WO2024005056A1 - Composition d'encre aqueuse pour instrument d'écriture, et instrument d'écriture contenant celle-ci - Google Patents

Composition d'encre aqueuse pour instrument d'écriture, et instrument d'écriture contenant celle-ci Download PDF

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Publication number
WO2024005056A1
WO2024005056A1 PCT/JP2023/023934 JP2023023934W WO2024005056A1 WO 2024005056 A1 WO2024005056 A1 WO 2024005056A1 JP 2023023934 W JP2023023934 W JP 2023023934W WO 2024005056 A1 WO2024005056 A1 WO 2024005056A1
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Prior art keywords
ink
pigment
ink composition
guanine
examples
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PCT/JP2023/023934
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English (en)
Japanese (ja)
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遊之 尾関
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株式会社パイロットコーポレーション
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Publication of WO2024005056A1 publication Critical patent/WO2024005056A1/fr

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B43—WRITING OR DRAWING IMPLEMENTS; BUREAU ACCESSORIES
    • B43K—IMPLEMENTS FOR WRITING OR DRAWING
    • B43K7/00—Ball-point pens
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B43—WRITING OR DRAWING IMPLEMENTS; BUREAU ACCESSORIES
    • B43K—IMPLEMENTS FOR WRITING OR DRAWING
    • B43K8/00—Pens with writing-points other than nibs or balls
    • B43K8/02—Pens with writing-points other than nibs or balls with writing-points comprising fibres, felt, or similar porous or capillary material
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D11/00—Inks
    • C09D11/16—Writing inks
    • C09D11/17—Writing inks characterised by colouring agents

Definitions

  • the present disclosure relates to a water-based ink composition for writing instruments and a writing instrument containing the same. More specifically, the present invention relates to an aqueous ink composition for a writing instrument that has excellent pigment dispersion stability and is capable of forming clear handwriting with excellent concealment properties, and a writing instrument containing the same.
  • ink compositions for writing instruments using white pigments such as titanium oxide have been known in order to obtain handwriting with hiding properties.
  • ink compositions for writing instruments that can form pastel-like handwriting by blending colorants of other colors with such ink compositions with high hiding properties are also preferably used.
  • titanium oxide is a pigment with a high specific gravity
  • the pigment tends to settle over time, and when a hard cake is formed, it becomes difficult to redisperse the pigment.
  • writing instruments using ink compositions containing titanium oxide tend to lose handwriting density when stored with the writing tip facing upward, and the ink ejection properties tend to decrease when stored with the writing tip facing downward. It becomes easier to decrease. For this reason, studies are being conducted to increase the viscosity of the ink using thickeners and the like to suppress the precipitation of titanium oxide.
  • Patent Document 1 discloses an aqueous pigment composition comprising titanium oxide, an aluminum silicate pigment, and a specific resin.
  • Patent Document 2 discloses an aqueous ink composition comprising at least titanium oxide, succinoglycan, and water.
  • Patent Document 3 discloses a water-based ink for ballpoint pens consisting of titanium oxide and oleic acid.
  • Patent Document 4 describes an aqueous writing instrument comprising titanium oxide, a chromatic pigment, silica powder and/or aluminosilicate, a water-soluble resin, a specific dispersant, a surfactant, and water.
  • a pigmented ink is disclosed.
  • titanium oxide may settle over time and form a hard cake, or in the ink. It was difficult to stably disperse titanium oxide in an ink composition because color separation was likely to occur.
  • the present disclosure aims to provide a water-based ink composition for a writing instrument that has excellent pigment dispersion stability and can form clear handwriting with excellent concealment properties, and a writing instrument containing the same.
  • Aspect 1 of the present invention is The present invention is an aqueous ink composition for a writing instrument comprising at least a pigment containing a guanine pigment and water.
  • Aspect 2 of the present invention is The ink composition according to aspect 1, further comprising a dispersant.
  • Aspect 3 of the present invention is The ink composition according to aspect 2, wherein the dispersant has an acidic group and/or a salt of an acidic group.
  • Aspect 4 of the present invention is The ink composition according to any one of aspects 1 to 3, wherein the guanine pigment has an average particle diameter of 0.1 to 1 ⁇ m.
  • Aspect 5 of the present invention is The ink composition according to any one of aspects 1 to 4, wherein the content of the guanine pigment with respect to the total mass of the ink composition is 1 to 50% by mass.
  • Aspect 6 of the present invention is The ink composition according to any one of aspects 1 to 5, further comprising a colorant.
  • Aspect 7 of the present invention is A writing instrument containing the ink composition according to any one of aspects 1 to 6.
  • an aqueous ink composition for writing instruments using a pigment containing a guanine pigment in which the pigment is difficult to settle over time, has excellent pigment dispersion stability, and has a clear color with excellent hiding properties. It is possible to provide a water-based ink composition for a writing instrument that can form handwriting, and a writing instrument containing the same.
  • the aqueous ink composition for writing instruments (hereinafter sometimes referred to as "ink composition” or “ink”) according to the embodiment of the present invention contains at least a pigment containing a guanine pigment and water.
  • a pigment containing a guanine pigment contained in the aqueous ink composition according to the embodiment of the present invention.
  • the ink composition according to the embodiment of the present invention contains a guanine pigment.
  • a guanine pigment is a pigment made of guanine.
  • Guanine is one of the main bases constituting nucleic acids, and is an organic substance derived from living organisms. For example, it exists in a crystalline state on the body surface of fish such as hairtail, herring, and sardines. Crystalline guanine (guanine crystals) forms a layered structure on the body surface of these fish, reflecting or refracting light, so fish such as hairtail, herring, and sardines have a glossy (pearlescent) surface on their body surfaces. gender).
  • guanine is considered to be a highly safe compound, and is safe for the human body and the environment. It has little impact.
  • Guanine can be obtained from commercial products, but natural guanine crystals collected from fish such as hairtail, herring, and sardines may also be used. Furthermore, artificial guanine crystals obtained by dissolving commercially available or natural guanine crystals in a solvent and recrystallizing the crystals can also be used.
  • Titanium oxide which is conventionally used as a white pigment, has a high specific gravity and therefore tends to settle in the ink composition, and when it settles, it tends to form a hard cake, which may make redispersion difficult.
  • guanine pigment since guanine pigment has a lower specific gravity than titanium oxide, it is less likely to settle over time and has excellent dispersion stability, thereby suppressing the formation of a hard cake.
  • the ink composition according to the embodiment of the present invention uses a pigment containing a guanine pigment, so that the pigment is difficult to settle over time and has excellent dispersion stability. Therefore, the ink composition according to the embodiment of the present invention can form clear handwriting with excellent concealment properties at a uniform density. Further, even when the ink composition according to the embodiment of the present invention contains a colorant described below, separation of the guanine pigment and the colorant in the ink composition is suppressed. Therefore, the ink composition according to the embodiment of the present invention can form colored handwriting with concealing properties at a uniform density.
  • the average particle diameter of the guanine pigment is not particularly limited, but is preferably 0.1 to 1 ⁇ m, more preferably 0.2 to 0.95 ⁇ m, even more preferably 0.25 to 0.65 ⁇ m, and particularly preferably 0. It is in the range of .25 to 0.4 ⁇ m. When the average particle diameter is within the above range, the hiding properties of the ink composition and the dispersion stability of the guanine pigment are both highly compatible.
  • the average particle diameter was measured using a dynamic light scattering particle size distribution measuring device [manufactured by Microtrac Bell Co., Ltd., product name], which was calibrated based on values measured using standard samples or other measurement methods. : NANOTRAC FLEX] is the value of the average particle diameter (median diameter) on a volume basis. Note that even if the ink composition according to the embodiment of the present invention contains pigments other than guanine pigments, the above can be achieved by separating guanine and other pigments by density gradient centrifugation using the difference in specific gravity. Similarly, the average particle size of guanine alone can be measured.
  • the content of the guanine pigment with respect to the total mass of the ink composition is not particularly limited, but is preferably in the range of 1 to 50% by mass, more preferably 5 to 30% by mass.
  • the content of the guanine pigment exceeds 50% by mass, the ink ejection stability of a writing instrument containing the ink composition tends to decrease, and writing defects such as blurring and line skipping tend to occur.
  • the content is less than 1% by mass, it will be difficult to obtain a suitable handwriting density for a writing instrument, and the concealability of handwriting will be likely to be impaired.
