JPS62172075A - Recording liquid - Google Patents

Abstract

PURPOSE:To provide a recording liquid containing plural kinds of water-soluble dyes having similar chromatographic characteristics and capable of reproducing desirable color tone of the ink itself without causing microscopic separation on the recording material. CONSTITUTION:The objective recording liquid contains preferably 0.5-30wt% plural kinds of water-soluble dyes having a mobility of e.g. <=0.3 measured by paper chromatography and having similar chromatographic characteristics to each other. The recording liquid enables the reproduction of desirable color tone by the combination of dyes resistant to microscopic phase separation on a recording material.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a recording liquid (hereinafter referred to as ink) for recording on a recording material such as paper or resin film using an inkjet method or a writing instrument such as a fountain pen or a felt pen. (referred to as ).

(Prior Art) The inkjet recording method is a method of forming ink droplets using various ink ejection methods and attaching some or all of them to a recording material such as paper to perform recording. As inks used in such inkjet recording methods, inks in which various water-soluble dyes or pigments are dissolved or dispersed in water or a liquid medium consisting of water and a water-soluble organic solvent are known and used. ing.

Further, inks similar to those described above are also used as inks for writing instruments such as fountain pens, felt pens, and ballpoint pens.

In addition, paper, a plastic film whose surface has been treated with processed paper, etc. are used as recording materials for recording with these inks.

Various color tones are known as water-soluble dyes used in inks such as those mentioned above, but if the desired color tone cannot be achieved alone, theoretical It is common to mix and use a plurality of dyes in proportions determined by .

(Problems to be Solved by the Invention) According to the above-described preparation method, ink itself can be prepared with a desired color tone in most cases. If the recording material is paper thread,
It is often difficult to reproduce the preferred color tone of the ink itself on a recording material.

Therefore, there is a need for an ink that can reproduce a desired color tone even on recording materials such as paper.

As a result of intensive research to meet the demands of the prior art as described above, the inventors of the present invention have found that the following problems with conventional compounded inks are related to the affinity of the water-soluble dye in the ink to the recording material. Even if the ink itself has a desired color tone, the desired color tone cannot be reproduced on the recording material because the multiple dyes in the ink have different affinities for the recording material. We discovered that this occurs due to microscopic separation on the recording material from dyes with low affinity. 1 As a standard for combining dyes that do not cause microscopic separation on such recording materials. The dye has the best chromatographic properties, and by using a combination of water-soluble dyes with similar chromatographic properties,
It has been found that the problems of the prior art described above can be easily solved.

(Disclosure of the Invention) That is, the present invention is a recording liquid containing a plurality of water-soluble dyes, characterized in that the plurality of water-soluble dyes have similar chromatographic characteristics to each other. .

Next, to explain the present invention in more detail, the ink of the present invention generally includes two or more water-soluble dyes, a liquid medium for dissolving these dyes, and optional additives added as necessary. These components may be the same as those of the conventional inks, except that the two or more water-soluble dyes have similar chromatographic properties to each other. The chromatographic properties of water-soluble dyes referred to in can be determined based on the mobility value by the vapor chromatography method described below, and those with similar mobility values are used in combination. Thus, the object of the present invention has been achieved.

That is, the mobility of the water-soluble dye is determined as follows.

First, mix the dye with water/diethylene glycol (volume ratio 55/
45) Dissolve in a mixed solvent to a concentration of 5% mold hole to prepare a test solution. This test liquid is filtered through Toyo Filter◆Paper N
After charging the lower end of 0.50 (trade name; Toyo Roshi Co., Ltd.) with a two-way blade, development is carried out in a conventional manner for a predetermined period of time using the mixed solvent described in fiii as a developing solution. At this time, the 1-mutual distance #(A) of the developing solvent from the charge and the moving layer #(B) of the dye 1 from the charge point are measured, and the ratio of the two is B/A=Rf. Ill'i is determined, and this Rf is taken as the mobility of the test dye.

The present inventor determined the chromatographic properties of various water-soluble dyes based on this mobility, and found that the maximum difference in mobility was 0.30 or less, more preferably 0.20 or less.
It has been found that even when a combination of one or more water-soluble dyes is used in an ink to record on a paper thread recording material, color tone reproducibility is present at a level that poses no practical problem. In addition, the above-mentioned difference in mobility refers to the difference in mobility between two types of water-soluble dyes, and in the case of three types or more, the difference in mobility between the highest and lowest mobility. This is the difference in mobility.

Furthermore, if the difference in mobility is 0.20 or less, almost the same color tone as the ink can be reproduced on the recording material,
It was possible to record a desired color tone.

In the case of a combination of dyes in which the difference in mobility exceeds 0.30, a color tone different from the color tone of the ink color as described above appears on the recording material, which is not preferable.

As the multiple water-soluble dyes used in the present invention, any water-soluble dyes used in conventional inks can be used as long as their chromatographic properties are similar, and the dyes listed below are: It is a particularly suitable dye in the present invention. It should be noted that all the numerical values in the column appended to the dye groups are the mobility values determined by the method described above.

