JP2006232924A - Recording liquid and its use - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dye and a recording liquid that, when recorded on a plain paper or an exclusive paper for inkjet by an inkjet recording method or the like, attain good printing qualities and form a recorded image excellent in density, saturation and color tones, particularly exhibiting good light resistance and ozone resistance. <P>SOLUTION: The recording liquid comprises at least water and a water-soluble dye, where the water-soluble dye is represented by general formula (1) (wherein L is a divalent linking group selected from the group consisting of -NX-, -S- and -O-, or a single bond; A is an aryl or heteryl group substituted with at least one sulfone group; m is an arbitrary integer of 1-8; R is an arbitrary substituent group other than the -L-A group and the sulfone group; n is an arbitrary integer of 0-7; X is a hydrogen atom, an optionally substituted 1-4C alkyl group or an optionally substituted 2-4C alkenyl group; and when two or more of L, A, R and X each exist, they can be each the same or different from each other). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a recording liquid and use thereof.

  A so-called ink jet recording method has been put to practical use in which recording is performed by ejecting droplets of a recording liquid containing a water-soluble dye such as a direct dye or an acid dye from a minute ejection orifice. With regard to the recording liquid used for ink jet recording, it is fast to fix on recording papers used for general office work such as PPC (plain paper copier) paper, fan hold paper (continuous paper for computers, etc.), and printing. It is required that the printing quality of the product is good, that is, that the printing has no blur and that the contour is clear, and that the stability when stored as a recording liquid is required, and therefore it is used. The solvent that can be produced is severely limited.

  On the other hand, the dye for the recording liquid has sufficient solubility in the limited solvent as described above, and is stable when stored as a recording liquid for a long period of time. However, it is required to have excellent hue and saturation, and excellent water resistance and light resistance. However, it has been difficult to satisfy many of these requirements at the same time.

  Furthermore, the market demand for inkjet images has further increased with the recent penetration of inkjet recording into society by increasing the definition of inkjet photographic image quality. In particular, along with the expansion of applications such as printing beautiful photographic-like images on glossy paper for exclusive use of inkjet and dedicated postcards, and displaying and viewing the obtained images, ozone, nitrogen oxides, and sulfur oxidation in the air Improvement of inkjet image degradation behavior by so-called oxidation active gas such as substances, in other words, it has come to be more strongly required to further improve the gas resistance of the image, Such a request has not always been sufficiently met. Gas resistance is generally determined by exposing an inkjet image to a certain concentration of ozone-containing air and using the degree of fading accompanying this as a measure. Therefore, in the present invention as well, an ozone exposure test is used to evaluate gas resistance. In the present invention, the above gas resistance is hereinafter referred to as ozone resistance.

  Conventionally, it is known that a specific azo dye is used as a yellow dye exhibiting relatively good fastness in ink jet recording. I. Direct yellow 132 is often used as a yellow coloring matter of an ink set that requires high fastness (see, for example, Patent Document 1). However, the market demand for a higher level of fastness, especially light resistance and ozone resistance, is increasing further with the spread of digital photography, and the fastness of inkjet dyes, especially ozone resistance, is even greater. The current situation is that improvement is required.

  By the way, in general, when an anthraquinone compound is used as a water-soluble dye, a compound in which an anthraquinone ring is directly sulfonated is used. However, when such a compound is used for water-based ink jet recording, it is empirically difficult to meet the more stringent requirements of light resistance and ozone resistance. Because of the presence of a sulfone group inside the anthraquinone skeleton, hydration to the dye occurs in the vicinity of the chromophore, and the dye is present in disorder in a form close to a single molecule in the recording liquid or on the recorded image. This is probably because the water-solubility of water is increased, but it is not sufficiently robust against light and gas attacks.

For example, Patent Document 2 describes an example in which a dye in which an anthraquinone ring is directly sulfonated is used for this purpose. However, comparison data with existing dyes that are currently widely used for this purpose are described. It has not been. Patent Document 2 also describes a compound in which a carboxyl group is bonded to a linking group bonded to an anthraquinone ring. Generally, a dye solubilized with only a carboxyl group is used as an inkjet dye. From the viewpoint, the water solubility is often insufficient, and it is presumed that a practical level of water solubility cannot be imparted to this dye.
JP 2003-253176 A Japanese Patent Laid-Open No. 2002-020658

  In the present invention, when recording on plain paper or inkjet exclusive paper by a method such as ink jet recording, the print quality is good and the density, saturation, and color tone of the recorded image are excellent, and particularly, light resistance and ozone resistance are also good. An object of the present invention is to provide a recording liquid capable of forming a simple recorded image.

