JP2020117590A - Coated colorant and production method of the same - Google Patents

Abstract

To provide a colorant having reduced coarse particles and showing excellent re-dispersibility and easy dispersibility, and to provide an ink for inkjet recording, an ink for flexographic printing, a toner and a coating material excellent in suppressing nozzle clogging and glossiness.SOLUTION: A coated colorant is provided, which comprises a colorant and a resin (P) coating the surface of the colorant. The resin (P) is a resin having a carboxyl group, which is a reaction product of a copolymer of α-olefin and a polycarboxyl group-containing or acid anhydride group-containing monomer with an oxycarboxylic acid having a divalent or tervalent carboxyl group.SELECTED DRAWING: None

Description

The present invention relates to a coating colorant which is particularly preferably used for an aqueous inkjet recording ink and a method for producing the coating colorant.

The inkjet recording method is a recording method in which ink droplets are directly ejected from fine nozzles and adhered to a recording medium to obtain a printed matter or the like on which characters and images are recorded. This method is easy to achieve full color and is inexpensive, and has a wide range of base materials including plain paper as a recording medium. In recent years, particularly, from the viewpoint of weather resistance and water resistance of recorded matter, the use of a pigment as a colorant has become the mainstream.

In the field of pigment dispersions that requires designability, there is a demand for easy dispersibility in which fine pigments with few coarse particles can be obtained more efficiently. To address this problem, Patent Document 1 discloses a colorant coated with a copolymer containing α-olefin, and Patent Document 2 discloses an aqueous colorant dispersion containing colorant particles containing a copolymer containing α-olefin. The body is disclosed.

On the other hand, in the ink jet recording ink using the pigment dispersion, if the redispersibility of the pigment is insufficient, the pigment may be fixed at the ink ejection nozzle portion and the nozzle may be clogged. The methods disclosed in Patent Documents 1 and 2 have room for improvement in nozzle clogging.

Therefore, Patent Document 3 proposes a block copolymer containing a structural unit derived from an N-vinyllactam-based monomer and a structural unit derived from an acid group-containing vinyl monomer.

JP, 2018-162430, A Patent No. 6402435 JP, 2005-093917, A

However, in the dispersant disclosed in Patent Document 3, the carboxyl group moiety that contributes to the repulsion effect is not properly arranged in the aqueous dispersion, and the coating material for providing easy dispersibility of the pigment and designability is obtained. Was not sufficiently glossy. It is required to achieve both redispersibility and easy dispersibility, suppression of nozzle clogging, and glossiness of the coating.

An object of the present invention is to provide a colorant having good dispersibility and redispersibility. That is, it is an object of the present invention to obtain an inkjet recording ink, a flexographic printing ink, a toner, or a paint which is excellent in glossiness and suppresses nozzle clogging.

The above object is achieved by the present invention described below.

<1> A coating colorant in which the surface of the colorant is coated with a resin (P),
The resin (P) comprises a copolymer of a monomer containing an α-olefin and a monomer containing a polycarboxylic acid group or an acid anhydride group, and water or an oxycarboxylic acid having a divalent or trivalent carboxyl group. A coating colorant which is a reaction product and is a resin having a carboxyl group.

<2> The coating colorant as described above, wherein the resin (P) has a number average molecular weight of 2,000 to 35,000.

<3> The coating colorant as described above, wherein the resin (P) has an acid value of 100 to 600 mgKOH/g.

<4> The coating colorant as described above, wherein the α-olefin has 6 to 50 carbon atoms.

<5> The coating colorant, wherein the oxycarboxylic acid has a molecular weight of 80 to 350.

<6> A coating colorant composition containing the coating colorant, water, and a basic substance.

<7> The coating colorant composition as described above, which further contains a crosslinking agent.

<8> The coating colorant for ink for inkjet recording, ink for flexographic printing, toner or paint.

<9> The coating colorant composition as described above, which is for ink for inkjet recording, ink for flexographic printing, toner, or paint.

<10> A method for producing the above coating colorant, comprising:
A method for producing a coating colorant, comprising mixing a water-soluble organic solvent, a water-soluble inorganic salt, a colorant, and a resin (P) with a kneader, and then removing the water-soluble inorganic salt and the water-soluble organic solvent.

<11> A method for producing the coating colorant composition, comprising:
A coating colorant composition in which a step of neutralizing a carboxyl group of the resin (P) by adding a coating colorant, a basic compound and water and a step of adding a crosslinking agent to crosslink the resin (P) are sequentially performed. Method of manufacturing things.

According to the present invention, a colorant having good redispersibility and easy dispersibility, an ink jet recording ink, a flexographic printing ink, a toner, a textile printing agent, a stationery, or a paint having excellent nozzle clogging suppression and glossiness can be obtained. You can
The reason is not clear, but it is considered as follows.
The coating colorant whose surface is coated with the resin (P) containing an α-olefin unit has a highly hydrophobic α-olefin unit having a high resin adsorption capacity for the colorant, and the An excellent electrostatic repulsion due to a high density of carboxyl groups and high hydrophilicity, and a strong coating of the colorant due to cross-linking of the resin (P), and a colorant capable of solving the above problems. Can be

The invention of the present application is a coating colorant in which the surface of the colorant is coated with a resin (P),
The resin (P) is a copolymer of α-olefin and a monomer containing a polycarboxylic acid group or an acid anhydride group-containing monomer with water or an oxycarboxylic acid having a divalent or trivalent carboxyl group. The reaction product is a resin having a carboxyl group.
The copolymer of the monomer containing the α-olefin and the polycarboxylic acid group- or acid anhydride group-containing monomer has a carboxyl group or an acid anhydride group. The carboxyl group or acid anhydride group reacts with water or an oxycarboxylic acid having a divalent or trivalent carboxyl group, and the reaction product becomes a resin having a carboxyl group.

Hereinafter, the coating colorant of the present invention and the method for producing the same will be described with reference to preferred embodiments.
In the present application, “C.I.” means a color index (C.I.).

[Coating colorant]
The coated colorant of the present invention has a colorant surface coated with a resin (P), and the resin is a monomer containing an α-olefin and a polycarboxyl group- or acid anhydride group-containing monomer. A reaction product of a copolymer with water or an oxycarboxylic acid having a divalent or trivalent carboxyl group, which has a carboxyl group.

In the present specification, the colorant can be appropriately selected and used from inorganic pigments, organic pigments, and dyes. Hereinafter, the colorant before coating may be simply referred to as a colorant.

Examples of the inorganic pigment include carbon black, metal oxides, metal complex salts, and other inorganic pigments. Examples of carbon black include furnace black, thermal lamp black, acetylene black, channel black and the like.
Examples of the metal oxide include titanium oxide, iron oxide, iron hydroxide, zirconia, alumina and the like.
Examples of the metal complex salt include metal complex salt dyes. For example, 1:1 type metal complex salt dye in which one metal atom is coordinate-bonded to one molecule of monoazo dye, and 1:2 type metal complex salt dye in which one metal atom is coordinately bonded to two molecules of monoazo dye are exemplified.
Other inorganic pigments include, for example, ultramarine, yellow lead, zinc sulfide, cobalt blue and the like.

