JPH08188722A - Cyclodextrin inclusion water-soluble dye and its related technology - Google Patents

Abstract

PURPOSE: To provide the subject dye useful as ink for writing tool, having excellent solution stability and weather resistance by including a specific slightly water-soluble metal complex dye in cyclodextrin. CONSTITUTION: This dye is obtained by including a slightly water-soluble metal complex dye of the formula [A and A' are each a diazo component residue from o-aminophenol or anthranilic acid replaced with one or two selected from the group consisting of a halogen and a nitro group; B and B' are each a coupling component residue from β-naphthol or a pyrazolone derivative which may be replaced with amino or an NHCOR (R is a 1-4C alkyl); M is a divalent or trivalent metal; X is O or COO; Ka is an alkali metal or NH4 ] in (B) cyclodextrin. The inclusion ratio of the component A and the component B is the component A: the component B=1:1 to 1:10 and an alcohol-soluble metal complex dye is preferably used as the component A.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a cyclodextrin clathrate dye which is water-solubilized by clathrating a poorly water-soluble 1: 2 type azo metal complex salt dye with cyclodextrin, a process for producing the same, and a clathrate thereof. The present invention relates to an aqueous ink composition containing a dye.

[0002]

2. Description of the Related Art Aqueous dyes and direct dyes having a water-soluble group such as a sulfonic acid group or a carboxylic acid group in the dye structure are generally used for water-based inks for writing instruments and ink jet recording. Has been. For such dyes for water-based inks, solubility, dyeability, and dyeability from the viewpoints of ink storage stability, writing / recording suitability, etc.
Required performance is required for various chemical properties such as fastness and hue. In particular, since the allowable amount of the inorganic salt is severely limited from the viewpoint of the stability of the ink, desalting and refining are indispensable for the dyes used in the above aqueous ink. Conventionally, the solubility stability of a water-based ink using a dye, particularly a direct dye, is usually maintained by controlling the pH value to 9 to 10 with a pH adjuster or the like. However, if the pH of the ink is kept on the alkaline side for a long period of time, there arises a problem that the quality of the ink is deteriorated due to deterioration of the dye. In the case of a basic dye, the pH of the aqueous ink using the basic dye is relatively low (7 or less), and it is generally characterized by vivid color and high absorbance, but few have excellent light resistance and dissolution stability.

On the other hand, in wood stains and the like, azo alloy dyes having excellent light resistance are used after being dissolved in a solvent such as an alcohol solvent or DMF (dimethylformamide). Not desirable for odor and safety and hygiene. By the way, cyclodextrin
It is known as a compound having an inclusion function. This function of cyclodextrin has been applied to medicines and cosmetics, and many proposals for improving the constitution of dyes and the functions required for various purposes have been reported. Regarding the dye, for example, invention of a light resistance improving method for improving light resistance of the dye by including methylene blue, rhodamine 6G and the like with cyclodextrin (JP-A-4-136075), a water-insoluble dye (for example, Invention of an ink composition suitable for an inkjet printing process in which a copper frotocyanine sulfamide dye) is complexed with cyclodextrin to improve the dispersion stability of the dye (JP-A-5-132642).
Etc. are disclosed. However, no proposal has yet been found to utilize the inclusion function of cyclodextrin to provide a dye excellent in dissolution stability and light resistance in an aqueous solvent.

The present invention has been made in view of the above problems existing in the prior art, and an object of the present invention is to have excellent dissolution stability in an aqueous solvent and light resistance, and to be used as an ink for writing instruments. Another object of the present invention is to provide a water-soluble dye useful for inkjet recording inks, stamp inks, printing inks, stains for woodworking, etc., a method for producing the same, and an aqueous ink composition containing the dye.

[0005]

Means for Solving the Problems In the process of studying the inclusion of an azo metal complex salt dye with various compounds having an inclusion function, the present inventors have found that a specific metal complex salt dye poorly soluble in water is The present invention has been completed by finding that it can be converted into a water-soluble dye by inclusion of one or more molecules of cyclodextrin. The water-soluble dye of the present invention comprises a water-insoluble metal complex salt dye (a) represented by the following general formula, which is included in cyclodextrin (b).

