JP2023119427A - Aqueous colorant dispersion, ink, ink set, and image formed object - Google Patents

Abstract

To provide an aqueous colorant dispersion which has high viscosity stability under temperature fluctuation after inking, has high compatibility with a binder resin, has good stability, and achieves both adequate flexibility and abrasion resistance of an ink film.SOLUTION: An aqueous colorant dispersion contains a colorant (A), a resin (B), a resin (C), a basic compound (D), and an aqueous medium (E), wherein the resin (B) is a polymer containing a hydrophobic group-containing monomer unit, an acid group-containing monomer unit, and a (poly)alkylene oxy group-containing monomer unit, and the resin (C) contains a hydrophobic group-containing monomer unit, and an acid group-containing monomer unit, and no (poly)alkylene oxy group-containing monomer unit.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a water-based colorant dispersion that can be used for ink for inkjet recording and the like.

From the standpoint of weather resistance and water resistance of printed matter, ink jet recording methods using pigments as colorants are becoming mainstream. In addition to paper, it can also print on soft resin substrates such as polyethylene terephthalate, polyvinyl chloride, polyethylene, polypropylene, and nylon, and is being used in fields such as product packaging and commercial labels.

As an ink for inkjet recording, for example, in Patent Document 1, as a white ink for inkjet capable of recording an excellent image in which at least one of the occurrence of cracks, a decrease in abrasion resistance, and a decrease in adhesion is resolved, a white color is used. a first resin made of a polyester resin; a second resin made of at least one of a fluorene resin and a styrene acrylic resin; and a third resin made of a polyolefin wax. An ink is disclosed.
Patent Document 2 discloses a water-based ink containing a coloring agent and polyester resin particles containing a polyester moiety and a polyolefin moiety, as an ink composition having excellent adhesion and abrasion resistance to a polyolefin recording medium. there is
In Patent Document 3, as an ink composition having excellent adhesion to polyethylene terephthalate, adhesion to nylon, and abrasion resistance, a colorant and resin particles having a polyester portion and a polyurethane portion are used. Disclosed is a water-based ink containing.

JP 2013-177526 A JP 2016-196619 A JP 2017-082189 A

A packaging container using a printed material made of a soft resin base material is bent by strongly pinching the base material with fingers, for example, when opening a packaging bag. At that time, the base material is bent, and the ink film is also bent following the base material. Also, the ink film may be lost due to rubbing between containers, including labeled containers, or packaging material during transportation, or scratching the ink film with a fingernail during use. Furthermore, packaging containers using printed materials on soft resin substrates do not absorb ink components unlike paper, so it is difficult for the ink film to adhere to the surface of the substrates. In order to utilize ink for inkjet recording in fields such as product packaging and commercial labels, the ink film must have crack resistance, abrasion resistance, and adhesion to withstand these usage environments. . However, in the inkjet recording ink described in Patent Document 1, the range of resin types and blending amounts in the ink that simultaneously satisfies all of the properties of cracking, abrasion resistance, and adhesion is limited. The image quality to the substrate was poor. The inks containing the water-based colorant dispersions of US Pat.

An object of the present invention is to provide a water-based colorant dispersion that has high viscosity stability under temperature fluctuations after being made into an ink, and that can form an ink film with good adhesion that achieves both moderate flexibility and abrasion resistance. .

The aqueous colorant dispersion of the present invention contains a colorant (A), a resin (B), a resin (C), a basic compound (D) and an aqueous medium (E),
the resin (B) is a polymer containing a hydrophobic group-containing monomer unit, an acid group-containing monomer unit, and a (poly)alkyleneoxy group-containing monomer unit;
The resin (C) is a water-based colorant dispersion which is a polymer containing hydrophobic group-containing monomer units and acid group-containing monomer units but not containing (poly)alkyleneoxy group-containing monomer units.

According to the present invention, a water-based colorant dispersion that has high viscosity stability under temperature fluctuations after being made into an ink and can form an ink film with good adhesion that achieves both moderate flexibility and abrasion resistance. can provide inks, ink sets, and image-formed products using

Terms used in the present invention are defined. "C.I." is the color index number. Monomers and monomers are ethylenically unsaturated group-containing monomers. A monomer unit is the state that is incorporated into the resin after polymerization of the monomer.
"(Meth)acrylate" includes acrylate and methacrylate.
(Poly)alkyleneoxy groups include both polyalkyleneoxy groups and alkyleneoxy groups. An alkyleneoxy group is, for example, an ethyleneoxy group, a propyleneoxy group, a butyleneoxy group, and the like. A unit in the (anhydrous) maleic acid unit means one of repeating units constituting a polymer obtained by polymerizing a (anhydride) maleic acid monomer. Other monomer units are the same as above. Moreover, the monomer is in an unpolymerized state. Dispersants are compounds used to disperse pre-micronized colorants. The coated colorant is a colorant whose surface is at least partly coated with a resin, which is finely divided together with a resin. The ink film is also called the image layer.

The aqueous colorant dispersion of the present invention contains a colorant (A), a resin (B), a resin (C), a basic compound (D) and an aqueous medium (E),
the resin (B) is a polymer containing a hydrophobic group-containing monomer unit, an acid group-containing monomer unit, and a (poly)alkyleneoxy group-containing monomer unit;
The resin (C) is a water-based colorant dispersion which is a polymer containing hydrophobic group-containing monomer units and acid group-containing monomer units but not containing (poly)alkyleneoxy group-containing monomer units.

The water-based colorant dispersion of the present invention has high viscosity stability under temperature fluctuations after being made into an ink, high compatibility with a binder resin, good storage stability, and appropriate flexibility and abrasion resistance of an ink film. It is a water-based colorant dispersion that satisfies both properties.
The reason for these effects is that by using polymers containing hydrophobic group-containing monomer units for the resin (B) and the resin (C) in which the colorant particles are dispersed, the hydrophobic structure is easily adsorbed to the colorant particles. viscosity stability improves. In addition, the steric hindrance effect of the hydrophobic group suppresses the aggregation of the colorants, thereby reducing the number of coarse particles.
In addition, by using a (poly)alkyleneoxy group-containing monomer unit for the resin (B), in addition to improving compatibility with the binder resin in the ink, a steric produce an impediment effect.
Here, by using the resin (B) and the resin (C) together, the distance between the colorant particles dispersed in the resin becomes irregular rather than uniform and can exist in an amorphous state. As compared with B) alone or resin (C) alone, it is possible to further suppress the aggregation of the colorants. As a result, the introduction of the (poly)alkyleneoxy group provides an appropriate degree of flexibility of the ink film, and also prevents the ink film from falling off due to the aggregation of the colorant particles, leading to the strengthening of the film. Furthermore, for the above reason, it is assumed that the interaction between the colorant particles due to the temperature change is reduced, and the increase in viscosity is less likely to occur. The problem can be solved by dispersing the colorant particles in the resin (B) and the resin (C), but the problem can be solved more effectively by coating the colorant particles with these resins.

<Colorant (A)>
The aqueous colorant dispersion of the present invention contains a colorant (A). Colorant (A) is a pigment or dye that is insoluble in an aqueous medium. A water-soluble dye can be used together.
Pigments are, for example, C.I. I. Pigment Red 3,5,19,22,31,38,42,43,48:1,48:2,48:3,48:4,48:5,49:1,53:1,57:1, 57:2, 58:4, 63:1, 81, 81:1, 81:2, 81:3, 81:4, 88, 104, 108, 112, 122, 123, 144, 146, 147, 149, 150, 166, 168, 169, 170, 176, 177, 178, 179, 184, 185, 202, 208, 216, 226, 242, 254, 255, 257, 269, 291;
C. I. Pigment Green 7,26,36,50,58,59,62,63;
C. I. Pigment Blue 1,15,15:1,15:2,15:3,15:4,15:6,16,17,17:1,22,27,28,29,36,60;
C. I. Pigment Orange 13, 16, 20, 34, 36, 38, 43, 62, 64, 71, 73;
C. I. pigment yellow 139, 150, 153, 154, 155, 157, 166, 167, 168, 174, 180, 185, 193, 213, 234;
C. I. Pigment Violet 3, 19, 23, 29, 30, 37, 50, 88;
C. I. Pigment Black 7, 28, 26;
C. I. Pigment White 6, 18, 21; and the like.

Disperse dyes include, for example, C.I. I. Disperse Red 11, 50, 53, 54, 55, 55: 1, 59, 60, 65, 70, 72, 73, 75, 86, 88, 91, 92, 93, 111, 126, 127, 134, 135 , 143, 145, 146, 152, 153, 154, 158, 159, 164, 167: 1, 177, 181, 190, 190: 1, 204, 206, 207, 221, 239, 240, 258, 277, 278 , 283, 311, 323, 343, 348, 356, 362;
C. I. bat red 41;
C. I. Disperse Green 6:1,9;
C. I. Disperse Blue 19,26,26:1,35,55,56,58,60,64,64:1,72,72:1,73,81,81:1,87,91,95,108,113 , 128, 131, 141, 143, 145, 148, 154, 158, 165, 165: 1, 165: 2, 176, 183, 185, 197, 198, 201, 214, 224, 225, 257, 266, 267 , 287, 354, 358, 359, 360, 365, 368;
C. I. Disperse Orange 1,1:1,5,13,20,25,25:1,29,31:1,33,49,54,55,56,66,73,76,118,119,163;
C. I. Disperse Yellow 3,5,7,8,23,39,42,51,54,60,64,71,79,82,83,86,93,99,100,119,122,124,126,160 , 184:1,186,198,199,201,204,224,237;
C. I. Disperse Violet 8, 17, 23, 27, 28, 29, 33, 36, 57;
C. I. Disperse Brown 2; and the like.

Water-soluble dyes include direct dyes, acid dyes, food dyes, basic dyes, reactive dyes, and the like. For example, C.I. I. Direct Red 2,4,9,23,26,31,39,62,63,72,75,76,79,80,81,83,84,89,92,95,111,173,184,207, 211,212,214,218,223,224,225,226,227,232,233,240,241,242,243,247;
C. I. Direct Violet 7, 9, 47, 48, 51, 66, 90, 93, 94, 95, 98, 100, 101;
C. I. Direct Yellow 8,9,11,12,27,28,29,33,35,39,41,44,50,53,58,59,68,86,87,93,95,96,98,100, 106, 108, 109, 110, 130, 132, 142, 144, 161, 163;
C. I. Direct Blue 1, 10, 15, 22, 25, 55, 67, 68, 71, 76, 77, 78, 80, 84, 86, 87, 90, 98, 106, 108, 109, 151, 156, 158, 159, 160, 168, 189, 192, 193, 194, 199, 200, 201, 202, 203, 207, 211, 213, 214, 218, 225, 229, 236, 237, 244, 248, 249, 251, 252, 264, 270, 280, 288, 289, 291;
C. I. Direct Black 9,17,19,22,32,51,56,62,69,77,80,91,94,97,108,112,113,114,117,118,121,122,125,132 146, 154, 166, 168, 173, 199
C. I. Acid Red 35, 42, 52, 57, 62, 80, 82, 111, 114, 118, 119, 127, 128, 131, 143, 151, 154, 158, 249, 254, 257, 261, 263, 266, 289, 299, 301, 305, 336, 337, 361, 396, 397;
C. I. Acid Violet 5,34,43,47,48,90,103,126;
C. I. Acid Yellow 17, 19, 23, 25, 39, 40, 42, 44, 49, 50, 61, 64, 76, 79, 110, 127, 135, 143, 151, 159, 169, 174, 190, 195, 196, 197, 199, 218, 219, 222, 227;
C. I. Acid Blue 9,25,40,41,62,72,76,78,80,82,92,106,112,113,120,127:1,129,138,143,175,181,205,207, 220,221,230,232,247,258,260,264,271,277,278,279,280,288,290,326
C. I. Acid Black 7,24,29,48,52:1,172;
C. I. Reactive Red 3, 13, 17, 19, 21, 22, 23, 24, 29, 35, 37, 40, 41, 43, 45, 49, 55;
C. I. Reactive Violet 1,3,4,5,6,7,8,9,16,17,22,23,24,26,27,33,34;
C. I. Reactive Yellow 2,3,13,14,15,17,18,23,24,25,26,27,29,35,37,41,42;
C. I. Reactive Blue 2,3,5,8,10,13,14,15,17,18,19,21,25,26,27,28,29,38;
C. I. Reactive Black 4,5,8,14,21,23,26,31,32,34;
C. I. Basic Red 12, 13, 14, 15, 18, 22, 23, 24, 25, 27, 29, 35, 36, 38, 39, 45, 46;
C. I. Basic Violet 1,2,3,7,10,15,16,20,21,25,27,28,35,37,39,40,48;
C. I. Basic Yellow 1,2,4,11,13,14,15,19,21,23,24,25,28,29,32,36,39,40;
C. I. Basic Blue 1,3,5,7,9,22,26,41,45,46,47,54,57,60,62,65,66,69,71;
C. I. basic black 8; and the like.

