JP2012006364A - Thermochromic writing utensil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermochromic writing utensil of which a pen tip can be sealed tightly by a cap, and of which a manufacturing cost can be suppressed low by reducing the number of components of the cap in spite of that the cap includes a ring-like seal part and friction part.SOLUTION: The cap 4 is structured of a cap body 5 of which front and rear ends are opened, and a closed body 6 which is arranged on a front end part of the cap body 5, is formed of elastic material, and closes the front end of the cap body 5. The ring-like seal part 51 is integrally formed on an inner surface of the cap body 5. The pen tip 31 is sealed tightly by fitting the ring-like seal part 51 to a pen tip side outer surface of a writing utensil body 2. The closed body 6 is projected forward than the front end of the cap body 5. A front end part of the closed body 6 is the friction part 7 that is formed of elastic material which frictions handwriting with thermochromic ink and can thermally discolor the handwriting by the generated frictional heat.

Description

The present invention relates to a thermochromic writing instrument. More specifically, a heat provided with a writing instrument body containing a thermochromic ink therein and having a nib capable of discharging the thermochromic ink at one end, and a cap attachable to the nib side of the writing instrument body. It relates to a discoloring writing instrument.

Conventionally, Patent Document 1 discloses a writing instrument cap in which a head member is fitted and fixed to a rear end portion of a cap body, and an inner cap is fitted and fixed to an inner surface of the cap body. Further, in Patent Document 1, an annular seal portion that can be airtightly fitted to the outer surface of the writing instrument main body is formed on the inner surface of the inner cap of the bottomed cylindrical body, and the head member formed of an elastic material. However, it is described that it is a frictional color changing member that rubs the surface of a thermochromic handwriting to thermally change the handwriting.

JP 2009-286065 A

In Patent Document 1, the cap is composed of at least three parts, that is, a cap body and two kinds of parts (head member and inner cap) attached to the cap body, and the number of parts is large, resulting in an increase in manufacturing cost. The

The present invention solves the above-mentioned conventional problems, the pen tip can be sealed by the cap, and the number of parts of the cap is reduced even though the cap includes the annular seal portion and the friction portion. It is an object of the present invention to provide a thermochromic writing instrument that can keep the manufacturing cost low.
Another object of the present invention is to provide a thermochromic writing instrument capable of easily and reliably frictionally discoloring the handwriting by the thermochromic ink.
Another object of the present invention is to provide a thermochromic writing instrument that can reliably and easily close the front end of the cap body.
Another object of the present invention is to provide a thermochromic writing instrument capable of obtaining a reliable airtight engagement with the pen tip side outer surface of the writing instrument body.
In the present invention, “front” refers to the closed side of the cap and the pen point side of the writing instrument body. In the present invention, “rear” refers to the opening side of the cap and the non-pen tip side of the writing instrument body.

The first invention of the present application is a writing instrument body 2 that contains a thermochromic ink inside and has a nib 31 capable of discharging the thermochromic ink at one end, and is attached to the nib side of the writing instrument body 2 A thermochromic writing instrument provided with a cap 4 capable of being provided, wherein the cap 4 is provided at a front end portion of the cap main body 5 with the front end and the rear end open, and the cap main body 5 A closing body 6 made of an elastic material that closes the front end, and an annular seal portion 51 is integrally formed on the inner surface of the cap body 5, and the annular seal portion 51 is fitted to the pen tip side outer surface of the writing instrument body 2. The pen tip 31 is sealed by causing the closure body 6 to protrude forward from the front end of the cap body 5, and the front end portion of the closure body 6 is rubbed against the handwriting by the thermochromic ink. Friction heat generated in該筆 trace possible thermochromic may be a requirement that the friction part 7 made of the elastic material.

