JP2002121441A - Ink composition for ink-jet recording and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water-based ink containing dispersed oil-soluble dye and having excellent picture quality, water resistance and especially storage stability of the ink. SOLUTION: The objective ink composition is produced by dissolving an oil-soluble dye compound in an organic solvent having high boiling point and dispersing the solution in an aqueous medium using a surfactant. The total content of anionic surfactant in the ink composition is >=0.8 wt.% and <5 wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

2. Description of the Related Art In recent years, with the spread of computers, ink-jet printers have been used not only in offices but also at home as paper,
It is widely used for printing on films, cloths and the like.
Oil-based, water-based, and solid inks are known as ink-jet inks, but water-based inks are mainly used in terms of manufacturing, handling, odor, safety, and the like. However,
Many water-based inks have the advantage of high transparency and color density because they use water-soluble dyes that dissolve in a molecular state, but have poor water resistance and cause bleeding when printed on so-called plain paper. It has the drawbacks that the quality is deteriorated and that the light resistance is extremely poor.

Various water-based inks using pigments and disperse dyes have been proposed to improve the above drawbacks. For example, JP-A-56-157468, JP-A-4-18468, JP-A-10-110126, and JP-A-10-110126
It is described in 195355. Although the water resistance is improved by these methods, it is not perfect.In particular, in the case of pigment inks, color development is inferior to dye inks, and the storage stability of the dispersion is liable to cause clogging at the discharge port due to lack of storage stability. Had disadvantages.

JP-A-58-45272 proposes a method of enclosing a dye in urethane polymer latex particles. However, if the dye is encapsulated at a desired concentration, it is difficult to obtain colored particles having excellent dispersion stability. Had disadvantages. Further, JP-A-10-279873 discloses a method of dissolving an acrylic polymer and an oil-soluble dye in an organic solvent and removing the organic solvent after dispersion to produce colored polymer fine particles. In particular, there was a problem in quality when recording on a paper medium for photographic quality and stability in continuous recording. On the other hand, Japanese Patent Publication No. 5-76977 discloses an ink composition in which an oil-soluble dye is dissolved and dispersed in an organic solvent, but the organic solvent specified here is generally compatible with the oil-soluble dye. Was insufficient, resulting in low recording density. In some cases, dye was precipitated during storage, causing clogging of nozzles. According to the research of the present inventor, when an ink composition in which an oil-soluble dye is dissolved and dispersed in an organic solvent is prepared and filled in an ink cartridge containing a porous filler (such as a urethane sponge), It has been found that the dye migrates from the dispersed particles to the porous filler during storage of the ink, and as a result, there is a problem that the optical density of an output product printed using this ink is reduced. The detailed mechanism must be elucidated in the future, but the present inventor believes that this is due to the adhesion of the dispersed particles to the porous filler or the dye due to the oil-soluble dye being solubilized by the surfactant. Think of it as a move.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide an aqueous dispersion ink of an oil-soluble dye having excellent image quality, water resistance and ink storage stability.

[0005]

It has been found that the object of the present invention can be solved by the following method. (1) In an ink composition obtained by dispersing an oil-soluble dye compound dissolved in a high boiling point organic solvent in an aqueous medium using a surfactant, the total content of anionic surfactant is 0.8% of the ink composition. An ink composition for ink jet, characterized in that the content is at least 5% by weight and less than 5% by weight. (2) The inkjet ink composition according to (1), wherein the anionic surfactant is an alkyl polyoxyethylene sulfate or an aryl polyoxyethylene sulfate. (3) An oil-soluble dye containing a compound represented by the following general formula (I) (1) or (2).
3. The ink composition for inkjet according to item 1. General formula (I)

[0006]

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In the formula, X is a residue of a color photographic coupler, and A is
-NR^FourR^FiveOr a hydroxy group, R^FourAnd R^Five
Are each independently a hydrogen atom, an aliphatic group, an aromatic group,
A cyclic group, B¹Is = C (R⁶)-Or = N-
Then B^TwoIs -C (R⁷) = Or -N =, R^Two,
R^Three, R⁶And R⁷Are each independently a hydrogen atom, halogen
Atom, aliphatic group, aromatic group, heterocyclic group, cyano group,-
OR⁵¹, -SR⁵², -CO _TwoR⁵³, -OCOR⁵⁴, -N
R⁵⁵R⁵⁶, -CONR⁵⁷R⁵⁸, -SO_TwoR⁵⁹, -SO _TwoN
R⁶⁰R⁶¹, -NR⁶²CONR⁶³R⁶⁴, -NR⁶⁵CO_TwoR
⁶⁶, -COR⁶⁷, -NR⁶⁸COR⁶⁹Or -NR⁷⁰SO
_TwoR⁷¹And R⁵¹, R⁵², R⁵³, R⁵⁴, R^{Five Five},
R⁵⁶, R⁵⁷, R⁵⁸, R⁵⁹, R⁶⁰, R⁶¹, R⁶², R⁶³, R
⁶⁴, R⁶⁵, R⁶⁶, R^{6 7}, R⁶⁸, R⁶⁹, R⁷⁰And R⁷¹Is
Each independently with a hydrogen atom, an aliphatic group or an aromatic group
Yes, R^TwoAnd R^Three, R^ThreeAnd R^Four, R^FourAnd R^Five, R^FiveAnd R⁶and
R⁶And R⁷May combine with each other to form a ring. (4) Anionic surfactant and nonionic surfactant
Any of (1) to (3), characterized by using
The ink composition for inkjet according to any one of the above. (5) The volume average particle size of the dye dispersion is 5-100.
(1) to (4).
3. The ink composition for inkjet according to item 1. (6) Ink containing white inorganic pigment particles on a support
Any one of (1) to (5) using an image receiving paper having a receiving layer
Forming an image using the ink composition described in (1).
The image forming method to be described.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in detail. The inkjet ink composition of the present invention is a so-called emulsified dispersion in which an oil-soluble dye and a water-immiscible organic solvent are dispersed as fine oil droplets in an aqueous medium. The `` aqueous medium '' in the present invention refers to water or a mixture of water and a small amount of a water-miscible organic solvent, to which a surfactant is added, and if necessary, additives such as wetting agents, stabilizers, and preservatives. Means added.

Next, the surfactant used in the present invention will be described. In the present invention, the surfactant has a hydrophobic portion having 10 or more carbon atoms and a molecular weight of 200 or more and 200 or more.
Represents less than 0. Specifically, the hydrophobic part has 10 carbon atoms.
The above are anionic, nonionic, amphoteric and cationic surfactants, preferably anionic surfactants and nonionic surfactants. Among the anionic surfactants, it is particularly preferable to use alkyl polyoxyethylene sulfate and aryl polyoxyethylene sulfate.
Further, an anionic surfactant and a nonionic surfactant can be used in combination for the purpose of improving the stability of the dye dispersion or controlling the physical properties of the ink. As a preferable combination, an anionic surfactant having emulsifying power such as alkylpolyoxyethylene sodium sulfate during emulsification and a nonionic surfactant such as polyoxyethylene alkyl ether for imparting emulsion stability are used in combination. Method and emulsification using sodium alkylpolyoxyethylene sulfate, and surfynol (SURFYNOLS), an acetylene-based polyoxyethylene oxide surfactant, which is a nonionic surfactant, for the purpose of adjusting the dynamic surface tension of the ink after emulsification (AirProduc
ts & Chemicals). When the amount and type of surfactant required for emulsification and the amount of surfactant required for stabilization after emulsification are different, the same or another type of surfactant can be added after emulsification. When the amount of the surfactant that is optimal for stability after emulsification is smaller than the amount of the surfactant that is required during emulsification, it is preferable to remove the surfactant by performing ultrafiltration or the like after the emulsification.

The following are specific examples of surfactants that can be preferably used in the present invention.

[0012]

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[0013]

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[0014]

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[0015]

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[0016]

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[0017]

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[0018]

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When the amount of the surfactant contained in the ink is small, the interface between the dye dispersion and the aqueous medium cannot be kept sufficiently stable, and the particles of the dispersion are united with each other, the ink cartridge and the porous filler. (Sponge), etc., which causes a decrease in print quality and a decrease in print density. Also,
Normally, the larger the amount of surfactant, the higher the stabilizing effect.However, the present inventor's research has newly revealed that if the amount of anionic surfactant exceeds a certain amount, problems such as a decrease in print density may occur. Became. Accordingly, the amount of the surfactant used is preferably 0.8% by weight to 10% by weight, more preferably 0.8% by weight to 5% by weight, based on the ink. Of these, the amount of the anionic surfactant used is preferably 0.8% by weight to 5% by weight based on the ink.
More preferably, it is from 5% by weight to 3.5% by weight.