Colorants (A) can be used alone or in combination of two or more.

<Resin (B)>
The aqueous colorant dispersion of the invention contains a resin (B). Resin (B) is a polymer containing hydrophobic group-containing monomer units, acid group-containing monomer units, and (poly)alkyleneoxy group-containing monomer units.

[Hydrophobic group-containing monomer unit]
Hydrophobic group-containing monomer units include (meth)acrylic acid alkyl ester units, aromatic monomer units, heterocyclic monomer units, and α-olefin monomer units. Two or more aromatic or heterocyclic rings may be condensed in the aromatic or heterocyclic group.

(Meth)acrylic acid alkyl esters, for example, methyl (meth)acrylate, butyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, cyclohexane (meth)acrylate, furfuryl (meth)acrylate , isobornyl (meth)acrylate, adamantane (meth)acrylate, 2-methyladamantane (meth)acrylate and the like.
Aromatic monomer units are, for example, styrene, α-methylstyrene, styrene macromers, 2-methylstyrene, 4-methylstyrene, 4-n-octylstyrene, 4-methoxystyrene, 4-aminostyrene, 4-nitrostyrene, 4-nitrostyrene, -vinylphenyl acetate, 2-vinylquinoline, 2-vinylnaphthalene, 4-vinylbiphenyl, 9-vinylanthracene, 9-vinylphenanthrene, phenyl (meth)acrylate, benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, phenoxy Diethylene glycol (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, pentafluorophenyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 2-(meth)acryloyloxyethyl phthalate, 2-( meth)acryloyloxyethyl-2-hydroxyethyl-phthalic acid, neopentyl glycol (meth)acrylic acid benzoate, 4-[(6-(meth)acryloyloxy)hexyloxy]-4'-cyanobiphenyl, N -Phenyl(meth)acrylamide, allylphenyl acetate, allylphenyl ether, allylphenoxyacetate and the like.
Examples of heterocyclic monomer units include 4-vinylpyridine, vinylimidazole, 1-vinyl-1H-indole and the like.
Examples of α-olefin monomer units include 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene and the like.

By having a hydrophobic group-containing monomer unit, the resin (B) is adsorbed to the colorant (A) and the viscosity stability is improved. In addition, the steric hindrance effect of the hydrophobic group suppresses the aggregation of the colorants, thereby reducing the number of coarse particles. As the hydrophobic group-containing monomer units, (meth)acrylic acid alkyl ester units, aromatic monomer units, heterocyclic monomer units and α-olefin monomer units are preferable, and α-olefin monomer units are more preferable.

The hydrophobic group-containing monomer units can be used alone or in combination of two or more.

The amount of the hydrophobic group-containing monomer used when synthesizing the resin (B) is preferably 20 to 90% by mass, more preferably 25 to 80% by mass, of the total monomers used when synthesizing the resin (B). , 30 to 70 mass % is more preferable. By setting the content of the hydrophobic group-containing monomer unit within the above range, the resin (B) is easily adsorbed to the colorant (A), and the colorant is easily dispersed to the level of primary particles.

[Acid group-containing monomer unit]
Acid group-containing monomer units include, for example, monomer units having a carboxy group, a sulfo group, or a phosphoric acid group.

[Carboxy group-containing monomer unit]
A carboxy group-containing monomer is a monomer having a carboxy group or an acid anhydride group. For example, (meth)acrylic acid, (meth)acrylic acid dimer, itaconic acid, itaconic acid half esters such as itaconic acid monomethyl ester, maleic acid, maleic acid half esters such as maleic acid mono-n-butyl ester and maleic acid monoisopropyl ester , maleic anhydride, fumaric acid, fumaric acid half ester of fumaric acid monoethyl ester, tetrahydrophthalic acid, tetrahydrophthalic acid half ester of tetrahydrophthalic acid monomethyl ester, crotonic acid, 2-(meth)acryloyloxyethyl phthalate, 2 -(meth)acryloyloxypropyl phthalate, 2-(meth)acryloyloxyethyl hexahydrophthalate, 2-(meth)acryloyloxypropyl hexahydrophthalate, ethylene oxide-modified succinic acid (meth)acrylate, β-carboxyethyl (Meth)acrylates, ω-carboxypolycaprolactone (meth)acrylates, compounds having a betaine structure, and salts thereof.

Half esters such as the above maleic acid half esters can be formed by reacting them with alcohols.
Alcohols include, for example, methanol, ethanol, propanol, butanol, pentanol, hexanol, decanol, structural isomers thereof, and the like. Among these, methanol, ethanol and propanol are preferred.

Alcohol can be used individually or in combination of 2 or more types.

[Sulfo group-containing monomer unit]
Sulfo group-containing monomers include, for example, vinylsulfonic acid, acrylamide tert-butylsulfonic acid, 2-sulfoethyl (meth)acrylate, 3-sulfopropyl (meth)acrylate, styrenesulfonic acid; and salts thereof. .

[Phosphate group-containing monomer unit]

Phosphate group-containing monomers include, for example, bis(methacryloxyethyl) phosphate, diphenyl-2-acryloyloxyethyl phosphate, diphenyl-2-methacryloyloxyethyl phosphate, and dibutyl-2-acryloyloxyethyl phosphate; and salts thereof, etc. are mentioned.

The acid group-containing monomer unit is preferably a carboxy group-containing monomer unit, more preferably maleic anhydride unit, maleic acid unit, maleic acid ester unit, (meth)acrylic acid, maleic anhydride unit, maleic acid unit, maleic acid Ester units are more preferred.

The acid group-containing monomer units can be used singly or in combination of two or more.

The amount of the acid group-containing monomer used in synthesizing the resin (B) is preferably 10 to 90% by mass, more preferably 20 to 80% by mass, based on the total monomers used in synthesizing the resin (B). 30 to 70% by mass is more preferable. By setting the content of the acid group-containing monomer unit within the above range, charge repulsion improves the viscosity stability, which is preferable. Among these, a carboxy group is preferable because it particularly improves viscosity stability due to charge repulsion.

[(Poly) alkyleneoxy group-containing monomer unit]
(Poly) alkyleneoxy group-containing monomers include, for example, polyethylene glycol allyl ether, polyethylene glycol polypropylene glycol allyl ether, polypropylene glycol allyl ether, methoxy (poly) ethylene glycol (meth) acrylate, ethoxy (poly) ethylene glycol (meth) acrylate , 2-ethylhexyl (poly) ethylene glycol acrylate, methoxy (poly) propylene glycol (meth) acrylate, ethoxy (poly) propylene glycol (meth) acrylate, ethoxy (poly) ethylene (poly) propylene glycol (meth) acrylate; mentioned.
Among these, polyethylene glycol allyl ether, polyethylene glycol polypropylene glycol allyl ether, and polypropylene glycol allyl ether represented by the following formula (1) are preferable, and polyethylene glycol polypropylene glycol allyl ether and polypropylene glycol allyl ether are more preferable.

formula (1)

In formula (1), m is 0 or an integer of 1 or more, n is 0 or an integer of 1 or more, and m+n≧1. R ₁ represents a hydrogen atom or a methyl group. R ₂ represents an optionally substituted alkyl group or aryl group having 1 to 30 carbon atoms. Further, when m≧1, n≧1, and m+n≧2, the bonding order of the CH ₂ CH ₂ O group (ethyleneoxy group) and the CH(CH ₃ )CH ₂ O group (propyleneoxy group) may be random. It's good, it's good to be alternating, it's good to be a block.

In formula (1), m is preferably 0-20. n is preferably 0-20. m+n is preferably 1-40. R ₁ is preferably a hydrogen atom or a methyl group. _R2 is preferably a methyl group, ethyl group, propyl group, isopropyl group, butyl group, hexyl group, cyclohexyl group, decyl group, phenyl group, phenylcarboxy group or phenol group.

The content of the (poly)oxyalkylene group-containing monomer unit used for synthesizing the resin (B) is preferably 1 to 50% by mass, preferably 2 to 30% by mass, based on the total monomers used for synthesizing the resin (B). % is more preferred, and 3 to 20% by mass is even more preferred. By setting the (poly)alkyleneoxy group-containing monomer unit within the above range, the distance between the resin-coated colorants tends to become irregular, which is preferable because it facilitates further suppression of aggregation.

Resin (B) may also contain monomer units other than hydrophobic group-containing monomer units, acid group-containing monomer units, and (poly)alkyleneoxy group-containing monomer units. Examples of other monomer units include other vinyl monomers.

<Resin (C)>
The aqueous colorant dispersion of the invention contains a resin (C). Resin (C) is a polymer containing hydrophobic group-containing monomer units and acid group-containing monomer units, but not containing (poly)alkyleneoxy group-containing monomer units.
As the hydrophobic group-containing monomer unit and the acid group-containing monomer unit, those described above can be used.

Commercially available products include Joncryl67, 586, 611, 678, 680, 682, 683, 690, 693, HPD671, HPD696 (styrene-acrylic acid copolymer) manufactured by BASF Japan, and Ceramer 67, 1608, 1251 manufactured by NUCERA. (α-olefin-maleic anhydride-maleic acid half ester copolymer), manufactured by Tomoe Kogyo SMA1000, 2000, 3000, EF30, EF40, EF60, EF80, 1400, 17352, 2625, 3840 coalescence) and the like.

As the method for polymerizing the resin (B) and the resin (C), any conventionally known polymerization method such as random polymerization, block polymerization, living radical polymerization, and alternating copolymerization can be employed.

In order to maximize the effect of the invention, the ratio of the resin (B) and the resin (C) is determined by the mass of the resin (B) relative to the total amount of the resin (B) and the resin (C) in the water-based colorant dispersion. %, preferably 10 to 90%, more preferably 20 to 80%, even more preferably 30 to 70%.

The acid value of resin (B) and resin (C) is preferably 1 to 400 mgKOH/g, more preferably 50 to 350 mgKOH/g, even more preferably 100 to 250 mgKOH/g. By setting the acid value within the above range, sufficient dispersion stability can be obtained by charge repulsion.

The number average molecular weight (Mn) of the resin (B) and the resin (C) is preferably 1,000 to 1,000,000, more preferably 3,000 to 80,000, and further preferably 4,000 to 30,000. preferable. Further, the polydispersity (Mw/Mn) obtained by dividing the weight average molecular weight (Mw) by the number average molecular weight (Mn) is preferably 5.0 or less, more preferably 3.0 or less, and further preferably 2.0 or less. , 1.5 or less is most preferred.

Resin (B) and resin (C) are preferably resins having a melting point. The melting point is preferably less than 100°C, more preferably 90°C or less, and even more preferably 80°C or less. If the temperature is 100° C. or higher, it may be necessary to disperse at a high temperature when dispersing in an aqueous medium, and water may evaporate violently, making it difficult to prepare a dispersion.

The amount of resin (B) and resin (C) added is preferably 1 to 200 parts by mass, more preferably 10 to 100 parts by mass, per 100 parts by mass of colorant (A). It is preferable that the resin (B) and the resin (C) cover part or all of the colorant (A).

