JP2695833B2 - Japanese musical instrument parts made of plastic - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a Japanese musical instrument component made of a polyamide-based composite material. More specifically, the present invention relates to a Japanese musical instrument part having the same tone, appearance, and feel as a ivory Japanese musical instrument part.

[Conventional technology and its problems] Japanese musical instrument parts such as shamisen repellents, pegs, pegs, koto-posts, koto nails, etc. have a high degree of elasticity, moderate weight, abrasion resistance, and feel to produce a good tone. , Balance and not to damage the strings.

For example, the timbre of the shamisen is determined by the state of the overtones contained therein, but in order to provide wide (particularly high-pitched) vibration of the strings, the repellent material of the playing tool must have high elasticity and moderate weight. Also, the quality of the feel has a great effect on a player who requires delicate movement, and also requires lubricity as well as abrasion resistance to prevent abrasion and damage of a string of silk thread. These are important factors that cannot be supplemented by acting or auxiliary means.

Currently, ivory is the most suitable material for these requirements for Japanese musical instrument parts. In particular, for concerts, ivory products are exclusively used for Japanese musical instrument parts such as shamisen repellents, pegs, pegs, and kotoshira and kotome.

However, elephants have been reduced in number from year-over-century overfishing to small animals now under heavy protection, and ivory collection is decreasing year by year. Especially in the case of large ivory products like shamisen repellent, large ivory is needed,
Production of ivory-made Japanese musical instrument parts has been steadily declining in recent years because the amount of ivory that can be obtained from a single ivory is limited. In addition, acoustically, fresh elastic ivory, which is commonly called live ivory, is required as a repellent material. As a result, today, ivory-made Japanese musical instrument parts are extremely expensive and difficult to obtain.

On the other hand, as well as wooden products for practice,
Although there are thermoplastic resins such as ABS resin and thermosetting resins such as urea resin, Japanese musical instrument parts obtained from these materials have considerably lower acoustic characteristics than ivory products, and silk strings for shamisen strings. Scratches were severe and unsatisfactory.

The present inventors have proposed in JP-A-59-195689 a composition in which a fibrous filler, a fluororesin powder, and a crystallization accelerator are mixed with a polyester resin. Shamisen repellent and koto nails made with that composition have the effect of imparting ivory-like lubricity by adding fluororesin powder, but on the other hand, exposed to the surface while playing the repellent or koto nail for a long time It has been found that there is a disadvantage that the particles of the fluororesin that have been separated come off, and the repellency and the claws gradually chip away.

The present invention has the same tone, feel, and appearance as ivory, and frequently used parts such as shamisen repellent and kotome are hardly damaged,
It is another object of the present invention to provide a plastic Japanese musical instrument part in which the shamisen strings made of silk thread are markedly scarred.

[Means for Solving the Problems] The present inventors have made intensive studies to achieve the above object, and as a result, completed the present invention.

The plastic Japanese musical instrument part of the present invention has the following composition: (A) 30 to 87% by weight of a polyamide resin, (B) 3 to 50% by weight of a fibrous filler, (C) 5 to 40% by weight of a whisker, And (D) a resin composition comprising 5 to 40% by weight of an inorganic filler, wherein the total of (A) to (D) is 100% by weight, and the specific gravity of the composition is 1.4 or more; The rate is 40,000 kg / cm ² or more.

 Next, the present invention will be described in more detail.

As the polyamide resin (A) used in the present invention, an aliphatic polyamide resin, an aromatic polyamide resin,
An alicyclic polyamide resin, a side-chain-substituted aliphatic polyamide resin and the like can be mentioned.

As the aliphatic polyamide resin, for example, nylon 6, nylon 11, nylon 12, etc. obtained from ω-lactam or ω-amino acid; for example, nylon 6,6, nylon 6,10, nylon 6 obtained from diamine and dicarboxylic acid , 1
And the like.

Examples of the aromatic polyamide resin include a reaction product of an aromatic dicarboxylic acid such as isophthalic acid and terephthalic acid with a diamine; and a reaction product of an aromatic diamine such as meta-xylylenediamine (MXD) with a dicarboxylic acid. Products and the like.

Further, examples of the alicyclic polyamide resin include a reaction product of bis (paraaminocyclohexyl) methane (PACM) and the like and a dicarboxylic acid, and examples of the side chain-substituted aliphatic polyamide resin include 2,2,4- / 2,4,4-trimethylhexamethylenediamine (TMD) and a reaction product of a dicarboxylic acid.

The average molecular weight Mw of the polyamide resin used in the present invention is 3,000 to 50,000.

The polyamide resin (A) is blended in an amount of 30 to 87% by weight based on the total composition. If the amount is less than 30% by weight, the fluidity decreases, and
If the content exceeds% by weight, it is difficult to improve specific gravity and elastic modulus, so that the intended purpose cannot be achieved.

