JP6896403B2 - Erasing writing tool - Google Patents

Description

The present invention relates to an erasable writing instrument in which a plurality of cursives are housed in a barrel and the handwriting by the cursives can be erased.

Conventionally, Patent Document 1 discloses a writing instrument in which a plurality of cursives are housed in a barrel and an erasing portion capable of erasing the handwriting by the cursive is housed in the rear part of the shaft.

JP 2013-173358 (Fig. 2, Fig. 7, etc.)

However, the invention disclosed in Patent Document 1 requires a position operation of the axis body when switching between a plurality of cursive bodies, and it is difficult to understand the infestation operation of the cursive body. Further, since the positions of the operation unit and the erasing unit are different, it is necessary to search for the erasing unit during the erasing operation.

Therefore, it is an object of the present invention to provide an erasable writing tool that makes it possible to easily perform an operation of appearing and disappearing a plurality of cursive bodies by one-handed operation and reduces the need to search for an erasing unit.

According to the present invention, in an erasable writing instrument in which a plurality of cursives are housed in a barrel, at least one of the cursives holds erasable ink, and an operation unit projecting rearward from the shaft cylinder is provided in the operation unit. By accommodating the cursive presser, which is pressed to move forward and rotates in the circumferential direction at the required angle, the cursive presser that transmits the knock pressure by sequentially contacting the pressing part with the rotation is housed in the barrel. , An erasable writing instrument provided with a knock mechanism for sequentially feeding out a plurality of cursive bodies in a barrel and an erasing unit capable of erasing erasable ink at the rear end of the operation unit. Since the only operating unit that operates multiple cursives housed in the cursive is the knock rod that protrudes rearward from the cursive, the rotating cam inside the cursive rotates due to the pressing operation of the operating unit to press the cursive. The cursive is pressed, the cursive attached to the front end of the cursive presser is extended, and the rotary cam in the barrel is rotated by the pressing operation of the operation unit to accommodate the cursive in the barrel, and the operation unit is further pressed. Since the rotary cam in the barrel can be rotated by the pressing operation of to feed another cursive, a plurality of cursives can be fed with one operation unit. In the present invention, the side capable of writing with the erasable ink, that is, the so-called writing portion side is referred to as "front" and "front", and the other end side is referred to as "rear".

In addition, by equipping the knock mechanism with a knock mechanism that can be mounted more than the number of cursives accommodated in the barrel, and mounting more cursive pressers than the number of cursives on the knock mechanism, the operation unit is moved back and forth. In some cases, the pressing part of the cam rotor abuts on an extra cursive press that does not press the cursive, or the pressing part of the cam rotor is located where the cursive press does not exist. It is more preferable.

According to the present invention, by operating the operation unit protruding from the rear portion of the barrel, it is possible to easily perform the operation of appearing and disappearing a plurality of cursive bodies and the operation of switching the cursive body by one-handed operation, and to provide an erasing unit at the rear end of the operation unit. As a result, it is possible to be aware of the erasing unit during operation, so that it is possible to reduce the need to confirm the position of the erasing unit. Further, by providing more cursive pressers than the number of cursives in the barrel, the total length can be shortened at the time of carrying, which is excellent in portability.

It shows the vertical sectional view of the carrying state of 1st Embodiment. It shows the vertical sectional view of the carrying state of the 2nd Embodiment.

FIG. 1 shows a carrying state of the multicolor writing instrument of the first embodiment, and is a so-called ballpoint pen refill having a structure in which a ballpoint pen tip 4 which is a writing portion is attached to the tip of an ink storage tube 5 containing erasable ink. Is a cursive, and a knock rod 1 which is an operation unit, a cam rotor 2 which is urged backward by a coil spring 3 and is pressed by the knock rod 1 to move forward and rotate at a required angle, and a cam rotation. When the child 2 rotates every 120 °, the knock mechanism is configured by three cursive pressers 6 that sequentially come into contact with the pressing portion of the cam rotor 2 and transmit the knock pressure from the cam rotor 2. Is.

In the second embodiment shown in FIG. 2, a so-called ballpoint pen refill having a structure in which a ballpoint pen tip 4 which is a writing part is attached to the tip of an ink containing tube 5 containing erasable ink is used as a cursive, and the operation part is used. When a knock rod 1, a cam rotor 2 urged backward by a coil spring 3 and pressed by the knock rod 1 to move forward and rotate at a required angle, and a cam rotor 2 rotate every 120 °. The knock mechanism is configured by three cursive presses 6 which are sequentially in contact with the pressing portion of the cam rotor 2 and the knock pressure is transmitted from the cam rotor 2. Then, a knock mechanism equipped with three cursive presses 6 connected to the rear ends of the ink storage tubes 5 of the three ballpoint pen refills to enable the appearance of the three ballpoint pen refills, and two With only the ballpoint pen refill attached and one free, that is, an extra cursive press 6 that is not connected to the ballpoint pen refill is provided, and the extra cursive press 6 is knocked, that is, the figure. As shown in 2, the ballpoint pen refill can be carried in a state in which the ballpoint pen refill does not protrude and the length of the knock rod 1 protruding from the barrel is shorter than that of the first embodiment. Here, the knock mechanism is equipped with three cursive presses 6 which are larger than the two ballpoint pen refills, but the cursive presses 6 are removed from the knock mechanism, that is, the ballpoint pens are preliminarily attached. Only the same number of two cursive presses 6 as the number of refills may be provided.

