JP5599666B2 - Water-based ink composition for ballpoint pen and ballpoint pen incorporating the same - Google Patents

Description

  The present invention relates to a water-based ink composition for ballpoint pens and a ballpoint pen incorporating the same. More specifically, the present invention relates to a water-based ink composition for a ballpoint pen that has excellent dry-up resistance and exhibits stable ink ejection even after long-term storage, and a ballpoint pen incorporating the same.

Several proposals have been disclosed regarding white or pastel inks for ballpoint pens that contain titanium oxide as a colorant, but this type of ink requires characteristics such as dark writing such as black instead of white. It is to form a clear writing line on the object. That is, high concealment is required. Therefore, it is necessary to blend the titanium oxide at a high concentration. For this reason, when the obtained ballpoint pen is left in a cap-off state, moisture tends to evaporate from the tip of the tip, and a solid content is deposited on the tip of the tip, which tends to cause a problem that inhibits the outflow of ink.
In order to solve this problem, it has been proposed to add a water-soluble organic solvent at a high blending ratio in an ink containing titanium oxide, water, and a water-soluble organic solvent (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 11-256090

However, the conventional titanium oxide-containing aqueous ballpoint pen ink composition is a water-soluble organic solvent such as glycerin, ethylene glycol, propylene glycol, butyl cellosolve, diethyl carbitol, propylene glycol monomethyl ether, or other glycol solvents or glycol ether solvents. Therefore, various problems such as poor ink followability at high speed writing due to an increase in ink viscosity, poor drying of handwriting, and bleeding of handwriting occur.
The present invention provides a water-based ink composition for ballpoint pens that solves the above-described problems and has excellent cap-off properties.

The present invention relates to titanium oxide surface-treated with at least zinc oxide, hollow resin particles, water, a thickener, a dispersant, and a naphthalene sulfonic acid formalin condensate and / or an alkyl naphthalene sulfonic acid formalin condensate for anti-drying. A water-based ink composition for ballpoint pens comprising: Further, the naphthalene sulfonic acid formalin condensate and / or the alkyl naphthalene sulfonic acid formalin condensate was blended in the range of 0.05 to 5.0% by mass in the total amount of the ink composition, and the titanium oxide and the hollow resin particles. The total added amount is required to be 15% by mass or more based on the total amount of the ink composition.
Furthermore, a ballpoint pen incorporating the above-described aqueous ink composition for ballpoint pens is also a requirement.

  The present invention is a water-based ink composition for ballpoint pens comprising titanium oxide surface-treated with zinc oxide, hollow resin particles, water, a thickener and a naphthalenesulfonic acid formalin condensate and / or an alkylnaphthalenesulfonic acid formalin condensate. Further, it is possible to provide a water-based ink composition for a ballpoint pen and a ballpoint pen using the same, wherein the handwriting has excellent concealability and a clear handwriting can be obtained even after being left in a cap-off state. .

In the present invention, titanium oxide surface-treated with zinc oxide is used as a colorant. Although titanium oxide is commercially available as a white pigment, the surface is generally treated with a metal hydrated oxide or an organic substance. As the metal hydrated oxide, oxides such as aluminum, silicon, zinc, and zirconium are used, and as the organic substance, a polyol compound, siloxane, a silane coupling agent, and the like are used. In the present invention, the surface is treated with zinc oxide. Titanium oxide is used.
Examples of the titanium oxide surface-treated with zinc oxide include Taipei R-820, Taipei R-830, Taipei R-930, and Taipei RF-742 (above, manufactured by Ishihara Sangyo Co., Ltd.), Titanics JR-701, Titanics. JRNC [above, manufactured by Teika Co., Ltd.], Tytone R650 [manufactured by Sakai Chemical Co., Ltd.], Kronos KR-380N [manufactured by Titanium Industry Co., Ltd.]
Etc.
The titanium oxide surface-treated with the zinc oxide is blended in the range of 5.0 to 20.0% by mass in the total amount of the ink composition. If it is less than 5.0% by mass, the hiding power of the handwriting is insufficient, and if it exceeds 20.0% by mass, the viscosity of the ink becomes too high, and smooth ink outflow from the chip is hindered.