  Another object of the present invention is to provide a recording liquid set, a recording method, an ink cartridge, an ink jet printer, and paper using such a recording liquid.

The inventors of the present invention have repeatedly studied to solve the above problems, and have a stable structure with a flat plate, but when water-solubilizing a dye having an anthraquinone skeleton without water solubility,
1) Rather than placing a water-soluble group on the anthraquinone skeleton, placing a water-soluble group on the aryl group or substituted heteryl group bonded to the anthraquinone skeleton;
2) While introducing a water-soluble group at a position distant from the dye skeleton, by combining two points of using a more water-soluble sulfone group, the water-solubility of the dye that can withstand practical use as a recording liquid is maintained. The anthraquinone rings are hydrophobic interactions, and a microscopic layered structure of molecules is realized in the recording liquid and on the recorded image. As a result, the microscopic structure is less susceptible to excitation relaxation of light absorption and gas attack. Based on the technical idea that a dye having a higher fastness can be obtained by forming an aggregated structure, by using a water-soluble dye having such a specific functional group introduced, a method such as inkjet recording can be used. When recorded on plain paper or inkjet paper, the print quality is good and the recorded image has excellent density, saturation, and color tone, especially light resistance and ozone resistance. Ensure that can form, it achieved the present invention.

（式中、Ｌは−ＮＸ−、−Ｓ−、及び−Ｏ−よりなる群から選ばれる２価の連結基又は単結合を表わし、Ａは少なくとも１個のスルホン基で置換された、アリール基若しくはヘテリル基を表わし、ｍは１〜８の任意の整数を表わし、Ｒは上記−Ｌ−Ａなる基以外で、かつスルホン基以外の任意の置換基を表わし、ｎは０〜７の任意の整数を表わし、Ｘは水素原子、置換されていてもよい炭素数１〜４のアルキル基、又は置換されていてもよい炭素数２〜４のアルケニル基を表わし、Ｌ、Ａ、Ｒ、Ｘが複数存するとき、それらは各々、同一でも異なっていてもよい。） That is, the gist of the present invention resides in a recording liquid characterized in that it contains at least water and a water-soluble dye, and the water-soluble dye is represented by the following general formula (1).

(In the formula, L represents a divalent linking group or a single bond selected from the group consisting of —NX—, —S—, and —O—, and A represents an aryl group substituted with at least one sulfone group. Alternatively, it represents a heteryl group, m represents an arbitrary integer of 1 to 8, R represents a substituent other than the group -LA, and other than a sulfone group, and n represents an arbitrary group of 0 to 7 Represents an integer, X represents a hydrogen atom, an optionally substituted alkyl group having 1 to 4 carbon atoms, or an optionally substituted alkenyl group having 2 to 4 carbon atoms, and L, A, R, and X represent When there are a plurality, they may be the same or different.)

  However, as described later, the water-soluble dye used in the present invention may be a free acid type represented by the general formula (1) or a salt type thereof.

（式中、ＴとＴ’はスルホン基以外の任意の置換基を表わし、ｐとｐ’は０〜４の整数を表わし、ｑとｑ’は１〜３の整数を表わし、ＴとＴ’、ｐとｐ’、ならびにｑとｑ’は、各々同一でも異なっていてもよい。Ｒ，ｎは一般式（１）におけると同義である。） Another gist of the present invention resides in the recording liquid according to claim 1, wherein the water-soluble dye is represented by the following general formula (2) (claim 2).

(In the formula, T and T ′ represent an arbitrary substituent other than the sulfone group, p and p ′ represent an integer of 0 to 4, q and q ′ represent an integer of 1 to 3, and T and T ′. , P and p ′, and q and q ′ may be the same or different. R and n have the same meanings as in general formula (1).

  Another gist of the present invention resides in a recording liquid set comprising the recording liquid according to claim 1 or 2 (claim 3).

  Another gist of the present invention resides in a recording method using the recording liquid according to claim 1 or 2 or the recording liquid set according to claim 3 (claim 4).

  Another subject matter of the present invention lies in a recording method according to claim 4, wherein the recording method is ink-jet recording (claim 5).

