Writing instrument product

Abstract

To provide a writing instrument product with a cap formed of a transparent material, which is free from condensation inside the cap and does not impair the appearance.SOLUTION: The writing instrument product is a writing instrument A including at least a barrel 10 containing an aqueous ink composition for writing instruments, a pen tip 20 capable of ejecting aqueous ink provided at a tip side of the barrel 10, and a cap 60 formed of a transparent material and detachably attached to the pen tip 20 side of the barrel 10. A difference between a temperature inside the writing instrument (x°C) and a dew point temperature inside the product (y°C) in that state is 1°C or more, as shown in the following formula (I): x°C-y°C≥1°C ...(I).SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a writing instrument product, such as a cap, in which condensation does not occur. [Background technology]

[0002] In recent years, some marking pens have been designed to show the pen tip. In order to prevent this, it is known that transparent materials and caps with large internal volumes are used. This type of writing instrument is subject to temperature changes and temperature gradients, and the inside of the cap In some cases, condensation would accumulate on the surface, resulting in an unsightly appearance. This problem is a problem of a pen having a large pen tip and using a transparent cap. Writing implements presented unique challenges.

[0003] Conventionally, in order to prevent condensation inside the cap, the internal volume of the cap is reduced. It was common to use opaque materials (so they were not noticeable), but now we have a window that allows you to see the writing direction. A writing instrument with a cap made of a transparent material, in particular, for showing the pen tip or the like In the past, it was difficult to make the cap out of an opaque material. In writing instruments that use inks that use reactive dyes, water-soluble dyes, and pigments as coloring materials, the color of the condensation liquid In addition, even if the cap is opaque, the inside of the cap may be contaminated. The problem of condensation accumulating in the drain was also an issue that needed to be resolved.

[0004] On the other hand, in the past, as a device for preventing water evaporation and condensation in a writing instrument, for example, In a writing instrument having an ink barrel containing water-based ink, a suction pen having continuous air holes in the barrel is used. The liquid is placed in a sealed atmosphere at room temperature with a relative humidity of 75 to 95%. A method for preventing evaporation of water and condensation in a writing implement characterized by absorbing a saturated aqueous solution of a given salt. An apparatus is known (see, for example, Patent Document 1).

[0005] In addition, the writing implement does not use a member such as a cap made of a transparent material. However, the marks made by the writing implement tend to fade or brown early on, damaging their appearance. To provide a writing instrument that allows the pen tip shape, color tone, and remaining amount of ink inside the writing instrument to be visually checked without any need for special tools. (a) an electron-donating organic compound, (b) an electron-accepting compound, (c) the compound (a) and (b) A reversible thermochromic material consisting of a reaction medium that determines the temperature at which a color reaction occurs. An ink containing a colorant selected from an organic material, a dye, and a fluorescent pigment, and an ink cartridge containing the ink. An ink occlusion body, a barrel housing the ink occlusion body therein, and a pen capable of discharging the ink. a pen tip, a holder for holding the pen tip, and a transparent pen holder attached to the pen tip side of the barrel in a freely detachable manner. A writing instrument comprising: a cap formed of a transparent material; The cap contains an ultraviolet absorbing agent or a transparent ultraviolet shielding agent, or has an ultraviolet absorbing agent on the surface of the cap. or a writing instrument provided with a light-stable layer containing a transparent ultraviolet shielding agent, and the cap a light stabilizer is contained in the light-stable layer; The support is made of a material having the above-mentioned properties, and the support contains an ultraviolet absorbing agent or a transparent ultraviolet shielding agent. or a light-stabilizing layer containing an ultraviolet absorbing agent or a transparent ultraviolet shielding agent is formed on the surface of the support. It is known that a magnetic field is provided (for example, see Patent Document 2).

[0006] The water evaporation prevention and condensation prevention device of the writing implement of the above-mentioned Patent Document 1 has continuous air holes in the barrel. The device is equipped with a liquid absorbent with specific physical properties to prevent water evaporation and condensation. The present invention discloses a method for suppressing or preventing condensation from the viewpoint of ink composition, physical properties, etc. The present invention and the above-mentioned Patent Document 1 have different technical concepts. In addition, the writing instrument of the above-mentioned Patent Document 2 allows the pen tip shape, the color tone of the ink inside the writing instrument, and the remaining amount of ink to be visually confirmed. In order to achieve this, when the cap or holder is made of a transparent material, the cap or holder The holder contains an ultraviolet absorbing agent or a transparent ultraviolet shielding agent, or the surface of the cap or holder The problem and technical concept of the present invention are different from those of the present invention. This is what we have in mind. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Utility Model Registration No. 61-40551 (Scope of claims, Figure 1, etc.) [Patent Document 2] JP 2020-29672 A (Claims, Figures 1 to 6, etc.) Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention is intended to solve the above-mentioned problems and current state of the prior art. To provide a writing instrument product that does not cause condensation inside the writing instrument product such as a cap, particularly, a transparent writing instrument product. Even if the writing implement product uses a cap or the like formed from a material having the above properties, the cap or the like There is no condensation inside the writing product, and it does not impair the appearance. The color of the water-based ink can be seen through the cap, so the quality of the writing instrument and the product value can be improved. The objective is to provide high-value writing instrument products. [Means for solving the problem]

[0009] In view of the above-mentioned problems, the present inventors have conducted intensive research and have discovered that at least A barrel containing an aqueous ink composition for a writing instrument and an aqueous ink composition for a writing instrument provided at the tip side of the barrel. a pen tip from which the composition can be discharged, and a transparent material that is detachably attached to the pen tip side of the barrel. A writing instrument product having a cap formed of a material, and a temperature inside the product (x°C) and By making the difference between the dew point temperature (y℃) inside the product and the temperature in the They found that a writing instrument product could be obtained, and thus completed the present invention.

[0010] That is, the writing instrument product of the present invention is at least a writing instrument water-based ink composition incorporated therein. a pen tip provided at the tip side of the barrel and capable of discharging an aqueous ink composition for a writing instrument; A cap made of a transparent material and detachably attached to the pen tip side of the barrel; A writing instrument product comprising: a product internal temperature (x°C) and The difference between the dew point temperature (y°C) inside the product and the temperature in that state is 1°C or more. Tool products. x℃-y℃≧1℃ ………(I) The dew point temperature (y°C) is calculated by calculating the water vapor pressure from the temperature inside the product and the relative humidity. It is preferable that the temperature be calculated by calculating the temperature at which the saturated water vapor pressure is obtained. It is preferable that the temperature inside the product (x°C) is 27°C or higher and the dew point temperature is 1°C or lower. When the temperature inside the product (x°C) is 27°C, the dew point temperature is preferably 26°C or lower. . The pen tip preferably has a window through which the writing direction can be visually confirmed. Effect of the Invention

[0011] According to the present invention, a writing instrument product is provided that does not cause condensation inside the writing instrument product, such as a cap. In particular, the writing instrument product uses a cap made of a transparent material. However, there is no condensation inside the cap or other writing products, and the appearance is not marred. In addition, the shape of the pen tip and the color of the water-based ink can be seen through the cap, etc. This allows for the provision of writing instrument products with high writing instrument quality and commercial value. The objects and advantages of the invention can be realized by means of the elements and combinations particularly pointed out in the claims. The general description above and the detailed description below are intended to provide a basis for understanding the present invention and the principles of the present invention. Both the above description and the accompanying drawings are exemplary and explanatory and are intended to provide a full understanding of the present invention as set forth in the claims. It does not limit the clarity. [Brief description of the drawings]