For the purpose of stabilization immediately after emulsification, a water-soluble polymer may be added in combination with the above surfactant. As the water-soluble polymer, polyvinyl alcohol, polyvinyl pyrrolidone, polyethylene oxide, polyacrylic acid, polyacrylamide, and copolymers thereof are preferably used. Also polysaccharides, casein,
It is also preferable to use a natural water-soluble polymer such as gelatin. Further, the stabilization of the dye dispersion is achieved by polymerization of derivatives of acrylates, methacrylates, vinyl esters, acrylamides, methacrylamides, olefins, styrenes, vinyl ethers and acrylonitriles which are substantially insoluble in aqueous media. And the like can be used. These polymers have -S
It is desirable to contain O ₃ ⁻ and —COO ⁻ . Examples of polymer dispersants that can be preferably used include methacrylic acid alkyl ester-carboxyethyl acrylic acid random copolymer, methacrylic acid alkyl ester-acrylic acid random copolymer, polyoxyethylene grafted polymethacrylic acid, oxyethylene -Oxypropylene block copolymer, N, N-dialkylacrylamide-carboxyethylacrylic acid copolymer, and the like. When these polymers which are substantially insoluble in an aqueous medium are used in combination, the polymer is preferably used at 0.1 to 20% by weight or less of the high boiling point organic solvent, and used at 0.1 to 10% by weight. Is more preferred.

Next, the oil-soluble dye used in the present invention will be described. The oil-soluble dye used in the present invention is any dye having a solubility in water of less than 1%,
More preferably, the solubility in water is less than 0.1%, and most preferably, the solubility in water is 0.01%.
Less than.

Any applicable yellow dye can be used. For example, phenols, naphthols, anilines, pyrazolones, pyridones, aryl or hetenylazo dyes having open-chain active methylene compounds as coupling components; for example, azomethine dyes having open-chain active methylene compounds as coupling components; Methine dyes such as benzylidene dyes and monomethine oxonol dyes; quinone dyes such as naphthoquinone dyes, anthraquinone dyes and the like; other dyes include quinophthalone dyes, nitro-nitroso dyes, acridine dyes, and the like. Acridinone dyes and the like can be mentioned.

As the applicable magenta dye, any dye can be used. For example, aryl or hetenylazo dyes having phenols, naphthols, and anilines as coupling components; azomethine dyes having pyrazolones and pyrazolotriazoles as coupling components; for example, arylidene dyes, styryl dyes, merocyanine dyes, and oxonol dyes Methine dyes; carbonium dyes such as diphenylmethane dyes, triphenylmethane dyes and xanthene dyes; quinone dyes such as naphthoquinone, anthraquinone and anthrapyridone; condensed polycyclic dyes such as dioxazine dyes; Can be mentioned.

Any applicable cyan dye can be used. For example, an indaniline dye, an indophenol dye or an azomethine dye having a pyrrolotriazole as a coupling component; a polymethine dye such as a cyanine dye, an oxonol dye, or a merocyanine dye; a carbonium dye such as a diphenylmethane dye, a triphenylmethane dye, or a xanthene dye Phthalocyanine dyes; anthraquinone dyes; examples of the coupling component include aryl or hetenylazo dyes having phenols, naphthols, and anilines, and indigo / thioindigo dyes. Also, a black dye such as a polyazo dye can be used.

Each of the above-mentioned dyes may exhibit each color of yellow, magenta and cyan only after a part of the chromophore is dissociated. In this case, the counter cation is an inorganic metal such as an alkali metal or ammonium. It may be a cation, an organic cation such as a pyridinium or quaternary ammonium salt, or a polymer cation having such a partial structure.

Among these dyes, the following general formula (I)
Further preferred is a compound represented by the formula: General formula (I)

[0027]

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[0028] In the general formula (I), X is the residue of the coupler, A represents a -NR ⁴ R ⁵ or a hydroxy group, R ⁴
And R ⁵ each independently represent a hydrogen atom, an aliphatic group, an aromatic group or a heterocyclic group. A is preferably -NR ⁴ R ^5. R ⁴ and R ⁵ are each independently preferably a hydrogen atom or an aliphatic group, more preferably a hydrogen atom, an alkyl group or a substituted alkyl group, and more preferably a hydrogen atom or an alkyl group having 1 to 18 carbon atoms. Most preferably, it is a substituted alkyl group having 1 to 18 carbon atoms.

In the general formula (I), B ¹ is ＣC (R ⁶ )-
Or = N- to represent, B ² is -C (R ⁷⁾ = or -N
= Represents It is preferable that B ¹ and B ² do not simultaneously become -N =, where B ¹ is = C (R ⁶ )-and B ² is -C (R ⁷ ) =
Is more preferable. In this case, in the general formula (I), R ² , R ³ , R ⁶ and R ⁷ are each independently a hydrogen atom, a halogen atom, an aliphatic group, an aromatic group, a heterocyclic group,
Cyano group, -OR ⁵¹ , -SR ⁵² , -CO ₂ R ⁵³ , -OC
^{OR 54, -NR 55 R 56,} -CONR 57 R 58, -SO 2 R
_{^{59, -SO 2 NR 60 R 61}} , -NR 62 CONR 63 R 64, -
_{^{NR 65 CO 2 R 66, -COR}} 67, a -NR ⁶⁸ COR ⁶⁹ or _{^{-NR 70 SO 2 R 71, R}} 51, R 5 2, R 53, R
⁵⁴ , ^R55 , ^R56 , ^R57 , ^R58 , ^R59 , ^R60 , ^R61 ,
^{R 62, R 63, R 6} 4, R 65, R 66, R 67, R 68, R 69, R
⁷⁰ and R ⁷¹ are each independently a hydrogen atom, an aliphatic group or an aromatic group.

R^TwoAnd R⁷Are, independently of each other,
Of which a hydrogen atom, a halogen atom, an aliphatic group, -OR⁵¹, −
NR⁶²CONR⁶³R⁶⁴, -NR⁶⁵CO_TwoR⁶⁶, -NR⁶⁸
COR⁶⁹Or -NR⁷⁰SO_TwoR⁷¹Preferably
Hydrogen, fluorine, chlorine, alkyl,
Substituted alkyl group, -NR⁶²CONR⁶³R⁶⁴Or -NR ⁶⁸
COR⁶⁹More preferably, a hydrogen atom, chlorine
Atom, alkyl group having 1 to 10 carbon atoms or carbon atom
More preferably, it is a substituted alkyl group of formulas 1 to 10.
Hydrogen atom, alkyl group having 1 to 4 carbon atoms, carbon atom
Most preferably, it is a substituted alkyl group having 1 to 4 children.
No.

R ³ and R ⁶ are each independently preferably a hydrogen atom, a halogen atom or an aliphatic group, preferably a hydrogen atom, a fluorine atom, a chlorine atom, an alkyl group or a substituted alkyl group. Is more preferably a hydrogen atom, a chlorine atom, an alkyl group having 1 to 10 carbon atoms, more preferably a substituted alkyl group having 1 to 10 carbon atoms, and a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, Most preferably, it is a substituted alkyl group having 1 to 4 carbon atoms.

In the general formula (I), R^TwoAnd R^Three, R^ThreeWhen
R^Four, R^FourAnd R^Five, R^FiveAnd R⁶Or R⁶And R ⁷Are joined to each other
To form a ring. The combination forming a ring is R^ThreeWhen
R^Four, R^FourAnd R^FiveOr R^FiveAnd R⁶It is preferred that
R^TwoAnd R^ThreeOr R⁶And R⁷Is a ring formed by bonding
Is preferably a 5- or 6-membered ring. Ring is good
Aromatic ring (eg, benzene ring) or unsaturated heterocyclic ring (eg,
Lysine ring, imidazole ring, thiazole ring, pyrimidine
Ring, pyrrole ring and furan ring). R
^ThreeAnd R^FourOr R^FiveAnd R⁶Are bonded to each other to form a ring,
It is preferably a 5- or 6-membered ring. Examples of rings include
A tetrahydroquinoline ring and a dihydroindole ring
No. R^FourAnd R^FiveAre bonded to each other to form a ring of 5
It is preferably a membered ring or a six-membered ring. Examples of rings include
Rolidine ring, piperidine ring and morpholine ring include
It is.

In the present specification, the aliphatic group means an alkyl group, a substituted alkyl group, an alkenyl group, a substituted alkenyl group, an alkynyl group, a substituted alkynyl group, an aralkyl group and a substituted aralkyl group. The alkyl group may have a branch and may form a ring. The alkyl group preferably has 1 to 20 carbon atoms,
More preferably, it is 1 to 18. The alkyl part of the substituted alkyl group is the same as the above-mentioned alkyl group. The alkenyl group may have a branch and may form a ring. The alkenyl group preferably has 2 to 20 carbon atoms, and more preferably 2 to 18 carbon atoms. The alkenyl part of the substituted alkenyl group is the same as the above alkenyl group. The alkynyl group may have a branch or may form a ring. The alkynyl group preferably has 2 to 20 carbon atoms, and has 2 to 18 carbon atoms.
Is more preferable. The alkynyl part of the substituted alkynyl group is the same as the above alkynyl group. The alkyl part of the aralkyl group and the substituted aralkyl group is the same as the above-mentioned alkyl group. The aryl part of the aralkyl group and the substituted aralkyl group is the same as the following aryl group. Examples of the substituent of the alkyl portion of the substituted alkyl group, the substituted alkenyl group, the substituted alkynyl group and the substituted aralkyl group include a halogen atom, a cyano group, a nitro group, a heterocyclic group, -OR ¹¹¹ , -SR ¹¹² , -CO ₂ R ¹¹³ , -NR ¹¹⁴
R ¹¹⁵ , -CONR ¹¹⁶ R ¹¹⁷ , -SO ₂ R ¹¹⁸ and -S
O ₂ NR ¹¹⁹ R ¹²⁰ is mentioned. R ¹¹¹ , R ¹¹² , R ¹¹³ ,
R ¹¹⁴ , R ¹¹⁵ , R ¹¹⁶ , R ¹¹⁷ , R ¹¹⁸ , R ¹¹⁹ and R
¹²⁰ are each independently a hydrogen atom, an aliphatic group or an aromatic group. Examples of the substituent of the aryl portion of the substituted aralkyl group are the same as the following examples of the substituent of the substituted aryl group.

