JPS6112773A - Ink composition for ball-point pen - Google Patents

Abstract

PURPOSE:The titled composition, obtained by adding a silicone block copolymer to an ink for ball-point pens containing an organic solvent, resin and colorant, capable of preventing the dropping of the ink and improving the extrusion properties. CONSTITUTION:An ink composition for ball-point pens obtained by adding preferably 0.1-1.0wt% silicone block copolymer which is a copolymer of dimethylsiloxane and ethylene oxide and/or propylene oxide to an ink for the ball-point pens containing at least one or more organic solvents, e.g. benzyl alcohol or dioxane, resin, e.g. vinyl resin or polyamide resin and colorant.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to an ink composition for a ballpoint pen.

In particular, the present invention relates to an ink composition for a ballpoint pen that prevents ink smudges peculiar to a ballpoint pen when writing and has good ink ejection properties.

(Prior art) Conventional gravity-fed ballpoint pen ink is considered to be almost a Newtonian fluid in the low shear velocity region, while it has only a slight thixotropic property in the high shear velocity region. Therefore, in order to prevent ink from leaking from the rear end of the ink storage tube or the nib, structural limitations were imposed on the settings of the ink storage tube's inner diameter, nib clearance, etc.

For ballpoint pens used under these conditions.

During continuous writing, some of the ink on the ball's surface comes into contact with the paper surface and is transferred, and the rest is scraped off by the tip of the nib and adheres to the nib. There is a problem of staining the surface, and improvements in this respect have been desired for some time.

In order to solve the problem of smudging peculiar to ballpoint pens, attempts have been made to impart thixotropic properties to the ink itself.

That is, the viscosity of the ink is reduced by the high shear force generated by the rotation of the ball during writing.

2. For example, 1. Solid fine particles such as carbon black or white carbon are added to commonly used ballpoint pen ink to obtain an ink with thixotropic properties with a large yield value. This is an attempt to do so. However, with such materials, the fluidity of the ink is poor (insufficient) when conventionally fed only by gravity, and new means such as pressurization must be taken.

A new inconvenience has arisen in that the ink does not eject properly.

(Problems to be Solved by the Invention) Based on the above knowledge, the present inventors have determined that 1. The occurrence of smearing in commonly used ballpoint pens is mainly caused by the large surface tension of the ink (approximately 40 dyn/(7)). As a result of various studies on additives that can reduce this surface tension and have no effect on ink ejection properties, we have developed the present invention. This is the completed version.

(Structure of the Invention) That is, the present invention provides a ballpoint pen ink comprising at least one organic solvent, at least one resin, and at least one colorant, and a soricone block copolymer. The gist of the present invention is an ink composition for a ballpoint pen, which is characterized in that it is formed by adding the following.

Hereinafter, nine aspects of the present invention will be described in detail.

The soricone block copolymer used in the present invention is
) An eight-unit combination of methylnoxane and ethylene oxide and/or propylene oxide, specifically L-720, L-7001, L-7002, L-75
00,L-7600,L-7602,L-7604(
that's all.

Examples include Nippon Unicar IV), and these can be used alone or in combination. The amount of silicone flock copolymer used is the total amount of the ink because the surface tension of the ink as a whole is too low.

Handwriting becomes more likely to smudge.

Further, the other main materials used in the present invention, ie, the organic solvent and the resin coloring agent, may be formulated by appropriately combining conventionally known materials. Specific examples include Henzl alcohol, glycol ethers, N-methyl-2-pyrrolidone, dioxin, isophoro/etc. as the organic solvent, and polyvinyl butyral as the resin.

Examples include vinyl resins such as polyhinylpyrrolidone, ketone-aldehyde condensation resins, polyamide resins, and colorants such as alcohol-soluble dyes and ili-soluble dyes. Incidentally, conventionally known lubricating additives such as oleic acid, butyl oleate, lauryl alcohol, etc. can be used in combination.

(Example) The present invention will be explained in more detail with reference to Examples, in which "parts" indicate "parts by weight".

Example 1 Benzyl alcohol 10.0 parts Phenyl glycol 40.0 parts SP Black 61
10.0 parts Paris First Violet 17
01 20.0 part Paris First Yellow AUM
5°0 parts - Hilac 110 H (manufactured by Hitachi Chemical) 145 parts Polyhinylpyrrolidone K-90'
0.5 part L-7602 (Noricorn Buronokukopo I)
o 5gmer (manufactured by Nippon Unicar)) The above components were heated at IOOO° C. for 1 hour to dissolve them, and then passed through one mouth to remove a small amount of insoluble matter to obtain a black ink for ballpoint pens.

Example 2 Henzl alcohol 50 parts Phenyl glycol 40.0 parts Isophorone
5. o si fly 'y G S K
50.0 parts Methylbioresol-Hase 5 parts Polyhinylpyrrolidone -900.5
-6040 parts to polyvinylpyrrolidone High Rank 110H (manufactured by Hitachi Chemical) 1 DO part L-7
4SOO (Noricone Bronokucoholimer 05 parts manufactured by Nippon Unicar ■) A black ink for a ballpoint pen was obtained using the above ingredients in the same manner as in Example 1.

Comparative Example 5 was prepared by adding 05 parts of oleic acid in place of L-7602 (manufactured by Noricone Floc Coposomer Nippon Unicar ■) in Example PA1t.

Above is Example 112. The hole pen ink obtained in the comparative example was filled into a conventional ballpoint pen, and the load was 200 f and the angle was 7.
00. 200 by a cotton wire machine at a speed of 7 cm/sec.
A written test was conducted and the results are shown in Table 1.

*1: The ink adhering to the pen tip falls onto the paper, creating a large stain.

*2...Things that look like whiskers or those that cause small spots.

As described above, the ink composition for ballpoint pens according to the present invention can prevent as much as possible the ink smearing that is characteristic of ballpoint pens during writing.

In addition, in terms of ink ejectability, it is expected that ink can be smoothly supplied to the pen tip without using any means such as pressurization, and it can be said to be an excellent ink composition for ballpoint pens.

Claims (1)

[Claims] An ink for a ballpoint pen, characterized in that it is made by adding a silicone block copolymer to an ink for a ballpoint pen, which is formed by blending at least one or more organic solvents, at least one or more resins, and at least one or more colorants. Composition.