JP2018159037A - Resin particle dispersion liquid, aqueous ink, ink cartridge, recording device, and recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin particle dispersion liquid that makes it possible to obtain a functional liquid with improved particle redispersibility when diluted after concentrated.SOLUTION: A resin particle dispersion liquid has an aqueous dispersion medium containing water, and a particle containing a resin containing alicyclic (meth) acrylate and 2-carboxyethyl (meth) acrylate as constitutional units.SELECTED DRAWING: None

Description

  The present invention relates to a resin particle dispersion, an aqueous ink, an ink cartridge, a recording apparatus, and a recording method.

  For example, the following is known as an aqueous ink in which particles containing a resin are dispersed in an aqueous dispersion medium.

  Patent Document 1 discloses a self-dispersing polymer containing an aqueous medium, colored particles containing a pigment and a water-insoluble polymer dispersant, a hydrophilic constituent unit, and a hydrophobic constituent unit derived from an alicyclic (meth) acrylate. And an aqueous ink composition containing the particles.

  Patent Document 2 includes colored particles including a pigment coated with a water-insoluble polymer dispersant, a structural unit derived from a hydrophilic monomer and a structural unit derived from a hydrophobic monomer, and has a glass transition temperature of 150 ° C. or higher. An inkjet ink composition is disclosed that includes self-dispersing polymer particles including a first polymer having an I / O value of 0.20 or more and 0.55 or less.

  Patent Document 3 discloses an aqueous ink for inkjet recording containing an aqueous dispersion of water-insoluble vinyl polymer particles containing a solid solution magenta pigment, wherein the water-insoluble vinyl polymer contains at least an alicyclic (meth) acrylate (A) and An aqueous ink for ink-jet recording, which is a water-insoluble vinyl polymer copolymerized with a salt-forming group-containing monomer (B), is disclosed.

JP 2010-77218 A JP 2010-202773 A JP 2005-29597 A

  In a functional liquid containing a resin particle dispersion having resin-containing particles and an aqueous dispersion medium (for example, an aqueous ink), the particles aggregate when concentrated, and are diluted again with an aqueous dispersion medium to obtain a concentration of particles. Even if the same as before concentration, the particles are difficult to redisperse, and the dispersibility of the particles may be lower than before concentration.

  The present invention, compared with a resin particle dispersion composed of an aqueous dispersion medium and particles composed of a resin containing only an alkyl (meth) acrylate and (meth) acrylic acid having no alicyclic structure as structural units, It is an object of the present invention to provide a resin particle dispersion in which a functional liquid with improved particle redispersibility when diluted after concentration is obtained.

  Specific means for solving the above-described problems include the following modes.

The invention according to claim 1
An aqueous dispersion medium containing water;
Particles containing a resin containing alicyclic (meth) acrylate and 2-carboxyethyl (meth) acrylate as structural units;
Resin particle dispersion liquid.

The invention according to claim 2
The resin particle dispersion according to claim 1, wherein the alicyclic (meth) acrylate has two or more alicyclic structures.

The invention according to claim 3
The resin particle dispersion according to claim 1 or 2, wherein the acid value of the resin is 10 mgKOH / g or more and 100 mgKOH / g or less.

The invention according to claim 4
The resin particle dispersion according to any one of claims 1 to 3, wherein the content of 2-carboxyethyl (meth) acrylate is 3% by mass or more and 30% by mass or less based on the entire constituent unit of the resin.

The invention according to claim 5
An aqueous ink comprising the resin particle dispersion according to any one of claims 1 to 4.

The invention according to claim 6
An ink cartridge containing the water-based ink according to claim 5.

The invention according to claim 7 provides:
Ink applying means for containing the water-based ink according to claim 5 and discharging the water-based ink from a nozzle and applying the ink to a recording medium;
Drying means for drying the water-based ink applied to the recording medium;
A recording apparatus comprising:

The invention according to claim 8 provides:
An ink applying step for discharging the water-based ink according to claim 5 from a nozzle and applying the ink to a recording medium;
A drying step of drying the water-based ink applied to the recording medium;
A recording method.

  According to the invention of claim 1, a resin composed of an aqueous dispersion medium and particles made of a resin containing only an alkyl (meth) acrylate and (meth) acrylic acid having no alicyclic structure as constituent units. Provided is a resin particle dispersion in which a functional liquid having improved redispersibility of particles when diluted after being concentrated as compared to a particle dispersion.

  According to the second aspect of the present invention, a functional liquid having improved redispersibility of particles when diluted after concentration is obtained compared to a case where the alicyclic (meth) acrylate has only one alicyclic structure. A resin particle dispersion is provided.

  According to the invention of claim 3, a functional liquid with improved particle redispersibility when diluted after concentration can be obtained as compared with the case where the acid value of the resin is less than 10 mgKOH / g or more than 100 mgKOH / g. A resin particle dispersion is provided.

  According to the invention which concerns on Claim 4, compared with the case where content of 2-carboxyethyl (meth) acrylate with respect to the whole structural unit of resin is less than 3 mass% or more than 30 mass%, the particle | grains at the time of diluting after concentration There is provided a resin particle dispersion from which a functional liquid with improved redispersibility can be obtained.

  According to the invention which concerns on Claim 5, the resin comprised with the aqueous dispersion medium and the particle | grains which consist of resin which contains only the alkyl (meth) acrylate and (meth) acrylic acid which do not have an alicyclic structure as a structural unit. A water-based ink in which nozzle clogging is suppressed as compared with the case where a particle dispersion is applied is provided.

  According to the invention which concerns on Claim 6, the resin comprised by the aqueous dispersion medium and the particle | grains which consist of resin which contains only an alkyl (meth) acrylate and (meth) acrylic acid which do not have an alicyclic structure as a structural unit. An ink cartridge containing a water-based ink in which nozzle clogging is suppressed as compared with the case where a particle dispersion is applied is provided.

  According to the invention of claim 7, a resin comprising an aqueous dispersion medium and particles made of a resin containing only an alkyl (meth) acrylate and (meth) acrylic acid having no alicyclic structure as constituent units. A recording apparatus using water-based ink in which nozzle clogging is suppressed as compared with the case where a particle dispersion is applied is provided.

  According to the invention according to claim 8, a resin composed of an aqueous dispersion medium and particles made of a resin containing only an alkyl (meth) acrylate and (meth) acrylic acid having no alicyclic structure as constituent units. A recording method using a water-based ink in which nozzle clogging is suppressed as compared with the case where a particle dispersion is applied is provided.

1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to an exemplary embodiment.

  Embodiments of the invention will be described below. These descriptions and examples illustrate embodiments and do not limit the scope of the invention.

  In the present disclosure, when referring to the amount of each component in the composition, when there are a plurality of substances corresponding to each component in the composition, the plurality of the substances present in the composition unless otherwise specified. It means the total amount of substance.

In the present disclosure, “alkane”, “alkyl”, “alkylene”, “alkene” and “alkenyl” include not only chain hydrocarbons but also cyclic hydrocarbons.
In the present disclosure, “(meth) acryl” means either “acryl” or “methacryl”, and “(meth) acrylate” means either “acrylate” or “methacrylate”. Means. In the present disclosure, “(meth) acryloyl” means that “acryloyl” or “methacryloyl” may be used.

<Resin particle dispersion>
The resin particle dispersion according to this embodiment includes an aqueous dispersion medium containing water,
Particles containing a resin containing alicyclic (meth) acrylate and 2-carboxyethyl (meth) acrylate as structural units;
Have

In the present disclosure, the “aqueous dispersion medium” means water or a mixed solvent of water and other solvents, and a mixed solvent containing water as a main solvent. In the present disclosure, the “main solvent” refers to a solvent having the largest mass among all the solvents constituting the mixed solvent.
In the present disclosure, a resin including alicyclic (meth) acrylate and 2-carboxyethyl (meth) acrylate as structural units is referred to as “specific resin”.
In the present disclosure, “alicyclic (meth) acrylate” means a (meth) acrylic acid ester having a hydrocarbon group containing an alicyclic structure, and “alicyclic structure” has aromaticity. Means a saturated or unsaturated carbocyclic ring.