[0012] [Figure 1] 1A to 1C are drawings showing an example (first embodiment) of an embodiment of a writing instrument product of the present invention, where (a) is a plan view, (b) is a front view, and (c) is a vertical cross-sectional view viewed from the front. [Diagram 2] 2A and 2B are enlarged perspective views of the pen tip of the writing instrument product of FIG. 1, in which (a) is an enlarged perspective view of the pen tip as viewed from one direction, and (b) is an enlarged perspective view of the pen tip as viewed from a direction expanded 180° from (a). [Diagram 3] 1A to 1C are drawings showing another embodiment (second embodiment) of a writing instrument product of the present invention, in which (a) is a plan view, (b) is a front view, and (c) is a vertical cross-sectional view as viewed from the front. [Figure 4]4A is an enlarged perspective view of the nib of the writing instrument product of FIG. 3, where (a) is an enlarged perspective view of the nib as viewed from one direction, and (b) is an enlarged perspective view of the nib as viewed from a direction expanded 180° from (a). [Diagram 5] 1A and 1B are drawings showing another embodiment (third embodiment) of a writing instrument product of the present invention, where (a) is a central vertical cross-sectional view, and (b) is a central horizontal cross-sectional view. [Figure 6] 6A and 6B are diagrams showing an example of the writing instrument product of FIG. 5 with the cap removed, in which (a) is a perspective view seen from the front side, and (b) is a perspective view seen from the rear side. [Figure 7] 6A to 6D are diagrams showing an example of the writing instrument product of FIG. 5 with the cap attached, where (a) is a front view, (b) is a plan view, (c) is a left side view, and (d) is a right side view. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, each embodiment of the present invention will be described in detail with reference to the drawings. The technical scope is not limited to the embodiments described below, but is within the scope of the claims. and equivalents thereof. and that the invention can be carried out based on common technical knowledge in the relevant field (including design matters and obvious matters). Cut.

[0014] <Writing instrument product of the first embodiment: Figs. 1 and 2> As shown in Figs. 1(a) to (c), the writing instrument product of this embodiment comprises at least a water-based ink. The ink is stored in a barrel 10 via an ink occlusion body 15, and a water-based ink is stored in the barrel 10 at the tip side. A pen tip 20 capable of ejecting ink and a transparent pen detachably attached to the pen tip 20 side of the barrel 10. The writing instrument A is provided with a product 60 having a cap formed of a transparent material. As shown in the following formula (I), the temperature inside the product (x°C) and the dew point inside the product at that state are It is characterized in that the difference from the temperature (y°C) is 1°C or more. x℃-y℃≧1℃ ………(I)

[0015] In the above formula (I), the dew point temperature (y°C) is the temperature at which condensation occurs when the gas is cooled. This can be measured directly using a dew point thermometer, but in this embodiment, the product internal temperature is The water vapor pressure (partial pressure of water vapor in moist air) is calculated from the temperature and relative humidity, and the water vapor pressure is calculated as the saturated water vapor pressure. This was obtained by calculating the temperature at which the vapor pressure was reached. Specifically, the dew point temperature (y°C) is calculated using the following formula: The water vapor pressure Px inside the product at the temperature inside the product (x°C) is (saturated water vapor pressure at x°C: Pmax) x [ In the present invention, the "temperature inside the product (x°C)" means , refers to the temperature of the space inside the cap. The saturated water vapor pressure Pmax at x°C is approximately calculated by the August Other formulas determine the saturation vapor pressure at a specified temperature. The saturated water vapor pressure (Pmax) is 6.111×10 t The temperature is calculated as t = (7.5 × x℃) / (x℃ + 237.3).

[0016] On the other hand, the water mole fraction: N is determined as follows. Water-based ink used in writing instruments is placed under a certain temperature and humidity environment. In this case, the evaporation of the water contained in the ink does not proceed until the water in the ink is gone. There is a correlation between humidity and evaporation end point. If the saturated water vapor pressure at a certain temperature is Pa, the partial pressure of water in the atmosphere is the mole fraction of water W (%) (i.e., relative humidity) is expressed as P×W / 100 (Pa). The frequency of evaporation of molecules is roughly proportional to the mole fraction C (%) of water in the ink, so the amount of water evaporated is is proportional to the mole fraction of water.

[0017] In the present invention, the "molar fraction of water: N" refers to the amount of water contained in the ink having a molecular weight of 300 or less. This refers to the mole fraction of water in a soluble compound (including water). The ink contains n types (n≧0) of water-soluble compounds with molecular weights of 300 or less other than water, in addition to water. In this case, the mole fraction of water is expressed as water-soluble compounds 1, 2, 3, …, n. When the molecular weight of water is 18, it can be calculated by the following formula (I): In (1), MW1, MW2, MW3, ..., MWn are the amounts contained in the ink. The molecular weights of the water-soluble compounds 1, 2, 3, ..., n that are 300 or less in molecular weight are shown. Cw represents the water content (mass%) in the ink, and C1, C2, C3, . . ., C n Yes, that The contents of water-soluble compounds 1, 2, 3, . . . , and n with molecular weights of 300 or less in the ink ( The ink contains no water-soluble compounds with a molecular weight of 300 or less other than water. If no water is present, the mole fraction of water in the ink is 100%.

[0018] [ka]

[0019] In the present invention, the "molar fraction of water" refers to the proportion of water-soluble compounds (water) having a "molecular weight of 300 or less". The value is calculated based on the following: The compounds with a molecular weight of 300 or less are used to calculate the water molar fraction. Compounds having a sufficiently large molecular weight compared to water are typically used in aqueous ink compositions for writing instruments. This is because the content does not substantially affect the molar fraction of water. Pigments, resins, surfactants, etc. that are usually used in the composition of a composition have molecular weights that are higher than that of water. The molar number is much larger than that of the ordinary content in an aqueous ink composition for writing instruments, and is extremely small. Furthermore, there is no need to consider the presence of compounds that dissolve in water in the aqueous ink composition for writing instruments. Considering the compounds whose content is 1.0 mass % or more, the effect of the present invention is substantially This is sufficient as a condition for realizing the results. As described above, the water vapor pressure Px inside the product is calculated by (saturated water vapor pressure at x°C: Pmax) × [molar water Rate: (N). The temperature at which this water vapor pressure Px is equal to the saturated vapor pressure is the dew point temperature (y°C). Therefore, y℃ = [237.3*Log10(6.11 / Px)] / [(Log10(Px / 6.11)-7.5)], and the dew point The temperature is calculated.

[0020] From the above, the temperature inside the product (x°C) and the dew point temperature inside the product at that state (y°C) can be calculated. The temperature inside the product (x°C) and the dew point temperature inside the product (y°C) in that state can be calculated. If the difference is 1°C or more, as shown in the above formula (I), the temperature inside the writing instrument product such as the cap This results in a writing instrument that is free from condensation. In particular, even if the writing implement has a cap made of a transparent material, There is no condensation in the writing products such as caps, and the appearance is not marred. The shape of the tip and the color of the water-based ink can be seen through the cap, making it a writing instrument. This will result in writing instruments of high quality and commercial value. The difference between the temperature inside the product (x°C) and the dew point temperature inside the product (y°C) in that state is calculated using the formula above. If condition (I) is not met, i.e., if the temperature is less than 1°C, the temperature may become too high in the cap or other writing instrument products. Condensation is likely to occur, and the effects of the present invention cannot be achieved. Preferably, the temperature inside the product (x°C) is 27°C or higher and the dew point temperature is 1°C or lower. It is preferable that the dew point temperature is 26°C or less when the temperature inside the product (x°C) is 27°C. Here, the reason why the above-mentioned temperature inside the product (x°C) is 27°C is that it is the same as that of a general hot This is the temperature inside the cap when it is placed on a carpet for one hour. The temperature inside the product (x°C) is usually around 20 to 25°C.

[0021] <Water-based ink> The water-based ink used in this embodiment is not particularly limited as long as it satisfies the above formula (I). For example, it is preferable that the ink contains at least a coloring material and water. <Coloring material> Usable coloring materials include those used for writing instruments, such as water-based coloring materials. Dyes that dissolve or disperse in water, conventional inorganic and organic pigments such as titanium oxide, coloring Resin particles or their dispersions (resin particles containing pigments, resin emulsions dyed with dyes) Colored pseudo pigments, white plastic pigments, hollow resin pigments (particles), etc.), silica A pigment with a multi-layer coating of iron oxide, titanium oxide, etc. on a base material of mica, Pigments, photochromic pigments, etc., and composite pigments thereof can be used. Examples of dyes include fluorescent dyes, water-soluble dyes, and oil-soluble dyes. .

