JP3557436B2 - Speaker member and method of manufacturing the same - Google Patents

Description

【００１６】
ここで、Ｍは、第４族遷移金属であり、好ましくはジルコニウムまたはチタンであり、さらに好ましくはジルコニウムである。Ｘは、それぞれ独立してハロゲンであり、好ましくはそれぞれ独立して臭素または塩素である。さらに好ましくは、上記メタロセン系触媒は、下記化学式で表されるメチルアミノキサンを助触媒として含有する：
【００１７】
【化２】

【００１８】
ここで、ｎは５〜２０の整数である。主成分（例えば、８０重量％）としてのジルコノセンと助触媒（例えば、２０重量％）としてのメチルアミノキサンとを含有するメタロセン系触媒が、本発明に用いられるポリマーを合成するに特に好ましい。
【００１９】
本発明に用いられる樹脂組成物は、上記シンジオタクティック型ポリマーに加えて、任意の適切な成分（例えば、強化材、着色剤）を含有し得る。本発明に用いられる樹脂組成物は、代表的にはペレット状である。
【００２０】
さらに、本発明のスピーカー用部材は、その表面に塗料が塗布されている。塗料は、エマルジョン塗料であっても水溶性塗料であっても溶剤系塗料であってもよい（ただし、溶剤系塗料の場合には、芳香族系溶媒は除かれる。膨潤する可能性があるからである）。代表的には、溶剤系塗料が用いられる。このような溶剤系塗料としては、例えば、アルキド樹脂塗料、アミノアルキド樹脂塗料、エポキシ樹脂塗料、ポリウレタン樹脂塗料、およびアクリル樹脂塗料が挙げられる。これらの塗料から形成される塗膜は、上記樹脂組成物から形成されたフィルムとは異なる特性（例えば、強度、内部損失）を有する。その結果、塗料が塗布されたフィルムから形成される振動板によれば、振動の際に塗膜とフィルムとの間で摩擦が生じるので、内部損失が大きくなる。特に好ましい塗料としては、アクリル樹脂塗料およびエポキシ樹脂塗料が挙げられる。
なお、塗料は、通常、バインダー樹脂と架橋剤と溶剤と着色剤とを含む。例えば、アクリル樹脂塗料のバインダー樹脂としては、ポリ（２−ヒドロキシエチルメタクリレート）、ポリ（２−ヒドロキシエチルアクリレート）、ポリアクリル酸、ポリメタクリル酸、ポリ（グリシジルメタクリレート）、ポリ（メチロール化アクリルアミド）が挙げられる。架橋剤としては、エーテル化尿素樹脂、メラミン樹脂、ベンゾグアナミン樹脂などのアミノ樹脂、あるいは有機ポリアミンが挙げられる。着色剤としては、代表的には、顔料（例えば，カーボンブラック）が挙げられる。
【００２１】
以下、本発明のスピーカー用部材の製造方法の好ましい一例について説明する。
まず、上記樹脂組成物を任意の適切な方法（例えば、押出成形）によりフィルム状に成形する。代表的には、フィルムの厚みは、５０〜７５μｍである。
次に、得られたフィルムの表面にコロナ放電処理を施す。コロナ放電処理を施すことにより、塗料への密着性を向上させることができる。
次いで、コロナ放電処理が施されたフィルムに塗料を塗布する。塗布および乾燥の方法は特に限定されず、任意の適切な方法が採用され得る。乾燥後の塗膜の厚みは、樹脂組成物フィルムの厚みに対して、好ましくは４〜３０％、さらに好ましくは６〜１５％である。樹脂組成物フィルムの厚みと塗膜の厚みがこのような関係を有することにより、塗膜強度および塗膜とフィルムとの密着性が顕著に改善され、その結果、非常に優れた内部損失および比弾性率を有するスピーカー用部材が得られる。
最後に、塗膜が形成されたフィルムを熱プレス成形することにより、本発明のスピーカー用部材が得られる。熱プレス成形の条件は、目的に応じて任意の適切な条件が採用され得る。
【００２２】
以下、本発明の作用について説明する。