[0006]

Embedded image

[Wherein A and A'are substituted with 1 or 2 selected from the group consisting of halogen and nitro group, o
-A diazo component residue from aminophenol or anthranilic acid, A and A'may be the same or different, B and B'are an amino group or -NHCOR
A group (where R is an alkyl group having 1 to 4 carbon atoms [eg, methyl, ethyl, propyl, iso-propyl, butyl, sec-
Butyl, tert-butyl]) optionally substituted with β-
A coupling component residue from a naphthol or pyrazolone derivative, B and B ′ may be the same or different, and M is a divalent or trivalent metal [eg, Cr,
Co, Ni, Fe, etc.] and X is —O— or —COO.
And Ka is an alkali metal [eg, Li, Na, K
Etc.] or NH ₄ . ]

Further, the method for producing a water-soluble dye of the present invention comprises adding the metal complex salt dye (a) and the cyclodextrin (b) in a weight ratio of (a) :( b) = 1: 50 to 1: 1 to water. It includes a step of mixing and dissolving and a step of removing water from the aqueous solution. The water-based ink composition of the present invention contains the above water-soluble dye. The inclusion ratio of the metal complex salt dye (a) and the cyclodextrin (b) in the cyclodextrin inclusion water-soluble dye of the present invention is in the range of (a) :( b) = 1: 50 to 1: 1 by weight. The range of can be mentioned. The preferable range of the inclusion ratio is 1:20 to 1: 1.
1, and a more preferable range is 1:10 to 1: 1.
The higher the inclusion ratio, the higher the coloring power (color value), and the concentration of the water-soluble dye of the present invention that can be dissolved in water or an aqueous solvent to exhibit good coloring power becomes low. It will be convenient. In the present specification, the inclusion ratio means the weight ratio or molar ratio (a) of the dye component [guest component (a)] and the cyclodextrin [host component (b)] in the cyclodextrin inclusion water-soluble dye: It means (b). The metal complex salt dye (a) in the cyclodextrin clathrate water-soluble dye of the present invention is CISolvent Violet 21 or CISolve among alcohol-soluble metal complex salt dyes.
Especially preferred is ntRed8. In this case, the inclusion ratio becomes remarkably large, and the inclusion ratio [weight ratio] (a) :( b)
Reaches a high concentration of approximately 3: 7 to 2: 3.

Examples of the diazo component of the monoazo dye (compound) in the metal complex salt dye (a) used in the present invention include:
The following can be mentioned. Incidentally, A and A ′ in the general formula of the metal complex salt dye (a) are residues of these diazo components. 4-chloro-2-aminophenol 4,6-dichloro-2-aminophenol 4-chloro-5-nitro-2-aminophenol 5-nitro-2-aminophenol 4-nitro-2-aminophenol 4,6- Examples of the coupling component of the monoazo dye (compound) in the 1: 2 type metal complex salt dye (a) used in the present invention include the following: o-aminophenol derivatives such as dinitro-2-aminophenol and anthranilic acid. Some of them can be mentioned. In addition,
B and B ′ in the general formula of the metal complex salt dye (a) are
Residues of these coupling components. β-naphthol 5-amino-2-naphthol 8-amino-2-naphthol 5-acetylamino-2 naphthol 8-acetylamino-2 naphthol 1-phenyl-3-methyl-5-pyrazolone 1- (m-chlorophenyl)- 3-Methyl-5-pyrazolone 1- (p-methylphenyl) -3-methyl-5-pyrazolone 1- (p-sulfamoylphenyl) -3-methyl-5
-Pyrazolone

As the 1: 2 type metal complex salt dye (a) used in the present invention, its monoazo dye is 4-chloro-2.
-With aminophenol and β-naphthol, 5
-Nitro-2-aminophenol and 1-phenyl-3-
Especially preferred is with methyl-5-pyrazolone. Specific examples of the metal complex dye (a) include commercially available CI solvent colors classified into CISolvent Violet 21 CISolvent Red 8 CISolvent Black 34 CISolvent Orange 62 CISolvent Red 122 CISolvent Yellow 82 and the like. Especially suitable is CI Solvent Viol
These are Na salt of et 21 and K salt of CI Solvent Red 8.

