JP3036198B2 - Speaker diaphragm and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

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

[0003]

However, in the above-mentioned conventional configuration, there is a problem that if the synthetic resin 3 only for preventing water from entering is attached, the diaphragm 1 becomes heavy and the sound pressure of the speaker is reduced.

[0004] Further, since there is only a layer of the synthetic resin 3 for preventing water from entering the surface, there is a problem that the waterproof property is lost if the surface is damaged due to a handling accident or the like.

In addition, the above-described conventional configuration has a problem that the manufacturing process of the diaphragm 1 becomes two steps and the manufacturing cost increases.

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

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is to form a diaphragm by forming paper pulp on which a synthetic resin having a fluorine group at the end is fixed.

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

[0009]

[Function] As described above, a synthetic resin having a fluorine group at the end has water repellency and can satisfy the waterproof performance as a diaphragm only by being fixed to a small amount of paper pulp, so that the weight of the diaphragm is reduced. There is no increase. Further, since the entire paper pulp constituting the diaphragm has a waterproof property, the waterproof property is not lost due to scratches in handling.

In addition, since synthetic resins having a fluorine group at the terminal are fixed collectively at the stage of raw material pulp, the number of production steps is not two, and the production 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 an 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 essential parts. The speaker diaphragm of the present invention is obtained by beating a softwood unbleached kraft pulp to Canadian freeness of 680 cc, adding a predetermined dye, a paper strength enhancer and a sizing agent, and then preparing an emulsion of an acrylic resin having a fluorine group at the terminal ( Dickguard F-400 manufactured by Dainippon Ink and Chemicals, Inc.)
Is added to the paper pulp raw material at 3 wt% and stirred. Next, aluminum sulfate (sulfuric acid sulfate manufactured by Sumitomo Chemical) is added with stirring until the pH of the pulp solution becomes 5.0.
The obtained pulp solution is formed into a paper by a diaphragm-shaped paper net to obtain the speaker diaphragm of the present invention.

1 and 2, reference numeral 4 denotes paper pulp, 5 denotes a synthetic resin having a terminal fluorine group, and 6 denotes a diaphragm.

With respect to the speaker diaphragm of the present invention, the weight increase rate of the diaphragm with or without the waterproofing agent was measured.
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 at a minimum water depth of 30 mm on the back of the diaphragm and left for 96 hours, and no water leakage occurred.

Further, with respect to the loudspeaker diaphragm of the present invention, a part of the diaphragm was cut to a thickness of about half between the layers and subjected to the same waterproof test, but no water leakage occurred.

[0017]

As described above, since the speaker diaphragm according to the present invention is constructed, the waterproof performance can be obtained effectively without increasing the weight of the diaphragm and without increasing the manufacturing process of the diaphragm. Can be of great industrial value.

[Brief description of the drawings]

FIG. 1 is a half sectional front view showing a configuration of a speaker diaphragm in one embodiment of the present invention.

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

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

FIG. 4 is an enlarged sectional view of the main part.

[Explanation of symbols]

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

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04R 7/02 H04R 31/00

Claims (2)

(57) [Claims] A speaker diaphragm made of paper pulp on which a synthetic resin having a fluorine group at the end is fixed. 2. An emulsion of a synthetic resin having a fluorine group at the end is put into a paper pulp suspension, and the synthetic resin having a fluorine group at the end is fixed with aluminum sulfate. Production method.