本発明によれば、４以下のＭｗ／Ｍｎを有するシンジオタクティック型オレフィン系ポリマーまたはスチレン系ポリマーを含む樹脂組成物を用いたスピーカー用部材が提供される。シンジオタクティックポリマーは結晶性が非常に高い。しかも、このような非常にシャープな分子量分布を有することに起因して、成形時の流動性が顕著に改善される。従って、得られる成形品の結晶化による収縮が顕著に抑制され得る。その結果、本発明のスピーカー用部材は、高弾性および高剛性であり（従って、音響特性に優れ）、かつ、成形性ならびに熱および湿度に対する寸法安定性に優れる。なお、汎用ポリマーのＭｗ／Ｍｎは６以上であり、汎用ポリマーを用いて得られたスピーカー用部材は、本発明のスピーカー用部材に比較して、弾性、剛性、成形性、ならびに熱および湿度に対する寸法安定性のいずれもが大幅に劣ることが実際に確認されている。このように非常にシャープな分子量分布を有するポリマーを用いて得られる効果は、予期せぬ優れたものである。
【００２３】
さらに、本発明のスピーカー用部材は、その表面に塗料が塗布されている。塗料から形成される塗膜は、上記樹脂組成物から形成されたフィルムとは異なる特性（例えば、強度、内部損失）を有する。その結果、塗料が塗布されたフィルムから形成される本発明のスピーカー用部材によれば、振動の際に塗膜とフィルムとの間で摩擦が生じるので、内部損失が大きくなる。従って、本発明のスピーカー用部材は、音響特性に優れる。しかも、上記のように、樹脂組成物フィルムは成形時の収縮がきわめて小さいので、フィルムと塗膜の収縮性の違いによるカーリングの問題も生じない。
【００２４】
好ましい実施態様においては、上記シンジオタクティックポリマーは、メタロセン系触媒を用いた重合反応により得られる。メタロセン系触媒を用いることにより、非常に高い立体規則性を有するシンジオタクティックポリマーが得られるので、弾性、剛性、成形性、ならびに熱および湿度に対する寸法安定性がさらに改善され得る。加えて、優れた耐薬品性および電気特性を有するスピーカー用部材が得られることも実際に確認した。
【００２５】
【実施例】
以下、実施例により本発明を具体的に説明するが、本発明はこれら実施例には限定されない。なお、特に示さない限り、実施例中の部およびパーセントは重量基準である。
【００２６】
（実施例１）
メタロセン系触媒を用いて重合されたシンジオタクティックポリスチレン（ＳＰＳ）樹脂（ペレット状）を、下記押出成形条件で厚さ５０μｍのフィルム状に形成した。

【００２７】
得られたフィルム表面にコロナ放電処理を施した後、下記処方のアクリル樹脂塗料を下記条件で塗布および乾燥して塗膜を形成した。
（塗料の処方）
２−ヒドロキシエチルメタクリレート １００（部）
アミノ樹脂（架橋剤） ５
カーボンブラック １
（塗布条件）
処理速度 ２０（ｍ／ｍｉｎ）
乾燥温度 １３０〜１５０（℃）
塗膜厚み ５〜 ７（μｍ）
塗膜が形成されたフィルムを、所定形状の金型を用いて、成形温度１６０〜１７０℃、成形時間３〜５秒で熱プレス成形し、２５φのドーム型スピーカー用振動板を得た。
【００２８】
得られた振動板について、通常の方法で、密度ρ、ヤング率（弾性率）Ｅ、比弾性率Ｅ／ρ、および内部損失を調べた。結果を、後述の実施例２ならびに比較例１〜３の結果と併せて下記表１に示す。さらに、この振動板の周波数特性を、振動板の軸上５０ｃｍ、出力１Ｗで調べた。結果を図１に示す。
【００２９】
【表１】

【００３０】
（実施例２）
下記処方のエポキシ樹脂塗料を下記条件で塗布および乾燥して塗膜を形成したこと以外は実施例１と同様にして振動板を作製した。
（塗料の処方）
エポキシ樹脂 １００（部）
有機ポリアミン（架橋剤） ５
カーボンブラック １
（塗布条件）
処理速度 ２０ （ｍ／ｍｉｎ）
乾燥温度 ４０〜８０ （℃）
塗膜厚み ５〜 ７ （μｍ）
得られた振動板について、実施例１と同様の評価に供した。結果を上記表１に示す。
