JP2001150858A - Barrel body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the barrel body of a writing utensil which has both an anti-skid function and elastic characteristics and has no tackiness. SOLUTION: In a barrel body formed by assembling a base material made of a rigid material and a handling part made of a flexible elastic material, a diamond-like carbon film is formed on the surface of the flexible elastic material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a writing instrument, a makeup tool,
A diamond-like carbon film (hereinafter referred to as DLC (Diamo
nd-LikeCarbon film).

[0002]

2. Description of the Related Art Conventionally, a method of mechanically forming grooves such as knurls on the surface of a shaft, or using silicone rubber, various thermoplastic elastomers, or NBR, to impart a non-slip function to a grip portion of the shaft is known. A method in which a member is formed and attached to a shaft body gripping portion, or as described in Japanese Utility Model Publication No. 6-38710, "the outer periphery of a shaft made of a hard synthetic resin is integrally coated with a non-slip soft material". (Different materials) A method of forming a shaft body holding portion by two-color molding has been proposed.

However, the method of mechanically forming grooves such as knurls merely forms irregularities on the shaft body surface.
Although an anti-slip function can be obtained, there is no characteristic such as elasticity to which a grasped finger fits. Therefore, in order to have both the anti-slip function and the elasticity, it is generally practiced to use a soft elastic material such as the above-mentioned silicone rubber, various thermoplastic elastomers, NBR, etc. for the grip of the shaft. Further, it has been proposed to control the hardness of the soft elastic material in order to improve the elasticity characteristics. For example, Japanese Patent No. 2681750 discloses that "a soft elastic material such as thermoplastic elastomer, NBR, natural rubber, or silicone rubber is used as a grip member of a ballpoint pen barrel, and the hardness of the grip member is Shore hardness Hs (JIS A). 30-90
Is preferable in the range of ".

[0004]

In a shaft such as a writing instrument, a makeup tool, an electronic input pen, etc., in order to have both an anti-slip function and an elastic characteristic, a soft elastic material used at least in a portion to be gripped of the shaft is required. The lower the hardness of the material, the higher the hardness of the base material located inside, the more the elasticity of the finger holding the shaft body that fits the soft elastic material can be obtained and gripped. The anti-slip function at the time is improved. However, when the soft elastic material has a low hardness, a different problem of stickiness when gripping occurs. For example, Japanese Patent No. 2681750 discloses that "a shore hardness of 30 or less gives a slightly sticky feel".
More specifically, the hardness Hs (JIS
A) Even if it is about 30 to 40, it has good anti-slip function and good fit to fingers when gripping,
It is known that dust and the like easily adhere. The adhesion of fingerprints, hand stains, dust and the like occurs due to the tackiness (sticking phenomenon) of the soft elastic material. This tackiness is caused by adding oil in the process of lowering the hardness or by increasing the compounding amount of rubber in the compounding ratio of resin and rubber. When this tackiness occurs, the writing feel deteriorates as described above. Further, there is a problem that the appearance is impaired due to adhesion of dust or the like due to tackiness. In view of the above viewpoint, the hardness Hs (JIS
It is preferable to use those having A) of 40 to 90. However, when a material having a hardness of Hs (JIS A) of 40 or more is used, it has a non-slip function but has poor elasticity characteristics. When a material having a hardness of less than Hs (JIS A) 40 is used, the anti-slip function and the elasticity are good as described above.
Stickiness and dust adhere when gripped.
Therefore, an object of the present invention is to provide a shaft body having both a non-slip function and an elastic property and having no tackiness even if the soft elastic material has low hardness.

[0005]

According to the present invention, there is provided a shaft comprising a base made of a hard material and a holding portion made of a soft elastic material, wherein the soft elastic material has a diamond-like carbon film on its surface. A gist is characterized by being formed.

