lysine, alanine, arginine, asparagine, aspartic acid, cysteine, glutamine, glutamic acid, glycine, histidine, isoleucine, leucine, methionine, phenylalanine, proline, serine, threonine Amino acids such as tryptophan, tyrosine and valine), malic acid, taurine, ethanolamine phosphate (EAP) and the like.

As a compound which has an acidic radical and an active hydrogen group, the following specific examples other than said compound are mentioned.

-Specific cross-linked polymer-
The specific cross-linked polymer is (1) a neutralization product of a reaction product A2 of water and a reaction product A1 of a compound having an acid group and an active hydrogen group with a compound having an acid group and an active hydrogen group Or (2) a reaction product of a trifunctional or higher functional isocyanate compound, a compound having an acid group and an active hydrogen group, and a bifunctional isocyanate compound, and another compound and water. It is preferable that it is a neutralized product of the reaction product B2.

Examples of the other compounds include a compound containing only one active hydrogen group among the compounds for introducing a polymerizable group described later, a compound containing only one isocyanate group among the isocyanate compounds having introduced a polymerizable group described later, Among the compounds for introducing an acid group to be described later, a compound containing only one active hydrogen group, a compound containing only one isocyanate group among isocyanate compounds having a hydrophilic group described later, and the like can be mentioned.

When the specific particle contains the specific crosslinked polymer, the specific particle preferably contains microcapsules (hereinafter also referred to as “MC”) including a shell made of the specific crosslinked polymer and a core.

Examples of compounds having two or more active hydrogen groups for forming a specific crosslinked polymer include diol compounds, as well as compounds having two active hydrogen groups for forming the specific linear polymer described above. Examples include diamine compounds and dithiol compounds.
Moreover, as a compound which has a 2 or more active hydrogen group for forming a specific crosslinked polymer, the trifunctional or more than trifunctional polyol compound, the trifunctional or more than trifunctional polyamine compound, and the trifunctional or more polythiol compound are also mentioned.

Examples of the compound having an acid group and an active hydrogen group for forming a specific crosslinked polymer include α-amino acids as in the compounds having an acid group and an active hydrogen group for forming the specific linear polymer described above. Amino acids such as (lysine, alanine, arginine, asparagine, aspartic acid, cysteine, glutamine, glutamic acid, glycine, histidine, isoleucine, leucine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine and valine), malic acid, Examples include taurine, ethanolamine phosphate (EAP), dimethylol propionic acid (DMPA), 2,2-bis (hydroxymethyl) butyric acid (DMBA) and the like.

The trifunctional or higher functional isocyanate compound for forming the specific crosslinked polymer is a compound having at least one selected from the group consisting of bifunctional isocyanate compounds and three or more active hydrogen groups (for example, trifunctional or higher functional compounds) It is preferable that it is a reaction product with at least 1 sort (s) selected from the group which consists of a polyol compound, a trifunctional or more than trifunctional polyamine compound, and a trifunctional or more than trifunctional polythiol compound).
The number of moles of bifunctional isocyanate compound (so-called number of molecules) to be reacted with a compound having three or more active hydrogen groups is the number of moles of active hydrogen groups in a compound having three or more active hydrogen groups (so-called activity) The number of equivalents of the hydrogen group is preferably 0.6 times or more, more preferably 0.6 times to 5 times, still more preferably 0.6 times to 3 times, and particularly preferably 0.8 times to 2 times.

As a bifunctional isocyanate compound for forming the trifunctional or more than trifunctional isocyanate compound, the thing similar to the bifunctional isocyanate compound for forming the specific chain | strand-shaped polymer as stated above is mentioned.

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

Examples of trifunctional or higher functional isocyanate compounds used to form the specific crosslinked polymer include adduct type trifunctional or higher isocyanate compounds, isocyanurate type trifunctional or higher isocyanate compounds, biuret type trifunctional or higher isocyanate compounds, and the like. It can be mentioned.
As commercial products of the adduct type trifunctional or higher isocyanate compound, Takenate (registered trademark) D-102, D-103, D-103H, D-103M2, P49-75S, D-110N, D-120N, D- 140N, D-160N (above, Mitsui Chemical Co., Ltd.), Desmodur (registered trademark) L75, UL57SP (Sumikawa Bayer Urethane Co., Ltd.), Coronate (registered trademark) HL, HX, L (Nippon Urethane Polymer (Japan Urethane Polymer Co., Ltd. ), P301-75E (Asahi Kasei Corporation) and the like.
As commercial products of isocyanurate type trifunctional or higher isocyanate compounds, Takenate (registered trademark) D-127N, D-170N, D-170HN, D-172N, D-177N (all, 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 (all, Asahi Kasei Corporation) and the like.
As commercial products of biuret type trifunctional or higher isocyanate compounds, Takenate (registered trademark) D-165N, NP1100 (Mitsui Chemical Co., Ltd.), Desmodur (registered trademark) N3200 (Suzuki Bayer Urethane Co., Ltd.) And Duranate (registered trademark) 24A-100 (Asahi Kasei Corporation).

In addition, when the specific particle includes an MC (that is, a microcapsule) containing a shell made of a specific crosslinked polymer and a core, the specific particle is hydrophilic as a dispersant for MC, among the specific linear polymers described above. You may contain the specific linear polymer of the aspect which has group. In the ink in this aspect, at least a part of the periphery of the shell of MC can be in a state of being coated with a specific linear polymer as a dispersant. In this aspect, the interaction between the urethane group and / or the urea group possessed by the shell of MC and the urethane group and / or the urea group possessed by the dispersant (specific chain polymer) and the hydrophilic group of the dispersant The dispersing action is combined to further improve the dispersion stability of the specific particles.
In this embodiment, the ratio of the amount of dispersant to the total solid content of MC (hereinafter also referred to as mass ratio [also referred to as dispersant / MC solid content]) is preferably 0.005 to 1.000, and 0.1. More preferably, it is from 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.

-Preferred weight average molecular weight (Mw) of specific polymer-
The weight average molecular weight (Mw) of the specific polymer is preferably 5000 or more, more preferably 7,000 or more, and 8000 or more from the viewpoint of the dispersion stability of the ink (that is, the dispersion stability of the specific particles). It is further preferred that
There is no particular limitation on the upper limit of Mw of the specific polymer. As an upper limit of Mw of a specific polymer, 150000, 100000, 70000, 50000 are mentioned, for example.

In the present disclosure, weight average molecular weight (Mw) means a value measured by gel permeation chromatography (GPC). However, for compounds whose accurate Mw can not be measured by GPC because of their small molecular weight, the molecular weight determined from the chemical structure of the compound is adopted as the Mw of the compound.
In the present disclosure, measurement by gel permeation chromatography (GPC) uses HLC (registered trademark) -8020 GPC (Tosoh Corporation) as a measurement device, and TSKgel (registered trademark) Super Multipore HZ-H (as a column). It is possible to use THF (tetrahydrofuran) as an eluent using three 4.6 mm ID × 15 cm, Tosoh Corporation. In addition, as measurement conditions, the sample concentration is 0.45 mass%, the flow rate is 0.35 ml / min, the sample injection amount is 10 μl, and the measurement temperature is 40 ° C., using a differential refractive index (RI) detector .
The standard curve is the standard sample TSK standard, polystyrene of Tosoh Corp .: “F-40”, “F-20”, “F-4”, “F-1”, “A-5000”, “A. It is made from eight samples of "-2500", "A-1000", and "n-propylbenzene".

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 It is particularly preferable that the content is less than%.

-Compound for introducing acid group-
When the specific polymer in the specific particle has an acid group, the introduction of the acid group to the specific polymer can be performed using a compound for introducing an acid group.
As a compound for introducing an acid group, a compound having an acid group and an active hydrogen group can be used.
As a compound for introducing an acid group, it is preferable to use a compound having one or more acid groups and two or more active hydrogen groups.

As a compound for introducing an acid group, for example, α-amino acids (specifically, lysine, alanine, arginine, asparagine, aspartic acid, cysteine, glutamine, glutamic acid, glycine, histidine, isoleucine, leucine, methionine, phenylalanine, proline, And serine, threonine, tryptophan, tyrosine, valine, etc.).
As a compound for introducing an acid group, in addition to the above-mentioned α-amino acid, a compound having an acid group and an active hydrogen group as described above can also be mentioned.

The compound for introducing an acid group may be used by neutralizing at least a part of the acid group using a volatile neutralizing agent and a non-volatile neutralizing agent.

-Isocyanate compound introduced with acid group-
When the specific polymer has an acid group, the introduction of the acid group to the specific polymer can also be performed using an isocyanate compound having an acid group introduced.
As the isocyanate compound having an acid group introduced therein, a reaction product of the compound for introducing an acid group described above and a bifunctional isocyanate compound; the compound for introducing an acid group described above, and an isocyanate compound having three or more functional groups, A compound selected from the group consisting of a compound for introducing an acid group, a bifunctional isocyanate compound, a trifunctional or higher functional polyol compound, a trifunctional or higher polyamine compound, and a trifunctional or higher polythiol compound; And the reaction product of
Among these, as the isocyanate compound having an acid group introduced, there are already mentioned compounds for introducing an acid group, isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), trimethylhexamethylene diisocyanate (TMHDI), and 1,3-bis. Preference is given to reaction products with (isocyanatomethyl) cyclohexane (HXDI), m-xylylene diisocyanate (XDI) or dicyclohexylmethane-4,4'-diisocyanate (HMDI).

-Nonionic group-
The specific polymer may further have a nonionic group as a hydrophilic group other than the aforementioned acid groups (neutralized acid group and non-neutralized acid group).
When the specific polymer further has a nonionic group, the dispersion action of the neutralized acid group and the dispersion action of the nonionic group may be combined to further improve the dispersion stability of the ink.
The nonionic group includes a group having a polyether structure, and is preferably a monovalent group containing a polyalkyleneoxy group.

-Compounds for introducing nonionic groups-
When the specific polymer has a nonionic group, the introduction of the nonionic group into the specific polymer can be performed using a nonionic group-introducing compound.
The nonionic group-introducing compound is preferably a compound having a polyether structure, and more preferably a compound having a polyoxyalkylene chain.
As the compound having a polyoxyalkylene chain, at least one compound selected from the group consisting of polyethylene oxide, polypropylene oxide, and polyethylene oxide-polypropylene oxide block copolymer is preferable, and polyethylene oxide is more preferable.
The compound having a polyether structure is selected from the group consisting of monoethers of polyethylene oxide (monomethyl ether, monoethyl ether, etc.) and monoesters of polyethylene oxide (monoacetic acid ester, mono (meth) acrylic acid ester, etc.) Preferred is at least one compound that is

Specific examples of the isocyanate compound having a nonionic group introduced include adducts of trimethylolpropane (TMP), m-xylylene diisocyanate (XDI) and polyethylene glycol monomethyl ether (EO) (for example, Mitsui Chemical Co., Ltd.) Takenate (registered trademark) D-116N).

-Polymerizable group-
The specific polymer preferably has at least one kind of polymerizable group.
When the specific polymer has a polymerizable group, the thickened ink film is polymerized after thickening the ink film by the volatilization of the volatile neutralizing agent that is neutralizing the acid group contained in the specific particles. It can be cured by the action of the sexing group.
This further improves the scratch resistance of the image.

As a polymeric group, a photopolymerizable group or a thermally polymerizable group is preferable.
The photopolymerizable group is preferably a radical polymerizable group, more preferably a group containing an ethylenic double bond, and still more 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 the hardness of the formed film.
As the thermally polymerizable 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.
The specific polymer having a polymerizable group can be confirmed, for example, by Fourier transform infrared spectroscopy (FT-IR) analysis.

-Compound for introducing polymerizable group-
When the specific polymer has a polymerizable group, the introduction of the polymerizable group into the specific polymer can be performed 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 for introducing a polymerizable group into a specific polymer is not particularly limited, but when synthesizing a specific polymer, at least one selected from the group consisting of a bifunctional isocyanate compound, water, a diol compound, a diamine compound and Particularly preferred is a method of reacting at least one selected from the group consisting of dithiol compounds, at least one of a compound for introducing a polymerizable group, and (optionally, at least one of a compound for introducing an acid group) .
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 a m + n-valent linking group, m and n each independently represent 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 aliphatic group, a divalent or higher aromatic group, a divalent or higher heterocyclic group, -O-, -S-, -NH-, -N <, -CO-, -SO It is preferable that-, -SO ₂ -or a combination thereof.
m and n each independently are preferably 1 to 50, more preferably 2 to 20, still 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 still more preferably a hydroxy group.

Hereinafter, although the example of the compound for polymeric group introduction is shown, the compound for polymeric group introduction is not limited to the following examples. Here, n in the compounds (a-3) and (a-14) represents, for example, an integer selected from 1 to 90.

-Isocyanate compound introduced with a polymerizable group-
When the specific polymer has a polymerizable group, the introduction of the polymerizable group into the specific polymer can also be carried out using an isocyanate compound having a polymerizable group introduced.
As an isocyanate compound which introduce | transduced the polymeric group, the reaction product of at least 1 sort (s) of the compound of polymeric group introduction as stated above, and at least 1 sort (s) of the bifunctional isocyanate compound;
Reaction product of at least one type of polymerizable group introducing compound described above and at least one type of trifunctional or higher functional isocyanate compound; at least one type of polymerizable group introducing compound described above and bifunctional Reaction products of at least one selected from the group consisting of at least one isocyanate compound and at least one trifunctional or higher functional polyol compound, trifunctional or higher functional polyamine compound, and trifunctional or higher functional polythiol compound; .

