JP2021107519A - Water-based ink composition for writing instruments and writing instrument that stores the same - Google Patents

Abstract

To provide a water-based ink composition for writing instruments that has excellent ink discharge stability, suppresses a failure in handwriting such as fading and line skipping, and can form clear handwriting, and also features excellent dryability of the handwriting formed on a paper surface, and a writing instrument that stores the same.SOLUTION: A water-based ink composition for writing instruments has at least a colorant, water, and alkyl polyglucoside having a C7-11 alkyl group, wherein: the alkyl polyglucoside is added in a range of 0.5-20 mass% relative to the total amount of the water-based ink composition; a surface tension of the water-based ink composition for writing instruments is set to 20-50 mN/m, and a viscosity thereof is set to 1-20 mPa s. There is also provided a writing instrument that stores the water-based ink composition for writing instruments.SELECTED DRAWING: None

Description

The present invention relates to a water-based ink composition for a writing tool and a writing tool containing the composition. More specifically, the present invention relates to a water-based ink composition for a writing tool, which has excellent ink ejection stability and good handwriting drying property, and a writing tool containing the composition.

Conventionally, inks using water as a main solvent (water-based inks) have been known, and are widely used because of their low odor and high safety. Water-based inks are inferior in dryness of handwriting compared to inks (oil-based inks) that use a volatile organic solvent as the main solvent, and touching the handwriting immediately after writing may stain the paper surface and fingers around the handwriting. Therefore, studies have been conducted to improve the dryness of handwriting formed by water-based ink (see, for example, Patent Document 1).
Patent Document 1 discloses an aqueous ink composition containing at least a colorant, water, and 1,4-cyclohexanedimethanol. The above-mentioned water-based ink composition accelerates the drying of the writing line immediately after writing, but the solvent is highly volatile and the stability over time is insufficient, and the ink ejection stability of the water-based ink composition is lowered to cause cassoulet. In some cases, it was not possible to form a clear handwriting due to poor handwriting such as line skipping.

Japanese Unexamined Patent Publication No. 2000-319570

The present invention is intended to provide a water-based ink composition for a writing instrument which is excellent in ink ejection stability, can form a clear handwriting, and has good drying property of the formed handwriting, and a writing instrument containing the composition.

The present invention requires at least a water-based ink composition for stationery, which comprises a colorant, water, and an alkyl polyglucoside having an alkyl group having 7 to 11 carbon atoms.
Further, the alkyl polyglucoside is added in the range of 0.5 to 20% by mass in the total amount of the aqueous ink composition, the surface tension is 20 to 50 mN / m, and the EL type viscosity at 20 ° C. It is required that the viscosity at a rotation speed of 20 rpm by the meter is 1 to 20 mPa · s.
Further, a writing tool containing the water-based ink composition for writing tools is required.

The present invention is an aqueous ink composition for writing instruments containing an alkyl polyglucoside having an alkyl group having 7 to 11 carbon atoms, and is excellent in ink ejection stability because it is smoothly supplied to the pen tip of a writing instrument. It is possible to provide a water-based ink composition for a writing instrument, which can suppress handwriting defects such as line skipping and line skipping, can form a clear handwriting having excellent color development, and have good dryness of the formed handwriting, and a writing instrument containing the composition.

The water-based ink composition for writing tools of the present invention (hereinafter, may be referred to as "water-based ink composition", "ink composition", or "ink") includes at least a colorant, water, and 7 to 11 carbon atoms. It consists of an alkyl polyglucoside having an alkyl group of. Hereinafter, each component constituting the water-based ink composition of the present invention will be described.

The colorant applied to the water-based ink composition of the present invention is not particularly limited as long as it is a dye or pigment that can be dissolved or dispersed in an water-based medium.
Examples of the dye include acid dyes, basic dyes, and direct dyes.
Specifically, as acid dyes, ponceau (CI 16255), tartrazine (CI 19140), acid blue black 10B (CI 20470), guinea green (CI 42085), Brilliant Blue FCF (CI 42090), Acid Violet 6B (CI 42640), Solve Blue (CI 42755), Naphthalene Green (CI 44825), Eosin (CI 45380) ), Phloxine (CI 45410), erythrosine (CI 45430), niglosin (CI 50420), acid flavin (CI 56205) and the like.
Specifically, as basic dyes, chrysoidine (CI 11270), methyl violet FN (CI 42535), crystal violet (CI 42555), malachite green (CI 42000), Victoria. Examples thereof include blue FB (CI 44045), rhodamine B (CI 45170), acridine orange NS (CI 46005), methylene blue B (CI 52015) and the like.
Specifically, as direct dyes, Congo Red (CI 22120), Direct Sky Blue 5B (CI 24400), Violet BB (CI 27905), Direct Deep Black EX (CI 30235). ), Kayaras Black G Conc (CI 35225), Direct First Black G (CI 35255), Phthalocyanine Blue (CI 74180) and the like can be exemplified.