[0022] The fluorescent dye that can be used is not particularly limited as long as it has good color development properties. For example, For example, Basic Yellow 1, Basic Yellow 40, Basic Red 1, Basic Red 1:1, Basic Red 13, Basic Red 1:2, Basic Red 1:1, Basic Red 1:2, Basic Yellow ... Chic Violet 1, Chic Violet 7, Chic Violet 10, Chic Violet 11:1, Basic Orange 22, Basic Kubreu 7, Basic Green 1, Acid Yellow 3, Acid Yellow 7, Acid Red 52, 77, 87, 92, Acid Blue 9, Disperse Yellow 121, 82, 83, Disperse Orange 11, Disperse Red 58, Disperse Blue 7, Da Direct Yellow 85, Direct Orange 8, Direct Red 9, Direct Blue 22, Direct Green 6, Solvent Yellow 44, Solvent Red 49, Sorbet Solvent Blue 5, Solvent Green 7, etc. In particular, From these points, among the above fluorescent dyes, azomethine, xanthene, triphenylmethane Fluorescent dyes of the azomethine system are preferably used. Specifically, the azomethine fluorescent dyes are , Basic Yellow 1, Basic Yellow 40, and xanthene fluorescent dyes include Basic Red Fluorescent dyes of the triphenylmethane family include: Basic Violet 1 and the like are particularly preferred fluorescent dyes. may be used alone or in combination of two or more.

[0023] Examples of oil-soluble dyes that can be used include CISolvent Black. k 7, 123, CISolvent Blue 2, 25, 55, 70, CISolvent Red 8, 49, 100, CISolvent V iolet 8, 21, CISolvent Green 3, CISOlv Cent Yellow 21, 44, 61, CISolvent Orange 37 etc.

[0024] Usable water-soluble dyes include acid dyes, basic dyes, direct dyes, and food dyes. For example, CI Acid Black 1, 2, 24, 26, 3 1, 52, 107, 109, 110, 119, 154, CI Acid I Yellow 1, Yellow 7, Yellow 17, Yellow 19, Yellow 23, Yellow 25, Yellow 29, Yellow 38, Yellow 42, Yellow 49, 61, 72, 78, 110, 127, 135, 141, 142, CI Acid Red 8, 9, 14, 18, 26, 27, 35, 37, 51 , 52, 57, 82, 83, 87, 92, 94, 111, 129, 131, 138, 186, 249, 254, 265, 276, CI Assist Red Violet 15, 17, 49, CI Acid Blue 1, 7, 9, 1 5, 22, 23, 25, 40, 41, 43, 62, 78, 83, 9 0, 93, 100, 103, 104, 112, 113, 158, CI Acid Green 3, 9, 16, 25, 27, CI Acid Orange 56, etc. Acid dyes, Malachite Green (CI42000), Victoria Blue FB (C. I.44045), Methyl Violet FN (CI42535), Rhodamine F4G (CI45160), basic dyes such as Rhodamine 6GCP (CI45160), CI Direct Black 17, 19, 22, 32, 38, 51, 71, CI Direct Yellow 4, 26, 44, 50, CI Direct Red 1 , 4, 23, 31, 37, 39, 75, 80, 81, 83, 225 , 226, 227, CI Direct Blue 1, 15, 41, 71, 86 , CI 87, CI 106, CI 108, CI 199 and other direct dyes, as well as CI Food Yellow 3, etc. Examples of food colorings include

[0025] Examples of inorganic pigments include azo lakes, insoluble azo pigments, chelate azo pigments, and phthalocyanine pigments. Examples include cyanine pigments, perylene and perinone pigments, and nitroso pigments. Specifically, carbon black, titanium black, zinc oxide, red iron oxide, aluminum oxide, Chromium, Iron Black, Cobalt Blue, Iron Oxide Yellow, Viridian, Zinc Sulfide, Lithopone, Cadmium Muello, vermilion, cadmium red, yellow lead, molybdate orange, zinc chromate, silver Trontium chromate, white carbon, clay, talc, ultramarine, precipitated barium sulfate , barite powder, calcium carbonate, white lead, navy blue, navy blue, manganese violet, aluminum Inorganic pigments such as aluminum powder, brass powder, CI Pigment Blue 15, 17, CI Pigment Blue CI Pigment Blue 17, 27, CI Pigment Red 5, 22, 38, 48, 4 9, 53, 57, 81, 104, 146, 245, CI Pigment Yellow Law 1, Law 3, Law 12, Law 13, Law 14, Law 17, Law 34, Law 55, Law 74, Law 95, Law 166, 167, CI Pigment Orange 5, 13, 16, CI Pigment Orange Violet 1, 3, 19, 23, 50, CI Pigment Green 7, etc. Organic pigments are included.

[0026] The colored resin particles or the dispersion thereof may, for example, have at least an acid functional group that is soluble in water. A carboxyl group-containing vinyl monomer (A) having a solubility of 10 mass % or less, and acrylic acid or is an ester monomer of methacrylic acid and a linear or cyclic alcohol having 2 to 18 carbon atoms ( B) and colored resin particles composed of a basic dye or an oil-soluble dye are dispersed in water. Dispersion of colored resin particles, (meth)acrylic acid cyclohexyl monomer, and basic dye or an oil-soluble dye, The content of hexyl monomer is 30% of the total polymer components that make up the colored resin particles. % or more, and the content of the basic dye or oil-soluble dye is 100% or more based on the total polymer component. A dispersion of colored resin particles in which 15% by mass or more of colored resin particles are dispersed in water. etc.

[0027] The thermochromic pigment is a leuco dye that functions as a color former and a leuco dye that causes the leuco dye to develop color. The color developer is a component having the ability to change color, and the color change temperature in the coloring of the leuco dye and the color developer is determined. A thermochromic composition containing at least a color-changing temperature regulator capable of controlling the color-changing temperature is provided. The average particle size of the microcapsules is 0.1 to 10 μm. Examples of the thermochromic pigment include those produced by The photochromic pigments include, for example, at least photochromic dyes (compounds), fluorescent dyes, etc. and a resin such as a terpene phenol resin. At least one of the following is selected from photochromic particles, photochromic dyes (compounds), fluorescent dyes, etc. and an organic solvent and additives such as an antioxidant, a light stabilizer, and a sensitizer. The color-changing composition is microdispersed so as to have a predetermined average particle size (for example, 0.1 to 10 μm). Examples of the photochromic pigment include photochromic pigments produced by encapsulation. In the present invention (including examples), the "average particle size" is measured using a particle size distribution analyzer HR Calculated using 9320-X100 (manufactured by Nikkiso Co., Ltd.) with a refractive index of 1.81 and based on volume The calculated D50 value.

[0028] These colorants may be used alone or in combination of two or more (hereinafter simply referred to as "at least one"). (hereinafter referred to as "us") can be used. The (total) (solid content) content of these coloring materials relative to the total amount of the aqueous ink is preferably The content is preferably 0.1 to 40% by mass, and more preferably 1 to 30% by mass. By making the content of this coloring material 0.1% by mass or more, it is possible to obtain sufficient line density. On the other hand, by making the content 40 mass % or less, the increase in viscosity is suppressed and the ink flowability is improved. This is preferable because it is favorable.

[0029] <Other ingredients> The aqueous ink of the present embodiment contains the above-mentioned coloring material and water (tap water, purified water, In addition to distilled water, ion-exchanged water, pure water, etc., other water may be used as necessary within the scope of the effects of the present invention. In addition, various components that are commonly used in water-based inks, such as dispersants, surfactants, glycols, Glycol ethers, hydrophilic polyhydric alcohols, water-soluble betaines, viscosity adjusters, adhesion It may contain resins, rust inhibitors, preservatives or antibacterial agents, pH adjusters, etc.

