JP2020179631A - Thermochromic writing instrument - Google Patents

Abstract

To provide a thermochromic writing instrument capable of preventing an outer surface of a barrel and an outer surface of a friction part from being contaminated and the outer surface of the barrel from being scratched even when it is placed on a horizontal placing surface when not used.SOLUTION: The thermochromic writing instrument includes a barrel 3 in which a thermochromic ink is stored inside and a pen tip 4 capable of discharging the thermochromic ink is provided at a front end, and a cap 8 detachably attached to a pen tip side of the barrel 3. A friction part 7 is disposed at a rear end of the barrel 3. An outer surface of the cap 8 is decreased in a diameter toward a front side. A gravity center G of the thermochromic writing instrument is positioned inside the cap 8 in a state in which the cap 8 is disposed at a pen tip side of the barrel 3. When placing the thermochromic writing instrument on a horizontal placing surface F, the outer surface of the cap 8 is brought into contact with the horizontal placing surface F, and an outer surface of the barrel 3 and an outer surface of the friction part 7 which are located at a rear side of the cap 8 stay in a non-contact state with the horizontal placing surface F.SELECTED DRAWING: Figure 3

Description

The present invention relates to a thermochromic writing instrument.

Conventionally, for example, in Patent Document 1, a writing instrument body containing a heat-discoloring ink, a cap for protecting the writing portion at the front end of the writing instrument body, and a cap provided at the rear end of the writing instrument body are provided for writing with the heat-discoloring ink. A writing instrument including an erasing member that discolors the drawn lines by frictional heat is disclosed.

Japanese Unexamined Patent Publication No. 2016-78418

In the writing instrument of Patent Document 1, when the writing instrument is placed on a horizontal mounting surface such as a desk or a work table when not in use, the outer surface of the shaft cylinder and the erasing member (corresponding to the friction portion of the present application) are placed on the horizontal mounting surface. Contact. Therefore, dirt such as dust on the water-based mounting surface may adhere to the outer surface of the shaft cylinder or the outer surface of the erasing member, or the outer surface of the shaft cylinder (for example, the decorative portion) may be scratched. In particular, when the handwriting on the paper surface is rubbed with the dirty erasing member, the paper surface becomes dirty.

The present invention solves the above-mentioned conventional problems, and when not in use, even when mounted on a horizontal mounting surface, the outer surface of the shaft cylinder and the outer surface of the friction portion become dirty, or the outer surface of the shaft cylinder is covered. It is intended to provide a thermochromic writing instrument that is not likely to be scratched.

In the present invention, "front" refers to the pen tip side of the barrel and the closed side of the cap, and "rear" refers to the tail end side of the barrel and the opening side of the cap.

According to the first invention of the present application, a shaft cylinder 3 having a pen tip 4 containing the heat-discoloring ink inside and capable of discharging the heat-discoloring ink at the front end, and a shaft cylinder 3 attached to and detached from the pen tip side of the shaft cylinder 3. A cap 8 that can be freely attached is provided, and a friction portion 7 is provided at the rear end of the barrel 3, and the friction portion 7 rubs the brush strokes of the heat-discoloring ink, and the frictional heat generated at that time causes the frictional heat. A heat-discoloring writing tool capable of thermally discoloring a brush stroke, in which the outer surface of the cap 8 is reduced in diameter toward the front, and the cap 8 is attached to the pen tip side of the barrel 3 of the heat-discoloring writing tool. When the heat-discoloring writing tool is placed on the horizontal mounting surface F with the center of gravity G located inside the cap 8 and the cap 8 mounted on the pen tip side of the barrel 3, the cap 8 It is a requirement that the outer surface comes into contact with the horizontal mounting surface F, and the outer surface of the barrel 3 behind the cap 8 and the outer surface of the friction portion 7 are in a non-contact state with the horizontal mounting surface F.

