JP2006257378A - Writing utensil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a writing utensil which is a writing utensil visually checking a color tone of an ink and having excellent convenience and high merchandise value because an ink housed in the writing utensil or a formed handwriting neither causes discoloration or browning from the beginning nor deteriorates a good appearance. <P>SOLUTION: The writing utensil is obtained by housing a water-based ink containing a pigment in a transparent shaft cylinder and fixing the writing tip part directly or through a relay member to the shaft cylinder tip. The writing utensil contains a compound selected from cysteine, cystine, methionine or derivatives thereof in the water-based ink. The writing utensil is prepared as follows. A refill is obtained by housing the water-based ink containing the pigment in a transparent ink housing tube and fixing the writing tip part directly or through the relay member to the tip of the ink housing tube. The resultant refill is housed in the transparent shaft cylinder. In the writing utensil, the compound is contained in the water-based ink. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a writing instrument. More particularly, the present invention relates to a writing instrument that improves the light resistance of ink contained therein.

2. Description of the Related Art Conventionally, there are many colorants that are contained in water-based ink accommodated in a writing instrument and whose color tone is faded or discolored by light.
Therefore, it is disclosed that an ultraviolet absorber such as benzophenone, salicylic acid, benzotriazole, or cyanoacrylate is added to the ink (for example, see Patent Documents 1 and 2).
However, the ultraviolet absorber has very poor solubility in a medium, and particularly when used in a water-based ink, since only a small amount can be added, it has been difficult to obtain a sufficient light resistance improvement effect.
In recent years, a writing instrument that can visually recognize the color tone of ink accommodated in a shaft cylinder or ink containing tube formed of a transparent material has been widely used. However, in the writing instrument, the contained ink itself tends to be exposed to light. Yes, even in systems that use pigments that are relatively light-faster than dyes as colorants, the colorants fade and brown in the ink, so the handwriting obtained by writing also appears to fade and brown. And the commercial value is easily lost.
JP-A 62-106971 JP 9-279080 A

  An object of the present invention is to provide a writing instrument that can visually recognize the color tone of ink in the writing instrument and that does not impair the appearance due to fading or browning of the handwriting formed by the writing instrument.

  The present invention is a writing instrument in which a water-based ink containing a pigment is accommodated in a transparent shaft tube, and a writing tip portion is fixed to the shaft tube tip directly or via a relay member, in the water-based ink, A writing instrument containing a compound selected from cysteine, cystine, methionine, or derivatives thereof, or a water-based ink containing a pigment is contained in a transparent ink containing tube, and directly or via a relay member at the tip of the ink containing tube. A writing instrument in which a refill formed by fixing a writing tip is contained in a transparent shaft cylinder, the aqueous ink containing a compound selected from cysteine, cystine, methionine, or a derivative thereof. A writing instrument is required.

  The present invention is a writing tool excellent in convenience for visually recognizing the color tone of the ink in the writing instrument, and the ink accommodated in the writing instrument or the formed handwriting is fading or browning from the beginning to impair the appearance. Since there is no, there can be provided a writing instrument with high commercial value.

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: Sandye 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 [Product 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.].
Among the above pigments, fluorescent pigments obtained by solid solution of fluorescent dyes in a resin matrix are relatively poor in light resistance. Therefore, a clear fluorescent color can be visually recognized by the structure of the present invention, and a handwriting is also clearly fluorescent color from the beginning. This is useful because it can form handwriting.
If desired, a pearl pigment, a metal powder pigment, a white pigment such as titanium dioxide, a reversible thermochromic capsule pigment, or the like can be used in combination.
The pigment is used in the range of 1 to 25% by weight, preferably 2 to 15% by weight, based on the total amount of ink.

The compound used in the present invention is selected from cysteine, cystine, methionine, or derivatives thereof, and has excellent solubility in ink and can suppress discoloration of the pigment.
Examples of the derivative include cysteine (L-cysteine) hydrochloride, sulfate, amine salt, alkanolamine salt, N-acetyl-L-cysteine, N-acetyl-L-methionine, and the like.
The compound is added in an amount of 0.01 to 10.0% by weight in the ink. Preferably 0.1 to 2.0 weight% is added.
If it is less than 0.01% by weight, it is difficult to show a sufficient effect of improving light resistance, and addition exceeding 10.0% by weight is possible, but no further effect of improving light resistance can be obtained, and the change in physical properties Since there is a case where the writing property is impaired due to the above, addition is not required.