Examples of the pigment include inorganic pigments, organic pigments, brilliant pigments, fluorescent pigments, phosphorescent pigments and the like.
Examples of the inorganic pigment include titanium oxide such as carbon black, rutile type and anatase type, zinc oxide, iron black, yellow iron oxide, petals, ultramarine blue and the like. Further, it is also possible to use an aqueous dispersion pigment or the like which is finely and stably dispersed in an aqueous medium by using a surfactant or a resin in advance.
Specifically, as an inorganic pigment, C.I. I. Pigment Blue 15: 3B [manufactured by Sanyo Dye Co., Ltd., trade name: Sandye Super Blue GLL-E (solid content: 24%)], C.I. I. Pigment Red 146 [manufactured by Sanyo Dye Co., Ltd., trade name: Sandye Super Pink FBL (solid content: 21.5%)], C.I. I. Pigment Yellow 81 [manufactured by Dainichiseika Kogyo Co., Ltd., trade name: TC Yellow FG (solid content: about 30%)], C.I. I. Pigment Red 220/166 [manufactured by Dainichiseika Kogyo Co., Ltd., trade name: TC Red FG (solid content: about 35%)] and the like can be exemplified.
Specific examples of the resin for dispersing the inorganic pigment include polyamide resin, polyurethane resin, polyester resin, epoxy resin, melamine resin, phenol resin, silicone resin, polyvinyl alcohol, polyvinylpyrrolidone, polyvinyl acetate resin, and polyvinyl chloride resin. , Polyvinylidene chloride resin, polystyrene resin, acrylic acid resin, maleic acid resin, gum arabic, cellulose, dextran, casein, derivatives thereof, copolymers of the above resins and the like can be exemplified.

Organic pigments include azo pigments, phthalocyanine pigments, quinacridone pigments, perylene pigments, perinone pigments, isoindolinone pigments, isoindolin pigments, dioxazine pigments, thioindigo pigments, anthraquinone pigments, and quinophthalone pigments. Examples thereof include pigments, diketopyrrolopyrrole pigments, slene pigments, indigo pigments, phthalone pigments, methine / azomethine pigments, and metal complex pigments.

Glittering pigments include metallic glossy pigments in which the surface of a core material such as a glass piece is coated with gold, silver, etc., and a metal oxide such as titanium oxide on the surface of a core material such as natural mica, synthetic mica, and flaky aluminum oxide. Metal pigments obtained by peeling off a metal vapor deposition film such as aluminum formed on a base material such as pearl pigments, cholesteric liquid crystal pigments, metal powder pigments, films, etc. coated with, and metals such as aluminum on colorless transparent or colored transparent films. Examples thereof include metal pigments having a vapor-deposited film formed and powder-treated.

Specifically, as a metallic luster pigment in which the surface of a core substance such as a glass piece is coated with gold, silver, etc., manufactured by Nippon Sheet Glass Co., Ltd., trade names: Metashine 5480PS, 5230PS, 5150PS, 5090PS, 2080PS , 1030PS, 2025PS, 1030GP, 2080GP and the like can be exemplified.

Specific examples of pearl pigments in which the surface of natural mica is coated with titanium oxide are manufactured by Merck & Co., Inc., trade names: Iriodin 100, 111, 120, 153, 201, 211, 223, 231. Examples thereof include the same 302, the same 323, the same 520, the same 522, and the same 524.
Further, as a pearl pigment in which the surface of synthetic mica is coated with titanium oxide, specifically, it is manufactured by Nippon Koken Kogyo Co., Ltd., trade name: TWINCLE PEARL SXB, YXB, RXB, BXB, SXD, YXD. , RXD, BXD, SX, YX, RX, BX,
Made by Nippon Koken Kogyo Co., Ltd., Product names: ULTIMICA SB-100, SD-100, SE-100, SF-100, SH-100, YB-100, YE-100, YF- 100 etc. can be exemplified.
Further, as a pearl pigment in which the surface of flaky aluminum oxide is coated with titanium oxide, specifically, manufactured by Merck Group, trade name: Xirallic T60-10 WNT Cristal Silver, T60-20 WNT Sunbeam Gold, T60- Examples thereof include 21 WNT Solaris Red, T60-23 WNT Galaxy Blue, T60-24 WNT Stellar Green, and T60-25 WNT Cosmic Turquoise.

Specific examples of the cholesteric liquid crystal pigment include Wacker Chemie's trade name: HELICONE HC Sapphire, Scarabeus, Jade, and Maple.

Examples of the metal powder pigment include metal powder pigments having a metallic luster such as aluminum powder, brass powder, stainless steel powder, and bronze powder, and metal powder pigments in which colorants such as dyes and pigments are adsorbed on these metal powder pigments. Can be mentioned. Further, it is also possible to use a pigment dispersion in which the above metal powder pigment is processed in advance with a surfactant, a resin, a solvent or the like and dispersed to form a paste, or a liquid metal powder pigment dispersion.

