JP2011061311A - Diaphragm for speaker, and speaker using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a diaphragm for a speaker excelling in workability, having appropriate flexibility, easily manufacturable, excelling in low-frequency reproduction, improved in heat resistance and having waterproofness added thereto. <P>SOLUTION: This diaphragm for a speaker includes a diaphragm body, a laminated body wherein all layers are formed of an acrylic modified epoxy resin, and an edge base material, and is achieved by the laminated body wherein the laminated body includes two or more low-molecular layers and one or more high-molecular layers, and also includes a laminate with the high-molecular layer sandwiched between one low-molecular layer and the other low-molecular layer, wherein the weight-average molecular weight of the high-molecular layer is larger than that of any of the one low-molecular layer and the other low-molecular layer. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a speaker diaphragm and a speaker using the same.

  The speaker is used for various acoustic devices and information communication devices. In recent years, speakers have been widely used not only for home and in-vehicle audio devices but also for various electronic devices such as personal computers, mobile phones, and game devices. At present, inexpensive, smaller, and thinner speakers are required, but a speaker with low sound output (characteristics) and excellent heat resistance is desired, and both are in a kind of trade-off relationship.

  Currently marketed speakers are classified by focusing on the diaphragm: 1) a fixed edge type in which the diaphragm body and the edge are integrally formed of the same material; and 2) the diaphragm body and the edge. It is roughly classified into a free edge type that is manufactured separately and joined to form a diaphragm. In a microspeaker or the like that is required to be small and thin, a fixed edge type in which a film such as PET (polyethylene terephthalate) is used as a diaphragm is often used for cost reduction. This eliminates the bonding step between the diaphragm main body and the edge, and is said to be able to improve productivity and reduce the price.

  However, since the physical properties required for the diaphragm main body and the physical properties required for the edge are inherently different, it is difficult to cover the physical properties with one kind of material. For example, if the thickness of the film is reduced in order to reduce the minimum resonance frequency, the rigidity of the diaphragm main body is reduced and abnormal resonance occurs. Further, if the thickness of the film is increased so as not to cause abnormal resonance, there is a problem that the rigidity at the edge portion is increased and the minimum resonance frequency is increased. Thus, it can be said that it is generally difficult to satisfy all of the small size, high reliability, and high sound quality in the fixed edge type speaker.

  On the other hand, in the free edge type, the sound quality is improved by using a diaphragm body made of a material having rigidity that does not cause abnormal resonance and an edge made of a material having low stiffness to lower the minimum resonance frequency. ing. In the free edge type, different types of materials are usually used for the diaphragm body and the edge. However, it is difficult to establish molding conditions between different types of materials, and the molding equipment becomes complicated. A method is employed in which the diaphragm main body and the edge are separately formed, and then both are fixed via an adhesive. For this reason, various steps relating to adhesion such as application of the adhesive, matching of the diaphragm main body and the edge, application of the adhesive, curing, and drying are required, resulting in a problem that productivity is lowered and manufacturing cost is increased. .

In order to solve the above problem, Patent Document 1 (Japanese Patent Laid-Open No. 6-189392: refer to FIG. 1) proposes a technique that enables cost reduction by simplifying the process while adopting a free edge type. Has been. However, in Patent Document 1, as shown in FIG. 1, a thermoplastic resin having adhesiveness when heated is directly applied to one side of an edge formed by a sheet-like member 21 made of open-cell soft polyurethane foam. The layer 22 is formed, and the diaphragm main body is superposed on the resin layer and heated and pressed, so that the bonding process and the edge molding process are performed simultaneously. For this reason, when the speaker is downsized, the edge diameter must be reduced and the edge material must be made thinner in order to reduce the stiffness to improve the edge characteristics. The operation of applying an adhesive on the surface involves an unstable and difficult operation, and it is difficult to improve productivity.
An adhesive is used to join the diaphragm main body and the edge formed using the polyester-based urethane resin. However, when a rubber adhesive is used after being dissolved in an organic solvent, it is necessary to perform aging for a certain time after application in order to avoid swelling of the organic solvent into the urethane resin. In addition, it is difficult to realize the demand for mass supply. Further, in Patent Document 1, since the edge of the urethane resin is used, as a pre-operation for bonding the diaphragm main body and the edge, a thermoplastic resin is directly applied to the surface of the polyurethane foam that is the material of the edge. A process for forming the film is necessary, which increases the production process and hinders productivity improvement.

