JP7402850B2 - writing implements - Google Patents

Description

The present invention relates to a writing instrument .

Traditionally, various parts have been attached to the rear end of a writing instrument. For example, when the writing instrument is a mechanical pencil, an eraser is often attached as such a part. Further, in the case of a ballpoint pen that uses thermochromic ink, a friction rubber may be attached to the rear end as such a component.
Patent Document 1 listed below discloses a multi-core writing instrument in which an elastic part having rubber-like elasticity is attached to a removable crown by screw fitting to the rear part of a barrel.
Further, Patent Document 2 listed below discloses a multi-core writing instrument in which a hole is provided at the rear end of the barrel to which an earphone jack accessory can be attached.

Japanese Patent Application Publication No. 2013-49192 Japanese Patent Application Publication No. 2015-143020

The present invention provides a mounting part that is easy to attach and detach to the rear end of a writing instrument, without requiring a rotational mounting operation such as screw fitting, and without requiring a structure such as a hole that reduces the design. The task is to do so.

In order to solve the above problems, the present invention accommodates a plurality of writing bodies 56 in a barrel 51, and a plurality of slides formed longitudinally from near the rear end of the barrel 51 toward the tip. A writing instrument attachment part 10 that is attached to the rear end of a writing instrument 50 having a window 53,
a tip surface 21 in contact with the rear end of the writing instrument 50;
a plurality of engaging claws 30 protruding from the distal end surface 21 toward the distal end of the writing instrument 50 and corresponding to each of the plurality of slide windows 53;
Each of the engaging claws 30 includes an extending piece 31 extending toward the tip, and a locking piece 32 bent toward the central axis of the writing instrument 50 at the tip of the extending piece 31. It is characterized by being locked to the rear end of the sliding window 53.

In the following description, the direction corresponding to the tip side of the writing instrument 50 will be referred to as the "tip" side, and the opposite side will be referred to as the "rear end" side.
The "slide window 53" is an opening provided as a space in which a slide button 55 for knocking the barrel 51 housed in the writing instrument 50 and the like slides back and forth. The writing instrument attachment component 10 according to the present invention is to be locked to the rear end of this slide window 53 when attached to the rear end of the writing instrument 50. Specifically, the extending piece 31 of the engaging claw 30 protruding from the distal end surface 21 of the writing instrument attachment component 10 extends from the rear edge of the writing instrument 50 toward the distal end of the writing instrument 50. The tip of the extending piece 31 is bent in the central axis direction to form a locking piece 32, which locks on the rear end of the slide window 53. This locking piece 32 locks at least a portion of each slide window 53.

The material of the engaging claw 30 is not particularly limited, but considering that some elastic deformation occurs when it is attached to and removed from the sliding window 53, it is preferable to use metal.
As described above, by providing the plurality of engaging claws 30 corresponding to the sliding windows 53 of the writing instrument 50, the writing instrument attachment part 10 can be easily attached to the writing instrument 50 with slight elastic deformation.

Further, the writing instrument attachment component 10 according to the present invention may include a base portion 20 having the distal end surface 21, and a functional portion 15 attached to the rear end side of the base portion 20. Here, the "functional section 15" refers to something that provides the writing instrument attachment part 10 with some kind of function. For example, if a mechanical pencil refill 61 is included in the plurality of writing fonts 56, an eraser as the erasing body 57 may be provided as the functional unit 15. Further, when the ballpoint pen refill 60 included in the plurality of writing bodies 56 is filled with thermochromic ink, a friction rubber serving as the eraser 57 may be provided as the functional part 15. Note that thermochromic ink maintains a predetermined color (first color) at room temperature (e.g. 25°C) and changes to a different color (second color) when heated to a predetermined temperature (e.g. 65°C). An ink that has the property of changing and then returning to its original color (first color) when cooled to a predetermined temperature (for example, 10° C.). Generally, the second color is colorless, and the drawn line written in the first color (for example, red) is heated to become colorless. In addition, the functional unit 15 may include a seal, a solid coloring tool, a strap, and accessories for decorative purposes. Note that the function of the functional unit 15 as the eraser 57 is not limited to the above, and various functions can be adopted depending on the nature of the lines drawn in the cursive 56.

Note that at least one of the plurality of cursive fonts 56 may be formed as an erasing body 57 for erasing the drawn lines of any one of the cursive fonts 56.

Furthermore, the writing instrument attachment component 10 according to the present invention may include a covering section 40 that covers the functional section 15. That is, a cap or cover for the functional section 15 can be used as the "covering section 40."
Further, the writing instrument 50 itself, which has the writing instrument attachment part 10 according to the present invention attached to its rear end, can also be used as a product. The writing instrument attachment part 10 can be replaced as necessary due to wear or damage, or as desired by the user.

Since the present invention is configured as described above, there is no need for a rotational attachment operation such as screw fitting at the rear end of the writing instrument, and there is no need for a structure such as a hole that reduces the design. This makes it possible to provide mounting parts that can be easily attached and detached without any problems.

In the writing instrument equipped with the writing instrument attachment part according to the first embodiment of the present invention, (A) a stored state of the writing instrument and (B) a protruding state of the writing instrument are both shown in right side views. A writing instrument attachment part according to a first embodiment of the present invention is shown in (A) a top perspective view, (B) a plan view, (C) a front view, and (D) a right side view. A writing instrument attachment part according to a first embodiment of the present invention is shown in (A) a lower perspective view and (B) a bottom view. A sectional view taken along line IV-IV in FIG. 2(C) is shown. The base of the writing instrument attachment part according to the first embodiment of the present invention is shown in (A) a top perspective view, (B) a plan view, (C) a front view, and (D) a right side view. A sectional view taken along line VI-VI in FIG. 5(C) is shown. The covering portion of the writing instrument attachment part according to the first embodiment of the present invention is shown in (A) a front view, (B) a lower perspective view, and (C) a bottom view. A cross-sectional view taken along line VIII-VIII in FIG. 7(A) is shown. The state of attachment of the writing instrument attachment part to the writing instrument according to the first embodiment of the present invention is shown in (A) a lower perspective view and (B) an upper perspective view. 1 shows a right side sectional view of a writing instrument equipped with a writing instrument attachment part according to a first embodiment of the present invention. In the writing instrument equipped with the writing instrument attachment part according to the second embodiment of the present invention, the stored state of the writing instrument is shown in (A) front view, (B) right side view, and (C) XI-XI cross section of (A). Illustrated in the diagram. FIG. 7 is a perspective view of a writing instrument equipped with a writing instrument attachment part according to a second embodiment of the present invention, with the tip barrel removed. 3A and 3B are schematic drawings showing black particles used in a mechanical pencil lead used in a second embodiment of the present invention, in which (A) is a schematic side view and (B) is a schematic plan view. The eraser refill according to the second embodiment of the present invention is shown in (A) perspective view, (B) front view, (C) right side view, (D) XIV-XIV sectional view in (B), (E) It is shown in a rear view, (F) a bottom view, and (G) a plan view. The cylinder part in FIG. 14 is shown in (A) a perspective view with the back side facing upward, (B) a left side view with the back side facing upward, (C) a front view, (D) a right side view, and (E) (C ) is shown in the XV-XV cross-sectional view. The stopper in FIG. 14 is shown in (A) perspective view, (B) front view, (C) right side view, (D) XVI-XVI sectional view in (B), (E) rear view, and (F) bottom view. show. The solid core refill according to the second embodiment of the present invention is shown in (A) a perspective view with the left side facing upward, (B) a left side view, (C) a front view, (D) a right side view, and ( E) Shown in XVII-XVII cross-sectional view in (C). The cylinder part in FIG. 17 is shown in (A) a perspective view with the back side facing upward, (B) a rear view, (C) a left side view, (D) a front view, (E) a bottom view, and (F) a plan view. show. The stopper in FIG. 17 is shown in (A) lower perspective view, (B) front view, (C) upper perspective view, (D) bottom view, (E) right side view, (F) top view, and XIX in (B). -XIX cross-sectional view. A perspective view of a friction rubber refill according to a second embodiment of the present invention is shown. Regarding other examples of friction rubber refills according to the second embodiment of the present invention, (A) the state when the friction rubber is not used, (B) the state when the friction rubber is used, and (C) ( B) shows an enlarged cross-sectional view of the tip. A writing instrument attachment part according to a second embodiment of the present invention is shown in (A) an upper perspective view, (B) a plan view, (C) a front view, and (D) a right side view. A writing instrument attachment part according to a second embodiment of the present invention is shown in (A) a lower perspective view and (B) a bottom view. (A) XXIVa-XXIVa sectional view in FIG. 23(B) and (B) XXIVb-XXIVb sectional view in FIG. 22(C) are shown. The base of the writing instrument attachment part according to the second embodiment of the present invention is shown in (A) a top perspective view, (B) a plan view, (C) a front view, and (D) a right side view. Figure 25 shows the state of the base before the engagement claw is attached: (A) top perspective view, (B) top view, (C) front view, (D) rear view, (E) bottom view, and (F) bottom view. Shown in perspective view. The locking plate of the base shown in FIG. 25 is shown in (A) top perspective view, (B) top view, (C) front view, (D) rear view, (E) bottom view, and (F) bottom perspective view. FIG. 26 shows an assembled view of the base shown in FIG. 25 in a bottom perspective view. The state of attachment of the writing instrument attachment part to the writing instrument according to the second embodiment of the present invention is shown in (A) a lower perspective view and (B) an upper perspective view. A right side cross-sectional view shows a writing instrument equipped with a writing instrument attachment part according to a second embodiment of the present invention.

Embodiments of the present invention will be described below with reference to the drawings.
(1) First embodiment (1-1) Writing instrument 50
FIG. 1 shows a writing instrument 50 equipped with a writing instrument attachment part 10 according to the first embodiment. The writing instrument 50 is a so-called multifunctional writing instrument in which three ballpoint pen refills 60 as writing bodies 56 are housed in a barrel 51. A knock rod 54 is connected to the rear end of each writing body 56. A part of this knock bar 54 is formed as a protrusion projecting outward, and this is called a slide button 55. On the other hand, the shaft tube 51 is provided with a sliding window 53 corresponding to each writing body 56 along the longitudinal direction. Each slide button 55 projects outward from the corresponding slide window 53 and slides along the slide window 53 in the front-rear direction. In FIG. 1A, all the slide buttons 55 are located at the rear end of each slide window 53. In this state, none of the writing bodies 56 protrudes from the tip of the barrel 51 and is housed inside the barrel 51. From this state, slide one of the slide buttons 55 toward the tip, and when the slide button 55 reaches the tip of the corresponding slide window 53, the corresponding writing 56 will move toward the axis as shown in FIG. 1(B). It protrudes from the tip of the tube 51. Note that a writing instrument attachment part 10 is attached to the rear end of the writing instrument 50, and a method for attaching this will be described later.

(1-2) Writing instrument mounting parts 10
The writing instrument attachment part 10 has a structure as shown in FIGS. 2 to 4. That is, a substantially cylindrical covering portion 40 is attached to the rear end side of the substantially cylindrical base 20 (see FIGS. 2(A), (C), (D), FIGS. 3(A) and 4). ). Further, the distal end surface 21 of the base portion 20 is formed into a concave curved surface that matches the rear end surface of the writing instrument 50 (Fig. 4), and an engaging pawl 30 made of stainless steel and having an L-shaped cross section is protruded from there toward the distal end. (See FIG. 3(A) and FIG. 4). The engaging pawl 30 is composed of an elongated piece 31 extending along the longitudinal direction, and a locking piece 32 bent from the tip of the elongated piece 31 at right angles to the central axis direction (FIG. 2(C), (D), see FIG. 3(A) and FIG. 4). The engaging claw 30 is provided at a position corresponding to the sliding window 53 shown in FIG. Furthermore, a substantially cylindrical functional section 15 is attached to the base 20. The covering portion 40 also covers this functional portion 15 (see FIG. 4). In this embodiment, this functional section 15 is an eraser.