Examples of organic pigments include azo pigments, diazo pigments, phthalocyanine pigments, quinacridone pigments, isoindolinone pigments, dioxazine pigments, perylene pigments, perinone pigments, thioindigo pigments, anthoraquinone pigments, and quinophthalone pigments.

Specifically, for example,
C. I. PigmentRed 1, 2, 3, 4, 5, 6, 7, 9, 10, 14, 17, 22, 23, 31, 32, 38, 41, 48:1, 48:2, 48:3, 48:4, 49, 49:1, 49:2, 52:1, 52:2, 53:1, 57:1, 60:1, 63:1, 66, 67, 81:1, 81:2, 81:3, 83, 88, 90, 105, 112, 119, 122, 123, 144, 146, 147, 148, 149, 150, 155, 166, 168, 169, 170, 171, 172, 175, 176, 177, 178, 179, 184, 185, 187, 188, 190, 200, 202, 206, 207, 208, 209, 210, 216, 220, 224, 226, 242, 246, 254, 255, 264, 266, 269, 270, 272, 279,
C. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 10, 11, 12, 13, 14, 15, 16, 17, 18, 20, 24, 31, 32, 34, 35, 35:1, 36, 36: 1, 37, 37: 1, 40, 42, 43, 53, 55, 60, 61, 62, 63, 65, 73, 74, 77, 81, 83, 86, 93, 94, 95, 97, 98, 100, 101, 104, 106, 108, 109, 110, 113, 114, 115, 116, 117, 118, 119, 120, 123, 125, 126, 127, 128, 129, 137, 138, 139, 147, 148, 150, 151, 152, 153, 154, 155, 156, 161, 162, 164, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 179, 180, 181, 182, 185, 187, 188, 193, 194, 199, 213, 214,
C. I. Pigment Orange2, 5, 13, 16, 17:1, 31, 34,
36, 38, 43, 46, 48, 49, 51, 52, 55, 59, 60, 61, 62, 64, 71, 73,
C. I. PigmentGreen7, 10, 36, 37, 58, 59, 62, 63,
C. I. PigmentBlue 1, 2, 15, 15:1, 15:2, 15:3, 15:4, 15:6, 16, 22, 60, 64, 66, 79, 79, 80.
C. I. Pigment Violet 1, 19, 23, 27, 32, 37, 42
C. I. Pigment Brown 25, 28
C. I. PigmentBlack 1, 7
C. I. PigmentWhite 1, 2, 4, 5, 6, 7, 11, 12, 18, 19, 21, 22, 23, 26, 27, 28 and the like.

Among these, the following can be mentioned as colorants that can be preferably used.
C. I. PigmentRed 31, 48:1, 48:2, 48:3, 48:4, 57:1, 122, 146, 147, 148, 150, 170, 176, 177, 184, 185, 202, 242, 254, 255, 264, 266, 269,
C. I. Pigment Yellow 12, 13, 14, 17, 74, 83, 108, 109, 120, 150, 151, 154, 155, 180, 185, 213.
C. I. Pigment Orange 36, 38, 43, 64, 73
C. I. PigmentGreen7, 36, 37, 58, 62, 63,
C. I. PigmentBlue 15:1, 15:3, 15:6, 16, 22, 60, 66,
C. I. Pigment Violet 19, 23, 32,
C. I. Pigment Brown 25,
C. I. PigmentBlack 1, 7
C. I. PigmentWhite6

Examples of the dye include disperse dyes. The disperse dye is a dye having a property of being sublimated by heating. Examples of the disperse dye include C.I. I. Disperse Yellow 3, 7, 8, 23, 39, 51, 54, 60, 71, 86; C.I. I. Disperse Orange 1, 1:1, 5, 20, 25, 25:1, 33, 56, 76; C.I. I. Disperse Brown 2; C.I. I. Disperse Red 11, 50, 53, 55, 55:1, 59, 60, 65, 70, 75, 93, 146, 158, 190, 190:1, 207, 239, 240, 343; I. Butred 41; C.I. I. Disperse Violet 8, 17, 23, 27, 28, 29, 36, 57; C.I. I. Disperse Blue 19, 26, 26:1, 35, 55, 56, 58, 60, 64, 64:1, 72, 72:1, 81, 81:1, 91, 95, 108, 131, 141, 145 , 165, 359, 360 and the like.
Ink jet recording inks using these coating colorants can maintain sufficient color reproducibility and light resistance. However, the present invention is not limited to these colorants and is not limited to inks for inkjet recording.

The average primary particle diameter of the colorant may vary depending on the application, but is usually 5 to 1,000 nm. As the colorant used here, an untreated colorant is usually used, but a colorant that has undergone some treatment step may be used. Further, the colorant used may be a single type or a plurality of types. The average primary particle diameter can be obtained, for example, by measuring the primary particle diameters of all the colorant particles in the observed sample at 100,000 times using a transmission electron microscope, and calculating the average value thereof.

[Resin (P)]
The resin (P) used in the present invention is a copolymer of an α-olefin and a monomer containing a polycarboxyl group or an acid anhydride group-containing monomer, water, or an oxy group having a divalent or trivalent carboxyl group. It is a reaction product with a carboxylic acid and has a carboxyl group.
The method for obtaining the resin (P) is, for example, by polymerizing α-olefin and maleic anhydride to obtain a polymer having an α-olefin and an acid anhydride group (hereinafter, also referred to as polymer (p)), A method of reacting water or an oxycarboxylic acid having a divalent or trivalent carboxyl group is preferable.

The resin (P) is a copolymer of α-olefin and a monomer containing a polycarboxylic acid group or an acid anhydride group-containing monomer, and water or an oxycarboxylic acid having a divalent or trivalent carboxyl group. The reaction product is not particularly limited as long as it contains a carboxyl group. Specifically, it is a copolymer of an α-olefin, an acid anhydride group-containing monomer, and an ethylenically unsaturated monomer other than that, and those obtained by a general polymerization method can be used. For example, the method described in JP2007-58125A can be mentioned. It is also possible to modify and use a commercially available α-olefin maleic anhydride resin. For example, Diakarna M30 (manufactured by Mitsubishi Chemical Co., Ltd.) and the like can be mentioned. Instead of the acid anhydride group-containing monomer, a polycarboxyl group-containing monomer in which the acid anhydride group of the acid anhydride group-containing monomer is ring-opened may be used.

[Polymer (p) Having α-Olefin and Acid Anhydride Group]
[Α-olefin]
The α-olefin in the polymer (p) having an α-olefin and an acid anhydride group is not particularly limited, but it has a carbon number from the viewpoint of both the adsorption rate of the resin (P) to the colorant and a high acid value. It is preferable to use one having 6 to 50 carbon atoms, more preferable to use one having 8 to 38 carbon atoms, and most preferable to use one having 12 to 38 carbon atoms.
Specific examples include 1-hexene (6 carbon atoms), 1-heptene (7 carbon atoms), 1-octene (8 carbon atoms), 1-nonene (9 carbon atoms), 1-decene (10 carbon atoms), 1-dodecene (12 carbon atoms), 1-tetradecene (14 carbon atoms), 1-hexadecene (16 carbon atoms), 1-octadecene (18 carbon atoms), 1-eicosene (20 carbon atoms), 1-dococene (carbon atoms) Number 22), 1-tetracocene (carbon number 24), 1-octacocene (carbon number 28), 1-triacontene (carbon number 30), 1-dotriacontene (carbon number 32), 1-tetratriacontene (carbon 34), 1-hexatriacontane (36 carbon atoms), 1-octatriacontane (38 carbon atoms) and the like.

