JP2001098202A - Oil based ink and method for its preparation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an oil based marker ink which makes a pen point hard to dry even when the pen point is in the state exposed to the air and makes a handwriting easy to dry. SOLUTION: An oil based ink comprises impregnated particles which have absorbed a high boiling point solvent to swell.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a so-called felt pen having a fiber converging body as a pen tip, a synthetic resin molding pen tip having an ink passage, a ballpoint pen, and the like. The present invention relates to an oil-based ink containing a coloring material and a film-forming resin.

[0002]

2. Description of the Related Art Conventionally, oil-based inks use a solvent having a relatively low boiling point as a main solvent in order to speed up drying of handwriting on a non-absorbing surface. Therefore, when the marker is filled, if the cap is left with the cap removed, there is a disadvantage that the pen tip dries in a short time and writing becomes impossible. In addition, once the pen tip is dried, it takes a long time before it can be written even with the cap on. To solve this problem, add a solvent with a high boiling point to the solvent, or add a fatty acid ester of polyglycerin to the ink to form a soft film containing the ink on the pen tip when drying, and then use a solvent above It has also been practiced to suppress the volatilization of methane.

[0003]

However, when a solvent having a high boiling point is added, drying of the pen tip is delayed, however, drying of the handwriting is slow, and the handwriting is scraped off when the handwriting is rubbed shortly after writing. was there. In addition, the method of forming a polyglycerin fatty acid ester film on the pen tip has not yet obtained satisfactory results because the solvent of the ink diffuses and permeates through the film and evaporates.

[0004]

According to the present invention, there is provided an oil-based ink comprising at least a low-boiling solvent having a boiling point of less than 140 ° C., a colorant and a film-forming resin. An oil-based ink comprising impregnated particles obtained by absorbing and / or swelling at least one or more high-boiling solvents selected from alcohols, glycols, glycol derivatives and pyrrolidones at 150 ° C or higher. It is an abstract.

Hereinafter, the present invention will be described in detail. Boiling point is 1
The high-boiling solvent selected from alcohols, glycols, glycol derivatives and pyrrolidones having a temperature of 50 ° C. or higher absorbs and / or swells into the solvent-absorbable particles which are the material of the impregnated particles. As an example, the number in parentheses indicates its boiling point. 1-hexanol (151.7 ° C),
1-heptanol (176.3 ° C), 2-heptanol (160.4 ° C), 3-heptanol (156.2)
° C), 1-octanol (195 ° C), 2-octanol (178 ° C), 2-ethylhexyl alcohol (18 ° C).
4.7 ° C), 1-nonanol (214 ° C), 3,5,5
-Trimethyl-1-hexanol (194 ° C), 1-decanol (231 ° C), 1-undecanol (243
C), 1-dodecanol (259C), benzyl alcohol (205.5C), cyclohexanol (161C).
C.) and ethylene glycol (197.
9 ° C.), 1,2-propanediol (187.3 ° C.),
1,3-propanediol (214 ° C), 1,2-butanediol (190.5 ° C), 1,3-butanediol (207.5 ° C), 1,4-butanediol (229.
2 ° C.), 2,3-butanediol (181.7 ° C. (74
2mmHg)), 1,5-pentanediol (242.
4 ° C), 2-butene-1,4-diol (235 ° C),
2-methyl-2,4-pentanediol (197.1)
C), 2-ethyl-1,3-hexanediol (24
3.2 ° C), glycerin (290 ° C), trimethylolpropane (295 ° C), 1,2,6-hexanetriol (178 ° C (5 mmHg)), 2- (methoxymethoxy) ethanol (167.5 ° C), 2-butoxyethanol (170.2 ° C), 2-isopentyloxyethanol (181 ° C), 2-hexyloxyethanol (2
08.1 ° C.), 2-phenoxyethanol (244.7)
C), 2-benzyloxyethanol (256C), diethylene glycol (244.8C), diethylene glycol monomethyl ether (194.1C), diethylene glycol monoethyl ether (202C), diethylene glycol monobutyl ether (230.4C),
Triethylene glycol (288 ° C), triethylene glycol monomethyl ether (249 ° C), polyethylene glycol 200, 300, 400, dipropylene glycol (231.8 ° C), dipropylene glycol monomethyl ether (190 ° C), dipropylene Glycol monoethyl ether (197.8 ° C), tripropylene glycol monomethyl ether (243 ° C), polypropylene glycol, diacetone alcohol (16
8.1 ° C.), 2-pyrrolidone (245 ° C.), N-methyl-2-pyrrolidone, etc. (202 ° C.), but the boiling point is 15
The organic solvent is not limited to these as long as it is a liquid organic solvent at room temperature at a temperature of 0 ° C. or higher.

