JP2561099B2 - Marking ink composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a marking ink composition having excellent pen tip drying resistance, in which the pen tip is difficult to dry even when left with the cap removed. is there.

(Prior Art) Conventionally, marking ink compositions, that is, oil-based inks, can be written on both the absorbing surface of paper, cloth, etc. and the non-absorbing surface of plastic, glass, metal, etc. It is widely used because of its existence. Also, for these types of writing inks, which are of a type that has a strong ability to fix handwriting, you can erase the handwriting written on the non-absorbing surface by lightly rubbing with a dry cloth by adding a release material. There is erasable ink.

(Problems to be Solved by the Invention) However, in any of the types described above, when the marking ink composition is used in a writing instrument and left uncapped, the organic solvent evaporates and a coloring agent or There is a problem that resin or the like is deposited and not only the surface of the nib is clogged, but also the inside of the nib is clogged, ink is not ejected from the nib, the handwriting is faint, and writing is impossible.

(Means for Solving Problems) Then, the inventors of the present invention have finally completed the present invention as a result of intensive studies to solve the above problems. That is, the present invention is a marking ink composition comprising at least a colorant, an organic solvent, a resin soluble in the organic solvent, and a sorbitan fatty acid ester represented by the following general formula (I).

<General formula> (R represents hydrogen or an alkyl group, except when all are hydrogen).

 Hereinafter, each component of the present invention will be described in detail.

Examples of the colorant used in the present invention include oil-soluble dyes and pigments, and as the oil-soluble dye, almost any general oil-soluble dye that is soluble in an organic solvent can be used.
CI solvent yellow 2, same 6, same 16, same 19, same 21, same 33, same 5
6, same 61, CI solvent orange 1, same 2, same 5, same 14, same 37,
Same 40, Same 44, Same 45, CI Solvent Red 1, Same 3, Same 8, Same 23,
24, 25, 27, 30, 30, 49, 81, 82, 83, 84, 10
0, same 109, same 121, CI solvent violet 8, same 13, same 1
4, the same 21, the same 27, CI Solvent Blue 2, the same 11, the same 12, the same 25,
Same 35, same 36, same 55, same 73, CI solvent green 3, CI solvent brown 3, same 5, same 20, same 37, CI solvent black 3, same 5, same 7, same 22, same 23, same 123 and the like, the pigment is not particularly limited, azo pigments, phthalocyanine pigments, nitroso pigments, nitro pigments, basic dye pigments, acidic dye pigments, vat dye pigments, Organic pigments such as mordant dye-based pigments and natural dye-based pigments, ocher,
Barium yellow, navy blue, cadmium red, barium sulfate,
Examples thereof include inorganic pigments such as titanium oxide, red iron oxide, iron black, aluminum hydroxide, calcium carbonate, carbon black, and the like, and processed pigments whose surface is resin-coated can also be used. These oil-soluble dyes and / or pigments can be used alone or as a mixture, and the amount used varies depending on the type of colorant and other ink components, but is preferably 1 to 20% by weight with respect to the total amount of ink, preferably It is 2 to 17% by weight.

Examples of the organic solvent include lower alcohols such as ethanol, propanol, isopropanol and butanol, lower ethyl ketones such as methyl ethyl ketone and methyl isobutyl ketone, and lower alcohol esters of lower fatty acids such as ethyl acetate and butyl acetate, and aromatics such as toluene and xylene. Examples thereof include hydrocarbons, alicyclic hydrocarbons such as cyclohexane and ethylcyclohexane, aliphatic hydrocarbons such as hexane and heptane, and alkyl ethers of glycols. These can be used alone or in combination of two or more. The amount is 55 to 90% by weight based on the total amount of ink, preferably
65-85% by weight.

The resin is used to impart a film-forming ability, to impart adhesion to the surface to be coated, to adjust the viscosity of the ink, and also as a dispersant when a pigment is used as a colorant, which has been conventionally used. Natural resins and synthetic resins can be used. Specifically, rosin resins such as rosin, rosin ester, rosin-modified glycerin ester, rosin-modified maleic acid resin, rosin-modified phenol resin, rosin-modified phenol glycerin ester, ethyl cellulose, nitrocellulose, etc. Examples of the cellulose resin, petroleum-based resin, ketone resin, polyvinyl butyral, vinyl chloride-vinyl acetate copolymer, and the like.
-30% by weight, preferably 3-19% by weight.

