JPH0527783A - Sound quality changing plate - Google Patents

Abstract

PURPOSE:To obtain the listening feel stressed in an extremely low frequency range and an extremely high frequency range and to obtain sharp sound quality suppressed in reverberation by interposing a sheet consisting of a visco-elastic high-polymer material between the inside layers of a laminated plate to form a >=3-layered structural body and forming such structural body so as to have a specific vibration loss coefft. CONSTITUTION:This plate is constituted of the laminated layers interposed with the sheet consisting of the viscoelastic high-polymer material between restraining materials and is so formed that vibration energy is decreased by the thermal energy generated by the stress at the time of the shearing deformation generated during vibration and the friction generated at the time of the deformation of the vibration-damping material layer, by which the vibration- damping performance is exhibited. The viscoelastic high-polymer material includes, for example, rubber or thermoplastic elastomer. The rubber includes, for example, natural rubber and the thermoplastic elastomer includes, for example, polyestyrene elastomer. The coeffts. of the vibration losses at 20 deg.C of such molding are 0.02 to 0.16 respectively in a range from 200Hz to 3kHz, by which the vibration-damping property is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the sound quality of audio and visual devices (records, compact disc players, video players, amplifiers, speakers, etc.), which are collectively referred to as AV, and the sound reflected from the walls of music halls and sound reflectors. The present invention relates to a sound quality change plate that can be modified subtly to enhance the sound quality with high accuracy, suitable for music listening and sound effects.

[0002]

2. Description of the Related Art Conventionally, slabs of metal such as marble, glass, aluminum, ceramics or copper, compression molded plates of metal strips, and rubber slabs are laid under or placed on AV equipment. Was trying to change the sound quality by pasting.

[0003]

However, these conventional materials are rigid materials and have a high modulus, or elastic materials having a very low modulus, and in any case, the sound quality is changed. The effect was poor. As a result of intensive studies to improve such problems, the present invention has been able to provide a sound quality change plate having excellent sound quality and sound characteristics in extremely low tones and extremely high tones.

[Means for Solving the Problems] The present invention is
In order to achieve the above object, it has the following configuration. That is, the sound quality changing plate of the present invention is characterized in that the viscoelastic polymer material layer is interposed in at least one of the inner layers of the laminated body made of the constraining material.

[0005]

The present invention has been completed by investigating the fact that a specific viscoelastic polymer material which is soft and excellent in flexibility is sandwiched between constraining plates like a sandwich structure, and the vibration damping performance is surprisingly improved. It is a thing.

[0006] As in the prior art, the one in which the vibration damping material sheet is adhered to the surface of the substrate consumes the vibration energy by the thermal energy generated inside the vibration damping material due to the expansion and contraction motion at the time of vibration, thereby reducing the vibration. Met.

On the other hand, according to the present invention, as described above, by forming a laminated body in which a sheet made of a viscoelastic polymer material is interposed between constraining materials, stress at the time of shear deformation during vibration and damping material The vibration energy is reduced by the heat energy generated by the friction when the layer is deformed, and the vibration damping performance is exhibited. By adopting such a structure, the above-mentioned vibration damping sheet is simply attached to the surface. It was clarified that the vibration damping effect is remarkably improved as compared with the layered structure.

Further, in the present invention, when a material having high flexibility and flexibility is used as the viscoelastic polymer material, it follows large deformation and the inner layer of the damping material sheet is not broken. Deformation of the damping material layer is retained, and the excellent feature that the vibration damping effect is exhibited without loss of thermal energy due to friction is exhibited.

The viscoelastic polymer material used in the present invention may be any polymer substance having viscoelasticity, and includes, for example, those called rubber or thermoplastic elastomer. These materials can be used alone or in the form of a mixed system or a combined system.

Examples of such rubber include natural rubber,
Isoprene rubber, styrene / butadiene rubber, butadiene rubber, butyl rubber, ethylene / propylene rubber, chloroprene rubber, chlorosulfonated polyethylene, nitrile rubber, urethane rubber, polysulfide rubber, acrylic rubber, epichlorohydrin rubber, silicone rubber, fluorine rubber,
Hydrogenated nitrile rubber or the like can be used. These rubber materials can be used alone or in combination of two or more.

As the thermoplastic elastomer, for example, polystyrene type elastomer, polyolefin type elastomer, polyvinyl chloride type elastomer, polyurethane type elastomer, polyester type elastomer, polyamide type elastomer, ionomer type elastomer, fluorine type elastomer, etc. are used. be able to. These elastomers can be used in the form of one kind or a combination of two or more kinds.

