CN1526028B - Niobium monoxide powder,niobium monoxide sintered body using the niobium powder and capacitor using the sintered body - Google Patents

Abstract

The present invention provides a niobium powder for a capacitor having a tapping density of 0.5 to 2.5 g/ml, and average particle size of 10 to 1000 mu, angle of repose form 10 DEG to 60 DEG , the BET specific surface area from 0.5 to 40 m<2>/g and a plurity of pore diameter peak tops in the pore distribution, and a producing method therof; (2) a niobium sintered body, which is obtained by sintering the above niobium powderand, having a plurality of pore diameter peak tops in a range of 0.01 mu to 500 mu, preferably, the peak tops of two peaks among the plurality of pore diameter peak tops having a highest relative intensity are present in the range of 0.2 to 0.7 mu and in the range of 0.7 to 3 mu, respectively, and a produing method thereof; (3) a capacitor using the above sintered body and a producingmethod thereof; and (4) an electronic circuit and electronic device using the above capacitor.

Description

The electrical condenser of niobium powder, niobium sintered body and this sintered compact of use

The cross reference of related application

This application is based on the application of the regulation of 35 U.S.C. the 111st (a) joint, it is according to the regulation of 35 U.S.C. the 119th (e) (1) joint, requirement is according to the U.S. Provisional Application No.60/291 that propose May 21 calendar year 2001 that is defined in of 35 U.S.C.111 (b), 925 and the No.60/331 that proposes in November 9 calendar year 2001, the rights and interests of 200 the applying date.

Technical field

The present invention relates to niobium powder and sintered compact thereof, it can stably be produced has the unit mass high capacitance, the electrical condenser of the wet fastness of good leak current characteristic and excellence, and relate to use niobium powder and the electrical condenser of sintered compact and the manufacture method of niobium powder, sintered compact and electrical condenser.

Background technology

The electrical condenser that is used for electronic machine such as portable phone and PC requires to have small size and high capacitance.In these electrical condensers, tantalum capacitor is preferred, because with respect to its size, electrical capacity is big and performance good.

In addition, in recent years, require electron device under low voltage and high frequency, to operate, and have low noise, and, also require lower equivalent parallel resistance (ESR) for solid electrolyte capacitators.In this tantalum capacitor, the sintered compact of tantalum powder generally is used as anode part.With this powder forming, sintering then, thus make described powder integration and make the electrode that is called as sintered compact.This sintered compact inside forms the structure of 3 D complex by the electricity and the powder particle of mechanically connect each other, comprises the surface on internal void surface at this sintered compact, and formation dielectric film layer floods the material as counter electrode, thereby prepares a kind of electrical condenser.As long as the dielectric film layer evenly is attached to the internal surface or the outside surface of described sintered compact, the electrical capacity of the electrical condenser of manufacturing just depends primarily on the contact condition of counter electrode material and dielectric film layer on microcosmic.

In order to improve the electrical capacity of tantalum capacitor, must improve the quality of sintered compact or use the sintered compact that has increased surface-area by broken tantalum powder.

The method that improves Sintered Quality must relate to the expansion of electrical condenser shape, and can not satisfy the requirement of miniaturization.On the other hand, in the method for broken tantalum powder with increasing specific surface area, the aperture of tantalum sintered object reduces or increases in sintering stage blind hole crack, the result, and the dipping of negative electrode reagent becomes difficult in subsequent step.

For example, suppose when using phosphate aqueous solution as the counter electrode material, the contact condition of described solution and dielectric film layer is completely, and the electrical capacity of this moment is apparent to be 100% than (being also referred to as negative electrode reagent-impregnated ratio), has full-bodied counter electrode material in use, particularly under the situation of solid electrode material, almost can not obtain 100% the apparent ratio of electrical capacity.Especially, little or when having big shape by the sintered compact of tantalum powder manufacturing, difficulty increases and under extreme case, the apparent ratio of electrical capacity even may not reach 50% when the mean particle size of tantalum powder.Have the apparent ratio of such low-voltage capacity, the electrical condenser of manufacturing can not have sufficiently high wet fastness.

Have under the situation of small-bore at the tantalum powder of producing tantalum sintered object, it causes the small-bore of tantalum sintered object and the low apparent ratio of electrical capacity substantially.Therefore, produce the irreducible problem of ESR.

As one of measure that addresses these problems, can consider to use the electrical condenser of sintered compact as an electrode, this sintered compact uses has the dielectric materials production of specific inductivity greater than tantalum, and provides the apparent ratio of high-capacitance.

As can be at this class electrode materials of industrial supply, the specific inductivity of known niobium be greater than tantalum, and has big storage capacity.

JP-A-55-157226 (term used herein " JP-A " is meant " not examining open Japanese patent application ") discloses a kind of sintering device of producing electrical condenser, wherein, with granularity is the rectifying action metal-powder press molding of 2.0 microns or littler reunion, sintering then, formed thereby and agglomerating base substrate are cut into tiny sheet, with conductor part and its binding, and once more sintering these.But, the details of manufacture method and the character of niobium capacitor are not described in this patent disclosure.

