JPH0542469B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an aqueous pigment ink used for writing instruments, recorders, printing, stamps, jet printers, and the like.

(Prior art) Conventionally, when water-based pigment inks have been used as ink for writing instruments, especially ballpoint pens with metal tips, the tips not only corrode and damage the appearance, but also lead to blurred handwriting, squeaks, and poor writing quality. This was the trend.

Generally, cutting metal is used as the material for the metal tip for ballpoint pens due to its precision machining.
Ferritic and martensitic stainless steels, nickel silver, and brass are mainly used, but even stainless steels that are considered to be resistant to corrosion may corrode over a long period of time. Therefore, for water-based pigment inks used in metal tip ballpoint pens, it is necessary to use a rust preventive agent appropriate for the type of metal from among various rust preventive agents such as inorganic acid, organic acid, and amino acids. .

The present inventors investigated various rust preventive agents and found that amino acid type and/or amino acid derivative type rust preventive agents are effective. However, when the rust preventive agent was added to a water-based pigment ink, a new problem occurred in that the pigment dispersion was broken and agglomerated.

(Objective of the Invention) The object of the present invention is to obtain an aqueous pigment ink that does not impair rust prevention ability and has stable pigment dispersion.

(Structure of the Invention) As a result of extensive research, the present inventors have found that by using an amino acid type and/or amino acid derivative type rust preventive agent as a water-soluble alkanolamine salt, the rust preventive ability is not impaired and the pigment is dispersed. It was discovered that a stable aqueous pigment ink could also be obtained, and the present invention was completed. That is, the gist of the present invention is a water-based pigment ink characterized by containing a dispersant and a water-soluble alkanolamine salt of an α-β amino acid type and/or its derivative type rust preventive agent. It is something to do.

Each component of the present invention will be explained below.

The water-soluble alkanolamine salt of the amino acid type and/or amino acid derivative type rust preventive agent is added to the water-soluble alkanolamine described below or an aqueous solution thereof at room temperature or while stirring under heating in an equivalent amount of the amino acid type and/or amino acid derivative type rust preventive agent.
Alternatively, it can be obtained by injecting an amino acid derivative type rust preventive agent and stirring for about 5 to 60 minutes. The mechanism of this effect is presumed to be that the amino acid consumes the dissolved oxygen necessary for corrosion, or that the lone pair of electrons on the nitrogen atom of the amino acid derivative acts effectively on the metal without self-association, facilitating smooth adsorption. be done.
In addition, the amount used is approximately equivalent to the amount of amino acid type or amino acid derivative type rust preventive agent based on the total amount of ink.
Suitable results are obtained when using 0.01 to 10% by weight, preferably 0.1 to 5% by weight.

Examples of the amino acid type and/or amino acid derivative type rust preventive include alkylalanine, alkylglycine, alkylylsarcosine, alkylaminopropionic acid, and the like.

Examples of water-soluble alkanolamines include monoethanolamine, diethanolamine, triethanolamine, amine methylpropanol, and aminomethylpropanediol.

Inorganic pigments and/or organic pigments are used as pigments, and specific examples include carbon black, phthalocyanine blue, phthalocyanine green, Hansa Yellow, Disazo Yellow, Permanent Red 4R, Brilliant Carmine 6B,
Brilliant scarlet, quinacridone red, etc. can be used, and these can be used alone or in a mixture of two or more, and the amount used is preferably 3 to 20% by weight based on the total amount of the ink.

The dispersant is a commonly used dispersant, such as an acrylic acid and/or acrylic acid emulsion,
Vinyl acetate emulsions, natural resin acids, nonionic surfactants, anionic surfactants, etc. can be used.

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

In addition, antiseptic and fungicides, surface tension and viscosity regulators, complementary color dyes, and the like can be selected and used as appropriate.

Pigment ink is dispersed by mixing, grinding, and dispersing using a dispersing machine such as a ball mill, roll mill, sand mill, super mill, Dyno mill, or attritor.

When the water-based pigment ink obtained in this way is used in writing instruments, such as metal tip ballpoint pens,
Even if you leave it for a long time, you can write comfortably without corroding the tip, blurring your handwriting, or making any squeaks. or,
Even when used as an inkjet printer, good effects were obtained without corroding the nozzle.

(Examples and effects of the invention) Hereinafter, the present invention will be explained based on examples, and in the examples, "parts" indicates "parts by weight."

Example 1 Carbon black 5 parts Ethylene glycol 20 parts Julymer ET-410 (acrylic emulsion,
Nippon Junyaku Co., Ltd.) 20 parts Caustic soda 0.2 parts Nitcol Sarcosinate OH (N-oleyl sarcosine, Nippon Surf Actant Co., Ltd.) 5 parts Monoethanolamine 1 part Water 48.8 parts Among the above ingredients, water Dissolve the caustic soda, then add ethylene glycol, Dulymer ET-410, and carbon black, stir and premix.
After 20 hours of mixing and grinding in a ball mill, a mixture of Nitcol Sarcosinate OH and ethanolamine was added, and the same treatment was continued for another 1 hour. A water-based pigment ink was obtained.