Examples of the fluorescent pigment include synthetic resin fine particle fluorescent pigments in which various fluorescent dyes are solid-solved in a resin matrix.

As the phosphorescent pigment, a general-purpose pigment is used as long as it has the property of absorbing and accumulating light rays such as the sun and electric lamps, and gradually emitting light in a dark place to emit light (this is called afterglow). Examples thereof include phosphorescent pigments such as CaS / Bi-based, CaSrS / Bi-based, ZnS / Cu-based, ZnCdS / Cu-based, and SrAl2O4 / rare earth metal-based.

The above colorants may be used alone or in admixture of two or more, and are preferably blended in the range of 1 to 50% by mass, more preferably 3 to 30% by mass, based on the total amount of the ink composition. NS. If the blending ratio of the colorant exceeds 50% by mass, the ink ejection stability of the writing instrument containing the ink composition is lowered, and handwriting defects such as blurring and line skipping are likely to occur. On the other hand, if the blending ratio of the colorant is less than 1% by mass, it becomes difficult to obtain a suitable handwriting concentration as a writing tool.
When the above pigment is used as the colorant, a pigment dispersant can be used if necessary. Examples of the pigment dispersant include anionic and nonionic surfactants, anionic polymers such as polyacrylic acid and styrene acrylic acid, and nonionic polymers such as PVP and PVA.

Further, as the colorant, a microcapsule pigment containing a thermochromic composition, a microcapsule pigment containing a dye or a pigment together with the thermochromic composition, or the like can also be used.
The thermochromic composition includes (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) a reaction that determines the temperature at which the color reaction of the above (a) and (b) components occurs. Examples thereof include a reversible thermochromic composition composed of a medium.
Examples of the reversible thermochromic composition include those before and after a predetermined temperature (discoloration point) described in Japanese Patent Publication No. 51-44706, Japanese Patent Publication No. 51-44707, Japanese Patent Publication No. 1-2398, and the like. Discolored in the temperature range above the high temperature side discoloration point, and exhibited in the temperature range below the low temperature side discoloration point. Of both states, only one specific state exists in the normal temperature range, and the other. The state of is maintained as long as the heat or cold required for the state to develop is applied, but returns to the state exhibited at room temperature when the heat or cold is not applied, and the hysteresis width is relatively small. A heat-decoloring type (decoloring by heating and developing color by cooling) reversible thermochromic composition having a characteristic (ΔH = 1 to 7 ° C.) can be used.

Further, relatively large hysteresis characteristics (ΔH = 8 to 50) described in JP-A-4-17154, JP-A-7-179777, JP-A-7-33997, JP-A-8-39936 and the like. It exhibits a large hysteresis characteristic described in JP-A-2006-137886, JP-A-2006-188660, JP-A-2008-45062, JP-A-2008-280523, and the like. That is, the shape of the curve plotting the change in color density due to temperature change is large in the case where the temperature is raised from the lower temperature side than the discoloration temperature range and the case where the temperature is lowered from the higher temperature side than the discoloration temperature range. The color changes by following different paths, and the color development state in the temperature range of the _{complete color development temperature t 1 or less, or the decolorization state in the high temperature range of the complete decolorization temperature t 4} or more is the specific temperature range [color development start temperature t ₂ ~. (decolored by heating, color is by cooling) heat-decolorizable with color-memorizing in a temperature range of between decoloring starting temperature t ₃ (substantially two-phase retaining temperature region)] the reversible thermochromic composition of Can be used.
Specifically, as the reversible thermochromic composition having the above-mentioned color memory applied to the present invention, the complete color development temperature can be obtained only in a freezer, a cold region, or the like, that is, −50 to 0 ° C. , Preferably -40 to -5 ° C, more preferably -30 to -10 ° C, and the complete decolorization temperature is the frictional heat of the friction body, the temperature obtained from a familiar heating body such as a hair dryer, that is, 50 to 95 ° C. By specifying the temperature in the range of preferably 50 to 90 ° C., more preferably 60 to 80 ° C., and specifying the ΔH value to 40 to 100 ° C., it is effective in maintaining the color exhibited in the normal state (daily living temperature range). Can work.

Further, as a reversible thermochromic composition, a heat-coloring type using a gallic acid ester described in Japanese Patent Publication No. 51-44706, Japanese Patent Application Laid-Open No. 2003-253149, etc. (coloring by heating and decoloring by cooling). The reversible thermochromic composition of) can also be used.

The reversible thermochromic composition is a companion containing the above components (a), (b), and (c) as essential components, and the ratio of each component is the concentration, discoloration temperature, discoloration form, and type of each component. However, in general, the component ratio at which the desired characteristics are obtained is (a) component 1, (b) component 0.1 to 100, preferably 0.1 to 50, and more preferably 0. It is in the range of 5 to 20, (c) component 1 to 800, preferably 5 to 200, and more preferably 10 to 100 (the above ratios are all parts by mass).