United States Patent (USP) 4,084,965 disclose that to use mean particle size be the electrical condenser of sintered compact of 5.1 microns niobium powder, and described niobium powder is by hydrogenation and pulverize the niobium ingot and obtain.But disclosed electrical condenser has gross leak electric current (hereinafter abbreviating " LC " sometimes as) value, and has very little practical use.

JP-A-10-242004 (WO 98/38660) discloses a kind of part nitrided niobium powders and has therefore improved the technology of LC value.

The tap density that is used for the niobium powder of electrical condenser is the important factor of niobium powder shaping operation.The tap density of tradition niobium powder is 2.5g/ml or bigger, specifically is about 4g/ml, and this is not enough for shaping.

That is, if be shaped and the such niobium powder of sintering prepares sintered compact, then the niobium powder flow to the metal die from the hopper of forming mill indigently, and the niobium powder of the constant basis that is difficult to weigh and it is flow in the metal die.As a result, it produces some problems, as the dimensionally stable deficiency of molded article, and the undercapacity of molded article and sintered compact, and often produce electrical condenser with inferior LC.If use and also can handle the special former with inferior flowability, the cost that then is shaped too increases, and this is unpractical.

Like this, the conventionally known niobium powder that is used for electrical condenser exists this powder can not adapt to the low problem of productivity of continuous molding and electrical condenser fully.

Disclosure of an invention

The purpose of this invention is to provide the electrical condenser that a kind of unit mass electrical capacity is big, leakage current is little and wet fastness is high; A kind of sintered compact that can be used as the electrode materials of this electrical condenser and can obtain the apparent ratio of high-capacitance; A kind of material as this sintered compact is preferred, show good fluidity in shaping operation, promote continuous molding and niobium powder that can the stably manufactured electrical condenser; Manufacture method with described electrical condenser, described sintered compact and described niobium powder.

Result as the broad research that addresses the above problem, the inventor has been found that, when having specific pore size distribution, when preferably in pore size distribution, having the niobium powder of a plurality of apertures peak value to be used for electrode for capacitors, can obtain the apparent ratio of high-capacitance, and can produce leakage current little and the time moist good electrical condenser.The inventor also finds, the tap density that preferably has 0.5-2.5g/ml, more preferably mean particle size is 10～1,000 micron niobium powder, show good flowability, can continuous molding and be preferred as the material of above-mentioned sintered compact, when using this niobium powder, can stablize and produce the little electrical condenser of leakage current.The inventor has been found that more preferably, and using by pore size distribution range wide and a plurality of apertures peak value all is the electrical condenser as electrode of the niobium sintered body produced of 0.5 micron or bigger niobium powder, can obtain apparent ratio of high-capacitance and low ESR simultaneously.Based on these inventions, finished the present invention.

More particularly, the present invention relates to following niobium powder, niobium sintered body and the electrical condenser that uses it, and relate to the manufacture method of niobium powder, niobium sintered body and electrical condenser.

(1) a kind of niobium powder that is used for electrical condenser, having tap density is 05～2.5g/ml.

(2) the niobium powder described in above-mentioned 1, wherein, mean particle size is 10～1,000 micron.

(3) as above-mentioned 1 or 2 described niobium powder, wherein, the slope of repose is 10 °～60 °.

(4) as above-mentioned 1～3 each described in the niobium powder, wherein, the BET specific surface area is 0.5～40m ²/ g.

(5) as above-mentioned 1～4 each described in the niobium powder, have the pore size distribution of aperture peak value in 0.01～500 micrometer range.

(6) the niobium powder described in above-mentioned 5, wherein, pore size distribution has a plurality of apertures peak value.

(7) the niobium powder described in above-mentioned 5 or 6, wherein, any of aperture peak value is in 0.5～100 micrometer range.

(8) as above-mentioned 1～7 each described in the niobium powder, wherein, the content that is selected from least a element of nitrogen, carbon, boron and element sulphur is 200,000 quality ppm or still less.

(9) a kind of sintered compact, its use as above-mentioned 1～8 each described in the niobium powder.

(10) sintered compact described in above-mentioned 9, it has the aperture peak value and distributes in 0.01～500 micron pore size.

(11) a kind of niobium sintered body that is used for electrode for capacitors, wherein, the pore size distribution of niobium sintered body has a plurality of apertures peak value.

(12) niobium sintered body described in above-mentioned 11, wherein, pore size distribution has two aperture peak values.

(13) niobium sintered body described in above-mentioned 11 or 12 wherein, in the peak value of a plurality of apertures, has the peak value at two peaks of high relative intensity and is present in 0.2～0.7 micrometer range respectively and in 0.7～3 micrometer range.

(14) as above-mentioned 11～13 each described in niobium sintered body, wherein, in the peak value of a plurality of apertures, have the peak value at the peak of high relative intensity and be present in than having time side of the peak value larger diameter at the peak of high relative intensity.