The knock rod 1 is knocked and the pressing portion of the cam rotor 2 abuts on the extra cursive press 6 that does not press the cursive, or the pressing portion of the cam rotor 2 is present on the cursive press 6. Since the cursive does not protrude, it can be carried in this state when the state of being located in a place where it is not located is generated, and since the knock rod is knocked in this state, it can be removed from the barrel of the knock rod 1. The protruding length of is shortened to the same length as when writing. That is, since the ballpoint pen refill can be maintained in a state of being immersed in the barrel even when it is carried, the protruding length of the knock rod 1 from the rear end of the barrel is shortened, which is not only convenient for carrying but also looks good in appearance. Can also be improved.

In both the first embodiment and the second embodiment, two or three cam rotors 2 are pushed forward by being pressed by the knock rod 1 which is an operation unit and rotate in the circumferential direction at a required angle. The cursive or cursive press 6 can be sequentially extended, but a structure in which four or more cursive or cursive presses can be extended can also be formed by changing the angle of the cam rotor.

In both the first embodiment and the second embodiment, an erasing portion 8 capable of erasing erasable ink is provided at the rear end portion of the knock rod 1. The erasing portion 8 has a structure that does not easily come off by adhering or fitting to the knock rod 1, and may be integrated by multicolor molding such as two-color molding.

The erasable ink contained in the ink storage tube 5 indicates ink that can be erased by the frictional operation of the erasing unit 8. Specifically, an eraser erasable ink and a heat-discoloring ink are shown. The term "erasing" in the present invention means that the drawn lines, characters, etc. written are adsorbed or scraped off by an erasing portion such as an eraser, in addition to the case where the above-mentioned heat-discoloring ink is used. Therefore, the present invention can be applied to any writing tool that erases the drawn lines written by using the erasing unit 8.

The eraser erasable ink of the present invention contains colored resin particles having an average particle diameter of 2 to 20 μm and non-thermoplastic particles in an amount of 5 to 30% by weight based on the total amount of the ink composition, and has a glass transition point of less than 0 ° C. It is characterized by containing at least non-colored particles. The "average particle size" defined in the present invention is a value of D50 measured with a particle size analyzer [Microtrack HRA9320-X100 (manufactured by Nikkiso Co., Ltd.)].

The colored resin particles used in the present invention are composed of colored resin particles, and are required to be non-thermoplastic and colored resin fine particles having an average particle diameter of 2 to 20 μm. Examples of the colored resin particles used in the present invention include colored resin particles in which a colorant made of a pigment is dispersed in the resin particles, colored resin particles in which the surface of the resin particles is coated with a colorant made of a pigment, and resin particles. Examples thereof include colored resin particles dyed with a colorant made of a dye. In the present invention, if the colored resin particles are non-thermoplastic and satisfy the above average particle size, the structure [with hollow structure, without hollow structure (fine)], shape (spherical, polygonal, flat, Fibrous) and the like are not particularly limited, but preferably, the glass transition point is 150 ° C. or higher and close to the thermal decomposition temperature from the viewpoint of exhibiting excellent erasability, writability, and stability over time as an ink. Further, it is preferable to use spherical colored resin fine particles having an intramolecular cross-linking having a melt flow index value of less than 0.1, having no adhesiveness, and having an average particle diameter of 3 to 15 μm. is there. When the colored resin particles are thermoplastic and have adhesiveness, agglutination of the particles is likely to occur, the stability of the ink is impaired, and blurring is likely to occur when the colored resin particles are left with the cap removed, which is preferable. Absent. Further, if the average particle size of the colored resin particles is less than 2 μm, the colored resin particles easily enter the voids of the paper fibers and the erasability is deteriorated, which is not preferable. Further, when the average particle size of the colored resin particles exceeds 20 μm, the erasability is improved, but the concentration as an ink becomes thin, the colored resin particles are easily precipitated, and the stability over time. This is not preferable because it causes problems such as damage to the ink and a poor feel when writing. By setting the average particle size of the colored resin particles to 2 to 20 μm and using non-thermoplastic particles, for the first time, the colored resin particles stay near the surface of the paper without penetrating deep into the fibers of the paper and can be easily removed by an eraser. Will be able to.

Examples of the colorant used for the colored resin particles include direct dyes such as Eisen Primula Red 4BH and Eisen Primula Ero GCLH (all manufactured by Eisen Co., Ltd.), Eisen Bonso RH, Eisen Opal Pink BH, and Eisen Opal. Acid dyes such as Black WH Extra Conc (above, manufactured by Eisen Co., Ltd.), Orient Solple Blue OBX, Orient Solple Blue OBB (above, manufactured by Orient Chemical Co., Ltd.), tartrazine, acid red, floquilon (above, (above,) Food dyes such as (manufactured by Eisen Co., Ltd.) and fluorescent dyes can be mentioned. Examples of the pigment include inorganic pigments such as carbon black, titanium oxide and iron oxide, organic pigments such as phthalocyanine pigments and azo diameter pigments, inorganic fluorescent pigments such as calcium sulfide, and other fluorescent pigments. ..

