JP3483363B2 - Conductive fiber and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductive fiber, such as potassium aluminate titanate fiber having conductivity, a method for producing the same, and a conductive resin composition using the same. INDUSTRIAL APPLICABILITY The conductive fiber of the present invention is useful as a material for a functional composite material, and various kinds of conductive paint, ink, composite material for electroplating, antistatic material, electrostatic recording material, electromagnetic wave shield material, etc. It can be applied to the conductive composite material of.

[0002]

2. Description of the Related Art With the development of chemical technology and diversification of needs, development of high-performance and multifunctional materials has been actively carried out, and conductive polymer materials have been developed even in the plastics industry. Various studies have been attempted on the development of. For example, as the particulate conductive filler, carbon particles or metal powder such as copper, silver and gold is used.
Carbon fiber or the like is used as the fibrous conductive filler, which adds conductivity and acts as a reinforcing material in the added polymer matrix to improve mechanical properties.

However, when metal powder is used as the filler, its use is restricted because it has a unique color tone of the metal. Although carbon fiber is a conductive filler having a reinforcing property, it is difficult to make the fiber length uniform, and the aspect ratio becomes uneven, resulting in poor moldability and surface smoothness of the molded product. And inferior in abrasiveness.

In Japanese Unexamined Patent Publication (Kokai) No. 58-135129, a mixture of an alkali titanate and a carbon material is heated in a reducing or inert atmosphere and then heated and baked to form a reduced alkali titanate having conductivity. A method of manufacturing has been proposed. Further, JP-A-63-12759 proposes to produce a fibrous conductive filler having a uniform fiber length by coating the surface of alkali titanate with carbon.

However, in the production of these fibrous conductive fillers, a heating step is necessary, and particularly when forming a carbon coating on the surface of alkali titanate, in order to obtain high conductivity, high temperature is required. A heating process is required.
However, in the alkali titanate, precipitation of an alkaline component occurs on the surface thereof at around 800 ° C. or higher. This precipitation is remarkable especially in a high temperature state, and the precipitated alkali component is mixed into the alkali titanate as a free alkali component after cooling. Such precipitation and mixing of the alkaline component also occurs when the carbon coating is formed on the surface of the alkaline titanate. When a conductive alkali titanate mixed with an alkaline component is used as a conductive filler,
The alkaline component acts as an impurity and causes a harmful effect. In particular, when it is used as an electric / electronic material, such an adverse effect becomes a problem. Also, with the precipitation of such an alkaline component,
When alkali titanate is heated to around 800 ° C. or higher, the fiber shape is deteriorated, the aspect ratio is lowered, and the reinforcing performance is lowered.

In Japanese Patent Laid-Open No. 7-41316,
A technique has been proposed in which the surface of aluminum borate is coated with a carbonaceous conductive layer to impart conductivity to the aluminum borate. In the composition of the aluminum borate, especially _{9Al 2 O 3 · 2B 2 O} 3 has a high melting point, also useful as little reinforcement of alkali metal impurities from the composition. In particular, in the case of a fibrous shape, the shape can be utilized to form a conductive fiber. Since it has high heat resistance, it is possible to form a conductive layer at a relatively high temperature, so it is possible to form a highly crystalline carbonaceous conductive layer, which has excellent conductive properties compared to the case where potassium titanate is used as the core material. Can be given.

However, 9Al ₂ having a high melting point
O ₃ · 2B even ₂ O ₃ aluminum borate composition, at a temperature range of not lower than 1200 ° C., decomposition and elimination of boric acid component is produced. Since this desorption phenomenon is further promoted by a reducing atmosphere or an inert atmosphere, in the case of fiber-shaped aluminum borate, this desorption causes deterioration of the shape and decomposition of the conductive layer on the fiber surface. As a result,
It becomes difficult to produce good conductive aluminum borate at a heating temperature of 1200 ° C. or higher. Particularly in the case of compounding with a resin, it is necessary to compound a fibrous conductive material having a high aspect ratio to form a good conductive circuit. Due to various problems, a good conductive resin composition could not be obtained.