(15) as above-mentioned 9～14 each described in niobium sintered body, wherein, the volume of sintered compact is 10mm ³Or bigger, comprise the volume of hole.

(16) as above-mentioned 9～15 each described in niobium sintered body, wherein, the specific surface area of sintered compact is 0.2～7m ²/ g.

(17) as above-mentioned 9～16 each described in niobium sintered body, wherein, a part of sintered compact is by nitrogenize.

(18) as above-mentioned 12～17 each described in niobium sintered body, wherein, described sintered compact is the sintered compact that is obtained by a kind of niobium molding, described niobium molding produce a kind of when 1300 ℃ of sintering the CV value be the sintered compact of 40,000～200,000 μ FV/g.

(19) a kind of electrical condenser, comprise use as above-mentioned 9～18 each described in an electrode, a counter electrode and the intervenient dielectric materials of niobium sintered body.

(20) electrical condenser described in above-mentioned 19, wherein, dielectric materials mainly comprises niobium oxides.

(21) electrical condenser described in above-mentioned 19, wherein, counter electrode is at least a material that is selected from electrolyte solution, organic semiconductor and inorganic semiconductor.

(22) electrical condenser described in above-mentioned 21, wherein, counter electrode is an organic semiconductor, and organic semiconductor be selected from the organic semiconductor that comprises benzopyrrole quinoline tetramer and chloranil, mainly comprise the organic semiconductor of four thio naphthacene, mainly comprise the organic semiconductor of four cyano quinone bismethane and at least a material of electric conductive polymer.

(23) electrical condenser described in above-mentioned 22, wherein, electric conductive polymer is at least a composition that is selected from polypyrrole, Polythiophene, polyaniline and substitutive derivative thereof.

(24) electrical condenser described in above-mentioned 22, wherein, electric conductive polymer is by mix the electric conductive polymer that doping agent obtains in the polymkeric substance of the repeating unit that contains following formula (1) or (2) expression:

(wherein, R ¹～R ⁴Expression independently of one another is selected from hydrogen atom, contains saturated or unsaturated alkyl, alkoxyl group or alkyl ester group group, halogen atom, nitro, cyano group, primary, the second month in a season or uncle's amino, the CF of the straight or branched of 1～10 carbon atom ₃The univalent perssad of the phenyl of group, phenyl and replacement; Each is to R ¹And R ², R ³And R ⁴Can be at an arbitrary position in conjunction with forming the divalence chain, be used for by R ¹And R ²Or by R ³And R ⁴The carbon atom that replaces forms at least one 3-, 4-, the saturated or unsaturated hydrocarbons ring structure of 5-, 6-or 7-unit together; Ring-type bonded chain can contain carbonyl, ether, ester, acid amides, thioether, sulfinyl, alkylsulfonyl or imino-at an arbitrary position; X represents Sauerstoffatom, sulphur atom or nitrogen-atoms; R ⁵Only when X is nitrogen-atoms, just exist, and represent hydrogen atom independently or contain straight or branched, the saturated or unsaturated alkyl of 1～10 carbon atom).

(25) electrical condenser described in above-mentioned 24, wherein, electric conductive polymer is the electric conductive polymer that contains by the repeating unit of following formula (3) expression:

(wherein, R ⁶And R ⁷Represent hydrogen atom independently of one another, contain the saturated or unsaturated alkyl of the straight or branched of 1～6 carbon atom, perhaps a substituting group is used to form at least one 5-, the 6-that contain two Sauerstoffatoms or the 7-unit stable hydrocarbon ring structure that are obtained by the alkyl that mutually combines at an arbitrary position; And ring texture comprises having the structure of can substituted vinylidene key, can substituted phenylene structure).

(26) electrical condenser described in above-mentioned 22, wherein, electric conductive polymer is by mix the electric conductive polymer that doping agent obtains in poly-(3,4-ethylidene dioxy thiophene).

(27) electrical condenser described in above-mentioned 19, wherein, counter electrode is made by the material that has laminate structure to small part.

(28) electrical condenser described in above-mentioned 19, wherein, the material of counter electrode contains organic sulfonic acid root negatively charged ion as doping agent.

(29) a kind of produce above-mentioned 1～8 each described in the method for niobium powder, it comprises the activation treatment of niobium or niobium compound.

(30) method of the production niobium powder described in above-mentioned 29, wherein, the activation treatment of niobium or niobium compound is to be undertaken by at least one step that is selected from sintering step and broken step.

(31) method of the production niobium powder described in above-mentioned 29 or 30, wherein, the mixture of use niobium or niobium compound and activator carries out the activation treatment of niobium or niobium compound.

(32) as above-mentioned 29～31 each described in the method for production niobium powder, wherein, carrying out the niobium of activation treatment processing or the mean particle size of niobium compound is 0.01～10 micron.