Here, a resin particle dispersion having resin-containing particles (hereinafter, also referred to as “resin particles”) and an aqueous dispersion medium is intermittently discharged from a discharge unit such as a nozzle, as in the case of water-based ink used in an ink jet recording apparatus. When applied to functionally discharged functional liquid, nozzle clogging may occur, resulting in a decrease in ejection stability. This is because, when discharging the functional liquid, for example, it is concentrated by evaporation of the aqueous dispersion medium, etc., so that the resin particles agglomerate and are not easily redispersed even after being diluted again with the discharged liquid. This is probably because the dispersibility of the resin particles is lowered. Therefore, there is a need for a resin particle dispersion that provides a functional liquid with good redispersibility of resin particles when concentrated and then diluted again to the same concentration as before concentration.
And the resin particle dispersion which concerns on this embodiment can obtain the functional liquid which improves the redispersibility of the resin particle at the time of diluting after concentrating by setting it as the said structure. The reason is not clear, but is presumed as follows.

Compared to alkyl (meth) acrylates that do not have an alicyclic structure, alicyclic (meth) acrylates contained as constituent units in specific resins are bulky due to having an alicyclic structure and increase the glass transition temperature of the resin. There is a tendency to make it. In addition, 2-carboxyethyl (meth) acrylate contained as a structural unit in the specific resin has a longer alkyl chain and a smaller dissociation constant pKa of the carboxy group than (meth) acrylic acid.
And specific resin contains both alicyclic (meth) acrylate and 2-carboxyethyl (meth) acrylate as a structural unit. Therefore, in the resin particles containing the specific resin, the dispersion stability of the resin particles can be obtained by both the steric repulsion due to the alicyclic structure and the long alkyl chain and the electrostatic repulsion due to the carboxy group. In addition, since the glass transition temperature of the specific resin is high, even if the resin particles are aggregated by concentration, the resin particles are easily separated from each other when diluted again. Thereby, it is estimated that the redispersibility of the resin particles is improved when the functional liquid is concentrated and then diluted.

  The aqueous ink containing the resin particle dispersion according to the present embodiment has high resin particle redispersibility when diluted after being concentrated. For this reason, when the water-based ink is used in a recording apparatus having an ink applying unit that discharges water-based ink from a nozzle to be applied to a recording medium, such as an ink jet recording apparatus, nozzle clogging is suppressed, and discharge stability is improved. improves.

  The specific resin is preferably a resin that is dispersed in a solid state in an aqueous dispersion medium. That is, the resin particle dispersion is preferably a suspension (suspension) in which resin particles containing a specific resin are dispersed in an aqueous dispersion medium in a solid state.

  Hereinafter, the resin particles constituting the resin particle dispersion, the aqueous dispersion medium, other components, the method for producing the resin particle dispersion, and the like will be described in detail.

[Resin particles]
The resin particles contain at least a specific resin, and may contain other components as necessary.
In addition, when resin particles contain another component, as content of specific resin with respect to the whole resin particle, 35 mass% or more is mentioned, for example, 40 mass% or more is preferable and 50 mass% or more is more preferable.
Hereinafter, the specific resin and other components contained in the resin particles as necessary will be described.

(Specific resin)
The specific resin includes at least alicyclic (meth) acrylate and 2-carboxyethyl (meth) acrylate as structural units, and may include other structural units as necessary.
The specific resin is obtained by polymerizing alicyclic (meth) acrylate, 2-carboxyethyl (meth) acrylate, and other components as necessary. There is no particular limitation on the polymerization method of the specific resin, and the monomer mixture may be copolymerized by a known polymerization method.

-Alicyclic (meth) acrylate-
An alicyclic (meth) acrylate is a (meth) acrylic acid ester having a hydrocarbon group containing an alicyclic structure (hereinafter also referred to as “alicyclic hydrocarbon group”), and an alcohol having an alicyclic hydrocarbon group. And an ester of (meth) acrylic acid.

Although the number of alicyclic structures which alicyclic (meth) acrylate has is not specifically limited, 2 or more are preferable from a viewpoint of the redispersibility of a resin particle, 2 or more and 5 or less are more preferable, and 2 or more and 3 More preferred are:
In the form in which the alicyclic (meth) acrylate has two or more alicyclic structures, two alicyclic hydrocarbon groups having only one alicyclic structure (hereinafter also referred to as “monocyclic hydrocarbon groups”) 2 Both the form having the above and the form having an alicyclic hydrocarbon group having two or more alicyclic structures (hereinafter also referred to as “polycyclic hydrocarbon group”) are included.

Examples of the monocyclic hydrocarbon group include a cycloalkyl group such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group, and a cyclodecyl group; a cyclopropenyl group, a cyclobutenyl group, And cycloalkenyl groups such as cyclopentenyl group, cyclohexenyl group, cycloheptenyl group, cyclooctenyl group, cyclononenyl group and cyclodecenyl group.
Examples of the polycyclic hydrocarbon group include a bicyclohexyl group, norbornyl group, isobornyl group, dicyclopentanyl group, dicyclopentenyl group, adamantyl group, decahydronaphthalenyl group, perhydrofluorenyl group, tricyclo group. Examples include [5.2.1.0 ^2,6 ] decanyl group, bicyclo [4.3.0] nonyl group, and the like.

  The alicyclic hydrocarbon group may further have a substituent. Examples of the substituent that the alicyclic hydrocarbon group has include an alkyl group, an alkenyl group, an aryl group, an aralkyl group, an alkoxy group, a hydroxyl group, a primary amino group, a secondary amino group, a tertiary amino group, and an alkylcarbonyl group. , An arylcarbonyl group, and a cyano group.

The total number of carbon atoms constituting the alicyclic structure of the alicyclic (meth) acrylate is preferably 7 or more and 20 or less, and preferably 7 or more and 18 or less, from the viewpoint of the redispersibility of the resin particles and the ease of synthesis of the specific resin. More preferably, 7 or more and 12 or less are more preferable.
In addition, the carbon number which comprises the said alicyclic structure is the number of carbon which comprises a ring, and does not include carbon number of the group couple | bonded with a ring. When the alicyclic (meth) acrylate has two or more alicyclic structures, the total number of carbon atoms constituting the alicyclic structure is the number of carbon atoms constituting the ring in all the two or more alicyclic structures. Total. Specifically, for example, the total number of carbon atoms constituting the alicyclic structure in isobornyl methacrylate is 7.

The alicyclic (meth) acrylate may be an ester in which a (meth) acryloyloxy group and an alicyclic hydrocarbon group are directly bonded, and the (meth) acryloyloxy group and the alicyclic hydrocarbon group are linked. It may be an ester bonded through a group.
Examples of the linking group include divalent linking groups such as an alkylene group, -O-, -S-, -NH-, and a carbonyl group. A linking group in which two or more of these linking groups are combined (for example, Or an oxyalkylene group in which an alkylene group and —O— are combined.

Specific examples of the alicyclic (meth) acrylate include, for example, cyclopropyl (meth) acrylate, cyclobutyl (meth) acrylate, cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, cycloheptyl (meth) acrylate, cyclooctyl ( Cycloalkyl (meth) acrylates such as (meth) acrylate, cyclononyl (meth) acrylate, cyclodecyl (meth) acrylate; cyclopropenyl (meth) acrylate, cyclobutenyl (meth) acrylate, cyclopentenyl (meth) acrylate, cyclohexenyl (meth) acrylate , Cycloheptenyl (meth) acrylate, cyclooctenyl (meth) acrylate, cyclononenyl (meth) acrylate, cyclodecenyl (meth) acrylate Such as cycloalkenyl (meth) acrylate; bicyclohexyl (meth) acrylate, norbornyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, adamantyl (meth) acrylate , Decahydronaphthalenyl (meth) acrylate, perhydrofluorenyl (meth) acrylate, tricyclo [5.2.1.0 ^2,6 ] decanyl (meth) acrylate, bicyclo [4.3.0] nonyl ( And (meth) acrylate having a polycyclic hydrocarbon group such as (meth) acrylate, dicyclopentanyloxyethyl (meth) acrylate, and dicyclopentenyloxyethyl (meth) acrylate.