The object of the present invention is to solve the above-mentioned conventional problems, to have excellent heat resistance and reinforcing properties, to have a small amount of free alkali component, and to show excellent conductivity, a method for producing the same, and a method for producing the same. An object of the present invention is to provide a conductive resin composition using.

[0009]

The conductive fiber of the present invention comprises:
Chemical formula K _X Al _X Ti _8-X O ₁₆ (0.8 ≦ X ≦ 2.5)
It is characterized in that the potassium aluminate titanate fiber having the composition shown in is coated with a carbon conductive layer.

In the conductive fiber of the present invention, the coating amount of the carbon conductive layer is preferably 0.1 to 50% by weight, and more preferably 0.2 to 25% by weight based on the whole. If the coating amount of the carbon conductive layer is too small, sufficient conductivity cannot be imparted, and even if the coating amount of the carbon conductive layer becomes excessively high, high conductivity cannot be obtained in proportion to the coating amount. , Economically disadvantageous.

In the present invention, the potassium aluminate titanate fiber as the core material may have pores inside. The porosity is preferably 70% by volume or less, and more preferably 20 to 50% by volume. By using the potassium aluminate titanate fiber having a high porosity, the conductive fiber can be made lighter, and the mixing ratio by weight can be reduced.

The shape of the potassium aluminate titanate fiber used in the present invention is not particularly limited, but the fiber diameter is 0.1 to 10 μm and the fiber length is 5 to 100 μm.
It is preferably an acicular single crystal having m and an aspect ratio of 10 to 100.

The potassium aluminate titanate fiber has high strength, high elasticity, and high melting point, and is a useful material as a reinforcing material for various matrices. In addition, this fiber does not desorb potassium when it is combined with a binder such as a resin, and there is no risk of decomposing the matrix. In particular, when a resin composite material is produced by compounding with a binder such as a resin, generally, the fiber diameter is 0.1 to 10 μm, and the fiber length is 10
It is preferable to use those having a thickness of -100 μm. In particular,
When the resin composite having a fine shape or high planar smoothness is required, the fiber diameter is 0.3 to 5 μm, and the fiber length is 10 to 5
It is preferable to use 0 μm potassium aluminate titanate fiber as the core material. Further, potassium titanate aluminate fibers, in which the fibers are sufficiently isolated and defibrated without agglomerates such as pills, are preferable in terms of dispersibility.

The method for producing the conductive fiber of the present invention is a method capable of producing the conductive fiber of the present invention,
Chemical formula K _X Al _X Ti _8-X O ₁₆ (0.8 ≦ X ≦ 2.5)
The potassium aluminate titanate fiber having the composition shown by is heated and calcined in a hydrocarbon atmosphere or a mixed gas atmosphere of a hydrocarbon and a reducing gas and / or an inert gas to give a potassium aluminate titanate fiber The feature is that a carbon conductive layer is formed on the surface.

As the carbon hydrogen used in the production method of the present invention, either an aliphatic hydrocarbon or an aromatic hydrocarbon can be used. Examples of the aliphatic hydrocarbon, for example the general formula C _n H _{2n + 2} (wherein n is an integer of 1 to 20) saturated hydrocarbon represented by general formula C _n H _2n (where n is the And the acetylene hydrocarbons represented by the general formula C _n H _2n-2 (wherein n is the same as above), and the like. Examples of aromatic hydrocarbons include benzene, toluene, xylene and their homologues, polynuclear aromatic hydrocarbons such as naphthalene and anthracene, and halides of the above various hydrocarbons. These hydrocarbons are 1
They may be used alone or in combination of two or more.

In the production method of the present invention, the above-mentioned hydrocarbon atmosphere or the above-mentioned hydrocarbon and reducing gas and / or
Alternatively, heating and baking are performed in a mixed gas atmosphere with an inert gas. Examples of the reducing gas include hydrogen gas, carbon monoxide gas, ammonia gas and the like. Examples of the inert gas include nitrogen gas, argon gas, helium gas, xenon gas, carbon dioxide gas and the like. In the production method of the present invention, these reducing gas and inert gas may be used alone or in combination of two or more.