(33) as above-mentioned 29～32 each described in the method for production niobium powder, wherein, described niobium or niobium compound contain at least a element that is selected from nitrogen, carbon, boron and sulphur, its content is 200,000ppm or still less.

(34) as above-mentioned 29～33 each described in the method for production niobium powder, wherein, niobium compound is be selected from hydrogenated niobium, niobium alloy and hydrogenated niobium alloy at least a.

(35) method of the production niobium powder described in above-mentioned 34, wherein, the contained composition except that niobium is that to be selected from ordination number be 88 or at least a element of littler element in niobium alloy or the hydrogenated niobium alloy, but does not comprise hydrogen, nitrogen, oxygen, fluorine, chlorine, bromine, iodine, niobium, helium, neon, argon, krypton, xenon and radon.

(36) method of the production niobium powder described in above-mentioned 31, wherein, the mixture that contains niobium or niobium compound and activator obtains by using these compositions of solvent.

(37) method of the production niobium powder described in above-mentioned 36, wherein, described solvent is at least a solvent that is selected from water, alcohol, ether, cellosolve, ketone, aliphatic hydrocarbon, aromatic hydrocarbon and halohydrocarbon.

(38) method of the production niobium powder described in above-mentioned 31, wherein, by the total amount of niobium or niobium compound, the consumption of activator is 1～40 quality %.

(39) method of the production niobium powder described in above-mentioned 31 or 38, wherein, the mean particle size of activator is 0.01～500 micron.

(40) as above-mentioned 31,38 and 39 each described in the method for production niobium powder, wherein, activator has a plurality of granularity peak values.

(41) method of the production niobium powder described in each of above-mentioned 31,38-40, wherein, activator be a kind of 2,000 ℃ or following temperature with the removed material of gas form.

(42) method of the production niobium powder described in above-mentioned 41, wherein, activator is to be selected from naphthalene, anthracene, quinone, camphor, polyacrylic acid, polyacrylic ester, polyacrylamide, polymethyl acrylic acid, polymethacrylate, PMAm, polyvinyl alcohol, NH ₄Cl, ZnO, WO ₂, SnO ₂And MnO ₃At least a.

(43) method of the production niobium powder described in each of above-mentioned 31,38-40, wherein, activator is to be selected from water-soluble substances, the organic solvent soluble substance, the acid solution soluble substance, the alkaline solution soluble substance forms complex compound and becomes the material of the material of water-soluble, organic solvent, acid solution or alkaline solution, becomes at least a in the material of material of water-soluble, organic solvent, acid solution or alkaline solution under 2000 ℃ or lower temperature.

(44) method of the production niobium powder described in above-mentioned 43, wherein, activator is the compound that is selected from metal and carbonic acid, sulfuric acid, sulfurous acid, halogen, perhalogeno acid, hypohalous acid, nitric acid, nitrous acid, phosphoric acid, acetate, oxalic acid or boric acid, metal, metal hydroxides and metal oxide at least a.

(45) method of the production niobium powder described in above-mentioned 43, wherein, activator is be selected from lithium, sodium, potassium, rubidium, caesium, francium, beryllium, magnesium, calcium, strontium, barium, radium, scandium, yttrium, cerium, neodymium, titanium, zirconium, hafnium, vanadium, niobium, tantalum, molybdenum, tungsten, manganese, rhenium, ruthenium, osmium, cobalt, rhodium, iridium, nickel, palladium, platinum, silver, gold, zinc, cadmium, boron, aluminium, gallium, indium, thallium, silicon, germanium, tin, lead, arsenic, antimony, bismuth, selenium, tellurium, polonium and compound thereof at least a.

(46) as above-mentioned 29～40 and 43～45 each described in the method for production niobium powder, wherein, activation treatment is by the heating and/or the processing of under reduced pressure removing activator before sintering step or in the sintering step.

(47) as above-mentioned 29～40 and 43～45 each described in the method for production niobium powder, wherein, described activation treatment be behind the sintering step and in shattering process or after the shattering process by making solvent and sintering or broken product contacts processing with removal activator composition.

(48) method of the production niobium powder described in above-mentioned 47, wherein, described solvent is to be selected from water, organic solvent, acid solution, alkaline solution and to contain at least a in the solution of the part that forms soluble complexes.

(49) method of the production niobium powder described in above-mentioned 48, wherein, acid solution is at least a solution that is selected from nitric acid, sulfuric acid, hydrofluoric acid and the hydrochloric acid.

(50) method of the production niobium powder described in above-mentioned 48, wherein, alkaline solution contains at least a composition that is selected from alkali metal hydroxide and ammonia.

(51) method of the production niobium powder described in above-mentioned 48, wherein, described part is be selected from ammonia, glycine and ethylenediamine tetraacetic acid (EDTA) at least a.

(52) method of the production niobium powder described in above-mentioned 48, wherein, described organic solvent is a methyl iso-butyl ketone (MIBK).

(53) a kind of method of production nitrogenous niobium powder, it comprise with at least a method that is selected from wet nitriding, ion nitriding and gas nitriding handle above-mentioned 1～7 each described in the niobium powder.