According to the above configuration, the thermochromic writing instrument 1 of the first invention is mounted on the horizontal mounting surface F with the cap 8 mounted on the pen tip side when not in use. There is no risk that the outer surface and the outer surface of the friction portion 7 will become dirty or the outer surface of the barrel 3 will be scratched. Further, since the outer surface of the cap 8 whose diameter is reduced toward the front comes into contact with the horizontal mounting surface F, the axis C of the thermochromic writing instrument 1 rises from the horizontal mounting surface F toward the rear (that is, horizontally mounted). The distance from the mounting surface F is increased), and the outer surface of the barrel 3 behind the cap 8 and the outer surface of the friction portion 7 can be easily brought into a non-contact state with the horizontal mounting surface F.

A second invention of the present application is the outer surface of the shaft cylinder 3 behind the cap 8 in a state where the cap 8 is attached to the pen tip side of the shaft cylinder 3 in the thermochromic writing instrument of the first invention. Is reduced in diameter toward the rear, and when the thermochromic writing instrument is placed on the horizontal mounting surface F with the cap 8 attached to the pen tip side of the barrel 3, the friction portion 7 and the horizontal It is a requirement that the gap D between the mounting surface F and the mounting surface F is set to 3 mm or more.

In the second invention, the thermochromic writing instrument 1 has no possibility that the outer surface of the shaft cylinder 3 and the outer surface of the friction portion 7 are further soiled or the outer surface of the shaft cylinder 3 is scratched due to the above configuration.

In the third invention of the present application, in the thermochromic writing instrument of the first or second invention, an ink occlusion body 5 impregnated with a thermochromic ink is housed inside the barrel 3, and the barrel 3 is accommodated. It is a requirement that a length B of 1/2 or more of the total longitudinal dimension A of the ink occlusion body 5 is positioned inside the cap 8 with the cap 8 attached to the pen tip side of the ink storage body 5.

In the thermochromic writing instrument 1 of the third invention, the center of gravity G of the thermochromic writing instrument 1 is positioned inside the cap 8 with the cap 8 attached to the pen tip side of the barrel 3 according to the above configuration. Easy to obtain the configuration.

When not in use, the heat-discolorable writing instrument of the present invention does not have a risk of soiling the outer surface of the shaft cylinder and the outer surface of the friction portion or scratching the outer surface of the shaft cylinder even when placed on a horizontal mounting surface. ..

It is a vertical cross-sectional view of the state which attached the cap to the pen tip side of the embodiment of this invention. It is a vertical cross-sectional view of the state which the cap is removed from the shaft cylinder of FIG. It is a vertical cross-sectional view of the state where the thermochromic writing instrument of FIG. 1 is placed on the horizontal mounting surface.

The thermochromic writing instrument 1 of the embodiment of the present invention is shown in FIGS. 1 to 3. The thermochromic writing instrument 1 of the present embodiment includes a writing instrument main body 2 and a cap 8. The writing instrument main body 2 includes a shaft cylinder 3, an ink storage body 5 housed inside the shaft cylinder 3, a pen tip 4 fixed to the front end of the shaft cylinder 3, and a friction portion fixed to the rear end of the shaft cylinder 3. 7 and.

-Axle cylinder The axle cylinder 3 includes a tubular front shaft 31 and a tubular rear shaft 32 coupled to the rear portion of the front shaft 31. The front shaft 31 is radially outside the tapered portion 31a to which the pen tip 4 is fixed, the front tubular portion 31b integrally connected to the rear of the tapered portion 31a, and the rear end of the front tubular portion 31b. It includes a flange portion 31c that is integrally connected so as to project toward the direction, and a rear cylinder portion 31d that is integrally connected to the rear of the collar portion 31c. The front shaft 31 and the rear shaft 32 are obtained from a molded product of a synthetic resin (for example, polypropylene or the like).

