JPH10250282A - Writing utensil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a tip part hard to get worn during writing even when it is in abutment with the surface of a piece of paper by incorporating an additive in a synthetic resin composition forming the leading tip part of a writing tool for increasing the wear resistance. SOLUTION: A tip 6 of synthetic resin to be press fitted and secured at a front portion of a slider 5 in such a manner as to envelop a core holding portion 5a of a tip of the slider 5 is formed from POM (acetal) resin, ABS resin or polypropylene as a raw material and molybdenum, tungsten, silicone, graphite or carbon added in advance for increasing the wear resistance. When writing is continued while the slider 5 is being retracted that holds a core at a strength bearing the writing pressure generated during writing, the distal end of the tip 6 is put in a state in which it is brought into abutment with the surface of a piece of paper and the tip is subjected to easy wear. However, it is possible to make the tip difficult to wear by adding an additive in the synthetic resin composition forming the leading tip 6 of the slider 5 for increasing the wear resistance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a writing instrument such as a mechanical pencil and a ballpoint pen, and more particularly to a writing instrument having a wear-resistant synthetic resin tip which may be worn when writing.

[0002]

2. Description of the Related Art In a conventional writing instrument, in order to increase abrasion resistance, for example, a ball-point pen ball is formed into a spherical main body using a material such as a cemented carbide, and the surface of the spherical main body is mainly composed of molybdenum disulfide or the like. In some cases, a lubricating film formed by blending a thermosetting resin was formed. (The actual opening 53-
156634).

[0003]

However, the ball of the ball-point pen must be constantly in contact with the paper surface during writing from the viewpoint of the function of continuously sending out ink.
Moreover, the size of the ball itself is extremely small (0.5 to
0.8 mm), a somewhat expensive material could be used.
There are many leading-edge parts of a writing implement that require more material than the ball of such a ball-point pen and also require properties as a synthetic resin. These tip parts do not always contact the paper surface like the ball of a ballpoint pen, but depending on the writing state, these tip parts may come into contact with the paper surface and wear out.

[0004] In addition, the taste of writing implements varies widely, and the writing angle (the angle between the paper and the writing implement) varies from 40 to 80 degrees. The relationship between the writing angle, the holding position, the writing pressure, and the character size is roughly as shown in Table 1 below.

[0005]

[Table 1]

[0006] As described above, the writing implement is not written upright with respect to the paper surface, and writing is usually performed by laying down diagonally. In the case of a ballpoint pen or a mechanical pencil, the tip, the tip pipe, etc., are being written. The paper was worn by touching the paper surface. In particular, in the tip-sliding mechanical pencil, while the tip of the slider holding the lead fed out by the knocking operation retreats as much as the slider can retreat along with the wear of the lead by writing, the tip frequently contacts the paper surface. Was. In this case, when the tip part is a synthetic resin member, there is a problem that the degree of wear is extremely high as compared with metal.

In the case of a ball-point pen, when the holder constituting the chip is made of synthetic resin, the ball is held by the holder due to contact with the paper surface during writing or by rotational contact between the inner wall of the tip of the holder and the ball. There was a great risk that the synthetic resin holder would wear out and cause problems such as ball drop.

[0008] When such a tip part is worn, not only does it detract from the aesthetic appearance of a writing instrument, but also tends to lose writing due to writing habits, and it becomes easy to write only in a specific direction during writing. Come. In particular, in the case of a ballpoint pen, inconveniences such as "starting out" and "botting" of ink occur due to wear of the holder. Regardless of the type of ballpoint pen currently on the market, wear of the holder part is fatal to the ballpoint pen because of the phenomenon of crying out more or less.

[0009] In a mechanical pencil as well, the components at the tip end determine the performance of the mechanical pencil, and it may be said that the functional quality and durability are affected by the accuracy, material and the like. In particular, the role of the tip pipe is important, and if worn, it may cause breakage of the core during writing and clogging of the waste due to wear.

