JP2007002163A - Oily ink composition for writing utensil and writing utensil containing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oily ink composition for writing utensils, preventing ink and/or an ink backflow-proof element from leaking off an ink cartridge through chemically preventing the bubble generation in the ink, thus affording good handwritings, and to provide a writing utensil containing the ink composition. <P>SOLUTION: The ink composition essentially comprises a colorant, an organic solvent and curcumine. Specifically, the curcumine is contained at 0.01-5.0 wt.% in the ink composition. This ink composition also contains a shear viscosity-reducing agent. The writing utensil is such that the above ink composition is directly filled in an ink cartridge and an ink backflow-proof element acting in compliance as the ink is consumed is closely set on the rear end of the ink. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an oil-based ink composition for a writing instrument and a writing instrument incorporating the same.

Conventionally, as a writing instrument incorporating oil-based ink, a ballpoint pen having a simple structure in which an ink container is filled with ink and a ballpoint pen tip is fitted to the tip of the ink container.
In addition, by adding various shear thinning agents to the oil-based ink, the apparent viscosity in the stationary state is increased, ink leakage from the rear end of the ink containing tube is prevented, and the blotting of the handwriting on the paper surface Attempts have also been made to reduce the occurrence of this.
The writing instrument directly filled with the oil-based ink has a simple structure, and there is no need to make a sealed structure using a flow rate adjusting member (pen core) unlike the writing instrument directly filled with water-based ink. Therefore, since there is little change in the internal pressure, there is an advantage that the ink does not drop off, but special consideration is required when preparing and filling the ink. That is, when gas is mixed in the ink, the gas gathers over time and bubbles are generated, which adversely affects the ink output during writing, and writing may be impossible if bubbles exist at the writing tip. Because.
In particular, the ink back flow that follows the consumption of ink that prevents the solvent in the ink from evaporating on the rear end surface of the ink or prevents the back flow of the ink when the writing front end portion is in the upward state (upright state). The writing instrument filled with the prevention body (liquid stopper) is easily affected by the generation of bubbles because the ink is present in an airtight space that is blocked from the external air.
In order to solve the above-described problems, attempts have been made to add hydroxylamine or a salt thereof, a hydroxylamine derivative or a salt thereof that suppresses the generation of bubbles in the ink (for example, see Patent Document 1).
JP 2002-265844 A

  The present invention further examines a specific compound that chemically removes gas in the ink, and is suitable for a writing instrument of the type directly filled with the ink described above, and can provide good writing performance. An ink composition and a writing instrument incorporating the ink composition are provided.

The present invention is an oil-based ink composition comprising at least a colorant and an organic solvent, and requires an oil-based ink composition for a writing instrument comprising curcumin.
Furthermore, it is a requirement that the curcumin is contained in an ink composition in an amount of 0.01 to 5.0% by weight, a shear thinning agent is added.
Furthermore, a writing instrument in which the oil-based ink composition for a writing instrument is directly filled in an ink storage container and an ink backflow prevention body that follows as the ink is consumed is closely arranged at the rear end of the ink is required.

  The oil-based ink composition for a writing instrument of the present invention can remove bubbles in the ink by blending curcumin. Therefore, the writing instrument using the ink does not generate bubbles over time, the ink is smoothly led out to the writing tip, and the stable writing performance can be maintained, so that a good handwriting can be obtained continuously. It is done.

  The present inventor has little influence on various additives among the compounds that chemically remove the gas in the ink described above, and exhibits a sufficient gas removal function with a small amount of addition and permanently functions. As a result of intensive studies on the compound to be expressed, it was found that curcumin exhibits a remarkable gas removal function in the long term while maintaining good writing performance.

Curcumin is a naturally derived component that is a main component of turmeric and is also called turmeric, and has a strong antioxidant function.
The curcumin is used in an amount of 0.01 to 5.0% by weight, preferably 0.05 to 3.0% by weight, more preferably 0.1 to 2.0% by weight in the ink composition.
If it is less than 0.01% by weight, it is difficult to obtain the desired effect of inhibiting the generation of bubbles.
Although a large amount can be added, the desired effect can be sufficiently obtained at 5% by weight or less.