In the polymer (p) having an α-olefin and an acid anhydride group, it is possible to use a mixture of two or more α-olefins. By mixing and using it, it becomes easy to adjust the solubility and melting point of the resin to desired properties.

[Acid anhydride group-containing monomer]
Examples of the acid anhydride group-containing monomer in the polymer (p) having an α-olefin and an acid anhydride group include maleic anhydride and itaconic anhydride, with maleic anhydride being most preferred.

The polymer (p) having an α-olefin and an acid anhydride group is preferably obtained by adding a radical initiator and a chain transfer agent to α-olefin and maleic anhydride, and polymerizing. As a polymerization method, for example, a method of adding maleic anhydride, a radical initiator and a chain transfer agent to an α-olefin monomer and polymerizing is preferable. Further, the polymerization method of α-olefin and maleic anhydride may be carried out without a solvent or may be carried out in combination with a solvent. Further, maleic anhydride may be charged together with the α-olefin at once, or may be gradually added to the polymerization system. These polymerization methods are not particularly limited. The polymer obtained by the above-mentioned polymerization method is essentially an alternating polymer of α-olefin and maleic anhydride. However, the maleic anhydride content can be adjusted by changing the initial distribution ratio, and when two or more kinds of α-olefins are used, randomly arranged α-olefins can be used. The resulting polymer has maleic anhydride arranged alternately.

In the polymer (p) having an α-olefin and an acid anhydride group, the molar ratio of α-olefin to maleic anhydride used is such that the former/the latter molar ratio of the polymer obtained is from the viewpoint of dispersion stability. The ratio is preferably 30/70 to 99/1, more preferably 40/60 to 95/5, still more preferably 45/55 to 80/20.

Examples of the radical initiator used at this time include azobisisobutyronitrile, azobis compounds such as azobis2,4-dimethylvaleronitrile, cumene hydroperoxide, t-butyl hydroperoxide, benzoyl peroxide, diisopropyl peroxycarbonate, Examples thereof include peroxides such as di-t-butyl peroxide, lauroyl peroxide, t-butyl peroxybenzoate and t-butyl peroxy-2-ethylhexanoate.

In the case of solution polymerization, ethyl acetate, n-butyl acetate, isobutyl acetate, toluene, xylene, acetone, hexane, methyl ethyl ketone, cyclohexanone, etc. are used as the polymerization solvent, but the solvent is not particularly limited thereto. Two or more kinds of these polymerization solvents may be mixed and used, but it is preferable that they are solvents used in the final use.

From the viewpoint of adjusting the resin (P), the acid value of the polymer (p) is preferably 100 to 600 mgKOH/g, more preferably 150 to 500 mgKOH/g. When the acid value is less than 100 mgKOH/g, the coating colorant has a low affinity for water and a water-soluble solvent, and the redispersibility of the colorant may be poor. There is a tendency that the affinity for the solvent becomes excessive, the resin adsorption rate to the colorant decreases, and as a result, the redispersibility of the colorant deteriorates.

Further, the number average molecular weight of the polymer (p) is preferably 2,000 to 30,000, and more preferably 3,000 to 25,000, from the viewpoint of adjusting the resin (P). If the number average molecular weight is less than 2,000, the redispersibility of the colorant dispersion may decrease, and if it exceeds 30,000, the affinity for water or a water-soluble solvent may deteriorate. The viscosity may increase.

[Water or an oxycarboxylic acid having a divalent or trivalent carboxyl group]
The resin (P) of the present invention is prepared by reacting the polymer (p) having an α-olefin and an acid anhydride group with water or an oxycarboxylic acid having a divalent or trivalent carboxyl group, as described above. Specifically, it is obtained by esterification modification.

Examples of the oxycarboxylic acid having a divalent carboxyl group include tartronic acid, malic acid, 4-hydroxyphthalic acid and the like.

Examples of the oxycarboxylic acid having a trivalent carboxyl group include citric acid and the like.

Especially, water or an oxycarboxylic acid having a carboxyl group having a divalent or trivalent carboxyl group having a molecular weight of 80 to 350 is preferable, and water is more preferable.
When the molecular weight of the oxycarboxylic acid having a divalent or trivalent carboxyl group is 80 to 350, the esterification reaction with the polymer (p) is likely to proceed, and the coating has an excellent balance between hydrophilicity and hydrophobicity. Since the colorant composition is obtained, the effect of stabilizing the dispersion of the pigment is enhanced and the redispersibility is easily improved.
Further, in the resin (P) obtained by the esterification reaction of water and the polymer (p), redispersibility, suppression of nozzle clogging, and gloss are remarkably improved. It is considered that this is because the flexibility of the molecular chain due to the absence of an extra skeleton in the main chain skeleton and the provision of a high-density charge repulsion site could both be achieved.

Note that the oxycarboxylic acid having a monovalent carboxyl group cannot solve the problem of redispersibility. It is considered that this is because the density of the carboxyl group is smaller than that of the divalent or trivalent one, and it is not possible to provide a high-density charge repulsion site. However, the use of an oxycarboxylic acid having a monovalent carboxyl group is not excluded as long as the effects of the invention are not lost.
Examples of the oxycarboxylic acid having a monovalent carboxyl group include α-oxybutyric acid, 12-hydroxystearic acid, lactic acid, α-hydroxymyristic acid, α-hydroxypalmitic acid, α-hydroxystearic acid, α-hydroxyeicosanoic acid. , Α-hydroxydocosanoic acid, α-hydroxytetraeicosanoic acid, α-hydroxyhexaeicosanoic acid, α-hydroxyoctaeicosanoic acid, α-hydroxytriacontanoic acid, β-hydroxymyristic acid, 10-hydroxydecanoic acid , 15-hydroxypentadecanoic acid, 16-hydroxyhexadecanoic acid, ricinoleic acid, glycolic acid, hydroacrylic acid, α-hydroxyisobutyric acid, δ-hydroxycaproic acid, α-hydroxydotriacontanoic acid, α-hydroxytetratriacontanoic acid , Α-hydroxyhexatriacontanoic acid, α-hydroxyoctatriacontanoic acid, α-hydroxytetracontanoic acid, glyceric acid, salicylic acid, m-oxybenzoic acid, p-oxybenzoic acid, gallic acid, mandelic acid, trobaric acid, etc. Are listed.