Such viscoelastic polymer materials include aluminum hydroxide, magnesium hydroxide, antimony trioxide, paraffin chloride, zinc oxide, and aluminum bromide within a range that does not impair the viscoelasticity and the object of the present invention. Such flame retardants, colorants, deodorants, preservatives and other additives can be added.

The sound quality changing plate of the present invention comprises a layer made of the above-mentioned viscoelastic polymer material and a constraining material layer for sandwiching and constraining the viscoelastic polymer material layer. Can be used as long as it has a hardness (rigidity) and mechanical properties that can be restrained.
As the restraint material, for example, in addition to wood, inorganic materials such as glass and metal, plastics, and composite materials thereof can be used. Among these materials, a composite material and a resin composite material are preferable because they have excellent properties such as rust resistance and water / oil resistance.

As such a composite material, a fiber reinforced resin material is particularly preferably used because it has excellent strength properties. For such a fiber reinforced resin material, a thermoplastic resin or a thermosetting resin having sufficient strength and rigidity is preferably used, but a thermosetting resin is particularly preferably used because it has high rigidity.

Examples of the above-mentioned thermoplastic resin include polyamide resin, polyester resin, urethane resin, polycarbonate resin, ABS resin, polyvinyl chloride resin, polyacetal resin, polyacrylate resin, polystyrene resin. , Polyethylene resin,
Polyvinyl acetate-based resin, polyimide-based resin and the like and mixed resins thereof can be used.

As the thermosetting resin, for example,
An epoxy resin, an unsaturated polyester resin, a phenol resin, a urea resin, a melamine resin, a diallyl phthalate resin, a urethane resin, a polyimide resin, or the like and a mixed resin thereof can be used. Among these, epoxy resins and unsaturated polyester resins are preferably used in terms of mechanical properties and rigidity.

The above-mentioned fibers may be those having a reinforcing effect, and examples thereof include inorganic fibers such as metal fibers, carbon fibers and glass fibers, aramid fibers, polyester, polyacrylonitrile, polyethylene and polyvinyl alcohol. High tenacity fibers are preferably used.
These reinforcing fibers may be used alone or in a mixed system thereof, and may be used in the form of long fibers, short fibers or a mixture thereof.

As the fiber-reinforced resin material, generally, the above-mentioned reinforcing fibers are impregnated or coated with the above-mentioned resin to form a prepreg. Such a prepreg exerts a stronger reinforcing action depending on the orientation (arrangement) direction of the reinforcing fibers, and therefore, when laminating, the balance of the reinforcing effect is adjusted by a method such as changing the fiber arrangement angle of each prepreg. be able to.

The laminated body of the present invention has a vibration loss coefficient of
It is preferable that the coefficient is 0.01 or more, but this coefficient indicates the magnitude of the vibration damping performance, and can be obtained as follows.

That is, the sample (size 30 mm × 300 mm)
When a constant vibration is applied to the middle point part, the loss coefficient is calculated by the following equation from the mechanical impedance of the vibration point and the vibration mode of frequency (FIG. 2) obtained by the FFT analyzer. The larger this coefficient value, the greater the damping property.

[0021] In the vibration mode of FIG. 2, f _0: resonance frequency f _1: f frequency of 3dΒ reduced points from the impedance at ₀ (low frequency side) f _2: Frequency of points 3dΒ reduced from impedance at f ₀ (high-frequency Side) and substitute these values into the following formula to calculate the loss coefficient (η).

Η = (f ₂ −f ₁ ) / f ₀ The viscoelastic polymer material according to the present invention and the prepreg sheet may be bonded and laminated to each other after a sheet having a predetermined thickness is prepared and then bonded. There are a method of adhering with a chemical agent and a method of thermocompression-bonding a viscoelastic material and a prepreg sheet.

The adhesive used here is not particularly limited, but an epoxy adhesive is preferably used because of its excellent heat resistance and adhesiveness. For example, Ciba Geigy's Araldite AV138, Araldite AV121, Araldite AV129 (all main ingredients) and Araldite HV998,
A two-part epoxy adhesive consisting of Araldite HV997 and Araldite HY956 (above curing agent) can be used.

