JP2009013258A - Water-based ink composition for projecting/retracting ballpoint pen and projecting/retracting ballpoint pen containing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water-based ink composition for a projecting/retracting ballpoint pen and a projecting/retracting ballpoint pen containing the same, having excellent dry-up resistance, starting writing well in the initial time or after lapse of the time without causing a trouble such as lack of ink and a drip of ink in handwriting and maintaining stable writing performance to continuously obtain excellent handwriting. <P>SOLUTION: An ink composition housed in the projecting/retracting ballpoint pen wherein a handwriting tip part of a ballpoint pen refill projects/retracts from/into a front end opening of a shaft cylinder with operation of a projecting/retracting mechanism contains a dye, water, a water-soluble solvent and a copolymer salt of N-vinyl pyrrolidone and di-methyl aminoethyl methacrylate. The projecting/detracting ballpoint pen houses the water-based ink composition for projecting/retracting ballpoint pen. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a water-based ink composition for a retractable ballpoint pen and a retractable ballpoint pen incorporating the same. More specifically, for penetrating ballpoint pens that have drought resistance that suppresses the occurrence of blurring and inability to write due to drying of the nib even if it is exposed to the open air for a long period of time, and has excellent anti-sagging performance The present invention relates to a water-based ink composition and a retractable ballpoint pen incorporating the same.

Conventionally, a large number of retractable ballpoint pens have been put on the market in which a water-based ink for ballpoint pens is directly built in an ink storage tube, and a ballpoint pen refill provided with an ink backflow preventer at the rear end of the ink is stored in a shaft cylinder. In the retractable ballpoint pen, if the ink contained therein has a relatively high viscosity, it is possible to prevent the ink from dripping from the pen tip to some extent, but if the ink having a low viscosity is used, the ink tends to droop.
Further, water-based ink for ballpoint pens is important for drying resistance in a state where the pen tip is exposed, and an attempt has been made to increase the amount of urea or a derivative thereof as a pen tip drying inhibitor (for example, see Patent Document 1).
However, since urea or its derivative exhibits high water absorption performance and expresses drying resistance, the ink with excessive addition of these absorbs moisture locally at the nib when left under high humidity conditions. Become. For this reason, the ink viscosity at the nib portion decreases due to moisture absorption, and the “dripping” phenomenon in which the ink accumulates in the nib portion or the “bottom-off” phenomenon in which the accumulated ink falls tends to occur.
As described above, although there is a means for improving the drying resistance of the ink composition, it does not sufficiently satisfy other writing performance such as sagging or dripping, and especially the writing tip (ballpoint pen tip) when not writing When it is used for an intrusion type ballpoint pen that does not require a cap that is always open to the atmosphere, it is an important requirement to have drought resistance and not to sag or drop off.
Japanese Patent Publication No. 5-54875

  The present invention solves the problems of the ink composition applied to a ballpoint pen having a configuration that does not require a cap, i.e., satisfies the contradictory functions of drooping and drying resistance, and has an indented type with excellent writing performance. An object of the present invention is to provide a water-based ink composition for a ballpoint pen and a retractable ballpoint pen incorporating the same.

The present invention is an ink composition accommodated in a ballpoint pen in which the writing tip portion of the ballpoint pen refill appears and disappears from the front end opening portion of the shaft by the operation of the intrusion mechanism, and includes a dye, water, a water-soluble organic solvent, N A water-based ink composition for an intruding ballpoint pen comprising a copolymer salt of vinylpyrrolidone and dimethylaminoethyl methacrylate is a requirement.
Further, the copolymer salt of N-vinylpyrrolidone and dimethylaminoethyl methacrylate is contained in an amount of 0.1 to 5% by mass in the total amount of the ink composition, and the viscosity of the ink is in the range of 1 to 20 mPa · s. And the shear thinning index is in the range of 0.6 to 1.0.
Further, the water-based ink composition for a pendent ballpoint pen is incorporated in a ballpoint pen refill consisting of an ink containing tube in which a ballpoint pen tip holding a ball is attached directly or via a relay member, and the rear end face of the ink composition An ink backflow prevention body is provided on the head, and a retractable ballpoint pen in which the ballpoint pen tip of the ballpoint pen refill protrudes and retracts from the front end opening of the shaft cylinder by operating the retracting mechanism is a requirement.

  The present invention has excellent drying resistance, good writing at the beginning and after the lapse of time, and can maintain stable writing performance without causing problems such as blurring or sagging of the handwriting, which is continuously good. It is possible to provide a water-based ink composition for a retractable ballpoint pen that is excellent in writing performance from which a handwriting is obtained and a retractable ballpoint pen incorporating the same.

