JPH0364362A - Structural member of timepiece - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a component for a watch using a resin composition in which a thermoplastic resin is reinforced with vapor grown carbon fibers having acidic functional groups.

[Conventional technology]

Traditionally, watch components used WC-Co as exterior parts.
Recently, practical research using powdered SUS and powdered Ti is known. Furthermore, as a component for watches whose basic composition is thermoplastic resin, which has mechanical strength (i.e. wear resistance, chemical resistance, and thermal properties),
For example, in Japanese Patent Publication No. 55 45576, glass fiber,
Alternatively, a thermoplastic resin is filled with metal fibers, metal powder, etc. A high strength watch component is disclosed.

[Problems that the invention attempts to solve]

Watch components manufactured using conventional powder molding and sintering can achieve high accuracy (HV1300) that cannot be easily obtained using ordinary metals such as carbide cases, but at the same time, they have a high degree of freedom in terms of design. restrictions are very large. In addition, materials using powdered SUS or powdered T+, which are currently undergoing practical research, have reached 98% of the theoretical density through forming processing using the HIP method, but voids and uneven filling can be eliminated. However, if the surface of a watch component is polished, countless bits will appear, making it impossible to obtain the metallic luster and corrosion resistance required for the component, and furthermore, there is no freedom in terms of design in molding. It has many drawbacks such as very large restrictions on the degree of use, and has not been put into practical use.

Furthermore, if the thermoplastic resin is filled with glass fibers, metal fibers, metal powder, etc. to provide high strength, or if the thermoplastic resin has a large molecular weight, the flowability of the resin will be poor and the surface texture will be poor. In order to improve fluidity, fluidity is improved by selecting a resin with a low molecular weight or adding a lubricant, but even though the fluidity is improved, resin compositions that have been improved in this way do not cause paris during injection molding. mechanical strength is also reduced. Furthermore, the method of improving fluidity by adding a metal with high specific gravity such as tungsten poses a practical problem since high specific gravity metal powder such as tungsten is an extremely expensive metal powder.

The present invention solves these problems by using a high-molecular-weight thermoplastic resin, which is highly filled with vapor-grown carbon fiber and metal powder, and has high strength and fluidity. The purpose of the present invention is to provide an assembly for watch components that can produce components with good skin and high commercial value at low cost.

[Means to solve the problem]

The present inventors have so far developed a new carbon material.

Vapor grown carbon fiber 0 (hereinafter referred to as VGC) having acidic functional groups
We have been conducting research on the development of VGCF-A (abbreviated as F-A) and the practical application of the characteristics and reactivity of this material.
While conducting various practical tests focusing on the unique morphology, mechanical properties, chemical and thermal stability, and light resistance of
Not only does CCF-A have an excellent shape, agglomeration state, and dispersion state in other substances, the VCCF resin composition also has improved dimensional stability and weather resistance, and is a low-warping material that is suitable for watch components. Heading The present invention has been arrived at.

The present invention uses a thermoplastic resin of 20 to 70% by weight and a fiber diameter of 0.
01-4 pm, acidic functional groups 3-500 μeq/g
This is a component for a watch, characterized in that it is made of a resin Mi parabolite consisting of 5 to 50% by weight of vapor grown carbon fiber and 0 to 30% by weight of metal powder.

In the present invention, VCCF-A is a fibrous carbonaceous material produced by heating a carbon source such as a hydrocarbon in the presence of a catalyst and growing it in a vapor phase. These are carbonaceous substances in various forms or carbonaceous substances obtained by heat treatment of these substances, and the acidic functional groups of the present invention are
When VCCF-A having a concentration of 500 μeq/g is observed with an electron microscope, the core part and the surrounding area are seen as follows.
It is a fiber with a unique shape consisting of annual ring-shaped carbon layers, and it is processed by crushing, crushing, cutting, etc.

In the present invention, VGCF-A having acidic functional groups of 3 to 500 ueq/g has a diameter of 0.01 to 4 am, preferably 0.01 to 2 μm, more preferably 0.01 to 2 μm.
1 μm, most preferably 0.01-0.5 μm, and the fiber length is not particularly limited, generally 5000 μm.
m or less, but may be even shorter, such as 1000μ layer or 1
00 microns or 107 microns may be used, and fibrous materials obtained by crushing, cutting, or crushing these into shorter lengths, or granular or irregularly shaped materials may also be used. 3 acidic functional groups
V CCF-,A having ~500μeq/g has high carbon purity, generally 97.5% or more, particularly 98% or more,
Most preferably it is 98.5% or more.

Furthermore, the VCCF-A used in the present invention having 3 to 5.00 μeq/g of acidic functional groups is preferably a graphitizable carbonaceous material, and furthermore, in the structural analysis by X-ray analysis, the VCCF-A used in the present invention is Constant Go 7.10-6.8
Particularly preferred are those in the range of 8, most preferably 7.0.
~6.89.