  • the guanine pigment is not particularly limited as long as it can be dispersed in the ink composition.
  • the guanine pigment can be produced, for example, by mechanically pulverizing commercially available products or natural or artificial guanine crystals into particles using various dispersing machines such as jet mills, attritors, and bead mills. Alternatively, it can also be produced by dissolving commercially available or natural guanine crystals in a solvent and recrystallizing them into particles.
  • a colored guanine pigment itself can also be used.
  • the ink composition according to the embodiment of the present invention can further contain a dispersant.
  • the dispersant adsorbs to the surface of the guanine pigment and separates the guanine pigments from each other while keeping the distance between the guanine pigments above a certain level and preventing agglomeration, improving the dispersibility of the guanine pigment in the ink. be able to. Further, even when guanine pigments aggregate with each other to form aggregates, since aggregates with low density are formed, hard cake formation after the guanine pigments are precipitated can be easily suppressed.
  • dispersant examples include surfactants, polymer dispersants, inorganic compounds, and the like.
  • surfactant used as a dispersant examples include nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, and the like.
  • polymer dispersants used as dispersants include polyvinyl butyral; polyvinyl ether; ketone resin; carboxylic acid such as styrene-maleic acid copolymer, styrene-acrylic acid copolymer, acrylic acid-sulfonic acid copolymer
  • examples include resins containing groups; hydroxyethyl cellulose and derivatives thereof; acrylic polymers; PO/EO adducts; amine oligomers of polyesters.
  • Examples of the inorganic compound used as a dispersant include pyrophosphate, hexametaphosphate, and the like.
  • the dispersant preferably has acidic groups and/or salts of acidic groups.
  • An acidic group and/or a salt of an acidic group easily binds to guanine (for example, -NH 2 group in guanine, etc.), and the dispersant tends to gather around the guanine, so it is excellent as a dispersant.
  • the acidic group include a phosphoric acid group, a carboxy group, a sulfonic acid group, a phosphoric acid ester group, a sulfuric acid ester group, a nitric acid ester group, a phosphorous acid group, a phosphonic acid group, and a sulfinic acid group.
  • salts of acidic groups include metal salts such as potassium salts and sodium salts of the above-mentioned acidic groups, and 2-amino-2-methyl-1-propanol salts. These may be contained in one molecule or in combination of two or more.
  • Commercially available dispersants having acidic groups and/or salts of acidic groups include, for example, DISPER BYK series from BYK Chemie Japan Co., Ltd., Florene series from Kyoeisha Kagaku Co., Ltd., Aron series from Toagosei Co., Ltd., and BASF Japan Co., Ltd.
  • a dispersant having an acidic group and/or a salt of an acidic group can also function as a surfactant and/or a lubricant, such as a phosphate ester surfactant, but the embodiment of the present invention It is treated as a dispersant.
  • the molecular weight (mass average molecular weight) may be 300 or more and 200,000 or less, or 300 or more and 50,000 or less.
  • the dispersant preferably has an acid value. This makes it easier for the dispersant to bind to guanine.
  • the dispersant it is preferable that at least one of the following groups (a) to (e) is satisfied.
  • the acid value of the dispersant is 100 mgKOH/g or more
  • the acid value is 5 to 15 mgKOH/g, and the comb-shaped structure (i.e., a structure in which branch polymer parts are grafted to the main polymer part)
  • Both acid value and amine value are 15 or more and less than 30.
  • Examples of commercially available dispersants that have an acidic group and/or a salt of an acidic group and satisfy the above (a) include DISPER BYK-102 [manufactured by BYK Chemie Japan Co., Ltd.] and Joncryl 57J [manufactured by BASF Japan Co., Ltd.]. (manufactured by BASF Japan Ltd.), Jonkryl 63J (manufactured by BASF Japan Ltd.), Jonkryl 70J (manufactured by BASF Japan Ltd.), and the like.
  • Examples of commercially available dispersants having an acidic group and/or a salt of an acidic group and satisfying the above (b) include Solsperse 46000 (manufactured by Nippon Lubrizol Co., Ltd.) and Solsperse 47000 (manufactured by Nippon Lubrizol Co., Ltd.). [manufactured]] etc.
  • Examples of commercially available dispersants having an acidic group and/or a salt of an acidic group and satisfying the above (c) include Joncryl 57J [manufactured by BASF Japan Ltd.] and Joncryl 63J [manufactured by BASF Japan Ltd.]. [manufactured by BASF Japan Co., Ltd.], and Jonkryl 70J [manufactured by BASF Japan Co., Ltd.].
  • the acrylic-sulfonic acid copolymer may be in the form of a metal salt (preferably a sodium salt) or an unneutralized type, and is preferably an unneutralized type.
  • Examples of commercially available dispersants that have an acidic group and/or a salt of an acidic group and satisfy the above (e) include DISPER BYK-2010 [manufactured by BYK-Chemie Japan Co., Ltd.], Florene G-700AMP [Kyoeisha Chemical Co., Ltd.] Co., Ltd.].
  • the content of the dispersant relative to the guanine pigment is not particularly limited, but is preferably 0.1 to 100% by mass, more preferably 1 to 100% by mass.
  • the amount is 50% by weight, more preferably 5 to 30% by weight.
  • the content of the dispersant is within the above range, the dispersibility of the guanine pigment in the ink composition can be maintained more stably.
  • An ink composition according to an embodiment of the present invention comprises water.
  • Water is used as a dispersion medium to disperse the guanine. It is also possible to use an organic solvent or the like as a dispersion medium.
  • guanine is sparingly soluble in organic solvents (that is, slightly soluble), it is insoluble in water. It is important to use water in order to make more effective use of water.
  • many organic solvents have a small specific gravity (for example, ethanol has a specific gravity of 0.789), and when an organic solvent is used as a dispersion medium, the difference in specific gravity between the organic solvent and guanine becomes large, causing water to evaporate.
  • Water is not particularly limited, and examples include tap water, ion-exchanged water, ultrafiltrated water, and distilled water.
  • the content of water relative to the total mass of the ink composition is not particularly limited, but is preferably in the range of 10 to 90% by mass, more preferably 30 to 80% by mass.
  • the ink composition according to the embodiment of the present invention may further contain a colorant.
  • a colorant By using a guanine pigment and a coloring agent in combination, an ink composition exhibiting a colored (pastel-like color) having concealing properties can be obtained.
  • the colorant is not particularly limited as long as it is a dye or pigment that can be dissolved or dispersed in a solvent.
  • dyes examples include acid dyes, basic dyes, direct dyes, oil-soluble dyes, and disperse dyes.
  • acidic dyes examples include New Coccin (C.I. 16255), Tartrazine (C.I. 19140), Acid Blue Black 10B (C.I. 20470), Guinea Green (C.I. 42085), and Brilliant. Blue FCF (C.I.42090), Acid Violet 6B (C.I.42640), Soluble Blue (C.I.42755), Naphthalene Green (C.I.44025), Eosin (C.I.45380) , phloxine (C.I. 45410), erythrosin (C.I. 45430), nigrosine (C.I. 50420), acidflavin (C.I. 56205), and the like.
  • Examples of basic dyes include chrysoidine (C.I.11270), methyl violet FN (C.I.42535), crystal violet (C.I.42555), malachite green (C.I.42000), and Victoria blue.
  • Examples include FB (C.I.44045), Rhodamine B (C.I.45170), Acridine Orange NS (C.I.46005), and Methylene Blue B (C.I.52015).
  • direct dyes examples include Congo Red (C.I.22120), Direct Sky Blue 5B (C.I.24400), Violet BB (C.I.27905), and Direct Deep Black EX (C.I.30235). , Kayaras Black G Conch (C.I. 35225), Direct Fast Black G (C.I. 35255), and Phthalocyanine Blue (C.I. 74180).
  • oil-soluble dyes examples include C.I. I. Solvent Black 7, C. I. Solvent Black 123, C. I. Solvent Blue 2, C. I. Solvent Blue 25, C. I. Solvent Blue 55, C. I. Solvent Blue 70, C. I. Solvent Red 8, C. I. Solvent Red 49, C. I. Solvent Red 100, C. I. Solvent Violet 8, C. I. Solvent Violet 21, C. I. Solvent Green 3, C. I. Solvent Yellow 21, C. I. Solvent Yellow 44, C. I. Solvent Yellow 61, C. I. An example is Solvent Orange 37.
