JPH03252469A - Ink - Google Patents

Abstract

PURPOSE:To obtain ink having excellent clogging resistance, providing record having excellent printing quality and improved permeability, free from oozing on common paper, containing a water-soluble dye, a specific amount of a water- soluble organic solvent, water and a specific compound. CONSTITUTION:The objective ink containing a water-soluble dye, 1-40wt.% water-soluble organic solvent, water and preferably 1-10wt.% compound shown by the formula [R1 is carboxyl or (substituted) aryl; R2 to R4 are alkyl, hydroxyalkyl and one of R2 to R4 may be H].

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to ink used in various recording instruments such as writing instruments and printers, and more specifically, to an ink that has excellent clogging prevention properties and is generally used in offices, etc. The present invention relates to an ink that can perform good recording even on standard paper.

(Prior Art) Various compositions of inks for writing instruments (fountain pens, felt-tip pens, water-based ballpoint pens, etc.) and inkjet inks have been reported.

In particular, in recent years, various aspects such as composition and physical properties have been developed for ink, especially inkjet ink, for good recording even on plain paper commonly used in offices such as copy paper, report paper, notebooks, and stationery. Detailed research and development has been carried out since then.

For example, ink generally contains high boiling point organic solvents such as glycol for the purpose of preventing drying and clogging, but when printing with such ink on plain paper with a high degree of size, had problems with fixation, such as the ink not penetrating into the inside of the paper (the drying properties of the recorded area were poor, so when you touched the recorded matter with your hands, the ink would get on your hands, and the letters would rub and become smeared). .

Therefore, in order to increase the permeability of the ink into the inside of the paper, Japanese Patent Application Laid-Open No. 55-29546 proposes a method of adding a large amount of surfactant to the ink. In this case, depending on the paper, there may be a lot of bleeding, or if the ink is filled into a writing instrument, the ink may drip from the pen tip, or if it is filled into an inkjet head, the head structure may In some cases, the ink receded from the orifice surface and was not ejected, or conversely, the entire orifice surface became wet and ink was not ejected.

Furthermore, Japanese Patent Application Laid-Open No. 54-104933 and Japanese Patent Publication No. 62
-14189 discloses a method of adding N,N-bis[polyoxyethylene (or propylene)]-]P-toluenesulfonic acid amide to an ink,
Although this method is effective in improving the solubility of dyes, it requires the use of a fairly large amount of organic solvent such as polyhydric alcohol in order to sufficiently prevent clogging. There is a problem that the fixing properties of the paper are poor and stains occur even after a long period of time when it comes into contact with the recording material, so it is necessary to use a surfactant in combination to improve the permeability to the paper. As a result, bleeding occurs and the print quality is not sufficient.

Further, when used for inkjet recording and when ink ejection is interrupted, there is a problem that when water or the like evaporates, the above-mentioned compound retreats from the orifice surface, resulting in poor clogging prevention properties.

In addition to the above, various other improvements have been attempted, but unfortunately no ink has been found that can solve all of the problems of drying performance, printing quality, and clogging.

(Problem to be Solved by the Invention) Therefore, the purpose of the present invention is to prevent clogging of the printer head even when the pen tip of a writing instrument or printer device is temporarily stopped or stopped for a long period of time, and in the event that clogging occurs. It is an object of the present invention to provide an ink which is easily recoverable even when it is damaged, and which can form a high-quality image consisting of round dots with little irregular bleeding even on a recording material.

(Means for solving problems) The above objects are achieved by the present invention as described below.

That is, the present invention provides an ink containing a water-soluble dye, a water-soluble organic solvent, and water, in which the content of the water-soluble organic solvent is 1.
The ink is characterized in that it contains a compound represented by the following general formula (I) in an amount of 40% by weight.

(However, R1 is a carboxyl group, an aryl group, a hydroxyl group, a carboxyl group, a sulfonic acid group, a sulfamoyl group,
Indicates an aryl group substituted with an amino group or an acetylamino group, R2, R3 or R4 is an alkyl group or a hydroxyalkyl group, and any one of R, R, or R4 is a hydrogen atom. good. ) (Function) The inventors of the present invention have conducted intensive studies on various ink compositions in order to prevent clogging of nozzles during recording and to obtain high-quality images with less ink bleeding on paper. By containing 1 to 40% by weight of a water-soluble organic solvent and the compound represented by the general formula (I) together, the solubility of the dye in the concentrated state of the ink due to water evaporation is improved, and less water-soluble water is added. Yes! It is possible to prevent clogging by adding a solvent, and even if the volatile components in the ink at the tip of the nozzle of the printer head completely evaporate, the compound represented by the general formula (I) can be prevented together with the dye. It has been found that because the dye remains, the strong agglomeration 8 of the dye can be alleviated, and the recovery of ink ejection becomes much easier than before.