According to the thermochromic writing instrument 1 of the first invention, the cap 4 can be sealed with the cap 4 by the above-described configuration, and the cap 4 includes the annular seal portion 51 and the friction portion 7. The number of parts can be reduced, the structure becomes simple, and it can be provided at low cost. Furthermore, the thermochromic writing instrument 1 of the first invention has the above-described configuration in which the cap 4 is attached to the pen tip side of the writing instrument body 2 or the rear end portion of the writing instrument body 2, or the cap 4 is removed from the writing instrument body 2. In the detached state, the handwriting by the thermochromic ink can be easily and reliably changed in color by the friction portion 7 at the front end of the closing body 6. In the present invention, the closing body 6 and the cap body 5 are preferably fixed by, for example, press fitting, fitting, screwing, engagement, adhesion, welding, two-color molding, or the like.

According to a second invention of the present application, in the thermochromic writing instrument 1 of the first invention, a front portion of the closing body 6 protrudes forward from a front end of the cap body 5, and a rear outer surface of the closing body 6 is The cap body 5 is required to be annularly and airtightly fitted to the inner surface of the front end portion.

The thermochromic writing instrument 1 according to the second aspect of the present invention can reliably and easily close the front end portion of the cap body 5 by the above configuration.

The third invention of the present application requires that the cap body 5 is made of a material harder than the closing body 6.

The thermochromic writing instrument 1 of the third invention can maintain the stable shape and dimensions of the annular seal portion 51 on the inner surface of the cap body 5, and the pen seal side outer surface of the annular seal portion 51 on the inner surface of the cap body 5 and the writing instrument body 2. And a reliable airtight fitting. Examples of the hard material include synthetic resins such as polypropylene and polyethylene. The thermochromic writing instrument 1 according to the third aspect of the present invention is such that when the closing body 6 made of an elastic material is fixed to the inner surface of the cap body 55 by press-fitting, fitting or the like, the closing body 6 and the cap body 5 are firmly connected. Secure fixation.

In the present invention, examples of the annular seal portion 51 include an annular protrusion or an annular smooth surface. In the present invention, the outer surface of the cap body 5 can be provided with a convex portion, a clip that can be sandwiched between the outer surface of the cap body 5 and a pocket, or the like as an integral or separate member.

In the present invention, examples of the elastic material constituting the closing body 6 include elastic synthetic resins (rubber, elastomer), such as silicone resin, SBS resin (styrene-butadiene-styrene copolymer), SEBS. Examples thereof include resins (styrene-ethylene-butadiene-styrene copolymers), fluorine resins, chloroprene resins, nitrile resins, polyester resins, olefin resins, ethylene propylene diene rubber (EPDM), and the like.

The elastic material is preferably made of a low-abrasion elastic material that hardly generates wear debris during friction rather than a high-abrasion elastic material (for example, an eraser).

-Thermochromic ink In the present invention, the thermochromic ink is preferably a reversible thermochromic ink. The reversible thermochromic ink is a heat decoloring type that is decolored by heating from a colored state, a color memory retaining type that reversibly stores a colored state or a decolored state in a specific temperature range, or from a decolored state. Various types such as a heating coloring type that develops color by heating and returns to a decolored state by cooling from the colored state can be used alone or in combination.

In the present invention, as shown in FIG. 5, the shape of the curve plotting the change in the color density due to the temperature change is contrary to the case where the temperature is raised from the lower temperature side than the color change temperature range, and from the higher temperature side than the color change temperature range. The color changes by following a different path from the case of lowering, and the color development state in the low temperature range below the complete color development temperature (t ₁ ) or the color erase state in the high temperature range above the complete color erase temperature (t ₄ ) It is preferable to apply a color memory retention type thermochromic ink that can be stored and retained in a specific temperature range [temperature range between t _{2 and} t ₃ (substantially two-phase retention temperature range)]. In FIG. 5, ΔH indicates a temperature width (ie, hysteresis width) indicating the degree of hysteresis. When the value of ΔH is small, only one of the two states before and after the color change can exist. When the value of ΔH is large, it is easy to maintain each state before and after the color change.