When the reducing gas is mixed with the hydrocarbon, the mixing ratio of the reducing gas and the hydrocarbon is usually 9
The range of 0:10 to 10:90 is preferable, and considering the carbon deposition amount, about 50:50 is particularly preferable.

The temperature for heating and burning is 130 or higher when the temperature of carbon hydrogen used is decomposed, that is, the temperature at which carbon is deposited.
Temperatures within the range of 0 ° C. or lower are preferred. If the heating and firing temperature is too low, the carbon conductive layer cannot be formed on the fiber surface, and if the heating and firing temperature is too high, the shape of the potassium aluminate titanate fiber as the core material collapses, and the aspect ratio May decrease.

The decomposition temperature of carbon-hydrogen varies depending on the hydrocarbon used. For example, the precipitation temperature range of carbon in the case of methane is about 900 to 950 ° C, and that in the case of n-propane is about 950 to 1000 ° C. In the case of benzene, the temperature is low, and carbon is deposited at about 750 to 800 ° C.

From the viewpoint of the conductivity of the deposited carbon conductive layer, it is desirable to process at a temperature as high as possible. In the heating and firing atmosphere, a reducing gas is not necessarily required. For example, by introducing hydrocarbons at about 500 to 1000 ° C. under a stream of an inert gas such as nitrogen gas, and decomposing the hydrocarbons, It is also possible to deposit a carbon conductive layer.

In the manufacturing method of the present invention, after depositing the carbon conductive layer on the surface of the potassium aluminate titanate fiber, the temperature is lowered to room temperature. Also during this temperature drop, it is desirable to lower the temperature while flowing an inert gas, a hydrogen gas, a hydrocarbon gas or a mixed gas thereof. Further, if oxygen or air is mixed in in the process of lowering the temperature, the carbon conductive layer adhering to the surface of the potassium aluminate titanate fiber may burn, which is not preferable.

In the present invention, the heating and firing in a hydrocarbon atmosphere or a mixed gas atmosphere can be performed by using, for example, a tunnel kiln or an electric furnace. Also,
It can also be fired by a rotary kiln or a fluidized firing method.

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 aluminum hydroxide serving as an aluminum supplying component, and this is coated in the presence of a melting agent. It is a method of reacting by heating. According to this 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 ammonium hydroxides include ammonium hydroxide and the like. In addition to those exemplified above, water-soluble ones can be widely used.

When coating the aluminum compound, a method is preferred in which potassium titanate is dispersed in water and then reacted. 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 this method, alkali metal chlorides such as potassium chloride, sodium chloride and alkali metal sulfates such as potassium sulfate and sodium sulfate can be used, and these can 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% by weight. 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.

Further, in the case of producing potassium titanate aluminate whiskers having pores in the crystal, 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 non-pore-containing whisker, 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, the titanium supplying component is represented by the general formula TiO ₂ .nH ₂ O (n is 0 to 8).
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 supply component in this 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 illustrated. 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 potassium chloride, sulfate and bromide 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, and for example, a method of heating and firing as it is in a powder state, a method of firing after granulating 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 or the conductive fiber produced by the production method of the present invention and a binder. The binder is appropriately selected from synthetic polymer compounds such as thermoplastic resins and thermosetting resins, natural resins and their derivatives, coupling agents, inorganic binders, emulsions of organic polymer compounds, etc., depending on the application and purpose. Used by choice.

As the thermoplastic resin, in addition to general-purpose plastics such as polyethylene, polypropylene and polyvinyl chloride resin, polyamide, ABS resin, thermoplastic polyester, polycarbonate, polyacetal, polyphenylene sulfide, polyphenylene ether, polysulfone, polyether sulfone All engineering plastics such as phons, polyetherimides, polyetheretherketones and the like can be mentioned.

As the thermosetting resin, epoxy resin, unsaturated polyester, vinyl ester, phenol resin,
Examples thereof include alkyd resin, silicone resin, diallyl phthalate homopolymer, bismaleimide triazine resin, polyamide, urea and melamine-containing resin, and polyurethane.

These resins may be used alone or in combination of two or more kinds. Furthermore, as a so-called polymer alloy, it is also possible to use a composite of several different resins such as polycarbonate and ABS resin, polyphenylene ether and polystyrene in advance.