An alicyclic (meth) acrylate may contain only 1 type as a structural unit, and may contain 2 or more types.
The content of the alicyclic (meth) acrylate with respect to the entire constituent unit of the specific resin is, for example, 7% by mass or more and 50% by mass or less, and from the viewpoint of redispersibility of the resin particles, 12% by mass or more and 40% by mass or less. Is preferable, and 12 mass% or more and 35 mass% or less are more preferable.

-2-Carboxyethyl (meth) acrylate
As content of 2-carboxyethyl (meth) acrylate with respect to the whole structural unit of specific resin, 3 mass% or more and 30 mass% or less is mentioned, for example, From a redispersibility viewpoint of a resin particle, 3 mass% or more and 24 mass% is mentioned. % Or less is preferable, and 3 mass% or more and 18 mass% or less are more preferable.

-Other structural units-
The specific resin may further contain other structural units in addition to the alicyclic (meth) acrylate and 2-carboxyethyl (meth) acrylate. Another structural unit will not be specifically limited if it is a structural unit copolymerized with both alicyclic (meth) acrylate and 2-carboxyethyl (meth) acrylate.
Examples of other structural units include (meth) acrylates, monomers having a carboxy group, vinyl esters, (meth) acrylamides, olefins, vinyl ethers, and the like.

Among the (meth) acrylates, examples of the alkyl (meth) acrylate include alkyl (meth) acrylates other than alicyclic (meth) acrylate, and specifically include, for example, methyl (meth) acrylate, ethyl (meth) ) Acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, pentyl (meth) ) Acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, and the like.
The number of carbon atoms of the alkyl group in the alkyl (meth) acrylate is preferably 1 or more and 8 or less, and more preferably 1 or more and 4 or less from the viewpoint of dispersibility with respect to the aqueous dispersion medium.

  Among the (meth) acrylates, examples of the (meth) acrylate having an aromatic ring include phenyl (meth) acrylate, benzyl (meth) acrylate, naphthyl (meth) acrylate, 2-phenoxyethyl (meth) acrylate, 2 -Hydroxy-3-phenoxypropyl (meth) acrylate and the like.

  Among (meth) acrylates, examples of (meth) acrylate other than alkyl (meth) acrylate and (meth) acrylate having an aromatic ring include furfuryl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, and hydroxyethyl. (Meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, hydroxypentyl (meth) acrylate, hydroxyhexyl (meth) acrylate, 2,2-dimethyl-3-hydroxypropyl (meth) acrylate, 2, 2,2-tetrafluoroethyl (meth) acrylate, glycidyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2- (2-methoxyethoxy) ethyl (meth) acrylate, ethoxy Liethylene glycol (meth) acrylate, methoxypolyethylene glycol (molecular weight 200 to 1000) mono (meth) acrylate, polyethylene glycol (molecular weight 200 to 1000) mono (meth) acrylate, (meth) acryloyloxyalkanesulfonic acid (for example, (meth) Acryloyloxyethanesulfonic acid, (meth) acryloyloxypropanesulfonic acid, (meth) acryloyloxybutanesulfonic acid, etc.), mono 2- (meth) acryloyloxyethyl phosphate, and the like.

  Among monomers having a carboxy group, examples of monomers other than 2-carboxyethyl (meth) acrylate include, for example, acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, citraconic acid, crotonic acid, and monoalkyl itaconic acid. Examples thereof include esters (eg, monomethyl itaconate, monoethyl itaconate, monobutyl itaconate), maleic acid monoalkyl esters (eg, monomethyl maleate, monoethyl maleate, monobutyl maleate) and the like.

  Examples of vinyl esters include vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl caproate, vinyl chloroacetate, vinyl methoxyacetate, vinyl phenylacetate, vinyl benzoate, and vinyl salicylate. Can be mentioned.

  Examples of (meth) acrylamides include (meth) acrylamide, methyl (meth) acrylamide, ethyl (meth) acrylamide, propyl (meth) acrylamide, butyl (meth) acrylamide, tert-butyl (meth) acrylamide, and tert-octyl. (Meth) acrylamide, cyclohexyl (meth) acrylamide, benzyl (meth) acrylamide, hydroxymethyl (meth) acrylamide, methoxymethyl (meth) acrylamide, butoxymethyl (meth) acrylamide, methoxyethyl (meth) acrylamide, phenyl (meth) acrylamide , Dimethyl (meth) acrylamide, diethyl (meth) acrylamide, 2-cyanoethyl (meth) acrylamide, N- (2-acetoacetoxyethyl) ( T) acrylamide, diacetone (meth) acrylamide, (meth) acrylamide alkylsulfonic acid (for example, 2- (meth) acrylamide-2-methylethanesulfonic acid, 2- (meth) acrylamide-2-methylpropanesulfonic acid, 2- (Meth) acrylamido-2-methylbutanesulfonic acid and the like.

  Examples of olefins include dicyclopentadiene, ethylene, propylene, 1-butene, 1-pentene, vinyl chloride, vinylidene chloride, isoprene, chloroprene, butadiene, 2,3-dimethylbutadiene, styrenes (for example, styrene, Methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, isopropyl styrene, chloromethyl styrene, methoxy styrene, acetoxy styrene, chloro styrene, dichloro styrene, bromo styrene, vinyl benzoic acid methyl ester, styrene carboxylic acid, vinyl benzyl sulfonic acid, polystyrene And a styrene macromer having a structure).

  Examples of vinyl ethers include methyl vinyl ether, butyl vinyl ether, hexyl vinyl ether, methoxyethyl vinyl ether, and the like.

  Other components include, for example, butyl crotonate, hexyl crotonate, dimethyl itaconate, dibutyl itaconate, diethyl maleate, dimethyl maleate, dibutyl maleate, diethyl fumarate, dimethyl fumarate, and fumaric acid. Examples also include dibutyl, methyl vinyl ketone, phenyl vinyl ketone, methoxyethyl vinyl ketone, N-vinyl oxazolidone, N-vinyl pyrrolidone, vinylidene chloride, methylene malon nitrile, monovinyl phosphate, and the like.

It is preferable that specific resin contains alkyl (meth) acrylates other than alicyclic (meth) acrylate as another structural unit in addition to alicyclic (meth) acrylate and 2-carboxyethyl (meth) acrylate.
As for content of alkyl (meth) acrylate other than alicyclic (meth) acrylate with respect to the whole structural unit of specific resin, 20 mass% or more and 90 mass% or less are mentioned, From a viewpoint of the redispersibility of the resin particle, 35 mass % To 85% by mass is preferable, and 45% to 85% by mass is more preferable.

In addition to alicyclic (meth) acrylate and 2-carboxyethyl (meth) acrylate, the specific resin includes components having an aromatic ring (for example, (meth) acrylate having an aromatic ring, styrenes, etc.) as other structural units. It is preferable to include.
As content of the component which has an aromatic ring with respect to the whole structural unit of specific resin, 0 mass% or more and 40 mass% or less are mentioned, for example, from a viewpoint of the redispersibility of a resin particle, 0 mass% or more and 35 mass% or less are mentioned. Preferably, 0 mass% or more and 30 mass% or less are more preferable.

-Specific examples of specific resins-
Below, the specific example of specific resin is illustrated by description of a structural unit. Figures in parentheses are the mass ratio of the constituent units. The present invention is not limited to these compounds P01 to P20.

