WO2009139044A1

WO2009139044A1 - Edge material for microspeaker diaphragm, microspeaker employing the edge material for microspeaker diaphragm, and electronic appliance employing the microspeaker

Info

Publication number: WO2009139044A1
Application number: PCT/JP2008/058754
Authority: WO
Inventors: 山田精吾
Original assignee: 吾妻化成株式会社
Priority date: 2008-05-13
Filing date: 2008-05-13
Publication date: 2009-11-19

Abstract

An edge material for microspeaker diaphragms which is improved in heat resistance, cold resistance, moisture resistance, moldability, high internal loss, etc. The edge material for microspeaker diaphragms is obtained by heat-forming an elastomer sheet. The elastomer sheet is one made only of a polyester elastomer comprising a polyester resin having the structural formula given under the following [Chemical formula (1)] or of a mixture of the polyester elastomer and a functional elastomer such as a urethane elastomer as an internal additive, or is one obtained by disposing the functional elastomer on one or each side of a sheet of the polyester elastomer or between two sheets of the polyester elastomer.

Description

Diaphragm edge material for microspeaker, microspeaker using the microspeaker diaphragm edge material, and electronic device using the microspeaker

The present invention relates to an edge material technology of a micro speaker for an electric-acoustic converter used in an electronic device such as a mobile phone, a portable audio device, or a laptop computer, and in particular, heat resistance, cold resistance, moisture resistance, molding Microspeaker diaphragm edge material excellent in performance and high internal loss, etc., microspeaker using the microspeaker diaphragm edge material, and a mobile phone, a portable acoustic device, or a notebook computer using the microspeaker Relating to electronic devices.

Currently, most of the diaphragms of microspeakers used in small electronic devices such as mobile phones as described above are polyimide (PI), polyamideimide (PAI), polyphenylene sulfide (PPS), polyetherimide (PEI), polyethylene. Diaphragm with a single structure obtained by heating and pressing a single piece of engineering plastic such as naphthalate (PEN), polyethylene terephthalate (PET), or polyetheretherketone (PEEK) with a predetermined mold for general speakers In a diaphragm (also referred to as cone paper), an integrally molded product that inseparably functions as both a vibration body forming a diaphragm and an edge portion positioned on the outer periphery of the vibration body is the mainstream.

A speaker diaphragm in which a resin film such as polyimide (PI) or polyamideimide (PAI) is integrally formed in a dome shape is disclosed in, for example, Japanese Patent Laid-Open No. 2003-289594 “Speaker diaphragm, polyamide resin and polyimide resin used therefor” (Patent Document 1).

8, FIG. 9, and FIG. 10 are a perspective view of a mobile phone disclosed in Patent Document 1, a structural example of a diaphragm, and a structural diagram of a speaker.

In FIG. 8, 1 is a mobile phone, 2 (4) is a speaker section, and 3 is a microphone section (receiver speaker).
FIG. 9 shows an overall view of a diaphragm molded from a polyamideimide (PAI) resin film (or polyimide (PI) resin film). In the same figure, 3 is a diaphragm, 3a is a dome part (body) of the diaphragm, 3b is a recessed fitting part of the diaphragm, 3c is a peripheral part (edge) of the diaphragm, 3d is an external pasting part of the diaphragm, Reference numeral 5 denotes a speaker voice coil.

FIG. 10 is a diagram showing the structure of the speaker unit incorporating the diaphragm 3 shown in FIG. In the same figure, 3 is a diaphragm, 3a is a dome part (body) of the diaphragm, 3b is a recessed fitting part of the diaphragm, 3c is a peripheral part (edge) of the diaphragm, 3d is an external pasting part of the diaphragm, 4 Is a speaker using a diaphragm (corresponding to 2 in FIG. 4), 5 is a voice coil, 7a is an upper magnetic pole plate of the speaker, 7b is a lower magnetic pole plate of the speaker, 8 is a magnetic gap, 9 is an external terminal of the speaker, 10 Is a gasket, 14 is a magnet of the speaker, 15 is a magnetic circuit of the speaker, 17 is a frame, and 26 is a protector.