Specific examples of the natural resin include balsam rubber resin. Specific examples of the natural resin derivative include a natural resin-modified phenol resin. As the coupling agent, silane-based, titanate-based, aluminum-based, zirconium-based,
Zirco aluminum, chromium, boromium, phosphorus,
Examples thereof include amino acid coupling agents and the like, and are not particularly limited. Specific examples of the inorganic binder include water glass, silica sol, alumina sol, and alumina-silica sol. Also, as an emulsion of an organic polymer compound,
Specific examples thereof include polyvinyl acetate emulsion, vinyl acetate copolymer emulsion, acrylic acid ester copolymer emulsion, vinylidene chloride copolymer emulsion, polyethylene emulsion, and epoxy resin emulsion.

In the conductive resin composition of the present invention, if necessary, a filler such as talc, mica, wollastonite, calcium carbonate, a reinforcing material such as glass fiber or carbon fiber, a pigment, an antioxidant. Agents, antistatic agents, lubricants, heat stabilizers, flame retardants and the like may be added as appropriate.

In the production of the conductive resin composition of the present invention, a usual mixing operation, for example, a Banbury mixer method, an internal mixer method, an extrusion granulation method and the like can be appropriately adopted.

The blending amount of the conductive fiber in the conductive resin composition of the present invention is appropriately set according to the purpose and application of imparting conductivity, but generally 5 to 60% by weight is preferable. , And more preferably 15 to 50% by weight
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 resin composition of the present invention is suitable for various conductive composite materials such as conductive paints, inks, composite materials for electroplating, antistatic materials, electrostatic recording materials and electromagnetic wave shielding materials. Can be used for.

[0055]

Since the conductive fiber of the present invention uses potassium titanate aluminate fiber as the core material, it contains almost no alkali metal ion as an impurity and little elution of alkali metal ion. Therefore, it is excellent in heat resistance and chemical resistance, and has features such as reinforcing property and surface smoothness of the potassium aluminate titanate fiber when used as a composite material.

Therefore, it is suitable for use as an antistatic material, removing static electricity, and as a conductive material, and can be used particularly as a conductive material for plastic molded articles, sheets, papers, cloths, films and the like.

Further, the conductive fibers of the present invention are various conductive composites such as plastic reinforcing materials, conductive paints, inks, electroplating composite materials, antistatic materials, electrostatic recording materials, and electromagnetic wave shielding materials. It can be applied to materials.

[0058]

[Examples] Hereinafter, examples of producing potassium aluminate titanate fibers will be described, and the present invention will be specifically described with reference to Examples and Comparative Examples using the obtained potassium aluminate titanate fibers. The scope of the present invention is not limited by the following examples. In the following,% is weight%
Indicates.

Production Example 1 6 Potassium titanate fiber (trade name: TI, manufactured by Otsuka Chemical Co., Ltd.)
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 give 40%.
The solution of 0 ml was slowly added with stirring to react. During this period, the reaction temperature is kept at 30 to 40 ° C.
The reaction was continued for 3 hours. After the reaction was completed, the pH of the reaction solution was 7.4. The reaction was then filtered, washed with water to remove impurities and dried at 80 ° C. 26 as a dried product
3.0 g was obtained. As a result of analysis of this dried product, 15.1% in terms of aluminum oxide, and 0.005 as a sulfate salt
3%, and a loss on ignition of 8.09% potassium hexatitanate coated with an aluminum hydroxide compound.

To the potassium hexatitanate fiber coated with the aluminum hydroxide compound, potassium sulfate (K ₂ SO ₄ ) was added as a flux raw material (melting agent) in a weight ratio of 1: 4, and the mixture was placed in a mortar. After mixing sufficiently, pressure molding was performed and firing was performed at 1150 ° C. for 3 hours. 800 after firing
The temperature was cooled to a temperature of 5 ° C at a rate of 5 ° 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 yellow-light powder. This product had a K _2.0 A value from X-ray diffraction and elemental analysis.
It was a potassium aluminate titanate fiber having a composition of 1 _2.0 Ti _6.0 O ₁₆ , a fiber diameter of 2 μm, and a fiber length of 30 μm. Further, it had almost no pores.