[0030] The dispersant and adhesive resin that can be used may contain a water-soluble resin. For example, acrylic resin, polyvinyl alcohol, polyvinylpyrrolidone, polyethylene Water-soluble resins such as oxides and urethane resins, as well as acrylic emulsions and vinyl acetate Resin emulsions such as urethane emulsions, polyolefin emulsions, etc. At least one type can be selected from among the above.

[0031] The surfactants that can be used are not particularly limited, but include fluorine-based surfactants, a At least one selected from the group consisting of acetylene glycol surfactants and silicone surfactants A type of surfactant may also be used. Examples of glycols and glycol ethers that can be used include ethylene glycol. Recall, propylene glycol, diethylene glycol, triethylene glycol, Dipropylene glycol, tetraethylene glycol, dipropylene glycol, polyethylene Polyethylene glycol, polypropylene glycol, neopentyl glycol, 1,3-octyl glycol Ethylene glycol, hexylene glycol, tripropylene glycol, thiodiethylene Glycols such as glycol, glycerin, ethylene glycol monomethyl ether, Examples of the glycol ethers include diethylene glycol monomethyl ether. can be used alone or in combination of two or more. Examples of hydrophilic polyhydric alcohols include pentaerythritol, trimethylol ether, and the like. For example, ethane, trimethylolpropane, etc. can be used. Water-soluble betaines (amphoteric compounds) have non-adjacent positive and negative charges in the same molecule. A compound that has no charge as a whole molecule. The positively charged part is a quaternary ammonium cation. Such betaines are not particularly limited, but examples thereof include trime Tyrglycine, γ-butyrobetaine, homarine, trigonelline, carnitine, homoserine Betaine, valine betaine, lysine betaine, ornithine betaine, alanine betaine, Stachydrine, and glutamic acid betaine. Glycine, γ-butyrobetaine, and carnitine are preferred, and trimethylglycine is more preferred. By using such water-soluble betaines, the effects of the present invention can be further improved. The water-soluble betaines may be used alone or in combination of two or more. They may also be used in combination.

[0032] Viscosity adjusting agents that can be used include natural polymers such as polysaccharides and synthetic polymers. Examples of polysaccharides include gum arabic, gum tragacanth, guar gum, Locust bean gum, alginic acid, carrageenan, gelatin, xanthan gum, Elllan gum, succinoglycan, diutan gum, dextran, and methylcellulose cellulose, ethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, etc. Any cellulose derivative, starch glycolate and its salts can be used. Examples of the molecule include polyvinylpyrrolidone, polyvinyl methyl ether, and polyacrylonitrile. acid and its salts, polyethylene oxide, vinyl acetate-polyvinylpyrrolidone copolymer , styrene-acrylic acid copolymers and their salts, isobutylene-maleic anhydride copolymers and The salts thereof can be used.

[0033] Preservatives or antibacterial agents that can be used include phenol, sodium omadine, , sodium benzoate, benzisothiazoline, benzimidazole compounds, etc. In addition, examples of the rust inhibitor include benzotriazole, tolyltriazole, diphenyltriazole, and phenyltriazole. Cyclohexylammonium nitrite, saponins, etc. can be used. Examples of pH adjusters that can be used include triethanolamine and diethanolamine. , monoethanolamine, dimethylethanolamine, morpholine, triethylamine, etc. Ammonia, sodium hydroxide, potassium hydroxide, lithium hydroxide, For example, hydroxides of alkali metals such as tungsten can be used.

[0034] In this embodiment, the water-based ink may have a composition containing at least the above-mentioned coloring material and water. In a preferred embodiment, in addition to the above-mentioned glycols, polyhydric alcohols (pentaerythritol, Lithritol, trimethylolethane, trimethylolpropane), water-soluble betaines ( Amphoteric compounds) such as trimethylglycine (type, amount, etc.) are appropriately combined. This can be adjusted by:

[0035] The water-based ink of the present embodiment is a writing instrument ink containing at least the above-mentioned coloring material, water, and other components. Depending on the application of the ink (such as for marking pens), the inks should be appropriately combined and the appropriate blending ratio should be selected. In combination with the above-mentioned preferred embodiments, a homomixer, a homogenizer, Alternatively, the mixture may be stirred and mixed using a stirrer such as a disperser, and then filtered as necessary. By removing coarse particles from the ink composition by centrifugal separation or the like, Thus, a water-based ink for use in the ink-jet printing is obtained. In addition, the pH (25° C.) of the water-based ink of the present embodiment is determined based on usability, safety, and the stability of the ink itself. The pH is adjusted to 5 to 10 using a pH adjuster to ensure compatibility with the ink container. It is preferable that the ratio is set to 6 to 9.5, and more preferably, the ratio is set to 6 to 9.5.

[0036] <Specific configuration of the writing instrument product according to the first embodiment> FIG. 1(a) is a plan view of the writing instrument product of the present embodiment, (b) is a front view thereof, and (c) is a FIG. 2 is an enlarged perspective view of the pen tip of the writing instrument product of FIG. 1, (a) is a view in one direction. (b) is an enlarged perspective view of the pen tip as seen from the 180° expanded direction of (a). FIG. The writing instrument product A of this embodiment is equipped with the water-based ink having the above composition, and is shown in FIG. As shown in (a) to (c), water is supplied from the ink occlusion body 15 of the barrel (writing instrument body) 10. The pen tip has a window (visible portion) that guides the ink and allows the writing direction to be visually confirmed. The pen tip 20 is provided with a rod-shaped polyacetal pen tip 50 on the opposite side of the pen tip 20. In addition, the writing instrument body 10 has two self-detachable pens on both sides. The pen has a clip portion 60a formed of a transparent material that protects the pen tip 20. A cap 60 for protecting the pen tip 50 and a cap made of a transparent material for protecting the pen tip 50. 70 is attached.

[0037] The barrel 10 is formed of, for example, a thermoplastic resin, a thermosetting resin, or the like, and The ink cartridge is made of a cylindrical body that contains an ink occlusion body 15 that is impregnated with a water-based ink. The right end of the pen is fixed by fitting a holder 55 for holding a rod-shaped pen tip 50 for fine writing. The other end, which is the left side, has a holding part 11 with a fitting part for attaching the pen to the writing direction. The pen tip 20 has a window through which the pen can be seen. The tip 20 is fixed to the tip barrel 16. It is being done. The barrel 10 is formed in a cylindrical shape using a resin such as polypropylene. The barrel 10 functions as the main body (shaft body). The barrel 10 is molded to be opaque or transparent (and translucent). However, either may be adopted from the viewpoint of appearance and practicality.

[0038] The ink occlusion body 15 is impregnated with the water-based ink having the above composition, and is made of, for example, natural fibers. , animal hair fiber, polyacetal resin, acrylic resin, polyester resin, polyamide resin, polyurethane resin, polyolefin resin, polyvinyl resin, polycarbonate A combination of one or more of polyvinyl chloride resins, polyether resins, polyphenylene resins, etc. Fiber bundles made of laminated fibers, processed fiber bundles such as felt, sponges, resin particles The ink occlusion body 15 is a barrel that is the main body of the writing instrument. It is contained and held within 10.

[0039] As shown in FIGS. 2(a) and (b), the pen tip 20 is a writing tip having at least a writing portion 25. The pen is made up of a writing core 30 and a holder 40 having a visible portion. The recording core 30 is attached to the holder 40 (described later) by adhesion, welding, fitting, etc. . The writing core 30 is inclined (knife cut) to make it easier to write. The writing part 25 and the other parts are made of thin plates (sheet bodies) 31 and 32 from both ends of the writing part 25. 1, which are integrally connected, and the outer shape is formed into a substantially U-shape (including a U-shape). The cross section of the thin plate members 31, 31 is rectangular. This writing core 30 efficiently disperses the water-based ink having the above-mentioned vapor pressure characteristics stored in the barrel 10. However, there is no particular limitation as long as the ink is guided (supplied) to the writing part 25 via the thin plate members 31, 31. The material is not limited to a specific material, and may be, for example, a nonwoven fabric, a woven fabric, a knitted fabric, or a liquid-permeable foam, a sintered material, or the like. Examples of the material include those made of a material having liquid permeability such as a solid. The writing core 30 can be made of one type of material, but it can also be made of a composite material such as by laminating multiple materials. The writing part 25 and the parts other than the writing part 25 can be connected with each other using different materials. It may be configured by combining or the like.