[0006] The impregnated particles are particulate substances capable of absorbing and / or swelling the above high boiling point solvent, and include intramolecularly crosslinked high molecular compounds and clay compounds. Specific examples include cross-linked polystyrene, cross-linked polyacrylic acid and derivatives thereof, cross-linked polymethyl methacrylate, cross-linked polyvinyl methyl ether, cross-linked poly N-vinylformamide, cross-linked poly N-methyl-N-vinyl Formamide, cross-linked poly N-vinyl acetamide, cross-linked poly N-methyl-N-vinyl acetamide, bentonite, organic bentonite, etc., but do not dissolve when added to a high boiling point solvent or an oil-based ink solvent. Is not limited to these as long as they maintain the above-mentioned formula and absorb and / or swell the high boiling point solvent. The particle size of the impregnated body particles made from these materials is 30 μm in consideration of the ejection from the pen tip when the oil-based ink is filled in the writing implement.
m or less is preferable. Preparation of the impregnated particles can be achieved by mixing the solvent-absorbable particles, which are the material of the particles, with the high-boiling solvent and performing sufficient stirring.However, in order to increase the impregnation efficiency of the high-boiling solvent, a decompression device or the like is used. Pressure can be applied, or the original particles can be appropriately treated in advance so as to be easily wetted with a high boiling point solvent.
The amount of the impregnated particles added is 0.02 to the total amount of the ink in the state of the material particles before absorbing and swelling the high boiling point solvent.
~ 3% by weight is preferred. If the amount is less than 0.02% by weight, the effect of suppressing the drying of the pen tip and accelerating the drying of the handwriting is small, and
If the amount is more than the weight percentage, the drying of the handwriting on the non-absorbing surface becomes slow or the viscosity of the ink becomes high, which may cause a problem that the ejection of the ink is hindered at the time of writing. The ratio of the impregnated material to the high boiling point solvent depends on the amount of the solvent absorbed by the impregnated material, but the high boiling point solvent is preferably 5 to 200 parts by weight per 1 part by weight of the impregnated material particles. If the amount is less than 5 parts by weight, the impregnated body does not sufficiently absorb the solvent, and the oil-based ink component volatilizes through a place where the absorption of the high-boiling-point solvent is insufficient, causing a problem that the drying resistance of the pen tip is deteriorated. 2
If the amount is more than 00 parts by weight, the solvent that cannot be absorbed by the impregnated body will be present alone in the ink, adversely affecting the dryness of the handwriting.

The components of the oil-based ink are mainly composed of a colorant, a solvent and a resin, and those generally used conventionally can be used. As an example of the coloring agent, C.I. I. Solvent Black, 123, C.I. I.
Solvent Red 8, 49 and C.I. I. Solvent Blue 2, 25, 55, 70, C.I. I. Solvent Green 3, C.I. I. Solvent Yellow 21, 61
C. I. Solvent Orange 37, C.I. I. Solvent Violet 8, 21 and the like. Pigments include inorganic pigments such as ocher, barium yellow, navy blue, cadmium red, titanium oxide, red iron oxide, carbon black, etc., azo pigments, phthalocyanine pigments, nitroso pigments, Examples include organic pigments such as nitro pigments, basic dye pigments, acid dye pigments, vat dye pigments, mordant dye pigments, and natural dye pigments, but both dyes and pigments are limited to these. is not. The above-mentioned coloring agents can be used alone or as a mixture of two or more, and the amount used is preferably 1 to 20% by weight based on the total amount of the ink. If the content is less than 1% by weight, the concentration is too low and handwriting is difficult to confirm. If the content is more than 20% by weight, the ink viscosity becomes high and the ink ejection from the marker becomes insufficient. In particular, when a pigment is used as a colorant, a processed pigment having a resin-coated surface is preferably used in terms of dispersibility, stability over time, and workability. Specific examples thereof include Labester and Dirac TN.
(Manufactured by Dainippon Ink and Chemicals, Inc.), Polybrid N (manufactured by Nippon Oil & Fats Co., Ltd.), and Hi-Corp (manufactured by Tokusetsu Shigyo Kogyo KK).