P01: Isobornyl methacrylate / methyl methacrylate / acrylic acid-2-carboxyethyl copolymer (45/49/6)
P02: isobornyl methacrylate / phenoxyethyl methacrylate / methacrylic acid / acrylic acid-2-carboxyethyl copolymer (30/50/14/6)
P03: Isobornyl methacrylate / ethyl methacrylate / styrene carboxylic acid / acrylic acid-2-carboxyethyl copolymer (50/40/2/8)
P04: isobornyl methacrylate / isobutyl methacrylate / 2-acrylamido-2-methylpropanesulfonic acid / acrylic acid-2-carboxyethyl copolymer (50/45/2/3)
P05: Isobornyl methacrylate / styrene / phenoxyethyl methacrylate / methyl methacrylate / acrylic acid-2-carboxyethyl copolymer (30/30/20/15/5)
P06: Isobornyl methacrylate / ethyl acrylate / acrylic acid-2-carboxyethyl copolymer (45/50/5)
P07: Isobornyl methacrylate / butyl acrylate / ethyl methacrylate / acrylic acid-2-carboxyethyl copolymer (30/15/45/10)
P08: isobornyl methacrylate / styrene / methyl methacrylate / tetrahydrofurfuryl methacrylate / acrylic acid-2-carboxyethyl copolymer (30/20/25/20/5)
P09: Isobornyl methacrylate / dicyclopentenyloxyethyl methacrylate / methyl methacrylate / acrylic acid-2-carboxyethyl copolymer (30/20/45/5)
P10: isobornyl methacrylate / 4-t-butylstyrene / isobutyl methacrylate / acrylic acid-2-carboxyethyl copolymer (50/10/30/10)
P11: dicyclopentanyl methacrylate / styrene / methyl methacrylate / acrylic acid-2-carboxyethyl copolymer (30/20/44/6)
P12: dicyclopentanyl methacrylate / ethyl methacrylate / acrylic acid-2-carboxyethyl copolymer (50/45/5)
P13: Dicyclopentanyl methacrylate / methyl methacrylate / methacrylic acid / acrylic acid-2-carboxyethyl copolymer (45/48/3/4)
P14: dicyclopentanyl methacrylate / isobornyl methacrylate / methyl methacrylate / mono 2- (meth) acryloylethyl phosphate / acrylic acid-2-carboxyethyl copolymer (32/20/40/4/4)
P15: dicyclopentenyl acrylate / ethyl acrylate / acrylic acid-2-carboxyethyl copolymer (50/40/10)
P16: dicyclopentenyl acrylate / methyl methacrylate / ethoxytriethylene glycol methacrylate / acrylic acid-2-carboxyethyl copolymer (60/15/15/10)
P17: Dicyclopentenyl acrylate / styrene / methyl methacrylate / acrylic acid-2-carboxyethyl copolymer (40/15/39/6)
P18: dicyclopentenyloxyethyl acrylate / methyl methacrylate / hexyl acrylate / acrylic acid-2-carboxyethyl copolymer (40/40/5/15)
P19: Dicyclopentenyloxyethyl acrylate / ethyl methacrylate / styrene / acrylic acid-2-carboxyethyl copolymer (30/45/15/10)
P20: dicyclopentanyl acrylate / isobornyl methacrylate / methyl methacrylate / acrylic acid-2-carboxyethyl copolymer (40/10/40/10)

-Molecular weight of specific resin-
The molecular weight range of the specific resin is preferably 3000 or more and 200,000 or less, more preferably 5000 or more and 150,000 or less, and still more preferably 10,000 or more and 100,000 or less as a weight average molecular weight. When the weight average molecular weight is 3000 or more, the content ratio of the water-soluble component (that is, the component having high solubility in water) is reduced, and swelling of the resin particles and adhesion between the resin particles due to the water-soluble component are suppressed. Therefore, the dispersibility is good. On the other hand, when the weight average molecular weight is 200,000 or less, the solubility of the resin solution dissolved in the organic solvent is suppressed and the viscosity of the resin solution dissolved in the organic solvent is suppressed. Dispersion becomes easy, and as a result, the dispersion stability of the resin particles is excellent.
The weight average molecular weight of the resin is measured by gel permeation chromatography (GPC) and calculated in terms of polystyrene.

-Specific resin characteristics-
The acid value of the specific resin is preferably 10 mgKOH / g or more and 100 mgKOH / g or less, more preferably 15 mgKOH / g or more and 50 mgKOH / g or less, and further preferably 15 mgKOH / g or more and 40 mgKOH / g or less. .
When the acid value of the specific resin is in the above range, the dispersibility of the resin particles in the aqueous dispersion medium is higher than in the case where the acid value is lower than the above range, and the water solubility of the specific resin is higher than in the case where the acid value is higher than the above range. Since it becomes low, the dispersibility of the resin particle becomes high. In addition, when the acid value of the specific resin is within the above range, steric repulsion and electrostatic repulsion of alicyclic (meth) acrylate and 2-carboxyethyl (meth) acrylate contained in the specific resin as structural units are exhibited. By becoming easy to be done, the redispersibility of the resin particle improves.

  The glass transition temperature of the specific resin is preferably 40 ° C. or higher and 150 ° C. or lower. When the glass transition temperature is 40 ° C. or higher, the image formed using the ink containing the specific resin is excellent in scratch resistance and blocking resistance. When the glass transition temperature is 150 ° C. or lower, the ink containing the specific resin is used. Excellent in abrasion resistance of the image formed by using. Further, from the viewpoint of the redispersibility of the resin particles, the glass transition temperature of the specific resin is preferably 85 ° C. or higher. In addition to the viewpoint of the redispersibility of the resin particles, the image quality is improved by the good meltability of the resin. From the viewpoint, the glass transition temperature of the specific resin is more preferably 85 ° C. or higher and 140 ° C. or lower, and further preferably 85 ° C. or higher and 130 ° C. or lower.

(Other components contained in resin particles)
The resin particles may contain other components as necessary. For example, when the resin particle dispersion is used for an aqueous ink, the resin particles may contain an organic functional compound such as a dye, an infrared absorber, and an ultraviolet absorber.

-Organic functional compounds-
Examples of the organic functional compound include organic compounds that are insoluble or sparingly soluble in water and soluble in an organic solvent. Specific examples include dyes, infrared absorbers, and ultraviolet absorbers. It is done. Only 1 type may be used for an organic functional compound and it may use 2 or more types together. Two or more types of combination forms may be a plurality of types from one compound group having the same function (for example, a plurality of types from dyes), or may be a plurality of types over two or more compound groups having different functions (for example, from dyes). 1 type and 1 type from infrared absorber).

Examples of the dye include, for example, phenols, naphthols, anilines, pyrazolones, pyridones, or arylazo dyes or heteryl azo dyes having an open chain active methylene compound as coupling components; pyrazolones, pyrazolotriazoles as coupling components , Pyrrolotriazoles, or azomethine dyes having an open chain active methylene compound; methine dyes such as benzylidene dyes and monomethine oxonol dyes; quinone dyes such as naphthoquinone dyes, anthraquinone dyes and anthrapyridone dyes; arylidene dyes, styryl dyes, Methine dyes such as merocyanine dyes and oxonol dyes; carbonium dyes such as diphenylmethane dyes, triphenylmethane dyes and xanthene dyes; quinophthalone dyes, nitro dyes, nitroso dyes, Kurijin dyes, acridinone dyes, dioxazine dyes, indoaniline dyes, indophenol dyes, cyanine dyes, phthalocyanine dyes, indigo dyes, and the like thioindigo dyes.
When a dye is used as the organic functional compound, the resin particles are colored particles, and the resin particle dispersion is used, for example, as a material constituting an aqueous ink.

Examples of infrared absorbers include squarylium dyes, croconium dyes, naphthalocyanine dyes, cyanine dyes, aminium dyes, and the like.
When an infrared absorber is used as the organic functional compound, the resin particles are infrared absorbing particles, and the resin particle dispersion is used, for example, as a material constituting an aqueous ink that is fixed to a recording medium by infrared irradiation. .

Examples of the ultraviolet absorber include benzotriazole compounds and benzophenone compounds.
In the case where an ultraviolet absorber is used as the organic functional compound, the resin particles are ultraviolet absorbing particles, and the resin particle dispersion is a material constituting water-based ink, for example, for the purpose of suppressing fading due to ultraviolet rays of an image. Used as

[Aqueous dispersion medium]
The aqueous dispersion medium is water or a mixed solvent containing water as a main solvent. Examples of the mixed solvent include a mixture of water and a water-soluble organic solvent.