  On the other hand, in Patent Document 2 (Japanese Patent No. 3211566: see FIG. 2), the diaphragm 31 and the edge portion 32 of the woven fabric using the ultrafine fibers as the base material are provided with different physical properties of the respective materials required. It has been proposed to perform integral molding of the diaphragm and the edge by applying a polymer resin. According to this proposal, the contradiction caused by changing the physical properties of the material and intending to widen the band, which had previously been a single-piece product made of a single polymer resin film material, has been resolved. In addition, it is said that a diaphragm-edge integral molded product that has improved sound pressure by reducing the weight of the material can be realized. Further, it is disclosed that by applying an arbitrary polymer resin material to the woven fabric base material in a screen printing process, precision is improved and variation in characteristics is reduced. However, in Patent Document 2, it is essential to apply and mold different polymer resins to the woven fabric, the diaphragm and the edge portion using the ultrafine fibers that are the base material of the diaphragm. A considerable number of sub-processes such as a coating process, a coating accuracy confirmation process, and a confirmation process of molding accuracy are indispensable, and do not meet the demand for rapid and mass supply.

  Accordingly, a speaker diaphragm having excellent processability, moderate softness, easy to manufacture, and excellent in low-frequency reproduction as compared with conventional ones, which can be used with heat resistance and waterproofness, and There is an urgent need to provide the speakers used.

JP-A-6-189392 Japanese Patent No. 3211666

  The inventor has a structure in which a resin having a plurality of layers of the same material (acrylic-modified epoxy resin laminate) and having a high weight average molecular weight is sandwiched between at least two resins having a low weight average molecular weight at the time of the present invention. The laminated body which comprises the diaphragm for speakers which was employ | adopted was discovered. By adopting this laminate, it is easy to fix the edge base material and diaphragm main body, and also to fix the gasket at the same time, and it is superior in sound quality and low-frequency reproduction and heat resistance. It was found that a speaker diaphragm and a speaker using the same can be provided, which are improved and waterproof by adding a waterproof property by covering the surface of the diaphragm with an edge material. The present invention has been made based on such knowledge.

Therefore, the present invention is a diaphragm for a speaker comprising a diaphragm main body, a laminate in which all layers are formed of an acrylic-modified epoxy resin, and an edge base material,
The laminate includes two or more low molecular layers and one or more polymer layers, and the polymer layer is sandwiched between one low molecular layer and another low molecular layer. With things,
The weight average molecular weight of the polymer layer is larger than the weight average molecular weight of one low molecular layer and the other low molecular layer,
On the diaphragm main body, the outermost surface side layer or the outermost surface side layer in the laminate is attached,
The edge base material is adhered on the outermost surface layer or the outermost surface layer of the laminate.

A speaker provided by another aspect of the present invention includes:
A magnetic circuit;
A voice coil disposed in the magnetic gap of the magnetic circuit, capable of vibrating back and forth, and outer peripherally joined to a damper;
A damper whose outer periphery is supported by the frame and whose inner periphery is joined to the outer periphery of the voice coil;
The frame joined to the magnetic circuit;
The speaker diaphragm according to the present invention is provided with an outer periphery supported by the frame and an inner periphery joined to the voice coil.

  According to the present invention, it has excellent processability, has moderate softness, is easy to manufacture (high production efficiency), has excellent low-frequency reproduction and sound quality, and has improved heat resistance, There is an effect that it is possible to provide a speaker diaphragm that can be waterproofed, a speaker using the diaphragm, and a method for manufacturing the speaker.