(Polymerizable monomer)
The specific particles preferably contain a polymerizable monomer.
When the specific particle contains a polymerizable monomer, the ink film is thickened after the ink film is thickened by the volatilization of the volatile neutralizing agent that is neutralizing the acid group contained in the specific particle, It can be cured by the action of
This further improves the scratch resistance of the image.
The number of polymerizable monomers contained in the specific particles may be only one, or two or more.

As the polymerizable monomer contained in the specific particles, the compounds described in paragraphs [0097] to [0105] of WO 2016/052053 may be used.

As the polymerizable monomer contained in the specific particles, a photopolymerizable monomer or a thermally polymerizable monomer is preferable.
The photopolymerizable monomer has the property of polymerizing upon irradiation with light (ie, active energy ray).
The thermally polymerizable monomer has a property of polymerizing by heating or irradiation of infrared radiation.
As the photopolymerizable monomer, a radically polymerizable monomer having a radically polymerizable ethylenic double bond is preferable.

In the present specification, an ink of an embodiment in which the specific particles contain a photopolymerizable monomer may be referred to as a “photocurable ink”, and an ink of an embodiment in which the specific particles contain a thermally polymerizable monomer Sometimes referred to as "ink of".
When the ink of the present disclosure is a photocurable ink, curing of the ink film formed by the ink of the present disclosure can be performed by applying light to the ink film (curing process described later) A) When the ink of the present disclosure is a thermosetting ink, the ink film can be heated or subjected to infrared irradiation (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.
According to this aspect, since the hardenability of the image by the irradiation of the active energy ray is further improved, the scratch resistance of the image is further improved.

When the specific particle contains a photopolymerizable monomer as a polymerizable monomer, the specific particle preferably further contains a photopolymerization initiator described later.
When the specific particles contain a thermally polymerizable monomer as a 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.

The content of the polymerizable monomer contained in the specific particles (total amount in the case of containing two or more types) is 10 mass with respect to the total solid content of the specific particles from the viewpoint of improving the curing sensitivity of the film and the hardness of the film. % To 90% by mass is preferable, 20% by mass to 80% by mass is more preferable, and 30% by mass to 70% by mass is more preferable.

In the present disclosure, the total solid content of specific particles means the total amount of specific particles when the specific particles do not contain a solvent, and when the specific particles contain a solvent, the total amount of the specific particles excluding the solvent Means

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

-Photopolymerizable monomer-
As the photopolymerizable monomer, a polymerizable monomer having a radically polymerizable ethylenic unsaturated bond (ie, a radically polymerizable monomer) and a polymerizable monomer having a cationically polymerizable cationically polymerizable group (ie, a cationically polymerizable monomer Can be selected from

Examples of radically polymerizable monomers include acrylate compounds, methacrylate compounds, styrenic compounds, vinyl naphthalene 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 particle contains a radically polymerizable monomer, the specific particle may contain only one type of radically polymerizable monomer, or may contain two or more types.

As an acrylate compound, 2-hydroxyethyl acrylate, butoxyethyl acrylate, carbitol acrylate, cyclohexyl acrylate, tetrahydrofurfuryl acrylate, benzyl acrylate, tridecyl acrylate, 2-phenoxyethyl acrylate (PEA), bis (4-acryloxypoly) Ethoxyphenyl) propane, oligoester acrylate, epoxy acrylate, isobornyl acrylate (IBOA), dicyclopentenyl acrylate, dicyclopentenyl oxyethyl 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 di- Glycol acrylate, 2-hydroxybutyl acrylate, 2-acryloyloxyethyl hydrophthalic acid, ethoxydiethylene glycol acrylate, methoxy diethylene glycol acrylate, methoxy polyethylene glycol acrylate, methoxy propylene glycol acrylate, 2-hydroxy-3-phenoxy propyl acrylate, vinyl ether acrylate, 2 - Cryloyl oxyethyl succinic acid, 2-acryloyl oxy phthalic acid, 2-acryloxy ethyl 2-hydroxyethyl phthalic acid, lactone modified acrylate, acryloyl morpholine, acrylamide, substituted acrylamide (for example, N-methylol acrylamide and diacetone acrylamide) Etc. monofunctional acrylate compounds;

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, hydrogen Roxypine pentyl glycol diacrylate, propoxylated neopentyl glycol diacrylate, alkoxylated dimethylol tricyclodecane diacrylate, 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, etc. Two-functional Aclay Compound;

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 propoxy triacrylate, ethoxylated Zipe Data hexaacrylate, caprolactam modified dipentaerythritol hexaacrylate, propoxylated glycerol triacrylate, ethoxylated trimethylolpropane triacrylate, such as trifunctional or more acrylate compounds such as propoxylated trimethylol propane triacrylate.

As methacrylate compounds, methyl methacrylate, n-butyl methacrylate, allyl methacrylate, glycidyl methacrylate, benzyl methacrylate, dimethylaminomethyl methacrylate, methoxypolyethylene glycol methacrylate, methoxytriethylene glycol methacrylate, hydroxyethyl methacrylate, phenoxyethyl methacrylate, cyclohexyl methacrylate and the like Monofunctional methacrylate compounds;

Examples include difunctional 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 vinyl naphthalene compound include 1-vinyl naphthalene, methyl-1-vinyl naphthalene, β-methyl-1-vinyl naphthalene, 4-methyl-1-vinyl naphthalene, 4-methoxy-1-vinyl naphthalene and the like.

Examples of N-vinyl heterocyclic compounds include N-vinylcarbazole, N-vinylpyrrolidone, N-vinylethylacetamide, N-vinylpyrrole, N-binyphenothiazine, N-vinylacetanilide, N-vinylethylacetamide, N-vinylsuccinic acid Imide, N-vinyl phthalimide, N-vinyl caprolactam, N-vinyl imidazole and the like can be mentioned.

Other radically polymerizable monomers include N-vinylamides such as allyl glycidyl ether, diallyl phthalate, triallyl trimellitate, N-vinylformamide and the like.

Among these radically polymerizable monomers, as a radically polymerizable monomer having two or less functional groups, 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, diethylene glycol diacrylate, tetraethylene glycol diacrylate, dipropylene glycol diacrylate, tripropylene glycol Diacrylate (TPGDA), cyclohexanone dimethanol diacrylate, alkoxylated hexanediol diacrylate, polyethylene glycol diacrelay And at least one is preferably selected from the group consisting of polypropylene glycol diacrylate.
Moreover, as a radically polymerizable monomer having 3 or more functions, 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 ethoxy tetraacrylate, glycerin propoxy triacrylate, ethoxylated dipentaerythritol hexaacrylate, caprolactam modified dipentaeri Li hexaacrylate, propoxylated glycerol triacrylate, ethoxylated trimethylolpropane triacrylate, and at least one selected from the group consisting of propoxylated trimethylol propane triacrylate are preferred.

The specific particles may contain a combination of a difunctional or less radically polymerizable monomer and a trifunctional or more radically polymerizable monomer. In this case, the difunctional or less radically polymerizable monomer contributes to the adhesion between the image and the substrate, and the trifunctional or more radically polymerizable monomer contributes to the improvement of the image hardness.
As a combination of a difunctional or less radically polymerizable monomer and a trifunctional or more radically polymerizable monomer, a combination of a difunctional acrylate compound and a trifunctional acrylate compound, a difunctional acrylate compound and a pentafunctional acrylate compound And combinations of monofunctional acrylate compounds and tetrafunctional acrylate compounds.

From the viewpoint of further improving the adhesion between the image and the substrate, at least one of the radically polymerizable monomers that may be contained in the specific particles is also a radically polymerizable monomer having a cyclic structure (hereinafter, "cyclic radically polymerizable monomer") Is preferred.
As a cyclic radically polymerizable monomer, cyclohexyl acrylate, tetrahydrofurfuryl acrylate, benzyl acrylate, isobornyl acrylate, dicyclopentenyl acrylate, dicyclopentenyl oxyethyl acrylate, dicyclopentanyl acrylate, ethoxylated isocyanuric acid triacrylate, ε And caprolactone-modified tris- (2-acryloxyethyl) isocyanurate.
In addition, bifunctional or higher cyclic radical 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 radically polymerizable monomers that can be contained in the specific particles has one or more cyclic structures and two or more (meth) acryloyl groups, It is preferable that it is a polymerizable monomer containing (hereinafter also referred to as “a bifunctional or higher cyclic radical polymerizable monomer”).
As a bifunctional or more cyclic radically 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, cyclohexanone dimethanol di (meth) acrylate and the like.

When the specific particles contain a radically polymerizable monomer, the proportion of the bifunctional or higher cyclic radically polymerizable monomer in the entire polymerizable monomer is preferably 10% by mass to 100% by mass, and more preferably 30% by mass to 100% by mass. Preferably, 40% by mass to 100% by mass is particularly preferable.

In addition to the above-mentioned radically polymerizable monomers, Y. Yamashita, 3rd. Ed., "Crosslinking Agent Handbook", (1981 Taiseisha); Kato Seikohen, "UV · EB Curing Handbook (raw materials)" (1985) "Polymer publication"; Rad Tech Research Group, "Application and market of UV / EB curing technology", page 79, (1989, CMC); Eiichiro Takiyama, "Polyester resin handbook", (1988, Nikkan Kogyo Co., Ltd.) Commercial products described in Shimbunsha et al., 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.
As a cationically polymerizable monomer, 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, see "Advances in Polymer Science" by J. V. Crivello et al., 62, pages 1 to 47 (1984), "Handbook of Epoxy Resins" by Lee et al., McGraw Hill Book Company, New York (1967). And P. F. Bruins et al., “Epoxy Resin Technology”, (1968) may be used.

Also, as the photopolymerizable monomer, JP-A-77-159983, JP-B-7-31399, JP-A-8-224982, JP-A-10-863, JP-A-9-134011, and the like can be used. The photocurable polymerizable monomers used in the photopolymerizable compositions described in the respective publications such as Table 2004-514014 are known, and these may also be applied as polymerizable monomers which can be contained in specific particles. it can.

As a photopolymerizable monomer, you may use the commercial item marketed.
Examples of commercial products of the photopolymerizable monomer include AH-600 (bifunctional), AT-600 (bifunctional), UA-306H (six functional), UA-306T (six functional), UA-306I (six functional) ), UA-510H (10 functional), UF-8001G (bifunctional), DAUA-167 (bifunctional), light acrylate NPA (bifunctional), light acrylate 3EG-A (bifunctional) (all, Kyoeisha Chemical (stock) ), SR339A (PEA, monofunctional), SR506 (IBOA, monofunctional), CD262 (bifunctional), SR238 (HDDA, bifunctional), SR341 (3MPDDA, bifunctional), SR508 (bifunctional), SR306H (2 Functional), CD 560 (bifunctional), SR833S (bifunctional), SR444 (trifunctional), SR454 (trifunctional), SR492 (trifunctional), SR 99 (trifunctional), CD501 (trifunctional), SR502 (trifunctional), SR9020 (trifunctional), CD9021 (trifunctional), SR9035 (trifunctional), SR494 (tetrafunctional), SR399E (trifunctional) (above, Sartmar, A-NOD-N (NDDA, bifunctional), A-DOD-N (DDDA, bifunctional), A-200 (bifunctional), APG-400 (bifunctional), A-BPE-10 (bifunctional) Bifunctional), A-BPE-20 (bifunctional), A-9300 (trifunctional), A-9300-1CL (trifunctional), A-TMPT (trifunctional), A-TMM-3L (trifunctional), A-TMMT (4 functions), AD-TMP (4 functions) (above, Shin-Nakamura Chemical Co., Ltd.), UV-7510 B (3 functions) (Japan Synthetic Chemical Co., Ltd.), KAYARAD DPCA-30 (6 functions) ), KAYARA DPEA-12 (6 functional) (Nippon Kayaku Co.) and the like.
In addition, as polymerizable monomers, NPGPODA (neopentyl glycol propylene oxide adduct diacrylate), SR 531, SR 285, SR 256 (above, Sartomer), A-DHP (dipentaerythritol hexaacrylate, Shin-Nakamura Chemical Co., Ltd.) Commercial products such as Alonics (registered trademark) M-156 (Toagosei Co., Ltd.), V-CAP (BASF Corporation), and Viscote # 192 (Osaka Organic Chemical Industry Co., Ltd.) can be suitably used.
Among these commercially available products, SR506, SR833S, A-9300, or A-9300-CL, which is a photopolymerizable monomer having a cyclic structure, is particularly preferable, and SR833S is particularly preferable.

-Thermally polymerizable monomer-
The thermally polymerizable monomers can be selected from the group of polymerizable monomers that can be polymerized by heating or irradiation with infrared radiation. As a thermally polymerizable monomer, an epoxy compound, an oxetane compound, an aziridine compound, an azetidine compound, a ketone compound, an aldehyde compound, a block isocyanate compound etc. are mentioned, for example.

As an epoxy compound, 1,4-butanediol diglycidyl ether, 3- (bis (glycidyloxymethyl) methoxy) -1,2-propanediol, limonene oxide, 2-biphenyl glycidyl 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 Difunctional or less epoxy compounds such as fluorinated novolaks and alicyclic diepoxides;
Examples include polyglycidyl esters of polybasic acids, polyglycidyl ethers of polyols, polyglycidyl ethers of polyoxyalkylene glycols, polyglycidyl esters of aromatic polyols, urethane polyepoxy compounds, and epoxy compounds having three or more functional groups such as polyepoxy polybutadiene and the like. Be
Commercial products of epoxy compounds include EPICLON (registered trademark) 840 (DIC Corporation).

Examples of oxetane compounds include 3-ethyl-3-hydroxymethyl-1-oxetane, 1,4 bis [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.