Particularly important in the present invention is that the counter ion (Ka ⁺ ) of the metal complex salt dye (a) is an alkali metal ion or ammonium (NH ₄ ⁺ ). Other counter ions such as hydrogen ions (H ⁺ ) and aliphatic amine ammonium and quaternary ammonium generally have high oil solubility and are insoluble in water (almost not dissolved at all). Therefore, it is unsuitable as a metal complex salt dye used in the present invention. In the present invention, those that are sparingly soluble in water, that is, those that are slightly soluble are used. Preferably, the solubility in water is 0.1%
It is about w / v. Alkali metal ions such as lithium, sodium and potassium and ammonium ions (NH
₄ ⁺⁾ is providing such soluble metal complex dye (a) counter-ion (Ka ^+). It was found that the difficulty of inclusion with cyclodextrin differs depending on the counterion of the metal complex salt dye and also on the type and position of the substituent in the monoazo dye forming the 1: 2 type azo metal complex salt dye. It was Specific examples of the metal complex salt dye (a) preferably used in the present invention are shown in Table 1.

[0012]

[Table 1]

Cyclodextrin is a compound suitable for efficiently including the 1: 2 type azo metal complex salt dye (a) which is hardly soluble in water as described above and converting it into a water-soluble dye. Compounds having an inclusion function other than cyclodextrin (for example, cyclofructan, calix (n) arenes, crown ethers, cyclic compounds such as caffeine,
Also, linear polyether compounds and the like) were also investigated, but the objects of the present invention could not be achieved by them. Cyclodextrin (hereinafter simply “CD”)
There are also cases. ) Is generally a compound in which a large number of D-glucopyranose units form a ring by α-1,4-bonds, and α (6 units), β (7 units) depending on the number of glucose units constituting one molecule. ), Γ (8 units), ..., with the prefix letters α-CD, β-CD, γ, respectively.
-CD ... Also known are 9, 10, 11 and 12 glucose units.

In Japanese Patent Laid-Open No. 5-132642, α-
In addition to CD, β-CD, γ-CD, various cyclodextrins that can be used in the present invention are disclosed. That is, a cyclodextrin derivative in which a hydroxyl group or a methylol group of D-glucose is modified with a methyl group or an amino group, a cyclodextrin modified by addition of a substituent, and the like. The substituent in this case generally substitutes either the entire hydroxyl group of one or more hydroxyl groups of the cyclodextrin ring or the hydrogen atom.

Examples of substituents include one or more hydroxyl groups
-OA _C , -OC (O) CH ₂ CH ₃ , -OC (O) (CH ₂ ) ₂ CH ₃ , -OC (O) (CH ₂ ) ₃
An acyl group substituted with a group such as CH ₃ , -OC (O) CF ₃ , -OC (O) Ph, etc .; one or more hydroxyl groups being -OCH ₃ , -OCH ₂ CH ₃ , -O (C
H ₂ ) ₂ CH ₃ , -OC (CH ₃ ) ₃ , alkyl groups and aryl groups substituted with groups such as -OPh; tosyl (4-methyl) in which one or more hydroxyl groups are substituted with -OTs, etc. Benzenesulfonyl); mesyl in which one or more hydroxyl groups are substituted with -OMs or a similar group (methanesulfonyl or Ms); primary, secondary or one or more hydroxyl groups containing a cyclic amine and an aromatic amine; An amino group substituted with a group such as a tertiary amine group; 1
Azide group number or more hydroxyl groups is replaced with -N ₃ or similar group; 1 or more hydroxyl groups is -F, -Cl, -Br, or halo substituents are substituted with -I; 1 or more hydroxyl groups Is substituted with -ONO ₂ ; one or more hydroxyl groups are -OPO ₃ H ₂ , -OPO ₃ R
₂ (where R is alkyl or aryl), -OPO ₃ H
Or substituted with groups such as R, or two adjacent hydroxyl groups -OP (O) (CH ₃₎ phosphorus-containing group is substituted by O- or similar group; imidazole group and derivatives thereof; pyridine Group and its derivative; one or more hydroxyl groups are -SCH ₃ , -SCH ₂ CH ₃ , -S (C
H ₂ ) ₂ CH ₃ , -SC (CH ₃ ) ₃ , -OSO ₃ ^- Na ⁺ , -OCH ₂ CH ₂ SO ₃ ^- N
^{_{a +, -OCH 2 CH 2 SO}} 3 - Na +, O (CH 2) 3 SO 3 - sulfur-containing functional group is substituted with a group as such as Na ^+, alcohols, aldehydes, ketones, or oxime group; carboxylic Acid groups and derivatives thereof;
Carbonate and carbamate groups; one or more hydroxyl groups
-OSi (CH ₃ ) ₃ , -OSi (CH ₃ ) ₂ H, -CH ₂ OSi (CH ₃ ) ₃ , -CH ₂ OSi
_{(CH 3) 2 H, -OB} (CH 2 CH 2) 2, CH 2 OB (CH 2 CH 2) 2, -CH 2 OSn ((CH
₂ ) Silicon, boron, or tin-containing groups substituted with groups such as ₃ CH ₃ ) ₃ and the like; hydroxylalkyl groups such as hydroxylethyl group, hydroxylpropyl group and the like.