  The water is preferably purified water such as distilled water, ion-exchanged water, or ultrafiltered water from the viewpoint of suppressing contamination with impurities or generation of microorganisms.

  Examples of the water-soluble organic solvent include alcohols, polyhydric alcohols, polyhydric alcohol derivatives, nitrogen-containing solvents, and sulfur-containing solvents. Examples of the water-soluble organic solvent contained in the resin particle dispersion include a residue of the organic solvent used for dissolving the specific resin in the production process of the resin particle dispersion.

The content of water is preferably 50% by mass to 95% by mass, and more preferably 60% by mass to 90% by mass with respect to the total mass of the resin particle dispersion.
The content of the water-soluble organic solvent is preferably 30% by mass or less and more preferably 10% by mass or less with respect to the total mass of the resin particle dispersion.

[Other ingredients]
The resin particle dispersion may contain other components as needed in addition to the resin particles containing the specific resin and the aqueous dispersion medium. Examples of other components include neutralizers, surfactants, dispersion stabilizers, and resins other than specific resins.

[Method for producing resin particle dispersion]
Examples of the method for producing the resin particle dispersion include a phase inversion emulsification method.

  The phase inversion emulsification method prepares a solution in which the specific resin and other components contained in the resin particles as required are dissolved in an organic solvent, neutralizes the specific resin and the like by adding a neutralizing agent to the solution, In this method, water is gradually mixed to make a specific resin or the like dispersed. The dispersion state here may be emulsification or suspension, and suspension is preferred from the viewpoint of dispersion stability. The organic solvent is removed from the viewpoint of dispersion stability of resin particles containing a specific resin when the solubility of the organic solvent in water is 10% by mass or less, or when the vapor pressure of the organic solvent is higher than water. It is preferred that Neutralization is not an essential step, but when the specific resin has an unneutralized dissociable group, it is preferably performed from the viewpoint of pH adjustment of the dispersion.

  The organic solvent used for the phase inversion emulsification method is selected based on the solubility of the specific resin or the like. Specifically, for example, ketone solvents such as acetone, methyl ethyl ketone, and diethyl ketone; alcohol solvents such as methanol, ethanol, 2-propanol, 1-propanol, 1-butanol, and tert-butanol; chloroform, methylene chloride, and the like Chlorine solvents; aromatic solvents such as benzene and toluene; ester solvents such as ethyl acetate, butyl acetate and isopropyl acetate; ether solvents such as diethyl ether, tetrahydrofuran and dioxane; ethylene glycol monomethyl ether and ethylene glycol dimethyl ether Glycol ether solvents; and the like. These organic solvents may be used alone or in combination of two or more.

  The amount of the organic solvent used is preferably 10 parts by mass or more and 2000 parts by mass or less, and 100 parts by mass or more and 1000 parts by mass or less with respect to a total of 100 parts by mass of the specific resin and, if necessary, other components contained in the resin particles. Is more preferable. When the amount of the organic solvent used is 10 parts by mass or more, the dispersion of the resin particles containing the specific resin is stable, and when the amount of the organic solvent used is 2000 parts by mass or less, the step of removing the organic solvent is unnecessary or short. It takes time.

Examples of the neutralizing agent used in the phase inversion emulsification method include organic bases and inorganic alkalis because the specific resin has an anionic group. Examples of the organic base include triethanolamine, diethanolamine, N-methyldiethanolamine, dimethylethanolamine and the like. Examples of the inorganic alkali include alkali metal hydroxides (for example, sodium hydroxide, lithium hydroxide, potassium hydroxide, etc.), carbonates (for example, sodium carbonate, sodium hydrogencarbonate, etc.), ammonia and the like.
The addition amount of the neutralizing agent is preferably an addition amount in which the pH of the resin particle dispersion is in the range described later, from the viewpoint of dispersion stability of the resin particles containing the specific resin.

[Physical properties of resin particle dispersion]
From the viewpoint of dispersion stability, the volume average particle size of the resin particles contained in the resin particle dispersion is preferably 5 nm to 150 nm, more preferably 5 nm to 120 nm, still more preferably 10 nm to 100 nm, and even more preferably 10 nm to 80 nm. Is more preferable. The particle size distribution may be either a wide particle size distribution or a monodisperse particle size distribution. The average particle size and particle size distribution of the resin particles are measured using, for example, a light scattering method.

The pH of the resin particle dispersion is preferably 6.0 or more, more preferably 6.5 or more, and even more preferably 7.0 or more, from the viewpoint of dispersion stability of the resin particles containing the specific resin.
The pH of the resin particle dispersion is measured in an environment with a temperature of 23 ± 0.5 ° C. and a relative humidity of 55 ± 5%.

The surface tension of the resin particle dispersion is preferably 20 mN / m or more and 40 mN / m or less, and more preferably 25 mN / m or more and 35 mN / m or less. The surface tension is measured using a Wilhelmy surface tension meter in an environment of a temperature of 23 ± 0.5 ° C. and a relative humidity of 55 ± 5%.
The viscosity of the resin particle dispersion is preferably 1 mPa · s to 30 mPa · s, and more preferably 2 mPa · s to 20 mPa · s. The viscosity is measured under the conditions of a temperature of 23 ± 0.5 ° C. and a shear rate of 1400 s ⁻¹ using a TV-20 viscometer (Toki Sangyo) as a measuring device.

The ratio of the water-soluble component to the solid content contained in the resin particle dispersion is preferably 10% by mass or less.
Usually, the individual molecules constituting the polymer aggregate have variations in the composition of the constituent units, and therefore the individual molecules have variations in water solubility. A polymer molecule having a relatively high solubility in water corresponds to the “water-soluble component” referred to herein. A water-soluble component, that is, a polymer molecule having a relatively high solubility in water is not suitable for the dispersion of resin particles. Therefore, the smaller the water-soluble component contained in the resin particles of the resin particle dispersion, the better. Further, from the viewpoint of suppressing swelling of resin particles and adhesion between resin particles and maintaining stable dispersion, it is preferable that the amount of water-soluble components is small. From these viewpoints, the ratio of the water-soluble component to the solid content contained in the resin particle dispersion is preferably 10% by mass or less, more preferably 8% by mass or less, still more preferably 5% by mass or less, and the smaller the better.

The content ratio of the water-soluble component is measured by the following method.
The solid content concentration (liquid temperature 23 ± 0.5 ° C.) of the resin particle dispersion is adjusted to 10% by mass. At that time, a neutralizing agent is used as necessary for dispersing the resin particles. The resin particle dispersion liquid whose solid content concentration is adjusted to 10% by mass is centrifuged into a dispersoid and a medium using a centrifugal ultrafiltration filter unit, and the separated medium is dried to dry the mass of the solid product. The solid content of the resin particle dispersion (= the amount of resin particles contained in the resin particle dispersion + the mass of the neutralizing agent used in the process of adjusting the solid content concentration of the resin particle dispersion to 10% by mass) The ratio of the amount of dry matter of the medium relative to is calculated, and is defined as the ratio (mass%) of the water-soluble component.

  The resin particle dispersion according to the present embodiment is used for a functional liquid (for example, a water-based ink, a water-based paint, a coating material, a cosmetic product of an aqueous medium, etc., which will be described later).

<Water-based ink>
The water-based ink according to this embodiment includes the above-described resin particle dispersion.
Examples of the water-based ink include, for example, the above-described resin particle dispersion itself, a composition in which plural forms of the above-mentioned resin particle dispersion are mixed, a composition in which a colorant is added to the above-described resin particle dispersion, and a known water-based ink. Examples thereof include a composition obtained by adding the above-described resin particle dispersion to (for example, commercially available water-based ink).
The composition, manufacturing method, physical properties, and the like of the resin particle dispersion contained in the aqueous ink are as described above.

