JPS5855995B2 - Water-based ink composition for ballpoint pens - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a water-based ink composition for ball-point pens that is free from smearing and has good ink flow, particularly to a water-based ink composition for ball-point pens that causes less wear on the tip and ball.

Conventionally, ink for ballpoint pens, generally referred to as oil-based ink, is a high-viscosity ink in which oil-soluble dyes, resins, and additives are dissolved in an oil-based ink solvent.

Since it is an oil-based and highly viscous ink, if you fill a ballpoint pen with ink and write on it, you will get a writing line that is water resistant and does not bleed, but the ink that adheres to the ball at the beginning of writing may stick to the writing line. It may not be possible to write due to the nature of the paper.

In order to improve this shortcoming, a ballpoint pen using water-based ink was developed.

The writing part of the ballpoint pen consists of a metal or resin tip and a metal or jewel ball.

Therefore, when ink is filled into the ink filling portion and used for writing, the ink must be supplied from the space between the tip and the ball by the rotation of the ball.

An oil-based ink with a relatively high viscosity is required to ensure smooth ink supply and prevent chip and ball wear.

On the other hand, when using water-based ink for ballpoint pens,
■The ink does not come out smoothly due to its low viscosity.

■If you use direct dye in the ink to prevent bleeding,
Colloidal particles of dye accelerate the wear of the tip and ball; ■ Even if water-based ink is thickened and used as a highly viscous ink such as oil-based ballpoint pens, it does not have the threadability performance that oil-based ballpoint pens have; Water-soluble thickeners have disadvantages such as binding with dyes, causing aggregation and precipitation.

As a result of intensive research into an ink composition that overcomes these drawbacks, the present inventors have found that the properties required for a water-soluble ballpoint pen ink are as follows: By selecting a suitable agent, the dissolved dye does not precipitate ■ It has a thickening effect and also has the effect of solubilizing the dye ■ The viscosity characteristic of water-soluble ballpoint pen ink is stringy ■ The action of a lubricant This shows the effect of reducing the wear resistance of the tip and ball.

Based on this knowledge, they succeeded in obtaining a water-soluble ballpoint pen ink similar to the oil-based ballpoint pen ink of the present invention by blending additives.

The present invention is a water-based ink composition for a ballpoint pen, which comprises blending 0.1 to 10% by weight of polyethylene oxide into an aqueous solution of a water-soluble dye.

If the amount of polyethylene oxide used is less than 10% by weight, there will be no stringiness or thickening effect, and therefore the ink will not flow out smoothly, and if it is more than 10% by weight, the thickening effect will be significant, making it difficult to fill into a ballpoint pen. Even if the ink does not flow out.

The pH of the aqueous solution of polyethylene oxide is neutral,
There is no aggregation effect regardless of acid dyes, direct dyes, basic dyes, etc.

Water-based inks prepared from acidic or basic dyes are unsatisfactory in terms of bleed, but inks thickened by the addition of polyethylene oxide have less bleed properties and very low chip and ball wear. .

This is due to polyethylene oxide's stringiness, abrasion resistance reducing effect, and lubricant effect.

Polyethylene oxides having various average molecular weights ranging from 10,000 to 100,000 to 4,000,000 to 5,000,000 are suitable for the present invention.

Its method of use is to add a required amount of a 1 to 5% by weight aqueous solution of polyethylene oxide to an aqueous dye solution.

The viscosity of the water-soluble ink when added is 5 to 10,000 cp depending on the amount of polyethylene oxide added.

Aqueous dye solutions that can be used are obtained by dissolving acid dyes, direct dyes, and basic dyes in a water-soluble ink solvent and water.

As acidic dyes, CI Acid Yellow 3, CI Acid Yellow 7, CI Acid Yellow 11. 17, 76, CI Acid Orange 1, 7, 8, 10, 19, 24, 33, CI Acid Red 1, 6, 8, 9, 18, 26 ,
Same 27, Same 35, Same 87, CI Acid Violet 7, Same 11゜ Same 15, Same 34, Same 41, CI Acid Violet
Blue 1, 7, 9, 22, 25, 29, 4
0, 59, CI Acid Green 3, 9, 12
, 16, 19, 25, CI Acid Black 1
, 2, 7, 24, 26, 31, 48, etc.