The substantial two-phase holding temperature range can be set according to the purpose, but in the present invention, the high temperature side discoloration point [complete decoloring temperature (t ₄ )] is 25 ° C. to 95 ° C. (preferably 36 ° C. ˜90 ° C.), and the low temperature side discoloration point [complete color development temperature (t ₁ )] may be set in the range of −30 ° C. to + 20 ° C. (preferably −30 ° C. to + 10 ° C.). It is valid. Accordingly, it is possible to effectively maintain the color exhibited in the normal state (daily life temperature range), and it is possible to easily change the handwriting by the reversible thermochromic ink with the frictional heat generated by the friction body.

The thermochromic writing instrument of the present invention can seal the pen tip with a cap, and the cap has a reduced number of parts, a simple structure, and a low cost, despite the fact that the cap has an annular seal portion and a friction portion. Can be provided.

It is a principal part longitudinal cross-sectional view of the 1st Embodiment of this invention. It is a longitudinal cross-sectional view of the cap of FIG. It is a principal part longitudinal cross-sectional view of the 2nd Embodiment of this invention. It is a longitudinal cross-sectional view of the cap of FIG. It is explanatory drawing which shows the color change behavior of a thermochromic ink.

<First Embodiment>
A first embodiment of the present invention is shown in FIGS.
The thermochromic writing instrument 1 of the present embodiment includes a writing instrument body 2 and a cap 4 that can be attached to the writing instrument body 2.

Writing instrument body The writing instrument body 2 is composed of a barrel 3 having a pen tip 31 at the front end. An ink occlusion body 32 impregnated with thermochromic ink is accommodated in the shaft cylinder 3. The thermochromic ink is ejected from the pen tip 31, and a handwriting (thermochromic handwriting) of the thermochromic ink is obtained on a writing surface such as paper.

The shaft cylinder 3 includes a tapered cylindrical front shaft 3a and a cylindrical rear shaft 3b connected to a rear end portion of the front shaft 3a. On the pen tip side outer surface of the shaft tube 3 (the outer surface of the front shaft 3a), an annular seal portion 33 made of an annular protrusion is integrally formed. The front shaft 3a and the rear shaft 3b are formed of a molded body of synthetic resin (for example, polypropylene resin).

-Nib 31 The nib 31 is made of a fiber resin processed body. In addition to this, the nib 31 includes a synthetic resin porous foam, a synthetic resin extrusion molded body having an ink guide path in the axial direction, a brush pen body, and the like.

Ink occlusion body The ink occlusion body 32 may be formed of a member having continuous pores that can be impregnated with ink (that is, a porous material). Examples include a processed body, a felt resin processed body, a felt needle punch processed body, and an open-cell body of a synthetic resin. Further, the ink occlusion body 32 may be provided with an outer skin made of a synthetic resin film or the like on the outer peripheral surface thereof. The rear end portion of the pen tip 31 is pierced and connected to the front surface of the ink occlusion body 32.

- thermochromic ink the thermochromic ink is, the low-temperature side color change point (complete coloring temperature t ₁₎ is set to any temperature in the range of -30 ℃ ~-10 ℃, the high temperature side color change point (complete decoloring temperature A reversible thermochromic ink in which t ₄ ) is set to an arbitrary temperature in the range of 60 ° C. to 80 ° C. and the hysteresis width ΔH is in the range of 40 ° C. to 60 ° C. is employed.

The cap cap 4 includes a cap body 5 and a closing body 6 that is press-fitted and fixed to the front end portion of the cap body 5.

Cap body The cap body 5 is composed of a bottomed cylindrical body having a front end and a rear end opened. The cap body 5 is made of a molded body of synthetic resin (for example, polypropylene resin, polyethylene resin, polyethylene terephthalate resin, polycarbonate resin, etc.). The cap body 5 is formed of a material harder than the material of the closing body 6. An annular seal portion 51 made of an annular protrusion is integrally formed on the inner surface of the rear portion of the cap body 5. An inner surface of the front end opening of the cap body 5 includes an attachment portion 52 to which the closing body 6 is attached, and a step portion 53 that is connected to the rear end of the attachment portion 52.

Closed body The closed body 6 is formed of a cylindrical body having a convex curved front end. The closure body 6 is entirely formed of an elastic material (for example, polyester elastomer, silicone resin, SBS resin, SEBS resin, etc.). A rear end portion of the closing body 6 has a surface perpendicular to the axis.

