JPH0959427A - Conductive fiber, its production and conductive resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conductive fiber showing stable conductivity and reduced in elution of e.g. alkali ions. SOLUTION: This conductive fiber is prepared by forming 5-79wt.%, based on the entire composition, of a coating layer comprising 0.1-20wt.% of one or more metals selected from the group consisting of antimony, indium and niobium and the balance substantially consisting of tin oxide on the surface of a fiber such as a fibrous potassium aluminate titanate.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a conductive fiber, particularly a conductive fibrous aluminate titanate, which is excellent as a reinforcing material for resins, rubbers, fibers, papermaking, etc. and which is also useful as a filler. The present invention relates to potassium, a method for producing the same, and a conductive resin composition containing the fiber.

[0002]

2. Description of the Related Art With the recent remarkable development in the fields of electronics and electricity, the development of conductive materials as related materials has been desired. Examples of such a conductive material include, for example, a fibrous white conductive substance containing fibrous potassium titanate whose surface is covered with stannic oxide as disclosed in JP-B-61-26933. In addition, a conductive alkali metal titanate salt disclosed in Japanese Patent Publication No. 62-4328 is known. In the latter publication, (a) tin, indium, antimony, an aqueous dispersion of an alkali metal titanate,
A solution of one or more kinds of metal compounds selected from the group consisting of copper and nickel, and (b) both an aqueous solution of an alkali hydroxide or an alkali halide are added at the same time and produced by a reaction between both solutions. A technique for producing a conductive alkali metal titanate by depositing a water-insoluble metal oxide on the surface of the alkali metal titanate is disclosed.

[0003]

However, when the conductive coating layer is formed on the surface of the fibrous alkali metal titanate to impart conductivity, there are the following problems.
That is, the alkali metal titanate used as the core material is generally potassium hexatitanate, potassium octatitanate, or the like.
The reaction between the alkali ions present on the surface and the conductive coating layer tended to cause a decrease in conductive performance. In addition, it is feared that the alkaline ions are eluted from the alkali metal titanate salt which is the core material, which may have an adverse effect when compounded in a resin or the like.

The object of the present invention is to show stable conductivity,
Further, it is to provide a conductive fiber in which elution of alkali ions and the like is small, a method for producing the same, and a conductive resin composition containing the fiber.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies in order to achieve the above object, and as a result, have used a fibrous material such as fibrous potassium aluminate titanate as a core material, By forming a conductive coating layer on the surface, it has been possible to obtain a conductive fiber exhibiting stable conductivity and less elution of alkali ions and the like.

That is, according to the present invention, a coating containing 0.1 to 20% by weight of one or more metals selected from the group consisting of antimony, indium, and niobium, with the balance substantially consisting of tin oxide. Layer to 5 to 70 of total composition
The conductive fiber is characterized in that it is provided on the surface of the fiber so that the content of the conductive fiber is in a weight percentage.

In the present invention, the fiber serving as the core material is preferably fibrous potassium aluminate titanate, and has a general formula of K _X Al _X Ti _8-X O ₁₆ (0.8≤X≤2.5). It has a composition represented.

The potassium titanate potassium titanate as the core material is not particularly limited, but is 0.1 to 10 μm.
A needle-shaped single crystal having a fiber diameter of, a fiber length of 5 to 300 μm, and an aspect ratio of 10 to 100 is preferable.

In the present invention, the coating layer has a total composition of 5 to 7
It is formed on the fiber surface so as to be 0% by weight, preferably 6 to 30% by weight. When the amount of the coating layer is too small, it becomes difficult to uniformly coat the entire surface of the fiber, and the conductivity cannot be expressed or the conductivity becomes low. On the other hand, if the amount of the coating layer is too large, the particles are not uniformly coated and are adhered in a granular state or are not adhered to form a precipitate, which is inefficient and is economically disadvantageous.

In the present invention, the amount of the coating layer is determined, for example, by placing conductive fibers in a mold and press-working to obtain a green compact, and then measuring the metal content by fluorescent X-ray analysis to determine the metal oxide content. It can be obtained by converting to.

In the present invention, the coating layer contains 0.1 to 20 of one or more dopant metals selected from the group consisting of antimony, indium and niobium.
%, Preferably 0.3 to 5% by weight. If the content of these metals in the coating layer is too small, the doping effect on tin oxide becomes poor, and high conductivity cannot be obtained. Further, the upper limit of the content is not particularly limited from the viewpoint of conductivity, but when the content is large, a gray or blue chromatic color is obtained, and the whiteness tends to decrease. In addition, generally, when the content of these metals increases, it becomes expensive,
Not economically preferable.

In the present invention, the content of the dopant metal such as antimony in the coating layer is determined, for example, by placing conductive fibers in a mold and press-working to obtain a green compact, and then fluorescent X.
It can be determined by quantifying the metal content by line analysis and converting it into the amount of metal oxide.