The cyclodextrin suitable for the present invention is water-soluble α-CD, β-CD and γ-CD, and preferably has a solubility in water of about 10% w / v or more. α-
CD and γ-CD each have a solubility in water of 15.5.
Since they are g / 100 ml and 23.2 g / 100 ml, they can be advantageously used as the host component of the present invention. β-CD is
As it is, the solubility in water is low (about 1.85 g / 100 ml), which is not advantageous as the host component of the present invention. However, a lower alkyl group such as methyl, ethyl, or propyl, or hydroxymethyl, at one or more of the hydroxyl group of the glucose monomer and the hydrogen atom in the hydroxyl group,
Cyclodextrins (including β-CD) modified by the addition of hydroxyalkyl groups such as hydroxyethyl and hydroxypropyl show good water solubility and are desirable as the host component of the present invention. Examples of commercially available cyclodextrins that can be preferably used in the present invention include dimethyl-β-CD manufactured by Nippon Food Processing Co., Ltd., and methyl-β-CD, hydroxyethyl-β-CD manufactured by Shimizu Minato Sugar Co. And hydroxypropyl-β-CD and the like. The above α-CD, β-CD and γ
-The diameter of each inner hole of CD is said to be about 4.5 Å, 7.0 Å, and 8.5 Å, respectively. Therefore, as long as these cyclodextrins are used, the cyclodextrin clathrate water-soluble dye of the present invention is such that a part of the metal complex salt dye (a) is clathrated by the cyclodextrin, or the metal complex salt dye (a) is It is presumed to be included by a plurality of cyclodextrin molecules. The solubility of the cyclodextrin clathrate water-soluble dye of the present invention in water is 1
About 5 to 30 g / 00 ml was reached (25 ° C.). The solubility of the original metal complex salt dye is 1 to 10 g per 100 ml of water.

The method for producing the cyclodextrin clathrate water-soluble dye of the present invention comprises the metal complex salt dye (a) and the cyclodextrin (b) in a weight ratio of (a) :( b) = 1: 50 to 1: 1. It includes a step of mixing and dissolving in water and a step of removing water from the aqueous solution. More specifically, for example, the water-soluble dye of the present invention can be produced by the following first to sixth steps. First step: Cyclodextrin is dissolved in water. Second step: A water-insoluble metal complex dye (a), which is sparingly soluble in water, is added to and dissolved in the cyclodextrin aqueous solution. The first step and the second step may be performed at the same time. Third step: The metal complex salt dye (a) is completely dissolved by stirring and mixing while heating if necessary. Fourth step: If necessary, the mixed solution obtained in the third step is filtered to remove the undissolved or non-inclusion metal complex salt dye (a). Fifth step: Water is removed from the solution containing the cyclodextrin clathrate water-soluble dye obtained in the third step or the fourth step by means such as evaporation to dryness and vacuum drying. Sixth step: The water-soluble dye of the present invention obtained in the fifth step is recovered and, if necessary, pulverized.

