JP3287750B2 - Speaker damper and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speaker damper incorporated in a speaker such as an audio output device and a method of manufacturing the same. More specifically, the present invention relates to a speaker damper which is excellent in water resistance and dimensional stability, maintains speaker performance for a long period of time, and has improved workability in its manufacture, and a method for manufacturing the same.

[0002]

2. Description of the Related Art A speaker damper is one of components of a speaker of an audio output device, and is bonded to a coil bobbin for transmitting vibration to a diaphragm (speaker cone) that emits sound radially, and to a speaker frame. It has a function of elastically supporting them, and has a form in which concentric corrugations are spread in a plane. This speaker damper is required to have, as basic features, excellent holding stability of the coil bobbin, faithful reciprocation of the diaphragm in response to stress generated in the coil bobbin, that is, excellent hysteresis.

Conventionally, various structural materials have been proposed as speaker dampers. For example, a woven fabric of phenol fibers impregnated with a phenol resin (Japanese Patent Laid-Open No. Sho 53-4)
No. 8520), a woven fabric composed of wholly aromatic polyamide fibers and cotton impregnated with a phenol resin (Japanese Patent Laid-Open No. 62-258596), and a blended yarn of para-type aromatic polyamide and meta-type aromatic polyamide fiber. A woven fabric made of a woven fabric impregnated with a curable resin such as a phenolic resin has been proposed (Japanese Patent Laid-Open No. Hei 5-183991).
Each of these uses a prepreg in which a woven fabric is impregnated with a thermosetting resin as a base material, and shapes the base material into a predetermined shape simultaneously with curing in a heating mold to form a speaker damper. Is a way to get

[0004] However, the substrate used in the above method requires a step of preparing a prepreg impregnated with a thermosetting resin as an excipient.
In the molding process, a solution of a resin such as a phenol resin or a melamine resin used as an excipient has been pointed out as a problem in the working environment such as causing rash on the skin and generating toxic gas when dried.

[0005] The molding of the base material uses a process in which the excipient is a thermosetting resin, and is cured by a heating reaction in a predetermined heating mold to form a predetermined shape. The woven fabric, which is the matrix of the material, is made of natural fiber cotton fabric and heat-resistant fiber aramid fiber or phenol fiber as described above. Is held.

However, as a molding condition, the mold temperature is usually set to a high temperature of 180 ° C. or higher. For this reason, the excipient is relatively soft rubber-like in the mold even after the completion of the curing reaction, and when removed from the molded mold, the excipient is shaped by the internal stress of the relatively rigid matrix fabric. There was a problem regarding moldability that the agent was deformed and a predetermined shape could not be maintained.

Further, after cooling to room temperature, the excipient resin maintains a very high elastic modulus, but the phenol resin or melamine resin used as the excipient has an affinity for the fibers constituting the matrix fabric. Since the molded product is repeatedly subjected to bending or bending deformation as a speaker damper material, the exfoliation occurs at the interface between the matrix fabric and the excipient, or the molded product covers the matrix fabric surface in a thin film state. Excipient that cannot follow the deflection of the flexible fabric and causes crack fracture, with which the joints at the intersections of the yarns constituting the fabric are destroyed and the rigidity of the damper is significantly reduced. Also, there is a problem in terms of durability as a speaker member.

Further, as an application requiring water resistance,
For example, in the case of a speaker mounted on a car door, the damper is susceptible to water due to rainwater from the window or water leakage during car washing, so that it is particularly required to have water resistance, and it is difficult to repeatedly wet and dry. It is required that the deformation is small, but in the above-mentioned base material, the excipient resin has a relatively high water absorption rate, and the excipient itself is deformed upon absorbing water, and the fiber surface of the fabric is covered. A crack occurs in the excipient, and the water that penetrates through the crack causes deformation due to elongation due to the absorption of water between the fibers of the matrix fabric and the fibers themselves. As a result, the molded damper is deformed and affects the performance of the speaker. , Which is a problem in terms of water resistance of the damper substrate.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances. That is, a first object of the present invention is to provide a speaker damper which is less deteriorated in performance when used as a member of a speaker and is excellent in water resistance, moisture resistance and heat resistance.
A second object of the present invention is that when used as a member of a speaker, the shape retention is not reduced by long-term use,
An object of the present invention is to provide a speaker damper that does not deteriorate the characteristics of the speaker. A third object of the present invention is to provide a method of manufacturing a speaker damper which does not adversely affect the working environment in the manufacturing process, specifically, the impregnation process and the molding process are safe and no harmful gas is generated. Is to provide.