  Another gist of the present invention lies in an ink cartridge filled with the recording liquid according to claim 1 or claim 2 (claim 6).

  Another gist of the present invention resides in an ink jet printer comprising the recording liquid according to claim 1 or 2 or the recording liquid set according to claim 3 (claim 7). .

  Another gist of the present invention resides in a paper on which an image is printed, which is characterized in that it contains a water-soluble dye represented by the general formula (1) (Claim 8).

  In the present invention, “image” includes all recording objects such as characters, symbols, pictures, line segments, figures, and the like.

  According to the present invention, when recording on plain paper or ink jet dedicated paper by a method such as ink jet recording, the print quality is good and the density, saturation and color tone of the recorded image are excellent, especially light resistance and ozone resistance. Can form a good recorded image.

  Hereinafter, the recording liquid of the present invention and embodiments of its use will be described in detail.

[Water-soluble dye]
First, the water-soluble dye used in the present invention will be described.

（式中、Ｌは−ＮＸ−、−Ｓ−、及び−Ｏ−よりなる群から選ばれる２価の連結基又は単結合を表わし、Ａは少なくとも１個のスルホン基で置換された、アリール基若しくはヘテリル基を表わし、ｍは１〜８の任意の整数を表わし、Ｒは上記−Ｌ−Ａなる基以外で、かつスルホン基以外の任意の置換基を表わし、ｎは０〜７の任意の整数を表わし、Ｘは水素原子、置換されていてもよい炭素数１〜４のアルキル基、又は置換されていてもよい炭素数２〜４のアルケニル基を表わし、Ｌ、Ａ、Ｒ、Ｘが複数存するとき、それらは各々、同一でも異なっていてもよい。） The water-soluble dye used in the present invention has an anthraquinone skeleton having a flat structure represented by the following general formula (1) as a basic skeleton.

(In the formula, L represents a divalent linking group or a single bond selected from the group consisting of —NX—, —S—, and —O—, and A represents an aryl group substituted with at least one sulfone group. Alternatively, it represents a heteryl group, m represents an arbitrary integer of 1 to 8, R represents a substituent other than the group -LA, and other than a sulfone group, and n represents an arbitrary group of 0 to 7 Represents an integer, X represents a hydrogen atom, an optionally substituted alkyl group having 1 to 4 carbon atoms, or an optionally substituted alkenyl group having 2 to 4 carbon atoms, and L, A, R, and X represent When there are a plurality, they may be the same or different.)

<L>
The linking group L represents a divalent linking group or a single bond selected from the group consisting of -NX-, -S-, and -O-. X in —NX— represents a hydrogen atom, an optionally substituted alkyl group having 1 to 4 carbon atoms, or an optionally substituted alkenyl group having 2 to 4 carbon atoms.

  In order to facilitate the interaction between the anthraquinone rings, which are relatively small condensed rings, the linking group L is a pseudo-integrated aromatic ring or heteroaromatic ring derived from the substituent A further bonded to L and an anthraquinone ring. It is desired to chemically convert these into a planar condensed ring. Accordingly, the linking group L is preferably an atomic group having pi electrons and promoting electron conjugation between the aromatic ring or heteroaromatic ring derived from the substituent A and the anthraquinone ring. Is preferred. From this point of view, X of the linking group —NX— is preferably a relatively small atom or atomic group, specifically a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or 2 to 4 carbon atoms. Of the alkenyl group. Here, the alkyl group or alkenyl group is a halogen atom, amino group, hydroxyl group, mercapto group, cyano group, nitro group, formyl group, methylthio group, or methylsulfonyl group, and has about 1 to 7 constituent atoms. Although it may be substituted with a polar substituent, it is preferably unsubstituted. Particularly preferred as X is a hydrogen atom and a methyl group, most preferably a hydrogen atom.

  In addition, as described above, the linking group L represents a divalent linking group or a single bond selected from the group of -NX-, -S-, -O-, among which -NX-, -S-, -O. A divalent linking group selected from the group consisting of-is preferable, more preferably -NX- or -S-, and most preferably -S-.