The esterification modification reaction is carried out at 50 to 300° C., and may be carried out in the presence of a suitable solvent, if necessary. Further, if necessary, an esterification catalyst may be appropriately added. The esterification catalyst is not particularly limited, and examples thereof include sulfuric acid, hydrogen chloride, p-toluenesulfonic acid, triethylamine, dimethylbenzylamine, tetrabutylammonium bromide, 1,8-diazabicyclo[5.4.0]. Undecene-7 and the like can be mentioned, and it is preferable to use 0.03 to 5% by weight based on the solid content of the reaction system.

The acid anhydride value of the resin (P) is preferably small. 0 to 50 mgKOH/g is preferable, 0 to 30 mgKOH/g is more preferable, and 0 to 10 mgKOH/g is particularly preferable. When the acid anhydride value exceeds 50, the carboxyl group is not sufficiently produced by the ring-opening reaction due to the esterification, the electrostatic repulsion in the coating colorant is insufficient, and the redispersibility tends to decrease.

The acid value of the resin (P) is preferably 100 to 600 mgKOH/g, more preferably 150 to 500 mgKOH/g, and particularly preferably 150 to 400 mgKOH/g. When the acid value is less than 100 mgKOH/g, the coating colorant has a low affinity for water and a water-soluble solvent, and the redispersibility of the colorant may be poor. There is a tendency that the affinity for the solvent becomes excessive, the resin adsorption rate to the colorant decreases, and the redispersibility of the colorant deteriorates.

The number average molecular weight of the resin (P) is preferably 2,000 to 35,000, more preferably 3,000 to 25,000. When the number average molecular weight is less than 2,000, it becomes difficult to obtain the resin adsorption to the pigment and the steric repulsion effect, and the dispersibility decreases, so that the redispersibility may decrease, and the number average molecular weight exceeds 35,000. In some cases, the affinity for water or a water-soluble solvent may be poor, and the workability may be reduced due to the increased viscosity, and the amount of resin adsorbed on the colorant may be reduced.

[Production of coating colorant]
Specifically, the coating colorant of the present invention is preferably obtained by sequentially performing the following step (1) and step (2).
Step (1): A step of mixing a mixture containing a colorant, the resin (P), a water-soluble inorganic salt and a water-soluble organic solvent with a kneader to make the mixture finer.
Step (2): A step of removing the water-soluble inorganic salt and the water-soluble organic solvent.

The method of refining the colorant in the step (1) is not particularly limited, and any method can be applied, but a milling and kneading step by salt milling treatment or the like is preferable.
For example, a mixture containing at least a colorant, a resin (P), a water-soluble inorganic salt and a water-soluble organic solvent is mixed with a kneader, a two-roll mill, a three-roll mill, a ball mill, an attritor, a horizontal sand mill, a vertical sand mill and/or The milling and kneading can be performed using a kneader such as an annular type bead mill. Further, the treatment conditions and the like can be appropriately adjusted depending on the kind of the colorant, the required degree of miniaturization, and the like, and heating is preferably performed during mechanical kneading. Among these milling and kneading methods, it is preferable to use a kneader in order to dramatically improve the resin adsorption amount of the resin (P) to the colorant and improve the redispersibility.

The water-soluble inorganic salt acts as a crushing aid, and crushes the colorant by utilizing the high hardness of the water-soluble inorganic salt. The water-soluble inorganic salt used in the milling and kneading method is not limited as long as it is a water-soluble inorganic salt as its name implies and does not depart from the gist of the present invention. Preferred examples include sodium chloride, barium chloride, potassium chloride, sodium sulfate and the like. It is preferable to use sodium chloride (salt) from the viewpoint of price.

The water-soluble organic solvent used in the milling and kneading method functions to wet the colorant and the water-soluble inorganic salt, dissolves (mixes) in water, and does not substantially dissolve the water-soluble inorganic salt used. Must be one. Furthermore, it must have a suitable affinity with the resin (P).
Examples of such a water-soluble organic solvent include glycols such as ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, polyethylene glycol, polypropylene glycol; butanediol, pentanediol, hexanediol, and their homologs. Diols such as diols; glycol esters such as propylene glycol laurate; diethylene glycol monoethyl, diethylene glycol monobutyl, diethylene glycol monohexyl ethers, propylene glycol ethers, dipropylene glycol ethers, and cellosolves including triethylene glycol ethers Glycol ethers; alcohols such as methanol, ethanol, isopropyl alcohol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, butyl alcohol, pentyl alcohol, and alcohols homologous to these; or sulfolane; γ- Examples include lactones such as butyrolactone; lactams such as N-(2-hydroxyethyl)pyrrolidone; glycerin and its derivatives; and other various solvents known as water-soluble organic solvents. These water-soluble organic solvents can be used alone or in combination of two or more.

Among them, polyhydric alcohols having a high boiling point, low volatility and high surface tension are preferable, and glycols such as diethylene glycol and triethylene glycol are particularly preferable.

The amount of the water-soluble organic solvent added is not particularly limited, but 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 colorant. Further, the water-soluble inorganic salt is preferably used in an amount of 50 to 2,000 parts by mass, and more preferably 300 to 1,000 parts by mass, based on 100 parts by mass of the colorant, from both aspects of treatment efficiency and production efficiency. Further, the amount of the resin (P) is preferably 5 to 100 parts by mass based on 100 parts by mass of the colorant in terms of solid content, from the viewpoint of print evaluation and redispersibility of the ink for inkjet recording, and 10 to 80. It is preferable to use parts by mass.

In the step (2), for example, after performing the step (1), the mixture containing the colorant is taken out from the milling and kneading machine, ion-exchanged water is added and the mixture is stirred to obtain a suspension. The amount of water to be added is not particularly limited as long as it is an amount sufficient to obtain a suspension. You may heat if necessary. For example, 10 to 10,000 times the weight of water in step (1) is added and mixed and stirred. The mixing and stirring conditions at this time are not particularly limited, but it is preferable to carry out at a temperature of 25 to 90°C. Then, the water-soluble organic solvent and water-soluble inorganic salt used in the milling and kneading machine can be removed by removing the filtrate by an operation such as filtration, and the colorant was coated with the resin (P). A coating colorant can be obtained. Strictly speaking, since the coating colorant contains ion-exchanged water, a step of further removing water may be performed. It is not limited as long as it is a method of removing water, but a suitable method is a method of performing a drying treatment. The drying conditions include, for example, a method of performing drying under normal pressure in the range of 80 to 120°C for about 12 to 48 hours, a method of performing under reduced pressure in the range of 25 to 80°C for about 12 to 60 hours, and the like. It can be illustrated. The drying treatment is not particularly limited, but a method using a spray drying device can be exemplified. The pulverization treatment may be performed simultaneously with the drying treatment or after the drying treatment.

[Coating colorant composition]
The coating colorant composition of the present invention preferably contains at least a coating colorant, a basic compound, and water, and further contains a crosslinking agent. From the viewpoint of redispersibility of the colorant dispersion, it is preferable to sequentially perform the following step (3) and step (4) as a method for producing these coating colorant compositions.
Step (3): A coating colorant, a basic compound and water are added to neutralize the carboxyl groups of the resin (P) Step (4): A crosslinking agent is added to crosslink the resin (P) In the step of neutralizing the carboxyl group of the resin (P) and the step of adding a crosslinking agent to crosslink the resin (P) and the crosslinking agent, the temperature and time can be appropriately selected and determined. The time of the neutralization step is preferably 0.5 to 10 hours, more preferably 1 to 5 hours, and the temperature of the neutralization step is preferably 40 to 95°C. The time of the crosslinking step is preferably 0.5 to 10 hours, more preferably 1 to 5 hours, and the temperature of the crosslinking step is preferably 40 to 95°C.