The resin component is selected from, for example, polymers such as acrylic acid, methacrylic acid, acrylic acid ester, methacrylic acid ester, styrene, acrylonitrile, and butadiene, or copolymers thereof, benzoguanamine, phenol resin, epoxy resin, urethane resin, and the like. At least one of these may be mentioned, and may be subjected to a treatment such as cross-linking if necessary. As a method for coloring these resins, conventionally known methods such as suspension polymerization and dispersion polymerization are used. As the resin content of the colored resin particles, acrylic resin, urethane resin, and benzoguanamine are preferable from the viewpoints of price, mixing property with the coloring agent, and dyeability. Further, as the suitable colored resin particles, those having no adhesiveness and those having no thermoplasticity are suitable. If you write on a sticky material after leaving it for a certain period of time with the cap removed, it may be easy for blurring to occur and you may not be able to obtain good lines. Furthermore, if it is thermoplastic, it may not be possible to obtain good lines over time. This is because it tends to be unstable, and when the drawn lines are left at a temperature of room temperature or higher for a certain period of time, the erasability may decrease.

Examples of the colored resin particles having the above-mentioned characteristics that can be used in the present invention, that is, non-thermoplastic and non-adhesive, include commercially available Labcolor 220 (M) black (pigment-containing crosslinked PMMA particles, average particle size: 8.5 μm, structure: solid, shape: spherical, manufactured by Dainichi Seika Co., Ltd., Epocolor FP112 pink (fluorescent dye-dyed benzoguanamine / formaldehyde condensate, average particle size: 3-5 μm, structure: solid, shape: spherical ), Epocolor FP113 Red (fluorescent dye dyed benzoguanamine / formaldehyde condensate, average particle size: 3-5 μm, structure: solid, shape: spherical), Epocolor FP114 orange (fluorescent dye dyed benzoguanamine / formaldehyde condensate, average particle) Diameter: 3 to 5 μm, Structure: Solid, Shape: Spherical), Epocolor FP117 Yellow (Fluorescent dye-dyed benzoguanamine-formalhide condensate, Average particle size: 3 to 5 μm, Structure: Solid, Shape: Spherical, above Nippon Catalyst , Burnock CFB-620C-40 (black, pigment-containing crosslinked urethane particles, average particle size: 10 to 20 μm, structure: solid, shape: spherical, manufactured by Dainippon Ink and Chemicals), etc. It can be used alone or in combination of two or more. The content of the colored resin particles having these characteristics is preferably 5 to 30% by weight, preferably 8 to 20% by weight, based on the total amount of the ink composition. If the content of the colored resin particles is less than 5% by weight, a suitable drawing line cannot be obtained, and if it exceeds 30% by weight, the writing feeling becomes heavy and the drawing line tends to be blurred, which is preferable. Absent.

The non-colored particles used in the present invention are contained in order to further impart both erasability and scratch resistance, and it is necessary to use non-colored particles having a glass transition point of less than 0 ° C. is there. In the present invention, by using non-colored particles having a glass transition point of less than 0 ° C., preferably less than −10 ° C., a continuous film with the above-mentioned colored resin particles is formed on the drawn line, and the erasability is eliminated. Is even better. Further, since the non-colored particles having a glass transition point of less than 0 ° C. have weak adhesiveness, scratch resistance is imparted. In addition, when non-colored particles of 0 ° C. or higher are used, the continuous film-forming property of the particles is not sufficiently exhibited under low temperature conditions, so that the erasability is inferior.

Examples of the non-colored particles used in the present invention include non-colored styrene butadiene particles, styrene acrylic resin particles, acrylic acid ester particles, methacrylic acid ester particles, silicon acrylic particles, vinyl pyridine particles, and the like, and these non-colored particles are used. The particles may be modified. Preferably, styrene-butadiene particles (with or without modification), styrene acrylic resin particles (with or without modification), and acrylic acid ester particles (with modification) are preferable in terms of the strength of the continuous coating, moderate adhesiveness, and stability as an ink. Or without), methacrylic acid ester particles (with or without modification) are preferably used. The average particle size of these non-colored particles is preferably 0.01 to 10 μm, more preferably 0.1 to 2 μm. If the particle size of the non-colored particles is less than 0.01 μm, the non-colored particles easily penetrate into the voids of the paper fibers, so that the erasing effect is less likely to be exhibited. Further, if the particle size of the non-colored particles exceeds 10 μm, the scratch resistance is inferior. It is considered that this is because the contact area between the particles and the paper surface is reduced and because of its size, it is easily caught by scratches. Examples of non-colored particles having the above characteristics that can be used in the present invention include commercially available Nipol LX435 (modified styrene butadiene latex particles, average particle size: 0.12 μm, glass transition point: -14 ° C., structure: dense solid. , Shape: Spherical), Nipol 2518GL (Vinylpyridine particles, average particle size: 0.2 μm, glass transition point: −44 ° C., structure: solid, shape: spherical), Nipol LX603 (vinylpyridine particles, average particle size: 0.2 μm, glass transition point: -44 ° C, structure: solid, shape: spherical, manufactured by Nippon Zeon Co., Ltd., Nipol LX110 (styrene butadiene rubber, average particle size: 0.08 μm, glass transition point: -47 ° C, Structure: solid, shape: spherical, manufactured by Nippon Zeon), Joncryl 7100 (styrene acrylic particles, average particle diameter 0.1 μm, glass transition point -10 ° C, structure: solid, shape: spherical, manufactured by Johnson Polymer Co., Ltd. ), AE-200 (carboxy-modified acrylic particles, average particle diameter 0.25 μm, glass transition point -45 ° C, structure: solid, shape: spherical, manufactured by JSR), AE-517 (carboxy-modified acrylic particles, average particles) Diameter 0.15 μm, glass transition point -48 ° C, structure: solid, shape: spherical), AE-337 (carboxy-modified acrylic particles, average particle diameter 0.25 μm, glass transition point -37 ° C, structure: solid, Shape: Spherical), AE-8116 (Silicon / Acrylic colloidal dispersion, average particle size 0.06 μm, glass transition point -10 ° C, structure: solid, shape: spherical, manufactured by JSR), Ultrasol D-32 (Styrene acrylic particles, average particle diameter 0.24 μm, glass transition point −34 ° C., structure: solid, shape: spherical), Ultrasol SW-600 (acrylic particles, average particle diameter 0.25 μm, glass transition point -40) ℃, structure: solid, shape: spherical, manufactured by Ganz Kasei Co., Ltd.), etc., and these can be used alone or in combination of two or more. The content of the non-colored particles having these characteristics is preferably 0.1 to 10% by weight, more preferably 0.5 to 5% by weight, based on the total amount of the ink composition. .. If the content of the non-colored particles is less than 0.1% by weight, the erasability and scratch resistance that are the effects of the present invention cannot be exhibited, and if it exceeds 10% by weight, the adhesiveness becomes high. It becomes stronger and the scratch resistance becomes good, but the erasability is remarkably lowered, which is not preferable.