FIG. 1 is a cross-sectional view of the material of Patent Document 1. FIG. 2 is a cross-sectional view of the diaphragm disclosed in Patent Document 2. FIG. 3 shows a cross-sectional structure of a speaker according to the present invention. FIG. 4 shows a cross-sectional structure of the diaphragm 8 for a speaker shown in FIG. 3, where the edge 8b is joined to the front surface of the diaphragm body 8a. FIG. 5 is a partially enlarged cross-sectional view of FIG. 4 of the edge 8b of the speaker diaphragm 8 according to the present invention. FIG. 6 is a partially enlarged cross-sectional view when the diaphragm main body 8a is joined to the front surface of the edge 8b. FIG. 7 is a sound pressure frequency characteristic diagram of the product of the present invention and the conventional product. FIG. 8 shows the measurement width of the heat resistance test in (a), and the test result in (b). FIG. 9 shows a waterproof test.

Detailed Description of the Invention

1. Speaker diaphragm
Arrangement to Speaker A speaker incorporating the speaker diaphragm according to the present invention will be described with reference to FIG. FIG. 3 is a diagram showing a cross-sectional structure of a speaker according to an embodiment of the present invention. The speaker shown in FIG. 3 is a so-called internal magnet type speaker 1, a magnetic circuit 5 having a pot-shaped yoke 2, a columnar magnet 3, and a disk-shaped pole plate 4 fixed to a frame 9, and this magnetic circuit. The voice coil 6 supported in the magnetic gap 5 is disposed below the bending portion of the diaphragm body 8a, has the damper 7 that holds the voice coil 6 and is supported on the outer periphery of the frame 9, and the outer peripheral edge of the diaphragm 8 The edge 8b, which is a part, is provided with a speaker diaphragm 8 supported by the frame 9 and a gasket 12 on the outer periphery of the frame 9.

Configuration The configuration of the speaker diaphragm 8 according to the present invention will be described with reference to FIGS. 4 shows a sectional structure of the diaphragm 8 shown in FIG. 3, FIG. 5 shows a partially enlarged view of FIG. 4, and FIG. 6 shows a partially enlarged view of FIG. As shown in FIG. 4, the diaphragm 8 has a diaphragm body 8 a and an edge 8 b, and the edge 8 b is composed of a laminate 10 and an edge base material 11. As shown in FIG. 5, the first low molecular layer 10 a in the laminated body 10 is fixed to the diaphragm main body 8 a, and the second low molecular layer 10 b in the laminated body 10 is fixed to the edge base material 11. When waterproofing the speaker diaphragm 8, as shown in FIG. 5, the entire front surface of the speaker 1 is covered with the edge base material 11 up to the gasket 12 as well as the entire surface of the diaphragm body 8a. Is possible.

The speaker diaphragm in the present invention includes a diaphragm main body, a laminate in which all layers are formed of an acrylic-modified epoxy resin, and an edge base material.
1) The laminated body 10 is formed by forming all layers with an acrylic-modified epoxy resin. The laminate comprises two or more low molecular layers and one or more polymer layers, and the polymer layer is composed of one low molecular layer and another low molecular layer. It is something that has something in between. Therefore, in the present invention, it is possible to propose a laminate (preferred) in which at least one low molecular layer, a polymer layer, and another low molecular layer are formed in this order. Further, in the present invention, a laminate in which a plurality of these layers are stacked using one low molecular layer, a polymer layer, and another low molecular layer as a basic layer may be used. Further, according to another aspect of the present invention, one low molecular layer, a polymer layer, and another low molecular layer are used as basic layers, which are separated from the front surface or the back surface of one or a plurality of the laminates. One or more low molecular layers and / or another polymer layer may be formed. Preferably, one or more low molecular layers are laminated on the front or back surface of one or a plurality of the laminated bodies. What has been proposed is proposed. In this case, the molecular weights of the resins of the low molecular layers to be joined may be the same or different. In the present invention, each layer is preferably formed by close bonding.