Although the reversible thermochromic composition can be used as it is, it is preferable to enclose it in microcapsules and use it as a reversible thermochromic microcapsule pigment. This is because a physically stable pigment can be formed, and further, the reversible thermochromic composition can be kept in the same composition under various usage conditions and can exert the same action and effect.
Microencapsulation is performed by conventionally known isocyanate-based interfacial polymerization methods, melamine-formaline-based in-Situ polymerization methods, in-liquid curing coating methods, phase separation methods from aqueous solutions, phase separation methods from organic solvents, and melt dispersion. There are a cooling method, an aerial suspension coating method, a spray drying method, etc., which are appropriately selected according to the application. Examples of the material of the capsule include epoxy resin, urea resin, urethane resin, isocyanate resin and the like.
Further, a secondary resin film may be further provided on the surface of the microcapsules depending on the purpose to impart durability, or the surface characteristics may be modified for practical use.
The reversible thermochromic microcapsule pigment preferably has a mass ratio of inclusions: wall film of 7: 1 to 1: 1, and the mass ratio of inclusions and wall film is within the above range. , It is possible to prevent deterioration of color density and sharpness at the time of color development. More preferably, the mass ratio of inclusions: wall membrane is 6: 1 to 1: 1.

The reversible thermochromic microcapsule pigment has an average particle size of 0.01 to 50 μm, preferably 0.1 to 30 μm, and more preferably 0.5 to 20 μm.
When the average particle size of the reversible thermochromic microcapsule pigment exceeds 50 μm, dispersion stability and processability are likely to be lacking when blending into ink, paint, or resin. On the other hand, if the average particle size is less than 0.01 μm, it becomes difficult to exhibit high-concentration color development.
For the measurement of the average particle size, the particle area is determined using the image analysis type particle size distribution measurement software [Manufactured by Mountech Co., Ltd., trade name: MacView], and the projected area circle equivalent diameter is determined from the area of the particle area. (Heywood diameter) is calculated and measured as the average particle size of particles corresponding to equal volume spheres based on the value.
If the particle size of all or most of the particles exceeds 0.2 μm, use a particle size distribution measuring device [Beckman Coulter Co., Ltd., trade name: Multisizer 4e] to equal volume by the Coulter method. It is also possible to measure as the average particle size of particles corresponding to spheres.
Furthermore, a laser diffraction / scattering type particle size distribution measuring device calibrated based on the numerical values measured using the above software or the measuring device by the Coulter method [manufactured by HORIBA, Ltd., trade name: LA- 300] may be used to measure the volume-based particle size and average particle size.

The above-mentioned reversible thermochromic microcapsule pigment is preferably blended in the range of 5 to 40% by mass, more preferably 10 to 40% by mass, and further preferably 15 to 35% by mass with respect to the total amount of the ink composition. .. If the blending ratio of the pigment exceeds 40% by mass, the ink ejection stability of the writing instrument containing the ink composition is lowered, and handwriting defects such as blurring and line skipping are likely to occur. On the other hand, if the blending ratio of the pigment is less than 5% by mass, it is difficult to obtain suitable discoloration property and handwriting density as a writing instrument, and it is difficult to sufficiently satisfy the discoloration function.

The water-based ink composition of the present invention contains an alkyl polyglucoside having an alkyl group having 7 to 11 carbon atoms.
Alkyl polyglucoside having an alkyl group having 7 to 11 carbon atoms lowers the surface tension of the ink composition, so that the wettability to the writing instrument member is improved, and the ink composition is smoothly supplied to the pen tip of the writing instrument. .. Therefore, the water-based ink composition of the present invention can exhibit excellent ink ejection stability, suppress handwriting defects such as blurring and line skipping, and can form clear handwriting with excellent color development.
Further, since the above-mentioned alkyl polyglucoside improves the wettability of the ink composition to a base material such as paper, the handwriting formed on the paper surface is excellent in drying property, and the handwriting immediately after writing is touched or scratched. At that time, it is possible to prevent the paper surface and fingers around the handwriting from being soiled.

The alkyl polyglucoside having an alkyl group having 7 to 11 carbon atoms is preferably blended in the range of 0.5 to 20% by mass, more preferably 1 to 15% by mass, based on the total amount of the ink composition. .. When the blending ratio of the alkyl polyglucoside having an alkyl group having 7 to 11 carbon atoms is within the above range, the surface tension of the ink composition is appropriately lowered, excellent ink ejection stability is exhibited, and handwriting is achieved. It is possible to obtain an ink composition capable of forming a clearer handwriting by suppressing handwriting defects such as line skipping and line skipping, and improving the drying property of the handwriting formed on the paper surface.