Direct dyes include CI Direct Yellow 1, CI 8, 12, 26, 33, 50, CI Direct Orange 6, 10, 26, 39, 49, CI Direct Red 2, CI Direct 13, 23, 28, 46, C
I Direct Violet 1, 7, 12, 22
, CI Direct Blue 1, CI Direct Blue 6, CI Direct Blue 15, CI Direct Blue 25,
CI Direct Green 1, 28, CI Direct Brown 2, 25, CI Direct Black 17
, 19, 22, 32, 38, 51, etc.

As basic dyes, CI Basic Yellow 1, CI Basic Yellow 2,
Same 11. CI Basic Orange 2, 14, 21
, CI Basic Red 1, CI Basic 12, CI Basic Violet 1, CI Basic 3, CI Basic 7, CI Basic Flu 1, CI Basic 3, CI 5, CI 9, CI Basic 26, CI Basic Green 1, CI 4, CI Basic 6 etc.

Next, water-soluble ink solvents include glycols such as ethylene glycol, diethylene glycol, and triethylene glycol, cell solders such as methyl cellosolve, ethyl cellosolve, and butyl cellosolve, carbitols such as methyl carbitol, ethyl carbitol, thiodiglycol, and acid amides. 10 to 40% by weight, preferably 1 or more of formamide, acetamide, etc.
Use 0-30% by weight.

Add preservatives and surfactants if necessary.

Next, the present invention will be demonstrated by examples, but of course the present invention is not limited to these examples.

Note that parts indicate parts by weight. Example 1 Isen Eosin GH Conc (manufactured by Hodogaya Chemical Co., Ltd., CI Acid Shi 5.0 parts Tsudo 87
) Ethylene glycol 20.0115% polyethylene oxide aqueous solution (viscosity 70 cp) C iron chemical column.

. ,. 7, PE0-1 (average molecular weight 100,000 to 150,000) used] Water 54.5 // Potassium sorbate (antifungal agent) 0.5 By stirring the above at room temperature, a red aqueous solution with a viscosity of 10 cp is obtained. Obtained ballpoint pen ink.

When a cationic water-soluble resin such as cationically modified polyacrylamide was added as a thickener instead of polyethylene oxide, precipitation occurred.

For comparison, we prepared an ink with the same composition as the ink of the example except that polyethylene oxide was not added, filled it into a ballpoint pen, and wrote on it.The tip and ball of the latter had more wear, and the writing distance was 2000 m compared to the former. against 1
000m or less.

Also, there was less smearing of the writing lines on the front side. Example 2 By stirring and dissolving the above ingredients, the viscosity was 250.
A cp blue water-based ballpoint pen ink was obtained.

This ink had excellent spinnability, and when filled into a ballpoint pen, the ink came out smoothly.

Anionic water-soluble resins instead of polyethylene oxide, such as polyacrylic acid, styrene-maleic acid 1:1
When a copolymer was used, a precipitate in which the dye and resin were combined was formed, making it impossible to use it as a water-based ink for metal ballpoint pens.

The ink of Example 2 has bleeding, abrasion, and writing distance compared to Example 1.
Similar effects were seen.

Example 3 By stirring and dissolving the above ingredients, the viscosity was 55.
A black water-based ballpoint pen ink of cp was obtained.

Direct dyes have very strong colloidal properties, and ballpoint pens filled with ink without polyethylene oxide had severe wear on the tip and ball, and the writing distance was less than half of that with ink added.

Further, no interaction between polyethylene glycol and the dye was observed, and no precipitate was formed.

Since the ink of the present invention is a water-based ink, it solves the disadvantages of oil-based ballpoint pens, such as smearing and inability to write on paper, and also has the characteristics of oil-based inks (no bleeding and less wear on chips and balls). The present invention provides an ink that also has the following properties.

As explained above, blending polyethylene oxide into an aqueous solution of a water-soluble dye has the advantage of imparting viscosity to the water-soluble ink, and further reducing the frictional resistance between the ball and the chip and providing a lubricating effect.

Claims (1)

[Claims] 1 Add 0% polyethylene oxide to an aqueous solution of water-soluble dye.
．． A water-based ink composition for a ballpoint pen, characterized in that it contains 1 to 10% by weight.