JPS60186193A - Speaker diaphragm - Google Patents

Abstract

PURPOSE:To obtain a lightweight, high-elasticity speaker diaphragm by laminating a composite layer consisting of propylene resin and a flat inorganic filler and a proplylene resin layer having metal vapor-deposited on one surface. CONSTITUTION:Propylene resin pellets containing the flat inorganic filler are made into a sheet with 0.4mm. thickness at 240 deg.C by using an extruder which has a T die. When the fused sheet from the T-die is passed between a couple of metallic rolls whose surfaces are finished into specular surfaces so that the thickness of the sheet is 0.4mm., the proplylene resin is passed between the metallic roll and fused sheet at the same time to obtain a sheet on which the proplylene resin layer is laminated. This laminated sheet is treated at 180 deg.C sheet surface temperature by using a vacuum forming machine to manufacture the speaker diaphragm.

Description

DETAILED DESCRIPTION OF THE INVENTION [I] Object of the Invention The present invention relates to a speaker diaphragm with excellent acoustic characteristics and appearance. More specifically, the speaker vibration is made by laminating (A) a composition layer consisting of (1) a propylene resin and (2) a flat inorganic filler, and (B) a propylene resin layer with a metal □ vapor-deposited on one side. The object of this invention is to provide a speaker diaphragm with excellent appearance, high modulus of elasticity, high loss, and excellent acoustic properties. - [II] At the present time, natural fibers and heat-resistant plastic resins such as propylene resins, ethylene resins and iB vinyl-based cedar resins, as well as carbon fibers, metal whiskers, mica resins, etc. Speaker diaphragms are manufactured using materials filled with a mixture of inorganic fillers such as graphite and tar, and metal materials such as aluminum, beryllium, and boron. - Shikaji, natural ijX
#jl is moisture absorption +! Since it is large in size, it has the disadvantage of poor moisture resistance as a diaphragm. Also; the metal material
Speaker diaphragms manufactured using this have the disadvantage of not being able to obtain good frequency characteristics due to low internal loss. In order to improve these drawbacks, methods such as baking powder of synthetic resin, ceramic, or glue on one of the speaker diaphragms made of metal foil have been proposed. Problems arise due to the poor appearance and high coasting.Furthermore, attempts have been made to manufacture diaphragms using laminated materials made of metal foil and synthetic resin; Second, a speaker diaphragm is manufactured by attaching a metal such as aluminum to the surface of a sheet made of propylene resin or a propylene resin mixed with an inorganic filler. Attempts have been made to do so, but due to the high rigidity of the sheet, it was difficult to deposit a sufficient amount of metal on the surface of the sheet.

[I11] Based on the above 100 configurations, the present inventors have developed a speaker diaphragm that not only has excellent high-frequency characteristics and good acoustic characteristics such as high loss, but also has an excellent surface appearance. As a result of various searches, we found that (A) (t) a composition layer consisting of a propylene resin and (2) a flat inorganic filler; and CB) a laminate consisting of a propylene resin layer with a metal Q-coated on one side. The composition ratio of the propylene resin in the composition is 10 to 80% by weight, the thickness of this composition layer is 0.1 to 1.0+ om, and the thickness of the metal-deposited propylene resin layer is 10 to 80% by weight. The thickness is between 20 and 200 microns,
It has been discovered that a speaker diaphragm having a laminate pattern with a metal vapor deposited layer having a thickness of 300 to 1000 angstroms can be manufactured without destroying the above-mentioned defects and without any problems during molding. , arrived at the present invention.

[IV] Effects of the Invention The speaker diaphragm obtained by the present invention exhibits the following effects (features) including its manufacturing.

(1) It is lightweight and has high elasticity.

(2) It has excellent moldability, and almost no drawdown occurs during molding.

(3) There is no change in sound quality due to moisture absorption.

(4) Large loss and excellent high frequency characteristics.