As a block isocyanate compound, the compound which inactivated the isocyanate compound with blocking agent (what is called, active hydrogen containing compound) is mentioned.
As an isocyanate compound, for example, hexamethylene diisocyanate, isophorone diisocyanate, toluyl diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate trimer, trimethylhexylylene diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, hydrogenated xylylene diisocyanate, takenate (registration Trademarks: Commercially available isocyanates such as Mitsui Chemical Co., Ltd., Duranate (registered trademark; Asahi Kasei Co., Ltd.), Bayhydur (registered trademark; Bayer AG), etc., or difunctional or higher functional isocyanates combining these are preferred.

As the blocking agent, lactam [eg ε-caprolactam, δ-valerolactam, γ-butyrolactam etc.], oxime [eg acetoxime, methyl ethyl keto oxime (MEK oxime), methyl isobutyl keto oxime (MIBK oxime), cyclohexanone oxime etc] , Amines [eg aliphatic amines (dimethylamine, diisopyramine, di-n-propylamine, diisobutylamine etc.), alicyclic amines (methylhexylamine, dicyclohexylamine etc.), aromatic amines (aniline, diphenylamine etc.) etc.] Aliphatic alcohols [eg methanol, ethanol, 2-propanol, n-butanol etc], phenols and alkylphenols [eg phenol, cresol, ethylphenol, n-propyl phenol N, isopropylphenol, n-butylphenol, octylphenol, nonylphenol, xylenol, diisopropylphenol, 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.], JP-A-2002- Examples thereof include the blocking agents described in Japanese Patent Application Laid-Open No. 309217 and Japanese Patent Application Laid-Open No. 2008-239890, and mixtures of two or more of these. Among them, as the blocking agent, oxime, lactam, pyrazole, active methylene or amine is preferable.

As the blocked isocyanate compound, commercially available commercial products may be used. For example, Trixene (registered trademark) BI7982, BI7641, BI7642, BI7950, BI7960, BI7991 and the like (Baxenden Chemicals LTD), Bayhydur (registered trademark; Bayer AG) Company) is preferably used. In addition, a compound group described in paragraph [0064] of WO 2015/158654 is also suitably used.

The specific particle containing the specific polymer described above and the polymerizable monomer described above is produced, for example, by emulsifying a mixture of an oil phase component containing the specific polymer and the polymerizable monomer and an aqueous phase component. Can.

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

When the specific particles contain a photopolymerization initiator, the sensitivity to light (i.e., active energy ray) is high, and an image having an excellent hardness and an excellent adhesion to a substrate can be obtained.
In particular, when the specific particle contains a photopolymerization initiator, one specific particle has both a photopolymerizable monomer and a photopolymerization initiator. For this reason, since the distance between the photopolymerizable monomer and the photopolymerization initiator is close, the curing sensitivity of the film (hereinafter, also simply referred to as "sensitivity") as compared with the case of using a conventional photocurable composition. Improve. As a result, a film which is more excellent in hardness and more excellent in adhesion to a substrate is formed.

Furthermore, when specific particles contain a photopolymerization initiator, it has been difficult to use a photopolymerization initiator (for example, water solubility), which has high sensitivity but low dispersibility or low solubility in water. Can be used at 25 ° C. in an amount of 1.0 mass% or less. This broadens the choice of the photoinitiator to be used and thus also broadens the choice of the light source used. For this reason, curing sensitivity can be improved more than before.
Specific examples of the photopolymerization initiator described above, which have high sensitivity but low dispersibility or solubility in water but are difficult to use, include carbonyl compounds and acyl phosphine oxide compounds described later. Acyl phosphine oxide compounds are preferred.
Thus, 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 of the embodiment in which the specific particles contain a photopolymerization initiator is excellent in storage stability as compared with the conventional photocurable composition. The reason is considered to be that aggregation or sedimentation of the photopolymerization initiator is suppressed by containing the photopolymerization initiator in the specific particles.

As a photoinitiator which may be contained in specific particle | grains, a well-known photoinitiator can be selected suitably and can be used.
The photopolymerization initiator is a compound that absorbs light (that is, active energy rays) to generate a radical which is a polymerization initiation species.

Although a well-known compound can be used as a photoinitiator, As a preferable photoinitiator, (a) Carbonyl compounds, such as aromatic ketones, (b) Acyl phosphine 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, k) Active ester compounds, (l) compounds having a carbon halogen bond, (m) alkylamine compounds and the like.

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

As preferable examples of (a) a carbonyl compound, (b) an acyl phosphine oxide compound, and (e) a thio compound, “RADIATION CURE IN POLYMER SCIENCE AND TECHNOLOGY”, J. P. FOUASSIER, J.J. F. RABEK (1993), pp. And compounds having a benzophenone skeleton or a thioxanthone skeleton described in 77 to 117, and the like.
More preferable examples include an α-thiobenzophenone compound described in JP-B-47-6416, a benzoin ether compound described in JP-B-47-3981, an α-substituted benzoin compound described in JP-B-47-22326, and Benzoin derivatives described in JP-A-47-23664; aroyl phosphonic acid esters disclosed in JP-A-57-30704; dialkoxybenzophenones described in JP-B-60-26483; JP-B-60-26403; Benzoin ethers described in JP-A-62-81345, JP-B1-34242, U.S. Pat. No. 4,318,791 pamphlet, .alpha.-aminobenzophenones described in EP-A-0284561 A1, JP-A-2-211452 P-di (dimethylamino) described in Nzoyl) benzene, thio-substituted aromatic ketone described in JP-A-61-194062, acyl phosphine sulfide described in JP-B-2-9597, acyl phosphine described in JP-B-2-9596, JP-B-63-61950 Thioxanthones described in Japanese Patent Application Publication No. Hei 5 (1995), coumarins described in Japanese Patent Publication No. 59-42864, and the like can be mentioned.
In addition, a polymerization initiator described in JP-A 2008-105379 or JP-A 2009-114290 is also preferable.

Examples of commercial products of the photopolymerization initiator 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, BASF Corporation], ESACURE (registered trademark) KTO 37, KTO 46, KIP 150, EDB [all, Lamberti company], H-Nu (registered trademark) 470, 470X [all, Spectra Group Limited], Omnipol TX, 9210 [all, IGM Resins B. V. ], SPEEDCURE 7005, 7010, 7040 [above, LAMBSON company] etc. is mentioned.

Among these photopolymerization initiators, (a) a carbonyl compound or (b) an acylphosphine oxide compound is more preferable, and specifically, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (eg, BASF) Corporation IRGACURE® 819), 2- (Dimethylamine) -1- (4-morpholinophenyl) -2-benzyl-1-butanone (eg, IRGACURE® 369 from BASF), 2-methyl -1- (4-Methylthiophenyl) -2-morpholinopropan-1-one (eg, IRGACURE® 907 from BASF), 1-hydroxy-cyclohexyl-phenyl-ketone (eg, IRGACURE from BASF (Registered trademark) 184), 2,4,6-trimethylbenzoi - diphenyl - phosphine oxide (e.g., DAROCUR (R) TPO, LUCIRIN (TM) TPO (both BASF)), and the like.
Among these, from the viewpoint of sensitivity improvement and compatibility with LED light, as the encapsulated photopolymerization initiator (b), an acyl phosphine oxide compound is preferable, and a monoacyl phosphine oxide compound (particularly preferably 2, More preferred is 4,6-trimethylbenzoyl-diphenyl-phosphine oxide) or a bisacylphosphine oxide compound (particularly preferably bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide).
As a wavelength of LED light, 355 nm, 365 nm, 385 nm, 395 nm, or 405 nm is preferable.

In addition, from the viewpoint of suppressing migration, as the photopolymerization initiator, a polymer type photopolymerization initiator is also preferable.
As a polymeric photoinitiator, the above-mentioned Omnipol TX, 9210; SPEEDCURE7005, 7010, 7040 etc. are mentioned.

A specific particle containing a photopolymerization initiator can be produced, for example, by emulsifying a mixture of an aqueous phase component and an oil phase component containing a specific polymer, a photopolymerizable monomer, and a photopolymerization initiator. 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, still more preferably 1% by mass, based on the total solid content of the specific particles. It is ̃15% by mass.

(Sensitizer)
The specific particles may contain at least one sensitizer.
When the specific particles contain at least one photopolymerization initiator, the specific particles preferably contain at least one sensitizer.
When the specific particles contain a sensitizer, the decomposition of the photopolymerization initiator by irradiation of light (ie, active energy ray) can be further promoted.
A sensitizer is a substance that absorbs a specific activation energy ray to be in an electronically excited state. The sensitizer in the electronically excited state comes into contact with the photopolymerization initiator to produce actions such as electron transfer, energy transfer, heat generation, and the like. This promotes chemical change of the photopolymerization initiator, that is, decomposition, formation of radicals, acid or base, and the like.

Examples of the sensitizer include benzophenone, thioxanthone, isopropyl thioxanthone, anthraquinone, 3-acyl coumarin derivative, terphenyl, styryl ketone, 3- (aroyl methylene) thiazoline, camphor quinone, eosin, rhodamine, erythrosine and the like. .
Moreover, as a sensitizer, the compound represented by General formula (i) of Unexamined-Japanese-Patent No. 2010-24276, and the compound represented by General Formula (I) of Unexamined-Japanese-Patent No. 6-107718 are mentioned. Can also be suitably used.
Among the above, at least one selected from thioxanthone, isopropylthioxanthone, and benzophenone is preferable as the sensitizer from the viewpoint of compatibility with LED light and reactivity with a photopolymerization initiator, and from thioxanthone and isopropyl thioxanthone At least one selected is more preferable, and isopropylthioxanthone is more preferable.
When the specific particle contains a sensitizer, it may contain one sensitizer alone, or two or more sensitizers.

When the specific particles contain 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 with respect to the total solid content of the specific particles. %, More preferably 0.3% by mass to 10% by mass.

Specific particles containing a photopolymerization initiator and a sensitizer include, 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 emulsifying.

(Photothermal conversion agent)
When the specific particles contain a thermally polymerizable monomer as the polymerizable monomer, the specific particles may contain at least one photothermal conversion agent.
The photothermal conversion agent is a compound that absorbs infrared rays and generates heat to polymerize and cure the thermally polymerizable monomer. As the photothermal conversion agent, known compounds can be used.

As a photothermal conversion agent, an infrared absorber is preferable. Examples of infrared absorbers include polymethylindolium, indocyanine green, polymethine dyes, croconium dyes, cyanine dyes, merocyanine dyes, squarylium dyes, chalcogenopyryloarylidene dyes, metal thiolate complex dyes, bis (chalcogenopirillo) polymethine dyes And oxyindolizine dyes, bisaminoallyl polymethine dyes, indolizine dyes, pyrylium dyes, quinoid dyes, quinone dyes, phthalocyanine dyes, naphthalocyanine dyes, azo dyes, azomethine dyes, carbon black and the like.

Specific particles containing a photothermal conversion agent can be produced, for example, by emulsifying a mixture of an oil phase component containing a specific polymer, a thermally polymerizable monomer, and a photothermal conversion agent, and an aqueous phase component.

A photothermal conversion agent may be used individually by 1 type, and may use 2 or more types together.
The content of the photothermal conversion agent is preferably 0.1% by mass to 25% by mass, and more preferably 0.5% by mass to 20% by mass, with respect to the total solid content of the specific particles. It is more preferable that the content is 15% by mass.

(Thermosetting accelerator)
When the specific particles contain a thermally polymerizable monomer as a polymerizable monomer, the specific particles may contain at least one of a heat curing accelerator.
The thermal curing accelerator is a compound that catalytically accelerates the thermal curing reaction of the thermally polymerizable monomer.

Known compounds can be used as the heat curing accelerator. The heat curing accelerator is preferably an acid or a base, or a compound that generates an acid or a base by heating, for example, carboxylic acid, sulfonic acid, phosphoric acid, aliphatic alcohol, phenol, aliphatic amine, aromatic amine, imidazole (Phenylimidazole, 2-methylimidazole etc.), pyrazole etc. may be mentioned.

A specific particle containing a heat curing accelerator may be produced, for example, by emulsifying a mixture of 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 heat curing accelerator 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, and more preferably 0.5% by mass to 20% by mass, with respect to the total solid content of the specific particles. More preferably, it is 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% by mass or more, more preferably 60% by mass or more, and more preferably 70% by mass or more based on the total solid content of the ink. Is more preferably 80% by mass or more, and still more preferably 85% by mass or more.
Thereby, the dispersion stability is further improved, and the adhesion between the image and the substrate is further improved.

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, with respect to the total amount of the ink, and 5% by mass. More preferably, it is from 30% by mass.
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 substrate is further improved.
In addition, 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 size of the specific particles is not particularly limited, but is preferably 0.01 μm to 10.0 μm, more preferably 0.01 μm to 5 μm, from the viewpoint of dispersion stability, more preferably 0.05 μm. It is further preferably 1 to 1 μm, more preferably 0.05 μm to 0.5 μm, and still more preferably 0.05 μm to 0.3 μm.
In the present disclosure, "volume average dispersed particle size" refers to a value measured by a light scattering method. The measurement of the volume average dispersed particle diameter of the specific particles by the light scattering method is performed 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, based on the total amount of the ink % By mass, more preferably 30% by mass to 90% by mass, and particularly preferably 50% by mass to 90% by mass.

[Color material]
The ink of the present disclosure may be an ink containing at least one coloring material (so-called "colored ink") or an ink not containing coloring material (so-called "clear ink").
When the ink contains a coloring material, the coloring material is preferably contained outside the specific particle (that is, the specific particle does not contain the coloring material).
The colorant is not particularly limited, and may be selected from known colorants such as pigments, water-soluble dyes and disperse dyes. Among these, from the viewpoint of excellent weather resistance and rich color reproducibility, it is more preferable to include a pigment.

