JP2012036257A - Ink composition and colored material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink composition having high clarity and improved light resistance which is a weak point of a xanthene dye.SOLUTION: There is provided the ink composition containing two kinds of compounds which are the xanthene dye or a salt thereof and an anthrapyridone compound represented by formula (1) [wherein, Rrepresents 1-5C alkyl or the like; and X represents a group represented by a certain specific formula] or a salt thereof.

Description

The present invention relates to an ink composition containing at least one kind of xanthene dye and an anthrapyridone compound as a pigment, a recording method using the ink composition, and a colored body colored with the ink composition.

Among various color recording methods, various ink ejection methods have been developed for a recording method using an ink jet printer, which is one of the representative methods, that is, an ink jet recording method. These all generate ink droplets, which are attached to various recording materials such as paper, film, fabric, etc. for recording. In this method, since the recording head and the recording material are not in direct contact with each other, no noise is generated and the method is quiet. In addition, due to the features of miniaturization, high speed, and easy colorization, it has been spreading rapidly in recent years, and significant growth is expected in the future. Conventionally, as inks such as fountain pens and felt pens and inks for ink jet recording, inks in which a water-soluble dye is dissolved in an aqueous medium as a pigment are used. In these water-based inks, a water-soluble organic solvent is generally added to prevent clogging of the ink at the pen tip or the ink discharge nozzle. These inks provide a recording image with sufficient density, do not cause clogging of the pen tip and nozzles, have good drying properties on the recording material, have little bleeding, and have excellent storage stability. Is required. The formed recorded image is required to have various fastnesses such as water resistance, moisture resistance, light resistance, and gas resistance.
In addition, high solubility in water, solvents and additives is one of the properties required for pigments.

Among these, the gas resistance refers to the resistance to a phenomenon in which ozone gas having an oxidizing action existing in the air acts on the dye on the recording paper or in the recording paper to discolor the recorded image. . In addition to ozone gas, examples of the oxidizing gas having this kind of action include NOx and SOx. However, among these oxidizing gases, ozone gas is regarded as a main causative substance that promotes the discoloration phenomenon of ink jet recorded images, and particularly, ozone gas resistance is regarded as important. An ink receiving layer is provided on the surface of the exclusive inkjet paper capable of obtaining photographic image quality in order to expedite ink drying and to reduce bleeding at high image quality. In many cases, the ink receiving layer is made of a material such as a porous white inorganic material. On such a recording paper, the discoloration due to ozone gas or the like is noticeable. Since this discoloration phenomenon due to the oxidizing gas is characteristic of an ink jet recording image, improvement of gas resistance, particularly ozone gas resistance, is one of the important problems in ink jet recording.

  Due to the recent development of inkjet recording technology, the recording (printing) speed has been remarkably improved. For this reason, there is a movement to use an inkjet printer in the same manner as a laser printer using electronic toner for printing a document on plain paper, which is the main use in an office environment. Inkjet printers have the advantage that the type of recording paper is not limited; the price of the machine is relatively low; and are particularly popular in small to medium-sized office environments such as SOHO. As described above, when an inkjet printer is used for recording on plain paper, hue and image (printing) density tend to be more important among various qualities required for recorded matter.

Xanthene dyes are known as one of the magenta dyes used in water-soluble inks for ink jet recording. This dye is known to have excellent sharpness, hue, and image density, but poor lightfastness. For this reason, it is possible to provide a xanthene dye that gives a recorded image having excellent sharpness, hue, image density, and fastness such as light resistance and ozone gas resistance, and an ink composition containing the same. Is one of the market demands.
Examples of proposals for improving the light fastness of recorded images by blending a xanthene dye and a dye having another structural formula include the inventions described in Patent Documents 1 and 2, for example.
Patent Document 1 discloses an ink-jet ink formulation containing a mixture of a rhodamine dye, which is one of xanthene dyes, and a metal-containing magenta dye.
Patent Document 2 discloses C.I., a xanthene dye. I. Acid Red 52 and C.I. I. An ink containing at least one of Acid Red 289, a colorant represented by a specific formula, and an aqueous medium is disclosed.

JP 2003-238875 A JP 2004-182996 A

  An object of the present invention is to provide an ink composition that provides a recorded image with high sharpness and improved light resistance, which is a weak point of a xanthene dye, particularly an ink composition used for inkjet recording.

As a result of intensive studies, the present inventors have devised an ink composition containing a xanthene dye or a salt thereof and an anthrapyridone compound represented by the formula (1) or a salt thereof. It has been found that the above-mentioned problems can be solved, and the present invention has been completed.
That is, the present invention
1)
An ink composition containing, as pigments, at least one xanthene dye and at least one compound represented by the following formula (1) or a salt thereof.

[In Formula (1),
R ¹ represents a hydrogen atom, a C1-C5 alkyl group, a hydroxy C1-C5 alkyl group, a cyclohexyl group, or a cyano C1-C5 alkyl group,
X is a group represented by the following formula (2). ],

[In Formula (2),
* Represents a binding site with two amide groups,
R ² and R ³ each independently represent a hydrogen atom or a C1-C5 alkyl group,
R ² and R ³ may combine to form a C5-C10 cycloalkylene ring with the two carbon atoms that they each replace. ],

2)
The ink composition according to 1), wherein the xanthene dye is a dye represented by the following formula (3), an isomer at a cation position thereof, or a salt thereof:

[In Formula (3),
R ^{101 to} R ¹⁰⁴ are each independently a hydrogen atom; a C1-C10 alkyl group; a C1-C10 alkyl group having a group selected from the group consisting of a hydroxy group, a carboxy group, and a sulfo group as a substituent; a phenyl group; Represents a phenyl group having a group selected from the group consisting of a hydroxy group, a carboxy group, a sulfo group, a sulfamoyl group, a C1-C4 alkyl group, a C1-C4 alkoxy group and a halogen atom as a substituent;
R ¹⁰⁵ represents a sulfo group, a carboxy group, or a C1-C4 alkoxycarbonyl group,
R ¹⁰⁶ is a hydrogen atom; a C1-C10 alkyl group; a C1-C10 alkyl group having a group selected from the group consisting of a hydroxy group, a carboxy group and a sulfo group as a substituent; a sulfo group; a carboxy group; a sulfamoyl group; A group; or a halogen atom;
R ¹⁰⁷ and R ¹⁰⁸ each independently represent a hydrogen atom or a C1-C10 alkyl group,
R ^109- represents a halogen anion, hydroxide, acetate anion, tetrafluoroborate anion, hexafluorophosphate anion, sulfate anion, or toluenesulfonate anion.
However, when the dye represented by formula (3) forms a salt in the molecule, ^R109- does not exist. ],