The water-based ball pen ink composition of the present invention uses water (purified water, ion-exchanged water, pure water, etc.) as the main solvent, but further, as a solvent, water is provided from the viewpoint of imparting water retention and improving the writing feeling. A water-soluble polar solvent having a polar group compatible with the above can be used. Examples of the water-soluble polar solvent that can be used include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, ethylene glycol monomethyl ether, glycerin, pyrrolidone, and triethanolamine, which may be used alone or. Two or more kinds can be mixed and used.

Further, the thermochromic ink maintains a predetermined color (first color) at room temperature (for example, 25 ° C.), and changes to another color (second color) when the temperature is raised to a predetermined temperature (65 ° C.). Then, when it is cooled to a predetermined temperature (-10 ° C.), it refers to an ink having a property of returning to the original color (first color) again. In the multi-core writing instrument 1 using thermochromic ink, making the second color colorless and raising the temperature of the drawn line written with the first color (for example, red) to make it colorless is called "erasing" here. I will do it. Therefore, the drawn line is rubbed against the written surface or the like on which the drawn line is written by the erasing body to generate frictional heat, whereby the drawn line is changed to colorless, that is, erased. As a matter of course, the second color may be a color other than colorless.

As the thermochromic microcapsule pigment to be a thermochromic coloring material, any pigment that changes color due to heat such as frictional heat, for example, one having a function of being colored to colorless, colored to colored, colorless to colored, etc. The present invention is not particularly limited, and various substances can be used, and examples thereof include microencapsulated thermal discoloring compositions containing at least a leuco dye, a color developer, and a discoloration temperature adjusting agent.

The leuco dye that can be used is not particularly limited as long as it is an electron-donating dye and functions as a color former. Specifically, conventionally known inks such as triphenylmethane, spiropirane, fluorane, diphenylmethane, rhodamine lactam, indrillphthalide, and leucooramine are available from the viewpoint of obtaining ink having excellent color development characteristics. It can be used alone (1 type) or in combination of 2 or more types (hereinafter, simply referred to as "at least 1 type").

Specifically, 6- (dimethylamino) -3,3-bis [4- (dimethylamino) phenyl] -1 (3H) -isobenzofuranone, 3,3-bis (p-dimethylaminophenyl) -6. −Dimethylaminophthalide, 3- (4-diethylaminophenyl) -3- (1-ethyl-2-methylindole-3-yl) phthalide, 3- (4-diethylamino-2-ethoxyphenyl) -3- (1) -Ethyl-2-methylindol-3-yl) -4-azaphthalide, 1,3-dimethyl-6-diethylaminofluorane, 2-chloro-3-methyl-6-dimethylaminofluorane, 3-dibutylamino-6 -Methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-xylidinofluorane, 2- (2-chloroanilino) -6- Dibutylaminofluorane, 3,6-dimethoxyfluorane, 3,6-di-n-butoxyfluorane, 1,2-benz-6-diethylaminofluorane, 1,2-benz-6-dibutylaminofluorane, 1,2-Benz-6-ethylisoamylaminofluorane, 2-methyl-6- (N-p-tolyl-N-ethylamino) fluorane, 2- (N-phenyl-N-methylamino) -6- (N-p-tolyl-N-ethylamino) fluorane, 2- (3'-trifluoromethylanilino) -6-diethylaminofluorane, 3-chloro-6-cyclohexylaminofluorane, 2-methyl-6- Cyclohexylaminofluorane, 3-di (n-butyl) amino-6-methoxy-7-anilinofluorane, 3,6-bis (diphenylamino) fluorane, methyl-3', 6'-bisdiphenylaminofluorane , Chloro-3', 6'-bisdiphenylaminofluorane, 3-methoxy-4-dodecoxystylinoquinolin, and the like.