In addition, there is an example disclosed in JP-A-51-108925 as an ink containing an N-alkanolamine salt of a lower fatty acid, but when the N-alkanolamine salt of a lower fatty acid is used, the above effects are not obtained. It has the disadvantage that it may not be obtained in sufficient quantity, or that it requires a very large amount.

In addition, when an ink containing a compound represented by the following general formula (I) is ejected as droplets from a nozzle of a printer head, there is a sudden change in the composition of the ink due to evaporation and penetration onto the recording material. It was found that the compound represented by the general formula (I) rapidly thickens and crystallizes, so that the printed dots maintain a round shape with little irregular bleeding.

(Preferred Embodiments) Next, the present invention will be described in more detail by citing preferred embodiments.

The compounds represented by the general formula (I) used in the ink of the present invention include oxalic acid, benzoic acid, methylbenzoic acid, hydroxybenzoic acid, phthalic acid, aminobenzoic acid, acetamidobenzoic acid, and sulfamoylbenzoic acid. Trimethylamine salt, triethylamine salt, triethanolamine salt, diethylamine salt, jetanolamine salt, dipropylamine salt, etc. are used. Among these, triethylamine salts or triethanolamine salts of oxalic acid, benzoic acid, and sulfamoylbenzoic acid are particularly preferred.

The compounds of the general formula (1) can be used in combination of one or more of each, and the amount of the compound of the general formula (T) to be added to the ink depends on the dye used, other liquid medium components used in combination, etc. Although it varies depending on the type, the proportion in the ink is 0.1 to 20
The proportion accounts for 1 to 10% by weight, preferably 1 to 10% by weight.

Furthermore, the dye used in the present invention has a color index (C
Almost all of the water-soluble fast dyes, direct dyes, basic dyes, and reactive dyes described in Color 1ndex) can be used. Furthermore, even if the dye is not listed in the color index, any water-soluble dye can be used.

The amount of these dyes to be used is not particularly limited, but - for boat fishing, it is about 0.1 to 0.1% by weight of the total amount of ink.
A range of 15% is preferred, more preferably 0.1-10%.

Further, the liquid medium used in the present invention may be similar to the liquid medium of conventionally known inks (eg, a mixture of water and a water-soluble organic solvent).

Specific water-soluble organic solvents include amides such as dimethylformamide and dimethylacetamide; ketones 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, triethylene glycol, 1,2,6-hexandriol, thiodiglycol, hexylene glycol , alkylene glycols in which the alkylene group has 2 to 6 carbon atoms such as diethylene glycol, gutserine, ethylene glycol monomethyl (or ethyl) ether, diethylene glycol monomethyl (or ethyl) ether, triethylene glycol monomethyl (or ethyl) ether, etc. Lower alkyl ethers of polyhydric alcohols; lower dialkyl ethers of polyhydric alcohols such as triethylene glycol dimethyl (or ethyl) ether and tetraethylene glycol dimethyl (or ethyl) ether; sulfolane, N-methyl-2-pyrrolidone, 1, 3-dimethyl-2-
Examples include imidazolidinone.

The content of the water-soluble organic solvent is 1 to 40% by weight, preferably 3 to 30% by weight.

In particular, the amount of wetting agents such as polyhydric alcohols that are commonly used for the purpose of preventing clogging can be increased due to the anti-clogging effect of the compound represented by the following general formula (I) used in the present invention. There is no need to use it, and if it is contained in an amount of 40% by weight or more, the drying properties and print quality on paper will deteriorate.

In addition to the above ingredients, the ink of the present invention may optionally contain a water-soluble organic solvent, a surfactant, a pH adjuster, a rust preventive agent, a preservative, a fungicide, an antioxidant, an evaporation accelerator, and a chelating agent. agent,
Various additives such as water-soluble polymers may be added.

(Example) Next, the present invention will be explained in more detail by giving examples and comparative examples. In the text, parts and percentages are based on weight unless otherwise specified.

Examples 1 to 4 The following components were mixed and sufficiently stirred to dissolve, and then a Fluorobor filter with a pore size of 0.45 μm (manufactured by Sumitomo Electric ■) was prepared.
The mixture was filtered under pressure to obtain four types of inks of the present invention.