In the present invention, the watch component is VCCF-A&It
The composition ratio is 5 to 50% by weight, preferably 10 to 40% by weight.
, particularly preferably 10 to 35% by weight, most preferably 1
Weight at 0-35% weight.

If the amount is less than 5% by weight, the mechanical properties will not be improved, and if it is more than 50% by weight, the mechanical properties will be improved, but it will take a long time to improve the dispersion state, which is disadvantageous in terms of cost. Moreover, fluidity deteriorates, impairing molding processability.

In the present invention, thermoplastic resins include polyamide resins such as nylon 6 and nylon 66, polyester resins such as polyacecool resin and polyethylene terephthalate, polycarbonate resins, and ABS resins, which preferably have high molecular weights. Those with low molecular weight have low Binkers hardness and are not suitable for watch components.

Among thermoplastic resins, polyamide resin with excellent mechanical properties is preferable, and nylon 66 resin is more preferable.
A value in the range 0 is used. Preferably minute F=load (
0.3 kgf) S=<Surface area of the depression m2 d=<Length of the diagonal of the depression θ=Facing angle of the diamond indenter Example 1 VGCF-A with a diameter of 0.05 to 0.1 uts ()
Lys acetylacetonate iron and benzene 1400"C were introduced into a heating space and synthesized in a suspended state. The carbon content was 99% or more and the lattice constant was 7.02), and was oxidized with N2 gas containing 0.7% oxygen to form acidic functional groups. VCCF- with an amount of 140μeq/g
A was slightly crushed to make it easier to disperse. Further, the fiber length was determined by electron microscopy, and the fiber length was found to be substantially 5 μm or more.

250g of this VCCF-A and polyamide resin (Leona, type 1500 (Asahi Kasei Kogyo ■trade name) molecular weight 32
．． 500 was cryogenically ground and adjusted to an average particle size of 50 μm, and mixed with 650 g in a Henschel mixer for 5 minutes. 100 g of stainless steel metal powder with an average particle size of 80 μm layer was added to the resulting Mi powder and mixed for another 2 minutes. The composition obtained by dispersion was pelletized using a PCM30 type twin screw extruder manufactured by Ikegai Tekko ■.

Furthermore, after drying these pellets,
Test pieces were made by injection molding using a C-20 injection molding machine at an injection temperature of 320°C and a mold temperature of 85°C, and various physical properties were measured. The results are shown in Table 1.

Example 2 A test piece was prepared in the same manner as in Example 1, except that the blending amounts were changed to 350 g of VCCF-A, 550 g of polyamide resin, and 100 g of stainless metal powder, and the physical properties were evaluated. The results are shown in Table 1.

Example 3 A test piece was prepared in the same manner as in Example 1, except that the blending amounts were changed to 450 g of VCCP-A and 550 g of polyamide resin, and the physical properties were evaluated.

The results are shown in Table 1.

Comparative Example 1 Polyamide resin (Leonanoib 15 used in Example 1)
A test piece was prepared and evaluated using the method of Example 1. The results are shown in Table 1.

Comparative Example 2 Glass fiber (fiber diameter 9 μm, fiber length 3 am) was
A test piece was prepared and evaluated using the method of Example 1 using a blending amount of 50g of polyamide resin, 550g of polyamide resin, and 100g of stainless metal powder. The results are shown in Table 1.

From the results in Table 1, the mechanical properties of the test piece made with the VGCF-A mixed composition are improved by several steps in terms of tensile strength, bending strength, and bending elastic modulus, compared to Comparative Example 1, which uses only nylon resin. Further, a comparison between a test piece made from a composition containing 35% by weight of glass fiber and Example 2 shows that the VGCF-A-containing resin composition has excellent mechanical properties and Pinker's hardness.

(Margins below) Table 1 [Effects of the Invention] The watch component of the present invention has a decorative appearance, is lightweight due to the synthetic resin shape, has a clean surface and has a good feel, and has a fine surface of VCCF-A. Reinforcement by fiber diameter is strengthened, making it possible to perform fine injection molding not only on the exterior parts of watches, but also on interior parts, such as gear shafts, etc. VCCF-A's conductivity prevents static electricity, making it useful not only for preventing watches from getting dirty, but also for watch manufacturing. It is also effective during assembly and is the optimal material in terms of cost.

Claims (1)

[Claims] 1. Thermoplastic resin 20-70% by weight, fiber diameter 0.01-
A component for a watch comprising a resin composition comprising 5 to 50% by weight of vapor-grown carbon fibers having a diameter of 4 μm and acidic functional groups of 3 to 500 μeq/g and 0 to 30% by weight of metal powder. .