[0040] The shape, thickness, etc. of the writing core 30 having the writing portion 25 depend on the manner of attachment to the holder 40, the writing The shape of the writing part 25, the maximization of the visible area of ​​the visible part 43, and the efficient flow (supply) of ink to the writing part are The length in the width direction and the length in the length direction are preferably set based on the point of supplying the material. The width direction length, circumference, and width of the mounting surface of the holding body 40 to which the thin plate members 31, 31 of the writing core 30 are fixed are The length of the surface is determined by the length that allows the ink to flow efficiently to the writing part 25. The thickness of the thin plate members 31, 31 other than the writing portion 25 of the writing core 30 is set as follows. In order to maximize the area of ​​the visible portion of the recognition portion 43, the thickness is preferably 0.3 to 3.0 mm. , and most preferably 0.5 to 1.0 mm.

[0041] In this embodiment, the writing part 25 is integrally formed with the thin plate members 31, 31 of the writing core 30. It is designed with a knife cut slant to make it easier to write. The inclination and other aspects of the writing section 25 are appropriately set according to the ease of use for writing, etc. The line width is thick, preferably 1 mm or more, and more preferably 1 mm or more. It is preferable that the writing area be such that the line width is 2 mm or more. The writing tip 30 including the writing portion 25 of this embodiment is made of a sintered core made of sintered plastic powder. It is constructed as one unit.

[0042] In the above embodiment, the writing portion 25 of the writing core 30 and the thin plate members 31, 31 are integrally formed from the same material. However, the writing part 25 and the thin plate members 31, 31 are formed as separate members, and are connected, joined, or abutted against each other. The writing part 25 may be formed of a porous material having air holes, for example. Specifically, examples of the material include a sponge body, a sintered body, a fiber bundle body, a foam body, a spongy body, and a felt body. Examples of materials that form a porous body include natural Fiber, animal hair fiber, polyacetal resin, polyethylene resin, acrylic resin, polyethylene Styrofoam resins, polyamide resins, polyurethane resins, polyolefin resins, polyvinyl chloride resins Nyl resin, polycarbonate resin, polyether resin, polyphenylene resin, etc. Specifically, the writing part 25 can be made of sintered plastic powder or the like. The thin plate members 31, 31 are made of a sintered material, and are made of a fabric such as a nonwoven fabric, a woven fabric, or a knitted fabric. Alternatively, it may be made of a liquid-permeable material such as a liquid-permeable foam.

[0043] The holder 40 fixes the writing part 25 of the writing core 30 and the thin plate members 31, 31 to form a writing implement. It is fixed to the tip opening of the front barrel 16 of the body 10, and the writing direction can be visually confirmed. It has a visible portion (visible portion) 43 . In addition, the holder 40 has a portion (thin plate) that abuts against the side of the holder 40 of the writing core 30. The holder 40 has a rectangular cross section, and the front end of the holder 40 is a visible portion 43. The outer periphery is formed into inclined refractive surfaces 43a, 43a. By making the portion of the writing core 30 that comes into contact with the side surface of the holder 40 have a rectangular cross section, The width of the visual confirmation portion 43 relative to the cross-sectional area can be increased, and the visual confirmation portion 43 of the holder 40 can be By forming the outer peripheral edge into the inclined refractive surface 43a, 43a, the rectangular cross section can be made to look slimmer. As a result, the area of ​​the visible portion 43 can be made to appear larger than before.

[0044] The entire holder 40 thus configured is made of a hard material, and is, for example, Hard materials having elasticity, such as glass and resins that do not have rubber elasticity. Examples of resins that do not have rubber elasticity and are visible include PP, PE, PET, In addition to common nylons such as PEN, nylon 6, and nylon 12, amorphous nylon Visible light transmission of acrylic, polymethylpentene, polystyrene, ABS, etc. By forming the writing surface from a material with a ratio of 50% or more by molding, the writing surface can be seen in the writing direction at the visible portion 43. The characters can be effectively viewed. Only the first and second layers (including 43a) may be made of a material having visibility. The reflectance is measured using a multi-light source spectrophotometer (MSC-5N, manufactured by Suga Test Instruments Co., Ltd.). This can be found by: The holder 40 is made of one of the above materials, or a material that is more durable and has better visibility. Therefore, it may be made of two or more materials, and may be molded by various methods such as injection molding and blow molding. It can be formed by a molding method.

[0045] The thin plate body 31 of the writing core 30 is attached to the mounting surface of the U-shaped holding groove of the holding body 40. 31 is fixed to the writing part 25 by bonding with an adhesive, welding or the like. In this embodiment, in order to maximize the visual recognition area of ​​the visual recognition portion 43, The thickness of the writing part 25 is thinner than that of the ink guide part 31. It is preferable that the width of the visible portion 43 of the optical fiber 40 is less than 90%, and more preferably, 50 to 80%. stomach.

[0046] As shown in Figs. 1(a) to (c), the pen tip 50 is a rod-shaped pen tip for fine writing. The cross section is circular, and the rear end of the pen tip 50 (the ink occluder side) is The ink occlusion body 15 is inserted into the ink occlusion body 15, and the ink occlusion body 15 is filled with the water-based ink of the above-mentioned ink composition by capillary force. is supplied to the pen tip 50. The pen tip 50 is made of a porous material, for example, natural fiber or animal hair fiber. Fiber, polyacetal resin, polyethylene resin, acrylic resin, polyester resin , polyamide resin, polyurethane resin, polyolefin resin, polyvinyl resin, Polycarbonate resin, polyether resin, polyphenylene resin, etc. Processing parallel fiber bundles, felt, and other fiber bundles consisting of a combination of several types or more Resin-treated fiber core, or polyolefin resin, acrylic resin, polyester Plastic powders such as thermoplastic resins such as polyamide resins and polyurethane resins It consists of a porous body (sintered core) made by sintering powder, etc. Preferred pen tips 50 include fiber bundle cores, fiber cores, sintered cores, felt cores, sponge cores, The core is an inorganic porous body, and a fiber core is particularly preferable from the viewpoints of deformation moldability and productivity. In addition, the porosity, size, hardness, etc. of the pen tip 50 to be used depend on the type of ink and the type of writing instrument. For example, the porosity is preferably set to 30 to 60%. In the present invention, the "porosity" is calculated as follows. A writing lead having a certain amount and apparent volume is immersed in water, and after it is sufficiently saturated with water, it is removed from the water. The mass is measured with the tip pulled out. The volume of the water that has soaked into the writing tip is derived from the measured mass. The volume of this water is considered to be the same as the pore volume of the writing core, and the porosity is calculated from the following formula: can be. Porosity (unit: %) = (volume of water) / (apparent volume of nib 50) x 100

[0047] In this embodiment, as shown in FIGS. 1(a) to 1(c), one pen tip 20 of the barrel 10 The transparent member is detachably attached to the outer periphery of the pen tip 50 side by fitting with the outer periphery of the pen tip 50 side. The cap 60 has a clip 60a formed of a material having the inner cap 70a. A cap 70 is attached to the housing. The caps 60 and 70 are made of, for example, a transparent (visible) material, for example It is made of glass, resin that does not have rubber elasticity, etc. Transparency (visibility) Examples of resins that do not have rubber elasticity include PP, PE, PET, PEN, and nylon. Nylon (including amorphous nylon, in addition to common nylons such as nylon 6 and nylon 12), Visible light transmittance of 50% or more for acrylic, polymethylpentene, polystyrene, ABS, etc. By forming the cap 60 and the cap 61 from the material, The pen tips 20 and 50 can be seen (visually recognized) through 70. The caps 60 and 70 are entirely made of a transparent (visible) material. In addition, if you can see (visually confirm) the nib 20 and 50 and the color of the ink, The cap 60 or the cap 70 may be partially or entirely covered. When the above-mentioned water-based ink is used as a thermochromic ink, it is required to meet the requirements of JIS S 6050-200. The thermoplastic elastomer specified in 2 has a pencil line erasability (erasability rate) of less than 70%. The friction body is formed on the top of the tip 60, and generates friction heat easily and has low wear due to the rubbing action. This reduces the amount of eraser dust generated by friction and helps prevent dirt from getting on the surrounding area.