The production method of the present invention is one of the methods by which the conductive fiber of the present invention can be produced, and a group consisting of an aqueous dispersion of the fiber, a tin compound, and antimony, indium, and niobium. The surface of the fiber is obtained by adding one or more kinds of metal compounds selected from the above in a solution state, adhering the insoluble matter of the tin compound and the metal compound on the surface of the fiber, separating them, and then heat treating after separation. It is characterized in that a coating layer containing the above metal and the rest consisting essentially of tin oxide is formed thereon.

As the fiber, fibrous potassium aluminate titanate is preferable, and it has a general formula of K _X Al _X Ti _8-X O
Those having a composition represented by ₁₆ (0.8 ≦ X ≦ 2.5) are preferable.

As an aqueous dispersion of fibers such as fibrous potassium aluminate titanate, an aqueous dispersion having a fiber concentration of 0.1 to 50% by weight, preferably 1.0 to 30% by weight is preferable. If the fiber concentration is too low, the amount of liquid increases and the productivity decreases. If the fiber concentration is too high,
The viscosity of the aqueous dispersion becomes high, making it difficult to handle and making it difficult to form a uniform coating layer.

As the tin compound and the compound of each metal used in the production method of the present invention, those soluble in water or a water-soluble organic solvent are preferable, for example, halogenated salts,
Acidic or alkaline water-soluble substances such as oxides,
And those soluble in water-soluble organic solvents such as metal alcoholates and metal acetylacetonates. Specifically, SnCl ₂ , SnCl ₄ , SbCl ₃ , SbC
Examples thereof include water-soluble compounds such as l ₅ , InCl ₃ and NbCl ₃ , and compounds soluble in water-soluble organic solvents such as tin, attimone, indium and niobium methylates, ethylates, propionates, butyrates and acetylacetonates. However, these tin compounds and each metal compound are preferably used as an aqueous solution from the viewpoints of the Industrial Safety Law, environmental protection and the like.

In the production method of the present invention, the tin compound and each metal compound may be used as a solution in which they are separately dissolved, or may be used as a mixed solution in which both are dissolved. The concentration of the tin compound and the solution of each metal compound is not particularly limited, but can be adjusted as a solution having a concentration of, for example, about 10 to 60% by weight. If the concentration is too low, the liquid volume increases and the productivity decreases. On the contrary, if the concentration is too high, the deposition of the hydrolyzate of the tin compound and the metal compound to be formed on the fibrous material becomes non-uniform, and the conductivity of the target conductive fiber may vary.

In the production method of the present invention, the insoluble matter is precipitated by adding the solution of the tin compound and each metal compound to the aqueous dispersion of the fiber and hydrolyzing the tin compound and the metal compound. Then, the insoluble matter is attached to the surface of the fiber. Therefore, it is necessary to add these solutions to the fiber aqueous dispersion under the condition that the tin compound and the metal compound are hydrolyzed, or to add the solutions to the aqueous dispersion and then hydrolyze them.

As the first method of hydrolysis, organic compounds such as alcoholate and acetylacetonate are used as the tin compound and each metal compound, and these are dissolved in a water-soluble organic solvent to obtain the above fibrous material. There is a method in which the tin compound and each metal compound are hydrolyzed and deposited on the fiber surface by being added to the aqueous dispersion. These hydrolysis reactions may be carried out under heating or in the presence of an alkaline substance. As the alkaline substance, an alkali metal hydroxide, carbonate, ammonium compound or the like can be used.

As the second method of hydrolysis, there is a method of using a halide as a tin compound and each metal compound and adding an alcohol solution of these halides to an aqueous dispersion of the fibrous material. In this method, the hydrolysis reaction may be carried out under heating or in the presence of an alkaline substance. As the alkaline substance, the same substances as those used in the first method can be used.

A third method of hydrolysis is a method of adding an aqueous solution of a tin compound and each metal compound to an aqueous dispersion of the above fibrous material. Since this method does not use an organic solvent, it is a preferable method from the viewpoints of work environment property, environmental pollution property, disaster prevention, economical efficiency and the like. Also in this method, the hydrolysis can be carried out under heating or in the presence of an alkaline substance.

In the production method of the present invention, the solution of the tin compound and the solution of the respective metal compounds may be added to the aqueous dispersion of the fibrous material at the same time by mixing all the species and the total amount thereof. You may add the solution of a tin compound and the solution of each metal compound separately, or what mixed partially. The composition of the insoluble matter forming the coating layer can be adjusted by such an addition method and addition order. In addition, in the production method of the present invention, the addition method, order, etc. of the tin compound solution and the solution of each metal compound are not particularly limited.

