JPS6225184A - Oily ink - Google Patents

Abstract

PURPOSE:An oily ink having low toxicity and improved drying properties of the pen point, comprising a colorant, a resin, propylene glycol monomethyl ether, etc., and a specific polyglycerin fatty acid ester. CONSTITUTION:(A) 3-20wt% colorant (e.g., oily dye, etc.) is blended with (B) 1-20wt% resin (e.g., rosin, resin-based resin, etc.), (C) 60-90wt% propylene glycol monomethyl ether and/or propylene glycol monomethyl ether acetate and (D) 0.1-5wt% polyglycerin fatty acid ester (e.g., decaglycerin pentastearate, etc.,) shown by the formula (R is acyl or H; n is 0 or positive integer), to give the aimed ink.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an oil-based ink with low toxicity and excellent pen tip drying resistance, which prevents the pen tip from drying even when left uncamped. It is.

(Conventional technology) Traditionally absorbent surfaces such as paper, cloth, and plastic.

Oil-based inks, which can be written on both non-absorbing surfaces such as glass and metal and dry quickly, are widely used, and generally use xylene or toluene as the main solvent. However, these have the problem of having a strong odor, and in recent years, oil-based inks using ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, etc. instead of xylene or toluene have become popular.

(Problems to be Solved by the Invention) However, recently, the toxicity of ethylene glycol monomethyl ether and ethylene glycol monoethyl ether has become a problem because the primary alcohol group in the body transfers to highly toxic methoxyacetic acid via aldehyde. For example, at the American Council of Industrial Hygienists.

There are concerns about its future use as a solvent in oil-based inks, such as the announcement that the allowable concentration in the working environment will be reduced to 5 PPM or less, and an alternative solvent is desired. Also, an inherent problem with oil-based inks is that if you use them in writing instruments and leave them with the caps removed, the organic solvent will evaporate and colorants and resins will precipitate, clogging not only the surface of the nib but also the inside. This causes problems such as ink not being ejected from the pen tip, resulting in blurred handwriting or even an inability to write.There is a need for a solution to this problem.

(No way to solve the problem) Therefore, the inventors of the present invention have finally completed the present invention as a result of extensive research to obtain an oil-based ink with low toxicity and excellent pen tip drying resistance. .

That is, the gist of the present invention is an oil-based ink comprising at least a colorant, a resin, propylene glycol monomethyl ether and/or propylene glycol monomethyl ether acetate, and a polyglycerin fatty acid ester represented by the following general formula (I). be.

General Formula (Function) Propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate used in the oil-based ink of the present invention have the ability to prevent ethylene glycol monomethyl ether and hyethylene glycol monoethyl ether from converting into highly toxic methoxyacetic acid in the body. In order to shift to propylene glycol, which is less toxic to
It is highly safe even when used as a solvent for oil-based inks.

Furthermore, the allowable concentration in the working environment by the American Council of Industrial Hygienists also supports its low toxicity of 100 PPM or less. Again 1
The polyglycerin fatty acid ester represented by the general formula (I1) used in the oil-based ink of the present invention is simultaneously precipitated when the solvent evaporates in the pen nib and 1. the coloring material or resin is precipitated. This prevents strong bonding and prevents the formation of a complete film.

Since a very brittle film is formed on the surface of the pen tip, it is believed that further evaporation of the solvent is prevented and that the film is broken by normal writing pressure, allowing normal writing.

(Structure of the Invention) Each component of the oil-based ink of the present invention will be explained in detail below.

As the colorant, oil-soluble dyes, alcohol-soluble dyes, and dispersible pigments that are soluble in propylene glycol monomethyl ether and/or propylene glycol monomethyl ether acetate, which will be described later, can be used, and the amount of these used depends on the type of colorant and/or dispersible pigments. Although it varies depending on other ink components, it is preferably 3 to 20% by weight based on the total amount of ink.

The resin imparts film-forming ability, and any resin that is soluble in propylene glycol monomethyl ether and/or hapropylene glycol monomethyl ether acetate, which will be described later, can be used, and conventionally used natural resins can be used.

Synthetic resins can be used, specifically rosin, rosin ester, and rosin-modified glycerin ester.

Rosin-based resins such as rosin-modified maleic acid resin, rosin-modified phenol resin, rosin-modified phenol glycerin ester, and ethyl cellulose.

Cellulose 8J resin such as acetyl cellulose, petroleum resin, ketone resin, polyvinyl butyral.

Examples include vinyl chloride-vinyl acetate copolymer, vinylidene chloride-vinyl chloride copolymer, etc., and the amount of these used is preferably 1 to 20% by weight based on the total amount of the ink.

