JPH08143801A - Recording liquid - Google Patents

Abstract

PURPOSE: To prepare a recording liquid containing an aqueous medium and a black pigment having a specific structure, exhibiting excellent density of printed image, light resistance, water resistance, storage stability, etc., and useful for writing utensil. CONSTITUTION: This recording liquid contains (A) an aqueous medium, (B) a pigment expressed by formula I [R<8> to R<11> are each independently H, a 1-8C alkyl, cyclohexyl, etc.; R<12> is H or a (carboxyl-substituted)phenyl; G is sulfo or carboxyl; E is a 1-4C alkyl] as a free acid and (C) a pigment of formula II and/or formula III (A1 , A2 , D1 and D2 are each independently H, a 1-4C alkyl, a 1-4C alkoxy or a 2-5C acylamino; R<1> to R<7> are each independently H, a 1-8C alkyl, etc.; (l) and (m) are each 1 or 2). The mixing ratio of the pigments C and B (C/B) is 20/80 to 80/20, preferably 40/60 to 60/40. The component A is e.g. ethylene glycol or glycerol.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a recording liquid. More specifically, it relates to a black recording liquid suitable for inkjet recording.

[0002]

2. Description of the Related Art A so-called ink jet recording method has been put into practical use, in which a recording liquid droplet containing a water-soluble coloring matter such as a direct dye or an acid dye is ejected from a minute ejection orifice to perform recording. This recording liquid is capable of stable ejection for a long time, and is also widely used for general office work such as PPC (plain paper copier) paper such as electrophotographic paper and fan hold paper (continuous paper such as computers). It requires fast fixing to recording paper and good print quality, that is, the print has no bleeding and has a clear contour, and also has excellent stability when stored as a recording liquid. Therefore, the solvent that can be used for the recording liquid is extremely limited.

On the other hand, dyes for recording liquids have sufficient solubility in the above limited solvents and are stable even when stored as recording liquids for a long time.
Further, it is required that the printed image has a high density, has a hue close to true blackness, and is excellent in water resistance and light resistance. However, it is necessary to satisfy many of these requirements at the same time. Was difficult.

Therefore, various methods (for example, JP-A-55-55)
144067, JP-A-55-152747, JP-A-57-207660, JP-A-58-147470, JP-A-62-190269, JP-A-62-190271.
JP-A-62-190272, JP-A-62-250
082, JP-A-62-246975, JP-A-62-
No. 257971, JP-A-62-288659, JP-A-63-8463, JP-A-63-22867, JP-A-63-22874, JP-A-63-30567, JP-A-63-33484. , JP-A-63-63764, JP-A-63-105079, JP-A-64-31877.
JP-A-1-93389, JP-A-1-210464
JP-A-2-140270 and JP-A-3-16727.
No. 0, JP-A-3-200882, etc.) have been proposed, but a dye that satisfies the market requirements in terms of performance and is easy to manufacture has not been developed.

[0005]

DISCLOSURE OF THE INVENTION The present invention has good print quality even when recorded on plain paper for ink jet recording, writing instruments, etc., and has a high density of recorded images, which is excellent in water resistance and light resistance. It is an object of the present invention to provide a recording liquid which is excellent in stability and has good stability when stored for a long time.

[0006]

The present inventors have accomplished the present invention by confirming that when a black dye having a specific structure is used as a recording liquid component in combination, a performance particularly satisfying the above-mentioned object is obtained. It is a thing. That is, the gist of the present invention is a recording liquid containing an aqueous medium, a dye whose free acid form is represented by the general formula [III], and a dye represented by the general formula [I] and / or [II]. Exist in.

The present invention will be described in detail below. The dye used in the present invention is represented by the dye represented by the general formula [III] and the general formulas [I] and / or [II]. Specifically, in the general formulas [I], [II] and [III], A ₁ , A ₂ , D ₁ and D ₂ are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms (for example, a methyl group, A linear or branched alkyl group such as an ethyl group, an n-propyl group, an i-propyl group, and an n-butyl group), an alkoxy group having 1 to 4 carbon atoms (for example, a methoxy group, an ethoxy group, an n-propoxy group, A linear or branched alkoxy group such as i-propoxy group and n-butoxy group) and an acylamino group having 2 to 5 carbon atoms (for example, acetylamino group, n-propanoylamino group and the like).