3)
Ink composition as described in said 1) whose gross mass of the pigment | dye contained in an ink composition is 0.5-20 mass% with respect to the gross mass of this ink composition,
4)
R ² and R ³ are each independently a hydrogen atom, a methyl group, or R ² and R ³ bonded together, and these are cyclohexylene rings formed together with two carbon atoms that are substituted, respectively 1) to 3) The ink composition according to any one of
5)
The ink composition according to any one of 1) to 4), wherein R ¹ is a hydrogen atom or a methyl group.
6)
R ¹ is a hydrogen atom or a methyl group,
The ink composition according to any one of 1) to 5), wherein R ² and R ³ are hydrogen atoms;
7)
In the dye represented by formula (3),
R ¹⁰¹ is a C1-C10 alkyl group; or as a substituent, a phenyl group having a group selected from the group consisting of a sulfo group and a C1-C4 alkyl group;
R ¹⁰² is a hydrogen atom or a C1-C10 alkyl group,
R ¹⁰³ is a hydrogen atom; a C1-C10 alkyl group; or a phenyl group having a C1-C4 alkyl group as a substituent;
R ¹⁰⁴ is a hydrogen atom or a C1-C10 alkyl group,
R ¹⁰⁵ is a sulfo group, a carboxy group, or a C1-C4 alkoxycarbonyl group,
R ¹⁰⁶ is a hydrogen atom or a sulfo group,
R ¹⁰⁷ and R ¹⁰⁸ are each independently a hydrogen atom or a C1-C10 alkyl group,
The ink composition according to any one of 2) to 6), wherein R ^109- is a halogen anion;
However, when the dye represented by the formula (3) forms a salt in the molecule, R ^109- does not exist.
8)
The xanthene dye is C.I. I. Acid Red 289, or C.I. I. The ink composition according to any one of 1) to 7), which is Acid Red 52,
9)
The ink composition according to any one of 1) to 8), further comprising a water-soluble organic solvent,
10)
The ink composition according to any one of 1) to 9) used for inkjet recording,
11)
An ink jet recording method for performing recording by ejecting droplets of the ink composition according to any one of 1) to 10) according to a recording signal and attaching the droplets to a recording material;
12)
The inkjet recording method according to 11), wherein the recording material is an information transmission sheet,
13)
The inkjet recording method according to 12), wherein the information transmission sheet is a sheet having an ink receiving layer containing plain paper or a porous white inorganic substance;
14)
A colored body colored with the ink composition according to any one of 1) to 10),
15)
A colored body colored by the inkjet recording method according to 11),
16)
An inkjet printer in which a container containing the ink composition according to any one of 1) to 10) is loaded;
About.

  According to the present invention, it was possible to provide an ink composition that gives a recorded image with high sharpness and improved light resistance, which is a weak point of a xanthene dye, particularly an ink composition used for inkjet recording.

The present invention will be described in detail. In the present specification, unless otherwise specified, acidic functional groups such as sulfonic acid groups and carboxy groups are represented in the form of free acids. Further, the compound represented by formula (1) or a salt thereof contained in the ink composition of the present invention is simplified as “compound” hereinafter, including both “compound or salt thereof”, in order to avoid complexity. It shall be described and mean both.
The ink composition of the present invention is an aqueous and substantially solution ink composition, and is suitable as a magenta ink, particularly a magenta ink used for inkjet recording.

The compound represented by the formula (1), which is contained in at least one kind in the ink composition of the invention, will be described.

In the formula (1), examples of the C1-C5 alkyl group for R ¹ include linear or branched ones. Specific examples thereof include straight chain such as methyl, ethyl, n-propyl, n-butyl and n-pentyl; branched chain such as isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl and tert-pentyl. Thing; etc. are mentioned. Preferable specific examples include methyl and ethyl, and methyl is particularly preferable.

The hydroxy C1-C5 alkyl group in R ^1, the include those hydroxy groups at any of the carbon atoms in the "C1-C5 alkyl group for R ^1" are substituted, the hydroxy group and the nitrogen atom to the same carbon atom Those which are not substituted are preferred. Specific examples include straight-chain C1-C5 alkyl moieties such as 2-hydroxyethyl, 2-hydroxypropyl, 3-hydroxypropyl, 3-hydroxybutyl, 4-hydroxybutyl, etc .; 1-hydroxy-2-propyl, C1-C5 alkyl moieties such as 1-hydroxy-2-butyl, 1-hydroxy-3-butyl, 2-hydroxy-3-pentyl, 2-hydroxy-1,1-dimethylethyl, etc. are branched; It is done. A preferred specific example is 2-hydroxyethyl.

The cyano C1-C5 alkyl group for R ^1, a cyano group include those substituted to any carbon atom in the "C1-C5 alkyl group for R ^1". Specific examples include straight chain C1-C5 alkyl moieties such as 2-cyanoethyl, 2-cyanopropyl, 3-cyanopropyl, 3-cyanobutyl, 4-cyanobutyl, etc .; 1-cyano-2-propyl, 1-cyano C1-C5 alkyl moieties such as 2-butyl, 1-cyano-3-butyl, 2-cyano-3-pentyl, 2-cyano-1,1-dimethylethyl, etc. are branched; A preferred specific example is 2-cyanoethyl.

Among the above, preferable R ¹ includes a hydrogen atom or a C1-C5 alkyl group, and the latter is more preferable.

In formula (1), examples of the C1-C5 alkyl group in R ² and R ³ include the same ones as described in the above-mentioned “C1-C5 alkyl group in R ¹ ”, including preferable ones.

Examples of the C5-C10 cycloalkylene ring formed by combining R ² and R ³ include cyclopentylene, cyclohexylene, cycloheptylene, and cyclooctylene.
The range of the carbon number is usually C5-C10, preferably C5-C8, more preferably C5-C7, and particularly preferably C6.
A preferred specific example is cyclohexylene.

Preferable R ² and R ³ include a hydrogen atom, a methyl group, or cyclohexylene in which R ² and R ³ are bonded, more preferably a hydrogen atom and methyl, and particularly preferably a hydrogen atom.

As X in the compound represented by the formula (1), what specifically describes the group represented by the formula (2) is a compound represented by the following formula (14). That is, the compound represented by the formula (1) and the compound represented by the following formula (14) are the same compound.

In the formula (14), R ¹ has the same meaning as in formula (1), and R ² and R ³ have the same meanings as in formula (2), including preferred examples.

As for R ^{1 to} R ³ in the formula (1) (or formula (14), the same applies hereinafter), compounds in which preferable ones are combined are more preferable, and those in which more preferable ones are combined are more preferable. The same applies to combinations of preferable and more preferable ones.

The salt of the compound of the formula (1) is a salt formed with an inorganic or organic cation. Preferred examples of the salt formed with the inorganic cation include alkali metal salts such as lithium salts, sodium salts, potassium salts; and ammonium salts. Preferred examples of the salt formed with the organic cation include a salt formed with a quaternary ammonium salt represented by the following formula (4).

In formula (4), Z ^{1 to} Z ⁴ each independently represent a hydrogen atom, an alkyl group, a hydroxyalkyl group or a hydroxyalkoxyalkyl group, and at least one of Z ^{1 to} Z ⁴ is a group other than a hydrogen atom. is there.

In formula (4), specific examples of Z ^{1 to} Z ⁴ include C1-C6 alkyl groups (preferably C1-C4 alkyl groups) such as methyl, ethyl, butyl; hydroxymethyl, 2-hydroxyethyl, 3-hydroxy Hydroxy C1-C6 alkyl groups (preferably hydroxy C1-C4 alkyl groups) such as propyl, 2-hydroxypropyl, 4-hydroxybutyl, 3-hydroxybutyl, 2-hydroxybutyl; hydroxyethoxymethyl, 2-hydroxyethoxyethyl, And hydroxy C1-C6 alkoxy C1-C6 alkyl groups (preferably hydroxy C1-C4 alkoxy C1-C4 alkyl groups) such as 3-hydroxyethoxypropyl, 3-hydroxyethoxybutyl, 2-hydroxyethoxybutyl, and the like.