The copolymer salt of N-vinylpyrrolidone and dimethylaminoethyl methacrylate used in the present invention is stably present in the ink and is excellent in anti-sagging performance.
Further, the copolymer salt does not interfere with drying resistance unlike urea.
The copolymer salt of N-vinylpyrrolidone and dimethylaminoethyl methacrylate is 0.1 to 5% by mass, preferably 0.1 to 4% by mass, more preferably 0.3 to 3%, based on the total amount of the ink composition. It mix | blends in the range of the mass%. If the amount is less than 0.1% by mass, it is difficult to obtain a drooping prevention effect. If the amount exceeds 5% by mass, the viscosity of the ink increases, which may cause crying or blistering, and hinder followability. Furthermore, drying resistance may be deteriorated.
Specific examples of the copolymer salt of N-vinylpyrrolidone and dimethylaminoethyl methacrylate include acetate, sulfate, diethyl sulfate, nitrate, and chloride salts of the copolymer. Is preferred.
Commercially available products include those manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade names: V-2105, V-2255, V-2305, V-2355, manufactured by Osaka Organic Chemical Industry Co., Ltd. C. Polymer 1S (M), H.I. C. Polymer 2, H.I. C. Polymer 3A, H.I. C. Polymer 5 is mentioned.

The dye may be an acid dye, a basic dye, or a direct dye.
As an acid dye,
New coccin (CI. 16255),
Tartrazine (C.I. 19140),
Acid Blue Black 10B (C.I. 20470),
Guinea Green (C.I.42085),
Brilliant blue FCF (C.I.42090),
Acid Violet 6BN (C.I. 43525),
Soluble Blue (C.I. 42755),
Naphthalene green (C.I. 44025),
Eosin (C.I. 45380),
Phloxin (C.I. 45410),
Erythrosine (C.I. 45430),
Nigrosine (C.I. 50420),
Acid flavin (C.I. 56205) or the like is used.

As basic dye,
Chrysoidine (C.I. 11270),
Methyl violet FN (C.I. 42535),
Crystal violet (C.I. 42555),
Malachite green (C.I. 42000),
Victoria Blue FB (C.I. 44045),
Rhodamine B (C.I. 45170),
Acridine orange NS (C.I. 46005),
Methylene blue B (C.I. 52015) or the like is used.

As a direct dye,
Congo Red (C.I. 22120),
Direct Sky Blue 5B (C.I. 24400),
Violet BB (C.I. 27905),
Direct deep black EX (CI 30235),
Caillas Black G Conch (C.I. 35225),
Direct Fast Black G (C.I. 35255),
Phthalocyanine blue (C.I. 74180) or the like is used.
In a system using a dye as a colorant, in a system applied to a knock-type ballpoint pen that does not require a cap, drying at the writing tip is remarkable, and drying resistance is an important requirement.

Examples of the water-soluble organic solvent include ethanol, propanol, butanol, glycerin, sorbitol, triethanolamine, diethanolamine, monoethanolamine, ethylene glycol, diethylene glycol, thiodiethylene glycol, hexylene glycol, 1,3-butanediol, and neoprene. Glycol, polyethylene glycol, propylene glycol, butylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoether Ether, propylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, sulfolane, 2-pyrrolidone, N- methyl-2-pyrrolidone.
The water-soluble organic solvent can be used alone or in combination of two or more.

