JP2010287975A - Speaker diaphragm and speaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a loudspeaker diaphragm and a speaker having an excellent balance between Young's modulus and internal loss, high rigidity, and low environmental load.
The speaker diaphragm of the present invention is made of polyamide 11 fiber derived from natural castor oil. Preferably, the speaker diaphragm of the present invention has a support layer and a base material layer made of a woven fabric formed from the above-mentioned polyamide 11 fiber derived from natural castor oil, which is laminated on the support layer. Preferably, the loudspeaker diaphragm of the present invention has a base material layer in which at least one woven fabric and / or non-woven fabric formed from the above-described polyamide 11 fiber derived from natural castor oil is impregnated with a thermosetting resin.
[Selection figure] None

Description

  The present invention relates to a speaker diaphragm and a speaker.

  Many speaker diaphragms have been proposed in which a texture of a woven fabric is exposed and a paper board or the like is thermocompression-bonded to the back (for example, Patent Document 1). In addition, a vibration plate in which a plurality of woven fabrics and / or non-woven fabrics are laminated and impregnated with a thermosetting resin, or a vibration plate in which a woven fabric is further thermocompression bonded to such a vibration plate. The board is also known.

  All of the above speaker diaphragms are superior in strength to speaker diaphragms made of paper or natural fibers, but the woven fabrics, nonwoven fabrics and thermosetting resins that are constituent members and constituent materials are derived from petroleum. This has led to depletion of petroleum resources and greenhouse gas problems. Therefore, there is a need for a speaker diaphragm that maintains the excellent characteristics and uses as little petroleum-derived material as possible.

JP 2009-21832 A

  The present invention has been made in order to solve the above-described conventional problems, and an object of the present invention is to provide a speaker diaphragm and a speaker having an excellent balance between Young's modulus and internal loss, high rigidity, and low environmental load. It is to provide.

The speaker diaphragm of the present invention is made of polyamide 11 fiber derived from natural castor oil.
In a preferred embodiment, the speaker diaphragm of the present invention has a support layer and a base material layer made of a woven fabric formed of polyamide 11 fibers derived from the natural castor oil, laminated on the support layer.
In a preferred embodiment, the speaker diaphragm of the present invention includes a base material layer in which at least one woven fabric and / or non-woven fabric formed from the above-described natural castor oil-derived polyamide 11 fiber is impregnated with a thermosetting resin. Have.
According to another aspect of the present invention, a speaker is provided. The speaker includes the speaker diaphragm.

  According to the present invention, by using a woven fabric and / or a nonwoven fabric of polyamide 11 fiber derived from natural castor oil, the speaker diaphragm having an excellent balance between Young's modulus and internal loss, high rigidity, and low environmental load, And a speaker provided with the said diaphragm for speakers can be provided.

It is a graph which shows the sound pressure frequency characteristic of the speaker using the diaphragm for speakers obtained in Example 2. 10 is a graph showing sound pressure frequency characteristics of a speaker using the speaker diaphragm obtained in Example 5. It is a graph which shows the sound pressure frequency characteristic of the speaker using the diaphragm for speakers obtained by the comparative example 2. 10 is a graph showing sound pressure frequency characteristics of a speaker using the speaker diaphragm obtained in Comparative Example 4.

A. Polyamide fiber The polyamide 11 fiber is derived from natural castor oil. Specifically, the polyamide 11 fiber can be obtained by spinning a polyamide 11 resin obtained by polycondensation of 11-aminoundecanoic acid using ricinoleic acid in natural castor oil as a raw material. Arbitrary appropriate methods can be employ | adopted for the polymerization method of the said polyamide 11 resin. Moreover, you may use arbitrary appropriate additives in the case of superposition | polymerization. Examples of the additive include a catalyst and a heat stabilizer. A commercially available product may be used as the polyamide 11 resin. Examples of commercially available polyamide resins derived from natural castor oil include “Rilsan B” (trade name) manufactured by Arkema. By using such plant-derived fibers, it is possible to obtain a speaker diaphragm in which the amount of petroleum resources used is suppressed. Further, carbon dioxide generated when plant-derived materials are discarded and incinerated is originally present in the atmosphere, and can be returned to plants again by photosynthesis (carbon neutral). That is, the polyamide 11 fiber derived from natural castor oil is a circulating material, and the speaker diaphragm obtained by using this material has a low environmental load. Moreover, if the polyamide 11 fiber derived from natural castor oil is used, a speaker diaphragm having an excellent balance between Young's modulus and internal loss and high rigidity can be obtained.