<Basic compound (D)>
The aqueous colorant dispersion of the invention contains a basic compound (D). The basic compound is a compound capable of neutralizing acid groups such as carboxy groups, sulfo groups, and phosphoric groups contained in resin (B) and resin (C). The basic compound is not particularly limited as long as it is a compound capable of neutralizing the resin (B) and the resin (C). Basic compounds include inorganic bases and organic bases.
Examples of inorganic bases include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide and potassium hydroxide; alkali metal salts of silicic acid such as sodium orthosilicate, sodium metasilicate and sodium sesquisilicate; alkali metal salts of phosphoric acid, alkali metal salts of carbonic acid such as disodium carbonate, sodium hydrogencarbonate and dipotassium carbonate, alkali metal salts of boric acid such as sodium borate, ammonia;
Organic bases include, for example, alkylamines such as methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine and triethylamine, primary amino alcohols such as ethanolamine;
secondary amino alcohols such as butylaminoethanol and diethanolamine;
trimethanolamine, triethanolamine, tributanolamine, dimethylaminoethanol, diethylaminoethanol, dimethylaminopropanol, methoxypoly(oxyethylene/oxypropylene)-2-propylamine, N-methyldiethanolamine, N-ethyldiethanolamine, N-pentyl tertiary amino alcohols such as dibutanolamine; and the like.
Among these, inorganic bases or tertiary amino alcohols are preferred. Specifically, sodium hydroxide, potassium hydroxide, dimethylaminoethanol, diethylaminoethanol, dibutylaminoethanol, N-methyldiethanolamine, N-butyldiethanolamine and triethanolamine are preferred.

<Aqueous medium (E)>
The aqueous colorant dispersion of the present invention contains an aqueous medium (E). Examples of the aqueous medium (E) include water and water-soluble organic solvents that are miscible with water.

[water]
The water may be ordinary tap water, but preferably ion-exchanged water, distilled water, or purified water. The total amount of metal ions contained in water is preferably 10 ppm or less, more preferably 1 ppm or less, and even more preferably 100 ppb or less. In particular, divalent metal ions such as calcium and magnesium form an unintended crosslinked structure by reacting with two acid groups such as carboxy groups in resin (B) and resin (C). It is preferable to suppress as much as possible. As a result, nozzle clogging is less likely to occur in inkjet recording inks that use water-based colorant dispersions.

[Water-soluble organic solvent]
Water-soluble organic solvents include, for example, monoalcohols, polyhydric alcohols, polyhydric alcohol alkyl ethers, polyhydric alcohol aryl ethers, nitrogen-containing heterocyclic compounds, amides, amines, sulfur-containing compounds, propylene carbonate , ethylene carbonate, and other water-soluble solvents.

Examples of monoalcohols include methanol, ethanol, propanol, butanol, pentanol, 3-methoxy-3-methylbutanol; and the like.

Polyhydric alcohols include, for example, glycerin, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, 1,2-propanediol, 1,3-propanediol, propylene glycol, dipropylene glycol, tripropylene glycol. , polypropylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol, 1,5- Pentanediol, 1,2-hexanediol, 1,3-hexanediol, 1,4-hexanediol, 1,5-hexanediol, 1,6-hexanediol, 3-methyl-1,3-butanediol, tri methylolethane, trimethylolpropane, 1,2,6-hexanetriol, 1,2,4-butanetriol, 1,2,3-butanetriol, petriol, 2-ethyl-2-methyl-1,3-propane Diol, 3,3-dimethyl-1,2-butanediol, 2,2-diethyl-1,3-propanediol, 2-methyl-2-propyl-1,3-propanediol, 2,4-dimethyl-2 ,4-pentanediol, 2,5-dimethyl-2,5-hexanediol, 5-hexene-1,2-diol, 2-ethyl-1,3-hexanediol; and the like.

Examples of polyhydric alcohol alkyl ethers include ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, propylene glycol monoethyl ether, and propylene glycol monobutyl ether. ; and the like.

Examples of polyhydric alcohol aryl ethers include ethylene glycol monophenyl ether, diethylene glycol monophenyl ether, tetraethylene glycol chlorophenyl ether, ethylene glycol monobenzyl ether, ethylene glycol monoallyl ether; and the like.

Nitrogen-containing heterocyclic compounds include, for example, 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 1,3-dimethylimidazolidinone, ε-caprolactam, γ-butyrolactone; mentioned.

Amides include, for example, formamide, N-methylformamide, N,N-dimethylformamide; and the like.

Amines include, for example, monoethanolamine, diethanolamine, triethanolamine, monoethylamine, diethylamine, triethylamine; and the like.

Examples of sulfur-containing compounds include dimethylsulfoxide, sulfolane, thiodiethanol; and the like.

The aqueous medium (E) can be used alone or in combination of two or more.

<Crosslinking agent (F)>
The aqueous colorant dispersion of the present invention preferably contains a cross-linking agent (F). The cross-linking agent (F) reacts with two or more carboxy groups, sulfo groups, phosphoric acid groups, and amino groups of the resin (B) or the resin (C) to form the resin (B) or the resin (C) as a molecule. It is a compound that can be crosslinked between or within molecules. Examples of cross-linking agents include compounds having epoxy groups, oxetanyl groups, isocyanate groups, amino groups, quaternary ammonium bases, aziridinyl groups, carbodiimide groups, oxazoline groups, and the like. In particular, the addition of an epoxy group-containing compound is preferable because it reacts with the carboxyl group or the like in the resin (B) to form a strong three-dimensional structure. The weight average molecular weight or formula weight of the cross-linking agent is preferably 100 to 2,000, more preferably 120 to 1,500, even more preferably 150 to 1,000.

The amount of the cross-linking agent to be added is preferably 0.2 to 1.5 moles of the functional group of the cross-linking agent, and 0.5 to 1 mole of the acid groups in the resin (B) and the resin (C). .2 equivalents are more preferred. By setting the addition amount of the cross-linking agent within the above range, part or all of the particle surface of the colorant (A) is coated with the resin (B) or the resin (C) forming a strong three-dimensional structure. preferable.

Epoxy group-containing compounds include, for example, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, glycerin triglycidyl ether, glycerol polyglycidyl ether, polyglycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, sorbitol Examples include polyglycidyl ethers such as polyglycidyl ether, pentaerythritol polyglycidyl ether, resorcinol diglycidyl ether, neopentyl glycol diglycidyl ether, diglycidyl orthophthalate, and hydrogenated bisphenol A type diglycidyl ether.

Oxetanyl group-containing compounds include, for example, 4,4′-(3-ethyloxetan-3-ylmethyloxymethyl)biphenyl (OXBP), 3-ethyl-3-hydroxymethyloxetane (EHO), 1,4-bis[ {(3-ethyl-3-oxetanyl)methoxy}methyl]benzene (XDO), di[1-ethyl(3-oxetanyl)]methyl ether (DOX), di[1-ethyl(3-oxetanyl)]methyl ether ( DOE), 1,6-bis[(3-ethyl-3-oxetanyl)methoxy]hexane (HDB), 9,9-bis[2-methyl-4-{2-(3-oxetanyl)}butoxyphenyl]fluorene , 9,9-bis[4-[2-{2-(3-oxetanyl)}butoxy]ethoxyphenyl]fluorene and the like.

Isocyanate group-containing compounds include, for example, organic polyisocyanates or isocyanate group-terminated prepolymers, organic polyisocyanates include aliphatic diisocyanates such as hexamethylene diisocyanate and 2,2,4-trimethylhexamethylene diisocyanate; tolylene-2,4- aromatic diisocyanates such as diisocyanates and phenylene diisocyanates; alicyclic diisocyanates; aromatic triisocyanates;
The isocyanate group-terminated prepolymer can be obtained by reacting an organic polyisocyanate or a modified product thereof with a low-molecular-weight polyol or the like. The isocyanate group-containing compound is preferably a compound having three isocyanate groups.
Also included are compounds that generate isocyanate groups by pretreatment such as heat treatment, light treatment, acid treatment, base treatment, and the like, represented by blocked isocyanate compounds.

Amino group, quaternary ammonium salt-containing compounds, for example, diamines such as hydrazides, carbodihydrazides, thiocarbohydrazides, oxalyl dihydrazides;
ethylenediamine, 1,3-propanediamine, 1,2-propanediamine, 1,4-butanediamine, 1,6-hexamethylenediamine, 1,8-octamethylenediamine, 1,11-diaminoundecane, 1,12- Diaminododecane, 2-butyl-2-ethyl-1,5-pentanediamine, 1,5-diamino-2-methylpentane, 2,2-dimethyl-1,3-propanediamine, 2,4,4-trimethyl- 1,6-diaminohexane, lauryl propylene diamine, ethylene glycol bis(2-aminoethyl) ether, 1,4-butanediol bis(3-aminopropyl) ether, 1,13-diamino-4,7,10-trio xatridecane, polyoxypropylenediamine, methanetriamine, 1,2,3-propanetriamine, 1,8-diamino-4-aminomethyloctane, 3-(2-aminoethyl)pentane-1,5-diamine, 1 ,4,7-triaminocyclononane-1,4,7-triide, butane-1,1,4,4-tetraamine, 2,4-dimethyl-4-ethylamino-2,3,5-triaminohexane , 2,3-bis(diaminomethyl)butane-1,1,4,4-tetramine, 1,2-bis(methylamino)ethane, 2,5-diamino-2,5-dimethylhexane, butane-1, 1,4-trimethylamine, butane-1,1,4,4-tetramethylamine, 1,2-bis(dimethylamino)ethane, butane-1,1,4-tridimethylamine, butane-1,1,4 , 4-tetradimethylamine, hexamethylenetetramine, diethylenetriamine, dipropylenetriamine, bishexamethylenetriamine, triethylenetetramine, adipic acid dihydrazide, succinic acid dihydrazide, sebacic acid dihydrazide, eicosandioic acid dihydrazide, valine dihydrazide, tetraethylene penta amine, 3,3′-diamino-N-methyldipropylamine, tris(2-aminoethyl)amine, tris(4-aminoethyl)amine, 3,3′-diamino-N-methyldipropylamine, tris( alkylenediamines such as 2-aminoethyl)amine, tris(4-aminoethyl)amine, 1-methylamino-2-dimethylaminoethane, linear polyethyleneimine, branched polyethyleneimine;
1,2-cyclohexanediamine, 1,4-cyclohexanediamine, isophoronediamine, 1,3-bis(aminomethyl)cyclohexane, 3(4),8(9)-bis(aminomethyl)tricyclo[5.2.1 .0 ^2,6 ]decane (TCD diamine), isopropyl-2,4-diaminocyclohexane, isopropyl-2,6-diaminocyclohexane, 4,4′-methylenebis(cyclohexylamine), 4,4′-methylenebis(2- methylcyclohexylamine), adamantane-1,3-diamine, cyclohexane-1,3,5-triamine, 2,3,5-triaminobicyclo[2.2.1]heptane, piperazine, 2,5-dimethylpiperazine, Alicyclic diamines such as N-cyclohexyl-1,3-propanediamine;
o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 2,4-toluenediamine, 2,6-toluenediamine, 2,2'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 4,4'- Diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfone, xylylenediamine, tris(4-aminophenyl)methane, 1,2,4-benzenetriamine, melamine, benzene-1,2,4,5-tetramine, pyrimidine- aromatic ring diamines such as 2,4,5,6-tetraamine, 3,3′-diaminobenzidine, tetraaminophthalocyanine, and isophthalic dihydrazide;
Quaternary ammonium salt-containing compounds such as butane-1,4-bisammonium chloride are included.

