JP7145747B2 - compound writing instrument - Google Patents

Description

The present invention relates to compound writing instruments. More particularly, it relates to a compound writing instrument that forms handwriting that is erased by heating.

Currently, a large number of writing instruments containing ink that can be erased by heating are sold, and there are also commercially available multi-core writing instruments that contain a plurality of refill-type writing bodies with different colors of ink.
The multi-core writing instrument is excellent in portability and convenience because it accommodates a plurality of ballpoint pen refills containing inks of different hues in pen tips of the same ball diameter (see, for example, Patent Documents 1 to 3). ).

JP 2013-49192 A JP 2018-89947 A JP 2018-89782 A

Although the above-mentioned multi-core writing instruments differ in the mechanism of appearance and retraction of the writing body, they are all capable of forming handwriting of multiple colors by selecting and writing with a refill containing the desired hue ink with a single writing instrument. By rubbing each handwriting with the friction body, all handwritings are erased in the same temperature zone.
Therefore, when it is used for overwriting, even if it is desired to erase any of the handwritings, none of the handwritings can be left and the color is erased all at once.

INDUSTRIAL APPLICABILITY The present invention is capable of erasing handwritings for each cursive body without erasing all handwritings at once even when erasing handwritings after overwriting, and is applicable to a wide range of uses and is convenient. To provide an excellent multiple writing instrument.

The present invention is a compound writing instrument using two or more types of writing bodies, wherein at least two of the writing bodies use a thermochromic ink composition that becomes decolorized by heating, and each thermochromic It is required that the ink compositions have different decoloring temperatures.
Further, each thermochromic ink composition has a discoloration temperature (T _A < T _B ) with a discoloration temperature difference of 5° C. or more, and the thermochromic ink composition has (a) electron-donating coloration (b) an electron-accepting compound; and (c) a reaction medium for controlling the color reaction of the above (a) and (b). It is required to use discoloration pigments.
Further, it is required that the writing material is a marking pen using ink having a decoloring temperature _TA and a ballpoint pen using ink having a decoloring temperature _TB .
Furthermore, the writing material is a ball-point pen _A using ink having a decoloring temperature TA and a ball-point pen _B using ink having a decoloring temperature TB, the ball diameter DA of the ball-point pen _A and the ball of the ball-point pen B The discriminating means is provided for judging whether the diameter D _B satisfies D _A <D _B and whether the decoloring temperature of the ink contained in each cursive body is high (T _B ) or low (T _A ). is required.
Further, it comprises a friction member that discolors the handwriting by the writing body by friction heat, and the friction member consists of two types, one of which generates friction heat in the range of T _A to T _B due to friction with the paper surface. and the other generates frictional heat of _TB or more.

According to the present invention, overwriting can be performed with a writing body containing inks having different erasing temperatures using a single writing implement, so that even when erasing handwriting after overwriting, all handwriting can be erased at once. It is possible to decolor the handwriting for each cursive style. Therefore, it is possible to provide a dual writing instrument that can be used in a wide range of applications and has excellent convenience.

4 is a graph illustrating hysteresis characteristics in the color density-temperature curve of a reversible thermochromic composition. It is a vertical cross-sectional explanatory view showing an embodiment of a compound writing instrument of the present invention. It is a vertical cross-sectional explanatory view showing another embodiment of the compound writing instrument of the present invention. It is a vertical cross-sectional explanatory view showing another embodiment of the compound writing instrument of the present invention.

As the thermochromic ink composition contained in the writing material, any conventional general-purpose ink that can be decolored or discolored by heating can be applied. The colorants to be incorporated in the ink include (a) an electron-donating color-forming organic compound, (b) an electron-accepting compound, and (c) a reaction medium that determines the temperature at which the color reaction occurs between the two. It is preferable to use a reversible thermochromic composition containing at least the three essential components of (1), and particularly effective is a microcapsule pigment obtained by encapsulating the reversible thermochromic composition in microcapsules.

Examples of the reversible thermochromic composition include those described in Japanese Patent Publication No. 51-44706, Japanese Patent Publication No. 51-44707, Japanese Patent Publication No. 1-29398, etc. It changes color before and after, exhibits a discolored state in a temperature range above the high-temperature side color change point, and a colored state in a temperature range below the low-temperature side color change point. The other state is maintained as long as the heat or cold required to develop that state is applied, but returns to the state exhibited at room temperature when the heat or cold is no longer applied, and the hysteresis width is A reversible thermochromic composition having a relatively small characteristic (ΔH of 1° C. or more and 7° C. or less) can be exemplified, and a heat-discolorable microcapsule pigment obtained by encapsulating this in microcapsules can be applied.