These leuco dyes have a lactone skeleton, a pyridine skeleton, a quinazoline skeleton, a bisquinazoline skeleton, and the like, and develop color when these skeletons (rings) are opened.

The color developer that can be used is a component having an ability to develop the color of the leuco dye, and is, for example, a phenol resin compound, a salicylic acid metal chloride, a salicylic acid resin metal salt compound, a solid acid compound, or the like. Can be mentioned.

Specifically, o-cresol, tertiary butylcatechol, nonylphenol, n-octylphenol, n-dodecylphenol, n-stearylphenol, p-chlorophenol, p-bromophenol, o-phenylphenol, hexafluorobisphenol, p. -Hydroxybenzoate n-butyl, p-hydroxybenzoate n-octyl, resorcin, dodecyl gallate, 2,2-bis (4'-hydroxyphenyl) propane, 4,4-dihydroxydiphenylsulfone, 1,1-bis (4'-Hydroxyphenyl) ethane, 2,2-bis (4'-hydroxy-3-methylphenyl) propane, bis (4-hydroxyphenyl) sulfide, 1-phenyl-1,1-bis (4'-hydroxy) Phenyl) ethane, 1,1-bis (4'-hydroxyphenyl) -3-methylbutane, 1,1-bis (4'-hydroxyphenyl) -2-methylpropane, 1,1-bis (4'-hydroxyphenyl) ) N-hexane, 1,1-bis (4'-hydroxyphenyl) n-heptane, 1,1-bis (4'-hydroxyphenyl) n-octane, 1,1-bis (4'-hydroxyphenyl) n -Nonan, 1,1-bis (4'-hydroxyphenyl) n-decane, 1,1-bis (4'-hydroxyphenyl) n-dodecane, 2,2-bis (4'-hydroxyphenyl) butane, 2 , 2-Bis (4'-Hydroxyphenyl) ethyl propionate, 2,2-Bis (4'-Hydroxyphenyl) -4-methylpentane, 2,2-Bis (4'-Hydroxyphenyl) hexafluoropropane, At least one of 2,2-bis (4'-hydroxyphenyl) n-heptane, 2,2-bis (4'-hydroxyphenyl) n-nonane and the like can be mentioned.

The amount of the developer to be used may be arbitrarily selected according to the desired color density, and is not particularly limited, but is usually 0.1 to 1 parts by mass with respect to 1 part by mass of the leuco dye described above. It is preferable to select within the range of about 100 parts by mass.

The discoloration temperature adjusting agent that can be used is a substance that controls the discoloration temperature in the coloration of the leuco dye and the color developer. As the discoloration temperature adjusting agent that can be used, conventionally known ones can be used. Specific examples thereof include alcohols, esters, ketones, ethers, acid amides, azomethines, fatty acids, hydrocarbons and the like.

More specifically, bis (4-hydroxyphenyl) phenylmethane dicaprelate (C ₇ H ₁₅ ), bis (4-hydroxyphenyl) phenylmethane dilaurate (C ₁₁ H ₂₃ ), bis (4-hydroxyphenyl) phenyl. Methanedimilistate (C ₁₃ H ₂₇ ), bis (4-hydroxyphenyl) phenyl ethane dimilistate (C ₁₃ H ₂₇ ), bis (4-hydroxyphenyl) phenylmethane dipalmitate (C ₁₅ H ₃₀ ), bis At least one of (4-hydroxyphenyl) phenylmethanedibehenate (C ₂₁ H ₄₃ ), bis (4-hydroxyphenyl) phenylethylhexylidene dimystate (C ₁₃ H ₂₇ ) and the like can be mentioned.

The amount of the discoloration temperature adjusting agent used may be appropriately selected according to the desired hysteresis width, the color density at the time of color development, and the like, and is not particularly limited, but is usually based on 1 part by mass of the leuco dye. , It is preferable to use within the range of about 1 to 100 parts by mass.

The thermochromic microcapsule pigment is obtained by microencapsulating a thermochromic composition containing at least the leuco dye, a color developer, and a color change temperature adjusting agent so that the average particle size is 0.2 to 5 μm. Can be manufactured. Examples of the microencapsulation method include interfacial polymerization method, interfacial polycondensation method, insitu polymerization method, in-liquid curing coating method, phase separation method from aqueous solution, phase separation method from organic solvent, melting dispersion cooling method, and air. Examples thereof include a suspension coating method and a spray drying method, which can be appropriately selected depending on the intended use.

For example, in the phase separation method from an aqueous solution, a leuco pigment, a color developer, and a discoloration temperature adjuster are heated and melted, then put into an emulsifier solution, heated and stirred to disperse in the form of oil droplets, and then as a capsule film agent. Using a resin raw material, for example, an amino resin solution, an isocyanate-based resin solution, etc. are gradually added, and the reaction is continued to prepare the mixture, and then the dispersion is filtered to produce the desired thermochromic microcapsule pigment. be able to.

The contents of these leuco dyes, color developing agents, and discoloration temperature adjusting agents vary depending on the leuco dye, coloring agent, type of discoloring temperature adjusting agent, microencapsulation method, etc. used. The color developer 0.1 to 100 and the discoloration temperature adjusting agent 1 to 100 by mass ratio. Further, the capsule membrane agent has a mass ratio of 0.1 to 1 with respect to the capsule contents.