Specific examples of the alkyl polyglucoside having an alkyl group having 7 to 11 carbon atoms applied to the present invention are manufactured by SEPPIC, trade name: SIMULSOL SL 7 G (alkyl group having 7 carbon atoms), AS 48 (the same as AS 48). Alkyl group has 8 carbon atoms), B 865 (alkyl group has 8 to 10 carbon atoms), SL 8 (alkyl group has 8 to 10 carbon atoms), SL 11 W (alkyl group has 11 carbon atoms),
Manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., trade name: nonioside O-13 (alkyl group with 8 carbon atoms),
Examples thereof include Kao Corporation, trade name: Mydol 10 (10 carbon atoms of alkyl group) and the like.

The water applied to the water-based ink composition of the present invention is not particularly limited, and for example, tap water, ion-exchanged water, ultrafiltered water, distilled water and the like are used.

Further, the aqueous ink composition of the present invention contains, if necessary, a constitutional material such as kaolin, talc, mica, clay, bentonite, calcium carbonate, aluminum hydroxide, sericite, and potassium titanate, methanol, ethanol, and the like. Alcohols or glycols such as 1-propanol, 2-propanol, butanol, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, glycerin, diglycerin, and polyglycerin, Resin particles composed of polyolefin resin, acrylic resin, nylon resin, silicone resin, urethane resin, fluorine resin, etc., acrylic resin, urethane resin, styrene-butadiene copolymer resin, alkyd resin, sulfoamide resin, maleic acid resin, polyacetic acid. Vinyl resin, ethylene-vinyl acetate copolymer resin, vinyl chloride-vinyl acetate copolymer resin, copolymer of styrene and maleic acid ester, styrene-acrylonitrile copolymer resin, cyanate-modified polyalkylene glycol, ester gum, xylene resin, Fixation of urea resin, urea aldehyde resin, phenol resin, alkylphenol resin, terpenphenol resin, rosin resin and hydrogenated compound thereof, rosin phenol resin, polyvinyl alkyl ether resin, polyamide resin, polyolefin resin, polyester resin, cyclohexanone resin, etc. Agents, pH adjusters, benzotriazole, tolyltriazole, dicyclohexylammonium nitrate, diisopropylammonium nitrate, and rust preventives such as saponin, various surfactants such as urea, anion type, cationic type, nonionic type, and both sexes, polyvinyl Pigment dispersants consisting of alcohols, water-soluble resins such as polyvinylpyrrolidone, reduced or non-reduced starch hydrolysates, disaccharides such as trehalose, oligosaccharides, sucrose, cyclodextrin, glucose, dextrin, sorbit, mannit, and pyrrolin. Additives such as wetting agents such as sodium acid, chelating agents such as ethylenediamine tetraacetic acid and salts thereof, preservatives, bubble inhibitors, and bubble absorbers can also be applied.

The water-based ink composition of the present invention can be produced by any conventionally known method. Specifically, each of the above-mentioned components can be blended in a required amount and mixed with various stirrers such as a propeller stirrer, a homodisper, or a homomixer, or various dispersers such as a bead mill to produce the product.

The surface tension of the water-based ink composition of the present invention is preferably 20 to 50 mN / m, more preferably 20 to 40 mN / m, and even more preferably 25 to 40 mN / m. When the surface tension of the ink composition is within the above range, the ink ejection stability from the pen tip of the writing instrument is improved, handwriting defects such as blurring and line skipping are suppressed, and a clearer handwriting can be formed. , An ink composition having good wettability to a base material such as paper and excellent handwriting drying property can be obtained.
For the surface tension of the ink composition, an automatic surface tension meter [manufactured by Kyowa Interface Science Co., Ltd., trade name: DY-300] was used, and the ink composition was prepared using a platinum plate in an environment of 20 ° C. It is a value measured by the vertical flat plate method.

The viscosity of the aqueous ink composition of the present invention is preferably 1 to 20 mPa · s when measured at 20 ° C. under the condition of a rotation speed of 20 rpm, and more preferably 1 to 10 mPa · s. It is preferably 1 to 5 mPa · s, and more preferably 1 to 5 mPa · s. When the viscosity of the ink composition is within the above range, the ink ejection stability from the pen tip of the writing instrument is improved, handwriting defects such as blurring and line skipping are suppressed, and a clearer handwriting can be formed. Can be a thing.
The viscosity of the ink composition was measured using an EL type rotational viscometer [manufactured by Toki Sangyo Co., Ltd., trade name: RE-80L, cone type rotor: standard type (1 ° 34'x R24)]. The value.

The water-based ink composition of the present invention is a ballpoint pen, a marking pen, or a marking pen, which includes a pen tip, an ink filling mechanism, and an ink supply mechanism for supplying the ink composition to be filled in the ink filling mechanism to the pen tip. It is housed in various writing tools such as fountain pens.