(54) a kind of method of producing carbon containing niobium powder, it comprise with at least a method that is selected from solid phase carbonization and liquid phase carbonization handle above-mentioned 1～7 each described in the niobium powder.

(55) a kind of method of producing boracic niobium powder, it comprise with at least a method that is selected from gas phase boronation and solid phase boronation handle above-mentioned 1～7 each described in the niobium powder,

(56) a kind of method of producing sulfur-bearing niobium powder, it comprise with at least a method that is selected from gas phase sulfuration, ion sulfuration and solid phase vulcanizing handle above-mentioned 1～7 each described in the niobium powder.

(57) the niobium powder of the acquisition of the manufacture method described in each of a kind of usefulness above-mentioned 29～56.

(58) a kind of production method of niobium sintered body, use above-mentioned 1～8 and 57 each described in the niobium powder.

(59) a kind of method of producing electrical condenser, described electrical condenser comprises one electrode, the dielectric materials that forms on the sintered compact surface of niobium sintered body and the counter electrode that provides on dielectric materials is provided, wherein, niobium sintered body be by sintering above-mentioned 1～8 and 57 each described in the niobium powder obtain.

(60) method of the production electrical condenser described in above-mentioned 59, wherein, dielectric materials forms by electrolytic oxidation.

(61) a kind of method of producing electrical condenser, described electrical condenser comprises one electrode, the dielectric materials that forms on described sintered compact surface of niobium sintered body and the counter electrode that provides on described dielectric materials is provided, wherein, described niobium sintered body be above-mentioned 9～18 each described in niobium sintered body.

(62) a kind of use above-mentioned 19～28 each described in the electronic circuit of electrical condenser.

(63) a kind of use above-mentioned 19～28 each described in the electronic machine of electrical condenser.

Brief description of drawings

Fig. 1 is the enlarged view that illustrative has the niobium powder of the present invention of two or more apertures peak value.

Fig. 2 is the sketch map by the pore size distribution of the niobium powder of mercury penetration method measurement.

Implement mode of the present invention

Below describe have the moist electrical condenser of good leak current characteristic and excellent in resistance, can make it to have these performances and to provide the niobium sintered body of the apparent ratio of high-capacitance, preferably as this sintered material and have good fluidity and the niobium powder that can continuous molding and the manufacture method of this electrical condenser, niobium sintered body and niobium powder.

In the present invention, tap density is that the electrical condenser niobium powder (abbreviating " niobium powder " sometimes as) of 0.5～2.5g/ml is as satisfying the above-mentioned performance of electrical condenser and improving the niobium powder of the productivity of electrical condenser in producing.

Niobium powder for capacitor used herein is meant the niobium powder that mainly comprises niobium and energy conduct production capacitor material.This niobium powder can contain, and for example, can form the composition of alloy with niobium, i.e. composition except niobium is as nitrogen and/or oxygen.

By using following method shaping and sintering niobium powder for capacitor to obtain to be used for the niobium sintered body (abbreviating niobium sintered body sometimes as) of electrical condenser, form dielectric layer and counter electrode layer then thereon, can produce electrical condenser.

With niobium powder for capacitor join by be dissolved in the described tackiness agent in back in organic solvent such as toluene or the methyl alcohol and use shaking mixer or solution that V-type mixing machine thorough mixing is obtained in.Then, use moisture eliminator such as circular cone moisture eliminator under reduced pressure to distill out organic solvent, prepare the niobium mixed powder that contains tackiness agent.This mixed powder is put in the hopper of automatic forming machine, weighing and the niobium powder is flow through from hopper arrives feed-pipe the metal die of metal forming machine, makes it fall into metal die automatically, and is shaped with lead.After removing tackiness agent, this molded article is 500～2, and 000 ℃ of sintering under reduced pressure is to make niobium sintered body.

This niobium sintered body forms through electrochemical treatment, is in the electrolyte solvent of the phosphoric acid of 0.1 quality % and hexanodioic acid in concentration for example, at 30～90 ℃, under the voltage of 20～60V, handles 1～30 hour, to form the dielectric layer that mainly comprises niobium oxides.On this dielectric layer, form solid electrolyte layer such as Manganse Dioxide, plumbic oxide and electric conductive polymer and graphite linings and silver and stick with paste layer.After connecting cathode leg thereon by soldering, with resin-sealed to prepare solid electrolyte capacitators.

When being shaped, do not have under the situation of mixed powder at proper flow or slope of repose, this powder can not flow to the metal die glibly from hopper, and can not stably form.Especially, owing to use as methods such as vibrations and carry this mixed powder from hopper, excessive or the too small tap density of mixed powder or mean particle size cause the intensity of molded article quality or sintered compact or shape dispersed big, and in some cases, cause producing breach (chipping) or cracking, cause the leakage current value difference.Therefore, the tap density of mixed powder, mean particle size, flowability and slope of repose are the important factors of producing good sintered compact and good capacitors.

