JPH05247391A - Recording liquid - Google Patents

Abstract

PURPOSE:To provide a pigment dispersion type recording liquid having stable dispersibility and low viscosity. CONSTITUTION:A pigment dispersion type recording liquid comprising a liquid medium, a high molecular material soluble in the liquid medium, and a pigment is incorporated with a dyestuff having a sulfonic acid group or sulfonate salt group. Since the addition of the above dyestuff as a dispersing agent for the pigment gives the recording liquid having stable dispersibility and low viscosity, the energy required for extruding the small liquid drops can be reduced.

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 used in an ink jet recording method.

[0002]

2. Description of the Related Art Ink jet recording is a recording method that enables low-noise and high-speed printing, and is a recording method that is rapidly becoming popular recently. In such ink jet recording, recording liquid is ejected as small liquid droplets by a method such as heating or pressurizing and the recording liquid is adhered to a recording material such as paper to perform recording.

As a coloring material for the recording liquid, it is more advantageous to use a pigment than a dye in terms of storage stability such as water resistance and weather resistance of recording.

[0004]

However, when a polymer material is used as a dispersant for stably dispersing the pigment in the liquid medium, the viscosity of the recording liquid becomes high, and in order to eject small droplets. There was a problem that the required energy became large.

Therefore, an object of the present invention is to provide a pigment-dispersed recording liquid which is stable in dispersion and has a low viscosity.

[0006]

The recording liquid of the present invention comprises a dye having a sulfonic acid group or a sulfonate group as a dispersion aid, a liquid medium, a polymeric material soluble in the liquid medium as a dispersant, and a recording agent. As a pigment. That is, in the recording liquid of the present invention, by adding a dye having a sulfonic acid group or a sulfonate group as a dispersion aid for the pigment, the dispersion stability of the pigment is improved and the viscosity of the recording liquid is reduced. Further, various additives and the like may be added if necessary.

In the present invention, the liquid medium may be, in addition to water, aliphatic hydrocarbons such as n-hexane and n-heptane, aromatic hydrocarbons such as toluene and xylene, and n-.
Propyl alcohol, alcohols such as cyclohexyl alcohol, glycols such as triethylene glycol and dipropylene glycol, glycol derivatives such as tripropylene glycol monomethyl ether and cellosolve acetate, esters such as ethyl acetate and isopropyl acetate, methyl isobutyl ketone, Examples thereof include ketones such as cyclohexanone. These liquids can be used alone or as a mixture, but when a liquid that easily evaporates is used, it is desirable to use as a mixture with a high boiling point solvent.

Examples of the pigment include azo type, phthalocyanine type, quinacridone type, anthraquinone type, dioxazine type, indigo type, thioindigo type, perylene type, perinone type, isoindolinone type, quinophthalone type, titanium oxide, cadmium type, Examples thereof include iron oxide type and carbon black. These pigments can be used alone or in combination.

Examples of the polymer material include rosin derivative, maleic acid resin, fumaric acid resin, phenol resin,
Xylene resin, urea resin, melamine resin, ketone resin,
Examples thereof include alkyd resin, polyamide resin, acrylic resin, polyvinyl chloride, polyvinyl acetate, polyvinyl alcohol, butyral resin, styrene resin, epoxy resin, polyurethane and cellulose derivative. As these polymeric materials, those soluble in a liquid medium can be selected and used alone or in combination.

Examples of the dye having a sulfonate group or a sulfonate group include C.I. I. Acid Blue
89, 113, 158, C.I. I. Acid Red 9
7,134, C.I. I. Acid Black 54, 1
24, C.I. I. Acid Yellow 9, C.I. I.
Acid Orange 14, 52, C.I. I. Aci
d Brown 13, 103, C.I. I. Direct
Blue 65, 122, 231, C.I. I. Dire
ct Red 20, 80, C.I. I. Mordant
Blue 31, 44, C.I. I. Mordant Bl
ack 93, C.I. I. Mordant Yellow
20, 44, C.I. I. Mordant Violet
40, C.I. I. Food Red 1, C.I. I. Foo
d Black 2, C.I. I. Food Yellow
7, C.I. I. Reactive Blue 81,
C. I. Reactive Red 9, C.I. I. So
lubilized Vat Blue 1 and the like. These dyes can be used alone or in combination.

The liquid medium, the pigment, the polymer material and the dye having a sulfonic acid group or a sulfonic acid group as described above may satisfy desired properties such as mutual affinity, pigment dispersion stability and viscosity. It is the one that is selected and used.

