JP7103806B2 - Thermal discoloration writing tool - Google Patents

Description

The present invention relates to a heat-discoloring writing tool containing a heat-discoloring ink that discolors handwriting by frictional heat or the like.

Conventionally, in a thermochromic writing tool in which a thermochromic composition is housed in a barrel, for example, in Patent Document 1, the rear end of the shaft body of the writing tool containing the reversible thermochromic ink and the top of the cap for the writing tool are used. A structure provided with a friction body is described, and a structure capable of thermally discoloring a stroke made by a heat-discoloring composition written with a writing tool by a friction body provided with the writing tool is disclosed.

Further, in the thermochromic writing tool disclosed in Patent Document 1, the friction body made of an elastic material is always in a state of protruding to the outside, and it looks cheap to the outside, and moreover, dust adhering to the friction body when not in use. In some cases, the paper surface may be soiled during rubbing due to hand stains or the like. Therefore, in the thermochromic writing tool disclosed in Patent Document 2, a structure has been proposed in which the friction body protrudes from the cap when used, and the friction body is immersed in the indentation hole provided in the cap when not in use. However, in the structure of Patent Document 2, even when the friction body is immersed, the end portion of the friction body is exposed to the outside from the indentation hole, so that the friction body may be contaminated.

Therefore, in the writing tool disclosed in Patent Document 3, a heat-discoloring writing tool is disclosed in which the outer surface of the friction body is covered with a cover covering the friction body to prevent the friction body from becoming dirty.

Japanese Unexamined Patent Publication No. 2004-148744 JP-A-2009-126102 Japanese Unexamined Patent Publication No. 2014-124810

However, when the heat-discolorable writing tool disclosed in Patent Document 3 described above is used, it is difficult to grasp the cover because it is a cover composed of smooth straight lines and curves, and unnecessary force is required. In particular, there is a problem that it is difficult for men and women of all ages to remove it.

Therefore, the present invention has been invented in view of the above problems, and an object of the present invention is to provide a heat-discolorable writing tool to which a cover is attached to prevent the friction body from becoming dirty, which can be easily removed.

The thermochromic writing tool according to the present invention, which has been made to solve the above-mentioned problems, rubs the pen tip capable of ejecting the thermochromic composition with the brush stroke of the thermochromic composition, and the frictional heat generated at that time. A heat-discoloring writing tool provided with a friction body capable of thermally discoloring the brush stroke, wherein the heat-discoloring writing tool is attached to a shaft member, a friction body projecting from an end portion of the shaft member, and the shaft member. It has a cover member that is attached to cover the friction body, forms a protrusion protruding outward on the outer surface of the cover member, and is characterized in a shape that is easily caught by a finger or the like.

Further, as one aspect, by forming an elongated ventilation hole on the rear outer surface of the cover member, suffocation due to accidental ingestion can be prevented. The size of the ventilation holes is preferably 5 square millimeters or more in terms of the projected opening area from the rear end.

According to the heat-discolorable writing tool according to the present invention described above, when the friction body is not used, the friction body is attached so as to cover the friction body with a cover member to form protrusions, thereby preventing the friction body from becoming dirty and generally. It can be easily removed even by men and women of all ages with weak power.

The overall configuration of the thermochromic writing tool according to the present invention is shown, (a) is a plan view, (b) is a front view, and (c) is a vertical sectional view of (b). It is a perspective view from the rear end of a writing instrument with a cover member removed. It is a component drawing of the cover member attached to FIG. 1 and FIG. (A) is a perspective view from the front side, (b) is a side view shown from the front side, (c) is a plan view, (d) is a front view, (e) is a vertical sectional view of (d), and (f). ) Is a perspective view from the rear side, and (g) is a side view shown from the rear side. It is a parts drawing of the cover member of another example. (A) is a perspective view from the front side, (b) is a side view shown from the front side, (c) is a plan view, (d) is a front view, (e) is a vertical sectional view of (d), and (f). ) Is a perspective view from the rear side, and (g) is a side view shown from the rear side.

The thermochromic writing tool according to the present invention will be described based on the embodiment shown in the figure.
In each of the drawings shown below, the same parts are indicated by the same reference numerals. It may be explained by quoting the reference numerals attached to the drawings.