The thermochromic microcapsule pigment has a color development temperature (for example, color development at 0 ° C. or higher) and a decolorization temperature (for example, color development at 0 ° C. or higher) by appropriately combining the types and amounts of the leuco pigment, the color developer and the color change temperature adjusting agent. For example, (decoloring at 50 ° C. or higher) can be set to a suitable temperature, and it is preferable that the color changes from colored to colorless due to heat such as frictional heat. In the thermochromic microcapsule pigment, the wall film is preferably formed of a urethane resin, a urea / urethane resin, an epoxy resin, or an amino resin from the viewpoint of further improving the drawing density, storage stability, and writability. Examples of the urethane resin include compounds of isocyanate and polyol. Examples of the epoxy resin include a compound of an epoxy resin and an amine. Examples of the amino resin include melamine resin, urea resin, and benzoguanamine resin. The thickness of the wall film of the microcapsule coloring material is appropriately determined according to the required strength of the wall film and the drawing density. The average particle size of the heat-discoloring microcapsule pigment suppresses adverse effects on colorability, color development, easy decolorization, stability, fluidity in ink, and writeability, and photocolor change described later. From the viewpoint of compatibility with the microcapsule pigment, the thickness is preferably 0.2 to 5 μm, more preferably 0.3 to 3 μm. The "average particle size" specified here is a value obtained by measuring the average particle size (50% diameter) (refractive index 1.8) with a particle size analyzer [Microtrack HRA9320-X100 (manufactured by Nikkiso Co., Ltd.)]. Is. If the average particle size is less than 0.2 μm, a sufficient drawing density cannot be obtained, while if it exceeds 5 μm, the writing property is deteriorated, the dispersion stability of the heat-discoloring microcapsule pigment is lowered, and the ink due to vibration is generated. It is not preferable because backing is likely to occur. Further, the 90% diameter is 8 μm or less, preferably 6 μm or less. When particles having a large diameter are present in a certain proportion or more, the above-mentioned influence tends to become more remarkable. The microcapsule pigment in the above-mentioned average particle size range (0.2 to 5 μm) varies depending on the microencapsulation method, but in the phase separation method from an aqueous solution or the like, stirring is performed when producing the microcapsule pigment. It can be prepared by a suitable combination of conditions.

The specific gravity of the thermochromic microcapsule pigment is in the range of 0.9 to 1.3, preferably 1.0 to 1.2. If the specific gravity is out of this range, the dispersion stability of the microcapsule pigment tends to decrease. Further, the microcapsule pigment having a specific gravity of more than 1.3 is liable to cause ink back due to vibration.

In the water-based ink composition for writing tools, in addition to the above-mentioned heat-discoloring microcapsule pigment, water (tap water, purified water, distilled water, ion-exchanged water, pure water, etc.) as a solvent as a balance, and for each writing tool (ballpoint pen). Depending on the application (for marking pens, etc.), a water-soluble organic solvent, thickener, lubricant, rust preventive, preservative or antibacterial agent, etc. may be appropriately contained as long as the effect is not impaired. it can.

Examples of the water-soluble organic solvent that can be used include glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, polyethylene glycol, 3-butylene glycol, thiodiethylene glycol, and glycerin, ethylene glycol monomethyl ether, and diethylene glycol monomethyl. Ether can be used alone or in combination. Of these, glycerin is preferably used for the purpose of suppressing ink solidification in the writing portion due to ink back, and the amount of glycerin added is preferably 1 to 10% by mass with respect to the total amount of ink. The mechanism of action by glycerin is unknown, but it is presumed that it has the effect of reducing the cohesive force of pigments and ink components in a dry state.

As the thickener that can be used, for example, at least one selected from the group consisting of synthetic polymers, cellulose and polysaccharides is preferable. Specifically, Arabic gum, tragacant gum, guar gum, locust bean gum, alginic acid, carrageenan, gelatin, xanthan gum, welan gum, succinoglycan, dieutan gum, dextran, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, starch glycolic acid and The salt, propylene glycol alginate, polyvinyl alcohol, polyvinylpyrrolidone, polyvinylmethyl ether, polyacrylic acid and its salt, carboxyvinyl polymer, polyethyresioxide, copolymer of vinyl acetate and polyvinylpyrrolidone, crosslinked acrylic acid polymer and Examples thereof include the salt, the non-crosslinked acrylic acid polymer and its salt, the styrene acrylic acid copolymer and its salt, and the like.

Of these, it is preferable to use polysaccharides. Due to its rheological properties, polysaccharides tend to be less susceptible to fluidity due to vibration, and are less likely to cause problems such as writing defects due to ink back. In particular, xanthan gum is preferable because it has an excellent balance with other properties required for writing tool ink.

As the lubricant, fatty acid ester of polyhydric alcohol, which is also used as a surface treatment agent for pigments, higher fatty acid ester of sugar, polyoxyalkylene higher fatty acid ester, alkyl phosphate ester, alkyl sulfonate of higher fatty acid amide, alkyl allyl sulfone Examples thereof include esters, derivatives of polyalkylene glycols, fluorine-based surfactants, and polyether-modified silicones. Examples of the rust preventive include benzotriazole, tolyltriazole, dicyclohexylammonium nitrate, saponins and the like. Examples of the preservative or antibacterial agent include phenol, sodium omadin, sodium benzoate, and benzimidazole compounds.