As shown in FIGS. 5 and 6, the base portion 20 has a smaller outer diameter at its rear end portion, and this portion serves as a reduced diameter portion 22. As shown in FIGS. Furthermore, near the rear end of the outer periphery of this reduced diameter portion 22, an outer locking protrusion 23 is provided that projects outward along the circumferential direction. Furthermore, the internal space of this reduced diameter portion 22 serves as a housing portion 24 that accommodates the functional portion 15 (see FIG. 4) (see FIGS. 5(A), (B), and FIG. 6). This base portion 20 is formed by insert molding in which synthetic resin is injection molded with the engaging claw 30 inserted into a mold.

As shown in FIGS. 7 and 8, the covering portion 40 has a substantially cylindrical shape having an inner diameter slightly larger than the reduced diameter portion 22. As shown in FIGS. The rear end surface 41 of the covering part 40 is formed in the shape of a gently sloped truncated cone, and a ventilation hole 42 is formed in the center thereof (see FIGS. 7(C) and 8). Furthermore, an inner locking protrusion 43 that protrudes inward along the circumferential direction is provided on the inner circumferential surface of the covering portion 40 slightly toward the distal end side (see FIGS. 7(B) and 8). The covering portion 40 is formed by injection molding of synthetic resin. Incidentally, by kneading and molding sodium alkylsulfonate, sodium alkylbenzenesulfonate, etc. as an antistatic agent into the synthetic resin, it is possible to prevent adhesion of dirt and the like.

(1-3) Attaching and removing the writing instrument attachment part 10 When attaching the covering part 40 to the base 20, cover the covering part 40 from the rear end side of the reduced diameter part 22 so that the inner locking protrusion 43 is exposed. When the locking protrusion 23 is pushed toward the distal end so as to be overcome by elastic deformation, the installed state as shown in FIG. 4 is achieved. When using the internal functional part 15, when the covering part 40 is grasped and pulled backward, the inner locking protrusion 43 is elastically deformed again and gets over the outer locking protrusion 23, and the covering part 40 is removed. It will be separated from the base 20.

When attaching the writing instrument attachment part 10 to the writing instrument 50, as shown in FIGS. 9(A) and 9(B), the engaging claw 30 is aligned with the position of the slide window 53 and pressed toward the tip. As a result, the locking piece 32 engages with the rear end of the slide window 53 through a slight outward elastic deformation of the extending piece 31 (see FIG. 10). Further, when removing the writing instrument attachment part 10, by strongly pulling it backward, the extension piece 31 is elastically deformed outward, and the engagement between the locking piece 32 and the sliding window 53 is released.

(2) Second embodiment (2-1) Writing instrument 50
FIG. 11 shows a writing instrument 50 equipped with a writing instrument attachment part 10 according to the second embodiment. Like the first embodiment, this embodiment is also a so-called multi-functional writing instrument, but unlike the first embodiment, there are three writing bodies 56 and two erasers in the barrel 51. The difference is that a total of five refills (see FIGS. 11(C) and 12) of the body 57 are accommodated. Furthermore, the structure of the means for fixing the engaging claw 30 of the writing instrument attachment part 10 at the rear end of the barrel 51 is also different. These will be described later.

As shown in FIGS. 11(A) and 11(B), the shaft cylinder 51 has a structure in which a tapered substantially cylindrical front shaft 51B is screwed onto the tip of a substantially cylindrical rear shaft 51A. ing. This tip shaft 51B is removable when replacing the writing body 56 or the erasing body 57 or when making adjustments as will be described later.
As shown in the cross-sectional view of FIG. 11(C), a guide member 58 through which five refills pass is installed inside the rear shaft 51A. This guide member 58 includes five guide holes 58A (only one is visible in the figure) through which five refills pass through in the longitudinal direction.

Knock rods 54 are connected to the rear ends of the writing body 56 and the erasing body 57, respectively. A spring 59 is interposed between the tip of each knock rod 54 and the rear edge of the corresponding guide hole 58A to bias the refill backward. A part of this knock bar 54 is formed as a protrusion projecting outward, and this is called a slide button 55. Note that a clip 52 is connected to the knock bar 54 located at the front in place of the slide button 55.

On the other hand, the shaft tube 51 is provided with a sliding window 53 corresponding to each writing body 56 along the longitudinal direction. Each slide button 55 and clip 52 protrudes outward from the corresponding slide window 53 and slides along the slide window 53 in the front-rear direction. In FIGS. 11A and 11B, all the slide buttons 55 and clips 52 are located at the rear end of each slide window 53. In this state, neither the writing body 56 nor the erasing body 57 protrudes from the tip of the barrel 51 and is housed inside the barrel 51. From this state, slide either the slide button 55 or the clip 52 toward the tip, and when the slide button 55 or clip 52 reaches the tip of the corresponding slide window 53, the corresponding writing 56 or erasing body 57 will be removed. The tip protrudes from the tip of the shaft tube 51. Note that a writing instrument attachment part 10 is attached to the rear end of the writing instrument 50, and a method for attaching this will be described later.

When the front shaft 51B is removed from the rear shaft 51A, as shown in FIG. A solid core refill 62 (see FIG. 17) attached thereto, an eraser refill 63 as two erasers 57, and a friction rubber refill 64 are visible. Further, as the functional part 15, a covering erasing material 65 containing a concealing pigment is attached to the writing instrument attachment part 10 (see FIG. 11(C)).

(2-2) Ballpoint pen refill 60
The ballpoint pen refill 60 includes a holder 60B that holds a writing ball 60A at its tip, an ink storage tube 60C that stores ink, and a joint 60D that connects the holder 60B and the ink storage tube 60C.
In this embodiment, the ink stored in the ink storage tube 60C is a so-called non-thermochromic ink, which contains a coloring material, a solvent, water, a thickener, and a content of 0.01% by weight or more and 0.5% by weight or less. Crystalline cellulose is blended, and the particle size of 50% of the cumulative volume of the crystalline cellulose is 0.3 μm or more and 7 μm or less, and the maximum particle size is 60 μm or less.
"Crystalline cellulose" is generally used as a food additive, etc., and is made by partially depolymerizing α-cellulose obtained as pulp from fibrous plants with mineral acid to extract the cellulose crystalline region. It refers to the product that has been refined. Note that the cellulose crystal region refers to a portion where cellulose molecular regions are densely and regularly present.
As mentioned above, the optimal blending ratio of this crystalline cellulose is 0.01% by weight or more and 0.5% by weight or less. Here, if this blending ratio is less than 0.01% by weight, the effect of preventing the direct current phenomenon expected from crystalline cellulose cannot be obtained. On the other hand, if this blending ratio exceeds 0.5% by weight, although the effect of preventing the direct current phenomenon can be obtained, fading of drawn lines is observed and stability over time deteriorates, which is not preferable as an ink.

As coloring materials, all dyes that can be dissolved or dispersed in water, known inorganic and organic pigments including titanium oxide, pseudo-pigments obtained by coloring resin emulsions with dyes, and white plastic pigments are used according to the present invention. It may also be added to the ink composition. Specific examples of dyes include acid dyes such as eosin, phloxine, water yellow #6-C, acid red, water blue #105, brilliant blue FCF and nigrosine NB, direct black 154, direct sky blue 5B and violet BB. and basic dyes such as rhodamine and methyl violet. Examples of inorganic pigments include carbon black and the like. Examples of organic pigments include azo lakes, chelate azo pigments, phthalocyanine pigments, perylene and perinone pigments, anthraquinone pigments, quinacridone pigments, and dye lakes. When adding any of them, the amount added is preferably within the range of 0.1 to 40% by weight based on the total amount of the ink, and is appropriately increased or decreased depending on the line density of the ink.

As the solvent, a water-soluble organic solvent having a polar group that is compatible with water can be used. Specific examples include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, ethylene glycol monomethyl ether, glycerin, and pyrrolidone, which can be used alone or in a mixture of two or more.
A thickener is essential to prevent sedimentation of crystalline cellulose in the ink and to prevent deterioration of the performance of the ink. Various thickeners can be used as this thickener, but in particular, those that impart relatively weak shear thinning properties, such as alkali swelling emulsions, polyvinylpyrrolidone, and cellulose derivatives, can prevent sedimentation of crystalline cellulose. In addition, since it is difficult to aggregate, it can exist stably for a long period of time.

As this thickener, at least one selected from the group consisting of synthetic polymers, celluloses, and polysaccharides can be used. Examples of synthetic polymers include polyacrylic acids, polyvinyl alcohol, polyethylene oxide, polyvinylpyrrolidone, polyvinyl methyl ether, bisacrylamide methyl ether, polyacrylamide, polyethyleneimine, polyethylene glycol, polydioxolane, polystyrene sulfonic acid, polypropylene oxide, etc. Can be mentioned. Examples of celluloses include ethylcellulose, methylcellulose, hydroxypropylcellulose, hydroxymethylcellulose, and carboxymethylcellulose. Polysaccharides include xanthan gum, guar gum, casein, gum arabic, gelatin, amylose, agarose, agaropectin, arabinan, curdlan, callose, carboxymethyl starch, chitin, chitosan, quince seed, glucomannan, gellan gum, tamarin seed gum, and dextran. , nigeran, hyaluronic acid, pustulan, funoran, pectin, porphyran, laminaran, lichenan, carrageenan, alginic acid, gum tragacanth, gum alkacy, locust bean gum, and the like.

Here, the term "alkali-swelled emulsion" refers to an unneutralized acrylic polymer that mainly contains acid groups such as carboxyl groups in the three-dimensional structure of the polymer, and is neutralized with an alkali. This refers to something that swells once and then continues to be neutralized, eventually leading to dissolution.
In this embodiment, among the alkali swelling emulsions, an alkali swelling association emulsion is more desirable. Here, this "alkali swelling association type emulsion" means that when the polymer swells, the hydrophobic part of the molecule associates with that part of other molecules, forming loose bonds between the molecules. A substance that exhibits viscosity.

It is thought that an alkali swelling association type emulsion has two main thickening effects. The first viscosity-increasing effect is that when the molecule dissolves only in the alkaline region of a mixture with water or a polar solvent, hydrophilic groups such as carboxyl groups in the molecule expand upon hydration, creating steric hindrance in the solution, and increasing the viscosity. refers to the effect of increasing The second thickening effect is caused by the hydrophobic groups and hydrophilic groups in the molecule individually adsorbing together with the hydrophobic groups and hydrophilic groups of the components in the ink, such as pigments, solvents, and surfactants, to create a network-like structure. This refers to the action of forming aggregates and increasing viscosity.
The alkali-swelled association type emulsion of the present invention consists of a polymer having a carboxyl group and a hydrophobic group. Examples of the hydrophobic group include a chain or cyclic hydrocarbon group, an aromatic hydrocarbon group, a halogenated alkyl group, an organosilicon group (-SiR ₃ ), a fluorocarbon group (-C _n F2 _n+1 ), and the like. Can be done. Specific polymers include polyacrylic acid, polymethacrylic acid, polyacrylic acid copolymers, polymethacrylic acid copolymers, and the like.

