JP2009090565A - Frictional body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a frictional body capable of obtaining a contact area with a size suitable for a required heat discoloring area. <P>SOLUTION: The frictional body A of the present invention can perform heat discoloration of writing of a thermochromism ink by a frictional heat generated by rubbing the writing of the thermochromism ink, and is equipped with a frictional part consisting of an elastic material having a convex curved face. The frictional body A is equipped with a plurality of the frictional parts 1/2 with different radii of curvatures of the convex curved faces. A first frictional part 1 is formed on the top part, and a second frictional part 2 is formed in the neighborhood of the first frictional part 1. The radius R1 of curvature of the first frictional part 1 is set larger than the radius R2 of curvature of the second frictional part 2, and the first and second frictional parts 1 and 2 form a series of the convex curved faces. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a friction body. More specifically, the present invention relates to a friction body capable of rubbing the handwriting of a thermochromic ink on a writing surface (for example, paper) and thermally discoloring the handwriting of the thermochromic ink with frictional heat generated at that time.

Conventionally, Patent Document 1 describes that in a friction body for thermally discoloring handwriting by thermochromic ink with frictional heat, the shape of the friction body is a convex curved surface. It is described that a constant contact area can be obtained regardless of the contact angle with the handwriting.

JP 2004-148744 A

In the conventional convex curved friction body, the contact area between the friction body and the handwriting (that is, the contact area between the friction body and the writing surface) is constant regardless of the contact angle. When it is desired to thermally change a small area, or when it is desired to thermally change a large area of a handwriting of a thermochromic ink, there is a possibility that a contact area having a size suitable for the desired thermochromic area cannot be obtained. For example, when it is desired to thermally discolor a small area of the handwriting of the thermochromic ink, in the conventional friction body, there is a possibility that the portion of the thermochromic ink that is not desired to be thermally discolored may be thermally discolored, When it is desired to thermally discolor a large area of the handwriting of the thermochromic ink, the conventional friction body requires a large number of frictions.

The present invention is intended to solve the above-mentioned conventional problems and to provide a friction body capable of obtaining a contact area having a size suitable for a desired thermochromic area.

A first invention of the present application is a friction body capable of thermally discoloring the handwriting of the thermochromic ink by frictional heat generated by rubbing the handwriting of the thermochromic ink and having a convex curved surface. It is a requirement that a friction part made of a material is provided, and a plurality of friction parts having different curvature radii on the convex curved surface are provided. (See FIGS. 1 to 4)

The friction body A according to the first aspect of the present invention includes a plurality of friction portions 1 and 2 having different convex radii of curvature (i.e., at least two locations), thereby thermally discoloring a small area of the handwriting of the thermochromic ink. If you want to use a friction part with a relatively small radius of curvature, you can obtain a relatively small contact area with the writing surface at a constant load, on the other hand, a large area of the handwriting of thermochromic ink When it is desired to thermally discolor the surface, a relatively large contact area with the writing surface under a constant load can be obtained by using a friction portion having a relatively large radius of curvature. That is, the friction body A of the first invention can be used by selecting a friction portion having a contact area of an optimum size according to a desired thermochromic area.

According to a second invention of the present application, in the first invention, the first friction part 1 is formed at the top, the second friction part 2 is formed in the vicinity of the first friction part 1, The curvature radius R1 of the friction part 1 is set larger than the curvature radius R2 of the second friction part 2, and the first friction part 1 and the second friction part 2 form a series of convex curved surfaces. ) As a requirement. (See Fig. 1 and Fig. 2)

When the friction body A of the second invention is intended to thermally discolor a large area of the handwriting of the thermochromic ink, by using the first friction portion 1 having a relatively large curvature radius, A relatively large contact area with the writing surface can be obtained. On the other hand, when a small area of the handwriting of the thermochromic ink is desired to be thermally discolored, the second friction part 2 having a relatively small radius of curvature is used. By doing so, a relatively small contact area with the writing surface under a constant load can be obtained. That is, the friction body A of the second invention can be used by selecting a friction portion having a contact area of an optimum size according to a desired thermochromic area.

