JPS62179578A - Ink for marking pen - Google Patents

Abstract

PURPOSE:To obtain the titled ink which has controlled evaporation of the solvent at an exposed pen point and excellent fast-drying properties, by mixing a coloring agent, a film-forming resin, a volatile organic solvent, and a specified condensation ester compound. CONSTITUTION:0.5-20wt% coloring agent (A) (e.g., a basic dye) is mixed with 1-30wt% film-forming resin (B) (e.g., rosin), 40-95wt% volatile organic solvent (C) which dissolves component B (e.g., ethanol), and 0.1-10wt% condensation ester compound (D) which has a melting point of 30 deg.C or higher and is selected from among an intermolecular condensation ester compound that has no free carboxyl groups and is made from as polyol (e.g., glycerin), a fatty acid (e.g., caproic acid), and a dicarboxylic acid (e.g., succinic acid), and a partial fatty acid ester of pentaerythritol, trimethylolethane, trimethylolpropane, a self- condensation product of a sugar-alcohol, and a self-condensation product of a polyhydric alcohol selected from polyglycerins having 7 or more repeating units.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to ink for marking pens.
Specifically, this is a marking pen that has been improved to suppress the phenomenon of blurring handwriting or being unable to write at all due to solvent evaporation from the pen tip, which occurs when using a marking pen that uses ink containing volatile organic solvents or when opening a camp. Regarding ink.

Conventional technology: Ink for oil-based marking pens is required to be able to write on ink-permeable surfaces such as paper (because it is required to be able to write on ink-permeable surfaces as well, volatile organic solvents are used to quickly dry handwriting. Therefore, there is a problem in that the solvent evaporates at the pen tip during use or when the cap is opened, resulting in blurred handwriting or an inability to write.

JP-A-54-721)8 discloses the use of an alkylamide having 4 to 22 carbon atoms or a derivative thereof as an ink evaporation inhibitor at the pen tip. The handwriting remains sticky even over time. In addition, α-olefin was added to the ink for the purpose of suppressing ink drying at the pen tip (Japanese Patent Publication No. 57-3
9666) and the addition of a fluorine-based surfactant (Japanese Patent Application Laid-open No. 170676/1983). However, in the former case, the solvents that can dissolve the α-olefin are limited, and there is a disadvantage that, for example, lower aliphatic alcohols, which are most suitable as solvents for marking pen inks from the viewpoint of safety, cannot be used. In the latter case, it cannot be said that the effect of suppressing dryness at the pen tip is sufficient.

Problems to be Solved by the Invention As mentioned above, in the conventional technology, in order to suppress the evaporation of the solvent at the tip of the marking pen, the original function of the ink for oil-based marking pens, that is, the quick-drying property of the ink penetrating surface, has been applied. This results in a slight sacrifice in the characteristics that give handwriting, and restrictions on the type of solvent in the ink composition.

An object of the present invention is to provide an ink for a marking pen in which the evaporation of the solvent at the pen tip in an open state is sufficiently suppressed for practical use while maintaining the original function of a quick-drying ink.

Means for Solving the Problems The marking pen ink of the present invention contains a colorant, a film-forming resin, a volatile organic solvent that dissolves the resin, and a condensed ester compound.

As the coloring agent, basic dyes, solvent dyes, insoluble azo pigments, condensed polyazo pigments, metal complex salt pigments, phthalocyanine pigments, thioindigo pigments, threne pigments, acridine pigments, perinone/perylene pigments, dioxazine pigments,
Examples include organic pigments such as quinacridone pigments and isoindolinone pigments, carbon black, and titanium white. These colorants are used in the ink composition in an amount of 0.5 to 20% by weight, preferably 3 to 10fffffi%.

Examples of the resins include rosin resins such as rosin, esterified rosin, and maleic acid-modified rosin, ketone resins that are cyclohexanone-aldehyde condensates, phenol-formaldehyde condensation resins, ethyl cellulose, hydroxyalkyl cellulose, and styrene-maleic acid copolymers. polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, polyvinylpyrrolidone, etc., and the amount is 1 to 30% by weight, preferably 5 to 2% by weight in the ink composition.
It is used in a range of 0% by weight.

The volatile organic solvents include lower aliphatic alcohols such as ethanol, propatool and butanol, hydrocarbon solvents such as toluene, xylene, hexane, heptane, cyclohexane and ethylcyclohexane, ester solvents such as ethyl acetate and butyl acetate, and methyl. Examples include glycol ether solvents such as glycol, propyl glycol, and butyl glycol, and glycol ether ester solvents such as methyl glycol acetate, ethyl glycol acetate, and propyl glycol acetate, and the proportion thereof in the ink composition is 40 to 95% by weight, preferably 60 to 80% by weight. It is used in a range of % by weight.

The condensed ester compound is (1) a polyol compound,
An intermolecular condensed ester compound consisting of three components of fatty acid and dicarboxylic acid and having no free carboxyl group, and (2) pentaerythritol, trimethylolethane,
It is selected from the group of compounds of trimethylolpropane, self-condensates of sugar alcohols, and partial fatty acid esters of polyglycerin having 7 or more repeating units.

Examples of the polyol compounds include glycerin, trimethylolethane, trimethylolpropane, triethanolamine, jetanolamine, pentaerythritol, sorbitol, and self-condensates and intramolecular condensates thereof.

The fatty acids include straight chain saturated fatty acids such as caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, valmitic acid, stearic acid, arachic acid, cerotic acid, melisic acid, caproleic acid, myristoleic acid, oleic acid, Examples include straight-chain unsaturated fatty acids such as erucic acid, and branched unsaturated fatty acids such as linoleic acid and lilunic acid.