The fibrous filler (B) is a component that enhances the flexural modulus and strength of a plastic Japanese musical instrument part and improves its tone and the like.

Examples of the fibrous filler used in the present invention include glass fibers, inorganic fibers other than glass fibers, carbon fibers, and heat-resistant organic fibers.
~ 20μm, glass fiber or carbon fiber chopped strand of fiber length 10mm or less, glass fiber milled fiber,
Pitch-based carbon fibers, aromatic polyamide fibers, aromatic polyimide fibers, aromatic polyamideimide fibers, and combinations thereof.

Of these, glass fiber chopped strands are preferable, and carbon fiber is also preferable because a molded product becomes black and has an appearance having a unique feeling, and a characteristic product is obtained.

The fibrous filler (B) is incorporated in the entire composition at 3 to 50% by weight. If it is less than 3% by weight, the flexural modulus is low and the acoustic characteristics are inferior to those of Japanese ivory parts, while if it exceeds 50% by weight, the surface condition of the Japanese parts becomes worse and the parts themselves wear. The nature increases.

The whiskers (C) are compounds that form needle-like crystals, and include, for example, potassium titanate whiskers and silicon carbide whiskers, and preferably have a diameter of 0.05 μm or more. Whiskers are added to reduce the repellency of the shamisen and damage to koto nails. The compounding amount is 5 to 40% by weight of the total composition. If the amount is less than 5% by weight, slidability is inferior and repellency and damage to the koto nail are increased. On the other hand, if it exceeds 40% by weight, the cost increases, and it is impossible to provide inexpensive Japanese musical instrument parts.

The inorganic filler (D) is blended to increase the specific gravity of the polyamide resin composition.

Examples of the inorganic filler used in the present invention include glass beads, glass flakes, wollastonite, and neutral clay talc; metal oxides, sulfates, and silicates of Groups II and IV of the periodic table. For example, zinc oxide,
Examples include magnesium oxide, calcium sulfate, barium sulfate, calcium silicate, magnesium silicate, titanium oxide, lead oxide, and the like, which are used alone or in combination.

The inorganic filler (D) is blended in an amount of 5 to 40% by weight in the whole composition. If it is less than 5% by weight, the specific gravity is too small and the tone becomes poor, while if it exceeds 40% by weight, the workability of extrusion molding in the production process is reduced.

The specific gravity of the Japanese musical instrument part of the present invention is 1.4 or more. If it is less than 1.4, the same tone as ivory cannot be obtained, and the rugged weight peculiar to ivory is lacking.

The plastic Japanese musical instrument part of the present invention is prepared by, for example, weighing and mixing a predetermined amount of a polyamide resin (A), a fibrous filler (B), a whisker (C), and an inorganic filler (D), and then uniformly mixing them. And molded. As the mixing method, a known method, for example, a method in which the above weighed composition is loaded into a V-type tumbler, a double-cone tumbler, a Nauta mixer, or the like and mixed can be used.

The resin composition used in the present invention is usually provided as a pellet-shaped molding material which is subjected to heat shaping and is easy to handle. For heat shaping, a known single-screw or twin-screw extruder can be used.

Extruder cylinder head pressure is preferably 20 kg / c
m ² or more, and the resin temperature at the outlet is 350 ° C. or less, particularly preferably 240 to 320 ° C. The resin composition obtained under such conditions usually has a specific gravity of 1.4 or more. At this time, if necessary, a stabilizer against heat or light, a release agent for improving the releasability at the time of injection molding, and a dye or pigment for producing an ivory color can be added. The ivory color can be easily obtained by using a yellow pigment, a brown or red pigment, a white pigment, and a black pigment, but the amount of use thereof is determined according to the application.

Next, the above-mentioned pellet-like composition is molded into the Japanese musical instrument part of the present invention by, for example, an injection molding machine. At this time, special consideration is required for injection molding because Japanese musical instrument parts are often molded articles having a thick part. That is, it is preferable that the mold temperature is 60 ° C. or higher, the gate is thick, the injection time is long, and the injection pressure is 50 kg / cm ² more than the short shot pressure.
It is necessary to take into consideration such that the molded product is raised immediately above and is immediately immersed in hot or cold water. Also, when the molded article is annealed at a temperature equal to or higher than the mold temperature, the quality of the molded article tends to be improved.

Since the plastic Japanese musical instrument part of the present invention is fiber-reinforced by a fibrous filler having high tensile strength and elastic modulus, it has excellent mechanical properties.

Further, by adding a predetermined amount of whiskers, it is possible to reduce damage to frequently used parts such as repelling of shamisen and kotome.

Furthermore, since a polyamide resin having high crystallinity is used as a base material, the mechanical properties and heat resistance of the matrix are excellent, and the appearance such as gloss and gloss is similar to that of ivory. Furthermore,
Since it is a thermoplastic resin, conventional injection molding and extrusion molding methods can be applied to molding, and as a result, the plastic Japanese musical instrument parts of the present invention are excellent in mass productivity and the molded articles are inexpensive. It is.