As described above, the water-insoluble hydrolyzate formed from the tin compound and each metal compound is obtained by adding the solution of the tin compound and each metal compound to the aqueous dispersion of the fibrous material and hydrolyzing the solution. Are deposited on the surface of fibrous substances such as fibrous potassium aluminate titanate. Next, the solid matter in this slurry liquid is separated using a means such as filtration, decantation or centrifugation, and this is washed with water and dried.

According to the production method of the present invention, in order to improve the conductivity and stability of the fibrous material to be finally obtained, 200 to 1000 ° C., preferably 400 to 800 ° C.
Heat treatment. If the heat treatment temperature is too low, it is not possible to form a coating layer having stable conductivity, and if the heat treatment temperature is too high, the fibrous material as the core material may collapse. At the time of this heat treatment, it is possible to improve the conductivity by performing a reduction treatment, if necessary. In this reduction treatment, the reduction treatment can be performed by heat treatment in an atmosphere in which one or more reducing gases such as hydrogen gas, ammonia gas and carbon monoxide are used in combination.

The method for producing the fibrous potassium aluminate titanate used as the core material in the present invention is not particularly limited, but, for example, an aluminum supply component, a potassium supply component and a titanium supply component may be used as a melting agent. A method of producing potassium aluminate titanate fibers by reacting in the presence can be mentioned. Examples of such a method include the following specific manufacturing methods.

(First Production Method) Potassium titanate fibers serving as a potassium supplying component and a titanium supplying component are coated with an aluminum compound such as an aluminum hydroxide serving as an aluminum supplying component, and the coated fiber is provided in the presence of a melting agent. It is a method of reacting by heating. According to such a method,
Since the reaction proceeds with each component being in the closest vicinity,
It is speculated that whisker-shaped potassium aluminate titanate can be produced.

In the present method, the potassium supply component and chi
As the composition of potassium titanate fiber which is a tongue supply component
Is not particularly limited, for example, the general formula aK₂O ・ TiO₂・
mH ₂Titer indicated by O (0 <a ≦ 1, 0 ≦ m ≦ 10)
An example is potassium acid whiskers. Chita
The shape of potassium acid whiskers is 0.0
1 to 5 μm, fiber length 3 to 300 μm, preferably fiber diameter
0.1-3 μm, fiber length 5-200 μm, aspect ratio
Ten or more can be used. Fiber diameter or fiber
If the fiber length is too small, cohesiveness will increase and
Potassium aluminate titanate becomes a difficult-to-isolate aggregate
There is a tendency and it is not preferable. Also, the fiber diameter or fiber length is large.
If you use too much potassium titanate fiber as a raw material
In addition, the surface activity is reduced and the aluminum compound is uniformly coated.
Of the unreacted oxide in the target product.
May cause minium and potassium titanate to mix
Therefore, it is not preferable.

The potassium titanate fiber whose surface is coated with an aluminum compound is, for example, at least one selected from the group consisting of (1) aluminum sulfates, halides, nitrates, hydroxides and alcoholates. A method of reacting with potassium titanate or (2) at least one selected from the group consisting of aluminum sulfate, halide, nitrate, hydroxide and alcoholate, and alkali metal hydroxide and alkali metal Carbonate,
It can be obtained by a method of reacting with at least one selected from the group consisting of alkali metal aluminate, ammonium carbonate and ammonium hydroxide to deposit on the surface of potassium titanate fiber.

Here, as the aluminum sulfate,
For example, aluminum sulfate and the like can be mentioned. Aluminum chloride is an example of aluminum halide, aluminum nitrate is an example of nitrate, aluminum hydroxide is an example of hydroxide, and aluminum alcoholate is an example of alcoholate. It is not something that will be done. Examples of alkali metal hydroxides include sodium hydroxide and potassium hydroxide. Examples of the alkali metal carbonate include sodium carbonate, sodium hydrogen carbonate, potassium carbonate and the like. Examples of the alkali metal aluminate include sodium aluminate and potassium aluminate. As ammonium carbonate,
Examples thereof include ammonium carbonate and ammonium bicarbonate. Examples of the ammonium hydroxide include ammonium hydroxide. In addition to those exemplified above, water-soluble ones can be widely used.

When coating the aluminum compound, a method in which potassium titanate is dispersed in water and then the reaction is carried out is preferable. At that time, as the amount of the aluminum compound,
As the molar ratio to titanium in potassium titanate,
The ratio is preferably 1: 3 to 1:18. The coating reaction is usually 5 to 80 ° C., preferably 10 to 5
It can proceed at 0 ° C. for about 1 to 5 hours. In this way, the potassium titanate fiber coated with the aluminum compound can be washed with water or the like, if necessary, and then dried for the next step.