[0010]

According to the study of the present inventors, the present invention relates to a speaker damper comprising a fabric composed of wholly aromatic polyamide yarn as a matrix component, and The aromatic polyamide yarn is constituted as a mixed yarn with a thermoplastic aromatic polyester fiber having a heat fusion temperature of 100 ° C. or lower than its thermal decomposition temperature, and (ii) within the mixed yarn, the wholly aromatic polyamide fiber Is fixed by fusing the thermoplastic aromatic polyester fibers, (iii) in the mixed yarn, the fibers constituting the yarn and the fiber surface are fixed by an excipient containing a polyester resin, and (iv) In the fabric, the mixed yarns are cross-linked at the intersection by fusion of thermoplastic aromatic polyester fibers and to an excipient containing a polyester resin. This is achieved by a speaker damper that is more secure.

According to the study of the present inventors, another object of the present invention is to provide a method for producing a speaker damper using a fabric composed of wholly aromatic polyamide yarn as a matrix component. A fabric composed of a mixed yarn of an aromatic polyamide fiber and an aromatic polyester fiber is impregnated with an aqueous solution of a water-soluble polyester resin, then dried, and then completely aromatic by fusion of the aromatic polyester fiber in a mold. Manufacture of a damper for a speaker, characterized in that polyamide fibers are fixed to each other and are pressed into a desired shape under conditions of temperature and pressure sufficient to fix the fibers and mixed yarns in a mixed yarn made of polyester resin. Achieved by the method.

Hereinafter, the present invention will be described in more detail. The matrix component in the speaker damper of the present invention is a fabric composed of wholly aromatic polyamide yarn, and this yarn is composed of a mixed yarn of wholly aromatic polyamide fiber and aromatic polyester fiber. The mixed yarn may be a filament yarn composed of each filament of a wholly aromatic polyamide fiber and an aromatic polyester fiber, or may be a spun yarn composed of each short fiber.

[0013] The wholly aromatic polyamide fiber forming the mixed yarn is a fiber having extremely excellent heat resistance and high modulus, and is obtained by polymerizing an aromatic polyamide comprising an aromatic diamine component and an aromatic dicarboxylic acid component. Formed as a component. This wholly aromatic polyamide fiber usually has a softening point or decomposition temperature of 350 ° C. or higher, particularly 400 to 550 ° C., and is extremely excellent in heat resistance.

As the wholly aromatic polyamide, for example, a polyamide in which at least 50 mol% of the repeating units are a metaphenylene isophthalamide unit or a paraphenylene terephthalamide unit is a preferred example. Examples thereof include phthalamide, polyparaphenylene terephthalamide, and a copolymer thereof. Examples of the copolymer include polyamides containing 3,4′-diaminodiphenyl ether and paraphenylenediamine as a diamine component, and a terephthalic acid component as a dicarboxylic acid component. Of these, polymetaphenylene isophthalamide is preferred.

The fineness of the wholly aromatic polyamide fiber is 0.5 to 0.5.
10 denier, preferably 1 to 5 denier is suitable. In the case of short fibers, the fiber length is preferably in the range of 20 to 75 mm.

On the other hand, in the mixed yarn forming the fabric of the matrix component of the speaker damper of the present invention, the aromatic polyester fiber used by being mixed with the wholly aromatic polyamide fiber is the same as that of the wholly aromatic polyamide fiber. It is preferably formed from a polymer having a melting point or softening point lower by 100 ° C. or more, especially 150 to 200 ° C. than the softening point (or decomposition temperature) of the polymer. This aromatic polyester is specifically 120 to 270 ° C,
Preferably from 130 to 250 ° C., particularly preferably from 140 to 250 ° C.
It is desirable to have a melting point of 220 ° C. (softening point in the case of an amorphous polymer).