Furthermore, as the reversible thermochromic composition, a relatively large amount described in JP-B-4-17154, JP-A-7-179777, JP-A-7-33997, JP-A-8-39936, etc. Those that exhibit hysteresis characteristics (ΔH value is 8 ° C. or higher and 50 ° C. or lower), JP 2006-137886, JP 2006-188660, JP 2008-45062, JP 2008-280523, etc. can be exemplified by those exhibiting a large hysteresis characteristic described in . When the hysteresis characteristic is large, the shape of the curve plotting the change in color density due to temperature change is such that the temperature rises from the lower temperature side than the discoloration temperature range and decreases from the higher temperature side than the discoloration temperature range. It means that the color changes along a path that differs greatly depending on the case. Such a reversible thermochromic composition has a color memory property in a specific temperature range in a color development state in a low temperature range below the complete color development temperature or in a color disappearance state in a high temperature range above the complete color disappearance temperature, Heat-erasable microcapsule pigments enclosing them can also be applied.

Specifically, the reversible thermochromic composition having color memory is a temperature at which the complete color development temperature can be obtained only in a freezer room, a cold region, or the like, that is, -50 ° C. or higher and 0 ° C. or lower, preferably -40 ° C. or higher and -5 ° C. or lower, more preferably -30 ° C. or higher and -10 ° C. or lower, and the temperature at which the complete color disappearance temperature is obtained by the frictional heat of the friction body, that is, 50 ° C. or higher and 95 ° C. or lower, preferably 50 ° C. or higher and 90 ° C. or lower, more preferably 60 ° C. or higher and 80 ° C. or lower, and the ΔH value is specified as 40 ° C. or higher and 100 ° C. or lower, it functions effectively to maintain the color exhibited in the normal state (daily life temperature range). You can list what you can do.

When microcapsule pigments are used, those having an average particle diameter of, for example, 0.05 μm or more and 5.0 μm or less, preferably 0.1 μm or more and 4.0 μm or less, more preferably 0.5 μm or more and 3.0 μm or less are used for writing. It is suitable in terms of performance and handwriting density. Furthermore, for the purpose of more efficiently exhibiting the decoloring performance using the friction body of the present invention, when the average particle size of the microcapsule pigment is 2.0 μm or more, chemical decoloring due to frictional heat Since decoloring (discoloration) using physical erasing by adsorption and peeling becomes possible, it is highly effective for irreversible erasing and discoloration. In addition, the average particle diameter is determined by determining the particle region using the image analysis type particle size distribution measurement software "Macview" manufactured by Mountec, and calculating the projected area circle equivalent diameter (Heywood diameter) from the area of the particle region. , is the value measured as the average particle diameter of particles equivalent to a sphere of equal volume based on that value.

In addition, when the particle diameter of all or most of the particles exceeds 0.2 μm, a particle size distribution measuring device (manufactured by Beckman Coulter Co., Ltd., product name: Multisizer 4e) is used to measure equivolumetric spheres by the Coulter method. It is also possible to measure the average particle size as the average particle size of the particles of.

Further, as the colorant component, dyes, general pigments, and the like can be used in order to impart a desired hue to handwriting without thermal discoloration. For example, as dyes, acid dyes, basic dyes, direct dyes, and the like can be used. General pigments include inorganic pigments such as carbon black and ultramarine blue, organic pigments such as copper phthalocyanine blue and benzidine yellow, and dispersed pigment products that are stably dispersed in a medium using surfactants. be done. In addition, metallic luster pigments such as metal powders and pearl pigments, fluorescent pigments, phosphorescent pigments, and special pigments such as titanium dioxide can also be used. These coloring components may be used in combination with the microcapsule pigment described above, or may be included in the microcapsule pigment described above.

Various additives can also be added to the thermochromic ink as necessary. In the case of water-based inks, conventionally applied pH adjusters, rust inhibitors, antiseptics or anti-mold agents, wetting agents, antifoaming agents, surfactants, lubricants, fixing agents such as resins, shear thinning agents, etc. Viscosity-imparting agents, anti-drying agents for nib, anti-sagging agents, etc. can be added. In the case of oil-based inks, conventionally applied viscosity modifiers, preservatives, rust inhibitors, antifoaming agents, lubricants, dispersants, anti-scratching agents, anti-leaking agents, surfactants, etc. are added. can do.