In particular, the friction body A of the second invention has the first friction part 1 and the second friction part 2 as the first friction part 1 and the second friction part 2 form a series of convex curved surfaces. In the connecting portion, the first friction portion 1 and the second friction portion 2 are simultaneously brought into contact with the handwriting, so that a contact area having a middle size between a large contact area and a small contact area can be obtained. The ratio (R1 / R2) of the radius of curvature R1 of the first friction portion 1 to the radius of curvature R2 of the second friction portion 2 is 1.5 because a sufficient range of selection of the contact area can be obtained. The above is preferable. In the present invention, the top means the top of a series of convex curved surfaces formed by the first friction part 1 and the second friction part 2.

According to a third invention of the present application, in the first invention, the first friction portion 1 is formed at the top, the second friction portion 2 is formed in the vicinity of the first friction portion 1, The curvature radius R1 of the friction portion 1 is set smaller than the curvature radius R2 of the second friction portion 2, and the first friction portion 1 and the second friction portion 2 form a series of convex curved surfaces. ) As a requirement. (See Figs. 3 and 4)

When the friction body A of the third invention is intended to thermally discolor a small area of the handwriting of the thermochromic ink, by using the first friction portion 1 having a relatively small radius of curvature, the friction body A can be used at a constant load. A relatively small contact area with the writing surface can be obtained. On the other hand, when it is desired to thermally discolor a large area of the handwriting of the thermochromic ink, the second friction part 2 having a relatively large radius of curvature is used. By doing so, a relatively large contact area with the writing surface under a constant load can be obtained. That is, the friction body A of the second invention can be used by selecting a friction portion having a contact area of an optimum size according to a desired thermochromic area.

In particular, in the friction body A of the third invention, the first friction portion 1 and the second friction portion 2 are formed by the first friction portion 1 and the second friction portion 2 forming a series of convex curved surfaces. In the connecting portion, the first friction portion 1 and the second friction portion 2 are simultaneously brought into contact with the handwriting, so that a contact area having a middle size between a large contact area and a small contact area can be obtained. The ratio (R2 / R1) of the radius of curvature R2 of the second friction portion 2 to the radius of curvature R1 of the first friction portion 1 is 1.5 because a sufficient range of selection of the contact area can be obtained. The above is preferable. In the present invention, the top means the top of a series of convex curved surfaces formed by the first friction part 1 and the second friction part 2.

-Friction body In the present invention, the elastic material constituting the friction part of the friction body (or the elastic material constituting the friction body) includes an elastic resin (rubber, elastomer), for example, silicone resin, SBS Resin (styrene-butadiene-styrene copolymer), SEBS resin (styrene-ethylene-butadiene-styrene copolymer), fluorine resin, chloroprene resin, nitrile resin, polyester resin, ethylene propylene diene rubber (EPDM), etc. Can be mentioned. The elastic material constituting the friction part of the frictional body (or the elastic material constituting the frictional body) is lower in wear so that no debris is generated at the time of friction than that made of a highly wearable elastic material (for example, an eraser). It is preferable that it consists of an elastic material.

As an application example of the friction body, a part of a writing instrument (for example, an end portion of a writing instrument body or an end portion of a cap) that includes a thermochromic ink and has a pen tip capable of discharging the thermochromic ink is used. It may be attached, may be a single piece of a size that can be directly gripped, or may be attached to a holder that can be gripped.

-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 decolors by heating from a colored state, a color memory retaining type that reversibly stores and retains 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 conventionally known (a) electron donating color-forming organic compounds, (b) electron-accepting compounds, and (c) color reactions of both. A reversible thermochromic microcapsule pigment in which a reversible thermochromic composition containing at least three essential components of a reaction medium for determining the occurrence temperature of the microcapsule is preferably used.

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 depending on the descending state, 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.