FIG. 1 shows a writing tool 1 provided with a friction body according to the first embodiment of the present invention, (a) is a plan view, (b) is a front view, and (c) is a vertical sectional view of (b). be. The writing tool 1 is a so-called knock-type writing tool.

The knock-type writing tool 1 is a cursive formed in a tubular shape, a refill 5 which is a cursive body arranged in the shaft cylinder 2 and having a writing portion 5a which is a pen tip at one end, and a refill 5 rearward. An inner cylinder 10 having a spring 6 which is an elastic member to be urged, a clip attached to the rear end of the shaft cylinder 2 and gripping an article, and a hollow operating portion 20 arranged in the inner cylinder 10. Has. The axle tube 2 has a front shaft 3 and a rear shaft 4 having a grip rubber on the outer surface in the radial direction. The inner cylinder 10, the front shaft 3 and the rear shaft 4 are also collectively referred to as a shaft cylinder.

In the present specification, in the axial direction of the knock-type writing instrument 1, the writing portion 5a side is defined as the "front" side, and the side opposite to the writing portion 5a is defined as the "rear" side. Unless otherwise specified, the central axis refers to the central axis of the knock-type writing tool 1. In the knock-type writing tool 1, the refill 5 moves in the front-rear direction in the barrel 2 by the knock operation of pressing the operation unit 20 forward against the urging force of the spring 6. At this time, the state in which the writing portion 5a protrudes from the barrel 2 is referred to as a writing state, and the state in which the writing portion 5a is immersed in the barrel 2 is referred to as a non-writing state (FIG. 1).

The knock-type writing tool 1 includes a main rotor 30 which is an engaging member arranged in the operation unit 20, a deceleration rotor 40 arranged in front of the main rotor 30 in the operation unit 20, and an operation unit 20. A knock lock member 50 arranged in the front and formed in a tubular shape, a locking portion 60 for locking with the knock lock member 50, a friction body 70 attached to the rear end of the operation unit 20, and a friction body 70. Further includes a holding member 80 for attaching to the operation unit 20, and a cover member 90 for covering the friction body 70.

The main rotor 30 cooperates with the cam surface and the operation unit 20 formed in the inner cylinder 10, and the deceleration rotor 40 cooperates with the cam surface and the main rotor 30 formed in the inner cylinder 10. .. Further, the cam surface formed on the operation unit 20 and the cam receiving surface formed on the outer surface of the knock lock member 50 cooperate to rotate the knock lock member 50 around the central axis and lock the knock lock member 50 with the knock lock member 50. The unit 60 can be locked. The knock lock member 50 can move in the front-rear direction in the barrel 2 by gravity.

The refill 5 contains a thermochromic ink containing a thermochromic microcapsule pigment. Therefore, the writing tool 1 is a thermochromic writing tool. 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 (for example, 60 ° C.). After that, when cooled to a predetermined temperature (for example, −5 ° C.), the ink has a property of returning to the original color (first color). In the writing instrument 1 using the thermochromic ink, the second color is made colorless, and the temperature of the drawn line written with the first color (for example, red) is raised to make it colorless, which is referred to as "erasing" here. .. Therefore, the writing surface or the like on which the drawn lines are written is rubbed by the friction body 70 to generate frictional heat, whereby the drawn lines are changed to colorless, that is, erased. As a matter of course, the second color may be a color other than colorless.

More specifically, the thermochromic microcapsule pigment is particularly limited as long as it has a function of changing color due to heat such as frictional heat, for example, from colored to colorless, from colored to colored, and from colorless to colored. However, 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 type, spiropyran type, fluorane type, diphenylmethane type, rhodamine lactam type, indrillphthalide type, and leucooramine type are available from the viewpoint of obtaining an 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- (Np-tolyl-N-ethylamino) fluorane, 2- (N-phenyl-N-methylamino) -6- (Np-trill-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, and at least one of these can be used.

These leuco dyes have a lactone skeleton, a pyridine skeleton, a quinazoline skeleton, a bisquinazoline skeleton, and the like, and develop color development when these skeletons (rings) are opened. Preferably, it is preferable to use a leuco dye that changes from colored to colorless by heat.

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.