【００３１】
（比較例１）
ポリエーテルイミド（ＰＥＩ）（三菱樹脂（株）製、スペリオＵＴ）を用いて厚み５０μｍのフィルムを形成し、このフィルムを成形温度２００〜２２０℃、成形時間５秒という条件で熱プレス成形し、２５φのドーム型スピーカー用振動板を作製した。得られた振動板について、実施例１と同様の評価に供した。結果を上記表１に示す。
【００３２】
（比較例２）
ポリエーテルエーテルケトン（ＰＥＥＫ）（ビクトレックスエムシー（株）製、ＶＩＣＴＲＥＸ）を用いて厚み５０μｍのフィルムを形成し、このフィルムを成形温度２４０〜２６０℃、成形時間３〜５秒という条件で熱プレス成形し、２５φのドーム型スピーカー用振動板を作製した。得られた振動板について、実施例１と同様の評価に供した。結果を上記表１に示す。さらに、この振動板の周波数特性を、振動板の軸上５０ｃｍ、出力１Ｗで調べた。結果を図２に示す。
【００３３】
（比較例３）
塗料を塗布しなかったこと、および成形温度１５０〜１６０℃、成形時間３〜５秒という条件で熱プレス成形を行ったこと以外は実施例１と同様にして２５φのドーム型スピーカー用振動板を作製した。得られた振動板について、実施例１と同様の評価に供した。結果を上記表１に示す。さらに、この振動板の周波数特性を、振動板の軸上５０ｃｍ、出力１Ｗで調べた。結果を図３に示す。
【００３４】
表１から明らかなように、実施例１および２の振動板は、塗料を塗布しているにもかかわらず、エンジニアリングプラスチックを用いた比較例１および２の振動板に比べて約１４〜約２９％の軽量化が達成されている。しかも、実施例１および２の振動板は、比較例１および２に比べて顕著に優れたヤング率、比弾性率および内部損失を有する。また、実施例１および２と比較例３とを比較すると、塗料を塗布することにより内部損失が顕著に改善されていることがわかる。
さらに、図１と図２および３とを比較すると明らかなように、本発明のスピーカー用部材は、ｆｈ付近の特性が不連続な共振ピークとならずに滑らかに伸びている。また、図１と図２とを比較すると、本発明のスピーカー用部材は、高調波歪み（特に、２次歪み）が顕著に低減されていることがわかる。これは、塗料を塗布することにより内部損失が改善されたことに起因する。
【００３５】
【発明の効果】
本発明によれば、シンジオタクティックポリマーを用いて成形されたフィルムと塗料とを汲み合わせて用いることにより、高弾性および高強度でありながら内部損失が大きく、かつ軽量安価なスピーカー用部材が得られる。
【図面の簡単な説明】
【図１】実施例１で得られた振動板の周波数特性を示すグラフである。
【図２】比較例２で得られた振動板の周波数特性を示すグラフである。
【図３】比較例３で得られた振動板の周波数特性を示すグラフである。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a speaker member. More specifically, the present invention relates to a lightweight and inexpensive speaker member having high internal loss while having high elasticity and high strength.
[0002]
[Prior art]
Conventionally, various materials have been used as a material for forming a speaker member. In particular, metal foils and polymer films are suitably used as materials for forming the dome-shaped diaphragm.