[0048] In the writing instrument A thus constructed, the water-based ink having the above composition is stored in the writing instrument body 10. The ink occlusion body 15 is inserted and held in place, and the tip side of the ink occlusion body 15 is held in place by the tip shaft 16. The tip 20 is then fixed by fitting or the like, and the other end side is provided with a holder 55 to which the pen tip 50 is fixed. By fastening them together through fitting, it is possible to easily create a twin-type writing implement A. The water-based ink having the above-mentioned vapor pressure characteristics absorbed in the ink absorbing body 15 is absorbed by the pen tip due to capillary force. In the pen 20, the writing part 25 and the pen tip 50 are efficiently connected through the thin plate members 31, 31 of the writing core 30. The documents will be provided to the public and made available for writing.

[0049] In the marking pen type writing instrument A of this embodiment, in order to show the pen tip 20, A cap 60 (including a cap 70) made of a transparent material and having a large internal volume (hereinafter (similar) are used in environments with temperature changes or temperature gradients, such as in direct sunlight or Do not place the device near a heating vent, near a heat source such as a PC, or near an electric car. Even if the container is accidentally placed on a pet, the container can be sealed by a cap, etc., as shown in the above formula (I). The difference between the temperature inside the product (x℃) and the dew point temperature inside the product (y℃) in that state is 1℃ or more. Therefore, a writing instrument that does not cause condensation inside the cap or other writing instrument products can be obtained. In particular, even if the writing implement has a cap made of a transparent material, There is no condensation in the writing products such as caps, and the appearance is not marred. The shape of the tip and the color of the water-based ink can be seen through the cap, making it a writing instrument. This will result in a writing instrument of high quality and commercial value (more on this point in the implementation section below). (Details will be given in examples.)

[0050] In addition, in this writing instrument A, the pen tip 50 is the same as a conventional general-purpose pen tip. The function of the pen tip 20 will be described. As shown in FIG. 1 and FIG. 2, the pen tip 20 is a pen tip that visually recognizes the writing direction. The ink occlusion body 15 has a visible portion (window portion 43) through which the vapor of the ink occlusion body 15 can be seen. The water-based ink having pressure characteristics reaches the writing part 25 by the capillary force of the thin plates 31, 31 of the writing core 30. When writing, if you look at the viewing side through the viewing portion (window portion) 43, It makes it easier to align the starting position and also allows you to stop exactly where you want to stop at the end of the pull. This makes it possible to prevent over-pulling and overhanging.

[0051] Furthermore, the pen tip 20 is designed to guide ink from the ink occlusion body 15 to a thickness greater than that of the writing part 25. A thin, flowable writing core 30 is guided to the writing part 25 via thin plates 31, 31. In addition, since the thin plate members 31, 31 are made of a sheet-like porous body, The ink flow is good, there is no need to design it thick, the visible portion 43 is not obstructed, and By making the portion of the writing core 30 that abuts against the side surface of the holder 40 have a rectangular cross section, The width of the visible portion 43 can be increased relative to the holder 40. By forming the refracting surfaces 43a, 43a into an inclined shape, the rectangular cross section can be made to look slimmer. Therefore, when a right-handed person writes from left to right, the user can visually confirm the writing direction using the visual confirmation unit 43. The maximum effective area of ​​the visible part relative to the entire pen tip is In addition, the thin plate members 31, 31 having the above characteristics allow ink to flow efficiently to the integral writing portion 25. Since the ink is supplied, the ink flow is good, and the ink flow is not impaired. This results in a writing implement that can maximize the effective area of ​​the recognition portion 43.

[0052] <Writing instrument according to the second embodiment: Overall configuration: Figs. 3 and 4> As shown in FIG. 3, the writing instrument of the second embodiment has a structure in which at least the water-based ink is occluded. The barrel 10 is housed in the barrel 15, and the barrel 10 is provided at the tip side thereof with a nozzle capable of discharging water-based ink. and a transparent material that is detachably attached to the pen tip 20 side of the barrel 10. A writing instrument B having a cap 60 formed of the same material as the first embodiment. As shown in the above formula (I), the product internal temperature (x°C) and The difference between the dew point temperature (y°C) inside the product and the dew point temperature (y°C) inside the product at the time of drying is 1°C or more. do.

[0053] <Specific configuration of the writing instrument according to the second embodiment> FIG. 3(a) is a plan view of the writing implement of the second embodiment, (b) is a front view thereof, and (c) is a schematic view thereof. FIG. 4 is an enlarged perspective view of the pen tip of the writing instrument of FIG. 1, (a) is a view from one direction. (b) is an enlarged perspective view of the pen tip as seen from a 180° angle. FIG. As shown in FIG. 3, the writing instrument of the present embodiment contains at least the aqueous ink having the above-mentioned composition. The barrel 10 is built into the ink storage body 15, and the water-based ink is discharged from the tip of the barrel 10. The pen tip 20 is removable from the barrel 10 on the side of the pen tip 20. and a cap 60 formed of a material. In addition, when the writing instrument A has the same configuration and function as the writing instrument A of the first embodiment, In the embodiments, the same reference numerals are used in the drawings and the description thereof will be omitted.

[0054] The writing instrument B of the second embodiment uses the writing core 30 of the above embodiment having a U-shaped outer shape. However, in the second embodiment, as shown in Figs. 3 and 4, the writing core 35 has an L-shaped outer shape. The difference is that it is attached to the body 40. The writing portion 36 of the writing core 35 of the second embodiment has a shape similar to that of the writing portion of the above embodiment. The pen is angled (knife cut) to make it easier to write. The core 35 has a thin plate body 37 integrally connected to the end of the writing part 36, and has an L-shaped outer shape. The cross section of the thin plate 37 is rectangular. As shown in FIG. 4, the holder 40 fixes the writing part 36 of the writing core 35 and the thin plate body 37. The tip of the tip barrel 16 of the writing instrument body 10 is fixed to the tip opening of the tip barrel 16. In the previous embodiment, the thin plate members 31, 31 were provided with upper and lower mounting surfaces. In this embodiment, since the outer shape is L-shaped, it is attached only to the lower side of the holder 40. There are.

[0055] In the writing instrument B of the second embodiment, a transparent material is used to show the pen tip 20. Cap 60, which is made of high-quality material and has a large internal volume, is used in environments with temperature changes and temperature gradients, e.g. For example, do not place the device in direct sunlight, near a heating vent, or near a heat source such as a PC. Even if the device is placed near a wall or accidentally placed on an electric carpet, the above formula ( I) shows the temperature inside the product (x℃) of the cap, etc. and the exposure temperature inside the product at that state. Since the difference between the temperature at the tip and the temperature at the tip (y℃) is 1℃ or more, condensation may occur inside the cap or other writing instrument products. In particular, the cap formed of a transparent material is Even with writing instruments that use caps, there is no condensation inside the writing products such as caps. It does not spoil the appearance, and the shape of the pen tip and the color of the water-based ink can be changed through the cap, etc. This allows the quality of the writing utensils to be improved and the product value to be improved. (This point will be described in more detail in the examples below).