In the examples shown in FIGS. 8 to 10, thin film engineering plastics such as polyamide imide (PAI) (or polyimide (PI)) are used as the diaphragm to reduce the weight and weight of the diaphragm in consideration of the efficiency and heat resistance of the speaker. However, it is difficult to design an engineering plastic diaphragm in which the peripheral edge (edge) of the diaphragm and the dome (body) of the diaphragm are integrated, so that the lowest resonance frequency (F ₀ ) of the speaker is low. There is a problem that the lower limit frequency possible is insufficient and the sound quality tends to be hard.

As digitalization progresses year by year and the ubiquitous society is greeted, the evolution of the demand for mobile phones as a typical mobile function has been remarkable, and the microspeakers (diameter 20 mm ±) mounted there are also highly sensitive and have high power. There is an increasing demand for broadband covers such as sound quality.

By the way, although it is a conventional single structure diaphragm, in order to keep the lowest resonance frequency (F0) low and to cope with high power, the functions of the diaphragm body part and the edge part must be made compatible individually.

In order to reproduce sound that is easily transmitted to the air without distortion and without vibrations at each frequency mainly transmitted from the voice coil in the diaphragm body part, strength such as elastic modulus, rigidity and appropriate internal Loss is required.

On the other hand, since the edge portion is positioned on the outer periphery of the vibration portion body and fixed to the frame, a flexible damper function that mainly absorbs vibrations is required.

However, it is necessary to satisfy both the strength required for the diaphragm body and the softness and flexibility of the damper required for the edge portion for a single-structure diaphragm obtained by molding a single film. There is a limit, do not wait for words.

Japanese Patent Application Laid-Open No. 2004-312085 “Speaker diaphragm and speaker using the same” (Patent Document 2) discloses a speaker diaphragm having a wide frequency characteristic and a high frequency by lowering the lowest resonance frequency (Fo). For the purpose of improving sound quality, a polyimide resin base material provided with an elastomer layer on one or both sides thereof is disclosed. Japanese Patent No. 3996075 “Film for speaker diaphragm” (Patent Document 3) discloses polyetherimide. What provided the resin coating layer on the single side | surface or both surfaces of the film base material is disclosed.

JP 2003-289594 A JP 2004-312085 A Japanese Patent No. 3996075

An important role of the edge material of the diaphragm for microspeakers is to suppress the divided vibration from the diaphragm and stabilize the frequency characteristics.Viscoelasticity, considering various usage environments of electronic devices such as mobile phones to be incorporated Various physical properties such as high internal loss, high stress, heat resistance, cold resistance, flexibility, moldability for mass production, shape retention, etc. are required. It did not meet the requirements of.

In view of the above circumstances, the object of the present invention is to use a diaphragm edge material for a micro speaker and a diaphragm edge material for the micro speaker that are particularly excellent in heat resistance, cold resistance, moisture resistance, moldability, and high internal loss. And providing an electronic device such as a mobile phone, a portable audio device, or a notebook computer using the micro speaker.

A diaphragm edge material for a microspeaker according to the present invention comprises a polyester-based elastomer resin containing a substance having the chemical structural formula shown in (Chemical Formula 1) of Example 1 and having a tan δ value of 0.02 or more at room temperature. It is characterized by using a polyester elastomer sheet formed into a sheet.

In addition, an elastomer resin different from the polyester elastomer resin is internally added to the polyester elastomer resin, or one or both sides of the polyester elastomer sheet formed with the polyester elastomer resin or two sheets of the polyester It is characterized in that an elastomer resin layer different from the polyester elastomer resin is added between the elastomer elastomer sheets.

Further, the elastomer resin different from the polyester elastomer resin is a urethane elastomer, a silicon elastomer, a styrene elastomer, or EVA (ethylene / vinyl acetate polymer).

Furthermore, the micro speaker according to the present invention is characterized by using the above-described diaphragm edge material for a micro speaker, and the electronic device according to the present invention is characterized by using the micro speaker.