As the polyester forming the aromatic polyester fiber, it is advantageous that at least 50 mol%, preferably at least 60 mol%, of all the repeating units have ethylene terephthalate units. Specific examples include polyethylene terephthalate or a copolymerized polyester containing an ethylene terephthalate unit in an amount of 50 mol% or more. In the case of a copolymerized polyester, the copolymerization components include dicarboxylic acid components such as isophthalic acid and naphthalenedicarboxylic acid; propylene glycol,
4-butanediol, diethylene glycol, 1,6-
A glycol component such as hexanediol is exemplified.

One example of the copolymerized polyester is as follows: a dicarboxylic acid component having a terephthalic acid / isophthalic acid ratio of 60/40 by weight; and a glycol component having an ethylene glycol / diethylene glycol ratio of 88/12 by weight. There is a copolyester obtained from The ratio of these components is determined by the DS of the obtained copolymerized polyester.
The softening point is about 110 ° C and the melting point is 130-1 by C measurement method.
It can be changed to be in the range of 80 ° C.

Aromatic polyester fibers having a fineness of 0.5 to 10 denier, preferably 1 to 5 denier are advantageously used. In the case of short fibers, the fiber length is 20 to 75 m.
The range of m is desirable.

The mixed yarn constituting the fabric as the matrix component comprises the wholly aromatic polyamide fiber and the aromatic polyester fiber. The mixing ratio of the two fibers is 50:50 to 85:15, preferably 5 as a weight ratio of wholly aromatic polyamide fiber / aromatic polyester fiber.
The range is 5:45 to 80:20. If the proportion of the wholly aromatic polyamide fiber is smaller than this range, problems such as impairment of the heat resistance of the fabric may occur. On the other hand, if the proportion of the aromatic polyester fiber is smaller than the above range, the fabric may be rubbed in the manufacturing process of the speaker damper.

The mixed yarn is obtained by uniformly mixing the wholly aromatic polyamide fiber and the aromatic polyester fiber in the above-mentioned ratio, and has a denier of 150 to 500, preferably 200 to 500.
Configure the fabric as ~ 400 denier yarn.

The fabric which is a matrix component of the speaker damper of the present invention is constituted by the above-mentioned mixed yarn, and may be a woven or knitted fabric.
For example, it may be a woven fabric such as a plain weave, a twill weave or a satin weave; a knitted fabric such as a warp knit or a weft knit (horizontal knit or circular knit). Among these, a woven fabric, particularly a plain woven fabric, is advantageous from the viewpoint of the characteristics as a speaker damper and its processability.

The speaker damper of the present invention can be obtained by impregnating a suitable amount of a polyester resin with the above-described cloth as a substrate and subjecting the cloth to pressure molding in a mold under heating.

This polyester resin has a function as an excipient in a speaker damper. When the fabric is pressure-molded under heating without using any polyester resin, a shape as a speaker damper can be imparted.However, the obtained molded product has shape retention and hardness as a speaker damper. It is extremely inadequate and unpractical. However, when the cloth is impregnated with an appropriate proportion of the polyester resin under heat and pressure, the polyester resin is interposed between the fibers of the mixed yarns forming the cloth to fix the fibers together, and the intersection of the mixed yarns In this case, the mixed yarn is firmly fixed with the polyester resin interposed therebetween, and the fabric thus formed is a speaker damper having sufficient hardness and shape retention.

It is not clear why the polyester resin has excellent properties as an excipient of the speaker damper of the present invention, but it is arguably that the aromatic polyester fiber and the aromatic polyester fiber and the polyester which form the mixed yarn are mixed with the polyester resin. This is probably due to the affinity of the resin. Therefore, before forming the fabric under heat and pressure in the present invention,
It is important that the fabric be conveniently impregnated with a polyester resin.

A method for appropriately impregnating the polyester with the fabric is to use a solution of the polyester resin, preferably an aqueous solution. The simplest method is to immerse the fabric in a solution of a polyester resin. As the solution of the polyester resin, an aqueous solution is advantageous from an industrial and working environment viewpoint. Therefore, the water-soluble polyester resin from which the aqueous solution can be obtained will be specifically described.