In the present specification, the aromatic group means an aryl group and a substituted aryl group. The aryl group is preferably phenyl or naphthyl, and phenyl is particularly preferred. The aryl part of the substituted aryl group is the same as the above-mentioned aryl group. Examples of the substituent of the substituted aryl group, a halogen atom, a cyano group, a nitro group, an aliphatic group, a heterocyclic ^{group, -OR 121, -SR 122, -CO} 2 R 123,
—NR ¹²⁴ R ¹²⁵ , —CONR ¹²⁶ R ¹²⁷ , —SO ₂ R ¹²⁸ and —SO ₂ NR ¹²⁹ R ¹³⁰ . R ¹²¹ ,
R ¹²² , R ¹²³ , R ¹²⁴ , R ¹²⁵ , R ¹²⁶ , R ¹²⁷ , R ¹²⁸ ,
R ¹²⁹ and R ¹³⁰ are each independently a hydrogen atom, an aliphatic group or an aromatic group.

In the present specification, the heterocyclic group preferably contains a 5- or 6-membered saturated or unsaturated heterocyclic ring. An aliphatic ring, an aromatic ring or another hetero ring may be condensed to the hetero ring. Examples of heteroatoms in the heterocycle include B,
N, O, S, Se and Te. As hetero atoms, N, O and S are preferred. The heterocyclic ring preferably has a free valence (monovalent) at a carbon atom (the heterocyclic group is bonded at the carbon atom). Examples of the saturated heterocycle include a pyrrolidine ring, a morpholine ring, 2-bora-1,
Examples include a 3-dioxolane ring and a 1,3-thiazolidine ring. Examples of the unsaturated heterocycle include an imidazole ring, a thiazole ring, a benzothiazole ring, a benzoxazole ring, a benzotriazole ring, a benzoselenazole ring, a pyridine ring, a pyrimidine ring and a quinoline ring. The heterocyclic group may have a substituent. Examples of the substituent include a halogen atom, a cyano group, a nitro group, an aliphatic group,
Aromatic group, heterocyclic group, -OR ¹³¹ , -SR ¹³² , -CO ₂
R ¹³³ , -NR ¹³⁴ R ¹³⁵ , -CONR ¹³⁶ R ¹³⁷ , -SO ₂
R ¹³⁸ and -SO ₂ NR ¹³⁹ R ^140, and the like.
^{R 131, R 132, R 133} , R 134, R 135, R 136, R 13 7,
R ¹³⁸ , R ¹³⁹ and R ¹⁴⁰ are each independently a hydrogen atom,
It is an aliphatic group or an aromatic group.

The following couplers are preferred as the coupler represented by X in the general formula (I). Yellow coupler: U.S. Pat.Nos. 3,933,501, 4,022,620
No. 4,326,024, No. 4,401,752, No. 4,248,961,
Japanese Patent Publication No. 58-10739, British Patent 1,425,020, 1,476,760
No. 3,973,968, 4,314,023, 4,511,64
No. 9, European Patents 249,473A and 502,424A, Formulas (I) and (II)
A coupler represented by formulas (1) and (2) of 513,496A (especially Y-28 on page 18), a coupler represented by formula (I) of claim 1 of 568,037A, U.S.A. Patent 5,06
No. 6,576, column 1, lines 45 to 55, a coupler represented by the general formula (I), a coupler represented by the general formula (I) in paragraph 0008 of JP-A-4-274425, EP-A-498,381 A1, p. Couplers described in claim 1 (particularly D-35 on page 18);
Couplers represented by the formula (Y) on page 4 of 69A1 (especially Y-
1 (p. 17), Y-54 (p. 41)) and couplers represented by formulas (II) to (IV) in columns 7 to 36 of column 7 of U.S. Pat. No. 4,476,219 (particularly II-17, 19 (column 17) ), II-24 (column 19)).

Magenta coupler; US Pat. No. 4,310,619;
4,351,897, European Patent 73,636, U.S. Patent 3,061,432
No. 3,725,067, Research Disclosure No.
No. 24220 (June 1984), No. 24230 (June 1984),
33552, 60-43659, 61-72238, 60-35730
No. 55-118034, No. 60-185951, U.S. Patent 4,500,63
No. 0, 4,540,654, 4,556,630, International Publication WO88 / 04
No. 795, JP-A-3-39737 (L-57 (lower right of page 11), L-68 (lower right of page 12), L-77 (lower right of page 13), European Patent 456,257 (A-4) -
63 (p. 134), (A-4) -73, -75 (p. 139),
4, -6 (p. 26), M-7 (p. 27), M-45 of 571,959A (p. 19),
JP-A-5-204106, (M-1) (page 6), paragraph 0 of JP-A-4-36631.
237 M-22; U.S. Pat. Nos. 3,061,432 and 3,725,067.

Cyan coupler: US Pat. No. 4,052,212,
No. 4,146,396, No. 4,228,233, No. 4,296,200, European Patent 73,636, CX-1,3,4,5,11,12,14,15 of JP-A-4-04843
(Pages 14 to 16); C-7,10 (p. 35), 34, 35 (37
(Ip), (I-1), (I-17) (pages 42 to 43); a coupler represented by formula (Ia) or (Ib) of claim 1 of JP-A-6-67385.

In addition, JP-A-62-215272 (p. 91), JP-A-2
-33144 (p.3, p.30), EP 355,660A (p.4, p.5, p.45, p.4)
The couplers described on page 7) are also useful.

Further, magenta dyes represented by the following formula (II)
The compound represented by is particularly preferably used. The formula (I
I)

[0041]

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Where R¹Is hydrogen atom, aliphatic group, aromatic
Group, heterocyclic group, cyano group, -OR¹¹, -SR¹², -CO
_TwoR¹³, -OCOR¹⁴, -NR^FifteenR¹⁶, -CONR¹⁷R
¹⁸, -SO_TwoR¹⁹, -SO_TwoNR²⁰R^{twenty one}, -NR^{twenty two}CON
R^{twenty three}R^{twenty four}, -NR^{twenty five}CO_TwoR²⁶, -COR²⁷, -NR²⁸
COR²⁹Or -NR³⁰SO_TwoR³¹And R¹¹, R^1
Two, R¹³, R¹⁴, R^Fifteen, R¹⁶, R¹⁷, R¹⁸, R¹⁹,
R²⁰, R^{twenty one}, R^{twenty two}, R^{twenty three}, R^{Two Four}, R^{twenty five}, R²⁶, R²⁷, R
²⁸, R²⁹, R³⁰And R³¹Are each independently a hydrogen source
, An aliphatic group or an aromatic group. Also R^Two, R^Three,
A, B¹And B^TwoIs synonymous with general formula (I),
Is also the same. Z is an aliphatic group, aromatic
Group, heterocyclic group, cyano group, -OR⁸¹, -SR⁸², -CO
_TwoR⁸³, -OCOR⁸⁴, -NR⁸⁵R⁸⁶, -CONR⁸⁷R
⁸⁸, -SO_TwoR⁸⁹, -SO_TwoNR⁹⁰R⁹¹, -NR ⁹²CON
R⁹³R⁹⁴, -NR⁹⁵CO_TwoR⁹⁶, -COR⁹⁷, -NR⁹⁸
COR⁹⁹Or -NR¹⁰⁰SO_TwoR¹⁰¹At least one of
5- or 6-membered nitrogen-containing heterocyclic ring which may be substituted
Represents a group of atoms that form another heterocyclic ring
And a condensed ring may be formed. Where R⁸¹, R⁸², R⁸³,
R⁸⁴, R⁸⁵, R⁸⁶, R⁸⁷, R⁸⁸, R⁸⁹, R⁹⁰, R⁹¹, R
⁹², R⁹³, R⁹⁴, R⁹⁵, R⁹⁶, R⁹⁷, R⁹⁸, R⁹⁹, R
¹⁰⁰And R¹⁰¹Are each independently a hydrogen atom or an aliphatic group
Or an aromatic group.

