JP3048680B2 - Heat-resistant speaker diaphragm - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-resistant speaker diaphragm used in an electroacoustic transducer such as a speaker.

[0002]

2. Description of the Related Art In the past, asbestos (asbestos) paper was a typical heat-resistant paper in the general paper market, but recently there has been a strong suspicion of carcinogenic substances. It is said that there are few new hires from the industry. In recent years, glass fiber paper and carbon fiber paper have been put on the market as heat-resistant paper. However, in most cases, an organic material (polyvinyl alcohol) is used as the fibrous binder. The addition amount is also 10% when estimated from the heating loss (400 ° C + 2 hours).
That is all. In addition, the fiber paper strength is low, and the tensile strength is 0.5 kg / mm ² or less, and few products have a strength higher than this. Some products do not use organic materials, but their strength is sufficient to support their own weight.

[0003] On the other hand, some speaker diaphragms which are called heat-resistant paper are made by adding heat-resistant fibers (Kevlar fiber, glass fiber, etc.) to wood pulp by several percent. In view of maintaining the strength, the addition rate is limited to about 5 to 10%. Further additions have not been realized because they significantly reduce the strength of the paper. Under these circumstances, it was not a practical heat-resistant paper. It is difficult to make a fiberboard diaphragm that occupies 90% or more of highly elastic fibers that are more heat-resistant than cellulose fibers.

[0004] When a paper-like matrix is formed of fibers of high elasticity (more than general-purpose fibers in elastic modulus) irrespective of inorganic or organic, compared to paper made of cellulose fibers, 1. High elastic fibers have a chemical structure on the surface. Is non-polar and inert, and aromatic polyamide fibers have only slightly polar amide groups (-NHCO-) and imide groups (-N = (CO-) ₂ ), and hydrogen bonds between fibers And there is no strong polar group, ie, a hydroxyl group (-OH), which can significantly improve the inter-fiber bonding strength. Therefore, the surface of many fibers is hydrophobic, and these phenomena cause little water absorption and hygroscopicity, resulting in good insulation. 2.The contact area between fibers, which is important for the strength of the paper matrix, is because these fibers have a high modulus of elasticity, the fibers are rigid, and because of their high crystallinity they do not be beaten and do not fibrillate. Few. Also, like cellulose fibers, they swell and plasticize in water, and the effect of increasing strength (Campbell Campbell effect) due to the increase in the contact area between fibers cannot be expected. 3. Most of these high modulus fibers have a small fiber diameter to increase fiber strength, but still have a smaller specific surface area than wood pulp (specific surface area 1.0 m ² / g ). Although it depends on the diameter and density, it is about 0.25 m ² / g, and there is no improvement in mechanical strength due to an increase in the inter-fiber contact area due to the fibers themselves. 4. Naturally, the frictional resistance between the fibers is small, and the improvement of the internal loss as well as the strength cannot be expected. 5.Since inorganic fiber has small specific surface area and high fiber density,
Since the sedimentation speed in the slurry is high and the fiber surface is hydrophobic and the uniform dispersibility is not good, it is difficult to obtain a uniform paper.

[0005] 6. Since the high elasticity fiber is hydrophobic, rigid and has no Campbell effect, the water content of the paper-like fiber matrix is low, the bulkiness and the density are low, and the surface tension due to water between the fibers is low. It does not work and the web (Web = composite of fiber and water) is weak. Therefore, the web cannot be transferred or peeled off from the papermaking net during papermaking. High elastic fiber has no swelling and plasticization by water compared to cellulose fiber,
Rigid, water surface tension does not work, no Campbell effect can be expected, and web formability (Consolidation Consolidation
ation). That is, since there is little relation with water, it is difficult to obtain strength as in cellulose fiber paper. But,
High elastic fiber has high fiber strength, high elastic modulus, and excellent properties such as water resistance, humidity resistance, heat resistance, and flame retardancy far exceed those of cellulose fiber. If this is established, a useful fiber paper diaphragm having the characteristics of these fibers can be expected.

As described above, the conditions for obtaining a vibrating plate using highly elastic inorganic fibers and high elasticity organic fibers, etc., and having a practically strong endurance and further having an appropriate internal loss are determined by the physical properties of the fibers themselves. It is necessary to devise properties and papermaking technology to make paper, or to establish a post-treatment method (secondary treatment). On the other hand, in order to make a paper having heat resistance, flame retardancy, water resistance, moisture resistance, and the like, it is necessary to study the chemical conditions of the fibers themselves, the treatment method after paper formation, and the like.

However, even if these technologies are used to make paper, it is extremely difficult to obtain practical paper comparable to wood pulp in view of its strength. It is not expected that the internal loss using the frictional resistance will be generated. In order to obtain a paper strength that can withstand practical use, practical production of a diaphragm is impossible unless the addition of a fibrous binder or an adhesive is considered.

[0008] The mechanical strength of the paper-like matrix is physically related to the strength of the fiber material, fiber morphology (fiber length, cross-sectional shape, fiber diameter), fiber surface condition, etc., and the method of increasing the density of the paper. The effects and effects of strong paper are as follows. Operational effects a. The fiber form is as follows: 1. Strong fiber strength: strong and not brittle, toughness fiber 2. Long fiber length: reduction of fiber cut surface 3. Thin fiber diameter: expansion of specific surface area to increase contact area between fibers 4. The cross-sectional shape must be ribbon-shaped: the contact area between fibers increases, and the density increases. B. The surface condition of the fiber: 5. The surface has a polar group: a strong polar group (-0H) exists As a result, hydrogen bonding is established between the fibers and the drying strength is improved, and the strong surface tension of water also improves the web strength.6.Use of adhesive fibers and adhesives: Improves the bonding strength between fibers. Adhesiveness with binders and binders: Enhancement of strength by increasing entanglement between fibers 8.Plasticization by water absorption: Improvement of strength by increasing contact area (Campbell effect) between fibers

C. The density of the paper is as follows: 9. Increase the density by filling the fibers with short fibers: Filling the fibers with short fibers (milled, fibril-like fibers) or a combination of fine substances and long fibers Increase the web strength and dry strength by increasing the rate 10. Cover the fibers with a material having a large specific surface area: Increase the contact area between fibers to improve the web strength and dry strength Heat resistance, flame retardancy, water resistance of synthetic paper Properties such as water resistance and moisture resistance are related to the chemical properties of the fiber itself, and their actions and effects are as follows. 11. High binding energy of the main chain of the molecular structure: high heat resistance due to high decomposition temperature 12. Nitrogen, phosphorus, halogen, metal elements in the molecule: flame retardancy, heat resistance 13. Crystallinity High: Water and humidity resistance improved 14. Surface polarity inactive (non-polar): Water and humidity resistance improved 15. Larger diameter, increased density of papermaking: Reduced contact area with air Unless the above conditions are satisfied, a diaphragm having practical strength and having the above properties cannot be obtained.