<A>
The substituent A is a substituent for water-solubilizing the entire dye, and represents an aryl group or a heteryl group substituted with at least one sulfone group. The number of sulfone groups contained in A is related to the size of the aryl group or heteryl group, and the preferred number of sulfone groups in the case of a monocyclic residue represented by a phenyl group is 1 to 2, The number of the preferable sulfone group in the case of the bicyclic residue represented by group is 2-3. A may have any substituent other than the sulfone group, and examples thereof include a halogen atom, amino group, hydroxyl group, mercapto group, cyano group, nitro group, formyl group, and methylthio group. Preferred examples include polar substituents typified by methylsulfonyl groups and about 1 to 7 constituent atoms, preferably about 1 to 5, and hydrophobic groups typified by alkyl groups and alkenyl groups. Particularly preferable as the polar substituent having about 1 to 5 constituent atoms are a chlorine atom, a cyano group, a nitro group, and a formyl group, and these are dye molecules by hydrogen bonding or electrostatic interaction. It is effective in that the interaction between them can be promoted. Particularly preferred as the alkyl group or alkenyl group are substituents having a relatively short chain length of about 1 to 4 carbon atoms, specifically, a methyl group, an ethyl group, and a vinyl group, which are hydrophobic. This is effective in that the interaction between dye molecules can be promoted by sex interaction.

  The number of carbon atoms constituting the aryl group or heteryl group constituting the substituent A is not particularly limited as long as the performance of the dye is not impaired, but those having about 5 to 14 ring atoms are preferable, and more preferably 5 to 5. About ten. A heteryl group in which a hetero atom exists in the ring constituent atoms is preferable in that the number of ring constituent atoms is such that the interaction between the dye molecules can be promoted by hydrogen bonding or electrostatic interaction, An aryl group whose ring-constituting atom is only carbon is preferable in that the interaction between the dye molecules can be promoted by hydrogen bonding or electrostatic interaction.

  Specific examples of the substituent A include a phenyl group, a naphthyl group, a 5-membered heteryl group containing at least a sulfur atom and / or a nitrogen atom, or a 5-membered heteryl group containing at least a sulfur atom and / or a nitrogen atom. Furthermore, it is a residue condensed with an aromatic ring, more preferably a phenyl group.

<M>
M representing the number of substituents -LA in the general formula (1) represents an arbitrary integer of 1 to 8. However, since it is not preferable to reduce the light absorption intensity per molecular unit weight, it is usually preferably 1 to 8. 4, more preferably 1 to 3, particularly preferably 2.
In addition, the substitution position of the substituent -LA with respect to the anthraquinone skeleton is preferably any of the 1-position, 4-position, 5-position, and 8-position in the following description of the substitution position of the anthraquinone skeleton. Although all the positions may be substituted, it is preferably a disubstituted product of 1-position and 4-position, 1-position and 5-position, or 1-position and 8-position. Substitutes are preferred.

<R>
The substituent R is an arbitrary substituent other than the substituent -LA and the sulfone group, and those usually used as a substituent of the dye are used. For example, a halogen atom, an amino group, an alkylamino group, an arylamino group, a heterylamino group, an acylamino group, a hydroxyl group, an alkoxy group, an aryloxy group, a carbamoyl group, an alkylcarbamoyl group, an arylcarbamoyl group, a heterylcarbamoyl group, a sulfamoyl group, Alkylsulfamoyl group, arylsulfamoyl group, heterylsulfamoyl group, formyl group, acyl group, alkyloxycarbonyl group, aryloxycarbonyl group, heteryloxycarbonyl group, mercapto group, alkylthio group, arylthio group, heterylthio An atomic group generally called an “auxiliary color group” such as a group, an alkylsulfonyl group, an arylsulfonyl group, a heterylsulfonyl group, a cyano group, or a nitro group greatly affects the hue and absorbance of the dye residue. Runode, selected and used as appropriate in order to obtain an intended hue. On the other hand, an alkyl group, an alkenyl group, an aryl group, and the like are also used to adjust the hydrophilicity and hydrophobicity of a target dye to a desired one. Among these substituents, alkylamino group, acylamino group, alkoxy group, alkylcarbamoyl group, arylcarbamoyl group, heteroarylcarbamoyl group, alkylsulfamoyl group, arylsulfamoyl group, heteroarylsulfamoyl group, acyl group, For alkyloxycarbonyl group, aryloxycarbonyl group, heteryloxycarbonyl group, alkylthio group, alkylsulfonyl group, arylsulfonyl group, heterylsulfonyl group, alkyl group, and alkenyl group, further, halogen atom, amino group, hydroxyl group Group, mercapto group, cyano group, nitro group, formyl group, methylthio group, methylsulfonyl group, polar substituents having about 1 to 7 constituent atoms, sulfone group, phosphono group, carboxyl group, borate Such, it may be substituted with high water solubility ionic dissociative group, but is preferably unsubstituted. That is, as described above, the water-soluble dye represented by the general formula (1) water-solubilizes the entire dye by the sulfone group present in the atomic group of the substituent A, while the anthraquinone moiety prints higher fastness. Since it is necessary to have a self-assembling ability due to the interaction between hydrophobic molecules at the time of drying after printing in order to give to the product, as a substituent of the anthraquinone moiety, R is a sulfone group, a phosphono group, a carboxyl group, a borate group, It is necessary to avoid the use of highly water-soluble ion dissociable groups.