Next, the formula (II) will be described in more detail.
You. R¹Is a hydrogen atom, an aliphatic group, an aromatic group,
-OR¹¹, -SR¹², -NR^FifteenR¹⁶, -SO_TwoR¹⁹, −
NR^{twenty two}CONR^{twenty three}R^{twenty four}, -NR^{twenty five}CO_TwoR²⁶, -NR²⁸
COR²⁹Or -NR³⁰SO_TwoR ³¹Preferably
, Hydrogen atom, aliphatic group, aromatic group, -OR¹¹Or-
NR^FifteenR¹⁶And more preferably a hydrogen atom,
Kill group, substituted alkyl group, aryl group, substituted aryl
Group, alkoxy group, substituted alkoxy group, phenoxy group,
Substituted phenoxy, dialkylamino, or substituted di
More preferably, it is an alkylamino group,
, An alkyl group having 1 to 10 carbon atoms,
10 substituted alkyl groups, aryl having 6 to 10 carbon atoms
Group or a substituted aryl group having 6 to 10 carbon atoms.
Are more preferable, and a hydrogen atom, an alkyl group having 1 to 6 carbon atoms
A alkyl group or a substituted alkyl group having 1 to 6 carbon atoms.
Is most preferred. A is -NR^FourR^FiveWhat is
Preferred.

Z preferably forms a 5-membered nitrogen-containing heterocyclic ring, and examples of the 5-membered nitrogen-containing heterocyclic ring include an imidazole ring,
It includes a triazole ring and a tetrazole ring.

Of the compounds represented by the formula (II), oil-soluble pyrazolotriazole azomethine compounds represented by the following formula (III) are particularly preferred. Formula (III)

[0046]

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Where R ¹ , R ² , R ³ , R ⁴ , R ⁵ ,
R ⁶ and R ⁷ have the same meaning as in formula (I). The X ¹ and X ² each independently -C (R ⁸⁾ is = or represents -N =, R ⁸ represents a hydrogen atom, an aliphatic group, an aromatic group, X ¹
And X One of ² is always -N =, also X ¹ and X ² are not equal to -N = simultaneously.

At this time, R ⁸ is a hydrogen atom, an alkyl group,
It is preferably a substituted alkyl group, an aryl group or a substituted aryl group, more preferably a hydrogen atom, a substituted alkyl group having 1 to 150 carbon atoms, or a substituted aryl group having 1 to 150 carbon atoms, and more preferably 1 to 100 carbon atoms. Most preferred is a substituted alkyl group having 1 to 100 carbon atoms and a substituted aryl group having 1 to 100 carbon atoms. When X ¹ and X ² are simultaneously -C (R ⁸ ) =, each R ⁸ may be bonded to each other to form a ring;
The ring to be formed is preferably a 6-membered ring. The ring is preferably an aromatic ring (eg, a benzene ring).

In the formula (III), more preferably, X ¹ is-
A pyrazolotriazole azomethine compound in which N = and X ² is —C (R ⁸ ) =.

Examples of the pyrazolotriazole azomethine compound represented by the formula (III) will be given below.

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The compound examples of the present invention are further described in Japanese Patent Application Nos.
No. 5,189, but is not limited thereto.

The dye represented by the formula (III) of the present invention is described in, for example, JP-A-4-126772, JP-B-7-94180.
The compound can be synthesized with reference to the methods described in Japanese Patent Application Laid-Open Publication No. 11-365187 and Japanese Patent Application No. 11-365187.

As the cyan dye, the following formula (IV-
The pyrrolotriazole azomethine compounds represented by 1) to (IV-4) are particularly preferably used.

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In the formulas (IV-1) to (IV-4), A, R ² ,
R ³ , B ¹ and B ² have the same meanings as in formula (I), and their preferred ranges are also the same. R ²⁰¹ , R ²⁰² and R ²⁰³ each independently have the same meaning as R ¹ in formula (II). R ²⁰¹
And R ²⁰² may combine with each other to form a ring structure.

Further, the above-mentioned general formulas (IV-1) to (IV-4)
R of the pyrrolotriazole azomethine compound represented by
^{When 201} is an electron-withdrawing group having a Hammett substituent constant σ _p value of 0.30 or more, the absorption is sharp, and it is more preferable. And, R of the pyrrolotriazole azomethine compound
The sum of Hammett substituent constant σ _p values of ²⁰¹ and R ²⁰² is 0.
Those having a value of 70 or more exhibit excellent hue as a cyan color, and are more preferable.

The hue will be described in more detail. The pyrrolotriazole azomethine compound of the present invention has R ²⁰¹ ,
R ^202, R ²⁰³ and R ^2, R ^3, A, by way of the selected B ^1, B ^2, can have different hues. In the pyrrolotriazole azomethine compound of the present invention, when R ²⁰¹ is an electron-withdrawing substituent, the absorption waveform becomes sharper as compared with the case where R ²⁰¹ is not, which is preferable. The stronger the degree of electron withdrawing, the sharper the absorption waveform becomes. From this viewpoint, R ²⁰¹ is preferably an electron-withdrawing group having a Hammett substitution constant σ _p value of 0.30 or more, rather than an alkyl group or an aryl group. Further, an electron-withdrawing group having a Hammett substitution constant σ _p value of 0.45 or more is more preferable,
Zero or more electron-withdrawing groups are most preferred.

The pyrrolotriazole azomethine compound of the present invention is more preferably used as a cyan dye than as a magenta dye. The pyrrolotriazole azomethine compounds represented by formulas (IV-1) and (IV-2) of the present invention can be used as a magenta dye. In order to make the dye of the present invention a cyan dye, R ²⁰¹ and R
The sum of the Hammett substituent constant σ _p value of ²⁰² is preferably 0.70 or more. If the sum of the σ _p values is less than 0.70, the absorption maximum wavelength is a short wavelength for a cyan dye and looks blue to human eyes, which is not preferable. Among them, those having a Hammett substituent constant σ _p value of R ²⁰² of 0.30 or more are preferable. Hammett substituent constant σ _{p of} R ²⁰¹ and R ²⁰²
The sum of the values is preferably 2.0 or less.

Examples of the electron-withdrawing group having a Hammett substituent constant σ _p value of 0.30 or more include an acyl group, an acyloxy group,
Carbamoyl group, alkoxycarbonyl group, aryloxycarbonyl group, cyano group, nitro group, alkylsulfinyl group, arylsulfinyl group, alkylsulfonyl group, arylsulfonyl group, sulfamoyl group, halogenated alkyl group, halogenated alkoxy group, aryl halide Oxy group, halogenated alkylthio group, 2
An aryl group substituted with one or more electron-withdrawing groups having a σ _p value of 0.15 or more, and a heterocyclic ring can be given.
More specifically, an acyl group (for example, acetyl, 3-phenylpropanoyl), an acyloxy group (for example, acetoxy), a carbamoyl group (for example, N-ethylcarbamoyl, N, N-dibutylcarbamoyl, N- (2-dodecyloxyethyl) ) Carbamoyl, N-methyl-N-dodecylcarbamoyl), alkoxycarbonyl groups (eg, methoxycarbonyl, butyloxycarbonyl, dodecyloxycarbonyl, octadecyloxycarbonyl), aryloxycarbonyl groups (eg, phenoxycarbonyl), cyano group, nitro Group, alkylsulfinyl group (eg, 3-phenoxypropylsulfinyl), arylsulfinyl group (eg, 3-pentadecylphenylsulfinyl), alkylsulfonyl group (eg, methanesulfonyl) Le, C1-12alkyl), an arylsulfonyl group (e.g., benzenesulfonyl), a sulfamoyl group (e.g., N- ethylsulfamoyl,
N, N-dipropylsulfamoyl), a halogenated alkyl group (eg, trifluoromethyl, heptafluoropropyl), a halogenated alkoxy group (eg, trifluoromethyloxy), a halogenated aryloxy group (eg,
Pentafluorophenyloxy), a halogenated alkylthio group (eg, difluoromethylthio), two or more σ _p
An aryl group substituted with another electron-withdrawing group having a value of 0.15 or more (for example, 2,4-dinitrophenyl, 2,4,4)
6-trichlorophenyl, pentachlorophenyl), a heterocyclic group (for example, 2-benzoxazolyl, 2-benzothiazolyl, 1-phenyl-2-benzimidazolyl,
5-chloro-1-tetrazolyl, 1-pyrrolyl).

Examples of the electron-withdrawing group having a Hammett σ _p value of 0.45 or more include an acyl group (eg, acetyl, 3-phenylpropanoyl), an alkoxycarbonyl group (eg, methoxycarbonyl), and an aryloxycarbonyl group (eg, methoxycarbonyl). , M-chlorophenoxycarbonyl), a cyano group, a nitro group, an alkylsulfinyl group (for example, n
-Propylsulfinyl), arylsulfinyl group (eg, phenylsulfinyl), alkylsulfonyl group (eg, methanesulfonyl, n-octanesulfonyl), arylsulfonyl group (eg, benzenesulfonyl), sulfamoyl group (eg, N-ethylsulfamoyl) , N, N-dimethylsulfamoyl) and a halogenated alkyl group (eg, trifluoromethyl). Examples of the electron-withdrawing group having a Hammett substituent constant σ _p value of 0.60 or more include a cyano group (0.66), a nitro group (0.78), and a methanesulfonyl group (0.72).
Can be mentioned as an example.

