JP2884663B2 - Recording liquid - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a recording liquid suitable for inkjet recording.

[Prior Art] When plain paper such as electrophotographic paper, bond paper, stock form paper, or the like is used as recording paper in an ink jet recording method, an image shift occurs even after rubbing the recorded print with a finger or the like after recording. There are problems such as shortening of the time until disappearance (quick drying) and clearness of the print without blur (print quality). In order to solve this problem, as shown in JP-A-56-57862, p
Although a strongly basic recording liquid of H12 or higher has been proposed, there are problems in terms of safety and storage stability.

Also, it has been proposed to incorporate a specific surfactant, JP-A-56-95961, JP-B-62-10551, JP-B-62-10547, JP-B-62-14188, and JP-B-62-105. 14189
No., Japanese Patent Publication No. 62-34350, etc. have been filed, but sufficient effects have not been obtained.

As one means for solving the above problem, it has been proposed to incorporate a certain kind of polymer into the recording liquid. Conventionally, recording liquids containing specific polymers include:
For example, JP-A-50-17840, JP-A-50-102407, JP-A-51-9905, JP-A-52-9506, JP-A-54-62005
No., JP-A-55-48266, JP-A-55-80477, JP-A-56
-133376, JP-A-57-34169, JP-A-59-53563,
JP-A-59-53565, JP-A-60-69172, JP-A-60-76
No. 574 and JP-A-60-110770 are known, but these recording liquids do not provide a sufficient effect with respect to the above problems, or even if the effects are obtained, the nozzle tip Has a large defect such as easy clogging.

[Problems to be Solved by the Invention] An object of the present invention is to provide a recording liquid capable of obtaining a print excellent in quick drying and excellent print quality even when recording is performed on plain paper.

[Means for Solving the Problems] The present invention provides an aqueous medium comprising 10 to 50% by weight of a water-soluble organic solvent and water based on the total weight of a recording liquid, and a water-soluble dye of 0.1 to 50% based on the total weight of the recording liquid. 8% by weight, 1 to 5% by weight of urea and / or caprolactam, and 0.4% of ammonium chloride
An on-demand type ink jet recording liquid characterized by containing about 2% by weight.

 Hereinafter, the present invention will be described in detail.

Examples of the water-soluble dye used in the present invention include azo-based, anthraquinone-based, quinophthalone-based, indigo-based and phthalocyanine-based direct dyes and acid dyes.
CIDirect Black-17, -19, -22, -32, -51, -8
0, -91, -151 and -154, CIDirect Blue -86 and-
199, CIDirect Red-80, CIDirect Yellow-86 and -142, CIAcid Black-2, -24, -26, -48, -5
2, -63, -172, -194 and -208, CIAcid Blue-
9, -185 and -254, CIAcid Red-8, -35, -37 and -257, CIAcid Yellow-23 and -49 and CIFood B
lack-2 and the like.

The above water-soluble dyes can be used alone or in combination of two or more, and the content thereof is 0.1% based on the total weight of the recording liquid.
The range is 1 to 8% by weight, preferably the range of 2 to 6% by weight.

As the aqueous medium of the recording liquid of the present invention, in addition to water, for example, ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol (# 200), polyethylene glycol (# 400), glycerin, N- Contains water-soluble organic solvents such as methyl-pyrrolidone, N-ethyl-pyrrolidone, N-vinyl-pyrrolidone, 1,3-dimethyl-imidazolidinone, ethylene glycol monoallyl ether, ethylene glycol monomethyl ether, and diethylene glycol monomethyl ether. Preferably, the content of these organic solvents is in the range of 10 to 50% by weight based on the total weight of the recording liquid.

Urea or caprolactam may be used alone or in combination. When the content is too small, the effect of preventing clogging is small, and when the content is too large, the effect does not change. Therefore, the content is preferably 1 to 5% by weight based on the total weight of the recording liquid.

If the content of ammonium chloride is too small, the effect of suppressing bleeding is poor, and if it is too large, the water-soluble dye in the ink is salted out and clogging is easily caused.
0.4 to 2% by weight is preferred.

Conventionally, inorganic salts such as ammonium chloride have been devised so as not to be mixed into the ink in conventional on-demand type ink jet printers because they cause nozzle clogging.However, according to the present invention, inorganic salts such as ammonium chloride are used together with urea or caprolactam. Thereby, the clogging phenomenon of the nozzle is not caused, and the printing quality is improved by suppressing the bleeding at the time of printing.