These physical propertiess of mixed powder seldom change before and after mixing with tackiness agent, but by the physical properties decision of used niobium powder for capacitor.Therefore, the tap density of importantly used niobium powder, mean particle size, flowability and slope of repose.The flowability of niobium powder and slope of repose mainly are subjected to tap density or average particle size influences, and therefore, tap density and mean particle size become important factor.

In the present invention,, and improve liquidity or the slope of repose, thereby acquisition reduces the effect of leakage current, the preferred 0.5～2.5g/ml of tap density, more preferably 0.8～1.9g/ml for productivity and the intensity that improves sintered compact.Preferred 10～1,000 micron of the mean particle size of niobium powder of the present invention, more preferably 50～200 microns.

In order to make the niobium powder free drop to the metal die of forming mill preferred 10 °～60 ° of the slope of repose of niobium powder of the present invention, more preferably 10 °～50 ° from hopper.

By carrying out at least one sintering step and broken step successively, can produce niobium powder with the mixture (hereinafter referred to as " raw mix ") that contains niobium powder or niobium compound powder (hereinafter referred to as " raw material niobium powder ") and activator (be also referred to as " hole formation material ", and hereinafter be sometimes referred to as " additive ") with above-mentioned physical properties.

Produce niobium powder process of the present invention from raw mix, remove deactivator at sintering step or broken step.The removal of activator also is independent of described sintering step or broken step is carried out.

According to the chemical property of activator, can use the whole bag of tricks arbitrarily except that deactivator.Can use a method easily removing activator or unite multiple these methods of using.

The example that removes the method for deactivator comprises evaporation, distillation or thermolysis activator and the method removed with gas form and by making it be dissolved in the method for removing activator in the solvent.

Removing under the situation of activator with gas form, can remove at sintering step, perhaps a step of removing deactivator under heating and/or decompression is being set before the sintering.

It is dissolved under the situation of removing activator in the solvent, the solvent of the following stated is contacted with sintered product or breakdown products, thus dissolving and removal activator.

Can nitrogenize, boronation, carbonization be set in any stage produce niobium powder process of the present invention by raw mix in or vulcanize the step of a part of niobium powder.

Below describe the method for producing niobium powder of the present invention in detail.

Raw material niobium powder can be at least a powder that is selected from niobium, hydrogenated niobium, niobium alloy and the hydrogenated niobium alloy.Part powder can be by nitrogenize, sulfuration, carbonization or boronation.Used " alloy " comprises the sosoloid with other alloying constituent among the present invention.

The mean particle size of raw material niobium powder is preferably 0.01～10 micron, and more preferably 0.02～5 micron, more preferably 0.05～2 micron.

Acquisition comprises the method for hydrogenation, fragmentation and dehydrogenation niobium ingot, niobium particle or niobium powder as the example of the method for the niobium of raw material niobium powder; method with reduction potassium niobate fluoride such as sodium and broken reduzate; use at least a reduction-oxidation niobium and the method for broken reduzate and the method for hydrogen reduction halogenation niobium of hydrogen, carbon, magnesium and aluminium.

Acquisition comprises the method for hydrogenation and broken niobium ingot, niobium particle or niobium powder as the example of the method for the hydrogenated niobium of raw material niobium powder.

Acquisition comprises the method for the hydride of broken niobium alloy ingot, niobium alloy particle or niobium alloy powder as the example of the method for the hydrogenated niobium alloy of raw material niobium powder.Acquisition comprises the method that makes the hydrogenated niobium alloy dehydrogenation that as above obtains as the example of the method for the niobium alloy of raw material niobium powder.

As the alloying constituent except niobium, niobium alloy or hydrogenated niobium alloy contain that to be selected from ordination number be 88 or at least a element of littler element, do not comprise hydrogen, nitrogen, oxygen, fluorine, chlorine, bromine, iodine, niobium, helium, neon, argon, krypton, xenon and radon.

Activator is can be at the material of being removed by any step in the process of raw mix production niobium powder of the present invention.In niobium powder of the present invention, in removing the part of deactivator, form hole usually.

The aperture of the particle size influences of activator niobium powder of the present invention, the aperture of niobium powder influences the aperture of niobium sintered body, and the aperture of niobium sintered body influences the dipping ability of negative electrode agent in the electrical capacity of electrical condenser and the electrical condenser production stage.

The dipping ability of negative electrode agent has a significant impact in the electrical condenser of producing heavy body and low ESR.When shaping niobium powder was produced sintered compact under by decompression, the aperture nature of niobium sintered body was less than the aperture of niobium powder.Because be difficult to impregnated cathode agent in the niobium sintered body that the niobium powder little by the aperture produced, therefore, the mean pore size of niobium powder is preferably 0.5 micron or bigger, more preferably 1 micron or bigger.

The mean pore size of niobium powder is preferably 0.01～500 micron, and more preferably 0.03～300 micron, more preferably 0.1～200 micron.In order to have the aperture in this scope, the mean particle size of activator is preferably 0.01～500 micron, and more preferably 0.03～300 micron, more preferably 0.1～200 micron.