[0010]

However, wood pulp is excellent in most of the above conditions, but is inferior in fiber strength to high modulus fibers. Accordingly, the biggest problem with high modulus fiber papers concerns the papermaking technique of "how to increase the density of the formed paper."

The present invention has been made in view of the above points, and an object of the present invention is to use a highly elastic fiber to provide excellent flame retardancy or water resistance, humidity resistance, high strength and high strength. An object of the present invention is to provide a heat-resistant speaker diaphragm having an elastic modulus and a high internal loss.

[0012]

In order to achieve the above object, a heat-resistant speaker diaphragm according to the present invention comprises a high-elasticity inorganic fiber and a high-elasticity organic fiber short fiber or inorganic powder.
Super beaten wood pulp with a large specific surface area is added as a fibrous binder to make paper, and furthermore, a silicate compound, an organometallic polymer compound, an inorganic compound, an aromatic polyamide, an imide compound, etc. having excellent heat resistance are used. It is characterized by having excellent impregnated heat resistance, flame retardancy or water resistance, moisture resistance, high strength, high elastic modulus and high internal loss.

[0013]

The conditions for producing a strong paper with fibers having a low bonding force such as high elasticity fibers are strong, long and thin, and the fibers are filled with milled fibers, fibrillated fibers, and fine powder, and It is a condition that it is covered with a fibrous substance having a specific surface area or another substance and has a high density. The present invention uses a combination of short fibers of high elasticity (cut fibers, milled fibers, fibrillated fibers) to increase the interfiber filling rate, measure the density of papermaking, super beaten wood pulp, and have a large specific surface area. Ultra-beaten wood pulp (10.0 m ² / g or more) having the following formula is added as a fibrous binder in an amount of 0.5 to 30 parts to increase the fiber-to-fiber bond strength to make paper. Further, this is impregnated with a solution of a heat-resistant silicate having an adhesive property, an organic metal polymer compound, an organic polyamide, an imide compound or an inorganic compound to cover the space between the fibers, thereby providing high strength and high elastic modulus. An object of the present invention is to provide a diaphragm that has improved properties such as heat resistance, flame retardancy, water resistance, and humidity resistance by elevating physical properties. Since the internal loss uses ultra-beaten wood pulp having a large specific surface area, frictional resistance between fibers is improved, and a high internal loss can be obtained. Further, since the ultra-beaten wood pulp has a large specific surface area, it has a good dispersibility and a strong cohesive force. Therefore, the dispersibility of the inorganic fiber having a high density is excellent, and the sedimentation speed can be reduced to obtain a uniform slurry.

[0014]

The materials used in the present invention, such as the state and type of these highly elastic fibers and the impregnating agent, will be described. The cut fiber is
A fiber bundle (yarn) of long fibers is hardened with a sizing agent, cut with a rotary blade to a length of 1 to 72 mm, and most suitable for papermaking is 1 to 7 mm. Longer lengths are used for nonwovens. Almost all fibers are used regardless of organic or inorganic properties, which contributes to improvement of paper strength and elastic modulus. The elastic modulus and heat-resistant temperature of each fiber are described below, all of which are catalog values of the manufacturer. High elasticity inorganic fiber (elastic modulus To n / mm ² / heat-resistant temperature ℃) a. Glass fiber (7.5 / 650) Fiber diameter 9.6 microns: Nippon Sheet Glass, Nitto Boseki b. Carbon fiber (24-70 / 1000-1200) fiber 7 micron diameter: Toho Rayon, Toray, Mitsubishi Kasei c. Alumina fiber (15-40 / 1200-1600): Dupont, Mitsui Metal Mining, (Al ₂ O ₃ : 80% or more) Sumitomo Chemical d. Ceramic fiber (16- 25 / 1200-1600): Ibiden, Nippon _{Steel, (SiO 2 / Al 2 O} 3 = 4.0-0.1) Isolite e silicone carbide SiC fibers (18-20 / 1200):.. Nippon carbon "Nicalon" f boron tungsten B / W fiber (40/1600): New chemical and metal silicon carbide carbon SiC / C fiber (43/1600) Japan g. Titanium silica fiber (20/1300): Ube Industries "Tyranno" h. Silicon nitride fiber (25 / . 1200): Tonen "silicon nitride fibers" i cement fiber (- / 1300):. Japan cement "CMF" j calcium silicate fibers _{(- / 1300) CaSiO 3:} . Onoda cement k titanium Potassium whisker fiber (28/1350):. Otsuka Pharmaceutical "TISMO" l metal fiber (19/1450): Nippon Seisen "Nasuron"

High elasticity organic fiber a. Aromatic polyamide fiber Para system: Dupont Toray Kevlar "Kevlar (6.3-15.5 / 500) ー", Sumitomo Chemical "Twaron" (0.8-1.8 / 375) Meta system: Teijin "Conex" Dupont Toray “Nomex” Unitika “Apier” b. Aromatic polyetheramide fiber (7.1 / 500): Teijin “Technola” c. Liquid crystalline wholly aromatic polyester fiber (7.6 / 400): Kuraray “Vectran” and polyethylene Terephthalate copolymer fiber d. Polybenzimidazole (PBI) fiber: Teijin "PBI" fiber (0.6 / 560) e. Aromatic polyetherimide fiber (0.45 / 400): Teijin "PEI" f. Aromatic polyamideimide fiber: Rhone Poulin "Kermer" (0.8-1.3 / 380) g. Polyetherether fiber (0.5-1.5 / 350): Teijin "PEEK fiber", Mitsui Toatsu Chemical "Talpa" h. Polyphenylene sulfone fiber: Kureha, Teijin ( 0.5-1.0 / 280) i. Enol fiber (0.3- / 300): Nippon Kaynol "Kynol" j. Polyparaphenylenebenzbisthiazole: USA Air Force (PBT) fiber (25-28 / 600) k. Ultra-high molecular weight acrylic fiber (2.0 / 140): Asahi Kasei "Cashmilon", Mitsubishi Rayon l. Polyethersulfone fiber m. Polyoxymethylene fiber (4.0 / 190): Asahi Kasei "Tenac"

When the milled fiber is formed into a paper matrix with cut fibers cut with a fiber length of 1 to 7 mm, the density of the formed paper is reduced, the contact area between the fibers is reduced, and the strength is reduced. In order to prevent this decrease in density and increase the contact area between fibers, short milled fibers or fibrillated fibers described below are used for filling gaps between cut fibers. 0.5-0.7 m mainly from high elastic fiber scrap
With a fiber crushed to m, the fiber diameter can be crushed to several microns, and the specific surface area reaches 0.5 to 4 m ² / g. It is generally used as a reinforcing fiber for general-purpose resins, and can be used as a web-strength retention agent for paper when it is peeled off from a papermaking net, and acts to increase the density and increase the strength of the formed paper. Inorganic fibers are used more often than organic fibers, and are used to increase the density of inorganic fiber paper.