The sum of the σ _p values of R ²⁰¹ and R ²⁰² is 0.70
The combination of the above, R ²⁰¹ is a cyano group, an alkoxycarbonyl group, an alkylsulfonyl group, an arylsulfonyl group, selected from halogenated alkyl group, R ²⁰²
Is an acyl group, an acyloxy group, a carbamoyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a cyano group, an alkylsulfonyl group, an arylsulfonyl group,
A combination selected from a sulfamoyl group and a halogenated alkyl group is preferred.

The preferred structure of the pyrrolotriazoleazomethine compound used in the present invention is represented by the following general formula (IV-1)
a) a structure represented by a), wherein R ² is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a substituted alkyl group having 1 to 4 carbon atoms,
An alkoxy group having 1 to 4 carbon atoms, a halogen atom (fluorine,
Chlorine, bromine), an acylamino group having 1 to 5 carbon atoms, an aminocarbonylamino group having 1 to 5 carbon atoms, or 1 to 1 carbon atoms
Be a 5 alkoxycarbonylamino group; R ⁴ and R ⁵ each independently represent a hydrogen atom, an alkyl group or a substituted alkyl group having 1 to 18 carbon atoms having 1 to 18 carbon atoms; R ²⁰¹
And R ²⁰² are each independently an electron-withdrawing group having a Hammett substituent constant σ _p value of 0.30 or more, and R ²⁰³ has 1 carbon atom.
An alkyl group having 1 to 18 carbon atoms, a substituted alkyl group having 1 to 18 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 20 carbon atoms. Then, it preferably has 0.70 or more the sum of Hammett substituent constant sigma _p value of R ²⁰¹ and R ²⁰² Among time those described above for use as a cyan dye, even 1.00 or more the sum of sigma _p value Are preferred. Most preferred of the pyrrolotriazole azomethine compounds of the present invention have a structure represented by the following general formula (IV-1a); R ² is a hydrogen atom or a methyl group; R ⁴ and R ⁵ are each independently a carbon atom. R ²⁰¹ is a cyano group; R ²⁰² is an alkoxycarbonyl group; R ²⁰³
Is an aryl group.

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Here, the Hammett's substituent constant σ _p value used in the present specification will be described. The Hammett's rule is an empirical rule proposed by LP Hammett in 1935 to quantitatively discuss the effect of substituents on the reaction or equilibrium of a benzene derivative, and is widely accepted today. The substituent constants determined by Hammett's rule include σ _p values and σ _m values, and these values can be found in many general books. For example, JA Dean,
"Lange's Handbook of Chemistry", 12th edition, 197
9 (Mc Graw-Hill) and extra edition of "Chemistry", 122
No. 96-103, 1979 (Nankodo).
In the present invention, each substituent is limited or described by Hammett's substituent constant σ _p, but this is limited to only those substituents having a value known in the literature, which can be found in the above-mentioned books. Not to mention the meaning, but it goes without saying that even if the value is unknown in the literature, it also includes a substituent that would be included in the range when measured based on the Hammett rule. Although the compound represented by the general formula described in this specification is not a benzene derivative, the σ _p value is used as a measure of the electronic effect of the substituent regardless of the substitution position. The Hammett's substituent constant is described in Japanese Patent Application No. 11-3651.
No. 88 describes it, and the σ _p value of the present invention is the same as that defined therein.

Specific examples of the pyrrolotriazoleazomethine compound used in the present invention will be given below, but these are for describing the present invention in detail, and the present invention is not limited thereto.

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Further, examples of the compounds of the present invention are described in Japanese Patent Application Nos.
No. 5,188, but is not limited thereto.

The pyrrolotriazoleazomethine dyes represented by (IV-1) to (IV-4) of the present invention are disclosed in
No. 77959, No. 9-292679, No. 10-629
No. 26 and Japanese Patent Application No. 11-365188 can be used for synthesis.

The dye of the present invention is used in an amount of from 0.05 to
It is preferably 50% by weight, more preferably 0.1 to 10% by weight.

The boiling point of the high boiling organic solvent used in the present invention is preferably 150 ° C. or higher, and more preferably 170 ° C. or higher. Examples of the high boiling organic solvent used in the present invention include phthalic acid esters (for example, dibutyl phthalate, dioctyl phthalate, dicyclohexyl phthalate, di-2-ethylhexyl phthalate, decyl phthalate, bis (2,4-di-tert- Amylphenyl) isophthalate, bis (1,1-diethylpropyl) phthalate), esters of phosphoric acid or phosphon (eg, diphenyl phosphate, triphenyl phosphate, tricresyl phosphate, 2-ethylhexyl diphenyl phosphate, dioctyl butyl phosphate, Tricyclohexyl phosphate, tri-2-
Ethylhexyl phosphate, tridodecyl phosphate, di-2-ethylhexyl phenyl phosphate),
Benzoic acid (e.g., 2-ethylhexylbenzoate, 2,4-dichlorobenzoate, dodecylbenzoate, 2-ethylhexyl-p-hydroxybenzoate), amides (e.g., N, N-diethyldodecaneamide, N, N-diethyl) Laurylamide), alcohols or phenols (such as isostearyl alcohol, 2,4-di-tert-amylphenol),
Aliphatic esters (for example, dibutoxyethyl succinate, di-2-ethylhexyl succinate, 2-hexyldecyl tetradecanoate, tributyl citrate, diethylazelate, isostearyl lactate, trioctyl citrate), aniline derivatives (N , N-dibutyl-2-
Butoxy-5-tert-octylaniline, etc.), chlorinated paraffins (paraffins having a chlorine content of 10% to 80%), trimesic esters (for example, tributyl trimesate), dodecylbenzene, diisopropylnaphthalene, phenols ( For example, 2,4-di-te
rt-amylphenol, 4-dodecyloxyphenol, 4-dodecyloxycarbonylphenol, 4-
(4-dodecyloxyphenylsulfonyl) phenol), carboxylic acids (for example, 2- (2,4-di-te)
rt-amylphenoxybutyric acid, 2-ethoxyoctanedecanoic acid), alkyl phosphoric acids (eg, di-2 (ethylhexyl) phosphoric acid, diphenylphosphoric acid) and the like. The high-boiling organic solvent is 0.01% by weight based on the dye.
It is preferably used in an amount of 10 to 10 times, more preferably in an amount of 0.05 to 5 times. These high-boiling organic solvents may be used alone or in a mixture of several kinds [for example, tricresyl phosphate and dibutyl phthalate, trioctyl phosphate and di (2-ethylhexyl) sebacate, dibutyl phthalate and poly (N-t-butyl). Acrylamide)]
May be used in

Examples of other high-boiling point organic solvents used in the present invention and / or methods for synthesizing these high-boiling point organic solvents are described, for example, in US Pat. Nos. 2,322,027 and 2,322.
No. 533,514, No. 2,772,163, No. 2,835,579, No. 3,594,171, No. 3,676,137, No. 3,689,271
No. 3,700,454, No. 3,748,141, No. 3,764,
No. 336, No. 3,765,897, No. 3,912,515, No. 3,
936,303, 4,004,928, 4,080,209, 4,127,413, 4,193,802, 4,207,393
No. 4,220,711, No. 4,239,851, No. 4,278,
No. 757, No. 4,353,979, No. 4,363,873, No. 4,
430,421, 4,430,422, 4,464,464, 4,483,918, 4,540,657, 4,684,606
No. 4,728,599, No. 4,745,049, No. 4,935,
Nos. 321 and 5,013,639, EP 276,319A, 286,253A, 289,820A, 309,158A,
309,159A, 309,160A, 509,311A, 51
No. 0,576A, East German Patent No. 147,009, No. 157,147, No. 159,573, No. 225,240A, British Patent No. 2,091,124A
No., JP-A-48-47335, JP-A-50-26530, JP-A-51-25133,
No. 51-26036, No. 51-27921, No. 51-27922, No. 51-149
028, 52-46816, 53-1520, 53-1521,
53-15127, 53-146622, 54-91325, 54-1
06228, 54-118246, 55-59464, 56-64333
No. 56-81836, No. 59-204041, No. 61-84641, No.
62-118345, 62-247364, 63-167357, 63
-214744, 63-301941, 64-9452, 64-945
No. 4, No. 64-68745, JP-A No. 1-101543, No. 1-102454
No. 2-792, No. 2-4239, No. 2-43541, No. 4-2923
No. 7, No. 4-30165, No. 4-232946, No. 4-346338, etc. The high boiling organic solvent, with respect to the dye,
Preferably used in an amount of 0.01 to 10 times by weight,
More preferably, it is used in an amount of 0.05 to 5 times.

The low boiling organic solvent used in the present invention is an organic solvent having a boiling point of about 30 ° C. or more and 160 ° C. or less at normal pressure. For example, esters (eg, ethyl acetate,
Butyl acetate, ethyl propionate, β-ethoxyethyl acetate, methyl cellosolve acetate),
Alcohols (eg, isopropyl alcohol, n-butyl alcohol, secondary-butyl alcohol), ketones (eg, methyl isobutyl ketone, methyl ethyl ketone, cyclohexanone), amides (eg, dimethylformamide, N-methylpyrrolidone), ethers (eg, tetrahydrofuran, Dioxane) and the like are preferably used, but the invention is not limited thereto.