From the viewpoint of storage stability, the content of water in the coating colorant composition is preferably 30 to 85% by mass, and more preferably 30 to 80% by mass with respect to the entire composition. As water, it is preferable to use ion-exchanged water (deionized water) instead of general water containing various ions. Hereinafter, unless otherwise specified, water refers to ion-exchanged water.

From the viewpoint of printability and storage stability, the content of the coating colorant in the coating colorant composition is preferably 5 to 40% by mass, and more preferably 10 to 30% by mass or less based on the entire composition. The volume median diameter of the colorant particles of the coating colorant composition is preferably 20 to 200 nm, more preferably 25 to 150 nm, from the viewpoint of preventing clogging of nozzles of an inkjet printer and storage stability of the inkjet recording ink. 30-130 nm is more preferable, and 35-90 nm is the most preferable. A laser diffraction/scattering method is used to measure the volume median diameter.

[Basic compound]
The coating colorant composition of the present invention can stabilize the dispersion of the coating colorant by ionizing the carboxyl group of the resin (P). For this reason, the coating colorant composition and the inkjet recording ink using the same are preferably adjusted to be neutral or alkaline. However, if the alkalinity is too strong, it may cause corrosion of various members used in the ink jet recording apparatus, so that the pH range of 7 to 10 is preferable. Examples of the pH adjuster used in this case include the following. For example, various organic amines such as ammonia water, dimethylaminoethanol, diethanolamine and triethanolamine, inorganic alkali agents such as alkali metal hydroxides such as sodium hydroxide, lithium hydroxide and potassium hydroxide, organic acids and mineral acids. Etc. can be used. By ionizing the resin (P) of the coating colorant described later, the coating colorant is neutralized and dispersed or dissolved in the aqueous liquid medium.

The degree of neutralization of the resin (P) is preferably 10 to 100 mol%, more preferably 30 to 100 mol%, and more preferably 50 to 100 mol from the viewpoint of storage stability of the coating colorant composition. % Reaction is particularly preferred.
Here, the degree of neutralization is the molar equivalent of the basic compound divided by the molar amount of the carboxyl group of the resin (P). It can be calculated by the following formula.
{(Weight of basic compound (g)/equivalent of basic compound)/[(acid value of resin (P) (KOHmg/g) x weight of resin (P) (g)/(56.1x1000) ]}×100

[Crosslinking agent]
In the present invention, a crosslinking agent may be included. Since the crosslinking agent moderately crosslinks the resin (P) on the surface of the coating colorant in the coating colorant composition, a compound having a reactive functional group capable of reacting with two or more carboxyl groups in the molecule is preferable. Used. The reactive functional group is preferably at least one selected from the group consisting of an isocyanate group, an aziridine group, a carbodiimide group, an oxetane group, an oxazoline group and an epoxy group, and more preferably an aziridine group, a carbodiimide group and an epoxy group. It is at least one selected from the group, and particularly preferably an epoxy group. From the viewpoint of improving redispersibility as an inkjet recording ink, addition of a crosslinking agent is preferable.
From the viewpoint of easiness of reaction and redispersibility, the molecular weight (formula weight or number average molecular weight Mn) of the cross-linking agent is preferably 100 to 2,000, more preferably 120 to 1,500, and 150 to 1 1,000 is especially preferred. The number of reactive functional groups contained in the crosslinking agent is preferably 2 to 6 from the viewpoint of controlling the molecular weight of the resin (P) after crosslinking and improving redispersibility.

The following are specific examples of the crosslinking agent used in the present invention.
Compounds having two or more isocyanate groups in the molecule: for example, organic polyisocyanates or isocyanate group-terminated prepolymers.
Examples of the organic polyisocyanate include aliphatic diisocyanates such as hexamethylene diisocyanate and 2,2,4-trimethylhexamethylene diisocyanate; aromatic diisocyanates such as tolylene-2,4-diisocyanate and phenylene diisocyanate; alicyclic diisocyanates; aromatic Triisocyanate; examples thereof include modified products such as urethane modified products. 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.

Compounds having two or more aziridine groups in the molecule: for example, N,N′-diphenylmethane-4,4′-bis(1-aziridinecarboxite), N,N′-toluene-2,4-bis(1 -Aziridine carboxite), bisisophthaloyl-1-(2-methylaziridine), tri-1-aziridinylphosphine oxide, N,N'-hexamethylene-1,6-bis(1-aziridine carboxite) ,2,2′-bishydroxymethylbutanol-tris[3-(1-aziridinyl)propionate], trimethylolpropane tri-β-aziridinylpropionate, tetramethylolmethanetri-β-aziridinylpropionate , Tris-2,4,6-(1-aziridinyl)-1,3,5-triazine, 4,4′-bis(ethyleneiminocarbonylamino)diphenylmethane and the like.

Compounds having two or more carbodiimide groups in the molecule: For example, a high molecular weight polycarbodiimide produced by subjecting a diisocyanate compound to a decarboxylation condensation reaction in the presence of a carbodiimidization catalyst can be mentioned. Examples of such a high molecular weight polycarbodiimide include the carbodilite series manufactured by Nisshinbo Industries, Inc.

Compounds having two or more oxetane groups in the molecule: for example, 4,4′-(3-ethyloxetane-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- Examples include oxetanyl)}butoxyphenyl]fluorene and 9,9-bis[4-[2-{2-(3-oxetanyl)}butoxy]ethoxyphenyl]fluorene.

A compound having two or more oxazoline groups in the molecule: For example, a compound in which two or more, preferably 2-3 oxazoline groups are bonded to an aliphatic group or an aromatic group, more specifically 2,2′- Bisoxazoline compounds such as bis(2-oxazoline), 1,3-phenylenebisoxazoline and 1,3-benzobisoxazoline, and compounds having a terminal oxazoline group obtained by reacting the compound with a polybasic carboxylic acid.

Compounds having two or more epoxy groups in the molecule: for example, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, glycerin triglycidyl ether, glycerol polyglycidyl ether, polyglycerol polyglycidyl ether, tri Polyglycidyl ethers such as methylolpropane polyglycidyl ether, sorbitol polyglycidyl ether, pentaerythritol polyglycidyl ether, resorcinol diglycidyl ether, neopentyl glycol diglycidyl ether, hydrogenated bisphenol A type diglycidyl ether.

Among these, compounds having two or more epoxy groups in the molecule are preferable, and ethylene glycol diglycidyl ether and trimethylolpropane polyglycidyl ether are particularly preferable.