The mean pore size of niobium powder most preferably is 0.5～100 micron, and the mean particle size of activator most preferably is 0.5～100 micron.

Use the activator of small grain size can reduce aperture diameter, and the activator of use volume particle size can hole diameter enlargement.

By regulating the size-grade distribution of activator, can adjustment aperture distribute.

In order to obtain to have enough high capacitances and not have negative electrode agent dipping ability aspect to relate to the electrical condenser of problem, preferably in niobium sintered body, suitably provide enough little hole to produce the electrical capacity of wishing, suitably provide enough big hole to flood to guarantee the satisfied of negative electrode agent according to the physical properties of negative electrode agent.

In order to regulate the pore size distribution of niobium powder or niobium sintered body, for example, the activator (powder) by use has the size-grade distribution of two or more peak values can make the niobium powder have the pore size distribution of two or more peak values.By this niobium powder of sintering, can obtain in pore size distribution, to have the niobium sintered body in the equal aperture of two or more peak values.In this case, described aperture peak value preferably is present in 0.01～500 micrometer range, more preferably 0.03～300 micron, further preferred 0.1～200 micron, preferred especially 0.1～30 micron, most preferably is 0.2～3 micron.

The niobium powder of producing above niobium sintered body has two or more peak values in size-grade distribution.Preferred 0.5 micron or bigger of any of described two or more peak values.For example, in order to produce the niobium sintered body that two peak values 0.7 and 3 microns are arranged in size-grade distribution, two peak values of niobium powder can be adjusted to about 1.5 and about 2.5 microns.In order to obtain to have 1.5 microns small-bore and to have 25 microns wide-aperture niobium powder, need use mean pore size respectively is the activator of 1.5 microns and 25 microns.In general, when hole that has minor diameter in the niobium powder and large diameter hole, in the press molding process, large diameter hole diminishes.So large diameter peak value is preferably 20 microns or bigger.30 volume % of also preferred all volume of voids or have 20 microns or bigger aperture, more preferably 40 volume % or more more.

Describe above embodiment in detail based on accompanying drawing below.Fig. 1 is the enlarged view of illustrative niobium powder of the present invention.Niobium powder among Fig. 1 is the granulation powder, and it comprises the starting powder with the special pore size distribution that is formed by activator.Use mean diameter about 1.5 microns and about 25 microns activator to form hole (A) and (B) respectively.Like this, can starting powder be condensed mutually.Fig. 2 is the sketch map by the niobium powder pore size distribution of mercury penetration method mensuration.Peak (A) is corresponding to the hole (A) that is formed by the about 1.5 microns activator of mean diameter, and peak (B) is corresponding to the hole (B) that is formed by the about 25 microns activator of mean diameter.Peak (B) is than peak (A) height, and all volume of voids 44% have 20 microns or bigger aperture.

For example, by being blended in two or more activators that have different peak values in the size-grade distribution, can obtain to have in the size-grade distribution activator of two or more peak values.

Be included in sintering temperature or followingly become the material of gas and behind sintering, dissolve in material in the solvent at least as the example of the material of activator.

Comprise the material that becomes gas by evaporation, distillation or thermolysis in sintering temperature or the following example that becomes the material of gas.Even also can easily become gas at low temperatures and the cheap material that do not stay residue is preferred.The example comprises aromatics such as naphthalene, anthracene and quinone, camphor, NH ₄Cl, ZnO, WO ₂, SnO ₂, MnO ₃And organic polymer.

The example of organic polymer comprises polyacrylic acid, polyacrylic ester, polyacrylamide, polymethyl acrylic acid, polymethacrylate, PMAm and polyvinyl alcohol.

At least soluble material is that the residue of activator or its thermal decomposition product dissolve in the material in the solvent behind sintering.The material that can easily be dissolved in the solvent described below behind sintering or in shattering process or after the fragmentation is particularly preferred.Such material can be selected from many materials according to the combination of solvent.

The example comprises compound, metal oxide, metal hydroxides and the metal of metal and carbonic acid, sulfuric acid, sulfurous acid, halogen, perhalogeno acid, hypohalous acid, nitric acid, nitrous acid, phosphoric acid, acetate, oxalic acid or boric acid.

Wherein, preferably solvent described below as acid, alkali or ammonium salt solution in the big compound of solubleness.The example comprises the compound that contains at least a composition that is selected from lithium, sodium, potassium, rubidium, caesium, francium, beryllium, magnesium, calcium, strontium, barium, radium, scandium, yttrium, cerium, neodymium, erbium, titanium, zirconium, hafnium, vanadium, niobium, tantalum, molybdenum, tungsten, manganese, rhenium, ruthenium, osmium, cobalt, rhodium, iridium, nickel, palladium, platinum, silver, gold, zinc, cadmium, aluminium, gallium, indium, thallium, germanium, tin, lead, antimony, bismuth, selenium, tellurium, polonium, boron, silicon and arsenic.Wherein, preferable alloy salt, more preferably for example barium oxide, manganous nitrate (II) and lime carbonate.