  • disperse dyes examples include C.I. I. Disperse Yellow 82, C. I. Disperse Yellow 3, C. I. Disperse Yellow 54, C. I. Disperse Red 191, C. I. Disperse Red 60, C. I. An example is Disperse Violet 57.
  • pigments examples include inorganic pigments, organic pigments, glitter pigments, fluorescent pigments, and luminescent pigments.
  • inorganic pigments examples include carbon black, iron black, yellow iron oxide, Bengara, and ultramarine blue.
  • organic pigments examples include azo pigments, phthalocyanine pigments, quinacridone pigments, perylene pigments, perinone pigments, isoindolinone pigments, isoindoline pigments, dioxazine pigments, thioindigo pigments, anthraquinone pigments, Examples include quinophthalone pigments, diketopyrrolopyrrole pigments, threne pigments, indigo pigments, phthalone pigments, methine/azomethine pigments, and metal complex pigments.
  • the pigment it is also possible to use a water-dispersed pigment, etc., in which the pigment is finely and stably dispersed in an aqueous medium using a surfactant and/or resin in advance.
  • resins for dispersing pigments include polyamide, urethane resin, polyester, epoxy resin, melamine resin, phenol resin, silicone resin, polyvinyl alcohol, polyvinylpyrrolidone, polyvinyl acetate, polyvinyl chloride, polyvinylidene chloride, polystyrene, and acrylic.
  • acrylic resins include acid resins, maleic acid resins, gum arabic, cellulose, dextran, casein, derivatives thereof, and copolymers of the above resins.
  • Glittering pigments include metallic luster pigments in which the surface of a core material such as glass pieces is coated with gold, silver, etc., natural mica, synthetic mica, flaky aluminum oxide, etc., and metal oxides such as titanium oxide on the surface of a core material such as flaky aluminum oxide.
  • fluorescent pigments examples include fluorescent pigments in the form of synthetic resin fine particles in which various fluorescent dyes are made into a solid solution in a resin matrix.
  • Luminescent pigments are general-purpose pigments that have the property of absorbing and accumulating light from the sun and/or electric lamps, and gradually emitting light in a dark place (this is called afterglow). Examples include phosphorescent pigments such as CaS/Bi type, CaSrS/Bi type, ZnS/Cu type, ZnCdS/Cu type, and SrAl2O4/rare earth metal type.
  • One type of colorant or a combination of two or more types can be used.
  • a pigment dispersant can be used as necessary.
  • the pigment dispersant include anionic and nonionic surfactants; anionic polymers such as polyacrylic acid and styrene-acrylic acid; nonionic polymers such as PVP and PVA.
  • dyes or pigments are effective when used as they are, but microcapsule pigments in which dyes or pigments are encapsulated in microcapsules, and/or resin particles containing dyes or pigments may also be used as colorants. Can be done. In particular, dyes or pigments can be isolated and protected from the external environment by being encapsulated in microcapsules, and the water resistance and light resistance of the encapsulated material can be improved.
  • a microcapsule pigment can be formed by encapsulating a colored body in which the above dye or pigment is dissolved or dispersed in an oily medium in microcapsules.
  • oil-based media examples include monobasic acid esters, dibasic acid monoesters, dibasic acid diesters, esters such as partial or complete esters of polyhydric alcohols, aromatic hydrocarbons such as alkylbenzenes and alkylnaphthalenes, and higher-grade esters.
  • esters such as partial or complete esters of polyhydric alcohols, aromatic hydrocarbons such as alkylbenzenes and alkylnaphthalenes, and higher-grade esters.
  • examples include alcohols, ketones, and ethers.
  • the oil-based medium can be used alone or in combination of two or more.
  • Microcapsule pigments can be microencapsulated using conventionally known isocyanate-based interfacial polymerization methods, melamine-formalin-based in-situ polymerization methods, in-liquid curing coating methods, phase separation methods from aqueous solutions, and phase separation methods from organic solvents. , melting and dispersion cooling method, air suspension coating method, spray drying method, etc., which are appropriately selected depending on the application.
  • the material for the capsule include epoxy resin, urea resin, urethane resin, and isocyanate resin.
  • a secondary resin film can be further provided on the surface of the microcapsules to impart durability or to modify the surface characteristics for practical use.
  • resin particles containing a dye examples include resin particles in which the above-described dye is homogeneously dissolved or dispersed, and resin particles in which a dye is dyed onto the resin particles.
  • the resin constituting the resin particles is not particularly limited, but thermosetting resins are preferred.
  • Thermosetting resins are preferable because they have better solvent resistance and heat resistance than thermoplastic resins, and they also have better migration resistance for the dyes they contain, which prevents dyes from eluting from the resin. be.
  • thermosetting resins guanamine resin or melamine resin is preferable because they can further suppress dye elution.
  • Examples of the resin particles containing a pigment include resin particles in which the above pigment is homogeneously dispersed in the resin particles, and resin particles in which the surface of the resin particles is coated with a pigment.
  • the resin constituting the resin particles is not particularly limited, and general-purpose resins can be used.
  • the resin particles can be produced by a pulverization method, a spray drying method, or a polymerization method in which polymerization is performed in the presence of a dye or pigment in an aqueous or oily medium.
  • polymerization methods include suspension polymerization, suspension polycondensation, dispersion polymerization, and emulsion polymerization.
  • the shape of the resin particles is not particularly limited, and spherical, polygonal, flat, and other resin particles can be used. Among these, it is preferable to use spherical resin particles.
  • the content of the colorant with respect to the total mass of the ink composition is not particularly limited, but is preferably from 0.01 to The amount is 50% by weight, more preferably 0.1 to 30% by weight.
  • the content of the colorant exceeds 50% by mass, the ink ejection properties of the writing instrument containing the ink composition tend to decrease, and writing defects such as blurring and line skipping tend to occur.
  • the content is less than 0.01% by mass, it becomes difficult to obtain a suitable handwriting density as a writing instrument.
  • thermochromic materials that change color due to temperature changes and/or photochromic materials that change color due to light irradiation. These color changes may be reversible or irreversible. Reversible thermochromic materials and/or reversible photochromic materials are suitable because they can repeatedly exhibit color changes due to temperature changes or light irradiation.
  • the reversible thermochromic material 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 components (a) and (b) above occurs.
  • Examples include reversible thermochromic compositions comprising a medium.
  • the heat-decolorizing type means that the color is decolored by heating and the color is developed by cooling.
  • This reversible thermochromic composition changes color before and after a predetermined temperature (color change point), becomes decolored at a temperature above the high temperature side discoloration point, and changes color at a temperature below the low temperature side discoloration point.
  • the heat-decolorizing type means that the color is decolored by heating and the color develops by cooling.
  • the shape of the curve plotting the change in color density due to temperature change is such that the shape of the curve is such that the temperature increases from a lower side than the discoloration temperature range, and vice versa.
  • the reversible thermochromic composition has a complete color development temperature t 1 in a freezing room or in a cold room. Specify the temperature that can only be obtained from the ground, etc., and the complete discoloration temperature t4 to be within the range of frictional heat from a friction body and the temperature that can be obtained from a familiar heating body such as a hair dryer, and specify the ⁇ H value between 40 and 100 degrees Celsius. By doing so, it is possible to effectively maintain the color exhibited under normal conditions (in the everyday living temperature range).
  • the temperature that can only be obtained in a freezing room, a cold region, etc. is in the range of -50 to 0°C, preferably in the range of -40 to -5°C, and more preferably in the range of -30 to -10°C.
  • the temperature obtained from a familiar heating element such as a hair dryer is in the range of 50 to 95°C, preferably 50 to 90°C, more preferably 60 to 80°C.
  • thermochromic compositions using gallic acid ester, which are described in Japanese Patent Publication No. 51-44706, Japanese Patent Application Laid-Open No. 2003-253149, etc., can also be used.
  • the heat coloring type means that the color develops when heated and the color disappears when cooled.
  • the reversible thermochromic composition is a compatible solution containing the above components (a), (b), and (c) as essential components, and the proportion of each component depends on the concentration, color change temperature, color change form, and each component. Depends on the type.
  • the component ratio at which desired characteristics can be obtained is (a) component 1 to (b) component 0.1 to 100, preferably 0.1 to 50, more preferably 0.5 to 20, ( c) Component ranges from 1 to 800, preferably from 5 to 200, more preferably from 10 to 100 (all the above ratios are parts by mass).