Accordingly, the present invention has been made to solve the above-mentioned conventional drawbacks, and there is a possibility that a tip part of a writing instrument may come into contact with a paper surface during writing, and is made of synthetic resin which is more easily worn than metal. Also in this case, an object of the present invention is to provide a writing instrument in which a wear-resistant additive is previously contained in a synthetic resin so that these parts are hardly worn even when they come into contact with the paper surface during writing. That is, it is intended to improve wear resistance by adding an additive while taking advantage of the characteristics (suitable for mass production, low cost, and possibility of a complicated shape) as a synthetic resin as compared with a metal.

[0011]

According to the present invention, in order to attain the above object, according to the present invention, a tip part of a writing instrument which may be worn by contact with a paper surface during writing contains an additive which increases abrasion resistance. A writing instrument made of the synthetic resin composition is obtained.

Further, according to the present invention, the additive is molybdenum, tungsten, silicone, graphite,
A writing implement that is either carbon is obtained.

Still further, according to the present invention, the synthetic resin component of the writing instrument containing the additive is a tip,
A writing instrument that is either a tip pipe, a slider integrated with them, or a tip is obtained.

Further, according to the present invention, there is provided a writing implement wherein the additive is contained in an amount of 5 to 20% by weight based on the synthetic resin material.

Still further, according to the present invention, there is provided a writing instrument whose tip part is made of POM resin, ABS resin or polypropylene.

Further, according to the present invention, there is provided a writing implement in which the additive causes the tip part to be colored.

[0017]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a partial longitudinal sectional view of a writing instrument of a tip-tip slide type showing an embodiment of the present invention. In the drawings, reference numeral 1 denotes a shaft cylinder of a mechanical pencil with a sliding tip. A chuck 3 for feeding a lead through a lead tank 2 by a knocking operation is provided in the barrel 1.
Is provided.

A slider 5 which is pushed out while the core is held by the chuck 3 is slidably provided in the front tool 4 in front thereof. In addition, a front end tip 6 of a synthetic resin is press-fitted and fixed to a front portion of the slider 5 so as to surround the core holding portion 5a at the front end of the slider 5.

More specifically, the tip 6 of the synthetic resin is made of, for example, POM (acetal) resin, ABS, or the like.
A resin or polypropylene is used as a raw material, and molybdenum, tungsten, silicone, graphite or carbon, which increases abrasion resistance, is added in an amount of 5 to 20% by weight. When the ratio of the additive to the synthetic resin of the material is less than 5% by weight, sufficient abrasion resistance cannot be obtained. On the other hand, when the ratio exceeds 20% by weight, a soft touch on the paper surface, which is a characteristic of the synthetic resin of the material, is obtained. It is not suitable because it will damage it, so its critical value will be in the range described above.

The operation of the mechanical pencil according to the embodiment will be described below. At the time of writing, for example, when a rear knock portion (not shown) is knocked, the lead tank 2 is advanced. As the lead tank 2 advances, the chuck 3 also advances. In the process of moving the chuck 3 forward, the chuck ring 3a comes into contact with the locking step 1a formed on the inner periphery of the barrel 1, and the engagement with the chuck 3 is released.

Further, when the chuck 3a moves forward, it comes into contact with the rear end of the slider 5 to move the slider 5 forward. When the chuck 3 is advanced by a predetermined knock stroke, the knock is released, and the chuck 3 is retracted with the lead tank 2 by the return spring 7. In this case, the lead holding portion of the slider 5 is left at the advanced position together with the tip 6 while holding the lead.

Since the holding force of the slider 5 holds the lead with a strength enough to withstand the writing pressure during writing, the slider 5 is in the forward position while being worn during writing and the lead is shortened to the tip of the tip 6, Writing becomes possible. Then, the writing is continued while the slider 5 is retracted. However, the writing is performed in a state where the tip of the chip 6 is in contact with the paper surface by the writing in the retreating process. It is easily worn.

However, at this time, the tip 6 fixed to the tip of the slider 5, which is in contact with the paper surface,
As described above, although it is made of a synthetic resin, it contains an additive that increases abrasion resistance, so that it is hard to be worn. In this embodiment, the slider 5 and the tip 6
However, depending on the shape of the slider 5, it may be formed integrally.