<N>
N representing the number of substituents R in the general formula (1) represents an arbitrary integer of 0 to 7, but is preferably 0 to 4 because it is not preferable to reduce the light absorption intensity per unit molecular weight. More preferably, it is 0-2, Most preferably, it is 0 or 2.
In addition, the substitution position of the substituent R with respect to the anthraquinone skeleton is preferably any of the 2-position, 3-position, 4-position, 6-position, 7-position, and 8-position in the above-described substitution position display of the anthraquinone skeleton. The 4th, 6th and 8th positions are preferable, and the 2nd, 4th and 8th positions are particularly preferable.

（式中、ＴとＴ’はスルホン基以外の任意の置換基を表わし、ｐとｐ’は０〜４の整数を表わし、ｑとｑ’は１〜３の整数を表わし、ＴとＴ’、ｐとｐ’、ならびにｑとｑ’は、各々同一でも異なっていてもよい。Ｒ，ｎは一般式（１）におけると同義である。） <Preferred structure>
The water-soluble dye represented by the general formula (1) is particularly preferably represented by the following general formula (2).

(In the formula, T and T ′ represent an arbitrary substituent other than the sulfone group, p and p ′ represent an integer of 0 to 4, q and q ′ represent an integer of 1 to 3, and T and T ′. , P and p ′, and q and q ′ may be the same or different. R and n have the same meanings as in general formula (1).

  In the general formula (2), T and T ′ are those described above as optional substituents other than the sulfone group which may be substituted with the substituent A, and p and p ′ are preferably 0 to 3, More preferably, it is 1-2. Further, q and q ′ are preferably 1 to 2, more preferably 1. R and n are as described above.

  The substitution positions of T and T ′ are preferably ortho-position and meta-position, particularly ortho-position with respect to —S—, and the substitution position of the sulfone group is meta-position, para-position, particularly para-position with respect to —S—. It is preferable that

<Molecular weight>
Although there is no restriction | limiting in particular about the molecular weight of the water-soluble pigment | dye represented by General formula (1), Usually, about 300-2000, Preferably it is about 400-1500, More preferably, it is about 500-1000, Most preferably, it is about 600-800. Those are preferably used.

<Concrete example>
Suitable specific examples of the structure of LA constituting the water-soluble dye represented by the general formula (1), the structure of R, and the structure of the dye as a combination thereof are exemplified below in the form of a free acid. The present invention is not limited to the following examples.

<Free acid type / salt type>
The water-soluble dye represented by the general formula (1) used in the present invention may be used as it is in the free acid form, but may be used as it is when it is obtained in a salt form at the time of production. It may be used after being converted into a desired salt form. Examples of such salt types include salts of alkali metals such as Na, Li, and K, ammonium salts optionally substituted with alkyl groups or hydroxyalkyl groups, and organic amine salts. Examples of organic amines include lower alkyl amines, hydroxy-substituted lower alkyl amines, carboxy-substituted lower alkyl amines, and polyamines having 2 to 10 alkyleneimine units having 2 to 4 carbon atoms.

As the salt type exchange method, a known method can be arbitrarily used. For example, the following methods are mentioned.
1) A strong acid such as hydrochloric acid is added to an aqueous solution of a dye obtained in a salt form, the dye is acidified in the form of a free acid, and then dyed with an alkaline solution having a desired counter ion (for example, an aqueous lithium hydroxide solution). A method of neutralizing acidic groups and salt exchange.
2) A method of performing salt exchange in the form of a salting-out cake by adding a large excess of a neutral salt (for example, lithium chloride) having a desired counter ion to an aqueous dye solution obtained in a salt form.
3) An aqueous solution of a dye obtained in a salt form is treated with a strongly acidic ion exchange resin, the dye is acidified in the form of a free acid, and then an alkali solution having a desired counter ion (for example, an aqueous lithium hydroxide solution). To neutralize the acidic group of the dye and exchange the salt.
4) A method of performing salt exchange by allowing an aqueous solution of a dye obtained in a salt form to act on a strongly acidic ion exchange resin previously treated with an alkali solution having a desired counter ion (for example, an aqueous lithium hydroxide solution).