  • Examples of reversible photochromic materials include spirooxazine derivatives and spiropyran, which develop color when irradiated with sunlight, ultraviolet light, or blue light with a peak emission wavelength in the range of 400 to 495 nm, and disappear when irradiation is stopped.
  • Examples include photochromic compounds such as derivatives and naphthopyran derivatives.
  • spirooxazine derivatives include conventionally known indolinospirobenzoxazine compounds, indolinospironaphthoxazine compounds, indolinospirophenanthrooxazine compounds, and indolinospiroquinolinooxazine compounds.
  • photochromic compounds having photomemory properties include conventionally known fulgide derivatives, diarylethene derivatives, and the like.
  • a reversible photochromic composition in which the above photochromic compound is dissolved in various oligomers can also be used.
  • oligomers include styrene oligomers, acrylic oligomers, terpene oligomers, and terpene phenol oligomers.
  • styrenic oligomer examples include low molecular weight polystyrene, styrene/ ⁇ -methylstyrene copolymer, ⁇ -methylstyrene polymer, ⁇ -methylstyrene/vinyltoluene copolymer, and the like.
  • acrylic oligomer examples include acrylic ester copolymers.
  • terpene oligomer examples include ⁇ -pinene polymer, ⁇ -pinene polymer, and d-limonene polymer.
  • terpene phenol oligomer examples include ⁇ -pinene/phenol copolymer.
  • One type of oligomer or a combination of two or more types can be used.
  • thermochromic composition or reversible photochromic composition is effective when used as is, but it may be encapsulated in microcapsules to form a reversible thermochromic microcapsule pigment or a reversible photochromic microcapsule pigment. Alternatively, it can be dispersed in a thermoplastic resin or thermosetting resin to form reversible thermochromic resin particles or reversible photochromic resin particles, and used as a coloring agent applied to the embodiments of the present invention. can.
  • thermochromic microcapsule pigments and reversible photochromic microcapsule pigments may be referred to as "microcapsule pigments”
  • reversible thermochromic resin particles and reversible photochromic resin particles may be referred to as "resin particles”.
  • the reversible thermochromic composition or reversible photochromic composition is preferably encapsulated in microcapsules to form a reversible thermochromic microcapsule pigment or a reversible photochromic microcapsule pigment.
  • encapsulating it in microcapsules it is possible to construct chemically and physically stable microcapsule pigments, and furthermore, under various usage conditions, reversible thermochromic compositions or reversible photochromic compositions This is because the same composition can be maintained and the same effects can be achieved.
  • Microencapsulation can be achieved using conventionally known isocyanate-based interfacial polymerization methods, melamine-formalin-based in-situ polymerization methods, in-liquid curing coating methods, phase separation methods from aqueous solutions, phase separation methods from organic solvents, and melting and dispersion cooling. method, air suspension coating method, spray drying method, etc., which are appropriately selected depending on the purpose.
  • the material for the capsule include epoxy resin, urea resin, urethane resin, and isocyanate resin.
  • a secondary resin film can be further provided on the surface of the microcapsules to impart durability or to modify the surface characteristics for practical use.
  • the above microcapsule pigment preferably has a mass ratio of inclusions to wall film of 7:1 to 1:1, and when the mass ratio of inclusions to wall film is within the above range, Decrease in color density and sharpness can be prevented. More preferably, the mass ratio of inclusions to wall membrane is 6:1 to 1:1.
  • a microcapsule pigment that exhibits color change behavior from colored (1) to colored (2) can also be obtained.
  • the content of the colorant relative to the total weight of the ink composition is not particularly limited, but is preferably 5 to 40% by weight, more preferably 10 to 40% by weight. %, more preferably in the range of 15 to 35% by weight. If the content of the colorant exceeds 40% by mass, the ink ejection properties of the writing instrument containing the ink composition will be reduced, and writing defects such as blurring and line skipping will likely occur. On the other hand, if the content is less than 5% by mass, it is difficult to obtain suitable discoloration properties and handwriting density as a writing instrument, and it becomes difficult to fully satisfy the discoloration function.
  • the average particle diameter of the reversible thermochromic microcapsule pigment or resin particles or the reversible photochromic microcapsule pigment or resin particles is preferably 0.01 to 5 ⁇ m, more preferably 0.1 to 3 ⁇ m, and even more preferably 0. It is in the range of .5 to 3 ⁇ m.
  • the average particle diameter of the above-mentioned microcapsule pigment or resin particles exceeds 5 ⁇ m, it becomes difficult to obtain good ink ejectability when used in a writing instrument.
  • the average particle diameter is less than 0.01 ⁇ m, it becomes difficult to exhibit high-density color development.
  • the average particle diameter determines the particle area using image analysis particle size distribution measurement software [manufactured by Mountech Co., Ltd., product name: Macview], and calculate the projected area circle equivalent diameter from the area of the particle area. (Heywood diameter) is calculated, and the value is measured as the average particle diameter of particles equivalent to an equal-volume sphere based on the calculated value.
  • the particle diameter of all or most of the particles exceeds 0.2 ⁇ m, use a particle size distribution analyzer [manufactured by Beckman Coulter Co., Ltd., product name: Multisizer 4e] to divide the particles into equal volumes by the Coulter method. It is also possible to measure as the average particle diameter of particles equivalent to spheres.
  • a laser diffraction/scattering particle size distribution measuring device manufactured by Horiba, Ltd., product name: LA- 300] to measure the volume-based particle diameter and average particle diameter.
  • the ink composition according to the embodiment of the present invention can contain optional components within a range that does not impair the effects of the embodiment of the present invention.
  • the ink composition according to the embodiment of the present invention can be blended with a thickener to suppress aggregation and sedimentation of the pigment, thereby making it possible to obtain an ink composition having good stability over time.
  • a thickener conventionally known substances can be used, but it is preferable to use a substance that can impart shear thinning properties to the ink composition (shear thinning properties imparting agent).
  • An ink composition using a shear thinning agent has a high viscosity and is difficult to flow when it is left standing or under low stress, and easily lowers its viscosity when external stress is applied. Therefore, when not writing, ink leakage, ink separation and backflow can be prevented, and when writing, it is easy to improve the stability of ink discharge from the pen tip.
  • the ink composition when such an ink composition is used in a writing instrument (ballpoint pen) equipped with a ballpoint tip as a pen nib, the ink composition is high in viscosity when left standing without shearing stress, so the ink composition may not be present inside the ballpoint pen. is stably maintained. Therefore, during writing, strong shear stress is applied to the ink composition due to the rotation of the ball, and the ink composition near the ball is more likely to have a lower viscosity, so that the ink discharge stability can be improved.
  • the content of the thickener with respect to the total mass of the ink composition is not particularly limited, but is preferably 0.1 to 20% by mass. is within the range of
  • shear thinning agents include water-soluble polysaccharides, polymers with a molecular weight of 100,000 to 150,000 whose main component is an alkyl ester of methacrylic acid, crosslinked poly-N-vinylcarboxylic acid amide, benzylidene sorbitol, and its like.
  • examples include derivatives, benzylidene xylitol and its derivatives, alkali-thickened acrylic resins, cross-linked acrylic acid polymers, inorganic fine particles, nonionic surfactants with an HLB value of 8 to 12, metal salts or amine salts of dialkyl sulfosuccinic acid, etc. can.
  • shear thinning agent One type of shear thinning agent or a combination of two or more types can be used.
  • water-soluble polysaccharides examples include xanthan gum, welan gum, zetasea gum, diutan gum, macrohomopsis gum, and succinoglycan, which is an organic acid-modified heteropolysaccharide whose constituent monosaccharides are glucose and galactose (with an average molecular weight of about 1 million to 8,000,000), guar gum, locust bean gum and its derivatives, hydroxyethyl cellulose, alginate alkyl esters, glucomannan, agar, carrageenan, and other carbohydrates with gelling ability extracted from seaweed.
  • the ink composition according to the embodiment of the present invention may contain a polymer flocculant.
  • Polymer flocculants create a loose cross-linking effect between pigments, allowing the pigments to form loose aggregates via the polymer flocculant, suppressing direct aggregation of pigments and dispersing pigments. Stability can be improved.