When the titanium oxide surface-treated with zinc oxide as a colorant is blended alone, a white ink can be obtained, but a pastel ink can be obtained by using a general dye or pigment in combination.
As the dye and pigment, all dyes and pigments that can be dissolved or dispersed in an aqueous medium can be used, and specific examples thereof will be exemplified 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: 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: about 35%, manufactured by Dainichi Seika Kogyo Co., Ltd.].
In addition, as a water-dispersed pigment using a water-soluble resin,
C. I. Pigment Black 7 [Product name: WA color Black
A25, 15% pigment content, manufactured by Daiichi 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 Color 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, phosphorescent pigments, capsule pigments encapsulating a reversible thermochromic composition, and the like.

The water-based ink composition for ballpoint pens of the present invention further uses hollow resin particles. The hollow resin particles have the effect of lowering the average specific gravity of the solid content in the ink composition and improving the dispersion stability of the pigment.
Examples of the hollow resin particles include SX863 (A), SX864 (B), SX865 (B), SX866 (A), SX866 (B), SX8782 (D), AE865 (manufactured by JSR Corporation), Nipol MH5055. , Nipol MH5055A, Nipol MH8055 [above, manufactured by Nippon Zeon Co., Ltd.], Ropaque OP-84J, Ropaque Ultra E, Ropaque HP-1055 [above, manufactured by Rohm and Haas] and the like.
The hollow resin particles preferably have an average particle diameter in the range of 0.2 to 5.0 μm in order to obtain sufficient handwriting visibility and concealment, and 5.0 to 20.0 in the total amount of the ink composition. It is blended in the mass range. If it is less than 5.0% by mass, the hiding power of the handwriting is insufficient, and if it exceeds 20.0% by mass, the viscosity of the ink becomes too high, and smooth ink outflow from the chip is hindered.

  As the thickener, a substance soluble or dispersible in water is effective, and xanthan gum, welan gum, zetasy gum, dieutan gum, macrohomopsis gum, and organic acid-modified heteropolysaccharides whose constituent monosaccharides are glucose and galactose. Succinoglycan (average molecular weight about 100 to 8 million), guar gum, locust bean gum and its derivatives, hydroxyethyl cellulose, alginic acid alkyl esters, methacrylic acid alkyl ester Coalesce, glucomannan, carbohydrate having gelation ability extracted from seaweed such as agar and carrageenan, poly N-vinyl-carboxylic acid amide cross-linked product, benzylidene sorbitol and benzylidene xylitol or their derivatives, cross-linkable acrylic acid polymer, Inorganic fine Examples thereof include nonionic surfactants having an HLB value of 8 to 12, metal salts and amine salts of dialkylsulfosuccinic acid, and N-alkyl-2-pyrrolidone and anionic surfactants in the ink composition. May be added in combination.

The water-based ink composition for ballpoint pens of the present invention contains a naphthalene sulfonic acid formalin condensate and / or an alkyl naphthalene sulfonic acid formalin condensate.
Specifically, Demol N, Demol RN, Demol RNL, Demol T, Demol T-45 [above, manufactured by Kao Corporation: β-naphthalenesulfonic acid formalin condensate sodium salt], FT-500 [Electrochemical Industry ( Co., Ltd .: Alkylnaphthalenesulfonic acid formalin condensate], Cellflow 110P [Daiichi Kogyo Seiyaku Co., Ltd .: naphthalenesulfonic acid formalin condensate], Pole Fine 510N [Takemoto Yushi Co., Ltd .: alkylnaphthalenesulfonic acid formalin condensate] Product], Floric PS [manufactured by Nippon Paper Chemicals Co., Ltd .: alkyl naphthalene sulfonic acid formalin condensate], Tamol NN9401 [manufactured by BASF: sodium naphthalene sulfonic acid formalin condensate] and the like.
The naphthalene sulfonic acid formalin condensate and / or the alkyl naphthalene sulfonic acid formalin condensate have an acid type and a salt type such as alkali metal, ammonium, and organic amine, and both can be used.

