JPS58121898A - Manufacture for speaker diaphragm - Google Patents

Abstract

PURPOSE:To obtain a diaphragm excellent in corrosion-resistance and in adhesion with metallic foil, by forming a diaphragm with the metallic foil light in weight and excellent in the specific elasticity and heating and curing the diaphragm with silicone system resin. CONSTITUTION:The diaphragm 1 is formed with the metallic foil light in weight such as aluminum and high in the specific elasticity, and on the surface, a silicone resin having much silicon and colloidal silicon oxide diluted with a mixing solvent of glycol system and alcohol system and water the resine having 10-13wt% in terms of silicon are coated uniformly to form the surface layer 2. The coating thickness is prefered to be 5-13mu. The density is 30% and the viscosity is 10-50cps. The coated diaphragm is preliminarily heated at 35-90 deg.C (preferably at 40-50 deg.C). The diaphragm 1 is immersed in a metallic processing agent, picked up and rotated to obtain a uniform surface layer 2. To volatile the solvent, the diaphragm is heated and cured at 130-180 deg.C for 10-40min (preferably, at 150 deg.C for 30min).

Description

[Detailed description of the invention] Is non-invention metal 2? The present invention relates to a method of manufacturing a speaker diaphragm constructed using i. - Conventional diaphragms for Subino have been produced by paper-making natural valve fibers and molding them. The vibrations for speakers made of this natural valve fiber are 4. It is physically unsatisfactory, such as the high rigidity required for Y properties and a high specific bullet +'] ratio, and furthermore, it has poor moisture resistance and has many problems such as deterioration of i'f quality in a high humidity rolling atmosphere. It was something.

For this reason, aluminum foil, beryllium foil,
A speaker diaphragm made of light metal foil such as magnesium foil has been developed and is being put into practical use.

However, the appearance of the metal foil diaphragm is poor due to deterioration of the material due to corrosion. There is a problem of change in sound quality (1) Discoloration and corrosion caused by salt, sulfur gas, etc. are severe, and if you touch it directly with your hands, fingerprints will remain and the area will corrode, resulting in poor appearance. Moreover, over many years, changes in the material of the metal foil may cause changes in sound quality.

Furthermore, in recent years, diaphragms made of aluminum foil with a thin resin layer on the surface have been developed, but they have poor adhesion to the aluminum foil, lack heat resistance, and are not fully satisfactory in terms of corrosion resistance.・I can't say that.) f
? X□ The present invention eliminates the above-mentioned drawbacks of the conventional technology, and has the following features: 1. Excellent corrosion resistance and corrosion resistance. The present invention relates to a method for manufacturing a speaker diaphragm that is subjected to surface treatment that also provides excellent adhesion to metal foil.

In order to achieve the above object, the present invention applies colloidal silicon oxide and silicone resin with a high silicon content to a uniform film thickness on the surface of a metal foil diaphragm while the metal foil diaphragm is preheated. , which is characterized by being heated and hardened to form a surface layer.

Embodiments of the present invention will be described below with reference to the drawings.

The metal foil diaphragm 1 is formed into a cone shape using a metal foil made of aluminum, aluminum alloy, magnesium, beryllium, or beryllium alloy, which is lightweight, has poor corrosion resistance, and has a high specific impact ratio. (containing silicon) 11-rich silicone resin and colloidal silicon oxide are combined into a greenylene ether system and an alnylene yarn,
The silicone resin is diluted with a pre-mixed agent with water, and the silicone resin is manufactured by uniformly coating the silicone resin containing 10 to 13 wt% of silicon to form the surface layer 2.

The coating thickness is most preferably 5 ltγ13μ, and if the coating thickness is too thin, the corrosion resistance will be poor, and if it is too thick, cracks will easily occur when driving the speaker. 'Furthermore, the viscosity of the solution is desirably less than so cps, and the lower the viscosity, the easier coating and dipping will be, and the less variation in film thickness will occur. If the viscosity increases, the appearance will be poor, coating will be difficult, and it will be difficult to obtain a uniform film thickness. However, since resin concentration and viscosity are proportional, it is necessary to select a resin with low viscosity and high concentration in order to obtain the desired film thickness.

In this respect, the present invention has a high concentration of 30% and a viscosity of 1O-60%.
Since it has a low value of 0.09B, it is suitable as a metal processing agent.

