JPS6076576A - water-based pigment ink - Google Patents

Abstract

PURPOSE:To provide a water-based pigment ink having excellent dispersion stability and drying resistance, and suitable for the use in the state of low viscosity, e.g. for writing utensils, by adding a resin acid and a specific alkanolamine derivative to a water-based pigment ink. CONSTITUTION:The objective ink can be produced by mixing, grinding and dispersing (A) a pigment, (B) an alkanolamine derivative of formula (R1, R2 and R3 are H or lower alkanol) (e.g. monoethanolamine) or its addition product with 1- 50mol of ethylene oxide, (C) a resin acid such as shellac, (D) a water-soluble organic solvent such as glycol solvent, etc., and (E) water, etc. using a pigment dispersion machine. The preferable weight ratios of A:B:C:D:E are (5-20%): (0.05-20%):(1-30%):(10-30%):(70-40%). If necessary, the ink may be incorporated with 0.1-1% surfactant. USE:Writing utensils, fountain pen, recorder pen, printing, etc. using fiber tips, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an aqueous pigment ink, and more particularly to an aqueous pigment ink having excellent dispersion stability and drying resistance.

Conventionally, water-based pigment inks have excellent water resistance and light resistance, and have been used for valley printing purposes.

However, when used at low viscosity with writing instrument ink,
Pigment dispersibility is unstable and tends to aggregate.

There was a problem with not being able to write.

Therefore, it is used as a dispersant to disperse pigments.

Although various surfactants have been used, they are still not sufficient. In recent years, emulsions of acrylic acid copolymers, amines and ammonium salts of acrylic acid copolymers have also been used, but because emulsions dry quickly, they may dry on the nib of a writing instrument, for example, or may dry with some solvents. There was a problem that the emulsion was destroyed.

Furthermore, particularly for ink for writing instruments, it is necessary to prevent drying at the pen tip as much as possible.

As a result of various studies as an agent for improving the dispersibility and drying resistance of the above-mentioned aqueous pigment ink, the present inventors have found that the combination of resin acid and alkanolamine derivatives is effective in improving the dispersibility and drying resistance of the water-based pigment ink. The present invention has been completed based on the discovery that the present invention is excellent in the following properties.

That is, one aspect of the present invention is a water-based pigment ink characterized by containing a resin acid and an alkanolamine derivative represented by the following general formula.

The general formula resin acid is 1. It has been applied to pigment inks for a long time, but
This utilizes the film-forming ability of resin acids.
When a large amount of it is used in a writing instrument, there are problems in that if it dries at the tip of the pen, it becomes impossible to write, and the taste of T4 becomes bad.

Therefore, in the present invention, a resin acid is used as a dispersant and a salt is formed with the resin acid.

The above-mentioned problems are solved by using an alkanolamine derivative that prevents resin acid from forming a film and has an effect on drying resistance.

Hereinafter, one aspect of the present invention will be explained in detail.

Examples of the resin acid include shellac such as general shellac, dewaxed shellac, bleached shellac, and bleached shellac, humic acid, and rosin.

Examples of the compound represented by the general formula include monoethanolamine, jetanolamine, triethanolamine, and adducts of these with 1 to 50 moles of ethylene oxide.

As the pigment, all commercially available pigments can be used, and here are some examples.

Carbon blank, phthalocyanine blue (C, T, 7
4160), phthalocyanine green (0, ■, 7
4260), Hansa Yellow 5 G (C, I.

11670J, Disazo Yellow G It (0,1,2
1100), 4 liters of permanent red (0, 1, 12 tons red (0, 1, 46500), etc.)

The amount used is preferably 5 to 20% by weight based on the total amount of ink.

Incidentally, the proportion of each type of pigment to be used is selected as appropriate.

As the bath agent, not only water but also water-soluble organic solvents such as non-solvent glycol, glycol ether solvents, glycol ether ester solvents, glycerin, and pyrrolidone can be used.

In addition, 12-benzisothiazolin-3one, pentachlorophenol, cresolnato preservatives, and 1
Lubricants such as water-soluble silicone oil and various surfactants can be appropriately selected and used.

The manufacturing method of water-based pigment ink is as follows: 5 to 20% by weight of pigment, 7% of water.
0 to 40% by weight, water-soluble organic solvent 10 to 30% by weight, resin acid 1 to 30% by weight, A (To improve pigment wetting, surfactant may be used at 01 to 1% by weight. .)
And.

Ball mill, roll mill, sand mill, super mill,
Using a pigment dispersion machine such as a Dynomil water attritor,
Mix, grind and disperse.