(5) The surface of the speaker diaphragm has good gloss.

[V] Detailed description of the invention (A) Propylene resin The propylene resin used in the present invention includes:
Homopolymers of propylene and random or block copolymers of propylene with ethylene and/or other α-olefins having at most 12 carbon atoms (the copolymerization ratio of ethylene and other α-olefins may vary; 20%) can be mentioned. The melt flow index of these propylene resins (jl'3
According to K-8758, measured at a temperature of 230 ° C and a load of 2.18 kg, hereinafter referred to as "Gate I") is generally 0.01 to 50g710 minutes, and 0.1 to 50g710 minutes.
20 g/10 minutes is preferred, especially 0.
A propylene-based resin having a content of 1 to 1 Og 710 minutes is suitable. If a propylene resin with an MFI of less than 0.01 g/10 minutes is used, the moldability of the sheet will be poor and it will be difficult to obtain a sheet with a uniform thickness. On the other hand, 50 g/
If a propylene-based resin is used for more than 10 minutes, the melt tension of the sheet will be insufficient, and it will not only be difficult to produce a sheet with a uniform thickness, but also the resulting sheet will have a
f1J ti impact resistance is not sufficient.

These propylene-based resins are made by supporting a transition metal compound (for example, a titanium-based compound or a transition metal compound) on a carrier (for example, a magnesium-based compound, a processed product thereof), and then a rod-supported catalyst and an organic metal. The homopolymerization of propylene or the random or block combination of propylene with ethylene and/or the other α-olefins mentioned above in the presence of catalyst systems (so-called Ziegler-Natsuta catalysts) obtained from compounds (for example organoaluminum compounds) obtained by letting

(B) Flat inorganic filler Furthermore, the average particle size of the flat inorganic filler used in the present invention is 20 microns or less, preferably 10 microns or less, and particularly preferably 0.5 to 7.0 microns. It is. A flat surface with an average gamma diameter of over 20 microns! (Inappropriate use of machine fillers is undesirable because not only will the impact resistance of the sheets and containers obtained be poor, but also the amount of drawtown will increase during ripening, and the thickness of the molded products will vary widely.) , the average aspect ratio is 3-2
0, preferably 3 to 15, especially 5 to 15
15 is preferred. If an inorganic filler with an average asbec ratio of less than 3 is used, the resulting sheet and speaker diaphragm will have poor rigidity, which is not preferable. -force, 2
If a flat inorganic filler exceeding 0 is used, it will be difficult to maintain the shape of the flat inorganic filler and it may be destroyed during kneading, so there is no point in using it. Typical examples of this inorganic filler include talc, mica, crow flakes, and graphite. Among them, talc and mica are preferred.

(C) Production of composition (mixture) In the composition of the present invention, the composition ratio of the flat inorganic filler is 10 to 80% by weight, preferably 15 to 70% by weight, particularly 15 to 60% by weight. % is preferred.

Oblate! ! (If the composition ratio of the machine filler is less than 10% by weight, 7A%, the sheet will not have insufficient rigidity, and the sheet will warp as the temperature changes. On the other hand, if it exceeds 80% by weight, the composition The liquidity of
Not only is it not possible to obtain a sheet having a uniform thickness, but even if a sheet is obtained, the impact resistance is insufficient.

In producing the composition of the present invention, the object can be achieved by uniformly mixing the propylene resin and the flat inorganic filler. That is, the composition of the present invention may be triblended using a four-leg mixer such as a Henschel mixer commonly used in the polyolefin industry, a Banbury mixer, a kneader, a roll mill, and a screw extruder. fj (
can be done. At this time, a more homogeneous composition (Compound A'1) can be obtained by performing a rough tri-blend and then melting the resulting composition (Compound 49) and whitening it. In this case, the mixture is generally melt-kneaded, then molded into pellets, and subjected to the molding described later.