The dissolution of cyclodextrin in the first step is preferably carried out at 40 to 50 ° C.
In addition, in the first step, cyclodextrin may be dissolved to a saturated concentration. The dissolution of the metal complex salt dye (a) in the second step is preferably carried out by sufficiently stirring in a water solvent whose pH is adjusted to neutral or slightly alkaline. It is preferable that the addition amount of the metal complex salt dye (a) be slightly excessive with respect to the saturated concentration amount with respect to the cyclodextrin aqueous solution. In the case of a metal complex salt dye whose counter ion is hydrogen ion, it can be used after being treated with an equivalent amount of an alkali salt such as sodium hydroxide. The dissolution of the dye in the third step is basically completed by completely dissolving the metal complex salt dye (a) in an aqueous solution in which a predetermined ratio of cyclodextrin is dissolved. It is not preferable to use an excessive amount of cyclodextrin with respect to the metal complex salt dye (a), because it lowers the color value of the cyclodextrin clathrate water-soluble dye (see Example 3). In the fourth step, microfiltration is preferably performed using a membrane filter (1 μm) or the like. The water is removed in the fifth step preferably to a water content of 0.1% or less.

By such a method, it is possible to obtain a cyclodextrin clathrate water-soluble dye clathrated with 50 parts by weight or less of cyclodextrin per 1 part by weight of the metal complex dye, which has a large degree of clathrate of the metal complex salt dye, It is also possible to obtain inclusions with 10 parts by weight or less of cyclodextrin per 1 part by weight of the metal complex salt dye. Therefore, this cyclodextrin clathrate water-soluble dye is added to water 100
1 g of the original metal complex salt dye per ml or 100 ml of an aqueous solution containing an alcohol solvent (aqueous solvent)
The above can be dissolved. 5 with the original metal complex dye
It is possible to dissolve more than g. The aqueous ink composition of the present invention is prepared by dissolving the cyclodextrin clathrate water-soluble dye of the present invention in water or an aqueous solvent in which water is mixed with a water-soluble organic solvent.

Examples of water-soluble organic solvents which can be used in combination with water include monohydric alcohols (eg lower alcohols such as ethanol, n-propanol, iso-propanol, n-butanol; diacetone alcohol; ethylene glycol monomethyl ether). Monoalkyl ethers of diols such as ethylene glycol monoethyl ether, propylene glycol monoethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, dipropylene glycol monoethyl ether; diol monoalkyl ethers such as ethylene glycol monoacetate and propylene glycol monoacetate Acetate), dihydric alcohol (eg ethylene glycol, diethylene glycol, trimethylene glycol, triethylene glycol Call, tetraethylene glycol, polyethylene glycol, propylene glycol,
Glycols such as butanediol), trihydric alcohols (eg, glycerin, trimethylolpropane, 1,
2,6-hexanetriol), dioxane, pyrrolidones, lactic acid esters and the like. Of these, preferred are low-toxic or non-toxic ethanol, propyl alcohol, ethylene glycol, propylene glycol monoalkyl ether, lactic acid ethyl ester and the like.

The content of the water-soluble organic solvent in the aqueous ink composition of the present invention is generally 5 to 95% by weight, preferably 5 to 80% by weight, based on the total amount of the ink composition.
It is more preferably 5 to 40% by weight. The content of the cyclodextrin clathrate water-soluble dye of the present invention in the aqueous ink composition of the present invention varies depending on the use of the ink,
Although not particularly limited, examples of the content are 5 to 30% by weight for a ballpoint pen and 5 for a marking pen.
To 30% by weight, 3 to 2 for inkjet recording
0% by weight can be mentioned. Further, depending on the use and purpose of the ink, a water-soluble resin (for example, low-condensation product of vinylpyrrolidone, water-soluble alkyd resin, water-soluble acrylic resin), alcohol-soluble resin (for example, alcohol-soluble phenol resin, acrylic resin, styrene-maleic acid resin) , Ketone resin), a wetting agent, a pH adjusting agent, a surfactant, and the like, which are usually used, can be added in appropriate amounts.

[0022]