The cross-linking agent is preferably moderately water-soluble from the viewpoint of efficiently reacting with the carboxyl group of the resin (P) in water. For example, when the cross-linking agent is dissolved in 100 g of water at 25° C., the amount of dissolution Is preferably 0.1 to 50 g, more preferably 0.2 to 40 g, still more preferably 0.5 to 30 g.

The addition amount of the cross-linking agent is preferably an amount such that 10 to 150 mol% is reacted with the carboxyl group of the resin (P). Above all, it is more preferable to add 20 to 120 mol% of the reaction amount, and it is preferable to add 30 to 100 mol% of the reaction amount.

<Inkjet recording ink>
The coating colorant of the present invention can be suitably used, for example, as a colorant for inkjet recording inks.
The inkjet recording ink of the present specification contains a coating colorant or a coating colorant composition.
The inkjet recording ink of the present specification uses water as a solvent (medium), but it is preferable to use a water-soluble solvent together in order to prevent the ink from drying. Further, since the dispersion stability of the coating colorant is improved, the penetrability and wettability of the substrate after printing are improved.
Examples of the water-soluble solvent include polyhydric alcohols, polyhydric alcohol alkyl ethers, polyhydric alcohol aryl ethers, nitrogen-containing heterocyclic compounds, amides, amines, sulfur-containing compounds, propylene carbonate, ethylene carbonate, and others. Examples include water-soluble solvents.

Examples of the polyhydric alcohols include glycerin, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, 1,2-propanediol, 1,3-propanediol, 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, trimethylolethane Trimethylolpropane, 1,2,6-hexanetriol, 1,2,4-butanetriol, 1,2,3-butanetriol, petriol, 2-ethyl-2-methyl-1,3-propanediol, 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 can be mentioned. Among these, 2-ethyl-1,3-hexanediol, 2,2,4-trimethyl-1,3-pentanediol, 1,2-propanediol, 1,2-butanediol, 1,3-butanediol , 1,2-Pentanediol, 1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol and 1,2-heptanediol are preferred.

Examples of the 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, propylene glycol monoethyl ether. Butyl ether and the like can be mentioned.
Examples of the polyhydric alcohol aryl ethers include ethylene glycol monophenyl ether, diethylene glycol monophenyl ether, tetraethylene glycol chlorophenyl ether, ethylene glycol monobenzyl ether, and ethylene glycol monoallyl ether.

Examples of the nitrogen-containing heterocyclic compound include 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 1,3-dimethylimidazolidinone, ε-caprolactam and γ-butyrolactone. Can be mentioned.
Examples of the amides include formamide, N-methylformamide, N,N-dimethylformamide and the like.
Examples of the amines include monoethanolamine, diethanolamine, triethanolamine, monoethylamine, diethylamine, triethylamine and the like.
Examples of the sulfur-containing compounds include dimethyl sulfoxide, sulfolane, thiodiethanol and the like.

The other water-soluble solvent is preferably sugar. Examples of saccharides include monosaccharides, disaccharides, oligosaccharides (including trisaccharides and tetrasaccharides), and polysaccharides. Examples of the sugar include glucose, mannose, fructose, ribose, xylose, arabinose, galactose, maltose, cellobiose, lactose, sucrose, trehalose, maltotriose and the like. Here, the polysaccharide means a sugar in a broad sense, and includes substances widely existing in nature such as α-cyclodextrin and cellulose. In addition, the derivative of these sugars is represented by a reducing sugar of the above sugar (for example, sugar alcohol [general formula: HOCH ₂ (CHOH) _n CH ₂ OH (where n represents an integer of 2 to 5)]. ], oxidized sugars (eg, aldonic acid, uronic acid, etc.), amino acids, thioacids, etc. Among these, sugar alcohols are preferable, and maltitol and sorbit are preferable.

The water-soluble solvent can be used alone or in combination of two or more kinds.

The content of the water-soluble organic solvent is preferably 3 to 60% by mass, more preferably 3 to 50% by mass, based on the entire inkjet recording ink. Further, the content of water is preferably 10 to 90% by mass, and more preferably 30 to 80% by mass, based on the whole ink for inkjet recording. The proper content of the water-soluble organic solvent improves the stability of ink ejection from the head.

The inkjet recording ink preferably contains a binder resin. This improves the water resistance, solvent resistance, scratch resistance, etc. of the printed coating film.
Examples of the binder resin include (meth)acrylic resin, styrene-(meth)acrylic resin, urethane resin, styrene-butadiene resin, vinyl chloride resin, polyolefin resin, polyester resin and polyurethane resin.

The content of the binder resin is preferably 2 to 30 mass% and more preferably 3 to 20 mass% with respect to the entire nonvolatile content of the inkjet recording ink.

The inkjet recording ink of the present specification may contain an additive, if necessary. Examples of the additive include a surfactant, a defoaming agent, a preservative and the like. The content of the additive is preferably 0.05 to 10% by mass, and more preferably 0.2 to 5% by mass, based on the entire inkjet recording ink.

The inkjet recording ink of the present specification can be used in various inkjet printers. Examples of the inkjet system include a continuous ejection type such as a charge control type and a spray type, an on-demand type such as a piezo system, a thermal system, and an electrostatic suction system.

Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples. In the following description, "part" and "%" mean "part by mass" and "% by mass", respectively.

(Number average molecular weight (Mn))
The number average molecular weight (Mn) was measured using a TSKgel column (manufactured by Toso Corporation) and a GPC equipped with an RI detector (manufactured by Toso Corporation, HLC-8320GPC) using THF as a developing solvent. It is the converted number average molecular weight (Mn).

(Acid value)
About 1 g of a sample is precisely weighed in an Erlenmeyer flask, and 50 ml of a distilled water/dioxane (weight ratio: distilled water/dioxane=1/9) mixed solution is added and dissolved. A 0.1 mol/L potassium hydroxide/ethanol solution (titer F) was applied to the sample solution using a potentiometer (manufactured by Kyoto Denshi Kogyo Co., Ltd., device name “potentiometer automatic titrator AT-710M”). The amount of potassium hydroxide/ethanol solution (α (mL)) required by the end of the titration was measured. The acid value (mgKOH/g) was determined by the following formula as the value of the resin in the dry state.
Acid value (mgKOH/g)={(5.611×α×F)/S}/(nonvolatile matter concentration/100)
However, S: sampling amount (g)
α: 0.1 mol/L potassium hydroxide/ethanol solution consumption (ml)
F: titer of 0.1 mol/L potassium hydroxide/ethanol solution

(Acid anhydride value)
The acid anhydride value is calculated as follows. Specifically, the resin (P) is weighed in a (g) and then dissolved in xylene, and b (mmol) of octylamine in an amount equal to or more than the acid anhydride group is added to the acid anhydride group and the primary amino group. The groups were reacted. Then, the mixture was cooled to room temperature and the amount of octylamine remaining was quantified by titrating with 0.1 M ethanolic perchloric acid. When the titer is c (ml), the acid anhydride value of the resin (P) can be calculated from the following formula.
Acid anhydride value (mgKOH/g)=(b-0.1×c)×56.10/a

<Production of Polymer (p) Having α-Olefin and Acid Anhydride Group>
(Production Example 1)
A reaction vessel equipped with a gas inlet tube, a thermometer, a condenser, and a stirrer was charged with 53.4 g of 1-octene as an α-olefin and 46.6 g of maleic anhydride, xylene 10 g, and octyl thioglycolate 0 as a chain transfer agent. 0.2 g was charged into a flask and, after purging with nitrogen, heated and stirred at 130°C. While stirring, a mixture of 1.0 g of t-butylperoxy-2-ethylhexanoate and 20 g of xylene as an initiator was added dropwise thereto over 2 hours. Then, the mixture was reacted by further stirring for 1 hour while maintaining the temperature at 130° C., xylene was concentrated under reduced pressure to be completely removed, and α-olefin having a number average molecular weight of 4,000 and a nonvolatile content of 100% and an acid anhydride. A polymer (p-1) having a group was obtained.

