JP2006142511A - Aqueous ball-point pen - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aqueous ball-point pen, which has a writing feeling being the same smoothness after the passage of time as the smoothness at its early stage, with which a stable holograph can be formed and which is excellent in writing properties without blurring of the holograph nor writing impossibility. <P>SOLUTION: This aqueous ball-point pen is equipped with a water color ink, which consists of a colorant and water and has a pH of 5-13, and a ball-point pen tip holding a cemented carbide ball with a cobalt content of 2.98% by weight or below or with a water color ink, which consists of colorant, water and organic amine and has a pH of 8-11, and the ball-point pen tip holding the cemented carbide ball with the cobalt content of 2.98% by weight or below. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a water-based ballpoint pen. More particularly, the present invention relates to a water-based ballpoint pen having excellent writing performance.

Conventionally, metal balls are widely used as balls applied to ballpoint pens containing water-based ink.
Since the ball contacts with a ball receiving seat provided on the ballpoint pen tip during writing, if it is worn by friction with the receiving seat, a fine scratch is generated on the surface, the writing feeling is impaired and a uniform handwriting cannot be formed.
In order to prevent the above problems, a hard alloy ball mainly composed of tungsten or tungsten carbide is preferably used (see, for example, Patent Document 1). However, the ball contains a large amount of cobalt, and water-based ink. When it comes into contact with the steel, the cobalt tends to elute into the ink over time, and thus the surface of the ball tends to become rough due to corrosion.
As a result, the ball seat provided on the ballpoint pen tip is easily worn, and the amount of ink flowing out excessively changes with writing, so that a stable handwriting cannot be obtained, and the writing feeling is easily lost.
Furthermore, the cobalt eluted in the ink may react with dyes and various additives contained in the ink to cause solids to precipitate, which inhibits the outflow property of the ink and makes the handwriting faded or impossible to write. There is a fear.
JP 2004-122491 A

  An object of the present invention is to provide a water-based ballpoint pen that can form a stable handwriting with good ink ejection while maintaining a smooth writing feeling, and that the handwriting does not fade or become unwritable.

The present invention comprises a water-based ink comprising a water-based ink having a pH of 5 to 13 comprising at least a colorant and water, and a ballpoint pen chip holding a cemented carbide ball having a cobalt content of less than 2.98% by weight. Requires a ballpoint pen.
Furthermore, the cemented carbide alloy ball contains tungsten or tungsten carbide as a main component, and a water-based ballpoint pen or shaft cylinder provided with a ballpoint pen tip directly or via a relay member at the tip of a shaft cylinder filled with water-based ink. A water-based ballpoint pen containing a ballpoint refill with a ballpoint pen tip directly or via a relay member at the tip of the ink containing tube filled with water-based ink, and the cobalt content in the ball is less than 2.0% by weight A water-based ballpoint pen is required.
Furthermore, a water-based ink having a pH of 8 to 11 comprising at least a colorant, water, and an organic amine, and a ballpoint pen tip holding a cemented carbide ball having a cobalt content of 2.98% by weight are provided. Requires water-based ballpoint pen.

  The present invention can provide a water-based ballpoint pen that has the same smooth writing feeling as the initial stage even after the lapse of time and can form a stable handwriting, and has excellent writing performance that does not blur the handwriting or make writing impossible. .

The balls made of cemented carbide used in the present invention are balls that are obtained by sintering 4a, 5a, 6a group metals or their carbides together with metals such as cobalt and nickel and have high hardness and are difficult to wear.
Of the metals of Group 4a, 5a, and 6a or their carbides, cemented carbide balls using tungsten or tungsten carbide (tungsten carbide), which is chemically stable and has high hardness, as the main component are suitable.
In addition, titanium, vanadium, chromium, tantalum or a carbide thereof may be included as a metal of 4a, 5a, or 6a group.
Cobalt and nickel function as a binder. In particular, cobalt is easily eluted in water-based ink, and the ball surface becomes rough. Further, the elution of cobalt causes tungsten and tungsten carbide to fall off, making the ball surface even rougher. Therefore, if the ball rotates while in contact with the ball seat, the wear of the seat increases and the gap between the ball in the axial direction and the ball holding portion increases, resulting in an increase in ink outflow and a handwriting. It becomes easy to produce the problem which becomes thick.
In the present invention, the above-mentioned problem is solved by reducing the cobalt content contained in the cemented carbide ball, specifically, the cobalt content is less than 2.98% by weight, Preferably it is less than 2.0 weight%, More preferably, it is less than 0.9 weight%.
In addition, by reducing the cobalt content, the amount of cobalt to be eluted is also relatively reduced, so that it is possible to prevent the cobalt ions from chemically combining with various additives in the ink to form precipitates. , It is possible to prevent the problem that the ink is reduced and fading occurs or writing becomes impossible.
The cemented carbide ball used in the present invention may not contain cobalt (cobalt content is 0% by weight).