[0003]
Diaphragms made of metal foil (eg, aluminum, titanium) have high strength and, as a result, have excellent fh. However, the metal foil is heavy and has low internal loss.
[0004]
As the polymer film, engineering plastics such as polyetherimide (PEI) and polyetheretherketone (PEEK) are preferably used. Engineering plastics have increased strength compared to general-purpose plastics, but on the other hand, are heavier and have lower internal losses. As the weight increases, the specific elastic modulus decreases, so that only insufficient fh can be obtained. The reduction in the internal loss causes harmonic distortion in the middle and high frequencies. In addition, engineering plastics are more expensive than general-purpose plastics.
[0005]
As described above, there is a strong demand for a lightweight and inexpensive speaker member that has high internal loss while having high elasticity and high strength.
[0006]
[Problems to be solved by the invention]
The present invention has been made in order to solve the above-mentioned conventional problems, and an object of the present invention is to provide a speaker member that has high elasticity and high strength, has a large internal loss, and is lightweight and inexpensive. It is in.
[0007]
[Means for Solving the Problems]
The speaker member of the present invention is formed from a resin composition containing a syndiotactic olefin-based polymer or a syndiotactic styrene-based polymer having a Mw / Mn of 4 or less as a main component, and a paint is applied to the surface. Have been.
In a preferred embodiment, the syndiotactic olefin polymer or the syndiotactic styrene polymer is a polymer obtained by a polymerization reaction using a metallocene catalyst.
In a preferred embodiment, the metallocene-based catalyst contains zirconocene and methylaluminoxane.
In a preferred embodiment, the paint is selected from an emulsion paint, a water-soluble paint, an alkyd resin paint, an amino alkyd resin paint, an epoxy resin paint, a polyurethane resin paint, and an acrylic resin paint.
According to another aspect of the present invention, a method for manufacturing a speaker member is provided. This production method comprises a step of forming a film of a resin composition containing a syndiotactic olefin polymer or a syndiotactic styrene polymer having a Mw / Mn of 4 or less as a main component, and subjecting the film to corona discharge treatment. A coating step, a step of applying a paint to the film subjected to the corona discharge treatment, and a step of hot press molding the film to which the paint is applied.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
The speaker member of the present invention is formed from a resin composition containing a syndiotactic olefin polymer or a syndiotactic styrene polymer as a main component. Here, “containing as a main agent” means that the composition is contained in a proportion of 50% by weight or more in the composition. Thus, the term "resin composition" also includes the polymer alone.
[0009]
In the present invention, the syndiotactic polymer refers to a polymer having a syndiotactic structure. The syndiotactic structure refers to a structure in which substituents (for example, a phenyl group in the case of polystyrene) are alternately arranged with respect to a main chain composed of CC bonds. Preferably, the syndiotactic polymer used in the present invention has a tacticity of 30% or more by ¹³ C-NMR.
[0010]
Representative examples of the olefin-based polymer having such a syndiotactic structure include polypropylene, polyisobutylene, and polyamylene. Polypropylene is preferred because of its versatility and excellent characteristics of the resulting speaker member (eg, light weight, internal loss). Examples of the styrene-based polymer include polystyrene, polymethylstyrene, and polyethylstyrene. Polystyrene is preferred because it has excellent versatility and excellent characteristics (eg, lightweight) of the obtained speaker member.
[0011]
The syndiotactic polymer used in the present invention has an Mw / Mn of 4 or less, preferably 3 or less, more preferably 2 to 2.5 (lower limit of Mw / Mn). Is necessarily 1). When Mw / Mn is more than 4, the fluidity at the time of molding is often insufficient, and as a result, the stiffness, heat resistance, chemical resistance, and the like of the obtained speaker member may be insufficient. Many.
[0012]
The degree of polymerization of the syndiotactic polymer is preferably from 10 to 100,000, more preferably from 100 to 10,000, and particularly preferably from 500 to 5,000. By having a polymerization degree in such a range, a speaker member having excellent fluidity and dimensional stability during molding can be obtained.