The water-based ink composition of the present invention is smoothly supplied to the pen tip of a writing instrument, and excellent ink ejection stability can be exhibited regardless of the type of pen tip. The pen tip is not particularly limited, but a pen tip provided with various chips is used.
Among various tips, the ball pen tip includes, for example, 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, and cutting a metal material with a drill or the like. A chip formed by holding a ball in a ball holding portion formed by processing, a chip provided with a resin ball receiving seat inside a metal or plastic chip, or a ball held by the chip is forward by a spring body. Examples of those urged to the above can be given. The material of the ballpoint pen tip and the ball is not particularly limited, and specific examples thereof include cemented carbide, stainless steel, ruby, ceramic, resin, rubber, etc., and the diameter of the ball is 0.1 mm. Those in the range of ~ 2.0 mm are preferably used. Further, the ball may be subjected to a surface treatment such as DLC coating.
Examples of the marking pen tip include a fiber tip, a felt tip, a plastic tip, and a brush.
As the fountain pen-shaped tip (pen body), a metal plate such as a stainless steel plate or a gold alloy plate is cut into a tapered shape and bent or curved, or a pen tip shape is resin-molded. .. The pen body may be provided with a slit at the center or a ball portion at the tip.

The ink filling mechanism may be arranged behind the ink supply mechanism and directly fill the water-based ink composition, and an ink container or an ink occlusion body capable of filling the water-based ink composition may be provided. It may be provided.
When the writing instrument is configured to directly fill the water-based ink composition and a pigment is used as the colorant, the ink container is provided with a stirrer such as a stirrer ball for stirring the ink in order to facilitate the redispersion of the pigment. It is preferable to incorporate. Examples of the shape of the agitator include a spherical body and a rod-shaped body. The material of the agitator is not particularly limited, and specific examples thereof include metal, ceramic, resin, and glass.
When the writing tool is provided with an ink occlusion body capable of filling the water-based ink composition, a fiber bundle made of twisted fibers is preferably used as the ink occlusion body.

Further, the ink filling mechanism may be in the form of an ink cartridge as a detachable structure. In this case, since the writing tool body is used by replacing it with a new cartridge after the ink to be stored is used up, it is necessary to newly smoothly flow the ink composition in the ink storage part of the ink filling mechanism to the pen tip. Become. When the water-based ink composition of the present invention is applied to a writing instrument provided with an ink filling mechanism in the form of an ink cartridge, the ink composition in the ink storage unit smoothly flows to the pen tip when the ink cartridge is replaced with a new ink cartridge. A writing instrument exhibits excellent ink ejection stability, is less likely to cause poor writing marks, and has good drying properties of the writing marks formed on the paper surface, and is therefore preferably used.
As the ink cartridge, one that also serves as a shaft cylinder that constitutes a writing tool by being connected to the writing tool main body, or one that covers and protects the shaft cylinder (rear shaft) after being connected to the writing tool main body is used. In the latter case, in addition to using the ink cartridge alone, the writing instrument before use may be used by connecting the writing instrument body and the ink cartridge, or by connecting the ink cartridge in the barrel when the writing instrument user uses it. It may be any of those housed in the barrel in a disconnected state so as to start.

The ink supply mechanism is not particularly limited, but for example, (1) a mechanism provided with an ink guide core composed of a fiber bundle or the like as an ink flow rate regulator and supplying an ink composition to a pen tip, (2) a comb. A groove-shaped ink flow control body is provided, and a mechanism for supplying the ink composition to the pen tip via the groove-shaped ink flow control body. Through a pen core, which is provided with a slit-shaped ink guide groove and a ventilation groove wider than the groove, and an ink guide core for guiding ink from the ink filling mechanism to the pen tip is arranged at the axis. A mechanism for supplying the ink composition to the pen tip, (4) a mechanism for supplying the ink composition to the pen tip with an ink flow rate adjusting body by a valve mechanism, and (5) an ink container or a shaft provided with the pen tip. A mechanism for supplying the ink composition directly to the pen tip from the cylinder can be mentioned.
The material of the pen core is not particularly limited as long as it is a synthetic resin that can be injection-molded into a structure in which a large number of discs are formed into a comb groove shape. Specific examples of the synthetic resin include general-purpose polycarbonate resins, polypropylene resins, polyethylene resins, acrylonitrile-butadiene-styrene copolymer resins (ABS resins), and the like. In particular, an acrylonitrile-butadiene-styrene copolymer resin (ABS resin) is preferably used because it has high moldability and easily obtains pen core performance.
The ink container provided with the pen tip may be an ink refill having the above-mentioned ballpoint pen tip at the tip and filling the rear end with an ink backflow preventive body made of a viscous liquid such as grease.

The writing tool accommodating the water-based ink composition of the present invention can be configured by appropriately selecting each member from the above-mentioned pen tip, ink filling mechanism, and ink supply mechanism. The disk bodies are arranged in parallel with a comb groove-like interval, and a slit-shaped ink guide groove that runs through the disk body in the axial direction and a ventilation groove wider than the groove are provided, and a pen from the ink filling mechanism is provided at the axis. A writing tool provided with a pen core in which an ink guiding core for guiding ink is arranged first is used as a preferable writing tool in the present invention.
Normally, the pen core is molded from a synthetic resin, and the surface of the synthetic resin is relatively hydrophobic. Therefore, if the surface tension of the ink composition is high, the wettability to the pen core is poor and it is difficult to obtain ink ejection stability. Become. However, the writing instrument containing the water-based ink composition of the present invention has good wettability to the writing instrument member of the ink composition even when the writing instrument member such as the pen tip or the ink flow rate controller is made of synthetic resin, and the writing instrument. Since the ink composition is smoothly supplied to the pen tip of the writing instrument, the writing instrument can exhibit excellent ink ejection stability and form a clear writing instrument, and the writing instrument formed on the paper surface has good drying property. It is preferably used.