As the colorant contained in the water-based ink, all dyes and pigments that can be dissolved or dispersed in an aqueous medium can be used, and specific examples thereof are illustrated below.
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.

Examples of the pigment include inorganic pigments such as carbon black and ultramarine, and organic pigments such as copper phthalocyanine blue and benzidine yellow, as well as water dispersion finely and stably dispersed in an aqueous medium in advance using a surfactant or resin. Pigment products and the like are used. I. Pigment Blue 15: 3B [Product name: Sandy Super Blue GLL, pigment content 24%, manufactured by Sanyo Dye Co., Ltd.]
C. I. Pigment Red 146 [Product name: Sandye Super Pink FBL, pigment content 21.5%, manufactured by Sanyo Dye Co., Ltd.]
C. I. Pigment Yellow 81 [Product name: TC Yellow FG, pigment content about 30%, manufactured by Dainichi Seika Kogyo Co., Ltd.]
C. I. Pigment Red 220/166 [Product name: TC Red FG, pigment content of about 35%, manufactured by Dainichi Seika Kogyo Co., Ltd.].
As a water-dispersed pigment using a water-soluble resin,
C. I. Pigment Black 7 (trade name: WA color Black A25, pigment content 15%, manufactured by Dainichi Seika Kogyo Co., Ltd.),
C. I. Pigment Green 7 [trade name: WA-S color Green, pigment content 8%, manufactured by Dainichi Seika Kogyo Co., Ltd.]
C. I. Pigment Violet 23 [trade name: Micropigmo WMVT-5, pigment content 20%, manufactured by Orient Chemical Co., Ltd.]
C. I. Pigment Yellow 83 [trade name: Emacol NS Yellow 4618, pigment content 30%, manufactured by Sanyo Dye Co., Ltd.].

As fluorescent pigments, synthetic resin fine particle fluorescent pigments in which various fluorescent dyes are formed into a solid solution in a resin matrix can be used.
Other examples include metallic luster pigments, luminous pigments, white pigments such as titanium dioxide, silica and calcium carbonate, capsule pigments encapsulating a reversible thermochromic composition, and the like.

As the solvent, water and, if necessary, a water-soluble organic solvent are used.
Examples of the water-soluble organic solvent include ethanol, propanol, butanol, glycerin, sorbitol, triethanolamine, diethanolamine, monoethanolamine, ethylene glycol, diethylene glycol, thiodiethylene glycol, polyethylene glycol, propylene glycol, butylene glycol, and 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 monobutyl ether, ethylene glycol monomethyl ether acetate, sulfolane, 2-pyrrolidone, N-methyl-2- Pyrrolidone, and the like.

In addition, acrylic resin, styrene maleic acid copolymer, cellulose derivative, polyvinyl pyrrolidone, polyvinyl alcohol, dextrin, etc. are added for fixing to paper and imparting viscosity, metal soap, nonionic properties with long chain alkyl groups Surfactant, polyether-modified silicone oil, thiophosphite triesters such as thiophosphite tri (alkoxycarbonylmethyl ester) and thiophosphite tri (alkoxycarbonylethyl ester), polyoxyethylene alkyl ether or polyoxyethylene alkylaryl Phosphoric monoesters of ethers, phosphoric diesters of polyoxyethylene alkyl ethers or polyoxyethylene alkyl aryl ethers, or their metal salts, ammonium salts, amine salts, alkanolamine salts, etc. By adding a lubricant capable of imparting anti-wear effect of the seat receiving the ball.
Others, benzotriazole, tolyltriazole, dicyclohexylammonium nitrite, diisopropylammonium nitrite, saponin and other rust preventives, carboxylic acid, sodium salt of 1,2-benzthiazolin-3-one, sodium benzoate, sodium dehydroacetate, sorbic acid Preservatives or fungicides such as potassium, propyl paraoxybenzoate, 2,3,5,6-tetrachloro-4- (methylsulfonyl) pyridine, urea, nonionic surfactants, reduced or non-reduced starch hydrolysates , Oligosaccharides such as trehalose, sucrose, cyclodextrin, glucose, dextrin, sorbit, mannitol, sodium pyrophosphate, etc., wetting agents, antifoaming agents, dispersants, fluorosurfactants that improve ink permeability Nonionic surface activity It may also be used.