[0013]
The polymerization method of the syndiotactic polymer is not particularly limited, and any appropriate method can be adopted. Preferably, the syndiotactic polymer is polymerized using a metallocene-based catalyst. This is because the tacticity of the obtained polymer is increased, and as a result, a speaker member having excellent rigidity and internal loss can be obtained.
[0014]
The metallocene catalyst is represented by the following chemical formula:
[0015]
Embedded image

[0016]
Here, M is a Group 4 transition metal, preferably zirconium or titanium, and more preferably zirconium. X is each independently halogen, preferably each independently bromine or chlorine. More preferably, the metallocene-based catalyst contains methylaminoxan represented by the following chemical formula as a co-catalyst:
[0017]
Embedded image

[0018]
Here, n is an integer of 5 to 20. A metallocene-based catalyst containing zirconocene as a main component (for example, 80% by weight) and methylaminoxane as a co-catalyst (for example, 20% by weight) is particularly preferable for synthesizing the polymer used in the present invention.
[0019]
The resin composition used in the present invention may contain any appropriate component (for example, a reinforcing material, a colorant) in addition to the syndiotactic polymer. The resin composition used in the present invention is typically in the form of pellets.
[0020]
Further, a paint is applied to the surface of the speaker member of the present invention. The paint may be an emulsion paint, a water-soluble paint, or a solvent-based paint (however, in the case of a solvent-based paint, an aromatic solvent is excluded. Is). Typically, a solvent-based paint is used. Such solvent-based paints include, for example, alkyd resin paints, aminoalkyd resin paints, epoxy resin paints, polyurethane resin paints, and acrylic resin paints. Coatings formed from these paints have different properties (eg, strength, internal loss) from films formed from the resin compositions. As a result, according to the diaphragm formed from the film to which the paint is applied, friction occurs between the coating film and the film during vibration, so that the internal loss increases. Particularly preferred paints include acrylic resin paints and epoxy resin paints.
In addition, the coating material usually contains a binder resin, a crosslinking agent, a solvent, and a coloring agent. For example, as a binder resin of the acrylic resin paint, poly (2-hydroxyethyl methacrylate), poly (2-hydroxyethyl acrylate), polyacrylic acid, polymethacrylic acid, poly (glycidyl methacrylate), poly (methylolated acrylamide) are used. No. Examples of the crosslinking agent include an amino resin such as an etherified urea resin, a melamine resin, and a benzoguanamine resin, and an organic polyamine. A typical example of the colorant is a pigment (for example, carbon black).
[0021]
Hereinafter, a preferred example of the method for manufacturing the speaker member of the present invention will be described.
First, the resin composition is formed into a film by any appropriate method (for example, extrusion molding). Typically, the thickness of the film is 50-75 μm.
Next, the surface of the obtained film is subjected to a corona discharge treatment. By performing the corona discharge treatment, the adhesion to the paint can be improved.
Next, a paint is applied to the film subjected to the corona discharge treatment. The method of application and drying is not particularly limited, and any appropriate method can be adopted. The thickness of the dried coating film is preferably 4 to 30%, more preferably 6 to 15%, based on the thickness of the resin composition film. By having such a relationship between the thickness of the resin composition film and the thickness of the coating film, the coating film strength and the adhesion between the coating film and the film are remarkably improved, and as a result, a very excellent internal loss and ratio are obtained. A speaker member having an elastic modulus is obtained.
Finally, the film on which the coating film is formed is subjected to hot press molding to obtain the speaker member of the present invention. Any appropriate condition can be adopted as the condition of the hot press molding depending on the purpose.
[0022]
Hereinafter, the operation of the present invention will be described.