[0061]Production example 2 Take out the cooling after firing from the furnace and quench it in cold water.
Except for the above
Obtained. This is K from X-ray diffraction and elemental analysis _2.0Al
_2.0Ti_6.0O₁₆Has a composition of 2 μm, and has a fiber diameter of 2 μm,
Fiber length of 30 μm, about 50% by volume in the crystal with respect to the total volume
It is a potassium aluminate titanate fiber with pores
It was

Production Example 3 8 Potassium titanate fiber (trade name: TI, manufactured by Otsuka Chemical Co., Ltd.)
200 g of SMO-D) was dispersed in 2.5 liters of water, and then 47.3 g of aluminum sulfate 18-hydrate was dissolved in water to make 110 ml, and sodium aluminate (Na ₂ O.Al ₂ O ₃ ) 16.6 g and 5.2 g of sodium hydroxide were dissolved into 100 ml to prepare a solution of 20 to 3
While stirring at a temperature of 0 ° C., the reaction solution had a pH value of 7
The reaction was carried out for 5 hours, with slow additions to indicate a neutral range of -9. After the completion of the reaction, the pH of the reaction solution was 7.2. The reaction was then filtered, washed with water to remove impurities and dried at 90 ° C. As a dried product, 238.8 g was obtained. As a result of analysis of this dried material, potassium octatitanate fiber coated with a basic aluminum sulfate compound having 7.36% in terms of aluminum oxide, 3.31% as a sulfate and a loss on ignition of 5.19% was obtained. there were.

To the potassium octatitanate fiber coated with this basic aluminum sulfate compound, potassium chloride (KCl) and potassium sulfate (K ₂ SO ₄ ) were used as a flux raw material (melting agent) in a molar ratio of 1: 3. And mixed this powder with 8 potassium titanate fibers,
The mixture was added at a weight ratio of 1: 9, thoroughly mixed in a mortar, heat-molded, and baked at 1250 ° 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. This one is from X-ray diffraction and elemental analysis,
It has a composition of K _1.0 Al _1.0 Ti _7.0 O ₁₆ and a fiber diameter of 3 μm.
m and a fiber length of 50 μm were potassium aluminate titanate fibers. Further, it had almost no pores.

Example 1 5 g of potassium aluminate titanate fiber (K _2.0 Al _2.0 Ti _6.0 O ₁₆ ) obtained in the above Production Example 1 was placed in a 50 ml platinum crucible and placed in a tubular electric furnace made of siliconite. Then, nitrogen gas replacement was repeated twice, and then while introducing nitrogen gas at a flow rate of 150 ml / min, the temperature was changed from room temperature to 5
It was heated to 00 ° C. at a heating rate of 6 ° C./min. Next, the gas to be introduced is switched to propane gas, and while introducing propane gas at a flow rate of 120 ml / min, 850 ° C., 1
The temperature was raised to 100 ° C. or 1200 ° C. and maintained at each temperature for 30 minutes, the propane gas was turned off, and the furnace was cooled to room temperature while flowing nitrogen gas. After that, it was taken out of the furnace. A blackish-colored conductive potassium aluminate titanate fiber was obtained.

The amount of the potassium aluminate titanate fiber coated with the carbon conductive layer thus obtained was 5.5 g, so the weight of the carbon conductive layer was 0.5 g, and therefore 9.1% by weight of the total weight. It is covered with the carbon conductive layer.

Example 2 5 g of the potassium aluminate titanate fiber (K _2.0 Al _2.0 Ti _6.0 O ₁₆ ) obtained in the above Production Example 2 was placed in a 50 ml platinum crucible and placed in a silicon electric tubular electric furnace. Then, nitrogen gas replacement was repeated twice, and then while introducing nitrogen gas at a flow rate of 150 ml / min, the temperature was changed from room temperature to 5
It was heated to 00 ° C. at a heating rate of 6 ° C./min. Then, the gas to be introduced is switched to hydrogen gas, and the hydrogen gas flow rate is set to 120
While introducing at a rate of ml / min, the temperature was raised to 800 ° C. Next, benzene gas was introduced at a rate of 50 ml / min for 30 minutes through a branch pipe previously provided in the hydrogen gas introduction pipe, while the tubular electric furnace was heated to 850 ° C., 1100 ° C. or 1200 ° C. After holding at each temperature for 10 minutes, the electric furnace was turned off and the furnace was cooled while flowing hydrogen gas. When the temperature dropped to 300 ° C., the introduced gas was switched to nitrogen gas, the furnace was cooled to room temperature, and the furnace was taken out of the furnace. A blackish-colored conductive potassium aluminate titanate fiber was obtained.