The diaphragm edge material for a microspeaker of the present invention is excellent in heat resistance, cold resistance, moisture resistance, moldability, high internal loss, and the like due to the adoption of the above configuration. Is incorporated into a microspeaker, or the microspeaker is incorporated into an electronic device such as a mobile phone, a portable audio device, or a notebook personal computer, so that a microspeaker or an electronic device having excellent characteristics can be realized.

FIG. 1 is a view for explaining the configuration of a diaphragm edge material for a micro speaker according to the present invention. FIG. 2 is a view for explaining an example of a diaphragm according to the present invention (part 1). FIG. 3 is a view for explaining an example of a diaphragm according to the present invention (part 2). FIG. 4 is a view for explaining an example of a diaphragm according to the present invention (part 3). FIG. 5 is a view for explaining another example of the diaphragm according to the present invention (part 1). FIG. 6 is a view for explaining another example of the diaphragm according to the present invention (part 2). FIG. 7 is a structural diagram of a micro speaker using the diaphragm of FIG. FIG. 8 is a perspective view of a conventional mobile phone. FIG. 9 is a diagram showing a diaphragm in the prior art. FIG. 10 is a structural diagram of a speaker in the prior art.

Explanation of symbols

1: Mobile phone 2: Speaker using diaphragm 20: Highly elastic material (paper, engineering plastic film, or light metal sheet such as aluminum or magnesium)
30: Diaphragm edge material for a

micro speaker

3a, 30a: Dome part (body) of the diaphragm
3b, 30b: concave fitting portion of

diaphragm

3c, 30c: peripheral edge (edge) of diaphragm
3d, 30d: External pasting part of diaphragm 300: Diaphragm 4: Micro speaker using diaphragm 5: Voice coil 7a: Upper magnetic pole plate of speaker 7b: Lower magnetic pole plate of speaker 8: Magnetic gap 9: Outside of speaker Terminal 10: Gasket 14: Magnet of speaker 15: Magnetic circuit of speaker 17: Frame 26: Protector A: Polyester elastomer B: Functional elastomer (urethane elastomer, silicone elastomer, styrene elastomer, EVA (ethylene / vinyl acetate) Polymer))

Hereinafter, examples of the present invention will be described with reference to chemical structural formulas and drawings.

Example 1
The present invention contains at least 50% or more of a substance having the chemical structural formula shown below (Chemical Formula 1) and has a loss tangent tan δ value of 0.02 or more at room temperature (eg, 5 ° C. to 35 ° C.) A polyester elastomer sheet is produced by forming a polyester elastomer sheet using a ceramic elastomer resin, and the polyester elastomer sheet is molded by a hot press to obtain a diaphragm edge material for a micro speaker.

In Example 1 of the present invention, a polyester elastomer sheet having good characteristics is produced using a material having an appropriate thickness (for example, 10 μ to 60 μ) of a polyester elastomer resin having the above composition, and is molded by a hot press. Thus, a diaphragm edge material for a micro speaker is obtained. As a result, a diaphragm edge material for a microspeaker having excellent characteristics such as heat resistance, cold resistance, moisture resistance, moldability, and high internal loss as compared with the prior art can be obtained.

(Example 2)
In Example 2 of the present invention, as shown in FIG. 1 (b), a functional elastomer resin (urethane elastomer, silicon elastomer, styrene elastomer) is placed inside the polyester elastomer A having the contents described in Example 1 above. Alternatively, using a material in which EVA (ethylene / vinyl acetate polymer) B is internally added, a polyester-based elastomer sheet having good characteristics is prepared and molded by a hot press to obtain a diaphragm edge material for a micro speaker. . By incorporating functional elastomer resin, it can be adjusted to meet the requirements of proper physical properties (f ₀ ± softness adjustment, thickness ± adjustment, tan δ adjustment, Young's modulus adjustment, moldability adjustment etc), a diaphragm edge material for a microspeaker having characteristics excellent in heat resistance, cold resistance, moisture resistance, moldability, high internal loss, and the like as compared with the prior art can be obtained.