Further, a writing tool having an ink filling mechanism for directly filling the ink composition is used as a preferable writing tool in the present invention.
Writing instruments in which the ink composition is directly filled in the ink filling mechanism can form clear handwriting due to the large amount of ink ejected, and the ink composition can be used up to the end, and the ink filling mechanism is transparent. In this case, it is preferably used because the remaining amount of ink can be confirmed, but the dryness of the handwriting formed on the paper surface may be poor, and when the handwriting is touched or rubbed immediately after writing, the paper surface or fingers around the handwriting It is easy to get dirty. However, the writing instrument having the above configuration containing the water-based ink composition of the present invention is excellent in ink ejection stability, can suppress handwriting defects such as blurring and line skipping, and can form a clear handwriting, and at the same time, the ink composition. Since the wettability to a base material such as paper is good, the dryness of the handwriting formed on the paper surface is good, and it is difficult to stain the paper surface and fingers around the handwriting when touching or rubbing the handwriting immediately after writing. It is preferably used as a writing instrument.

A writing instrument equipped with a pen tip, an ink filling mechanism, and an ink supply mechanism is provided with a cap that is attached so as to cover the pen tip, or a pen tip that allows the pen tip to appear and disappear from the writing instrument body (shaft cylinder). It is preferable to provide a haunting mechanism, which can prevent the pen tip from becoming dry and unable to write, and the pen tip from being contaminated or damaged.
The pen tip infestation mechanism is as follows: (1) An operating portion (clip) that can move in the front-rear direction from the rear side wall of the barrel is projected outward in the radial direction, and the operating portion is slid forward to operate the pen of the writing tool. Side slide type infestation mechanism where the tip is infested, (2) Rear end knock type infestation mechanism in which the pen tip is infested by pressing the operation unit provided at the rear end of the shaft cylinder forward, (3) Outer surface of the side wall of the shaft cylinder A side knock type infestation mechanism in which the pen tip appears and disappears by pressing the more protruding operation part inward in the radial direction, and (4) a rotary type in which the pen tip appears and disappears by rotating the operation part at the rear of the barrel. Haunting mechanism can be mentioned.

As a writing tool accommodating the water-based ink composition of the present invention, the ink filling mechanism has a configuration in which the ink composition is directly filled, and the ink supply mechanism has a large number of discs arranged in parallel with a comb groove-like interval. A slit-shaped ink guide groove that runs through the disk in the axial direction and a ventilation groove wider than the groove are provided, and an ink guide core for guiding ink from the ink filling mechanism to the pen tip is provided at the axis. A writing tool provided with an arranged pen core is a more preferable writing tool in the present invention, and the ink ejection stability is further excellent, a clearer writing stroke can be formed, and the drying property of the writing stroke is good. It is more preferably used as a practical writing tool that does not easily stain the paper surface and fingers around the brush when it is touched or rubbed immediately after.

Examples are shown below, but the present invention is not limited thereto. In addition, the part in an Example shows a mass part.

Example 1
Preparation of Aqueous Ink Composition The following materials were blended in the following amounts and stirred and mixed at room temperature for 1 hour to prepare an aqueous ink composition.
・ 30.0 parts of black dye solution [Manufactured by Orient Chemical Industries Co., Ltd., trade name: Water Black 191-L (solid content: 15%)]
-Alkyl polyglucoside A 0.5 part (manufactured by SEPPIC, trade name: Simulsol SL 7 G)
-0.2 parts of preservative [manufactured by Lonza Japan Co., Ltd., product name: Proxel XL-2 (S)]
・ Ion-exchanged water 69.3 parts

Tables 1 and 2 below show the compositions of the water-based ink compositions of Examples 1 to 17 and Comparative Examples 1 to 6.
In each of the water-based ink compositions of Examples 2 to 17 and Comparative Examples 1 to 6, the types and amounts of the materials to be blended were changed as shown in Table 1 or Table 2 with respect to Example 1. Prepared.