In general, when the tip of a ballpoint pen tip is exposed to air and left to stand, there is a phenomenon in which moisture evaporates and the local viscosity increases. However, the naphthalene sulfonic acid formalin condensate and / or the alkyl naphthalene sulfonic acid formalin condensate are present. Suppresses the abrupt increase in viscosity and functions as a better pigment dispersant, so that it is possible to maintain good writing performance after cap-off or after standing for a long time in a cap-mounted state.
The naphthalene sulfonic acid formalin condensate and / or the alkyl naphthalene sulfonic acid formalin condensate is blended in an amount of 0.05 to 5.0% by mass in the total amount of the ink composition. If it is less than 0.05% by mass, the writing performance after cap-off is insufficient, and if it exceeds 5.0% by mass, problems such as poor viscosity increase, pigment separation and sedimentation occur.

Further, if necessary, a conventional general-purpose water-soluble organic solvent compatible with water can be used. Specifically, ethanol, propanol, butanol, glycerin, sorbitol, triethanolamine, diethanolamine, monoethanolamine, ethylene glycol, diethylene glycol, thiodiethylene glycol, polyethylene glycol, propylene glycol, butylene glycol, ethylene glycol monomethyl ether, ethylene glycol mono Examples include ethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, ethylene glycol monomethyl ether acetate, sulfolane, 2-pyrrolidone, and N-methyl-2-pyrrolidone.
In addition, the said water-soluble organic solvent can be used 1 type or in combination of 2 or more types, and is used in 2-60 mass%, Preferably it is 5-35 mass%.

  Furthermore, a water-soluble resin can be added in order to impart adhesion and viscosity to the paper surface. Examples of the water-soluble resin include alkyd resins, acrylic resins, styrene maleic acid copolymers, cellulose derivatives, polyvinyl pyrrolidone, polyvinyl alcohol, and dextrin. The water-soluble resin can be used alone or in combination of two or more, and is used in the range of 1 to 30% by mass in the ink composition.

  In addition, if necessary, pH adjusters such as inorganic salts such as sodium carbonate, sodium phosphate and sodium acetate, organic basic compounds such as water-soluble amine compounds, rust preventives such as benzotriazole, tolyltriazole and saponin , Carboxylic acid, sodium salt of 1,2-benzthiazolin-3-one, sodium benzoate, sodium dehydroacetate, potassium sorbate, propyl paraoxybenzoate, 2,3,5,6-tetrachloro-4- (methylsulfonyl) A preservative or antifungal agent such as pyridine, an antifoaming agent, a fluorine-based surfactant or a nonionic surfactant that improves ink permeability may be used. In addition, other wetting agents such as sorbitol, mannitol, sucrose, glucose, reduced starch hydrolyzate, urea, sodium pyrophosphate can be used in combination.

Furthermore, a lubricant can be added, such as metal soap, polyalkylene glycol fatty acid ester, ethylene oxide addition type cationic surfactant, phosphate ester type surfactant, dicarboxylic acid type surfactant, β-alanine type surfactant, 2,5-dimercapto-1,3,4-thiadiazole and its salts and oligomers, 3-amino-5-mercapto-1,2,4-triazole, thiocarbamate, dimethyldithiocarbamate, N-acyl-L -A condensate of glutamic acid and L-lysine or a salt thereof is used.
Ascorbic acid, erythorbic acid, α-tocopherol, catechins, synthetic polyphenol, kojic acid, alkylhydroxylamine, oxime derivative, α-glucosylrutin, α-lipoic acid, phosphonate, phosphinate, sulfite, sulfoxylate It is also possible to chemically remove bubbles by adding dithionite, thiosulfate, thiourea dioxide or the like.

The ink composition 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 in the shaft cylinder and ink is supplied to the writing tip, the inside of the shaft cylinder Ink is directly contained in the ink flow adjusting member having a comb groove shape and an ink flow adjusting member composed of a fiber bundle, and an ink containing tube filled with the ink composition in the shaft cylinder. Can be exemplified by a ballpoint pen having a structure in which a ball is in communication with a tip mounted on 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 may be about 0.2 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 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.

Hereinafter, Table 1 shows the formulation of Examples, and Table 2 shows the formulation of Comparative Examples.