(Production Examples 2-5)
Polymers (p-2 to p-6) were obtained by synthesizing in the same manner as the polymer (p-1) except that the raw materials and the charged amounts shown in Table 1 were changed. The molecular weight was adjusted by changing the addition amounts of the chain transfer agent and the initiator. The number average molecular weight, acid value, and nonvolatile content of each are as described in Table 1.

<Production of resin (P)>
(Production Example 7)
In a reaction vessel equipped with a gas inlet tube, a thermometer, a condenser and a stirrer, 92.1 g of a polymer p-1 having an α-olefin and an acid anhydride group, 7.9 g of water, 20 g of xylene and diaza as a catalyst. 0.2 g of bicycloundecene was added and heated to 90° C. with stirring. After 1 hour, the temperature was changed to 100° C. and kept for another 1 hour, further changed to 90° C. and kept for 4 hours, and the solvent was concentrated under reduced pressure to be completely removed to obtain a resin (P-1). The number average molecular weight of the obtained copolymer was 4,300.

(Production Examples 8 to 20)
Resins P-2 to P-14 were obtained by carrying out the synthesis in the same manner as the resin (P-1) except that the raw materials and the charged amounts shown in Table 2 were changed.

(Production Example 21)
100 g of the polymer p-1 having an α-olefin and an acid anhydride group and 20 g of xylene were added to a reaction vessel equipped with a gas introduction tube, a thermometer, a condenser, and a stirrer, and heated to 90°C while stirring. After 1 hour, the temperature was changed to 100° C. and kept for 1 hour, further changed to 90° C. and kept for 4 hours, and the solvent was concentrated under reduced pressure to be completely removed to obtain a resin (P-15). The number average molecular weight of the obtained copolymer was 4,000.

・12-HSA (12-hydroxystearic acid)

<Production of coating colorant>
(Example 1)
As a colorant, C.I. I. Pigment Red 122, manufactured by DIC, "FASTOGEN Super Magenta RGT" 35.0 parts, sodium chloride 175.0 parts, P-1 as a resin (P) 12.25 parts in terms of solid content, diethylene glycol 35.0 parts as a water-soluble solvent. Was charged into a stainless steel gallon kneader (manufactured by Inoue Seisakusho) and kneaded at 80° C. for 3 hours. This mixture was poured into 1,000 parts of water and stirred at a high speed mixer for about 1 hour while heating to about 40° C. to form a slurry, which was repeatedly filtered and washed with water to remove sodium chloride and the water-soluble organic solvent, and the pressure was reduced. It was dried at 40° C. under to obtain a coating colorant.

<Production of coating colorant composition>
20 parts of the obtained coating colorant and a 10% aqueous solution of potassium hydroxide as a basic compound were added so that the degree of neutralization would be 100% from the acid value of the resin (P) used in the production of the coating colorant. , 0.03 part of PROXELGXL(S) (manufactured by Lonza) as a preservative, and ion-exchanged water so that the nonvolatile content becomes 22%, and stirring with a disper for about 1 hour while heating in an oil bath at 70°C. did. Then, using an ultrasonic homogenizer with an output of 600 W, treatment was performed for 5 minutes while adjusting the internal temperature to 15°C.
Next, at room temperature (25° C.), Denacol EX321 (epoxy group-containing compound, manufactured by Nagase Chemtex, nonvolatile content 100%, epoxy equivalent 140 g/eq) was used as a cross-linking agent in a molar ratio to the carboxyl group of the resin (P). At 0.5 eq. Next, the mixture was stirred with a disper for about 1 hour while being heated in an oil bath at 70° C., and adjusted with ion-exchanged water so that the nonvolatile content was 22% to obtain a coating colorant composition.

<Production of Inkjet Recording Ink Containing Coating Colorant Composition>
33.3 parts of the obtained coating colorant composition, 16.65 parts of propylene glycol, 16.65 parts of 1,2-hexanediol, 33.3 parts of ion-exchanged water, Surfynol DF110D (as a leveling agent) 0.1 part of Air Products Japan) was mixed to produce an inkjet recording ink.

[Examples 2 to 13, Comparative Examples 1 to 9]
A coating colorant, a coating colorant composition, and an inkjet recording ink containing the coating colorant composition were obtained in the same manner as in Example 1 except that the colorant and the resin (P) used were changed according to Table 3.

・PR150 (CI Pigment Red 150, Tokyo Color Material, "TOSHIKIRED 150TR")
-PV19 (CI Pigment Violet 19, manufactured by Clariant Japan, "In
kJetMagenta E5B02")
-PY74 (CI Pigment Yellow 74, manufactured by Clariant, "Hansayellow 5GX01")
PB15:3 (C.I. Pigment Blue 15:3, manufactured by Toyo Color Co., Ltd., "LIONOLBLUEFG-7351")
PB17 (CI Pigment Black 7, manufactured by Orion Engineered Carbons, "Printex35")

<Coarse grain amount test>
With respect to the coating colorant compositions obtained in Examples and Comparative Examples, the amount of coarse particles in the dispersion was evaluated as follows. Specifically, the time required for passing a fixed amount of the coating colorant composition through a 25 mmφ glass fiber filter (GF/BGE Healthcare Life Science) was evaluated. When the number of coarse particles is large, the filter is clogged and the passage time is long. Further, if the number of coarse particles is large, the filter is clogged and the colorant dispersion cannot be completely filtered. Generally, the filter used in the route for supplying the ink to the inkjet head is larger than 1 μm, and the colorant concentration of the inkjet recording ink is generally lower than that of the coating colorant composition. It can be said that it is sufficient if it passes through, but it can be said that the faster the filtration rate is, the higher the redissolvability and crushability of the coated colorant particles are, and the higher the productivity is. The specific evaluation conditions are shown below. 25mm diameter filter holder (manufactured by ADVANTEC) with a funnel with 15ml scale and a 25mmφ glass fiber filter (manufactured by GF/BGE Healthcare Life Sciences) on a suction vessel equipped with a vacuum pump via a cock. Put on. Operate the decompression pump using a cock so that the inside of the suction vessel is not decompressed. 15 g of the coating colorant composition is weighed into a funnel. Starting the opening pressure of the pump and the suction vessel, the time taken for the entire amount of the coating colorant composition to pass through the filter is measured. The pressure in the suction vessel at this time is 0.05 MPa to 0.07 MPa.
◎: Filtration is possible in less than 30 seconds (very good)
◯: Filtration is possible in 30 seconds or more and less than 60 seconds (good)
Δ: Filtration is possible in 60 seconds or more and less than 90 seconds (no problem in practical use)
×: Cannot be filtered in less than 90 seconds (defective)