Examples of the organic solvent include ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, sec-butyl alcohol, tert-butyl alcohol, tert-amyl alcohol, benzyl alcohol, ethylene glycol, diethylene glycol, Propylene glycol, benzyl glycol, ethylene glycol monomethyl ether, ethylene glycol diethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, ethylene glycol monophenyl ether, diethylene glycol monoethyl ether, diethylene glycol monophenyl ether, propylene Glycolmo Methyl ether, propylene glycol monoethyl ether, propylene glycol monophenyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monophenyl ether, tripropylene glycol monomethyl ether, tripropylene glycol monoethyl ether, tripropylene glycol monophenyl ether, n -Heptane, n-octane, isooctane, methylcyclohexane, ethylcyclohexane, toluene, xylene, ethylbenzene, methyl isobutyl ketone, methyl n-propyl ketone, methyl n-butyl ketone, di-n-propyl ketone, n-butyl formate, isobutyl formate , N-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, ethyl propionate, propionate Phosphate n- butyl, methyl butyrate, ethyl butyrate and the like.
The said organic solvent may be used 1 type or in mixture of 2 or more types, and is used in 40-80 weight% in an ink composition.

Conventional dyes and pigments can be used as the colorant. Examples of the dye include organic solvent-soluble dyes classified as solvent dyes in the color index.
Specific examples of the solvent dye include Bali First Black 3806 (CI Solvent Black 29), 3807 (trimethylbenzylammonium salt of the dye of CI Solvent Black 29), Spirit Black SB (C.I. Solvent Black 5), Spiron Black GMH (CI Solvent Black 43), Bali First Red 1308 (Salt Form of Dye of CI Basic Red 1 and Dye of CI Acid Yellow 23), Bali First Yellow AUM (Salt of CI Basic Yellow 2 dye and CI Acid Yellow 42 dye), Spiron Yellow C2GH (organic acid salt of CI Basic Yellow 2 dye), Ron Violet CRH (CI Solvent Violet 8-1), Refast Violet 1701 (Salt of dyes of CI Basic Violet 1 and CI Acid Yellow 42), Spiron Red CGH (organic acid salt of CI Basic Red 1 dye), Spiron Pink BH (C CI Solvent Red 82), Nigrosine Base EX (CI Solvent Black 7), Oil Blue 613 (CI Solvent Blue 5), Neozapon Blue 808 (CI Solvent Blue 70), etc. Can be mentioned.

Examples of pigments include inorganic pigments such as carbon black, ultramarine and titanium dioxide pigments, azo pigments, phthalocyanine pigments, indigo pigments, thioindigo pigments, selenium pigments, quinacridone pigments, anthraquinone pigments, selenium pigments, diketopyrrolopyrrole. -Based pigments, dioxazine-based pigments, perylene-based pigments, perinone-based pigments, isoindolinone-based pigments and other organic pigments, aluminum pigments and metal pigments whose surfaces are treated with colored resins, transparent or colored transparent films such as aluminum From metallic pigments with a thickness of 0.01 to 0.1 μm, gold, silver, platinum, and copper, obtained by peeling a metallic vapor-deposited film such as aluminum formed on a base material such as a metallic luster pigment and a film. Colloidal particles, fluorescent pigments, phosphorescent pigments and core materials with an average particle size of 5-30 nm Natural mica, synthetic mica, glass pieces, alumina, pearl pigment and the like to the surface of the transparent film pieces were coated with a metal oxide such as titanium oxide.
The colorant may be used alone or in combination of two or more, and is used in the range of 3 to 40% by weight in the ink composition.

Furthermore, the following resins can also be used for the purpose of suppressing handwriting blurring, improving fixability, and providing fastness.
Specifically, ketone resins, ketone-formaldehyde resins, amide resins, alkyd resins, rosin-modified resins, rosin-modified phenol resins, phenol resins, xylene resins, polyvinylpyrrolidone, α- and β-pinene / phenol polycondensation resins, polyvinyl Examples include butyral resin and acrylic resin.

  Further, if desired, waxes such as carnauba wax, candelilla wax, rice wax, beeswax, ozokerite, ceresin, montan wax, montan acid wax and montan ester wax can be added.

  When the oil-based ink composition of the present invention is applied to a ballpoint pen, a higher fatty acid such as oleic acid, a nonionic surfactant having a long chain alkyl group, a polyether-modified silicone oil, a thiophosphorous acid tri (alkoxycarbonylmethyl ester) ) And thiophosphite triester (alkoxycarbonylethyl ester) and other lubricants such as thiophosphite triesters can be added as necessary. In particular, polyoxyethylene alkyl ether or polyoxyethylene alkyl aryl ether phosphoric acid When a monoester, polyoxyethylene alkyl ether or polyoxyethylene alkyl aryl ether phosphate diester, or a metal salt, ammonium salt, amine salt, alkanolamine salt, or the like is used, the wear resistance of the ball seat is excellent.