The content of water with respect to the total mass of the water-based ink is preferably 40% by mass or more and 80% by mass or less, and more preferably 50% by mass or more and 80% by mass or less.
The content of the water-soluble organic solvent with respect to the total mass of the water-based ink is preferably 50% by mass or less, and more preferably 40% by mass or less.

[Additive]
The water-based ink may contain various additives as necessary. Examples of the additive include a surfactant, a penetrating agent, a viscosity adjusting agent, a pH adjusting agent, a pH buffering agent, an antioxidant, an antiseptic and an antifungal agent.

[Physical properties of water-based ink]
The pH of the water-based ink is preferably 6.5 or more and 9.5 or less, more preferably 7.0 or more and 9.0 or less, and even more preferably 7.0 or more and 8.5 or less.
The surface tension of the water-based ink is preferably 20 mN / m or more and 40 mN / m or less, and more preferably 25 mN / m or more and 35 mN / m or less.
The viscosity of the water-based ink is preferably 1 mPa · s to 30 mPa · s, and more preferably 2 mPa · s to 20 mPa · s.

<Ink cartridge>
The ink cartridge according to the present embodiment is a cartridge that contains the above-described aqueous ink. The ink cartridge is provided in a form that can be attached to and detached from an ink jet recording apparatus, for example.

<Recording apparatus and recording method>
The recording apparatus according to the present embodiment contains the above-described water-based ink, an ink-applying unit that discharges the water-based ink from a nozzle and applies the ink to a recording medium, and a drying unit that dries the water-based ink applied to the recording medium. . The recording apparatus realizes a recording method including an ink application step for applying the aqueous ink to the recording medium by ejecting the water-based ink from a nozzle and a drying step for drying the aqueous ink applied to the recording medium.

  Examples of the ink application unit include an ejection unit that ejects ink by an inkjet method, and an application unit that ejects aqueous ink from a nozzle such as a spray.

  As the ink application unit, an ejection unit that ejects ink by an inkjet method is suitable. A recording apparatus and a recording method to which the ink jet system is applied are excellent in ejection stability by using the above-described water-based ink.

  Examples of drying means for drying the water-based ink applied to the recording medium include, for example, infrared irradiation means for irradiating infrared rays; contact-type heating means such as a heating roll, a heating drum, and a heating belt; hot air blowing including a heating element and a blower Means; combinations thereof; and the like.

  Examples of the recording medium include paper; paper coated with a resin; films and plates made of resin, metal, glass, ceramics, silicon, rubber, and the like;

  The recording apparatus may include an ink cartridge that contains the above-described water-based ink and is formed into a cartridge so as to be attached to and detached from the recording apparatus.

  Hereinafter, an example of a recording apparatus and a recording method according to the present embodiment will be described with reference to the drawings.

  FIG. 1 is a schematic configuration diagram illustrating an example of a recording apparatus according to the present embodiment. A recording apparatus 12 shown in FIG. 1 is an ink jet recording apparatus.

  A recording apparatus 12 shown in FIG. 1 includes a container 16 that houses a recording medium P before image recording, an endless conveyance belt 28 supported by a drive roll 24 and a driven roll 26, and ink inside a casing 14. Ink discharge heads (ink discharge heads 30Y, 30M, 30C, and 30K, collectively referred to as ink discharge heads 30), which are examples of applying means, and drying means (drying means 50Y, 50M, 50C, and 50K, collectively) In some cases, it is referred to as a drying means 50) and a container 40 for storing the recording medium P after image recording.

  Between the container 16 and the transport belt 28 is a transport path 22 through which the recording medium P before image recording is transported. The transport path 22 includes a roll 18 for taking out the recording medium P one by one from the container 16, and a recording. A plurality of roll pairs 20 that convey the medium P are arranged. A charging roll 32 is disposed on the upstream side of the conveyance belt 28. The charging roll 32 is driven while sandwiching the conveyance belt 28 and the recording medium P with the driven roll 26, generates a potential difference with the grounded driven roll 26, and applies an electric charge to the recording medium P to convey the conveyance belt. 28 is electrostatically adsorbed.

  The ink discharge head 30 is disposed above the conveyance belt 28 so as to face the flat portion of the conveyance belt 28. A region where the ink discharge head 30 and the conveyance belt 28 face each other is a region where ink droplets are discharged from the ink discharge head 30.

  Ink discharge heads 30Y, 30M, 30C, and 30K are respectively a head that records a Y (yellow) color image, a head that records an M (magenta) color image, a head that records a C (cyan) color image, and K This is a head for recording a (black) color image. The ink discharge heads 30Y, 30M, 30C, and 30K are arranged from the upstream side to the downstream side of the conveyance belt 28 in this order, for example. The ink ejection heads 30Y, 30M, 30C, and 30K are connected to the ink cartridges 31Y, 31M, 31C, and 31K of each color that are attached to and detached from the recording apparatus 12 through supply tubes (not shown), and the inks of the respective colors are ejected from the ink cartridges. Supplied to the discharge head.

  As the ink discharge head 30, for example, an effective recording area (arrangement area of nozzles that discharge ink) is longer than the width of the recording medium P (the length in the direction orthogonal to the conveyance direction of the recording medium P). And a carriage head that is shorter than the width of the recording medium P and moves in the width direction of the recording medium P to eject ink.

  As the ink jet system employed by the ink ejection head 30, a piezoelectric system that utilizes the vibration pressure of the piezoelectric element; a charge control system that ejects ink using electrostatic attraction; an electrical signal is converted into an acoustic beam and the ink is irradiated And an acoustic ink jet method in which ink is ejected using radiation pressure; a thermal ink jet method in which bubbles are formed by heating the ink and the generated pressure is used; and the like.

  The ink discharge head 30 is, for example, a low-resolution recording head (for example, a 600 dpi recording head) that discharges ink droplets in a range of 10 pL to 15 pL, and discharges ink droplets in a range of less than 10 pL. This is a recording head for high resolution (for example, a recording head of 1200 dpi). dpi means “dots per inch”.

  The recording apparatus 12 is not limited to a form including four ink ejection heads. The recording apparatus 12 may have a form including four or more ink discharge heads obtained by adding intermediate colors to YMCK; a form including one ink discharge head and recording an image of only one color.

  On the downstream side of the ink discharge head 30, drying means 50Y, 50M, 50C, and 50K are arranged above the transport belt 28 for each color ink discharge head. The drying unit 50 dries the ink applied to the recording medium P.

  When the recording device 12 uses water-based ink containing an infrared absorbent, the drying unit 50 is preferably an infrared irradiation unit. When the recording device 12 uses water-based ink that does not contain an infrared absorbent, the drying unit 50 is preferably at least one of a contact heating unit and a hot air blowing unit.

  An example of the drying unit 50 includes an infrared irradiation device 60 (an example of an infrared irradiation unit) that irradiates ink on the recording medium P with infrared rays. The recording device 12 includes, for example, infrared irradiation devices 60Y, 60M, 60C, and 60K downstream of the ink ejection heads 30Y, 30M, 30C, and 30K, respectively. Examples of the light source of the infrared irradiation device 60 include a light emitting diode, a semiconductor laser, a surface emitting semiconductor laser, a halogen lamp, and a xenon lamp.

  As the infrared irradiation device 60, for example, a long infrared irradiation device in which an effective infrared irradiation region (arrangement region of a light source for irradiating infrared rays) is equal to or larger than the width of the recording region by the ink discharge head 30; And a carriage-type infrared irradiation device that moves in the width direction of the recording medium P and irradiates infrared rays.

The irradiation conditions of the infrared irradiation device 60 are set according to the infrared absorption performance of the infrared absorbent contained in the ink, the amount of water in the ink, and the like. As the irradiation condition, the irradiation condition for drying the water content in the ink applied on the recording medium P to 10% by mass or less is preferable. Specifically, for example, a central wavelength of 700nm or more 1200nm or less (preferably not more than 780nm or 980 nm), irradiation intensity 0.1 J / cm ² or more 10J / cm ² or less (preferably 1 J / cm ² or more 3J / cm ² The irradiation time is from 0.1 milliseconds to 10 seconds (preferably from 10 milliseconds to 100 milliseconds).

