JP2520658B2 - Water based ink - Google Patents

Description

TECHNICAL FIELD The present invention relates to a water-based ink excellent in abrasion resistance without aggregation of dyes and / or pigments and excellent in writing performance.

(Conventional technology and its problems) Conventionally, water-based inks, especially water-based inks for ball-point pens, have been used with various lubricants to prevent abrasion of the ball seat. Since problems such as agglomeration occur, it is not possible to add an amount sufficient to obtain a sufficient lubrication effect, and there is a problem that the bearing wear is large and the writing distance is short.

(Means for Solving Problems) The present invention has been made in view of the above-mentioned problems, and a dye and / or a pigment and 0.001
To 1.0% by weight of the compound represented by the following general formula, 0.01 to 1.5% by weight of the total amount of the ink, a water-soluble amine salt or sodium salt of a carboxylic acid having 9 to 20 carbon atoms, a water-soluble organic solvent, and water. The subject is a water-based ink comprising at least

The present invention will be described in detail below.

The compound represented by the above general formula is used as a lubrication aid, and the addition amount is 0.001 to 1.0% by weight.
This is because if it is less than 001% by weight, the effect as a lubricating aid cannot be obtained, and if it is more than 1.0% by weight, bleeding becomes large.

In the general formula, n is in the range of 5 to 15 because the effect of lubricity cannot be obtained when it is 4 or less, and it becomes difficult to dissolve it in water when it is 16 or more, and it dissolves in water when R is C ₅ or more. Since it becomes difficult to do so, the range of C _{1 to} C ₄ is appropriate.

The water-soluble amine salt or sodium salt of carboxylic acid having 9 to 20 carbon atoms is used as a lubricant, and its addition amount is preferably 0.01 to 1.5% by weight. If it is less than 0.01% by weight, the lubricating effect cannot be obtained. If it is more than 1.5% by weight, dyes and pigments agglomerate.

The carbon number of the carboxylic acid is 9 to 20 because the carbon number is 9
If it is smaller than 20, sufficient lubrication effect cannot be obtained, and if it is larger than 20, it is difficult to dissolve in water.

The carbon number of the carboxylic acid in the present invention does not include the carbon of the carboxyl group.

Examples of the water-soluble amine salts of carboxylic acids include capric acid, undecylic acid, lauric acid, myristic acid, palmitic acid, stialic acid, oleic acid, linoleic acid, dimer acid, oleoylsarcosine, naphthenic acid, and linolenic acid. Salts such as monoethanolamine, diethanolamine, triethanolamine, aminomethylpropanol and aminomethylpropanediol are used.

Dyes and / or pigments are used as colorants, and are commonly used basic dyes, acid dyes,
Dyes such as direct dyes and pigments such as inorganic pigments and organic pigments can be used alone or in combination.

When the colorant contains a pigment, various dispersants such as anionic activators, nonionic activators and polymer activators can be used alone or in combination, and as a dispersion stabilizer, glue etc. These water-soluble natural polymers and water-soluble polymers such as Poval can be used alone or in combination.

As the water-soluble organic solvent, glycols such as ethylene glycol and propylene glycol, glycol ethers such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether, and the like can be used alone or in combination.

Other antiseptics, rust preventives, etc. can be appropriately selected and used according to the purpose.

(Function) It is not clear why the water-based ink according to the present invention is excellent in lubricity and there is no aggregation of dyes and pigments, but it is presumed as follows.

That is, the compound represented by the above general formula makes it possible to sufficiently supply the ink to the ball seat, and as a result, an ink layer is formed between the ball and the seat, so that the carbon number of the lubricant is 9 to 9
The water-soluble amine salt or sodium salt of 20 carboxylic acids is 0.
It is presumed that even with a small amount of 01 to 1.5% by weight, a sufficient circulation effect can be obtained, seat wear is small, and there is no aggregation of dyes and pigments.

(Example) The following will describe the present invention in more detail with reference to Examples,
In the comparative examples, simply "parts" means "parts by weight".

Example 1 The above components were mixed, heated to 40 to 50 ° C, and stirred for 2 hours to obtain a black aqueous ink.

Comparative Example 1 of Example 1 Except that the amount of water was increased, and a black aqueous ink was obtained in the same manner as in Example 1 except that the amount of water was increased by that amount.

Example 2 The above components were blended and dispersed in a ball mill for 30 hours, and then coarse particles of carbon black were removed by centrifugation to obtain a black aqueous ink.

Comparative Example 2 of Example 2 Except that the amount of water was increased, and a black aqueous ink was obtained in the same manner as in Example 2.

Example 3 The above components were mixed, heated to 40 to 50 ° C, and stirred for 3 hours to obtain a red aqueous ink.

Comparative Example 3 of Example 3 Example 1 except that the water content was increased to 1.5 parts and the water content was reduced to 1.495 parts.
A red aqueous ink was obtained in the same manner as in.

Example 4 A red aqueous ink was obtained in the same manner as in Example 2 except that the above components were blended.

Comparative Example 4 The sodium salt of stearic acid of Example 4 was added to 2.0 parts,
A red aqueous ink was obtained in the same manner as in Example 4 except that 1.5 parts of water was reduced.

Example 5 A blue aqueous ink was obtained in the same manner as in Example 1 except that the above components were mixed.

Comparative Example 5 A blue aqueous ink was obtained in the same manner as in Example 5, except that the monoethanolamine palmitate of Example 5 was removed and the amount of water was increased by that amount.

Example 6 The above components were blended and dispersed in a sand mill for 3 hours, after which coarse particles of CI Pigment Blue 15 were removed by centrifugation to obtain a blue water-based ink.

Comparative Example 6 of Example 6 Was obtained in the same manner as in Example 6 except that 1.4 parts of triethanolamine arachidate was increased to 1.8 parts and 2.28 parts of water was decreased.

(Effect) 2.0 g of the water-based inks obtained in Examples 1 to 6 and Comparative Examples 1 to 6 were filled in a commercially available water-based metal ballpoint pen (Super Ball BH16, manufactured by Pentel Co., Ltd.), and a writing test was conducted.

The result of measuring the writing distance and ball sinking by the writing test,
The results of the heat resistance test and bleed test of the ink are shown in Table-1.
It was shown to.

As described above, the water-based ink of the present invention is excellent in lubricity, has a long writing distance, and is an excellent water-based ink that prevents aggregation due to dyes and pigments.

The water-based ink of the present invention can be used not only for the above-mentioned ballpoint pen but also for various writing instruments such as a needle pen and a resin pen, or for a recorder.

Claims (1)

(57) [Claims] 1. A dye and / or pigment, and 0.001 to 1.0% by weight of a compound represented by the following general formula with respect to the total amount of the ink:
A water-based ink comprising at least 0.01 to 1.5% by weight of a water-soluble amine salt or sodium salt of a carboxylic acid having 9 to 20 carbon atoms, a water-soluble organic solvent and water.