The dicarboxylic acids include succinic acid, adipic acid, sebacic acid, decanniic acid, dodecanniic acid, tetrazocanicic acid,
Examples include hexadecanic acid, ophtadecanoic acid, eicosanniic acid, and phthalic acid.

The temperature of these condensed ester compounds is 30°C or higher, preferably 4°C.
An ink with a melting point of 0°C or higher is used, and 0°C is used in the ink composition.
．． It is used in a range of 1 to 10% by weight, preferably 0.5 to 3% by weight.

In addition, when used as an ink for writing board marking pens that provides erasable handwriting, a surfactant may be added as a release agent.
Higher fatty acid esters, dibasic acid esters, phthalate esters, olefin waxes, etc. are added.

Function: The condensed ester compound in the ink composition of the present invention precipitates on the pen tip surface during the evaporation process of the ink solvent in the open nib of the marking pen, forming a brittle thin film and acting as an ink drying inhibitor. perform an action. Since the thin film on the surface of the pen tip is easily destroyed by contact between the pen tip and the writing surface, it does not have any adverse effect on ink flow during rewriting. Further, the drying speed of the ink handwriting is the same as that of the ink handwriting that does not contain the drying inhibitor. This is because the amount of ink in the handwriting is extremely small, and most of the solvent evaporates before the drying inhibitor forms a thin film, thereby maintaining the quick drying properties of the handwriting.

Examples Examples of the ink for marking pens of the present invention will be described below in comparison with comparative examples.

Ink Preparation Method Examples 1 to 9 and Comparative Example 1.2 Add a drying inhibitor to the entire amount of organic solvent, stir and dissolve for 1 hour while heating to 40°C, then apply resin and dye or surface resin processing. The processed pigments are stirred and mixed. In the case of ink for writing board marking pen (Example 4~
9. In Comparative Examples 1 and 2), a release agent was further added and thoroughly stirred and mixed to prepare an ink.

Comparative Examples 3 to 9 Inks were prepared in the same manner as described above, except that no drying inhibitor was added.

The composition of each ink is shown in Table 1.

All ink composition values in the table are expressed in parts by weight.
The contents of the ingredients are as follows.

(1) C, 1, Solvent Black 29 (21C,
1, Acid Yellow 23 and C,1, Basic Red 1 salt forming product (31C,1, Solvent Blue 5 (4) Carbon black surface treated with vinyl chloride-vinyl acetate copolymer (C,!, 77265) (5)
Red pigment surface-treated with vinyl chloride-vinyl acetate copolymer (C, 1,12465) (6) Blue pigment surface-treated with vinyl chloride-vinyl acetate copolymer (C, 1,69)
800') (7) Carbon black surface treated with polyvinyl butyral (C, 1,77265) (8
) Red pigment surface-treated with polyvinyl butyral (C
, 1,15585) The pigment/resin weight ratio of the processed pigment is approximately 4/6 for the black processed pigment, and approximately 1/1 for all others (9) Rosin 4, specific gravity 1.07 to 1.08. Softening point 53-60℃ α0 Phenol-formaldehyde condensation resin, specific gravity 1
．． 03-1.08. Melting point 61-70℃ α9 Cyclohexanone-acetaldehyde condensation resin, specific gravity 1.14-1
．． 16. Acid value approximately 0.2. Softening point: 105-1) at 5°C, 0-0 Condensed ester compound α Enoki α-olefin α having 20-28 carbon atoms Florard (registered trademark of 3M Company) FC-430 (2m Polyoxy Ethylene alkyl ether sulfate ammonium salt Examples and Comparative Examples The following performance comparison tests were conducted for each ink.

Test Method A marking pen equipped with a pen body made of a resin-processed acrylic fiber bundle and an ink storage body made of a polyester fiber bundle is filled with a predetermined amount of each sample ink to prepare a sample marking pen.

(1) Time until pen body dries up 20-25℃
, 60±5χR1), the cap of each sample marking pen was opened and the pen was allowed to stand horizontally, and then writing was performed at regular intervals, and it was observed whether or not writing could be performed normally.

Display of results (status at each time) O Can be written immediately Δ Can be written within 10 characters × Cannot be written (2) Handwriting drying time 20-25°C 160 ± 5χR) Under the conditions of I, each sample was marked on a glass plate with a marking pen. A predetermined handwriting was written on it, and the time (seconds) until it was dry to the touch was measured.

Effect of the invention The results of the test are shown in Table 3.

As seen in Table 3, even with the marking pens using the comparative inks, even the samples (Comparative Examples 1 and 5) that showed the best results in terms of dry-up time were less than 45 minutes, and it took nearly 10 minutes to finish writing. Some things were impossible.

In the sample marking pen using the ink of the present invention, the handwriting drying speed on the ink penetrating surface (glass plate surface) is the same as that of an ink that does not contain a drying inhibitor (condensed ester compound), and the ink dries at the pen tip. The suppressing effect was remarkable, with the time required to reach the pen body dry amplifier ranging from 60 minutes at the shortest to 240 minutes at the longest.

Claims (1)

[Scope of Claims] A marking pen comprising a colorant, a film-forming resin, a volatile organic solvent that dissolves the resin, and a condensed ester compound selected from the group of compounds shown in (1) and (2) below. ink. (1) Polyol compound, fatty acid and dicarboxylic acid 3
(2) An intermolecular condensed ester compound consisting of components and having no free carboxyl groups (2) A polyester compound selected from pentaerythritol, trimethylolethane, trimethylolpropane, self-condensates of sugar alcohols, and polyglycerin having 7 or more repeating units. Partial fatty acid ester of alcohol self-condensate