EFFECTS OF THE INVENTION The cyclodextrin clathrate water-soluble dye of the present invention has a high clathrate ratio, that is, a large degree of clathrate with a metal complex salt dye, and exhibits high solubility in water. Therefore, of these water-soluble dyes, even when only the inclusion of the metal complex salt dye is taken into consideration, extremely high solubility in water is achieved compared to the original metal complex salt dye. Therefore, it exhibits good coloring power (color value) and is also excellent in light resistance. Also,
Since the cyclodextrin clathrate water-soluble dye of the present invention has high dissolution stability over time when dissolved in water and an aqueous liquid medium, it is suitable as a dye for use in a water-based ink for writing instruments and a recording liquid for inkjet recording. Further, it was difficult to remove the inorganic salt which is a hindrance to the stability of the ink with the conventional water-soluble dye, but the cyclodextrin clathrate water-soluble dye of the present invention is a metal complex salt dye which is poorly soluble in water, and cyclodextrin. Therefore, a high-performance ink containing substantially no inorganic salt can be provided. Furthermore, the cyclodextrin clathrate water-soluble dye of the present invention has a good re-solubility in water, and the solubility is hardly changed even if the volatile components such as water are removed by means such as concentration drying. . According to the production method of the present invention, the cyclodextrin inclusion water-soluble dye of the present invention can be easily obtained in a dry state. The water-based ink of the present invention has high solubility stability of the cyclodextrin clathrate water-soluble dye of the present invention contained therein, and its handwriting, printing, recorded images, etc. are excellent in light resistance and water resistance. Is also good. In particular, since the cyclodextrin in the cyclodextrin clathrate water-soluble dye of the present invention is clathrated with an inorganic salt, a water-based ink containing substantially no inorganic salt has extremely excellent dissolution stability over time.

[0023]

The present invention will be described in more detail with reference to examples. In the following description, "part by weight" is abbreviated as "part". Preparation of Water-soluble Dye Example 1 8 parts of dimethyl-β-CD (manufactured by Nippon Shokuhin Kako Co., Ltd.) was added to 70 parts of water.
Dissolved in 45 parts at 45 ° C. with stirring. Next, the metal complex dyes (1) shown in Table 1 [CISolvent Violet
21 (Na salt)] was added with stirring and the stirring was continued for 1 hour. As a result, the metal complex salt dye (1) was included in dimethyl-β-CD and dissolved in water. 1 of this aqueous solution
The mixture was filtered using a μm membrane filter, the filtrate was transferred to an evaporation dish, and dried at 70 ° C. to obtain 11 parts of a water-soluble dye. When the concentration of the metal complex salt dye in the obtained water-soluble dye was determined, it was about 30% by weight, and dimethyl-β-CD
It was confirmed that the degree of inclusion of the metal complex salt dye (1) was extremely large.

Preparation of Water-Soluble Dye Example 2 8 parts of dimethyl-β-CD (manufactured by Nippon Shokubai Co., Ltd.) was added to 70 parts of water
Dissolved in 45 parts at 45 ° C. with stirring. Next, the metal complex salt dyes (5) shown in Table 1 [CISolvent Red 8
(K salt)] was added under stirring and the stirring was continued for 7 hours. As a result, the metal complex salt dye (5) was included in dimethyl-β-CD and dissolved in water. 1 μm of this aqueous solution
After filtration using a membrane filter, the filtrate was transferred to an evaporation dish and dried at 70 ° C. to obtain 13 parts of a water-soluble dye. The concentration of the metal complex salt dye in the obtained water-soluble dye was determined to be about 40% by weight, and it was confirmed that the inclusion degree of the metal complex salt dye (5) by dimethyl-β-CD was extremely large. It was Preparation of Water-soluble Dye Example 3 2 parts of dimethyl-β-CD (manufactured by Nippon Shokubai Co., Ltd.) was added to 20 parts of water.
Dissolved in 45 parts at 45 ° C. with stirring. Next, the metal complex salt dyes (5) shown in Table 1 [CISolvent Red 8
(K salt)] 0.5 part was added with stirring, and stirring was continued at 70 ° C. for 3 hours. As a result, the metal complex salt dye (5) was dimethyl-β.
-It was included in CD and dissolved in water. This aqueous solution was filtered using a 1 μm membrane filter, the filtrate was transferred to an evaporation dish, and dried at 60 ° C. to dryness to give a water-soluble dye.2.
I got 3 parts. When the concentration of the metal complex salt dye component in the obtained water-soluble dye was determined, it was about 20% by weight.
It was found that β-CD was in excess of the metal complex dye (5).

Water-soluble dye Examples 4 to 8 and Comparative Example 1 and
2 Water-soluble dye examples 4 to 8 of the present invention were prepared according to Example 1 or Example 2, and Comparative Examples 1 and 2 were performed according to Example 1 or Example 2 for comparison. Table 2 shows Examples 1 to 8 of the water-soluble dyes and Comparative Examples 1 and 2. The hue and λmax (visible maximum absorption wavelength) of the cyclodextrin clathrate water-soluble dye of the present invention are the same as those of the original metal complex salt dye. Incidentally, the λmax of the water-soluble dye example 1 and the water-soluble dye example 2 are 572 nm and 526 nm, respectively.