As the melting agent used in the present method, alkali metal chlorides such as potassium chloride, sodium chloride and alkali metal sulfates such as potassium sulfate and sodium sulfate may be used, and these may be used alone or in combination with 2. A mixture of two or more species can be used. If necessary, the melting agent may be used by making the particle size fine with a pulverizer such as a jet mill. The melting agent may be dissolved in an aqueous solution when the surface of potassium titanate is coated with the aluminum compound.

The amount of the melting agent added is 50 to 9 of the total amount of potassium titanate coated with an aluminum compound.
It is preferable to add it so as to be 0 wt%. In the presence of a melting agent, potassium titanate coated with an aluminum compound is usually used in the temperature range of 900 to 1300 ° C.
The potassium aluminate titanate whiskers can be obtained by reacting for about 10 minutes to 10 minutes. At this time, if the heating temperature is lower than 900 ° C., the raw material remains unreacted and it is difficult to obtain a single phase of potassium aluminate titanate whiskers, which is not preferable. On the other hand, if the reaction temperature exceeds 1300 ° C., welding between whiskers, a decrease in aspect ratio, or coarsening and polycrystallization of crystals are likely to occur, which is not preferable.

When the potassium aluminate titanate whiskers having pores in the crystal are produced, after reacting and growing at a predetermined temperature, furnace cooling to about 800 ° C. at a cooling rate of 10 ° C./min or more or It may be quenched with water or the like. In this case, the volume ratio of the pores in the crystal can be controlled by the firing temperature and the cooling temperature. Furthermore, when a potassium aluminate titanate whisker containing no pores in the crystal is generated, after reacting and growing at a predetermined temperature, 1
The cooling rate may be 0 ° C./min or less and the temperature may be gradually cooled to around 800 ° C.

When a potassium aluminate titanate whisker having 1 to 70% by volume of pores in a crystal is used as a core material, the whisker has a smaller bulk specific gravity than a whisker having no pores, and therefore has a small bulk specific gravity. It can be a fiber. Therefore, when producing a conductive resin composition from the conductive fiber and the binder of the present invention, by using a potassium aluminate titanate whiskers having pores as the core material, a resin composition having a lower weight blending You can

(Second Production Method) In the present method, as the titanium supply component, the general formula TiO ₂ .nH ₂ O (n is 0 to 8) is used.
Particle number or fiber-shaped titanium oxide represented by the formula (1), and at least one selected from aluminum hydroxide, hydrous aluminum oxide, aluminum inorganic acid salt, and alkali metal aluminate as an aluminum supply component. At least one selected from chloride, sulfate and bromide of potassium is used as a potassium supply component, and these are added in the presence of a melting agent at 900-
It is a method of producing by reacting and growing by heating to a temperature of 1300 ° C. and further cooling. Examples of the melting agent include alkali metal chlorides, sulfates,
Bromide or the like can be used.

In the present method, specific examples of the particle shape or fiber shape represented by the general formula TiO ₂ .nH ₂ O (n is a real number of 0 to 8) used as the titanium supplying component are as follows.
Examples thereof include hydrated titania particles, monoclinic titanium oxide particles, anatase titanium oxide particles, rutile titanium oxide particles, and fibrous materials thereof. Even when a fibrous material is used as a raw material, the method for producing the fibrous material is not particularly limited, and examples thereof include a titanium oxide or titanium hydroxide fibrous substance produced by direct wet reaction and a heat-treated product of the fibrous substance.

Specific examples of the aluminum supplying component in the present method include aluminum hydroxide, as described above.
At least one selected from hydrous aluminum oxide, aluminum inorganic acid salt, and alkali metal aluminate is used. Examples of the aluminum hydroxide include aluminum hydroxide and the like. Examples of hydrous aluminum oxide include boehmite (AlO (O
H)), diaspore, and toudite can be exemplified. Examples of the inorganic acid salts of aluminum include sulfates, nitrates, chlorides and water-insoluble aluminum basic salts. As the aluminum sulfate, aluminum sulfate, aluminum sulfate 14-18 hydrate, potassium aluminum sulfate, potassium aluminum sulfate 12
Examples thereof include hydrates, sodium aluminum sulfate, sodium aluminum sulfate dodecahydrate, aluminum ammonium sulfate, and ammonium aluminum sulfate dodecahydrate. Examples of aluminum nitrates include aluminum nitrate and aluminum nitrate nonahydrate. Examples of aluminum chlorides include aluminum chloride and aluminum chloride hexahydrate. As the water-insoluble aluminum basic salt, a general formula Al. (X) a. (OH) b.mH ₂ O (wherein X is SO ₄ or Cl, and a, b and m are 0.02 respectively).
5 ≦ a ≦ 0.250, 0.257 ≦ b ≦ 3.00, 0 ≦
Represents a number of m ≦ 2.0. ) Can be exemplified. Examples of the alkali metal aluminate include potassium aluminate and sodium aluminate.