Furthermore, a shear thinning agent can be added.
By adding the shear thinning agent, it is possible to suppress the aggregation and sedimentation of the colorant and to suppress the bleeding of the handwriting.
Furthermore, it is possible to prevent ink leakage from the gap between the ball and the chip when not in use, and to prevent backflow of ink when the writing tip is left facing upward (upright state).
The viscosity of the ink composition to which the shear thinning agent is added is 20 to 300 mPa · s at a shear rate of 3.84 S ⁻¹ by an E-type rotational viscometer at 20 ° C., and It is preferable that the shear thinning index is 0.1 to 0.9.
By showing the above-mentioned viscosity range and shear thinning index, it is possible to further leak ink and prevent ink backflow.
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 using a viscometer such as a shear stress value (T) and a shear rate value (j). It is a value calculated by fitting.

Examples of the shear thinning agent include xanthan gum, welan gum, succinoglycan (average molecular weight of about 1 to 8 million) whose constituent monosaccharide is an organic acid-modified heteropolysaccharide of glucose and galactose, guar gum, locust bean gum and derivatives thereof , Hydroxyethyl cellulose, alginic acid alkyl esters, polymers having a molecular weight of 100,000 to 150,000, mainly composed of alkyl esters of methacrylic acid, thickening agent having gelling ability extracted from seaweed such as glucomannan, agar and carrageenan Sugars, benzylidene sorbitol and benzylidene xylitol or their derivatives, crosslinkable acrylic acid polymer, inorganic fine particles, polyglycerin fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyethylene glycol fatty acid ester, polio Shi polyoxyethylene alkyl ether-polyoxypropylene alkyl ethers, polyoxyethylene alkyl phenyl ether, nonionic HLB value, such as fatty acid amide is 8-12 surfactants, salts of dialkyl or dialkenyl sulfosuccinic acid. Examples thereof include a mixture of N-alkyl-2-pyrrolidone and an anionic surfactant, and a mixture of polyvinyl alcohol and an acrylic resin.
The shear thinning agent can be used in combination, and the polymer can be used as a resin.

The water-based ink is prepared by adjusting the pH to 5 to 13.
In general, ink compositions having a weakly acidic to neutral, or neutral to alkaline pH range are widely used. This is because the lubricant used does not function when it is strongly acidic, or is colored. This is because an acidic dye suitably used as an agent does not exhibit good color development in the acidic region.
In order to solve the above-mentioned problems, it is more preferable to adjust the pH of the ink to 8 to 11. As the pH adjuster used for that purpose, inorganic salts such as sodium carbonate, sodium phosphate and sodium acetate, water-soluble Organic amines are used.
Among the pH adjusting agents, organic amines that can adjust pH stably in ink are suitable, and as the organic amines, methylamine, ethylamine, propylamine, butylamine, isobutylamine, monoethanolamine, dimethylamine, Examples include diethylamine, dipropylamine, dibutylamine, diethanolamine, trimethylamine, triethylamine, tripropylamine, triethanolamine and the like.
Of these, alkanolamines such as monoethanolamine, diethanolamine, and triethanolamine are preferably used.
However, the organic amines, particularly alkanolamines, are likely to elute by forming a complex compound with cobalt in the balls, which promotes ball corrosion. Therefore, a water-based ballpoint pen comprising a cemented carbide ball having a cobalt content of less than 2.98% by weight and a water-based ink having an ink containing an organic amine having a pH of 8 to 11 is more writable. Can be satisfied.

The water-based ink is put into practical use by filling a ballpoint pen.
The structure and shape of the ballpoint pen itself are not particularly limited. For example, a structure in which ink is impregnated with a fiber bundle housed inside the shaft tube and ink is supplied to the writing tip, and the shaft tube A structure that directly accommodates ink and interposes an ink flow rate adjustment member composed of a comb groove-shaped ink flow rate adjustment member or a fiber bundle, and has an ink storage tube filled with an ink composition in a shaft cylinder, An example is a ballpoint pen having a structure in which a ball is communicated with a tip attached to the tip, and a liquid stopper for preventing backflow is in close contact with the end face of the ink.

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.
The ball has a diameter of 0.2 to 3.0 mm.

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 water-based ball-point pen obtained as described above may be in the form of a retractable (knock-type or rotary-type) ball-point pen that does not have a cap, in addition to a cap-type ball pen provided with a cap that covers the writing tip when not in use.

