JPS5815578A - Water ink - Google Patents

Abstract

PURPOSE:To obtain water ink which is improved in the drying resistance and would not precipitate crystals on a pen tip, by adding an w-hydroxy sulfonic acid derivative to an ink containing water and water-soluble dyes having no cation groups. CONSTITUTION:0.5-30wt% water-soluble dye (i) having no cation group (e.g. acid dyes such as Water Black #21, direct dyes such as Direct Deep Black EX), 1-50wt% w-hydroxy sulfonic acid derivative (ii) of the formula (wherein X stands for H, an alkali metal or NH4 and; n=1-20) and the balance of water or a mixture (iii) of water with a water-soluble organic solvent (e.g. glycol ethers) are mixed to obtain the intended ink. USE:For a fountain pen and a writing device having a pen point of fiber, felt or monofilament.

Description

[Detailed description of the invention] The present invention relates to water-based inks, and more particularly.

This invention relates to water-based ink with excellent drying resistance.

Traditionally, writing instruments, implements, and physically textiles and felt.

A writing instrument with a pen tip that uses monofilament.

In capillary writing instruments such as fountain pens, urea is added to the water-based ink composition to prevent solvents such as water from evaporating from the pen tip (improving drying resistance) when the cap is removed from the writing instrument body. An attempt was made to
It is having some effect. However, the drying resistance is still not sufficient, and urea is crystalline.

When used in large quantities, crystals precipitate at the nib, clogging the nib, causing problems such as blurred ink and clogging.

The present inventors have investigated various substances that do not have the above-mentioned problems of urea and have an effect greater than that of urea, and have found that the general formula H-(OOH20H2)n-8o5X
(X = 11, alkali metal + NH4i
The present invention has been completed by discovering a monohydroxysulfonic acid derivative represented by (1) (n=an integer of 1 to 20). That is, 1. the present invention comprises an ω-hydroquine sulfonic acid derivative represented by the general formula % NH4i (an integer of n-1"-2'0) (1), a water-soluble dye having no cationic group, The gist of the invention is a water-based ink comprising at least water.

It is not clear why the water-based ink of the present invention has higher drying resistance than the ink using urea and does not cause crystal precipitation at the pen tip, but it is speculated as follows.

That is, ω- represented by the general formula (1) used in the present invention
Since hydroquine sulfonic acid derivatives are non-crystalline and hygroscopic, they do not cause crystal precipitation at the pen tip even when used in large amounts.

Moreover, it has the effect of significantly increasing the solubility of dyes in solvents such as water, which improves the stability of the ink system.
It is thought that, in combination with the above-mentioned hygroscopicity, it improves the drying resistance of the ink.

Next, each component used in the present invention will be explained.

As water-soluble dyes without cationic groups, water-soluble acid dyes, direct dyes, and other dyes can be used. To give a specific example, as an acid dye, Eiseneosin QH (
0, I, 45380).

Water Pluck +21 (0,1,15985゜4
Mixed dye of 2090.42745), Negro = 3-/N N8 Conc (0,1,50420), Water Pruner 9 (0,1,42090), Water Pink≠2 (C1■, 45410), Kayaftatrazine ( a, ■, 1q 140), etc.
As a direct dye, Water Pinkna 100 (0,I
.

35255), Direct Deep Pluck EX
(0,1,35225), Direct Deep Black
These can be used alone or mixed as appropriate, and the amount used varies depending on the purpose, but when used as an ink for writing instruments, it is 0.5 to 0.5 to the total amount of ink.
60% by weight is preferred.

The monohydroxysulfonic acid derivative mentioned above is used for the purpose of imparting drying resistance to the ink. The amount used varies depending on the purpose, but when used as an ink for writing instruments, it is used in the total amount of the ink. 1 to 50% by weight
is preferably less than 11% by weight, the effect is small, and 50% by weight.
If the amount is more than 4% by weight, problems such as precipitation of dyes etc. may occur due to salting out effect.