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.
Specific examples of the water-based ink used in the present invention include a shear-thinning ink containing a shear-thinning agent, a cohesive ink obtained by suspending a pigment in a gentle aggregation state with a water-soluble polymer flocculant, and a viscosity of A low viscosity ink of about several mPa · s can be mentioned.

By adding a polymer flocculant in the ink, the flocculant causes a loose bridging action between the pigments and exhibits a loose flocculent state. Ink showing such a loose aggregation state does not cause separation of the colorant in the capillary gap between the ink occlusion body (batting) made of a fiber bundling body and the marking pen body made of a resin bundling fiber.
Therefore, it is possible to obtain a marking pen having a storage performance equivalent to that of a marking pen filled with a dye ink by suppressing the occurrence of darkening or lightening of handwriting by separating the colorant by standing upright or inverted. .
As the water-soluble polymer flocculant, a nonionic water-soluble polymer compound is used, and examples thereof include polyvinyl pyrrolidone, polyethylene oxide, and water-soluble polysaccharides.
Examples of the water-soluble polysaccharide include tragacanth gum, guar gum, pullulan, cyclodextrin, nonionic water-soluble cellulose derivatives and the like, and specific examples of nonionic water-soluble cellulose derivatives include methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, Hydroxyethyl methylcellulose, hydroxypropyl methylcellulose and the like can be mentioned.
In the ink composition of the present invention, any water-soluble polymer exhibiting a loose bridging action between colorants can be applied, and among them, a nonionic water-soluble cellulose derivative works most effectively.

In addition, by adding a shear thinning agent to the ink, ink leakage from the gap between the ball and the tip can be prevented when the ballpoint pen that fills the ink is not used, or the writing tip is directed upward (upright state) ), It is possible to prevent backflow of ink and to prevent aggregation and sedimentation of the pigment.
The viscosity of the ink composition added with the shear thinning agent is 200 to 3000 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 0.6.
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.
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, alka gum, guar gum, locust bean gum and A gel having the ability to be extracted from seaweeds such as glucomannan, agar, carrageenan, etc., polymers having a molecular weight of 100,000 to 150,000 mainly composed of derivatives thereof, hydroxyethyl cellulose, alginic acid alkyl esters, alkyl esters of methacrylic acid Viscous polysaccharides, benzylidene sorbitol and benzylidene xylitol or derivatives thereof, crosslinkable acrylic acid polymer, inorganic fine particles, polyglycerin fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyethylene glycol fatty acid ester , Polyoxyethylene alkyl ether, polyoxypropylene alkyl ether, polyoxyethylene alkylphenyl ether, fatty acid amide and other nonionic surfactants having an HLB value of 8 to 12, salts of dialkyl or dialkenylsulfosuccinic acid, N-alkyl Examples thereof include a mixture of -2-pyrrolidone and an anionic surfactant, and a mixture of polyvinyl alcohol and an acrylic resin.

  Further, when the ink is incorporated into a ballpoint pen for practical use, 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 thiophosphorous acid triesters such as thiophosphorous acid tri (alkoxycarbonylethyl ester), polyoxyethylene alkyl ether or polyoxyethylene alkyl aryl ether phosphoric acid monoester, polyoxyethylene alkyl ether or polyoxyethylene alkyl aryl ether It is preferable to add a lubricant such as phosphoric acid diesters or their metal salts, ammonium salts, amine salts, alkanolamine salts and the like to impart an effect of preventing wear of the ball seat.