Specific examples of the color-developing agent that can be used include o-cresol, tertiary butylcatechol, nonylphenol, n-octylphenol, n-dodecylphenol, n-stearylphenol, p-chlorophenol, and p-bromophenol. o-Phenylphenol, Hexafluorobisphenol, n-butyl p-hydroxybenzoate, n-octyl p-hydroxybenzoate, resorcin, dodecyl carbate, 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'-hydroxyphenyl) 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-nonane, 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) At least one such as 4'-hydroxyphenyl) hexafluoropropane, 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 part 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. Specific examples thereof include alcohols, esters, ketones, ethers, acid amides, azomethines, fatty acids, hydrocarbons and the like. For example, bis (4-hydroxyphenyl) phenylmethane dicaprilate (C7H15), bis (4-hydroxyphenyl) phenylmethane dilaurate (C11H23), bis (4-hydroxyphenyl) phenylmethane dimyristate (C13H27), bis ( 4-Hydroxyphenyl) Phenyl ethanedimilistate (C13H27), bis (4-hydroxyphenyl) phenylmethane dipalmitate (C15H30), bis (4-hydroxyphenyl) phenylmethane dibehenate (C21H43), bis (4-hydroxyphenyl) At least one such as hydroxyphenyl) phenylethylhexylidene dimillistate (C13H27) can be mentioned.

FIG. 2 is a perspective view of the rear end portion of the writing tool 1 of FIG. As shown in FIG. 2, the friction body 70 is formed so that the cross-sectional shape of the portion exposed from the inner cylinder 10 in a state of being attached to the operation portion 20 via the holding member 80 is circular. .. Specifically, the rear end surface 71 of the friction body 70 is formed in a convex curved surface shape. The cross-sectional shape is not limited to a circle, and may be another polygon such as a triangle, a quadrangle, or a hexagon.

The friction body 70 uses polypropylene resin in an amount of 50% by mass or more as a material constituting the friction body 70, and the tensile elastic modulus (JIS K 7161: 2014-1) of the friction body is 70 MPa or more. is necessary. By using a friction body having this characteristic, there is little resistance when the handwriting formed by the heat-discoloring ink is rubbed to discolor or decolorize, and sufficient frictional heat can be obtained even with a light force. , It is easy to erase small parts.

Polypropylene-based resins that can be used are those that serve as the substrate for the friction material, such as propylene homopolymers; propylene and other small amounts of α-olefins (eg, ethylene, 1-butene, 1-hexene, 1). -Copolymers with octene, 4-methyl-1-pentene, etc.) (including block copolymers and random copolymers); and the like. As the polypropylene-based resin, one kind or a mixture of two or more kinds of these can be used. The effect of the present invention can be exhibited by using 50% by mass or more of the polypropylene resin in the total amount of the friction body, and the effect of the present invention cannot be exhibited when the polypropylene resin is less than 50% by mass. ..

Examples of the resin that can be used other than the polypropylene-based resin include polyethylene and ionomer. These resins are preferably 0.5 to 30% by mass based on the total amount of the friction body from the viewpoint of further exerting the effects of the present invention.

Further, the material constituting the friction body 70 is preferably a rosin-based resin, a terpene-based resin, a petroleum-based resin, a phenol-based resin, from the viewpoint of adjusting the adhesiveness and exhibiting sufficient frictional heat even with a light force. At least one resin selected from a coal-based resin and a xylene-based resin can be contained. Among these resins, those having a molecular weight of several hundred to several thousand are selected, and by blending them in a polypropylene-based resin compounding system which is the main component of the friction body, the friction body is imparted with adhesiveness. ”The present invention. The effect of can be further exerted. Specifically, the molecular weights of natural resins such as rosin-based resins and terpene-based resins, petroleum-based resins, phenol-based resins, coal-based resins, and xylene-based resins are preferably 500 to 5000, and more preferably 700 to 4000. The above various resins can be used.

Examples of the rosin-based resin include gum rosin, tall oil rosin, wood rosin, hydrogenated rosin, disproportionated rosin, polymerized rosin, modified rosin glycerin, pentaerythritol ester, and the like. Examples thereof include β-pinene-based and dipentene-based terpene resins, aromatic-modified terpene resins, terpene phenol resins, hydrogenated terpene resins and the like. Among these resins, polymerized rosin, terpene resin, hydrogenated terpene resin, aromatic-modified hydrogenated terpene resin, and terpene phenol resin are preferable from the viewpoint of further stability.