  In addition, the dye used in the present invention may have a part of the acid group in a salt form, or a mixture of a salt form dye and a free acid form dye. Here, whether the acidic group takes the free acid type or the salt type depends on the pKa of the recording liquid and the pH of the ink. Usually, it is preferable that the sulfo group takes a salt form and has more carboxyl groups in view of the difficulty of clogging the ink. On the other hand, a dye having a carboxyl group in an acid form is preferably used when importance is attached to water resistance and bleeding resistance. Examples of the salt type include salts of alkali metals such as Na, Li and K, ammonium salts optionally substituted with an alkyl group or hydroxyalkyl group, and organic amine salts. Examples of organic amines include lower alkyl amines, hydroxy-substituted lower alkyl amines, carboxy-substituted lower alkyl amines, and polyamines having 2 to 10 alkyleneimine units having 2 to 4 carbon atoms. In the case of these salt types, the type is not limited to one type, and a plurality of types may be mixed.

The type of counter ion is also freely selected according to the characteristics to be emphasized in the ink. Since many intermediates and reagents for dye synthesis contain Na, water-soluble dyes are generally obtained in the form of Na salts, but when water resistance is important, they are often converted to NH ₄ salts, When it is necessary to increase the solubility of the dye and maintain the clogging property of the ink at a higher level, it may be converted into a Li salt or an alkanolamine salt typified by triethanolamine.

  In the structure of the dye represented by the general formula (1) used in the present invention, when one molecule contains a plurality of acid groups, the plurality of acid groups are salt type or acid type and are different from each other. It may be a thing.

<Water soluble>
As the water solubility of the water-soluble dye represented by the general formula (1), for example, the solubility in water at 25 ° C. is about 0.1 to 30% by weight, preferably 1 to 25%. Preferably it is 4-20 weight%, Most preferably, it is 8-15 weight%. Here, the one having higher solubility in water is preferable when higher clogging resistance is required because the dye is less likely to precipitate even when the ink is dried with a nozzle head. Those having a low solubility are suitable for cases where higher water resistance is required, since many of the printed materials have better water resistance.

<Production method>
The water-soluble dye represented by the general formula (1) can be produced according to a known method, for example, as shown in the synthesis examples described later.

[Recording liquid]
Next, the recording liquid of the present invention containing at least the water-soluble dye represented by the general formula (1) and water will be described.

  The content of the water-soluble dye of the general formula (1) in the recording liquid is preferably 0.5% by weight or more, particularly preferably 2% by weight or more with respect to the total amount of the recording liquid. Moreover, 10 weight% or less, Especially 8 weight% or less are preferable. In order to reduce the risk of dye deposition from the recording liquid and an increase in the viscosity of the recording liquid, the content of the dye is preferably small. In order to obtain a high-quality image, the content of the dye is preferably large.

  The recording liquid of the present invention preferably contains a solvent other than water. Examples of the solvent other than water include water-soluble organic solvents such as ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, and triethylene. Glycol, polyethylene glycol (# 200), polyethylene glycol (# 400), glycerin, N-methylpyrrolidone, N-ethylpyrrolidone, 1,3-dimethylimidazolidinone, thiodiethanol, dimethylsulfoxide, ethylene glycol monoallyl ether, ethylene Examples include glycol monomethyl ether, diethylene glycol monomethyl ether, 2-pyrrolidone, sulfolane, ethyl alcohol, and isopropanol.

  These water-soluble organic solvents are usually used in the range of 1 to 50% by weight based on the total amount of the recording liquid. On the other hand, water is used in the range of 45 to 95% by weight based on the total amount of the recording liquid. In order to increase the solubility of the dye, it is desirable that the content of the water-soluble organic solvent is not too high and the content of water is not too low. In order to easily adjust the viscosity and surface tension of the recording liquid, it is desirable that the water-soluble organic solvent content is not too small and the water content is not too large.