The pigment is not particularly limited and may be appropriately selected according to the purpose. Examples thereof include known organic pigments and inorganic pigments, and resin particles dyed with a dye, commercially available pigment dispersions and surfaces Treated pigments (for example, pigments in which the pigment is dispersed in water, a liquid compound, an insoluble resin or the like as a dispersion medium, and pigments on which the pigment surface is treated with a resin or a pigment derivative or the like) are also included.
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, white pigments, and the like.

When a pigment is used as the colorant, a pigment dispersant may be used as necessary.
When a pigment is used as the coloring material, a self-dispersible pigment having a hydrophilic group on the surface of the pigment particle may be used as the pigment.
With regard to the coloring material and the pigment dispersant, paragraphs [0180] to [0200] of JP-A-2014-040529 and paragraphs [0122] to [0129] of WO 2016/052053 can be appropriately referred to.

When the ink of the present disclosure contains a colorant, the content of the colorant is preferably 0.1% by mass to 20% by mass, and more preferably 0.5% by mass to 10% by mass, with respect to the total amount of the ink. 5% to 5% by weight is particularly preferred.

[Other ingredients]
The ink of the present disclosure may optionally contain other components other than those described above.
The other components may be contained in the specific particle or may not be contained in the specific particle.

(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 with respect to the total amount of the ink, and 0.1% by mass to 5% by mass It is more preferable that
Specific examples of the organic solvent are as follows.
・ Alcohols (methanol, ethanol, propanol, isopropanol, butanol, isobutanol, secondary butanol, tertiary butanol, pentanol, hexanol, cyclohexanol, benzyl alcohol etc.)
· Polyhydric alcohols (ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, butylene glycol, hexanediol, pentanediol, glycerin, hexanetriol, thiodiglycol, 2-methylpropane Diol etc)
・ Polyhydric alcohol ethers (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 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 Vinyl ether, propylene glycol monophenyl ether)
· Amines (ethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N-ethyldiethanolamine, morpholine, N-ethylmorpholine, ethylenediamine, diethylenediamine, triethylenetetramine, tetraethylenepentamine, polyethyleneimine, pentamethyldiethylenetriamine , Tetramethyl propylene diamine etc.)
・ Amidides (formamide, N, N-dimethylformamide, N, N-dimethylacetamide etc.)
・ Heterocycles (2-pyrrolidone, N-methyl-2-pyrrolidone, cyclohexyl pyrrolidone, 2-oxazolidone, 1,3-dimethyl-2-imidazolidinone, γ-butyrolactone etc.)
・ Sulphoxides (eg, dimethyl sulfoxide)
· 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 substrate is improved.
As the surfactant, for example, higher fatty acid salt, alkyl sulfate, alkyl ester sulfate, alkyl sulfonate, alkyl benzene sulfonate, sulfosuccinate, naphthalene sulfonate, alkyl phosphate, polyoxyalkylene alkyl ether Phosphate, polyoxyalkylene alkyl phenyl ether, polyoxyethylene polyoxypropylene glycol, glycerin ester, sorbitan ester, polyoxyethylene fatty acid amide, amine oxide and the like can be mentioned.
Among these, as the surfactant, at least one surfactant selected from alkyl sulfates, alkyl sulfonates and alkyl benzene sulfonates is preferable, and alkyl sulfates are particularly preferable.
The surfactant is preferably an alkyl sulfate having an alkyl chain length of 8 to 18 from the viewpoint of dispersibility of specific particles, and sodium dodecyl sulfate (SDS, alkyl chain length: 12) and sodium cetyl sulfate (SCS) And at least one selected from alkyl chain length: 16).

Further, as surfactants other than the surfactants described above, those described in JP-A-62-173463 and JP-A-62-183457 can also be mentioned. For example, as other surfactants, nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, acetylene glycols, polyoxyethylene / polyoxypropylene block copolymers, siloxanes, etc. It can be mentioned.
Moreover, organic fluoro compounds are also mentioned as surfactant.
The organic fluoro compound is preferably hydrophobic. Examples of the organic fluoro compound include fluoro surfactant, oily fluoro compound (for example, fluoro oil), and solid fluoro compound resin (for example, tetrafluoroethylene resin), and JP-B-57-9053 Those described in columns 8 to 17) and JP-A-62-135826 may be mentioned.

In addition, the ink of the present disclosure can also contain substantially no surfactant (for example, an anionic surfactant).
Here, "does not substantially contain" indicates that the content is less than 1% by mass (preferably less than 0.1% by mass) based on the total amount of the ink.
The embodiment in which the ink substantially does not contain an anionic surfactant has an advantage that the foaming of the ink can be suppressed, an advantage that the water resistance of the image can be improved, an advantage that the whitening due to the bleed out after the image formation can be suppressed, etc. Have. Further, in particular, when using a pigment dispersion having an anionic dispersing group for 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. Therefore, it also has the advantage of being able to suppress the decrease in 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 may be further improved.
As a polymerization inhibitor, p-methoxyphenol, quinones (hydroquinone, benzoquinone, methoxybenzoquinone, etc.), phenothiazine, catechols, alkylphenols (eg, dibutyl hydroxytoluene (BHT)), alkyl bisphenols, zinc dimethyldithiocarbamate, Dimethyldithiocarbamic acid copper, dibutyldithiocarbamic acid copper, salicylic acid copper, thiodipropionic acid esters, mercaptobenzimidazole, phosphites, 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), 2,2 And 6,6-tetramethyl-4-hydroxypiperidine-1-oxyl (TEMPOL), cuperone Al, tris (N-nitroso-N-phenylhydroxylamine) aluminum salt and the like. That.
Among these, at least one member selected from the group consisting of p-methoxyphenol, catechols, quinones, alkylphenols, TEMPO, TEMPOL, cuperone Al, and tris (N-nitroso-N-phenylhydroxylamine) aluminum salt is Preferably, at least one selected from the group consisting of p-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 a UV absorber.
When the ink of the present disclosure contains a UV absorber, the weather resistance and the like of the image can be further improved.
As a ultraviolet absorber, well-known ultraviolet absorbers, for example, a benzotriazole type compound, a benzophenone series compound, a triazine type compound, a benzoxazole type compound, etc. are mentioned.

In addition, the ink of the present disclosure may be a polymerizable monomer, a photopolymerization agent, or the like outside the specific particle, as needed, from the viewpoint of image hardness, adhesion between the image and the substrate, and control of ink discharge stability. It may contain an initiator, a resin and the like.
It is preferable that these components have water solubility or water dispersibility.
Here, "water-soluble" refers to a property in which the amount of dissolution with respect to 100 g of distilled water at 25 ° C. exceeds 1 g when dried at 105 ° C. for 2 hours.
Also, "water dispersible" refers to the property of being water insoluble and 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.
Further, "the ink contains a polymerizable monomer outside the specific particle" means that the ink contains a polymerizable monomer which is not contained in the specific particle. The same applies to the case where the photopolymerization initiator, the water-soluble resin, the water-dispersible resin and the like are contained outside the specific particles.

Examples of the polymerizable monomer that can be contained outside the specific particle include the polymerizable monomers described in paragraphs [0148] to [0156] of WO 2016/052053.
As polymerizable monomers that can be contained outside the specific particles, compounds having an ethylenically unsaturated group, radically polymerizable monomers such as acrylonitrile, styrene, unsaturated polyester, unsaturated polyether, unsaturated polyamide, unsaturated urethane, etc. It can be mentioned.
Among these, as a polymerizable monomer that can be contained outside the specific particle, 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, as a polymerizable monomer that can be contained outside the specific particle, at least one selected from the group consisting of an amide structure, a polyethylene glycol structure, a polypropylene glycol structure, a carboxy group, and a salt of a carboxy group Compounds having one type are preferred.

From the viewpoint of water solubility or water dispersibility, examples of the polymerizable monomer that can be contained outside the specific particle include, for example, (meth) acrylic acid, sodium (meth) acrylate, potassium (meth) acrylate, N, N- Dimethyl acrylamide, N, N-diethyl acrylamide, morpholine acrylamide, N-2-hydroxyethyl (meth) acrylamide, N-vinyl pyrrolidone, N-vinyl caprolactam, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) Acrylate, 2-hydroxypropyl (meth) acrylate, glycerol monomethacrylate, N- [tris (3-acryloylaminopropyloxymethylene) methyl] acrylamide, diethylene glycol bis (3-acryloylaminopropyl) ether Polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, compounds represented by the following general formula (a) to general formula (d), and ethoxylated trimethylolpropane triacrylate (for example, SR 9035 from Sartmar) (Meth) acrylic acid, N, N-dimethyl acrylamide, N-2-hydroxyethyl (meth) acrylamide, 2-hydroxyethyl (meth) acrylate, glycerin monomethacrylate, N- [tris (3-Acryloylaminopropyloxymethylene) methyl] acrylamide, diethylene glycol bis (3-acryloylaminopropyl) ether, polyethylene glycol di (meth) acrylate, and polypropylene glycol At least one member selected from the group consisting of: di- (meth) acrylates, compounds represented by the following general formula (a) to general formula (d), and ethoxylated trimethylolpropane triacrylate (for example, SR9035 from Sartmar) More preferable.

In 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, Plural 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 , And p each independently represent 0 or 1, and a plurality of m 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 each independently represent an integer of 1 to 8 and l is an integer of 0 or 1 Represent.
In formula (d), Z ¹ represents a residue obtained by removing q hydrogen atoms from a hydroxyl group of a polyol, q represents an integer of 3 to 6, and plural R ^{5 s} each independently represent a hydrogen atom or And a plurality of L ³ 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.

Paragraphs [0139] to [0147] and [0157] of WO 2016/052053 can be appropriately referred to for the photopolymerization initiator and the resin that can be contained outside the specific particle.

[Preferred physical properties of ink]
The ink of the present disclosure preferably has a viscosity of 3 mPa · s to 15 mPa · s, more preferably 3 mPa · s to 13 mPa · s, when 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 (VISCOMETER TV-22, Toki Sangyo Co., Ltd.).

[Use of ink]
The ink of the present disclosure can be used for image formation by a coating method, an immersion method, a gravure method, a flexo method, an inkjet method and the like.
The ink of the present disclosure is particularly preferably used for image formation by an inkjet method (i.e., used as an inkjet ink).

[Form of ink]
In the case where the ink of the present disclosure is a photocurable ink or a thermosetting ink, particularly preferred embodiments include the following Forms 1 to 4.

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

<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.
As Form 2, it is preferable that the specific particle is a microcapsule 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. The more preferable range of the molecular weight of the above-mentioned polymerizable monomer can be referred to for the more preferable range of the molecular weight of a photopolymerizable monomer.

<Form 3>
Form 3 is a thermosetting ink in which the specific particle contains a thermally polymerizable monomer and the specific polymer is a specific linear polymer.
In the form 3, it is preferable that Mw of a specific chain polymer is 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 described above can be referred to.
In Form 3, the molecular weight of the thermally polymerizable monomer is preferably 100 to 4000. For the more preferable range of the molecular weight of the thermally polymerizable monomer, the more preferable range of the molecular weight of the above-mentioned polymerizable monomer can be referred to.

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

[One Example of Method of Producing Ink (Procedure A)]
Although there is no restriction | limiting in particular in the method to manufacture the ink of this indication, An example (the manufacturing method A) of the following is mentioned.
Production method A mixes specific particles by mixing and emulsifying an organic solvent and an oil phase component containing a specific polymer, and an aqueous phase component containing water, a volatile neutralizing agent, and a non-volatile neutralizing agent. To form the
In the process A, when a specific chain polymer is used as the specific polymer, an ink of an embodiment containing specific particles containing the specific chain polymer is manufactured.
In Process A, when a specific crosslinked polymer is used as the specific polymer, an ink of an embodiment containing specific particles containing the specific crosslinked polymer is manufactured.

In the step of forming the specific particle, the specific particle is formed by mixing the oil phase component described above and the aqueous phase component, and emulsifying the obtained mixture. The specific particles formed function as dispersoids in the manufactured ink.
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 in the process of forming the specific particles and after the formation of the specific particles.

The oil phase component may be, for example, a photopolymerizable 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), in addition to the above components. It can contain an isocyanate compound having a polymerizable group introduced, an isocyanate compound having an acid group introduced, and the like.

The water phase components are not particularly limited except for containing water, a volatile neutralizing agent and a non-volatile neutralizing agent.
The aqueous phase components may include components other than water, volatile neutralizing agents, and non-volatile neutralizing agents.
For example, the aqueous phase component may contain a compound for introducing an acid group (preferably, a compound having an acid group and an active hydrogen group described above).

The total amount of the oil phase component and the water phase component excluding the organic solvent and water in the production method A corresponds to the total solid content of the specific particles in the manufactured ink.
For the preferable range of the amount of each component that can be used in the production method A, the above-mentioned "ink" can be referred to. In this reference, "content" and "total solid content of specific particles" in the section of "ink" described above are respectively "amount used" and "oil phase component and water phase component from organic solvent and water It is read as "the total amount excluding".

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

In the step of forming the specific particles, the method of emulsification is not particularly limited, and examples thereof include emulsification with an emulsifying device such as a homogenizer (for example, a dispersing machine).
The rotation speed of the disperser in the emulsification is, for example, 5000 rpm to 20000 rpm, preferably 10000 rpm to 18000 rpm.
The rotation time in emulsification is, for example, 1 minute to 120 minutes, preferably 3 minutes to 60 minutes, more preferably 3 minutes to 30 minutes, and still more preferably 5 minutes to 15 minutes.