A pen tip mounting hole 31e is provided in the tapered portion 31a of the front shaft 31 in the axial direction. The pen tip 4 is press-fitted and fixed to the pen tip mounting hole 31e. The ink storage body 5 is housed inside the front shaft 31, and the front end portion of the ink storage body 5 and the rear end portion of the pen tip 4 are connected to each other. The rear end of the ink storage body 5 projects rearward from the rear end of the front shaft 31. A contact wall portion 31f is formed behind the pen tip mounting hole 31e on the inner surface of the front shaft 31, and the front end of the ink storage body 5 is brought into contact with the contact wall portion 31f.

Rear axle The rear axle 32 has an outer surface that shrinks in diameter toward the rear. The rear shaft 32 is open at both ends and has an inner hole that penetrates in the axial direction. An annular seal portion 32a and a locking wall portion 32b located behind the annular seal portion 32a are integrally formed on the inner surface of the intermediate portion of the rear shaft 32. The annular seal portion 32a and the outer surface of the inner plug 6 are airtightly fitted in the radial direction, and the locking wall portion 32b and the rear end of the inner plug 6 are brought into axial contact with each other. The friction portion 7 is press-fitted and fixed to the rear end opening of the rear shaft 32. The inner surface of the front portion of the rear shaft 32 and the outer surface of the rear cylinder portion 31d of the front shaft 31 are fixed by airtight fitting. The outer surface of the rear shaft 32 is provided with a decorative portion by transfer printing.

-Pen tip The pen tip 4 is a resin processed body of a synthetic resin (for example, polyester) fiber bundle. The front end of the pen tip 4 is formed in a chisel shape (flea shape). The rear end of the pen tip 4 has a tapered surface that shrinks in diameter toward the rear. The rear end of the pen tip 4 is pierced and connected to the front end of the ink storage body 5.

-Ink storage body The ink storage body 5 is composed of a synthetic resin fiber bundle (for example, a polyester fiber bundle) and a cylindrical outer skin surrounding the outer periphery thereof. The exodermis is made of a synthetic resin cylinder (for example, an extruded polypropylene resin). The ink storage body 5 is impregnated and held with the heat-discoloring ink.

-Heat-changing ink The heat-changing ink uses a heat-changing microcapsule pigment, and is (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) both of the above. An aqueous ink composition containing a reversible thermochromic microcapsule pigment containing a reversible thermochromic composition comprising a reaction medium for determining the occurrence temperature of a color reaction is adopted. Examples of the heat-discoloring ink include a type that decolorizes by heating and a type that develops color by heating.

-Inner stopper The inner stopper 6 is obtained from a molded product of a synthetic resin (for example, polypropylene). The inner plug 6 is a bottomed cylinder having an open front end and a closed rear end. The outer surface of the inner plug 6 is airtightly fitted with the annular seal portion 32a on the inner surface of the rear shaft 32. The rear end of the inner plug 6 is axially locked to the locking wall portion 32b on the inner surface of the rear shaft 32. The front end of the inner plug 6 is brought into contact with the rear end (rear end of the outer skin) of the ink storage body 5. The inner plug 6 blocks the ventilation between the rear end opening of the rear shaft 32 and the inside of the rear shaft 32.

-Friction portion The friction portion 7 includes a cylindrical small diameter portion 71 and a convex curved large diameter portion 72 integrally connected to the rear of the small diameter portion 71. The small diameter portion 71 is press-fitted and fixed to the rear end opening of the rear shaft 32, and the large diameter portion 72 projects rearward from the rear end of the rear shaft 32. The maximum outer diameter of the portion (large diameter portion 72) protruding rearward from the rear end of the rear shaft 32 is set to be equal to or less than the outer diameter of the rear end of the rear shaft 32.