In the present invention, the color change temperature due to frictional heat of the friction part of the thermochromic ink is set to 25 ° C. to 95 ° C. (preferably 36 ° C. to 95 ° C.). That is, in the present invention, the high temperature side discoloration point [complete decoloring temperature (t ₄ )] is set in a range of 25 ° C. to 95 ° C. (preferably 36 ° C. to 90 ° C.), and the low temperature side discoloration point [ It is effective to set the complete color development temperature (t ₁ )] in the range of −30 ° C. to + 20 ° C. (preferably −30 ° C. to + 10 ° C.). Thereby, 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 part.

The reversible thermochromic microcapsule pigment preferably has an average particle diameter in the range of 0.5 to 5.0 μm, preferably 1 to 4 μm. When the average particle diameter 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 diameter 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.

The friction body of the present invention can obtain a contact area having a size suitable for a desired thermochromic area.

<First Embodiment>
A first embodiment of the present invention is shown in FIGS.
The friction body A of the present embodiment is made of an elastic material (for example, SEBS resin, SBS resin). The friction body A has a convex curved surface.

A first friction portion 1 having a convex curved surface (specifically, a convex spherical surface) is provided on the top of the convex curved surface, and a convex portion is provided around the first friction portion 1. A second friction portion 2 made of a curved surface is provided in an annular shape. The second friction part 2 is provided close to the first friction part 1. The first friction body A and the second friction body A are smoothly connected to form a series of convex curved surfaces. The curvature radius R1 of the convex curved surface of the first friction part 1 is set larger than the curvature radius R2 of the convex curved surface of the second friction part 2 (that is, R1> R2).

The ratio (R1 / R2) of the curvature radius R1 of the first friction part 1 to the curvature radius R2 of the second friction part 2 is set to 1.5 or more. Thereby, a sufficient range of selection of the contact area during frictional discoloration can be obtained.

The friction body A of FIG. 1 has a convex curved surface formed at one end of a cylindrical main body. The friction body A of FIG. 1 can be used by directly gripping the outer surface of the main body when the color of friction is changed.

Moreover, the friction body A of FIG. 1 is attached to one end of the holder 3 as shown in FIG. 2, and can be used by gripping the holder 3 when discoloring the friction. In the present embodiment, the outer surface of the friction body A is press-fitted into the inner surface of the mounting hole formed at one end of the holder 3.

In the friction body A of the present embodiment, the first friction portion 1 when the first friction portion 1 is pressed with a constant load because the curvature radius R1 of the first friction portion 1 is larger than the curvature radius R2 of the second friction portion 2. Is set larger than the contact area between the second friction portion 2 and the writing surface when pressed with a constant load. When the large area of the handwriting of the thermochromic ink is thermally discolored using the friction body A of the present embodiment, the first friction part 1 having a large contact area with the writing surface at a constant load (that is, the first friction part 1). The first friction part 1) having a large curvature radius R1 can be selected and used. On the other hand, when a small area of the handwriting of the thermochromic ink is to be discolored, the contact area with the writing surface at a constant load is small. The second friction part 2 (that is, the second friction part 2 having a small curvature radius R2) can be selected and used. Thereby, the friction body A can select and use a friction part having a contact area having a size suitable for a desired thermal discoloration area.

The holder 3 may be a member having only the function of holding the friction body A, but other than this, for example, the thermochromic ink is incorporated inside and the thermochromic ink can be discharged to the outside. Examples include a writing instrument body in a thermochromic writing instrument provided with a nib or a detachable cap on the nib side of the thermochromic writing instrument.

In addition to the cylindrical shape, the shape of the main body of the friction body A of the present invention may be a cone, a pyramid, a prism, a rectangular parallelepiped shape, a plate shape exhibiting an arbitrary figure (for example, a star shape, a heart shape, etc.), an arbitrary shape, etc. Any shape such as a shape imitating a figurine may be used.