  • the polymer flocculant has the effect of suppressing sedimentation of the pigment in the ink composition in the capillary gaps of the ink storage body provided in the marking pen described below. Therefore, it is suitable that an ink composition containing a polymer flocculant is applied to a marking pen equipped with an ink storage body.
  • the polymer flocculant can also be used in combination with the above-mentioned dispersant.
  • the dispersibility of loose aggregates formed via the polymer flocculant can be improved.
  • the content of the polymer flocculant with respect to the total mass of the ink composition is not particularly limited, but is preferably 0.05 to 1. It is in the range of % by mass.
  • polymer flocculants examples include polyvinylpyrrolidone, polyethylene oxide, water-soluble polysaccharides, and the like.
  • water-soluble polysaccharides examples include gum tragacanth, guar gum, pullulan, cyclodextrin, and water-soluble cellulose derivatives.
  • water-soluble cellulose derivatives include carboxymethylcellulose, methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxyethylmethylcellulose, and hydroxypropylmethylcellulose.
  • the ink composition according to the embodiment of the present invention can contain a surfactant, and the surface tension of the ink composition can be adjusted to an appropriate range.
  • Surfactants used to adjust the surface tension include nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, and any of them can be suitably used.
  • the content of the surfactant used for adjusting surface tension with respect to the total mass of the ink composition is not particularly limited. However, it is preferably in the range of 0.01 to 2% by weight, more preferably 0.05 to 1% by weight.
  • a pH adjuster can be added to the ink composition according to the embodiment of the present invention, and the pH of the ink composition can be adjusted to an appropriate range.
  • Various acidic or basic substances can be used as the pH adjuster.
  • acidic substances include hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, carbonic acid, boric acid, lactic acid, citric acid, tartaric acid, and malic acid.
  • Examples of basic substances include ammonia, sodium carbonate, sodium hydrogen phosphate, potassium hydrogen phosphate, sodium hydroxide, potassium hydroxide, sodium acetate, and alkanols such as monoethanolamine, diethanolamine, and triethanolamine. Amines can also be applied.
  • the content of the pH adjuster based on the total mass of the ink composition is not particularly limited, but is preferably 0.1 to 5% by mass. , more preferably in the range of 0.5 to 2% by mass.
  • the ink composition according to the embodiment of the present invention can contain a water-soluble organic solvent that is compatible with water, and can suppress water evaporation from the nib of a writing instrument.
  • water-soluble organic solvents examples include ethanol, propanol, butanol, glycerin, sorbitol, triethanolamine, diethanolamine, monoethanolamine, ethylene glycol, diethylene glycol, thioethylene 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 etc. can be exemplified.
  • the water-soluble organic solvents can be used alone or in combination of two or more.
  • the content of the water-soluble organic solvent with respect to the total mass of the ink composition is not particularly limited, but is preferably 1 to 40% by mass. , more preferably 5 to 30% by weight, and still more preferably 10 to 25% by weight. If the content of the water-soluble organic solvent exceeds 40% by mass, the ink viscosity tends to increase, the ink ejection performance of the writing instrument containing the ink composition decreases, and writing defects such as blurring and line skipping are likely to occur. On the other hand, if the content is less than 1% by mass, the effect of suppressing moisture evaporation will be poor.
  • the ink composition according to the embodiment of the present invention may contain a water-soluble resin such as an alkyd resin, an acrylic resin, a styrene-maleic acid copolymer, a cellulose derivative, a polyvinylpyrrolidone, a polyvinyl alcohol, or a dextrin. It can provide adhesion and viscosity to paper surfaces.
  • a water-soluble resin such as an alkyd resin, an acrylic resin, a styrene-maleic acid copolymer, a cellulose derivative, a polyvinylpyrrolidone, a polyvinyl alcohol, or a dextrin. It can provide adhesion and viscosity to paper surfaces.
  • One type of water-soluble resin or a combination of two or more types can be used.
  • the content of the water-soluble resin with respect to the total mass of the ink composition is not particularly limited, but is preferably 1 to 30% by mass, or more. It is preferably in the range of 1 to 10% by mass.
  • the ink composition according to the embodiment of the present invention may also contain various other additives as necessary.
  • additives examples include rust preventives, antiseptics, antifungal agents, bubble absorbers, wetting agents, antifoaming agents, specific gravity adjusters, and the like.
  • rust preventive agent examples include dicyclohexylammonium nitrite, diisopropylammonium nitrite, and saponin.
  • Preservatives or antifungal agents include carbolic acid, sodium salt of 1,2-benzothiazolin 3-one, sodium benzoate, sodium dehydroacetate, potassium sorbate, propyl paraoxybenzoate, 2,3,5,6-tetra Examples include chloro-4-(methylsulfonyl)pyridine.
  • Foam absorbers include ascorbic acids, erythorbic acids, ⁇ -tocopherol, catechins, synthetic polyphenols, kojic acid, alkylhydroxylamines, oxime derivatives, ⁇ -glucosylrutin, ⁇ -lipoic acid, phosphonates, phosphinates, Examples include sulfites, sulfoxylates, dithionites, thiosulfates, and thiourea dioxide.
  • wetting agents include reduced or non-reduced starch hydrolysates, disaccharides such as trehalose, oligosaccharides, sucrose, cyclodextrin, glucose, dextrin, sorbitol, mannitol, sodium pyrophosphate, and the like.
  • a lubricant can also be blended into the ink composition.
  • the lubricant improves the lubricity between the ball receiving seat provided inside the tip body and the ball provided at the front end of the tip body, making it easier to prevent wear on the ball receiving seat and improving the writing feel. It is something that can be done.
  • lubricant examples include higher fatty acids such as oleic acid, nonionic surfactants having long-chain alkyl groups, and polyether-modified silicone oil.
  • the method for producing the ink composition according to the embodiment of the present invention is not particularly limited, and any conventionally known method can be used.
  • the ink composition is prepared by stirring a mixture of the above-mentioned components with various stirrers such as propeller stirring, homodisper, or homomixer, or by dispersing it with various dispersion machines such as bead mills. can manufacture things.
  • the viscosity characteristics are not particularly limited.
  • ink compositions with viscosity characteristics such as high shear thinning ink compositions (gel inks), low viscosity and low shear thinning ink compositions, and low viscosity non-shear thinning ink compositions (Newtonian inks). objects can be used.
  • the guanine pigment applied to the embodiment of the present invention has excellent dispersion stability, and the pigment does not easily settle even if the ink composition has a low viscosity.
  • the following ink compositions are suitable.
  • the ink composition according to the embodiment of the present invention is used for a ballpoint pen, its viscosity is determined by the dispersion stability of the pigment when measured at a rotation speed of 1 rpm (shear rate 3.84 sec -1 ) in an environment of 20°C.
  • the following ranges are preferable because the properties can be more stabilized.
  • the viscosity of the ink composition in this case is preferably in the range of 1 to 2000 mPa ⁇ s, more preferably 10 to 1500 mPa ⁇ s, and still more preferably 100 to 1000 mPa ⁇ s.
  • the viscosity when measured at a rotational speed of 100 rpm (shear rate 384 sec -1 ) in an environment of 20°C, the viscosity is within the following range because the ink ejection performance from the tip of a ballpoint pen can be made good. is preferred.
  • the viscosity of the ink composition in this case is preferably in the range of 1 to 200 mPa ⁇ s, more preferably 10 to 100 mPa ⁇ s, and even more preferably 20 to 50 mPa ⁇ s.
  • the viscosity of the ink composition is within the above range, the dispersion stability of the pigment and the free flowability of the ink within the mechanism of the ballpoint pen can be maintained at a high level.
  • the viscosity of the ink composition was measured using a rheometer [manufactured by TA Instruments, product name: Discovery HR-2, cone plate (diameter 40 mm, angle 1°)] by placing the ink in an environment of 20°C. , a rotation speed of 1 rpm (shear rate 3.84 sec ⁇ 1 ), or a rotation speed of 100 rpm (shear rate 384 sec ⁇ 1 ).
  • the viscosity of the ink composition is determined to have a high fluidity of the ink and a high dispersion stability of the pigment when measured at a rotation speed of 50 rpm in an environment of 20°C.
  • the following ranges are preferable because they can be maintained at the same level.
  • the viscosity of the ink composition in this case is preferably in the range of 1 to 30 mPa ⁇ s, more preferably 1 to 20 mPa ⁇ s, even more preferably 1 to 10 mPa ⁇ s.