Aziridinyl group-containing compounds include, for example, N,N'-diphenylmethane-4,4'-bis(1-aziridine carboxysite), N,N'-toluene-2,4-bis(1-aziridine carboxysite), bis isophthaloyl-1-(2-methylaziridine), tri-1-aziridinylphosphine oxide, N,N'-hexamethylene-1,6-bis(1-aziridinecarboxysite), 2,2'-bis hydroxymethylbutanol-tris[3-(1-aziridinyl)propionate], trimethylolpropane tri-β-aziridinylpropionate, tetramethylolmethane tri-β-aziridinylpropionate, tris-2,4, 6-(1-aziridinyl)-1,3,5-triazine, 4,4′-bis(ethyleneiminocarbonylamino)diphenylmethane and the like.

Examples of carbodiimide group-containing compounds include high-molecular-weight polycarbodiimides produced by subjecting a diisocyanate compound to a decarboxylation condensation reaction in the presence of a carbodiimidation catalyst. Examples of commercial products of high-molecular-weight polycarbodiimide include the Carbodilite series manufactured by Nisshinbo Co., Ltd., and the like.

The oxazoline group-containing compound is, for example, a compound in which two or more, preferably 2 to 3, oxazoline groups are bonded to an aliphatic group or an aromatic group, 2,2-bis(2-oxazoline), 1,3-phenylene Examples include bisoxazoline compounds such as bisoxazoline and 1,3-benzobisoxazoline, terminal oxazoline group-containing compounds obtained by reacting these compounds with polybasic carboxylic acids, and the like.

Among these, epoxy group-containing compounds are preferred, and ethylene glycol diglycidyl ether, trimethylolpropane polyglycidyl ether, glycerol polyglycidyl ether, polyglycerol polyglycidyl ether, neopentyl glycol diglycidyl ether, diglycidyl orthophthalate, sorbitol polyglycidyl ether. , resorcinol diglycidyl ether and hydrogenated bisphenol A diglycidyl ether are preferred, and trimethylolpropane polyglycidyl ether is more preferred. From the viewpoint of cross-linking efficiency, the cross-linking agent (E) is preferably moderately soluble in water. The solubility is preferably 0.1 to 50 g, more preferably 0.2 to 40 g, more preferably 0.5 to 30 g when the cross-linking agent is dissolved in 100 g of water at 25°C. Commercially available products include Denacol EX321 manufactured by Nagase ChemteX Co., Ltd., and ADEKA Glycyrol ED-505 manufactured by ADEKA.

<Other additives>
The aqueous colorant dispersion of the present invention can contain other additives. Additives include, for example, acidic compounds, basic compounds, cross-linking agents, sugars, binder resins, surfactants, antiseptic and antifungal agents, chelating agents, rust inhibitors, antioxidants, ultraviolet absorbers, oxygen absorbers, Light stabilizers, dye derivatives and the like can be mentioned.

[Acidic compound]
Acidic compounds can be used to adjust the pH of the dispersion. Examples of acidic compounds include inorganic acids and organic acids.
Examples of inorganic acids include hydrochloric acid, sulfuric acid, phosphoric acid, phosphorous acid, phosphonous acid, phosphinic acid, phosphine, nitric acid;
Organic acids include formic acid, acetic acid, citric acid, oxalic acid, malic acid, benzenesulfonic acid; and the like.

[Sugars]
Various conventionally known sugars can be used as sugars. Since the saccharide has a polar group, it can be adsorbed on the surface of the colorant to suppress the aggregation of the colorants. Moreover, in the case of polysaccharides, in addition to the effect of the polar group, the steric hindrance effect due to the three-dimensional structure can suppress the aggregation of the colorants.

Sugars are, for example, monosaccharides such as glycerylaldehyde, threose, xylose, glucose, mannose, galactose;
disaccharides such as sucrose, lactulose, lactose, maltose, trehalose, cellobiose;
Amylose, amylopectin, glycogen, cellulose, methylcellulose, ethylcellulose, carboxymethylcellulose, hydroxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, methylhydroxyethylcellulose, methylhydroxypropylcellulose, cellulose nanofibers, cellulose nanocrystals, cellulose nanowhiskers, TEMPO oxidized cellulose nano Polysaccharides such as fiber, chitin, galrageenan, alginic acid, heparin, hyaluronic acid, pectin, xanthan gum, tamarind seed gum, locust bean gum, gellan gum, guar gum, gum arabic, agar, karaya gum, succinoglycan, dextrin; .

Commercially available products include Sunrose APP-84, A02SH, A01MC, F04HC, A20SH, SN30C, F120MC, F350HC, F1000LC (carboxymethyl cellulose) manufactured by Nippon Paper Industries Co., Ltd.; Hard SL, (methyl cellulose), Nisshin Kasei Ethocel STD, MED (ethyl cellulose), Unitech Foods Heat Gel Soft, Soft L, Soft SL, Soft, Soft L, Soft MH (methyl hydroxypropyl cellulose), Sumitomo Seika AL-15, AL-15F, A-15F, AH-15F, AV-15F, AW-15F, AX-15, SW-25F, SZ-25F, CF-G, CF-V, CF-W, CF-X, CF-Y (hydroxyethyl cellulose) and the like.

[Binder resin]
The aqueous colorant dispersion of the present invention can contain a binder resin. Examples of binder resins include acrylic resins, olefin resins, ester resins, ether resins, urethane resins, and the like. In terms of solubility in water, binder resins include water-soluble resins and water-insoluble resins. The water-insoluble resin includes emulsions and resin particles.

The content of the binder resin is preferably 2 to 30% by mass, more preferably 3 to 20% by mass, based on 100% by mass of the non-volatile content of the dispersion.

The aqueous colorant dispersion of the present invention can contain other additives described below.

[Surfactant]
Surfactants include anionic surfactants, cationic surfactants, nonionic surfactants, amphoteric surfactants and the like.

[Anionic surfactant]
Anionic surfactants include fatty acid salts, alkyl sulfates, alkyl aryl sulfonates, alkyl naphthalene sulfonates, dialkyl sulfonates, dialkyl sulfosuccinates, alkyl diaryl ether disulfonates, alkyl phosphates, poly Oxyethylene alkyl ether sulfates, polyoxyethylene alkyl aryl ether sulfates, polyoxyethylene alkyl ether acetates, alkylbenzene sulfonates (e.g. NH4 _, Na, Ca, etc.), alkyldiphenyl ether disulfonates (e.g. _NH4 , Na , Ca, etc.), naphthalene sulfonic acid formalin condensate and its salts, dialkyl succinate sulfonic acid Na salt, polyoxyethylene alkyl phosphate ester salt, glycerol borate fatty acid ester, polyoxyethylene glycerol fatty acid ester, polyoxyethylene poly ring phenyl ether sulfate (e.g., NH ₄ , Na, etc.), laurate, polyoxyethylene alkyl ether sulfate, oleate, perfluoroalkylsulfonic acid, perfluoroalkylsulfonate, perfluoroalkylcarboxylic acid, Perfluoroalkyl carboxylates, perfluoroalkyl phosphates, salts of perfluoroalkyl phosphates, polyoxyalkylene ether polymers having perfluoroalkyl ether groups in side chains, polyoxyalkylene ethers having perfluoroalkyl ether groups in side chains Sulfuric acid ester salts of oxyalkylene ether polymers, salts of polyoxyalkylene ether polymers having perfluoroalkyl ether groups in side chains, and the like. Counterions in the salts _of these fluorosurfactants are, for example, LI, Na, K, _{NH4 , NH3CH2CH2OH , NH2 ( CH2CH2OH} ) ₂ , NH( _CH2CH2OH ) ₃ and the like.

[Cationic surfactant]
Cationic surfactants include alkylamine salts, quaternary ammonium salts, alkylpyridinium salts, alkylimidazolium salts and the like.

[Nonionic surfactant]
Nonionic surfactants include, for example, polyoxyethylene alkyl ethers, polyoxyalkylene alkyl ethers, polyoxyethylene alkylaryl ethers, polyoxyethyleneoxypropylene block copolymers, polyoxyethylene polycyclic phenyl ethers, sorbitan fatty acid esters, polyoxy Ethylene sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, glycerin fatty acid ester, polyoxyethylene alkylphenyl ether, polyoxyethylene alkylamine, polyoxyethylene alkylamide, polyoxyethylene fatty acid ester, acetylene glycol, polyoxyethylene alkylamine, Examples include nonionic surfactants such as fluorine-based and silicone-based surfactants. In particular, acetylene glycol-based surfactants are 5-dimethyl-1-hexyn-3-ol and the like. Examples of commercially available acetylene glycol-based surfactants include Surfynol 104, 82, 465, 485, TG and DF110D manufactured by Air Products (USA).

Fluorinated surfactants can also be used. For example, Surflon S-111, S-112, S-113, S-121, S-131, S-132, S-141, S-145 (all manufactured by AGC), Flurard FC-93, FC-95 , FC-98, FC-129, FC-135, FC-170C, FC-430, FC-431 (all manufactured by Sumitomo 3M), Megafac F-470, F1405, F-474 (all manufactured by DIC ), ZonylTBS, FSP, FSA, FSN-100, FSN, FSO-100, FSO, FS-300, UR (all manufactured by DuPont), FT-110, FT-250, FT-251, FT-400S, FT -150, FT-400SW (all manufactured by Neos), PF-151N (manufactured by Omnova), and the like.

[Amphoionic Surfactant]
Amphoteric surfactants include alkylbetaines, alkylamine oxides, phosphatidylcholines and the like. For example, laurylaminopropionate, lauryldimethylbetaine, stearyldimethylbetaine, lauryldihydroxyethylbetaine, lauryldimethylamine oxide, myristyldimethylamine oxide, stearyldimethylamine oxide, dihydroxyethyllaurylamine oxide, polyoxyethylene coconut alkyldimethylamine. oxide, coconut oil alkylbetaine, dimethyllaurylbetaine and the like.

[Preservative and antifungal agent]
Examples of antiseptic and antifungal agents include sodium dehydroacetate, sodium sorbate, sodium 2-pyridinethiol-1-oxide, sodium benzoate, sodium pentachlorophenol, methylisothiazolinone, and benzisothiazolinone.

[Chelating agent]
Chelating agents include, for example, sodium ethylenediaminetetraacetate, sodium nitrilotriacetate, sodium hydroxyethylethylenediaminetriacetate, sodium diethylenetriaminepentaacetate, sodium uramil diacetate and the like.

[anti-rust]
Rust inhibitors include, for example, acid sulfite, sodium thiosulfate, ammonium thiodiglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, dicyclohexylammonium nitrite, benzotriazole and the like.

[Antioxidant]
Antioxidants include, for example, phenol antioxidants (including hindered phenol antioxidants), amine antioxidants, sulfur antioxidants, phosphorus antioxidants, and the like.
Phenolic antioxidants include, for example, butylated hydroxyanisole, 2,6-di-tert-butyl-4-ethylphenol, stearyl-β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate , 2,2-methylenebis(4-methyl-6-tert-butylphenol), 2,2-methylenebis(4-ethyl-6-tert-butylphenol), 4,4-butylidenebis(3-methyl-6-tert-butylphenol ), 3,9-bis[1,1-dimethyl-2-[β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl]2,4,8,10-tetraiki Suspiro[5,5]undecane, 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris ( 3,5-di-tert-butyl-4-hydroxybenzyl)benzene, tetrakis[methylene-3-(3′,5′-di-tert-butyl-4′-hydroxyphenyl)propionate]methane and the like.
Amine antioxidants include, for example, phenyl-β-naphthylamine, α-naphthylamine, N,N-di-sec-butyl-p-phenylenediamine, phenothiazine, N,N-diphenyl-p-phenylenediamine, 2,6 -di-tert-butyl-p-cresol, 2,6-di-tert-butylphenol, 2,4-dimethyl-6-tert-butyl-phenol, butylhydroxyanisole, 2,2-methylenebis(4-methyl-6 -tert-butylphenol), 4,4-butylidenebis(3-methyl-6-tert-butylphenol), 4,4-thiobis(3-methyl-6-tert-butylphenol), tetrakis[methylene-3(3,5- di-tert-butyl-4-dihydroxyphenyl)propionate]methane, 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane and the like.
Sulfur antioxidants include, for example, dilauryl 3,3-thiodipropionate, distearyl thiodipropionate, lauryl stearyl thiodipropionate, dimyristyl-3,3-thiodipropionate, distearyl-β,β -thiodipropionate, 2-mercaptobenzimidazole, dilauryl sulfide and the like.
Phosphorus antioxidants include triphenylphosphite, octadecylphosphite, triisodecylphosphite, trilauryltrithiophosphite, trinonylphenylphosphite and the like.