  The thickness of the polyamide 11 fiber derived from natural castor oil is preferably 50 dtex to 1200 dtex, more preferably 70 dtex to 300 dtex. When the thickness of the fiber is less than 50 dtex, the fabric weight is often lowered and the strength is insufficient. When the thickness of the fiber exceeds 1200 dtex, the weight increases, and as a result, the sound pressure often decreases.

B. Speaker diaphragm The speaker diaphragm of the present invention is made of polyamide 11 fiber derived from natural castor oil. In one embodiment, the speaker diaphragm includes a support layer, and a base material layer made of a woven fabric formed of polyamide 11 fibers derived from the natural castor oil, laminated on the support layer. The support layer and the base material layer are laminated (integrated) by, for example, thermocompression bonding via a thermoplastic adhesive or a hot melt film. Preferably, the texture of the base material layer is exposed on the front side or the back side of the diaphragm that radiates sound waves.

  Any appropriate structure can be adopted as the woven structure of the polyamide 11 fiber woven fabric derived from natural castor oil. Specific examples include plain weave, twill weave, satin weave, and combinations thereof. A plain weave is preferred. The weaving density of the woven fabric is preferably 20 × 20 / inch to 150 × 150 / inch.

Polyamide 11 fiber woven fabric basis weight from the natural castor oil is preferably ^{60g / m 2 ~400g / m 2} . This is because if the basis weight is less than 60 g / m ² , the fibers rub against each other due to vibration, and as a result, unnecessary sound may be generated. The natural case derived from castor oil of polyamide 11 fibers of the fabric weave structure is plain weave, basis weight of the woven fabric is preferably ^{60g / m 2 ~400g / m 2} , more preferably ^80g / m 2 ^~120g / a m ^2. If the natural castor oil-derived polyamide 11 fiber woven fabric weave structure of twill, basis weight of the woven fabric is preferably ^{180g / m 2 ~300g / m 2} , more preferably 200g ^/ m 2 ~280g / M ² .

  Specific examples of the support layer include papermaking paper, woven fabric, and non-woven fabric. Examples of the material constituting the woven or non-woven fabric of the support layer include nylon (for example, nylon 6, nylon 66), polyester (for example, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate), polyolefin (for example, polyethylene, ultrahigh molecular weight). Polyethylene, polypropylene, poly-4-methylpentene-1), polystyrene, polyvinyl chloride, polyurethane, polysulfone, polyether ketone, polyether ether ketone, polyacetal, polyarylate, polyaramid, polyamideimide, polycarbonate, modified polyphenylene ether, polyphenylene Sulfide, polyacrylate, polymethyl methacrylate, polyetherimide, polyethersulfone, polytetrafluoroethylene, It includes crystalline polymers and thermoplastic elastomers. These are used alone or in combination of two or more. Or you may use the copolymer from these 2 or more types of these resin monomers. In the case of using a woven fabric or a non-woven fabric, it may be further impregnated with a thermosetting resin and cured to form a support layer.

