JP3317052B2 - Speaker diaphragm and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a loudspeaker diaphragm used for various kinds of audio equipment and a method of manufacturing the same.

[0002]

2. Description of the Related Art Materials conventionally used for speaker diaphragms include metal materials such as aluminum, titanium, beryllium and magnesium, ceramic materials such as alumina and boron, and paper pulp such as wood pulp and bast fiber. Materials, synthetic resins such as polypropylene, and reinforced plastic materials are used.

[0003] Recently, door-mounted speakers for vehicles and speakers for PAs used outdoors have been required to be waterproof to a shampoo solution for washing a car or rainwater, so that conventional paper pulp is mainly used. Vibration plates made of synthetic resins such as olefin resins such as polypropylene and polymethylpentene, thermosetting resins such as phenol resins and epoxy resins, and super engineering plastic resins such as liquid crystal polymers are increasing.

[0004]

However, the above-mentioned olefin-based synthetic resin has poor adhesiveness due to poor wettability of its surface, and the diaphragm must be subjected to special treatments such as corona surface treatment and low-temperature plasma treatment. However, there is a problem that the adhesiveness cannot be ensured. Further, even if a filler is added, there is a problem that the bending elastic modulus of the material is low and the reproduction frequency band as a speaker is narrow. Further, since the heat resistance of the polypropylene resin is low, there is a limitation on the use site of the speaker.

[0005] Phenolic resins and epoxy resins have poor moldability in the shape of a diaphragm, and have a problem that the productivity as a diaphragm is poor because the molding takes time. In addition, there is a problem that the internal loss of the material is low, the peak dip of the sound pressure is severe as a characteristic of the speaker, the harmonic distortion is large, and the sound quality is unpleasant.

Further, the liquid crystal polymer has the advantage that the reproduction frequency band is wide and the internal loss is large, but the adhesiveness is poor like the olefin resin. Further, there is another problem that a general-purpose speaker cannot be adopted because the material is expensive.

SUMMARY OF THE INVENTION An object of the present invention is to solve these problems and to provide a low-cost speaker diaphragm having good sound quality and performance and high productivity.

[0008]

In order to solve this problem, a speaker diaphragm according to the present invention comprises a mixture of an amorphous polyphenylene ether resin and a styrene resin obtained by polymerization of 2-6 xylenol, or the aforementioned polyphenylene ether. 0 to 50 parts of a rubbery substance and 0 to 50 parts of an inorganic filler with respect to 100 parts of a resin comprising a graft polymer of a resin and a styrene resin and a crystalline polyamide resin.
Parts, a thermoplastic resin composition obtained by blending 0.01 to 10 parts of a compatibilizer for improving the compatibility between the polyphenylene ether resin and the polyamide resin, and heat-melting the thermoplastic resin composition into a desired shape. Is what you do.

[0009]

With this structure, the non-crystalline and highly polar polyphenylene ether resin and the styrene resin are used, so that the adhesiveness is good. In addition, the addition of a compatibilizer that improves the compatibility of both resins increases the cohesive strength of the resins, thereby improving the adhesiveness.

[0010] Further, the heat resistance is high as a whole because it is mainly composed of a polyamide resin or a polyphenylene ether resin having high heat resistance. Also, by forming a polymer alloy of an amorphous polyphenylene ether resin and a polyamide resin, the dimensional stability at the time of moldability is good due to the effect of the micro-sea-island structure of both, and the flowability at the time of hot melting of the polyamide resin is good. Good nature. In addition, since both the main polyphenylene ether resin and the polyamide resin have higher rigidity than the olefin resin, a larger flexural modulus can be obtained by adding scaly mica, talc or the like. In addition, a large internal loss can be obtained by adding a rubber-like substance,
The impact strength is improved.

[0011]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a front half sectional view showing a speaker diaphragm according to the embodiment, and FIG. 2 is an enlarged sectional view for explaining the structure of the diaphragm in detail. In FIG. 10A is a neck portion of the diaphragm 10, 1 is a polyphenylene ether resin, 2 is a polyamide resin, 3 is a compatibilizer using maleic anhydride, and 4 is a filler.

In order to examine the acoustic properties of the speaker diaphragm according to the present invention, the compositions of Examples 1 to 5 described in (Table 1) and Comparative Examples described in (Table 1) were applied to a diaphragm 10 having a diameter of 16 cm as shown in FIG. 1 and 2, the neck 10 of the diaphragm 10
Injection molding was performed from A to the peripheral portion. In addition, since injection molding cannot be performed for Comparative Example 3, press molding was performed using a hot press mold. At this time, the shaping time for the diaphragm was 15 seconds in Examples 1 to 5, 15 seconds for Comparative Examples 1 and 2, but 15 minutes for Comparative Example 3.

[0014]

[Table 1]

The most preferable method for forming the vibration plate 10 is injection molding from the neck portion 10A of the vibration plate 10 toward the outer peripheral portion. Then, the diaphragm 10 is once extruded into a sheet having a predetermined thickness. A method of vacuum forming or hot pressing a sheet into a diaphragm shape may be used.