Furthermore, the term "cellulose derivative" refers to a substance having a molecular structure in which a suitable residue such as a methyl group is added to cellulose.
Furthermore, in the present embodiment, the particle diameter of 50% of the cumulative volume of crystalline cellulose is 0.3 μm or more and 7 μm or less, and the maximum particle diameter is 60 μm or less.
The "particle diameter at 50% cumulative volume" in this embodiment refers to the spherical equivalent diameter of the particles when the cumulative volume is 50% of the total volume of the particles. If the particle size is less than 0.3 μm, the direct current prevention performance will be poor. On the other hand, if this particle size exceeds 7 μm, the writability will be adversely affected. Moreover, the "maximum particle diameter" herein refers to the spherical equivalent diameter of particles when the cumulative volume is 99%. If the maximum particle diameter exceeds 60 μm, the writability will be adversely affected.

It is preferable to first prepare a suspension of crystalline cellulose, disperse it with a sand mill, etc., and use it in a specified size. By controlling the dispersibility, an ink with a high sealing effect and high stability over time can be obtained.
Furthermore, as other additives, any, some, or all of a pigment dispersant, a pH adjuster, a preservative, a rust preventive, and a lubricant may be added to the ink composition according to the present invention.
Examples of pigment dispersants include water-soluble polymers such as ammonium salts of styrene maleic acid and ammonium salts of styrene acrylic acid.
Examples of pH adjusters include ammonia, urea, monoethanolamine, diethanolamine, triethanolamine, aminomethylpropanol, alkali metal salts such as sodium tripolyphosphate and sodium carbonate, and alkali metal hydroxides such as sodium hydroxide. can be mentioned.

Examples of preservatives include phenol, sodium omazine, sodium pentachlorophenol, 1,2-benzisothiazolin-3-one, 2,3,5,6-tetrachloro-4(methylsulfonyl)pyridine, and benzimidazole-based preservatives. compounds and alkali metal salts of benzoic acid, sorbitanic acid and dehydroacetic acid, and the like.
Examples of lubricants include phosphoric acid esters, polyalkylene glycol derivatives such as polyoxyethylene lauryl ether, fatty acid alkali salts, nonionic surfactants, and polyether-modified silicones such as polyethylene glycol adducts of dimethylene polysiloxane. can be mentioned.

Examples of rust preventives include saponin, tolyltriazole, benzotriazole, octyl phosphate, dioctyl thiophosphate, imidazole, benzimidazole, 2-mercaptobenzothiazole, octyloxymethanephosphonic acid, dicyclohexylammonium nitrite, diisopropylammonium nitrite, etc. Compounds such as nitrite, propargyl alcohol, dialkylthiourea, etc. can be used.

(2-3) Covered erasing material 65
In this embodiment, a covering erasing material 65 for covering and erasing drawn lines written with the ballpoint pen refill 60 is attached to the writing instrument attachment part 10 as the functional part 15 (FIG. 11(C) reference). This coated erasing material 65 contains a wax, an extender, and a hiding pigment, and further includes a C:12-30 dibasic acid or its derivative, a tackifier, and a base material with a melting point of 60. ~90° C. of ethylene vinyl acetate copolymer, ethylene acrylic acid copolymer, and ethylene ethyl acrylate copolymer, and/or a mixture of two or more thereof at 20 to 80% by weight.
"Wax" in this embodiment refers to components of the covered erasing material 65 that are generally classified as wax. Wax as a component of the covering eraser 65 contributes to shape retention when not in use, but quickly disintegrates when force is applied, providing lubricity during writing. In addition, it is compatible with the tackifying material described below and imparts fixability to the writing surface. The wax preferably has a low melting point of about 45 to 100°C. Specifically, paraffin wax, microcrystalline wax, sumac wax, beeswax, Japanese wax, montan wax, hydrogenated castor oil, hydrogenated palm oil, and the like can be used as the wax in the present invention. Further, the blending amount thereof is desirably 50% by weight or less of the total weight.

The "enhancing material" in this embodiment is a component that contributes to improving the strength and writability of the covered erasing material 65. It also exhibits the auxiliary effect of the hiding pigment described below. Specifically, talc, kaolin, mica, boron nitride, calcium carbonate, potassium titanate whiskers, and the like can be used as the extender in the present invention. Further, the blending amount thereof is preferably 10 to 50% by weight of the total.
The "concealing pigment" in this embodiment is a component that contributes to the coating film obtained by this covering/erasing material 65 concealing the base. Specifically, a concealing white pigment or a concealing black pigment can be used. As the opaque white pigment, titanium dioxide, which is an inorganic pigment, is most suitable for the present invention. Further, the blending amount thereof is preferably 10 to 50% by weight of the total. Examples of other hiding white pigments include zinc oxide and white resin particles, but titanium dioxide is most preferred from the viewpoint of hiding power. Specifically, carbon black, graphite, and iron black can be used as the hiding black pigment.

In this embodiment, the dibasic acid having C: 12 to 30 or its derivative is used to improve the fixing property to the writing surface and the hiding property. Here, "C: 12-30 dibasic acid" is a chain organic compound having carboxyl groups at both ends, as shown in the following chemical formula 1, and the chain portion other than carbon of the carboxyl groups at both ends. ("R" in the following chemical formula 1) has 12 to 30 carbon atoms.

Here, "-R-" may be a straight chain as shown in Chemical Formula 2 below, a branched chain as shown in Chemical Formula 3 below, or a double bond as shown in Chemical Formula 4 below. It may be something that you have.

In addition, "derivatives thereof" refer to derivatives in which carboxyl groups at both ends are chemically modified, such as ester compounds such as diglycidyl ester (chemical formula 5 below) and methyl ester (chemical formula 6 below), diol Substituents such as (Chemical formula 7 below) and diamines (Chemical formula 8 below), polymers such as polyacid polyanhydride (Chemical formula 9 below), sodium salts (Chemical formula 10 below) and amine salts (Chemical formula 11 below). There are salts like this.

If the melting point of the C:12-30 dibasic acid or its derivative exceeds 70°C, it will be difficult to improve the fixing properties and hiding properties, so the melting point is preferably 70°C or lower. Furthermore, in order to obtain the above-mentioned quality improvement effect, it is desirable that the content of the dibasic acid having C: 12 to 30 or its derivative is in the range of 1 to 12% by weight based on the entire coated erasing material 65. This is because if it is less than 1% by weight, the effect of improving the coloring property is not expressed, and on the other hand, if it exceeds 12% by weight, the coloring property is not further improved and the writing taste becomes poor. More preferably, the weight ratio of the C:12-30 dibasic acid or its derivative to the total waxes contained in the coated erasing material 65 is such that the dibasic acid or its derivative:the wax=2:100. It is desirable that the ratio is in the range of 20:100. This is because if the ratio of the dibasic acid or its derivative is less than 2:100, the above-mentioned quality improvement effect will not be exhibited, and on the other hand, if the ratio exceeds 20:100, the quality will not be improved any further and the writing taste will be poor.

The "tackifying agent" in the present invention is used for the purpose of improving the fixation of the lines drawn by the coated erasing material 65 to the writing surface.
In the present invention, "ethylene vinyl acetate copolymer", "ethylene acrylic acid copolymer", and "ethylene ethyl acrylate copolymer" are those that form the base material of the coated erasing material 65 of the present embodiment. . When not in use, it serves as a base material to give flexibility to the covering erasing material 65 and contribute to shape retention. In addition, when writing, it wears like a coating film due to frictional heat with the writing surface and adheres to the writing surface, thereby contributing to concealability. Furthermore, this component also contributes to the so-called "self-erasing property" in which the coated erasing material 65 itself rubs against the coating to break it into fine pieces and remove it. In order to exhibit these properties, the ethylene vinyl acetate copolymer, ethylene acrylic acid copolymer, and ethylene ethyl acrylate copolymer having a melting point of 60 to 90°C are used.
The melt flow rate of the ethylene vinyl acetate copolymer, ethylene acrylic acid copolymer, and ethylene ethyl acrylate copolymer as defined in JIS K7210:1999 is preferably 400 to 800 g/10 min.

Further, the ethylene-vinyl acetate copolymer is preferably one in which vinyl acetate monomer is polymerized in a proportion of 10% by weight or more.
Further, the tackifier comprises a terpene resin, a modified terpene resin, a maleic acid resin derivative, a coumaron-indene resin, a coumaron-indene resin derivative, a styrene resin, an isoprene resin, a pine resin, a rosin ester, and a petroleum resin. Preferably, it is one or a mixture of two or more selected from the group.
As other components, for example, a small amount of oil having a melting point of 45° C. or less, specifically less than 5% by weight, can be used for the purpose of imparting lubricity. Such oils include jojoba oil, liquid paraffin, squalane, squalene, liquid paraffin, and the like.

The covered erasing material 65 of this embodiment is formed into a short cylindrical shape using the above-mentioned components, and is attached to the writing instrument attachment part 10 as the functional part 15 as described above. Details of the writing instrument attachment part 10 will be described later.

(2-4) Mechanical pencil refill 61
The mechanical pencil refill 61 includes a lead storage tube 61A that accommodates a mechanical pencil lead 61C, and a mechanical part 61B that is attached to the tip and is involved in feeding out the mechanical pencil lead 61C (see FIG. 11(C)).
In the present embodiment, the mechanical pencil lead 61C has graphite particles whose area on the a-b plane is more than 8 μm ² and less than 500 μm ² , and where the area on the a-b plane of the graphite particles is selected from the following group A. Contains black particles to which carbon nanoparticles containing black particles are adhered.
Group A: carbon nanofibers, carbon nanotubes, fullerenes, nanodiamonds, graphitized carbon black FIG. 13 is a schematic drawing showing black particles used in the mechanical pencil lead 61C of this embodiment, and (A) is a schematic side view; (B) is a schematic plan view, in which symbol A is a black particle, B is a graphite particle, and C is a carbon nanoparticle. Note that in the figure, they are differentiated for clarity, but it is actually difficult to differentiate them after bonding and firing.

The graphite particles used in the mechanical pencil lead 61C of this embodiment have an area of the a-b plane of the graphite particles exceeding 8 μm ² and less than 500 μm ² , and the above-mentioned Carbon nanoparticles containing black particles selected from Group A are adhered to each other.
Examples of the graphite particles to be used include graphite particles such as scaly graphite, scale-like (bulk) graphite, earthy graphite, spheroidized graphite, exfoliated graphite, artificial graphite, quiche graphite, expanded graphite, and expanded graphite. Can be done.

In the mechanical pencil lead 61C of this embodiment, it is necessary to use graphite particles whose a-b plane area exceeds 8 μm ² and is less than 500 μm ² from the viewpoint of core strength, wear, and friction. In terms of core strength, abrasion, and friction, it is desirable that the core is 9 μm ² or more and 100 μm ² or less.
If the area of the a-b plane of these graphite particles is less than 8 μm ² , the strength and smoothness of the mechanical pencil lead 61C will decrease, while if it is more than 500 μm ² , the strength and smoothness of the mechanical pencil lead 61C will decrease. This results in a decrease in wear and excessive wear, which is undesirable.
In addition, the aspect ratio of the graphite particles is preferably 2 or more and 220 or less, more preferably 5 or more and 100 or less, from the viewpoint of further improving the writing feel and strength and formability. .

In the mechanical pencil lead 61C of this embodiment, carbon nanoparticles containing black particles selected from Group A are adhered to the a-b planes of the graphite particles.
The carbon nanoparticles containing black particles selected from the above group A to be used preferably have an average primary particle diameter of 5 nm or more and 200 nm or less, from the viewpoint of further improving strength and concentration and adhesion of graphite particles. A material containing black particles, more preferably a material containing black particles with a size of 5 nm or more and 50 nm or less is desirable.
In the present invention, the "average primary particle diameter" refers to scanning electron microscopy (SEM) images obtained using software Mac-View ver. In the following, for example, when the average primary particle diameter is 5 nm, it is expressed as D50=5 nm.