In addition to the above components, alkyd resin, acrylic resin, styrene maleic acid copolymer, cellulose derivative, polyvinyl pyrrolidone, polyvinyl alcohol, λ-carrageenan, ι-carrageenan, methylcellulose, carboxymethylcellulose, carboxymethylcellulose within the category that does not impair drying resistance One or more water-soluble polymers such as alkali metal salts can be added.
In particular, λ-carrageenan and ι-carrageenan are stably present in the ink and can further improve the sagging prevention performance.
Further, the λ-carrageenan and ι-carrageenan do not interfere with the drying resistance unlike urea.
In addition, a pH adjuster, a rust inhibitor, an antiseptic or an antifungal agent, a lubricant, and a wetting agent can be added as necessary.
Examples of the pH adjusting agent include inorganic salts such as sodium carbonate, sodium phosphate, sodium hydroxide and sodium acetate, and organic basic compounds such as water-soluble amine compounds such as triethanolamine and diethanolamine.
Examples of the rust inhibitor include benzotriazole and derivatives thereof, tolyltriazole, dicyclohexylammonium nitrite, diisopropylammonium nitrite, sodium thiosulfate, ethylenediaminetetraacetate, saponin, and dialkylthiourea.
Examples of the preservative or antifungal agent include carboxylic acid, sodium salt of 1,2-benzisothiazolin-3-one, sodium benzoate, sodium dehydroacetate, potassium sorbate, propyl paraoxybenzoate, 2, 3, 5, 6 -Tetrachloro-4- (methylsulfonyl) pyridine and the like.
Examples of the lubricant include higher fatty acids such as oleic acid, nonionic surfactants having a long chain alkyl group, polyether-modified silicone oil, thiophosphite tri (alkoxycarbonylmethyl ester) and thiophosphite tri (alkoxycarbonylethyl). Esters), phosphoric acid monoesters of polyoxyethylene alkyl ethers or polyoxyethylene alkyl aryl ethers, phosphoric acid diesters of polyoxyethylene alkyl ethers or polyoxyethylene alkyl aryl ethers, or metals thereof Examples include salts, ammonium salts, amine salts, alkanolamine salts, and the like.
Examples of the wetting agent include urea, nonionic surfactant, sorbit, mannitol, sucrose, glucose, reduced starch hydrolyzate, sodium pyrophosphate and the like.
In addition, an antifoaming agent such as a fluorine-based surfactant that improves the permeability of the solvent, a nonion, an anion, a cationic surfactant, or dimethylpolysiloxane may be added.

  When the ink composition is incorporated in an ink containing tube and used in a ballpoint pen of a type in which an ink backflow preventer is disposed on the rear end surface of the ink composition, if the gas is mixed in the ink, Bubbles gather and adversely affect the ink output at the time of writing, and if there is a bubble at the tip of writing, there is a possibility that writing becomes impossible, so ascorbic acid, ascorbic acid derivative, erythorbic acid, ersorbic acid derivative, α-tocopherol, catechin, catechin derivative, synthetic polyphenol, kojic acid, alkylhydroxylamine, oxime derivative, α-glucosyl rutin, phosphonate, phosphinate, sulfite, sulfoxylate, dithionite, thiosulfate , Adding thiourea dioxide, formamidinesulfinic acid, glutathione, etc. It is preferable to remove air bubbles.

The aqueous ink composition for ballpoint pens of the present invention comprises a shear thinning agent, for example, water soluble or dispersible, xanthan gum, welan gum, or a monosaccharide composed of organic acid-modified heteropolysaccharides of glucose and galactose. A polymer having a molecular weight of 100,000 to 150,000 mainly composed of a certain succinoglycan (average molecular weight of about 1 to 8 million), guar gum, locust bean gum and derivatives thereof, hydroxyethyl cellulose, alkyl alginate, and alkyl ester of methacrylic acid , Glucomannan, thickened polysaccharide with gelling ability extracted from seaweed such as agar and carrageenin, benzylidene sorbitol and benzylidene xylitol or their derivatives, crosslinkable acrylic acid polymer, inorganic fine particles, polyglycerin fatty acid ester, poly Oxyethylene Nonionic surfactants having an HLB value of 8 to 12, such as rubitan fatty acid ester, polyethylene glycol fatty acid ester, polyoxyethylene alkyl ether / polyoxypropylene alkyl ether, polyoxyethylene alkyl phenyl ether, fatty acid amide, dialkyl or dialkenyl sulfosucci Acid salts and the like can be exemplified, and they can be used alone or in combination.
Furthermore, a mixture of N-alkyl-2-pyrrolidone and an anionic surfactant, a mixture of polyvinyl alcohol and an acrylic resin can also be used.
Ink shear thinning is a rheological property that has a high viscosity and is difficult to flow in a static state or when stress is low, and it exhibits low fluidity and good fluidity when stress increases. It means liquidity called pseudo plasticity.

As the viscosity characteristics of the ink of the present invention, the viscosity (20 ° C.) measured with a viscometer is in the range of 1 to 20 mPa · s, and the shear thinning index [shear stress value (T) and shear rate by viscometer] (J) The empirical formula (T = Kj ^n, where K is a calculated constant) derived from rheological measurement of the value, is 0.6 to 1. The ink is 0, preferably 0.6 to 0.99, more preferably 0.7 to 0.99.
When the viscosity exceeds 20 mPa · s, it is difficult to satisfy the ink following ability by writing, and the handwriting when writing at high speed is likely to be blurred.
If the shear thinning index is less than 0.6, the writing feeling is inferior and the ink is difficult to transfer to the ball at the initial writing.
Furthermore, handwriting with ink having a shear thinning index of less than 0.6 is difficult to dry, and tends to be transferred to a blank portion of the writing surface and contaminated by finger touch or rubbing between papers.
By satisfying the above-mentioned viscosity and shear thinning index, in addition to satisfying the drooping and drying resistance, it is possible to satisfy the writing performance, that is, the writing feeling, initial writing, the drying property of the handwriting and the formation of a good handwriting. .