A other than hydrogen atom₁And A₂, D₁And D₂Is
It is better to substitute the target position of each benzene ring.
E is an alkyl group having 1 to 4 carbon atoms (A₁, A₂,
D₁, D₂The same as the alkyl group represented by
R¹~ R¹¹Are each independently a hydrogen atom or an alkyl group having 1 to 8 carbon atoms
Kill group, (alkyl group represented by E, and n-hexyl
Group, n-octyl group), cyclohexyl group, carboxy
A phenyl group optionally substituted with a sil group (for example,
Phenyl group, metacarboxyphenyl group, p-carboxy
Phenyl group, 3,5-dicarboxylphenyl group, etc.)
I, R¹²Is substituted with a hydrogen atom or a carboxyl group
Phenyl group (R¹~ R¹¹Represented by
R group) and R₁And R ₂, R₃And R_Four, R_Five
And R₆, R₈And R₉, R_TenAnd R₁₁At least one of which is water
It is better to be elementary atoms. G is a sulfo group or carboxyl
Represents a group, and l and m each represent 1 or 2.

The dye used in the present invention is represented by the general formula [I],
The free acid form represented by [II] or [III] may be used as it is, but when it is obtained in the form of a salt during production, it may be used as it is, or converted into a desired salt form. May be. Further, a part of the acid group may be in a salt form, and a salt form dye and a free acid form dye may be mixed. Examples of such salts include salts of alkali metals such as Na, Li and K, salts of ammonium which may be substituted with an alkyl group or hydroxyalkyl group, salts of organic amine and the like. Examples of organic amines include lower alkyl amines,
Examples thereof include hydroxy-substituted lower alkylamines, carboxy-substituted lower alkylamines, and polyamines having 2 to 10 alkyleneimine units having 2 to 4 carbon atoms. In the case of these salts, the type is not limited to one type, and a plurality of types may be mixed. Further, in the structure of the dye used in the present invention, when a plurality of acid groups are contained in one molecule, the plurality of acid groups may be different in salt form or acid form.

As specific examples of these dyes, for example, the following No. 1 to No. An azo dye having a structure shown in 16 is mentioned. Examples of dyes of general formula [I]

[0011]

Embedded image

[0012]

Embedded image

Examples of dyes of the general formula [II]

[0014]

[Chemical 4]

[0015]

Embedded image

Examples of dyes of the general formula [III]

[0017]

[Chemical 6]

[0018]

[Chemical 7]

The azo dyes represented by the general formulas [I], [II] and [III] can be prepared by a method known per se [for example, Yutaka Hosoda, "New Dye Chemistry" (published December 21, 1973 by Gihodo). ), Pp. 396-409].
It can be manufactured through a coupling step and a triazinylation step. The content of the dye of the general formula [III] and [I] and / or [II] in the recording liquid is
The amount is preferably 1 to 6% by weight, particularly preferably 2 to 4% by weight, based on the total amount of the recording liquid.

The dye of [I] and / or [II] and [II]
The mixing ratio of the dye of I] is 20/80 to 80/2.
0, preferably 40/60 to 60/40.
The dye represented by [I] or [II] has a bluish black color, and the dye represented by [III] has a bluish black color. By using these in combination, it is possible to approximate true black. In addition, by adjusting the blending ratio,
A desired color tone can be obtained in the black range.

As the aqueous medium used in the present invention, water and a water-soluble organic solvent are used. For example, ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol (# 200), polyethylene glycol (# 400), glycerin, N-methylpyrrolidone,
Contains N-ethylpyrrolidone, 1,3-dimethylimidazolidinone, thiodiethanol, dimethylsulfoxide, ethylene glycol monoallyl ether, ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, 2-pyrrolidone, sulfolane, ethyl alcohol, isopropanol, etc. Is preferred. These water-soluble organic solvents are usually used in the range of 5 to 30% by weight based on the total amount of the recording liquid. On the other hand, water is used in the range of 65 to 85% by weight with respect to the total amount of the recording liquid. In the recording liquid of the present invention, the total amount is 0.1-10.
By adding a compound selected from urea, thiourea, biuret and semicarbazide in an amount of 0.5% by weight, preferably 0.5 to 5% by weight, or adding a surfactant in an amount of 0.001 to 5.0% by weight, The quick-drying property after printing and the printing quality can be further improved.