The carbon nanoparticles containing black particles selected from Group A, which adhere to the a-b planes of the graphite particles, will be described in detail below.
The carbon nanofibers used are often indicated by the outer diameter of the tube, and examples of nanofibers include those with a diameter of 50 to 200 nm, examples of carbon nanotubes include those with a diameter of 5 to 50 nm, and examples of carbon nanotubes include those with an outer diameter of 50 to 50 nm. As nanodiamonds, C60, C70, etc. can be used. In this case, the primary particle size is very small, about 0.7 to 10 nm, and because of its large cohesive force, it is usually 30 to 70 μm. As nanodiamonds, Any of cluster diamonds, polycrystalline diamonds, and single-crystalline diamonds can be used, including those having a particle size of 10 nm to 200 nm.
In addition, examples of the graphitized carbon black include Toka Black manufactured by Tokai Carbon Co., Ltd., induction field combustion graphitized carbon black, etc., or after adhering carbon black obtained by the Ness method etc. to the a-b plane of graphite particles, The carbon black may be graphitized (graphitized carbon black) during the production (firing) of black particles or the production (firing) of the mechanical pencil lead 61C. In addition, if the carbon nanoparticles are not graphitized, they will not wear out even though they have no strength, and if the carbon nanoparticles are too large, they will inhibit the orientation of graphite, and the strength will decrease, but the adhesion with graphite will decrease, and the concentration will decrease. will not increase. Graphitization can be carried out at a temperature of about 1,400 to 3,000°C.

In the mechanical pencil lead 61C of this embodiment, as a method for adhering carbon nanoparticles containing black particles selected from the above group A to the a-b plane of the graphite particles, for example, the graphite surface can be coated with thermoplastic resin or thermosetting resin. After coating carbon nanoparticles containing black particles selected from Group A with a mortar or the like using a mortar or the like, the binder component is applied to the graphite surface by baking in a non-oxidizing atmosphere or This can be done by preparing a metal coating by plating, and then firing (welding) carbon nanoparticles containing black particles selected from Group A above and the metal coating in a non-oxidizing atmosphere.
Preferably, the blending ratio of carbon nanoparticles and graphite particles is within the range of 1:1 to 1:100, more preferably within the range of 1:1 to 1:50, in order to further improve strength and writing feel. It is desirable that

Graphite particles that can be specifically used can be obtained, for example, by the following manufacturing methods 1 to 4.
Manufacturing method 1: Apply a thermosetting resin such as phenol resin or furan resin to the graphite surface by the above-mentioned method, and add carbon nanoparticles such as carbon nanofibers, carbon nanotubes, fullerenes, nanodiamonds, graphitized carbon black, etc. of the above group A to graphite. It is adhered to the surface and fired in a nitrogen gas atmosphere.
Manufacturing method 2: Apply a thermoplastic resin such as vinyl chloride resin or polyvinyl acetate polyvinyl chloride copolymer to the graphite surface by the above method to produce carbon nanofibers, carbon nanotubes, fullerenes, nanodiamonds, graphitized carbon black, etc. of the above group A. Carbon nanoparticles are adhered to the graphite surface and fired in a nitrogen gas atmosphere.

Manufacturing method 3: A metal coating such as a nickel coating, a copper coating, or a silver coating is formed on the graphite surface by the above method, and carbon nanoparticles such as carbon nanofibers, carbon nanotubes, fullerenes, nanodiamonds, graphitized carbon black, etc. of the above A group are formed on the graphite surface. Welded to metal coating.
Manufacturing method 4: A thermosetting resin such as a phenol resin or a furan resin is applied to the graphite surface by the above method, carbon black is adhered to the graphite surface, and the mixture is fired in a nitrogen gas atmosphere or the like.
In addition to the nitrogen gas atmosphere described above, the firing can be performed in a non-oxidizing atmosphere such as argon (Ar), helium (He), or vacuum. Further, the firing temperature and time vary depending on the adhesive means used, etc., but are preferably 800 to 1,700°C and 30 to 720 minutes.

The mechanical pencil lead 61C of this embodiment contains graphite particles having the characteristics obtained above, and the content thereof is preferably 1 to 50% by mass in the total amount of the mechanical pencil lead 61C. , more preferably 2 to 50% by mass.
If the graphite particle content is less than 1% by mass, the effect will be small, and if it exceeds 50% by mass, the strength and writing feel will be significantly inferior.

The mechanical pencil lead 61C of this embodiment is made by mixing black particles to which carbon nanoparticles including black particles selected from the above group A and a resin selected from the following groups B and C are mixed, and after molding, After low temperature curing or flame resistance at a temperature of 150°C or higher and 300°C or lower, firing at a temperature of 1,000°C or higher and 2,200°C or lower, preferably 1,000°C or higher and 2,000°C or lower. It can be manufactured by
Group B: polyvinyl chloride, polyvinyl acetate polyvinyl chloride copolymer, pitch, vinyl alcohol resin, vinylidene chloride resin Group C: furan resin, phenolic resin, cellulose resin, acrylonitrile resin, imide resin, Diaryl phthalate resin, silicone resin, urea melanin resin, epoxy resin

In the above manufacturing method, if the temperature for low-temperature curing after molding is less than 150°C, the plasticizer may not completely vaporize or thermosetting may not occur, whereas if the temperature exceeds 300°C, decomposition and oxidation may occur. It progresses rapidly and is undesirable.
Furthermore, if the firing temperature is less than 1,000°C, the strength will be low and the material will not be stable. On the other hand, if the temperature exceeds 2,200°C, graphitization will proceed rapidly and the strength will also become weak, which is not preferable.

In the mixture of the black particles having the above characteristics and the resin selected from the above group B, each component such as an organic solvent, a stabilizer, a lubricant (molding aid), etc. can be appropriately selected and mixed. After firing, it may be impregnated with an impregnating oil such as an α-olefin oligomer, fatty acid ester, spindle oil, or wax.

Specifically, the mechanical pencil lead 61C of this embodiment contains 20 to 70% by mass of black particles having the above characteristics and 20 to 70% by mass of a resin selected from Groups B and C above, in terms of strength and writing feel. and 5 to 30% by mass of sodium stearate, etc., were dispersed and mixed using a Henschel mixer, kneaded using a pressure kneader and two rolls, and molded into a predetermined shape and size using an extrusion molding machine. Low-temperature hardening or flame resistance at a temperature of 1,000 to 2,200 °C in a non-oxidizing atmosphere (nitrogen gas atmosphere, inert gas atmosphere, etc.) at a temperature of 1,000 to 2,200 °C. However, it can be produced by filling the pores of the fired core with an α-olefin oligomer, a synthetic oil such as silicone oil or ester oil, a vegetable oil such as castor oil, or a lubricant such as grease, by impregnation or the like.

(2-5) Eraser refill 63
As shown in FIG. 14, the shape of the eraser refill 63 is a combination of a cylindrical portion 63B, a connecting portion 63C, a stopper 63D, and an eraser 63A. More specifically, at the rear end of the elongated cylindrical cylindrical portion 63B, which has a plurality of stopper holes 63E and the same number of stopper holes 63E on the front (FIG. 14(B)) and back (FIG. 14(E)), Almost the same connection part 63C is installed. A connecting hole 63I into which the tip of the knock rod 54 is inserted and connected is provided at the rear end of the connecting portion 63C (FIGS. 14(D) and (G)). Further, a cylindrical eraser 63A is inserted into the inside of the cylindrical portion 63B (FIG. 14(D)), and its tip protrudes from the tip of the cylindrical portion 63B (FIGS. 14(A) to (E)). Further, the stopper 63D is attached with a portion inserted into one of the stopper holes 63E from the outer surface of the cylindrical portion 63B (FIG. 14(D)) (FIGS. 14(A) to (G)). )).

The shape of the cylindrical portion 63B is shown in FIG. The cylindrical portion 63B is formed by plastically deforming a substantially rectangular brass material into a cylindrical shape with the short side in the circumferential direction. Thereby, a long slit 63G is formed between the original long sides (FIGS. 15(A), (B), and (E)). In addition, two short slits 63H are formed at the tip of the cylindrical portion 63B at a distance of 120° from each other in the circumferential direction with respect to the long slit 63G (FIGS. 15(A) and 15(C)). , (D) and FIG. 14(F)). Although the tip of the cylindrical portion 63B is slightly narrowed toward the tip (Fig. 15 (B) to (E)), the formation of these short slits 63H and long slits 63G narrows the radial direction slightly. It is possible to deform elastically. This elastic deformation makes it possible to insert the eraser 63A stored inside, and by further tightening in the axial direction, it becomes possible to hold the inserted eraser 63A (Fig. 14). D)).

As described above, the same number of stopper holes 63E are formed in the front (FIG. 15(C)) and back (FIG. 15(A)) of the cylindrical portion 63B along the longitudinal direction. This stopper hole 63E is a place into which a part of a stopper 63D, which will be described later, is inserted.

The shape of the stopper 63D is shown in FIG. The stopper 63D consists of a semi-cylindrical half-tube 63J and a cylindrical insertion section 63L protruding from the center of the concave surface of the half-tube 63J (Figs. 16(A), (C), (D)). , (E) and (F)). When viewed from above, the stopper 63D is visually recognized as a rectangular shape in which the convex portion of the half-cylindrical portion 63J is slightly elongated in the front-rear direction (FIG. 16(B)). The cross section along the longitudinal direction has a substantially T-shape (FIG. 16(D)). When inserted into the stopper hole 63E, the insertion portion 63L corresponding to the "vertical bar" of this T-shape comes into contact with the rear end of the eraser 63A inserted into the cylindrical portion 63B, and the eraser 63A is pressed backwards. (See FIG. 14(D)).

In this embodiment, the eraser 63A attached to the eraser refill 63 is characterized by containing at least an acrylic thermoplastic resin powder, a plasticizer, and an inorganic powder.

The acrylic thermoplastic resin powder used for the eraser 63A of this embodiment is a base material of the eraser 63A, and is not particularly limited as long as it is an acrylic thermoplastic resin powder.
Examples of monomers that can be used as the acrylic thermoplastic resin include methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, i-butyl (meth)acrylate, and t-butyl (meth)acrylate. , (meth)acrylates of alkyl alcohols such as hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and octyl (meth)acrylate, or (meth)acrylates of cyclic alkyl alcohols such as cyclohexyl (meth)acrylate. Examples include copolymers as the main component (containing 50 mol% or more).

Other monomers copolymerizable with (meth)acrylates include, for example, methacrylic acid, acrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, and 2-succinoloyloxyethyl-2-methacryloyloxy methacrylate. Ethylsuccinic acid, 2-maleinoloyloxyethyl methacrylate-2-methacryloyloxyethylmaleic acid, 2-phthaloyloxyethyl methacrylate-2-methacryloyloxyethyl phthalate, 2-hexahydrophthaloyloxyethyl methacrylate Carboxyl group-containing monomers such as 2-methacryloyloxyethyl hexahydrophthalic acid, sulfonic acid group-containing monomers such as allylsulfonic acid, carbonyl group-containing (meth)acrylates such as acetoacetoquiethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, hydroxyl group-containing (meth)acrylates such as 2-hydroxypropyl (meth)acrylate, epoxy group-containing (meth)acrylates such as glycidyl (meth)acrylate, N-dimethylaminoethyl (meth)acrylate, Amino group-containing (meth)acrylates such as N-diethylaminoethyl (meth)acrylate, (poly)ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, Polyfunctional (meth)acrylates such as trimethylolpropane tri(meth)acrylate, and acrylamide and its derivatives such as diacetone acrylamide, N-methylolacrylamide, N-methoxymethylacrylamide, N-ethoxymethylacrylamide, N- Examples include butoxymethylacrylamide, styrene and its derivatives, vinyl acetate, urethane-modified acrylates, epoxy-modified acrylates, silicone-modified acrylates, and the like.