Examples of the material constituting the friction portion 7 include elastic synthetic resins (rubber, elastomer), and examples thereof include silicone resin, SBS resin (styrene-butadiene-styrene copolymer), and SEBS resin (styrene-ethylene). -Butadiene-styrene copolymer), fluororesin, chloroprene resin, nitrile resin, polyester resin, olefin resin, ethylene propylene diene rubber (EPDM) and the like. The friction portion 7 is not made of a highly wear-resistant elastic material (for example, an eraser or the like), but is made of a low-wear elastic material that does not generate wear debris during friction. The friction portion 7 can also be integrally formed with the shaft cylinder 3 (rear shaft 32) by two-color molding. Further, the entire axle tube 3 (the entire rear axle 32) may be integrally formed of an elastic synthetic resin, and the friction portion 7 may be provided at the rear end of the axle tube 3 (rear end of the rear axle 32).

The cap cap 8 includes a cylindrical cap body 81, a clip 81b integrally formed on the outer surface of the cap body 81, and a seal cylinder 82 fixed inside the cap body 81.

The outer surface of the cap body 81 has a diameter-reduced shape portion 81a having a shape in which the diameter is reduced toward the front (that is, a shape in which the outer diameter becomes smaller toward the front). Examples of the shape of the reduced diameter portion 81a include a tapered surface, a convex curved surface, and a concave curved surface. The cap body 81 is obtained by molding a synthetic resin (for example, polycarbonate). The seal cylinder 82 is obtained by molding a synthetic resin (for example, polypropylene). The seal cylinder 82 is a bottomed cylinder having a closed front end and an open rear end. When the cap 8 is attached to the pen tip side, the inward projection 81c on the inner surface of the cap body 81 and the outward projection 31g on the outer surface (outer surface of the front shaft 31) of the shaft cylinder 3 get over and fit (retaining fitting). At the same time, the inner surface of the seal cylinder 82 and the outer surface of the shaft cylinder 3 on the pen tip side (outer surface of the front shaft 31) are hermetically fitted in an annular shape. An object to be held such as a pocket can be sandwiched between the clip 81b and the outer surface of the cap body 81.

FIG. 3 shows a state in which the thermochromic writing instrument 1 of the present embodiment is placed on the horizontal mounting surface F.
The center of gravity G of the entire heat-discolorable writing instrument 1 is located inside the cap (inward in the radial direction of the reduced diameter shape portion 81a) when the cap 8 is attached to the pen tip side. The length B in the longitudinal direction of the portion where the ink storage body 5 is located inside the cap when the cap 8 is attached to the pen tip side is 1/2 or more (50% or more) of the total longitudinal dimension A of the ink storage body 5. ) Has a length. When the thermochromic writing instrument 1 is placed on the horizontal mounting surface F, the clip 81b comes into contact with the horizontal mounting surface F, and the reduced diameter portion 81a on the outer surface of the cap 8 comes into contact with the horizontal mounting surface F. The axis C of the thermochromic writing instrument 1 is separated from the horizontal mounting surface F as it faces rearward. The outer surface of the axle cylinder 3 (the outer surface of the rear shaft 32) and the outer surface of the friction portion 7 are in a non-contact state with the horizontal mounting surface F. The gap D between the friction portion 7 and the horizontal mounting surface F is set to 3 mm or more.

In the thermochromic writing instrument 1 of the present embodiment, the outer surface of the cap 8 is reduced in diameter toward the front, and the center of gravity G of the thermochromic writing instrument 1 is attached to the pen tip side of the barrel 3 with the cap 8 attached. When the heat-discoloring writing instrument 1 is placed on the horizontal mounting surface F with the cap 8 mounted on the pen tip side of the barrel 3 located inside the cap 8, the outer surface of the cap 8 is placed horizontally. The cap 8 is attached to the pen tip side when not in use because it comes into contact with the surface F and the outer surface of the barrel 3 behind the cap 8 and the outer surface of the friction portion 7 are in a non-contact state with the horizontal mounting surface F. Even if it is placed on the horizontal mounting surface F in this state, there is no risk that the outer surface of the shaft cylinder 3 and the outer surface of the friction portion 7 will be soiled or the outer surface of the shaft cylinder 3 will be scratched. Further, since the outer surface (diameter-reduced shape portion 81a) of the cap 8 whose diameter is reduced toward the front comes into contact with the horizontal mounting surface F, the axis of the thermochromic writing instrument 1 is moved from the horizontal mounting surface F toward the rear. As it rises, the outer surface of the barrel 3 behind the cap 8 and the outer surface of the friction portion 7 can be easily brought into a non-contact state with the horizontal mounting surface F.