The amount of the potassium aluminate titanate fiber coated with the carbon conductive layer thus obtained was 5.5 g, so that the weight of the carbon conductive layer was 0.5 g, and therefore 9.1% by weight of the total weight. It is covered with the carbon conductive layer.

Example 3 5 g of potassium titanate aluminate fiber (K _1.0 Al _1.0 Ti _7.0 O ₁₆ ) obtained in the above Production Example 3 was placed in a 50 ml platinum crucible and placed in a tubular electric furnace made of siliconite. Then, the treatment was carried out under the same conditions as in Example 2 to obtain a conductive potassium aluminate titanate fiber colored in black.

Since the obtained potassium aluminate titanate fiber coated with the carbon conductive layer was 5.5 g, the weight of the carbon conductive layer was 0.5 g, and therefore 9.1% by weight of the whole was used. It is covered with the carbon conductive layer.

Comparative Example 1 6 Potassium titanate fiber (manufactured by Otsuka Chemical Co., Ltd., trade name: TI
5 g of SMO-N, K ₂ O.6TiO ₂ ) was put in a 50 ml platinum crucible, placed in a silicon electric tubular electric furnace, and treated under the same conditions as in Example 2 to give a black belt. Colored conductive potassium hexatitanate fibers were obtained. Since the amount of potassium hexatitanate fiber coated with the obtained carbon conductive layer was 5.5 g, the weight of the carbon conductive layer was 0.5 g, which was 9.1% by weight of the whole.

Comparative Example 2 Aluminum borate fiber (manufactured by Shikoku Chemicals, trade name:
Arbolex Y, 9Al ₂ O ₃ · 2B ₂ O ₃ ) 5g
Was placed in a 50 ml platinum crucible, placed in a tubular electric furnace made of silicon knit, and treated under the same conditions as in Example 2 above to obtain aluminum borate fibers having a black-colored conductivity. It was The weight of the obtained carbon conductive layer was 5.2 g, and the weight of the carbon conductive layer was 0.2 g, which was 3.8% by weight of the whole.

Test Example 1 90 parts by weight of each conductive material obtained in each of the examples and comparative examples and 10 parts by weight of liquid paraffin were thoroughly mixed in a mortar, and then a mold having an inner diameter of 10 mm and a length of 20 mm was prepared. After being pressed and molded under the condition of 50 kg / cm ² for 10 minutes, a digital multimeter (manufactured by Advantest)
Was used to measure the electrical conductivity, and the volume resistivity was calculated according to the following formula. The results are shown in Table 1. Volume resistivity (Ω · cm) = measured resistance (Ω) × electrode area (cm ² ) / distance between electrodes (cm)

Test Example 2 60 ml of distilled water was added to 1 g of each conductive material obtained in each of the above Examples and Comparative Examples, the mixture was stirred at 50 ° C. for 20 minutes, and then filtered with a filter paper (No. 5C). The filtrate was diluted to 100 ml with distilled water, and K ions were measured with a flame photometric analyzer using the diluted water to determine the free K component. The results are shown in Table 1.

Test Example 3 The conductive materials obtained in each of the above Examples and Comparative Examples were uniformly dispersed on an electron microscope sample stand, and the magnification was 1000.
Each conductive material was photographed with an electron microscope at a magnification of 2. Further, at the stage of printing on photographic paper, the final magnification was expanded to 3000 times, and the fiber length, diameter or particle diameter of the conductive substance on the photograph was measured using a caliper (minimum measured value 1/100 mm). The average value of 500 pieces was defined as the average fiber length, average fiber diameter or average particle diameter. The results of this measurement are shown in Table 1.