[0056] In addition, in the writing instrument B of the second embodiment, the writing core 35 has an L-shaped outer shape. 1 has a U-shaped outer shape, and the thin plate body 31 is not attached to the upper surface side of the visual recognition portion 43. Therefore, there is nothing blocking the view, and the area of ​​the visible portion can be enlarged accordingly. By making the portion that comes into contact with the side of the support 40 rectangular in cross section, the bottom side is The width of the visible portion 43 can be increased, and the outer periphery of the visible portion 43 of the holder 40 is inclined. By forming the refractive surfaces 43a, 43a in the shape of a rectangle, the rectangular cross section can be made to look slimmer, This makes the area of ​​43 appear even larger than in Figure 1.

[0057] The pen tip 20 of this second embodiment is attached in the same manner as the writing instrument of FIG. The ink occlusion body has a visual confirmation portion (window portion) 43 through which the writing direction can be visually confirmed. The water-based ink 15 reaches the writing part 35 by the capillary force of the writing core 36 and is used for writing. When writing, if you look at the visible side through the visible portion (window portion) 43, you can easily align the starting position of the writing. It is also easier to stop the pull at the exact point you want to stop, so you don't have to pull too much or This makes it possible to prevent the ink from sticking out.

[0058] In the second embodiment, the pen tip 20 guides the water-based ink from the ink occlusion body 15 to the writing part. The writing core 35 is thinner than the writing core 35 and is guided to the writing part 36 through the thin plate 37 of the writing core 35 which has a flowability. The thin plate 37 has a superior ink supplying power to the embodiment shown in FIG. It is made of a material that is thick and has good ink flow properties. There is no need to insert the writing tip 35 into the holder 40, so the visible portion 43 is not obstructed, and the writing tip 35 does not come into contact with the side of the holder 40. By making the contact portion rectangular in cross section, the width of the visual recognition portion 43 relative to the cross-sectional area can be increased. The outer periphery of the visual confirmation portion 43 of the holder 40 is formed into inclined refracting surfaces 43a, 43a. This makes the rectangular cross section look thinner, so it is recommended for right-handed people writing from left to right. When writing, the user can draw a line with the writing unit 36 ​​while visually checking the writing direction with the visual checking unit 43. In addition, the effective area of ​​the visible portion relative to the entire pen tip is maximized, and the thin plate body 37 having the above characteristics is Since the ink is efficiently supplied to the writing part 36, which is integrally constructed, the ink flows out smoothly. 1. The effective area of ​​the visible portion 43 is larger than that of the embodiment shown in FIG. This results in a writing instrument that can achieve maximum efficiency.

[0059] <Writing instrument according to the third embodiment: Overall configuration: Figs. 5 to 7> The writing instrument C of the third embodiment is a marking pen type writing instrument, and is at least A barrel 80 in which water-based ink is contained, and a nozzle provided at the tip of the barrel 80 capable of ejecting water-based ink. A pen tip 90 and a transparent material that is detachably attached to the pen tip 90 side of the barrel 80. The writing instrument C is provided with a cap 65 formed by the above-mentioned method, and is calculated in the same manner as in the first embodiment. As shown in the above formula (I), the temperature inside the product (x°C) and its state The difference between the dew point temperature (y°C) inside the product at y°C is 1°C or more.

[0060] As shown in FIGS. 5 to 7, the writing instrument C of the third embodiment includes a barrel 8 constituting the main body of the writing instrument. 0, an ink occlusion body 85, a relay core 95, a pen tip 90, and a cap body 65. The barrel 80 is made of the same material as the barrel 10 of the first embodiment. The ink occlusion body 85 is impregnated with the water-based ink having the above-mentioned characteristics. The ink occlusion body 85 is a cylindrical rear barrel 81 with a bottom. and a tip shaft 86 to which the tip 40 is fixed. The rear axle 81 is molded in the shape of a long, bottomed elliptical cylinder using synthetic resin such as PP. This rear barrel 81 functions as the main body (barrel tube) of the writing instrument. In this manner, the rear end of the ink occluding body 85 is held by a holding member 82 having a holding piece. The entire rear barrel and the front barrel, which will be described later, are made opaque or transparent (and translucent). However, either may be adopted from the viewpoint of appearance and practicality. The front barrel 86 is secured to the opening of the pen by fitting or the like.

[0061] The ink occlusion body 85 is made of the same material as the ink occlusion body 15 of the first embodiment. It is something that can be done. The intermediate core 95 transfers the water-based ink from the ink occlusion body 85 to the ink guide provided in the holder 96 described later. The ink occlusion bodies 15 and 85 are made of fibers, and serve as a core for supplying ink to the ink guide 97. Fiber bundle cores made from processed fiber bundles such as fiber bundles and felt, or hard sponges and sintered resin particles It has continuous pores (flow paths) such as a resin particle porous body or a sliver core. The ink occlusion body 85 is impregnated with the water-based ink having the above-mentioned vapor pressure characteristics or blending characteristics, and the ink occlusion body 85 is then filled with the water-based ink having the above-mentioned vapor pressure characteristics or blending characteristics. As long as the ink can be supplied to the ink guide portion 97 of the holder 96 via the ink guide portion 97, the ink may be supplied to the ink guide portion 97 of the holder 96 through the ink guide portion 97. The cross-sectional shape of the relay core 95 may be, for example, a circle, an ellipse, a square, or the like. Examples of shapes include a rectangular shape, a trapezoid, a parallelogram, a rhombus, a kamaboko shape, and a half moon shape. In the embodiment, the cross-sectional shape is circular. The pen tip 90 has a pen core 98 which is a writing part, and a pen core 98 which holds the pen core 98 and applies ink to the writing part. and a holder 96 having an ink guide portion 97 for supplying the ink.

[0062] The entire pen tip 90 configured in this manner or the holder 96 described later is made of a material having visibility. For example, PP, PE, PET, PEN, nylon (6 nylon, 12 nylon, etc.) (In addition to typical nylon, amorphous nylon, etc.) Acrylic, Polymethylpentene, Poly It is made of materials such as polyethylene and ABS, and has a visible light transmittance of 50% or more. It is preferably made of the material. The entire pen tip 90 or the holder 96 described later is made of one of the above materials or a durable material. In order to further improve the visibility and durability, it can be made of two or more materials. If it is made up of two or more materials, at least one of them must have a visible light transmittance of 50% or more. It is preferable that the material is made of the material, and the material is molded by various molding methods such as injection molding and blow molding. It can be molded.

[0063] 6(a) and (b) show the writing instrument C of this embodiment with the cap removed. 7(a) to (d) are drawings showing an example of a state in which a cap is attached. Each drawing. In the writing instrument C of this embodiment, ink is stored in the rear barrel 81 that constitutes the barrel of the writing instrument. The ink occlusion body 85, the intermediate core 95, the pen tip 90 to which the pen core 98 is attached, and the tip shaft 86 By sequentially fitting the above together, writing implement C can be easily produced. It is. The cap 65 is detachably attached to the front barrel 86 by fitting or the like. The outer cap 67 is made up of an inner cap 66 that protects the core 98 and a cylindrical outer cap 67. The cap portion 67 has a structure in which a concave portion 68 is formed on the surface thereof to improve design. There are. The cap 65 has transparency (visibility) similar to the cap of the first embodiment. By molding the material with a visible light transmittance of 50% or more, The pen tip 90 can be seen (visually recognized) through the cap 65. .