In addition, benzotriazole, tolyltriazole, dicyclohexylammonium nitrite, diisopropylammonium nitrite, saponin and other rust preventives, carboxylic acid, sodium salt of 1,2-benzthiazolin-3-one, sodium benzoate, dehydro as necessary Preservatives or antifungal agents such as sodium acetate, potassium sorbate, propyl paraoxybenzoate, 2,3,5,6-tetrachloro-4- (methylsulfonyl) pyridine, urea, nonionic surfactants, reduced or non- Reduced starch hydrolyzate, oligosaccharides such as trehalose, sucrose, cyclodextrin, glucose, dextrin, sorbit, mannitol, sodium pyrophosphate, etc. wetting agents, antifoaming agents, dispersants, fluorine that improves ink permeability Surfactants and noni The emissions-based surfactant may be used.
If necessary, acrylic resin, styrene maleic acid copolymer resin, polyvinyl pyrrolidone, polyvinyl alcohol, dextrin and the like can be used for fixing to the paper surface and imparting viscosity.

The ink 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, structure in which ink is stored directly in the shaft cylinder, and an ink flow rate adjusting member consisting of a comb groove-like ink flow rate adjusting member or fiber bundle is interposed, a chip with a ball attached to the tip is directly or via a connecting member Examples include a structure in which a liquid stopper for preventing ink and backflow is accommodated in a connected shaft cylinder, and a structure in which a ball pen refill in which a liquid stopper for preventing ink and backflow is accommodated in an ink accommodating tube is accommodated in the axis cylinder.

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 may be about 0.1 to 3 mm in diameter, such as cemented carbide, stainless steel, ruby, ceramic, resin or rubber.
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 transparent molded body made of a thermoplastic resin such as polyethylene, polypropylene, polyethylene terephthalate, or nylon is used for the shaft cylinder or the ink storage tube for storing ink.
The transparency includes colored transparency, translucency, and colored translucency, and can confirm the ink color, the ink remaining amount, and the like.
In addition, the transparent shaft cylinder or the ink storage tube may have transparency as a whole, or may have a partially transparent portion where the remaining amount of ink can be visually recognized.

In the present invention, the light resistance of the ink can be further improved by providing a light-stable layer containing or containing an ultraviolet absorber in the ink containing tube or the shaft tube.
Specifically, ink is contained in a shaft cylinder, the shaft cylinder contains an ultraviolet absorber, or a light-stable layer containing an ultraviolet absorber is provided, and a refill containing ink in an ink containing tube. In the shaft cylinder, containing a UV absorber in the shaft cylinder, or provided with a light stabilizing layer containing the UV absorber, a refill containing ink in the ink storage tube is stored in the shaft cylinder. Thus, the ink containing tube contains an ultraviolet absorber or is provided with a light stabilizing layer containing the ultraviolet absorber.
In addition, when using an ink storage tube and a shaft cylinder together, the structure which provided the light stable layer which contains an ultraviolet absorber in both the ink storage tube and the shaft cylinder, or contains an ultraviolet absorber may be sufficient.
When applying the ultraviolet absorber, it is preferable to contain the ultraviolet absorber in the shaft tube from the viewpoint of cost.
In the configuration of the writing instrument described above, when a transparent cap that covers the writing tip is provided, the cap may contain an ultraviolet absorber, or a light stabilizing layer containing an ultraviolet absorber may be provided on the cap surface. The cap preferably contains an ultraviolet absorber.

As the ultraviolet absorber,
2,4-hydroxybenzophenone,
2-hydroxy-4-methoxybenzophenone,
2,2′-dihydroxy-4,4′-dimethoxybenzophenone,
2,2 ′, 4,4′-tetrahydroxybenzophenone,
2-hydroxy-4-methoxybenzophenone-5-sulfonic acid,
2-hydroxy-4-octoxybenzophenone,
Bis- (2-methoxy-4-hydroxy-5-benzoylphenyl) -methane 2- [2′-hydroxy-3′-5′-di-t-amylphenyl] -benzophenone,
2-hydroxy-4-dodecyloxy-benzophenone [trade name: Seasorb 103, manufactured by Cypro Kasei Co., Ltd.]
2-hydroxy-4-octadecyloxybenzophenone,
2,2′-dihydroxy-4-methoxybenzophenone,
2-hydroxy-4-benzyloxybenzophenone,
Benzophenone-based ultraviolet absorbers such as 2- [2′-hydroxy-3′-5′-di-t-amylphenyl] -benzophenone.