[0017] Carbon fiber: For papermaking For resin mixing Carbon fiber manufacturing companies Glass fiber: For papermaking resin mixing Companies Aromatic polyamide fiber: For papermaking resin mixing Kevlar pulp Dupont Toray Kevlar Aromatic polyether fiber: Papermaking resin mixing Technora Pulp Teijin Alumina, ceramic fiber: For resin mixing Whole aromatic polyester fiber: Vectran pulp for papermaking Kuraray

The fibrillated fiber acts as a filler between the fibers as in the case of the above-mentioned milled fiber, and can increase the density of the formed paper. However, since the specific surface area is much larger than that of the milled fiber, the fibrillated fiber has a larger interfiber bond. The strength can be improved, and it greatly contributes to the improvement of web strength and dry strength. Although the specific surface area of wood pulp can be increased to several m ² / g by the usual beating method, the high elasticity fiber does not fibrillate by general beating and cannot increase its specific surface area. The only alternative is to increase the specific surface area using another mechanical method, or to fibrillate and use another fiber. There are a method of increasing the specific surface area by fibrillating organic synthetic fibers and cellulosic fibers to a submicron by a special method, and a method of using a material having a large specific surface area from the beginning.

One of the methods for producing fibrillated fibers (fibrillated fibers) is to dissolve a fiber material in an organic solvent, jet this into a stirring non-solvent, disperse the fibril, and fibrillate. Thus, the fiber length is 3 to 5 mm, the fiber diameter is up to submicron, and the specific surface area is 1 to 10 m ^2.
/ G. This fibrillated fiber is called a fibrillated fiber. At present, this method is only possible with organic synthetic fibers and has a great effect on increasing the density of synthetic fiber paper. It is also said to be possible to increase the specific surface area up to several m ² / g to speed 10 m ² / g by selecting the type of non-solvent. This method is currently only possible with meta-aromatic polyamide fibers.

Teijin: "Corness pulp" Unitika: "Apier pulp IAW IBT" Dupont: "Fibrit 102 103"

There is also a method for ultra-beaten wood pulp in which the wood pulp is made into ultra-fibrillated wood. This is accomplished by pushing a web-like wood pulp into a gap (slit) between a piston and a cylinder having different diameters by applying a high pressure to the wood pulp. This is a method in which the fibers are rotated and repeated several times to ultra-beat to submicron along the fiber axis to fibrillate. The specific surface area of the obtained ultra-beaten wood pulp is 10.0 m
² / g or more to reach, it is possible to super beaten up 200 meters ² / g. A binder that maintains a fiber shape with a large specific surface area and is effective in improving the paper strength of inorganic and organic fiber papers with no binding properties. Increase rapidly. By super-beating synthetic fibers and processed fibers other than the above-mentioned wood pulp, it is possible to obtain a fibrous binder that improves the strength and the like of the fiber paper.

A. Ultra-beating of wholly aromatic polyester fiber Vectran (Kuraray), a liquid crystalline and thermoplastic wholly aromatic polyester fiber, is cut into 3 mm, made into a slightly web-like form, and ultra-beaten in the same manner as wood pulp. An ultra-beaten Vectran fiber having a large specific surface area can be obtained. This ultra-beaten fiber is mixed with ultra-beaten wood pulp and inorganic fibers such as carbon fibers. After papermaking, the paper is hot-pressed near the melting point of Vectran fibers. A carbon fiber (inorganic fiber) paper having high internal loss, high strength, high elasticity, excellent heat resistance, and excellent flame retardancy can be obtained. b. Ultra-beaten aromatic polyamide fiber Kevlar (para-Du), a short fiber of aromatic polyamide
Pont Toray), Conex (meta Teijin), Apière (meta Unitika), etc. can be ultrabeaten in the same manner as wood pulp, and ultrabeaten aromatic amide fibers having a large specific surface area can be obtained. When the ultra-beaten fibers are mixed with the short fibers together with the ultra-beaten wood pulp, an aromatic amide fiber paper having strength, heat resistance and flame retardancy can be obtained. c. Ultra-beaten chitosan Chitosan can be beaten in the same manner as the above wood pulp. By mixing with chitosan fiber, strong biopaper can be obtained. d. Ultra-beating of phosphorylated wood pulp The hydroxyl group and methylol group of wood pulp are converted to polyphosphates,
When phosphoric acid esterification is performed with phosphoric acid or the like, extremely excellent flame-retardant pulp can be obtained. This phosphorylated pulp can be ultrabeaten in the same manner as the above wood pulp, and a flame-retardant superbeaten phosphorylated pulp having a large specific surface area can be obtained. When this ultra-beaten phosphorylated pulp and ultra-beaten wood pulp are mixed with organic high elastic fibers, short fibers such as high elastic inorganic fibers, or ordinary wood pulp, they have high strength, high elastic modulus, and heat resistance,
A fiber paper with good flame retardancy can be obtained.

Although the web strength at the time of papermaking is determined by the water content, the high elastic fiber has a low water content as compared with the cellulose fiber paper, and the surface strength of water does not act between the fibers, so that the web strength is weak. The corn paper making process has a batch type transfer process and requires a certain level of web strength. The ultra-beaten wood pulp is also useful as a web strength improver for increasing the strength, but sepiolite (epiolite), which is a fine needle-like crystal, has long been used for heat-resistant inorganic fiber paper. I have. Add 10% hydrogen peroxide to sepiolite to form a 3% slurry. The rotation speed is 3000
Stir for 30 minutes with a disintegrator at rpm to separate completely. When 10% of this slurry is added to the fiber suspension, the strength of the web paper at the time of papermaking is remarkably improved, and it can be easily peeled off from the papermaking net. The pulp having a large specific surface area formed as described above becomes a fibrous binder and can be a binder for a high elastic fiber material having a low binding performance. 100% sepiolite paper is also commercially available as heat resistant paper.