  • the viscosity of the ink composition was measured using an E-type rotational viscometer [manufactured by Toki Sangyo Co., Ltd., product name: RE-85L, cone rotor: standard type (1°34' x R24)]. This is a value measured with the composition placed in an environment at 20°C.
  • the ink composition according to the embodiment of the present invention is used for a ballpoint pen or a marking pen, its pH is preferably in the range of 6 to 10, more preferably 7 to 9.
  • the pH is within the above range, excessive increase in viscosity and deterioration of the ink composition can be suppressed.
  • the pH of the ink composition is a value measured using a pH meter [manufactured by DKK Toa Co., Ltd., product name: IM-40S] with the ink placed in an environment of 20°C.
  • the structure and shape of the ballpoint pen itself are not particularly limited. It is used as
  • a ballpoint pen tip consists of a tip body and a ball provided at the front end of the tip body.
  • a ballpoint pen tip is a tip in which a ball is held in a ball holding part where the tip of the tip body made of a metal pipe is deformed by pressing inward from the outer surface, or a tip made of a metal pipe with a ball held in the tip body.
  • An example is one in which a spring body urges forward.
  • the material of the chip body and the ball is not particularly limited, and examples thereof include cemented carbide (carbide), stainless steel, ruby, ceramic, resin, and rubber. Furthermore, the ball can also be subjected to surface treatment such as DLC coating.
  • the diameter of the ball is generally 0.2 to 3 mm, preferably 0.2 to 2 mm, more preferably 0.2 to 1.5 mm, and still more preferably 0.2 to 1 mm.
  • An example of the ink filling mechanism is an ink container that can be directly filled with ink.
  • the ink container for example, a molded body made of a thermoplastic resin such as polyethylene, polypropylene, polyethylene terephthalate, or nylon, or a metal tubular body is used.
  • a thermoplastic resin such as polyethylene, polypropylene, polyethylene terephthalate, or nylon
  • a ballpoint pen refill (hereinafter sometimes referred to as "refill") can be formed by connecting a ballpoint pen tip to the ink container directly or via a connecting member and directly filling the ink container with ink. can.
  • a ballpoint pen can be formed by housing this refill in the barrel.
  • An ink backflow prevention body is filled at the rear end of the ink filled in the ink container.
  • the ink backflow preventer include a liquid stopper or a solid stopper.
  • the liquid stopper consists of a non-volatile liquid and/or a slightly volatile liquid, such as vaseline, spindle oil, castor oil, olive oil, refined mineral oil, liquid paraffin, polybutene, ⁇ -olefin, oligomer or cooligomer of ⁇ -olefin, dimethyl
  • a slightly volatile liquid such as vaseline, spindle oil, castor oil, olive oil, refined mineral oil, liquid paraffin, polybutene, ⁇ -olefin, oligomer or cooligomer of ⁇ -olefin, dimethyl
  • silicone oil methylphenyl silicone oil, amino-modified silicone oil, polyether-modified silicone oil, and fatty acid-modified silicone oil.
  • the non-volatile liquid and/or the hardly volatile liquid can be used alone or in combination of two or more.
  • a thickener to the non-volatile liquid and/or the slightly volatile liquid to thicken it to a suitable viscosity.
  • Thickeners include, for example, silica with a hydrophobically treated surface, fine particle silica with a methylated surface, aluminum silicate, swelling mica, clay-based thickeners such as hydrophobically treated bentonite and montmorillonite; magnesium stearate. , fatty acid metal soaps such as calcium stearate, aluminum stearate, and zinc stearate; dextrin-based compounds such as tribenzylidene sorbitol, fatty acid amide, amide-modified polyethylene wax, hydrogenated castor oil, and fatty acid dextrin; and cellulose-based compounds.
  • solid plugs examples include solid plugs made of polyethylene, polypropylene, polymethylpentene, and the like.
  • the above-mentioned liquid plug and solid plug can also be used in combination.
  • a ballpoint pen equipped with a ballpoint pen tip and an ink filling mechanism further includes an ink supply mechanism for supplying the ink filled in the ink filling mechanism to the pen tip. may be provided.
  • the ink supply mechanism is not particularly limited, and includes, for example, (1) a mechanism that includes an ink guide core made of a fiber bundle or the like as an ink flow rate regulator and supplies ink to the pen tip through this intervening mechanism; ) A mechanism that includes a comb groove-shaped ink flow rate regulator and supplies ink to the pen tip through this intervening mechanism; (3) A large number of disc bodies are arranged in parallel with comb groove-shaped intervals, and the disc bodies are arranged in parallel in the axial direction. A slit-shaped ink guide groove running vertically through the pen core 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 arranged at the axis of the pen core. Examples include a mechanism that supplies ink to the pen tip.
  • 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 comb-like structure with a large number of discs.
  • the synthetic resin include general-purpose polycarbonate, polypropylene, polyethylene, acrylonitrile-butadiene-styrene copolymer (ABS resin), and the like.
  • ABS resin acrylonitrile-butadiene-styrene copolymer
  • ABS resin acrylonitrile-butadiene-styrene copolymer
  • an ink storage body that can be filled with ink can be used as the ink filling mechanism.
  • the ink storage body is a fiber bundle in which crimped fibers are bundled in the longitudinal direction.
  • the ink storage body is a fiber bundle in which crimped fibers are bundled in the longitudinal direction, and is built into a plastic cylinder or a covering such as a film so that the porosity is in the range of approximately 40 to 90%. It is configured by adjusting.
  • an ink storage body impregnated with ink is housed in the ink storage body, and an ink supply mechanism is provided at the front end of the ink storage body so as to be connected to the ink storage body.
  • a ballpoint pen refill including a ballpoint pen tip, an ink filling mechanism, and an ink supply mechanism can also be formed by connecting the tip to the ink supply mechanism directly or via a connecting member.
  • the ink storage body houses an ink storage body impregnated with ink, and an ink supply mechanism is provided inside the ink storage body so as to be connected to the ink storage body, and a ballpoint pen is connected to the ink supply mechanism.
  • a ballpoint pen refill can also be formed by connecting the tip to the ink container directly or via a connecting member.
  • the structure of the ballpoint pen that accommodates the ink composition according to the embodiment of the present invention is as follows: (1) It has an ink container filled with ink in the barrel, and the ink container is provided with a direct or connecting member. (2) A ballpoint pen whose end face is filled with an ink backflow preventer; (2) A ballpoint pen whose barrel is directly filled with ink and a comb-shaped ink flow regulator, or a fiber bundle, etc.
  • a ballpoint pen that is equipped with a mechanism for supplying ink to the nib by interposing an ink guiding core as an ink flow rate regulator;
  • An example is a ballpoint pen, etc., which is equipped with a mechanism for supplying ink to the pen tip.
  • the structure and shape of the marking pen itself are not particularly limited.
  • a marking pen refill including a marking pen tip and an ink filling mechanism is used. Or it can be filled into a marking pen.
  • a porous material with continuous pores selected from a conventional general-purpose material with a porosity in the range of 30 to 70%, such as a resin-processed fiber, a fusion-processed heat-fusible fiber, a felt material, etc.
  • a resin-processed fiber such as a resin-processed fiber, a fusion-processed heat-fusible fiber, a felt material, etc.
  • An example is a member or a synthetic resin extrusion molded body having a plurality of ink outlet holes extending in the axial direction, and one end can be processed into a shape according to the purpose such as a bullet shape, a rectangular shape, a chisel shape, etc. and used for practical use. be done.
  • the ink filling mechanism is an ink storage body that can be filled with ink.
  • the ink occlusion body is a fiber bundle in which crimped fibers are bundled in the longitudinal direction.
  • the ink storage body is a fiber bundle in which crimped fibers are bundled in the longitudinal direction, and the porosity is adjusted to a range of approximately 40 to 90% by incorporating it into a plastic cylinder or a covering such as a film. configured.
  • a marking pen is formed by accommodating an ink absorbing body impregnated with ink in the barrel, and connecting the marking pen tip to the barrel directly or through a connecting member so as to be connected to the ink absorbing body. be able to.
  • the marking pen refill can be made by accommodating an ink storage body impregnated with ink in the ink storage body, and connecting the marking pen tip to the ink storage body directly or through a connecting member. (hereinafter sometimes referred to as a "refill") can be formed.
  • a marking pen can be formed by housing this refill in a barrel.