FIG. 2 shows a mechanical pencil with a fixed tip pipe according to another embodiment of the present invention. In this example, the leading tool 4 and the tip pipe 4a are integrally formed of synthetic resin. For example, molybdenum, tungsten, silicone, graphite, or carbon of 5 to 20% by weight, which increases wear resistance, is added in advance using, for example, POM resin, ABS resin, or polypropylene as a material.

That is, a tip 4 is provided at the tip of the barrel 1, and the tip 4 is formed integrally with the tip body 4b and the tip pipe 4a. The tip pipe 4a may come into contact with and wear on the paper surface. (See the dotted line in FIG. 3).
a has a function to make it easier to see the characters being written even during writing in the case of fine writing (preventing blind spots) and to hold against a ruler etc. and to protect the strength of the core. If the function is impaired, the core will rattle during writing and cause a break in the core, etc. However, since the tip pipe 4a has abrasion resistance, it is the same as in the above embodiment. The effect is obtained. .

FIGS. 4 and 5 show examples of the use of a normal ballpoint pen, and an appropriate angle with respect to the paper is usually 60 degrees as shown in FIG. 4 (a). However, depending on the person, there is a case where the writing is performed while lying down as shown in FIG. 4B, and in this case, the portion indicated by the arrow may be worn. By the way, characters can be written on a ballpoint pen by transferring the attached ink onto the paper by rotating the ball. However, not all of the ink adhering to the ball is transferred to the paper, only the portion of the sphere that is in contact with the inner paper is transferred, and the rear one rotates while adhering to the ball. If it is normal, it returns as it is, but if the distance between the holder and the ball is narrowed due to wear, the appearance of the ink attached to the edge of the holder holding the ball will be removed.

As a result, a state in which the ink is solidified and adhered between the ball and the holder portion, that is, a so-called "crying" occurs. In addition, a phenomenon called “bottom” occurs in which the excess ink mass forms stains on the paper surface. This is due to wear and deformation of the chip and the like caused by contact with the paper surface. Normally, the paper surface and the holder part come into direct contact with each other, such as a person who has a habit of writing with writing down, and the part holding the ball gradually wears.

That is, FIG. 5A is a side view, and the arrow Y
The direction is the writing direction, and the ball rotates in the arrow X direction. The portion indicated by the symbol a in the drawing indicates the portion transferred to the paper. FIG. 5B is a front view, and reference numeral b in FIG.
The portion indicated by indicates the ink that is not transferred to the paper. Further, FIG. 5C is a cross-sectional view, and what is indicated by reference numeral c is so-called “crying”, and d is “bottom”.

In the case of a ball-point pen using water-based ink, if a person uses a water-based ball-point pen with the writing angle constantly set, the ball does not come into contact with the paper surface, but the tip of the holder always touches the paper surface. Will be. In the case of an oil-based ballpoint pen, it is impossible to write in this state, so you must try to write it upright, but in the case of an aqueous ballpoint pen, you can write beautifully, so write it in that state. Then, the holder part which is always in contact with the paper surface is worn due to friction with the paper surface, causing a ball drop or the like.

FIG. 6 shows a ball-point pen according to another embodiment of the present invention.
In other words, the tip 14 of the barrel 11 integrally formed of synthetic resin is shown. The tip of the ballpoint pen refill 12 is made of synthetic resin such as POM resin, ABS resin or polypropylene, and is made of molybdenum or tungsten which has increased wear resistance in advance. , Silicone, graphite or carbon 5
A tip tip 16 to which about 20% by weight is added is fixedly mounted.
4.

FIG. 7 is a partially enlarged cross-sectional view of the chip 16, in which silicone is added to the holder portion 9 made of synthetic resin as a wear-resistant substance. An ink guide hole 9b is formed in the inner wall at the tip of the holder 9 following the taper 9a. The ball guide 9 is located in the ink guide hole 9b.
The ball 10 is rotatably mounted on the ball seat 9c so as to form a gap 9d with the holder 9.

In order to use the ball-point pen shown in FIG. 6, a knock portion (not shown) is knocked to advance the refill 12 against the urging force of the spring 17 rearward. Protruding to a position indicated by a dotted line, and then retreat to the position indicated by the dashed line, but can be written at this position. Therefore, even when such a holder portion 9 is used lying down as shown in FIG. 4B, the holder portion 9 also has abrasion resistance, so that the same effect as in the above embodiment can be obtained. .