As the water-soluble polyester resin, a resin formed mainly from a dicarboxylic acid component and a diol component and copolymerized with a component having a hydrophilic group to enhance water solubility is advantageously used.

Examples of the dicarboxylic acid component forming the water-soluble polyester resin include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid and phthalic acid, and aliphatic dicarboxylic acids such as adipic acid, succinic acid, sebacic acid and dodecane diacid. On the other hand, examples of the diol component include ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, cyclohexanedimethanol, and bisphenol. In order to make the resin water-soluble, a hydrophilic group is copolymerized. As the component, a component having a sulfone group or a derivative group in a side chain such as sodium 5-sulfoisophthalate or polyethylene glycol is used. Used as a polymerization component.

The aromatic dicarboxylic acid component of the water-soluble polyester resin includes terephthalic acid, isophthalic acid,
Examples thereof include phthalic acid, naphthalenedicarboxylic acid, and 4,4'-oxybenzoic acid. Of these, terephthalic acid and isophthalic acid are preferable. In particular, the molar ratio of terephthalic acid / isophthalic acid is desirably in the range of 65/35 to 50/50.

The diol component has 2 to 6 carbon atoms.
And ethylene glycol, propylene glycol, tetramethylene glycol, hexamethylene glycol and the like, and diethylene glycol. Among them, ethylene glycol and diethylene glycol are desirable.

Examples of dicarboxylic acids having an SO ₃ M group (M is a metal) include sulfone terephthalic acid, 5-sulfoisophthalic acid, 4-sulfophthalic acid, and 4-sulfonaphthalene-2,7-dicarboxylic acid. Examples of the metal salt of an acid include alkali metal salts such as sodium, potassium, and lithium. Among them, particularly preferred is 5-sodium sulfoisophthalic acid. The copolymerization ratio of such a dicarboxylic acid having an SO ₃ M group is 40 mol% or less, especially 5 mol%, based on the total dicarboxylic acid component of the copolymerized polyester.
Occupies preferably about 20 mol%, and 40 mol%
If the temperature exceeds the above range, the melt viscosity will increase dramatically, and it will be difficult to obtain a polymer having a desired degree of polymerization by the melt polymerization method, which is not preferable.

Further, polyoxyalkylene glycols that can be used as a copolymer component in the synthesis of the water-soluble polyester resin include polyoxyethylene glycol, polyoxypropylene glycol, polyoxyethylene glycol / polyoxypropylene glycol copolymer and the like. Among them, polyoxyethylene glycol is preferable. In these polyoxyalkylene glycols, one hydroxyl group may be blocked by an ether bond, and for example, monomethyl ether, monoethyl ether, monophenyl ether, and the like can be used.
The average molecular weight of the polyoxyalkylene glycol is
Usually 500 to 12000, especially 1000 to 60
00 is preferred. The copolymerization amount is preferably from 20 to 90% by weight, and more preferably from 30 to 80% by weight, based on the weight of the produced copolymerized polyester.

The water-soluble polyester comprising the aromatic carboxylic acid, the diol component and the dicarboxylic acid having an SO ₃ M group (M is a metal ion) and / or a polyalkylene glycol is within a range not to impair the object of the present invention. May contain a small amount of a copolymer component other than the above.

The intrinsic viscosity (measured in o-chlorophenol at 25 ° C.) of such a water-soluble polyester is 0.2 to 0.2.
A range of 0.55 is preferred. Further, the term "water-soluble" as used in the present invention is not limited to a completely water-soluble one as long as it can be finely dispersed in water.

The solubility of the water-soluble polyester resin in water is as follows.
It is desirable that 5 g, preferably 25 to 40 g, can be dissolved. When the fabric is immersed in the aqueous solution of the polyester resin, the concentration of the resin in the aqueous solution is suitably in the range of 15 to 40% by weight, preferably 20 to 35% by weight.

When the polyester resin is impregnated into the fabric and then molded by applying heat and pressure, it is advantageous that the resin crosslinks and cures, and various crosslinking agents are used. As the crosslinking agent, for example, melamine, methylolated melamine, triisocyanate and the like are used. By using a cross-linking agent, an appropriate hardness can be imparted to the molded article. Among these crosslinking agents, melamine or methylolated melamine is preferable because it can impart desirable physical properties to a molded article and does not contaminate a mold during molding. The amount of the cross-linking agent added is not constant depending on the type, but a ratio of 20 to 30% by weight based on the polyester resin (solid content) is appropriate.