(Example 3)
In Example 3 of the present invention, the polyester-based elastomer sheet (10 μ to 60 μ) A having the contents described in Example 1 above is further provided on one side (see FIG. 1 (c)) or both sides (see FIG. 1 (d)). Functional elastomer resin (urethane elastomer, silicon elastomer, styrene elastomer, EVA (ethylene / vinyl acetate polymer), etc.) B is added to make it multilayer, so that it meets the requirements of more appropriate physical properties. (F ₀ ± softness adjustment, thickness ± adjustment, tan δ adjustment, Young's modulus adjustment, moldability adjustment etc). These multi-layered materials are molded by a hot press, and are adapted to a diaphragm edge material for a micro speaker.

Example 4
In Example 4 of the present invention, as shown in FIG. 1 (e), a functional elastomer resin (between two polyester-based elastomer sheets (10 μ to 60 μ) A having the contents described in Example 1 above is provided. By adding a urethane elastomer, silicon elastomer, styrene elastomer, or EVA (ethylene / vinyl acetate polymer) B to make it multilayer, it can be adjusted to meet the requirements of more appropriate physical properties. (F0 ± softness adjustment, thickness ± adjustment, loss tangent tan δ adjustment, Young's modulus adjustment, moldability adjustment etc). These multi-layered materials are molded by a hot press, and are adapted to a diaphragm edge material for a micro speaker.

According to the above diaphragm edge material for a micro speaker, a polyester elastomer resin containing 50% or more of the polyester resin having the chemical structural formula (Chemical Formula 1) (10 μ to 60 μ) or the polyester elastomer resin Functional elastomers (urethane elastomer, silicon elastomer, styrene elastomer, EVA (ethylene / vinyl acetate polymer), etc.) may be added internally, or one or both sides or two of the polyester elastomer resin. An elastomer sheet made by adding a functional elastomer layer (urethane-based elastomer, silicon-based elastomer, styrene-based elastomer, EVA (ethylene / vinyl acetate polymer), etc.) between these polyester-based elastomers is heated. By forming it into an edge material for a micro speaker diaphragm, it is possible to obtain a material having the following excellent physical properties that are mainly required for a diaphragm edge material for a micro speaker.
(A) Heat resistance: High heat resistance next to super engineering plastics Melting point / 200 ° C ±
(B) Heat resistant retention ratio: No change in retention ratio in a test at 120 ° C. × 1000 hours.
(C) Brittle temperature: -60 degrees ±
(D) Loss tangent tan δ: It is far superior to polyethylene naphthalate (PEN) (tan δ = 0.04), which is the highest in super engineering plastics that are currently used in micro speaker diaphragms. Depending on the formulation, the loss tangent tan δ can be more than twice that of super engineering plastics (tan δ = 0.08 or more), and an elastomer layer (urethane elastomer, silicone elastomer, styrene elastomer, or EVA (ethylene) on one or both sides・ By adding vinyl acetate polymer) etc., it is possible to give more effects.
(E) Minimum fre- quency frequency (F ₀ ) ... A polyester elastomer alone containing 50% or more of a polyester resin having the chemical structural formula can lower f ₀ significantly compared to conventional super engineering plastics. In addition, functional elastomers (urethane elastomers, silicone elastomers, styrene elastomers, EVA (ethylene / vinyl acetate polymer), etc.) can be internally added to polyester elastomer resins, or they can function on one or both sides. By adding a flexible elastomer layer (urethane-based elastomer, silicon-based elastomer, styrene-based elastomer, EVA (ethylene / vinyl acetate polymer), etc.), it is possible to achieve further effects.
(F) Q value: A polyester elastomer alone containing 50% or more of a polyester resin having the chemical structural formula of (Chemical Formula 1) can significantly lower the Q value compared to a conventional super engineering plastic. Or by adding an elastomer layer (urethane elastomer, silicone elastomer, styrene elastomer, EVA (ethylene / vinyl acetate polymer), etc.) on both sides, it is possible to give more effects.
(G) Molding mass productivity: A polyester elastomer containing 50% or more of a polyester resin having the chemical structural formula of (Chemical Formula 1) is a super engineering plastic molding temperature (180-250 ° C.) that is currently used in micro speaker diaphragms. ) Low temperature molding (120 ° C to 150 ° C) is possible, and mass productivity is excellent.