[Ultraviolet absorber]
Examples of the ultraviolet absorber include benzophenone-based ultraviolet absorbers, benzotriazole-based ultraviolet absorbers, salicylate-based ultraviolet absorbers, cyanoacrylate-based ultraviolet absorbers, and nickel complex salt-based ultraviolet absorbers.
Benzophenone UV absorbers include, for example, 2-hydroxy-4-n-octoxybenzophenone, 2-hydroxy-4-n-dodecyloxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2 , 2,4,4-tetrahydroxybenzophenone and the like.
Benzotriazole-based UV absorbers include, for example, 2-(2′-hydroxy-5′-tert-octylphenyl)benzotriazole, 2-(2′-hydroxy-5′-methylphenyl)benzotriazole, 2-(2 '-hydroxy-4'-octoxyphenyl)benzotriazole, 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole and the like.
Salicylate-based ultraviolet absorbers include, for example, phenyl salicylate, p-tert-butylphenyl salicylate, p-octylphenyl salicylate and the like.
Cyanoacrylate UV absorbers include, for example, ethyl-2-cyano-3,3'-diphenyl acrylate, methyl-2-cyano-3-methyl-3-(p-methoxyphenyl) acrylate, butyl-2-cyano- 3-methyl-3-(p-methoxyphenyl)acrylate and the like.
Examples of nickel complex ultraviolet absorbers include nickel bis(octylphenyl) sulfide, 2,2-thiobis(4-tert-octylferrate)-n-butylamine nickel (II), 2,2-thiobis(4-tert -octylferrate)-2-ethylhexylamine nickel (II), 2,2-thiobis(4-tert-octylferrate)triethanolamine nickel (II), and the like.

[Dye derivative]
A dye derivative can be added to the aqueous pigment dispersion of the present invention, if necessary.

A dye derivative is a compound having an acidic group, a basic group, a neutral group, or the like in an organic dye residue. Dye derivatives include, for example, compounds having an acidic substituent such as a sulfo group, a carboxy group, and a phosphoric acid group, amine salts thereof, compounds having a basic substituent such as a sulfonamide group or a terminal tertiary amino group A compound having a neutral substituent such as a phenyl group or a phthalimidoalkyl group can be mentioned.
Organic dyes include, for example, diketopyrrolopyrrole pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, perinone pigments, perylene pigments, thiazineindigo pigments, triazine pigments, benzimidazolone pigments, benzoiso Indole pigments such as indole, isoindoline pigments, isoindolinone pigments, quinophthalone pigments, naphthol pigments, threne pigments, metal complex pigments, azo pigments such as azo, disazo and polyazo. .

Other additives can be used alone or in combination of two or more.

<Production of water-based colorant dispersion>
The method for producing an aqueous colorant dispersion of the present invention preferably includes the following steps.
Step I: Step of coating resin (B) and resin (C) on the surface of colorant (A) particles Step II: Step of adding aqueous medium (E) and mixing and stirring

[Process I]
As the step of coating the surface of the colorant (A) particles with the resin (B) and the resin (C), a conventionally known production method can be employed. A salt milling method is preferred, which allows coating of B) and resin (C).

[Salt milling method]
The salt milling method preferably has the following steps.
Step I-1: A step of adding at least a water-soluble inorganic salt and a water-soluble organic solvent to the colorant (A), the resin (B) and the resin (C), and grinding and kneading Step I-2: a water-soluble inorganic salt and Process for removing water-soluble organic solvent

The manufacturing method is particularly effective when the colorant is an organic pigment.

First, a step of mixing the colorant (A), the resin (B) and the resin (C), the water-soluble inorganic salt and the water-soluble organic solvent with a kneader (salt milling treatment) is performed (step I-1), and the water-soluble It is preferable to carry out a step of washing to remove the inorganic salt and the water-soluble organic solvent (washing treatment) (step I-2).

The salt milling treatment is a mixture of a pigment, a water-soluble inorganic salt, and a water-soluble organic solvent, for example, a kneader, a trimix, a two-roll mill, a three-roll mill, a ball mill, an attritor, a sand mill, or a planetary mixer. After mechanically kneading with heating using a batch or continuous kneader, the mixture is washed with water to remove water-soluble inorganic salts and water-soluble organic solvents. The water-soluble inorganic salt acts as a grinding aid and the water-soluble organic solvent acts as a particle growth agent. During salt milling, the high hardness of the inorganic salt is used to crush the primary particles of the pigment. Also, the primary particles of the pigment grow when it comes into contact with a water-soluble organic solvent. By optimizing the conditions for the salt milling process of the pigment, this crushing and growth are repeated, resulting in a pigment with an extremely fine primary particle size and a narrow distribution width, with a sharp particle size distribution. Obtainable. In addition, as for the shape of the primary particles, since the crushing and growth of the primary particles are repeated uniformly from all directions, the primary particles do not have a flat particle shape and are nearly spherical.

The kneading temperature during salt milling is preferably -10°C to 300°C, more preferably 30°C to 90°C. By performing salt milling at an appropriate temperature, the primary particles of the colorant (A) can be refined and the resin (B) or resin (C) can coat the colorant particles.

The kneading time during salt milling is preferably 0.1 to 100 hours, more preferably 3 to 24 hours. By performing salt milling for an appropriate kneading time, the primary particles of the pigment can be made finer, and the resin (B) or resin (C) can coat the colorant (A) particles. The instantaneous electric power representing the load applied during kneading can be arbitrarily set by adjusting the kneading speed of the kneader, the viscosity of the mixture of the coloring agent (A), the water-soluble inorganic salt, and the water-soluble organic solvent. Part of resin (B) and resin (C) may exist as free resin. The amount of free resin is about 0.01 to 30% by mass based on the total amount of resin (B) and resin (C).

[Water-soluble inorganic salt]
Examples of water-soluble inorganic salts include sodium chloride, barium chloride, potassium chloride, sodium sulfate and the like. Sodium chloride (salt) is preferred from the point of view of price. The amount of the water-soluble inorganic salt (X) to be used is preferably 50 to 2,000 parts by mass, more preferably 300 to 1,000 parts by mass, based on 100 parts by mass of the pigment, in terms of both processing efficiency and production efficiency. The particle size of the water-soluble inorganic salt is preferably 0.001-100 μm, more preferably 0.1-10 μm. In addition, since sodium chloride used industrially is sometimes produced from natural products such as seawater, impurities such as potassium chloride, calcium chloride, magnesium chloride, calcium sulfate, magnesium sulfate, etc. May contain.

[Water-soluble organic solvent]
The water-soluble organic solvent is preferably the polyhydric alcohols described above. The amount of the water-soluble organic solvent used is preferably 5 to 1,000 parts by mass, more preferably 50 to 500 parts by mass, based on 100 parts by mass of the pigment. By appropriately selecting the amount of the water-soluble organic solvent used, the kneaded material can be made to have a viscosity suitable for the salt milling treatment.

In the washing treatment, a mixture containing the coloring agent (A), the resin (B) or the resin (C), the water-soluble inorganic salt, and the water-soluble organic solvent is taken out from the grinding kneader, the solvent is added, and the mixture is stirred. to obtain a suspension. The type of solvent to be added is not particularly limited as long as it can dissolve the water-soluble inorganic salt and the water-soluble organic solvent, but tap water, acid aqueous solution such as hydrochloric acid aqueous solution, and ion-exchanged water are preferable. The amount of solvent to be added is not particularly limited as long as it is sufficient to obtain a suspension. For example, 10 to 10,000 times the mass of the solvent is added and mixed with stirring. It may be warmed if necessary. The mixing and stirring conditions at this time are not particularly limited, but the temperature is preferably 5 to 100°C. Subsequently, by removing the filtrate by an operation such as filtration, the water-soluble inorganic salt and water-soluble organic solvent used in the kneader can be removed, and the coloring agent (A) and the resin (B) or resin A pigment composition containing (C) can be obtained.

After the washing treatment, a step of removing the solvent may be performed. Suitable methods include, for example, a method of performing a drying treatment. Drying conditions include, for example, a method of drying under normal pressure in the range of 80 to 120°C for about 12 to 48 hours, and a method of drying in the range of -180 to 80°C under reduced pressure for about 12 to 60 hours. mentioned. Although the drying treatment is not particularly limited, a method using a spray drying device is also included. The pulverization treatment may be performed simultaneously with the drying treatment or after the drying treatment.

As for the average primary particle size of the colorant (A), the average primary particle size of the colorant before salt milling is preferably about 10 nm to 10,000 nm, and the average primary particle size of the colorant after salt milling is about 5 nm to 200 nm. It is preferable that the average primary particle size of the colorant before salt milling>the average primary particle size of the colorant after salt milling. A smaller average primary particle size is preferable because it improves coloring power and transparency. The average primary particle size can be determined by arithmetically averaging the major diameters of 100 pigment primary particles extracted from a plurality of photographs taken with a transmission electron microscope at a magnification of 10,000. The aspect ratio obtained by dividing the major axis by the minor axis of the primary particles is preferably 1.0 to 5.0, more preferably 1.0 to 3.0. When used as an inkjet ink, the average primary particle size after salt milling is preferably 100 nm or less, preferably 60 nm or less.

[Step II]
Next, a step of adding the solvent (E) and the basic compound (D) to the washed colorant composition and mixing the mixture while heating or cooling as necessary (step II). Mixing devices include, for example, high-speed mixers, homogenizers, high-pressure homogenizers, Silverson mixers, planetary mixers, trimixes, kneaders, extruders, horizontal sand mills, vertical sand mills or/and annular bead mills, paint shakers, ball mills, ultra A disperser equipped with a sonic oscillator, a high-pressure disperser, an opposing impingement disperser, an oblique impingement disperser, a batch rotor-stator, an in-line rotor-stator, a two-roll mill, a three-roll mill, and the like. Through these steps, aggregates of pigment particles are crushed to the level of primary particles, and an aqueous colorant dispersion can be produced.

Mixing devices include, for example, Powrex Microfluidizer (interaction chamber: Z type, Y type), Sugino Machine Star Burst (chamber shape: oblique collision chamber, ball collision chamber, separation chamber, single nozzle chamber, Slit type chamber, circulating cooling type chamber, multi-liquid injection reaction chamber), Ashizawa Finetech Starmill LMZ (bead mill), Asada Iron Works Pikomill, Silverson in-line high shear mixer (rotor stator), Silverson A batch mixer (rotor stator) manufactured by Co., Ltd., etc., can be appropriately selected according to the desired physical properties.

Process II may be processed by combining a plurality of devices. It is preferable to use a plurality of devices because the number of coarse particles can be reduced and an ink having a sharper particle size distribution can be obtained. For example, the following combinations are preferred.
- A method of mixing using an in-line high shear mixer (rotor stator) manufactured by Silverson, and further mixing using a starburst (oblique collision chamber) manufactured by Sugino Machine.
・A method of mixing using a batch mixer (rotor stator) manufactured by Silverson and further mixing using a starburst (oblique collision chamber) manufactured by Sugino Machine,
- A method of mixing using Starmill LMZ (bead mill) manufactured by Ashizawa Finetech, and further mixing using Starburst (oblique collision chamber) manufactured by Sugino Machine.
- A method of mixing using a Star Burst (oblique collision chamber) manufactured by Sugino Machine Co., Ltd. and further mixing using a Star Mill LMZ (bead mill) manufactured by Ashizawa Fine Tech.