  Of these, more preferable are salts formed with sodium, potassium, lithium, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, ammonium and the like. Of these, particularly preferred are the salts formed with lithium, ammonium and sodium.

The manufacturing method of the said salt is described.
For example, a reaction solution, a wet cake, or a dried product containing the compound of the formula (1) is dissolved in water, sodium chloride is added thereto for salting out, and the precipitated solid is separated by filtration to obtain the formula (1 The sodium salt of the compound can be obtained as a wet cake. Further, the obtained wet cake is dissolved again in water, and a mineral acid such as hydrochloric acid is added to adjust the pH to a strong acidity (usually pH 1 or less), and a solid obtained by filtration is separated by filtration (1) The free acid of the compound represented by can be obtained as a wet cake. At this time, it is also possible to obtain a mixture of sodium salt and free acid at a desired ratio by appropriately adjusting pH. Furthermore, each salt is formed by adding, for example, potassium hydroxide, lithium hydroxide, aqueous ammonia, or a quaternary ammonium salt corresponding to the above formula (4) to the wet cake of the free acid in water. Corresponding potassium salts, lithium salts, ammonium salts, quaternary ammonium salts and the like can also be obtained. At this time, a wet cake of a mixture of free acid and sodium salt, for example, is used, and potassium hydroxide is added to obtain a mixed salt of sodium and potassium, or a mixture of sodium salt, potassium salt and free acid, etc. It is possible as well.

Specific examples of the compound represented by the formula (1) of the present invention are shown in Table 1 below, but the present invention is not limited to these specific examples.
In Table 1, No. 11 and no. The “cyclohexylene ring” in 12 means a cyclohexylene ring formed together with two carbon atoms substituted by R ² and R ³ in the above formula (1).

A method for producing the compound represented by the formula (1) will be described below. In addition, R < ¹ > -R < ³ > as described in following formula (7)-(10) represents the same meaning as the said Formula (1).
The compound represented by the formula (1) is produced, for example, by the following method. That is, a compound represented by the following formula (7) can be obtained by synthesizing according to a known method described in Patent Document 3 or the like, or according to the method.

Next, 1 mol of the compound of the formula (7) thus obtained was neutralized as an aqueous solution of pH 7 by adding an aqueous solution of sodium hydroxide and the like, water; alcohols such as methanol, ethanol, ethylene glycol, and polyols; N, N -In a solvent such as dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, etc .; and the like, the following formula (9 ) Is obtained. Rather than using the aqueous solution containing the compound of formula (7) after neutralization as it is, it is preferable to use it for the next reaction after drying to obtain a solid containing the compound of formula (7).

In the formula (9), Z is a group represented by the following formula (10).

In the formula (10), * represents a bonding site with two amide groups.

Next, 1 mol of the obtained compound of the formula (9) and 1 mol of a copper compound such as copper acetate, copper sulfate, copper halide (for example, copper chloride, copper iodide, etc.), water; methanol, ethanol, ethylene Alcohol and polyols such as glycol; Amides such as N, N-dimethylformamide, N, N-dimethylacetamide and N-methylpyrrolidone; An anthrapyridone compound of the above formula (1) is obtained that is contained in at least one ink composition.
Any base can be used to adjust the pH in this reaction, but alkali metal carbonates (eg, lithium carbonate, sodium carbonate, potassium carbonate, etc.), alkali metal hydroxides (eg, lithium hydroxide, hydroxide) Sodium, potassium hydroxide, etc.) are preferred.

The xanthene dye contained in the ink composition of the present invention will be described.
The xanthene dye generally means a dye having a structure represented by the following formula (5), as described in, for example, Sadaharu Abeda et al.

Among the xanthene dyes, a dye represented by the following formula (6) is preferable.

In formula (6),
R ^{201 to} R ²⁰⁴ each independently represents a hydrogen atom or a substituent,
R ²⁰⁵ represents a sulfo group, a carboxy group, or a C1-C10 alkoxycarbonyl group,
R ²⁰⁶ represents a hydrogen atom; or a substituent,
R ²⁰⁷ and R ²⁰⁸ each independently represent a hydrogen atom or a substituent,
R ^209- represents a counter anion.
However, when the dye represented by the formula (2) forms a salt in the molecule, R ^209- does not exist.

The dye represented by the formula (6) has isomers having different cation positions, for example, as represented by the following formula (11) or formula (12). In the present specification, the “xanthene dye” is meant to include all such isomers.

Of the xanthene dyes represented by formula (6), xanthene dyes represented by formula (3) are preferred.

In the formula (3), the C1-C10 alkyl group for R ¹⁰¹ to R ^104, include a straight chain or branched chain. The range of carbon number is usually C1-C10, preferably C1-C8, more preferably C1-C6, and still more preferably C1-C4.
Specific examples thereof include, for example, straight chain such as methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-octyl, n-nonyl and n-decyl; isopropyl, isobutyl, sec- Branched chain such as butyl, tert-butyl, isopentyl, tert-pentyl, 2-ethylhexyl; and the like.
Among specific examples, methyl, ethyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl are preferable, methyl and ethyl are more preferable, and ethyl is particularly preferable.

As the C1-C10 alkyl group having a group selected from the group consisting of a hydroxy group, a carboxy group and a sulfo group as a substituent in R ^{101 to} R ¹⁰⁴ , the “C1-C10 alkyl group in R ^{101 to} R ¹⁰⁴ ” is described above. In which any carbon atom in these groups has these groups. The range of carbon number is usually C1-C10, preferably C1-C8, more preferably C2-C6, and still more preferably C2-C4. The number of the substituents is usually 1 or 2, and preferably 1. The position of the substituent is not particularly limited, but when the substituent is a hydroxy group, it is preferable that the hydroxy group and the nitrogen atom are not substituted with the same carbon atom.
Specific examples include those having a hydroxy group such as 2-hydroxyethyl, 2-hydroxypropyl, 3-hydroxypropyl, 6-hydroxyhexyl, 3-hydroxyoctyl; carboxymethyl, 2-carboxyethyl, 3-carboxypropyl , 6-carboxyhexyl, 8-carboxyoctyl and the like having a carboxy group; 2-sulfoethyl, 3-sulfopropyl, 4-sulfobutyl and the like having a sulfo group;
Preferable specific examples include 2-hydroxyethyl, 2-carboxyethyl, and 2-sulfoethyl.