In order to produce this water-based ink composition for writing utensils, a conventionally known method can be adopted. It is obtained by blending and stirring and mixing with a stirrer such as a homomixer or a disper. Further, if necessary, coarse particles in the ink composition may be removed by filtration or centrifugation.

The viscosity value of the water-based ink composition for writing tools is preferably 500 to 2000 mPa · s at 25 ° C. and a shear rate of 3.83 / s, and 20 to 100 mPa · s at a shear rate of 383 / s. By setting the viscosity in the above range, it is possible to obtain an ink having excellent writability and stability over time. Further, S = αD ⁿ (where 1>n> 0) (S is shear stress (dyn / cm ² ), D is shear rate (s ^-1 ), α is non-Newtonian viscosity coefficient). The required non-Newtonian viscosity index n is preferably 0.2 to 0.6. By setting the non-Newtonian viscosity index n in the above range in addition to the above viscosity range, it is possible to appropriately set the fluidity of the ink with respect to vibration, and it is possible to prevent the occurrence of ink back. The surface tension of the water-based ink composition for writing tools is preferably 25 to 45 mN / m, more preferably 30 to 40 mN / m. Within this range, the balance between the inside of the pen tip and the wettability of the ink becomes appropriate, and it is possible to prevent the occurrence of ink back.

In the refill, the ink follower may be placed immediately behind the ink. The material constituting the follower can be composed of at least a non-volatile or refractory organic solvent and a thickener. The non-volatile or refractory organic solvent used for the ink follower is used as a base oil for the ink follower, and for example, liquid paraffin is used. Mineral oil and chemically synthesized oil are used as the liquid paraffin, and polybutene, poly α-olefin, ethylene α-olefin oligomer and the like can be used as the chemically synthesized oil. Specific examples of the mineral oil that can be used include commercially available Diana process oils NS-100, PW-32, PW-90, NR-68, and AH-58 (manufactured by Idemitsu Kosan Co., Ltd.). Specific polybutenes that can be used include, for example, commercially available Nissan polybutene 200N, polybutene 30N, polybutene 10N, polybutene 5N, polybutene 3N, polybutene 015N, polybutene 06N, polybutene 0N (all manufactured by Nippon Oil & Fats Co., Ltd.), and polybutene. Examples include HV-15 (manufactured by Nippon Petrochemical Co., Ltd.) and 35R (manufactured by Idemitsu Kosan Co., Ltd.). Specific poly-α-olefins that can be used include, for example, commercially available barrel process oils P-26, P-46, P-56, P-150, P-350, P-1500, P-2200, and the like. (P-10000, P-37500) (manufactured by Matsumura Petroleum Co., Ltd.) and the like. Specific ethylene α-olefin oligomers that can be used include, for example, commercially available Lucant HC-10, HC-20, HC-100, HC-150, (HC-600, HC-2000) (above, Mitsui). (Made by Chemicals), etc. These non-volatile or non-volatile organic solvents can be used alone or in combination of two or more.

Examples of the thickener used for the ink follower include calcium salt of phosphate ester, fine particle silica, polystyrene-polyethylene / butylene rubber-polystyrene block copolymer, polystyrene-polyethylene / propylene rubber-polystyrene block copolymer, and hydrogenated styrene. Examples thereof include-butadiene rubber, block copolymers of styrene-ethylenebutylene-olefin crystals, block copolymers of olefin crystals-ethylenebutylene-olefin crystals, and acetoalkoxyaluminum dialchelates, and these can be used alone or in combination of two or more. Preferred commercially available products of the calcium salt of the phosphoric acid ester that can be used include Crodax DP-301LA (manufactured by Croda Japan Co., Ltd.) and the like. Fine particle silica that can be used includes hydrophilic fine particle silica and hydrophobic fine particle silica, and preferable commercially available products of hydrophilic silica include AEROSIL-300 and AEROSIL-380 (manufactured by Nippon Aerosil Co., Ltd.). Preferred commercially available products of hydrophobic silica include AEROSIL-974D, AEROSIL-972 (manufactured by Nippon Aerosil Co., Ltd.) and the like. Preferred commercially available polystyrene-polyethylene / butylene rubber-polystyrene block copolymers include Clayton GFG-1901X, Clayton GG-1650 (above, Shell Japan), Septon 8007, Septon 8004 (above, Kuraray), and the like. Can be mentioned. Further, preferable commercially available products of polystyrene-polyethylene / propylene rubber-polystyrene block copolymers include Clayton GG-1730 (manufactured by Shell Japan Co., Ltd.), Septon 2006, Septon 2063 (manufactured by Kuraray Co., Ltd.) and the like. Preferred commercially available products of hydrogenated styrene-butadiene rubber include DYNARON1320P, DYNARON1321P (above, manufactured by JSR Corporation), Toughtech Hl041, Toughtech Hl141 (above, manufactured by Asahi Kasei Kogyo Co., Ltd.) and the like. Preferred commercial products of the block copolymer of styrene-ethylenebutylene-olefin crystal include DYNARON4600P (manufactured by JSR Corporation), and preferred commercial products of the block copolymer of olefin crystal-ethylenebutylene-olefin crystal include DYNARON6200P and DYNARON6201B (manufactured by JSR Corporation). (Made by JSR) and the like. Preferable commercially available products of acetoalkoxyaluminum dialchelates include Plenact AL-M (manufactured by Ajinomoto Fine-Techno Co., Ltd.) and the like.