Z Niue Presentation C, 1, Acid Blue 254 (0,84)
C, I, 7side blue 1 (0
,99)C,1,Acid Blue 9 (0
,99) C,1, Acid Blue 290 (0
,82) C,1, Acid Blue 103 (0
,92) C,1, Acid Blue 40 (0
,97) C,1, Acid Blue 127 (0
,97) C,1, Ashi, Dobrou86 (0
,813) C,1, Acid Blue 113 (
0,9Ef) C,1, Acid Blue 120
(0,91) Nijiku Eku μ C, 1, Acid Red 276 (0,74)
C, X, Ashintrend 274 (1), 95
) C, 1, Asintrend 289 (0,99
) C, 1, Asindred 122 (0,96
) C, 1, Acid Red 155 (0,96
) C,1, Acid Red 161 (0,88
) C,1, Acid Red 131 (0,96
) C, 1, Asindred 249 (0,94
)C,1,Acid Red 35 (0,9
5) C, 1, Asindre Ndo l 06 (0
,99)C,1,Acid Red 2 [34(0,97
) C, 1, Acid Red 254 (0,99
) C, 1, Acid Red 52 (0,91
) C,1, Acid Red 27 (0,9
1) C,1, Acid Red 265 (0,9
1) C,1, Acid Red 257 (0,7
9) C,1, Acid Red 42 (0,9
3) C, 1, Ashi Ndred I L l (
(1,H)C,1,Acid Red 145 (
0,92) Kosansanjikanmu C,1, Acid Yellow 23 (0,90)
C,1, Acid Yellow 29 (0,82
) c, r, acid yellow 38 (0,85
)C,1, Acid Yellow 65 (0,8
5) C,1, acid yellow 12 (0,8
7) 222ヱλ piece C, 1, acid black 24 (0,93)
C,1, Acid Black 26 (0,90)
C,1, Acid Black 107 (0,85)
c, r, acid black 110 (0,86)
C, 1, acid black 52: 1 (0,9
7) C,1, acid blank 139 (0,9
0) The dyes exemplified above are particularly preferred in the present invention, and the water-soluble dyes used in the present invention are not limited to the dyes exemplified above. Any other water soluble dye can also be used.

These water-soluble dyes are generally used as a plurality of dyes in an amount of 0.5 to 30% by weight, more preferably about 1 to 10% by weight, in the ink.

The solvent used in the ink of the present invention is water or a mixed solvent of water and a water-soluble organic solvent, and a particularly preferable one is a mixed solvent of water and a water-soluble organic solvent. It contains polyhydric alcohol which has a preventive effect.

Further, as water, it is preferable to use deionized water rather than ordinary water containing various ions.

Examples of water-soluble organic solvents used in combination with water include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, and isobutyl alcohol. Carbon number 1~
4-alkyl alcohols; amides such as dimethylformamide and dimethylacetamide; ketone or keto alcohols such as acetone and diacetone alcohol; ethers such as tetrahydrofuran and dioxane; polyalkylene glycols such as polyethylene glycol and polypropylene glycol; ethylene glycol , propylene glycol, butylene glycol, l-diethylene glycol, 1,2,6-hexandriol, thiodiglycol, hexylene glycol, diethylene glycol, and other alkylene glycols in which the alkylene group has 2 to 6 carbon atoms; glycerin; Lower alkyl ethers of polyhydric alcohols such as ethylene glycol methyl (or ethyl) ether, diethylene glycol methyl (or ethyl) ether, triethylene glycol monomethyl (or ethyl) ether; N-methyl-2-pyrrolidone, 1.3 -dimethyl-2-imidazolidinone and the like. Among these many water-soluble organic solvents, polyhydric alcohols such as diethylene glycol and lower alkyl ethers of polyhydric alcohols such as triethylene glycol monomethyl (or ethyl) ether are preferred.

The content of the above-mentioned water-soluble organic solvent in the ink is generally O to 95% by weight, preferably 10 to 80% by weight, more preferably 20 to 50% by weight based on the total weight of the ink. range.

The wood content at this time is determined within a wide range depending on the type of the solvent component2, its composition, and the desired properties of the ink, but it is generally determined that the wood content is within a wide range based on the total weight of the ink.
o% by weight, preferably from 10 to 70% by weight, more preferably from 20 to 70% by weight.

The basic composition of the ink of the present invention is as described above, in addition to various conventionally known dispersants, surfactants, and viscosity modifiers.
A surface tension adjuster and the like can be added as necessary.

For example, viscosity modifiers such as polyvinyl alcohol, celluloses, and water-soluble resins; cationic, anionic, or nonionic surfactants; surface tension modifiers such as jetanolamine and triethanolamine;
Examples include H regulators, antifungal agents, and the like.