However, when the metal foil diaphragm 1 is immersed in the treatment agent used in the present invention and the solvent is evaporated, the film thickness becomes about 3 to 6 μm.
Further, since the metal foil diaphragm 1 has a cone shape, variations in film thickness occur.

Therefore, in the present invention, the metal foil diaphragm 1 is preheated in order to obtain the desired thickness of the surface layer 2.

The temperature of this preheating is preferably in the range of 35 to 40 to 60°C, provided that the resin solution does not foam. The higher the preheating temperature, the thicker the film becomes, but as mentioned above, there is a risk of foaming.

The preheated metal foil diaphragm 1 is immersed in a metal treatment agent, taken out, attached to a rotating jig, and rotated to evenly and uniformly coat the surface layer 2 on the metal foil diaphragm 1. be done. To volatilize this solvent, 130
~180°C for 10-40 minutes, preferably 150°C
The speaker diaphragm of the present invention is obtained by heating and curing at .degree. C. for 30 minutes.

The heat curing described above proceeds as the silicone resin reacts with colloidal silicon oxide, and strong adhesion is obtained by bonding with the metal foil diaphragm 1 made of aluminum or the like. Surface layer 2 is formed by immersion treatment in a stock solution containing about 30 wt% silicon oxide and silicone resin solids and heating and curing.
It is extremely tough and has excellent corrosion resistance and heat resistance. The film thickness varies depending on the preheating temperature of the metal diaphragm 1, and in order to reduce the variation in film thickness, a rotating jig is used to rotate the film after immersion to eliminate resin pools and at the same time increase the film thickness. Measure the uniformity of This rotation speed is 160~s o o
If the rpm is lower than this, resin pooling or variations in film thickness will occur, and if it is higher than this, the film will be thin even if it is uniform, resulting in poor corrosion resistance.

How the preheating temperature and rotation conditions affect the thickness of the surface layer 2 will be shown below. However, as shown in the table above, the thickness of the surface layer of the diaphragm using a metal treatment agent with a solid content of 30 wt% is determined by heating the metal foil diaphragm 1 and the rotation speed of the diaphragm using centrifugal force. The most favorable conditions are selected.

Considering the appearance, it is preferable to use a film M6 to 7μ under the following conditions: +7 JIl heat 40° C. 9 rotation speed 16° r4.

Note that as the metal treatment agent, VKSTAR treatment agent (manufactured by Dow Corning, USA) can be used.

Next, a comparison of various characteristics between a speaker diaphragm obtained by the manufacturing method of the present invention and a conventional speaker diaphragm will be shown.

[Corrosion resistance]

A 5% sodium chloride solution was prepared and a salt spray test was conducted.

A conventional speaker diaphragm with a 10μ thick acrylic resin film formed on it and corrosion occurring after 24 hours - an uninvented speaker with a 7μ thick surface layer formed on the power diaphragm aluminum diaphragm without corrosion. Vibration Plate [Heat Resistance] The results of observing the film after one hour under each temperature condition of 100°C, 160°C, 200°C, and 300°C are shown in the table below.

[Impact resistance]

After being left in an atmosphere of 100°C, 150'C, 200°C, and 300'C for 1 hour, the film was immediately put into water at 20 to 26°C, and the state of the film was observed. The results are shown in the table below.

[Solvent resistance]

The product of the present invention does not change at all when exposed to alcohols and organic solvents.

As described above, according to the manufacturing method of the speaker diaphragm of the present invention, the speaker diaphragm has excellent corrosion resistance, solvent resistance, and heat resistance, and maintains excellent quality without discoloration or deterioration even after long-term use. A diaphragm can be obtained, which is of great industrial value.

[Brief explanation of drawings]

The drawing is a half-sectional front view of a speaker diaphragm obtained by the method of manufacturing a speaker diaphragm of the present invention. 1... Metal foil diaphragm, 2... Surface layer.

Claims (1)

[Claims] A metal foil with a light tt and excellent specific elastic modulus and poor corrosion resistance is formed into a metal foil diaphragm, and this gold-1 diaphragm is
1. A method for manufacturing a speaker diaphragm, which comprises preheating to ℃, applying a metal treatment agent made of silicone resin, and curing it by heating.