Among these thickeners, thermoplastic olefin-based elastomers such as styrene-ethylenebutylene-olefin crystal block copolymers and olefin crystals-ethylenebutylene-olefin crystal block copolymers are used from the viewpoint of further exerting the effects of the present invention. Preferable to use.

Further, from the viewpoint of obtaining an ink follower that prevents the occurrence of ink back, the average value of the tan δ values measured for each frequency while increasing exponentially in the frequency domain 1 to 63 rad / s should be 1.0 or more. Is preferable, and 1.7 to 3.4 is more preferable.

Here, tan δ is a value meaning the loss elastic modulus / storage elastic modulus, and conventionally, the average value of the tan δ values measured for each frequency while increasing exponentially in the frequency domain “1-63 rad / s”. It has been known that a value of 1.0 or less is preferable. In the present invention, by setting the average value of the tan δ values measured for each frequency at 1 to 63 rad / s to 1.0 or more, it is possible to absorb vibration and prevent the occurrence of ink back.

Thermosetting rubbers such as silicone rubber, nitrile rubber, ethylene propylene rubber, and ethylene propylene diene rubber, and thermoplastic elastomers such as styrene-based elastomers, olefin-based elastomers, and polyester-based elastomers are used as materials for forming the eraser body of the erasing unit 8. A mixture of two or more kinds of rubber elastic materials and a mixture of rubber elastic materials and synthetic resin can be used, and this is loaded with a load 9 in the abrasion test (ASTM D1044) specified in JIS K7204. In an environment of 8.N and 1000 rpm, the amount of taber wear on the wear wheel CS-17 of the taber wear tester is configured to be 5 mg or more, and an eraser is formed.

Further, an alkyl sulphonic acid phenyl ester or a cyclohexanedicarboxylic acid ester may be added to the material of the eraser. By containing the alkyl sulphonic acid phenyl ester and the cyclohexanedicarboxylic acid ester in the eraser, it is possible to erase the handwriting without damaging the paper surface and blurring the printed characters and the like. Further, the eraser preferably has a durometer D hardness specified in JIS K6203 of 25 or more and 45 or less. As a result, a predetermined hardness can be secured, and a more stable scraping operation becomes possible. The eraser can also be applied as a touch pen or a stylus pen, and may be provided with conductivity.

Further, the eraser is preferably colored with a color having a brightness value lower than that of the heat-discoloring ink contained in the multi-core writing tool 1. That is, when the heat-discoloring ink of the multi-core writing tool 1 is transferred to the surface of the eraser without discoloration when the eraser is used, the transfer of the heat-discoloring ink can be made inconspicuous. In particular, by setting the color of the eraser to black or having a lightness value of 2.5 or less, stains on the surface due to the use of the eraser can be made inconspicuous.

The brightness value uses the Mansell color system using a measuring device such as a general-purpose color difference meter (TC-8600A, manufactured by Tokyo Denshoku Co., Ltd.), and the brightness value of the eraser measures the surface of the heat-discolorable ink. The brightness value is a writing speed of 4.5 m / min on a paper surface (former JIS P3201; high-quality paper made from 100% chemical pulp, basis weight range 40 to 157 g / m2, whiteness 75.0% or more). It is obtained by measuring the ink on the drawn line written with a pitch interval of 0.1 mm.

The present invention relates to an erasable writing instrument in which a plurality of cursives containing erasable ink are built in a barrel and the cursives are sequentially replaced and projected by a knock operation.

1 …… Knock bar (operation unit)
2 …… Cam rotor 3 …… Coil spring 4 …… Ballpoint pen tip (writing part)
5 …… Ink storage tube 6 …… Cursive presser 7 …… Shaft tube 8 …… Eraser

Claims (2)

In an erasable writing instrument in which a plurality of cursives are housed in a barrel, at least one of the cursives holds erasable ink, an operating portion protruding rearward from the barrel is provided, and the operating portion is pressed to move forward. In addition, as the cam rotor that rotates in the circumferential direction for each required angle rotates, the cursive press that sequentially abuts the pressing portion and transmits the knock pressure is housed in the barrel, thereby causing the inside of the barrel. A knock mechanism for sequentially feeding out a plurality of cursive writing instruments is provided, and an erasing unit capable of erasing erasable ink is provided at the rear end of the operation unit, and the erasing unit is brighter than the color of the erasable ink contained in the cursive. An erasable writing instrument characterized by being colored with a low value color. The erasable ink is indicated by S = αD ⁿ (where 1>n> 0) (S is shear stress (dyn / cm ² ), D is shear rate (s ^-1 ), α is non-Newtonian viscosity coefficient). The non-Newtonian viscosity index n obtained by the viscosity formula is 0.2 to 0.6, and is measured for each frequency while increasing exponentially in the frequency region 1 to 63 rad / s behind the erasable ink. An ink follower having an average tan δ value of 1.0 or more is placed.
The erasing type writing tool according to claim 1 , wherein the erasing unit is provided with an alkyl sulphonic acid phenyl ester and a cyclohexanedicarboxylic acid ester.

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