The inorganic powder has the greatest effect of increasing the density of the paper, and the physical properties of the paper vary depending on the shape. The higher the aspect ratio, the higher the strength and elastic modulus. In particular, mica has a great effect on these properties. Sepiolite alone forms a paper, but has a large specific surface area and is suitable for improving the strength of the web. Granular talc tankal strength fibrous asbestos strength flaky mica glass flake graphite bending elasticity, internal loss acicular sepiolite web strength

The impregnating agent such as a silicate compound, an organometallic polymer, an inorganic compound, an aromatic polyamide, an imide compound and the like, and the substances studied for use in the present invention will be described. It is natural that high heat resistance cannot be expected with only the short fibers of high elasticity fiber and the ultra-beaten wood pulp as the fibrous binder, and silicates, organic metals, etc. are wrapped around this ultra-beaten wood pulp. By impregnating the compound, a high strength and a high elastic modulus are obtained, and further, heat resistance and flame retardancy are provided.

As silicate compounds, sodium silicate and potassium silicate are known, but lithium silicate Li ₂ SiO _{3 n}
H ₂ O (Li ₂ O / SiO ₂ = 7.2-7.8) is different from the above two,
After drying, it does not become water-soluble again, has no water absorption, has water resistance and humidity resistance, and has no heat loss up to 1000 ° C.

Many of the organometallic compounds have a structure in which silicon is contained in a main metal, and titanium and boron (boron) are combined with the main metal. At high temperatures, organic substances disappear, the metal components increase, and ceramics conversion (metal oxide)
Is done. Compound name Main chain structure Heat resistance a. Organometallic polymer compound Polysilane -Si-Si- 450 ° C or more Silicon varnishes Polycarbosilane -Si-C- 1000 ° C or more Nippon Carbon `` Nicalocoat '' Alcokisside compounds M (OR) _{n M = Ti, Si, Zr} , Zn R = -C n H 2n + 1 Si- (OC 2 H 5) 4 R C less ones such hydrolyzes in air, the amorphous SiO ₂ , and the heat resistance becomes 400 ° C or more. Nippon Synthetic Rubber, Catalyst Chemicals, Nippon Soda, etc. b. Organic boron-containing, silicon compound borosiloxane -BO-Si-O- 800 ° C or higher Showa Densen Denki "Borosiloxan" c. Organic titanium-containing silicon compound polytitanocarbosilane- Ti-Si-OC-1200 ℃ or higher Ube Industries "Tyranno coat" d. Organic nitrogen-containing silicon compound polysilazane -N = Si 1200 ℃ or higher Tonen "Polysilazane" e. Organic aluminum-containing silicon compound Polyaluminoxane -Al-O- 1000 ℃ or higher as non-400 ° C. or higher Idemitsu Petrochemical Dainichiseika silicon salt inorganic compound -. Sumitomo chemical f organosol sol Al ₂ O ₃ 650 ℃ or more companies silica sol SiO ₂ 1200 ° C. or more companies g organophosphazene -N = P (oR) _2. Is also used alumina sol, silica sol and the like.

The vibrating plate after press drying is impregnated with a resin of an aromatic polyamide or imide compound, and the polyamic acid-type compound is cured at a high temperature. The representative manufacturing company and product name are described. a.Aromatic polyamide compound Unitika "Apier" b.Aromatic polyimide compound Toray "Trenez", Dupont "Vail" Mitsubishi Gas Chemical "BT resin" c.Aromatic polyamideimide compound Hitachi Chemical "HI-400", Sumitomo Electric Sumitherm "Amco" Amco AI-10 "d.Aromatic polyesterimide compound Sumitomo Electric" Sumitherm F-555 "Dainichi Seika" Telebec "e.Aromatic polyhidatoin compound Sumitomo Bayer" Resirham PH-10 "f.Aroma Aromatic benzimidazole compounds g. Aromatic polybenzothiazole compounds h. Aromatic polypyromellitic imide compounds i. Polyparalambanic acid Tonen "Sollac"

Although the present invention does not have the binding performance as described above, it is intended to use a highly elastic fiber (cut fiber, milled fiber, fibrillated fiber) having excellent heat resistance and flame retardancy as a paper-like matrix and to make it practical. By adding 0.5 to 30% of a mechanically super-beaten super-beaten wood pulp having a large specific surface area (10.0 m ² / g or more) as a fibrous binder, its strength and elasticity are improved. With a large specific surface area that cannot be obtained with a normal beater, the frictional resistance between fibrils is significantly improved, the internal loss is increased, and silicates,
Organometallic polymer compounds, inorganic compounds, organic polyamides,
The diaphragm is impregnated with a solution such as an imide compound to produce a heat-resistant and flame-retardant diaphragm.

Description of various test evaluation methods 1. Tensile strength and tensile modulus Calculated from stress-strain curve (SS-Curve). 2.Measured from internal loss torsion free viscoelasticity measuring device (Lesca)
calculate. 3. Heat resistance The loss on heating at 400 ° C. for 2 hours is measured. 4. Flame retardancy In accordance with JIS D 1201 "Test method for flame retardancy of organic materials for automobile interiors". Details will be described with reference to examples, and physical properties, heat resistance, and flame retardancy of fiber paper (diaphragm) will be described in a separate table.

Items common to the examples are a papermaking chemical and an impregnating agent. 1. Chemicals for papermaking PH during papermaking was neutral, and the principle was to use the same chemicals as for the production of neutral paper. However, when using glass fiber, acid papermaking was used to improve strength. The same drug was used. In order to prevent "floating" in fiber slurry,
Nonionic and anionic surfactants were added for the purpose of improving the wetting between the fiber surface and water, and a silicone-based defoaming agent was used for removing bubbles in the fiber matrix. As a result, uniform paper was obtained. In order to fill the fine substance into the paper matrix, a polymer flocculant, sodium polyacrylate, is added. Mica powder, potassium titanate whisker fiber,
It is used in the case of cement fiber, calcium silicate fiber and the like.