In R ¹⁰¹ to R ^104, as a substituent, a hydroxy group, a carboxy group, a sulfo group, a sulfamoyl group, C1-C4 alkyl group, a phenyl group having a group selected from the group consisting of C1-C4 alkoxy group and a halogen atom Includes those having any of these groups as a substituent on any carbon atom of the phenyl group. The number of substituents is usually 1 to 5, preferably 1 to 4, more preferably 2 or 3.
As a C1-C4 alkyl group as a substituent, a linear or branched thing is mentioned, A linear thing is preferable. Specific examples thereof include linear ones such as methyl, ethyl, n-propyl and n-butyl; branched ones such as isopropyl, isobutyl, sec-butyl and tert-butyl.
As a C1-C4 alkoxy group as a substituent, a linear or branched thing is mentioned, A linear thing is preferable. Specific examples thereof include linear ones such as methoxy, ethoxy, n-propoxy and n-butoxy; branched ones such as isopropoxy, isobutoxy, sec-butoxy and tert-butoxy.
Examples of the halogen atom as a substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Among these, a fluorine atom, a chlorine atom, and a bromine atom are preferable. More preferred are a fluorine atom and a chlorine atom, and still more preferred are a chlorine atom.
Although the substitution position on the phenyl group of the above group is not particularly limited, the bonding position with the nitrogen atom in the formula (3) is the 1st position,
When the number of substituents is 3, the 2-position, 3-position and 6-position; or the 2-position, 4-position and 6-position;
When the number of substituents is 2, 2 and 3 positions; 2 and 4 positions; 2 and 5 positions; 2 and 6 positions; 3 and 4 positions; 3 and 5 positions;
When the number of substituents is two, substitution at the 2-position and the 6-position is more preferable.
Specific examples include those having a hydroxy group such as 2-hydroxyphenyl, 3-hydroxyphenyl, 4-hydroxyphenyl; 2-carboxyphenyl, 3-carboxyphenyl, 4-carboxyphenyl, 2,5-dicarboxyphenyl, Those having a carboxy group such as 2,6-dicarboxyphenyl and 3,5-dicarboxyphenyl; 2-sulfophenyl, 3-sulfophenyl, 4-sulfophenyl, 2,5-disulfophenyl, 2,6- Those having a sulfo group such as disulfophenyl and 2,4-disulfophenyl; Those having a sulfamoyl group such as 2-sulfamoylphenyl, 3-sulfamoylphenyl and 4-sulfamoylphenyl; 2-methyl Phenyl, 3-ethylphenyl, 4-methylphenyl, 2,5-diethylpheny Having a C1-C4 alkyl group such as 2,6-dimethylphenyl, 2,4-dimethylphenyl, 2,4,6-trimethylphenyl; 2-methoxyphenyl, 3-ethoxyphenyl, 4-methoxyphenyl, 2 Having a C1-C4 alkoxy group such as 1,5-diethoxyphenyl; having a halogen atom such as 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 3-bromophenyl, 3-fluorophenyl; 3-methyl-4 -What has 2 or more types of groups selected from said groups, such as sulfophenyl and 2, 6- dimethylsulfophenyl; etc. are mentioned.
Of these, 2-carboxyphenyl, 2,6-dicarboxyphenyl, 2-sulfophenyl, 2-methylphenyl, 2,6-dimethylphenyl, and 2,6-dimethylsulfophenyl are preferred, and 2,6 -Dimethylphenyl and 2,6-dimethylsulfophenyl are particularly preferred.

Among the above, preferable R ¹⁰¹ to R ¹⁰⁴ are each independently a hydrogen atom; a C1-C10 alkyl group; a phenyl group having a group selected from the group consisting of a sulfo group and a C1-C4 alkyl group as a substituent. Is preferred.

As a preferable combination of R ^{101 to} R ¹⁰⁴ , R ¹⁰¹ is a phenyl group having a group selected from the group consisting of a sulfo group and a C1-C4 alkyl group, R ¹⁰² is a hydrogen atom, and R ¹⁰³ is a substituent as C1-C4. A phenyl group having an alkyl group, and a combination in which R ¹⁰⁴ is a hydrogen atom; or a combination in which R ^{101 to} R ¹⁰⁴ are a C1-C10 alkyl group.

In formula (1), examples of the C1-C4 alkoxycarbonyl group for R ¹⁰⁵ include linear or branched ones, and linear ones are preferred. Specific examples thereof include linear ones such as methoxycarbonyl, ethoxycarbonyl, n-propoxycarbonyl and n-butoxycarbonyl; branched ones such as isopropoxycarbonyl, isobutoxycarbonyl, sec-butoxycarbonyl and tert-butoxycarbonyl; Is mentioned.

Of the above, R ¹⁰⁵ is particularly preferably a sulfo group.

In formula (3), examples of the C1-C10 alkyl group for R ¹⁰⁶ include the same groups as those described above in “C1-C10 alkyl group for R ^{101 to} R ¹⁰⁴ ”, including preferable ones.

As the C1-C10 alkyl group having a group selected from the group consisting of a hydroxy group, a carboxy group and a sulfo group in R ¹⁰⁶ , the above-mentioned “substituents in R ¹⁰¹ to R ¹⁰⁴ are a hydroxy group, a carboxy group and a sulfo group. The same as those described in the “group C1-C10 alkyl group selected from the group consisting of” and preferable examples.

Examples of the halogen atom for R ¹⁰⁶ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Among these, a fluorine atom, a chlorine atom, and a bromine atom are preferable. More preferred are a fluorine atom and a chlorine atom, and still more preferred are a chlorine atom.

Among the above, R ¹⁰⁶ is preferably a hydrogen atom, a C1-C10 alkyl group, a sulfo group, a carboxy group, and a halogen atom, and particularly preferably a hydrogen atom or a sulfo group.

In the formula (3), the C1-C10 alkyl group for R ¹⁰⁷ and R ^108, the same thing can be mentioned, including those described, the preferred or the like the "C1-C10 alkyl group for R ¹⁰¹ to R ^104" It is done.

Of the above, R ¹⁰⁷ and R ¹⁰⁸ are particularly preferably hydrogen atoms.

In the formula (3), R ¹⁰⁹⁻ means a counter anion with respect to the charge of the cation in the xanthene dye (that is, the “+” charge described in the formula (3)). When a strongly acidic group such as a sulfo group is present in the xanthene dye, a salt can be formed in the dye molecule, so that a counter anion represented by R ^109- is not required. For this reason, when the dye represented by the formula (3) forms a salt in the molecule, ^R109- does not exist.

Examples of the halogen anion for R ^109- include fluoride, chloride, bromide, iodide and the like. Among these, chloride (Cl ⁻ ) is particularly preferable.

In R ^109- , the hydroxide, acetate anion, tetrafluoroborosan anion, hexafluorophosphate anion, sulfate anion and toluenesulfonate anion are respectively “OH ⁻ ”, “CH ₃ COO ⁻ ” and “BF ₄ ⁻ ”. , “PF ₆ ⁻ ”, “HSO ₄ ⁻ ”, and “CH ₃ C ₆ H ₄ SO ₃ ⁻ ”. Among these, for the toluenesulfonate anion, there are isomers in which the substitution position of the methyl group on the benzene ring is ortho, meta, or para with respect to the substitution position of the sulfonate anion. Including the body.

Among the above, R ^109- is preferably a halogen anion.
Further, as the dye represented by the formula (3), a dye that does not exist, that is, a dye that forms a salt in the molecule is more preferable than that in which R ^109- is present.

Among the dyes described as R ^{101 to} R ^109- in the formula (3), dyes in which preferable ones are combined are more preferable, and dyes in which more preferable ones are combined are more preferable. The same applies to combinations of more preferable ones and combinations of preferable ones and more preferable ones.

As a particularly preferable dye represented by the formula (3), C.I. I. Acid Red 289 and C.I. I. Acid Red 52 is exemplified. Among these, the former is particularly preferable in terms of sharpness, hue, and ozone resistance.
C. I. Acid Red 289 is No. in Table 101 below. 108 and no. A mixture of 109 dyes (monosodium salt thereof); I. Similarly, Acid Red 52 is No. 107 dyes (monosodium salts thereof) are known.