<Second Embodiment>
A second embodiment of the present invention is shown in FIGS.
The friction body A of the present embodiment is made of an elastic material (for example, SEBS resin, SBS resin). The friction body A has a convex curved surface.

A first friction portion 1 having a convex curved surface (specifically, a convex spherical surface) is provided on the top of the convex curved surface, and a convex portion is provided around the first friction portion 1. A second friction portion 2 made of a curved surface is provided in an annular shape. The second friction part 2 is provided close to the first friction part 1. The first friction body A and the second friction body A are smoothly connected to form a series of convex curved surfaces. The curvature radius R1 of the convex curved surface of the first friction part 1 is set smaller than the curvature radius R2 of the convex curved surface of the second friction part 2 (that is, R1 <R2).

The ratio (R2 / R1) of the curvature radius R2 of the second friction part 2 to the curvature radius R1 of the first friction part 1 is set to 1.5 or more. Thereby, a sufficient range of selection of the contact area during frictional discoloration can be obtained.

The friction body A of FIG. 3 has a convex curved surface formed at one end of a cylindrical main body. The friction body A of FIG. 3 can be used by directly gripping the outer surface of the main body when the color of friction is changed.

Further, as shown in FIG. 4, the friction body A of FIG. 3 is attached to one end of the holder 3, and can be used by gripping the holder 3 when discoloring the friction. In the present embodiment, the outer surface of the friction body A is press-fitted into the inner surface of the mounting hole formed at one end of the holder 3.

In the friction body A of the present embodiment, the radius of curvature R2 of the second friction portion 2 is larger than the radius of curvature R1 of the first friction portion 1, so that the writing surface and the second surface when pressed with a constant load are used. The contact area with the friction part 2 is set larger than the contact area between the writing surface and the first friction part 1 when pressed with a constant load. When the large area of the handwriting of the thermochromic ink is thermally discolored using the friction body A of the present embodiment, the second friction portion 2 having a large contact area with the writing surface under a constant load (that is, The second friction part 2) having a large radius of curvature R2 can be selected and used. On the other hand, when the small area of the handwriting of the thermochromic ink is to be thermally discolored, the contact area with the writing surface at a constant load is small. The first friction part 1 (that is, the first friction part 1 having a small curvature radius R1) can be selected and used. Thereby, the friction body A can select and use a friction part having a contact area having a size suitable for a desired thermal discoloration area.

The holder 3 may be a member having only the function of holding the friction body A, but other than this, for example, the thermochromic ink is incorporated inside and the thermochromic ink can be discharged to the outside. Examples include a writing instrument body in a thermochromic writing instrument provided with a nib or a detachable cap on the nib side of the thermochromic writing instrument.

In addition to the cylindrical shape, the shape of the main body of the friction body A of the present invention may be a cone, a pyramid, a prism, a rectangular parallelepiped shape, a plate shape exhibiting an arbitrary figure (for example, a star shape, a heart shape, etc.), an arbitrary shape, etc. Any shape such as a shape imitating a figurine may be used.

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

Explanation of symbols

A friction body 1 first friction portion 2 second friction portion 3 holder R1 radius of curvature R2 of first friction portion radius of curvature of second friction portion

Claims (3)

A friction body capable of thermally changing the handwriting of the thermochromic ink by rubbing the handwriting of the thermochromic ink and the frictional heat generated at that time, and comprising a friction part made of an elastic material having a convex curved surface, A friction body comprising a plurality of friction portions having different curvature radii on a convex curved surface. A first friction part is formed at the top, a second friction part is formed in the vicinity of the first friction part, and the curvature radius of the first friction part is set larger than the curvature radius of the second friction part. The friction body according to claim 1, wherein the first friction portion and the second friction portion form a series of convex curved surfaces. A first friction part is formed at the top, a second friction part is formed in the vicinity of the first friction part, and the radius of curvature of the first friction part is set smaller than the radius of curvature of the second friction part. The friction body according to claim 1, wherein the first friction portion and the second friction portion form a series of convex curved surfaces.

Images