For petroleum-based resins, for example, a cracked oil distillate containing unsaturated hydrocarbons such as olefins and diolefins produced as a by-product together with basic petrochemical raw materials such as ethylene and propylene by thermal decomposition of naphtha in the petrochemical industry remains as a mixture. It is obtained by polymerization with a Friedelcrafts type catalyst. The petroleum-based resin is an aliphatic petroleum resin obtained by (co) polymerizing a C5 distillate obtained by thermal decomposition of naphtha, and a C9 distillate obtained by (co) polymerization of a C9 distillate obtained by thermal decomposition of naphtha. Aromatic petroleum resin, copolymerized petroleum resin obtained by copolymerizing the C5 and C9 distillates, alicyclic compound petroleum resin such as hydrogenated, dicyclopentadiene, styrene, substituted styrene. , Petroleum-based resins such as styrene-based resins such as copolymers of styrene and other monomers. The C5 distillate obtained by thermal decomposition of naphtha is usually an olefin-based hydrocarbon such as 1-pentene, 2-pentene, 2-methyl-1-butene, 2-methyl-2-butene, 3-methyl-1-butene. Diolefin hydrocarbons such as hydrogen, 2-methyl-1,3-butadiene, 1,2-pentadiene, 1,3-pentadiene and 3-methyl-1,2-butadiene are included. The aromatic petroleum resin obtained by (co) polymerizing the C9 distillate is a resin obtained by polymerizing an aromatic having 9 carbon atoms having vinyl toluene and indene as main monomers, and is obtained by thermal decomposition of naphtha. Specific examples of the obtained C9 distillate include styrene homologues such as α-methylstyrene, β-methylstyrene and γ-methylstyrene, and inden homologues such as inden and kumaron. Product names include Petrodin manufactured by Mitsui Chemicals, Petrite manufactured by Mikuni Chemicals, Neopolymer manufactured by JX Nikko Nisseki Energy, Petcol manufactured by Tosoh, and Petrotac.

Further, the modified petroleum resin obtained by modifying the petroleum resin composed of the C9 distillate is preferably used in the present invention as a resin having both adhesiveness and adhesive durability. Examples of the modified petroleum resin include a C9-based petroleum resin modified with an unsaturated alicyclic compound, a C9-based petroleum resin modified with a compound having a hydroxyl group, and a C9-based petroleum resin modified with an unsaturated carboxylic acid compound. Preferred unsaturated adiene compounds include cyclopentadiene and methylcyclopentadiene, and Diels-Alder reaction products of alkylcyclopentadiene include dicyclopentadiene, cyclopentadiene / methylcyclopentadiene codimenes and tricyclopentadiene. However, dicyclopentadiene is particularly preferable. The dicyclopentadiene-modified C9-based petroleum resin can be obtained by thermal polymerization or the like in the presence of both dicyclopentadiene and a C9 fraction. Examples of the dicyclopentadiene-modified C9 petroleum resin include Neopolymer 130S manufactured by JX Nikko Nisseki Energy.

Examples of the compound having a hydroxyl group include an alcohol compound and a phenol compound. Specific examples of the alcohol compound include alcohol compounds having a double bond such as allyl alcohol and 2-butene-1,4diol. As the phenol compound, alkylphenols such as phenol, cresol, xylenol, pt-butylphenol, p-octylphenol, and p-nonylphenol can be used. These hydroxyl group-containing compounds may be used alone or in combination of two or more.

A hydroxyl group-containing C9-based petroleum resin is obtained by thermally polymerizing a (meth) acrylic acid alkyl ester or the like together with a petroleum distillate to introduce an ester group into the petroleum resin, and then reducing the ester group. It can also be produced by a method of hydrating the double bond after the bond remains or is introduced.
Further, as the hydroxyl group-containing C9-based petroleum resin, those obtained by various methods as described above can be used, but from the viewpoint of performance and production, it is preferable to use phenol-modified petroleum resin or the like, and phenol-modified petroleum. The resin is obtained by cationically polymerizing the C9 fraction in the presence of phenol, is easily modified, and is inexpensive. Examples of the phenol-modified C9 petroleum resin include Neopolymer-E-130 manufactured by JX Nikko Nisseki Energy.

