JPS58105690A - Manufacture of diaphragm - Google Patents

Abstract

PURPOSE:To obtain a diaphragm having an excellent characteristic, by manufacturing a fibrous diaphragm by heating and pressing a deposit obtained from a dispersed substance which is obtained by dispersing inorganic substances in a compound obtained from vinyltrissilane, and by setting the water resisting property and Young's modulus to required values. CONSTITUTION:Vinyltris( beta-methoxyethoxy )silane[structured formula: CH2= CHSi(OCH2CH2OCH3)]is hydrolyzed in water and dehydrated and condensed into pulp fibers, and a compound is obtained. Then, powder or mixed powder selected from inorganic substances, such as mica, titanium, etc., is dispersed in the compound in water and a dispersed substance is obtained. The dispersed substance is scooped up together with the making water on a shaped wire cloth, and a deposit is obtained. Finally, the semi-dried deposit is heated and pressed in a metal mold and the inorganic substances are reacted with the organic reactive group of the vinyltrissilane, and a diaphragm is formed simultaneously. Then the water resisting property and Young's modulus of the diaphragm are set to required values. Thus a diaphragm having an excellent characteristic is manufactured.

Description

[Detailed description of the invention] The present invention relates to a method for manufacturing a fibrous diaphragm.

To make a fibrous diaphragm, a paper making apparatus shown in FIG. 1 is usually used. This papermaking device has a structure in which a cock 4 is provided at the bottom of a cylindrical clamping funnel-shaped suction device 2. Then, an appropriate amount of pulp fibers is injected together with a large amount of water into the holding papermaking tank 1, and after thorough stirring, when the cock 4 is opened, the water in the papermaking tank 1 is drawn into the fine transparent paper of the papermaking mold 3 by gravity. The pulp fibers falling through the holes and floating in the water are deposited on the upper surface of the paper mold 3. This deposit still contains a large amount of water, and a manufacturing method is used in which the wet deposit is dried to a semi-dry state and then heated and pressurized in a mold to form the product.

This invention is a method for manufacturing a fibrous diaphragm such as a slanted diaphragm, in which vinyltris(β-methoxy)silane is hydrolyzed in water and dehydrated and condensed between the pulp fibers and vinyltris(β-methoxy)silane. a first step to obtain a compound with methoxyethoxy)7ran; a second step to obtain a dispersion by dispersing this compound in water with an inorganic substance in the form of powder, short fibers, or whiskers; A fourth step is to heat and pressurize the semi-dry deposit in a mold to react the inorganic substance with the organic reactive group of vinyltris(β-methoxyethoxy)silane, and at the same time mold it. This is a method of manufacturing a diaphragm, characterized by the following steps.

Powdered inorganic substances are preferably mica powder, white titanium powder, silica powder, and alumina powder, and short fiber inorganic substances are glass fiber, silicon fiber, alumina fiber, carbon fiber, boron tenodide fiber, and boron carbide. fiber,
Boron titanide fibers, silicon carbide fibers, zirconia fibers, and potassium titanate fibers are common, and the whisker-like inorganics include graphite, alumina, beryllium oxide, boron carbide, silicon carbide, silicon tinide, chromium, copper, iron, and Nickel whiskers are good.

An example using this method will be described below.

Kraft valve fiber with a freeness of 700 was added in an amount of 5% by weight based on water, and 0.4% by weight of vinyltris (β-methoxyethoxy) silane based on the amount of pulp fiber was added, stirred, and then left at room temperature for 15 hours. After the β-methoxyethoxy) silane is hydrolyzed, it undergoes a dehydration condensation reaction with the hydroxyl groups of the pulp fibers to produce a compound of vinyltris(β-methoxyethoxy)silane and the pulp fibers. Next, while stirring this compound in a papermaking tank, 15% by weight of silicic acid powder is added to the pulp fibers and thoroughly dispersed. When the cock 4 is opened in this dispersed state, water drops. As a result, deposits are formed on the paper mold 3. By heating and pressurizing this deposit in a semi-dry state in a mold, the reactive group of vinyl tris (β-methoxyethoxy) 7-ran reacts with the silicic acid powder and molding can be achieved at the same time. The diaphragm is completed by cutting out unnecessary parts of this molded product.

The diaphragm obtained by this method is shown in Figures 2 and 3.
It has physical properties as shown in FIG. Figure 2 shows the Young's modulus, internal loss (tan δ), density, and water contact angle in comparison with other examples, and Figure 3 shows the deformation due to moisture resistance tests in comparison with other examples. Figure 4 shows the reproduced sound pressure frequency characteristics when the diaphragm is used as a speaker in comparison with other examples, and when taken together, the diaphragm obtained by the method of this invention , a diaphragm with excellent moisture resistance, high efficiency due to its low density, high internal loss (tan δ), which can reduce the level of vibration splitting resonance, and a Young's modulus that is a necessary and sufficient value. Because of this, it has excellent physical properties such as being versatile as a diaphragm in speakers and the like.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view showing a commonly used fibrous diaphragm paper-making apparatus, Fig. 2 is a diagram showing the physical properties of a diaphragm produced by the method of the present invention, and Fig. 3 is a diagram showing the physical properties of a diaphragm produced by the method of the present invention. FIG. 4 is a diagram showing deformation and weight increase due to a moisture resistance test, and FIG. 4 is a diagram showing reproduced sound pressure frequency characteristics when a diaphragm according to the method of the present invention is used in a speaker. 1... Paper-making tank, 2... Funnel-shaped suction device, 3...
Paper mold, 4...Cook. 1st illustration 2 □ 1 rise 1? Kaitoshi I Douichi Kazuichi -------Sahei Example 1;! 5tln class "1OO" [- 0 Fig. 4

Claims (1)

[Claims] 1. A method for manufacturing a fibrous diaphragm, in which vinyl tris (
β-methoxyethoxy)nran [structural formula CH2-CHS
A first step of hydrolyzing l(OCH2CH20CHa)8) in water and dehydration condensation with pulp fibers to obtain a compound, a second step of dispersing an inorganic substance in the compound in water to obtain a dispersion, A third step is to obtain a deposit by scooping the dispersion together with water onto a mold, and heating and pressurizing the semi-dried material outside the deposit in a mold to form the vinyl tris (β- A method for manufacturing a diaphragm, comprising a fourth step of reacting the inorganic substance with the organic reactive group of 7-run (methkin ethoxy) and simultaneously molding the diaphragm. 2. The method according to claim 1, wherein the inorganic substance is one powder or a mixed powder of two or more appropriately selected from powders of mica, white titanium, silica, and alumina. 3 The inorganic substance is one short fiber or a mixture of two or more short fibers appropriately selected from short fibers of glass, silicon, alumina, carbon, boron titanide, boron carbide, boron titanide, silicon carbide, zirconia, and potassium titanate. A method according to claim 1. 4 Inorganic substances include graphite, alumina, oxide,
Boron carbide, silicon carbide, silicon titanide, chromium, copper,
2. The method according to claim 1, wherein the whisker is one whisker or a mixture of two or more whiskers appropriately selected from the group consisting of iron and nickel (whisker strength).