Discoloration of the thermochromic ink will be described with reference to FIG.
The ink using the reversible thermochromic pigment is completely colored when it reaches the complete color development temperature (t ₁ ) due to the temperature decrease from the color development state, and the complete color development temperature (t ₄ ), the color is completely erased.
Specifically, in FIG. 1, the hysteresis characteristic in the color density-temperature curve is represented by the color density on the vertical axis and the temperature on the horizontal axis. Changes in color density due to temperature changes progress along the arrows. Here _, t4 is the point indicating the density at the temperature at which the color reaches a completely decolored state ₍ hereinafter referred to as the complete decoloring temperature), and t3 is the temperature at which the color begins to be decolored (hereinafter referred to as the decoloring start temperature). ), t2 is the _point indicating the density at the temperature at which color development starts ₍ hereinafter referred to as the color development start temperature), and t1 is the temperature at which the color is completely developed (hereinafter referred to as the complete color development temperature (referred to as ).
In addition, the vertical distance between the upper straight line between t ₁ and t ₃ and the lower straight line between t ₂ and t ₄ is a scale showing the color change contrast, and the vertical line between t ₁ and t ₂ and the vertical line between t ₃ and t The distance between the vertical line and the median value between ₄ is the temperature width indicating the degree of hysteresis (hereinafter referred to as hysteresis width ΔH), and the larger the ΔH value, the easier it is to maintain each state before and after discoloration. .
Here, the difference between t4 and t3 _, or the difference between _t2 and t1 ₍ Δt) is _a measure of the color change sensitivity.
The _decoloring temperature of the thermochromic ink composition in the present invention is basically the complete _decoloring temperature _t4 . It says the temperature at which it becomes impossible.

In the present invention, two or more types of writing bodies are used, at least two of the writing bodies contain the above-described thermochromic ink composition that becomes decolorized by heating, and each thermochromic ink composition is erasable. Consists of different color temperatures. In particular, the discoloration temperature of each thermochromic ink composition is a discoloration temperature difference of 5° C. or more [that is, the discoloration temperature of each thermochromic ink composition is _TA , _TB ( _TA < _TB ), T _B −T _A ≧5° C.] is preferable. In this case, after overwriting with each ink, by heating the overwritten part, all the handwriting will not be erased at once, but one will be erased and the other handwriting will remain. It becomes possible to decolor the handwriting. Therefore, it is possible to configure a writing utensil excellent in convenience that can be used in a wide range of applications.

As the form of the multiple writing instrument using the writing body containing the thermochromic ink, there is a retractable form in which two or more refills can be stored and a desired refill can be selectively retracted, and a pen tip of a different form is attached to the barrel. Either a double-headed form in which a nib that draws out different hues of ink is attached to both ends of the barrel, or a retractable double-headed form in which a writing body is combined behind a retractable writing instrument. good too.
The retractable form includes a retractable mechanism such as a knock type, a rotary type, a slide type, or a combination of these, and a form in which the nib of a cursive body housed in the barrel can be retracted by operation. is applicable. Also, in the double-headed form, a form provided with a cap covering the nib (tip) is preferable.

Examples of the writing material include marking pens, ballpoint pens, fountain pens, and the like, and if necessary, a retractable solid writing instrument or the like can also be used.
As the marking pen, for example, a marking pen tip such as a fiber tip, a felt tip, a plastic tip, or a metal tip is attached to the tip of the writing tip, and the ink is stored in the ink occluding body made of the fiber bundle accommodated in the barrel. A structure in which ink is impregnated and supplied to the writing tip, ink is stored directly inside the barrel, and a predetermined amount of ink is supplied to the writing tip by interposing a comb groove-like ink flow rate adjusting member or an ink flow rate adjusting member consisting of a fiber bundle. and a marking pen having a structure in which ink is directly stored in the barrel and a predetermined amount of ink is supplied to the writing tip by a valve mechanism.

A ball-point pen has, for example, an ink containing tube filled with an ink composition in a barrel, the ink containing tube communicating with a tip having a ball attached to the tip thereof, and an end face of the ink to prevent the ink from flowing back. A structure in which the preventive body is in close contact, a tip is connected to the tip of the barrel, the ink composition is directly filled in the barrel, and an ink backflow preventive body is in close contact with the end surface of the ink, and is housed inside the barrel. A structure in which ink is impregnated in an ink occluding body made up of a fiber bundle to supply ink to the tip, and a predetermined amount of ink is supplied to the tip by interposing a comb groove-shaped ink flow rate adjusting member or an ink flow rate adjusting member made up of a fiber bundle. A ball-point pen or the like having a structure that

For example, when a marking pen containing ink having a decoloring temperature T _A and a ballpoint pen containing ink having a decoloring temperature T _B are used as the writing bodies in the multiple writing instrument, normal writing by each writing body, In addition to erasing, when applying to learning applications such as memorization where characters are written in a notebook with a ballpoint pen and the handwriting is highlighted with a marking pen, when you want to erase the highlighted part after memorization etc. It is possible to erase only the highlighted part while leaving it as it is.

Further, when using a ball-point pen A containing ink with a decoloring temperature T _A and a ball-point pen B containing ink with a decoloring temperature T _B as cursive bodies, in addition to normal writing and erasing with each cursive body, When applied to a draft fair copy application in which a ballpoint pen A is used to write an address as a draft on a postcard or the like, and the handwriting is traced with a ballpoint pen B, when it is desired to erase the draft part after tracing, the draft can be written while leaving the draft. Only part of it can be erased.
Furthermore, by setting the ball diameter D A of the ball-point pen _A and the ball diameter D _B of the ball-point pen B to D _A <D _B , the ball-point pen A for rough drafts can be applied to the above-mentioned applications for draft characters in fine characters and neat characters in bold characters. It is possible to clearly leave clean letters without conspicuous handwriting dents due to the ball and unerased drafts.

The compound writing instrument can also be provided with identification means for determining whether the decoloring temperature of the ink contained in each writing body is high (T _B ) or low (T _A ). Since the decoloring temperature of the ink can be confirmed by the identifying means without erasing the handwriting, it is possible to easily select the desired writing without removing the cap or protruding the writing.
As the identification means, any structure that can be visually identified or touched can be used, such as attaching a figure or a symbol or providing a mark having a different color or shape.

A friction member that heats and discolors by rubbing the handwriting using each writing body can be used in the compound writing instrument.
As the friction member, an elastic body such as an elastomer or a soft resin, which is rich in elasticity and capable of generating moderate friction when rubbed and generating frictional heat, is suitable.
An eraser can be used to rub the handwriting, but since eraser shavings are generated at the time of rubbing, it is preferable to use the above-described friction member that hardly generates eraser shavings.
Silicone resin, SEBS resin (styrene-ethylene-butadiene-styrene block copolymer), polyester-based resin, or the like is used as the material of the friction member.

It should be noted that it is also possible to provide two or more types of the friction member. In that case, due to friction with the paper surface, one generates frictional heat in the range of T _A to T _B , which is the handwriting discoloration temperature (that is, only one handwriting can be erased), and the other is T _B or more, which is the handwriting discoloration temperature. of frictional heat (i.e., both handwritings can be erased). By doing so, it is possible to easily and reliably develop a desired discoloration stage according to each friction member without worrying about the amount of force applied when handwriting is rubbed.
Specifically, it is configured by adjusting the coefficient of friction and thermal conductivity according to the material (including a mixture of a plurality of materials, etc.), the shape, etc. of the friction body, and by imparting self-destructibility.

The friction member is provided integrally or separately (that is, in the form of a writing set) with the writing instrument case that constitutes the multiple writing instrument described above, and has a structure in which the friction surface can come into contact with handwriting (paper surface). Specific exteriors include a cap, a clip, a head cap, a cap, a barrel, a tail plug, a grip, a knock member (pressing member for a retraction mechanism), and the like. Furthermore, the structure may be such that a covering member is covered to prevent contamination during storage. When it is formed as a separate body, it can be constructed with an elastic body alone or together with a hard material.

<First Embodiment>
A first embodiment of the invention is shown in FIG.
In the dual writing instrument 1 of the present embodiment, a plurality of (specifically, two) writing bodies 3 are accommodated in a barrel 2 so as to be movable in the front-rear direction. Each writing element 3 is urged backward by an elastic body 6 (specifically, a compression coil spring).

(shaft cylinder)
The shaft tube 2 comprises a front shaft 2a formed of a tapered cylindrical body, and a cylindrical rear shaft 2b attached to the rear end portion of the front shaft 2a by screwing or press-fitting. A front end hole 21 through which a pen tip 31 of the writing body 3 can protrude is provided axially through the front end of the front barrel 2a. The front axle 2a and the rear axle 2b are obtained by injection molding of synthetic resin (for example, polycarbonate or the like).

A plurality (specifically, two) of elongated window holes 22 extending in the front-rear direction are radially penetrating through the rear side wall of the rear axle 2b. The two window holes 22 are formed symmetrically with respect to the axis. Further, an opening 23 is formed at the rear end of the rear shaft 2b so as to penetrate in the axial direction and open radially outward. The opening 23 communicates with the window hole 22 at the rear end of the rear shaft 2b (that is, the rear end of the barrel 2), so that the rear end of the window hole 22 is notched rearward and is opened rearward. The writing body 3 to which the operation body 4 is attached can be inserted into the barrel 2 and removed from the barrel 2 through the opening 23 .

An engaging wall portion (not shown) consisting of ribs extending in the front-rear direction is formed on the inner surface of the side wall between the window holes 22 of the rear barrel 2b. The rear end of the operating body 4 of the writing body 3 when projected is locked. A clip is provided on the outer surface of the side wall between the window holes 22 of the rear axle 2b.

(Lid)
A lid portion 5 for opening and closing the opening portion 23 is rotatably provided at the rear end portion of the rear shaft 2b. One end of the lid portion 5 is rotatably connected to the clip base by a hinge portion.
The lid portion 5 is rotatable substantially in the front-rear direction. A contact wall portion is formed on the front surface of the lid portion 5 . The rear end of each operation body 4 connected to the rear end of the writing body 3 in the pen point retracted state is brought into contact with the contact wall portion. The contact wall portion may be formed integrally with the barrel 2 (rear shaft 2b) instead of being formed on the front surface of the lid portion 5. As shown in FIG.

On the front surface of the other end portion of the lid portion 5, an engaging portion made of a concave portion or a hole portion is provided. The rear end of the rear shaft 2b is provided with an engaged portion which is a protrusion that can be engaged with the engaging portion. An inward projection is formed on the inner surface of the engaging portion, and an outward projection that can be locked over the inward projection is formed on the outer surface of the engaged portion.

(friction body)
A mounting portion 51 (specifically, a convex portion projecting rearward) is formed on the rear surface of the lid portion 5 . The mounting portion 51 is engaged with the mounted portion 71 (specifically, the concave portion) of the friction body 7 (specifically, the convex portion is press-fitted into the concave portion). Thereby, the friction portion 7 is fixed to the rear surface of the lid portion 5 . In addition to this, the attachment portion 51 may be a concave portion, and the attached portion may be a convex portion. The friction body 7 is made of an elastic material (specifically, SEBS resin). The friction body 7 has a convex curved surface whose outer diameter decreases toward the rear. The friction portion 7 may be detachable from the rear surface of the lid portion 5 so as to be replaceable.
By rubbing the handwriting with the convex curved surface, it is possible to generate frictional heat with a light force due to moderate elasticity, and to easily erase a desired portion by heat.

(Cursive)
Each writing body 3 is a ball-point pen refill, and has a ball-point pen tip (i.e., pen point 31) having a ball rotatably held at its front end, and an ink reservoir having the ball-point pen tip at its front end and an opening at its rear end. a tube 32; Inside the ink storage tube 32, thermochromic ink, which is water-based gel ink using thermochromic microcapsule pigment, and high-viscosity fluid disposed at the trailing end of the ink and advancing as the ink is consumed. body is filled.
As the thermochromic ink, light blue ink (ink A) with a decoloring temperature of 55°C and black ink (ink B) with a decoloring temperature of 100°C are used.

The ball-point pen tip has a configuration in which a ball rotatably held at the front end is urged forward by an elastic body or the like to bring the ball into close contact with the inner surface of the front edge. The ballpoint pen tip may be attached directly to the front end opening of the ink containing tube 32 by press fitting or the like, but in this embodiment, it is fixed to the front end opening of the ink containing tube 32 via a pen tip holder.
As the ball, a writing body containing light blue ink (ink A) has a diameter of 0.4 mm, and a writing body containing black ink (ink B) has a diameter of 0.7 mm.

(operator)
An operating body 4 is attached to the rear end of each of the writing bodies 3 (that is, the rear end opening of the ink containing tube 32). Each of the operation bodies 4 includes an operation portion 41 formed at the rear end portion and protruding outside from the window hole 22 of the barrel 2, a rear projection portion 43 provided on the opposite side of the operation portion 41, and the A front protruding portion 42 provided in front of the rear protruding portion 43 on the opposite side of the operating portion 41, a fitting portion 44 formed at the front end and fitted into the rear end opening of the ink containing tube 32, and the fitting portion. 44 and a collar portion 45 formed on the rear side. Also, the rear end of the elastic member 6 is engaged with the front surface of the brim portion 45 .
Each operation body 4 is made of a synthetic resin (for example, polyacetal resin, ABS resin, etc.) and is colored substantially the same as the color of ink contained therein. Furthermore, in the present embodiment, on the operation body 4 connected to the writing body 3 containing light blue ink (ink A), the back of the operation part 41 is configured as a white identification part 41a by two-color molding, It is an identification means that can be visually confirmed from the outside that the cursive writing can be used for rough drafts.

In the multi-type writing instrument 1 having the above configuration, in addition to normal writing with each writing body 3 and erasing of handwriting with the friction body 7 or heat source, the ball-point pen A containing the ink A can be used to write on postcards, gold seals, etc., and the handwriting can be written. is traced with a ballpoint pen B containing an ink B, and after tracing, the draft part is erased by friction with the friction body 7 to leave only the clean copy.
In particular, since the ball diameter of the ball-point pen A is smaller than that of the ball-point pen B, it can be used as described above for draft letters in fine letters and fair letters in bold letters. It is possible to clearly leave fair writing without making it stand out.

<Second Embodiment>
A second embodiment of the invention is shown in FIG.
The dual writing instrument 1 of this embodiment comprises a barrel 2, a first nib 31a made of a ball-point pen tip provided at one end of the barrel 2, and a porous pen body provided at the other end of the barrel 2. A second pen tip 31b, a first cap 8a attachable to the barrel 2 on the side of the first pen tip 31a, and a second cap 8a attachable to the barrel 2 on the side of the second pen tip 31b. and a cap 8b. A ball-point pen refill 3a (writing body 3) having a first nib 31a and an ink absorbing body 33 to which a second nib 31b is connected are accommodated in the barrel 2. As shown in FIG. The first pen tip 31a protrudes from one end of the barrel 2, and the second pen tip 31b protrudes from the other end of the barrel 2. As shown in FIG.

The barrel 2 comprises a cylindrical barrel body 2c, and a first front shaft 2a and a second front shaft 2a' attached to both ends of the barrel body 2c. The first front shaft 2a and the second front shaft 2a' are detachably attached to the barrel main body 2c by screwing or press-fitting. Both ends of the barrel body 2c are opened, and a partition wall is formed inside.

(Ballpoint pen refill)
The ball-point pen refill 3a has a first pen point 31a made up of a ball-point pen tip at its tip, and contains a first thermochromic ink 34 inside. The first thermochromic ink 34 is discharged from the first nib 31a to the outside, and handwriting with the first thermochromic ink 34 can be obtained. An elastic body (spring) is accommodated in the first pen tip 31a. The elastic body urges the ball of the first pen tip 31a forward and presses it against the inner surface of the crimped portion (tip edge portion inner surface) of the first pen tip 31a, thereby Prevents ink leakage from the tip and air intrusion.

The first pen tip 31a is attached to the ink containing tube 32 via a pen tip holder. Specifically, the first pen tip 31 a is fixed to one end of the pen tip holder, and the other end of the pen tip holder is fixed to the opening of the ink containing tube 32 . The pen tip holder has a flange on its outer peripheral surface, and the flange is sandwiched between the inner surface of the first front barrel 2a and one end of the barrel main body 2c.

(First thermochromic ink)
A first thermochromic ink 34 is contained in the ink containing tube 32 . The first thermochromic ink 34 has a low temperature side color change point (complete color development temperature t ₁ ) set to an arbitrary temperature in the range of −30° C. to −10° C. (−20° C. in this embodiment). The side discoloration point (complete discoloration temperature t ₄ ) is set to an arbitrary temperature in the range of 55° C. to 80° C. (65° C.: T _B in this embodiment), and the hysteresis width ΔH is 40° C. to 100° C. (this embodiment A reversible thermochromic ink (black in this example) is employed which exhibits a range of 80° C. in the example.

A follower 35 is accommodated at the rear end of the first thermochromic ink 34 in the ink accommodating tube 32 . The follower 35 advances as the ink is consumed and prevents the ink from retreating (that is, backflow). The structure etc. which were made to accommodate are mentioned.

(first cap)
The first cap 8a of the caps 8 is a cylindrical member obtained by injection molding of synthetic resin. The first cap 8a is internally provided with a pen tip sealing member 82 made of an elastic material. When the first cap 8a is attached to the outer peripheral surface of the barrel on the side of the first pen tip 31a, the pen tip sealing member 82 comes into close contact with the tip of the first pen tip 31a, and the first pen tip 31a is closed. seal the tip of the A clip 81 is provided on the side wall of the first cap 8a either integrally or by attachment of a separate part. In the present embodiment, the clip 81 functions as the identification portion 41a, thereby serving as identification means for visually confirming from the outside that the writing body (ballpoint pen) can be used for writing characters.

A friction body 7 made of an elastic material (SEBS resin in this embodiment) and generating frictional heat of 65° C. (T _B ) or more by friction with the paper surface is attached to the top of the first cap 8a. The friction body 7 can also be integrally formed with the first cap by two-color molding. Furthermore, it can also be colored with the ink color to be accommodated, and exhibit a color display function.

(Second pen tip)
The second pen tip 31b is attached to the other end of the barrel main body 2c via the second front shaft 2a'. Specifically, a second pen tip 31b is fixed to one end of the second front barrel 2a', and the other end of the second front barrel 2a' is fixed to the other end opening of the barrel main body 2c. be done. The second front shaft 2a' has a flange on its outer peripheral surface, and the flange is brought into contact with the other end of the barrel main body 2c. The tip of the second pen tip 31b is formed in a chisel shape.

(Second thermochromic ink)
The inside of the second ink occluding body 33 is impregnated with the second thermochromic ink. The second thermochromic ink is ejected from the second pen tip 31b to the outside, and handwriting can be obtained with the second thermochromic ink. The second ink occluding body 33 is made of a porous material (fiber processed body, porous foam body).

The second thermochromic ink has a low-temperature side color change point (complete color development temperature t ₁ ) set to an arbitrary temperature in the range of -30 ° C. to -10 ° C. (-20 ° C. in this embodiment), and the high temperature side The discoloration point (complete discoloration temperature t ₄ ) is set to an arbitrary temperature in the range of 40° C. to 60° C. (50° C.: T _A in this embodiment), and the hysteresis width ΔH is set in the range of 45° C. to 85° C. (this A reversible thermochromic ink (fluorescent yellow in this example) exhibiting a temperature of 65° C. in the example is employed.

By configuring the color (black) of the first thermochromic ink 34 in the coloring state and the color (fluorescent yellow) of the second thermochromic ink in the coloring state to be different, normal writing by each cursive In addition to writing and erasing, it can be used for learning purposes such as memorization by writing letters in a notebook with a ballpoint pen and highlighting the handwriting with a marking pen. It becomes possible to erase only the highlighted part while leaving the characters.

(second cap)
The second cap 8b is a cylindrical member obtained by injection molding of synthetic resin. When the second pen tip 31b is not used, the second cap 8b is airtightly fitted to the outer peripheral surface of the barrel 2 on the side of the second pen tip 31b to seal the second pen tip 31b.

The top of the second cap 8b is made of an elastic body (polyester elastomer in this embodiment), and generates frictional heat in the range of 50° C. (T _A ) to 65° C. (T _B ) by friction with the paper surface. A friction body 7 is attached. The friction body 7 can also be integrally formed with the second cap by two-color molding. Furthermore, it can be colored with the ink color (yellow) to be accommodated and exhibit an ink color display function.

(Connection of caps)
When using the second nib 31b, the inner peripheral surface of the opening of the second cap 8b can be fitted so as to cover the outer peripheral surface of the top portion of the first cap 8a with the friction body 7. As shown in FIG. Further, when using the first pen tip 31a, the inner peripheral surface of the opening of the first cap 8a can be fitted so as to cover the outer peripheral surface of the top portion of the second cap 8b with the friction body 7. As shown in FIG. The structure allows the cap to be inserted backwards during writing.

<Third Embodiment>
A third embodiment of the invention is shown in FIG.
The multiple-type writing instrument 1 of the present embodiment has the structure of the marking pen side provided with the second nib of the second embodiment changed from the filling type using the ink occluding body 33 to the liquid type (pumping type). ) and its cap (second cap) does not have a friction body.

That is, the barrel 2 includes a ballpoint pen refill 3a (cursive body 3) having a first pen tip 31a and a marking pen refill 3b (ink tank type) having a second pen tip 31b. The other end of the marking pen refill is fixed to the other end opening of the ballpoint pen refill.

(First thermochromic ink)
A first thermochromic ink 34 is stored in the ink storage tube 32 of the ballpoint pen refill 3a. The first thermochromic ink 34 has a low temperature side color change point (complete color development temperature t ₁ ) set to an arbitrary temperature in the range of −30° C. to −10° C. (−20° C. in this embodiment). The side discoloration point (complete discoloration temperature t ₄ ) is set to an arbitrary temperature in the range of 55° C. to 80° C. (65° C. in this embodiment), and the hysteresis width ΔH is set to 40° C. to 100° C. (80° C. in this embodiment). °C) is employed (red in this example).

(Second pen tip)
The second pen tip 31b is attached to the opening of the second barrel 2' that constitutes the ink tank so as to be slidable in the axial direction. The opening of the second barrel 2' is provided with a valve device 9 which is opened by pressing the second pen tip 31b axially inward (writing pressure of the second pen tip 31b during writing). be done. The valve device 9 includes a valve body 91 having a second nib 31b at one end, a valve seat 92 with which the valve body 91 can come into close contact, and an elastic body that urges the valve body 91 axially outward. 93 (coil spring); Further, a stirring member 95 made of a metal ball for stirring ink is accommodated in the ink tank. The tip of the second pen tip 31b is formed in a chisel shape.

(Second thermochromic ink)
A second thermochromic ink 34 is accommodated in the second barrel 2' (ink tank). The second thermochromic ink is ejected from the second pen tip 31b to the outside, and handwriting can be obtained with the second thermochromic ink.

The second thermochromic ink has a low-temperature side color change point (complete color development temperature t ₁ ) set to an arbitrary temperature in the range of -30 ° C. to -10 ° C. (-20 ° C. in this embodiment), and the high temperature side The discoloration point (complete discoloration temperature t ₄ ) is set to an arbitrary temperature within the range of 40° C. to 60° C. (50° C. in this embodiment), and the hysteresis width ΔH is set to a range of 45° C. to 85° C. (in this embodiment, 65° C.) is employed (fluorescent green in this example).

By configuring the color (red) of the first thermochromic ink in the coloring state and the color (fluorescent green) of the second thermochromic ink in the coloring state different, normal writing by each writing body In addition to erasing, it can be applied to learning purposes such as memorization by writing characters in a notebook with a ballpoint pen and highlighting the handwriting with a marking pen. It becomes possible to erase only the highlighted part while leaving the

(second cap)
The second cap 8b is a cylindrical member obtained by injection molding of synthetic resin. The second cap 8b is attached to the outer peripheral surface of the barrel 2 (specifically, the outer peripheral surface of the second front barrel 2a') on the side of the second pen tip 31b when the second pen tip 31b is not used. It is hermetically fitted to seal the second nib 31b.

(Connection of caps)
When using the second nib 31b, the inner peripheral surface of the opening of the second cap 8b can be fitted so as to cover the outer peripheral surface of the top portion of the first cap 8a with the friction body 7. As shown in FIG. The above structure enables the cap to be inserted backwards when writing with a marking pen.

1 Duplex writing instrument 2, 2' Axle tube 2a, 2a' Front barrel 2b Rear barrel 2c Axle barrel body 21 Front end hole 22 Window hole 23 Opening 3 Writing body 3a Ballpoint pen refill 3b Marking pen refill 31 Pen tip 31a Ballpoint pen tip 31b Marking pen Tip 32 Ink storage tube 33 Ink storage body 34 Thermochromic ink 35 Follower body 4 Operation body 41 Operation part 41a Identification part 42 Front projection part 43 Rear projection part 44 Fitting part 45 Flange part 5 Lid part 51 Mounting part 6 Elasticity Body 7 Friction body 71 Attached portion 8 Cap (8a, 8b)
81 clip (identification part)
9 valve device 91 valve body 92 valve seat 93 elastic body 94 valve housing cylinder 95 agitating member t ₁ complete color development temperature t ₂ color development start temperature t ₃ color change start temperature t ₄ complete color change temperature

Claims (8)

A compound writing instrument using two or more types of writing bodies, wherein a thermochromic ink composition that becomes decolorized by heating is used in at least two of the writing bodies, and each thermochromic ink composition A dual writing instrument characterized by having different erasing temperatures. 2. The compound writing instrument according to claim 1, wherein the color erasing temperature (T _A <T _B ) of each thermochromic ink composition is a color erasing temperature difference of 5° C. or more. The thermochromic ink composition comprises (a) an electron-donating color-developing organic compound, (b) an electron-accepting compound, and (c) a reaction medium for controlling the color reaction of (a) and (b). 3. The compound writing instrument according to claim 1, wherein the reversible thermochromic pigment is encapsulated in microcapsules. 3. The dual writing instrument according to claim 2, wherein said writing bodies are a marking pen using ink having a decoloring temperature _TA and a ball-point pen using ink having a decoloring temperature _TB . The writing material is a ball-point pen _A using ink having a decoloring temperature TA and a ball-point pen _B using ink having a decoloring temperature TB, the ball diameter DA of the ball-point pen _A and the ball diameter D of the ball-point pen B 3. The compound writing instrument of claim 2, wherein _B is such that D _A <D _B. 6. A compound writing instrument according to claim 5, further comprising identifying means for determining whether the decoloring temperature of ink contained in each writing body is high (T _B ) or low (T _A ). 7. The compound writing instrument according to any one of claims 1 to 6, further comprising a friction member for discoloring handwriting by said writing body due to frictional heat. 8. The compound writing instrument according to claim 7, wherein said friction member consists of two types, one of which generates frictional heat in the range of T _A to T _B and the other generates frictional heat of T _B or more by friction with the paper surface. .

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