11 ink.

C, 1, Disect Black 154 3 parts Glycerin 10 parts Oxalic acid/triethylamine salt 5 parts Isopropyl alcohol
3 parts water
79 parts 12 ink.

C, 1, Direct Black 154 3 parts diethylene glycol 5 parts 0-sulfamoylbenzoic acid/triethylamine salt
5 parts isopropyl alcohol
3 parts water
84 parts Mu Iu 糺dan亙hi 仁ＧＧ郎” 1 part C, 1, Food Black 2 3 parts Glycerin 10 parts Benzoic acid/triethanolamine salt 4 parts Isopropyl alcohol 3 parts Water
80 copies [4 inks.

C, 1, Food Black 2 4 parts diethylene glycol 15 parts diethylene glycol monophenyl ether 3 parts p-aminobenzoic acid/triethanolamine salt 5 parts water 73
Part Comparative Examples 1 to 4 General formula (I) contained in the inks of Examples 1 to 4
Comparative inks 1 to 4 were prepared in the same manner as in Example 1, except for the compound represented by the following formula and whose content was replaced by water.

15 ink, and C81, Direct Blue 86 2 parts diethylene glycol 20 parts ethylene glycol 25 parts ethanol
5 parts water
Comparative ink 6 was prepared by replacing the benzoic acid/triethanolamine salt in the ink components of 48 parts 6.7 and Example 3 with benzoic acid, and
Comparative Ink 7 was obtained by replacing the ink with propionic acid/monoethanolamine salt.

Next, using the obtained inks of Examples 1 to 4 and Comparative Examples 1 to 7, an inkjet printer BJ-130 (product name: Canon @ I (manufactured by J.D. Co., Ltd.) was used to evaluate print drying properties, clogging properties, and print quality.

The results are shown in Table 1 below.

[Evaluation method and evaluation criteria] (1) Evaluation of printing dryness Regarding printing dryness, alphanumeric characters were printed on commercially available continuous slip paper using a printer, and then 10.20.30.40.
After 50 and 60 seconds, filter paper [Toyo Paper Co., Ltd., No. 2 (
(trade name)] and the judgment was made based on the number of seconds until the printed area became clean (measured at 20 copies at 5°C and 50 copies at 10% RH).

○...within 15 seconds △...16-30 seconds , stop printing, apply a cap and leave it for 30 days (Leaving conditions: 260℃ and 10 parts 5%
After RH) t, a nozzle clogging recovery operation was performed, alphanumeric characters were printed again, and judgment was made based on the number of recovery operations until the initial printing condition could be reproduced.

0: Printing equivalent to the initial value is possible without recovery operations.

○...Printing equivalent to initial printing is possible after 1 to 5 recovery operations.

△...Printing equivalent to the initial state is possible after 6 to 10 recovery operations.

×...Printing equivalent to the initial one is possible after 11 or more recovery operations.

(3) Print quality evaluation After printing on commercially available copy paper (XEROX 4024), leave it for more than an hour, and then there will be no bleeding at the dot level.
Edge sharpness was evaluated under environmental conditions of 25° C. and 60% RH.

○...The edges are sharp.

△: Some bleeding is seen, and the edges are also a little blurred.

×: There is a lot of blurring (dots and edges are blurred.

(Hereinafter referred to as the margin) 1'=J's (effect) As explained above, according to the ink of the present invention, it can be printed on plain paper commonly used in offices such as copy paper, report paper, notebooks, and stationery. However, it is possible to obtain records with excellent print quality and good permeability without bleeding.

Further, according to the present invention, highly reliable recording can be performed without clogging of the pen tip of a writing instrument or the nozzle of an inkjet head.

Procedure Nefu Seisho (self-motivated) April 12, 1990

Claims (1)

[Claims] (1) Ink containing a water-soluble dye, a water-soluble organic solvent, and water, the content of the water-soluble organic solvent being 1 to 40% by weight, and containing a compound represented by the following general formula (I). An ink featuring ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (I) (However, R_1 represents a carboxyl group, an aryl group, or an aryl group substituted with a hydroxyl group, a carboxyl group, a sulfonic acid group, a sulfamoyl group, an amino group, or an acetylamino group. , R_2, R_3 or R_4 is an alkyl group or a hydroxyalkyl group, and R_2, R_3 or R
Any one of _4 may be a hydrogen atom. )