  The recording device 12 is not limited to a mode including an infrared irradiation device for each color ink discharge head, and may be a mode including only one infrared irradiation device on the downstream side of the most downstream ink discharge head. The recording device 12 may include at least one of a contact-type heating unit and a hot-air blowing unit as an ink drying unit together with the infrared irradiation device 60.

  In the recording apparatus 12, when the drying unit 50 is at least one of a contact heating unit and a hot air blowing unit, for example, the drying is performed under the condition that the surface temperature of the recording medium is raised to a range of 50 ° C. or more and 120 ° C. or less. Do.

  A peeling plate 34 is disposed on the downstream side of the drying means 50 so as to face the driving roll 24. The peeling plate 34 peels the recording medium P from the conveyance belt 28.

  Between the conveyance belt 28 and the container 40 is a conveyance path 36 through which the recording medium P after image recording is conveyed, and a plurality of pairs of rolls 38 that convey the recording medium P are arranged in the conveyance path 36. .

The operation of the recording device 12 will be described.
The recording medium P before image recording is taken out one by one from the container 16 by the roll 18 and is conveyed to the conveying belt 28 by the plural roll pairs 20.
Next, the recording medium P is electrostatically attracted to the conveyance belt 28 by the charging roll 32, and is conveyed below the ink discharge head 30 by the rotation of the conveyance belt 28.
Next, ink is ejected from the ink ejection head 30 onto the recording medium P, and an image is recorded.
Next, the ink on the recording medium P is dried by the drying means 50. When the drying means 50 is the infrared irradiation device 60, infrared rays are irradiated from the infrared irradiation device 60, and in the ink containing the infrared absorber, the infrared absorber in the ink generates heat, and the ink temperature rises. The ink dries.
Next, the recording medium P on which the ink is dried and the image is fixed is peeled off from the transport belt 28 by the peeling plate 34 and is transported to the container 40 by a plurality of roll pairs 38.

  The recording apparatus according to the present embodiment is not limited to a mode in which ink is directly applied to the recording medium from the ink applying unit, and after the ink is applied from the ink applying unit to the intermediate transfer member, the ink on the intermediate transfer member is applied to the recording medium. A form to be transferred may be used.

  The recording apparatus according to the present embodiment is not limited to a sheet-fed press using the recording apparatus 12 illustrated in FIG. 1 as an example, and may be a rotary press.

  Hereinafter, embodiments of the present invention will be described in detail by way of examples, but the embodiments of the present invention are not limited to these examples. In the following description, “part” and “%” are all based on mass unless otherwise specified.

<Resin particle dispersion>
[Synthesis of Resin 01]
A three-necked flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen gas inlet tube was charged with 25 parts of methyl ethyl ketone and heated to 80 ° C. While maintaining the reaction vessel temperature at 80 ° C., 45 parts of isobornyl methacrylate (manufactured by Wako Pure Chemical Industries, Ltd.), 49 parts of methyl methacrylate (manufactured by Wako Pure Chemical Industries, Ltd.), 2-carboxyethyl acrylate (A Solvay Nikka Co., Ltd. product: Sipomer β-CEA) 6 parts, methyl ethyl ketone 70 parts, and a polymerization initiator (Wako Pure Chemical Industries, Ltd., V-601) 2 parts mixed solution in 2 hours It was dripped. After completion of the dropwise addition, a solution comprising 0.4 part of a polymerization initiator (manufactured by Wako Pure Chemical Industries, Ltd., V-601) and 10 parts of methyl ethyl ketone was added, stirred at 80 ° C. for 2 hours, and further a polymerization initiator (Wako Pure Chemical Industries, Ltd.). A solution consisting of 0.4 parts by Yakugyo Co., Ltd., V-601) and 10 parts of methyl ethyl ketone was added and stirred at 80 ° C. for 2 hours, then heated to 85 ° C. and further stirred for 2 hours. Thus, a resin 01 solution in which resin 01 (compound P01 in the specific example of the specific resin described above) was dissolved in methyl ethyl ketone was obtained. The obtained resin 01 has a weight average molecular weight (Mw) of 30000 (calculated in terms of polystyrene by GPC), an acid value of 21 (mgKOH / g), a glass transition temperature (Tg) of 130 (° C.), and a resin in the resin 01 solution. The concentration of the component was 48% by mass.

[Synthesis of Resin 02 to Resin 16]
Resin solutions in which each resin was dissolved in methyl ethyl ketone were obtained in the same manner as the synthesis of Resin 01 except that the types and amounts of monomers were changed according to Tables 1 and 2. Tables 1 and 2 show the weight average molecular weight (Mw), acid value, and glass transition temperature (Tg) of the obtained resin. In addition, the unit of the quantity of the monomer of Table 1 and Table 2 is a mass part, and "-" in Table 1 and Table 2 means that a corresponding component is not included.

[Production of resin particle dispersion AD-1]
16.7 parts of the resin 01 solution was placed in the flask, and 6 parts of methyl ethyl ketone and 2 parts of isopropyl alcohol were added and stirred to mix. Next, a 10% by mass aqueous solution of sodium hydroxide was added with stirring, 0.8 equivalent of all carboxy groups contained in the resin 01. Next, 60 parts of water was gradually added while mixing and mixed. After the mixture becomes nearly uniform, a distillation tube and a vacuum pump are attached to the flask, and the mixture is heated to 30 ° C to 35 ° C and depressurized while stirring. Part was distilled off. The operation of concentrating while replacing the organic solvent with water was repeated until the odor of the organic solvent disappeared while adjusting the amount of water added so that the solid content concentration calculated from the material did not exceed 17% by mass. The concentrate was filtered through a 230 mesh nylon mesh to obtain a resin particle dispersion. With respect to this resin particle dispersion, the solid content was measured by the method described in “(1) Yield” described later, and the yield was determined. Based on the measured solid content, water was added to this resin particle dispersion to adjust the solid content concentration to 10% by mass, and this was designated as resin particle dispersion AD-1.

[Production of resin particle dispersions AD-2 to 16]
According to Table 1 and Table 2, except that the type of resin and the degree of neutralization (addition amount (equivalent) of sodium hydroxide with respect to all carboxy groups contained in the resin) were changed, the same as in the production of the resin particle dispersion AD-1. Thus, resin particle dispersions AD-2 to 16 having a solid content concentration of 10% by mass were obtained.

[Evaluation]
(1) Yield A part of the resin particle dispersion was dried by heating at 120 ° C. under atmospheric pressure for 2 hours, the solid content (mass) was measured, the yield was determined according to the following formula, and classified as follows: . The results are shown in Tables 1 and 2.
Formula: solid content of resin particle dispersion ÷ (solid content of polymer solution used for production of resin particle dispersion + mass of sodium hydroxide used for neutralization in production process of resin particle dispersion) × 100

G1: The yield is 90% or more.
G2: Yield 70% or more and less than 90%.
G3: Yield less than 70%.
G4: Aggregates are generated and a resin particle dispersion cannot be obtained.

(2) Particle size Volume-based median diameter of particles dispersed in a resin particle dispersion (solid concentration: 10% by mass) using a dynamic light scattering particle size distribution analyzer LB-500 (Horiba Seisakusho) (Nm) was measured. The results are shown in Tables 1 and 2.

(3) Amount of water-soluble component 5 mL of a resin particle dispersion (solid content concentration: 10% by mass) is placed on a filter of a centrifugal ultrafiltration filter unit (Millipore, Amicon Ultra-15, molecular weight cut off Mw 100,000). Centrifugation was performed at 10 ° C. and a centrifugal acceleration of 4000 G for 40 minutes using a small high-speed cooling centrifuge (manufactured by Tommy Seiko Co., Ltd., SRX-201), and the filtrate (resin particle dispersion medium) was collected. The collected filtrate was heated at 120 ° C. under atmospheric pressure for 30 minutes, and then allowed to stand at 120 ° C. under reduced pressure (degree of vacuum of 0.1 MPa or less) for 2 hours, and then the mass of the dried solid was measured. The ratio of the dry solid content of the filtrate to the solid content of the resin particle dispersion was calculated and classified as follows. The results are shown in Tables 1 and 2.

