JP2008197450A - Resin composition for woodwind musical instrument reed - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reed for a woodwind musical instrument with stable quality. <P>SOLUTION: The reed for a wood wind musical instrument is obtained by applying a known injection molding method, by using a resin composition for a woodwind musical instrument reed containing cellulose fiber of 5-200 pts.mass based on a thermoplastic resin of 100 pts.mass. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a woodwind instrument lead resin composition and a woodwind instrument lead formed by molding the resin composition.

  Bamboo leads have been used for woodwind instruments such as clarinet and saxophone. However, bamboo has a problem in that it is difficult to make the quality uniform.

Patent Document 1 discloses an invention in which a bamboo product smoke-treated in a smoke atmosphere containing superheated steam is used as a lead for woodwind instruments. Patent Document 2 discloses an invention of a reed musical instrument lead using wood acetylated with acetic anhydride. Patent Document 3 discloses an invention in which at least a vibrating portion is made into a woodwind instrument lead whose surface is treated with a silicone-based resin. Patent Document 4 discloses an invention of a woodwind instrument lead formed of a liquid crystal polymer.
Japanese Patent Laid-Open No. 2002-18815 Japanese Patent No. 2974652 JP-A-8-202349 JP 2001-75556 A

  The inventions of Patent Documents 1 and 2 are not sufficient in terms of stabilization of quality, and the inventions of Patent Documents 3 and 4 have problems in that the process is complicated and the manufacturing cost is high.

  It is an object of the present invention to provide a woodwind instrument lead resin composition capable of supplying lead of stable quality and a woodwind instrument lead obtained from the resin composition.

  The invention of claim 1 provides, as means for solving the problems, a resin composition for a woodwind instrument lead containing 5 to 150 parts by mass of cellulose fibers with respect to 100 parts by mass of a thermoplastic resin, and a woodwind instrument lead obtained therefrom. To do.

  By using a resin composition for a woodwind instrument lead of the present invention and applying a known resin molding method, it is possible to supply a woodwind instrument lead having a stable quality.

<Resin composition for woodwind instrument lead>
As thermoplastic resins, olefin resins (preferably polyethylene, polypropylene), styrene resins (homopolymer, AS resin, HIPS, etc.), rubber-containing styrene resins (ABS resin, AES resin, ABSM resin, AAS resin, etc.) , Polyamide resin, polybutylene terephthalate resin, polyphenylene sulfide resin, polyether ether ketone resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polyphenylene sulfide resin, polycarbonate resin, amorphous (transparent) nylon, liquid crystal polymer, (meth) acrylic Resin, polyacetal resin, polyphenylene ether resin, acrylonitrile / styrene copolymer resin, biodegradable resin (PBS, PBSA, PCL, PLA, cellulose acetate And the like can be given. These thermoplastic resins can be used alone or in admixture of two or more.

  Examples of the cellulose fiber include hemp fiber, bamboo fiber, cotton fiber, wood fiber, kenaf fiber, hemp fiber, jute fiber, banana fiber, and coconut fiber. The cellulose fiber preferably has a high α-cellulose content from the viewpoint of high thermal stability, more preferably 80% by mass or more, still more preferably 85% by mass or more, and particularly preferably 90% by mass or more.

  The average fiber diameter of the cellulose fibers is preferably 0.1 to 1000 μm, more preferably 1 to 500 μm, still more preferably 5 to 200 μm, and particularly preferably 10 to 50 μm.

  The average fiber length of the cellulose fibers is preferably 0.01 to 100 mm, more preferably 0.01 to 50 mm, still more preferably 0.1 to 10 mm, and particularly preferably 0.1 to 5 mm.

  The aspect ratio (length / diameter) of the cellulose fiber is preferably 2 to 1000, more preferably 3 to 500, still more preferably 5 to 200, and particularly preferably 5 to 100.

Cellulose fibers may be surface-treated with a coupling agent (a silane coupling agent having a functional group such as an amino group, a substituted amino group, an epoxy group, or a glycidyl group). It is 5-200 mass parts with respect to a mass part, Preferably it is 30-190 mass parts, More preferably, it is 50-180 mass parts.

  In the composition of the present invention, an inorganic pigment, an organic pigment, a dye, an auxiliary colorant, a dispersant, a stabilizer, a plasticizer, a modifier, an ultraviolet absorber or a light stabilizer, an antioxidant, if necessary. An antistatic agent, a lubricant, a release agent, a crystal accelerator, an elastomer for improving impact resistance, and the like can be blended.

  The composition of the present invention is not limited in its production method as long as the contained cellulose maintains a fibrous form. For example, cellulose fiber is blended with a thermoplastic resin and melt-kneaded by an extruder. It can manufacture by applying well-known methods, such as. As the cellulose fiber, in addition to known products including commercially available products, for example, those obtained by applying the first step of the production method shown below can be used.

  The composition of the present invention is a first step shown below from the viewpoint of improving the stability of quality when a thermoplastic resin and cellulose fiber are mixed so as to be more uniform and the molded product is used as a lead for woodwind instruments. It is preferable to obtain by applying the production method having the third step.