<Redispersibility test>
As a liquid for evaluating redispersibility, glycerin 5% (Kao Corporation, concentrated glycerin for cosmetics), triethylene glycol 10%, acetylenol E100 (Kawaken Fine Chemical Co., 2,4,7,9-tetramethyl-) 5-decyne-4,7-diol (10 mol ethylene oxide adduct) was adjusted to 0.5%, ion-exchanged water was added, and the total amount was adjusted to 100%. The mixture was stirred with a magnetic stirrer and mixed well. Created.
10 μL of each coating colorant composition was dropped on a slide glass using a micropipette and left standing in an environment of 60° C. and 40% RH for 24 hours to evaporate and dry the coating colorant composition. 200 μL of the redispersibility evaluation liquid was dropped on the solid matter on the slide glass, and the redispersibility of the solid matter was visually observed and evaluated according to the following evaluation criteria.
⊚: The solid matter was uniformly redispersed in less than 30 seconds. (Very good)
◯: The solid matter was uniformly redispersed in 30 seconds or more and less than 60 seconds. (Good)
Δ: The solid matter was redispersed, but there was a residue even after 60 seconds or more. (No practical problems)
X: Solid matter was not redispersed. (Defective)

<Discharge nozzle clogging test>
The inkjet recording ink obtained above was loaded into an inkjet printer (Seiko Epson Corporation, model number: EM-930C, piezo method), left for 1 week in an environment of 40° C. and 20 RH, and then a nozzle check pattern was printed. The clogging of the discharge nozzle was evaluated according to the following criteria.
A: All nozzles ejected without cleaning. (Very good)
◯: Clogging recovered after one cleaning. (Good)
Δ: Clogging recovered after two cleanings. (No practical problems)
X: There was a nozzle in which the clogging was not recovered even after cleaning twice. (Defective)

<Gloss test>
The inkjet recording inks obtained in Examples and Comparative Examples were loaded into a cartridge of an inkjet printer (“PM-750C” manufactured by Epson Corp.), and coated paper (OK Top Coat+ manufactured by Oji Paper Co., Ltd., 104.7 g/m2). ² ) printed on.
The printed matter was allowed to stand at 25° C. and 50% relative humidity for 24 hours and then measured using a gloss meter “Gloss Checker IG-330” (manufactured by Horiba Ltd.). The measurement angle was 60°. The value obtained by calculating the average value of a total of 5 points was changed as the gloss value. The larger the value, the better the gloss.
⊚: Gloss (60°) 50 or more (very good)
◯: Gloss (60°) 40 or more and less than 50 (good)
Δ: Gloss (60°) 30 or more and less than 40 (no problem in practical use)
X: Gloss (60°) less than 30 (poor)

From the results in Table 3, when the coating colorant of the present invention is used, a coating colorant composition having good redispersibility and easy dispersibility, excellent nozzle clogging suppression and glossiness, and an inkjet recording ink are obtained. It was shown that
The highly hydrophobic α-olefin unit of the resin (P) has a high adsorptivity for the colorant, and electrostatic repulsion sites are formed at a high density by esterification with water or oxycarboxylic acid, resulting in high steric repulsion. It is considered that, since the effect was obtained, a coating colorant having excellent dispersibility and redispersibility, and an inkjet recording ink having excellent nozzle clogging suppression and glossiness were obtained.
It was also shown that the redispersibility and suppression of nozzle clogging are improved by setting the number average molecular weight of the resin (P) to 3,000 to 25,000. It is considered that when the number average molecular weight of the resin (P) is within an appropriate range, the resin (P) was adsorbed to the colorant and the steric repulsion was effectively performed.
When the acid value of the resin (P) is 150 to 400 mgKOH/g, it is considered that the hydrophilicity and electrostatic repulsion of the resin are in a more preferable range and the redispersibility is improved.
When the carbon number of the α-olefin constituting the resin (P) is 12 to 38, the hydrophobicity of the resin is in a more preferable range, the function as a dispersant is optimized, and the redispersibility is improved. It is thought that
In addition, when the molecular weight of the oxycarboxylic acid constituting the side chain of the resin (P) is 80 to 350, the esterification reaction with the polymer (p) easily proceeds, and the hydrophilicity and hydrophobicity are excellent in balance. It was confirmed that the redispersibility was improved because a coating colorant composition having the above properties was obtained. Further, the resin (P) obtained by the esterification reaction of water with the polymer (p) resulted in significantly improved redispersibility, suppression of nozzle clogging, and gloss. It is considered that this is because the flexibility of the molecular chain due to the absence of an extra skeleton in the main chain skeleton and the provision of a high-density charge repulsion site can both be achieved, leading to both the resin coating and high hydrophilicity. This effect does not appear in the resin (P-15) which has not undergone the esterification reaction, and is considered to be the effect of ring opening of the acid anhydride site in the esterification reaction of the resin (p) and water.

Claims (11)

A coating colorant in which the surface of the colorant is coated with a resin (P),
The resin (P) comprises a copolymer of a monomer containing an α-olefin and a monomer containing a polycarboxylic acid group or an acid anhydride group, and water or an oxycarboxylic acid having a divalent or trivalent carboxyl group. A coating colorant which is a reaction product and is a resin having a carboxyl group. The coating colorant according to claim 1, wherein the resin (P) has a number average molecular weight of 2,000 to 35,000. The coating colorant according to claim 1 or 2, wherein the resin (P) has an acid value of 100 to 600 mgKOH/g. The coating colorant according to any one of claims 1 to 3, wherein the α-olefin has 6 to 50 carbon atoms. The coating colorant according to any one of claims 1 to 4, wherein the oxycarboxylic acid has a molecular weight of 80 to 350. A coating colorant composition comprising the coating colorant according to any one of claims 1 to 5, water, and a basic substance. The coating colorant composition according to claim 6, further comprising a crosslinking agent. The coating colorant according to any one of claims 1 to 5, which is used for an ink jet recording ink, a flexographic printing ink, a toner, or a paint. The coating colorant composition according to claim 6 or 7, which is used for an ink jet recording ink, a flexographic printing ink, a toner, or a paint. It is a manufacturing method of the coating colorant according to any one of claims 1 to 5,
A method for producing a coating colorant, comprising mixing a water-soluble organic solvent, a water-soluble inorganic salt, a colorant, and a resin (P) with a kneader, and then removing the water-soluble inorganic salt and the water-soluble organic solvent. A method for producing the coating colorant composition according to claim 6 or 7, wherein
A coating colorant composition in which a step of neutralizing a carboxyl group of the resin (P) by adding a coating colorant, a basic compound and water and a step of adding a crosslinking agent to crosslink the resin (P) are sequentially performed. Method of manufacturing things.