2. Impregnating Agent In order to impart better heat resistance and flame retardancy to the diaphragm, the diaphragm is impregnated with a solution of a silicate, an organometallic polymer compound, an inorganic compound, an organic polyamide, an imide compound or the like. Since there are so many types as described above, in each of the present Examples, the following treating agents were mainly used and are abbreviated. Compound name Abbreviation Processing condition Manufacturer a. Lithium silicate 10% solution Li-Si first-class reagent b. Organometallic polymer polyborosiloxane B-Si 10% solution Showa Densen Denki, "Borosiloxane" c. Same as above . Porichita Bruno siloxane Ti-Si 10% solution Ube Industries' Chiranokoto "d ibid polycarbosilane Si-C 10% solution by Nippon carbon" Nikarokoto "e metal alkoxide compound ethyl silicates _{Si -. (OC 2 H 5} ) 4 (SiO ₂ ) 10% solution Nippon Synthetic Rubber Butylated titanate Ti- (OC ₄ H ₉ ) ₄ (TiO ₂ ) 10% solution Mitsubishi Edogawa Chemical f. Aromatic polyamide resin Apier Apiere 10% solution Unitika g. Aromatic polyimide resin BT resin BT resin 10% solution Mitsubishi Gas Chemical

The above lithium silicate, metal alkoxide, aromatic polyamide, imide compound and the like can sufficiently exhibit the heat resistance of the compound only by volatilizing the solvent after impregnation with the solution. siloxane, Porichita Roh siloxane, polycarbosilane, organometallic polymer compounds such as polysilazane is not a was sufficiently exhibit the heat resistance possessed by the compounds only to volatilize the impregnating after solvent. The organometallic compound has an organic property at a low temperature, but when treated at a high temperature of 400 ° C. or more, turns into a ceramic and changes to an inorganic property. During the conversion to ceramics, the ultra-beaten wood pulp, which is the fibrous binder added, is burned off, and instead, strong ceramics are formed between the fibers, thereby improving the strength of the fiber paper. Thereby, heat resistance is also improved, and the fiber paper is ceramicized. The treatment method is as follows depending on the type of the compound.

In the case of polycarbosilane, Nippon Carbon “Nicalocoat” polycarbosilane crystals were converted to toluene,
It is dissolved in an organic solvent such as xylene at a ratio of 30 to 40%, and impregnated with the inorganic fiber paper shown in Examples 1 to 7 such as ceramic fiber paper and carbon fiber paper, and dried at room temperature for about 1 hour. Most of the organic solvents are volatilized and 5
0% or more is contained. Next, it is calcined at 250 ° C. for 30 minutes, and then gradually calcined to 600 ° C. to form silicon carbide SiC to be ceramicized, remarkably improving the bonding strength between fibers at high temperature, and giving heat resistance to the fiber paper. .

In the case of polysilazane, Tonen "polysilazane" is dissolved in an organic solvent such as toluene or xylene at a concentration of 30 to 40% as described above, and this solution is impregnated with the inorganic fiber paper shown in Examples 1 to 7 below. Similarly, the solvent is volatilized and dried at room temperature to make the fiber paper contain 50% or more. This is calcined at 250 ° C. for 30 minutes and then 700 to 8
When calcined at 00 ° C., siloxane nitride Si is obtained in a yield of 95%.
ON (silicon oxynitride) is formed and ceramicized. Thereby, the bonding strength between fibers at a high temperature is remarkably improved, and heat resistance is given to the fiber paper.

In the case of polytitanic Roh Rokisan, impregnated inorganic fiber paper shown below in Examples 1-7 to Ube Industries' Chiranokoto "toluene, Porichita Bruno siloxane dissolved 30-40% in an organic solvent such as xylene, at room temperature Evaporate the solvent and leave 5
0% is contained in calcined for 30 minutes at 250 ° C., is then ceramicized to form a titanosilicate shea <br/> Rokisan TiOSi yield of 96% when the firing at about 700 ° C..
Thereby, the bonding strength between fibers at a high temperature is improved, and heat resistance is given to the fiber paper.

In the case of polyborosiloxane, the inorganic fiber papers shown in the following Examples 1 to 7 were impregnated with 30 to 40% of polyborosiloxane and calcined at 400.degree. And when calcined at 600 to 700 ° C., boron carbide BC and boron siloxane SiOB are obtained in a yield of 98%.
Are formed between the fibers to be ceramicized. Thereby, the bonding strength between fibers at a high temperature is improved, and heat resistance is given to the fiber paper. It withstands continuous use at a high temperature of 450 ° C, and withstands 1000 ° C instantaneously without losing its flexibility even at 600 ° C.

Example 1 A ceramisk staple fiber (ibiden ibi wool, electrochemical arsen) produced by a blowing method was applied to a separator to remove shots (particulate matter) as much as possible, and the content was reduced to 15%. 30 to 70 parts of the following short fibers and glass fibers (species E-Glass Nippon Sheet Glass) cut into 3 mm to 5 mm with ultrafine fibers having a fiber diameter of 6 μm are added. 100P each of surfactant and defoamer as fiber wetting agent
PM is added, 10 to 15 parts of ultra-beaten wood pulp is added as a fibrous binder, and a 3% slurry is sufficiently disintegrated with a disintegrator (pulper), and a papermaking agent is added.
The paper is set to 0 and the paper is made with an ordinary paper machine and press-dried. It is impregnated with a solution of silicate compound, organometallic compound, etc. to improve heat resistance, strength and elastic modulus, or flame retardancy and water resistance, and has dry flame retardancy and high elastic modulus. A heat-resistant speaker diaphragm can be obtained. a. The following are used as the fiber material. Ceramic short fiber (blowing method) shot 15% or less: 70 parts Glass fiber E-Glass Diameter 6 micron 3 mm cut product: 30 parts Super beaten wood pulp: 10 parts b. The following are used as papermaking chemicals. Wet strength improver Ethylene urea resin: 1.50% Size rosin: 0.50% PH adjustment Dilute sulfuric acid: PH 4.0 c. Impregnation treatment The following impregnation treatment is performed to improve the flame retardancy, heat resistance and high elastic modulus of the above fiber paper. 1. Impregnation of 10% lithium silicate solution The fiber paper obtained above is sufficiently impregnated with a 10% aqueous solution of lithium silicate, dried at 60 ° C, and then pressed at 100 ° C for about 1 minute to correct the shape. I do. 2. Impregnation of polycarbosilane solution Dissolve 30% of crystalline polycarbosilane in organic solvent toluene, gently impregnate the above-mentioned fiber paper, and dry at room temperature. When the odor of the organic solvent has disappeared, temporary baking is performed at 400 ° C. for 60 minutes. Even in this state, it can withstand 300 ° C., but if necessary, it is further heated to a higher temperature (600 ° C. for 2 hours) to be ceramicized. 3. Impregnation of polysilazane solution The fiber paper is sufficiently impregnated with a 30% toluene solution of polysilazane, dried at room temperature until odor is eliminated, and then temporarily baked at 400 ° C. for 1 hour. Even in this state, it can withstand 300 ° C. for a long time, but when it is further treated at 600 ° C. for 2 hours at high temperature, the formation of ceramics progresses and the fiber paper can withstand up to about 1000 ° C.