Furthermore, when manufacturing the composition of the present invention, all composition components may be mixed in the same proportion. Alternatively, a part of them may be mixed in advance to create a masterbatch, and the remaining composition components may be mixed into the prepared composition (masterbatch). In short, in order to produce the composition of the present invention, it is necessary to maintain the above-mentioned composition ratios of all composition components and to produce the composition uniformly.
If you do this, you can achieve target 1.

In producing the composition of the present invention, it may be made of a propylene resin and a flat inorganic filler, but if desired, it may be further resistant to heat, light (ultraviolet) and elemental resistance commonly used in the field of olefin resins. Additives such as stabilizers, flame retardants, lubricants, processability improvers, and antistatic agents may be added (blended) within ranges that do not impair the aforementioned effects (characteristics).

(D) Production of sheets and films of 71 propylene resin with full bending The method for forming the compositions and propylene resins or films produced in this way into sheets is generally carried out in the synthetic resin industry. Examples of methods include the T-Guy method, the inflation method, and the calendar method. Well, the method for vapor depositing metal on a propylene resin sheet or film is 10n+llll.
A typical example is a method in which the metal to be deposited on the surface under a vacuum of about -Hg is melted by heating at a temperature above the melting point, and the metal is stuck onto the surface of the film or sheet. If the adhesion of the propylene resin layer is insufficient, it is also possible to apply a surface treatment such as corona treatment or coat the surface with a primer such as acrylic, polyamide, or polyurethane, and then vapor-deposit the metal. be. Furthermore, the surface of the film or sheet after metal 7A is coated with a synthetic resin such as polyurethane or polyamide to protect the gold 14 layer, and 2iL, filon or sheet is also used. can do. Here, gold J deposited in Table 1r11
f is aluminum! 111 Examples include lead, silver, copper, and cadmium. In addition, the jlf thickness of the vapor deposited layer is 3
00-1000 on guest row 1, 300-8
00 angstroms is preferred. 7A deposition layer thickness is 3
If it is less than 0.00 angstroms, the frequency characteristics in the high temperature range will be poor. On the other hand, if the thickness exceeds 1000 angstroms, cranks will occur in the adhesive layer when forming the speaker diaphragm, causing problems in appearance.

(E) Production of laminate (laminated sheet) The method for producing the laminate (laminated sheet) used to produce the speaker diaphragm of the present invention is the dry lamination method generally used in the synthetic resin industry. , extrusion lamination method, etc. In a particularly preferred method, at least one surface has a luminous intensity rAJ
An example of this method is to pre-form a sheet of propylene resin having a ratio of at least 30%, and then laminate the sheets of propylene resin by T-tie molding using cooled polygingerol during molding.

The thickness of the metallized propylene resin layer of the resulting laminate is 20 to 300 microns, preferably 20 to 200 microns, and particularly preferably 25 to 150 microns. If the J thickness of the metal-deposited propylene resin layer is less than 20 microns, wrinkles will easily occur during the production of the laminate, while if it exceeds 300 microns, the stiffness of the laminate will decrease and the characteristics of the diaphragm will deteriorate. decreases, which is not preferable in either case.

Further, the thickness of the flat inorganic filler-containing propylene resin layer is 0.1 to 1.0 mm, preferably 0.1 to Q, 8 mm, and particularly preferably 0.1 to 0.7 mm.

If the thickness of the flat inorganic filler-containing propylene resin layer is less than 0.1 mm, the moldability of the speaker diaphragm will deteriorate; If it exceeds Omm, speaker-1 linear movement 4
f as anti! ! The product becomes brittle and the efficiency of the speaker decreases, both of which are undesirable.

The ratio of the thickness (A) of the propylene resin layer to the thickness B of the flat inorganic filler-containing propylene resin layer (A)
/B) is 0.02 to 03 for -fJ, and 0.02
-0.2 or more, and 0.04 to 0.2 is particularly suitable.