These aluminum supplying components can be used alone or in admixture of two or more. These aluminum supply components are decomposed by heating in the air to generate active aluminum oxide, and the reaction proceeds at a lower temperature or at a shorter time than when aluminum oxide is directly used as the aluminum supply component. Can be made. Further, it does not require a melting agent component having a very high solubility such as potassium carbonate.

As a specific example of the potassium supply component, as described above, at least one selected from chloride, sulfate and bromide of potassium can be used. Examples of potassium chloride include potassium chloride, examples of sulfate include potassium sulfate, potassium sulfite, potassium pyrosulfate, and potassium pyrosulfite, and examples of potassium bromide include potassium bromide.
These potassium-providing components simultaneously act as a fusing agent.

As the melting agent, the above-mentioned potassium chloride,
Alkali metal chlorides, alkali metal sulfates, alkali metal bromides and the like can be used with at least one selected from sulfates and bromides as an essential component.
Examples of the alkali metal chloride include sodium chloride and lithium chloride in addition to potassium chloride. As the alkali metal sulfate, in addition to potassium sulfate, sodium sulfate, sodium sulfate decahydrate, sodium sulfite, sodium sulfite heptahydrate,
Examples thereof include sodium pyrosulfate, sodium pyrosulfite, and lithium sulfate monohydrate. Examples of alkali metal bromides include sodium bromide and lithium bromide, in addition to potassium bromide.

The titanium supply component and the aluminum supply component are mixed at a molar ratio of titanium oxide and aluminum oxide of 18: 1 to 22: 5, and the total amount of the potassium supply component and the melting agent is the total weight%. It is preferable to add it in the range of 30 to 95% by weight, preferably 50 to 80% by weight. In addition, the total weight including at least one selected from potassium chloride, potassium sulfate, and potassium bromide, and at least one selected from other alkali metal chlorides and alkali metal sulfates. It is preferable to mix it in an amount of 70% by weight or more.

Titanium supply component, aluminum supply component,
And the mixing of the melting agent (potassium supply component) is not particularly limited in the method, and after mixing,
If each supply component and the melting agent are finely dispersed, it can be used as a good raw material powder. From the viewpoint of fine dispersion, it is preferable to carry out the mixing by a method having a step of both mixing and crushing. In addition, raw materials in which the respective components are homogeneously dispersed by evaporating and drying the water by a method such as spray-drying, tray-drying, or drum-dryer-drying the solution in which each supply component and the melting agent are dissolved and dispersed. It may be powder.

The general formula Al. (X) a. (OH) b
MH ₂ O (where X is SO ₄ or Cl, and a, b and m are 0.025 ≦ a ≦ 0.250 and 0.257, respectively)
It represents a number of ≦ b ≦ 3.00 and 0 ≦ m ≦ 2.0. When a water-insoluble aluminum basic salt represented by the formula (4) is used as an aluminum supplying component, in addition to simply mixing the titanium supplying component and the melting agent by dry mixing, the water-insolubility is utilized to obtain the titanium supplying component surface. It is possible to use a product obtained by adhering an aluminum basic salt, which is an aluminum supply component, to the. This is an aqueous dispersion of titanium feed component,
For example, aluminum sulfate, halide, nitrate,
At least one selected from the group consisting of hydroxides and alcoholates, and a group consisting of alkali metal hydroxides, alkali metal carbonates, alkali metal aluminates, ammonium carbonates, and ammonium hydroxides. It can be obtained by a method of reacting with at least one selected and depositing an aluminum basic salt on the titanium supplying component. The mixture obtained by this method is washed with water, which is a by-product salt produced as a by-product during the production, or dried without water washing, or dried with a melting agent added. The mixture obtained by drying without mixing the melting agent is used as a raw material powder by dry mixing with a predetermined amount of the melting agent. The composition and shape of the titanium supplying component used here are not particularly limited, but fine particle-shaped products or fiber-shaped products having a large surface area are preferable from the viewpoint of fine mixing.

When heating and firing the above mixture, the state and shape thereof are not particularly limited. For example, a method of heating and firing as it is in a powder state, a method of heating and firing in the form of granules, and a method of heating and firing in a sheet form. Alternatively, a method of heating and baking in block form may be used. Examples of the method of granulating and then heating and firing include a method of granulating while adding water or an organic binder that is easily gasified by heating as needed in a mixer or a blender having a stirring function. . Examples of the method for firing in sheet form include a method in which a mixed powder is formed into a sheet under pressure, or a sheet is formed using an extruder or the like after adding an organic binder that is easily gasified by moisture or heating. it can. As a method of molding into a block shape and heat-molding, the raw material powder as it is or after adding water or an organic binder that is easily gasified by heating to facilitate the molding, put the raw material powder in a predetermined mold. Another example is a method of molding by pressurization to obtain a block-shaped raw material.