Example 2 Ceramic short fibers obtained by the blowing method (Blowing method)
(Shot = non-fibrous particles, content 15% or less)
Parts, 3% slurry, surfactant and defoamer 1 each
Adds 00 PPM to improve wettability. To this, 10 to 15 parts of ultra-beaten wood pulp as a fibrous binder is added, sufficiently disintegrated and stirred to form a uniform slurry. A papermaking chemical was added to adjust the pH to 4.0, which was then formed into paper using a conventional paper machine, and press-dried to obtain a diaphragm. Furthermore, a diaphragm for a heat-resistant speaker having flame retardancy, high elastic modulus and high rigidity can be obtained by impregnation with a solution of a silicate compound and an organic metal compound. a. The following are used as the fiber material. Ceramic short fiber (blowing method) shot 15% or less: 70 parts Ceramic fiber 6 μ × 3 mm cut product: 30 parts Super beaten wood pulp: 10 parts b. The following are used as papermaking chemicals. Wet strength improver Ethylene urea resin: 1.50% Size rosin: 0.50% PH adjustment Dilute sulfuric acid: PH 4.0 c. Impregnation treatment The fiber paper obtained by the above operation is treated with lithium silicate, polycarbosilane, polysilazane or the like in the same manner as in Example 1 to measure flame retardancy, heat resistance and high elastic modulus.

Example 3 25 parts of a 3 mm glass fiber cut product and 15 parts of potassium titanate whisker fiber were added to the above 60 parts of the ceramic short fiber, and a polymer flocculant (polystyrene) was used to capture the whisker fiber (Otsuka Pharmaceutical Tismo). Sodium acrylate) 100
PPM and 10 parts of sepiolite are added, and 10 to 15 parts of ultra-beaten wood pulp as a fibrous binder is added thereto, sufficiently disintegrated and stirred, and a predetermined amount of a papermaking agent is added.
It is made 4.0, it is made into a paper by a usual paper machine, and press-dried to obtain a diaphragm. Further, a diaphragm of a heat-resistant speaker having flame retardancy, high elastic modulus and high rigidity can be obtained by impregnating a solution of a silicate compound and an organic metal compound. a. The following are used as the fiber material. Ceramic short fiber: 60 parts Glass fiber 6 μ × 3 mm cut product: 25 parts Potassium titanate whisker fiber: 15 parts Sepiolite: 10 parts Super beaten wood pulp: 10 parts b. The following are used as papermaking chemicals. Wet strength improver Ethylene urea resin: 1.50% Size rosin: 0.50% Polymer flocculant Sodium polyacrylate: 100 PPM PH adjustment Dilute sulfuric acid: PH 4.0 c. Impregnation treatment The fiber paper obtained by the above operation is treated with a lithium silicate salt to measure flame retardancy, heat resistance and high elastic modulus.

Example 4 Acrylic nitrile (PAN) -based carbon fiber (Toho Rayon, Vesfite) was cut into 7 μ × 3 mm, and 30 to 50 parts of milled carbon fiber (Nippon Sheet Glass Donacarbo) was added thereto. And a surfactant and an antifoaming agent of 100
PPM is added to improve wettability, and 10 to 15 parts of ultra-beaten wood pulp is added as a fibrous binder, and sufficiently defibrated and stirred. This is made into paper by a usual paper machine, and press-dried to obtain a diaphragm. Furthermore, a diaphragm for a heat-resistant speaker having flame retardancy, high elastic modulus and high rigidity can be obtained by impregnation with a solution of a silicate compound and an organic metal compound. a. The following are used as the fiber material. Carbon fiber 3 mm cut product: 50 parts Milled carbon fiber: 50 parts Super beaten wood pulp: 10 parts b. The following are used as papermaking chemicals. Infiltration strength improver Epoxy polyamide resin: 1.50% Size dimer acid ester: 0.50% PH: 6.5 c. Impregnation treatment The fiber paper obtained by the above operation is treated with lithium silicate, polycarbosilane, polysilazane or the like in the same manner as in Example 1 to measure flame retardancy, heat resistance and high elastic modulus.

Example 5-1 PAN-based carbon fiber 25 parts of the 7 μ × 3 mm cut product, milled carbon fiber, and 0.5 to 0.7 mm 25 parts were added with 50 parts of papermaking mica (Nippon Mica). A 3% slurry was prepared, and a surfactant and an antifoaming agent were added to the slurry as a wetting agent.
PPM was added, and a polymer flocculant, sodium polyacrylate, 100 PPM was added to sufficiently capture the mica powder. 10-15 parts of ultra-beaten wood pulp, which is a fibrous binder, is added thereto, sufficiently disintegrated with a disintegrator, and stirred to form a uniform slurry. A predetermined amount of a papermaking chemical is added thereto, the paper is made with a normal paper machine, and press-dried to obtain a diaphragm. If necessary, further impregnate with a solution of silicate compound, organometallic polymer compound, inorganic compound to improve various properties such as flame retardancy, water resistance, humidity resistance, etc., high strength, high elastic modulus, high internal A heat-resistant speaker diaphragm having loss can be obtained. a. The following are used as the fiber material. Carbon fiber 7μ × 3mm cut product: 25 parts Milled carbon fiber: 25 parts Mica for papermaking: 50 parts Super beaten wood pulp: 10 parts b. The following are used as papermaking chemicals. Wet strength improver Epoxy polyamide resin: 1.50% Size dimer acid ester: 0.50% PH: 6.5 c. Impregnation treatment The fiber paper obtained by the above operation is treated with lithium silicate, polycarbosilane, polysilazane or the like in the same manner as in Example 1 to measure flame retardancy, heat resistance and high elastic modulus.