The contents of the raw materials in the table are explained according to the note numbers.
(1) Product name: Titanics JR-707 (surface treatment; SiO2 + Al2O3 + ZnO) manufactured by Teika Co., Ltd.
(2) Ishihara Sangyo Co., Ltd., trade name: Taipei R-820 (surface treatment; SiO2 + Al2O3 + ZnO)
(3) Ishihara Sangyo Co., Ltd., trade name: Taipei CR-85 (surface treatment; SiO2 + Al2O3)
(4) Product name: DISPER BYK-2015, manufactured by Big Chemie Japan Co., Ltd.
(5) Rohm and Haas Co., Ltd., trade name: Ropeke Ultra E, resin solid content 30%
(6) Sanyo Dye Co., Ltd., trade name: Sundai Super Blue GLL, 24% active ingredient
(7) Nikko Chemicals Co., Ltd. dioctyl sodium sulfosuccinate, active ingredient 75%, trade name: OTP-75,
(8) Powdered dextrin manufactured by Sanwa Starch Co., Ltd., trade name: Sandeck # 30
(9) Daiichi Kogyo Seiyaku Co., Ltd. polyoxyethylene distyrenated phenyl ether phosphate monoester and diester mixture, trade name: F6312
(10) 1,2-benzisothiazolin-3-one manufactured by Avicia Co., Ltd., trade name: Proxel XL-2,
(11) Thickening polysaccharide (succinoglycan) manufactured by Sanki Co., Ltd., trade name: Leozan (12) Kao Co., Ltd., β-naphthalenesulfonic acid formalin condensate sodium salt, trade name: Demol N

Preparation of ink The inks of the examples and comparative examples were prepared as follows.
(1) Titanium oxide, water, glass beads (2 mm), and a dispersant were placed in a container and shaken with a paint conditioner for 3 hours to obtain a titanium oxide dispersion.
(2) Additives other than the dispersion, colorant, and thickener were mixed in a container, and then the thickener was added.
(3) The ink was stirred at 1000 rpm for 20 minutes with a disper to obtain an ink.
Preparation of Ink Backflow Preventing Body After adding 15 parts by weight of fatty acid amide as a thickener to 85 parts by weight of polybutene as a base oil, the mixture was kneaded with three rolls to obtain an ink backflow preventing body.

Preparation of ballpoint pen Each of the ink compositions obtained as described above was filled in a ballpoint pen refill fitted with one end of a polypropylene pipe with a stainless steel chip holding a ball having a diameter of 0.4 mm. After the ink backflow preventer was disposed, the ballpoint pen refill was incorporated into a shaft tube to produce a ballpoint pen.

Cap-off test Ten ballpoint pens obtained as described above were prepared. After removing the caps and leaving the chips exposed, left at 20 ° C for 14 days in a horizontal position. Twelve pieces were written continuously in one line, and the number of pieces that can be written normally was visually observed and evaluated according to the following criteria.
○: Can be written within one circle of export △: Can be written within one line ×: Cannot be written within one line or cannot be written

Write test after lapse of time Each of the 20 ballpoint pens obtained as described above was prepared, and 10 of each were left in an upright (cap upward) and inverted (cap downward) state for 60 days, and then the cap was removed to expose the chip. In this state, after standing for 14 days in a horizontal position at 20 ° C., handwritten on black drawing paper, writing 12 circles in a row in succession, from what number can be normally written, and compared with the initial handwriting. Whether or not there is a difference in shading was visually observed and evaluated according to the following criteria.
○: Writable within 1 circle and no difference in density △: Written within 1 circle, but there is a difference in shade in handwriting ×: Impossible to write

Table 3 shows the test results.

Claims (4)

It comprises at least titanium oxide surface-treated with zinc oxide, hollow resin particles, water, a thickener, a dispersant, and a naphthalene sulfonic acid formalin condensate and / or an alkyl naphthalene sulfonic acid formalin condensate for anti-drying. A water-based ink composition for ballpoint pens.   The aqueous ballpoint pen according to claim 1, wherein the naphthalene sulfonic acid formalin condensate and / or the alkyl naphthalene sulfonic acid formalin condensate are blended in an amount of 0.05 to 5.0% by mass in the total amount of the ink composition. Ink composition.   The water-based ink composition for ballpoint pens according to claim 1 or 2, wherein the total addition amount of the titanium oxide and the hollow resin particles is 15% by mass or more based on the total amount of the ink composition. 4. A ballpoint pen comprising the water-based ink composition for ballpoint pens according to claim 1 incorporated therein.