The assembly of the closure body and the cap body The closure body 6 is inserted from the front end opening of the cap body 5, and the outer surface of the rear end portion of the closure body 6 is annular to the inner surface of the front end portion of the cap body 5 (the inner surface of the mounting portion 52). And the rear end of the closing body 6 is brought into contact with the stepped portion 53 on the inner surface of the cap body 5. At this time, the front end portion of the closing body 6 projects forward from the front end of the cap body 5.

-Cap mounting When the cap 4 is mounted on the pen tip side of the writing instrument body 2, the annular seal portion 51 on the inner surface of the cap body 5 and the annular seal portion 33 on the outer surface of the shaft cylinder 3 get over and airtightly fit, and the pen tip 31. Is sealed by the cap 4.

Friction part The front end part of the closing body 6 (that is, the front end part having a convex curved surface) protrudes forward from the front end of the cap body 5, and the outer surface of the front end part of the closing body 6 is made of the elastic material. 7 In the state where the cap is attached to the pen tip side of the writing instrument body 2 or the rear end portion of the writing instrument body 2 or the state where the cap 4 is detached from the writing instrument body 2, the friction portion 7 at the front end portion of the cap 4 is used. The handwriting with the thermochromic ink can be easily and reliably changed in color by friction.

<Second Embodiment>
A second embodiment of the present invention is shown in FIGS.
The thermochromic writing instrument 1 of the present embodiment includes a writing instrument body 2 and a cap 4 that can be attached to the writing instrument body 2.

Writing instrument body The writing instrument body 2 is composed of a barrel 3 having a pen tip 31 at the front end. An ink occlusion body 32 impregnated with thermochromic ink is accommodated in the shaft cylinder 3. The thermochromic ink is ejected from the pen tip 31, and a handwriting (thermochromic handwriting) of the thermochromic ink is obtained on a writing surface such as paper.

The shaft cylinder 3 includes a tapered cylindrical front shaft 3a and a cylindrical rear shaft 3b connected to a rear end portion of the front shaft 3a. On the pen tip side outer surface of the shaft cylinder 3 (the outer surface of the front shaft 3a), an annular seal portion 33 made of an annular protrusion or an annular smooth surface, and an engagement protrusion 34 (for example, an annular protrusion) positioned rearward of the annular seal portion 33 Protrusions or a plurality of dispersed protrusions) are integrally formed. The front shaft 3a and the rear shaft 3b are formed of a molded body of synthetic resin (for example, polypropylene resin).

-Nib 31 The nib 31 is made of a fiber resin processed body. In addition to this, the nib 31 includes a synthetic resin porous foam, a synthetic resin extrusion molded body having an ink guide path in the axial direction, a brush pen body, and the like.

Ink occlusion body The ink occlusion body 32 may be formed of a member having continuous pores that can be impregnated with ink (that is, a porous material). Examples include a processed body, a felt resin processed body, a felt needle punch processed body, and an open-cell body of a synthetic resin. Further, the ink occlusion body 32 may be provided with an outer skin made of a synthetic resin film or the like on the outer peripheral surface thereof. The rear end portion of the pen tip 31 is pierced and connected to the front surface of the ink occlusion body 32.

- thermochromic ink the thermochromic ink is, the low-temperature side color change point (complete coloring temperature t ₁₎ is set to any temperature in the range of -30 ℃ ~-10 ℃, the high temperature side color change point (complete decoloring temperature A reversible thermochromic ink in which t ₄ ) is set to an arbitrary temperature in the range of 60 ° C. to 80 ° C. and the hysteresis width ΔH is in the range of 40 ° C. to 60 ° C. is employed.

The cap cap 4 includes a cap body 5 and a closing body 6 that is press-fitted and fixed to the front end portion of the cap body 5.