Furthermore, a shear thinning agent can be added.
By adding the shear thinning agent, ink leakage from the gap between the ball and the tip when not in use can be prevented, or the back flow of ink when the writing tip is left upward (upright state). Can be prevented.
When a shear thinning agent is added, the ink viscosity at a shear rate of 3.84S ⁻¹ by an E-type viscometer at 20 ° C. is 10 mPa · s (20 ° C.) or more, preferably 10 to 10000 mPa · s. s and the shear thinning index is preferably adjusted to a range of 0.3 to 0.99. By showing the above-described viscosity range and the shear thinning index, ink leakage is further caused and ink backflow is reduced. Can be prevented.
Further, when a pigment is used as the colorant, aggregation and sedimentation of the pigment can be suppressed.
When the ink viscosity is less than 10 mPa · s, the effect of shear thinning is not appropriate, and ink ejection properties and handwriting performance may be hindered.
The shear thinning index (n) is expressed by an empirical formula T = Kj ⁿ (K is a non-Newtonian viscosity coefficient) obtained from rheological measurement by a viscometer such as a shear stress value (T) and a shear rate value (j). It is a value calculated by fitting.

The shear thinning agent is exemplified below.
Cross-linked acrylic resin, emulsion type of cross-linked acrylic resin, cross-linked N-vinyl carboxylic acid amide polymer or copolymer, non-cross-linked N-vinyl carboxylic acid amide polymer or copolymer non-cross-linked N-vinyl carboxylic Aqueous acid amide polymer or copolymer aqueous solution, hydrogenated castor oil, fatty acid amide wax, wax such as polyethylene oxide wax, fatty acid metal salt such as aluminum stearate, aluminum palmitate, aluminum octylate, aluminum laurate, di Examples include benzylidene sorbitol, dextrin fatty acid ester, N-acyl amino acid compound, smectite inorganic compound, montmorillonite inorganic compound, bentonite inorganic compound, hectorite inorganic compound, silica, etc., viscosity of ink composition, shear thinning index( ) Is added in amounts shown the preferred value.
By adding the shear thinning agent, it is possible to suppress bleeding of the handwriting, so that even if writing on a fiber material such as a highly penetrating cloth as well as paper, the handwriting does not bleed and a good handwriting is achieved. Can be formed.

The ink composition is put into practical use by filling a marking pen or ballpoint pen with a tip attached to the writing tip.
When filling the marking pen, the structure and shape of the marking pen itself are not particularly limited. For example, a fiber tip, felt tip, plastic tip is attached to the writing tip, and the fiber bundle contained in the shaft cylinder is used. The ink occlusion body is impregnated with ink, the ink is supplied to the tip of the writing, the ink is directly stored inside the shaft cylinder, and the ink flow rate adjustment member consisting of a comb groove-like ink flow rate adjustment member or fiber bundle is interposed Examples include a marking pen having a structure in which ink is directly stored in the shaft cylinder and a predetermined amount of ink is supplied to the writing tip portion by a valve mechanism.
When filling the ball-point pen, the structure and shape of the ball-point pen itself are not particularly limited. For example, an ink occlusion body composed of a fiber bundle housed in the shaft tube is impregnated with ink and supplied to the writing tip. Structure, ink is stored directly inside the shaft cylinder, and there is an ink storage tube filled with the ink composition in the shaft cylinder, with a comb groove-shaped ink flow control member and an ink flow control member consisting of fiber bundles interposed The ink containing tube communicates with a tip having a ball attached to the tip, and a ballpoint pen having a structure in which a liquid stopper for backflow prevention is in close contact with the end face of the ink can be exemplified.

The ballpoint pen tip will be described in more detail. A tip formed by holding a ball in a ball holding portion obtained by pressing and deforming the vicinity of the tip of a metal pipe inward from the outer surface, or a metal material is cut by a drill or the like A chip formed by holding the ball in the ball holding part formed by the above, a chip provided with a resin ball receiving seat inside a metal or plastic chip, or a ball held by the chip is moved forward by a spring body Energized items can be applied.
Moreover, the said ball | bowl can use the thing about 0.3-3 mm diameters, such as a cemented carbide alloy, stainless steel, a ruby, a ceramic, resin, rubber | gum.
In addition, the writing instrument filled with the ink of the present invention includes those provided with a rolling mechanism such as a roller at the tip of the writing for forming a handwriting by the same rolling operation as that of the ball.

For example, a molded body made of a thermoplastic resin such as polyethylene, polypropylene, polyethylene terephthalate, or nylon is used as the ink storage tube that stores the ink composition.
Furthermore, by using a transparent, colored transparent, or translucent molded body as the ink containing tube, the ink color, the remaining amount of ink, and the like can be confirmed.
In addition to directly connecting the chip to the ink storage tube, the ink storage tube and the chip may be connected via a connecting member.
The ink storage tube may be a refill type in which the refill is accommodated in the shaft cylinder, or the shaft cylinder itself having a tip mounted on the tip is used as an ink container to directly fill the shaft cylinder with ink. May be.

