JPH0912946A - Recording liquid - Google Patents

Abstract

PURPOSE: To obtain a receding liquid excellent in rapid dryability after recording and print quality, thus high in the optical concentration of the prints, and good in water resistance and recording characteristics, etc., comprising a water-soluble dye, aqueous medium and specific compound. CONSTITUTION: This recording liquid comprises (A) pref. 2-8wt.% of a water-soluble dye [pref. a dye of formula I (R<1> is a 1-4C alkyl; B is a sulfo-substituted naphthylene or 1-4C alkyl-substituted phenylene)], (B) an aqueous medium (pref. containing pref. 10-50wt.% of a water-soluble organic solvent such as ethylene glycol, other than pref. 45-90wt.% of water), and (C) pref. 0.5-2wt.% of a compound of formula II (R is a 1-4C alkyl; (n) is 1 or 2). The pH value of this recording liquid is normally adjusted to 8-10. Besides, addition of 0.5-5wt.% of urea, biuret etc., to the whole amount of this recording liquid further improves the rapid dryability, etc., after printing, therefore being favorable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording liquid, and more particularly to a recording liquid for ink jet recording and writing instruments.

[0002]

2. Description of the Related Art In an ink jet recording method, when plain paper such as electrophotographic paper, bond paper and stock foam paper is used as recording paper, the water resistance after printing is inferior, or the optical density (hereinafter In addition to the problem that the "OD value" is low, the storage stability of the ink tends to be unstable. Therefore, by reducing the water solubility of the dye in order to improve the water resistance, or by introducing a hydrogen-bonding amino group or the like into the dye structure, the dye's association property (aggregation property) is increased, and The so-called "bronzing" phenomenon occurs when the aggregates of the pigments have a metal-like luster, and the OD value of the printed matter decreases, or the pigments aggregate during storage of the ink,
There is a problem of precipitation.

As one of the means for solving these problems, it has been proposed to incorporate a certain nitrogen-containing compound in the recording liquid. As an example of this, JP-A-55-12
0676, JP-A-2-41369, JP-A-62-1
19280, JP-A-5-125311, JP-A-1-
152176, JP-A-64-6072, JP-A-6-
Although the inventions described in JP-A No. 128515 and JP-A No. 6-228483 are known, these recording liquids do not have sufficient effect or have no effect with respect to the above problems. However, it also has major defects such as easy clogging at the tip of the nozzle, decomposition of the dye during storage of the ink, and bleeding of the printed matter.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a recording liquid which has a high OD value of a printed matter even when recording on plain paper and has excellent water resistance and which does not have a bronzing phenomenon. To do.

[0005]

The present invention provides a water-soluble dye,
The gist is a recording liquid containing an aqueous medium and a compound represented by the following general formula [I].

[0006]

Embedded image

(In the formula, R represents an alkyl group having 1 to 4 carbon atoms, and n represents 1 or 2.) The present invention will be described in detail below. The water-soluble dye used in the present invention is not particularly limited, and azo-based, anthraquinone-based, quinophthalone-based, indigo-based and phthalocyanine-based direct dyes and acid dyes, and dyes developed for recording liquids can of course be used. For example, C.I. I. Direct B
rack-17, -19, -22, -32, -51,-
80, -91, -151, -168, -195 and -1
54, C.I. I. Direct Blue-86 and -1
99, C.I. I. Direct Red-80, C.I. I.
Direct Yellow-86 and -142, C.I.
I. Acid Black-2, -24, -26, -4
8, -52, -63, -172, -194 and -20.
8, C.I. I. Acid Blue-9, -185 and-
254, C.I. I. Acid Red-8, -35, -3
7, -52, -289 and -254, C.I. I. Acid
Yellow-23 and -49 and C.I. I. Food
Black-2 etc. are mentioned. The water-soluble dye represented by the following general formula [II] is particularly preferably used in the recording liquid of the present invention.