The raw material in a desired state can be placed in a heat-resistant container such as a ceramic material, and heated and fired by a method such as heating and firing using a tunnel kiln or an electric furnace together with the heat-resistant container. When using a raw material in the form of powder or granulated, it can be fired by a rotary kiln or a fluidized firing method. When a sheet-shaped raw material is used, it is possible to employ a method in which the raw material is placed in a heat-resistant container such as a ceramic material or a heat-resistant plate, and continuously heated and fired.

The heating and firing conditions are 900 to 1300.
C., preferably 1000 to 1200.degree. C. for about 10 minutes to 10 hours, preferably about 30 minutes to 5 hours,
Cool at room temperature. At this time, if the firing temperature is too low, the raw material powder remains unreacted, so that the desired single-phase whiskers cannot be obtained, which is not preferable. If the firing temperature is too high, adhesion between whiskers, decrease in aspect ratio,
It is not preferable because coarsening and polycrystallization of crystals occur.

The potassium aluminate titanate whiskers obtained by the above-mentioned first method and second method or other methods are water-soluble components, if necessary, with hot water, warm water, dilute aqueous acid solution or dilute alkaline solution. After dissolving
Impurities are removed by filtering, washing with water, drying and preferably classifying to obtain fine potassium aluminate titanate whiskers with a regular fiber shape.

The conductive resin composition of the present invention is characterized by comprising the conductive fiber of the present invention and a binder.
Examples of the binder include synthetic polymer compounds such as thermoplastic resins and thermosetting resins, natural resins and their derivatives, metal-containing organic compounds, inorganic binders, inorganic compounds or emulsions of organic compounds. Specific examples of the thermoplastic resin include nylon 6, nylon 12, nylon 66.
Polyamide resin, aramid resin, ABS resin, etc.
Examples thereof include POM resin, PBT resin, PPS resin and the like. Specific examples of the thermosetting resin include phenol resin and epoxy resin. Other synthetic polymer compounds include polyphosphazene and the like.

As the binder in the conductive resin composition of the present invention, one or more polymer alloys of the above binders can be freely selected and used according to the purpose and application.

In the conductive resin composition of the present invention, if necessary, a filler such as talc, mica, wollastonite or calcium carbonate, a reinforcing agent such as glass fiber or carbon fiber, a pigment or an antioxidant. , Antistatic agent, lubricant, heat stabilizer,
You may add flame retardants etc. suitably.

If necessary, the surface of the conductive fiber may be surface-treated with a coupling agent or the like, and the surface-treated conductive fiber may be mixed with a binder. In the production of the conductive resin composition of the present invention, a normal mixing operation, for example, a mixing method such as a Banbury mixer method, an internal mixer method, and an extrusion granulation method can be appropriately employed.

The content of the conductive fibers in the conductive resin composition of the present invention is appropriately set depending on the purpose and application of imparting conductivity, but generally 5 to 60% by weight is preferable. , And more preferably 15 to 50% by weight
It is. If the blending amount is too small, sufficient conductivity cannot be imparted to the conductive resin composition, and if the blending amount is too large, moldability and the like are deteriorated, which is not preferable.

The conductive fiber of the present invention can be used for resin moldings, paints, coatings, printing, etc. which require conductivity, and for other uses and methods of use requiring conductivity. It can be used widely.

[0054]

The present invention will be described below in more detail with reference to examples. The percentages used below indicate weight percentages.

Synthesis Example 6 Potassium titanate fiber (Otsuka Chemical Co., trade name: TI
200 g of SMO-N) was dispersed in 2.5 liters of water, 228.4 g of ammonium bicarbonate was added, and 188.5 g of aluminum chloride hexahydrate was dissolved in water to 400 m.
The solution designated as 1 was slowly added to react with stirring. During this period, the reaction temperature is kept at 30 to 40 ° C.
The time reaction was continued. After completion of the reaction, the pH of the reaction solution is 7.
It was 4. The reaction was then filtered, washed with water to remove impurities and dried at 80 ° C. 263.0 g of dried reaction product was obtained. As a result of analysis of this dried product, potassium hexatitanate fiber was coated with an aluminum hydroxide compound having an aluminum oxide conversion of 15.1% and an ignition loss of 8.09%.

Further, potassium sulfate (K ₂ SO ₄ ) was added as a flux raw material (melting agent) to the potassium hexatitanate fiber coated with the aluminum hydroxide compound in a weight ratio of 1: 4. After mixing well in a mortar, the mixture was heat-molded and baked at 1100 ° C. for 3 hours. After firing, it was cooled to a temperature of 800 ° C. at a rate of 1 ° C./minute, and then cooled to room temperature by furnace cooling to obtain a fired product. The fired product was boiled in water, washed with water, filtered and dried to obtain a pale yellow powder. From the results of X-ray diffraction and elemental analysis, this product was K _2.0 A _2.0 Ti _6.0 O ₁₆ and had a fiber diameter of 1.0 μm.
m, and a fibrous potassium aluminate titanate having a fiber length of 20 μm.