  • the ink container for example, a molded body made of a thermoplastic resin such as polyethylene, polypropylene, polyethylene terephthalate, or nylon, or a metal tubular body is used.
  • a thermoplastic resin such as polyethylene, polypropylene, polyethylene terephthalate, or nylon
  • the marking pen equipped with a marking pen tip and an ink filling mechanism may further include an ink supply mechanism for supplying the ink composition to be filled in the ink filling mechanism to the pen tip.
  • the ink supply mechanism is not particularly limited, and for example, in addition to the ink supply mechanism included in the ballpoint pen described above, it may include (4) an ink flow rate regulator using a valve mechanism, and ink is supplied to the pen tip by opening the valve. Examples include mechanisms for
  • the valve mechanism can be a conventionally general-purpose pumping type that opens by pressing the tip, and preferably has a spring pressure that allows the valve to be opened by pressure from a pen.
  • an ink storage body that can be directly filled with ink can be used as the ink filling mechanism.
  • the barrel itself may be used as an ink filling mechanism to directly fill ink.
  • the ink storage body houses an ink storage body impregnated with ink, and an ink supply mechanism is provided at the front end of the ink storage body so as to be connected to the ink storage body, and markings are provided so as to connect to the ink supply mechanism.
  • a marking pen refill including a marking pen tip, an ink filling mechanism, and an ink supply mechanism can also be formed by connecting the pen tip to the ink supply mechanism directly or via a connecting member.
  • an ink storage body impregnated with ink is housed in the ink storage body, and an ink supply mechanism is provided inside the ink storage body so as to be connected to the ink storage body, and markings are provided so as to be connected to the ink supply mechanism.
  • a marking pen refill can also be formed by connecting the pen tip to the ink reservoir directly or via a connecting member.
  • the configuration of the marking pen that accommodates the ink composition according to the embodiment of the present invention is as follows: (1) An ink storage body made of a fiber bundle impregnated with ink is housed in the barrel, and capillary gaps are formed. (2) A marking pen in which a marking pen tip made of a fiber processed body or a resin molded body is connected to a barrel directly or through a connecting member so that the ink storage body and the tip are connected to the barrel; (2) a barrel; A marking pen, which is directly filled with ink and is equipped with a mechanism for supplying ink to the pen tip by interposing an ink guide core made of a comb-shaped ink flow rate regulator or a fiber bundle as an ink flow rate regulator, (3 ) A marking pen with a mechanism in which the barrel is directly filled with ink and a mechanism for supplying ink to the nib via the above-mentioned pen core; (4) A marking pen that is equipped with a mechanism that supplies ink to the nib via the above-mentioned pen core
  • stirring is performed to stir the ink in the ink container or barrel filled with the ink in order to facilitate redispersion of the pigment.
  • a stirring body such as a ball.
  • the shape of the stirring body include a spherical body and a rod-shaped body.
  • the material of the stirring body is not particularly limited, and examples include metal, ceramic, resin, and glass.
  • a writing instrument such as a ballpoint pen or a marking pen according to an embodiment of the present invention can also be in the form of an ink cartridge as a removable structure. In this case, after the ink stored in the ink cartridge of the writing instrument is used up, the writing instrument can be used again by replacing it with a new ink cartridge.
  • the ink cartridge used is one that doubles as a barrel that constitutes the writing instrument by being connected to the writing instrument body, or one that covers and protects the barrel (rear barrel) after being connected to the writing instrument body.
  • the ink cartridge can also be used with writing instruments in which the writing instrument body and ink cartridge are connected before use, and with the user of the writing instrument connecting the ink cartridge inside the barrel during use. It may be any of those that are housed in the shaft cylinder in an unconnected state so as to start.
  • a writing instrument such as a ballpoint pen or a marking pen according to an embodiment of the present invention is provided with a cap that is attached to cover the pen tip (writing tip) to make it a cap-type writing instrument, so that the pen tip dries and prevents writing. It is possible to prevent the writing tip from being lost and the writing tip from being contaminated or damaged.
  • a writing instrument such as a ballpoint pen or a marking pen in which a refill is stored in the barrel can be made into a retractable writing instrument by providing a retractable mechanism in the barrel that allows the writing tip to retract from the barrel. , it is possible to prevent the writing tip from being contaminated or damaged.
  • Any retractable writing instrument can be used as long as the writing tip is housed in the barrel with the writing tip exposed to the outside air, and the writing tip protrudes from the barrel opening by the operation of the retractable mechanism.
  • an operating section (clip) that can be moved in the front-rear direction from the rear side wall of the barrel is protruded radially outward, and by sliding the operating section forward, the front end of the barrel can be moved.
  • a rear end knock that makes the writing tip come out and go out from the opening at the front end of the barrel by pushing forward the operating section provided at the rear end of the barrel.
  • a side-knock-type ejection mechanism that causes the writing tip to protrude and retract from the front end opening of the barrel by pressing an operating part protruding from the outer surface of the side wall of the barrel in the radial direction; (4) a shaft;
  • An example is a rotary ejection mechanism that causes the writing tip to protrude and retract from the front end opening of the barrel by rotating an operating section at the rear of the barrel.
  • Ballpoint pens and marking pens are not limited to the configurations described above; they may be equipped with tips of different shapes, tips that produce ink of different tones or hues, or tips of different shapes. Additionally, it may be a composite writing instrument (double-ended type, pen-tip type, etc.) in which the tone or hue of the ink derived from each tip is different.
  • thermochromic composition a reversible thermochromic microcapsule pigment, a reversible thermochromic resin particle, or the like
  • a writing instrument containing an ink composition is used to coat the writing surface.
  • the handwriting formed can be discolored by rubbing with a finger or by using a heating or cooling tool.
  • heating tools include electrical heating discoloration tools equipped with a resistance heating element such as a PTC element, heat discoloration tools filled with a medium such as hot water, heat discoloration tools using steam or laser light, hair dryers, etc.
  • a resistance heating element such as a PTC element
  • heat discoloration tools filled with a medium such as hot water
  • heat discoloration tools using steam or laser light etc.
  • friction members and friction bodies are preferable because they can be changed in color by a simple method.
  • cooling device examples include an energized cold/heat discoloration device using a Peltier element, a cold/heat discoloration device filled with a refrigerant such as cold water and/or ice chips, a cold storage agent, and applications for refrigerators and freezers.
  • an elastic body such as an elastomer or plastic foam, which has a rich elastic feel and can generate appropriate friction and generate frictional heat during rubbing, but plastic molded bodies, stone, wood, etc. Metal, cloth, etc. can also be used.
  • the handwriting may be rubbed using a general eraser used for erasing pencil handwriting, but since eraser scum is generated during rubbing, the above-mentioned friction member that hardly generates eraser scum and A friction body is preferably used.
  • Examples of the material for the friction member and the friction body include silicone resin, styrene-ethylene-butadiene-styrene block copolymer (SEBS resin), and the like.
  • SEBS resin is more preferably used because silicone resin tends to adhere to areas erased by rubbing and handwriting tends to be repelled when written repeatedly.
  • the above-mentioned friction member or friction body may be a member of any shape separate from the writing instrument, but by providing it on the writing instrument, it can be made highly portable. Further, a writing instrument set can also be obtained by combining a writing instrument and a friction member or friction body of an arbitrary shape that is separate from the writing instrument.
  • the friction member or the location where the friction body is provided is not particularly limited.
  • the cap itself may be formed from a friction member
  • the barrel itself may be formed from a friction member
  • a clip may be provided.
  • the clip itself may be formed of a friction member, or a friction member or a friction body may be provided at the tip (top) of the cap, the rear end of the barrel (the portion where the writing tip is not provided), or the like.
  • the friction member or the location where the friction body is provided is not particularly limited.
  • the barrel itself is formed of a friction member, or if a clip is further provided, the clip itself is A friction member or a friction body may be provided in the vicinity of the opening of the barrel, at the rear end of the barrel (the part where the writing tip is not provided), or in the knock portion.
  • the ink composition according to the embodiment of the present invention can be used for purposes other than writing instruments.
  • printing ink used for screen printing, offset printing, process printing, gravure printing, coater, tampo printing, etc. for brush coating, spray coating, electrostatic coating, electrodeposition coating, flow coating, roller coating, dip coating, etc. It can be used as a paint; an inkjet ink; an ultraviolet curable ink; an ink for applicators; an ink for stamps; a paint; a cosmetic; and a coloring liquid for textiles.