Phenyl salicylate,
Para-t-butylphenyl salicylate,
Paraoctylphenyl salicylate,
2-4-di-t-butylphenyl-4-hydroxybenzoate,
1-hydroxybenzoate,
1-hydroxy-3-tert-butyl-benzoate,
1-hydroxy-3-t-octylbenzoate,
Salicylic acid UV absorbers such as resorcinol monobenzoate.

Ethyl-2-cyano-3,3′-diphenyl acrylate,
2-ethylhexyl-2-cyano-3,3′-diphenyl acrylate,
Cyanoacrylate ultraviolet absorbers such as 2-ethylhexyl-2-cyano-3-phenylcinnato.

2- [5-t-butyl-2-hydroxyphenyl] -benzotriazole [trade name: Tinuvin-PS, manufactured by Ciba-Geigy Corporation],
2- [5-methyl-2-hydroxyphenyl] -benzotriazole,
2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] -2H benzotriazole,
2- [3,5-di-t-butyl-2-hydroxyphenyl] -benzotriazole,
2- [3-t-butyl-5-methyl-2-hydroxyphenyl] -5-chlorobenzotriazole,
2- [3,5-di-tert-butyl-2-hydroxyphenyl] -5-chlorobenzotriazole,
2- [3,5-di-t-amyl-2-hydroxyphenyl] -benzotriazole [trade name: Tinuvin 328, manufactured by Ciba-Geigy Corporation],
Methyl-3- [3-t-butyl-5- (2H-benzotriazol-2-yl) -4-hydroxyphenyl] propionate-polyethylene glycol molecular weight 300 [trade name: Tinuvin 1130, manufactured by Ciba-Geigy Corporation],
2- [3-dodecyl-5-methyl-2-hydroxyphenyl] benzotriazole,
Methyl-3- [3- (2H-benzotriazol-2-yl) -5-tert-butyl-4-hydroxyphenyl] propionate-polyethylene glycol molecular weight 300,
2- [3-t-butyl-5-propyl octylate-2-hydroxyphenyl] -5-chlorobenzotriazole,
2- [2-hydroxyphenyl-3,5-di- (1,1′-dimethylbenzyl) phenyl] -2H-benzotriazole,
2- [2-hydroxy-5-t-octylphenyl] -2H-benzotriazole,
2- [3-t-butyl-5-octyloxycarbonylethyl-2-hydroxyphenyl] -benzotriazole [trade name: Tinuvin 384, manufactured by Ciba-Geigy Corporation],
2- [2-hydroxy-5-tetraoctylphenyl] -benzotriazole,
2- [2-hydroxy-4-octoxy-phenyl] -benzotriazole,
2- [2′-hydroxy-3 ′-(3 ″ 4 ″ 5 ″ 6 ″ -tetrahydrophthalimidomethyl) -5′-methylphenyl] -benzotriazole,
Benzotriazole ultraviolet absorbers such as 2- (2-hydroxy-5-t-butylphenyl) -benzotriazole.

Ethanediamide-N- (2-ethoxyphenyl) -N ′-(4-isododecylphenyl),
2,2,4,4-tetramethyl-20- (β-lauryl-oxycarbonyl) -ethyl-7-oxa-3,20-diazodispiro (5,1,11,2) heneic acid-21-one, etc. An oxalic acid anilide type ultraviolet absorber etc. can be illustrated.