[0064] In the writing instrument C of this embodiment thus configured, Even if the cap and its structure or shape are different, the cap can be determined from the content shown in the above formula (I). If the difference between the temperature inside the product (x℃) and the dew point temperature inside the product (y℃) at that state is 1℃ or more, For example, as in the first and second embodiments, condensation does not occur inside the cap 65. , without impairing the appearance, and the shape of the pen tip 90 and the color tone of the water-based ink (e.g., The ink color (yellow, pink, etc.) can be seen through the cap 65, so the quality of the writing instrument can be confirmed. This results in a writing instrument with high commercial value. In addition, the water-based ink having the above characteristics is transported from the ink absorbing body 85 to the relay core 95 and the ink guide portion 97. Since the ink is continuously and efficiently supplied to the pen core 98 by capillary action, the appropriate ink can be The ink flow rate is ensured to prevent writing from smearing, and the ink occlusion body 85 water-based ink has a stable writing flow rate. This results in a writing instrument that can be used to its full potential. Furthermore, as described above, the pen tip 90 includes a pen core 98 that serves as a writing portion and a pen core holder that holds the pen core 98. a holder 96 having at least one ink guide portion 97 for supplying ink to the writing portion; The water-based ink contained in the ink occlusion body 85 is absorbed by the ink holder 96. The ink guide portion 97 is provided with a relay core 95 for supplying the ink to the ink guide portion 97, and the holder 96 is provided with a visible ink guide portion 97. Since the holder 96 is made of a material having the above-mentioned properties, the entire surface of the holder 96 other than the ink guide portion 97 is (whole) is the visible part where the writing direction can be visually confirmed, and the area ratio of the visible part is 86 The tip of the pen protruding from the tip of the pen may be 40% or more, and preferably the tip of the pen may be The visible area of ​​the side of the holder 96 is set to 40% or more. Furthermore, the ink guide portion 97 is arranged along the longitudinal direction of the holder 96. The ink guide portion 97 is formed in the center in the width direction, and the length, diameter, cross-sectional area, etc. in the width direction of the ink guide portion 97 are set to a desired predetermined value. By appropriately setting the range, characters written in the writing direction can be read more reliably than before. It is possible to provide sufficient visibility for the writing to be possible, and the writing instrument can be used until the end of the stroke. It will be provided.

[0065] In the writing instruments A to C of the first embodiment, the ink occlusion bodies 15 and 85 are We have explained the type that absorbs water-based ink with vapor pressure characteristics, but the type that can be detachably attached to the pen tip side of the barrel. If the cap is made of a transparent material, it can be used for writing instruments, e.g. For example, water-based ink can be stored directly in the barrel and then applied to the writing part of the pen tip via a relay core. The writing implement may be of a collector type or the like. In addition, in each of the writing instruments of the above-mentioned embodiments A to C, the writing direction of the pen tip 20, 90 can be visually confirmed. It had a window, but it was equipped with a cap that was detachably attached to the tip side of the barrel. There are no particular limitations on the shape and structure of the pen tip and cap as long as they are suitable. EXAMPLES

[0066] [Examples 1 to 9 and Comparative Examples 1 to 2] According to the formulation shown in Table 1 below, aqueous ink compositions for each writing instrument were prepared by a conventional method. Made. In addition, each of the obtained aqueous ink compositions for writing instruments was applied to writing instruments having the following configurations. Using each of the resulting writing implements, the presence or absence of condensation and writing performance were evaluated using the following methods. The results are shown in Table 1 below.

[0067] (Writing Instrument Composition) The following configuration and the pen tip and writing implement conforming to Figs. 1 and 2 were used. The dimensions of the pen tip, holder, etc. The methods and physical properties used are as follows:

[0068] (Pen tip 20 configuration) Made of acrylic resin, visible light transmittance 85% [manufactured by Suga Test Instruments, multi-light source spectrophotometer (MSC The reflectance was measured at -5N and used as the visible light transmittance. Size of the viewing area (window) 43 (square): 9mm x 8mm x 5mm x 4mm Visible width: 3.0mm Writing core 30: Thin plate body 31, 31 composition: polyethylene sintered core, width direction length: 2 mm, Longitudinal length: 20 mm, thickness: 0.5 mm, writing part 25: polyethylene sintered core, air hole Rate: 50%, 4 x 3 x 6 mm, thickness = 3 mm, longitudinal length = 5.5 mm

[0069] Ink occlusion body 15: PET fiber bundle, porosity 85%, φ6×77mm Writing instrument body 10, caps 60 and 70: Made of polypropylene (PP) Pen tip 50: Polyester fiber bundle core, porosity 60%, φ2.0×40.0mm Cap 60: Made of polypropylene (PP), Transmittance: 70% Cap 70: Made of polypropylene (PP), transparency: 60%

[0070] The temperature inside the cap 60 product is 27°C, and the saturated water vapor pressure at 27°C is Pmax, the mole fraction of water The water vapor pressure Px inside the product was calculated from (N). This water vapor pressure Px becomes equal to the saturated vapor pressure. The temperature was calculated using the above formula with the dew point temperature (y°C). The difference in dew point temperature (y°C) inside the product under that condition was determined. Saturated water vapor pressure: Pmax, mole fraction of water: (N), water vapor pressure in the product Px, dew point temperature (y°C), The difference between the temperature inside the product (27°C) and the dew point temperature inside the product (y°C) at that state is recorded.

[0071] (Method for evaluating the presence or absence of condensation) Using each of the obtained writing instruments, we tested the ink on a heated carpet (internal temperature: 32°C, etc.) for 9 hours. After leaving it for a certain period of time, the presence or absence of condensation was evaluated according to the following criteria. Evaluation criteria: ◎: No condensation. ○: It's a bit cloudy. △: Mostly cloudy. △△: droplets are generated. ×: Liquid has accumulated.

[0072] (Writing performance evaluation method) Using each of the obtained writing implements, a straight line of 25 cm was written on PPC paper, and the following evaluation criteria were used. The writing performance was evaluated according to the standard. Evaluation criteria: ○: No abnormality in the written lines. △: Some parts are scratched. ×: Almost completely scratched.

[0073] [Table 1]

[0074] As is clear from the results in Table 1 above, each of the writing instruments in Examples 1 to 9 within the scope of the present invention has the following properties: Compared with Comparative Examples 1 and 2, which are outside the scope of the present invention, the cap is made of a transparent material. Even if a writing instrument is attached, condensation does not occur inside the cap without impairing writing performance. The shape of the pen tip and the color of the water-based ink can be changed without removing the cap. This allows the quality of the writing utensils to be high and the product to have high commercial value. Confirmed. In addition, as Example 9, a writing instrument with a cap made of an opaque material was created and When evaluated in the same manner as the example (with the internal temperature of the product at 30°C), the writing performance was not significantly impaired. It was also confirmed that no condensation occurred inside the cap.

[0075] In addition, each of the writing instruments in Examples 1 to 9 conforms to the ink occlusion body 1 shown in FIG. The ink is guided from the writing part 25 to the writing part 26 by thin plates 31, 31 having a flowability and a thickness smaller than that of the writing part 25. The writing part 25 is guided to the writing part 25, and the thin plate members 31, 31 are guided to the writing part 25. The U-shaped writing core 30 is made of the polyethylene sintered core described above, so The strength of the capillary force relative to the porosity is large, and the thickness can be made extremely thin, resulting in excellent ink outflow properties. It is not necessary to design the ink guide portion to be thick, and the visible portion 43 is not obstructed. By making the portion of the writing core 30 that comes into contact with the side surface of the holder 40 into a rectangular cross section, The width of the visual confirmation portion 43 relative to the cross-sectional area can be increased, and the visual confirmation portion 43 of the holder 40 can be By forming the outer peripheral edge into the inclined refractive surface 43a, 43a, the rectangular cross section can be made to look slimmer. Therefore, when a right-handed person writes from left to right, the user can visually check the writing direction using the visual confirmation unit 43. The effective area of ​​the visible part relative to the entire pen tip is In addition, the thin plate members 31, 31 with the above characteristics allow efficient input to the integrally-constructed writing portion 25. Since the ink is supplied, the ink flow is also good, and the ink flow is not impaired. It has been confirmed that a writing instrument capable of maximizing the effective area of ​​the visible portion 43 can be obtained. It was also confirmed that the pen could be used to write without any scratches even after being dropped from a height of 1m. Done. [Industrial Applicability]

[0076] It can be used effectively for writing instruments such as felt-tip pens and marking pens. Cut. [Explanation of symbols]

[0077] 10 shaft cylinder 20 Pen Tip 25 Writing section 30 writing lead 40 Holder 43 Visibility section 60 Cap

Claims

[Claim 1] The invention described in the specification.

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