[First step]
In the first step, the cellulose fiber aggregate is put into a mixer having rotating blades as stirring means, and the cellulose fiber aggregate is defibrated by stirring at high speed.

  The mixer only needs to have rotating blades as stirring means, and preferably has heating means. For example, a Henschel mixer manufactured by Mitsui Mining Co., Ltd., FM20C / I (capacity 20 L), ( Kawata Supermixer SMV-20 (capacity 20 L) can be used.

  The rotating blades are usually composed of two upper blades and lower blades, or three upper blades, intermediate blades, and lower blades, but the number is not limited. The shape of the blade is not limited, but for example, the kneading type is used for the upper blade, the high circulation / high load is used for the lower blade, and the melt is used when the intermediate blade is used.

  In the first step, it is preferable to stir in the range of the average peripheral speed of the rotating blades during stirring in the range of 10 to 100 m / second, more preferably the average peripheral speed is 10 to 90 m / second, and still more preferably the average peripheral speed is 10 Stir at ~ 80 m / sec.

  The treatment in the first step is not limited as long as the cellulose fiber aggregate can be sufficiently defibrated. For example, the point in time when the cellulose fiber aggregate has been visually confirmed to be cottony can be confirmed. The end of Since the average peripheral speed and stirring time of the rotating blades change depending on the type, shape, size, input amount, and the like of the cellulose fiber aggregate, the time point when it changes to cotton as described above may be used as a reference. Is preferred.

  Cellulose fiber aggregates are a combination of many cellulose fibers, which may be natural or industrial products, hemp fiber, bamboo fiber, cotton fiber, wood fiber, kenaf fiber, hemp fiber, jute fiber, banana Aggregates such as fibers and coconut fibers can be used.

  The cellulose fiber preferably has a high α-cellulose content from the viewpoint of high thermal stability, more preferably 80% by mass or more, still more preferably 85% by mass or more, and particularly preferably 90% by mass or more.

  As the cellulose fiber aggregate, a pulp sheet or a cut product thereof is preferable. The thickness, shape, and size of the pulp sheet or the cut product thereof are not particularly limited, and can be selected within a range in which the operation of adding to the mixer and the stirring operation can be performed smoothly.

  When the cellulose fiber aggregate is a sheet, for example, a sheet having a thickness of 0.1 to 5 mm, preferably 1 to 3 mm, a width of 1 to 50 cm, and a length of about 3 to 100 cm can be used.

  When the cellulose fiber aggregate is a cut product of a sheet, for example, a strip having a thickness of 0.1 to 5 mm, preferably 1 to 3 mm, a width of 2 mm to 1 cm, and a length of about 3 mm to 3 cm, or A rectangular shape having a side of about 2 mm to 1 cm is preferable.

  The moisture content of the cellulose fiber aggregate is preferably 20% by mass or less, more preferably 17% by mass or less, and still more preferably 15% by mass or less. A water content of 20% by mass or less is preferable because the temperature rise due to generation of frictional heat is facilitated in the next step, and the cellulose fiber aggregate is easily defibrated and no aggregate remains. The moisture content is determined by moisture measurement using the Karl Fuscher method.

  If necessary, organic fibers other than cellulose fibers can be used. In the total amount of cellulose fibers and organic fibers, the ratio of cellulose fibers is preferably 50% by mass or more, more preferably. It is 55 mass% or more. Examples of organic fibers other than cellulose fibers include nylon fibers, polyester fibers, and acrylic fibers.

[Second step]
In the second step, a mixture in which the thermoplastic resin is adhered to the fibrillated cellulose fiber by melting the thermoplastic resin by the generated frictional heat by stirring after the thermoplastic resin is put in the mixer. Get. The 1st process and the 2nd process can be made into one continuous process, without stopping stirring of a mixer.

  In the first step, since the cellulose fiber aggregate is defibrated in the mixer, a required amount of thermoplastic resin is added thereto and stirred at a high speed. This high-speed stirring generates frictional heat and raises the temperature in the mixer, so that the thermoplastic resin melts and adheres to the fibrillated cellulose fibers, and a mixture of cellulose fibers and the thermoplastic resin is obtained.

  In the second step, it is preferable to stir in the range of the average peripheral speed of the rotating blades during stirring in the range of 10 to 100 m / second, more preferably the average peripheral speed is 10 to 90 m / second, and still more preferably the average peripheral speed is 10 Stir at ~ 80 m / sec. If stirring is continued, the temperature in the mixer will continue to rise, and the power of the motor will increase. It is preferable to reduce the rotational speed by gradually or decelerating the stirring speed in accordance with the increase in power and the temperature in the mixer so that the average peripheral speed falls within the above range.

  When stirring is continued in this state, the power increases again, so the mixture is discharged to the cooling mixer used in the next third step to be connected. At this time, in this mixture, the fibrillated cellulose fibers are adhered almost uniformly in the thermoplastic resin.

  In the second step, the mixer can be heated by a heating means in order to assist the temperature increase in the mixer and facilitate the production of the mixture of cellulose fibers and thermoplastic resin. The temperature at this time is preferably about 120 to 140 ° C.