The acrylic resin powder used in the eraser 63A of this embodiment not only has its composition ratio changed, but also preferably has the following properties: It is desirable that the primary particle size is 20 to 80 μm, and the glass transition temperature (Tg) is preferably 50 to 115°C, more preferably 75 to 95°C. In this embodiment, the term "glass transition temperature (Tg)" refers to the temperature at which the amorphous portion of the acrylic resin powder becomes more mobile and becomes rubbery.
Furthermore, from the viewpoint of sol stability and sintering uniformity, the acrylic resin powder used preferably has a concentric shape from the center of the particle toward the periphery, such as a core-shell structure or a gradient structure. Examples include structures in which constituent monomer units are distributed in two or more stages or in a stepless manner, and in particular, acrylics with a core-shell structure in which the glass transition temperature differs between the core part (core part) and the shell part (outer shell part). It is preferable to use resin powder.
The composition of the core and shell is not particularly limited, but it is preferable to have a shell with a relatively high glass transition temperature (Tg) and a core with a relatively lower glass transition temperature (Tg) than the shell. If the glass transition temperature (Tg) is 75 to 115°C, the glass transition temperature (Tg) of the core is 50 to ₉₅ °C. ₈ ) A copolymer of alkyl acrylate or various esters; the shell is composed of methyl methacrylate alone, a copolymer of methyl methacrylate and acrylic acid, or a copolymer of methyl methacrylate, a C ₂ to C ₈ alkyl acrylate, and acrylic acid, etc. be able to.

The acrylic resin powder used in the eraser 63A of this embodiment can be polymerized by emulsion polymerization in an aqueous medium, seed emulsion polymerization, soap-free polymerization, suspension polymerization, fine suspension polymerization, dispersion polymerization in an organic medium, water/ By methods such as dispersion polymerization in an organic mixed medium and precipitation polymerization in an organic medium, it is possible to polymerize various structures such as a core-shell structure, and the resulting polymer dispersion is subjected to a spray drying method (spray drying method). It can be powdered using methods such as dry method), coagulation method using salt or acid, freeze-drying method, centrifugation method, filtration method, etc., and if commercially available products are available, they can be used.
Examples of the acrylic resin powder that can be used include DIANAL LP-3106 (core-shell structure, core Tg 75°C, shell Tg 85°C, primary particle size 70 μm), which is an acrylic resin powder for plastisol manufactured by Mitsubishi Rayon Co., Ltd. Examples include Dianal LP-3202 (core-shell structure, core Tg 85°C, shell Tg 95°C, primary particle size 60 μm).

The content of these acrylic resin powders is desirably 0.5 to 50% by weight, preferably 1 to 20% by weight, based on the total amount of the eraser 63A.
If the content is less than 0.5% by weight, almost no effect of inclusion will be obtained, while if it exceeds 50% by weight, the erasability will be markedly reduced, which is not preferable.

The plasticizer used in the eraser 63A of this embodiment is not particularly limited as long as it is a plasticizer that can plasticize or gel a base material such as acrylic resin powder. For example, dioctyl phthalate (DOP, Dioctyl phthalate), dioctyl adipate (DOA), dioctyl sebacate (DOS), butityl sebacate (DBS), dimethyl phthalate (DMP), diisononyl phthalate (DINP), dihexyl phthalate, and the like. . Dioctyl phthalate (DOP) is preferred from the viewpoint of wear characteristics and strength.
The content of these plasticizers is preferably 10 to 70% by weight based on the total amount of the eraser 63A. More preferably, the content is 30 to 60% by weight.
If this content is less than 10% by weight, the erasability will be extremely low, while if it exceeds 70% by weight, the strength will be below practical strength, which is not preferable.

Examples of the inorganic powder used in the eraser 63A of this embodiment include magnesium carbonate, calcium carbonate, calcium phosphate (including hydroxyapatite), magnesium sulfate, silica, zinc white, carbon (carbon black, Ketjenblack), and various other powders. clay minerals (talc, kaolin, pyrophyllite, mica, smectite) and their respective complexes (silica-coated calcium carbonate, etc.). Preferably, calcium carbonate and /or magnesium carbonate.
The inorganic powder to be used is particularly preferably one having a liquid-absorbing porous structure, and is desirably an inorganic powder composed of a porous body having a large specific surface area and a high liquid-absorbing property. In particular, inorganic powder consisting of particles with a specific surface area of 100 to 500 m ² /g and a liquid absorption rate of 100 to 1,000 ml/100 g can be mentioned. The above specific surface area is the specific surface area determined by the BET method, and the liquid absorption rate is determined by dropping linseed oil onto a pile of 100 g of powder, and determining the lowest amount of linseed oil that changes from a sand ball state to a trough (fluid state). means. If the inorganic powder has a liquid absorption rate of less than 100 ml/100 g, the adsorption power described below will be insufficient and the erasability will not be sufficient. In addition, inorganic powder with a liquid absorption rate exceeding 1,000 ml/100 g is not currently on sale and is probably difficult to manufacture, so it is virtually impossible to manufacture Eraser 63A using this powder. .
Inorganic powders that can be specifically used include basic magnesium carbonate porous bodies, petal-like porous structures of calcium phosphate, porous silica particles, basic magnesium sulfate inorganic fibers, secondary aggregates of calcium carbonate, and carbonic acid. Inorganic powders such as calcium petal-shaped porous materials can be mentioned, and in particular, inorganic powders made of liquid-absorbing porous materials that satisfy the above ranges of specific surface area and liquid absorption rate, and basic magnesium carbonate. It is preferable to use a porous material.

Among these inorganic powders, it is particularly preferable to use inorganic powders such as basic porous magnesium carbonate and secondary aggregates of calcium carbonate from the viewpoint of manufacturability, availability, cost, and the like. The basic magnesium carbonate porous material is agglomerated tubular particles made of flaky microcrystals, and the tubular particles preferably have an outer diameter of 1 to 20 μm and a length of 5 to 200 μm.
The above basic magnesium carbonate is represented by the chemical formula mMgCO ₃ .Mg(OH) ₂ .nH ₂ O, and the values of m and n are not particularly limited. For example, the value of m is 3 to 5, and the value of n is 3 to 8. In addition, the tubular particles of basic magnesium carbonate do not agglomerate, where flaky microcrystals are easily dispersed by simple stirring or changes in the environment such as temperature and pH, but instead form flaky particles of basic magnesium carbonate. It is a collection of microcrystals that are physically fixed.

In the eraser 63A of the present embodiment, the production of a liquid-absorbing porous material such as the above-mentioned basic magnesium carbonate porous material is known. By using a water-soluble magnesium salt and a water-soluble carbonate, basic magnesium carbonate that becomes tubular particles of flaky microcrystals can be produced.
As this basic magnesium carbonate porous body, various grades of commercially available MagTube (manufactured by Nippon Steel Mining Co., Ltd.) or grades whose particle surfaces have been treated with alumina, various fatty acids, etc. can be used.

The content of these inorganic powders is preferably 10 to 50% by weight, more preferably 10 to 30% by weight, based on the total amount of the eraser 63A.
If this content is less than 10% by weight, the effect of scraping pencil powder etc. from the paper surface will be small and erasability will be reduced, while if it exceeds 50% by weight, there will be too much wear and eraser residue. Undesirable.

The eraser 63A of this embodiment preferably contains other base material components in addition to the acrylic resin powder, plasticizer, and inorganic powder, and if necessary, may be used in ordinary erasers or the like. By blending and molding the desired amount of various compounding agents, it is possible to erase written lines using a mechanical pencil lead 61C without staining the paper surface, ensuring reliable erasing, and creating an eraser that produces almost no eraser residue. 63A can be manufactured.
Other base material components that can be used are not particularly limited, and for example, at least one of various thermoplastic resins and synthetic rubbers can be used, with thermoplastic resins being preferred.
Examples of thermoplastic resins include vinyl chloride resins (PVC), vinyl chloride resins such as copolymers thereof (for example, vinyl chloride vinyl acetate copolymers), ethylene vinyl acetate copolymers, and ethylene acrylic acid copolymers. , polyolefin, chlorinated polyolefin, etc. Examples of the synthetic rubber include butyl rubber, butadiene rubber, nitrile rubber, nitrile-butadiene rubber, and styrene-butadiene rubber. Particularly preferred are vinyl chloride resins (PVC) or a copolymer thereof (vinyl chloride/vinyl acetate copolymer).

Specifically, the above-mentioned vinyl chloride resins that are preferably used include polyvinyl chloride such as Kanevinyl series (manufactured by Kaneka Corporation), Vinica series (manufactured by Mitsubishi Kasei Vinyl Corporation), and Ryuron Paste series (homopolymers and copolymers: (manufactured by Tosoh Corporation), and these may be used alone or in combination of two or more.
The content of other base material components such as these thermoplastic resins is preferably 10 to 50% by weight, more preferably 10 to 50% by weight, based on the total amount of the eraser, in terms of hardness, elasticity, erasability, and amount of eraser residue. is preferably contained in an amount of 15 to 30% by weight.

In addition, if necessary, heat stabilizers such as Ca-Zn stearate may be used to prevent the deterioration of various compounding agents, such as the above-mentioned base material components (especially vinyl chloride resin) at high temperatures. can. In addition, appropriate amounts of viscosity modifiers, lubricants, solvents, colorants, ultraviolet absorbers, preservatives, antifungal agents, fragrances, and the like can be added.
Furthermore, when rubber or elastomer is used as the base material component, appropriate amounts of softeners, vulcanizing agents, vulcanization accelerators, fillers, anti-aging agents, coloring agents, etc. can be blended.

The eraser 63A of this embodiment is prepared by kneading predetermined amounts of the acrylic thermoplastic resin powder, plasticizer, inorganic powder, and, if necessary, other base components and various compounding agents by a conventional method. After the preparation, it can be molded into a desired shape.
The eraser 63A has a cylindrical shape as described above.

Why is it that the eraser 63A of this embodiment is able to more reliably erase the lines written by the mechanical pencil lead 61C without staining the paper surface than the conventional eraser that produces eraser residue? Moreover, the fact that almost no eraser residue or surface burrs occur is due to the following mechanism of action.
That is, the eraser 63A of the present embodiment contains at least the above acrylic thermoplastic resin powder, a plasticizer, and an inorganic powder, and for example, the acrylic thermoplastic resin powder is an acrylic thermoplastic resin powder with a core-shell structure. By containing at least a plasticizer such as basic calcium carbonate porous material as an inorganic powder, graphite is adsorbed to the liquid-absorbing porous material inside the eraser 63A when rubbed against the written line, and the graphite is erased from the paper surface. The adsorbed graphite is diffused by the adsorption ability of the liquid-absorbing porous material, and the adsorption power is enhanced by the inclusion of the acrylic thermoplastic resin powder, which almost eliminates the generation of eraser scum and burrs on the surface of Eraser 63A. In addition, since the graphite once adsorbed does not transfer to the paper surface again, it does not stain the paper surface and can be erased reliably. Therefore, the eraser 63A of the present embodiment hardly generates eraser residue, has excellent erasability of written lines, and does not generate burrs on the surface of the eraser 63A. Note that the eraser 63A of this embodiment diffuses and accumulates graphite and the like adsorbed into the eraser each time it is erased. For example, if the eraser 63A is white, The color of the eraser 63A increases in blackness with each degree.