The aqueous pigment ink thus obtained has unprecedented dispersion stability.

Hereinafter, the present invention will be described in detail based on Examples, where "parts" in the Examples indicate "parts by weight."

Example 1 Carbon black 10.0 parts Propylene glycol 5 o parts Ethylene glycol 15.0 parts Shellac 2.0 parts Monoethanolamine 20.0 parts Uverin (Daiichi Kogyo Seiyaku Co., Ltd., anionic surfactant) 0.1 parts Emulgen 931 (Kao Atlas (prepared, nonionic surfactant) 01 parts Sodium pentachlorophenol (preservative) 01 parts Water 47.7 parts Among the above ingredients, add rank 7 to a bath solution of water and monoethanolamine and stir at room temperature. Stir and dissolve. 3. Next, add Emuldan 931. Ethylene glycol and Zanto ingredients one after another.
After premixing with a stirrer for 2 hours and grinding with a ball mill for 20 hours, coarse particles are removed by filtration or the like.

The black aqueous pigment ink obtained in this way was filtered through Toyo Roshi A 5 C by suction of 1 (] Oml).
The entire amount passed through the filter paper within 0 seconds.

Almost no residue was observed on the paper.

Also, use this ink in a centrifugal separator.

rpm for 30 minutes, but no pigment sedimentation was observed.

Furthermore, fill a ballpoint pen with this ink, remove the cap, and leave it in a constant temperature and humidity room at a temperature of 20° C. and a humidity of 65% for 10 days.

The pen tip did not dry out and writing was possible.

Comparative Example 1 A water-based pigment ink was obtained in the same manner as in Example 1 except that shellac was removed and water was added. This ink has many coarse particles.

It was not possible to filter with Toyo Roshi A5c.

Example 2 Copper phthalone anine blue 15.0 parts Ethylene glycol 15.0 parts Propylene glycol 50 parts Decolorized shellac 10 parts Noethanolamine io, o part Groxel G BX (manufactured by 1,0,1).

Preservative 01 parts Water 539 parts Same as Example 1 1. '4% (i premix.

Mixed in a sand mill for 10 hours and crushed to 1λ.

Coarse particles were removed to obtain a blue water-based pigment ink.

When this ink was suction filtered through Toyo Roshi A 5 C for 100 m/suction, the entire amount passed through the filter paper within 30 seconds, and no residue was observed on the filter paper.

Also, this ink is s, oo in a centrifuge.

rpm for 30 minutes, but no pigment sedimentation was observed.

Furthermore, you can fill a ballpoint pen with this ink, remove the cap, and leave it in a constant temperature and humidity room at 20°C and 65% humidity for 10 days.

The pen tip did not dry out and writing was possible.

Comparative Example 2 A water-based pigment ink was obtained in the same manner as in Example 2 except that jetanolamine was removed and water was added. The pen tip of this ink dried in one day under the same conditions as in Example 2.

Example 3 a""'+'ffl r't~Nomasogol. 10
0 parts Disazo Yellow - 50 parts Glycerin 20 parts Ethylene glycol 200 parts Humic acid 20 parts 20 moles of ethylene oxide adduct of monoethanolamine 100 parts Emulgen A-60 (manufactured by Kako Soap ■, nonionic surfactant) 01 parts Water 509 parts A water-based pigment ink of color N was obtained in the same manner as in Example 1.

When this ink was subjected to 10 row suction filtration using Toyo Roshi Ama 50, the entire amount passed through the filter paper within 30 seconds, and almost no residue was observed on the filter paper.

Also, use this ink in a centrifugal separator.

rpm for 30 minutes, but no pigment sedimentation was observed.

Furthermore, fill a ballpoint pen with this ink, remove the cap, and heat it to a temperature of 20°C, f! Even if I leave it in a constant temperature and humidity room at 65% for 10 days.

The pen tip did not dry out and writing was possible.

As explained above, the aqueous pigment ink of the present invention using a resin acid and an alkanolamine derivative has excellent 1-dispersion and 5-dispersion stability, and has good drying resistance, so it can be particularly used as a low-viscosity ink.

Specifically, it can be suitably used for fibers, felt, and monofilament writing instruments, capillary type writing instruments such as fountain pens, narrow rod type and ball point type writing instruments, and further for recorders, printing, and stamps. It can also be applied to jet printers.

Patent applicant: Pentel Co., Ltd.

Claims (1)

[Scope of Claims] An aqueous pigment ink comprising a resin acid and an alkanolamine rust conductor represented by the following general formula. general formula