Further, as the C9-based petroleum resin modified with an unsaturated carboxylic acid compound, a C9-based petroleum resin modified with an ethylenically unsaturated carboxylic acid can be used. Typical examples of such ethylenically unsaturated carboxylic acids include (maleic anhydride) maleic acid, fumaric acid, itaconic acid, tetrahydro (anhydrous) futaric acid, (meth) acrylic acid and citraconic acid. The unsaturated carboxylic acid-modified C9-based petroleum resin can be obtained by thermally polymerizing a C9-based petroleum resin and an ethylene-based unsaturated carboxylic acid. In the present invention, maleic acid-modified C9 petroleum resin is preferable.

Examples of the unsaturated carboxylic acid-modified C9 petroleum resin include Neopolymer 160 manufactured by JX Nikko Nisseki Energy. Further, a copolymer resin of C5 fraction and C9 fraction obtained by thermal decomposition of naphtha can be preferably used. Here, the C9 fraction is not particularly limited, but is preferably the C9 fraction obtained by thermal decomposition of naphtha. Specific examples thereof include TS30, TS30-DL, TS35 and TS35-DL of the Struktor series manufactured by SCHILL & SEILACHER.

Examples of the phenol-based resin include alkylphenol formaldehyde-based resins and rosin-modified products thereof, alkylphenol acetylene-based resins, modified alkylphenol resins, terpenephenol resins and the like. Specifically, the trade name Hitanol 1502 (Hitachi) is a novolak type alkylphenol resin. (Manufactured by Kasei Kogyo Co., Ltd.), pt-butylphenol acetylene resin, trade name Collesin (manufactured by BASF), and the like. Further, examples of the coal-based resin include kumaron inden resin and the like, and examples of the xylene-based resin include xylene formaldehyde resin and the like. In addition, polybutene can also be used as a resin having adhesiveness. Among these resins, from the viewpoint of adhesiveness and adhesive durability, a copolymer resin of C5 fraction and C9 fraction, an aromatic petroleum resin obtained by (co) polymerization of C9 fraction, and a phenol resin. And Kumaron inden resin are preferred.

These resins preferably have a softening point of 200 ° C. (measurement method: ASTM E28-58-T) or less, and more preferably in the range of 80 to 150 ° C. If the softening point exceeds 200 ° C., the workability may be deteriorated, and if it is less than 80 ° C., the adhesive performance may be deteriorated. From these viewpoints, the softening point is more preferably in the range of 90 to 120 ° C. The above resin may be used alone or in combination of two or more.

The blending amount of at least one resin selected from the above-mentioned rosin-based resin, terpene-based resin, petroleum-based resin, phenol-based resin, coal-based resin, and xylene-based resin used for the purpose of adjusting these adhesiveness is the amount of the present invention. From the viewpoint of further exerting the effect, it is preferably 0.05 to 20% by mass, more preferably 0.05 to 10% by mass, based on the total amount of the friction body.

In addition to the above-mentioned polypropylene-based resin and the above-mentioned resin used for the purpose of adjusting the adhesiveness, the friction body 70 includes a heat stabilizer, an antioxidant, and a light stabilizer, if desired, as long as the effects of the present invention are not impaired. Agents, UV absorbers, crystal nucleating agents, blocking inhibitors, sealing improvers, mold release agents (eg stearic acid, silicon oil, etc.), lubricants such as polyethylene wax, colorants, pigments, inorganic fillers (eg, , Alumina, talc, calcium carbonate, mica, valastenite, clay, etc.), foaming agents (organic, inorganic), antibacterial agents (eg, imidazole, phenol, silver, etc.) and flame retardants (eg, hydration). Any component such as a metal compound, red phosphorus, ammonium polyphosphate, an antimony compound, and silicon) can be appropriately contained. Further, the material of the friction body may further contain an alkyl sulphonic acid phenyl ester and a cyclohexanedicarboxylic acid ester. By containing the alkyl sulphonic acid phenyl ester and the cyclohexanedicarboxylic acid ester in the friction body, it is possible to further erase the handwriting without damaging the paper surface and blurring the printed characters and the like. The friction body 70 can be manufactured by a method such as extrusion molding or injection molding using the polypropylene resin or the like.