According to the present invention, there is provided a speaker member using a resin composition containing a syndiotactic olefin-based polymer or a styrene-based polymer having Mw / Mn of 4 or less. Syndiotactic polymers are very crystalline. Moreover, due to having such a very sharp molecular weight distribution, the fluidity during molding is remarkably improved. Therefore, shrinkage due to crystallization of the obtained molded article can be significantly suppressed. As a result, the speaker member of the present invention has high elasticity and high rigidity (accordingly, excellent acoustic characteristics), and is excellent in moldability and dimensional stability against heat and humidity. In addition, Mw / Mn of the general-purpose polymer is 6 or more, and the speaker member obtained by using the general-purpose polymer has elasticity, rigidity, moldability, and heat and humidity in comparison with the speaker member of the present invention. It has actually been confirmed that both of the dimensional stability are significantly inferior. The effect obtained using such a polymer having a very sharp molecular weight distribution is unexpectedly excellent.
[0023]
Further, a paint is applied to the surface of the speaker member of the present invention. The coating film formed from the paint has different properties (for example, strength and internal loss) from the film formed from the resin composition. As a result, according to the speaker member of the present invention formed from the film on which the paint is applied, friction occurs between the coating film and the film during vibration, so that the internal loss increases. Therefore, the speaker member of the present invention is excellent in acoustic characteristics. In addition, as described above, since the resin composition film has a very small shrinkage during molding, there is no problem of curling due to a difference in shrinkage between the film and the coating film.
[0024]
In a preferred embodiment, the syndiotactic polymer is obtained by a polymerization reaction using a metallocene catalyst. By using a metallocene-based catalyst, a syndiotactic polymer having a very high stereoregularity can be obtained, so that the elasticity, rigidity, moldability, and dimensional stability against heat and humidity can be further improved. In addition, it was actually confirmed that a speaker member having excellent chemical resistance and electrical characteristics could be obtained.
[0025]
【Example】
Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited to these Examples. Unless otherwise indicated, parts and percentages in the examples are on a weight basis.
[0026]
(Example 1)
A syndiotactic polystyrene (SPS) resin (pellet) polymerized using a metallocene catalyst was formed into a 50 μm thick film under the following extrusion molding conditions.

[0027]
After subjecting the obtained film surface to a corona discharge treatment, an acrylic resin paint having the following formulation was applied and dried under the following conditions to form a coating film.
(Prescription of paint)
2-hydroxyethyl methacrylate 100 (parts)
Amino resin (crosslinking agent) 5
Carbon black 1
(Application conditions)
Processing speed 20 (m / min)
Drying temperature 130-150 (℃)
Film thickness 5-7 (μm)
The film on which the coating film was formed was subjected to hot press molding using a mold having a predetermined shape at a molding temperature of 160 to 170 ° C. and a molding time of 3 to 5 seconds to obtain a 25φ dome-shaped speaker diaphragm.
[0028]
With respect to the obtained diaphragm, the density ρ, the Young's modulus (elastic modulus) E, the specific elastic modulus E / ρ, and the internal loss were examined by ordinary methods. The results are shown in Table 1 below together with the results of Example 2 and Comparative Examples 1 to 3 described below. Further, the frequency characteristics of the diaphragm were examined at 50 cm on the axis of the diaphragm and at an output of 1 W. The results are shown in FIG.
[0029]
[Table 1]

[0030]
(Example 2)
A diaphragm was prepared in the same manner as in Example 1 except that an epoxy resin paint having the following formulation was applied and dried under the following conditions to form a coating film.
(Prescription of paint)
Epoxy resin 100 (parts)
Organic polyamine (crosslinking agent) 5
Carbon black 1
(Application conditions)
Processing speed 20 (m / min)
Drying temperature 40-80 (℃)
Coating thickness 5-7 (μm)
The obtained diaphragm was subjected to the same evaluation as in Example 1. The results are shown in Table 1 above.
[0031]
(Comparative Example 1)
A film having a thickness of 50 μm is formed using polyetherimide (PEI) (manufactured by Mitsubishi Plastics, Inc., Superior UT), and the film is hot-pressed at a molding temperature of 200 to 220 ° C. and a molding time of 5 seconds. A 25φ dome-shaped speaker diaphragm was produced. The obtained diaphragm was subjected to the same evaluation as in Example 1. The results are shown in Table 1 above.