When the eraser refill 63 protrudes from the tip shaft 51B, the writing instrument 50 functions as an eraser capable of erasing the lines drawn with the mechanical pencil lead 61C by means of the eraser 63A protruding from the tip. If the tip of the eraser 63A becomes black due to use and it becomes difficult to erase, remove the front shaft 51B from the rear shaft 51A to obtain the state shown in FIG. 12, and then pinch the eraser refill 63 and pull it apart. It can be isolated as shown in FIG. 14(A). In this state, first remove the stopper 63D, then pinch and pull out the tip of the eraser 63A, and cut off the blackened part with a cutter or the like. Then, insert the eraser 63A again into the cylindrical portion 63B so that the tip of the eraser 63A protrudes by an appropriate length, and insert the insertion portion 63L of the stopper 63D into the stopper hole 63E near the rear end of the eraser 63A, which has become shortened (Fig. 14 (D). ), the eraser 63A is fixed again.

(2-6) Solid core refill 62
As shown in FIG. 17, the shape of the solid core refill 62 is a combination of a cylindrical portion 62B, a connecting portion 62C, a stopper 62D, and a solid core 62A. More specifically, the rear end of the cylindrical part 62B has an elongated cylindrical shape and has a plurality of stopper holes 62E in the front (FIG. 17(C)) and back (FIGS. 17(D) and (E)) respectively. A connecting portion 62C with approximately the same outer diameter is attached to the connector. A connecting hole 62I is provided at the rear end of the connecting portion 62C, into which the tip of the knock rod 54 is inserted and connected (FIG. 14(E)). Furthermore, a cylindrical solid core 62A with a conically cut tip is inserted into the cylindrical portion 62B (FIG. 17(E)), and its tip protrudes from the tip of the cylindrical portion 62B (FIG. 17(E)). (A)-(E)). Further, a stopper 62D is inserted into the cylindrical portion 62B with a portion protruding from one of the pair of stopper holes 62E facing the front and back faces (FIG. 17(E)). 17(A)-(E)).

The shape of the cylindrical portion 62B is shown in FIG. The cylindrical portion 62B is formed by plastically deforming a substantially rectangular brass material into a cylindrical shape with the short side in the circumferential direction. As a result, a long slit 62G is formed between the original long sides (FIGS. 18(A), (C), (E), and (F)). In addition, two short slits 62H are formed at the tip of the cylindrical portion 62B at a distance of 120° from each other in the circumferential direction with respect to the long slit 62G (see FIGS. 18(A) and 18(B)). , (D) and (E)). The tip portion of the cylindrical portion 62B can be slightly elastically deformed in the radial direction by forming the short slits 62H and the long slits 62G. This elastic deformation makes it possible to insert the solid core 62A stored inside, and further tightens in the axial direction after insertion, making it possible to hold the inserted solid core 62A. (Figure 17(E)).

As described above, the same number of stopper holes 62E are formed in the front (FIG. 18(D)) and back (FIG. 18(B)) of the cylindrical portion 62B along the longitudinal direction. Adjacent stopper holes 62E communicate with each other through a communication portion 62F having a width narrower than the diameter of the stopper hole 62E. This stopper hole 62E is a location where a portion of a stopper 62D, which will be described later, protrudes from inside the cylindrical portion 62B.

The shape of the stopper 62D is shown in FIG. The stopper 62D has a pair of elastic parts 62J extending in the longitudinal direction and a connecting part 62K that connects them on the rear end side, and has a substantially U-shaped shape when viewed from the side (Fig. 19(A), ( C), (E) and (G)). In addition, a substantially short cylindrical insertion portion 62L that projects outward from the vicinity of the tip of each elastic portion 62J is provided (FIGS. 19(A), (C), (D), (E), (F) and (G)). Of this stopper 62D, a pair of elastic parts 62J and a connecting part 62K are accommodated inside the cylindrical part 62B, but only a pair of insertion parts 62L are inserted into the stopper hole 62E from inside (Fig. 17(E)). ). As a result, the tips of the pair of elastic parts 62J come into contact with the rear ends of the solid core 62A inserted into the cylindrical part 63B, preventing the solid core 62A from being pushed back by pressure (FIG. 17(E)) reference).

In this embodiment, the solid core 62A attached to the solid core refill 62 contains at least a resin component, a wax component, a thermochromic coloring material, and a white body material, and as the resin component, rosin and modified rosin are used. The wax component contains at least one of glycerin fatty acid ester and pentaerythritol fatty acid ester having a melting point of 45° C. or higher in a range of 8% or more and 50% by weight. % or less provides thermochromic properties.

In the solid core 62A of this embodiment, the rosin and modified rosin used as the "resin component" are not particularly limited as long as they are generally classified as rosin and modified rosin, and any of them can be used. can. It is also possible to use abithienic acid, which is the main component of rosin. Note that the term "modified rosin product" as used herein refers to glycerin ester of rosin and the like.
These can be used alone or in a mixture of two or more without distinguishing between chemical products and natural products, and are appropriately selected depending on the colorability and hardness of the intended solid core 62A.
The content of this resin component is supposed to be in the range of 0.5% by weight or more and 20% by weight or less. If this content is less than 0.5% by weight, the fixing properties on smooth surfaces will be poor, the coloring will be insufficient, and the strength will be weak, making it impractical. On the other hand, if it exceeds 20% by weight, it will be hard and the fixing properties on smooth surfaces will be poor, resulting in insufficient coloring.

In the solid core 62A of this embodiment, the glycerin fatty acid ester used as the "wax component" is not particularly limited as long as it has a melting point of 45° C. or higher and is generally classified as a glycerin fatty acid ester. can also be used. For example, palmitic acid glyceride, stearic acid glyceride, etc. having a melting point of 45°C or higher, as well as monoglyceride, diglyceride, and triglyceride can be used. Furthermore, other than these, any natural products such as wax waxes such as Japanese wax wax and Japanese urushi wax, and sumac waxes such as Yamaha Japanese wax wax and Japanese Urushi wax, which have glycerin fatty acid ester as a main component, can be used.

In the solid core 62A of this embodiment, the pentaerythritol fatty acid ester used as the "wax component" is not particularly limited as long as it has a melting point of 45°C or higher and is generally classified as a pentaerythritol fatty acid ester. , both can be used. For example, any of pentaerythritol palmitate, pentaerythritol stearate, monopentaerythritol, dipentaerythritol, tripentaerythritol, and tetrapentaerythritol having a melting point of 45° C. or higher can be used. Note that if the melting point is lower than 45°C, the practical strength will be too low, and if the solid core 62A is formed into a thin shape, it will easily break.

These glycerin fatty acid esters and pentaerythritol fatty acid esters used in the solid core 62A of this embodiment can be used alone or in a mixture of two or more, without distinguishing between chemical products and natural products, depending on the purpose. It is selected as appropriate depending on the colorability and hardness of the solid core 62A.
The content of the wax component is in the range of 8% by weight or more and 50% by weight or less. If this content is less than 8% by weight, the solid core 62A will be hard and have poor fixability on smooth surfaces, resulting in insufficient coloring. On the other hand, if it exceeds 50% by weight, the solid core 62A becomes weak in strength and is not practical.

The "thermochromic color material" used in the solid core 62A of this embodiment is, for example, a thermochromic composition composed of at least a leuco dye, a color developer, and a color change temperature regulator, and these materials are It also includes those that are encapsulated to form microcapsule pigments. In order to strengthen the wall material of microcapsule pigments, the wall material of microcapsule particles is made from a polymer resin wall material formed from a monomer, a polymer, or a polymer containing a crosslinking material that enables crosslinking. It is desirable to form a thermochromic composition and encapsulate the thermochromic composition.

The leuco dye used in the solid core 62A of this embodiment is not particularly limited as long as it is an electron-donating dye and functions as a coloring agent. Specifically, in order to obtain excellent coloring properties, for example, 3,3-bis(p-dimethylaminophenyl)-6-dimethylaminophthalide, 3-(4-diethylaminophenyl)-3-(1- Ethyl-2-methylindol-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)fluoran, 2-(N-phenyl-N--methylamino)-6-(N-p-tolyl-N-ethylamino)fluoran, 2-(3'- Examples include trifluoromethylanilino)-6-diethylaminofluorane, 3-chloro-6-cyclohexylaminofluorane, 2-methyl-6-cyclohexylaminofluorane, 3-methoxy-4-dodecoxystyrinoquinoline, etc. These can be used alone (one type) or in combination of two or more types (hereinafter simply referred to as "at least one type").
Furthermore, pyridine-based compounds, quinazoline-based compounds, bisquinazoline-based compounds, etc. that develop yellow to red coloring can also be used.
These leuco dyes have a lactone skeleton, a pyridine skeleton, a quinazoline skeleton, a bisquinazoline skeleton, etc., and develop color when these skeletons (rings) open.

The color developer used in the solid core 62A of this embodiment is one that causes leuco dye to develop color. It is composed of particles in a crystalline state, and is contained in the ink in this crystalline state.
Specific examples of color developers that can be used include o-cresol, tert-butylcatechol, nonylphenol, n-octylphenol, n-dodecylphenol, n-stearylphenol, from the viewpoint of obtaining ink with excellent coloring properties. p-chlorophenol, p-bromophenol, o-phenylphenol, hexafluorobisphenol, n-butyl p-hydroxybenzoate, n-octyl p-hydroxybenzoate, resorcinol, 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)propane, -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)ethylpropionate, 2,2-bis(4'-hydroxyphenyl)-4 -Methylpentane, 2,2-bis(4'-hydroxyphenyl)hexafluoropropane, 2,2-bis(4'-hydroxyphenyl)n-heptane, 2,2-bis(4'-hydroxyphenyl)n- Examples include nonane, and at least one of these can be used.

The discoloration temperature regulating agent used in the solid core 62A of this embodiment is heated and melted to block the bond between the leuco dye and the color developer to achieve a decolorized state, and then the discoloration temperature regulating agent is cooled again below the melting point. As a result, the discoloration temperature regulating agent crystallizes and becomes a colored state repeatedly, and the change occurs reversibly at the melting point of the discoloration temperature regulating agent. In addition, even if the bond between the leuco dye and the color developer is blocked in the heated and molten state, and the color is erased, and the color change temperature regulator is cooled again to the melting point of the color change temperature regulator, the color change temperature regulator will not crystallize at that melting point. , one that maintains a decolored state can be used. The latter discoloration temperature regulator exhibits a quasi-reversible change with hysteresis characteristics that crystallizes and develops color by lowering the temperature several to several tens of degrees below the melting point, and then is heated and cooled again. This change causes the color to repeatedly fade and develop.

The discoloration temperature adjusting agent that can be used in the solid core 62A of this embodiment is not particularly limited as long as it has the above-mentioned functions. , specifically, a compound having at least one of decanoic acid, dodecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid, nonadecanoic acid, icosanoic acid, docosanoic acid, tetradocosanoic acid, hexadocosanoic acid, octadocosanoic acid Saturated fatty acids such as caprylic alcohol, lauryl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, behenyl alcohol, isostearyl alcohol, palmitrail alcohol, etc., amides of the above fatty acids and amines, esters of the above fatty acids and alcohols , ethers of the above-mentioned higher alcohols and glycerin, propylene glycol, and ethylene glycol, and diphenylpropanedione, dibendioxybenzene, diphenoxybenzene, diisopropylnaphthalene, benzyl biphenyl, benzyl naphthyl ether, and dibenzyl sulfoxide. , dimethyl terephthalate, diphenyl carbonate, diphenyl sulfone, fluoranthene, fluorene, methylhydroxynaphthalate, phenylhydroxynaphthalate, steranilide, and other aromatic compounds, and at least one of these can be used.