[0008] Low boiling solvents having a boiling point of 140 ° C or lower include aromatic hydrocarbons such as toluene and xylene, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, pentanol, and the like.
Alcohols such as amyl alcohol, methyl cellosolve, ethyl cellosolve, propylene glycol monomethyl ether, ethylene glycol dimethyl ether, glycol ethers such as ethylene glycol diethyl ether, petroleum ether, pentane, hexane, cyclohexane, heptane, octane, methylcyclohexane,
Examples include hydrocarbons such as ethylcyclohexane, but are not limited thereto. The amount of the low boiling point solvent used is preferably 40 to 95% by weight based on the total amount of the ink. When the amount is less than 40% by weight, the viscosity of the ink becomes too high and the ejection from the marker becomes insufficient. When the amount is more than 95% by weight, there occurs a problem that the handwriting density becomes insufficient.

The resin is formed into a film by the volatilization of the ink solvent mainly by handwriting and functions as a fixing agent. Natural resins such as rosin resin, ketone resin, phenol resin and shellac, nitrocellulose, Cellulose resins such as ethyl cellulose, vinyl chloride-vinyl acetate copolymer, acrylate resins and the like can be used.
The amount of these resins used is preferably 0.5 to 25% by weight based on the total amount of the ink. If the amount is less than 0.5% by weight, the fixability of the handwriting becomes insufficient, and if the amount is more than 25% by weight, the viscosity of the ink becomes too high, and the ink is insufficiently ejected from the marker or the pen tip is easily dried. Failure occurs.

[0010] In addition to the above components, various additives such as a surfactant and a rust inhibitor conventionally used in conventional inks can be used as needed. To give an example of a surfactant,
POE alkyl ether, glycerin fatty acid ester,
Polyglycerin fatty acid ester, sorbitan fatty acid ester, POE sorbite fatty acid ester, POE castor oil, POE hardened castor oil, PEG fatty acid ester, PO
EPOP alkyl ether, POE alkylamine, P
OE alkyl ether phosphoric acid and the like. Examples of the rust preventive include benzotriazole, cyclohexylammonium chloride, 2-mercaptobenzotriazole, benzoylaminocaproic acid, and calcium nitrate.

To prepare the ink of the present invention, a boiling point of 15
A high-boiling solvent selected from alcohol, glycol, and glycol derivatives at 0 ° C. or higher and raw material particles of the impregnated particles are mixed and stirred to prepare a high-boiling solvent dispersion of impregnated particles impregnated with the high-boiling solvent in advance. Thereby, even if the impregnated particles are mixed with other ink components, it becomes difficult for the solvent and the like in the ink components to permeate and transfer to the impregnated particles. The impregnated particles may be mixed and stirred with another ink component to uniformly dissolve or disperse, or the impregnated particles may be previously mixed with another ink component and uniformly mixed or dispersed and stirred. Further, after that, another compound may be further added, or other ink components other than the low-boiling solvent may be mixed in the high-boiling solvent dispersion of the impregnated particles. The mixing step with the low-boiling solvent may be separated so that the high-boiling solvent is impregnated. When a pigment is used as a colorant, a pigment obtained by dispersing a pigment with a conventionally known disperser using a dispersant or the like may be used, or a commercially available pigment dispersed in advance may be used. At this time, the coarse pigment in the ink may be removed by filtration or centrifugation.