Cap body The cap body 5 is composed of a bottomed cylindrical body having a front end and a rear end opened. The cap body 5 is made of a molded body of synthetic resin (for example, polypropylene resin, polyethylene resin, polyethylene terephthalate resin, polycarbonate resin, etc.). The cap body 5 is formed of a material harder than the material of the closing body 6. The cap body 5 includes a small-diameter portion 5a and a large-diameter portion 5b integrally connected to the rear of the small-diameter portion 5a. An inner surface of the front end portion of the small-diameter portion 5 a includes an attachment portion 52 to which the closing body 6 is attached, and a step portion 53 that is connected to the rear end of the attachment portion 52. An annular seal portion 51 (for example, an annular protrusion or an annular smooth surface) is integrally formed on the inner surface of the rear portion of the small diameter portion 5a. An engagement protrusion 54 (for example, an annular protrusion or a plurality of dispersed protrusions) is integrally formed on the rear inner surface of the large diameter portion 5b.

Closed body The closed body 6 is formed of a cylindrical body having a convex curved front end. The closure body 6 is entirely formed of an elastic material (for example, polyester elastomer, silicone resin, SBS resin, SEBS resin, etc.). A rear end portion of the closing body 6 has a surface perpendicular to the axis.

The assembly of the closure body and the cap body The closure body 6 is inserted from the front end opening of the cap body 5, and the outer surface of the rear end portion of the closure body 6 is annular to the inner surface of the front end portion of the cap body 5 (the inner surface of the mounting portion 52). And the rear end of the closing body 6 is brought into contact with the stepped portion 53 on the inner surface of the cap body 5. At this time, the front end portion of the closing body 6 projects forward from the front end of the cap body 5.

-Cap mounting When the cap 4 is mounted on the pen tip side of the writing instrument main body 2, the engaging protrusion 54 on the inner surface of the cap main body 5 and the engaging protrusion 34 on the outer surface of the shaft tube 3 get over and engage with each other. The annular seal portion 51 and the annular seal portion 33 on the outer surface of the shaft tube 3 are airtightly fitted, and the pen tip 31 is sealed by the cap 4.

Friction part The front end part of the closing body 6 (that is, the front end part having a convex curved surface) protrudes forward from the front end of the cap body 5, and the outer surface of the front end part of the closing body 6 is made of the elastic material. 7 In the state where the cap 4 is attached to the pen tip side of the writing instrument body 2 or the rear end portion of the writing instrument body 2, or the cap 4 is detached from the writing instrument body 2, the friction portion 7 at the front end portion of the cap 4 is used. The handwriting with the thermochromic ink can be easily and reliably changed in color by friction.

DESCRIPTION OF SYMBOLS 1 Thermochromic writing instrument 2 Writing instrument main body 3 Shaft cylinder 31 Pen tip 32 Ink occlusion body 33 Annular seal part 34 Engagement protrusion 3a Front shaft 3b Rear axis 4 Cap 5 Cap main body 51 Annular seal part 52 Attachment part 53 Step part 54 Engagement Protrusion 5a Small diameter part 5b Large diameter part 6 Closure 7 Friction part

Claims (3)

A thermochromic writing instrument comprising: a writing instrument body containing a thermochromic ink therein and a pen tip capable of discharging the thermochromic ink at one end; and a cap attachable to the pen tip side of the writing instrument body The cap includes: a cap body having an opening at a front end and a rear end; and a closure body made of an elastic material provided at a front end portion of the cap body and closing the front end of the cap body. An annular seal portion is integrally formed on the inner surface of the main body, and the pen tip is sealed by fitting the annular seal portion to the pen tip side outer surface of the writing instrument main body. The closure body is formed from the front end of the cap main body. Protruding forward, the front end portion of the closing body is a friction portion made of the elastic material capable of rubbing the handwriting with the thermochromic ink and heat-discoloring the handwriting with frictional heat generated at that time. Thermochromic writing instrument and butterflies. The thermochromic writing instrument according to claim 1, wherein a front portion of the closure body projects forward from a front end of the cap body, and a rear outer surface of the closure body is annularly and airtightly fitted to an inner surface of the front end portion of the cap body. The thermochromic writing instrument according to claim 1 or 2, wherein the cap body is made of a harder material than the material of the closing body.

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