In step II, a basic compound (D) can be added. It is particularly preferred that the resin (B) and the resin (C) have acid group-containing monomer units such as carboxy groups and phosphoric acid groups. Addition of a basic compound neutralizes acid groups and stabilizes the dispersion system by charge repulsion, which is preferable. Moreover, reactivity with a cross-linking agent (F), which will be described later, may be generated in some cases. The basic compound is preferably added in an amount of 0.1 to 2.0 equivalents, more preferably 0.4 to 1.5 equivalents, relative to the acid group.

In step II, the cross-linking agent (F) described above can be added. When the resin (B) and the resin (C) have a functional group capable of reacting with the cross-linking agent (F), the cross-linking reaction forms a strong three-dimensional structure on the surface of the colorant particles, resulting in severe temperature fluctuations. It is preferable because the viscosity stability is improved even in the environment, and the ejection stability is improved when used as an ink for inkjet recording. The temperature at which the cross-linking agent (F) is added can be arbitrarily selected according to the reactivity of the cross-linking agent. For example, a method of adding and stirring the cross-linking agent (F) at a temperature below the reaction temperature of the cross-linking agent (F) and the resin (B) and the resin (C) and then raising the temperature above the reaction temperature; and a method of adding the cross-linking agent (F) at a reaction temperature of the resin (B) and the resin (C) or higher.

After completion of the reaction, if the pH needs to be adjusted, the above-described acidic compound or basic compound (D) can be added to adjust to the desired pH. Specific examples of the acidic compound include inorganic acids such as phosphoric acid, hydrochloric acid, sulfuric acid and nitric acid, and organic acids such as acetic acid and citric acid. Specific examples of basic compounds include inorganic bases such as sodium hydroxide and potassium hydroxide, and organic bases such as dimethylaminoethanol, dibutylaminopropanol and triethanolamine. It is particularly preferable if the resin (B) has an acid group-containing monomer unit such as a carboxy group or a phosphoric acid group. Addition of a basic compound neutralizes acid groups and stabilizes the dispersion system by charge repulsion, which is preferable. In addition, an aqueous medium (E) may be added in order to adjust the non-volatile content.

The pH of the water-based colorant dispersion after pH adjustment is preferably 7 to 10, more preferably 7.1 to 9.5.

The obtained water-based pigment dispersion is preferably subjected to filtering, centrifugal separation, removal of magnetic foreign matter by a magnetic filter, and removal of impurity ions by a cation exchange resin, an anion exchange resin, a chelating agent, or the like. Coarse particles can be removed by filtration or centrifugation, magnetic foreign matter is removed by a magnetic filter, and impurity ions such as calcium ions and magnesium ions are removed by an ion exchange resin, etc., making it possible to use it as an inkjet ink. Ejectability is improved when the Filtration, centrifugation, removal of magnetic contaminants by magnetic filters, removal of impurity ions by ion exchange resins, etc., can employ any of the conventionally known methods, but for filtration, membrane filters, depth filters, ultrafiltration filters, etc. can do. The mesh size of the filter is preferably 0.1 μm to 10 μm. A cylindrical centrifuge, a basket-type centrifuge, or the like can be used for centrifugation. Magnet filters include a high-gradient magnetic separator CS-X manufactured by Nippon Magnetics Co., Ltd., a mag catch filter MGCF-100 and MGCF-125 manufactured by Maeda Shell Service Co., Ltd., a high-efficiency mag filter manufactured by Eishin (1.0T to 1.35T), A high magnetic force mag filter (1.7 T) or the like can be employed. Impurity ions can be removed by the methods described in, for example, JP-A-2002-179961 and JP-A-2003-277672.

The volume average particle diameter D50 of the colorant (A) contained in the aqueous colorant dispersion is preferably 5 nm to 200 nm. Within the above range, the colorant (A) in the water-based colorant dispersion has less aggregation and is dispersed down to the primary particle level, and coloring power and transparency are improved, which is preferable. The volume-average particle size D50 of the colorant (A) in the ink is obtained from the volume-based particle size distribution measured using FPAR-1000 manufactured by Otsuka Electronics Co., Ltd. As an inkjet ink, the volume average particle diameter D50 is preferably 10 to 150 nm, more preferably 30 to 90 nm.

The average circularity of the particles containing the colorant (A) contained in the resulting aqueous colorant dispersion is preferably about 0.60 to 1.00. When the average circularity value increases, the particle shape becomes almost spherical, and when the ink is made into ink, the contact between the primary particles of the colorant tends to be point contact, and the contact area decreases, which reduces the viscosity. preferable. The average circularity is obtained by calculating the peripheral length and area of the primary particles of 100 primary particles of the colorant extracted from a plurality of photographs taken with a transmission electron microscope at a magnification of 10,000, and using the following formula. It can be obtained by arithmetically averaging the obtained circularity. Since the average circularity represents the shape of the pigment particles when viewed from above, the three-dimensional shape of the colorant particles is not directly observed. As described above, in the salt milling method, the pigment particles are uniformly crushed and grown repeatedly from all directions, so the primary particles are not flattened and are nearly spherical, so the arithmetic average of 100 colorant particles is By doing so, the three-dimensional shape of the pigment particles can be obtained approximately.
Circularity = 4π × (area) ÷ (perimeter) ^ 2

In addition to the above-described production method, the phase inversion emulsification method described in [0025] to [0029] of JP-A-2020-143201, and the specification [0034] of JP-A-2018-028080 Colorant (A ) can be coated with resin (B) and resin (C).

<Other additives>
The water-based colorant dispersion of the present invention can contain the additives described above. Examples of additives include basic compounds, surfactants, antiseptic and antifungal agents, chelating agents, rust inhibitors, antioxidants, ultraviolet absorbers, oxygen absorbers, light stabilizers and the like.

<Application of composition>
The water-based colorant dispersion of the present invention is preferably used for inks, conductive material compositions, and the like. Inks include letterpress printing inks used in letterpress printing, flexo printing, etc., intaglio printing inks used in gravure printing, etc., lithographic printing inks used in offset printing, etc., stencil printing inks used in screen printing, etc., inkjet printing, static Ink for on-demand printing used for charge development toner printing, and the like. Examples of the conductive material composition include electrode members for secondary batteries such as lithium ion batteries. Other applications include paints for building materials and automobiles, inks for writing instruments, color filters, solid-state imaging devices, and sensors such as LIDAR.
Among these, the ink for inkjet recording used for inkjet printing is preferable.

<Ink for inkjet recording>
The inkjet recording ink of the present invention contains an aqueous colorant dispersion. The ink for inkjet recording can contain a water-soluble organic solvent that is miscible with water as an optional component. As the water-soluble organic solvent, the water-based medium already described can be used. Among these, polyhydric alcohols or polyhydric alcohol alkyl ethers are preferred. These solvents are very fast in penetrating into the base material, and can also quickly penetrate low liquid-absorbing base materials such as coated paper and art paper. Therefore, it dries quickly during printing, and accurate printing can be achieved. In addition, since it has a high boiling point, it works well as a wetting agent.

A water-soluble organic solvent can be used individually or in combination of 2 or more types.

The content of the water-soluble organic solvent is preferably 3 to 60% by mass, more preferably 3 to 50% by mass, in the ink for inkjet recording. The total content of the water-soluble organic solvent and water is preferably 10 to 95% by mass, more preferably 30 to 80% by mass, in the ink for inkjet recording.

The ink for inkjet recording of the present invention can contain additives such as the above-described binder resin as other additives.

Impurity ions are preferably removed from the ink for inkjet recording by filtration, centrifugation, magnetic separation using a magnet filter, cation exchange resin, anion exchange resin, chelating agent, or the like. As a result, the ejection property from the ink jet printer is improved. For filtration, centrifugation, magnetic filters, cation exchange resins, anion exchange resins, chelating agents, etc., the materials already described can be used.

The inkjet recording ink can be suitably used for various inkjet printers. Examples of the ink ejection method of an inkjet printer include a charge control method, a continuous ejection method such as a spray method, a piezo method, a thermal method, an electrostatic attraction method, and the like. The printing methods of inkjet printers include, for example, a multi-pass method (serial head method) in which printing is performed on a base material while reciprocating the inkjet head left and right, and a single-pass method (line head method) in which printing is performed with the inkjet head fixed. are mentioned.

<Ink set>
The inkjet recording ink can be an ink set containing two or more colors of inkjet recording ink.
Specifically, a three-color ink set including cyan ink, magenta ink, and yellow ink is exemplified. Other examples include a so-called 4-color process color ink set that adds black to this, and an ink set that expands the color reproduction range by adding special color inks such as red ink, orange ink, and green ink. . Furthermore, an ink set with a white ink as an undercoat layer or a pretreatment liquid containing an ink-aggregating component such as calcium ions, an acidic compound, or a polymer aggregating agent may also be used.

<Image formation>
The image-formed article of the present invention has a substrate and a printing layer formed from the ink of the present invention or the ink set of the present invention.
When the ink of the present invention is used as an ink for inkjet recording and installed in an inkjet printer, for example, it can be installed as a set of cyan ink, magenta ink, yellow ink, and black ink. By mounting these 4-color ink sets called process colors together and adjusting the printing amount of each color, printed areas (images) of various hues can be formed on the base material (printing material). In addition, if necessary, inks other than process colors such as red ink and green ink can be loaded to form a printing portion (image) with higher color reproducibility. The pigment concentration, viscosity, dynamic viscoelasticity, surface tension, printing order, evaporation rate of volatile matter, etc. of each ink are design items, and can be appropriately adjusted according to desired characteristics. The thickness of the image layer is preferably 0.01 μm to 1 cm. In printing on the base material, the coating may be performed with the base material horizontal or vertical.

[Base material]
The inks of the present invention can be printed on various substrates. Substrates include plain paper, fabric, highly absorbent substrates such as knits, art paper, coated paper, vinyl chloride, natural leather, artificial leather, synthetic leather, wood, concrete, egg shells, tablets, food, polyethylene film, Low water-absorbing substrates such as polypropylene films and polyethylene terephthalate films, and non-water-absorbing substrates such as metals (aluminum, stainless steel, copper, nickel, titanium, etc.) and glass. The substrate may be smooth, uneven, flat, or curved. The thickness of the substrate is preferably 0.01 mm to 1 cm. If it is a base material used for building materials, etc., it is preferably 1 cm to 1 m.

EXAMPLES The present invention will be specifically described below by way of examples, but the present invention is not limited to the examples. In addition, "part" is a mass part and "%" is the mass % unless there is particular notice. Also, NV means nonvolatile content.