Furthermore, a light stabilizer can be used in combination with the ultraviolet absorber.
Examples of the light stabilizer include an antioxidant, an antioxidant, a singlet oxygen quencher, a superoxide anion quencher, an ozone quencher, a visible light absorber, and an infrared absorber.
Among them, a hindered amine-based light stabilizer is preferably used. For example, poly [[6- (N-morpholino) -1,3,5-triazine-2,4-diyl] [(2,2,6,6-6- Tetramethyl-4-piperidyl) imino] hexamethylene [(2,2,6,6-tetramethyl-4-piperidyl) imino] [trade name: Sumisolv 500, manufactured by Sumitomo Chemical Co., Ltd.], 1,2, 3,4-Butanetetracarboxylic acid tetra (2,2,6,6-tetramethyl-4-piperidyl) (manufactured by Adeka Argus), poly [[6-1,1,3,3-tetramethylbutyl) imino -1,3,5-triazine-2,4-diyl] (2,2,6,6-tetramethyl-4-piperidyl) imino] hexamethylene [(2,2,6,6-tetramethyl-4- Piperidyl) imino] (trade name: Chi Bin 944-LD, manufactured by Ciba-Geigy), dimethyl-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate (trade name: Tinuvin 622LD, Ciba-Geigy) ), 2- (3,5-di-t-butyl-4-hydroxybenzyl) -2-n-butylmalonate bis (1,2,2,6,6-pentyl-4-piperidyl) (trade name) : Tinuvin 144, manufactured by Ciba Geigy Co., Ltd.), N, N ^, -bis (3-aminopropyl) ethylenediamine-2,4-bis [N-butyl-N- (1,2,2,6,6-pentamethyl-4- Piperidyl) amino] -6-chloro-1,3,5-triazine condensate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate [trade name: Sanol LS770, Sankyo (stock) Manufactured], bis (N-methyl-2,2,6,6-tetramethyl-4-piperidyl) sebacate [trade name: Sanol LS292, manufactured by Sankyo Co., Ltd.], 4-benzoyloxy-2,2,6, 6-tetramethyl-4-piperidine [trade name: SANOL LS-744, manufactured by Sankyo Co., Ltd.], 8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro [4.5] Decane-2,4-dione [trade name: Sanol LS-440, manufactured by Sankyo Co., Ltd.], 1- [2- [3- (3,5-di-t-butyl-4-hydroxy] Phenyl) propionyloxy] ethyl] -4- [3-3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy] -2,2,6,6-tetramethylpiperidine [manufactured by Sankyo Co., Ltd.] 2,2,4,4-tetramethyl- 0- (β-lauryl-oxycarbonyl) -ethyl-7-oxa-3,20-diaza dispio (5,1,11,2) heneicosan-21-one (trade name: Sanduvor 305, manufactured by Sand Corp.), [ N- (2,2,6,6-tetramethyl-4-piperidyl) -β-alanine] dodecyl ester, myristyl ester mixture (trade name: Sanduvor 3052, manufactured by Sand Corp.), 5-norbornene-2,3-dicarboxy Rick acid bis (2,2,6,6-tetramethyl-4-piperidyl) ester, 5-norbornene-2,3-dicarboxylic acid bis (N-methyl-2,2,6,6-tetramethyl- 4-piperidyl) ester and the like.

The back end of the ink stored in the ink storage tube or the shaft 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 writing instrument form of the present invention is not limited to the one described above, and may be a double-headed writing instrument in which pen bodies having different forms are mounted or pen bodies that lead out inks having different colors are mounted.
As the double-headed writing instrument, a partition wall is provided in the shaft cylinder, and the writing tip is fixed to the both ends of the shaft cylinder directly or via a relay member, respectively. In a writing instrument or a shaft tube, two refills are stored so that the writing tip is located at both ends of the shaft tube, and each of the two refills has a different color tone. The writing instrument which accommodates can be illustrated.
Among these, in the case of a double-headed writing instrument equipped with a pen body that derives inks of different colors, a colorful writing instrument that can visually recognize the color tone of each ink is obtained, but the light resistance of the pigment contained in each ink is Since they are different from each other, when the pigment in one ink is fading or browning with time, the appearance is impaired as compared with the ink with the other clear color tone, and the commercial property is impaired. Therefore, the structure which can visually recognize the vivid color tone of the present invention is useful for a double-headed writing instrument.

Examples will be described below. In addition, the part in an Example shows a weight part.
Example 1
Preparation of water-based ink for marking pen Red pigment dispersion (manufactured by Dainichi Seika Kogyo Co., Ltd., trade name: TC Red FG, pigment content 35%) 20 parts, L-cysteine hydrochloride 0.5 part, glycerin 15.0 Part, phenol 0.3 part, preservative [made by Hokuko Chemical Co., Ltd., trade name: Hokuside R-150], surfactant [made by Nippon Oil & Fats Co., Ltd., trade name: Rapisol A-30] 0.3 parts of water and 63.4 parts of water were mixed and stirred to obtain a water-based ink composition for a marking pen.