(Example 5)
Hereinafter, an embodiment in which the diaphragm edge material for a micro speaker having the above-described excellent characteristics is used for a micro speaker will be described with reference to the drawings.
2 and 3 are diagrams for explaining an example of the diaphragm according to the present invention.

In FIG. 2, 20 is a highly elastic material (paper, engineering plastic film, or light metal sheet such as aluminum or magnesium), and 30 is a diaphragm edge material for a micro speaker described in the above embodiment according to the present invention. .

The diaphragm edge material 30 for a micro speaker has a ring shape, and is integrally molded after being aligned so that the outer peripheral portion thereof overlaps the inner peripheral portion of the highly elastic material 20.

The highly elastic material 20 mainly forms the dome portion or body portion of the diaphragm, and the diaphragm edge material 30 for the microspeaker is aligned and integrated so as to mainly form the peripheral edge or edge portion of the diaphragm. Molded and attached to a microspeaker.

At least one of the highly elastic material 20 and the diaphragm edge material 30 for the microspeaker is provided with an adhesive function in advance (adhesive material may be applied, or characteristics of a material that causes an adhesive action during integral molding may be used). At the time of integral molding, the highly elastic material 20 and the diaphragm member 30 for microspeaker are bonded and molded to produce a diaphragm for microspeaker with a free edge specification.

FIG. 3 is a configuration diagram when the diaphragm manufactured by simultaneous molding as described above is attached to the voice coil of the micro speaker. FIG. 3 shows an example in which the diaphragm edge material 30 for microspeaker is placed on the highly elastic material 20, but conversely, the diaphragm edge material 30 for microspeaker is made of a highly elastic material as shown in FIG. It is also possible to be below 20. Whether to make it as shown in FIG. 3 or as shown in FIG. 4 is a matter determined in consideration of the structure of the micro speaker. Needless to say, the shape of the molding in the case of integral molding should be an optimum shape according to that.

5 and 6 are diagrams showing another example of the diaphragm according to the present invention.
In FIG. 5, 20 is a highly elastic material (paper, engineering plastic film, or light metal sheet such as aluminum or magneto), 30 is a diaphragm edge material for a micro speaker, and the high elastic material 20 is used for a micro speaker. The highly elastic material 20 is aligned on the sheet of the diaphragm edge member 30 so as to be positioned at the position of the diaphragm dome, that is, the body (usually the center), and integrally molded.

In the case of this example, the highly elastic material 20 forms the dome portion, that is, the body portion of the diaphragm, and the diaphragm edge material 30 for the microspeaker includes both the dome portion, that is, the body portion of the diaphragm, and the peripheral portion, that is, the edge portion of the diaphragm. Will be formed. In other words, the dome portion of the diaphragm is formed by a portion where the high elastic material 20 and the diaphragm edge material 30 for the micro speaker overlap, and the peripheral edge portion of the diaphragm is formed only by the diaphragm edge material 30 for the micro speaker.

In this case as well, at least one of the highly elastic material 20 and the diaphragm edge member 30 for microspeakers is provided with an adhesive function in advance (adhesive material may be applied, or the characteristics of the material that causes an adhesive action during integral molding are utilized. Alternatively, at the time of integral molding, the high elastic material 20 and the diaphragm edge material 30 for microspeaker are bonded and integrally molded, and a diaphragm for microspeaker is manufactured with a free edge specification.

6 and 7 are diagrams showing the diaphragm manufactured as described above and a micro speaker using the diaphragm.

6, 300 is a diaphragm produced by bonding and molding the highly elastic material 20 and the diaphragm edge material 30 for the microspeaker as described in FIG. 1, and 30a is a dome portion (body) of the diaphragm, 30b. Is a recessed fitting portion of the diaphragm, 30c is a peripheral edge (edge) of the diaphragm, and 30d is an external attachment portion of the diaphragm. The dome portion (body) 30a of the diaphragm is formed by laminating the highly elastic material 20 and the diaphragm edge material 30 for the micro speaker, and the peripheral edge (edge) 30c of the diaphragm and the external pasting portion 30d of the diaphragm are It is formed only with the diaphragm edge material 30 for microspeakers. Reference numeral 5 denotes a speaker voice coil. The microspeaker diaphragm edge member 30 is attached so that the sheet side is in contact with the voice coil 5.