The acoustic change plate of the present invention is constituted by laminating three or more sheets of the above viscoelastic polymer material and a prepreg sheet with the viscoelastic polymer material sheet layer interposed. In particular, it is preferable that the viscoelastic polymer material layers and the fiber reinforced resin material layers are alternately laminated.

The plate referred to as the acoustic change plate of the present invention is essentially not limited in thickness, and includes sheet-like and plate-like ones.

[0026]

EXAMPLES The present invention will be specifically described below with reference to examples.

Examples 1 to 4 and Comparative Examples 1 to 2 Glass fibers made of E glass were used, and epoxy resin was used for the glass fibers, the fiber weight ratio was 65%, and the basis weight was 350 g /
A unidirectional prepreg sheet of m ² was obtained. The prepreg sheets were laminated to form a composite sheet having a thickness of 5 mm. Each of the following viscoelastic polymer sheets is sandwiched between two composite sheets, and then press-molded under curing conditions of 130 ° C. for 60 minutes to obtain a sound quality change plate having a three-layer structure. It was

(Viscoelastic polymer sheet: thickness 1 mm) Example 1: Natural rubber sheet Example 2: Butyl rubber sheet Example 3: Polyester ether sheet (Toray Co., Ltd .: Hytrel # 5527) Example 4: Polyamide ether sheet (Toray Industries, Inc .: Pebax # 6333) Separately, a 10 mm-thick prepreg sheet made of the above glass fiber was prepared, and hot-pressed under the same curing conditions to obtain a press-molded product (Comparative Example 1). Further, a 1 mm thick sheet of natural rubber was laminated with a 10 mm thick prepreg sheet made of the above glass fiber to obtain a press-molded article (Comparative Example 2) having two layers.

These sound quality changing plates or molded products are 30 mm
Each sample was cut into a size of × 300 mm and used as a sample for vibration damping evaluation. The vibration damping characteristics of this sample were measured by the mechanical impedance method.

As a result, the molded articles of Comparative Examples 1 and 2 were heated to 20 ° C.
Vibration loss coefficient at 200Hz to 3kHz respectively
Was 0.008 to 0.024. On the other hand, the vibration loss coefficients of the sound quality changing plates of Examples 1 to 4 were 0.02 to 0.16 under the same condition and the same range, and the vibration damping property was significantly improved. It is to be noted that FIG. 1 shows a graph of measurement data obtained by plotting the vibration loss coefficient against frequency.

Furthermore, the sound quality changing plates of the above-mentioned Examples 1 to 4,
The molded products shown in Comparative Examples 1 and 2 were cut into a rectangle of 440 mm × 350 mm, which was laid under an audio CD player for CD performance.

As a result, the sound quality changing plates of Examples 1 to 4 were
As compared with the molded products of Comparative Examples 1 and 2, all exhibited excellent acoustic profiles in which extremely low and high tones were emphasized.

[0033]

The sound quality changing plate of the present invention has a selection function of showing an excellent acoustic profile in which extremely low and extremely high tones are emphasized among sounds emitted from audio equipment.

That is, the sound quality changing plate according to the present invention provides an enhanced audibility in the extremely low and high treble ranges and a sharp sound quality in which residual sound is suppressed.
Suitable for visual appreciation (records, compact disc players, video players, amplifiers, speakers, etc.) and music hall components (walls, sound reflectors, etc.) for music listening, sound effects, and sound production. It is a material.

Moreover, the sound quality changing plate of the present invention is excellent in workability and workability at the time of molding, and exerts an excellent effect even in a thin thickness, so that it has a feature of great freedom in design.

[Brief description of drawings]

FIG. 1 is a sound quality changing plate of Examples 1 to 4 and Comparative Example 1
The graph which plotted with respect to the frequency of the vibration loss coefficient measured about the molded article of -2.

FIG. 2 is an explanatory diagram of a method of calculating a vibration loss coefficient.

Claims (5)

[Claims] 1. A sound quality changing plate, characterized in that a viscoelastic polymer material layer is interposed in at least one of the inner layers of a constraining material laminate. 2. The sound quality changing plate according to claim 1, wherein the viscoelastic polymer material is a thermoplastic elastomer. 3. The sound quality change plate according to claim 4, wherein the composite material is a fiber reinforced resin material. 4. The sound quality changing plate according to claim 5, wherein the fiber-reinforced resin material is composed of reinforcing fibers and a thermosetting resin. 5. The sound quality changing plate according to claim 6, wherein the thermosetting resin is a resin selected from an epoxy resin and an unsaturated polyester resin.