Example 5-2 PAN-based carbon fiber 20 to 50 parts of papermaking mica (Nippon Mica) was added to the 7 μ × 3 mm cut product to prepare a 3% slurry. A surfactant and an antifoaming agent are added at 100 PPM each as a wetting agent, and 10 to 15 parts of ultra-beaten wood pulp is added as a fibrous binder, and the mixture is sufficiently disintegrated with a disintegrator and stirred. To this was added a papermaking chemical, and the paper was made with a normal paper machine.
Press drying to make a diaphragm. Further, a diaphragm for a heat-resistant speaker having high strength, high elastic modulus and high internal loss can be obtained by impregnation with a solution of a silicate compound, an organometallic polymer compound or the like. a. The following are used as the fiber material. Carbon fiber 7μ × 3mm cut product: 70 parts Mica for papermaking: 30 parts Super beaten wood pulp: 10 parts b. The following are used as papermaking chemicals. Wet strength improver Epoxy polyamide resin: 1.50% Size dimer acid ester: 0.50% PH: 6.5 c. Impregnation treatment The fiber paper obtained by the above operation is treated with lithium silicate, polycarbosilane, polysilazane or the like in the same manner as in Example 1 to measure flame retardancy, heat resistance and high elastic modulus.

Example 6 Cement fiber (Nippon Cement CMF) cut into 5-7 mm cut product and polymer flocculant (sodium acrylate) 100
PPM and 10 parts of sepiolite are added, and 10 to 15 parts of ultra-beaten wood pulp as a fibrous binder is added thereto, sufficiently disintegrated and stirred, and a predetermined amount of a papermaking agent is added. And press-dried to form a diaphragm. Furthermore, impregnated with a solution of a silicate compound and an organometallic compound,
A heat-resistant speaker diaphragm having flame retardancy, high elastic modulus and high rigidity can be obtained. a. The following are used as the fiber material. Cement fiber: 100 parts Sepiolite: 10 parts Super beaten wood pulp: 10 parts b. The following are used as papermaking chemicals. Wet strength improver Epoxy polyamide resin: 1.50% Size dimer acid ester: 0.50% Polymer flocculant Sodium polyacrylate: 100 PPM PH: 6.5 c. Impregnation treatment No impregnation in this study.

Example 7 100 PPM of a polymer flocculant (sodium polyacrylate) and 10% of sepiolite were added to calcium silicate fiber (Onoda cement), and 10 to 15 parts of ultra-beaten wood pulp as a fibrous binder was added thereto. Is added, the mixture is sufficiently disintegrated and stirred, a predetermined amount of a papermaking chemical is added, the paper is made with a usual paper machine, and press-dried to obtain a diaphragm. Further, a diaphragm of a heat-resistant speaker having flame retardancy, high elastic modulus and high rigidity can be obtained by impregnating a solution of a silicate compound and an organic metal compound. a. The following are used as the fiber material. Calcium silicate: 100 parts Sepiolite: 10 parts Super beaten wood pulp: 10 parts b. The following are used as papermaking chemicals. Wet strength improver Epoxy polyamide resin: 1.50% Size dimer acid ester: 0.50% Polymer flocculant Sodium polyacrylate: 100 PPM PH: 6.5 c. Impregnation treatment The fiber paper obtained by the above treatment is treated with lithium silicate, polycarbosilane, polysilazane and the like in the same manner as in Example 1 to measure flame retardancy, heat resistance and high elastic modulus.

Example 8-1 Vectran HT 5.0, a liquid crystalline wholly aromatic polyester fiber
To a De × 3 mm cut product (Kuraray), 50 to 100 parts of a 3 mm cut product of PAM-based carbon fiber (Toho Rayon) and 50 to 100 parts of milled carbon fiber (Nippon Sheet Glass) are added, and a surfactant is used as a wetting agent. And an antifoaming agent for each 100PP
Add M to make a 3% slurry. 10 to 15 parts of the ultra-beaten wood pulp are added thereto, sufficiently disintegrated and agitated by a disintegrator, a papermaking chemical is added, the paper is made by an ordinary paper machine, and press-dried. Next, by pressing at a temperature of 300 to 350 ° C. and a pressure of 4.0 kg / cm ² with a pressing machine, melting the liquid crystalline wholly aromatic polyester fiber and bonding between the carbon fibers, high strength, high elasticity, and high internal loss And a flame-retardant heat-resistant speaker diaphragm. If necessary
The above properties can be further improved by impregnation with a solution of a silicate compound, an organometallic polymer compound or the like. a. The following are used as the fiber material. Vectran HT 5.0 De × 3 mm cut product: 40 parts Carbon fiber 7 μ × 3 mm cut product: 30 parts Milled carbon fiber: 30 parts Super beaten wood pulp: 10 parts b. The following are used as papermaking chemicals. Wet strength improver Epoxy polyamide resin: 1.50% Size dimer acid ester: 0.50% PH: 6.5 c. Impregnation treatment The above-mentioned fiber paper is hot-pressed with a press at a temperature of 350 ° C., a pressure of 4 kg / cm ² and a time of 5 minutes to melt the liquid crystalline thermoplastic wholly aromatic polyester fibers and bond the carbon fibers. By doing so, the strength between fibers is increased. Further, thereby, the large internal resistance and heat resistance of the liquid crystalline fiber can be imparted to the fiber paper.

Example 8-2 Milled carbon fibers (Nippon Sheet Glass Donacarb) were added to short carbon fibers (Toho Rayon, Vesfight), and a super-beaten liquid crystalline wholly aromatic polyester was used as a fibrous binder. Fibers (Krela, Vectran HT101) and ultra-beaten wood pulp are added, and a surfactant and an antifoaming agent are added at 100 PPM each as a wetting agent to form a 3% slurry, which is sufficiently disintegrated with a disintegrator and stirred. This slurry is formed on a normal paper machine and press-dried to form a diaphragm. Next, press temperature 3
Pressing is performed at a temperature of 00 to 350 ° C. and a pressure of 4 kg / cm ² or more. This heats the ultra-beaten wholly aromatic polyester fiber, bonds the carbon fibers together, increases the fiber-to-fiber strength, and has high strength, high elasticity, high internal loss, and flame resistance for heat-resistant speakers It can be a diaphragm. If necessary, further silicate, organic polymer compound,
The above properties can be further improved by impregnation with a solution of an inorganic compound or the like. a. The following are used as the fiber material. Carbon fiber 7 μ × 3 mm cut product: 50 parts Milled carbon fiber 0.5 to 0.7 mm: 50 parts Ultra-beaten liquid crystalline wholly aromatic polyester fiber: 30 parts Super-beaten wood pulp: 10 parts b. The following are used as papermaking chemicals. Wet strength improver Epoxy polyamide resin: 1.50% Size dimer acid ester: 0.50% PH: 6.5 c. Impregnation treatment The above-mentioned fiber paper is hot-pressed with a press at a temperature of 350 ° C., a pressure of 4 kg / cm ² and a time of 5 minutes to melt the liquid crystalline thermoplastic wholly aromatic polyester fibers and bond the carbon fibers. By doing so, the strength between fibers is increased. Further, thereby, the large internal resistance and heat resistance of the liquid crystalline fiber can be imparted to the fiber paper.

