JPH05183985A - Diaphragm for speaker and its manufacture - Google Patents

Abstract

PURPOSE:To obtain a diaphragm for speaker in which a problem such as the increase of the weight of a diaphragm due to the attainment of waterproof for a paper pulp diaphragm or requirement for two manufacturing processes can be solved and superior performance can be obtained in the diaphragm for speaker used in every kind of acoustic equipment. CONSTITUTION:Waterproof performance can be effectively obtained without increasing the weight of the diaphragm 6 and the manufacturing process of the diaphragm 6 by fixing synthetic resin 3 provided with fluorine radical at its terminal on paper pulp 4 at the stage of raw material before the making the paper pulp diaphragm, and performing the molding of the raw material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diaphragm for a speaker used in various audio equipment and a method for manufacturing the speaker diaphragm.

[0002]

2. Description of the Related Art Conventionally, a speaker diaphragm made of waterproof paper pulp used for a vehicle-mounted door mount speaker or the like has been constructed as shown in FIGS.
That is, the diaphragm 1 formed by making the paper pulp 2 into paper is dipped in a synthetic resin solution in a later step, and the synthetic resin 3 is attached to the surface of the paper to prevent water from entering.

[0003]

However, in the above-mentioned conventional structure, when the synthetic resin 3 for preventing the infiltration of water is attached, the diaphragm 1 becomes heavy and the sound pressure of the speaker is lowered.

Further, there is a problem that the waterproof property is lost when the surface is scratched due to a handling accident or the like because the layer of the synthetic resin 3 for preventing the infiltration of water is only on the surface.

Further, in the above-mentioned conventional structure, there is a problem that the manufacturing cost of the diaphragm 1 increases because the manufacturing process of the diaphragm 1 becomes two steps.

An object of the present invention is to provide a speaker diaphragm capable of solving the above-mentioned conventional problems and exhibiting excellent waterproof performance, and a manufacturing method thereof.

[0007]

In order to solve the above-mentioned problems, the present invention provides a diaphragm by paper-forming a paper pulp having a synthetic resin having a fluorine group at its end fixed.

Further, in order to fix the synthetic resin having a fluorine group at the terminal to the paper pulp, a certain amount of the emulsified synthetic resin having a fluorine group at the terminal is added to the suspension of the paper pulp, and sulfuric acid as a fixing agent is added. It is fixed to paper pulp with aluminum.

[0009]

[Function] As described above, the synthetic resin having a fluorine group at the terminal has water repellency, and the waterproof performance as a diaphragm can be satisfied by fixing it to a very small amount of paper pulp. It will not increase. In addition, since the entire paper pulp that constitutes the diaphragm has a waterproof property, the waterproof property will not be lost due to scratches in handling.

Further, since the synthetic resin having a fluorine group at the end is fixed in a batch at the stage of pulp as a raw material, the number of manufacturing steps is not two and the manufacturing cost of the diaphragm does not increase.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A speaker diaphragm and a method of manufacturing the same according to one embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a half sectional front view showing the structure of a speaker diaphragm according to the present invention, and FIG. 2 is an enlarged sectional view of the main part thereof. The speaker diaphragm of the present invention is prepared by beating coniferous unbleached kraft pulp to a Canadian freeness of 680 cc, adding a predetermined dye, a paper-strengthening agent and a sizing agent, and then emulsion of an acrylic resin having a fluorine group at the end ( DIC GUARD F-400 manufactured by Dainippon Ink and Chemicals)
Is added to the paper pulp raw material in an amount of 3 wt% and the mixture is stirred. Next, aluminum sulfate (Sumitomo Chemical's sulfate band) is added with stirring until the pH of the pulp liquid reaches 5.0.
The obtained pulp liquid is subjected to papermaking using a diaphragm-shaped papermaking net to obtain the speaker diaphragm of the present invention.

In FIGS. 1 and 2, 4 is paper pulp, 5 is a synthetic resin having a fluorine group at the terminal, and 6 is a diaphragm.

With respect to the speaker diaphragm of the present invention, the weight increase rate of the diaphragm depending on the presence / absence of the waterproof agent was measured.
It was 5%. This is much less than the 12% weight gain of the conventional synthetic resin dipping method.

The speaker diaphragm of the present invention was subjected to a waterproof test in which water was stored on the back surface of the diaphragm at a minimum water depth of 30 mm and left for 96 hours, and no water leakage occurred.

Further, with respect to the speaker diaphragm of the present invention, a similar waterproof test was conducted by cutting a part of the diaphragm between layers to a thickness of about half, but no water leakage occurred.

[0017]

Since the speaker diaphragm according to the present invention is configured as described above, the waterproof performance is effectively obtained without increasing the weight of the diaphragm and without increasing the manufacturing process of the diaphragm. It is of great industrial value.

[Brief description of drawings]

FIG. 1 is a front view of a half section showing a configuration of a speaker diaphragm according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of the main part.

FIG. 3 is a half cross-sectional front view of a conventional speaker diaphragm.

FIG. 4 is an enlarged cross-sectional view of the relevant part.

[Explanation of symbols]

 4 Paper pulp 5 Synthetic resin having a fluorine group at the end 6 Vibration plate

Claims (2)

[Claims] 1. A diaphragm for a speaker, which is made by making paper pulp from which a synthetic resin having a fluorine group is fixed at a terminal. 2. A speaker diaphragm for papermaking, which comprises adding a synthetic resin emulsion having a fluorine group at the terminal to a suspension of paper pulp and fixing the synthetic resin having a fluorine group at the terminal with aluminum sulfate. Production method.