close

Вход

Забыли?

вход по аккаунту

?

JP2007096498

код для вставкиСкачать
Patent Translate
Powered by EPO and Google
Notice
This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate,
complete, reliable or fit for specific purposes. Critical decisions, such as commercially relevant or
financial decisions, should not be based on machine-translation output.
DESCRIPTION JP2007096498
PROBLEM TO BE SOLVED: To provide a speaker diaphragm with little deterioration in strength
and sound quality even when used under high temperature and high humidity environment, and
a method of manufacturing the same. SOLUTION: A speaker diaphragm is formed by molding an
acrylic foam. Here, maleic anhydride and methacrylamide are used as raw materials as an acrylic
foam. Thereby, the saturated water absorption can be reduced. Therefore, when used in a
speaker device, it is possible to prevent strength reduction and sound quality deterioration due to
water absorption even in a humid environment. [Selected figure] Figure 1
Speaker diaphragm and method of manufacturing the same
[0001]
The present invention relates to a diaphragm used for a speaker device and a method of
manufacturing the same.
[0002]
A speaker diaphragm using acrylic foam is known, and an example thereof is described in Patent
Document 1.
The speaker diaphragm described in Patent Document 1 uses a poly (meth) acrylimide foam as a
core layer.
10-05-2019
1
[0003]
Japanese Patent Publication No. 2004-37243
[0004]
The poly (meth) acrylimide foam has a saturated water absorption of 30% by weight (hereinafter,
also referred to as "wt%").
Because it is high enough, the decrease in strength due to water absorption is large. Therefore,
when applied to a speaker diaphragm, deterioration in sound quality due to a reduction in
strength is large when used in a humid environment. In particular, when this diaphragm is used
for a vehicle-mounted or ship speaker or the like, the strength deterioration and the sound
quality deterioration due to water absorption are significant.
[0005]
The problems to be solved by the present invention are as mentioned above. An object of the
present invention is to provide a speaker diaphragm with little deterioration in strength and
sound quality even when used in a high temperature and high humidity environment, and a
method of manufacturing the same.
[0006]
The invention according to claim 1 is a diaphragm for a speaker, which is formed by molding an
acrylic foam using methyl methacrylate, methacrylic acid, styrene, maleic anhydride and
methacrylamide as raw materials. It is characterized by
[0007]
The invention according to claim 3 is a method of manufacturing a diaphragm for a speaker,
which manufactures an acrylic resin using methyl methacrylate, methacrylic acid, styrene, maleic
anhydride, and methacrylamide as raw materials. It is characterized by comprising a process, a
process of foaming the acrylic resin at a foaming ratio of 5 to 30 times to produce an acrylic
foam, and a process of molding the acrylic foam.
10-05-2019
2
[0008]
In a preferred embodiment of the present invention, the speaker diaphragm is formed by
molding an acrylic foam made of methyl methacrylate, methacrylic acid, styrene, maleic
anhydride, and methacrylamide as raw materials.
[0009]
The above speaker diaphragm is formed by molding an acrylic foam.
Here, maleic anhydride and methacrylamide are used as raw materials as an acrylic foam.
Thereby, the saturated water absorption can be reduced.
Therefore, when used in a speaker device, it is possible to prevent strength reduction and sound
quality deterioration due to water absorption even in a humid environment.
[0010]
In a preferred example of the above speaker diaphragm, the acrylic foam comprises 30 to 70%
by weight of methyl methacrylate, 10 to 40% by weight of methacrylic acid, and 5 to 30% by
weight of styrene. From 1 to 20% by weight of maleic anhydride and 1 to 20% by weight of
methacrylamide.
[0011]
In another preferred embodiment of the present invention, a method of manufacturing a speaker
diaphragm produces an acrylic resin using methyl methacrylate, methacrylic acid, styrene, maleic
anhydride, and methacrylamide as raw materials. And a step of foaming the acrylic resin at a
foaming ratio of 5 to 30 times to produce an acrylic foam, and a step of molding the acrylic foam.
[0012]
10-05-2019
3
In the above-described method of manufacturing the speaker diaphragm, the acrylic foam is
molded to manufacture the speaker diaphragm.
Here, as the acrylic foam, maleic anhydride and methacrylamide are used as raw materials.
Thereby, the saturated water absorption can be reduced. Therefore, when used in a speaker
device, it is possible to prevent strength reduction and sound quality deterioration due to water
absorption even in a humid environment.
[0013]
Hereinafter, preferred embodiments of the present invention will be described based on the
drawings.
[0014]
FIG. 1 shows a speaker diaphragm according to an embodiment of the present invention
(hereinafter simply referred to as “diaphragm”).