  • Example 1 Preparation of pigment dispersion 10 parts of guanine [manufactured by Tokyo Chemical Industry Co., Ltd.], 2.5 parts of a dispersant [manufactured by Toagosei Co., Ltd., product name: Aron A-12SL (solid content: 40%)], 87.5 parts of water were mixed. Then, 200 parts of zirconia beads with a diameter of 1.4 to 1.6 mm were added as a media, and pulverization and dispersion treatment was performed using a bead mill for 6 hours to prepare a pigment dispersion (guanine pigment dispersion).
  • the content of the dispersant with respect to the total mass of the pigment dispersion was 1%, and the content of the dispersant with respect to the guanine pigment was 10%. Furthermore, the average particle diameter of the guanine pigment dispersed in the pigment dispersion was measured by the above method and was found to be 0.35 ⁇ m.
  • Examples 2-4 Preparation of Pigment Dispersion
  • Each of the pigment dispersions of Examples 2 to 4 was prepared in the same manner as in Example 1, except that the types and amounts of the materials to be blended were changed to those listed in Table 1 below.
  • the content ratio of the dispersant to the total mass of the pigment dispersion, the content ratio of the dispersant to the guanine pigment, and the average particle diameter of the guanine pigment dispersed in the pigment dispersion are shown in Table 1 below.
  • Comparative example 1 Preparation of pigment dispersion 10 parts of titanium oxide [manufactured by Teika Co., Ltd., product name: JR-707] and a dispersant [manufactured by BYK Chemie Japan Co., Ltd., product name: DISPER BYK-190 (solid content: 40%) ] and 87.5 parts of water were mixed. Then, 100 parts of glass beads with a diameter of 2.0 mm were added as a media, and pulverization and dispersion treatment was performed using a bead mill for 1 hour to prepare a pigment dispersion (titanium oxide dispersion).
  • the content of the dispersant with respect to the total mass of the pigment dispersion was 1%, and the content of the dispersant with respect to titanium oxide was 10%.
  • the average particle diameter of titanium oxide dispersed in the pigment dispersion was 0.3 ⁇ m.
  • Example 5 Preparation of water-based ink composition for writing instruments 20 parts of guanine [manufactured by Tokyo Chemical Industry Co., Ltd.] and a dispersant [manufactured by Toagosei Co., Ltd., product name: Aron A-12SL (solid content: 40%)] 7.5 1 part and 72.5 parts of water were mixed. Then, 200 parts of zirconia beads with a diameter of 1.4 to 1.6 mm were added as a media, and pulverization and dispersion treatment was performed using a bead mill for 5 hours to prepare a water-based ink composition for writing instruments. Note that the content of the dispersant with respect to the total mass of the ink composition was 3%, and the content of the dispersant with respect to the guanine pigment was 15%.
  • the ink storage body made of polyester sliver covered with a synthetic resin film is impregnated with the above water-based ink composition for writing instruments, and the result is housed in a barrel made of polypropylene resin, and a resin-treated pen made of polyester fiber is attached to the tip of the barrel.
  • the body (shell-shaped) was assembled in a connected state via a resin holder, and a cap was attached to produce a filling-type writing instrument (marking pen).
  • Comparative example 2 Preparation of water-based ink composition for writing instruments 20 parts of titanium oxide [manufactured by Teika Co., Ltd., product name: JR-707] and a dispersant [manufactured by BYK Chemie Japan Co., Ltd., product name: DISPER BYK-190 (solid content: 40%)] and 72.5 parts of water were mixed. Then, 100 parts of glass beads with a diameter of 2.0 mm were added as a media, and pulverization and dispersion treatment was performed using a bead mill for 1 hour to prepare a water-based ink composition for writing instruments. Note that the content of the dispersant with respect to the total mass of the ink composition was 3%, and the content of the dispersant with respect to titanium oxide was 15%.
  • B The white color of the handwriting was slightly lighter than the initial handwriting, but it had a level of concealment that was not a problem in practical use.
  • C The color of the handwriting was lighter than the initial handwriting, and the concealability was low. It was insufficient. Or it was impossible to write.
  • Example 6 Preparation of water-based ink composition for writing instruments 20 parts of guanine [manufactured by Tokyo Kasei Kogyo Co., Ltd.] and a dispersant [manufactured by BYK Chemie Japan Co., Ltd., product name: DISPER BYK-2010 (solid content: 40%)]7. 5 parts and 72.5 parts of water were mixed. Then, 200 parts of zirconia beads with a diameter of 1.4 to 1.6 mm were added as a media, and pulverization and dispersion treatment was performed using a bead mill for 5 hours to prepare a pigment dispersion (guanine pigment dispersion).
  • the content of the dispersant i.e., the total of "DISPER BYK-2010” and “Plysurf AL" with respect to the total mass of the ink composition is 3.6%, and the content of the dispersant for the guanine pigment (i.e., "DISPER BYK-2010") is 3.6%. 2010" and "Plysurf AL) is 21%.
  • the tip provided in the ballpoint pen refill is stored in the barrel while being exposed to the outside air, and the front end of the barrel is pushed forward by the operating section provided at the rear end of the barrel.
  • a rear end knock-type retractable structure is provided in which the tip protrudes from the opening.
  • Example 6 When the ballpoint pen of Example 6 was used to write by hand on black high-quality paper (medium thickness, manufactured by Katsueisha Co., Ltd.) at room temperature (20°C), there were no writing defects such as blurring or line skipping. , a clear white handwriting was formed. In addition, this handwriting concealed the writing surface and was a good handwriting with excellent concealment properties.
  • black high-quality paper medium thickness, manufactured by Katsueisha Co., Ltd.
  • Example 7 Preparation of pigment dispersion 10 parts of guanine [manufactured by Tokyo Chemical Industry Co., Ltd.], 2.5 parts of a dispersant [manufactured by Toagosei Co., Ltd., product name: Aron A-12SL (solid content: 40%)], 87.5 parts of water were mixed. Then, 200 parts of zirconia beads with a diameter of 1.4 to 1.6 mm were added as a media, and pulverization and dispersion treatment was performed using a bead mill for 6 hours to prepare a pigment dispersion (guanine pigment dispersion).
  • the content of the dispersant with respect to the total mass of the pigment dispersion was 1%, and the content of the dispersant with respect to the guanine pigment was 10%. Furthermore, the average particle diameter of the guanine pigment dispersed in the pigment dispersion was measured by the above method and was found to be 0.35 ⁇ m.
  • Examples 8-13 Preparation of Pigment Dispersion
  • Each of the pigment dispersions of Examples 8 to 13 was prepared in the same manner as Example 7, except that the types and amounts of the materials to be blended were changed to those listed in Table 5 below.
  • the content ratio of the dispersant to the total mass of the pigment dispersion, the content ratio of the dispersant to the guanine pigment, and the average particle diameter of the guanine pigment dispersed in the pigment dispersion are shown in Table 5 below.
  • the colored layer was clearly white and had good hiding properties, and the black color of the underlying paper was not visible through the colored layer. Furthermore, since the guanine pigment had excellent dispersibility in the liquid composition, the colored layer had a uniform concentration and a good appearance.

Abstract

L'invention concerne une composition d'encre aqueuse pour instrument d'écriture qui contient au moins un pigment contenant à son tour un pigment à base de guanine, et une eau.
PCT/JP2023/023934 2022-06-29 2023-06-28 Composition d'encre aqueuse pour instrument d'écriture, et instrument d'écriture contenant celle-ci WO2024005056A1 (fr)

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JP2022105011 2022-06-29

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5566978A (en) * 1978-11-15 1980-05-20 Shion Kagaku Kogyo Kk Ink for writing utensil
JP2004502822A (ja) * 2000-07-03 2004-01-29 ベロル・コーポレイション パールインキ、筆記用具、及び方法
US20050257718A1 (en) * 2004-05-22 2005-11-24 Engelhard Corporation Natural Pearl in Butylene Glycol

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5566978A (en) * 1978-11-15 1980-05-20 Shion Kagaku Kogyo Kk Ink for writing utensil
JP2004502822A (ja) * 2000-07-03 2004-01-29 ベロル・コーポレイション パールインキ、筆記用具、及び方法
US20050257718A1 (en) * 2004-05-22 2005-11-24 Engelhard Corporation Natural Pearl in Butylene Glycol

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