G1: The dry matter amount (water-soluble component amount) of the filtrate is less than 5% by mass.
G2: The dry solid content (water-soluble component amount) of the filtrate is 5% by mass or more and less than 10% by mass.
G3: The dry solid content (water-soluble component amount) of the filtrate is 10% by mass or more.

The meanings of the abbreviations in Table 1 and Table 2 are as follows.
-IBOMA: Isobornyl methacrylate-DCPMA: Dicyclopentanyl methacrylate-DCPA: Dicyclopentenyl acrylate-PhOEMA: Phenoxyethyl methacrylate-St: Styrene-MMA: Methyl methacrylate-EMA: Ethyl methacrylate-BA: Butyl acrylate · CHMA: cyclohexyl methacrylate · CEA: 2-carboxyethyl acrylate (2-carboxyethyl acrylate, Shipomer β-CEA)
・ MAA: Methacrylic acid

<Water-based ink>
[Preparation of cyan pigment dispersion]
In a reaction vessel, 6 parts of styrene, 11 parts of stearyl methacrylate, 4 parts of styrene macromer AS-6 (manufactured by Toa Gosei), 5 parts of Blenmer PP-500 (manufactured by NOF), 5 parts of methacrylic acid, 0.05 of 2-mercaptoethanol And a mixed solution (mixed solution 1) consisting of 24 parts of methyl ethyl ketone was prepared.
On the other hand, 14 parts of styrene, 24 parts of stearyl methacrylate, 9 parts of styrene macromer AS-6 (manufactured by Toa Gosei), 9 parts of Bremer PP-500 (manufactured by NOF), 10 parts of methacrylic acid, 0.13 part of 2-mercaptoethanol, A mixed solution (mixed solution 2) consisting of 56 parts of methyl ethyl ketone and 1.2 parts of 2,2′-azobis (2,4-dimethylvaleronitrile) was prepared and placed in a dropping funnel.

  Next, in a nitrogen atmosphere, the mixed solution (mixed solution 1) in the reaction vessel was heated to 75 ° C. while stirring, and the mixed solution (mixed solution 2) in the dropping funnel was gradually added dropwise over 1 hour. . After 2 hours from the end of the dropwise addition, a solution prepared by dissolving 1.2 parts of 2,2′-azobis (2,4-dimethylvaleronitrile) in 12 parts of methyl ethyl ketone was added dropwise over 3 hours, and further at 75 ° C. for 2 hours. After the reaction, the mixture was aged at 80 ° C. for 2 hours to obtain a polymer solution.

  A part of the obtained polymer solution was isolated by removing the solvent, the obtained solid content was diluted to 0.1% by mass with tetrahydrofuran, and the weight average molecular weight was measured by GPC. As a result, the isolated solid content had a polystyrene equivalent weight average molecular weight of 25,000.

In addition, 5 parts of the obtained polymer solution in terms of solid content, 10 parts of cyan pigment (Pigment Blue 15: 3, manufactured by Dainichi Seika Kogyo), 40 parts of methyl ethyl ketone, 8 parts of 1 mol / L aqueous sodium hydroxide solution, ion-exchanged water 82 parts were supplied to a vessel together with 300 g of 0.1 mm zirconia beads, and dispersed at 1000 rpm for 6 hours with a ready mill disperser (manufactured by IMEX).
The obtained dispersion was concentrated under reduced pressure using an evaporator to remove methyl ethyl ketone and concentrated until the pigment concentration became 10% by mass. Thus, a cyan pigment dispersion liquid CD1 in which the cyan pigment whose surface was coated with the polymer dispersant was dispersed was obtained. The obtained cyan pigment dispersion CD1 had a volume average particle size of 77 nm.

[Production of Cyan Ink C-1]
After the following materials were mixed, coarse particles were removed with a 5 μm filter to prepare cyan ink C-1 as a water-based ink.
-Cyan pigment dispersion CD1 ... 6% by mass (in terms of solid content)
・ Resin dispersion AD-1 2% by mass (solid content conversion)
・ Propylene glycol (manufactured by Wako Pure Chemical Industries) ・ ・ ・ 25%
・ Propylene glycol monobutyl ether 3% by mass
・ Olfin E1010 (Nisshin Chemical Industry) 0.7 mass%
・ Orphine E1004 (Nissin Chemical Industry) ・ ・ ・ 0.3% by mass
・ Ion-exchanged water: the remaining amount of total 100% by mass

[Production of Cyan Inks C-2 to C-16]
Except for changing the resin particle dispersion AD-1 to any one of the resin particle dispersions AD-2 to AD-16, the cyan inks C-2 to C-18 are respectively the same as the production of the cyan ink C-1. Got.

[Evaluation]
(4) Concentration redispersibility The resin particle dispersion was placed in a glass petri dish and concentrated by heating at 40 ° C. After concentrating until the concentration of the resin particles reaches 40% by mass, the state of the concentrated re-dispersed liquid obtained by adding ion exchange water and diluting the concentration of the resin particles to 10% by mass is visually observed. Based on the evaluation. The results are shown in Tables 1 and 2.
-Evaluation criteria-
G1: The concentrated redispersion becomes liquid, and there is no solid matter in the concentrated redispersion or on the petri dish.
G2: The concentrated re-dispersed liquid becomes liquid, but solid matter is seen in at least one of the concentrated re-dispersed liquid and the petri dish.
G3: The concentrated redispersed liquid becomes liquid, but solid matter is seen both in the concentrated redispersed liquid and on the petri dish.
G4: The concentrated re-dispersion liquid is partially liquid, but most remains as a solid.

From the results of Tables 1 to 4, it can be seen that the concentration redispersibility is better in the Examples than in the Comparative Examples. In addition, among the examples, the acid value of the resin is 10 mgKOH / g or more and 100 mgKOH / g or less, compared to Example A-2 and Example A-6 in which the acid value of the resin is out of the above range. The yield was good.
In the example where the concentration redispersibility is good, it is presumed that the ejection stability is good and nozzle clogging is suppressed as compared with the comparative example.

12 recording device 14 housing 16 container 18 roll 20 roll pair 22 transport path 24 drive roll 26 driven roll 28 transport belts 30Y, 30M, 30C, 30K ink ejection head (an example of ink applying means)
31Y, 31M, 31C, 31K Ink cartridge 32 Charging roll 34 Release plate 36 Transport path 38 Roll pair 40 Containers 50Y, 50M, 50C, 50K Drying means 60Y, 60M, 60C, 60K Infrared irradiation device (an example of drying means)
P Recording medium

Claims (8)

An aqueous dispersion medium containing water;
Particles containing a resin containing alicyclic (meth) acrylate and 2-carboxyethyl (meth) acrylate as structural units;
Resin particle dispersion liquid.   The resin particle dispersion according to claim 1, wherein the alicyclic (meth) acrylate has two or more alicyclic structures.   The resin particle dispersion according to claim 1 or 2, wherein the acid value of the resin is 10 mgKOH / g or more and 100 mgKOH / g or less.   The resin particle dispersion according to any one of claims 1 to 3, wherein the content of 2-carboxyethyl (meth) acrylate is 3% by mass or more and 30% by mass or less based on the entire constituent unit of the resin.   An aqueous ink comprising the resin particle dispersion according to any one of claims 1 to 4.   An ink cartridge containing the water-based ink according to claim 5. Ink applying means for containing the water-based ink according to claim 5 and discharging the water-based ink from a nozzle and applying the ink to a recording medium;
Drying means for drying the water-based ink applied to the recording medium;
A recording apparatus comprising: An ink applying step for discharging the water-based ink according to claim 5 from a nozzle and applying the ink to a recording medium;
A drying step of drying the water-based ink applied to the recording medium;
A recording method.