The microcapsule pigment has an average particle diameter of 0.1 to 20 μm, and the wall film is made of epoxy resin, polyamide resin, acrylonitrile resin, polyurethane resin, polyurea resin, urea-formaldehyde resin, melamine-formaldehyde resin, benzoguanamine resin. In addition to amino resins such as butylated melamine resin, butylated urea resin, urea-melamine resin, etc., acrylic resin, maleic acid resin, silicone resin, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polystyrene, etc. This thermochromic composition is encapsulated. In addition to these resins, it may be formed from gelatin, starch, gum arabic, sodium polyacrylate, hydroxyethylcellulose, methylcellulose, polyacrylate, ethylcellulose, cellulose acetate, and the like.

When the "thermochromic color material" of the solid core 62A of this embodiment is a microcapsule pigment, the thermochromic composition consisting of at least the above leuco dye, color developer, and color change temperature regulator has an average particle size of It can be manufactured by microcapsulating it to a size of 0.1 to 20 μm.
Examples of microencapsulation methods include interfacial polymerization method, interfacial polycondensation method, in situ polymerization method, submerged curing coating method, phase separation method from aqueous solution, phase separation method from organic solvent, melting dispersion cooling method, and gas dispersion cooling method. Examples include a medium suspension coating method and a spray drying method, which can be appropriately selected depending on the application.
For example, in the phase separation method from an aqueous solution, a leuco dye, a color developer, and a discoloration temperature regulator are heated and melted, then added to an emulsifier solution, heated and stirred to disperse in the form of oil droplets, and then, as a capsule membrane agent, For example, by using a resin raw material whose wall film can be formed from an amino resin, and gradually adding each solution such as an amino resin solution, specifically, a methylolmelamine aqueous solution, a urea solution, a benzoguanamine solution, etc., and allowing the reaction to continue. By filtering this dispersion, the desired thermochromic microcapsule pigment can be produced.

The contents of these leuco dyes, color developers, and color change temperature regulators vary depending on the types of leuco dyes, color developers, and color change temperature regulators used, and the microencapsulation method. The mass ratio is 0.1 to 100 for the color developer and 1 to 100 for the color change temperature regulator. Furthermore, the mass ratio of the capsule membrane agent to the capsule contents is 0.1 to 1.
In the microcapsule pigment of the solid core 62A of this embodiment, by suitably combining the types and amounts of the above-mentioned leuco dye, color developer, and color change temperature regulator, the color of each pigment can be adjusted to any desired color development temperature and decolorization temperature. It can be temperature.

When the "thermochromic coloring material" of the solid core 62A of this embodiment is a microcapsule pigment, it is preferable that the wall film is formed of resin, and more preferably, it has good manufacturability, storage stability, and writability. From this point of view, it is preferable to use a thermosetting resin such as an amino resin containing a melamine resin. The thickness of the wall film of the microcapsule pigment is appropriately determined depending on the required strength of the wall film and the density of drawn lines.

When the "thermochromic coloring material" is a microcapsule pigment, the average particle diameter is 0.0000. The thickness is preferably 1 to 20 μm, more preferably 0.2 to 5.0 μm. Note that the "average particle diameter" referred to in the solid core 62A of this embodiment is measured using a laser diffraction/scattering type particle size distribution measuring device (laser diffraction/scattering type particle size distribution meter MT3000 (manufactured by Nikkiso Co., Ltd.)). This is the value obtained by measuring the average particle diameter (arithmetic mean diameter based on volume-based distribution).
If the average particle diameter is less than 0.1 μm, sufficient line density cannot be obtained, while if it exceeds 20 μm, the writing property deteriorates, the dispersion stability of the microcapsule pigment decreases, and the writing surface becomes resistant to friction due to friction. Desorption occurs, which is undesirable.
Note that the average particle diameter of the microcapsule pigment in the above range (0.1 to 20 μm) varies depending on the microcapsule method, but in the phase separation method from an aqueous solution, etc., the stirring conditions when producing the microcapsule pigment It can be prepared by suitably combining these.

In the solid core 62A of this embodiment, the content of the "thermochromic colorant" is preferably 5 to 30% by weight, more preferably 10 to 25% by weight, based on the total amount of the ink composition.
If the content of the thermochromic coloring material (color developer particles) is less than 5% by weight, the coloring power and color development will be insufficient, while if it exceeds 30% by weight, fading tends to occur, which is not preferable.

In addition to the "thermochromic coloring material" in the solid core 62A of this embodiment, ordinary pigments can be included as the coloring material. The pigments include azo organic pigments such as disazo yellow AAA and pyrazolone orange, cyanine organic pigments such as phthalocyanine blue and phthalocyanine green, high grade organic pigments such as quinacridone red, dyeing pigments such as final color, fluorescent pigments, and carbon black. , Tetsukuro, Bengara, Prussian blue, and other inorganic pigments can all be used.

The "white body material" in the solid core 62A of this embodiment includes whiskers of titanium dioxide, calcium carbonate, kaolin, talc, precipitated barium sulfate, mica, boron nitride, potassium titanate whiskers, and basic magnesium sulfate whiskers. Any known body material that exhibits white color can be used.
Here, as the "titanium dioxide", all conventionally known titanium dioxides can be used, regardless of rutile or athanase. However, if the purpose is to draw clearly and densely on a transparent plate surface such as transparent plastic or glass, titanium dioxide for catalyst has a fine particle size and will result in a thin drawing surface, which is not preferable. On the contrary, it is advantageous when using as an underline marker that can be seen through.
Also, for example, if you compose the color-changing solid core 62A by adding only these white extenders without adding titanium dioxide, you can draw translucent lines and use it as an underline marker with the underlying layer visible. In addition, if you cover the drawn lines with a translucent sheet and make a copy, the areas where the drawn lines were drawn will be erased, making it an impromptu fill-in-the-blank problem book.

When the solid lead refill 62 protrudes from the tip shaft 51B, the writing instrument 50 becomes capable of writing thermochromic lines with the solid lead 62A protruding from the tip. When the solid core 62A wears out and becomes short due to use, once the front shaft 51B is removed from the rear shaft 51A to create the state shown in FIG. 12, the solid core refill 62 is pinched and pulled apart. It can be isolated as shown in A). In this state, first, the tip of the solid core 62A protruding from the tip of the cylindrical portion 62B is pinched and pulled out, and the tip is appropriately cut. Then, insert it into the cylindrical portion 62B again. Next, press the pair of insertion parts 62L inward to bend the elastic part 62J, slide the stopper 62D forward, and release the pressure when it comes into contact with the rear end of the solid core 62A to release the shortened solid core. The insertion portion 62L is inserted from inside as shown in FIG. 17(E) into the stopper hole 62E near the rear end of the core 62A, and the solid core 62A is fixed again.

(2-7) Rubber refill for friction 64
As shown in FIG. 20, the shape of the friction rubber refill 64 is a combination of a cylindrical portion 64B, a connecting portion 64C, a stopper 64D, and a friction rubber 64A, and the eraser 63A is replaced with the friction rubber 64A. The configuration of each member other than the above is the same as the configuration of each member of the eraser refill 63.
In this embodiment, the friction rubber 64A attached to the friction rubber refill 64 includes silicone resin, styrene-containing resin, fluorine resin, chloroprene resin, nitrile resin, polyester resin, and ethylene propylene diene rubber (EPDM). ), and hard resins such as polyacetal resin, polyethylene resin, polypropylene resin, ABS resin, polycarbonate resin, and polyester resin can be used. Particularly, among the above-mentioned hard resins, hard resins having a durometer type A hardness of 60 or more according to JIS K 6253 are preferred. If the hardness is less than 60, it is too soft and it becomes difficult to generate frictional heat when rubbing handwriting to cause discoloration. If it is preferably 65 or more and 100 or less, more preferably 70 or more and 90 or less, handwriting can be discolored by frictional heat without any problem.

Note that as another example of the friction rubber refill 64, one having a shape as shown in FIG. 21 can also be used. The friction rubber refill 64 in this example includes a metal cylindrical front cylinder 64E and a metal cylindrical rear cylinder 64F, which is longer than the front cylinder 64E, connected by an intervening part 64H made of metal or synthetic resin. It has a structure. Furthermore, a cylindrical middle cylinder 64G made of metal and having a smaller diameter and shorter length is slidably inserted into the front half of the front cylinder 64E. A pair of slits 64P are formed along the longitudinal direction from the front end of the middle cylinder 64G to a point halfway toward the rear. The meaning of this slit 64P is the same as the long slit 62G and short slit 62H in the cylindrical portion 62B of the solid core refill 62 and the long slit 63G and short slit 63H in the cylindrical portion 63B of the eraser refill 63. Using the elastic deformation of the tip of the middle tube 64G due to the slit 64P, the cylindrical friction rubber 64A can be inserted from the tip of the middle tube 64G, and after insertion, it is held by the restoring force of this elastic deformation. It has become a thing.
The intervening part 64H includes a cylindrical sliding part 64J that is slidably inserted from the rear end of the front cylinder 64E, and a cylindrical sliding part 64J that is located in front of this sliding part 64J and has a slightly smaller outer diameter and is located behind the middle cylinder 64G. A cylindrical front insertion part 64I, which is a part that is fixed by press fitting or punching at the end, a cylindrical rear insertion part 64L, which is fixed by press fitting or punching from the front end of the rear cylinder 64F, and a sliding part. It is composed of a cylindrical reduced diameter part 64K that has a smaller diameter than 64J and the rear insertion part 64L and connects them, and a flange 64M that is located at the boundary of the reduced diameter part 64K and the rear insertion part 64L and abuts the front end of the rear cylinder 64F. Ru. Here, the rear end of the middle cylinder 64G is in contact with the front step part 64N between the sliding part 64J and the front insertion part 64I (FIG. 21(C)). Further, a spring 64Q is extrapolated to the outer periphery of the reduced diameter portion 64K (FIGS. 21(A) and 21(B)). The front end of the spring 64Q is in contact with a rear stepped portion 64O formed at the rear end edge of the front cylinder 64E. Further, the rear end of the spring 64Q is in contact with the flange 64M of the intervening portion 64H. That is, the spring 64Q is interposed between the front cylinder 64E and the rear cylinder 64F.
In addition, the open rear end of the rear cylinder 64F (FIGS. 21(A) and (B)) has a connecting portion (not shown) similar to the connecting portion 62C of the solid core refill 62 and the connecting portion 63C of the eraser refill 63. The friction rubber refill 64 is connected to the corresponding knock rod 54 through this connection.

When housed inside the shaft cylinder 51, the front cylinder 64E is urged in a direction away from the rear cylinder 64F by the urging force of the spring 64Q, as shown in FIG. The tube 64E completely covers the tip of the friction rubber 64A. This is because when the friction rubber 64A moves forward due to the knocking action, the front tube 64E covers the friction rubber 64A, so the tip of the friction rubber 64A does not come into contact with the inner diameter part of the tip shaft 51B. There is.
From this state, when the corresponding knock rod 54 is operated, the friction rubber refill 64 moves forward. At this time, as shown in FIG. 21(B), the tip of the front tube 64E comes into contact with the vicinity of the tip opening of the tip shaft 51B, and is prevented from moving forward there. On the other hand, the pressing force applied from the knock rod 54 to the rear cylinder 64F and the intervening part 64H compresses the spring 64Q and further advances the middle cylinder 64G connected to the tip, thereby moving the tip of the middle cylinder 64G to the tip of the front shaft 51B. Make it protrude from the opening. In this state, the friction rubber 64A is exposed from the tip of the tip shaft 51B, making it possible to erase the lines drawn by the friction rubber.
When the knock rod 54 is moved back to its original position from the state shown in FIG. 21(B), the restoring force of the compressed spring 64Q causes the intervening portion 64H to move rearward, which causes the middle cylinder 64G to also move back. , as shown in FIG. 21(A), the friction rubber 64A returns to a state completely covered by the middle cylinder 64G.