[0033]

【Example】

(Example 1) A slider of a mechanical pencil as shown in FIG. 1 was formed from a synthetic resin composition in which molybdenum disulfide was added in an amount of 5% by weight to an ABS resin, and the tip of the slider was tapered using a taper abrasion tester. As a result, it was found that the characteristics of the synthetic resin were sufficiently retained and the abrasion resistance was good.

(Example 2) A tip of a mechanical pencil shown in FIG. 2 was formed from a synthetic resin composition in which 10% by weight of tungsten disulfide was added to a POM resin, and the tip of a core pipe of the tip was used. Was tested using a taper abrasion tester, and it was found that the properties of the synthetic resin were retained and the abrasion resistance was good.

(Example 3) As shown in FIG. 5, a holder portion of a ball-point pen was formed from a synthetic resin composition in which 20% by weight of graphite (graphite) was added to a polypropylene resin, and the tip portion of the holder portion was tapered. As a result of a test using a tester, it was found that the properties of the synthetic resin were retained and the abrasion resistance was very excellent.

(Example 4) As shown in FIG. 5, a holder portion of a ball-point pen was formed from a synthetic resin composition in which 10% by weight of silicone was added to an ABS resin, and the tip of the holder portion was tapered with a taper wear tester. As a result of the test, it was found that the properties of the synthetic resin were retained and the abrasion resistance was good.

(Example 5) As shown in FIG. 5, a holder portion of a ball-point pen was formed from a synthetic resin composition in which 5% by weight of carbon was added to a POM resin. As a result of using and testing,
It was found that the properties of the synthetic resin were sufficiently retained and the abrasion resistance was good.

[0038]

Since the writing implement of the present invention is implemented in the above-described form, the tip parts which easily come into contact with the paper surface during writing increase abrasion resistance, so that various inconveniences due to wear, for example, aesthetic appearance are impaired. Not only that, it has a remarkable effect of preventing the writing implement from rotating and the writing implement to rotate during writing, and the ink from a ballpoint pen, such as "crying out", "bottom" and dropping of a ball.

Since the above-mentioned substances which increase wear resistance except silicone also have a coloring action, when managing various kinds of parts, the coloring makes it easy to discriminate, which is extremely effective in parts management. .

[Brief description of the drawings]

FIG. 1 is a sectional view showing a main part of a mechanical pencil using a slider according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a main part of a mechanical pencil according to another embodiment of the present invention.

FIG. 3 is an enlarged cross-sectional view showing the leading tool of FIG. 2 whose tip is worn.

FIG. 4 is an explanatory diagram showing a writing angle of a ballpoint pen.

FIG. 5 is an enlarged explanatory view showing a relationship between a tip and a ball of the ballpoint pen in FIG. 4;

FIG. 6 is a sectional view of a main part showing an operation state of a ballpoint pen refill;

FIG. 7 is an enlarged sectional view showing the ballpoint pen tip of FIG. 6;

[Explanation of symbols]

 1,11 shaft cylinder 2,12 core tank 3 chuck 4,14 tip 5 slider 6,16 tip 7,17 spring 9 holder part 10 ball

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 101/00 C08L 101/00

Claims (6)

[Claims] 1. A writing implement characterized in that a tip part of the writing implement which is likely to be abraded by contacting the paper surface during writing is made of a synthetic resin composition containing an additive which increases abrasion resistance. 2. The writing implement according to claim 1, wherein the synthetic resin composition contains any of molybdenum, tungsten, silicone, graphite, and carbon. 3. The writing instrument according to claim 1, wherein the tip component of the writing instrument is one of a tip, a tip pipe, a slider integrated with them, and a tip. 4. The writing instrument according to claim 1, wherein the additive is contained in an amount of 5 to 20% by weight based on the synthetic resin material. 5. The writing implement according to claim 1, wherein the tip part is made of POM resin, ABS resin or polypropylene. 6. The writing implement according to claim 1, wherein the additive causes the tip part to be colored.