Although the specific example of a xanthene dye is shown in following Table 2, the xanthene dye which can be used by this invention is not limited to these specific examples. For convenience, acidic functional groups such as carboxy groups and sulfo groups are described in the form of free acids.
In Table 2, No. 106 thru | or No. Since 109 dye forms a salt in the molecule, R ^109- does not exist. These dyes are generally considered to form a salt in the molecule when the sulfo group of R ¹⁰⁵ becomes an anion in the form of “SO ₃ ⁻ ”.
The abbreviations used in Table 2 have the following meanings.
Et: ethyl.
DM-3S-Ph: 2,6-dimethyl-3-sulfophenyl.
DM-4S-Ph: 2,6-dimethyl-4-sulfophenyl.
H: A hydrogen atom.
DM-Ph: 2,6-dimethylphenyl.
Me: methyl.

The xanthene dye can be synthesized according to a known method (for example, the method described in Yutaka Hosoda, Gihodo Publishing "Theoretical Manufacturing Dye Chemistry" pages 373-375 and pages 788-791) or a known method. There are also many dyes available as commercial products.

The xanthene dye may form a salt in addition to a salt using a cation charge existing in the molecule.
For example, in Table 1 above, 104 and no. Since the dye shown in 105 has a carboxy group as R ¹⁰⁵ , this group can be converted into a salt.
In Table 1, No. 106 and no. Since the dye shown in 107 has a sulfo group as R ¹⁰⁶ , this group can be similarly converted into a salt.
Such salts include salts with inorganic or organic cations. Specific examples of the inorganic cation salt include ammonium (NH ₄ ⁺ ); alkali metals such as cations such as lithium, sodium and potassium; and the like. Examples of the organic cation include, but are not limited to, quaternary ammonium represented by the formula (4).

Preferable examples of the salt include sodium, potassium, lithium, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine salt, and ammonium salt. Of these, particularly preferred are lithium, sodium, potassium and ammonium salts.
Any of these salts can be easily synthesized according to a known method, a method according thereto, or a method for producing a salt of the compound of formula (1).
Therefore, the xanthene dye contained in the ink composition of the present invention can also be formed by a formula (6) or a formula (3) that can be formed in addition to a salt using a cation charge existing in the molecule. It contains both the xanthene dyes represented or their salts. For the sake of convenience, these “dyes” or “salts thereof” as well as both “dyes” will be described in abbreviated form for the sake of convenience.

The salt of the compound may change the physical properties such as solubility or the performance of the ink when used as an ink, particularly the performance related to fastness, depending on the type of the salt. For this reason, it is also preferable to select the type of salt according to the intended ink performance.

The compound represented by the formula (1) and the xanthene dye contained in the ink composition of the present invention are isolated as a solid free acid by adding a mineral acid such as hydrochloric acid after the final step in the synthesis reaction. be able to. In addition, by washing the obtained free acid solid with water or acidic water such as hydrochloric acid, for example, an inorganic salt contained as an impurity, for example, a metal cation chloride such as sodium chloride; sodium sulfate or the like In other words, the alkali metal salt of a sulfate cation; etc., that is, the “inorganic impurities” referred to in this specification can be removed.
These inorganic impurities adversely affect the storage stability of the ink composition and the ejection stability when performing ink jet recording using the ink composition as ink when preparing the ink composition of the present invention. Often given. For this reason, the content of the inorganic impurities in the total mass of the pigment contained in the ink composition of the present invention is preferably 1% by mass or less with respect to the total mass of the pigment, and the lower limit is 0% by mass. That is, it may be below the detection limit in the analytical instrument.
Examples of a method for producing a pigment with few inorganic impurities include a purification method using a reverse osmosis membrane; a method of dissolving a dried pigment compound or a wet cake in water and crystallization by adding a C1-C4 alcohol such as methanol; Various methods such as a method of adding a dried product or wet cake of a compound in a mixed solvent of C1-C4 alcohol such as methanol and water and suspending purification: or a known method using an anion and a cation exchange resin as appropriate Is mentioned.

The ink composition of the present invention contains both at least one compound represented by the formula (1) and at least one xanthene dye as pigments.
The compound represented by the formula (1) and the xanthene dye are each as a single compound; as a mixture in which either one is single and the other is plural; or as a mixture in which each is plural; It may be contained in the ink composition. Of these, the compound represented by the formula (1) is preferably contained as a single compound.

The total mass of the coloring matter contained in the ink composition of the present invention is usually 0.5 to 20 mass%, preferably 1 to 10 mass%, more preferably 1.5 to the total mass of the ink composition. It is good to contain-6 mass%, More preferably, it is 3-6 mass%.
As will be described later, for the purpose of fine-tuning the hue of magenta to a desired hue, the ink composition of the present invention further contains a known dye as long as the effects obtained by the present invention are not impaired. May be. However, as the coloring matter contained in the ink composition of the present invention, it is preferred that all of the coloring matter is substantially both the xanthene dye and the compound represented by the formula (1).

The mass ratio of the total mass of the xanthene dye and the total mass of the compound represented by the formula (1) contained in the ink composition of the present invention is usually from 1/20 to 10/1, preferably from 1/15. 5/1, more preferably 1/10 to 2/1, particularly preferably 1/9 to 1/1.

The ink composition of the present invention is prepared using water as a medium. If necessary, the ink composition may contain a water-soluble organic solvent and an ink preparation agent as long as the effects of the present invention are not impaired. The water-soluble organic solvent is used in anticipation of effects such as dissolution of dye, prevention of drying (maintaining wet state), adjustment of viscosity, promotion of penetration, adjustment of surface tension, defoaming, and the like. It is preferable to contain the product. Other ink preparation agents include, for example, antiseptic / antifungal agents, pH adjusting agents, chelating reagents, rust preventing agents, UV absorbers, viscosity adjusting agents, dye dissolving agents, antifading agents, surface tension adjusting agents, antifoaming agents. And the like, and known additives.
The content of the water-soluble organic solvent is 0 to 60% by mass, preferably 10 to 50% by mass with respect to the total mass of the ink, and the ink preparation agent is similarly 0 to 20% by mass, preferably 0 to 15% by mass. Use. The remainder other than the above is water.

Examples of the water-soluble organic solvent include C1-C4 alkanols (alcohols) such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol and tert-butanol; N, N-dimethylformamide Or amides such as N, N-dimethylacetamide; 2-pyrrolidone, N-methyl-2-pyrrolidone, hydroxyethyl-2-pyrrolidone, 1,3-dimethylimidazolidin-2-one or 1,3-dimethylhexahydro Heterocyclic ketones such as pyrimido-2-one; ketones or ketoalcohols such as acetone, methyl ethyl ketone, 2-methyl-2-hydroxypentan-4-one; cyclic ethers such as tetrahydrofuran, dioxane; ethylene glycol, 1,2 -Or 1,3-propylene rubber C2- such as coal, 1,2- or 1,4-butylene glycol, 1,6-hexylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, or thiodiglycol Mono, oligo or polyalkylene glycol or thioglycol having C6 alkylene unit; polyol (triol) such as glycerin, hexane-1,2,6-triol; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol Monoethyl ether, diethylene glycol monobutyl ether (butyl carbitol), triethylene glycol monomethyl Ether, C1-C4 monoalkyl ether of polyhydric alcohol such as triethylene glycol monoethyl ether; .gamma.-butyrolactone; or dimethyl sulfoxide and the like.

