JPH0711181A - Recording fluid - Google Patents

Abstract

PURPOSE:To obtain an ink jet recording fluid excellent in water and light resistances and also in print quality by dissolving an oil-soluble dye in a fat or oil of a specified melting point and emulsifying the solution in an aqueous medium. CONSTITUTION:This recording fluid is prepared by emulsifying a fat or oil containing a dissolved oil-soluble dye in an aqueous medium, wherein the melting point of the fat or oil is 0 deg.C or below. It is desirable that the mean particle diameter of the fat or oil is 0.5mum or below. The aqueous medium means the one prepared by adding additives such as a surfactant, a wetting agent, a dispersion stabilizer and an antiseptic to water. Examples of the fat or oil used include linseed oil, sesame oil, walnut oil, poppy seed oil, soybean oil, rape oil, tobacco seed oil, sunflower-seed oil, corn oil and castor oil. It is desirable that the mixing ratio of the aqueous medium to the dye solution is in the range of 50:50 to 90:1 by weight.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording liquid for ink jet recording.

[0002]

2. Description of the Related Art Ink jet recording is a recording method suitable for colorization because it is capable of high-speed printing with low noise. In such ink jet recording, recording liquid is discharged as droplets by a method such as pressurization or heating using an electric signal, and the droplets are attached to a recording material such as paper to perform recording.

Conventional recording liquids are usually composed mainly of a water-soluble dye, an additive such as a wetting agent, and three components of water. The water-soluble dye is an important component for coloring the recording material, and water is a carrier medium for transferring the water-soluble dye to the recording material.

However, the conventional recording liquid using a water-soluble dye has problems in water resistance and light resistance due to the characteristics of the water-soluble dye itself.

In order to solve the above problem, Japanese Patent Laid-Open No. 62-
JP-A-207375 proposes a recording liquid in which an organic solvent in which an oil-soluble dye is dissolved is atomized and dispersed in an aqueous medium.

Water resistance of recording liquid due to the introduction of oil-soluble dye
The problem of light fastness has been solved. However, the print quality is not sufficient, and there are problems such as bleeding when printing on plain paper which is a recording material.

[0007]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a recording liquid which is excellent in water resistance and light resistance and printing quality.

[0008]

The recording liquid of the present invention is characterized in that fats and oils in which an oil-soluble dye is dissolved are finely dispersed in an aqueous medium, and the melting point of the fats and oils is 0 ° C. or lower. To do.

Further, in the recording liquid of the present invention, it is preferable that the fat and oil in which the oil-soluble dye is dissolved has an average particle size of 0.5 μm or less.

[0010]

In the present invention, the aqueous medium means water to which additives such as a surfactant, a wetting agent, a dispersion stabilizer and a preservative are added.

The recording liquid of the present invention is a state in which fats and oils in which an oil-soluble dye is dissolved are made into fine particles and emulsified and dispersed in an aqueous medium.

The fats and oils used in the present invention have a melting point of 0 ° C. or lower, and include, for example, linseed oil, perilla oil, walnut oil, poppy oil, soybean oil, rapeseed oil, tobacco seed oil, sunflower seed oil, corn oil, Fats and oils such as castor oil may be mentioned.

In the recording liquid of the present invention, only one kind of oil or fat may be used, or two or more kinds of oil or fat may be used.

The oil-soluble dye used in the present invention includes:
There is no particular limitation as long as it is insoluble in water and soluble in the fat or oil used. For example, Solvent Yellow 4, 10, 12, 19, 2, 5, 25, 26, 28, 2
9, 36, 38, 76, Solvent Red 19, 24,
27, 29, 19, 63, 66, 67, 68, 97, 1
27, 128, Solvent Blue 33, 52, 55, 6
7, 70, Solvent Black 10, 11, 13, 1
4, 8, 19, 20, 21, Disperse Yellow 3,
16, Sudan I, II, III, IV, Black B, Disperse Black 3, 7 and the like.

The recording liquid of the present invention is obtained by dissolving an oil-soluble dye in oil and fat to prepare a dye solution, adding the dye solution to an aqueous medium, and emulsifying and dispersing it. Here, the mixing ratio of the aqueous medium and the dye solution is 50:50 to 90: by weight.
The range of 1 is preferable, and more preferably 65:35 to 8
It is 5:15.

Oils and fats in which an oil-soluble dye is dissolved are made into fine particles,
And in order to stably emulsify and disperse, a surfactant in water,
It is desirable to add a wetting agent or a dispersion stabilizer. Moreover, you may make a fat and oil contain a surfactant.