The friction body 70 needs to have a tensile elastic modulus (JIS K 7161: 2014-1) of 70 MPa or more, preferably 80 to 80, from the viewpoint of imparting durability and exerting the effect of the present invention. It is preferably 5000 MPa. If the tensile elastic modulus is less than 70 MPa, the effect of the present invention cannot be exhibited, which is not preferable. The tensile elastic modulus of this friction body can be adjusted to 70 MPa or more by appropriately combining the type and blending amount of the polypropylene-based resin to be used, other resin types, and the content thereof.

More preferably, the permanent elongation of the friction body (JIS K6273: 2006) is 50% or more, particularly preferably 50 to 100%, from the viewpoint of further exerting the effect of the present invention and reducing the feeling of resistance. .. The "permanent elongation" defined in the present invention means that the test piece is held at 23 ° C. for 6 hours in a state of being stretched twice, and then the stress is removed. The value (%) obtained by dividing the stretched length by the length before stretching. The friction body 70 can also be applied as an input pen to an electronic device or the like.

Further, the friction body 70 is preferably colored with a color having a brightness value lower than that of the heat-discoloring ink contained in the writing tool 1. That is, when the heat-discoloring ink of the writing tool 1 is transferred to the surface of the friction body 70 without discoloration when the friction body 70 is used, the transfer of the heat-discoloring ink can be made inconspicuous. In particular, by making the color of the friction body 70 black, it is possible to make the surface stains due to the use of the friction body 70 inconspicuous.

The lightness value uses the Munsell color system using a measuring device such as a general-purpose color difference meter (TC-8600A, manufactured by Tokyo Denshoku Co., Ltd.), and the lightness value of the friction body measures the surface of the thermochromic 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 on the drawn line written with a pitch interval of 0.1 mm.

A cylindrical fitting portion 81 that fits with the cover member 90 is formed at the rear end portion of the holding member 80. The fitting portion 81 is substantially complementary to the outer shape of the friction body 70 so as not to interfere with the knock operation of the operation unit 20 via the friction body 70 and to receive the operation unit 20 and the friction body 70. Is formed in. The cover member 90 is complementary to the outer peripheral surface of the fitting portion 81 so as to protect the friction body 70 by closing the rear end and to fit into the fitting portion 81 formed on the holding member 80. It has an inner peripheral surface.