The sorbitan fatty acid ester represented by the general formula (I) and / or (II) is used for improving the nib dry resistance, and specific examples thereof include sorbitan trioleate, sorbitan tristearate, There is sorbitan tripalmitate, etc., and these usages are 0.05 to 8% by weight, preferably 0.15 to 5% by weight, based on the total amount of the ink.
Is.

Further, in order to obtain an erasable ink for a writing plate of a type capable of erasing the handwriting written on the non-absorption surface by light rubbing with a dry cloth, etc., in addition to the above-mentioned respective components, it is dissolved in the organic solvent and The vapor pressure is lower than that of the solvent, and it is sufficient to add a hardly volatile or non-volatile release agent. As the release agent, higher fatty acid ester, higher fatty acid hydrocarbon, polyoxyethylene alkyl ether type nonionic surfactant and Examples thereof include derivatives thereof, polyoxyethylene alkylphenol ether type nonionic surfactants and derivatives thereof,
The erasability can be imparted to the handwriting by using one of these or a mixture of a plurality thereof.

In addition to the above components, if necessary, a rust preventive agent, a wetting agent,
Various additives such as a viscosity modifier, an antifreezing agent, an antifoaming agent, a dispersion aid, and a surfactant can be appropriately used.

Further, the marking ink composition of the present invention can be obtained by mixing and dissolving each component when an oil-soluble dye is used as a colorant, and when a pigment is used, each component is homomixer, ball mill, lab. It can be easily obtained by mixing and dispersing with a disperser such as a mixer.

(Function) It is not clear why the marking ink composition of the present invention has excellent resistance to drying at the nib, but it is presumed as follows.

The sorbitan fatty acid ester represented by the general formula (I) used in the present invention is deposited at the same time when the organic solvent evaporates at the nib and the colorant or resin is deposited, and the sorbitan fatty acid ester is strong between the colorant and the resin. To prevent binding, to prevent the formation of a complete film, and to form a very brittle film on the surface of the pen tip, to prevent further evaporation of the organic solvent and to break the film due to normal writing pressure. , It seems that writing will be possible.

(Examples) Hereinafter, the present invention will be described in more detail with reference to Examples.
The numerical values in Table 1 indicate parts by weight.

Hereinafter, in Table 1, Example 1 and Comparative Examples 3 and 4 obtain marking ink compositions by mixing and dispersing each component with a ball mill, and Comparative Examples 1 and 2 include marking ink compositions by mixing and dissolving each component. Got

In addition, Examples 1, 2, 3 and 5 show examples of general oil-based inks in Comparative Examples 1, 2 and 3, and Example 4 Comparative Example 4 shows an example of erasable ink for writing board.

<Supplementary explanation of Table 1> (1) Oil Blue BOS: manufactured by Orient Chemical Industry Co., Ltd.,
CI Solvent Blue 25 (2) Neozapon Black RE: BASF, CI Solvent Blue 27 (3) Printex # 35: Degussa, carbon black (4) Fuji IK Blue: Fuji Dye Co., Ltd., processed pigment <Pigment: Phthalocyanine blue (50% by weight), resin, vinyl chloride
Vinyl acetate copolymer (50% by weight)> (5) Tamanol 100S: Arakawa Chemical Industry Co., Ltd., oil-soluble phenolic resin (6) Gum rosin: People's Republic of China, rosin-modified glycerin ester (7) Denka Butyral # 2000 -L: Denki Kagaku Kogyo Co., Ltd.
(8) SO-30: Nikko Chemicals Co., Ltd., sorbitan trioleate (9) ADEKA COL W-934: Asahi Denka Co., Ltd., oil-soluble alkanol amide compound (effect) A nib dry resistance test was conducted using the marking ink compositions obtained in Examples 1 to 5 and Comparative Examples 1 to 4, and the results are shown in Table 2.

(Note) Test method: Using a fiber core as a pen tip, fill a writing instrument using batting with each marking ink composition, remove the cap and leave it in the room (temperature 20 ° C, temperature 50%), and after leaving it 1 hour every 5 minutes, 1 hour after 1
Writing was done every hour, and the time until the handwriting faded was measured.

As described above, the marking ink composition of the present invention has excellent resistance to drying at the nib when used in a writing instrument.

Claims (1)

(57) [Claims] 1. A marking ink composition comprising at least a colorant, an organic solvent, a resin soluble in the organic solvent, and a sorbitan fatty acid ester represented by the following general formula (I). <General formula> (R represents hydrogen or an alkyl group, except when all are hydrogen.)