  The recording liquid of the present invention may contain components other than the water-soluble dye represented by the general formula (1), water and the water-soluble organic solvent blended as necessary. 0.1 to 10% by weight, preferably 0.5 to 5% by weight, of the compound selected from urea, thiourea, biuret and semicarbazide is added to the recording liquid, or 0.001 to 5. By adding 0% by weight of a surfactant, quick drying after printing and printing quality can be further improved.

  The recording liquid of the present invention may contain a dye other than the water-soluble dye represented by the general formula (1) (hereinafter referred to as “other dye”), and contains other dyes. The total dye content in the recording liquid is preferably 0.5% by weight or more, particularly preferably 2% by weight or more, more preferably 8% by weight or less, and particularly preferably 5% by weight or less, based on the total amount of the recording liquid. The ratio of the other dyes to the dye amount is preferably 50% by weight or less, and particularly preferably 25% by weight or less in order to ensure the effects of the present invention.

  The recording liquid of the present invention is a solution prepared by mixing a predetermined amount of water-soluble dye represented by the general formula (1), water and preferably a water-soluble organic solvent, and other components blended as necessary. It is easily prepared. The mixed solution is preferably filtered through a membrane filter or the like in order to remove insoluble components such as inorganic particles, and is preferably used after being deaerated to improve ejection stability.

[Use of recording liquid]
The recording liquid set of the present invention includes such a recording liquid of the present invention. For example, the recording liquid of the present invention and other water-soluble dye-based recording liquids, or pigments such as carbon black and organic pigments. It consists of a base recording liquid.
The recording method of the present invention performs recording using such a recording liquid or recording liquid set of the present invention, and is particularly effective for ink jet recording.
The ink cartridge of the present invention is filled with the recording liquid of the present invention.
The ink jet printer of the present invention is loaded with the recording liquid or recording liquid set of the present invention.
The paper of the present invention contains a water-soluble dye represented by the general formula (1), and is an image printed with the recording liquid or recording liquid set of the present invention.
In particular, glossy paper used for inkjet photographic image quality printing is preferable because it provides a recorded image with excellent image quality and light resistance and ozone resistance.

  EXAMPLES The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

<Synthesis example>
A mixture of 2.77 g of 1,5-dichloro-9,10-anthraquinone (reagent), 2.46 ml of thiophenol (reagent), 3.04 g of sodium carbonate (reagent) and 40 ml of dimethylformamide (reagent) at 140 ° C. After stirring for 3 hours, the mixture was cooled to room temperature and poured into ice water. The precipitate was collected by filtration and washed successively with water, hexane, and methanol to obtain 4.01 g of 1,5-bis (phenylthio) -9,10-anthraquinone.

To 1.00 g of the obtained 1,5-bis (phenylthio) -9,10-anthraquinone, 10 ml of concentrated sulfuric acid (reagent) was added at room temperature, stirred at room temperature for 30 minutes, and then stirred at 80 ° C. for 30 minutes. Thereafter, after cooling to room temperature, the mixture was poured into ice water, and the deposited precipitate was collected by filtration, dried and suspended and washed with ethyl acetate to obtain 1.4 g of the exemplified dye (1) as the target product. ESI-MS m / z 528.7 ([M-H] ^- ).

  1.4 g of the obtained dye was suspended in 28 g of water, neutralized with lithium hydroxide to pH = 10, 84 g of isopropyl alcohol was added, and the crystals were collected by filtration. The obtained crystals were suspended and washed with 56 g of isopropyl alcohol, and then dried under reduced pressure at 40 ° C. to obtain 1 g of a dye evaluation sample. The maximum absorption wavelength of this dye in water at pH 10 was 453 nm.

<Example 1>
Orphine E1010 (surfactant, available from Nissin Chemical Industry) 2 parts by weight, triethylene glycol monobutyl ether 11 parts by weight, diethylene glycol 13 parts by weight, glycerin 12 parts by weight, triethanolamine 0.8 parts by weight, urea 11 parts by weight In addition, water was added to 8 parts by weight of the dye (1) produced in the above synthesis example, and the pH was adjusted to 9 with a 1N aqueous sodium hydroxide solution to make the total amount 100 parts by weight. This composition was sufficiently mixed and dissolved, filtered under pressure with a membrane filter having a pore size of 0.45 μm, and then deaerated with an ultrasonic cleaner to prepare a recording liquid.