[0012]

In the present invention, the impregnated particles impregnated with one or more high-boiling solvents selected from alcohols, glycols and glycol derivatives having a boiling point of 150 ° C. or higher are mixed with the oil-based ink component. The reason why the dryness of the pen tip and the dryness of the handwriting can be balanced is presumed as follows. First, regarding the drying resistance of the pen tip, the affinity between the high-boiling solvent captured by the impregnated particles and the solvent of the ink component acts to suppress the volatilization of the solvent of the ink component, resulting in slow drying of the pen tip. It seems to be. Furthermore, if you remove the cap and expose the pen tip to the air,
As the solvent of the oil-based ink component evaporates from the pen tip, the impregnated body is left on the pen tip surface. Since the ink is replenished from the rear when the solvent of the ink component is further volatilized, the portion of the pen tip surface without the impregnated body is eventually covered with the impregnated body contained therein in the form of a film. It is considered that this has the effect of suppressing the volatilization of the solvent of the oil-based ink component by causing the pen tip surface to be covered with the impregnated body.

Regarding the dryness of handwriting, the swelling agent, which is a high-boiling solvent, is absorbed in the impregnated body in the case of the present invention. A high-boiling solvent that dissolves uniformly and a high-boiling solvent that is difficult to volatilize, such that the high-boiling solvent inhibits the resin from forming a film, or the film becomes swollen by taking in a polymer solvent and becomes a soft film Instead, the particles impregnated with the high boiling point solvent are scattered in the resin to be formed into a film, so that the formation of the resin film is not hindered, and the formed film is relatively hard to be broken in a short time. It seems that the film has sufficient strength.

[0014]

The present invention will be described in more detail with reference to the following examples. In the examples and comparative examples, “parts” simply indicates “parts by weight”.

Example 1 Rheogic GX205 (manufactured by Nippon Pure Chemical Industries, Ltd., poly-N-vinylacetamide) 0.3 part Ethylene glycol 9.7 parts Ethanol 80.0 parts Harimac AS-5 (Harima Chemical Co., Ltd.) 5.0 parts Nigrosine-based EX (CI Solvent Black 7, manufactured by Orient Chemical Industry Co., Ltd.) 5.0 parts Of the above components, the entire amount of Rheogic GX205 was mixed with ethylene glycol. Stir for 3 hours. After confirming that the mixture became uniform, this liquid was mixed and stirred with the remaining components to obtain a uniformly dissolved liquid, followed by stirring for 1 hour until the mixture became uniform to obtain a black oil-based ink.

Example 2 Rheoic GX205 0.6 part Glycerin 4.8 parts Propylene glycol monomethyl ether 84.6 parts Harimac AS-5 5.0 parts Balifast Red 1306 (CI Solvent 109, Orient Chemical Industry Co., Ltd.) 5.0 parts) The whole amount of Rheogic GX205 among the above components was mixed with glycerin and stirred for 3 hours. After confirming that the mixture became uniform, the liquid was mixed and stirred with the remaining components, and mixed with a uniformly dissolved liquid, and stirred for 1 hour until the mixture became uniform to obtain a red oil-based ink.

Example 3 Junlon PW-110 (crosslinked polyacrylic acid, manufactured by Nippon Pure Chemical Industries, Ltd.) 0.2 parts Ethylene glycol 6.8 parts Xylene 83.0 parts Oil Yellow 129 (CI Solvent) Yellow 29, manufactured by Orient Chemical Industry Co., Ltd.) 5.0 parts Hariphenol 512 (rosin-modified phenolic resin, manufactured by Harima Chemicals, Inc.) 5.0 parts Of the above components, the entire amount of Junlon PW-110 is mixed with ethylene glycol. And stirred for 3 hours. After confirming that the mixture became uniform, this liquid was mixed and stirred with the remaining components to obtain a uniformly dissolved liquid, and the mixture was stirred for 1 hour until the mixture became uniform to obtain a yellow oil-based ink.