In another embodiment, the speaker diaphragm has a base material layer obtained by impregnating a thermosetting resin into a woven fabric and / or a non-woven fabric formed from the polyamide 11 fiber derived from the natural castor oil. The configuration of the polyamide 11 fiber woven fabric derived from natural castor oil is as described above. The nonwoven fabric can be formed by any suitable method. Specific examples of the method for forming the nonwoven fabric include a water entanglement method and a needle punch method. Basis weight of the nonwoven fabric is preferably ^{20g / m 2 ~80g / m 2} . The base material layer may be a single layer of woven fabric or non-woven fabric, and may have a laminated structure. When the base material layer has a laminated structure, the number of layers can be appropriately set according to the purpose and the like. The laminated structure may be composed only of a woven fabric, may be composed only of a nonwoven fabric, or may be composed of a combination of a woven fabric and a nonwoven fabric. The base material layer was cured by impregnating a laminate of a woven fabric and / or non-woven fabric formed from the above-described natural castor oil-derived polyamide 11 fibers and another woven fabric and / or non-woven fabric with a thermosetting resin. It may be a base material layer. As the other woven or non-woven fabric, for example, a woven or non-woven fabric that can be used as the support layer can be used.

  Any appropriate thermosetting resin can be adopted as the thermosetting resin. An unsaturated polyester resin, a melamine resin, a phenol resin or an epoxy resin is preferable, and an unsaturated polyester resin is particularly preferable. This is because a speaker diaphragm having a high curing speed and a low curing temperature, which is easy to manufacture and has excellent internal loss, can be obtained.

  The ratio of the polyamide 11 fiber derived from natural castor oil and the thermosetting resin (polyamide 11 fiber / resin ratio) is preferably in the range of 20/80 to 80/20, more preferably in the range of 50/50 to 70/30. It is. If the polyamide 11 fiber / resin ratio is in such a range, a speaker diaphragm having an extremely excellent internal loss can be obtained without lowering the Young's modulus. Moreover, generation | occurrence | production of the resin specific sound can be prevented. In this specification, “polyamide 11 fiber / resin ratio” refers to the ratio of the weight of the woven fabric and / or nonwoven fabric before impregnation to the weight of the impregnated resin.

  In still another embodiment, the speaker diaphragm is laminated on a base material layer obtained by impregnating and curing a woven fabric and / or a nonwoven fabric formed from the polyamide 11 fiber derived from the natural castor oil with a thermosetting resin. A surface layer. In this case, the surface layer is disposed on the sound wave emission side. Specific examples of the surface layer include woven fabrics or nonwoven fabrics made of polyamide 11 fibers derived from natural castor oil described above, and woven fabrics or nonwoven fabrics that can be used as the support layer.

C. Speaker The speaker of the present invention includes the above-described speaker diaphragm. The speaker of the present invention can be applied to any application. For example, the speaker of the present invention may be for in-vehicle use, for portable electronic devices (for example, a mobile phone or a portable music player), or may be stationary. For example, the speaker of the present invention may have a large diameter, a medium diameter, or a small diameter. For example, the speaker of the present invention may be a woofer or a tweeter. The speaker of the present invention may have an appropriate structure depending on the application. Since their structures are well known in the art, a detailed description is omitted.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited by these Examples. Unless otherwise indicated, parts and percentages in the examples are based on weight.

[Production Example 1] Formation of Woven Fabric (1) Polyamide 11 derived from natural castor oil (trade name “Rilsan B”, manufactured by Arkema Co., Ltd.) was spun to obtain a fiber of 280 dtex. A plain woven fabric having 40 pieces / inch × 40 pieces / inch and a basis weight of 100 g / m ² was obtained.

[Production Example 2] Formation of Woven Fabric (2) Polyamide 11 derived from natural castor oil (trade name “Rilsan B”, manufactured by Arkema Co., Ltd.) was spun to obtain a 78 dtex fiber. A twill-woven fabric of length (3 twists × 140) / inch × width (6 twists × 55) / inch, basis weight 236 g / m ² was obtained.

[Production Example 3] Formation of Woven Cloth (3) A plain woven fabric having a density of 40 / inch × 40 / inch and a basis weight of 100 g / m ² was obtained using polyester fibers of 280 dtex vertically and horizontally.