Example 1 15 g of fibrous potassium aluminate titanate obtained by the above synthesis example was dispersed in 200 g of water to form a slurry,
Heated to 60 ° C. Then, 18 g of 50% stannous chloride aqueous solution (containing 2% hydrochloric acid) and 17N of 3.7N hydrochloric acid were added.
A mixed solution of both metal compounds, in which 1.5 g of antimony trichloride was dissolved in 1 ml, was homogeneously mixed, and 75 ml of 3.7N aqueous sodium hydroxide solution was mixed with each other by using a metering pump. Into the existing slurry, quantitative simultaneous addition was performed over about 1 hour. After that, the reaction was further held at 60 ° C. for 30 minutes. Then, the solid content is filtered, washed with water,
After dehydration and drying, the product 2 was baked at 600 ° C for 1 hour.
1 g was obtained. Therefore, the coating layer is 6 g, and the total 2
This corresponds to 8.6% by weight. The coating layer was tin oxide containing 13% antimony. The obtained conductive fiber is 100K
When a disk-shaped green compact having a diameter of 30 mm and a thickness of 2 mm was produced at a pressure of gf / cm ² and the resistivity was measured,
It was 1.4 × 10 ¹ Ω · cm.

40 parts by weight of the obtained conductive fiber was added to 100 parts by weight of various binders as shown in Table 1 and kneaded, and then formed into a sheet to obtain a volume resistivity (Ω · cm) and a surface resistance. The rate (Ω) was measured. Table 1 shows the measurement results.

The trade name of the silicone resin is "silicone resin" (manufactured by Toray Dow Corning Silicone Co., Ltd.)
The urethane resin used is the trade name "V Top" (manufactured by Dainippon Paint Co., Ltd.), the fluororesin used is the trade name "NEOFLON" (manufactured by Daikin Industries, Ltd.), and the epoxy resin the trade name is "Araldite" (Manufactured by Ciba Geigy) was used.

Further, 40 parts by weight of the obtained conductive fiber was added to 100 parts by weight of various binders shown in Table 2 and kneaded, followed by molding to prepare a test piece, and to obtain the mechanical strength. Was measured. The measurement results are shown in Table 2.

Trade name "Duracon" (manufactured by Poly Plastics Co.) was used as the polyacetal resin, trade name "Ube Nylon" (manufactured by Ube Industries) as the 6-nylon resin, and trade name "Duracon" as the PBT resin. NEX "(manufactured by Poly Plastics Co., Ltd.) was used.

Further, 1 g of the obtained conductive fiber is added to 200 m
Dispersion in 1 l of water and elution of alkali ions were measured by flame photometry. The measurement results are shown in Table 3. In addition,
The measured values in this example were measured based on the following measuring methods.

(Volume resistivity) width 2 cm, length 10 c
A sheet-shaped sample of m is prepared, and silver foil is pressure-bonded to both ends and a cross section of the sample, and then the electric resistance between electrodes composed of two silver foils is measured and calculated based on the following formula.

Volume resistivity (Ω · cm) = P / Q P: sheet thickness (cm) × electrode width (cm) × electric resistance (Ω) Q: spacing between electrodes (cm)

(Surface Resistivity) A square sheet-like sample having a side of 10 cm was prepared and measured in accordance with JIS-K-6911 in the same manner as in the above method of measuring the volume resistivity. Calculate based on

Surface resistivity (Ω) = πRs (D + d) / (D−d) π: Circular ratio D: Inner diameter (cm) of annular electrode on the surface d: Outer diameter (cm) of inner circle of the surface electrode Rs : Surface electrical resistance to measured value (Ω)

(Mechanical Strength) A test piece was prepared in accordance with JIS, and tensile strength (JIS-K-7113) and bending strength (JIS-K-7213) were measured.

Example 2 15 g of fibrous potassium aluminate titanate obtained by the above-mentioned synthesis example was dispersed in 200 g of water to form a slurry, which was then heated to 70 ° C. with stirring. Then, 35 g of a 50% stannous chloride aqueous solution (containing 2% hydrochloric acid), 3.
A solution of both metal compounds was prepared by dissolving 3 g of indium trichloride in 17 ml of 7N hydrochloric acid and mixing them homogeneously. Separately, a 3.7N aqueous sodium hydroxide solution of 110 m was prepared.
1 and 2 were separately added to the slurry quantitatively at the same time using a metering pump over about 1 hour, and then 70 ° C.
Was maintained for 30 minutes to terminate the reaction. Then, the solid content was filtered, washed with water, dehydrated and dried, and then baked at 600 ° C. for 1 hour to obtain 20 g of a product. Therefore, the coating layer on the surface of fibrous potassium aluminate titanate is 5 g,
This corresponds to 5% by weight. The coating layer was formed of tin oxide containing 12% indium.