[Third step]
In the third step, the mixture obtained in the second step is stirred at a low speed while being cooled. By the treatment in this step, the mixture is solidified (granulated by solidification). In the third step, in order to increase the cooling efficiency of the mixer, it is preferable to use a mixer (preferably having a cooling means) different from the mixer used in the first step and the second step.

  In the third step, it is preferable to stir in the range of 1 to 30 m / sec of the average peripheral speed of the rotating blades during stirring, more preferably 2 to 25 m / sec, more preferably 3 to 3. Stir at ~ 25 m / sec. The stirring speed in the third step is smaller than the stirring speed in the first step and the second step.

  In the treatment in the third step, the point in time when the mixture of the cellulose fiber and the thermoplastic resin is solidified to such an extent that it can be handled as a molding material can be terminated. In addition, since the thermoplastic resin once solidified will melt again if the temperature in the mixer rises too much due to generation of frictional heat, it is preferable to manage the temperature in the mixer also in the third step.

[Fourth step]
By the processes of the first step to the third step, a solidified product (granulated product) containing a thermoplastic resin and cellulose fibers is obtained. An arbitrary component can be mixed with the granulated product as necessary to obtain the composition of the present invention.

<Lead for woodwind>
A woodwind instrument lead having a predetermined size can be obtained by applying a known molding method such as an injection molding method, a press molding method, or cutting using the composition of the present invention. The reed for woodwind instruments is suitable as a reed for woodwind instruments such as clarinet genus and saxophone genus.

Examples and Comparative Examples Using the components shown in Table 1, compositions of the present invention were produced by the following method.

[First step]
Heat the heater mixer (upper blade: kneading type, lower blade: high circulation / high load, with heater and thermometer, capacity 20L, Henschel mixer FM20C / I, manufactured by Mitsui Mining Co., Ltd.) to 140 ° C. The cellulose fiber products shown in Table 1 were charged and stirred at an average peripheral speed of 50 m / sec. After about 2 minutes, the cellulose fiber product changed to cotton.

[Second step]
Subsequently, after the thermoplastic resin shown in Table 1 was put into the heater mixer, stirring was continued at an average peripheral speed of 50 m / sec. The power of the motor at this time was 2.5 kW. When the mixer temperature reached 120 ° C., MPP was added and stirring was continued.

  At about 10 minutes, power started to increase. One minute later, the power increased to 4 kW, so the peripheral speed was reduced to a low speed of 25 m / sec. Furthermore, the power started to increase again due to the continued low speed stirring. After 1 minute and 30 lines from the start of low speed rotation, the current value reached 5 kW, so the outlet of the mixer was opened and discharged to the connected cooling mixer.

[Third step]
Cooling mixer [Rotating blade: Standard blade for cooling, with water cooling means (20 ° C) and thermometer, capacity 45L, product name cooler mixer FD20C / K, manufactured by Mitsui Mining Co., Ltd.) Start stirring at an average peripheral speed of 10m / sec. The stirring was terminated when the temperature in the mixer reached 80 ° C. By the treatment in the third step, the mixture of the thermoplastic resin and the cellulose fiber was solidified, and a granulated product having a diameter of about several mm to 2 cm was obtained.

Using the obtained granulated material, it was molded by the following method.
(injection molding)
PP-based composition Molding temperature: 170-200 ℃, mold temperature: 70 ℃, cooling time 40sec
Polylactic acid-based composition Molding temperature: 180-210 ℃, mold temperature: 40 ℃, cooling time 60sec
(Injection molding-cutting)
A 120 × 120 × 6mm thick side gate mold, injection molded under the following conditions, and then machined with an NC cutting machine to the same dimensions as a commercially available lead for clarinet.

PP-based composition Molding temperature: 170-200 ℃, mold temperature: 70 ℃, cooling time 40sec
Polylactic acid-based composition Molding temperature: 180-210 ℃, mold temperature: 40 ℃, cooling time 60sec
Details of each component shown in Table 1 are as follows.
PP: Sanalomar J139
Polylactic acid: LASEA H100 manufactured by Mitsui Chemicals
Wood fiber: Dissolved pulp NDP-T manufactured by Nippon Paper Industries Co., Ltd.
Bamboo Fiber: Thai Phoenix Co. Bamboo Pulp Commercial Lead: VANDOREN Clarinet Lead No. 3
(Test method)
The details of the test method shown in Table 1 are as follows.
(1) Reaction of sound Ten clarinet players used each lead, and the evaluation was made based on the number of players who said that the sound was not interrupted and the reaction was good.
(2) Balance of pitch Ten clarinet players used each lead and evaluated by the number of players who were good.

(3) Sound of sound Ten clarinet players were asked to use each lead, and the number of leads with a variation in volume was considered to be one or less, and the number of players considered good was evaluated.

Evaluation was obtained that there was no difference between the leads of Examples 1 to 10, and the sound response, sounding, and pitch balance were good.

Claims (2)

  A resin composition for a woodwind instrument lead, comprising 5 to 200 parts by mass of cellulose fibers with respect to 100 parts by mass of a thermoplastic resin. A woodwind reed comprising the resin composition according to claim 1.