Next, the diaphragm 1 thus obtained is
A test piece of 4 × 20 mm was punched out from 0 along the radial direction, and the sound velocity and the internal loss (tan δ) were measured by the vibration reed method. In addition, test specimens were prepared in accordance with the specifications in parentheses, and the thermal deformation temperature (ASTMD648) and the flexural modulus (ASTMD790) were measured. In order to measure the adhesive strength, a chloroprene phenolic adhesive (Diabond Industrial Co., Ltd. DB)
-1600 W), and the adhesive strength of the diaphragm of each of Examples and Comparative Examples was measured. These results are summarized in (Table 2).

[0017]

[Table 2]

Next, as a cloth edge material, a material shown in the following example and a material described below as a comparative example were used by using an adhesive by using the diaphragm 10 of the above-mentioned Example 1, and the coating resin of the cloth material was changed to gold. Mold temperature 200 ° C, 1kg / cm ²
The vibration plate 10 was adhered by heat fusion under the following pressure, and the adhesive strength was measured. This is summarized in (Table 3).

[0019]

[Table 3]

The main body of the diaphragm 10 and the diaphragm 1
A method of bonding a cloth edge to an outer peripheral portion of the diaphragm 10 to prevent the ventilation of the cloth edge and heat and melt a polymer material coated on the surface at the time of edge molding and at the same time to the outer peripheral portion of the diaphragm 10 Take the method of heat bonding. At this time, the adhesive force to the main body of the diaphragm 10 is improved by using either a polyamide resin latex or a polystyrene resin latex as a polymer material coated on the cloth edge, or a mixture of these and other resins. is there.

The specifications of the edge material of the sixth embodiment are as follows.
Thread thickness is 30th in both length and width.
This is a cloth material in which a total weight of 175 g / cm ^{2 of} latex obtained by mixing styrene butadiene rubber latex and polyamide resin latex in an equal ratio to a plain cotton base cloth of 0 cotton is coated. The specifications are
Thread thickness is 30th in both length and width.
This is a cloth material in which a total weight of 175 g / cm ^{2 of} latex obtained by mixing styrene-butadiene rubber latex and polystyrene resin latex in an equal ratio to a plain cotton woven base fabric of zero is coated. Is
Thread thickness is 30th in both length and width.
This is a cloth material in which a styrene-butadiene rubber latex is coated to a total weight of 175 g / cm ^{2 on} zero cotton plain-woven base cloth.

[0022]

The loudspeaker diaphragm of the present invention configured as described above has a high sound velocity, a large internal loss, a high heat resistance, and an excellent adhesiveness required for the diaphragm. In addition, the speaker diaphragm can be provided at a low cost with good production efficiency, thereby increasing the industrial value.

[Brief description of the drawings]

FIG. 1 is a front half sectional view of a speaker diaphragm according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of the same.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Polyphenylene ether resin 2 Polyamide resin 3 Compatibilizer (maleic anhydride) 4 Filler 10 Vibration plate 10A Neck

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-255537 (JP, A) JP-A-59-86993 (JP, A) JP-A-3-274999 (JP, A) 255161 (JP, A) JP-A-62-283183 (JP, A) JP-A-4-198268 (JP, A) JP-A-57-1733 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04R 7/02 C08L 21/00 C08L 71/12 C08L 77/00

Claims (7)

(57) [Claims] 1. A mixture of an amorphous polyphenylene ether resin and a styrene resin obtained by polymerization of 2-6 xylenol, or 100 parts of a resin comprising a graft polymer of the polyphenylene ether resin and a styrene resin and a crystalline polyamide resin. On the other hand, when the rubbery substance is 0 to 5
0 parts, 0-50 parts of an inorganic filler, and 0.01-10 parts of a compatibilizer for improving the compatibility between the polyphenylene ether resin and the polyamide resin are heat-melted and molded. Diaphragm for speaker formed into desired shape. 2. A polyamide resin comprising 6-6 nylon or 6
The speaker diaphragm according to claim 1, wherein the diaphragm is nylon. 3. The rubbery substance is ethylene propylene rubber,
The speaker diaphragm according to claim 1, wherein the diaphragm is a single or a plurality of rubber-like substances selected from styrene-butadiene rubber, styrene-butadiene-styrene block copolymer, and maleic anhydride-grafted ethylene propylene rubber. 4. The diaphragm for a speaker according to claim 1, wherein one or a plurality of fillers selected from flaky mica, graphite, talc, and glass fiber are used as the inorganic filler, and these are kneaded. 5. The speaker diaphragm according to claim 1, wherein the compatibilizer is at least one selected from maleic anhydride, maleic acid, and fumaric acid. 6. An edge made of cloth having a surface coated with a polymer material for preventing ventilation is disposed on the outer peripheral portion of the diaphragm and heated, whereby the polymer material is heated and melted at the edge, and the edge and the diaphragm are heated. 2. The method for manufacturing a speaker diaphragm according to claim 1, wherein the speaker is bonded by thermal bonding. 7. A loudspeaker according to claim 6, wherein the polymer material coated on the cloth edge is a polyamide resin latex or a polystyrene resin latex, or a mixture of these resins and another resin. Manufacturing method of diaphragm.