[0026]

[Table 2]

In Table 2, DM-β-CD is dimethyl-β-
CD, M-β-CD is methyl-β-CD, HP-β
-CD is hydroxypropyl-β-CD, α-CD
Represents α-cyclodextrin, respectively. The inclusion ratio in Table 2 was determined by measuring the concentration of the metal complex salt dye in the cyclodextrin inclusion water-soluble dye by spectral analysis according to the following measurement method, and evaluated according to the following evaluation method. [Measurement method] 1) 50 to 500 mg / 1000 of the cyclodextrin clathrate water-soluble dye of the present invention was prepared by using methylcellosob (ethylene glycol monomethyl ether) as a solvent.
Dissolve to a concentration of ml. On the other hand, a control solution is prepared by dissolving uncomplexed metal complex salt dye in a concentration of 20 mg / 1000 ml. 2) Using a spectrophotometer, measure the absorption value at the maximum absorption wavelength (λmax) of each of the dye solutions. 3) From each absorption value, the concentration of the metal complex salt dye in the cyclodextrin clathrate water-soluble dye is calculated.

[Evaluation Method] The evaluation is based on the concentration of the metal complex salt dye component in the cyclodextrin clathrate water-soluble dye. ◎: 10% by weight or more ○: 5% by weight or more and less than 10% by weight Δ: 1% by weight or more and less than 5% by weight ×: less than 1% by weight Further, the solubility column in Table 2 shows that the cyclodextrin clathrate water-soluble dye is It shows an example of the concentration that can actually be dissolved in water, and does not show the solubility.

Water- based ink example 1 Ion-exchanged water: 69 parts Propylene glycol: 10 parts Water-soluble dye example 1: 20 parts Surfactant (trade name: Unidyne DS-401, manufactured by Daikin Industries, Ltd. ) ... 1 part A black ink for water-based ballpoint pens is prepared with the above composition,
When the writing performance was tested, it was possible to write smoothly over a long period of time. Further, as shown in Table 3, the stability of the ink over time and the light resistance of the handwriting were excellent, and the water resistance of the handwriting was good. Aqueous ink example 2 Ion-exchanged water ... 75 parts Ethylene glycol ... 5 parts Diethylene glycol ... 5 parts Water-soluble dye example 2 ... 15 parts Surfactant (Score Roll DS900 manufactured by Kao)・ ・ ・ ・ 0.
3 parts A red ink for felt-tip pens was prepared with the above composition, and the writing performance was tested. As a result, it was possible to write smoothly over a long period of time. Further, as shown in Table 3, the stability of the ink over time and the light resistance of the handwriting were excellent, and the water resistance of the handwriting was good.

Aqueous ink example 3 -Recording liquid for ink jet recording-5% glycerin aqueous solution (for light resistance test), or 5% 1-
Methyl-2-pyrrolidone aqueous solution (for water resistance test) to which the water-soluble dye of the present invention is added is sonicated for 10 minutes to dissolve the water-soluble dye, which is then filtered through a 1 μm membrane filter to remove metal. Complex salt dye concentration is 3% by weight
Recording liquids A, B and C having the following composition were prepared. Recording liquid A 5% glycerin aqueous solution ... 90 parts Water-soluble dye example 1 ... 10 parts Recording liquid B 5% 1-methyl-2-pyrrolidone aqueous solution ... 90 parts Water-soluble dye example 1 ... ··· 10 parts Recording liquid C 5% glycerin aqueous solution ···· 92 parts Water-soluble dye example 2 ··· 8 parts Recording liquids A, B and C were recorded using a commercially available inkjet printer to improve recording performance. Upon examination, it was possible to print without clogging the orifice for a long period of time. In addition, as shown in Table 3, the stability of the recording liquid over time and the light resistance of the handwriting were excellent, and the water resistance of the handwriting was good or excellent. In order to compare the recording characteristics, recording liquids a and b having the following formulations were prepared in the same manner as above. The evaluation is shown in Table 3.