The back end of the ink composition accommodated in the ink accommodating tube may be filled with an ink backflow prevention body.
The ink backflow prevention body composition is composed of a non-volatile liquid or a hardly volatile liquid.
Specifically, petroleum jelly, spindle oil, castor oil, olive oil, refined mineral oil, liquid paraffin, polybutene, α-olefin, α-olefin oligomer or co-oligomer, dimethyl silicone oil, methylphenyl silicone oil, amino-modified silicone oil, Examples thereof include polyether-modified silicone oil and fatty acid-modified silicone oil, and one or more can be used in combination.

It is preferable to add a gelling agent to the nonvolatile liquid and / or the hardly volatile liquid to increase the viscosity to a suitable viscosity. The surface of the silica is hydrophobized, the surface is methylated fine particle silica, and aluminum silicate. , Swellable mica, hydrophobic thickeners such as bentonite and montmorillonite, fatty acid metal soaps such as magnesium stearate, calcium stearate, aluminum stearate, zinc stearate, tribenzylidene sorbitol, fatty acid amide, amide modified Examples include dextrin compounds such as polyethylene wax, hydrogenated castor oil, fatty acid dextrin, and cellulose compounds.
Furthermore, the liquid ink backflow prevention body composition and a solid ink backflow prevention body composition can be used in combination.

  The oil-based ink composition for a writing instrument of the present invention is charged with a dye or pigment (pigment dispersion), curcumin, if necessary, a shear thinning agent and various additives in an organic solvent, and heated and stirred as necessary. It is prepared by dissolving and dispersing, and is used by filling a writing instrument in the form of a ballpoint pen, a sign pen, a felt pen, a brush pen or the like.

  The following table shows the formulations of Examples and Comparative Examples.

The contents of the raw materials in the table will be explained according to the note numbers.
(1) CIBA (Switzerland), C.I. I. Pigment Blue 60, trade name: Chromophthal Blue A3R
(2) C.I. manufactured by Orient Chemical Co., Ltd. I. Solvent Black 29, trade name: Bali First Black 3806
(3) Orient Chemical Industry Co., Ltd., C.I. I. Acid Yellow 23 and C.I. I. Basic red 1 salt-forming dye, trade name: Bali First Red 1308
(4) Sekisui Chemical Co., Ltd., trade name: ESREC BL-1
(5) Product name: Synthetic Resin SK, manufactured by Huls (Germany)
(6) Arakawa Chemical Industries, Ltd., trade name: Tamanol 903
(7) Product name: Rubytech K-90, manufactured by BASF (Germany)
(8) Nippon Pure Chemical Industries, Ltd., trade name: Leogic GX205
(9) Product name: Biscarex HV-30, manufactured by Allied Colloid Chemical Co. (UK)
(10) Product name: Prisurf A207H, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.
(11) Product name: Esomine C25, manufactured by Lion Akzo Co., Ltd.
(12) Nihon Stange Co., Ltd., trade name: Turmeric Extract Powder ET

  Each said component was mixed and it stirred with the disper for 1 hour, and obtained the oil-based ink composition for writing instruments of Examples 1-6 and Comparative Examples 1-6.

Preparation of Ballpoint Pen The ink of the above examples and comparative examples was filled in a ballpoint pen refill in which a stainless steel chip holding a ball having a diameter of 0.5 mm was fitted to one end of a polypropylene pipe, and the ink rear end face The ballpoint pen refill was incorporated into a shaft tube to obtain a ballpoint pen.

After the ballpoint pen was left at 25 ° C. for 30 days, the presence or absence of bubbles in the ink containing tube and the state of the handwriting were visually observed by a writing test.
Separately from this, the ballpoint pen was left at 50 ° C. for 30 days, and then the presence or absence of bubbles in the ink containing tube and the state of the handwriting were visually observed by a writing test.
The results are shown below.

The criteria for the written test in the table are as follows.
Evaluation: ○ Good handwriting is obtained.
× Handwriting is faint.

Claims (5)

  An oil-based ink composition for a writing instrument, comprising an oil-based ink composition comprising at least a colorant and an organic solvent, and comprising curcumin.   The oil-based ink composition for a writing instrument according to claim 1, comprising 0.01 to 5.0% by weight of the curcumin in the ink composition.   The oil-based ink composition for a writing instrument according to claim 1 or 2, comprising a shear thinning agent.   The oil-based ink composition for a writing instrument according to any one of claims 1 to 3 is directly filled in an ink storage container, and an ink backflow preventive body that follows as the ink is consumed is closely arranged at the rear end of the ink. Writing instrument to do.   The writing instrument according to claim 4, wherein the writing instrument is in the form of a ballpoint pen.