Incidentally, if necessary, solvents such as glycol-based, glycol ether-based, glycol ether ester-based solvents, dimethyl sulfoxide, 2-pyrrolidone, and N-methyl-2-pyrrolidone may be used.

Alternatively, preservatives, rust preventives, urea, etc. may be selected and used as appropriate.

Next, a method for preparing the water-based ink of the present invention will be briefly described. The water-based ink of the present invention can be easily obtained by simply mixing and dissolving the above components, but it is more preferable to first mix water and a water-soluble organic solvent, and then add other components to the mixed solution to form an ink. This is the way to obtain. In addition, it is also possible to heat the mixture during stirring, if necessary.

The present invention will be explained in detail below based on examples.

In the examples, "parts" simply indicate "parts by weight."

Example 1 5- Water Pinkna 21 (0, I.

159 B 5. 42090. 42745 mixed dye, manufactured by Orient Chemical Industry ■) 6.5 parts Nigrosine NO
Conch (0,1,50420, manufactured by Sumitomo Chemical ■) 1.
0 parts Formalin (preservative) 1.0 parts Ethylene glycol 20.0 parts The above components were mixed and stirred for about 1 hour to obtain a black ink.

Comparative Example 1 A black ink was obtained in the same manner as in Example 1, except that urea was added in place of isethionic acid in Example 1.

Example 2 Water black ÷ 100 (0, 1, '35255
(manufactured by Orient Kagaku Kogyo ■) 6.5 parts Sodium pentachlorophenol (preservative) 1.0 parts 6-Ethylene glycol 20,000 parts ω-Hydroxyethoxyethoxyethoxyethanesulfonummonium salt (H(OOH20H2)5803NH4,)
20.0 parts water
525 parts In each of the above items, first mix water and ethylene glycol, then mix the remaining components into the mixture, and stir while heating to 40-50°C for about 1 hour to make black ink. I got it.

Comparative Example 2 A black ink was obtained in the same manner as in Example 2, except that urea was added in the same amount as the ω-hydroxyethoxyethoxyethoxyethanesulfonic acid ammonium salt in Example 2.

Example 3 Water Pruner 9 (manufactured by Orient Kagaku Kogyo ■) 6.0 parts Formalin (preservative) 1.0 parts Diethylene glycol 200 parts ω-Hydroxytetradecaethoxy 7-ethanesulfonic acid (H(001(20H2), 5806H)
30.0 parts water
46.0 parts Of the above components, water and ethylene glycol were first mixed, then the remaining components were mixed into the mixture, and the mixture was back-stirred for about 1 hour at room temperature to obtain a blue ink.

Comparative Example 3 A blue ink was obtained in the same manner as in Example 6, except that urea was added in place of ω-hydroquine tetradecane ethoxyethanesulfonate in Example 6.

Above are Examples 1 to 3. The drying resistance tests of the inks obtained in Comparative Examples 1 to 3 are shown in the table below.

<Table> *Drying resistance test examples 1 to 3. Fill a writing instrument with the ink obtained in Comparative Example 1 and leave it under conditions of a temperature of 20'C and a humidity of 65% with the cap removed.The time until the pen tip dries and becomes impossible to write is measured. It was measured.

As shown in the above test results, the ink of the present invention has excellent characteristics such as eliminating the drawbacks of conventional inks using urea and significantly improving drying resistance. Although the ink of the present invention has been described as being used for writing instruments, it can also be widely used for stamps, printing, recording, and jet printing.

Patent applicant: Pentel Co., Ltd. 10-

Claims (1)

[Claims] General formula +-+-(oarI2at-I2). -805X
(X = H, alkali metal, NH4i n ”
” A water-based ink comprising at least an ω-hydroquinesulfonic acid derivative represented by an integer J −=(1) of 1 to 20, a water-soluble dye having no cationic group, and water.