The contents of the materials in the table will be explained along with the note numbers.
(1) Black dye solution [manufactured by Orient Chemical Industries Co., Ltd., trade name: Water Black 191-L (solid content: 15%)]
(2) Blue pigment dispersion [manufactured by Sanyo Dye Co., Ltd., trade name: Sandye Super Blue GLL-E (solid content: 24%)]
(3) Alkyl polyglucoside A
[Manufactured by SEPPIC, trade name: Simulsol SL 7 G (7 carbon atoms of alkyl group)]
(4) Alkyl polyglucoside B
[Manufactured by SEPPIC, trade name: Simulsol AS 48 (alkyl group having 8 carbon atoms)]
(5) Alkyl polyglucoside C
[Manufactured by SEPPIC, trade name: Simulsol B 865 (alkyl group having 8 to 10 carbon atoms)]
(6) Alkyl polyglucoside D
[Manufactured by SEPPIC, trade name: Simulsol SL 8 (alkyl group having 8 to 10 carbon atoms)]
(7) Alkyl polyglucoside E
[Manufactured by SEPPIC, trade name: Simulsol SL 11 W (alkyl group having 11 carbon atoms)]
(8) Alkyl polyglucoside F
[Manufactured by SEPPIC, trade name: Simulsol SL 4 (4 carbon atoms of alkyl group)]
(9) Alkyl polyglucoside G
[Manufactured by SEPPIC, trade name: Simulsol SL 26 C (alkyl group having 12 to 16 carbon atoms)]
(10) Preservative [manufactured by Lonza Japan Co., Ltd., trade name: Proxel XL-2 (S)]

Surface Tension Measurement For each aqueous ink composition prepared in Examples 1 to 17 and Comparative Examples 1 to 6, an automatic surface tension meter [manufactured by Kyowa Interface Science Co., Ltd., trade name: DY-300] was used. The surface tension was measured by the vertical plate method using a platinum plate in a room temperature (20 ° C.) environment.

Viscosity measurement For each water-based ink composition prepared in Examples 1 to 17 and Comparative Examples 1 to 6, an EL type rotational viscometer [manufactured by Toki Sangyo Co., Ltd., trade name: RE-80L, cone type rotor: A standard type (1 ° 34'x R24)] was used to measure the viscosity under the condition of a rotation speed of 20 rpm in an environment of room temperature (20 ° C.).

Preparation of Writing Tools Each water-based ink composition prepared in Examples 1 to 17 and Comparative Examples 1 to 6 is provided with a fountain pen-shaped writing tip and a pen core, and the ink composition is directly applied to the ink filling mechanism. A writing tool with a filled structure [manufactured by Pilot Corporation, trade name: V-pen middle character (SVP-4M)] was filled with 1.8 g in the ink storage part of the ink filling mechanism, and a cap was attached to prepare the writing tool. .. The pen core of the writing instrument was manufactured by injection molding an ABS resin material.

Evaluation of Ink Discharge Stability Using each writing instrument containing each of the water-based ink compositions of Examples 1 to 17 and Comparative Examples 1 to 6, handwritten on a test paper 15 cm in an environment of room temperature (20 ° C.). A straight line was written in 1 second, the formed handwriting was visually confirmed, and the ink ejection stability was evaluated from the state of the handwriting according to the following criteria. As the test paper, a writing paper conforming to the old JIS P3201 was used.
A: The writing was good, and no blurring or line skipping was confirmed in the handwriting.
B: The writing was slightly blurred, and the handwriting was also confirmed to have blurring and line skipping.

Evaluation of Handwriting Dryness Using each writing instrument containing each of the water-based ink compositions of Examples 1 to 17 and Comparative Examples 1 to 6, handwritten "permanent" on a test sheet in an environment of room temperature (20 ° C.). After a certain period of time had passed since the writing, the letters "Ei" were rubbed with a finger, and it was visually confirmed whether the ink spread around the handwriting. From the time until the handwriting dries, the handwriting dryness was evaluated according to the following criteria, and the evaluation "C" or higher (the handwriting dried within 5 seconds after writing) was regarded as acceptable. As the test paper, a writing paper conforming to the old JIS P3201 was used.
A: The handwriting dried within 1 second after writing.
B: The handwriting dried more than 1 second after writing and within 3 seconds.
C: The handwriting dried more than 3 seconds after writing and within 5 seconds.
D: The handwriting did not dry even after 5 seconds after writing.

Tables 3 and 4 below show the surface tension measurement, viscosity measurement, ink ejection stability, and handwriting drying property of each of the aqueous ink compositions of Examples 1 to 17 and Comparative Examples 1 to 6. The result of the evaluation is shown.

Claims (5)

A water-based ink composition for writing utensils, which comprises at least a colorant, water, and an alkyl polyglucoside having an alkyl group having 7 to 11 carbon atoms. The water-based ink composition for writing tools according to claim 1, wherein the alkylpolyglucoside is added in the range of 0.5 to 20% by mass in the total amount of the water-based ink composition. The water-based ink composition for writing tools according to claim 1 or 2, wherein the surface tension is 20 to 50 mN / m. The water-based ink composition for writing tools according to any one of claims 1 to 3, wherein the viscosity is 1 to 20 mPa · s at a rotation speed of 20 rpm by an EL type rotational viscometer at 20 ° C. A writing tool containing the water-based ink composition for writing tools according to any one of claims 1 to 4.