Example 4 Rheogic GX205 0.05 parts Ethylene glycol 7.45 parts Ethanol 82.5 parts Harimac AS-5 5.0 parts Nigrosine base EX 5.0 parts Black oil-based ink made in the same manner as in Example 1. I got

Example 5 Rheoic GX205 2.5 parts 2-Pyrrolidone 23.0 parts Ethylene glycol dimethyl ether 64.5 parts Harimac AS-5 5.0 parts Varifast Red 1306 5.0 parts Same as Example 2 A red oil-based ink was obtained.

Comparative Example 1 A black oil-based ink was obtained in the same manner as in Example 1, except that 0.3 parts by weight of decagrin 5S (decaglyceryl pentastearate, manufactured by Nikko Chemicals Co., Ltd.) was added instead of Rheological GX205.

Comparative Example 2 A red oil-based ink was obtained in the same manner as in Example 2 except that glycerin was added instead of Rheological GX205.

Comparative Example 3 A yellow oil-based ink was obtained in the same manner as in Example 3, except that xylene was added instead of Junlon PW110 and ethylene glycol.

Comparative Example 4 In Example 1, all components were mixed and stirred at the same time to obtain a black oil-based ink.

Comparative Example 5 Rheoic GX205 0.01 part Ethylene glycol 7.45 parts Ethanol 82.5 parts Harimac AS-5 5.0 parts Nigrosine base EX 5.0 parts Black oil-based ink made in the same manner as in Example 1. I got

Comparative Example 6 Rheoic GX205 3.4 parts 2-Pyrrolidone 33.0 parts Ethylene glycol dimethyl ether 41.4 parts Acetone 10.0 parts Harimac AS-5 5.0 parts Balifast Red 1306 5.0 parts Example 2 And a red oil-based ink was obtained.

[0026]

The inks obtained from Examples 1 to 5 and Comparative Examples 1 to 6 were filled in a filling of Pentel N50 manufactured by Pentel Co., Ltd. to test the drying resistance and handwriting dryness of the pen tip. Was done. Table 1 shows the results. Pen tip drying resistance: After removing the cap in an environment of room temperature and no wind, the tip was left for 2 hours and then written on high-quality paper, and the length of the handwriting until the initial handwriting was obtained was measured. Handwriting dryness: After writing on the surface of a polypropylene plate, Advantech filter paper No. 2 and put 50 on this
The weight of g was placed on the left and right five times, and the time until transfer to the filter paper was stopped was measured.

[0027]

[Table 1]

As described in detail above, the oil-based ink according to the present invention is an excellent one in which the difficulty in drying the nib with the cap removed and the speed of drying the handwriting are balanced.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J039 AB02 AB08 AB09 AD03 AD05 AD06 AD08 AD09 AD10 AD23 AE01 AE02 BA04 BA13 BA23 BA30 BA31 BA35 BA37 BC01 BC02 BC03 BC07 BC09 BC12 BC13 BC16 BC36 BC39 BC50 BC60 BE01 BE07 BE12 CA04 CA07 EA10 EA11 EA15 EA16 EA17 EA19 GA26 GA27

Claims (4)

[Claims] 1. An oil-based ink comprising at least a low-boiling solvent having a boiling point of less than 140 ° C., a coloring material and a film-forming resin, wherein the solvent-absorbable particles have a boiling point of 150 ° C.
An oil-based ink comprising an impregnated particle obtained by absorbing and / or swelling one or more kinds of high-boiling solvents selected from the above alcohols, glycols, glycol derivatives and pyrrolidones. 2. The oil-based ink according to claim 1, wherein the impregnated particles are incorporated in an amount of 0.02% by weight or more and 3% by weight or less based on the total amount of the oil-based ink. 3. The oil-based ink according to claim 1, wherein the solvent-absorbable particles are intramolecularly crosslinked polymer compound particles. 4. Mixing and stirring at least one or more high-boiling solvents selected from alcohols, glycols, glycol derivatives and pyrrolidones having a boiling point of at least 150 ° C. or more with particles capable of absorbing the solvent, A method for producing an oil-based ink, comprising impregnating the solvent-absorbable particles with the high-boiling-point solvent, and mixing the resulting impregnated particle dispersion with another oil-based ink formulation.