Further, in order to prepare ink used in an inkjet recording method of the type in which the recording liquid is charged, a resistivity adjuster such as inorganic salts such as lithium chloride, ammonium chloride, and sodium chloride is added. When applied to the Infusiera i method, which ejects ink through the action of thermal energy, the thermal properties (e.g., specific heat, coefficient of thermal expansion, thermal conductivity, etc.) may be adjusted. .

The ink of the present invention as described above has sufficiently solved the problems of the prior art, and can be used to record on various recording materials, such as paper thread, using the Infusiera I method or a general writing instrument. The desired color tone, which is toned by a plurality of water-soluble dyes in the ink, can be reproduced on the recording material to such an extent that there is no problem in practical use, not only with ordinary black ink.

Even in full-color recording using multiple color inks, it is possible to perform clear, high-contrast, high-quality recording.

On the other hand, in the case of conventional compounded inks, the focus was only on the color mixing of the water-soluble dyes used in them, so it was easy to obtain the desired color tone of the ink. It was difficult to reproduce the color tone on the recording material, but in the invention of Fukui, in addition to mixing the dyes, the above-mentioned color tone was achieved by adopting a new standard called chromatographic characteristics. The problems of the prior art have been satisfactorily solved.

Next, the present invention will be explained in more detail with reference to Examples, Comparative Examples, and Usage Examples. In the text, parts and percentages are based on weight unless otherwise specified.

Examples 1 to 6 and Comparative Example 1 After stirring the components of the composition below to dissolve the water-soluble dye, insoluble matter was removed using a filter to obtain six types of inks of the present invention and one type of comparative ink. Ta.

Note that the numerical value in parentheses appended to the dye group represents the mobility of the dye.

Fire Dragon C.1, Acid Black 107 4.5 parts (0.8
5) C,1, Acid Red 276 0.5 part (O17
4) Diethylene glycol 30 parts Ion-exchanged water 65 parts
0) g, r, acid blue 103 2.5 parts (0,9
2) Diethylene glycol 30 parts Ion-exchanged water 65 parts Acid Yellow 29 2.5 parts (0.8
2) C,1, Acid Red 161 2.5 parts (0,8
6) Diethylene glycol 30 parts ion-exchanged water 65 parts C.1 Acid Red 145 2.5 parts (0.9
2) C,1, Acid Blue 103 2.5 parts (0,9
2) Diethylene glycol 30 parts Ion-exchanged water 65 parts Mitsukij C.1, Acid Blue 254 4.0 parts (0.9
4) C, I, 7 C) Doini l: +-230, 5 parts (0
,90) C,1, Acid Red 145 0.5 part (O49
2) Diethylene glycol 30 parts Ion exchange water 65 parts
0) C,1, Acid Black 139 2.5 parts (0,9
0) Diethylene glycol 30 parts Ion exchange water 65 parts Le Kasa week C.1, Acid black 24 4.5 parts (0.9
3) C, 1, acid red l-'99 o, s part (
0, 61) Diethylene glycol 30 parts Ion exchange water 65 parts Usage example 1 Using the inks of the above examples and comparative examples, an on-demand recording head (discharge orifice diameter 50 Bm, piezo vibrator drive When recording was performed on the following various recording materials using a recording device having a voltage of 60 V and a frequency of 4 KHz, it was found that when the ink of the present invention was used, there was no separation of multiple water-soluble dyes and the desired color tone was obtained. was able to be reproduced and a clear image was obtained. On the other hand, when the ink of the comparative example was used, the color tone of the ink could not be reproduced, and an image with unclear color tone was obtained.

Shocked materials (1) Silver layer (trade name, Hokusei, manufactured by Chūyō Kokusaku Valve) (2) Seven Stars (trade name, high quality paper, manufactured by Hokuetsu Paper) (3) Hakupeony (trade name, medium quality paper) 2 manufactured by Honshu Paper Industries) (4) Toyo Roshi No. 4 (trade name, non-size paper, manufactured by Toyo Roshi Paper Industries) Usage example 2 Each ink of the above example and comparative example was filled into separate felt tubes, and the paper When writing on paper, it was found that when using the ink of the present invention, there was no separation of colors on paper;
A clear image with the same color tone as the ink was reproduced. On the other hand, when the ink of the comparative example was used, separation of the dye occurred on the paper, and the clear color tone of the ink was not reproduced, resulting in an image with an unclear color tone.

Sender Canon Co., Ltd. 19・、−゛

Claims (4)

[Claims] (1) A recording liquid containing a plurality of water-soluble dyes, characterized in that the plurality of water-soluble dyes have similar chromatographic characteristics to each other. (2) The difference in chromatographic properties expressed by the mobility of a plurality of water-soluble dyes is 0.3 or less at the maximum value (
The recording liquid described in section 1). (3) The difference in chromatographic properties expressed by the mobility of a plurality of water-soluble dyes is 0.2 or less at maximum.
The recording liquid described in section 1). (4) The recording liquid according to claim (1) for use in an inkjet system.