FIG. 7 is a diagram showing the structure of the speaker unit incorporating the diaphragm 300 shown in FIG. In the same figure, 30 is a vulcanized rubber, 30a is a dome part (body) of the diaphragm, 30b is a recessed fitting part of the diaphragm, 30c is a peripheral part (edge) of the diaphragm, 30d is an external pasting part of the diaphragm, 4 is a speaker using a diaphragm (corresponding to the speaker 2 in FIG. 8), 5 is a voice coil, 7a is an upper magnetic pole plate of the speaker, 7b is a lower magnetic pole plate of the speaker, 8 is a magnetic gap, 9 is an external terminal of the speaker Reference numeral 10 denotes a gasket, 14 denotes a speaker magnet, 15 denotes a speaker magnetic circuit, 17 denotes a frame, and 26 denotes a protector. 7 is different from FIG. 10 in the portion of the diaphragm, and the configuration other than the diaphragm 30 is the same as that in FIG.

When the peripheral part (edge) and dome part (body) of the microspeaker diaphragm are molded from the same material engineering plastic film as in the prior art described in FIGS. 8 to 10, the lowest resonance of the speaker It is difficult to design a low frequency (F ₀ ), there is a problem that the lower limit frequency that can be reproduced is insufficient, and the sound quality tends to be hard, and the peripheral edge (edge) of the diaphragm and the diaphragm The conventional method of forming the dome part (body) separately and bonding them together leaves low-frequency playback and input issues (input is low if low-frequency playback is important, and low-frequency limits are important if input is important) However, in the present invention, there is a problem that productivity is poor. In the present invention, a highly elastic material (paper, engineering plastic film, aluminum, magnet Vibration and adaptable to high-power speakers by a simple and highly productive method of bonding and integrally molding the diaphragm edge material for micro speakers shown in the above example) It became possible to realize the board.

The diaphragm edge material for a micro speaker according to the present invention is excellent in characteristics, and is an electro-acoustic converter for any electronic device that requires a speaker, such as an electronic device such as a mobile phone, a portable audio device, or a notebook computer. It can also be used as an edge material for microspeakers.

Claims

A polyester elastomer sheet comprising a substance having the chemical structural formula shown below (chemical formula 1) and a polyester elastomer resin having a tan δ value of 0.02 or more at room temperature is formed into a sheet shape. Diaphragm edge material for microspeakers characterized by
The diaphragm edge material for a micro speaker according to claim 1,
The polyester elastomer resin is internally mixed with an elastomer resin different from the polyester elastomer resin, or one or both sides of the polyester elastomer sheet formed with the polyester elastomer resin, or the two polyester elastomers. A diaphragm edge material for a micro speaker, wherein a layer of an elastomer resin different from the polyester elastomer resin is added between sheets.
The diaphragm member for a micro speaker according to claim 2,
The diaphragm edge material for a micro speaker, wherein the elastomer resin different from the polyester elastomer resin is a urethane elastomer.
The diaphragm member for a micro speaker according to claim 2,
A diaphragm edge material for a micro speaker, wherein the elastomer resin different from the polyester elastomer resin is a silicon elastomer.
The diaphragm member for a micro speaker according to claim 2,
A diaphragm edge material for a micro speaker, wherein the elastomer resin different from the polyester elastomer resin is a styrene elastomer.
The diaphragm member for a micro speaker according to claim 2,
A diaphragm edge material for a micro speaker, wherein the elastomer resin different from the polyester elastomer resin is EVA (ethylene / vinyl acetate polymer).
A micro speaker using the diaphragm edge material for a micro speaker according to any one of claims 1 to 6.
An electronic device using the microspeaker according to claim 7.