  Using the obtained recording liquid, inkjet recording was performed on glossy paper exclusively for inkjet (trade name PR101, manufactured by Canon Inc.) using an inkjet printer (trade name BJ F890, manufactured by Canon Inc.) to obtain a solid yellow image. .

  When the obtained images were evaluated for ozone resistance and light resistance by the following methods, as shown in Table 1, good results were obtained.

<Evaluation of ozone resistance>
The obtained image was exposed to ozone-containing air having a temperature of 40 ° C., a relative humidity of 55%, and an ozone concentration of 10 ppm for 4 hours. The degree of discoloration of the image before and after exposure was quantified in the form of OD residual rate with a colorimetric device (trade name Spectroeye, manufactured by Gretag Macbeth). Here, the OD remaining rate is a numerical value representing the degree of fading, and the smaller the numerical value, the larger the degree of fading, that is, inferior in ozone resistance in this evaluation.

<Evaluation of light resistance>
The image was irradiated with xenon light for 80 hours using a xenon weatherometer Ci4000 (product of Atlas Tester). Thereafter, the degree of fading (OD remaining rate) of the image was measured with the above-described colorimetric device. As described above, the OD remaining rate is a numerical value indicating the degree of fading, and the smaller the numerical value, the larger the degree of fading, that is, inferior light resistance in this evaluation.

<Comparative example 1>
The dye is C.I. I. Instead of direct yellow 132, a recording liquid was prepared by the same operation as in Example 1 while adjusting the color density (OD) of the recording liquid to be the same as that in Example 1. Using this recording liquid, ink jet recording and evaluation of the obtained image were performed in the same manner as in Example 1. As shown in Table 1, the light resistance was as good as that in Example 1. As for ozone resistance, the color fading was nearly twice that of Example 1.

Comparative Example 2
A recording liquid was prepared in the same manner as in Comparative Example 1 except that the dye was changed to that shown in Comparative Example 2 in Table 1 (reagent). Similarly, inkjet recording and the obtained image As a result of evaluation, as shown in Table 1, both ozone resistance and light resistance were extremely low.

Claims (8)

A recording liquid comprising at least water and a water-soluble dye, wherein the water-soluble dye is represented by the following general formula (1).

(In the formula, L represents a divalent linking group or a single bond selected from the group consisting of —NX—, —S—, and —O—, and A represents an aryl group substituted with at least one sulfone group. Alternatively, it represents a heteryl group, m represents an arbitrary integer of 1 to 8, R represents a substituent other than the group -LA, and other than a sulfone group, and n represents an arbitrary group of 0 to 7 Represents an integer, X represents a hydrogen atom, an optionally substituted alkyl group having 1 to 4 carbon atoms, or an optionally substituted alkenyl group having 2 to 4 carbon atoms, and L, A, R, and X represent When there are a plurality, they may be the same or different.) The recording liquid according to claim 1, wherein the water-soluble dye is represented by the following general formula (2).

(In the formula, T and T ′ represent an arbitrary substituent other than the sulfone group, p and p ′ represent an integer of 0 to 4, q and q ′ represent an integer of 1 to 3, and T and T ′. , P and p ′, and q and q ′ may be the same or different. R and n have the same meanings as in general formula (1).   A recording liquid set comprising the recording liquid according to claim 1.   A recording method using the recording liquid according to claim 1 or 2 or the recording liquid set according to claim 3.   The recording method according to claim 4, wherein the recording method is inkjet recording.   An ink cartridge filled with the recording liquid according to claim 1.   An inkjet printer comprising the recording liquid according to claim 1 or 2 or the recording liquid set according to claim 3. A paper on which an image is printed, which contains a water-soluble dye represented by the following general formula (1).

(In the formula, L represents a divalent linking group or a single bond selected from the group consisting of —NX—, —S—, and —O—, and A represents an aryl group substituted with at least one sulfone group. Alternatively, it represents a heteryl group, m represents an arbitrary integer of 1 to 8, R represents a substituent other than the group -LA, and other than a sulfone group, and n represents an arbitrary group of 0 to 7 Represents an integer, X represents a hydrogen atom, an optionally substituted alkyl group having 1 to 4 carbon atoms, or an optionally substituted alkenyl group having 2 to 4 carbon atoms, and L, A, R, and X represent When there are a plurality, they may be the same or different.)