[Production Example 4] Formation of Woven Fabric (4) Using polyethylene naphthalate fibers of 78 dtex in the vertical and horizontal directions, the density is vertical (3 strands x 140 strands) / inch x lateral (6 strands × 55 strands) / inch. A twill-woven fabric with a basis weight of 236 g / m ² was obtained.

[Production Example 5] Formation of non-woven fabric (1) Polyamide 11 derived from natural castor oil (trade name “Rilsan B”, manufactured by Arkema Co., Ltd.) is spun to obtain a fiber, which is used to obtain a weight of 60 g / m ² by a hydroentanglement method. A non-woven fabric was obtained.

[Production Example 6] nonwoven (2) of the forming wholly aromatic polyamide fibers used (manufactured by Teijin Ltd., trade name "Technora"), by the hydroentanglement method to obtain a basis weight 60 g / m ² non-woven fabric.

[Production Example 7] Preparation of unsaturated polyester solution An unsaturated polyester solution having the following composition was prepared:
Unsaturated polyester resin (Japan Composite Co., Ltd .; Polyhope N350L):
100 (parts)
Low shrinkage agent (Nippon Yushi Co., Ltd .; Modiper S501): 5 (parts)
Curing agent (Nippon Yushi Co., Ltd .; Perocta O): 1.3 (part)

[Example 1]
A thermoplastic adhesive was applied to the surface on the front side forming a hollow space of a paper cone having a dry weight of 150 g / m ² and dried. On the surface of the thermoplastic adhesive coating film of the paper cone, the woven fabric (1) obtained in Production Example 1 was pressed at 105 ° C. for 5 seconds and thermocompression integrated, and the inner diameter was 26.2 mm, the outer diameter was 117 mm, A speaker diaphragm with a total height of 24 mm was obtained.

[Example 2]
A hot melt film was placed on the front side surface forming a hollow space of a paper cone having a weight of 150 g / m ² dried after papermaking. On the surface of the hot melt film of the paper cone, the woven fabric (2) obtained in Production Example 2 was pressed at 110 ° C. for 5 seconds and thermocompression integrated, and the inner diameter was 26.2 mm, the outer diameter was 117 mm, and the total height was 24 mm. A speaker diaphragm was obtained.

[Example 3]
The unsaturated polyester solution obtained in Production Example 7 is applied to the laminate in which the nonwoven fabric (1) obtained in Production Example 5 and the woven fabric (2) obtained in Production Example 2 are overlaid, and at 130 ° C. Press molding was performed for 30 seconds to obtain a speaker diaphragm (inner diameter: 26.2 mm, outer diameter: 117 mm, overall height: 24 mm) disposed on the front surface side where the woven fabric forms a hollow space of a cone that emits sound waves.

[Example 4]
The unsaturated polyester solution obtained in Production Example 7 was applied to the laminate in which two nonwoven fabrics (1) obtained in Production Example 5 were stacked, and press-molded at 130 ° C. for 30 seconds to obtain a cone. A thermoplastic adhesive was applied to the resulting cone and dried, and then the woven fabric (2) obtained in Production Example 2 was used as a surface layer, pressed at 105 ° C. for 5 seconds, and thermocompression integrated to obtain an inner diameter of 26. A speaker diaphragm having a diameter of 2 mm, an outer diameter of 117 mm, and an overall height of 24 mm was obtained.

[Example 5]
The unsaturated polyester solution obtained in Production Example 7 was applied to the laminate in which the nonwoven fabric (1) obtained in Production Example 6 was stacked, and press-molded at 130 ° C. for 30 seconds to obtain a cone. A thermoplastic adhesive was applied to the resulting cone and dried, and then the woven fabric (2) obtained in Production Example 2 was used as a surface layer, pressed at 105 ° C. for 5 seconds, and thermocompression integrated to obtain an inner diameter of 26. A speaker diaphragm having a diameter of 2 mm, an outer diameter of 117 mm, and an overall height of 24 mm was obtained.