With respect to the obtained conductive fiber, a green compact was prepared in the same manner as in Example 1 above, and the resistivity was measured and found to be 3.5 × 10 ¹ Ω · cm. Further, the obtained conductive fiber was mixed with various binders in the same manner as in Example 1 above, and the volume specific resistivity, surface resistivity and mechanical strength were measured. The respective results are shown in Tables 1 and 2. The eluted alkali ions were measured in the same manner as in Example 1 above, and the results are shown in Table 3.

Example 3 A conductive fiber was prepared in the same manner as in Example 2 except that the same amount of indium trichloride used in Example 2 was changed to niobium trichloride. The conductive fiber obtained was 21 g, therefore the coating layer was 6 g,
This corresponds to 8.6% by weight. The coating layer was formed of tin oxide containing 13% niobium. With respect to the obtained conductive fibers, a green compact was prepared in the same manner as in Examples 1 and 2 above, and the resistivity was measured to be 7.4 × 10 ¹ Ω · cm.
Met.

The obtained conductive fibers were mixed with various binders in the same manner as in Examples 1 and 2, and the volume specific resistance, surface resistivity and mechanical strength were measured.
The respective results are shown in Tables 1 and 2. Table 3 shows the measurement results of the eluted ions.

Comparative Example 1 With respect to a commercially available conductive potassium titanate fiber (Otsuka Chemical Co., Ltd., trade name: Dentol WK-300), a green compact was prepared in the same manner as in the above-mentioned Example, and the resistivity was measured. When measured, it was 5.3 × 10 ¹ Ω · cm. In addition, in the same manner as in the above-mentioned examples, various binders were blended and the volume resistivity, surface resistivity, and mechanical strength were measured, and the measurement results are shown in Table 1 and Table 2, respectively. Further, the eluted ions were measured in the same manner as in the above example, and the measurement results are shown in Table 3.

Comparative Example 2 Commercially available needle-shaped conductive titanium oxide (manufactured by Ishihara Sangyo Co., Ltd.,
With respect to the product name: FT-2000), a green compact was prepared in the same manner as in the above example, and the resistivity was measured.
It was 5 × 10 ⁰ Ω · cm. In addition, various binders were mixed in the same manner as in the above-mentioned examples, and the volume resistivity, surface resistivity, and mechanical strength were measured, and the measurement results are shown in Table 1 and Table 2, respectively. Further, the eluted ions were measured in the same manner as in the above example, and the measurement results are shown in Table 3.

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[Table 1]

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[Table 2]

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[Table 3]

As is clear from Tables 1 to 3, the conductive fiber according to the present invention shows stable conductivity and is also excellent in the reinforcing effect on plastics and the like. Further, it is found that the alkali metal ions as impurities are less eluted. Therefore, it is possible to obtain the conductive resin composition which is required in the electronics field and the like.

Claims (6)

[Claims] 1. A coating layer containing 0.1 to 20% by weight of one or more metals selected from the group consisting of antimony, indium and niobium, and the balance substantially consisting of tin oxide. The conductive fiber is provided on the surface of the fiber in an amount of 5 to 70% by weight. 2. The fiber is of the general formula K _X Al _X Ti _8-X O ₁₆
The conductive fiber according to claim 1, which is a fibrous potassium aluminate titanate having a composition represented by (0.8 ≦ X ≦ 2.5). 3. A tin compound and a compound of one or more metals selected from the group consisting of antimony, indium and niobium are added to an aqueous dispersion of fibers in a solution state, and the surface of the fiber is added. Forming a coating layer containing the metal and the rest substantially consisting of tin oxide on the surface of the fiber by separating the tin compound and the insoluble matter of the metal compound after adhering them and then performing a heat treatment after separation. A method for producing a conductive fiber, comprising: 4. The fiber is of the general formula K _X Al _X Ti _8-X O ₁₆
The method for producing a conductive fiber according to claim 3, which is a fibrous potassium aluminate titanate having a composition represented by (0.8 ≦ X ≦ 2.5). 5. A conductive resin composition comprising the conductive fiber according to any one of claims 1 to 4 and a binder. 6. The binder is selected from the group consisting of synthetic polymer compounds such as thermoplastic resins and thermosetting resins, natural resins and their derivatives, metal-containing organic compounds, inorganic binders, inorganic compounds or emulsions of organic compounds. The conductive resin composition according to claim 5, which is one kind or two or more kinds selected.