In the thermochromic writing instrument 1 of the present embodiment, with the cap 8 attached to the pen tip side of the barrel 3, the outer surface of the barrel 3 behind the cap 8 is reduced in diameter toward the rear, and the barrel 3 is reduced in diameter. When the heat-discoloring writing instrument is placed on the horizontal mounting surface F with the cap 8 attached to the pen tip side, the gap D between the friction portion 7 and the horizontal mounting surface F is set to 3 mm or more. As a result, there is no possibility that the outer surface of the shaft cylinder 3 and the outer surface of the friction portion 7 are further soiled or the outer surface of the shaft cylinder 3 is scratched.

In the thermochromic writing instrument 1 of the present embodiment, an ink occlusion body 5 impregnated with a thermochromic ink is housed inside the barrel 3, and the cap 8 is attached to the pen tip side of the barrel 3. Then, the length B of 1/2 or more (50% or more) of the total longitudinal dimension A of the ink occlusion body 5 is positioned inside the cap 8, so that the cap 8 is attached to the pen tip side of the barrel 3. It is easy to obtain a configuration in which the center of gravity G of the thermochromic writing instrument 1 is located inside the cap 8 in this state.

1 Thermal discoloration writing tool 2 Writing tool body 3 Shaft cylinder 31 Front shaft 31a Tapered part 31b Front side cylinder part 31c Flange part 31d Rear side cylinder part 31e Pen tip mounting hole 31f Contact wall part 31g Outward protrusion 32 Rear shaft 32a Circular seal part 32b Locking wall 4 Pen tip 5 Ink storage body 6 Inner plug 7 Friction part 71 Small diameter part 72 Large diameter part 8 Cap 81 Cap body 81a Reduced diameter shape part 81b Clip 81c Inward protrusion 82 Seal cylinder A Total length of ink storage body B Length of ink occlusion body located inside the cap C Axis D Gap G Center of gravity F Horizontal mounting surface

Claims (3)

A shaft cylinder containing a heat-discoloring ink inside and having a pen tip capable of ejecting the heat-discoloring ink at the front end, and a cap detachably attached to the pen tip side of the shaft cylinder are provided. A heat-discoloring writing instrument in which a friction portion is provided at the rear end of the barrel, and the friction portion rubs the brush stroke of the heat-discoloring ink, and the brush stroke can be thermally discolored by the frictional heat generated at that time.
The outer surface of the cap is reduced in diameter toward the front, and the center of gravity of the thermochromic writing instrument is located inside the cap with the cap attached to the pen tip side of the barrel, and the pen tip side of the barrel. When the thermochromic writing instrument is placed on the horizontal mounting surface with the cap attached, the outer surface of the cap comes into contact with the horizontal mounting surface, and the outer surface of the barrel and the friction behind the cap. A thermochromic writing instrument characterized in that the outer surface of the part is in a non-contact state with the horizontal mounting surface. With the cap attached to the pen tip side of the barrel, the outer surface of the barrel behind the cap is reduced in diameter toward the rear, and the cap is attached to the pen tip side of the barrel. The thermal discoloration writing instrument according to claim 1, wherein when the thermochromic writing instrument is placed on the horizontal mounting surface, the gap between the friction portion and the horizontal mounting surface is set to 3 mm or more. An ink occlusion body impregnated with heat-discoloring ink is housed inside the shaft tube, and with the cap attached to the pen tip side of the shaft tube, 1/2 of the total longitudinal dimension of the ink storage body. The thermochromic writing instrument according to claim 1 or 2, wherein the above length is located inside the cap.

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