In the present invention, the outermost layer or the outermost layer in the laminate is attached on the diaphragm main body, and the outermost layer or the outermost layer in the laminate. An edge base material is adhered on the layer.
Therefore, in the case of a laminate comprising only one low molecular layer, a polymer layer and another low molecular layer as a basic layer, or in the case of a laminate in which a plurality of these are laminated, the outermost surface side The layer or the backmost layer is one low molecular layer or another low molecular layer. In addition, a laminate composed of only one low molecular layer, a polymer layer, and another low molecular layer as a basic layer, or another low molecule on the front or back surface of a laminate in which a plurality of these are laminated. In the case of a laminate in which one or more layers and / or other polymer layers are formed (another aspect of the present invention), the outermost layer or the outermost layer is composed of one low molecular layer, another It becomes a low molecular layer, another low molecular layer, a polymer layer, and another polymer layer. In the present invention, “one”, “other”, and “other” are defined in order to clarify the positional relationship of the layers constituting the laminate in the present invention. In addition, the “outermost layer or outermost layer” means that when the “outermost layer” is attached on the diaphragm main body, the edge substrate is naturally formed in the “outermost layer”. It means that it adheres and vice versa.

The acrylic modified epoxy resin “acrylic (or methacrylic, hereinafter the same) modified epoxy resin” is a reaction product obtained by reacting an epoxy resin with acrylic acid (or methacrylic acid, hereinafter the same). And according to the ratio of the epoxy group and acrylic acid in the epoxy resin, an epoxy resin in which a part of the epoxy group is acrylated (or methacrylated, the same shall apply hereinafter), a partially acrylated epoxy resin, and all of the epoxy groups are completely An acrylated epoxy resin is produced. Also, a mixture of partially acrylated epoxy resin and fully acrylated epoxy resin may be formed. Partially acrylated epoxy resin, when the epoxy resin and acrylic acid are reacted, part of the epoxy group of the epoxy resin is opened and acrylated, but one or more epoxy groups are not opened It means what remains.

  Specific examples of the epoxy resin include bisphenol A type or bisphenol F type epoxy resin, novolac type epoxy resin, cresol novolac type epoxy resin, alicyclic epoxy resin, and the like. If necessary, a photopolymerization initiator and an epoxy curing agent may be added to adjust the acrylic-modified epoxy resin.

  Specifically, the acrylic-modified epoxy resin may be adjusted as follows. An epoxy resin and acrylic acid are mixed, and both are reacted in the presence of a basic catalyst according to a conventional method. The mixing ratio can be determined as appropriate. For example, the mixing ratio can be 0.5 to 2 equivalents of carboxylic acid groups of acrylic acid with respect to 2 equivalents of epoxy groups of the epoxy resin. By changing the mixing ratio of acrylic acid to the epoxy group, the degree of partial acrylation (that is, the number of acrylic groups added by ring opening of the epoxy group) can be freely changed. A fully acrylated epoxy resin refers to an acrylated epoxy resin that has all of the epoxy groups ring-opened during the above reaction. For example, when a bisphenol A type epoxy resin is used, a resin in which two acrylic groups are bonded in one molecule can be mentioned.

Weight average molecular weight According to the present invention, the polymer layer is provided by sandwiching one low molecular layer and another low molecular layer, and the weight average molecular weight of the acrylic-modified epoxy resin in the polymer layer is one. The weight average molecular weight of the acrylic modified epoxy resin in the low molecular weight layer and the other low molecular weight layers is larger. At this time, the weight average molecular weights of the acrylic-modified epoxy resins constituting the two low molecular layers (one low molecular layer and another low molecular layer) may be the same (preferred) or different. The weight average molecular weight is specified in the relative comparison of the acrylic-modified epoxy resin constituting the polymer layer and the low molecular layer.

  The weight average molecular weight of the acrylic-modified epoxy resin constituting the polymer layer is from 2,000 to 1,500,000, preferably the lower limit is 200,000 or more and the upper limit is 300,000 or less. The weight average molecular weight of the acrylic-modified epoxy resin constituting the low molecular layer is 1,000 or more and 500,000 or less, preferably the lower limit is 2,000 or more and the upper limit is 40,000 or less. In the above numerical range, the weight average molecular weight of the resin constituting the polymer layer and the weight average molecular weight of the resin constituting the low molecular layer may overlap in number, but of course, the resin constituting the polymer layer It will be understood by those skilled in the art that the selection is made so that a magnitude relationship is generated between the weight average molecular weight of the resin and the weight average molecular weight of the resin constituting the low molecular layer.