[0008]

Embedded image

(In the formula, R ¹ represents an alkyl group having 1 to 4 carbon atoms, B represents a naphthylene group substituted with a sulfo group, or a phenylene group substituted with an alkoxy group having 1 to 4 carbon atoms. The alkoxy group as the substituent of the alkyl group of R ¹ and the phenylene group of B may be linear or branched. Specific examples thereof include the following Dye-A and D represented by the free acid form.
Examples are ye-B and Dye-C.

[0010]

Embedded image

These water-soluble dyes may be used alone or in combination. The content of the water-soluble dye is usually in the range of 0.2 to 12%, preferably 2 to 8% with respect to the total weight of the recording liquid. Examples of the aqueous medium used in the present invention include, in addition to water, ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol (weight average molecular weight 190 to 400), glycols such as glycerin, and N-methyl. Ethers such as -pyrrolidone, N-ethyl-pyrrolidone, N-vinyl-pyrrolidone, 1,3-dimethyl-imidazolidinone, ethylene glycol monoallyl ether, ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, 2
-Pyrrolidone, sulfolane, alcohols such as ethyl alcohol and isopropanol, diethanolamine, it is preferable to contain a water-soluble organic solvent such as alkanolamines such as triethanolamine, as the content of these water-soluble organic solvents , With respect to the total weight of the recording liquid
The range is 0 to 50% by weight. On the other hand, the amount of water is
It is used in the range of 45 to 90% by weight based on the total amount of the recording liquid.

The recording liquid of the present invention is characterized by using the compound represented by the general formula [I]. In the general formula [I], the alkyl group having 1 to 4 carbon atoms represented by R may be linear or branched. Specific examples of this compound include the following No. 1 to No. Compounds such as 4 may be mentioned.

[0013]

[Chemical 6] No. 1 (H ₃ C) ₂ NC ₂ H ₄ N (CH ₃ ) C ₂ H ₄ N (CH ₃ ) ₂ No. 2 (H ₃ C) ₂ NC ₂ H ₄ N (CH ₃ ) C ₂ H ₄ N (CH ₃ ) C ₂ H ₄ N (CH ₃ ) ₂ No. 3 (H ₅ C ₂ ) ₂ NC ₂ H ₄ N (C ₂ H ₅ ) C ₂ H ₄ N (C ₂ H ₅ ) ₂ No.4 (H ₇ C ₃ -i) ₂ NC ₂ H ₄ N (iC ₃ H ₇ ) C ₂ H ₄ N (iC ₃ H ₇ ) ₂

This compound may be used alone or in combination. The content of the above compound is usually in the range of 0.1 to 4% by weight, preferably 0.5 to 2 with respect to the total weight of the recording liquid.
% By weight.

The pH of the recording liquid of the present invention is usually adjusted to 8-10. Further, the recording liquid of the present invention contains 0.1 to 10% by weight, preferably 0.5 to 5% by weight, of a compound selected from urea, thiourea, biuret and semicarbazide, or 0% by weight based on the total weight of the recording liquid. 0.001 to 0.5% by weight
By adding the above-mentioned surfactant, the quick drying property after printing and the printing quality can be further improved.

[0016]

EXAMPLES The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. Example 1

[0017]

[Table 1] Composition of recording liquid Amount used (% by weight) C.I. I. Direct Black-195 3 Diethylene glycol 10 The No. Compound of 1 1 Residual amount of water ──────────────────────────────── Total 100

The above components were thoroughly mixed and dissolved in a container, filtered under pressure with a Teflon filter having a pore size of 1 μm, and then deaerated using a vacuum pump to prepare a recording liquid.
The obtained recording liquid was used to perform inkjet recording with an inkjet printer (trade name: HG-3000, manufactured by Epson Corporation), and quick-drying property and print quality were evaluated according to the following methods (a) and (b). .