The structure and shape of the retractable ballpoint pen containing the waterborne ink composition for the retractable ballpoint pen of the present invention is not particularly limited, and the writing tip provided on the ballpoint pen refill is exposed to the outside air in the shaft cylinder. The writing tip protrudes from the shaft tube opening by the operation of the retracting mechanism.
Examples of the operation method of the retracting mechanism include a knock type, a rotary type, and a slide type.
The knock type has a knock portion on the rear end portion of the shaft tube and the side surface of the shaft tube, and by pressing the knock portion, the writing tip portion of the ballpoint pen refill is projected and retracted from the front end opening portion of the shaft tube, or on the shaft tube. A configuration in which the writing tip portion of the ballpoint pen refill is projected and retracted from the front end opening portion of the shaft cylinder by pressing the provided clip portion can be exemplified.
The rotary type has a rotating part at the rear part of the shaft cylinder, and can be exemplified by a configuration in which the writing tip part of the ballpoint pen refill is projected and retracted from the front end part of the shaft cylinder by turning the rotating part.
The slide type has a slide part on the side surface of the shaft cylinder, and the sliding tip of the writing point of the ballpoint pen refill is projected and retracted from the front end opening of the shaft cylinder by operating the slide, or the clip part provided on the shaft cylinder is slid. By doing so, it is possible to exemplify a configuration in which the writing tip of the ballpoint pen refill is projected and retracted from the opening at the front end of the shaft cylinder.
The retractable ballpoint pen may be a composite ballpoint pen in which a plurality of ballpoint pen refills are accommodated in a shaft cylinder.
The ink storage tube constituting the ballpoint pen refill may be made of resin or metal.

The ball-point pen tip is formed, for example, by cutting a metal to form a ball receiving seat and an ink lead-out portion inside, and providing a plurality of inward protruding portions on the inner surface near the tip of a metal pipe by pressing deformation from the outer surface. It is possible to apply an ink outflow gap extending radially outward from the central portion between the inwardly protruding portions, and the tip, especially the chip formed by pressing deformation, has a comparative contact area with the rear end of the ball. It is small and can give a smooth writing feeling with a low writing pressure.
The ball held by the ballpoint pen tip is 0.1 to 2.0 mm in outer diameter of cemented carbide, stainless steel, ruby, ceramic, etc., preferably 0.3 to 1.5 mm, more preferably 0.4 to A 1.0 mm ball is effective, and the moving distance in the radial direction between the inner diameter of the ball holding portion of the chip and the ball is in the range of 10 to 50 μm, and the moving distance in the axial direction of the ball is in the range of 10 to 30 μm. preferable.
The ballpoint pen tip is provided with a resilient member for projecting the rear end of the ball forward in the tip. When not writing, the ball is pressed against the inner edge of the tip of the tip to bring it into close contact, and when writing, it is The ball can be retracted to allow ink to flow out, and ink leakage when not in use can be suppressed.
Examples of the elastic member include a metal thin wire spring, a member provided with a straight portion (rod portion) at one end of the spring, a linear plastic processed body, and the like, and can be pressed by an elastic force of 10 to 40 g. Applied.

The back end of the ink stored in the ballpoint pen refill can 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.

Examples will be described below, but the present invention is not limited to these examples. The composition of the water-based ink for ballpoint pens of Examples and Comparative Examples is shown in the following table.
In addition, the numerical value of a composition in a table | surface shows a mass part.
The ink viscosities of Examples 1 and 2 and Comparative Examples 1 and 2 were measured at 60 ° C. using a B-type rotational viscometer (manufactured by Tokyo Keiki Co., Ltd., using BL adapter) at 20 ° C.
The ink viscosities of Examples 3 and 4 and Comparative Examples 3 and 4 were measured at 20 ° C. using an E-type rotary viscometer (manufactured by Tokyo Keiki Co., Ltd., using a standard cone rotor).
The shear thinning index (n) of each Example and Comparative Example was calculated by measuring the ink viscosity at 20 ° C. using an E-type rotational viscometer [manufactured by Tokyo Keiki Co., Ltd.].