  The weight average molecular weight of the acrylic-modified epoxy resin is within the above numerical range, and within this numerical range, by appropriately determining the numerical value of the weight average molecular weight of the resin constituting the polymer layer and the two low molecular layers, Or it becomes possible to obtain the speaker diaphragm which has the desired mechanical characteristic calculated | required by the speaker according to installation environment. More specifically, since the weight average molecular weight of the acrylic modified epoxy resin constituting the polymer layer and the low molecular layer is within the above numerical range, the speaker vibration having excellent shape stability, flexibility, flexibility, etc. The durability as a speaker diaphragm can be improved. The speaker diaphragm according to the present invention having such characteristics can effectively prevent the low-frequency reproduction limit frequency from increasing with time, and can perform wide-band reproduction stably for a long period of time. It becomes possible. More preferably, the polymer layer and the low-molecular layer are formed from an acrylic-modified epoxy resin, and the weight-average molecular weight is within the above numerical range, so that the two low-molecular layers behave softly, and the reproduction limit of the low region is low. The frequency can be lowered, and on the other hand, the shape stability as the speaker diaphragm can be maintained by maintaining the polymer layer at an appropriate strength.

According to a preferred embodiment of the layer thickness present invention, the total thickness of the laminate is at 6μm than 300μm or less, preferably the upper limit is the lower limit value is 30μm or 100μm or less. According to a preferred embodiment of the present invention, the thickness of each layer of the polymer layer is 1 μm or more and 100 μm or less, preferably the lower limit is 10 μm or more and the upper limit is 34 μm or less. The thicknesses of the first low molecular layer and the second low molecular layer may be the same or different, but are 1 μm or more and 100 μm or less, preferably the lower limit is 10 μm or more and the upper limit is 34 μm or less. When the total thickness of the laminate and the layer thickness of each layer are within the above numerical range, the formed speaker diaphragm is excellent in shape stability and more effective in flattening frequency characteristics. It becomes. Moreover, according to a more preferable aspect of the present invention, it is preferable that the thicknesses of the two low molecular layers are the same. By using the same thickness, the stress balance of the surfaces of the respective layers can be made uniform, and physical fluctuations such as warpage can be easily prevented from occurring in the speaker diaphragm.

2) The edge base material 11 for the edge base speaker includes a sheet-like material (film-like material), for example, a woven or non-woven fabric (preferred) made of a fiber material such as synthetic fiber or natural fiber. A “sealing sheet-like material” in which the material is impregnated with a resin for impregnation such as rubber, thermosetting resin, polyurethane resin or the like can also be preferably used. In the present invention, the sheet-like material formed from a thermoplastic elastomer can be used more preferably. The thermoplastic elastomer is selected from the group consisting of polystyrene, polyolefin, polyurethane, polyester, polyamide, polybutadiene, ethylene-vinyl acetate, polyvinyl chloride, and mixtures thereof. Good. In the present invention, the speaker edge base material 11 includes a cellular foam (having bubbles), in particular, an open-celled flexible foam such as foamed urethane.

  According to a preferred aspect of the present invention, the edge base material is joined only at the outer peripheral portion of the diaphragm main body, or the edge base material is joined throughout the diaphragm main body, and the edge base material It is possible to propose a loudspeaker diaphragm that is joined to the whole diaphragm main body and a gasket. Further, according to another preferred embodiment, the laminate and the edge provided with the edge base material are bonded from the front side of the diaphragm main body, and are joined to cover the entire surface of the diaphragm from the outer periphery of the frame, A speaker diaphragm having a waterproof effect can be proposed.

3) Diaphragm body The diaphragm body 8a is generally used as a speaker. For example, diaphragm bodies made of various materials such as a papermaking cone and a plastic molded product can be used. However, in the case of plastic molded products, when bonding edge substrates and laminates, a hole is made in the plastic molded product that is the diaphragm body for venting air between the plastic molded products and the edge substrate. Processing is required.