(A) Quick-drying: Printing is performed on electrophotographic paper (product of Xerox Co., Ltd.), bond paper and stock form paper (product of Lion Office Equipment Co., Ltd.), and after 30 seconds, the printing portion is rubbed with a finger to prevent misalignment of the image. The presence or absence was judged. All of them showed no deviation and showed excellent fixability. (B) Print quality: Each dot printed on the recording paper was observed under a microscope, and the presence or absence of feathering (whisker-like bleeding) around the dots and the sharpness of the outline were visually evaluated. Both have no feathering,
The contour was also sharp.

Further, ink jet recording was evaluated according to the following methods (c) to (f). (C) Long-term storability of recording liquid: After the recording liquid was sealed in a glass container and stored at 0 ° C. and 60 ° C. for 6 months, no precipitation of insoluble matter was observed, and the physical properties and color tone of the liquid did not change. There wasn't. (D) Ejection stability: Continuous ejection was performed for 24 hours in each of the atmospheres at room temperature, 5 ° C., and 40 ° C., and stable high-quality recording was always possible under any of the conditions. (E) Discharge responsiveness: Intermittent discharge every 2 seconds and discharge after being left for 2 months were examined, and in both cases, stable and uniform recording was performed without clogging at the tip of the orifice. (F) Quality of recorded image: The recorded image has an OD value of 1.
It was as high as 3, showing a bluish black color.

Comparative Example 1 In Example 1, the No. As a result of evaluation in the same manner as in Example 1 except that the compound No. 1 was not added, the formed image had a copper-colored metallic luster and had an OD value as low as 1.1. Further, insoluble matter was precipitated in the recording liquid stored at 60 ° C. for 6 months, and a precipitate was observed. Example 2

[0022]

[Table 2] Composition of recording liquid Amount used (% by weight) Dye-A 3 glycerin 10 ethylene glycol 10 No. 2 compound 1 water residual amount ──────────────────────────────── Total 100

A recording liquid having the above composition was prepared in the same manner as in Example 1, and the results of (a) to (f) were examined. As a result, good results were obtained. The OD value was high at 1.4, which was a medium black color. Comparative Example 2 In Example 2, the No. As a result of performing evaluation in the same manner as in Example 2 except that the compound of 2 was not added,
The formed image has a brown metallic luster and an OD value of 1.
It was as low as 1. Further, insoluble matter was precipitated in the recording liquid stored at 60 ° C. for 6 months, and a precipitate was observed.

Examples 3 to 14 According to the method of Example 1, recording liquids having the compositions shown in Table 1 below were prepared, and (a) to (f) described in Example 1 were prepared.
As a result of evaluation according to the above method, all were good.

[0025]

[Table 3]

[0026]

[Table 4]

[0027]

[Table 5]

[0028]

[Table 6]

[0029]

[Table 7]

[0030]

INDUSTRIAL APPLICABILITY The recording liquid of the present invention is used for ink jet recording, writing instruments, etc., and is excellent in quick-drying property after recording and printing quality. No rubbing of the image even if rubbed, and
An image with no bleeding and a sharp contour can be obtained. When the recording liquid of the present invention is used for inkjet recording, in addition to the above effects, recording characteristics (signal responsiveness, droplet formation stability, ejection stability, long-term continuous recording property), storage stability The OD value of the recorded image, light resistance, weather resistance, water resistance, etc. are all good. Further, some dyes cause a so-called "bronzing" phenomenon by aggregating on the recording paper, and the present invention can also prevent this phenomenon.

Claims (2)

[Claims] 1. A recording liquid containing a water-soluble dye, an aqueous medium and a compound represented by the following general formula [I]. Embedded image (In the formula, R represents an alkyl group having 1 to 4 carbon atoms, and n represents 1 or 2.) 2. When the water-soluble dye is represented by a free acid form,
The recording liquid according to claim 1, which is a compound represented by the following general formula [II]. Embedded image (In the formula, R ¹ represents an alkyl group having 1 to 4 carbon atoms, and B 1
Is a naphthylene group substituted with a sulfo group, or a carbon number of 1 to
4 represents a phenylene group substituted with an alkoxy group of 4. )