Preparation of writing instrument Impregnated with an ink occlusion body in which a polyester sliver is coated with a synthetic resin film, impregnated with the ink, accommodated in a shaft tube made of polycarbonate resin, and connected to a resin processing pen body of polyester fiber attached to the tip of the shaft tube Assembling into a state, wearing a cap, a marking pen was obtained.

Example 2
Preparation of water-based ink for marking pen Pink fluorescent pigment dispersion [manufactured by Nippon Fluorochemicals, trade name: Lumicol NKW-3907E, pigment content 33.5%] 40.0 parts, L-methionine 0.5 parts, glycerin 10.0 parts, 0.5 parts of triethanolamine, 0.3 parts of phenol, 0.5 part of preservative [made by Hokuko Chemical Co., Ltd., trade name: Hokuside R-150], surfactant [Nikko Chemicals Corporation ), Trade name: Nikkor PBC-34] 0.5 parts and 47.7 parts of water were mixed and stirred to obtain a water-based ink composition for a marking pen.

Preparation of Writing Instruments The ink was stored in a liquid state in a shaft cylinder made of polycarbonate resin, a polyester fiber resin processing pen body was provided at the tip of the shaft cylinder, and a cap was attached to obtain a marking pen. In addition, a comb groove-shaped ink flow rate adjusting member is provided at the rear part of the pen body in the shaft cylinder.

Example 3
Preparation of water-based ink for marking pen Yellow fluorescent pigment dispersion [manufactured by Sinloihi Co., Ltd., trade name: Sinroihi SF5015 (yellow), pigment content 30.0%] 50.0 parts, N-acetyl-L-cysteine 0.5 Parts, 10.0 parts of glycerin, 0.5 parts of triethanolamine, 0.3 parts of phenol, 0.5 part of an antiseptic [made by Hokuko Chemical Co., Ltd., trade name: Hokuside R-150], surfactant [Nikko Chemicals Co., Ltd., trade name: Nikkor PBC-34] 0.5 parts and 37.7 parts of water were mixed and stirred to obtain an aqueous ink composition for marking pens.

Preparation of Writing Instruments The ink was stored in a direct liquid state in a shaft tube made of polycarbonate resin, a polyester fiber resin processing pen body was provided at the tip of the shaft tube, and a cap was attached to obtain a marking pen.
In addition, a comb groove-shaped ink flow rate adjusting member is provided at the rear part of the pen body in the shaft cylinder.

Example 4
Preparation of aqueous ink for marking pen Pink fluorescent pigment dispersion [manufactured by Nippon Fluorochemicals, trade name: Lumicol NKW-3907E, pigment content 33.5%] 40.0 parts, N-acetyl-L-cysteine 0 part, 10.0 parts of glycerin, 0.5 part of triethanolamine, 0.3 part of phenol, 0.5 part of preservative [made by Hokuko Chemical Co., Ltd., trade name: Hokuside R-150], 47.7 of water The parts were mixed and stirred to obtain a water-based ink composition for a marking pen.

Preparation of Writing Instruments The ink was stored in a direct liquid state in a shaft tube made of polycarbonate resin, a polyester fiber resin processing pen body was provided at the tip of the shaft tube, and a cap was attached to obtain a marking pen.
In addition, a comb groove-shaped ink flow rate adjusting member is provided at the rear part of the pen body in the shaft cylinder.

Example 5
Preparation of writing instrument 2- (2H-benzotriazol-2-yl) -4,6-bis (1,1-dimethylpropyl) phenol (Nippon Ciba-Geigy Co., Ltd., trade name: Tinuvin 328, UV absorber) A shaft made of a polycarbonate resin containing 25 parts and 0.25 parts of bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate [manufactured by Ciba Geigy Japan, trade name: Tinuvin 770, light stabilizer] The ink prepared in Example 2 was stored in a cylinder in a direct liquid state, a polyester fiber resin processing pen body was provided at the tip of the shaft cylinder, and a cap was attached to obtain a marking pen.
In addition, a comb groove-shaped ink flow rate adjusting member is provided at the rear part of the pen body in the shaft cylinder.