2. Manufacture of diaphragm One polymer layer, one low molecular layer and another low molecular layer are all formed of an acrylic-modified epoxy resin, and this resin has adhesiveness. As a result, one polymer layer is sandwiched between one low molecular layer and another low molecular layer, and an edge substrate such as a thermoplastic elastomer or a sealing cloth material is laminated and pressed, so that each layer can be easily formed. A desired speaker diaphragm integrally formed with the diaphragm main body can be obtained by being in close contact with each other and heating, pressurizing, and cooling simultaneously with the diaphragm main body. At this time, the low molecular layer and the diaphragm main body have an advantage that they are fixed without applying an adhesive. Further, the edge 8b may be formed on either the front side (FIG. 5) or the back side (FIG. 6) of the diaphragm main body 8a via the laminate.

3. Use of speaker diaphragm / speaker The speaker diaphragm according to the present invention is mounted on a speaker as described above and in FIG. In the present invention, the speaker on which the speaker diaphragm according to the present invention is mounted can be used for an inner magnet type speaker (an example has already been shown) and an outer magnet type speaker. The shape of the speaker diaphragm 8 according to the present invention when mounted on the speaker is not particularly limited, and may be a dome shape, a conical shape, a flat shape, or an elliptical shape.

  Embodiments of the present invention will be described with reference to FIGS. 3 to 6 and will be further described with reference to the following examples. However, the present invention is not construed as being limited to these descriptions. Various modifications can be made without departing from the spirit of the invention.

Example A speaker diaphragm according to the present invention (below) was prepared, and a speaker shown in FIG.
Preparation of speaker diaphragm Prepare an acrylic-modified epoxy resin laminate in which two low molecular layers (one low molecular layer and another low molecular layer) placed in close contact with both sides of one polymer layer are laminated, By adhering the edge substrate of thermoplastic elastomer to this one side, and forming the laminated body in a mold that can form a predetermined shape, the diaphragm main body is set at the same time as the gasket, and heated, pressurized, and cooled, A diaphragm for a speaker was obtained by bonding. The weight average molecular weight of the polymer layer is from 5,000 to 1,500,000, the weight average molecular weight of one low molecular layer is from 1,000 to 50,000, and others The weight average molecular weight of the low molecular layer was 1,000 or more and 50,000 or less.

Comparative Example Without using the laminate 10 according to the present invention, a diaphragm having an edge bonded to the outer periphery of a normal diaphragm main body was prepared by an adhesive, and a mounted speaker was prepared. The diaphragm main body was a paper cone, and the edge material was a thermoplastic urethane elastomer.

Evaluation Tests The following evaluation tests were performed on the speakers of Examples and Comparative Examples.

Evaluation test 1
For the speaker of Example and Comparative Example (caliber: 40 mm), the output sound pressure-frequency characteristic was measured using a frequency characteristic measuring machine (B & K: # 4939) under the measurement conditions of a measurement distance of 1 m and an input of 1 W. The result was as shown in FIG. FIG. 7 is a diagram showing a comparison of measurement results of output sound pressure-frequency characteristics (hereinafter also referred to as frequency characteristics) of the speakers of the example and the comparative example. In FIG. 7, the solid line portion A is the frequency characteristic of the example, and the dotted line portion B is the frequency characteristic of the comparative example. As shown in FIG. 7, the low frequency characteristics of the example are improved as compared with the comparative example.

Evaluation test 2
About heat resistance, this invention product and the conventional product were created with the same edge base material, and the comparison confirmation was performed. The test product used the same urethane foam material, and a laminate of 50 μ acrylic modified epoxy resin was bonded to the product of the present invention. This was placed in a thermostat bath at 130 ° C. and 150 ° C. for 5 minutes, and the width of the edge roll shown in FIG. 8A was measured and compared. In the present invention product, the heat resistance of the acrylic-modified epoxy resin layer was FIG. 8B shows the case at 150 ° C. compared to the conventional product. An improvement in heat resistance of about 18% was confirmed.