Abbreviations and product names in the examples mean the following.
MALAH: maleic anhydride MAA: methacrylic acid MMA: methyl methacrylate St: styrene AS-6: Toagosei Co., Ltd. styrene macromer (number average molecular weight 6,000)
PEMA: Phenoxyethyl methacrylate LA: Lauryl acrylate VI: Vinylimidazole light acrylate 130A: Methoxypolyethylene glycol acrylate manufactured by Kyoeisha Chemical Co., Ltd.
Monomer 1: Formula (2) below, m = 6 to 14 (average 10), n = 0, R = methyl group Monomer 2: Formula (2) below, m = 0, n = 6 to 14 (average 10), R = methyl group monomer 3: formula (2) below, m = 4 to 12 (average 8), n = 0 to 6 (average 2), R = methyl group monomer 4: formula (2) below, m = 10 ~ 20 (average 15), n = 0, R = n-butyl group monomer 5: the following formula (2), m = 0, n = 10 to 20 (average 15), R = n-butyl group monomer 6: the following formula (2), m = 0 to 8 (average 3), n = 6 to 18 (average 12), R = n-butyl group monomer 7: the following formula (2), m = 15 to 25 (average 20), n = 0, R = n-hexyl group monomer 8: formula (2) below, m = 0, n = 15 to 25 (average 20), R = n-hexyl group monomer 9: formula (2) below, m = 5 ~15 (average 10), n = 5-10 (average 10), R = n-hexyl group Note that the C ₂ H ₄ O group (ethylene oxide group) and the C ₃ H ₆ O group ( The order of bonding of the propylene oxide group) may be random or alternate, and the C ₂ H ₄ O group and the C ₃ H ₆ O group each form a block portion. Also good.

formula (2)

Hereinafter, a monomer having an acid value has an acid group-containing monomer unit.
Epoxy-based cross-linking agent: ADEKA ADEKA GLYCIROL ED-505 (mixture of trimethylolpropane triglycidyl ether, trimethylolpropane diglycidyl ether, and trimethylolpropane monoglycidyl ether)
MEK: methyl ethyl ketone MeOH: methanol IPA: isopropyl alcohol Resin (C-1): Ceramer 1608 manufactured by NUCERA (maleic anhydride-maleic acid monoisopropyl ester-olefin copolymer, acid value 160 mgKOH/g)
Resin (C-2): Joncryl 611 manufactured by BASF Japan (styrene-acrylic acid copolymer, acid value 53 mgKOH/g, Mw 8,100, Tg 50° C.)
Resin (C-3): Joncryl 683 manufactured by BASF Japan (styrene-acrylic acid copolymer, acid value 165 mgKOH/g, Mw 8,000, Tg 75° C.)
Resin (C-4): Joncryl 690 manufactured by BASF Japan (styrene-acrylic acid copolymer, acid value 240 mgKOH/g, Mw 16,500, Tg 84° C.)
Resin (C-5): XIRAN3000P manufactured by Polyscope Polymers BV (styrene-maleic anhydride copolymer, acid value 285 mgKOH/g, Mw 10,000, Tg 125° C.)
Resin (C-6): SMA3000H manufactured by CrayValley (styrene-maleic acid copolymer ammonium salt aqueous solution, acid value 265-305 mgKOH/g, Mw 9,500, Tg 125°C)
Resin (C-7): Marquedo No. manufactured by Arakawa Chemical Co., Ltd. 32 (maleated rosin resin, acid value 120-140 mgKOH/g, softening point 130-140°C)
J-780: Joncryl 780 manufactured by BASF Japan (polyacrylic emulsion, NV48%)
W-5030: Mitsui Chemicals Takelac W-5030 (polyurethane emulsion, NV30%)
S-DF110D: Surfynol DF110D manufactured by Evonik Industries (acetylenic surfactant)
Proxel GXL: Preservative from Lonza (1,2-benzisothiazolin-3-one)
PG: propylene glycol BDG: butyl diglycol PB15:3: C.I. I. Pigment Blue 15:3 (RAMDEV CHEMICAL INDUSTRIES Ramafast Blue WP/L-143)
PY74: C.I. I. Pigment Yellow 74 (FAST YELLOW 7416 manufactured by Sanyo Pigment Co., Ltd.)
PY12: C.I. I. Pigment Yellow 12 (LIONOL YELLOW TCH1205 manufactured by Toyocolor Co., Ltd.)
PY14: C.I. I. Pigment Yellow 14 (DIC SYMULER FAST Yellow 4400)
PY138: C.I. I. Pigment Yellow 138 (BASF Japan PalIotol Yellow L0960HD)
PY155: C.I. I. Pigment Yellow 155 (LYSOPAC YELLOW 5513P manufactured by Cappelle Pigments NV)
PY180: C.I. I. Pigment Yellow 180 (Novoperm Yellow P-HG manufactured by Clariant Chemicals)
PR122: C.I. I. Pigment Red 122 (CInquasIa PInk K4410 manufactured by BASF Japan)
PV19: C.I. I. Pigment Violet 19 (Inkjet Magenta E5B02 manufactured by Clariant Chemicals)
PR122+PV19: C.I. I. Pigment Red 122 and C.I. I. Solid solution of Pigment Violet 19 (Chromophthal Jet Magenta 2BC manufactured by Ciba Japan)
PR31: C.I. I. Pigment Red 31 (ToshIkI Red 31N manufactured by Tokyo Shikizai Kogyo Co., Ltd.)
PR150: C.I. I. Pigment Red 150 (ToshIkI Red 150TR manufactured by Tokyo Shikizai Kogyo Co., Ltd.)
PR150+PR31: mixture of PR150 and PR31 (mixing ratio 75:25)
PR254: C.I. I. Pigment Red 254 (CInIlex DPP Red SR2P manufactured by CINIC ChemIcals)
PG36: C.I. I. Pigment Green 36 (LIONOL GREEN 8390 manufactured by Toyocolor Co., Ltd.)
PO34: C.I. I. Pigment Orange 34 (Permanent Orange RL01-MX manufactured by Clariant Chemicals)
PO43: C.I. I. Pigment Orange 43 (PV Fast Orange GRL manufactured by Clariant Chemicals)
PBk7: C.I. I. Pigment Black 7 (PRINTEX85 manufactured by Orion Engineered Carbons)

Physical properties were determined according to the following methods.

(Number average molecular weight (Mn))
Measured by gel permeation chromatography (GPC) equipped with an RI detector. HLC-8220GPC (manufactured by Tosoh Corporation) was used as the apparatus, two separation columns were connected in series, and "TSK-GEL SUPER HZM-N" was used as both packing materials, and the oven temperature was 40 ° C. , using a THF solution as an eluent, the measurement was carried out at a flow rate of 0.35 ml/min. Samples were dissolved in a solvent consisting of 1% of the above eluent and injected in 20 microliters. Molecular weight is a polystyrene conversion value.

(acid value)
The number of moles of acid groups contained in 1 g of resin was calculated from the monomer composition. The theoretical acid value (mgKOH/g) was calculated assuming that the number of moles of this acid group was equal to the number of moles of potassium hydroxide (molecular weight: 56.1) required for neutralization. It is well known that maleic anhydride contained in the acid group-containing resin (B-60) in Table 3, which will be described later, is easily hydrolyzed in an aqueous medium, particularly water, to form maleic acid. Therefore, it is considered that maleic acid, not maleic anhydride, exists in the pigment dispersion of the present invention. Therefore, the acid value of the resin containing maleic anhydride was determined on the assumption that maleic anhydride was hydrolyzed to maleic acid.

(Nonvolatile content)
The non-volatile content was determined from the loss on drying when 0.5 g of the object to be measured was accurately weighed and placed in a 180° C. dryer for 20 minutes.

・ Synthesis of resin (B-1) [first reaction]
20 parts (60 mol %) of MALAH as a monomer mixture and 30 parts (36 mol %) of 1-octadecene as an α-olefin are added to a reaction vessel equipped with a gas inlet tube, a thermometer, a condenser, a dropping funnel, and a stirrer. ), monomer 1 (4 mol %), 100 parts of MEK, and 0.5 part of octyl thioglycolate as a chain transfer agent. A mixture of 2.0 parts of dimethyl asobisisobutyrate (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd., trade name: V-601) as a radical polymerization initiator and 5 parts of MEK was added dropwise thereto over 1 hour. Thereafter, while stirring at a temperature of 85 ° C., a mixture of 5 parts of V-601 and 12 parts of MEK was added dropwise over 6 hours, and the temperature was maintained at 85 ° C. and allowed to react in a reflux state for 1 hour, resulting in an acid anhydride group. A polymer having maleic anhydride as was obtained.
[Second reaction]
Subsequently, 7 parts (60 mol %) of methanol and 0.1 part of diazabicycloundecene as a catalyst are added, and the temperature is kept at 85° C. and stirred under reflux for 6 hours for reaction to produce maleic anhydride. The acid was ring-opened and half-esterified. The resulting product was concentrated under reduced pressure to remove MEK and methanol, resin (B-1) (number average molecular weight (Mn): 4,400, weight average molecular weight (Mw): 10,500, acid value: 148 mgKOH/g ).

Synthesis of resins (B-2) to (B-17) Resin (B-2) to (B-17) were obtained. The molecular weight was adjusted appropriately by changing the amount of V-601 added. In addition, the resin that does not use maleic anhydride does not undergo the second reaction.

・ Synthesis of resin (C-8) [first reaction]
10 parts (50 mol %) of MALAH as a monomer mixture and 25 parts (50 mol %) of 1-octadecene as an α-olefin are added to a reaction vessel equipped with a gas inlet tube, a thermometer, a condenser, a dropping funnel, and a stirrer. ), 100 parts of MEK, and 0.5 part of octyl thioglycolate as a chain transfer agent were charged, and after purging with nitrogen, the mixture was heated to 105° C. while stirring. A mixture of 2.0 parts of dimethyl asobisisobutyrate (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd., trade name: V-601) as a radical polymerization initiator and 5 parts of MEK was added dropwise thereto over 1 hour. Then, while stirring in a reflux state at a temperature of 85 ° C., a mixture of 5 parts of V-601 and 12 parts of MEK was added dropwise over 6 hours, and the temperature was maintained at 85 ° C. and reacted for 1 hour to obtain an acid anhydride group. A polymer having maleic anhydride as was obtained.
[Second reaction]
Subsequently, 4 parts of methanol (50 mol %) and 0.1 part of diazabicycloundecene as a catalyst are added, and the temperature is maintained at 85° C. and stirred under reflux for 6 hours for reaction to produce maleic anhydride. The acid was ring-opened and half-esterified. The resulting product was concentrated under reduced pressure to remove MEK and methanol, resin (C-8) (number average molecular weight (Mn): 4,500, weight average molecular weight (Mw): 11,000, acid value: 147 mgKOH/g ).

Synthesis of resins (C-9) to (C-16) Resin (C-9) to (C-16) were obtained. The molecular weight was adjusted appropriately by changing the amount of V-601 added. In addition, the resin that does not use maleic anhydride does not undergo the second reaction.

<Preparation of water-based colorant dispersion>
[Example 1]
・Production of water-based colorant dispersion (1) 80 parts of PB15:3, 10 parts of resin (B-1) as nonvolatile matter, 10 parts of resin (C-1), 450 parts of sodium chloride, 180 parts of diethylene glycol was charged into a stainless steel 1-gallon kneader (manufactured by Inoue Seisakusho) and kneaded at 75° C. for 3 hours to obtain a kneaded product.
The resulting kneaded product is put into 2,000 parts of ion-exchanged water, stirred, filtered, and washed with water. This process is repeated to remove sodium chloride and diethylene glycol, thereby converting PB 15:3 particles into resin (B -1) and a wet cake containing colorant coated with resin (C-1) was obtained.
Dimethylaminoethanol as a basic compound was added to the obtained wet cake so that the total amount of carboxyl groups in Resin (B-1) and Resin (C-1) was 80 mol%, and deionized water was added to NV. was adjusted to 34% by mass, and stirred and mixed with a disper to obtain a mixture.
The resulting mixture was dispersed using a Starmill LMZ (0.5 mmφ zirconia beads 90% filled) manufactured by Ashizawa Finetech Co., Ltd. under conditions of 40° C. and a residence time of 15 minutes to obtain a pre-dispersion.
The obtained pre-dispersed material is treated with a high-pressure homogenizer (Sugino Machine Starburst Lab HJP-25005, equipped with an oblique collision chamber, processing pressure 200 MPa), and 100 kg of the mixture is heated to a liquid temperature of 30 to 80 ° C. during dispersion (apparatus Circulation dispersion was carried out for 5 hours at an outlet temperature of 60 to 80°C and cooled in a circulation tank to 30 to 50°C.
As a post-treatment step, magnetic foreign matter was removed from the dispersion using a Mag Catch Filter MGCF-125 manufactured by Maeda Shell Service Co., Ltd. Subsequently, in a temperature range of 30 to 70 ° C., it was supplied to a cylindrical centrifuge (ultracentrifuge ASM260FH, rotor volume 7.7 L, manufactured by Tomoe Kogyo Co., Ltd.) at a liquid feeding rate of 1.0 L / min, and 20000 G The centrifugal separation was continuously performed at a centrifugal acceleration of .
Add 1.0 part of Proxel GXL as a preservative, and adjust the pH to 9.0 ± 0.5 using 48 wt% potassium hydroxide aqueous solution and 35% hydrochloric acid aqueous solution as pH adjusters, and NV becomes 27% by mass. Ion-exchanged water was added, the mixture was stirred to be uniform, and filtered using a polypropylene roll depth filter 750L-SLS-050 (filtration accuracy: 5 μm) manufactured by Roki Techno to obtain an aqueous colorant dispersion (1). .