Preferred as the water-soluble organic solvent are isopropanol, glycerin, mono-, di- or triethylene glycol, dipropylene glycol, 2-pyrrolidone, N-methyl-2-pyrrolidone and butyl carbitol, more preferably isopropanol, Glycerin, diethylene glycol, 2-pyrrolidone, N-methyl-2-pyrrolidone and butyl carbitol. These water-soluble organic solvents are used alone or in combination.

Examples of antiseptic / antifungal agents include organic sulfur, organic nitrogen sulfur, organic halogen, haloaryl sulfone, iodopropargyl, N-haloalkylthio, benzothiazole, nitrile, pyridine, 8- Oxyquinoline, isothiazoline, dithiol, pyridine oxide, nitropropane, organotin, phenol, quaternary ammonium salt, triazine, thiadiazine, anilide, adamantane, dithiocarbamate, brominated indanone And compounds such as benzyl bromacetate and inorganic salts.
An example of the organic halogen compound is sodium pentachlorophenol.
Examples of pyridine oxide compounds include sodium 2-pyridinethiol-1-oxide.
Examples of isothiazoline compounds include 1,2-benzisothiazolin-3-one, 2-n-octyl-4-isothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one, 5- Chloro-2-methyl-4-isothiazolin-3-one magnesium chloride, 5-chloro-2-methyl-4-isothiazolin-3-one calcium chloride, 2-methyl-4-isothiazolin-3-one calcium chloride and the like It is done.
Other antiseptic / antifungal agents include sodium sorbate, sodium acetate and sodium benzoate.
Other specific examples of antiseptic / antifungal agents include, for example, trade names Proxel ^RTM GXL (S) and Proxel ^RTM XL-2 (S) manufactured by Arch Chemicals Japan Co., Ltd. In the present specification, the superscript “RTM” means a registered trademark.

As the pH adjuster, any substance can be used as long as it can control the pH of the ink within the range of 6.0 to 11.0 for the purpose of improving the storage stability of the ink. For example, alkanolamines such as diethanolamine and triethanolamine, alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide, ammonium hydroxide, or alkali metals such as lithium carbonate, sodium carbonate, and potassium carbonate. And carbonates.

Examples of chelating reagents include sodium ethylenediaminetetraacetate, sodium nitrilotriacetate, sodium hydroxyethylethylenediaminetriacetate, sodium diethylenetriaminepentaacetate, sodium uracil diacetate, and the like.

Examples of the rust inhibitor include acidic sulfite, sodium thiosulfate, ammonium thioglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, and dicyclohexylammonium nitrite.

Examples of the ultraviolet absorber include benzophenone compounds, benzotriazole compounds, cinnamic acid compounds, triazine compounds, and stilbene compounds. Further, a compound that absorbs ultraviolet rays typified by a benzoxazole-based compound and emits fluorescence, a so-called fluorescent brightener can also be used.

Examples of the viscosity modifier include water-soluble polymer compounds in addition to water-soluble organic solvents, such as polyvinyl alcohol, cellulose derivatives, polyamines, and polyimines.

Examples of the dye solubilizer include urea, ε-caprolactam, ethylene carbonate, and the like. It is preferred to use urea.

The anti-fading agent is used for the purpose of improving image storage stability. As the antifading agent, various organic and metal complex antifading agents can be used. Examples of organic anti-fading agents include hydroquinones, alkoxyphenols, dialkoxyphenols, phenols, anilines, amines, indanes, chromans, alkoxyanilines, and heterocycles. Includes nickel complexes and zinc complexes.

Examples of the surface tension adjusting agent include surfactants, and examples thereof include anionic surfactants, amphoteric surfactants, cationic surfactants, and nonionic surfactants.

Anionic surfactants include alkyl sulfocarboxylates, α-olefin sulfonates, polyoxyethylene alkyl ether acetates, N-acyl amino acids and salts thereof, N-acyl methyl taurate, alkyl sulfate polyoxyalkyl ether sulfates Salt, alkyl sulfate polyoxyethylene alkyl ether phosphate, rosin acid soap, castor oil sulfate ester, lauryl alcohol sulfate ester, alkylphenol type phosphate ester, alkyl type phosphate ester, alkylaryl sulfonate, diethylsulfate , Diethylhexylsylsulfosuccinate, dioctylsulfosuccinate and the like.

Examples of the cationic surfactant include 2-vinylpyridine derivatives and poly-4-vinylpyridine derivatives.

Amphoteric surfactants include lauryldimethylaminoacetic acid betaine, 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, coconut oil fatty acid amidopropyldimethylaminoacetic acid betaine, polyoctylpolyaminoethylglycine, and other imidazoline derivatives. Is mentioned.

Nonionic surfactants include polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene dodecyl phenyl ether, polyoxyethylene oleyl ether, polyoxyethylene lauryl ether, polyoxyethylene alkyl ether, and other ethers; Ester systems such as polyoxyethylene oleate, polyoxyethylene distearate, sorbitan laurate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquioleate, polyoxyethylene monooleate, polyoxyethylene stearate; 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol, 3,5-dimethyl -1-hexyne-3-acetylene glycol ol (alcohol) based; As another example, for example, manufactured by Nissin Chemical Industry Co., Ltd., trade name Surfynol ^RTM 104, 82, 465, Olfine ^RTM STG; etc. Is mentioned.

As the antifoaming agent, a highly oxidized oil-based, glycerin fatty acid ester-based, fluorine-based, or silicone-based compound is used as necessary.

These ink preparation agents are used alone or in combination. The surface tension of the ink containing the ink composition of the present invention is usually 25 to 70 mN / m, more preferably 25 to 60 mN / m. Similarly, the viscosity of the ink is preferably 30 mPa · s or less, and more preferably adjusted to 20 mPa · s or less.

In order to produce the ink composition of the present invention, there is no particular limitation on the order of dissolving each component such as an additive. In preparing the ink composition, water to be used is preferably water with few impurities such as ion exchange water or distilled water.
Furthermore, if necessary, fine filtration may be performed using a membrane filter or the like to remove impurities from the ink composition. When used as an ink for an ink jet printer, it is preferable to perform microfiltration. The pore diameter of the filter for performing microfiltration is usually 1 μm to 0.1 μm, preferably 0.8 μm to 0.1 μm.

In order to provide a higher-definition inkjet recording image, two similar colors of ink having high and low dye concentrations may be used for inkjet recording as an ink set. In this case, a high dye density is called, for example, magenta ink, and a low dye density is called light magenta ink. In such a case, two types of ink compositions of the present invention having different dye concentrations may be prepared and used as an ink set. Further, the ink composition of the present invention may be used for only one of them.
In addition, the ink composition of the present invention can also be used for toning of other colors, such as black ink, or for the purpose of preparing red ink or blue (or violet) ink by mixing with yellow dye or cyan dye. .