Other various additives are appropriately added to the recording liquid to be prepared, if necessary. Examples of such additives include a surface tension adjusting agent, an antioxidant, an ultraviolet absorber and a stabilizer.

[0013]

By preparing the recording liquid with the combination as described above, it is possible to obtain a pigment dispersion type recording liquid having stable dispersion and low viscosity.

[0014]

EXAMPLES Next, the present invention will be described in more detail by way of examples.

Example 1 A recording liquid was prepared by dissolving and dispersing the following components using a paint shaker. The viscosity of the obtained recording liquid was 11.6 cp (25 ° C.). Tripropylene glycol monomethyl ether 90.0% by weight Polyvinyl butyral 4.5% by weight Copper phthalocyanine blue 5.0% by weight C.I. I. Acid Blue 158 0.5% by weight

Example 2 A recording liquid was prepared by dissolving and dispersing the following components using a paint shaker. The viscosity of the obtained recording liquid was 8.8 cp (25 ° C.). Diethylene glycol mono-n-butyl ether 90.0% by weight Polyvinylpyrrolidone 4.6% by weight Carbon black 5.0% by weight C.I. I. Direct Red 20 0.4% by weight

Example 3 A recording liquid was prepared by dissolving and dispersing the following components using a paint shaker. The viscosity of the obtained recording liquid was 9.2 cp (25 ° C.). Tripropylene glycol monomethyl ether 90.0% by weight Polyvinylpyrrolidone 4.5% by weight Carbon black 5.0% by weight C.I. I. Acid Blue 113 0.5% by weight

Example 4 A recording liquid was prepared by dissolving and dispersing the following components using a paint shaker. The viscosity of the obtained recording liquid was 8.5 cp (25 ° C.). Water 83.0% by weight Diethylene glycol 10.2% by weight Polyvinyl alcohol 1.5% by weight Carbon black 5.0% by weight C.I. I. Direct Blue 122 0.3% by weight

Comparative Example 1 Among the recording liquids prepared in Example 1, C.I. I. A recording liquid was prepared except for Acid Blue 158. The viscosity of the obtained recording liquid is 12.0 cp
(25 ° C).

Comparative Example 2 Among the recording liquids prepared in Example 2, C.I. I. A recording liquid was prepared except for Direct Red 20. The viscosity of the obtained recording liquid is 9.1 cp (2
5 ° C.).

(Comparative Example 3) Of the recording liquids prepared in Example 3, C.I. I. A recording liquid was prepared except for Acid Blue 113. The viscosity of the obtained recording liquid is 9.7 cp (2
5 ° C.).

(Comparative Example 4) Of the recording liquids prepared in Example 4, C.I. I. A recording liquid was prepared except for Direct Blue 122. The viscosity of the obtained recording liquid is 8.8 cp
(25 ° C).

As described above, the addition of a dye having a sulfonic acid group or a sulfonate group to the pigment dispersion type recording liquid resulted in a decrease in the viscosity of the recording liquid.

Example 5 These recording liquids of the present invention were used in 20
The pigment was not precipitated even after centrifugation at 00 rpm for 1 hour, and the dispersion was stable. When the recording liquids prepared in Comparative Examples were also centrifuged in the same manner, sedimentation of the pigments occurred in all cases.

Example 6 Examples 1 to 4 and Comparative Example 1
Each of the recording liquids prepared in Examples 1 to 4 was printed on several kinds of plain paper by using an on-demand type piezoelectric inkjet printer head, and the recording liquid was ejected well. At that time, when comparing the example of the same number and the comparative example, since the recording liquid of the example had a lower viscosity, it was ejected with a smaller energy (voltage). Further, when the dot shape on the paper of the recording liquid of the example was examined, a good circle was obtained for all the papers and a high reflection density was exhibited. Furthermore, even if each printed sample was immersed in running water for 5 minutes or exposed to a fade meter for 50 hours, no decrease in density occurred.

[0026]

As described above, in the present invention, by adding a dye having a sulfonic acid group or a sulfonate group to a pigment-dispersed recording liquid, a recording liquid having stable dispersion and low viscosity can be obtained. I was able to. Therefore, the energy required to eject the recording liquid as small droplets can be reduced. Further, since this recording liquid uses a pigment as a coloring material, the recording liquid is very excellent in water resistance and light resistance. Therefore, according to the present invention, it is possible to eject a small droplet with a small amount of energy, and it is possible to provide a recording liquid having excellent storage stability of recording.

Claims (1)

[Claims] 1. A recording liquid comprising a dye having a sulfonate group or a sulfonate group, a liquid medium, a polymer material soluble in the liquid medium, and a pigment.