[Examples 2 to 45, 91 to 113, Comparative Examples 1 to 6]
・Production of water-based colorant dispersions (2) to (45), (91) to (113) Except for changing the colorants and resins used as shown in Tables 3-1, 3-3, and 3-5 Aqueous colorant dispersions (2) to (45), (91) to (113), and (137) to (142) were obtained in the same manner as in Example 1.

[Example 46]
- Production of water-based colorant dispersion (46) 80 parts of PB15:3, 10 parts of resin (B-1) as nonvolatile matter, 10 parts of resin (C-1) as nonvolatile matter, 450 parts of sodium chloride, diethylene glycol 180 parts of the mixture was placed in a stainless steel 1-gallon kneader (manufactured by Inoue Seisakusho) and kneaded at 80° C. for 3 hours to obtain a kneaded product.
The resulting kneaded product is put into 2,000 parts of ion-exchanged water, stirred, filtered, and washed with water. This process is repeated to remove sodium chloride and diethylene glycol, thereby converting PB 15:3 particles into resin (B -1) and a wet cake containing colorant coated with resin (C-1) was obtained.
To the obtained wet cake, 48% potassium hydroxide aqueous solution was added as a basic compound so that the total amount of carboxyl groups in resin (B-1) and resin (C-1) was 80 mol%, and ion-exchanged water was added. was added to adjust the NV to 34% by mass, followed by stirring and mixing with a disper to obtain a mixture.
The resulting mixture was dispersed using a Starmill LMZ (0.5 mmφ zirconia beads 90% filled) manufactured by Ashizawa Finetech Co., Ltd. under conditions of 40° C. and a residence time of 15 minutes to obtain a pre-dispersion.
The obtained pre-dispersed material is treated with a high-pressure homogenizer (Sugino Machine Starburst Lab HJP-25005, equipped with an oblique collision chamber, processing pressure 200 MPa), and 100 kg of the mixture is heated to a liquid temperature of 30 to 80 ° C. during dispersion (apparatus Circulation dispersion was carried out for 5 hours at an outlet temperature of 60 to 80° C. and cooled in a circulation tank to 30 to 50° C. to obtain a dispersion.
After cooling the resulting dispersion to 45° C., the cross-linking agent (F) is added to the moles of the functional groups of the cross-linking agent (F) with respect to the moles of the carboxyl groups of the resins (B-1) and resin (C-1). The carboxy groups in the resin (B-1) and the resin (C-1) are crosslinked with a cross-linking agent by adding and stirring so that the number becomes 0.9 equivalent, raising the temperature to 75° C., and stirring for 2 hours. Modified.
As a post-treatment step, magnetic foreign matter was removed from the dispersion using a Mag Catch Filter MGCF-125 manufactured by Maeda Shell Service Co., Ltd. Subsequently, in a temperature range of 30 to 70 ° C., it was supplied to a cylindrical centrifuge (ultracentrifuge ASM260FH, rotor volume 7.7 L, manufactured by Tomoe Kogyo Co., Ltd.) at a liquid feeding rate of 1.0 L / min, and 20000 G The centrifugal separation was continuously performed at a centrifugal acceleration of .
Add 1.0 part of Proxel GXL as a preservative, and adjust the pH to 9.0 ± 0.5 using 48 wt% potassium hydroxide aqueous solution and 35% hydrochloric acid aqueous solution as pH adjusters, and NV becomes 27% by mass. Ion-exchanged water was added, and filtration was performed using a polypropylene roll depth filter 750L-SLS-050 (filtration accuracy: 5 μm) manufactured by Roki Techno Co., Ltd. to obtain a colorant dispersion (46). The resin (B)/total resin mass ratio of 0.5 in Table 3-1 means that 50% of the resin (B) is contained in the total resin. The total resin does not include binder resin.

[Examples 47-90, 114-136, Comparative Examples 7-12]
・Production of water-based colorant dispersions (47) to (90), (114) to (136), and (143) to (148) Tables 3-2, 3-4, and 3-5 show the colorants and resins used. Aqueous colorant dispersions (47) to (90), (114) to (136), and (143) to (148) were obtained in the same manner as in Example 46, except for changing as shown in .

[Example 1-1]
• Production of ink (1) Materials other than the water-based colorant dispersion (1) were stirred and mixed with a disper until uniform. This mixture was added dropwise into the water-based colorant dispersion (1) being stirred by a disper, and stirred until sufficiently uniform. Thereafter, filtration was performed with a membrane filter having a pore size of 1 μm to obtain Ink (1).
Aqueous colorant dispersion (1) 20 parts J-780 10 parts W-5030 6 parts S-DF110D 0.5 parts Triethanolamine 1 part Ethylene glycol 0.01 part Diethylene glycol 0.1 part Dipropylene glycol 0.1 part PG 10 parts BDG 1 part Proxel GXL 0.05 parts Ion-exchanged water 47.66 parts

[Examples 2-1 to 136-1, Comparative Examples 1-1 to 12-1]
・Production of inks (2) to (148) In the same manner as in Example 1-1, except that the aqueous colorant dispersion was changed as shown in Tables 4-1 to 4-5, Inks (2) to ( 148) was obtained.

<Viscosity stability>
The viscosity at 25° C. of the obtained ink for ink jet recording and the viscosity at 25° C. after storage at 60° C. for 10 days were measured, and the rate of viscosity increase was evaluated. The measurement was performed using an E-type viscometer ("ELD type viscometer" manufactured by Toki Sangyo Co., Ltd.) under the condition of a rotation speed of 20 rpm.
○: Viscosity increase rate less than 1.1 times (good)
△: Viscosity increase rate is 1.1 to 1.5 times (practically no problem)
×: Viscosity increase rate exceeds 1.5 times (not practical)

<Compatibility evaluation>
A mixed aqueous solution containing the resin (B) and the resin (C) used in the preparation of each ink of Examples and Comparative Examples and the binder resin in the ink composition in the same amounts as those used in each ink was prepared. Then, the mixed aqueous solution was uniformly coated on glass with an applicator (manufactured by BYK-Gardner) and dried by heating at 100° C. to prepare a polymer film having a thickness of 25 μm. Then, the transmittance at 600 nm of each obtained polymer film was measured with a spectrophotometer (U-3300 manufactured by Hitachi, Ltd.). The measured transmittances were classified as follows and used as compatibility evaluation criteria to evaluate compatibility with various binder resins.
○: transmittance of 90% or more (good)
△: transmittance of 85% or more (no practical problem)
×: Transmittance less than 80% (not practical)

<Bending resistance>
The obtained ink for ink jet recording was applied to a biaxially oriented polypropylene film (“FOR#12” manufactured by Futamura Chemical Co., Ltd.) using a K control coater (manufactured by RK Printcoat Instruments Co., Ltd.), and a coater bar No. 1 was applied thereto. 0 (equivalent to a wet film thickness of 4 μm) and a coating speed of 10 m/min, dried in an oven at 80° C. for 3 minutes, and then stored for 1 day in an environment with a temperature of 25° C. and a humidity of 50%. A coated product was produced. As a test for evaluating the flexibility of the coating film, the coated material prepared with each ink was folded 180 degrees on both the peak side and the valley side, and the bending property after printing was evaluated according to the following evaluation criteria.
○: No creases or fine cracks in the coating film when folded (good)
△: Minor cracks occur when bent (practically no problem)
×: Crease cracks occur when folded (impossible to use)

<Abrasion resistance>
A coated product was prepared by the same method as described in the bending resistance evaluation above. Using a Gakushin type friction tester "RT-300" (manufactured by Daiei Kagaku Seiki Seisakusho), the coated surface of the sample is coated with coated paper ("OK Top Coat +", manufactured by Oji Paper Co., Ltd., basis weight 128 g / m ² ), after rubbing with a load of 500 g/100 times, the state of the coated surface was visually evaluated according to the following evaluation criteria.
○: No scratches on the coated surface (good)
△: Scratches can be seen on the coated surface, but the level can be used (no practical problem)
×: Scratches easily occur on the coated surface (not practical)

<Adhesion>
A coated product was prepared by the same method as described in the bending resistance evaluation above. A 15 mm wide, 5 cm long cellophane tape "Cellotape CT-15" (manufactured by Nichiban Co., Ltd.) was strongly pressed against the coated material, and then 10 cm/ The tape was peeled off at a speed of 1 second, and the remaining area of the coated surface was visually evaluated according to the following evaluation criteria.
○: Not peeled from the coated surface at all (good)
△: Partially peeled off from the coated surface, but 80% or more of the area remained (practically no problem)
×: Peeled off from the coated surface, and the remaining area was less than 80% (not practical)

Evaluation results are shown in Tables 4-1 to 4-5.

From the results of Tables 4-1 to 4-5, the inks of Examples 1-1 to 136-1 contain the water-based colorant dispersion of the present invention, so they have high viscosity stability and compatibility with the binder resin. It achieves both high flexibility and good abrasion resistance of the ink film with good storage stability, and also has good adhesion.
In particular, inks using α-olefin as hydrophobic group-containing monomers for resin (B) and resin (C) give particularly good evaluation results.

Similar results were obtained when the base material was changed to A4 size plain paper, coated paper, polyethylene terephthalate film, aluminum foil, artificial leather (made of polyurethane), and fabric (made of cotton). When the base material was not paper, the base material was attached to A4 plain paper.

In addition, an ink set prepared based on these inks was mounted on MAXIFYMB5430 (thermal inkjet printer) manufactured by Canon Inc., and used as substrates were A4 size plain paper, coated paper, polypropylene film (OPP film), and polyethylene terephthalate film. , aluminum foil, artificial leather (made of polyurethane), and cloth (made of cotton) were printed in the same manner, dried with hot air, and evaluated. Similar results were obtained.

In addition, the inks of Examples 1-1 to 136-1 were mounted on EFI NozomI C18000 Plus (single-pass inkjet printer) manufactured by EFI, and A4 size plain paper, coated paper, polypropylene film (OPP film) was used as the base material. , polyethylene terephthalate film, and aluminum foil were printed in the same manner, dried with hot air, and evaluated. Similar results were obtained.

Claims (10)

Colorant (A), resin (B), resin (C), basic compound (D) and aqueous medium (E),
the resin (B) is a polymer containing a hydrophobic group-containing monomer unit, an acid group-containing monomer unit, and a (poly)alkyleneoxy group-containing monomer unit;
An aqueous colorant dispersion in which the resin (C) is a polymer containing a hydrophobic group-containing monomer unit and an acid group-containing monomer unit, but not containing a (poly)alkyleneoxy group-containing monomer unit. The claim that the hydrophobic group-containing monomer unit is a monomer unit containing one or more selected from (meth)acrylic acid alkyl ester units, aromatic monomer units, heterocyclic monomer units, and α-olefin monomer units. 1. The water-based colorant dispersion according to 1. 3. The acid group-containing monomer unit according to claim 1 or 2, wherein the monomer unit contains one or more selected from maleic anhydride units, maleic acid units, maleate ester units and (meth)acrylic acid units. Aqueous colorant dispersion. 4. The aqueous colorant dispersion according to any one of claims 1 to 3, wherein the resin (B) and the resin (C) have an acid value of 1 to 400 mgKOH/g. 5. The water-based colorant dispersion according to any one of claims 1 to 4, further comprising a cross-linking agent (F). 6. The aqueous colorant dispersion according to any one of claims 1 to 5, wherein the hydrophobic group-containing monomer unit of the resin (B) is an α-olefin monomer unit. 7. The aqueous colorant dispersion according to any one of claims 1 to 6, wherein the hydrophobic group-containing monomer units of the resin (C) are α-olefin monomer units. An ink comprising the aqueous colorant dispersion according to any one of claims 1-7. An ink set comprising the ink of claim 8 . An image formed article comprising a substrate and an image layer formed from the ink according to claim 8 or the ink set according to claim 9.