Emulsification in the step of forming the specific particles may be performed under heating.
By carrying out the emulsification under heating, specific particles can be formed more efficiently.
In addition, by performing emulsification under heating, at least a portion of the organic solvent in the oil phase component can be easily removed from the mixture.
The heating temperature in the case of carrying out the emulsification under heating is preferably set appropriately according to the boiling point of the volatile neutralizing agent from the viewpoint of suppressing the volatilization of the volatile neutralizing agent.
The emulsification in the step of forming the specific particles is preferably performed at a temperature 10 ° C. or more lower than the boiling point of the volatile neutralizing agent, and more preferably 20 ° C. or more lower.

Also, the step of forming the specific particles may include an emulsification step of emulsifying the mixture, and a heating step of heating the emulsion obtained by the emulsification step.
In the aspect including the emulsification step and the heating step, it is possible to form the specific particles more efficiently particularly in the heating step.
In the embodiment including the emulsification step and the heating step, particularly at the heating step, it is easy to remove at least a part of the organic solvent in the oil phase component from the mixture.
The heating temperature in the heating step is preferably set to a temperature at which the volatile neutralizing agent does not easily volatilize and the organic solvent in the oil phase component tends to volatilize, for example, volatile neutralizing agent and organic solvent It is preferable to set appropriately according to the type and amount.
The heating time in the heating step may be appropriately set according to the types and amounts of the volatile neutralizing agent and the organic solvent, and the heating temperature.

Moreover, the manufacturing method A may have other processes other than the process of forming specific particle | grains as needed.
As another process, the process of adding another component (for example, pigment) is mentioned after the process of forming specific particle | grains.
The other components (eg, pigments) to be added are as already described as the other components that may be contained in the ink.

[Another example of the method for producing the ink (production method B)]
As a method of producing an ink of an embodiment containing specific particles containing a specific crosslinked polymer, Production Method B shown below is also suitable.
Production method B comprises an oil phase component containing an organic solvent, a trifunctional or higher functional isocyanate compound, and an isocyanate compound having an acid group introduced therein, an aqueous phase component containing water, a volatile neutralizing agent, and a non-volatile neutralizing agent , And emulsifying to form specific particles.
A preferred embodiment of the production process B is the same as the preferred embodiment of the production process A except that a trifunctional or higher functional isocyanate compound is used as the oil phase component instead of the specific polymer.

[Image forming method]
The image forming method of the present disclosure includes a step of forming an ink film by applying the above-described ink of the present disclosure on a substrate (hereinafter, also referred to as “application step”), and a step of heating the ink film. (Hereafter, it is also called a "heating process").
The image forming method of the present disclosure may have other steps as necessary.
According to the image forming method of the present disclosure, a fine image is formed on a substrate. Further, according to the image forming method of the present disclosure, an image excellent in scratch resistance is formed on a substrate.

(Applying process)
The application step is a step of forming an ink film by applying the ink of the present disclosure on a substrate.
As an aspect which applies an ink on a base material, you may employ | adopt any of the aspect using well-known methods, such as a coating method, an immersion method, and an inkjet method. Among them, the inkjet method is preferable in that a film (for example, an image) can be formed on various substrates (including a recording medium).

The substrate is not particularly limited, and, for example, known substrates provided as a support and a recording medium can be appropriately selected and used.
As a substrate, paper, paper (plastic, polyethylene, polypropylene, polystyrene, etc.) laminated, metal plate (plate of metal such as aluminum, zinc, copper, etc.), plastic film (polyvinyl chloride (PVC) resin , Cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose nitrate, polyethylene terephthalate (PET: Polyethylene Terephthalate), polyethylene (PE: Polyethylene), polystyrene (PS: Polystyrene), polypropylene (PP: Films made of Polypropylene, PC (Polycarbonate), polyvinyl acetal, acrylic resin, etc., paper laminated or vapor-deposited metal, plastic fiber laminated or vapor-deposited metal Beam and the like.

Moreover, a textiles base material is also mentioned as a base material.
Materials for textile base materials include natural fibers such as cotton, silk, hemp and wool; chemical fibers such as viscose rayon and rheocel; synthetic fibers such as polyester, polyamide and acrylic; natural fibers, chemical fibers and synthetic fibers And mixtures of at least two selected from the group consisting of As the textile substrate, the textile substrate described in paragraphs [0039] to [0042] of WO 2015/158592 may be used.

As a substrate, plastics such as polyvinyl chloride (PVC) substrate, polystyrene (PS) substrate, polycarbonate (PC) substrate, polyethylene terephthalate (PET) substrate, polypropylene (PP) substrate, acrylic resin substrate and the like Substrates are preferred.

The application of the ink by the inkjet method can be performed using a known inkjet recording device.
The ink jet recording apparatus is not particularly limited, and any known ink jet recording apparatus capable of achieving the target resolution can be selected and used.
Examples of the inkjet recording apparatus include an apparatus including an ink supply system, a temperature sensor, a heating unit, and the like.
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 in front of an inkjet head, a filter, and a piezoelectric inkjet head. The piezo type inkjet head preferably has 1 pl to 100 pl, more preferably 8 pl to 30 pl multi-size dots, preferably 320 dpi (dot per inch; the same below) x 320 dpi to 4000 dpi x 4000 dpi, more preferably 400 dpi x 400 dpi It can be driven so as to be capable of discharging at a resolution of ̃1600 dpi × 1600 dpi, more preferably 720 dpi × 720 dpi. In addition, dpi represents the number of dots per 2.54 cm (1 inch).

In addition, in the application step, the ink may be applied to a substrate that has been preheated.
In the application step, when the ink is applied to the preheated substrate, the following heating step can be performed by the heated substrate (that is, the ink film is formed by the heated substrate) Can be heated).
The heating of the substrate 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 substrate.
By heating the ink film in the heating step, thickening of the ink film occurs, and as a result, an image excellent in 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, curing of the ink film (that is, thermal polymerization by a thermally polymerizable monomer) is performed by heating in the heating step. May be In other words, when the above-described thermosetting ink is used as the ink of the present disclosure, the heating step may also serve as the curing step B described later.

As an aspect of the heating in a heating process, the aspect which heats the ink provided on the base material by a heating means is mentioned.
Further, as described above, when the ink is applied to the substrate heated in advance in the application step, an embodiment of heating the ink by the heated substrate may be mentioned as an embodiment of the heating in the heating step.

The heating means is not particularly limited, and examples thereof include a heat drum, a warm air, an infrared lamp, an infrared LED, an infrared heater, a thermal oven, a heat plate, an infrared laser, an infrared dryer and the like. Among them, a light emitting diode having an emission wavelength in the near infrared to far infrared rays, having a maximum absorption wavelength at a wavelength of 0.8 μm to 1.5 μm or 2.0 μm to 3.5 μm, from the point that the ink can be efficiently heat-cured An LED), a heater emitting near infrared to far infrared radiation, a laser having an emission wavelength of near infrared to far infrared radiation, or a dryer emitting near infrared to far infrared radiation is preferable.

The heating temperature during heating is preferably 40 ° C. or higher, more preferably 40 ° C. to 200 ° C., still more preferably 45 ° C. to 100 ° C., and further preferably 50 ° C. to 80 ° C. from the viewpoint of more effectively thickening the ink film. More preferably, 55 ° C to 70 ° C is more 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 (Nippon 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 more, more preferably 5 seconds to 5 minutes, more preferably 10 seconds to 1 minute, and still more preferably 20 seconds to 1 minute.

(Curing process)
The image forming method of the present disclosure can have a curing step of curing the ink film heated by the heating step.
By the 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 thus 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, the ink film is irradiated with light (that is, active energy ray) as the curing step by irradiating the ink film heated in the heating step. A curing step (hereinafter, "curing step A") for curing can be provided.

In the image forming method of the present disclosure, when a thermosetting ink is used, a curing step of subjecting the ink film heated in the heating step to heating or irradiation of infrared rays as a curing step to thermally cure the ink film ( Hereinafter, "hardening process B" can be provided.
However, when using a thermosetting ink, thickening and thermal curing of the ink film are performed by the above-described heating step without providing the curing step B (that is, the curing step B different from the above-described heating step). May be
That is, in the case of using a thermosetting ink in the image forming method of the present disclosure, a heating step for thickening the ink film and a curing step B for thermosetting the ink film may be separately provided. Alternatively, a single heating step may be provided to both thicken and thermally cure the ink film.

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

As an active energy ray which can be used by hardening process A, an ultraviolet ray (UV light), a visible ray, an electron beam etc. are mentioned, Among these, UV light is preferred.

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

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.
The exposure energy when the active energy ray (light) is irradiated is, for example, 10 mJ / cm ² to 2000 mJ / cm ² , preferably 20 mJ / cm ² to 1000 mJ / cm ² .

As sources for generating active energy rays (light), mercury lamps, metal halide lamps, UV fluorescent lamps, gas lasers, solid lasers and the like are widely known.
Also, the replacement of the light source exemplified above with a semiconductor ultraviolet light emitting device is very useful both industrially and environmentally.
Among semiconductor ultraviolet light emitting devices, LEDs (Light Emitting Diodes) and LDs (Laser Diodes) are small in size, high in life, high in efficiency, and low in cost, and are expected as light sources.
As a 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 using a sensitizer and a photopolymerization initiator in combination, an ultra-high pressure mercury lamp capable of light irradiation with a wavelength of 365 nm, 405 nm or 436 nm, 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 light irradiation with a wavelength of 355 nm, 365 nm, 385 nm, 395 nm or 405 nm is more preferable, and an LED capable of light irradiation 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 methods disclosed in Japanese Patent Application Laid-Open No. 60-132767 can be applied similarly.
Specifically, a light source is provided on both sides of a head unit including an ink discharge device as an active energy ray irradiation method, and the head unit and the light source are scanned by a so-called shuttle method, or by another light source without driving. It is preferable to use an active energy ray irradiation method.
The irradiation of the active energy ray is preferably performed after a certain time (for example, 0.01 seconds to 120 seconds, preferably 0.01 seconds to 60 seconds) after the ink is landed and the heating and drying are performed.

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

EXAMPLES Hereinafter, the present invention will be more specifically described by way of examples. However, the present invention is not limited to the following examples as long as the gist thereof is not exceeded.
In the following examples, "parts" represents parts by mass unless otherwise specified.
Moreover, "*" in chemical formula represents a bonding position.

<Synthesis of Specific Chain Polymer>
(Synthesis of Polymer 1)
The following polymer 1 was synthesized as a specific linear polymer according to the following reaction scheme.

In a three-necked flask, dimethylol propionic acid (DMPA) (16.9 g), dicyclohexylmethane-4,4'-diisocyanate (HMDI) (82.5 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. Thereto, 0.2 g of Neostan U-600 (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.
Next, thereto was added isopropanol (IPA) (80 g) as an end capping agent and ethyl acetate (110 g), and the mixture was stirred at 70 ° C. for 3 hours. After stirring for 3 hours, the reaction solution is allowed to cool to room temperature (25 ° C .; the same applies hereinafter), and the concentration is adjusted with ethyl acetate to obtain a 30% by weight solution of polymer 1 (solvent: IPA and ethyl acetate) Mixed solution of
The weight average molecular weight (Mw) of the polymer 1 was 8000, and the acid value was 0.70 mmol / g.
The polymer 1 has an acryloyl group as a photopolymerizable group.

(Synthesis of Polymer 2)
As a specific chain polymer, Polymer 2, which is a chain (meth) acrylic polymer, was synthesized. Details are shown below.
Propylene glycol monomethyl ether (37.5 g) was charged into a three-necked flask, and heated at 75 ° C. for 30 minutes under a nitrogen stream of 20 mL / min.
Then, there were added thereto 2-ethylhexyl methacrylate (30.0 g), methyl methacrylate (10.0 g), methacrylic acid (3.0 g), allyl methacrylate (7.0 g), 2,2'-azobis A mixture of (methyl isobutyrate) (2.2 g) and propylene glycol monomethyl ether (37.5 g) was added dropwise over 2 hours. After completion of the dropwise addition, the mixture was stirred at 75 ° C. for 2 hours and then allowed to cool to room temperature. The resulting reaction solution was added dropwise to 5 liters of water with stirring to obtain a powder of (meth) acrylic polymer. The obtained powder was dried using an oven at 60 ° C. for 6 hours, and then dissolved in ethyl acetate and concentration adjusted to obtain a 30% by mass solution of polymer 2 (solvent: ethyl acetate).
The weight average molecular weight (Mw) of the polymer 2 was 20000, and the acid value was 0.70 mmol / g.

(Synthesis of Polymer 101)
The following polymer 101 was synthesized as a specific linear polymer according to the following reaction scheme.

In a three-necked flask, dimethylol propionic acid (DMPA) (6.4 g), dicyclohexylmethane-4,4'-diisocyanate (HMDI) (41.2 g), tricyclodecane dimethanol (compound (2-5)) (20 2 g) and ethyl acetate (67.7 g) were charged and heated to 70.degree. To the resulting heated product, 0.14 g of U-600 was added and stirred at 70 ° C. for 5 hours.
Next, there was added isopropanol (IPA) (10 g) as an end capping agent and ethyl acetate (32.9 g), 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 concentration adjustment was performed using ethyl acetate to obtain a 30% by mass solution of polymer 101 (solvent: mixed solution of IPA and ethyl acetate) .
The weight average molecular weight (Mw) of the polymer 101 was 8000, and the acid value was 0.70 mmol / g.

Example 1 (Photocurable Ink)
<Preparation of water dispersion>
-Preparation of oil phase components-
A 30% by weight solution of polymer 1 (53 parts as polymer 1), Sartmar photopolymerizable monomer SR833S (44 parts), BASF photopolymerization initiator IRGACURE® 819 (2.5 parts) Hereinafter, “IRG 819”), 2-isopropylthioxanthone (0.5 part; hereinafter, also referred to as “ITX”) of Tokyo Chemical Industry Co., Ltd. as a sensitizer, and ethyl acetate are mixed, By stirring for 15 minutes, 44 g of an oil phase component having a solid content of 36% by mass was obtained.