The ratio (A/B) of the thickness of the propylene resin layer and the J size of the J propylene resin layer that has an uneven shape and an inorganic filler is 0.0.
If it is less than 2, the gloss of the speaker diaphragm will be insufficient. On the other hand, if it exceeds 0.3, the rigidity of the speaker diaphragm is not good, which is not desirable.

1) In the case of melting and molding as described in 1j,
In both cases, the softening intention of the propylene resin used must be carried out at a temperature of L, but if the temperature reaches 2 tl (1° above 1'O), a part of the propylene resin may undergo thermal deterioration. Therefore, it is natural that the process must be carried out at a temperature below this temperature.

(F) Manufacture of speaker-4hM dynamic plate The method of molding a speaker diaphragm using the laminated sheet thus produced is the vacuum forming method normally practiced in the propylene resin industry; A molding method such as a pressure molding method, a press molding method, or a stamping molding method may be applied. When carrying out the vacuum forming method or the pressure forming method, the suitable forming temperature is a surface temperature of 165 to 175°C. Further, in the case of performing a press molding method, a suitable molding temperature is a surface temperature of 130 to 160°C. Furthermore, when carrying out the stamping molding method, the surface temperature is 125~
135°C is preferred.

Hereinafter, the speaker diaphragm of the present invention will be explained with reference to the drawings. ffr, FIG. 1 is a sectional view of a speaker manufactured using the speaker diaphragm of the present invention, and FIG. 2 is a partially enlarged sectional view of the speaker diaphragm. In Figure 1,
1 is a speaker diaphragm, and 2 is a voice coil. Further, 3 is a mucknet, and 4 is a plate.

, 5 is a center pole and a yoke, and 6 is a damper. Furthermore, 7 is the center camp and 8 is the edge. Further, 8 is a frame, and 10 is a gasket I. Furthermore, 11 is the input terminal r-, 12
is a Kinshi wire. In addition, in Fig. 2, A is full flexion h
'lj is a propylene-based resin layer, and B is a polarized
! (This is a propylene-based resin layer containing a disintegrating agent.

[IV. EXAMPLES AND COMPARATIVE EXAMPLES The present invention will be explained in more detail with reference to Examples below.

In addition, in the examples and comparative examples, bending elasticity -
I decided to use ASTM D-790 and decided on four standards. Further, 'k' and 'degrees were measured according to JIS K-6758. Furthermore, the light reflectance was determined according to JIS Z-8701, gloss-C, l, -1'. The speaker characteristics were determined by measuring frequency 4 in an anechoic chamber.

The physical properties and properties of the propylene resin and flat inorganic filler used in Examples and Comparative Examples are shown in Table 1.

[Propylene Qi small aggregate] As a propylene resin, the density is 0.900 g/c
PP(1)J
] was used.

[Ethylene-propylene propylene compound] As a propylene resin, the ethylene content is 10.5% by weight, the MFI is 0.7g/[0 min, and the density is 0.5% by weight.
An ethylene-propylene block copolymer 1 (hereinafter referred to as "PP(2)") having a weight of 900 g/cm' was used.

[Ethylene-propylene lantum copolymer] Ethylene-propylene lantum copolymer with a density of 0.900 g/cm' as a propylene resin [ethylene content 3.0 weight! -11%, MFI 0.8g/'10min,
Hereinafter referred to as rPP(3)J] was used.

[Flat-shaped inorganic filler] As a flat-shaped inorganic filler, 77 pek (・curk with a ratio of about 7 (average γ diameter 3 microns), wide graphite with an aspect I ratio of about 20 (average)・L diameter 10 microns)
Buoy force with an aspect ratio of approximately 30 (・1・-Jar
7 micron diameter) was used.

Examples 1 to 5 and Comparative Examples 1 to 3 Propylene resin and flat inorganic filler JM! The shavings were prepared using the formulations shown in Table 1 (all heavy fil
, Fi+() was preliminarily tested using a Henschel mixer for 2 minutes each. Each of the obtained compositions was extruded into a vent pipe of 2 1 lll + ff 1 (diameter 75 m).
M) was used to produce 41 kneaded pellets I.