The proportion of the polyester resin adhered to the fabric by impregnation affects the performance and physical properties of the speaker damper. The proportion of the polyester resin adhered to the fabric is desirably in the range of 15 to 40% by weight, preferably 20 to 35% by weight based on the dry weight. If the proportion of the polyester resin (excipient) is less than the above range, the hardness of the molded product will be insufficient, and furthermore, if used as a speaker damper for a long time, the physical properties will be significantly reduced. on the other hand,
When the adhesion amount of the polyester resin exceeds the above range,
The heat resistance of the molded product may be reduced, and the characteristics as a speaker damper may also be reduced.

As described above, after the cloth is impregnated with the polyester resin solution, the amount of the resin adhering to the above-mentioned range can be adjusted by appropriately selecting the concentration of the solution and the squeezing of the impregnated cloth using a mangle. Just control. Thereafter, the dried fabric to which the resin has adhered is subjected to molding.

The mold is a mold that gives the shape of the speaker damper, and the temperature and pressure are selected so that the cloth to which the polyester resin adheres has sufficient hardness and form. . Due to the heat and pressure in the mold, the whole aromatic polyamide fibers are fixed together by fusion of aromatic polyester fibers in the mixed yarn in the fabric, and the fibers between the fibers constituting the yarn and the fiber surface in the mixed yarn are polyester resin. Is obtained, and the mixed yarns are fixed in the fabric at the intersections thereof by fusion of aromatic polyester fibers and fixed by the excipient containing the polyester resin.

The temperature of the mold depends on the fusion temperature of the aromatic polyester fiber, the fixing temperature of the polyester resin, the structure of the fabric, and the like, but is usually in the range of 130 to 250 ° C, preferably 140 to 230 ° C. The molding time is 30 seconds to 10 minutes, preferably 1 to 5 minutes.

Since the speaker damper of the present invention is used for the purpose of holding and stabilizing the coil bobbin in the speaker and needs to vibrate the diaphragm (speaker cone) faithfully, it is lightweight, thin and suitable. Air permeability is required. The speaker damper has a cloth thickness of 0.1 to 0.7 mm, preferably 0.2 to 0.5 m.
m, which is usually disk-shaped, and is given a waveform of a concentric circle.

Further, the speaker damper of the present invention is J
When the air permeability measured according to IS L-1096 is 70
１７０170 cm ³ / cm ² · sec, preferably 100 to ¹
Those having a range of 40 cm ³ / cm ² · sec are desirable.

The speaker damper of the present invention has the desired hardness by using the above-mentioned cloth and polyester resin by fusing and fixing in and between mixed yarns, and furthermore has excellent water resistance and moisture resistance. have. In particular, the speaker damper of the present invention is a speaker damper molded with respect to water resistance at room temperature (20 ° C.).
° C) for 24 hours after being immersed in water for 5% or less, particularly 3% or less.

[0044]

According to the damper for a speaker of the present invention, the aromatic polyester fiber in the fabric has an appropriate flexibility, and the polyester resin used as an excipient is a polyester fiber or a wholly aromatic polyamide. Because it has good affinity with fiber, even if it repeatedly undergoes bending or bending deformation, the rigidity of the damper does not significantly decrease, and the speaker using this has the performance even if it is operated continuously for a long time. There is no significant deterioration. Also,
Since the water absorption of the polymer, which is the material of the fibers constituting the fabric, is extremely low, the speaker damper, which is a molded product of the fabric constituted by the fibers, is deformed due to the elongation of the fibers due to the water absorption, and the performance of the speaker is reduced. There is no influence. Moreover, according to the present invention, it is possible to manufacture a speaker damper having good moldability, excellent water resistance and excellent durability in a simple operation step and without lowering the operation environment as compared with the conventional method. Hereinafter, the present invention will be described specifically with reference to examples.