Comparative Example 1
A water-based ink was prepared in the same manner as in Example 1 except that L-cysteine hydrochloride was not mixed in the preparation of the water-based ink of Example 1, and a marking pen was obtained.

Comparative Example 2
A water-based ink was prepared in the same manner as in Example 2 except that L-methionine was not mixed in the preparation of the water-based ink of Example 2, and a marking pen was obtained.

Comparative Example 3
A water-based ink was prepared in the same manner as in Example 3 except that N-acetyl-L-cysteine was not mixed in the preparation of the water-based ink of Example 3, and a marking pen was obtained.

Comparative Example 4
A water-based ink was prepared in the same manner as in Example 4 except that N-acetyl-L-cysteine was not mixed in the preparation of the water-based ink of Example 4, and a marking pen was obtained.

Light Resistance Test The following light resistance tests were performed using the marking pens of Examples 1 to 4 and Comparative Examples 1 to 4.
Light resistance test A
Each marking pen was irradiated with light for 20 hours with a fade meter (Suga test machine, long life carbon arc applied), and then the color tone of the appearance and the handwriting written on the paper surface with the cap removed were compared with the initial one.
Light resistance test B
Each marking pen was irradiated with light by a fade meter (Suga test machine, long life carbon arc applied) for 100 hours, and then the color tone of the appearance and the handwriting written on the paper surface after removing the cap were compared with the initial one.
Light resistance test C
After each marking pen was exposed to sunlight (south facing) for 30 days in accordance with JIS L-0841, the color tone of the appearance and the handwriting on the paper surface after removing the cap were compared with the initial one.
The light resistance test results are shown in the following table.

In addition, the evaluation regarding the symbol of the test result in a table | surface is as follows.
○: No change compared to the initial stage.
(Triangle | delta): Browning was seen compared with the initial stage.
X: Significant color resistance and browning were observed compared to the initial stage.

Application example 1
Preparation of double-headed writing instrument Preparation of double-headed color-changing writing instrument The water-based ink prepared in Example 3 was accommodated in one of the two end-opened shaft cylinders provided with a partition wall having a volume of 5: 5 inside the shaft cylinder, and a comb A chisel-type fiber marking pen tip was attached to the tip of the shaft cylinder through a groove-shaped ink flow rate adjusting member.
Next, the water-based ink prepared in Example 4 was accommodated on the other side, and a chisel-type fiber marking pen tip was attached to the tip of the shaft cylinder through a comb groove-shaped ink flow rate adjusting member to obtain a double-headed discoloring writing instrument.
As a result of conducting the above light resistance test using the double-headed writing instrument, no fading or browning of each ink was observed, and the merchantability was not impaired.

Claims (9)

  A water-based ink containing a pigment is contained in a transparent shaft tube, and is a writing instrument formed by fixing a writing tip portion directly or via a relay member to the shaft tube tip, in the water-based ink, cysteine, cystine, A writing instrument comprising a compound selected from methionine or a derivative thereof.   A partition wall is provided in the shaft cylinder, and a writing tip is fixed to each end of the shaft cylinder directly or via a relay member, and water-based inks having different colors are accommodated in the shaft cylinder. Writing instrument as described.   A writing instrument in which a water-based ink containing a pigment is accommodated in a transparent ink storage tube, and a refill formed by adhering a writing tip to the ink storage tube directly or via a relay member is accommodated in a transparent shaft tube. A writing instrument comprising a compound selected from cysteine, cystine, methionine, or a derivative thereof in the water-based ink.   4. The shaft tube includes two refills such that a writing tip is positioned at both ends of the shaft tube, and water inks having different colors are stored in the two refills. Writing instruments.   The writing instrument according to any one of claims 1 to 4, wherein the water-based ink is stored in a direct liquid state in a shaft cylinder or an ink storage tube.   The writing instrument according to any one of claims 1 to 5, wherein the compound is N-acetyl-L-cysteine.   The writing instrument according to any one of claims 1 to 6, wherein the pigment is a fluorescent pigment.   The writing instrument according to any one of claims 1 to 7, wherein the shaft tube contains an ultraviolet absorber.   The writing instrument according to claim 1, further comprising a transparent cap, wherein the cap contains an ultraviolet absorber.