In addition, a T-tie molding machine (diameter [(5 m)
m) to a thickness of 2 m at a resin temperature of 240°C.
m sheets were produced. Each filter obtained in this way was subjected to corona treatment in advance, and 13 m
On aluminum under 1°C atmosphere of m-Hg, i! t
5L of alumina L-79-coated propylene resin film to a thickness of 600 angstroms (1,200 angstroms in comparative example 1).
, I built it.

Furthermore, the propylene-based resin Perene 1 containing a flat inorganic filler described in +iiij was similarly adjusted so that the resin/1iAIllk was 240°.
A sheet with a thickness of about 0.4 mm was produced under the conditions of C using an extruder (diameter 85 mm) equipped with a T-tie. At this time, the molten sheet exiting the T-die has a thickness of 0.
A pair of mirror-finished, double-sided metal rolls set to 4mm (roll surface 7ilA temperature 80°C)
), the propylene-based resin is impregnated with a part of the metal roll between the melted sheets to form a propylene; Sea I of propylene resin containing loosening filler
was manufactured.

Using a vacuum forming machine, the laminated sheet produced in this way was heated to a diameter of 20' at a sheet surface temperature of 180°C.
A speaker diaphragm of cm was manufactured. The density, bending elastic modulus, and light reflectance of the speaker diaphragm were measured. The results are shown in Table 1.

(Hereinafter, blank space) Note that cracks occurred in the vapor deposited layer of the speaker diaphragm obtained in Comparative Example 1.

The speaker diaphragms (diameter 20CI11) manufactured in Example 1 and Comparative Example 3 were assembled into a speaker, and the frequency characteristics were measured. The results are shown in FIG. In FIG. 3, the vertical axis is sound pressure (dB), and the horizontal axis is frequency (hertz). In this figure, ■ is the frequency characteristic obtained in Example 1, and II is the frequency characteristic obtained in Comparative Example 3. As is clear from Fig. 3, the speaker diaphragm obtained by the present invention has flat characteristics in the high frequency range compared to a speaker diaphragm that does not have a metal vapor deposited film laminated thereon, and has a smoother sound in the mid-to-high range. It also had excellent sound separation and reproduction characteristics, with no noise in the high frequency range.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a speaker manufactured using the speaker diaphragm of the present invention. FIG. 2 is a partially enlarged sectional view of the speaker diaphragm. FIG. 3 is a frequency characteristic diagram of speaker diaphragms manufactured according to Example 1 (I) and Comparative Example 3 (TI). l...Speaker diaphragm, 2...Voice coil, 3
...magnet, -4...plate, 5...center pole, yoke, 6...dunnogu-,? ... Center cap, 8°°° edge, 8... Frame, lO... Gasket, 11... Input terminal, 12.
... Tinsel wire, A... Propylene resin layer on which metal is vapor-deposited, B... Propylene resin layer containing flat inorganic filler... Frequency of the speaker diaphragm manufactured according to Example 1 Characteristic diagram II: Frequency characteristic diagram of the speaker diaphragm manufactured according to Comparative Example 1 Patent applicant: Showa Kameko Co., Ltd. Representative Patent attorney: Sei Kikuchi

Claims (1)

[Claims] (A) A laminate consisting of a composition layer consisting of (1) a propylene resin and (2) a flat inorganic filler, and (B) a propylene resin layer on which a metal is vapor-deposited on one side, and The composition ratio of propylene resin is 10~
80% by weight, and the thickness of this composition layer is 0.1-1.
On + m, and the thickness of the metal-deposited propylene resin layer -
A speaker diaphragm having a laminate structure in which the total bending E adhesion layer has a thickness of 300 to 1000 angstroms.