In emulsification dispersion, an oil phase in which a dye is dissolved in a mixed solvent of a high-boiling organic solvent and, in some cases, a low-boiling organic solvent is dispersed in an aqueous phase mainly composed of water, and fine oil droplets of the oil phase are dispersed. Done to make. At this time, the above-mentioned surfactant is added to one or both of the water phase and the oil phase, and further additives such as a wetting agent, a dye stabilizer, an emulsion stabilizer, a preservative, and a fungicide are required. It can be added according to. As the emulsification method, a method of adding an oil phase to an aqueous phase is generally used. However, a so-called phase inversion emulsification method in which an aqueous phase is dropped into an oil phase can also be preferably used.

When an aqueous ink is prepared by dispersing a hydrophobic dye by emulsification and dispersion, the particle size control is particularly important. In order to increase color purity and density when an image is formed by inkjet, it is essential to reduce the average particle size. Therefore, the volume average particle size is most preferably in the range of 5 to 100 nm. It was also found that the presence of coarse particles plays a very important role in printing performance. That is, it has been found that coarse particles clog the nozzles of the head or form dirt even if they are not clogged, causing non-ejection of ink or ejection distortion, which has a significant effect on printing performance. In order to prevent this, it is important to reduce the number of particles of 5 μm or more to 10 or less and 1 μm or more to 1000 or less in 1 μl of the ink. As a method for removing these coarse particles, a known centrifugal separation method, a microfiltration method, or the like can be used. These separation means may be performed immediately after emulsification and dispersion, or may be performed immediately before filling the ink cartridge after adding various additives such as a wetting agent and a surfactant to the emulsified dispersion. As an effective means to reduce the average particle size and eliminate coarse particles,
A mechanical emulsifying device can be used.

As the emulsifying device, known devices such as a simple stirrer, an impeller stirring system, an in-line stirring system, a mill system such as a colloid mill, and an ultrasonic system can be used, but the use of a high-pressure homogenizer is particularly preferable. is there. High pressure homogenizer is US-45332
No. 54, Japanese Patent Application Laid-Open No. 6-47264, etc. describe a detailed mechanism, and commercially available devices include a Gorin homogenizer (APV GAULIN INC.) And a microfluidizer (MICROFLUIDEX IN).
C. ), And Ultimate (Sugino Machine Co., Ltd.). Further, a high-pressure homogenizer provided with a mechanism for forming fine particles in an ultrahigh-pressure jet stream, as described in US Pat. No. 5,720,551, is particularly effective for the emulsification and dispersion of the present invention. DeBEE2000 (BEE IN) is an example of an emulsifying apparatus using this ultrahigh-pressure jet stream.
TERNATIONAL LTD. ).

The pressure at the time of emulsification with a high-pressure emulsifying and dispersing apparatus is 5
It is 0 MPa or more, preferably 60 MPa or more, and more preferably 180 MPa or more. For example, it is a particularly preferable method to use two or more emulsifiers in combination, for example, by emulsifying with a stirring emulsifier and then passing through a high pressure homogenizer. Also, once emulsified and dispersed in these emulsifiers,
A preferred method is to add an additive such as a wetting agent or a surfactant, and then pass the ink through the high-pressure homogenizer again while filling the cartridge with the ink. When a low-boiling organic solvent is contained in addition to the high-boiling organic solvent, it is preferable to remove the low-boiling solvent from the viewpoint of the stability of the emulsion and safety and health. Various known methods can be used to remove the low-boiling solvent depending on the type of the solvent. That is, there are an evaporation method, a vacuum evaporation method, an ultrafiltration method and the like. This step of removing the low-boiling organic solvent is preferably performed as soon as possible immediately after emulsification.

The average particle size and the particle size distribution can be measured by a static light scattering method, a dynamic light scattering method, a centrifugal sedimentation method, or a method described in Experimental Chemistry Course, 4th edition, pages 417 to 418. Can be used. The dynamic light scattering method using the laser Doppler effect is particularly preferable because the particle size can be measured down to a small size. The volume average particle size is the average particle size weighted by the particle volume, and is obtained by dividing the sum of the diameters of the individual particles multiplied by the volume of the particles in the aggregate of the particles by the total volume of the particles. For the volume average particle size, see "Chemistry of Polymer Latex (Souichi Muroi,
Polymer Publishing Association) ”on page 119.

When the emulsified dispersion of the colored fine particles of the hydrophobic dye obtained in the present invention is used as an ink for ink-jet recording, a drying inhibitor for preventing clogging due to drying operation at the ink ejection port, Penetration enhancers, UV absorbers, antioxidants,
Additives such as a viscosity adjuster, a surface tension adjuster, a dispersant, a dispersion stabilizer, a fungicide, a rust preventive, a pH adjuster, an antifoaming agent and a chelating agent can be appropriately selected and used in an appropriate amount.

As the drying inhibitor used in the present invention, a water-soluble organic solvent having a lower vapor pressure than water is preferable. Specific examples include ethylene glycol, propylene glycol, diethylene glycol, polyethylene glycol,
Thiodiglycol, dithiodiglycol, 2-methyl-
Polyhydric alcohols represented by 1,3-propanediol, 1,2,6-hexanetriol, acetylene glycol derivatives, glycerin, trimethylolpropane, ethylene glycol monomethyl (or ethyl) ether, diethylene glycol monomethyl (or ethyl)
Lower alkyl ethers of polyhydric alcohols such as ether and triethylene glycol monoethyl (or butyl) ether, 2-pyrrolidone, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, N-ethylmorpholine And the like, sulfur-containing compounds such as sulfolane, dimethyl sulfoxide and 3-sulfolene, polyfunctional compounds such as diacetone alcohol and diethanolamine, and urea derivatives. Of these, polyhydric alcohols such as glycerin and diethylene glycol are more preferred. The above-mentioned drying inhibitors may be used alone or in combination of two or more. These anti-drying agents are preferably contained in the ink in an amount of 10 to 50% by weight.

Examples of the penetration enhancer used in the present invention include alcohols such as ethanol, isopropanol, butanol, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether and 1,2-hexanediol, sodium lauryl sulfate, sodium oleate and the like. Nonionic surfactants listed as surfactants for emulsification and dispersion can also be used. These have sufficient effects if they are contained in the ink in an amount of 10 to 30% by weight, and it is preferable to use them within the range of the addition amount that does not cause printing bleeding or paper loss (print-through).

The ultraviolet absorber used in the present invention to improve the storability of an image is disclosed in JP-A-58-1856.
Nos. 77, 61-90537 and JP-A-2-
No. 782, No. 5-1970075, No. 9-34
Benzotriazole compounds described in JP-A-557 / 057, JP-A-46-2784, JP-A-5-1944
No. 83, U.S. Pat. No. 3,214,463, benzophenone-based compounds described in JP-B-48-30492, JP-B-56-21141, and JP-A-10-881.
No. 06, etc., cinnamic acid-based compounds,
298503, 8-53427 and 8-
Nos. 339368, 10-182621, and JP-A-8-501291, and the like. 2423
No. 9 and the stilbene compounds disclosed in
No. 215272 (page 125, upper right column, second line to page 127, lower left column, last line), and JP-A-2-33144 (page 37, lower right column 14)
Line to page 38, upper left column, line 11), European Patent No. 0.35
An ultraviolet absorber described in 5.600A2 (p. 85, lines 22 to 31), a compound that absorbs ultraviolet light and emits fluorescence as represented by a benzoxazole compound, a so-called fluorescent whitening agent, can also be used.

The fungicides used in the present invention include sodium dehydroacetate, sodium benzoate, sodium pyridinethione-1-oxide, ethyl p-hydroxybenzoate, 1,2-benzisothiazoline-3-
And its salts. These are preferably used in the ink at 0.02 to 1.00% by weight.

The rust preventive used in the present invention is disclosed in
No. 104448 (column 39, line 50 to column 70, line 9), JP-A-7-77775 (column 61, line 50 to column 62, line 49), JP-A 7-301895 (column 87, line 49) To column 88, line 48).

The pH adjuster used in the present invention can be suitably used in terms of pH adjustment, dispersion stability imparting, and the like, and is preferably added so as to have a pH of 4.5 to 10.0. More preferably, it is added so as to have a pH of 6 to 10.0. As the pH adjuster, organic bases as basic ones, inorganic alkalis and the like, organic acids as acidic ones,
And inorganic acids. Examples of the organic base include triethanolamine, diethanolamine, N-methyldiethanolamine, dimethylethanolamine and the like. Examples of the inorganic alkali include hydroxides of alkali metals (eg, sodium hydroxide, lithium hydroxide, potassium hydroxide, etc.), carbonates (eg, sodium carbonate, sodium hydrogen carbonate, etc.), and ammonia. In addition, examples of the organic acid include acetic acid, propionic acid, trifluoroacetic acid, and alkylsulfonic acid. Examples of the inorganic acid include hydrochloric acid, sulfuric acid, and phosphoric acid.