SR833S is a bifunctional photopolymerizable monomer having a cyclic structure, and specifically, it is tricyclodecanedimethanol diacrylate (molecular weight 304).
IRG 819 is an acyl phosphine oxide type photoinitiator, specifically, bis (2,4,6-trimethyl benzoyl) -phenyl phosphine oxide.

-Preparation of water phase components-
Mix distilled water (45 g), triethylamine (boiling point: 89 ° C.) as a volatile neutralizing agent, and sodium hydroxide (NaOH) (boiling point: 1388 ° C.) as a non-volatile neutralizing agent, 15 The aqueous phase component was prepared by stirring for a minute.
The amount of volatile neutralizing agent used and the amount of non-volatile neutralizing agent used were adjusted so that the degree of neutralization of the acid groups (i.e., carboxy groups) in the specific particles to be produced was 90%.
The specific amounts of volatile neutralizing agent and non-volatile neutralizing agent were determined by the following formula.

Amount of volatile neutralizing agent (g) = total amount of oil phase component (g) × (solid content concentration of oil phase component (% by mass) / 100) × (specific linear polymer relative to total solid content of oil phase component That is, the content of polymer-1) (% by mass) / 100) × the acid value (mmol / g) of the specific linear polymer (ie, polymer-1) × 0.9 × [the number of moles of the volatile neutralizing agent (Mol) / (mol of volatile neutralizing agent (mol) + mol of non-volatile neutralizing agent (mol)) × molecular weight of volatile neutralizing agent (g / mol) / 1000
Amount of non-volatile neutralizing agent (g) = total amount of oil phase component (g) × (solid content concentration of oil phase component (mass%) / 100) × (specific chain polymer relative to total solid content of oil phase component) (Namely, content of polymer-1) (mass%) / 100) × acid value of specific chain polymer (namely, polymer-1) (mmol / g) × 0.9 × [nonvolatile neutralizing agent Number of moles (mol) / (number of moles of volatile neutralizing agent (mol) + number of moles of non-volatile neutralizing agent (mol)) × molecular weight of non-volatile neutralizing agent (g / mol) / 1000

The oil phase component and the water phase component were mixed, and the obtained mixture was emulsified at room temperature for 10 minutes at 18,000 rpm using a homogenizer to obtain an emulsion.
The resulting emulsion was added to distilled water (25 g) and the resulting liquid was stirred at room temperature for 30 minutes. Next, the liquid was heated to 50 ° C. and stirred at 50 ° C. for 6 hours to distill off ethyl acetate from the liquid. The liquid from which ethyl acetate was distilled off was further stirred at 50 ° C. for 24 hours to form specific particles in the liquid.
Next, an aqueous dispersion of specific particles was obtained by diluting the liquid containing the specific particles with distilled water so as to have a solid content of 20% by mass.

<Preparation of Photocurable Ink>
Each component of the following composition was mixed to prepare a photocurable ink.

-Composition of photocurable ink-
-82 parts of the above aqueous dispersion-13 parts of pigment dispersion (Pro-jet Cyan APD 1000 (FUJIFILM Imaging Colorants), pigment concentration: 14% by mass)
・ Fluorinated surfactant 0.3 parts (Capstone FS-31 (DuPont), solid content: 25% by mass)
-4.7 parts of 2-methyl propane diol

<Evaluation>
The following evaluation was performed using the photocurable ink obtained above.
The results are shown in Table 3.

1. Ink Ejectability As one of the indicators of the dispersion stability of the ink, the ejection property was evaluated.
After the preparation, the above-mentioned photocurable ink stored at room temperature for less than 1 day was discharged from the head of an ink jet printer (Roland DG Corporation, SP-300V) for 30 minutes, and then the discharge was stopped.
After a predetermined time (specifically, 5 minutes, 8 minutes, and 10 minutes, respectively) has elapsed from the stop of the discharge, the ink is discharged again from the head onto the substrate, and a solid of 5 cm × 5 cm is obtained. An image was formed.
As a substrate, CORREX (registered trademark) which is a polypropylene (PP) substrate of DUROplastic was used.
These images were visually observed to confirm the presence or absence of dot defects due to the occurrence of non-ejection nozzles and the like, and the ink ejection properties were evaluated according to the following evaluation criteria.
In the following evaluation criteria, A is the one with the best ink dischargeability.

-Evaluation criteria for ink dischargeability-
A: At the time of discharge evaluation after 10 minutes from the stop of discharge, occurrence of dot missing due to the generation of a non-discharge nozzle or the like was not observed, and a good image was obtained.
B: At the time of discharge evaluation after 8 minutes from the stop of discharge, occurrence of dot missing due to the occurrence of non-discharge nozzle etc. was not recognized and a good image was obtained, but at the time of discharge evaluation after 10 minutes non-discharge nozzle Was observed, and the occurrence of dot missing was observed.
C: A non-ejection nozzle was generated at the time of ejection evaluation 8 minutes after the ejection was stopped, and occurrence of dot chipping was recognized.

2. Storage stability of ink Storage stability was evaluated as one of the indicators of dispersion stability of ink.
The above photocurable ink was sealed in a container and allowed to age at 60 ° C. for 2 weeks.
The evaluation test similar to the evaluation test of the dischargeability of the said ink was implemented about the ink after two weeks progress, and the storage stability of the ink was evaluated according to the same evaluation standard.
Among the above evaluation criteria, A is the one with the best storage stability of the ink.

3. Fineness of the image The substrate is heated to 60 ° C. by a print heater, and the photocurable ink is discharged from the head of the ink jet printer to the heated substrate, and the character image shown in FIG. , 7 points, and 10 points in each size.
As a substrate, CORREX (registered trademark) which is a polypropylene (PP) substrate of DUROplastic was used.

The character image shown in FIG. 1 of each size formed was observed with a kraft loupe (Etsumi Co., Ltd.) at a magnification of 10 times. Based on the observed results, the definition of the image was evaluated according to the following evaluation criteria. In the following evaluation criteria, A is the one with the highest definition of the image.

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

4. Scratch Resistance of Cured Film A coated film having a thickness of 12 μm was formed on the substrate by applying the photocurable ink stored on the substrate for 1 day or less after preparation to the substrate.
As a substrate, CORREX (registered trademark) which is a polypropylene (PP) substrate of DUROplastic was used.
Moreover, the said application is No. 1 of the K hand coater of RK PRINT COAT INSTRUMENTS company. It carried out using 2 bars.

Next, the coated film was heated at 60 ° C. for 3 minutes to be dried.
The coating film after drying was irradiated with ultraviolet light (UV) to cure the coating film and obtain a cured film.
For UV (UV) irradiation, an ozone-less metal halide lamp MAN 250L is mounted as an exposure light source, and an experimental UV mini-conveyor device CSOT (traded) set at a conveyor speed of 35 m / min and an exposure intensity of 1.0 W / cm ² GS Yuasa Power Supply was used. This UV irradiation was performed at an exposure energy of 1000 mJ / cm ² .

The scratch test of the following conditions was implemented with respect to the cured film formed above.

-Conditions of scratch test-
Equipment: Haydn's reciprocating wear tester "TYPE 30S"
Scratching needle: SUS (stainless steel) scratching needle having a tip radius of curvature of 1.0 mm Loading: 100 g and 200 g two conditions Scratching speed: 3000 mm / min.
Number of scratches: 5 round trips

After 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 is the one with the best scratch resistance of the cured film.

-Evaluation criteria for scratch resistance of cured film-
A: No scratch marks were observed on the cured film under any of the conditions of 100 g load and 200 g load.
B: No scratch marks were observed on the cured film under the condition of a load of 100 g, but slight scratches were observed on the cured film under the condition of the load of 200 g.
C: A slight scratch was observed on the cured film under a load of 100 g.
D: Scratch marks were clearly observed on the cured film under a load of 100 g.

Example 2 (Photocurable Ink)
The same operation as in Example 1 was carried out except that the type and amount of the photopolymerizable monomer were changed as shown in Table 3.
The results are shown in Table 3.
Here, SR399E is a pentafunctional photopolymerizable monomer having no cyclic structure, and specifically, is dipentaerythritol pentaacrylate (molecular weight 525).

Example 3 (Photocurable Ink)
The same operation as in Example 1 was performed except that the type of non-volatile neutralizing agent was changed as shown in Table 3.
The results are shown in Table 3.

[Examples 4 to 7 and 13 to 18] (Photocurable Ink)
The same operation as in Example 1 was performed except that the type of volatile neutralizing agent was changed as shown in Table 3.
The results are shown in Table 3.

[Examples 8 to 12] (Photocurable Ink)
The amounts of volatile neutralizing agents used and the amounts of non-volatile neutralizing agents used are shown in Table 3, molar ratio of volatile neutralizing agent to non-volatile neutralizing agent [volatility / non-volatility (molar ratio The same operation as Example 1 was performed except having changed so that it might become].
The results are shown in Table 3.

Example 19 (Photocurable Ink)
The same operation as in Example 1 is carried out except using a 30% by mass solution of Polymer 2 (53 parts as the amount of Polymer 2) instead of the 30% by mass solution of Polymer 1 (53 parts as the amount of Polymer 1) went.
The results are shown in Table 3.

Comparative Example 1 (Photocurable Ink)
<Preparation of water dispersion>
-Preparation of oil phase components-
A 30% by weight solution of polymer 1 (53 parts as polymer 1), Sartmar photopolymerizable monomer SR833S (44 parts), BASF photopolymerization initiator IRGACURE® 819 (2.5 parts) IRG 819), 2-isopropylthioxanthone (0.5 part; ITX) of Tokyo Chemical Industry Co., Ltd. as a sensitizer, and ethyl acetate are mixed, and the solid content is 36% by mass by stirring for 15 minutes 44 g of an oil phase component of

-Preparation of water phase components-
Mix distilled water (45 g), ammonia (boiling point: -33 ° C) as a volatile neutralizing agent, and sodium hydroxide (NaOH) (boiling point: 1388 ° C) as a non-volatile neutralizing agent, The aqueous phase component was prepared by stirring for 15 minutes.
The amount of non-volatile neutralizing agent used was adjusted so that the degree of neutralization of the acid groups (i.e., carboxy groups) in the specific particles to be produced was 90%.
The amount of volatile neutralizing agent used was 1/10 of the amount of nonvolatile neutralizing agent used.
The specific amounts of volatile neutralizing agent and non-volatile neutralizing agent were determined by the following formula.

Amount of volatile neutralizing agent (g) = total amount of oil phase component (g) × (solid content concentration of oil phase component (% by mass) / 100) × (specific linear polymer relative to total solid content of oil phase component That is, the content of polymer 1) (% by mass) / 100) × acid value (mmol / g) of a specific linear polymer (ie, polymer 1) × 0.9 × (1/10) × volatile Molecular weight of Japanese agent (g / mol) / 1000
Amount of non-volatile neutralizing agent (g) = total amount of oil phase component (g) × (solid content concentration of oil phase component (mass%) / 100) × (specific chain polymer relative to total solid content of oil phase component) (Namely, content of polymer-1) (mass%) / 100) × acid value of specific chain polymer (namely, polymer-1) (mmol / g) × 0.9 × molecular weight of non-volatile neutralizing agent (G / mol) / 1000

The oil phase component and the water phase component were mixed, and the resulting mixture was emulsified at 25 ° C. using a homogenizer at 18,000 rpm for 10 minutes to obtain an emulsion.
The resulting emulsion was added to distilled water (25 g) and the resulting liquid was stirred at room temperature for 30 minutes. Next, the liquid is heated to 60 ° C. and stirred at 60 ° C. for 6 hours under reduced pressure (2.7 kPa) to distill off ethyl acetate and a volatile neutralizing agent (that is, ammonia) from the liquid. did. The liquid from which ethyl acetate and the volatile neutralizing agent were distilled off was further stirred at 50 ° C. under normal pressure for 24 hours to form particles in the liquid.
Next, an aqueous dispersion of particles was obtained by diluting the liquid containing the particles with distilled water so that the solid content would be 20% by mass. The odor of the volatile neutralizing agent was not felt from the aqueous dispersion of the obtained particles, and the amount of the acid group neutralized by the volatile neutralizing agent was measured by the above-mentioned potentiometric titration method, It was 0 mmol.
A photocurable ink was prepared in the same manner as in Comparative Example 1 using the obtained particle dispersion liquid.
The results are shown in Table 3.

Comparative Example 2 (Photocurable Ink)
An emulsion was obtained in the same manner as in Comparative Example 1 except that the type of volatile neutralizing agent was changed as shown in Table 3.
The resulting emulsion was added to distilled water (25 g) and the resulting liquid was stirred at room temperature for 30 minutes. Next, the liquid is heated to 60 ° C. and stirred at 60 ° C. under reduced pressure (2.7 kPa) for 6 hours to distill off ethyl acetate and a volatile neutralizing agent (that is, triethylamine) from the liquid. did. The liquid from which ethyl acetate and the volatile neutralizing agent were distilled off was further stirred at 50 ° C. under normal pressure for 24 hours to form particles in the liquid.
Next, an aqueous dispersion of particles was obtained by diluting the liquid containing the particles with distilled water so that the solid content would be 20% by mass. The odor of the volatile neutralizing agent was not felt from the aqueous dispersion of the obtained particles, and the amount of the acid group neutralized by the volatile neutralizing agent was measured by the above-mentioned potentiometric titration method, It was 0 mmol.
A photocurable ink was prepared in the same manner as in Comparative Example 1 using the obtained particle dispersion liquid.
The results are shown in Table 3.

Comparative Example 3 (Photocurable Ink)
The same operation as in Example 1 was performed except that the volatile neutralizing agent was not used.
The results are shown in Table 3.