Example 8-3 Carbon fiber (Toho Rayon, Vesfight) and liquid crystalline wholly aromatic polyester fiber (Clera, Vectran HT)
Milled carbon fibers are added to the short fibers, and ultra-beaten liquid crystalline wholly aromatic polyester fibers (Krela, Vectran HT) and ultra-beaten wood pulp are added as fibrous binders, and a surfactant is used as a wetting agent. 100P each and defoamer
PM is added to make a 3% slurry. The slurry is sufficiently disintegrated with a disintegrator to form a uniform slurry, which is then formed into a diaphragm by making an ordinary paper machine. Next, the temperature of 300 ~
Pressing is performed at 350 ° C. and a pressure of 4 kg / cm ² or more.
This heats the ultra-beaten wholly aromatic polyester fiber, bonds the carbon fibers together, increases the fiber-to-fiber strength, and has high strength, high elasticity, high internal loss, and flame resistance for heat-resistant speakers It can be a diaphragm. If necessary, the above properties can be further improved by further impregnation with a solution of a silicate, an organic polymer compound, an inorganic compound, or the like. a. The following are used as the fiber material. Carbon fiber 7μ x 3mm cut product: 25 parts Liquid crystalline wholly aromatic polyester fiber 3mm cut product: 50 parts Milled carbon fiber 0.5-0.7mm: 25 parts Super beaten Liquid crystalline wholly aromatic polyester fiber: More than 30 parts Beated wood pulp: 10 parts b. The following are used as papermaking chemicals. Wet strength improver Epoxy polyamide resin: 1.50% Size dimer acid ester: 0.50% PH: 6.5 c. Impregnation treatment The above-mentioned fiber paper is hot-pressed with a press at a temperature of 350 ° C., a pressure of 4 kg / cm ² and a time of 5 minutes to melt the liquid crystalline thermoplastic wholly aromatic polyester fibers and bond the carbon fibers. By doing so, the strength between fibers is increased. Further, thereby, the large internal resistance and heat resistance of the liquid crystalline fiber can be imparted to the fiber paper.

Example 9 Para-aromatic polyamide fiber Kevlar (Dupont Toray) 1
49 To a 1.5 De × 3 mm cut product, 50 to 100 parts of a milled fiber of para-aromatic polyetheramide fiber Technora (Teijin) were added, and a surfactant and an antifoaming agent were added as a wetting agent at 100 PPM. % Slurry. 10 to 15 parts of the ultra-beaten wood pulp are added thereto, sufficiently disintegrated by sufficiently stirring with a disintegrator, a papermaking chemical is added, the paper is formed by a normal paper machine, and press-dried. Furthermore, it can be impregnated with a solution of a silicate compound, an organometallic polymer compound or the like to obtain a heat-resistant, flame-retardant, high-strength heat-resistant speaker diaphragm. a. The following are used as the fiber material. Para-based aromatic amide fiber short fiber Kevlar 149 1.5 De x 3 mm cut product: 50 parts Para-based aromatic ether amide fiber Milled fiber Technora pulp: 50 parts Super beaten wood pulp: 10 parts b. The following are used as papermaking chemicals. Wet strength improver Epoxy polyamide resin: 1.50% Size dimer acid ester: 0.50% PH: 6.5 c. Impregnation treatment The above fiber paper is impregnated with a solution of 10% of bismaleimiso fiber (Mitsubishi Gas Chemical, BT resin), 10% of aromatic polyamide fiber (Unitika, Apière varnish) and 10% of lithium silicate, and dried at 60 ° C or less. Gives flame resistance and heat resistance.

Example 10 Para-aromatic polyamide fiber Kevlar 149 1.5D
× 3mm cut product with Kevlar milled fiber 50 ~ 1
Add 100 parts and add a surfactant and a defoamer as a wetting agent at 100 PPM each to make a 3% slurry. 10 to 15 parts of the ultra-beaten wood pulp are added thereto, sufficiently disintegrated by sufficiently stirring with a disintegrator, a papermaking chemical is added, the paper is formed by a normal paper machine, and press-dried. Furthermore, it can be impregnated with a solution of a silicate compound, an organometallic polymer compound or the like to obtain a heat-resistant, flame-retardant, high-strength heat-resistant speaker diaphragm. a. The following are used as the fiber material. Para-aromatic amide fiber Short fiber Kevlar 149 1.5 De x 3 mm cut product: 50 parts Para-aromatic polyamide fiber Milled fiber Kevlar pulp: 50 parts Super beaten wood pulp: 10 parts b. The following are used as papermaking chemicals. Wet strength improver Epoxy poamide resin: 1.50% Size dimer acid ester: 0.50% PH: 6.5 c. Impregnation treatment The above fiber paper is impregnated with a solution of 10% of bismaleimiso fiber (Mitsubishi Gas Chemical, BT resin), 10% of aromatic polyamide fiber (Unitika, Apière varnish) and 10% of lithium silicate, and dried at 60 ° C or less. Gives flame resistance and heat resistance.

[0051]

As described above, according to the present invention, ultra-beaten wood pulp having a large specific surface area as a fibrous binder is added to short fibers of highly elastic inorganic fibers and highly elastic organic fibers or inorganic powder. Paper and silicate compounds, organometallic compounds, inorganic compounds, aromatic polyamide,
Since the imide compound is impregnated, it is possible to obtain a heat-resistant speaker diaphragm having excellent flame retardancy, water resistance, humidity resistance, high strength, high elastic modulus and high internal resistance.

Claims (1)

(57) [Claims] An ultra-beaten wood pulp having a large specific surface area as a fibrous binder is added to short fibers or inorganic powders of highly elastic inorganic fibers and highly elastic organic fibers to form a paper. Excellent heat resistance, flame retardancy or water resistance, high moisture resistance and high strength, high elastic modulus impregnated with excellent silicate compounds, organometallic polymer compounds, inorganic compounds, aromatic polyamides, imide compounds, etc. And a heat-resistant speaker diaphragm characterized by having high internal loss.