  The form of the ballpoint pen is not limited to that described above, but a double-pointed ballpoint pen with a ballpoint pen tip having different ball diameters or a ballpoint pen tip for deriving different color inks, or a different ball A ball-point pen refill provided with a ball-point pen tip having a diameter, or a composite type knock-type ball-point pen in which a ball-point refill filled with inks of different colors is accommodated in a shaft cylinder may be used.

Examples are shown below.
Preparation of aqueous ink 25.7 parts by weight of microcapsule pigment encapsulating a reversible thermochromic composition, 0.2 parts by weight of succinoglycan (shear thinning agent), 5.5 parts by weight of urea, 7.5 parts by weight of glycerin Part, nonionic permeability imparting agent [manufactured by San Nopco Co., Ltd., trade name: Nopco SW-WET-366] 0.03 part by weight, preservative [manufactured by Zeneca Co., Ltd., trade name: Proxel XL-2] 0 A water-based ink comprising 0.5 part by weight of a phosphate ester surfactant [Pricesurf A212C manufactured by Daiichi Kogyo Seiyaku Co., Ltd.], 0.5 part by weight of triethanolamine and 59.97 parts by weight of water Prepared.
The pH of the water-based ink was 8.7.

Preparation of Ink Backflow Preventer Body In 85 parts of polybutene as a base oil, 15 parts of fatty acid amide as a thickener was added, and then kneaded with three rolls to obtain an ink backflow preventer body.

Example 1
Preparation of water-based ballpoint pen The above-mentioned water-based ink is filled with a ballpoint pen refill fitted on one end of a polypropylene pipe with a stainless steel tip that holds a cemented carbide ball having a diameter of 1.0 mm, and the back end of the ink is prevented from flowing back. After arranging the body, the ballpoint pen refill was incorporated into a shaft tube to produce a ballpoint pen.
The composition of the cemented carbide ball is shown below.
WC 82.0% by weight
Co 0.6% by weight
Cr 1.8% by weight
Ti 6.9% by weight
Ni 2.9% by weight

Comparative Example 1
Preparation of water-based ballpoint pen The above-mentioned water-based ink is filled with a ballpoint pen refill fitted on one end of a polypropylene pipe with a stainless steel tip that holds a cemented carbide ball having a diameter of 1.0 mm, and the back end of the ink is prevented from flowing back. After arranging the body, the ballpoint pen refill was incorporated into a shaft tube to produce a ballpoint pen.
The composition of the cemented carbide ball is shown below.
WC 85.0% by weight
Co 10.0% by weight
Cr 5.0 wt%

Initial test Write on paper using the water-based ballpoint pen obtained as described above, and write 200 m with a writing tester under the conditions of writing feeling, load 100 g, writing speed 4 m / min, writing angle 70 °. The state of the handwriting was visually observed.
Time test After each of the ballpoint pens was left at 60 ° C. for 3 months, it was written on the paper surface, and 200 m was written on the writing tester under the conditions of writing feeling, load 100 g, writing speed 4 m / min, writing angle 70 °. The state of the handwriting when it was performed was visually observed.
The test results are shown in the following table.

The criteria for writing feeling and writing test in the table are as follows.
Writing feeling ○: Smooth writing feeling.
X: Grainy writing feeling with a catch.
Written test ○: A good handwriting can be formed.
X: The handwriting width increases with writing.

Claims (6)

  A water-based ballpoint pen comprising a water-based ink having a pH of 5 to 13 consisting of a colorant and water, and a ballpoint pen tip holding a cemented carbide ball having a cobalt content of less than 2.98% by weight.   The water-based ballpoint pen according to claim 1, wherein the cemented carbide ball comprises tungsten or tungsten carbide as a main component.   The water-based ballpoint pen according to claim 1 or 2, wherein a ballpoint pen tip is provided directly or via a relay member at the tip of the shaft cylinder filled with water-based ink.   The water-based ballpoint pen according to claim 1 or 2, wherein a ballpoint pen refill provided with a ballpoint pen tip is housed in the shaft tube directly or via a relay member at the tip of the ink housing tube filled with water-based ink.   The water-based ballpoint pen according to any one of claims 1 to 4, wherein a content of cobalt contained in the ball is less than 2.0% by weight.   A water-based ballpoint pen comprising a water-based ink having a pH of 8 to 11 comprising at least a colorant, water, and an organic amine, and a ballpoint pen tip holding a cemented carbide ball having a cobalt content of less than 2.98% by weight .