When the friction body 70 is not used, it is covered by the cover member 90, so that the friction body 70 can be prevented from being soiled or deteriorated. Further, by forming the cover member 90 into a transparent or translucent synthetic resin, the state of the friction body 70 can be easily visually recognized. Further, it is preferable that the material of the cover member 90 contains a component that prevents ultraviolet rays. In addition, it is safe for the environment by setting the total amount including components that do not contain harmful substances such as lead, mercury, cadmium, hexavalent chromium, polybrominated biphenyls, and polybrominated diphenyl ethers to 0 or more and 100 ppm (ug / g) or less. It is preferable because a flexible cover member can be obtained. The components can be measured by an ICP emission spectrophotometer (product name: SPS3100, manufactured by SII). In addition, as an antibacterial agent, 2- (4-thiazolyl) benzimidazole, 2-benzimidazole carbamine methyl, 1- (butylcarbamoyl) 2-benzimidazole carbamate methyl, 2- (methoxycarbonylamino) benzimidazole, 2- (Benzimidazole) Imidazoles such as methyl carbamate, 1,2-benzisothiazolin-3-one, 2-n-octyl-4-isothiazolin-3-one, 2- (4-thiocyanomethylthio) benzthiazole, 5 -Thiazoles such as chloro-2-methyl-4-isothiazolin-3-one, 3-iodo-2-propagilbutylcarbamic acid, 4-chlorophenyl-3-iodopropagilformal, diiodomethyl-p-tolylsulfone, 3 Iodes such as -ethoxycarbonyloxy-1-brom-1,2-diiodo-1-propene, 2,3,5,6-tetrachloroisophthalonitrile, 5-chloro-2,4,6-trifluoroisofu Phosphorus such as taronitrile, p-chloro-m-cresol, phenolic such as 2,4,4'-trichloro-2'-hydroxydiphenyl ether, N- (fluorodichloromethylthio) phthalimide, N, N-dimethyl-N ′-(Dichlorofluoromethylthio) -N′-phenylsulfamide, N, N-dimethyl-N′- (dichlorofluoromethylthio) -N′-trilsulfamide, N- (trichloromethylthio) phthalimide, tetrachloroethyl Haloalkylthios such as thiotetrahydrophthalimide, N-trichloromethylthio-4-cyclohexene-1,2-dicarboxyimide, 2-pyridinethiol-1-oxide sodium, 2-pyridinethiol-1-oxide zinc, 2,3 Phosphorus such as 5,6-tetrachloro-4- (methylsulfonyl) pyridine, hexahydro-1,3,5-tris (2-hydroxyethyl) S-triazine, hexahydro-1,3,5-triethyl-S- Triazine-based such as triazine, brom-based such as 2-promo-2-nitro-1,3-propanediol, 1,2-dibromo-2,4-dicyanobutane, silver-zeolite, zinc zeolite, silver-apatite, phosphorus Zirconic acid-silver, titania-silver, water-soluble glass-silver, calcium phosphate-silver, zeolite-copper, zeolite-zinc, zinc oxide, magnesium oxide, amorphous copper, sodium percarbonate, hypochlorite Inorganic systems such as sodium and barium metaborate, halodialyl urea systems such as trichlorocarban, chlorohexazine gluconate, chlorohexazine gluconate + cyclopyroxolamine, guanidine system such as polyhexamethylenepiguanidine hydrochloride, propyl glycol mono Fatty acid esters such as fatty acid esters and glycerin fatty acid esters, cellulose copper, copper crosslinked acrylonitrile / acrylic acid copolymers, metal oxide-coordinated aminosilicon-based polymers, zinc-coordinated acrylic acid polymers and other polymer-coordinated metal-based products, etc. 10'-oxybisphenoxyarcin, 8-oxyquinoline copper, methylene histhiocyanate, bis (dimethyldithiocarbamoyl) disulfide, 1- (3-chloroallyl) -3,5,7-triaza-1-azonia adamantanchloride, 3 , 5-Dimethyltetrahydro-1,3,5-thiadiadin-2-thione, zinc dimethyldithiocarbamate, 4,4'-(2-ethyl-2-nitrotrimethylene) dimorpholin, levan-degrading enzyme agent, N- (2- (2-) Substances such as hydroxypropyl) aminomethanol, 2- (methoxycarbonylamino) benzimidazolin + 8-oxyquinolin copper, 5- (chlor-2-methyl-4-isothiazolin-3-one + 1,2-benzisothiazolin-3-one) By adding ester, it is hygienic even if it is touched by hand when putting on and taking off. The antibacterial effect is preferably an antibacterial activity value of 2.0 or more after performing an antibacterial processed product-antibacterial property test based on JIS Z2801 that meets the guidelines established by the Antibacterial Product Council.

The holding member 80 is formed with a fitting portion 81 that fits with the cover member 90, so that the cover member 90 can be attached when the friction body 70 is not in use, and the friction body 70 is used to erase the handwriting after writing. In some cases, it is removable. At the time of removal, by pinching the protrusion 91 protruding outward from the outer surface of the cover member 90, it becomes easy to be caught by a finger or the like and can be easily removed. When not in use, the outer surface of the friction body 70 can be covered with the cover member 90 to prevent the friction body 70 from becoming dirty due to dust or the like.

FIG. 3 is a component diagram of the cover member 90. 3 (a) is a perspective view from the front side, FIG. 3 (b) is a side view shown from the front side, FIG. 3 (c) is a plan view, FIG. 3 (d) is a front view, and FIG. 3 (e) is a front view. 3 (d) is a vertical sectional view, FIG. 3 (f) is a perspective view from the rear side, and FIG. 3 (g) is a side view shown from the rear side.