[0075]

[Table 1]

Example 4 Each conductive material prepared in the same manner as in each of the above Examples was added to and mixed with various binders shown in Table 2 to form a sheet, and the surface resistance was measured. The surface resistivity was measured by the following formula.

[0077] Surface resistivity (Ω) = π · (D + d) · Rs / (D−d) π: Pi = 3.14 D: Inner diameter (cm) of the annular electrode on the surface d: outer diameter of inner circle of surface electrode (cm) Rs: Surface resistance measurement value (Ω)

Further, each conductive material produced in the same manner as in each of the above-mentioned examples was kneaded with various binders shown in Table 3, and then a test piece was produced in accordance with JIS method to obtain tensile strength (JIS -K-7113), bending strength (JIS-K-7
203) was measured. The measurement results are shown in Table 3.

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 is used the trade name "Araldite". (Manufactured by Ciba Geigy) was used.

Trade name "Duracon" (manufactured by Poly Plastics) is 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.

Comparative Example 3 A conductive material prepared in the same manner as in the above Comparative Examples was kneaded with various binders in the same manner as in Example 4 above, and then the surface resistance was measured in the same manner as in Example 4 above. . Further, the tensile strength and the bending strength were measured in the same manner as in Example 4 above. The respective results are shown in Table 3.

[0082]

[Table 2]

[0083]

[Table 3]

As is clear from the results shown in Table 1, the conductive fiber of the present invention has a conductivity equal to or higher than those in Comparative Examples 1 and 2, and is treated at a high temperature of 1200 ° C. However, it can be seen that the aspect ratio hardly decreases. Further, it can be seen that the amount of free K component is smaller than that in Comparative Example 1.

As is clear from Table 2, the conductive fibers of Examples 1 to 3 of the present invention can be mixed with various binders to obtain excellent conductivity. Particularly, the one treated at a high temperature of 1200 ° C. shows excellent conductivity.

As is clear from Table 3, the conductive fibers of Examples 1 to 3 according to the present invention can be blended with various engineering plastics to give high tensile strength and bending strength even in the reinforcing effect. Recognize. Especially 1200 ℃
Even when treated at a high temperature, the reduction in aspect ratio is small, and therefore, the reinforcing effect is superior to the conductive fibers of Comparative Example 1 and Comparative Example 2.

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) C08L 1/00-101/16

Claims (8)

(57) [Claims] 1. The chemical formula of K _X Al _X Ti _8-X O ₁₆ (0.8
Conductive fiber characterized by coating potassium aluminate titanate fiber having a composition represented by ≦ X ≦ 2.5) with a carbon conductive layer. 2. The potassium aluminate titanate fiber comprises 7
The conductive fiber according to claim 1, which is a potassium aluminate titanate fiber having 0% by volume or less of pores. 3. The chemical formula K _X Al _X Ti _8-X O ₁₆ (0.8
≦ X ≦ 2.5) by heating and burning potassium titanate aluminate fiber having a composition represented by a hydrocarbon atmosphere or a mixed gas atmosphere of a hydrocarbon and a reducing gas and / or an inert gas, A method for producing a conductive fiber, which comprises forming a carbon conductive layer on the surface of the potassium aluminate titanate fiber. 4. The method for producing a conductive fiber according to claim 3, wherein the heating and firing temperature is within the range of the decomposition (carbon deposition) temperature of the hydrocarbon used and 1300 ° C. or less. 5. The method for producing a conductive fiber according to claim 3, wherein a potassium aluminate titanate fiber having a pore volume of 70% by volume or less is used as the potassium aluminate titanate fiber. 6. The method for producing a conductive fiber according to claim 3, wherein the hydrocarbon is an aliphatic hydrocarbon or an aromatic hydrocarbon. 7. The method for producing a conductive fiber according to claim 3, wherein the reducing gas is hydrogen gas, carbon monoxide gas, or ammonia gas. 8. A conductive resin composition comprising the conductive fiber according to claim 1 or 2 or the conductive fiber produced by the method according to any one of claims 3 to 7 and a binder.