Examples 1 to 5 and Comparative Examples 1 to 4 Polymetaphenylene isophthalamide staple fiber (Conex, type HG, single denier 2 denier, manufactured by Teijin Limited)
And low-melting polyester short fibers (manufactured by Teijin Limited, softening point: 110 ° C., fineness: 2 denier), and these were blended at a weight ratio of 70/30 to give a spun yarn of 250 denier. Using the obtained spun yarn, a fabric (plain weave) was obtained at a weave density of 38 yarns / inch for both the length and width. On the other hand, a water-soluble polyester resin (manufactured by Yoyo Chemical Co., Ltd., trade name:
To 200 g of Pluscoat, Z-561, 25% in concentration, 15 g of melamine (for example, trimethylol melamine, manufactured by Sumitomo Chemical Co., Ltd., trade name: M-3, 80% in concentration) and a reaction accelerator (Alkanol, manufactured by Sumitomo Chemical Co., Ltd.) Amine hydrochloride, trade name: Sumitex ACX, concentration 30%) 1
5 g were mixed, the amount of water added was changed according to the target amount of impregnation, and the mixture was stirred to obtain an aqueous solution. The previously prepared fabric was immersed in this aqueous solution, squeezed uniformly with a mangle, and subsequently dried in a dryer at 120 ° C. for 3 minutes.

Next, the cloth to which the polyester resin had adhered was cut into a predetermined size, placed in a mold, and thermoformed with a press at 180 ° C. for 2 minutes. About the obtained molded body,
The flat portion was cut to a width of 5 mm, one of which was held, a weight was hung on the other end of a rectangular fabric having a length of 20 mm, and the hardness of the sample was determined by the weight of the weight required for the fabric to bend. In Comparative Examples 2 and 3, a phenol resin was impregnated. In Table 1, the moldability is determined by visually judging the moldability of the corners of the concave and convex portions of the mold. ○ The corners are clearly molded. Rather, the ones with rounded corners are marked X. The middle of those was judged as Δ.

[0047]

[Table 1]

For evaluation of the damper characteristics, the base material was previously set at a mold temperature of 180 ° C., and a pressing pressure of 2 kg / cm ^{2 was used.}
Then, the mold was opened, the molded product was taken out, and the outer shape was cut to obtain a donut type damper having an outer diameter of 6 mm and a neck diameter of 19 mm. The speaker dampers obtained in Example 1, Example 2, Example 3, Example 4, and Example 5 showed almost the same appearance and flexibility. FIG. 1A is an enlarged view of the surface state before molding of the speaker damper in this embodiment, and FIG. 1B is an enlarged view of the surface state after molding. As is clear from FIGS. 1a and 1b, the heat-fused fibers constituting the woven fabric are melted and solidified by the heating during molding, and the yarns are fused at the intersections and covered with the surface of the yarn. . As a result of observation with a microscope, the molded products in each Example showed the same form.

Table 2 shows the dimensional accuracy and water resistance of the molded article of the speaker damper in this embodiment. The dimensional accuracy of the molded product was represented by the flatness of the outer periphery of the molded speaker damper. For the measurement of the surface degree, the damper was placed on a smooth surface plate, and the warpage of the lower surface outer peripheral portion was measured with a height gauge. As for the water resistance, a value before and after immersion in tap water for 24 hours was measured as a change in the flexibility in a wet state. The degree of flexibility is as follows: A very lightweight disk with a diametrical cross section to be fitted is placed in the center of the damper at the center of the damper, and the size of the deflection when a 50 g weight is placed on the disk is mm.
It is represented by The dimensional stability was evaluated by the above-mentioned warpage after the above operation.

For comparison, as a conventional product, a plain woven cotton fabric woven at a weft density of 38 threads / inch and a warp of 38 threads / inch using a No. 20 cotton yarn was impregnated with 5% by weight of a phenolic resin. As a material, with a mold set at a mold temperature of 220 ° C,
The same result was obtained when molded under pressure of 2 kg / cm ² for 5 seconds.

[0051]

[Table 2]

It can be seen that the damper of this embodiment has a small warpage of the molded product and is excellent in dimensional accuracy. Further, it is understood that both the flexibility and the dimensional stability in a wet state are lower than those of the conventional product, and the water resistance is excellent.