In the cover member 90, a bowl-shaped main body 95 is integrally formed with a cylindrical bottom 94 that is a base of the main body 95 and has an open front in front of the main body 95. The bottom portion 94 has two chamfered portions 94a formed at point-symmetrical positions on the central axis. On the rear side of the main body 95, two substantially triangular protrusions 91 are formed when visually recognized from the longitudinal direction from the outer surface of the main body 95 and the vertical cross section protruding from the rear end surface. The protrusions 91 are preferably formed at a plurality of positions symmetrical about the central axis with respect to the circumferential direction so that the protrusions 91 can be easily picked up by fingers or the like. Further, by making the width B [mm] of the protrusion 91 in the circumferential direction shorter than the maximum diameter D [mm] of the main body 95 or the bottom 94, it is easy to pinch only the width of the protrusion 91 and remove it from the holding member 80. be. Regarding the size of the protrusion 91, the maximum outer diameter A [mm] of the protrusion 91 and the maximum outer diameter D [mm] of the main body 95 or the bottom 94 satisfy the relationship of D <A, and the width B [mm] is 0. It is preferable that the relationship of .5 <B <D is satisfied, and the protrusion length C [mm] from the rear end surface of the main body 95 satisfies the relationship of (AD) / 2 <C <A. The protrusion 91 can also have a function as a friction body by using a substantially triangular corner portion.

A ventilation hole 92 that penetrates the inner surface of the main body 95 is formed on the rear end surface of the main body 95. By forming the ventilation holes, it is possible to prevent suffocation due to accidental ingestion, but it is preferable to form an elongated shape at the intermediate position of the protrusion 91 in order to secure the amount of ventilation. The size of the ventilation holes 92 is preferably 5 square millimeters or more in terms of the opening area E projected from the rear end of the cover member 90. On the inner surface of the main body 95, a fitting portion 93a and a support portion 93b that fit and lock with the fitting portion 81 of the holding member 80 are formed. By forming a plurality of fitting portions 93a and supporting portions 93b and arranging them in different shapes at equal intervals, a fitting force with little variation between the parts can be obtained with the holding member 80, and the cover member 90 can be attached to the holding member 80. It can suppress rattling.

FIG. 4 is a component diagram of another example of the cover member 90. 4 (a) is a perspective view from the front side, FIG. 4 (b) is a side view shown from the front side, FIG. 4 (c) is a plan view, FIG. 4 (d) is a front view, and FIG. 4 (e) is a front view. 4 (d) is a vertical sectional view, FIG. 4 (f) is a perspective view from the rear side, and FIG. 4 (g) is a side view shown from the rear side. The parts common to FIG. 3 are shown as the same reference numerals.
The difference from FIG. 3 is that the protrusions 96 are not ring-shaped, and are integrally attached to the rear portion of the main body 95 as one place instead of a plurality of protrusions 96. The protrusion 96 is integrally molded with the main body 95 or fixed as a separate part by adhesion, welding, or the like. Since the protrusion 96 protrudes from the outer surface of the main body 95 in the circumferential direction, it is easily caught by a finger or the like and can be easily removed. The other description is the same as that of the cover member 90 of FIG. 3, and will be omitted.

Further, the cover member of the present invention can be used not only to cover the friction body of the heat-discolorable writing tool, but also to cover an eraser such as a mechanical pencil, an operation portion of an input pen for operating an electronic device, and the like.

1 Knock type writing tool 2 Axle cylinder 3 Front shaft 4 Rear shaft 5 Refill 6 Spring 7 Biasing spring 10 Inner cylinder 13 Slope 20 Operation part 30 Main rotor 40 Deceleration rotor 50 Knock lock member 60 Locking part 70 Friction body 80 Holding Member 90 Cover member

Claims (3)

A thermochromic writing tool provided with a pen tip capable of ejecting a thermochromic composition and a friction body capable of thermally discoloring the stroke with frictional heat generated at that time by rubbing the stroke of the thermochromic composition. The thermochromic writing tool has a shaft member, a friction body projecting from an end of the shaft member, and a cover member attached to the shaft member to cover the friction body. A thermochromic writing instrument characterized in that a plurality of protrusions protruding from the rear end surface in the circumferential direction are formed on the rear end surface. The thermochromic writing tool according to claim 1, wherein one elongated vent hole is formed at an intermediate position between the plurality of protrusions on the rear outer surface of the cover member. The thermochromic writing tool according to claim 1 or 2, wherein the protrusion has a function as a friction body.

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