Composition proportional to the acrylic foam constituting the The speaker diaphragm of the
present embodiment is manufactured by molding an acrylic foam in which an acrylic resin is
foamed. As acrylic resin, as shown in FIG. 1, (1) methyl methacrylate, (2) methacrylic acid, (3)
styrene, (4) maleic anhydride, and (5) methacrylamide are used as raw materials, The
composition ratio shown in FIG. 1 is used. Here, in the present embodiment, the pressure
resistance temperature can be improved without decreasing the strength by blending maleic
anhydride and methacrylamide.
[0015]
The characteristic comparison result of two comparative examples and this invention is shown in
FIG. All of Comparative Examples 1 and 2 and the product of the present invention exhibit the
characteristics of the acrylic foam. The comparative example 1 uses (1) methyl methacrylate, (2)
methacrylic acid, and (3) styrene as a raw material of a foam. That is, in comparison with the
product of the present invention, maleic anhydride and methacrylamide are not used. On the
10-05-2019
4
other hand, Comparative Example 2 uses a poly (meth) acrylimide foam as in Patent Document 1
described above. In the present invention, as shown in FIG. 1, (1) methyl methacrylate, (2)
methacrylic acid, (3) styrene, (4) maleic anhydride, and (5) methacrylamide are used. It is In
addition, as shown in FIG. 2, the expansion ratio is unified 15 times in all.
[0016]
As shown in FIG. 2, the product of the present invention is substantially equivalent to the
comparative example 2 in terms of compressive strength, and the saturated water absorption
rate is significantly smaller than that of the comparative example 2. Therefore, it is understood
that the saturation water absorption can be improved by blending maleic anhydride and
methacrylamide. As a result, the level of strength reduction can be reduced, and it is possible to
make it difficult to cause the sound quality to deteriorate even under a severe environment such
as a humid environment.
[0017]
FIG. 3 is a graph showing the temperature change of the compressive strength for Comparative
Examples 1 and 2 and the product of the present invention. In addition, Comparative Example 1
illustrates that the expansion rate is 10 times, Comparative Example 2 that the expansion rate is
15 times, and the product of the present invention that the expansion rates are 10 times and 15
times.
[0018]
When Comparative Example 1 is compared with the product of the present invention having a
foaming ratio of 10 times, the compressive strength of the product of the present invention is
excellent at each temperature. Therefore, it can be seen that the pressure resistance temperature
is improved by blending maleic anhydride and methacrylamide. Next, when Comparative
Example 2 is compared with the product of the present invention having a foaming ratio of 15
times, it can be seen that the compressive strength is almost equal at each temperature. That is,
when compared with Comparative Example 2, it is understood that the product of the present
invention is advantageous in that the saturated water absorption can be improved without
sacrificing the strength.
10-05-2019
5
[0019]
As described above, when compared with Comparative Examples 1 and 2, overall, the product of
the present invention can improve the pressure resistance temperature and reduce the saturated
water content without reducing the strength. Therefore, even under severe environments such as
a high temperature and high humidity environment, it is possible to obtain a diaphragm with
little deterioration in strength and sound quality.
[0020]
FIG. 4 shows a flow chart of a method of manufacturing a diaphragm according to the present
invention. First, as shown in FIG. 1, (1) methyl methacrylate, (2) methacrylic acid, (3) styrene, (4)
maleic anhydride, and (5) methacrylamide as raw materials, acrylic resin 20 The raw material
block of (1) is produced (process S1). Next, the acrylic resin 20 is foamed to produce an acrylic
foam 21 (step S2). Next, the acrylic foam 21 is sliced to a predetermined thickness to prepare a
foam sheet 22 (step S3), which is heated and pressed into a diaphragm shape (for example, a
cone shape) by pressing to form a molded article 23 It produces (process S4). Next, the molded
product 24 is taken out of the mold (step S5), the outer peripheral portion 24 is trimmed, and the
diaphragm 25 is manufactured.
[0021]
The composition proportionality of the diaphragm for speakers by an Example is shown. The
physical properties comparison results, such as compressive strength and saturation water
absorption, of this invention and a comparative example are shown. The temperature change of
the compressive strength of this invention and a comparative example is shown. It is process
drawing which shows the manufacturing method of the diaphragm for speakers.
Explanation of sign
[0022]
20 acrylic resin 21 acrylic foam 22 foam sheet 23 molded body 25 diaphragm
10-05-2019
6
10-05-2019
7
Документ
Категория
Без категории
Просмотров
0
Размер файла
14 Кб
Теги
jp2007096498
1/--страниц
Пожаловаться на содержимое документа