Evaluation test 3
A waterproof thermoplastic elastomer was used as the edge substrate, and a gasket and a diaphragm main body were made of paper, and samples for evaluation were prepared. The product according to the present invention is in a state where the edge base material covers all of the paper diaphragm main body and the gasket as shown in FIG. In contrast, the conventional product uses the same edge base material, but the edge base material and diaphragm main body are bonded together with an adhesive that is only partially applied, and the gasket is also edged with the gasket surface visible. The substrate is bonded with an adhesive.
As a waterproof test, as shown in FIG. 9, a speaker mounting hole is made in a plate having an acrylic thickness of about 5 mm, and a speaker made using the above-mentioned conventional product and the product of the present invention is just against this hole. The test was carried out with no gaps attached.
The speaker attached to the acrylic plate is sprayed with water at a rate of 1 ml away from the surface side of the speaker at 200 ml / min for 72 hours from the spray nozzle for the opposite side of the speaker surface (the back side of the diaphragm main body). It was visually judged whether there was any water leak.
As a result, in the conventional product, water leakage was confirmed between the paper diaphragm body, the gasket, and the edge material bonded with the adhesive and the diaphragm body. There was no leakage and waterproofness was confirmed. Further, the diaphragm main body was made of waterproof resin such as polypropylene, and the gasket was made of ABS resin. The waterproofness was confirmed not only on the front surface side where the edge material was stuck on the entire surface but also on the back surface side. Moreover, since the characteristics of the edge material directly become the chemical resistance on the surface side of the product of the present invention, it was confirmed that chemical resistance against detergents and the like can be added depending on the type of the edge base material.

DESCRIPTION OF SYMBOLS 1 Speaker 2 Yoke 3 Magnet 4 Pole plate 5 Magnetic circuit 6 Voice coil 7 Damper 8 Diaphragm 8a Diaphragm body 8b Edge 9 Frame 10 Laminated body 10a, 10b Low molecular layer 10c Polymer layer 11 Edge base material 12 Gasket 13 Spray nozzle 14 Acrylic plate 15 Front side 16 Back side 21 Sheet-like member 22 Resin layer 31 Diaphragm 32 Edge portion 33 Substrate with a large amount of resin impregnation 34 Inorganic metal, inorganic compound

Claims (8)

A diaphragm for a speaker comprising a diaphragm main body, a laminate in which all layers are formed of an acrylic-modified epoxy resin, and an edge base material,
The laminate includes two or more low molecular layers and one or more polymer layers, and the polymer layer is sandwiched between one low molecular layer and another low molecular layer. With things,
The weight average molecular weight of the polymer layer is larger than the weight average molecular weight of one low molecular layer and the other low molecular layer,
On the diaphragm main body, the outermost surface side layer or the outermost surface side layer in the laminate is attached,
A loudspeaker diaphragm, wherein the edge base material is adhered on the outermost layer or the outermost layer of the laminate. The polymer layer has a weight average molecular weight of 2,000 or more and 1,500,000 or less; and
2. The speaker diaphragm according to claim 1, wherein the weight average molecular weight of one low molecular layer and the other low molecular layer is 1,000 or more and 500,000 or less.   The speaker diaphragm according to claim 1, wherein the edge base material is a sheet-like material or a sealing sheet-like material.   The speaker diaphragm according to any one of claims 1 to 3, wherein the edge base material is joined only at an outer peripheral portion of the diaphragm main body.   The speaker diaphragm according to any one of claims 1 to 3, wherein the edge base material is bonded to the entire diaphragm main body.   The diaphragm for a speaker according to any one of claims 1 to 3, wherein the edge base material is joined to the entire diaphragm main body and a gasket.   The laminate and the edge provided with the edge base material are bonded together from the front side of the diaphragm main body, and are joined so as to cover the entire surface of the diaphragm from the outer periphery of the frame, thereby providing a waterproof effect. Item 4. The speaker diaphragm according to any one of Items 1 to 3. A magnetic circuit;
A voice coil disposed in the magnetic gap of the magnetic circuit, capable of vibrating back and forth, and outer peripherally joined to a damper;
A damper whose outer periphery is supported by the frame and whose inner periphery is joined to the outer periphery of the voice coil;
The frame joined to the magnetic circuit;
A speaker comprising the speaker diaphragm according to any one of claims 1 to 7, wherein an outer peripheral edge is supported by the frame, and an inner peripheral portion is joined to the voice coil.

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