(2-8) Writing instrument mounting parts 10
The writing instrument attachment part 10 has a structure as shown in FIGS. 22 to 24. That is, a substantially cylindrical covering portion 40 is attached to the rear end side of the substantially cylindrical base 20 (FIGS. 22(A), (C), (D), FIGS. 23(A), and 24()). See A). Further, the distal end surface 21 of the base 20 is formed into a concave curved surface that matches the rear end surface of the writing instrument 50 (FIG. 24(A)), and a stainless steel engagement claw 30 is protruded from there toward the distal end. (See FIGS. 23(A) and 24(A)). The engaging claw 30 is a part that is visible from the outside as shown in FIGS. 22(C), (D), and 23(A), and includes a stretched piece 31 extending in the longitudinal direction and this stretched piece. A locking piece 32 is bent at a right angle from the tip of the piece 31 toward the center axis, and a mounting piece 33 is bent at a right angle from the rear end of the extension piece 31 toward the center axis as a part that is not visible from the outside. 24(A) and FIG. 28). The engaging claws 30 are provided at positions corresponding to three of the five sliding windows 53 shown in FIG. The engagement claw 30 is attached to the base 20 using two mounting holes 25 and two long and short mounting grooves 26 formed on the distal end surface 21 of the base 20, but this will be described further later. do. Furthermore, a disc-shaped locking plate 35 is fitted into the bottom of the base 20, and the substantially cylindrical functional part 15 is installed in the housing part 24 so as to sandwich this locking plate 35 (see FIG. 24). See A). Two fitting protrusions 36 protruding from the front end surface of the locking plate 35 fit into the mounting holes 25, respectively (see FIG. 23(B)), and this point will also be described later. The covering portion 40 also covers this functional portion 15 (see FIG. 24(A)). In this embodiment, this functional section 15 is the covering erasing material 65 as described above. As shown in FIG. 24(B), which is a cross section perpendicular to the axial direction of the base 20, two locking pieces 32 are fitted into the longer one of the two arc-shaped mounting grooves 26. On the other hand, one locking piece 32 is fitted on the shorter side. In addition, a fitting protrusion 36 is fitted into each of the two mounting holes 25 having a wider arcuate shape.

As shown in FIGS. 25(A), 25(C), and 25(D), the base portion 20 has a smaller outer diameter at its rear end portion, and this portion serves as a reduced diameter portion 22. Further, on the outer periphery of this reduced diameter portion 22, an outer locking protrusion 23 is provided that protrudes outward along the circumferential direction (see FIGS. 25A, 25C, and 25D). 26(A), (C), (D) and (F)). Furthermore, the internal space of this reduced diameter portion 22 serves as a housing portion 24 that accommodates the functional portion 15 (see FIG. 4) (see FIGS. 25(A) and (B) and FIGS. 26(A) and (B)). reference). Further, in a plan view of the base 20 (FIG. 25(B)), a circular locking plate 35 attached to the bottom surface of the accommodating portion 24 is visible. This will be discussed later.

As shown in FIGS. 22 and 24(A), the covering portion 40 has a substantially cylindrical shape having an inner diameter slightly larger than the reduced diameter portion 22. As shown in FIGS. The rear end surface 41 of the covering portion 40 is formed in the shape of a gently sloped truncated cone. Furthermore, an inner locking protrusion 43 that protrudes inward along the circumferential direction is provided on the inner circumferential surface of the covering portion 40 slightly toward the tip side (see FIG. 24(B)). The covering portion 40 is formed by injection molding of synthetic resin. Incidentally, by kneading and molding sodium alkylsulfonate, sodium alkylbenzenesulfonate, etc. as an antistatic agent into the synthetic resin, it is possible to prevent adhesion of dirt and the like.

FIG. 26 shows the base 20 before the engaging claw 30 and the locking plate 35 are attached. As described above, two mounting holes 25 and two long and short mounting grooves 26 are formed in the distal end surface 21 of the base 20 (FIGS. 26E and 26F). A wider arcuate mounting hole 25 is formed in the middle of the longer one of the two arcuate mounting grooves 26 . Furthermore, a mounting hole 25 having a wider arc shape is also formed at one end of the shorter mounting groove 26. These two attachment holes 25 penetrate to the bottom surface of the housing portion 24 (FIGS. 26(A) and (B)).

The locking plate 35 has a disk shape as described above (FIGS. 27(A), (B), (E), and (F)). Two short arc-shaped fitting protrusions 36 protrude from the periphery of the distal end surface of the locking plate 35 (FIGS. 27(A), (C), (D), (E) and (F)). . These fitting protrusions 36 have positions and shapes that fit into the two attachment holes 25 of the base 20, respectively.

As shown in FIG. 28, three engaging claws 30 and a locking plate 35 are attached to the base 20. Two of the three engaging claws 30 are inserted one by one from the mounting hole 25 in the longer mounting groove 26 toward the rear, and are slid to either end of the mounting groove 26, respectively. The mounting piece 33 is locked to the bottom surface of the accommodating portion 24 (see FIG. 24(A)). On the other hand, the other engagement claw 30 is inserted backward from the mounting hole 25 in the shorter mounting groove 26, slides to the opposite end of the mounting groove, and similarly accommodates the mounting piece 33. It is latched to the bottom surface of the section 24. Then, the engagement claw 30 is fixed by inserting the locking plate 35 into the housing portion 24 and fitting the two fitting protrusions 36 into the corresponding attachment holes 25, respectively. Here, since the attachment hole 25 and the fitting protrusion 36 are each formed in an asymmetrical position and shape, the positions where they fit into each other are determined in the same way.

(2-9) Attaching and removing the writing instrument attachment part 10 When attaching the covering part 40 to the base 20, cover the covering part 40 from the rear end side of the reduced diameter part 22 so that the inner locking protrusion 43 is exposed. When the locking protrusion 23 is pushed toward the distal end so as to be overcome by elastic deformation, the installed state as shown in FIG. 24(A) is achieved. When using the internal functional part 15, when the covering part 40 is grasped and pulled backward, the inner locking protrusion 43 is elastically deformed again and gets over the outer locking protrusion 23, and the covering part 40 is removed. It will be separated from the base 20.

When attaching the writing instrument attachment part 10 to the writing instrument 50, as shown in FIGS. , align it with any two adjacent positions among the five slide windows 53, and at the same time, align the other engaging claw 30 with the position of the slide window 53 that is one space apart, and move it toward the tip. Press. As a result, the locking piece 32 engages with the rear end of the slide window 53 through a slight outward elastic deformation of the extending piece 31 (see FIG. 30). Further, when removing the writing instrument attachment part 10, by strongly pulling it backward, the extension piece 31 is elastically deformed outward, and the engagement between the locking piece 32 and the sliding window 53 is released.

Note that the functional section 15 is not limited to the covered erasing material 65 described in the second embodiment, but may also accommodate a solid core 62A, an eraser 63A, or a friction rubber 64A. In addition, not limited to the embodiments shown in the first embodiment or the second embodiment, various writing fonts 56 and erasing bodies 57 corresponding to each can be freely combined and attached as a refill or functional part 15. Thus, it is possible to provide a writing instrument that includes writing fonts of various erasing or color-changing methods and corresponding erasing or color-changing tools.

The present invention can be used as an attachment part for attaching functional members such as an eraser, a friction rubber, a seal, a solid coloring tool, a strap, etc. to the rear end of a writing instrument. It can also be used as a mounting part for attaching decorative members such as accessories to the rear end of the writing instrument.

10 Writing instrument attachment parts 15 Functional parts
20 Base 21 Tip surface 22 Reduced diameter part
23 Outer locking protrusion 24 Accommodation part 25 Mounting hole
26 Mounting groove
30 Engaging claw 31 Extension piece 32 Locking piece
33 Mounting piece
35 Locking plate 36 Fitting protrusion
40 Covering section 41 Rear end surface 42 Ventilation hole
43 Inner locking protrusion
50 Writing instruments
51 Shaft cylinder
51A Rear axle 51B Front axle
52 Clip 53 Sliding window 54 Knock bar
55 Slide button 56 Cursive 57 Erase
58 Guide member
58A guide hole
59 Spring
60 ballpoint pen refill
60A Writing ball 60B Holder 60C Ink storage tube
60D fitting
61 mechanical pencil refill
61A Lead storage tube 61B Mechanical part 61C Mechanical pencil lead
62 Solid core refill
62A Solid core 62B Cylindrical part 62C Connection part
62D Stopper 62E Stopper hole 62F Connection part
62G long slit 62H short slit 62I connection hole
62J Elastic part 62K Connecting part 62L Insertion part
63 Eraser refill
63A Eraser 63B Cylinder 63C Connection
63D Stopper 63E Stopper hole 63G Long slit
63H Short slit 63I Connection hole 63J Half cylinder part
63L insertion tube
64 Rubber refill for friction
64A Friction rubber 64B Cylinder part 64C Connection part
64D Stopper 64E Front cylinder 64F Rear cylinder
64G Middle cylinder 64H Interposed part 64I Front insertion part
64J Sliding part 64K Reduced diameter part 64L Rear insertion part
64M Flange 64N Front step 64O Rear step
64P slit 64Q spring
65 Coated erasing material A Black particles B Graphite particles C Carbon nanoparticles

Claims (2)

In addition to accommodating multiple cursive letters in the barrel,
a plurality of sliding windows formed longitudinally from near the rear end of the barrel toward the tip;
a functional part attached to the rear end of the shaft cylinder;
a knock bar connected to the rear ends of the plurality of cursive letters;
A writing instrument comprising a slide button formed as a part of the knock bar and protruding outward from the slide window,
At least two of the plurality of writing fonts and the functional part are each formed as an erasing tool that is any one of an eraser, a friction rubber, and a coated erasing material,
Each of the erasing tools corresponds to erasing a drawn line by one of the plurality of cursives other than those formed as the erasing tool, and
At least one of the plurality of cursive writing has a structure in which the cylindrical erasing tool is inserted inside a cylindrical part,
A plurality and the same number of stopper holes are formed on the front and back surfaces of the cylindrical portion, respectively,
A writing instrument characterized in that a stopper having a T-shaped cross section along the longitudinal direction is inserted into the stopper hole to prevent the eraser from being pushed back by pressure. . In addition to accommodating multiple cursive letters in the barrel,
a plurality of sliding windows formed longitudinally from near the rear end of the barrel toward the tip;
a functional part attached to the rear end of the shaft cylinder;
a knock bar connected to the rear ends of the plurality of cursive letters;
A writing instrument comprising a slide button formed as a part of the knock bar and protruding outward from the slide window,
At least two of the plurality of writing fonts and the functional part are each formed as an erasing tool that is any one of an eraser, a friction rubber, and a coated erasing material,
Each of the erasing tools corresponds to erasing a drawn line by one of the plurality of cursives other than those formed as the erasing tool, and
At least one of the plurality of cursive writing has a structure in which a cylindrical front cylinder and a cylindrical rear cylinder longer than the front cylinder are connected by an intervening part,
The eraser having a cylindrical shape with a middle cylinder inserted therein is inserted into the front cylinder,
The intervening part includes a cylindrical sliding part that is slidably inserted from the rear end of the front cylinder, and a cylindrical sliding part that is located in front of the sliding part and has a slightly smaller outer diameter and is located at the rear end of the middle cylinder. A cylindrical front insertion part that is inserted and fixed, a cylindrical rear insertion part that is inserted from the front end of the rear cylinder and fixed, and a smaller diameter than the sliding part and the rear insertion part. and a cylindrical reduced diameter part on the outer periphery of which the spring is inserted.
By pressing the slide button corresponding to the cursive hand forward along the slide window, the rear cylinder and the intervening part press the middle cylinder forward, and the eraser is exposed from the tip of the shaft cylinder. A writing instrument characterized by the ability to