The contents of the raw materials in the table will be described along the note numbers.
(1) Orient Chemical Industry Co., Ltd., trade name: FISCO BLACK 886, active ingredient 15%
(2) Eisen Hodogaya Co., Ltd., C.I. I. 45410, trade name: Phloxine (3) manufactured by Sumitomo Chemical Co., Ltd., C.I. I. 42655, Product Name: Acid Blue PG
(4) Product name: Special Yellow NS, manufactured by LANXESS
(5) Daiichi Kogyo Seiyaku Co., Ltd., trade name: V-2105, active ingredient 20%
(6) Daiichi Kogyo Seiyaku Co., Ltd., trade name: V-2355, active ingredient 20%
(7) Taiyo Chemical Co., Ltd., trade name: Sankara 634
(8) Product name: GJ500, manufactured by Chuo Material Co., Ltd.
(9) Made by Sanki Co., Ltd., trade name: Leozan (10) 1,2-Benzthiazolin-3-one, manufactured by Avicia Co., Ltd., trade name: Proxel XL-2
(11) Made by Daiichi Kogyo Seiyaku Co., Ltd., trade name: Prisurf AL, polyoxyethylene distyrenated phenyl ether phosphate monoester and diester mixture

Ballpoint Pen Refill The ballpoint pen refill is composed of a ballpoint pen tip that rotatably holds a ball having a diameter of 0.7 mm at the tip, a connection member having the ballpoint tip fixed to the front, and the connection member at the tip opening. The ink receiving tube is fixed and includes an ink and an ink backflow prevention member, and a tail plug fixed to a rear end opening of the ink storing tube.
The ink described in each example and comparative example is used.
The ink backflow prevention body is an ink backflow prevention body in which polybutene is kneaded as a base oil and fatty acid amide is kneaded as a thickener.

Ballpoint Pen The ballpoint pen is formed with a clip on the outer surface of the rear portion of the shaft tube, and each ballpoint pen refill is accommodated in a rearward biased state by a spring (coil spring) inside the shaft tube. By knocking the knock operation portion forward, the ball-point pen tip protrudes from the tip hole of the shaft tube.

The following tests were performed with each of the ballpoint pens.
Sagging test Using each ballpoint pen, expose the ballpoint pen tip from the barrel, hold the tip downward, and leave it in an atmosphere of 20 ° C and 90% relative humidity for 20 hours, and then visually observe the appearance of the tip of the tip. And evaluated according to the following criteria.
Drying resistance test Using each ballpoint pen, the ballpoint pen tip is exposed from the barrel and held in a horizontal position, left at a temperature of 20 ° C. for 30 days, and then handwritten on JIS P3201 writing paper A with 12 circles in a line. Writing was continuously performed, and the number of pieces that can be normally written was visually observed.

The test results are shown in the following table.

The contents of the test result evaluation symbols are as follows.
Sag test ○: No ink leakage (sag) was observed.
Δ: Ink droplets are observed at the tip of the chip.
X: Large ink droplets are observed at the tip of the chip, or ink leaking from the tip of the chip is falling.
Drying resistance test ○: Writing is possible within one circle.

Claims (5)

  An ink composition accommodated in a ballpoint pen in which a writing pen tip of a ballpoint pen refill appears and disappears from an opening at the front end of a shaft cylinder by the operation of a retracting mechanism, comprising a dye, water, a water-soluble organic solvent, N-vinylpyrrolidone, A water-based ink composition for an intruding ballpoint pen comprising a copolymer salt with dimethylaminoethyl methacrylate.   The water-based ink composition for an intruding ballpoint pen according to claim 1, wherein the copolymer salt of N-vinylpyrrolidone and dimethylaminoethyl methacrylate is contained in an amount of 0.1 to 5% by mass in the total amount of the ink composition.   The water-based ink composition for an intruding ballpoint pen according to claim 1 or 2, wherein the viscosity of the ink is in the range of 1 to 20 mPa · s and the shear thinning index is in the range of 0.6 to 1.0.   The water-based ink composition for a retractable ballpoint pen according to any one of claims 1 to 3 is incorporated in a ballpoint pen refill comprising an ink storage tube to which a ballpoint pen tip holding a ball is attached directly or via a relay member. And a retractable ballpoint pen in which an ink backflow prevention body is disposed on the rear end surface of the ink composition, and the ballpoint pen tip of the ballpoint pen refill is projected and retracted from the front end opening of the shaft cylinder by the operation of the retracting mechanism.   The ball-point pen tip is provided with a resilient member that bounces the rear end of the ball forward. When not writing, the ball is pressed against the inner edge of the tip to bring it into close contact, and when writing, the ball is retracted by writing pressure. The retractable ballpoint pen according to claim 4, wherein the ink pen is configured to be allowed to flow out.