In the ink jet recording method of the present invention, a container containing the ink composition of the present invention is loaded in a predetermined position of an ink jet printer, and droplets of the ink composition are ejected in accordance with a recording signal to form a recording material. This is a method of recording by adhering.
The ink jet recording method of the present invention uses, in combination with the ink composition of the present invention, yellow, cyan, and, if necessary, each ink such as green, blue (or violet), red, and black to produce a full color recorded image. It can also be reproduced. In this case, the ink of each color is contained in each container, and these containers may be used by being loaded into a predetermined position of the ink jet printer.
Examples of the ink jet printer include those using a piezo method using mechanical vibration; a bubble jet (registered trademark) method using bubbles generated by heating; and the like. The ink jet recording method of the present invention can be used by any method.

Examples of the recording material include information transmission sheets such as paper and film, fibers and cloth (cellulose, nylon, wool, etc.), leather, and a base material for a color filter. Among these, an information transmission sheet is preferable.

The information transmission sheet is not particularly limited, and plain paper as well as surface-treated sheets, specifically, paper, synthetic paper, films and other substrates provided with an ink receiving layer are used. be able to. Here, the ink receiving layer is, for example, a method of impregnating or coating the base material with a cationic polymer; or inorganic fine particles capable of absorbing pigments in inks such as porous silica, alumina sol, and special ceramics. A method of coating the surface of the base material together with a hydrophilic polymer such as pyrrolidone; Those provided with such an ink receiving layer are usually called ink jet exclusive paper, ink jet exclusive film, glossy paper, or glossy film. Examples of the commercially available product include Seiko Epson Corporation, trade name: Photographic Paper Crispia ^RTM (high gloss); Brother Industries, Ltd., trade name: Photographic Glossy Paper BP71G;
Plain paper means paper that is not particularly provided with an ink-receptive layer, and various papers are commercially available depending on the application. An example of commercially available plain paper includes, for inkjet, double-sided fine plain paper manufactured by Seiko Epson; color plain paper manufactured by Canon; Multipurpose Paper, All-in-one Printing Paper; manufactured by Hewlett Packard. is there. In addition, PPC paper and the like whose application is not limited to inkjet printing are also plain paper.

The colored body of the present invention means a substance colored with the ink composition of the present invention. Although there is no restriction | limiting in particular in the material of a colored body, For example, the said recording material etc. are mentioned preferably. Examples of the coloring method include a dip dyeing method, a textile printing method, a printing method such as screen printing, and a method using ink jet recording. In these, the inkjet recording method is preferable, and the colored body colored with the inkjet recording method of this invention is especially preferable.

The ink composition of the present invention is suitable for use in printing, copying, marking, writing, drawing, stamping, or recording (printing), particularly in inkjet recording. In addition, the ink composition of the present invention has very good storage stability without solid precipitation, physical property change, hue change and the like after long-term storage. A printed matter using the ink composition of the present invention as an ink for inkjet recording is an ideal hue as a magenta hue without selecting a recording material (for example, paper, film, etc.), and a photographic color image is obtained. It is also possible to reproduce it faithfully on paper.
Furthermore, the ink composition of the present invention has high color developability and sharpness even on plain paper. In addition, even when recording on a recording material coated on the surface with a porous white inorganic material, such as an inkjet exclusive paper or film used to obtain a photographic recording image, various fastness properties, that is, water resistance, moisture resistance, Gas resistance such as ozone gas resistance and particularly light resistance are good, and the long-term storage stability of photographic-tone recorded images is also excellent. For this reason, it is suitable for inkjet recording, which is one of the characteristics that a recording material is not selected. In addition, when the ink composition of the present invention is used for ink jet recording, solid deposition due to drying of the ink composition in the vicinity of the nozzle is very unlikely to occur, and the ejector (ink head) is not blocked.
Thus, the ink composition of the present invention is extremely useful as an ink, particularly as an inkjet recording ink.

  Hereinafter, the present invention will be described more specifically with reference to examples. In the text, “parts” and “%” are based on mass unless otherwise specified. About operation, such as reaction and crystallization in an Example, all were performed under stirring unless there is particular notice. Further, among the compounds described in the examples, the maximum absorption wavelength (λmax) was measured in an aqueous solution.

[Example 1]
(Process 1)
97.5 parts of a wet cake of a compound of the following formula (13) obtained by following the method described in Patent Document 3 was added to 70 parts of water (purity 45.9% by diazotization value analysis), and further 25% water. An aqueous solution of pH 7 was obtained by adding an aqueous sodium oxide solution. The obtained aqueous solution was dried with a hot air dryer at 80 ° C. to obtain a solid containing the compound of the formula (13).

(Process 2)
To 320 parts of N-methylpyrrolidone, the total amount of the compound of formula (13) obtained in Example 1 (Step 1) and 7.8 parts of ethylenediaminetetraacetic acid dianhydride are added and heated to 75 to 85 ° C. for 6 hours. Reacted. The obtained reaction solution was filtered to remove insoluble matters, and 400 parts of 2-propanol was added to the filtrate, and the precipitated solid was collected by filtration. The obtained solid was suspended and purified with 120 parts of 2-propanol, whereby R ¹ in the formula (9) was methyl and Z was a group represented by the formula (10). 220 parts of a wet cake of a compound in which R ² and R ³ are hydrogen atoms were obtained.

(Process 3)
After adding 220 parts of a wet cake of the compound of the formula (9) obtained in Example 1 (Step 2) and 6.6 parts of copper (II) acetate monohydrate to 300 parts of water to make a solution, 15% carbonate A sodium aqueous solution was appropriately added to react at room temperature for 10 hours while maintaining the pH of the reaction solution at 6.5 to 7.5. To the obtained reaction solution, 300 parts of methanol and 300 parts of 2-propanol were added, and the precipitated solid was collected by filtration to obtain a wet cake. The obtained wet cake was added to 300 parts of ion-exchanged water to form a solution, and 75 parts of anion exchange resin Diaion ^RTM SA10AOH and 26 parts of cation exchange resin Diaion ^RTM SK1BH (both manufactured by Mitsubishi Chemical Corporation) were added appropriately. The solution was desalted by stirring at a liquid temperature of 20 to 30 ° C. for 2 hours while maintaining the pH of the liquid at 6 to 8. After removing the ion exchange resin by filtering the resulting liquid, 400 parts of ethanol and 800 parts of 2-propanol were added to the filtrate and stirred for 15 hours. The solid precipitated from this liquid is separated by filtration and dried, whereby R ¹ in the formula (1) is methyl, X is a group represented by the formula (2), and R in the formula (2) 47.8 parts of the compound of the invention in which ² and R ³ are hydrogen atoms were obtained.
λmax: 513 nm.

[Examples 2-3]
(A) Preparation of ink C.I. I. Acid Red 289 and the compound obtained in Example 1 as the compound represented by Formula (1) were both used as pigments, and the ink compositions were prepared by blending the components shown in Table 3 below. Furthermore, the ink-jet ink for evaluation was obtained by filtering with a 0.45 micrometer membrane filter. In preparing the ink, ion-exchanged water was used as water. The ink composition was adjusted with a 25% aqueous sodium hydroxide solution so that the pH was 8 to 10, and water was added so that the total amount was 100 parts. This pH and the total amount of added water are abbreviated as “aq. NaOH” in Table 3 below.
As described above, two types of inks having different blending ratios of the two types of dyes were prepared, and were set as Example 2 and Example 3, respectively.
The abbreviations used in Table 3 below have the following meanings.
AR289: C.I. I. Acid Red 289.
NMP: N-methyl-2-pyrrolidone.
IPA: isopropanol.
BuCt: Butyl carbitol.
EDTA · 2Na: disodium ethylenediaminetetraacetic acid.
In Table 3 below, as the “surfactant”, trade name Surfinol ^RTM 104PG50 manufactured by Nissin Chemical Co., Ltd. was used.