Furthermore, the recording liquid of the present invention is 0.001 to 0.001 to the total weight of the recording liquid.
By adding 0.5% by weight of a surfactant, quick drying after printing and printing quality can be further improved.

The recording liquid of the present invention is suitably used for an on-demand type ink jet printer.

[Effect of the Invention] The recording liquid of the present invention is used for ink jet recording, and is excellent in quick drying after printing and printing quality.
Even when recording is performed on plain paper, even if the printed portion is rubbed with a finger, the image does not shift, and an image having no blur and a sharp outline can be obtained.

When the recording liquid of the present invention is used for ink jet recording, in addition to the above effects, recording characteristics (signal responsiveness, stability of droplet formation, ejection stability, continuous recording for a long time), storage stability Also, the light resistance, weather resistance, water resistance and the like of the recorded image are all good.

[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.

Thoroughly mixed and dissolved. Example 1 Composition amount of recording liquid (wt%) CIDirect Black-154 3 ethylene glycol monoallyl ether 25 Ethylene glycol 22 ammonium 0.5 urea chloride 3 water remaining amount Total 100 The above components in a vessel And a hole diameter of 1μ
After passing through a Teflon filter under pressure, deaeration was performed using a vacuum pump to prepare a recording solution.

Using the obtained recording liquid, ink jet recording was performed by an ink jet printer (HG-2500, manufactured by Epson Corporation), and quick drying and print quality were evaluated according to the following methods (a) and (b).

(A) Quick-drying: Print on electrophotographic paper (manufactured by Fuji Xerox Co., Ltd.), bond paper and stock form paper (manufactured by Lion Office Equipment Co., Ltd.), and after 30 seconds, rub the printed area with your finger to check for any misalignment of the image. Judged.

 In each case, there was no shift and excellent fixing properties were exhibited.

(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.

All had no feathering and the outline was sharp.

In addition, according to the following methods (c) to (f), evaluations regarding ink jet recording were performed.

(C) Long-term storage of the recording solution: Even after the recording solution was sealed in a glass container and stored at 0 ° C and 60 ° C for 6 months, no precipitation of insoluble components was observed, and there were no changes in the physical properties or color tone of the solution. Did not.

(D) Discharge stability: Continuous discharge was performed for 24 hours in an atmosphere of room temperature, 5 ° C., and 40 ° C., respectively, and stable high-quality recording was always performed under any conditions.

(E) Discharge response: Intermittent discharge every 2 seconds and discharge after leaving for 2 months were examined. In each case, recording was stable and uniform without clogging at the tip of the orifice.

(F) Quality of recorded image: The recorded image was high in density and clear. The density reduction rate after exposure to room light for 3 months was 1% or less, and when immersed in water for 1 minute, the bleeding of the image was extremely slight.

In the same manner as in Example 2 composition used amount of the recording liquid (wt%) CIDirect Black-19 3 Glycerin 10 Ethylene glycol 10 Ammonium chloride 0.8 caprolactam 4 water remaining amount Total 100 Example 1 to prepare a recording liquid having the above composition,
As a result of the examination of (a) to (f), good results were obtained in all cases.

Examples 3 and 4 According to the method of Example 1, recording solutions having the compositions shown in Table 1 below were prepared, and (a) to (a) described in Example 1 were prepared.
As a result of evaluation according to the method (f), all were good.

Example 5 CIDirect Black-51 or-
91, CIDirect Blue-86, CIDirect Yellow-86,-
142, CIAcid Black-26 or -63, CIAcid Blue
-9, or CIAcid Red-8 or -37, CIFood
A recording solution was prepared according to the method described in Example 1 except that Black-2 was used alone, and the same as in Example 1 (a) to (a).
(F) was studied. In each case, good results were obtained.

Example 6 CIDirect Black-80 or-
151, CIDirect Red-80, CIAcid Black-48, -5
2, -172, -194 or -208, CIAcid Blue-254,
CIAcid Red-35 or -257 or CIAcid Yell
A recording liquid was prepared using the composition of Example 3 except that ow-23 or -49 was used alone.
(F) was studied. In each case, good results were obtained.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) C09D 11/00-11/20 CA (STN)

Claims (1)

(57) [Claims] 1. An aqueous medium comprising 10 to 50% by weight of a water-soluble organic solvent and water based on the total weight of a recording liquid, 0.1 to 8% by weight of a water-soluble dye, urea and / or Caprolactam 1-5% by weight, and ammonium chloride 0.4
An on-demand type recording liquid for inkjet, characterized by containing about 2% by weight.