Comparative Example 4 (Photocurable Ink)
The same operation as in Example 1 was performed except that the non-volatile neutralizing agent was not used.
The results are shown in Table 3.

“-” In Table 3 indicates that there is no corresponding one.
“Volatile / non-volatile (molar ratio)” in Table 3 is the ratio of the non-volatile neutralizing agent to the total of 100 mol% of the volatile neutralizing agent and the non-volatile neutralizing agent The ratio of the ratio of volatile neutralizer to (mol%) (mol%) [ratio of volatile neutralizer (mol%) / ratio of non-volatile neutralizer (mol%)] is meant.
“Volatile neutralized acid group / non-volatile neutralized acid group (molar ratio)” in Table 3 are the acid group neutralized by the volatile neutralizing agent and the nonvolatile neutralization Neutralized by the volatile neutralizing agent with respect to the ratio (mol%) of the acid group neutralized by the non-volatile neutralizing agent, assuming that the total with the acid agent neutralized by the agent is 100 mol% Ratio of acid group proportion (mol%) [proportion of acid group neutralized by volatile neutralizing agent (mol%) / ratio of acid group neutralized by non-volatile neutralizing agent (mol%)] Means

As shown in Table 3, particles containing water, a volatile neutralizing agent having a boiling point of 25 ° C. or more and 250 ° C. or less, and an acid group neutralized by a non-volatile neutralizing agent having a boiling point of 250 ° C. or higher (ie, Examples 1 to 19 using a photocurable ink containing specific particles (A) and (B) are excellent in the test of the ink dischargeability and the storage stability of the ink as an index for evaluating the dispersion stability of the ink. Show the results. In addition, Examples 1 to 19 showed excellent results in the test of image definition. Furthermore, Examples 1-19 also showed excellent results in the scratch resistance test of the cured film.

On the other hand, it is neutralized by a volatile neutralizing agent having a boiling point of 25 ° C. or more and 250 ° C. or less although it contains water and an acid group neutralized by a non-volatile neutralizing agent whose boiling point exceeds 250 ° C. In Comparative Examples 1 to 3 using a photocurable ink containing particles having no acid group, the ink dischargeability and the ink storage stability test serving as an index for evaluating the dispersion stability of the ink Although excellent results were shown, in the test of the definition of the image, the evaluation result is “D”, and inferior results are shown as compared with Examples 1 to 19. In addition, in Comparative Examples 1 to 3, the evaluation result was “D” also in the test for scratch resistance of the cured film, and inferior results were obtained as compared with Examples 1 to 19.
In addition, an acid group containing water and an acid group neutralized with a volatile neutralizing agent having a boiling point of 25 ° C. or more and 250 ° C. or less, but having a boiling point exceeding 250 ° C. is neutralized In Comparative Example 4 using a photocurable ink containing particles not containing water, the evaluation results of the test of the ink dischargeability and the storage stability of the ink as an index of the evaluation of the dispersion stability of the ink are “ C "and showed inferior results compared to Examples 1-19.

From the results of Examples 1, 4 to 7 and 13 to 19, when the boiling point of the volatile neutralizing agent is 25 ° C. or more and 100 ° C. or less (Examples 1 and 4 to 7), the image definition and the cured film are obtained It is understood that scratch resistance is more excellent.

For example, from the results of Examples 17 and 18, when the amine compound is contained as a volatile neutralizing agent having a boiling point of 25 ° C. or more and 250 ° C. or less, the valence number of the amine compound is 1 (Example 17). It can be seen that the dischargeability of the ink and the storage stability of the ink are better.

For example, from the results of Examples 13 and 16, when the amine compound is contained as a volatile neutralizing agent having a boiling point of 25 ° C. or more and 250 ° C. or less, all substituents of the amine compound are alkyl groups (Example 13) It can be seen that the ink dischargeability and the storage stability of the ink are more excellent.

From the results of Examples 1 and 8 to 12, the molar ratio of the acid group neutralized by the volatile neutralizer to the acid group neutralized by the non-volatile neutralizer contained in the specific particle (during the volatility The number of moles of acid groups neutralized by the common agent / the number of moles of acid groups neutralized by the non-volatile neutralizing agent is in the range of 60/40 to 90/10 (Examples 1 and 9 and 10) It can be seen that all of the ink dischargeability, the storage stability of the ink, the definition of the image, and the scratch resistance of the cured film are all superior.

Using the aqueous dispersion of specific particles in each of Examples 1 to 19 described above, the volume average dispersed particle size of the specific particles was measured.
The volume average dispersed particle size of the specific particles was measured by a light scattering method using LA-960 (Horiba, Ltd.).
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 preparation of the ink, SR833S, IRG819, and ITX a, 60 ° C. and 2.67kPa Trixene ^TM BI7982 propylene glycol monomethyl ether was distilled off under reduced pressure under the conditions of (20 torr) (thermally polymerizable monomer; blocked isocyanate; Baxenden Chemicals Ltd.) (Hereafter, it is also referred to as "BI 7982"; the amount is as shown in Table 4; molecular weight 793), and in the same manner as in Example 1 except that the polymer 1 is changed to the same amount of polymer 101, Sex ink was prepared.

<Evaluation>
The following evaluation was performed using the thermosetting ink obtained above.
The results are shown in Table 4.

1. Ink Ejectability The ink ejection properties were evaluated in the same manner as in the evaluation of the ink ejection properties in Example 1.

2. Storage Stability of Ink The storage stability of the ink was carried out in the same manner as the evaluation of the storage stability of the ink in Example 1.

3. Image Fineness The image fineness was evaluated in the same manner as in the evaluation of the image fineness in Example 1.

4. Scratch resistance of the cured film For evaluation of the scratch resistance of the cured film, the coated film is dried by heating at 60 ° C. for 3 minutes, and the coated film is irradiated with ultraviolet light (UV) at 120 ° C. The evaluation was conducted in the same manner as in the evaluation of the scratch resistance of the cured film in Example 1 except that the operation was changed to heating for 5 minutes in an oven of

Example 102 (Thermosetting Ink)
The BI7982, EPICLON ^TM 840 is a thermally polymerizable monomer having an epoxy group (DIC Corporation; hereinafter referred to as "EP840"; the amount is as shown in Table 4; molecular weight 340) is a and the thermal curing accelerator 2-methylimidazole The operation is the same as in Example 101 except that the amount is also changed as shown in Table 4 and the type of volatile neutralizing agent is changed as shown in Table 4. Did.
The results are shown in Table 4.

[Examples 103 to 106] (Thermosetting ink)
The same operation as in Example 101 was performed except that the type of volatile neutralizing agent was changed as shown in Table 4.
The results are shown in Table 4.

Comparative Example 101 (Thermosetting Ink)
Dispersion of particles in the same manner as Comparative Example 1 except that SR833S, IRG 819, and ITX were changed to BI7982 (amounts are as shown in Table 4), and polymer 1 was changed to the same amount of polymer 101. I got The odor of the volatile neutralizing agent was not felt from the obtained dispersion liquid of the particles, and the amount of the acid group neutralized by the volatile neutralizing agent was measured by the above-mentioned potentiometric titration method. Met.
A thermosetting ink was prepared in the same manner as in Comparative Example 1 using the obtained dispersion of particles.
The results are shown in Table 4.

Comparative Example 102 (Thermosetting Ink)
Dispersion of particles in the same manner as Comparative Example 2 except that SR833S, IRG 819, and ITX were changed to BI7982 (as shown in Table 4), and Polymer 1 was changed to the same amount of Polymer 101. I got The odor of the volatile neutralizing agent was not felt from the obtained dispersion liquid of the particles, and the amount of the acid group neutralized by the volatile neutralizing agent was measured by the above-mentioned potentiometric titration method. Met.
A thermosetting ink was prepared in the same manner as in Comparative Example 2 using the obtained dispersion of particles.
The results are shown in Table 4.

Comparative Example 103 (Thermosetting Ink)
The same operation as in Example 101 was performed except that the volatile neutralizing agent was not used.
The results are shown in Table 4.

Comparative Example 104 (Thermosetting Ink)
The same operation as in Example 101 was performed except that the non-volatile neutralizing agent was not used.
The results are shown in Table 4.

“-” In Table 4 indicates that there is no corresponding one.
“Volatile / non-volatile (molar ratio)” in Table 4 is the ratio of non-volatile neutralizing agent to the total of 100 mol% of the volatile neutralizing agent and non-volatile neutralizing agent The ratio of the ratio of volatile neutralizer to (mol%) (mol%) [ratio of volatile neutralizer (mol%) / ratio of non-volatile neutralizer (mol%)] is meant.
“Volatile neutralized acid group / non-volatile neutralized acid group (molar ratio)” in Table 4 are the acid group neutralized by the volatile neutralizing agent and the nonvolatile neutralization Neutralized by the volatile neutralizing agent with respect to the ratio (mol%) of the acid group neutralized by the non-volatile neutralizing agent, assuming that the total with the acid agent neutralized by the agent is 100 mol% Ratio of acid group proportion (mol%) [proportion of acid group neutralized by volatile neutralizing agent (mol%) / ratio of acid group neutralized by non-volatile neutralizing agent (mol%)] Means

As shown in Table 4, the same results as in Examples 1 to 19 for the photocurable ink were obtained also in Examples 101 to 106 for the thermosetting ink.

Using the aqueous dispersion of specific particles in each of Examples 101 to 106 described above, the volume average dispersed particle size of the specific particles was measured.
The volume average dispersed particle size of the specific particles was measured by a light scattering method using LA-960 (Horiba, Ltd.).
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 Water Dispersion of Microcapsule (MC)>
A microcapsule (MC) comprising a shell comprising 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 follows: Water dispersion was prepared.
In this example, microcapsules (MC) correspond to specific particles.

-Preparation of oil phase components-
Mitsui Chemicals, Inc. Takenate (registered trademark) D-110N (43 parts as the amount of solid trifunctional isocyanate compound; hereinafter, this solid is also referred to as “D110N”) and a solution of the following NCO1 (solid 10 parts as the amount of NCO1 which is the following; hereinafter, this solid content is also referred to as "NCO1"), the above-mentioned SR833S (44 parts) which is a photopolymerizable monomer, and the above-mentioned IRG 819 (2. 55.7 parts), the above-mentioned ITX (0.5 part) which is a sensitizer, and ethyl acetate are mixed and stirred for 15 minutes to obtain 45.7 g of an oil phase component having a solid content of 30% by mass. The

Takenate D-110N is a 75% by mass ethyl acetate solution of an adduct of trimethylolpropane (TMP) and m-xylylene diisocyanate (XDI) (trifunctional isocyanate compound “D110N”).

NCO1 is an isocyanate compound having a carboxy group introduced, and specifically, an adduct of 2,2-bis (hydroxymethyl) butyric acid (DMBA) and IPDI (DMBA / IPDI = 1/3 (molar ratio)) It is.
The above solution of NCO1 is a 35% by mass solution of NCO1 in ethyl acetate.
A solution of NCO1 was added to a three-necked flask, 18 g of 2,2-bis (hydroxymethyl) butyric acid (DMBA), 82 g of isophorone diisocyanate (IPDI) and 186 g of ethyl acetate (AcOEt), and heated to 50.degree. 0.3 g of neostanne U-600 was added to the obtained heating thing, and it prepared by making it react for 3 hours.
The acid value of NCO1 was 1.20 mmol / g.

-Preparation of water phase components-
Distilled water (43.1 g), triethylamine (boiling point: 89 ° C.) as a volatile neutralizing agent, and sodium hydroxide (NaOH) (boiling point: 1388 ° C.) as a non-volatile neutralizing agent The aqueous phase component was prepared by stirring for 15 minutes.
The amount of volatile neutralizing agent used and the amount of non-volatile neutralizing agent used are such that the degree of neutralization of the acid group (ie, carboxy group) in the specific particle (ie, MC) to be produced is 90% It was adjusted.
The specific amounts of volatile neutralizing agent and non-volatile neutralizing agent were determined by the following formula.

Amount of volatile neutralizing agent (g) = total amount of oil phase component (g) × (solid content concentration of oil phase component (mass%) / 100) × (content of NCO 1 with respect to total solid content of oil phase component [Mass%) / 100] × NCO 1 acid value (mmol / g) × 0.9 × [mol number of volatile neutralizing agent (mol) / (mol number of volatile neutralizing agent (mol) + non-volatile] Number of moles of neutralizing agent (mol)] × molecular weight of volatile neutralizing agent (g / mol) / 1000
Amount of non-volatile neutralizing agent (g) = total amount of oil phase component (g) × (solid content concentration of oil phase component (mass%) / 100) × (content of NCO1 with respect to total solid content of oil phase component) (Mass%) / 100) × NCO 1 acid value (mmol / g) × 0.9 × [number of moles of non-volatile neutralizing agent (mol) / (number of moles of volatile neutralizing agent (mol) + non- Number of moles of volatile neutralizing agent (mol)] × molecular weight of non-volatile neutralizing agent (g / mol) / 1000

The oil phase component and the water phase component were mixed, and the resulting 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 evaporate ethyl acetate from the liquid. Next, the liquid from which ethyl acetate was distilled off was further stirred at 50 ° C. for 3 hours to form microcapsules (MC) in the liquid.
Next, the liquid containing MC was diluted with distilled water so as to have a solid content of 20% by mass, to obtain an aqueous dispersion of MC.

The polymer which is the shell of this microcapsule is a urethane polymer having a three-dimensional crosslinked structure formed by the reaction of D110N, which is a trifunctional isocyanate compound, and NCO1, which is an isocyanate compound having a carboxy group introduced therein.
The polymer which is the shell of this microcapsule is formed by the reaction of water with the urethane group originally contained in NCO1, the urethane group originally contained in D110N, and the isocyanate group in D110N or NCO1. It has a urea group.