(B) Inkjet recording Inkjet recording is performed on the following two types of recording materials (glossy paper 1 and glossy paper 2) using the ink prepared in each example and using an inkjet printer (trade name: Pixus ^RTM iP4500, manufactured by Canon Inc.). Went.

Glossy paper 1:
Product name: Photographic Paper Crispia ^RTM (high gloss), manufactured by Seiko Epson Corporation.
Glossy paper 2:
Product name: Photo Glossy Paper BP71G, manufactured by Brother Industries, Ltd.

During ink jet recording, an image pattern was prepared so that gradations of 100, 85, 70, 55, 40, and 25% were obtained, and a recorded matter was obtained. The obtained recorded matter was used as a test piece, and the following xenon light resistance test was performed. The reflection density in the xenon light resistance test was measured for the 70% gradation portion of each test piece. The reflection density was measured using a colorimetric system (trade name: SpectroEye ^RTM , manufactured by X-right). Colorimetry was performed under the conditions of DIN, a viewing angle of 2 degrees, and a light source D65 as a density reference.
Various test methods for recorded images are described below.

[(C) Xenon light resistance test]
Each test piece was placed in a holder and irradiated with a xenon weatherometer XL75 (manufactured by Suga Test Instruments Co., Ltd.) at a temperature of 24 ° C., a humidity of 60% RH, and a 100 klux illuminance for 168 hours. The reflection density of each test piece before and after the test was measured by the above colorimetry system, and the dye residual ratio was calculated by (reflection density after test / reflection density before test) × 100 (%). The results are shown in Table 4 below.

[(D) Clarity evaluation test]
The reflection density was measured for the 100% gradation portion of each test piece.
The sharpness (C *) was calculated from chromaticity (a *, b *) as C * = [(a *) ² + (b *) ² ] ^1/2 .
The results of the calculated C * values are shown in Table 4 below. In addition, the larger the C * value, the better the clarity.

As is clear from the results in Table 4, each ink containing at least one xanthene dye and at least one compound represented by the formula (1) as a pigment has high sharpness and light resistance. Indicated.

The ink composition of the present invention having high sharpness and excellent light resistance is extremely useful as an ink for various recordings, particularly for ink jet recording.

Claims (16)

An ink composition containing, as pigments, at least one xanthene dye and at least one compound represented by the following formula (1) or a salt thereof.

[In Formula (1),
R ¹ represents a hydrogen atom, a C1-C5 alkyl group, a hydroxy C1-C5 alkyl group, a cyclohexyl group, or a cyano C1-C5 alkyl group,
X is a group represented by the following formula (2). ],

[In Formula (2),
* Represents a binding site with two amide groups,
R ² and R ³ each independently represent a hydrogen atom or a C1-C5 alkyl group,
R ² and R ³ may combine to form a C5-C10 cycloalkylene ring with the two carbon atoms that they each replace. ]. The ink composition according to claim 1, wherein the xanthene dye is a dye represented by the following formula (3), an isomer at a cation position thereof, or a salt thereof.

[In Formula (3),
R ^{101 to} R ¹⁰⁴ are each independently a hydrogen atom; a C1-C10 alkyl group; a C1-C10 alkyl group having a group selected from the group consisting of a hydroxy group, a carboxy group, and a sulfo group as a substituent; a phenyl group; Represents a phenyl group having a group selected from the group consisting of a hydroxy group, a carboxy group, a sulfo group, a sulfamoyl group, a C1-C4 alkyl group, a C1-C4 alkoxy group and a halogen atom as a substituent;
R ¹⁰⁵ represents a sulfo group, a carboxy group, or a C1-C4 alkoxycarbonyl group,
R ¹⁰⁶ is a hydrogen atom; a C1-C10 alkyl group; a C1-C10 alkyl group having a group selected from the group consisting of a hydroxy group, a carboxy group and a sulfo group as a substituent; a sulfo group; a carboxy group; a sulfamoyl group; A group; or a halogen atom;
R ¹⁰⁷ and R ¹⁰⁸ each independently represent a hydrogen atom or a C1-C10 alkyl group,
R ^109- represents a halogen anion, hydroxide, acetate anion, tetrafluoroborate anion, hexafluorophosphate anion, sulfate anion, or toluenesulfonate anion.
However, when the dye represented by formula (3) forms a salt in the molecule, ^R109- does not exist. ]. The ink composition according to claim 1, wherein the total mass of the pigment contained in the ink composition is 0.5 to 20 mass% with respect to the total mass of the ink composition. R ² and R ³ are each independently a hydrogen atom, a methyl group, or R ² and R ³ are bonded to each other, and each of these is a cyclohexylene ring formed with two substituted carbon atoms. The ink composition according to any one of the above. The ink composition according to any one of claims 1 to 4, wherein R ¹ is a hydrogen atom or a methyl group. R ¹ is a hydrogen atom or a methyl group,
The ink composition according to any one of claims 1 to 5, wherein R ² and R ³ are hydrogen atoms. In the dye represented by formula (3),
R ¹⁰¹ is a C1-C10 alkyl group; or as a substituent, a phenyl group having a group selected from the group consisting of a sulfo group and a C1-C4 alkyl group;
R ¹⁰² is a hydrogen atom or a C1-C10 alkyl group,
R ¹⁰³ is a hydrogen atom; a C1-C10 alkyl group; or a phenyl group having a C1-C4 alkyl group as a substituent;
R ¹⁰⁴ is a hydrogen atom or a C1-C10 alkyl group,
R ¹⁰⁵ is a sulfo group, a carboxy group, or a C1-C4 alkoxycarbonyl group,
R ¹⁰⁶ is a hydrogen atom or a sulfo group,
R ¹⁰⁷ and R ¹⁰⁸ are each independently a hydrogen atom or a C1-C10 alkyl group,
The ink composition according to any one of claims 2 to 6, wherein R ^109- is a halogen anion.
However, when the dye represented by formula (3) forms a salt in the molecule, ^R109- does not exist. The xanthene dye is C.I. I. Acid Red 289, or C.I. I. The ink composition according to any one of claims 1 to 7, which is Acid Red 52. The ink composition according to any one of claims 1 to 8, further comprising a water-soluble organic solvent. The ink composition according to claim 1, which is used for ink jet recording. An ink jet recording method for performing recording by ejecting droplets of the ink composition according to any one of claims 1 to 10 in accordance with a recording signal and attaching the droplets to a recording material. The inkjet recording method according to claim 11, wherein the recording material is an information transmission sheet. 13. The ink jet recording method according to claim 12, wherein the information transmission sheet is a plain paper or a sheet having an ink receiving layer containing a porous white inorganic substance. A colored body colored with the ink composition according to any one of claims 1 to 10. A colored body colored by the ink jet recording method according to claim 11. An ink jet printer loaded with a container containing the ink composition according to claim 1.