[0022]

EXAMPLES The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples as long as the gist thereof is not exceeded. Example 1 10 parts by weight of diethylene glycol, 3 parts by weight of isopropyl alcohol, No. 2 pigment 1.5
Parts by weight and No. Add water to 1.5 parts by weight of the dye of 13,
The pH was adjusted to 9 with aqueous ammonia to make the total amount 100 parts by weight. This composition is thoroughly mixed and dissolved to give a pore size of 1 μm.
After pressure filtration with a Teflon filter of m, a degassing treatment was performed with a vacuum pump and an ultrasonic cleaner to prepare a recording liquid. Using the obtained recording liquid, inkjet recording was performed on an electrophotographic paper (product of Xerox Co., Ltd.) using an inkjet printer (trade name: MJ-700, product of Epson Co.) to obtain a high-concentration black printed material. Also below (a),
The result of having performed various evaluations by the method of (b) and (c) is shown.

(A) Light resistance of recorded image: 100% on recording paper using a xenon fade meter (manufactured by Suga Test Instruments Co., Ltd.)
After irradiation for a long time, the discoloration after irradiation was small. (B) Water resistance of recorded image: The bleeding of the image was examined after the recording paper was immersed in water for 5 seconds. The bleeding of the image was slight and the decrease in density was small. (C) Storage stability of recording liquid: When the recording liquid was sealed in a Teflon container and stored at 5 ° C. and 60 ° C. for 1 month, the change was examined. No precipitation of insoluble matter was observed.

Example 2 5 parts by weight of glycerin, 10 parts by weight of ethylene glycol, the above-mentioned No. 2 parts by weight of dye No. 7 and No. 7 Water was added to 3 parts by weight of the dye of 13 and the pH was adjusted to 9 with aqueous ammonia to make the total amount 100 parts by weight, and this composition was treated by the method described in Example 1 to prepare a recording liquid. Printing was carried out in the same manner as in Example 1 using this recording liquid, and as a result, a high density black recorded material was obtained. Further, various evaluations according to (a) to (c) of Example 1 were performed on the recorded matter. As a result, good results were obtained as in the case of Example 1.

[Example 3] 10 parts by weight of diethylene glycol, 5 parts by weight of N-methylpyrrolidone, 3 parts by weight of isopropyl alcohol, the above-mentioned No. 2 parts by weight 2 parts by weight, N
o. 11 parts by weight of dye, and No. 11 dye. Water was added to 2 parts by weight of the dye of 13 and the pH was adjusted to 9 with aqueous ammonia to make 100 parts by weight, and the composition was treated by the method described in Example 1 to prepare a recording liquid. Printing was carried out in the same manner as in Example 1 using this recording liquid, and as a result, a high density black recorded material was obtained. Further, various evaluations according to (a) to (c) of Example 1 were performed on the recorded matter. As a result, good results were obtained as in the case of Example 1.

[Examples 4 to 9] The No. 1 used in Example 1 was used. 2 and No. A recording liquid was prepared and printing was carried out by the method of Example 1 except that the dyes shown in the following table were used instead of the dye of 13 and the recorded matter was subjected to (a) to (c) of Example 1. An evaluation was made. As a result, as in Example 1, good results were obtained.

[0027]

[Table 1]

[0028]

INDUSTRIAL APPLICABILITY The recording liquid of the present invention is used for ink jet recording and writing instruments, and when recorded on plain paper, a black recorded matter can be obtained, and its printing density, light resistance, and water resistance. In addition to being excellent in storage stability as a recording liquid.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Toru Nishimura 1000 Kamoshida-cho, Aoba-ku, Yokohama-shi, Kanagawa Mitsubishi Chemical Corporation Yokohama Research Institute

Claims (1)

[Claims] 1. A record containing an aqueous medium and a dye whose free acid form is represented by the following general formula [III] and a general formula [I] and / or [II]. liquid. Embedded image (In the formula, A ₁ , A ₂ , D ₁ and D ₂ each independently consist of a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms and an acylamino group having 2 to 5 carbon atoms. Represents a group selected from the group, E represents an alkyl group having 1 to 4 carbon atoms, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R
⁹ , R ¹⁰ and R ¹¹ are each independently a hydrogen atom, having 1 to 8 carbon atoms.
Represents a phenyl group which may be substituted with an alkyl group, a cyclohexyl group or a carboxyl group, R ¹² represents a hydrogen atom or a phenyl group which may be substituted with a carboxyl group, and G represents a sulfo group or a carboxyl group. , L and m each represent 1 or 2. )