FIG. 2 shows the change over time of the minimum resonance frequency in the continuous operation of a speaker having a diameter of 16 cm using a damper molded of the same base material. It can be seen that the minimum resonance frequency change rate in the continuous operation of the speaker is extremely low as compared with the conventional speaker damper using a cotton cloth as a base material. FIG. 2 shows the data of the third embodiment together with the data of the conventional product.
For the speaker dampers of Examples 1, 2, 4 and 5, the change rate of the lowest resonance frequency was examined.
After the lapse of time, all were in the range of -4% to -7%.

[Brief description of the drawings]

FIG. 1 (a) is an enlarged view showing a surface state before impregnating a fabric of the present invention with a polyester resin. (B) It is an enlarged view which shows the state of the surface after shaping | molding of the speaker damper of this invention.

FIG. 2 is a characteristic diagram comparing a change in the lowest resonance frequency in a continuous operation test of a speaker using the speaker damper obtained in Example 3 with a conventional product.

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masatoshi Okazaki 2460-1, Kamikawa-cho, Matsusaka-shi, Mie Prefecture Inside Matsushita Electronic Components Co., Ltd. (72) Inventor Shinya Mizone 2460-2, Kamikawa-cho, Matsusaka-shi, Mie Matsushita Electronics JP-A-7-274284 (JP, A) JP-A-6-62494 (JP, A) JP-A-62-258596 (JP, A) JP-A-5-115095 (JP) , A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04R 9/02 103 D04H 1/54 H04R 31/00 D06M 15/507

Claims (11)

(57) [Claims] 1. A speaker damper comprising a fabric composed of wholly aromatic polyamide yarn as a matrix component, wherein (i) the wholly aromatic polyamide yarn has a heat fusing temperature lower by at least 100 ° C. than its thermal decomposition temperature. (Ii) in the mixed yarn, the wholly aromatic polyamide fibers are fixed by fusion of the thermoplastic aromatic polyester fibers, and (iii) In the blended yarn, the fibers constituting the yarn and the fiber surface are fixed by an excipient containing a polyester resin, and (iv) in the fabric, the blended yarns are crosslinked at the intersection by a thermoplastic aromatic polyester. A speaker damper fixed by fusion of fibers and by an excipient containing a polyester resin. . 2. The speaker damper according to claim 1, which has an air permeability of 70 to 170 cc / cm ² · sec. 3. The mixed yarn according to claim 1, wherein the ratio of wholly aromatic polyamide fibers: aromatic polyester fibers is 50:50 by weight.
2. The speaker damper according to claim 1, wherein the damper has a ratio of about 85:15. 4. The speaker damper according to claim 1, wherein the wholly aromatic polyamide fiber is formed of a polymer comprising at least 50 mol% of meta-phenylene isophthalamide units or para-phenylene terephthalamide units of all repeating units. 5. The aromatic polyester fiber has an ethylene terephthalate unit content of at least 50 mol% of all repetitions.
The speaker damper according to claim 1, wherein the damper is formed of a polymer comprising: 6. The speaker damper according to claim 1, wherein the polyester resin as the excipient is a thermoset polyester resin. 7. A shape formed by heating and press forming.
The described speaker damper. 8. The speaker damper according to claim 1, wherein the damper has a water resistance of 5% or less in the degree of change in flexibility after immersion in water for 24 hours. 9. The speaker damper according to claim 1, wherein the content of the polyester resin as an excipient is 15 to 40% by weight based on the fabric. 10. A method for producing a speaker damper using a fabric composed of wholly aromatic polyamide yarns as a matrix component, comprising: a fabric composed of a mixed yarn of wholly aromatic polyamide fibers and aromatic polyester fibers; An aqueous solution of a water-soluble polyester resin is impregnated and then dried, and thereafter, the whole aromatic polyamide fibers are fixed by fusion of aromatic polyester fibers in a mold, and the fibers and the mixed yarn in the mixed yarn by the polyester resin are mixed. A method of manufacturing a speaker damper, comprising press-molding into a desired shape under conditions of temperature and pressure sufficient for mutual bonding. 11. The water-soluble polyester resin is a polyester resin that can be cured under pressure molding conditions.
A method for manufacturing the speaker damper according to the above.