[0032]
(Comparative Example 2)
A film having a thickness of 50 μm is formed using polyetheretherketone (PEEK) (Victrex, manufactured by Victrex MC Co., Ltd.), and the film is hot pressed at a molding temperature of 240 to 260 ° C. and a molding time of 3 to 5 seconds. It was molded to produce a 25φ dome-shaped speaker diaphragm. The obtained diaphragm was subjected to the same evaluation as in Example 1. The results are shown in Table 1 above. Further, the frequency characteristics of the diaphragm were examined at 50 cm on the axis of the diaphragm and at an output of 1 W. FIG. 2 shows the results.
[0033]
(Comparative Example 3)
A 25φ dome-shaped speaker diaphragm was produced in the same manner as in Example 1 except that no paint was applied and that hot press molding was performed under the conditions of a molding temperature of 150 to 160 ° C. and a molding time of 3 to 5 seconds. Produced. The obtained diaphragm was subjected to the same evaluation as in Example 1. The results are shown in Table 1 above. Further, the frequency characteristics of the diaphragm were examined at 50 cm on the axis of the diaphragm and at an output of 1 W. The results are shown in FIG.
[0034]
As is clear from Table 1, the diaphragms of Examples 1 and 2 were about 14 to about 29 in comparison with the diaphragms of Comparative Examples 1 and 2 using engineering plastics, despite the application of paint. % Weight reduction has been achieved. Moreover, the diaphragms of Examples 1 and 2 have significantly superior Young's modulus, specific elastic modulus and internal loss as compared with Comparative Examples 1 and 2. In addition, when Examples 1 and 2 are compared with Comparative Example 3, it can be seen that the internal loss is significantly improved by applying the paint.
Further, as is apparent from a comparison between FIG. 1 and FIGS. 2 and 3, the speaker member of the present invention has a characteristic in the vicinity of fh extending smoothly without a discontinuous resonance peak. 1 and 2, it can be seen that the speaker member of the present invention has significantly reduced harmonic distortion (particularly second-order distortion). This is because the internal loss was improved by applying the paint.
[0035]
【The invention's effect】
According to the present invention, by using a film and a paint formed using a syndiotactic polymer in combination with each other, a speaker member having high elasticity, high strength, large internal loss, and light weight and low cost can be obtained. Can be
[Brief description of the drawings]
FIG. 1 is a graph showing frequency characteristics of a diaphragm obtained in Example 1.
FIG. 2 is a graph showing frequency characteristics of the diaphragm obtained in Comparative Example 2.
FIG. 3 is a graph showing frequency characteristics of a diaphragm obtained in Comparative Example 3.

Claims (5)

A speaker diaphragm made of a resin composition containing a syndiotactic olefin-based polymer or a syndiotactic styrene-based polymer having a Mw / Mn of 4 or less as a main component and having a surface coated with a paint. . The speaker diaphragm according to claim 1, wherein the syndiotactic olefin polymer or the syndiotactic styrene polymer is a polymer obtained by a polymerization reaction using a metallocene catalyst. 3. The speaker diaphragm according to claim 1, wherein the metallocene-based catalyst contains zirconocene and methylaluminoxane. 4. The speaker according to any one of claims 1 to 3, wherein the paint is selected from an emulsion paint, a water-soluble paint, an alkyd resin paint, an amino alkyd resin paint, an epoxy resin paint, a polyurethane resin paint, and an acrylic resin paint. Diaphragm. Film-forming a resin composition containing a syndiotactic olefin-based polymer or a syndiotactic styrene-based polymer having a Mw / Mn of 4 or less as a main component,
Performing a corona discharge treatment on the film;
Applying a paint to the corona-discharged film;
Hot press-molding the film to which the coating material has been applied.

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