Fill a metal tip ballpoint pen with this ink,
After using it for 6 months, it was still possible to write smoothly, and the appearance of the tip was the same as when filled with ink, with no corrosion.

Comparative Example 1-1 In Example 1, Nitukol Sarcosinate
A black aqueous pigment ink was obtained in the same manner as in Example 1, except that OH and monoethanolamine were removed and water was added in the same amount.

Fill a metal tip ballpoint pen with this ink,
After 6 months of use, the tip became cloudy, made an unpleasant squeaking sound when writing, and noticed that the writing lines were skipped.

Comparative Example 1-2 A black aqueous pigment ink was obtained in the same manner as in Example 1, except that monoethanolamine was removed and water was added in the same amount.

Fill a metal tip ballpoint pen with this ink,
When I used it, my handwriting became blurry. When the ink was examined, agglomeration of the pigment was observed.

Example 2 Carbon black 7 parts Ethylene glycol 10 parts Ceramic GSN (Ceramic, manufactured by Gifu Ceramics Manufacturing Co., Ltd.) 5 parts Caustic soda 1 part Aminesuft HS-11 (N-stearoyl-L-
Sodium glutamate, manufactured by Ajinomoto Co., Inc.) 3 parts Aminomethylpropanol 1 part Emulgen A-60 (nonionic surfactant, manufactured by Kao Soap Co., Ltd.) 0.1 part Water 67.9 parts A water-based pigment ink was obtained.

When this ink was tested in the same manner as in Example 1, it was possible to write smoothly even after 6 months, and the appearance of the chips was not corroded and was the same as when filled with ink.

Comparative Example 2-1 A black aqueous pigment ink was obtained in the same manner as in Example 2, except that Amine Soft HS-11 and aminomethylpropanol were removed and water was added in the same amount.

When this ink was tested in the same manner as in Example 2, after 6 months, the tip became cloudy, an unpleasant squeaking sound was produced when writing, and the writing lines were also found to be skipped.

Comparative Example 2-2 A black aqueous pigment ink was obtained in the same manner as in Example 2, except that aminomethylpropanol was removed and water was added in the same amount.

When this ink was tested in the same manner as in Example 2, handwriting blurred. When the ink was examined, agglomeration of the pigment was observed.

Example 3 Copper phthalocyanine blue 10 parts Ethylene glycol 10 parts Diethylene glycol 5 parts Dyurimer ET-410 15 parts Caustic soda 0.1 part Clink PA-12 (alanine type activator, manufactured by Yoshimura Yukagaku Co., Ltd.) 2 parts Diethanolamine 1 part Water 56.9 parts A blue aqueous pigment ink was obtained using the same ingredients as in Example 1.

When this ink was tested in the same manner as in Example 1, it was possible to write smoothly even after 6 months, and the appearance of the chips was not corroded and was the same as when filled with ink.

Comparative Example 3-1 A blue water-based pigment ink was obtained in the same manner as in Example 3, except that Clink PA-12 and diethanolamine were removed and water was added in the same amount.

When this ink was tested in the same manner as in Example 3, the tip became cloudy after 6 months, an unpleasant squeaking sound was produced when writing, and skipping of the writing lines was observed.

Comparative Example 3-2 Except for diethanolamine in Example 3,
A blue aqueous pigment ink was obtained in the same manner as in Example 3, except that water was added in the same amount.

When this ink was tested in the same manner as in Example 3, handwriting blurred. When the ink was examined, agglomeration of the pigment was observed.

Example 4 Brilliant Scarlet 10 parts Ethylene glycol 20 parts Julymer ET-410 10 parts Serac GSN 3 parts Caustic soda 0.5 parts Garcon O (N-acyl sarcosine, Tetsuno Yuka)
Co., Ltd.) 5 parts Aminomethylpropanediol 1 part Water 50.5 parts A red aqueous pigment ink was obtained using the same ingredients as in Example 1.

When this ink was tested in the same manner as in Example 1, it was possible to write smoothly even after 6 months, and the appearance of the chips was not corroded and was the same as when filled with ink.

Comparative Example 4-1 A red aqueous pigment ink was obtained in the same manner as in Example 4, except that Galcon O and aminomethylpropanediol were removed and water was added in the same amount.

When this ink was tested in the same manner as in Example 4, after 6 months, the tip became cloudy, an unpleasant squeaking sound occurred when writing, and line skipping was observed in the writing lines.

Comparative Example 4-2 A red aqueous pigment ink was obtained in the same manner as in Example 4, except that aminomethylpropanediol was removed and water was added in the same amount.

When this ink was tested in the same manner as in Example 4, handwriting blurred. When the ink was examined, agglomeration of the pigment was observed.

As shown in Examples 1 to 4 above, the water-based pigment ink of the present invention has excellent rust prevention effects and pigment dispersibility over time, and is particularly suitable for use in metal tip ballpoint pens. It can also be sufficiently effective when used in inkjet printers using nozzles.

Claims (1)

[Claims] 1. An aqueous pigment ink comprising a dispersant and a water-soluble alkanolamine salt of an α-β amino acid type and/or its derivative type rust preventive agent.