JPH07166121A - Ink composition for aqueous ball-point pen - Google Patents

Abstract

PURPOSE:To obtain a composition capable of smoothly starting writing, having excellent writing performance, not becoming blurred, sufficiently standing use even in writing upward by adding a specific amount of an amine salt or a Na salt of a specific vinylpyrrolidone-acrylic acid polymer. CONSTITUTION:This composition comprises a dye or a pigment as at least colorant, a water-soluble organic solvent (e.g. ethylene glycol) as a solvent, water, optionally a rust preventive, a water-soluble resin and further 0.1-5% of an amine salt or a Na salt of a vinylpyrrolidone-acrylic acid polymer of the formula (X:Y=25-75:75-25; R is NH2 or Na).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink composition for water-based ballpoint pens, more specifically, it enables smooth writing, has a good writing feel, does not fade, and can withstand sufficient use even when written upwards. The present invention relates to an ink composition for a water-based ballpoint pen that can be used without using a mechanism such as a bellows mechanism required for a conventional water-based ballpoint pen.

[0002]

2. Description of the Related Art Conventionally, oil-based inks have been generally used for ball-point pens, but in recent years, water-based inks have become commercially available, and even if it is called a ball-point pen, it is divided into oil-based ball-point pens and water-based ball-point pens depending on the ink used. In reality. These oil-based ball-point pens and water-based ball-point pens have their respective advantages and disadvantages in their production method and use performance. In the manufacturing method, the oil-based ballpoint pen is very simply constructed by simply joining the tip to the hollow ink storage tube filled with ink, whereas in the water-based ballpoint pen, it is a porous or molded capillary tube called a relay core. In addition, an ink distribution conductor part for holding the ink is required, and further, a bellows-like part for controlling the ink flow or a part made of a fiber bundle called batting for absorbing the ink is required. In terms of usage performance, the oil-based ballpoint pen has no bleeding and has a line width narrower than the diameter of the ball used, but the writing start is slightly heavier than that of the water-based ballpoint pen, and the ink consumption is low, so the handwriting is thin. The ink tends to leak due to its high viscosity, and writing with the pen tip facing upward makes writing impossible. On the other hand, a water-based ballpoint pen can be written well from the beginning, and even with the pen tip facing upward, it can be written without problems, and since it consumes a large amount of ink, it gives thick handwriting, but the viscosity is low, so the handwriting is thicker than the diameter of the ball. Prone. As a ball-point pen ink having both advantages, a ball-point pen of medium viscosity water-based ink called neutral ball-point pen has recently appeared. That is, it has a structure such as an oil-based ballpoint pen, and its writing performance is extremely smooth like a water-based ballpoint pen. This medium-viscosity water-based ink is a conventionally known water-based ink with a water-soluble resin, a high-viscosity water-soluble organic solvent, etc.
The viscosity is increased from (20 ° C) to about 10 to 1000 cp (20 ° C).

[0003]

However, when a conventionally known water-based ink is simply thickened with a water-soluble resin, a high-viscosity water-soluble organic solvent, etc., when writing with the pen tip facing upward, the same writing as an oil-based ballpoint pen is performed. It becomes impossible. This phenomenon is that when writing with the pen tip facing upward, the ink in the ink storage tube is affected by gravity in the opposite direction of the pen tip, and the ink consumed by the pen tip cannot be supplied and writing becomes impossible. Is.

[0004]

The gist of the present invention is an ink composition for a water-based ballpoint pen which has a structure such as an oil-based ballpoint pen and is thickened to about 10 to 1000 cp (20 ° C.) to enable upward writing. is there. That is, in the present invention, the following chemical formula 2 is added to the conventionally known ink for water-based ballpoint pens.
The viscosity of the ink is 10 to 1000 cp (20 ° C) by adding 0.1 to 5% of the amine salt or / and sodium salt of vinylpyrrolidone represented by
It thickens to a certain degree and enables upward writing.

[0005]

[Chemical 2] Here, X: Y = 25 to 75:75 to 25, and R represents NH ₂ or / and Na.