Examples of the surfactant usable in the present invention include sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, polyoxyethylene lauryl ether, polyoxyethylene oleyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene nonylphenyl. Examples thereof include ether, sodium alkyl diphenyl ether disulfonate, sodium alkyl allyl sulfosuccinate, and the like.

The wetting agent usable in the present invention includes, for example, ethylene glycol, glycerin, diethylene glycol, triethylene glycol, polyethylene glycol # 200, # 300, # 400, N-.
Methyl-2-pyrrolidone, triethanolamine and the like can be mentioned.

The fat and oil can be emulsified and dispersed by a conventional method. In order to prevent the nozzle from clogging, it is preferable to remove unnecessary solid matter by filtering the aqueous medium, the dye solution, etc. prior to the emulsification and dispersion.

As a disperser used for emulsifying and dispersing, a lab stirrer, an attritor, a ball mill, a dyno mill, a magnetic stirrer, a homogenizer, a film emulsifying device and the like can be used.

[0021]

EXAMPLES The recording liquid of the present invention will be described in more detail with reference to Examples. However, the present invention is not limited to the examples. In the examples, “part” means “part by weight”.

(Example 1) Sodium dodecyl sulfate
A 5% aqueous solution was filtered through a membrane filter made of nitrocellulose having a film thickness of 0.45 μm to prepare solution A. Disperse black (5% by weight) was added to linseed oil and dissolved using an ultrasonic cleaner, and then filtered through a regenerated cellulose membrane filter having a film thickness of 0.8 μm to prepare solution B. A recording liquid was obtained by mixing and dispersing 90 parts of solution A and 10 parts of solution B with a membrane emulsifying device. .

Example 2 A 1.0% aqueous solution of polyoxyethylene lauryl ether was filtered through a membrane filter made of nitrocellulose having a film thickness of 0.45 μm to prepare solution A. Add 5% by weight of Sudan Black B to soybean oil, dissolve using an ultrasonic cleaner, and then filter with a membrane filter made of regenerated cellulose having a film thickness of 0.8 μm to obtain Solution B.
Was produced. A recording liquid was obtained by mixing and dispersing 80 parts of solution A and 20 parts of solution B in a membrane emulsifying device.

(Example 3) A 1.0% aqueous solution of polyoxyethylene lauryl ether was filtered through a membrane filter made of nitrocellulose having a film thickness of 0.45 µm to prepare a solution A. 5% by weight of Solvent Red 19 was added to rapeseed oil, dissolved using an ultrasonic cleaner and impurities were removed by a centrifuge to prepare a solution B. Solution A 80 parts and solution B
A recording liquid was prepared by dispersing 20 parts by a membrane emulsifying device.

Comparative Example 1 A recording liquid was prepared in the same manner as in Example 1 except that linseed oil was replaced with dodecylbenzene.

Comparative Example 2 A recording liquid was prepared in the same manner as in Example 2 except that soybean oil was replaced with m-dichlorobenzene.

Comparative Example 3 A recording liquid was prepared in the same manner as in Example 3 except that rapeseed oil was replaced with benzophenone.

(Example 4) Examples 1 to 3 and Comparative Examples 1 to 3
Each of the recording liquids prepared in step 1 was mounted on an on-demand type inkjet head and printed on several types of plain paper. As a result, when the dot shape was examined, in the case of the recording liquid of each example, good circularity coefficient was obtained and high reflection density was shown on all the papers. However, in the case of each of the recording liquids of Comparative Examples, bleeding was observed and the print quality was not good.

[0029]

The recording liquid of the present invention has a good circularity coefficient on plain paper, exhibits a high reflection density, and has excellent printing quality. Further, since it uses an oil-soluble dye, it has excellent water resistance and light resistance. Furthermore, since the recording liquid of the present invention uses fats and oils, it is excellent in safety.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yamada ▲ Yori ▼ Nobu 840 Takeno, Shimotomi, Tokorozawa, Saitama Prefecture Citizen Watch Co., Ltd.

Claims (2)

[Claims] 1. A recording liquid comprising an oil / fat in which an oil-soluble dye is dissolved and dispersed in an aqueous medium, and the melting point of the oil / fat is 0 ° C. or lower. 2. The recording liquid according to claim 1, wherein the oil and fat in which the oil-soluble dye is dissolved has an average particle diameter of 0.5 μm or less.