[0006]

FIG. 1 shows an embodiment. FIG. 1 shows a longitudinal sectional view of a shaft 1 of a writing instrument. This shaft 1
Is composed of a grip portion 2 and a base material 3. The following method can be employed for manufacturing the shaft body 1. For example, a method of manufacturing the shaft body 1 by forming the grip portion 2 and the base material 3 by two-color molding or insert molding. Or
First, the grip part 2 and the base material 3 are separately formed by compression molding, transfer molding, injection molding, extrusion molding, vacuum casting, or the like, and the grip part 2 is coated and mounted on the base material 3 to manufacture the shaft 1. Is the way.

It is necessary to use a soft elastic material for the grip portion 2 constituting the shaft body 1. This is to provide the shaft body 1 with a non-slip function and elastic characteristics. Examples of the soft elastic material include silicone rubber, various thermoplastic elastomers (styrene, olefin, urethane, polyamide, polyester, etc.), NBR, natural rubber, urethane rubber, and the like. Among the soft elastic materials, silicone rubber is particularly preferable because it has excellent anti-slip properties and elasticity, and has effects of improving writing feel and preventing fatigue. The base material 3 maintains the shape of the shaft body 1 and uses a hard material. The material is AS, AB
A thermoplastic resin such as S, polyethylene, polypropylene, polycarbonate, and PET, or a metal such as brass and aluminum can be used.

A coating layer 4 of a DLC film is formed on the surface of the grip 2. The DLC film has the same carbon bond as natural diamond, but has an amorphous structure without a fixed crystal structure because it partially includes a bond with hydrogen or the like. DLC films are characterized by high hardness and excellent wear resistance. Further, the surface of the DLC film has minute irregularities (schematic diagram in FIG. 2). Even if tackiness occurs by using a low-hardness soft elastic material as the material of the grip portion 2, the tackiness can be eliminated by the DLC film, and the fine irregularities on the surface reduce the contact area with the finger. It can reduce and give a smooth feel when gripped. Further, the gripping portion 2 is coated with a DLC film only on the surface thereof, and the inside of the gripping portion 2 has a low hardness, so that it can have both a non-slip function and elasticity.

As a method for forming a DLC film, there are conventionally known various processing methods, such as a plasma CVD method, a sputtering method, and an ion plating method. The DLC film may be formed on the entire soft elastic material layer 2 or may be formed on a part thereof.

In the above-described embodiment, a writing instrument has been exemplified as a product. This is because a writing instrument often grips the shaft for a particularly long time. However, the shaft according to the present invention,
The present invention is not limited to the embodiments, and can take various forms.
Therefore, the present shaft can be used for a handle of a screwdriver or a shaft of an applicator such as a makeup tool. Further, in the above-described embodiment, the gripping portions 2 constituting the shaft body 1 have the same outer diameter. However, the shape is not limited to such a shape. Or
The unevenness may be formed by a physical / chemical method. Further, the grip portion 2 located outside the substrate 3 may be formed so as to entirely cover the substrate 3 as shown in FIG.
It may be formed only on the grip portion. Further, each layer constituting the shaft body 1 may be colorless, colored, or a combination thereof.

[0011]

As described above, the present invention provides a writing implement, a makeup implement,
In a shaft body such as an electronic input pen, in a shaft body in which a base material made of a hard material and a grip portion made of a soft elastic material are combined, the soft material is formed by forming a diamond-like carbon film on a surface thereof. Therefore, it is possible to obtain a shaft body having both a non-slip function and elastic characteristics and having no tackiness.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an embodiment.

FIG. 2 is a schematic diagram of a shaft body surface of an example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shaft 2 Grasping part 3 Base material 4 Coating layer

Claims (3)

[Claims] 1. A shaft body in which a base material made of a hard material and a gripping part made of a soft elastic material are combined, wherein the soft elastic material has a diamond-like carbon film formed on a surface thereof. And the shaft body. 2. A material of a grip portion made of a soft elastic material,
The shaft according to claim 1, wherein the shaft is silicone rubber. 3. The shaft according to claim 1, wherein the shaft is used for a body of a writing instrument.