 Hereinafter, the present invention will be described in detail with reference to examples.

[Examples] Examples 1 to 6 Polyamide resin (A), chopped strand glass fiber (B) having a fiber length of 3 mm (in the following table, this was GF
And the whiskers (C) and the inorganic fillers (D) as compounds shown in the following table were blended in the ratios shown in the following table, and then mixed in a double-cone tumbler for 5 minutes. It has become.

Next, these formulations were applied at a cylinder temperature of 270 ° C and a pressure of 30 ° C.
~ 70kg / cm ² , screw rotation speed 90rpm, 65mmφ, L / D =
The mixture was extruded by a vent single screw extruder having a screw at 36, and the extruded strand was cut and shaped into pellets.
The specific gravity of each of the obtained pellets was 1.40 or more.

Next, these pellets were injected into a Japanese steel injection molding machine N-14.
Loading the 0B II, using a single-piece shamisen repellent die with a gate size of 10 × 10 mm, cylinder temperature 270 ° C., molding cycle 150 seconds, injection time 45 seconds, cooling time 90 seconds, injection pressure 300 kg / A shamisen repellent having a weight of 135 g was molded at a mold temperature of 120 ° C. at a mold temperature of cm ² .

Also, using another mold, 8 oz, 45 mm diameter screw type injection molding machine, cylinder temperature 270 ° C, mold temperature 120 ° C, molding cycle 30 seconds, injection time 10 seconds, cooling time 10 seconds, injection Under the conditions of a pressure of 400 kg / cm ² , a bending test piece of ASTM D 790 was formed from the pellet and subjected to a bending elastic modulus measurement test.

Next, the shamisen repellent obtained by the above method was tested for its appearance, feel, tone, degree of damage to the strings of the shamisen, and degree of damage to the repellent. The timbre test was determined by playing the shamisen and repeatedly playing the open string III of four tones.

The evaluation of the appearance, feel, tone, and the degree of damage to the strings of the shamisen repellent and the degree of damage to the repellent are compared based on high-quality ivory products, and these characteristics are classified into the following three categories, ○, △, and ×. Performed by classification.

The results of these tests are summarized in the following table.

Comparative Examples 1 to 3 Resin compositions were produced in the same manner as in Examples 1 to 6, except that the compounds shown in the following table were used as the respective components, and the compounds were blended in the ratios shown in the following table. The same test as in Example 6 was performed. The results are shown in the following table.

In the table, nylon MXD6, nylon 6, and nylon 6,6 mean a polyamide represented by the following formula.

Nylon MXD6 (Renny 1022, Mitsubishi Gas Chemical Co., Ltd.) Nylon 6 (T-802, Toyobo _{(Ltd.)) HNH-C 5 H 10} -CO n OH nylon 6,6 (Leona 1300S, from Asahi Kasei _{(Inc.)) HNH-C 6 H 12} -NHCO-C 4 H 8 -CO _n OH As is clear from the table, the repellency of the shamisen molded from a composition in which the respective components of the polyamide resin (A), the fibrous filler (B), the whiskers (C) and the inorganic filler (D) are blended in predetermined amounts, It can be said that it is a plastic Japanese musical instrument part with little damage and the same physical properties as ivory.

[Effects of the Invention] According to the present invention, it is possible to provide an inexpensive plastic musical instrument part that has the same physical properties as ivory, is not easily damaged, is inexpensive, and has excellent mass productivity.

Continued on the front page (72) Inventor Mitsuru Takahashi 4-1, 1-1 Ushikawa-dori, Toyohashi-shi, Aichi Prefecture Inside Mitsubishi Rayon Co., Ltd. (72) Inventor Sadao Kondo 2-3-1 Kyobashi, Chuo-ku, Tokyo Mitsubishi Rayon Co., Ltd. (72) Inventor Masahiro Takehashi 2-8-17 East Coast South, Chigasaki City, Kanagawa Prefecture (56) References JP-A-49-40923 (JP, A) JP-A 63-43756 (JP, B2) 52-37766 (JP, B2) JP-B 52-39285 (JP, B2) Jiko 54-19145 (JP, Y1)

Claims (2)

(57) [Claims] (A) 30 to 87% by weight of a polyamide resin, (B) 3 to 50% by weight of a fibrous filler, (C) 5 to 40% by weight of a whisker, and (D) 5 to 40% by weight of an inorganic filler. A resin composition wherein the total of (A) to (D) is 100% by weight, and the specific gravity of the composition is 1.4 or more and the flexural modulus is 40,000 kg / cm ² or more Japanese plastic musical instrument parts characterized by: 2. Japanese plastic musical instrument parts are repellent of shamisen,
2. A piece, a bobbin, a kotoboshi or a kotome.
Japanese plastic musical instrument parts described in.