The surface tension of the ink of the present invention is from 20 to 60.
mN / m is preferred. More preferably, 25 to 45 mN /
m. Examples of the surface tension modifier used in the present invention include nonionic, cationic and anionic surfactants. For example, the surfactant used for the above-mentioned emulsification and dispersion can be used. The surfactant used here preferably has a solubility in water at 25 ° C. of 0.5% or more.

The viscosity of the ink of the present invention is preferably 30 mPa · s or less. Further, it is more preferably adjusted to 20 mPa · s or less, and most preferably adjusted to 10 mPa · s or less. Examples of the viscosity modifier include a high-viscosity water-soluble organic solvent such as glycerin, and a water-soluble polymer such as polyethylene glycol and polyvinyl alcohol.

In the present invention, the above-mentioned various cationic, anionic and nonionic surfactants are used as dispersants and dispersion stabilizers, and fluorine-based, silicone-based compounds and EDs are used as defoamers.
A chelating agent represented by TA and the like can be used as needed. These various additives are generally added to the emulsified dispersion after emulsification of the hydrophobic dye, but may be added to the oil phase or the aqueous phase at the time of emulsification and dispersion, so-called co-emulsification.

The ink of the present invention is a known recording material, that is, plain paper or resin-coated paper, for example, JP-A-8-169172, JP-A-8-27693, JP-A-2-276670, and JP-A-7-276789. Gazette, pp. 9-323475
JP, JP-A-62-238873 and JP-A-10-23878
Nos. -1538989 and 10-217473,
10-235959, 10-337947, 10-217597, and 10-3379
No. 47, etc.
It can be used to form an image on film, electrophotographic paper, fabric, glass, metal, ceramics, and the like.

Hereinafter, recording paper and recording film used for ink-jet printing using the ink of the present invention will be described. Supports for recording paper and film are chemical pulp such as LBKP and NBKP, GP, P
Consists of mechanical pulp such as GW, RMP, TMP, CTMP, CMP and CGP, waste paper pulp such as DIP, etc., and if necessary, conventionally known pigments, binders, sizing agents, fixing agents, cationic agents, and paper strength And various additives such as a fourdrinier paper machine, a round paper machine, etc., into which an additive such as an agent is mixed can be used. In addition to these supports, any of synthetic paper and plastic film sheets may be used. The support has a thickness of 10 to 250 μm and a basis weight of 10 to 250 g / m.
² is preferred. The support may be provided with the ink receiving layer and the back coat layer as they are, or after providing a size press or an anchor coat layer with starch, polyvinyl alcohol or the like, the ink receiving layer and the back coat layer may be provided. Further, the support may be subjected to a flattening treatment by a calender device such as a machine calender, a TG calender, and a soft calender. In the present invention, as the support, paper and plastic films laminated on both sides with a polyolefin (eg, polyethylene, polystyrene, polyethylene terephthalate, polybutene and copolymers thereof) are more preferably used. It is preferable to add a white pigment (eg, titanium oxide, zinc oxide) or a coloring dye (eg, cobalt blue, ultramarine, neodymium oxide) to the polyolefin polyolefin.

In the ink receiving layer provided on the support,
Contains a pigment and an aqueous binder. As the pigment, a white pigment is good, and as the white pigment, calcium carbonate, kaolin, talc, clay, diatomaceous earth, synthetic amorphous silica,
Aluminum silicate, magnesium silicate, calcium silicate, aluminum hydroxide, alumina, lithopone, zeolite, barium sulfate, calcium sulfate, titanium dioxide,
Examples include inorganic white pigments such as zinc sulfide and zinc carbonate, and organic pigments such as styrene pigment, acrylic pigment, urea resin, and melamine resin. As the white pigment contained in the ink receiving layer, a porous inorganic pigment is preferable, and in particular, synthetic amorphous silica having a large pore area is preferable. As the synthetic amorphous silica, both silicic anhydride obtained by a dry production method and hydrous silicic acid obtained by a wet production method can be used, and it is particularly preferable to use hydrous silicic acid.

Examples of the aqueous binder contained in the ink receiving layer include polyvinyl alcohol, silanol-modified polyvinyl alcohol, starch, cationized starch, casein, gelatin, carboxymethylcellulose, hydroxyethylcellulose, polyvinylpyrrolidone, polyalkylene oxide, and polyalkylene oxide derivatives. Such as water-soluble polymers, styrene butadiene latex,
A water-dispersible polymer such as an acrylic emulsion can be used. These aqueous binders can be used alone or in combination of two or more. In the present invention, among these, polyvinyl alcohol and silanol-modified polyvinyl alcohol are particularly preferable in terms of adhesion to the pigment and peel resistance of the ink receiving layer. The ink receiving layer is a mordant, a water-proofing agent, a light-fastness improver, in addition to a pigment and an aqueous binder,
Surfactants and other additives can be included.

The mordant added to the ink receiving layer is preferably immobilized. For this purpose, a polymer mordant is preferably used. Polymer mordants are described in JP-A-48-28325 and JP-A-54-74430.
No. 54-124726, No. 55-22766,
No. 55-142339, No. 60-23850, No. 6
Nos. 0-23851, 60-23852, 60-2
No. 3853, No. 60-57836, No. 60-6064
No. 3, No. 60-118834, No. 60-122940
No. 60-122941, No. 60-122942
No. 60-235134, JP-A-1-161236
Nos. 2,484,430 and 25,485.
Nos. 64, 3148061, 3309690, 4115124, 4124386, 41938
No. 00, No. 4,273,853, No. 4,282,305, and No. 4,450,224. JP 1
An image receiving material containing a polymer mordant described on pages 212 to 215 of 161236 is particularly preferred. By using the polymer mordant described in the publication, an image with excellent image quality is obtained, and the light fastness of the image is improved.

The waterproofing agent is effective for making the image waterproof.
As these waterproofing agents, cationic resins are particularly desirable. Examples of such a cationic resin include polyamide polyamine epichlorohydrin, polyethyleneimine, polyamine sulfone, dimethyldiallylammonium chloride polymer, cationic polyacrylamide, and colloidal silica. Among these cationic resins, polyamide polyamine epichlorohydrin is particularly preferable. is there. The content of these cationic resins is preferably from 1 to 15% by weight, more preferably from 3 to 15% by weight, based on the total solid content of the ink receiving layer.
Preferably it is 10% by weight.

Examples of the light resistance improver include zinc sulfate, zinc oxide, hinderamine antioxidants, and benzotriazole-based ultraviolet absorbers such as benzophenone.
Of these, zinc sulfate is particularly preferred.

Surfactants include coating aids, release improvers,
It functions as a slipperiness improver or an antistatic agent. The surfactants are described in JP-A Nos. 62-173463 and 62-183457. An organic fluoro compound may be used instead of the surfactant. Preferably, the organic fluoro compound is hydrophobic. Examples of the organic fluoro compound include a fluorinated surfactant, an oily fluorinated compound (eg, fluorinated oil), and a solid fluorinated compound resin (eg, an ethylene tetrafluoride resin).
About the organic fluoro compound, Japanese Patent Publication No. 57-9053
No. (columns 8 to 17), JP-A No. 61-20994, 6
It is described in each gazette of 2-135826. Other additives added to the ink receiving layer include a pigment dispersant,
Examples include a thickener, an antifoaming agent, a dye, a fluorescent whitening agent, a preservative, a pH adjuster, a matting agent, and a hardening agent. The ink receiving layer may be a single layer or two layers.

The recording paper and the recording film may be provided with a back coat layer. Examples of components that can be added to this layer include a white pigment, an aqueous binder (aqueous binder), and other components.

Examples of white pigments contained in the back coat layer include light calcium carbonate, heavy calcium carbonate, kaolin, talc, calcium sulfate, barium sulfate, titanium dioxide, zinc oxide, zinc sulfide, zinc carbonate, and satin white. , Aluminum silicate, diatomaceous earth, calcium silicate, magnesium silicate, synthetic amorphous silica, colloidal silica, colloidal alumina, pseudo-boehmite, aluminum hydroxide, alumina, lithopone, zeolite, hydrohaloysite, magnesium carbonate, magnesium hydroxide, etc. Pigments, styrene-based plastic pigments, acryl-based plastic pigments, polyethylene, microcapsules, organic pigments such as urea resins and melamine resins, and the like.

As the aqueous binder contained in the back coat layer, styrene / maleate copolymer, styrene / acrylate copolymer, polyvinyl alcohol, silanol-modified polyvinyl alcohol, starch, cationized starch, casein, gelatin And water-soluble polymers such as carboxymethylcellulose, hydroxyethylcellulose and polyvinylpyrrolidone, and water-dispersible polymers such as styrene-butadiene latex and acrylic emulsion. Other components contained in the back coat layer include an antifoaming agent, an antifoaming agent, a dye, a fluorescent whitening agent, a preservative, and a waterproofing agent.