<Evaluation>
The same evaluation as performed in Example 1 was performed using the photocurable ink obtained above.
The results are shown in Table 5.

Example 202 (Photocurable Ink Containing MC)
The same operation as in Example 201 was carried out except that the type and amount of the photopolymerizable monomer were changed as shown in Table 5.
The results are shown in Table 5.

Example 203 (Photocurable Ink Containing MC)
The same operation as in Example 201 was carried out except that the type of non-volatile neutralizing agent was changed as shown in Table 5.
The results are shown in Table 5.

[Examples 204 to 207 and 209] (Photocurable Ink Containing MC)
The same operation as in Example 201 was performed except that the type of volatile neutralizing agent was changed as shown in Table 5.
The results are shown in Table 5.

Example 208 (Photocurable Ink Containing MC)
Example 208 is an example in which the polymer 1 used in Example 1 was used as a dispersant for microcapsules.
In this example, the complex of the microcapsule and the dispersant corresponds to the specific particle.
In the preparation of the oil phase component, an example except that the solution of NCO1 (10 parts as the amount of NCO1) was changed to a 30% by mass solution of polymer 1 prepared in Example 1 (10 parts as the amount of polymer 1) The same operation as in 201 was performed.
The results are shown in Table 5.

Comparative Example 201 (Photocurable Ink Containing MC)
-Preparation of oil phase components-
D110N (43 parts) described above, NCO1 (10 parts) described above, SR833S (44 parts) described above as a photopolymerizable monomer, and IRG 819 (2.5 parts) described above as a photopolymerization initiator The aforementioned ITX (0.5 part) as a sensitizer and ethyl acetate 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.

-Preparation of water phase components-
Distilled water (43.1 g), ammonia (boiling point: -33 ° C) as a volatile neutralizing agent, and sodium hydroxide (NaOH) (boiling point: 1388 ° C) as a non-volatile neutralizing agent The aqueous phase component was prepared by stirring for 15 minutes.
The amount of non-volatile neutralizing agent used was adjusted so that the degree of neutralization of the acid groups (ie, carboxy groups) in the specific particles (ie, MC) to be produced was 90%.
The amount of volatile neutralizing agent used was 1/10 of the amount of nonvolatile neutralizing agent used.
The specific amounts of volatile neutralizing agent and non-volatile neutralizing agent were determined by the following formula.

Amount of volatile neutralizing agent (g) = total amount of oil phase component (g) × (solid content concentration of oil phase component (mass%) / 100) × (content of NCO 1 with respect to total solid content of oil phase component Mass%) / 100) × NCO 1 acid value (mmol / g) × 0.9 × (1/10) × molecular weight of volatile neutralizing agent (g / mol) / 1000
Amount of non-volatile neutralizing agent (g) = total amount of oil phase component (g) × (solid content concentration of oil phase component (mass%) / 100) × (content of NCO1 with respect to total solid content of oil phase component) (Mass%) / 100) × NCO 1 acid value (mmol / g) × 0.9 × molecular weight of non-volatile neutralizing agent (g / mol) / 1000

The oil phase component and the water phase component were mixed, and the resulting mixture was emulsified at room temperature for 10 minutes at 12000 rpm using a homogenizer to obtain an emulsion.
The obtained emulsion is added to distilled water (15.3 g), and the obtained liquid is heated to 60 ° C., and stirred at 60 ° C. for 5 hours under reduced pressure (2.7 kPa) to obtain acetic acid from the above liquid Ethyl and volatile neutralizing agent (i.e. ammonia) were distilled off. Microcapsules (MC) were formed in the liquid by further stirring the liquid from which ethyl acetate and the volatile neutralizing agent were distilled off at 50 ° C. under normal pressure for 3 hours.
Next, the liquid containing MC was diluted with distilled water so as to have a solid content of 20% by mass, to obtain an aqueous dispersion of MC. The amount of acid groups neutralized to the volatile neutralizing agent was measured by the above-mentioned potentiometric titration method and found to be 0 mmol.
A photocurable ink was prepared in the same manner as in Example 201, using the obtained dispersion of particles.
The results are shown in Table 5.

Comparative Example 202 (Photocurable Ink Containing MC)
The same operation as in Comparative Example 201 was carried out except that the type of volatile neutralizing agent was changed as shown in Table 5, to obtain an emulsion.
The obtained emulsion is added to distilled water (15.3 g), and the obtained liquid is heated to 60 ° C., and stirred at 60 ° C. for 5 hours under reduced pressure (2.7 kPa) to obtain acetic acid from the above liquid Ethyl and volatile neutralizing agent (ie, triethylamine) were distilled off. Microcapsules (MC) were formed in the liquid by further stirring the liquid from which ethyl acetate and the volatile neutralizing agent were distilled off at 50 ° C. under normal pressure for 3 hours.
Next, the liquid containing MC was diluted with distilled water so as to have a solid content of 20% by mass, to obtain an aqueous dispersion of MC. The amount of acid groups neutralized to the volatile neutralizing agent was measured by the above-mentioned potentiometric titration method and found to be 0 mmol.
The results are shown in Table 5.

Comparative Example 203 (Photocurable Ink Containing MC)
The same operation as in Example 201 was carried out except that the volatile neutralizing agent was not used.
The results are shown in Table 5.

Comparative Example 204 (Photocurable Ink Containing MC)
The same operation as in Example 201 was carried out except that the non-volatile neutralizing agent was not used.
The results are shown in Table 5.

“-” In Table 5 indicates that there is no corresponding one.
“Volatile / non-volatile (molar ratio)” in Table 5 is the ratio of non-volatile neutralizing agent to the total of 100 mol% of the volatile neutralizing agent and non-volatile neutralizing agent The ratio of the ratio of volatile neutralizer to (mol%) (mol%) [ratio of volatile neutralizer (mol%) / ratio of non-volatile neutralizer (mol%)] is meant.
“Volatile neutralized acid group / non-volatile neutralized acid group (molar ratio)” in Table 5 are the acid group neutralized by the volatile neutralizing agent and the nonvolatile neutralization Neutralized by the volatile neutralizing agent with respect to the ratio (mol%) of the acid group neutralized by the non-volatile neutralizing agent, assuming that the total with the acid agent neutralized by the agent is 100 mol% Ratio of acid group proportion (mol%) [proportion of acid group neutralized by volatile neutralizing agent (mol%) / ratio of acid group neutralized by non-volatile neutralizing agent (mol%)] Means

As shown in Table 5, the particles are also as polymers in Examples 201 to 209, which relate to a photocurable ink in which the particles comprise a three-dimensional crosslinked polymer which is a shell of MC (so-called specific crosslinked polymer) as a polymer. The same results as in Examples 1 to 19 were obtained for a photocurable ink containing the specific linear polymer (Polymer 1).

Using the aqueous dispersion of MC in each of Examples 201 to 209 described above, the volume average dispersed particle size of MC was measured.
The volume average dispersed particle size of MC was measured by a light scattering method using LA-960 (Horiba, Ltd.).
As a result, in any of the examples, the volume average dispersed particle size 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) containing a shell composed of a urethane polymer which is a specific crosslinked polymer having a three-dimensional crosslinked structure, and a core containing a thermally polymerizable monomer was prepared.
In this example, microcapsules (MC) correspond to specific particles.

Specifically, a thermosetting ink was prepared in the same manner as in the preparation of the photocurable ink in Example 201 except that SR833S, IRG 819, and ITX were changed to BI7982 (the amounts are as shown in Table 6). Prepared.

<Evaluation>
The same evaluation as that performed in Example 101 was performed using the thermosetting ink obtained above.
The results are shown in Table 6.

Example 302 Thermosetting Ink Containing MC
The same operation as in Example 301 was performed, except that BI7982 was changed to EP 840 and 2MI (amounts are as shown in Table 6).
The results are shown in Table 6.

[Examples 303 to 306] (Thermosetting ink containing MC)
The same operation as in Example 301 was performed except that the type of volatile neutralizing agent was changed as shown in Table 6.
The results are shown in Table 6.

Comparative Example 301 (Thermosetting Ink Containing MC)
A dispersion of particles was obtained in the same manner as in Comparative Example 201 except that SR833S, IRG 819, and ITX were changed to BI7982 (the amount is as shown in Table 6). The odor of the volatile neutralizing agent was not felt from the obtained dispersion liquid of the particles, and the amount of the acid group neutralized by the volatile neutralizing agent was measured by the above-mentioned potentiometric titration method. Met.
In the same manner as in Comparative Example 201, a thermosetting ink was prepared using the obtained dispersion liquid of particles.
The results are shown in Table 6.

Comparative Example 302 Thermosetting Ink Containing MC
A dispersion of particles was obtained in the same manner as in Comparative Example 202 except that SR833S, IRG 819, and ITX were changed to BI7982 (the amounts are as shown in Table 6). The odor of the volatile neutralizing agent was not felt from the obtained dispersion liquid of the particles, and the amount of the acid group neutralized by the volatile neutralizing agent was measured by the above-mentioned potentiometric titration method. Met.
In the same manner as in Comparative Example 202, a thermosetting ink was prepared using the obtained dispersion of particles.
The results are shown in Table 6.

Comparative Example 303 (Thermosetting Ink Containing MC)
The same operation as in Example 301 was performed except that the volatile neutralizing agent was not used.
The results are shown in Table 6.

Comparative Example 304 (Thermosetting Ink Containing MC)
The same operation as in Example 301 was carried out except that the non-volatile neutralizing agent was not used.
The results are shown in Table 6.

“-” In Table 6 indicates that there is no corresponding one.
“Volatile / non-volatile (molar ratio)” in Table 6 is the ratio of the non-volatile neutralizing agent to the total of 100 mol% of the volatile neutralizing agent and the non-volatile neutralizing agent The ratio of the ratio of volatile neutralizer to (mol%) (mol%) [ratio of volatile neutralizer (mol%) / ratio of non-volatile neutralizer (mol%)] is meant.
“Volatile neutralized acid group / non-volatile neutralized acid group (molar ratio)” in Table 6 are the acid group neutralized by the volatile neutralizing agent and the nonvolatile neutralization Neutralized by the volatile neutralizing agent with respect to the ratio (mol%) of the acid group neutralized by the non-volatile neutralizing agent, assuming that the total with the acid agent neutralized by the agent is 100 mol% Ratio of acid group proportion (mol%) [proportion of acid group neutralized by volatile neutralizing agent (mol%) / ratio of acid group neutralized by non-volatile neutralizing agent (mol%)] Means

As shown in Table 6, in Examples 301 to 306 of the thermosetting ink containing MC, the same results as in Examples 201 to 209 of the photocurable ink containing MC were obtained.

Using the aqueous dispersion of MC in each of Examples 301 to 306 described above, the volume average dispersed particle size of MC was measured.
The volume average dispersed particle size of MC was measured by a light scattering method using LA-960 (Horiba, Ltd.).
As a result, in any of the examples, the volume average dispersed particle size of MC was in the range of 0.15 μm to 0.25 μm.

The disclosure of Japanese Patent Application No. 2017-176704 filed on Sep. 14, 2017 is incorporated herein by reference in its entirety.
All documents, patent applications, and technical standards described herein are as if each individual document, patent application, and technical standard is specifically and individually incorporated by reference. To the extent, it is incorporated herein by reference.

Claims

water and,
Particles containing an acid group neutralized by a volatile neutralizing agent having a boiling point of 25 ° C. or more and 250 ° C. or less and a non-volatile neutralizing agent having a boiling point of 250 ° C. or higher;
An ink composition containing
The particles comprise a polymer,
The ink composition according to claim 1, wherein the polymer has an acid group neutralized by a volatile neutralizing agent having a boiling point of 25 ° C to 250 ° C and a nonvolatile neutralizing agent having a boiling point of 250 ° C or more. .
The ink composition according to claim 1 or 2, wherein the volatile neutralizing agent is at least one selected from the group consisting of an amine compound and a quaternary ammonium hydroxide.
The ink composition according to claim 3, wherein the valence of the amine compound is one.
The at least one selected from the group consisting of a compound represented by the following formula (1), a compound represented by the formula (2), and a compound represented by the formula (3): The ink composition according to claim 3 or 4.
Formula (1): NR 1 R 2 R 3
Formula (2): NR 4 R 5 H
Formula (3): NR 6 H 2
In formula (1), R 1 , R 2 and R 3 each independently represent an alkyl group. Any two of R 1 , R 2 and R 3 may be bonded to each other to form a ring containing a nitrogen atom.
In formula (2), R 4 and R 5 each independently represent an alkyl group, and R 4 and R 5 may combine with each other to form a ring containing a nitrogen atom.
In formula (3), R 6 represents an alkyl group.
The ink composition according to any one of claims 1 to 5, wherein the boiling point of the volatile neutralizing agent is 25 属 C or more and 100 属 C or less.
The ink composition according to any one of claims 1 to 6, wherein the non-volatile neutralizing agent is a hydroxide of an alkali metal.
The molar ratio of the acid group neutralized by the volatile neutralizing agent to the acid group neutralized by the non-volatile neutralizing agent in the particles is in the range of 60/40 to 90/10. The ink composition according to any one of claims 1 to 7.
The ink composition according to any one of claims 1 to 8, wherein the polymer is a linear polymer.
The ink composition according to any one of claims 1 to 9, wherein the polymer is a urethane polymer, a urea polymer, or a (meth) acrylic polymer.
The ink composition according to any one of claims 1 to 10, which is used as an inkjet ink.
Forming an ink film by applying the ink composition according to any one of claims 1 to 11 on a substrate;
Heating the ink film;
An image forming method including: