JP5794730B2 - Writing instrument cap with writing instrument and erasable ink - Google Patents

Description

  The present invention relates to a writing instrument capable of erasing handwriting such as ballpoint pen ink and a sharp lead.

Conventionally, a rubbing member serving as a friction body for discoloring the handwriting of thermochromic ink by frictional heat is attached to the front end of the cap body, and a pen point sealing member (hereinafter referred to as a sealing member) is disposed inside the cap body. A writing instrument is disclosed (Patent Document 1). Since the conventional thermochromic ink tends to volatilize, a seal member is attached inside the cap to prevent the ink from volatilizing. Therefore, in order to eliminate the two types of parts (abrasion member and seal member) attached to the cap body, the number of parts increases, the assembly process increases, and the manufacturing cost is inevitably increased. There is disclosed a writing instrument cap and a writing instrument that can reduce the number of these and reduce the manufacturing cost (Patent Document 2).

JP 2006-123324 A JP 2009-208312 A

However, in the invention of Patent Document 1, if the rubbing member and the seal member are separately arranged, the length of the cap and the writing instrument becomes unnecessarily long, and thus the length of the conventional writing instrument becomes significantly longer and the appearance is impaired. Sometimes. Further, in the invention described in Patent Document 2, since it is a kind of material, it is difficult to sufficiently ensure the erasability of handwriting and the volatilization prevention property of ink.
SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to ensure sufficient erasability of handwriting and prevention of volatilization of ink while preventing the overall length of the writing instrument from being attached due to the attachment of the rubbing member.

Therefore, the inventor has achieved the following invention after intensive development.
(1) An erasing tool capable of erasing or erasing the handwriting by rubbing the handwriting, a seal member for sealing the front of the pen tip in close contact with the pen tip, and the erasing tool sandwiching the seal member forward A writing instrument cap comprising an attached cap body, wherein the eraser is made of a material different from that of the seal member. By sandwiching the seal member in the eraser, the total length of the seal member and the length in the longitudinal direction where the seal member is arranged can be shortened, and the handwriting can be made by using different materials for the eraser and the seal member. Erasability and ink volatilization prevention performance can be ensured.
(2) Further, in the erasing tool, an opening is formed at the rear of the erasing tool, and a plurality of ribs extending toward the central axis in the longitudinal direction are provided on the inner wall in front of the opening. It is sandwiched between the plurality of ribs. By sandwiching the seal member with the plurality of ribs, it is possible to prevent a decrease in the ink volatilization prevention performance due to creep deformation of the seal member, and to secure a stable holding force with the erasing tool.
(3) Further, the erasing tool is formed of a material having higher hardness than the seal member. By making the eraser harder than the seal member, even when the seal member is sandwiched in the eraser, it is possible to prevent deformation of the eraser to the appearance due to the shape of the seal member.
(4) A writing instrument in which the writing instrument cap described in the above (1) to (3) is fitted to a shaft body and erasable ink is accommodated in the shaft body.

As described above, the present invention can achieve both the erasability of handwriting and the volatilization prevention property of ink, and can prevent the entire length of the writing instrument from becoming long due to the arrangement of the erasing tool.

It is component drawing of the assembly cap of the writing instrument in embodiment of this invention. FIG. 2 is a component diagram of the erasing tool of the writing tool shown in FIG. 1. It is the component drawing which assembled the eraser and seal member of the writing instrument shown by FIG. 1 is an overall view of a writing instrument in an embodiment of the present invention.

Embodiments of the present invention will be described below with reference to the drawings.
In addition, in this specification, the front means the writing part side, and the rear means the writing part side means the other end side.
In addition, erasing means that a writing line using a thermochromic ink can change the color of the written line to a discolored or decolored state, and a writing tool using an eraser erasing ink can erase the drawn lines, characters, etc. This means that it can be absorbed or scraped off.

  FIG. 1 is a component diagram of a writing instrument cap according to an embodiment of the present invention. FIG. 1 (a) is a front view, and FIG. 1 (b) is a longitudinal sectional view of FIG. The cap includes a cap body 1, an erasing tool 2 capable of erasing a handwriting in front, and a seal member 3 capable of preventing volatilization of a writing portion fitted to the erasing tool 2.

  An erasing tool 2 serving as a scraping member is mounted in front of the cap body 1. The erasing tool 2 can erase the handwriting by pressing the erasing tool 2 against the writing surface and rubbing it on the writing surface such as paper. In FIG. 1, the erasing tool 2 is attached to the cap body 1 by concavity and convexity. However, if the erasing tool is not removed by a rubbing operation on the handwriting, a method such as press-fitting, adhesion, or welding may be used. Although the inner surface of the cap body 1 is formed in a cylindrical shape, there is a fitting portion 11 formed by chamfering a part of the cylindrical shape at a substantially central portion. The fitting part 11 is formed in four places in this embodiment, and can be fitted by the fitting part 11 to the front side edge part or back side edge part of a writing instrument.

As the material for forming the cap body 1, a hard plastic such as polycarbonate, polystyrene, acrylonitrile / butadiene / styrene (ABS) is preferable.

FIG. 2 is a component diagram of the writing instrument erasing tool 2 in the embodiment of the present invention, FIG. 2 (a) is a left side view, FIG. 2 (b) is a perspective view from the front, and FIG. 2 (c) is a front view. 2A is a cross-sectional view taken along the line AA ′ of FIG. 2A (a longitudinal cross-sectional view of FIG. 2C), FIG. 2E is a perspective view from the rear, and FIG. It is a right view.

An opening 21 is formed in the erasing tool 2 from the rear, and an inner wall 22, a step 23, and a space 24 are formed toward the front of the opening 21. Since the opening diameter behind the opening 21 is formed larger than the inner diameter of the inner wall 22, the insertion of the erasing tool 2 can be facilitated. The inner wall 22 of the erasing tool 2 is provided with a plurality of ribs 25 extending in the longitudinal direction toward the central axis, and has a structure in which the seal member 3 is sandwiched while being elastically deformed. Although the number of ribs 25 is six in the drawing, it is preferable that the number of ribs 25 be four or more that are arranged substantially equidistantly and opposed to each other from the axial center in order to securely clamp. When the sealing member 3 is arranged in the erasing tool 2 in the assembly process, since the erasing tool 2 and the sealing member 3 are made of a rubber elastic body, the erasing tool is also elastically deformed when the sealing member is inserted. Even if there is some variation, it can be reliably arranged. The diameter of the inscribed circle of each rib 25, 25... Is more preferably 0.05 to 0.1 mm smaller than the outer diameter of the seal member 3 in order to prevent creep deformation of the seal member 3. The space portion 24 in which a space is formed in the erasing tool 2 can prevent sink marks (dents) on the surface of the curved surface portion 26.
A curved surface portion 26 is formed on the outer surface of the erasing tool 2 from the front, and a flange portion 27 and a trunk portion 28 insertion portion 30 are formed toward the rear. The curved surface portion 26 has a certain curvature when viewed from the front, so that an appropriate erasing feeling can be obtained. As for the surface roughness of the surface of the curved surface part 26, arithmetic mean roughness Ra = 0.0009micrometer-0.014micrometer are preferable. If Ra is smoother than 0.009 μm, the writing surface (for example, paper surface) may slide, and if Ra is 0.014 μm or more, the writing surface may be caught carelessly to break the paper surface. When the collar portion 27 is attached to the cap main body 1, the full length of the cap can be stabilized by contacting the front end portion of the cap main body 1. A concave portion 29 is formed in a substantially middle portion of the body portion 28 and can be attached to the convex portion 12 by fitting. The insertion portion 30 formed by reducing the diameter toward the rear of the body portion 28 can be easily attached to the cap body 1 by making the outer diameter smaller than the inner diameter of the convex portion 12 of the cap body 1. it can.

The erasing part 2 is preferably made of a material having rubber elasticity. Examples thereof include thermoplastic elastomers such as styrene elastomers (styrene-butadiene-styrene copolymers, styrene-ethylene-butadiene-styrene copolymers, etc.), fluorine elastomers, urethane elastomers, polyester elastomers, and olefin elastomers. It is done. In particular, it is composed of a mixture of a thermoplastic resin and a thermoplastic elastomer, and the blending ratio is 1: 1 to 1: 4 by weight, respectively, and preferably contains no abrasive, plasticizer, and filler. A commercially available eraser that has existed in the past may be used, but it is more preferable that an eraser that does not contain a plasticizer is less likely to generate erase chips. Furthermore, it is preferable not to contain plasticizers such as dibutyl phthalate (dibutyl phthalate) and dioctyl phthalate (dioctyl phthalate) from the viewpoint of safety to the human body and problems caused by adhesion when coming into contact with other plastics. The reason for not containing an abrasive (abrasive particles) is that it does not contain an abrasive (abrasive particles) in order to erase the handwriting without damaging the paper surface.

Further, it is necessary to be a semi-rigid rubber or a hard rubber made of a material having a durometer hardness A defined in JIS K6253 of 70 ° to 100 °, preferably 75 ° to 95 °, more preferably What becomes 80 degrees-93 degrees is preferable. If the hardness is less than 70 °, the handwriting cannot be easily erased because it is too soft. On the other hand, if the hardness exceeds 100 °, the eraser 2 itself is not flexible and thus exceeds the adhesive force between the handwriting and the paper surface. Since frictional force does not occur, it cannot be erased.

In addition, JIS provides a erasing tool that cannot be erased by scratching with a finger or the like and cannot be erased by a conventional commercially available eraser, and that does not further damage the paper surface. It is preferable that the erasing ability (erasure rate) of the pencil stroke specified in S 6050 (2002) is 70% or less. The pencil used in this test is a pencil (HB) specified in JIS S 6006.

Further, within the range not impairing the effect of the present invention, a colorant for coloring the ink together with the ink color, a fragrance for giving an image of the ink color, etc. may be mixed in the material.

3A and 3B are part drawings in which the erasing tool 2 and the seal member 3 according to the embodiment of the present invention are assembled. FIG. 3A is a left side view, FIG. 3B is a perspective view from the front, and FIG. 3C is a front view, FIG. 3D is a cross-sectional view taken along the line AA ′ of FIG. 3A (a vertical cross-sectional view of FIG. 3C), FIG. 3E is a perspective view from the rear, and FIG. (F) is a right side view. It is clamped by a plurality of ribs 25 formed on the inner wall 22 on the rear side of the eraser 2. Furthermore, due to the material having rubber elasticity for the erasing tool 2 and the seal member 3, the adhesion in attachment becomes difficult to come off due to the mutual adhesion force.

The sealing member 3 preferably has a spherical shape because it can be easily put into the erasing tool 2. The material is preferably a material different from the eraser and softer than the eraser 2. The seal member 3 is formed of synthetic rubber such as isopropylene rubber, butadiene rubber, nitrile rubber, silicone rubber, butyl rubber, ethylene propylene diene rubber, styrene butadiene rubber, and fluorine rubber. In particular, butyl rubber (IIR) can further improve processability and volatilization prevention performance at the tip of the writing part. That is, butyl rubber is not only excellent in processability, but also excellent in airtightness (gas barrier property) among various rubbers. For this reason, by forming the seal member 3 from butyl rubber, it is possible to more reliably prevent the tip of the writing portion from drying and prevent the solvent component in the ink from volatilizing. Alternatively, the seal member 3 can be made of a rubber composition obtained by adding a phthalate ester plasticizer to nitrile rubber (NBR). By adding the amount of phthalate ester plasticizer to more than 0 and less than 15% by weight, the stickiness of the surface due to bleed-out of the seal member 3 is reduced, thereby preventing the tip of the writing part from becoming dirty. It is doing. However, if the addition amount of the phthalate ester plasticizer exceeds 15% by weight, it cannot be suppressed due to surface stickiness or bleed-out during use, which induces dirt on the tip of the chip, and further bleed-out. There is a risk that ink will be attacked by the components and the writing becomes impossible.

The seal member 3 is preferably a soft rubber having a durometer A hardness specified in JIS K6253 and having a degree of 5 ° to 35 °. By setting the durometer A hardness to 5 ° or more and 35 ° or less, the sticking of the tip of the writing part is not incomplete due to the stickiness of the surface of the seal member 3, preventing the tip of the writing part from being dried, This sufficiently prevents the solvent component from volatilizing. When the durometer A hardness is 35 ° or more, the rebound resilience of the seal member 3 is large, the cap is easily disengaged, the tip of the writing part is incompletely sealed, and the tip of the writing part is prevented from drying. In addition, there is a possibility that the solvent component in the ink cannot be sufficiently prevented from volatilizing. On the other hand, if the durometer A hardness is less than 5 °, the surface of the seal member 3 becomes more sticky, which causes the tip of the writing part to become dirty or the ink to deteriorate, making it impossible to write. There is a risk of becoming. When the durometer A hardness of the seal member 3 is different from that of the erasing tool 2, the same kind of material as that of the erasing tool 2 depending on the grade may be used.

4 is an overall view of the writing instrument in the embodiment of the present invention, FIG. 4 (a) is a front view, and FIG. 4 (b) is a longitudinal sectional view of FIG. 4 (a). The fitting when the writing instrument cap is mounted on the writing instrument body will be described. The writing instrument body includes a shaft body 4 for storing a writing refill, a tail plug 5 fitted to the rear end portion of the shaft body 4, a writing portion 6 that is received in the shaft body 4 and applies ink 8 from the front tip, and the ink 8. The ink storage tube 7 is filled with ink, the ink 8, the ink follower 9 that prevents leakage of the ink 8 from the ink storage tube 7 and drying, and the refill tail plug 10.

When the writing instrument cap is fitted to the shaft body 4, the front end of the writing unit 6 is buried in the seal member 3, whereby the sealing member 3 covers the tip of the writing unit 6. This prevents the tip of the ink from drying and prevents the solvent component of the ink 8 from volatilizing. The writing unit 6 shown in FIG. 4 is a ballpoint pen tip, and the seal member 3 is shown in a state where it is not elastically deformed for convenience.

The ink 8 filled in the ink storage tube 7 in the present embodiment uses thermochromic ink that can be decolored or discolored by rubbing the handwriting with the erasing tool 2. The thermochromic ink is preferably a reversible thermochromic ink. Alternatively, it may be an irreversible color-changing ink which is not reversible and is not reversible. The reversible thermochromic ink is a heat decoloring type that decolors 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. The coloring material contained in the reversible thermochromic ink includes (A) an electron-donating color-forming organic compound, (B) an electron-accepting compound, and (C) a reaction that determines the temperature at which the color reaction occurs. A reversible thermochromic microcapsule pigment in which a reversible thermochromic composition containing at least three essential components of a medium is encapsulated in a microcapsule is preferably used. The reversible thermochromic microcapsule pigment has an average particle diameter of 0.5 to 5.0 μm, preferably 1 to 4 μm. When the average particle size exceeds 5.0 μm, the outflow from the capillary gap of the ballpoint pen tip or the porous pen body decreases, and when the average particle size is 0.5 μm or less, it is difficult to show high density color development. . The reversible thermochromic microcapsule pigment can be blended in an amount of 2 to 50% by weight (preferably 3 to 40% by weight, more preferably 4 to 30% by weight) based on the total amount of the ink composition. If it is less than 2% by weight, the color density is insufficient, and if it exceeds 50% by weight, the ink outflow is reduced and the writing property is impaired.

  In the reversible thermochromic ink, the color change temperature due to rubbing heat of the erasing part 2 is preferably set to 36 ° C to 95 ° C. That is, in the present invention, the high temperature side color change point [complete color erasing temperature] is preferably set in the range of 36 ° C. to 90 ° C., and the low temperature side color change point [complete color development temperature] is preferably −30. It is effective to set the temperature in the range of ° C to + 10 ° C. 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 color of the image or handwriting by the reversible thermochromic ink by the scrubbing heat by the erasing unit.

The ink 8 may be an eraser erasable ink that can be erased by rubbing the eraser instead of a thermochromic ink. The eraser erasable ink is composed of water and non-thermoplastic colored resin particles having an average particle diameter of 1.0 to 15 μm in an amount of 3 to 30% by weight and 0.1 to 10% by weight based on the total amount of the ink composition. It is necessary to contain at least particles. The colored resin particles used for the water-based ink of the present invention are made of colored resin particles, are non-thermoplastic, and have an average particle diameter of 1.0 to 15 μm. For example, resin particles Colored resin particles in which a colorant made of pigment is dispersed, colored resin particles in which the surface of the resin particle is coated with a colorant made of pigment, colored resin particles in which a colorant made of dye is dyed on the resin particle, etc. Is mentioned. In this embodiment, if the colored resin particles are non-thermoplastic and satisfy the above average particle diameter, the structure (with hollow structure, without hollow structure (solid)), shape (spherical, polygonal, flat) Is not particularly limited, but preferably has a glass transition point of 150 ° C. or higher and a thermal decomposition temperature from the viewpoint of exhibiting excellent eraser erasability, writing property, and stability over time as an ink. In addition, particles having an intramolecular cross-link having a melt flow index value of less than 0.1 are not sticky, and spherical colored resin fine particles having an average particle size of 1.0 to 15 μm Use is desirable.

  INDUSTRIAL APPLICABILITY The present invention is an industrially useful beneficial invention that can achieve both the erasability of handwriting and the volatilization prevention property of ink, and can prevent the length of the writing instrument from becoming longer due to the arrangement of the erasing tool. .

1 Cap body 2 Eraser (Abrasion member)
3 Seal member 4 Shaft body 5 Tail plug 6 Writing part 7 Ink containing tube 8 Ink 9 Ink follower 11 Fitting part 12 Protruding part 21 Opening part 22 Inner wall 23 Step part 24 Space part 25 Rib 26 Curved surface part 27 Girder part 28 Body Part 29 recessed part 30 insertion part

Claims (3)

And erasing or erasable erase member the該筆traces by rubbing the handwriting, in close contact with the pen tip to seal the nib front, a spherical sealing member made of a material having rubber elasticity, the erasing device is In the eraser, a writing instrument cap comprising a cap body having an opening formed at the rear of the eraser, the seal member being sandwiched in the opening and attached to the front, the eraser having rubber elasticity Rutotomoni formed of a different material than the member, a writing instrument cap the protruding portion is formed in the cap, characterized by comprising a recess to be fitted to the convex portion to the trunk portion of the erase tool exterior surface. A plurality of ribs extending in the longitudinal direction toward the central axis are provided on the inner wall on the front side from the opening, and a space portion in which a space is formed is provided in front of the rib, and the sealing member is a phthalate ester It is composed of a nitrile rubber to which an added amount of plasticizer is added in a proportion of more than 0 and less than 15% by weight, and is sandwiched by the plurality of ribs , and the eraser is made of a material having a hardness higher than that of the seal member. and writing instrument cap according to claim 1, wherein the are. A writing instrument having erasable ink, wherein the erasable ink is accommodated in the shaft body and the writing instrument cap according to claim 1 or 2 is fitted to the shaft body.

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