To the constituent layers (including the back layer) of the ink jet recording paper and the recording film, a polymer fine particle dispersion (polymer latex) may be added. The polymer latex is used for the purpose of improving film physical properties such as dimensional stabilization, curl prevention, adhesion prevention, and film crack prevention.
For polymer latex, see JP-A-62-2452.
No. 58, No. 62-136648, No. 62-1100
No. 66 describes each of the publications. When a polymer latex having a low glass transition temperature (40 ° C. or lower) is added to the layer containing a mordant, cracking and curling of the layer can be prevented. Also, curling can be prevented by adding a polymer latex having a high glass transition temperature to the back layer.

The ink of the present invention is not limited to an ink jet recording method, and is a known method, for example, a charge control method for discharging ink using electrostatic attraction, a drop-on-demand method using vibration pressure of a piezo element ( Pressure-pulse method), acoustic ink-jet method in which an electric signal is converted into an acoustic beam to irradiate the ink to discharge ink using radiation pressure, and thermal ink-jet that heats the ink to form bubbles and uses the generated pressure It is used for the method. Ink jet recording methods include a method of ejecting a large number of low density inks called photo inks in small volumes,
A method of improving image quality by using a plurality of inks having substantially the same hue and different densities, and a method of using colorless and transparent ink are included.

[0108]

The present invention will be described below with reference to examples.
The present invention is not limited to this.

Example 1 (Preparation of Ink Set 101) 8 g of dye (M-6), 5 g of sodium dioctylsulfosuccinate, 6 g of high-boiling organic solvent (s-1) and 10 g of high-boiling organic solvent (s-2)
g, UV1 to UV3 (mixture of weight ratio = 1: 1: 1)
It was dissolved at 70 ° C. in 6.0 g and 50 ml of ethyl acetate. 500 ml of deionized water was added to this solution while stirring with a magnetic stirrer to prepare an oil-in-water type coarse particle dispersion. Next, this coarse particle dispersion was passed through a microfluidizer (MICROFLUIDEXINC) five times at a pressure of 60 MPa to form fine particles. The solvent was removed from the resulting emulsion using a rotary evaporator until the odor of ethyl acetate disappeared. 140 g of diethylene glycol, 64 g of glycerin and SURFYNOL 465 (SURFYNOL 465) were added to the fine emulsion of the hydrophobic dye thus obtained.
Products & Chemicals, Inc.) and additives such as urea. From the obtained emulsion, a sample was collected in an amount such that the content of the dye became 5 g, 7 g of sodium dioctylsulfosuccinate was further added, deionized water was added so that the total amount became 1 liter, and KOH 1
By adjusting the pH to 9 at 0 mol / l, a light magenta ink according to Table 1 was produced. The volume average particle size of the obtained emulsified dispersion ink was determined by using Microtrack UP.
A (Nikkiso Co., Ltd.) measured 51 nm
Met.

Further, the kind and amount of the dye to be used and the amounts of the high boiling point organic solvent and additives were changed, and the ink set 10 shown in Table 1 was used.
1 magenta ink, light cyan ink, cyan ink, yellow ink, and black ink were prepared.

[0111]

[Table 1]

[0112]

Embedded image

[0113]

Embedded image

The ink sets 102 and 103 were changed by changing the amount of sodium dioctyl sulfosuccinate as shown in Table 2.
It was created. Next, a fine dispersion of the dye was prepared in the same manner as in the ink set 103, and the same ink set 104 was prepared except that the amount of sodium dioctylsulfosuccinate was reduced as shown in Table 2 by ultrafiltration. Ultrafiltration was performed by repeating the process of diluting the dye dispersion 10 times with ion-exchanged water and concentrating it to the original amount three to five times using a hollow fiber membrane module ACP-1050 manufactured by Asahi Kasei. At this time, nothing other than dioctyl sodium sulfosuccinate was found in the filtrate, and the dye and the high-boiling organic solvent remained in the dye dispersion. Next, the same ink sets 105 to 115 were prepared except that the surfactants were changed from those of the ink set 102 to those shown in Tables 2 and 3. Further, as a comparative example, a dye dispersion was prepared by changing the type of surfactant from the ink set 101 according to Tables 2 and 3, and then ultrafiltration was performed in the same manner as when the ink set 104 was prepared. An ink set 116 was prepared with a reduced amount of activator. In addition, an ink set 117 according to Table 4 was prepared as a comparative ink set using a water-soluble dye.

[0115]

[Table 2]

[0116]

[Table 3]

[0117]

[Table 4]

[0118]

Embedded image

[0119]

Embedded image

Next, these ink sets 101-117
To the inkjet printer PM670C (EPSON
The cartridges were packed in cartridges, and the same machine was used to print images on PM photo paper (EPSON inkjet paper), and the following evaluations were made. As for the printing performance, after setting the cartridge in the printer and confirming the ejection of ink from all the nozzles, 20 sheets of A4 paper were output, and the printing disorder was evaluated. A: There is no printing disturbance from the start to the end of printing. B: Output with printing disturbance is generated. C: There is the printing disturbance from the printing start to the end. Water resistance is as follows.
The occurrence of bleeding was visually evaluated. When the occurrence of bleeding was clearly recognized, the evaluation was x, and when the occurrence of bleeding was not visually observed, the evaluation was ○. Regarding the storage stability of the ink, the following two items were evaluated. That is, (1) After packing the ink in a cartridge, before, after storage at 60 ° C. for one week, cyan, magenta, yellow and black solids were printed, and the optical density of the printed sample was measured.
The evaluation was as follows. A: The decrease in density before and after storage for all colors is 5% or less. B: 10% reduction in density before and after storage for all colors
It is as follows. C: There is a color whose density is reduced by 10% or more. D: Some colors have a density reduction of 50% or more, or some colors cannot be printed due to clogging or the like. (2) After packing the ink in a cartridge, it was stored at 40 ° C. for one month, and the same test and evaluation as in (1) were performed. Tables 5 and 6 show the obtained results.

[0121]

[Table 5]

[0122]

[Table 6]

It can be seen that when the ink composition of the present invention is used, excellent printing performance can be obtained, and that excellent performance can also be obtained in terms of water resistance and storage stability of the ink.

Example 2 The same ink prepared in Example 1 was packed in a cartridge of an inkjet printer BJ-F850 (manufactured by CANON), and an image was printed on the inkjet paper photo glossy paper EX manufactured by Fuji Photo Film using the same machine. When the same evaluation as in Example 1 was performed, the same result as in Example 1 was obtained.

[0125]

According to the present invention, it has been shown that an aqueous dispersion ink of an oil-soluble dye can be provided which is excellent in image quality, water resistance, and especially storage stability of the ink.

Claims (6)

[Claims] 1. An ink composition comprising an oil-soluble dye compound dissolved in a high-boiling organic solvent and dispersed in an aqueous medium using a surfactant, wherein the total content of the anionic surfactant is 0% of the ink composition. 0.8 to less than 5% by weight of the inkjet ink composition. 2. The ink composition according to claim 1, wherein the anionic surfactant is an alkyl polyoxyethylene sulfate or an aryl polyoxyethylene sulfate. 3. An oil-soluble dye represented by the following general formula (I):
The compound according to claim 1 or 2,
3. The ink composition for inkjet according to 2. General formula (I)Wherein X is the residue of a color photographic coupler and A is -NR^FourR^FiveMa
Or a hydroxy group, R^FourAnd R^FiveIs German
It is a hydrogen atom, an aliphatic group, an aromatic group, a heterocyclic group,
B¹Is = C (R⁶)-Or = N-, B^TwoIs -C
(R⁷) = Or -N =, R^Two, R^Three, R⁶and
R⁷Are independently hydrogen, halogen, aliphatic
Group, aromatic group, heterocyclic group, cyano group, -OR⁵¹, -SR
⁵², -CO _TwoR⁵³, -OCOR⁵⁴, -NR⁵⁵R⁵⁶, -C
ONR⁵⁷R⁵⁸, -SO_TwoR⁵⁹, -SO _TwoNR⁶⁰R⁶¹, -N
R⁶²CONR⁶³R⁶⁴, -NR⁶⁵CO_TwoR⁶⁶, -CO
R⁶⁷, -NR⁶⁸COR⁶⁹Or -NR⁷⁰SO_TwoR⁷¹In
What, R⁵¹, R⁵², R⁵³, R⁵⁴, R^{Five Five}, R⁵⁶, R⁵⁷, R
⁵⁸, R⁵⁹, R⁶⁰, R⁶¹, R⁶², R⁶³, R⁶⁴, R⁶⁵,
R⁶⁶, R^{6 7}, R⁶⁸, R⁶⁹, R⁷⁰And R⁷¹Is German
And a hydrogen atom, an aliphatic group or an aromatic group,^Two
And R^Three, R^ThreeAnd R^Four, R^FourAnd R^Five, R^FiveAnd R⁶And R⁶And R⁷
May combine with each other to form a ring. 4. An ink-jet ink composition according to claim 1, wherein an anionic surfactant and a nonionic surfactant are used in combination. 5. A dye dispersion having a volume average particle size of 5-1.
The ink composition for inkjet according to any one of claims 1 to 4, wherein the thickness is 00 nm. 6. An image is formed by using an ink receiving paper having an ink receiving layer containing white inorganic pigment particles on a support, using the ink composition according to any one of claims 1 to 5. Image forming method.