[Comparative Example 1]
A speaker diaphragm was obtained in the same manner as in Example 1 except that the woven fabric (3) obtained in Production Example 3 was used instead of the woven fabric (1) obtained in Production Example 1.

[Comparative Example 2]
A speaker diaphragm was obtained in the same manner as in Example 2 except that the woven fabric (4) obtained in Production Example 4 was used instead of the woven fabric (2) obtained in Production Example 2.

[Comparative Example 3]
In place of the laminate in which the nonwoven fabric (1) obtained in Production Example 5 and the woven fabric (2) obtained in Production Example 2 are stacked, the nonwoven fabric (2) obtained in Production Example 6 and Production Example 4 are used. A speaker diaphragm was obtained in the same manner as in Example 3 except that the laminated body obtained by overlapping the obtained woven fabric (4) was used.

[Comparative Example 4]
A speaker diaphragm was obtained in the same manner as in Example 5 except that the woven fabric (4) obtained in Production Example 4 was used instead of the woven fabric (2) obtained in Production Example 2.

<Evaluation>
Table 1 shows the ratio of plant-derived materials in the obtained speaker diaphragm. Here, the plant-derived material is paper used for paper cone and polyamide 11 derived from natural castor oil.

  With respect to the obtained speaker diaphragm, density, Young's modulus (E) and internal loss (tan δ) were measured by ordinary methods. Further, using these values, specific elasticity (E / density) and rigidity (E × (thickness of thickness)) were calculated. The obtained results are shown in Table 2 below.

  The sound pressure frequency characteristics of the speakers using the speaker diaphragms obtained in Example 2, Example 5, Comparative Example 2 and Comparative Example 4 were measured. The results of Example 2 are shown in FIG. 1, the results of Example 5 are shown in FIG. 2, the results of Comparative Example 2 are shown in FIG. 3, and the results of Comparative Example 4 are shown in FIG.

  As is apparent from Table 1, according to the present invention, a speaker diaphragm in which the use ratio of the petroleum-derived material is suppressed can be obtained. Further, carbon dioxide generated when plant-derived material is discarded and incinerated is originally present in the atmosphere and can be returned to the plant again by photosynthesis (carbon neutral). That is, the polyamide 11 fiber derived from natural castor oil is a circulating material, and the speaker diaphragm obtained by using this material has a low environmental load.

  Further, as apparent from Table 2, the speaker diaphragm of Example 2 has a lower density than that of Comparative Example 2, so that the thickness can be increased to increase rigidity, and the Young's modulus and internal loss can be increased. Excellent balance. As shown in FIG. 1, the loudspeaker diaphragm of Example 2 having such characteristics has a sound pressure frequency characteristic with a relatively small peak dip up to about 4 kHz.

  The speaker diaphragm of Example 5 is superior in balance between Young's modulus and internal loss and has high rigidity due to the large value of specific elasticity as compared with Comparative Example 4. As shown in FIG. 2, the speaker diaphragm of Example 5 having such characteristics has a sound pressure frequency characteristic with a small peak dip and a high high frequency limit frequency.

  Thus, the diaphragm for the speaker of the example is compared with the diaphragm for the speaker of the comparative example, which has the same configuration as the example except that a petroleum-derived material is used instead of the polyamide 11 fiber derived from natural castor oil, The use ratio of the plant-derived material can be greatly increased without deteriorating the characteristics as the speaker diaphragm.

  The speaker diaphragm of the present invention can be suitably used for speakers of any application.

Claims (4)

  A loudspeaker diaphragm made of polyamide 11 fiber derived from natural castor oil.   The speaker diaphragm according to claim 1, further comprising: a support layer; and a base material layer made of a woven fabric formed of the polyamide 11 fiber derived from the natural castor oil, which is laminated on the support layer.   The speaker diaphragm according to claim 1, further comprising a base material layer in which a thermosetting resin is impregnated in at least one woven fabric and / or nonwoven fabric formed from polyamide 11 fibers derived from the natural castor oil.   A speaker comprising the speaker diaphragm according to claim 1.

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