Although the detailed reason for this is not clear, the ink is prepared by adding 0.1 to 5% of the vinylpyrrolidone and the amine salt or / and sodium salt of the acrylic acid polymer used in the present invention to the ink for water-based ballpoint pens. It has a spinnability, and by writing upward, even if the ink in the ink storage tube is affected by gravity in the opposite direction to the pen tip, the ink at the pen tip pulls the ink in the ink storage tube and the ink does not easily run out. It is presumed that it becomes possible to write upwards and to write upwards. Next, the present invention will be described in more detail. The amount of vinylpyrrolidone and amine salt or / and sodium salt of acrylic acid polymer used is 0.1 in the ink composition.
~ 5%. If the addition amount is less than 0.1%, the ink does not show spinnability, and if the addition amount is more than 5%, the viscosity of the ink becomes too high and the flow of the ink tends to be inhibited. As the components other than vinylpyrrolidone and the amine salt and / or sodium salt of the acrylic acid polymer of the water-based ballpoint pen ink of the present invention, conventionally known materials may be preferably used. That is, the water-soluble organic solvent and / or water should be suitably selected as a dye dissolving agent for ink, a viscosity adjusting agent, and an anti-drying agent for ink. The water may be tap water or ion-exchanged water, but distilled water is preferable from the viewpoint of rust prevention in the case of a ballpoint pen using metal parts. Examples of the water-soluble organic solvent include glycols such as ethylene glycol, propylene glycol, diethylene glycol, and triethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, glycol ethers such as 3-methylmethoxybutanol, and the like. Ethylene glycol monomethyl acetate, glycerin,
1.3.5-Pentatriol, triethanolamine, etc. can be mentioned. The colorant used in the present invention can be suitably used as long as it can be dissolved or uniformly dispersed in an aqueous medium containing water or / and a water-soluble organic solvent. For example, Naphthol Yellow S (C.I. 1
0316), Tartrazine (C.I. 19140), Sunset Yellow (C.I. 15985), Eosin G
H (C.I. 45380), Neucoccin (C.I.
16255), Acid Phloxine PB (C.I. 45)
410), cyanine green 5G (C.I. 626)
0), and acidic dyes such as Nigrosine BR (CI.50420), Scarlet GSH (CI.2916).
5), Direct Sky Blue 5B (C.I. 2440)
0), Villet BB (C.I. 27905), and direct dyes such as Deep Black EX (C.I. 30235), Flavin 8G (C.I. 49005), Methyl Violet (C.I. 42535), Crystal. Violet (C.I. 42555), and Rhodamine (C.I.
I. 45160), organic dyes such as basic dyes, azo dyes, phthalocyanine dyes, quinacridone dyes, anthraquinone dyes, quiocosadine dyes, indico / thioindico dyes, perinone / perylene dyes, cadmium dyes, titanium oxide, carbon black, etc. I can give you. Other rust preventives for metal parts, lubricants for smooth writing performance, surfactants for adjusting the surface tension of the ink, and preservatives for preventing the ink from spoiling can also be added. It does not interfere with the present invention.

[0007]

The present invention will be described more specifically with reference to the following examples. Example 1 The following components were mixed and dispersed in a ball mill for 24 hours, and then filtered with a 1 μm filter to give a viscosity of 1
A black aqueous ballpoint pen ink of 00 cp (25 ° C.) was obtained. Comparative Example 1 A black aqueous ballpoint pen ink having a viscosity of 100 cp (25 ° C.) was obtained in the same manner as in Example 1 except that polyvinylpyrrolidone and an amine salt of an acrylic acid polymer were not added and polyvinyl alcohol was added instead. Example 1 Comparative Example 1 Carbon black 10.0 parts 10.0 parts Pigment dispersant 5.0 5.0 Ethylene glycol 20.0 20.0 Glycerin 14.0 14.0 Water 50.3 50.3 Rust inhibitor 0.1 0.1 Vinylpyrrolidone and amine salt of acrylic acid polymer 1.0-Polyvinyl alcohol-1.0 Example 2 The following components were mixed, dissolved in a stirrer for 6 hours, and then filtered with a 1 μm filter. , Viscosity 80cp (25 ℃)
To obtain a red water-based ballpoint pen ink. Comparative Example 2 A red aqueous ballpoint pen ink having a viscosity of 80 cp (25 ° C.) was obtained in the same manner as in Example 1 except that vinylpyrrolidone and the sodium salt of an acrylic acid polymer were not added and polyvinyl alcohol was added instead. Example 2 Comparative Example 2 Neucoccin (CI. 162555) 8.0 parts 8.0 parts Ethylene glycol 20.0 20.0 Glycerin 14.0 14.0 Water 57.3 57.3 Anticorrosion agent 0 0.1 Sodium salt of vinylpyrrolidone and acrylic acid polymer 1.0-Polyvinyl alcohol-1.0 When the ink obtained in each of the above Examples and Comparative Examples was filled in a ballpoint pen and written upward, We compared their writing performance. Example 1; upward writing possible Comparative Example 1; upward writing impossible Example 2; upward writing possible Comparative Example 2; upward writing not possible

[0008]

As described above, according to the present invention, by adding vinylpyrrolidone and an amine salt or / and sodium salt of an alcohol acid polymer, the pen tip is turned upward as seen in each of the above examples. I was able to write smoothly until I ran out of ink without being unable to write.

Claims (1)

[Claims] 1. A water-based ballpoint pen ink comprising at least a dye or / and a pigment as a colorant, a water-soluble organic solvent or / and water as a solvent, and optionally a rust preventive agent and a water-soluble resin. An aqueous ink composition for a ball-point pen, wherein the vinylpyrrolidone represented by Formula 1 and an amine salt or / and a sodium salt of an acrylic acid polymer are added in an amount of 0.1 to 5%. [Chemical 1] Here, X: Y = 25 to 75:75 to 25, and R represents NH ₂ or / and Na.