Comparative Example 3 (Recording Liquid a) 5% Glycerin Aqueous Solution ... 95 parts CIAcid Black 52: (b) [Metal complex salt dye having sulfonic acid group] ... 3 parts Comparative Example 4 (Recording Liquid) b) 5% 1-methyl-2-pyrrolidone aqueous solution: 95 parts CIAcid Red 87: (b) [acid dye]: 3 parts [Evaluation method] The above inks (recording liquids) are evaluated as follows. It was done like. 30 ml of ink with stability over time is placed in a glass bottle and kept in a low temperature / high temperature tester (trade name: Incubator Sanyo Electric Co., Ltd.) for 2 months, and the temperature change is repeated every 60 minutes between -5 ° C and 50 ° C. After that, the precipitation and alteration of the dye etc. were observed and evaluated as follows. Excellent (⊚): No precipitation or alteration of the dye was observed. Good (∘): Precipitation and alteration of dye etc. were slightly observed. Poor (x): Deposition and alteration of dyes were recognized.

The light resistance test ink was set in each pen or ink jet printer, and written or printed on JIS P3201 writing paper.
After exposure for a month, the discoloration of the handwriting or the printing was observed and evaluated as follows. Excellent (⊚): Almost no discoloration of writing / printing was observed. Good (○): A slight discoloration of writing / printing was recognized. Bad (x): Discoloration of writing / printing was observed. Set the water resistance test ink on each pen or ink jet printer and write or print on JIS P3201 writing paper, add a drop of water drop with a dropper to the handwriting or printing and leave it for 30 seconds, then wipe off the water drop with filter paper Alternatively, the printing was observed and evaluated as follows. Excellent (⊚): Almost no decrease in density or bleeding was observed in the written / recorded image. Good (∘): A slight decrease in the density of the written / recorded image and bleeding were observed. Poor (x): A decrease in the density of the written / recorded image and bleeding were observed.

[0033]

[Table 3]

[Brief description of drawings]

FIG. 1 shows a spectrum of a water-soluble dye example 1 (one-dot chain line) and a spectrum of a metal complex salt dye (1) (solid line) which are dissolved in methylcellosob at the same concentration.

FIG. 2 shows a spectrum of a water-soluble dye example 2 (one-dot chain line) and a spectrum of a metal complex salt dye (5) (solid line) which are dissolved in methyl cellosob at the same concentration.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuo Uesaka 8-1-1 Tsukaguchi Honcho, Amagasaki City Mitsubishi Electric Corporation Material Devices Laboratory (72) Inventor Etsuko Hirose 8-1-1 Tsukaguchi Honcho, Amagasaki Mitsubishi Electric Device Co., Ltd. Material Device Research Center

Claims (5)

[Claims] 1. A water-soluble dye obtained by clathrating a water-insoluble metal complex salt dye (a) represented by the following general formula with a cyclodextrin (b). Embedded image [Wherein A and A ′ are diazo component residues from o-aminophenol or anthranilic acid, which are substituted with 1 or 2 selected from the group consisting of halogen and nitro groups, and A and A ′ are May be the same or different, B
And B ′ are an amino group or an —NHCOR group (provided that R is
Is a β-naphthol optionally substituted with an alkyl group having 1 to 4 carbon atoms) or a coupling component residue from a pyrazolone derivative, and B and B ′ may be the same or different. , M is a divalent or trivalent metal, X
Is -O- or -COO-, Ka is an alkali metal or NH _4. ] 2. The water-soluble compound according to claim 1, wherein the inclusion ratio of the metal complex salt dye (a) and the cyclodextrin (b) is (a) :( b) = 1: 1 to 1:10 by weight. dye. 3. The metal complex dye (a) is an alcohol-soluble metal complex dye CISolvent Violet21 or CISolven.
The water-soluble dye according to claim 1 or 2, which is t Red 8. 4. A step of mixing the metal complex salt dye (a) and the cyclodextrin (b) in a weight ratio of (a) :( b) = 1: 50 to 1: 1 with water to dissolve them, and an aqueous solution thereof. The method for producing a water-soluble dye according to claim 1, further comprising the step of removing water from the solution. 5. A water-based ink composition containing the water-soluble dye according to claim 1, claim 2, or claim 3.