Propylene glycol monomethyl ether topropylene glycol monomethyl ether acetate is used as a solvent, and due to its low toxicity, it imparts low toxicity to the oil-based ink of the present invention, and can be used alone or in combination, The amount used is 40 to 95% by weight, preferably 60 to 90% by weight, based on the total amount of ink.

The polyglycerol fatty acid ester represented by the general formula (I) is used to improve the drying resistance of the pen tip, and specific examples include diglyceryl monooleate, diglyceryl monostearate, diglyceryl dioleate, decaglyceryl heptaoleate, decaglyceryl decaoleate, decaglyceryl pentastearate,
Decaglyceryl hebutastearate, decaglyceryl decastearate, etc. are used in an amount of 0.05 to 10% by weight, or 0.1 to 5% by weight, based on the total amount of the ink. If it is less than 0.1%, it will have little effect.
When the amount is more than 5% by weight, the viscosity becomes high and handwriting may become blurred.

In addition to the above-mentioned components, small amounts of other solvents such as ethanol, propatool, benzyl alcohol, phenyl cellosolve, etc. can be used in conjunction with the above components, as required, as rust preventives, fungicides, and wetting agents.

Two kinds of additives such as viscosity modifiers, antifreeze agents, antifoaming agents, and surfactants can be used as appropriate.

Furthermore, the oil-based ink of the present invention can be easily obtained by mixing the above-mentioned components using a stirrer or a disperser.

(Example) The present invention will be described in more detail below according to Examples, and in the Examples, "parts" indicate "parts by weight."

Example 1 Barry 7 Earth Top 2 Tsuk #3806 (oil-based dye, manufactured by Orient Kagaku Kogyo ■) 10.0 parts Tamanol 1008 (oil-soluble phenol resin) 5.0 parts Propylene glycol monomethyl ether 84.0 parts Decaglin 58 (decaglyceryl pentane) Stearate (manufactured by Nikko Chemicals ■) 1.0 part The above components were mixed and stirred for 4 hours to obtain a black ink.

Comparative Example 1 A black ink was obtained in the same manner as in Example 1, except that Decaglin 5S of Example 1 was removed and only propylene glycol monomethyl ether was added.

Example 2 Barry 7 Earthstred #1308 (oil-based dye, manufactured by Oriesito Chemical Industry ■) aO part Gum rosin (rosin modified glycerin ester) 3.0 parts Propylene glycol monomethyl ether acetate 86.0 parts Decagrin 78 (decaglyceryl heptasteate, Nikko) Chemicals ■ 5.0 parts A red ink was obtained using the above ingredients in the same manner as in Example 1.

Comparative Example 2 Example 20 A red ink was obtained in the same manner as in Example 2, except that Decaglin 7S was removed and propylene glycol monomethyl ether acetate was added in the same amount.

Example 5 Victoria Blue F4R (oil dye, manufactured by BASF) 4.0 parts Hilac 1111 (ketone resin) 15.0 parts Probile/glycol monomethyl ether 75.8 parts Benzyl alcohol 5.0 parts Decaglin 10S (
Decaglyceryl decastearate (manufactured by Nikko Chemicals ■) 0.2 parts A blue ink was obtained using the above ingredients in the same manner as in Example 1.

Comparative Example 3 Except for Decagrin 108 of Example 5, its it7'lt
Same as Example 3 except that 7" propylene glycol monomethyl ether was added.

A blue ink was obtained.

(Effect of the invention) As described above, Examples 1 to 3. The table below shows the results of a pen nib drying resistance test using the oil-based inks obtained in Comparative Examples 1 to 3.
Shown in 1.

(Note) Test method: Fill a writing instrument (cloth writing pen M10.Bentel (manufactured by Kiki)) with each oil-based ink using a fiber core as the nib and fill it indoors (at a temperature of 2 o'clock) with the cap removed. 50% humidity), and write every 5 minutes for 1 hour after leaving it, and every 1 hour after 1 hour (JIS
A circle was written on P3201 writing paper A, and the time it took for the handwriting to fade was measured.

As described above, the oil-based ink of the present invention has low toxicity and excellent pen tip drying resistance, and can be used not only for writing instruments but also for recorders, stamps, inkjet recording, etc. .

Claims (1)

[Scope of Claims] An oil-based ink comprising at least a colorant, a resin, propylene glycol monomethyl ether and/or propylene glycol monomethyl ether acetate, and a polyglycerol fatty acid ester represented by the following general formula (I). <General formula> ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(I) (In the formula, R represents an acyl group or hydrogen, and n represents 0 or a positive integer.)