These activators can use separately or its two or more be used in combination.

In order effectively to form special pore size distribution, the material that exists with solid form under sintering temperature is preferred as activator material.Reason is to hinder the excessive reunion of original niobium powder under sintering temperature with the solid-state activator that exists, and makes the niobium powder only can fuse mutually at the point of contact place.If activator exists with liquid or gas form under sintering temperature, then it is little and may form littler hole than hope to the effect that hinders this reunion.Therefore, can make the aperture become more stable with comprising more high-melting-point material such as barium oxide, lime carbonate, aluminum oxide and magnesian activator than the activator that comprises low melting point such as aluminum metal, magnesium metal, magnesium hydride and calcium metal.

If add activator on a small quantity, it is big that tap density and slope of repose become, and if a large amount of the adding, then tap density diminishes, and increases at the sintering stage hole of remaining silent.For the tap density that obtains 60 ° or littler slope of repose and 0.5～2.5g/ml and there is not the problem of the hole of remaining silent in sintering stage, the add-on of activator is generally 1～40 quality % or still less (unless otherwise indicated, quality % abbreviates % hereinafter as), be preferably 5～25%, more preferably 10～20%, by the raw material niobium, still, this can change according to the mean particle size of activator.

By not using solvent respectively the do for oneself activator of powder type and niobium raw material or, can obtain raw mix by using suitable solvent activator and niobium raw material and dry this mixture.

The example of operable solvent comprises water, alcohol, ether, cellosolve, ketone, aliphatic hydrocarbon, aromatic hydrocarbon and halohydrocarbon.

Can use mixing machine to mix.About mixing machine, can use common equipment such as shaking mixer, V-Mixer and Nauter mixing machine and without any problem.Temperature during mixing is limited by the boiling point of solvent and zero pour, but be generally-50～120 ℃, is preferably-50～50 ℃, more preferably-10～30 ℃.Mix the not restriction especially of used time,, still, mix preferably and in the oxygen-free atmosphere that uses rare gas element such as nitrogen or argon gas, carried out 1～6 hour as long as it is 10 minutes or more.

Under the situation of using solvent, be lower than 80 ℃, preferably be lower than 50 ℃, use the mixture of the dry gained of circular cone moisture eliminator or compartment drier.If dry described mixture under 80 ℃ or higher temperature, then contained oxygen increases unfriendly in niobium or hydrogenated niobium powder.

At activator under sintering temperature or the following situation that becomes gas, activator can be removed when sintering, but will can be arranged on the step that makes activator form gas and remove before the sintering independently such as the condition of condition enactment of temperature, pressure and time for promoting to remove by chemical property according to activator.In this case, activator under reduced pressure evaporates in a few hours at 100～800 ℃.

Using under hydrogenated niobium or the situation of hydrogenated niobium alloy as the raw material niobium, can realize dehydrogenation by carrying out above-mentioned steps, and irrelevant with the kind of activator.

500～2,000 ℃, preferred 800～1,500 ℃, more preferably 1,000～1300 ℃, under reduced pressure or in reducing atmosphere such as argon gas, carry out sintering step.After sintering is finished, the temperature (abbreviating " product temperature " sometimes as) that sintered product preferably is cooled to niobium becomes 30 ℃ or lower, add gradually and contain 0.01～10 volume %, be preferably rare gas element such as the nitrogen or the argon gas of 0.1～1 volume % oxygen, make the product temperature be no more than 30 ℃, and left standstill 8 hours or more how after, take out sintered product, obtain the sintering agglomerate.

In broken step, use crusher such as roll-type granulation machine that the sintering agglomerate is crushed to suitable granularity.

At activator at least under the situation that dissolves in solvent behind the sintering step, make behind suitable solvent and sintering agglomerate or the sintering and before the fragmentation, among or broken powder during afterwards or in a plurality of these steps contact, thereby described activator is dissolved and remove.Owing to remove easily, activator component is preferably dissolved and removal the broken powder after fragmentation.

Here used solvent is to treat that the dissolved activator has the solvent of enough high-dissolvabilities therein.Cheap and residual hardly solvent is preferred.For example, under the situation of water-soluble activator, can make water; Under the situation of organic solvent solubility activator, can use such as mibk, ethanol or methyl-sulphoxide organic solvents such as (DMSO); Under the situation of solubility in acid activator, can use such as acid solutions such as nitric acid, sulfuric acid, phosphoric acid, boric acid, carbonic acid, hydrofluoric acid, hydrochloric acid, Hydrogen bromide, hydroiodic acid HI or organic acids; Under the situation of caustic solubility activator, can use such as alkaline solutions such as alkali metal hydroxide, alkaline earth metal hydroxides or ammonia; Under the situation of the activator that forms soluble complexes, can use become the complex compound part such as amine aqueous solutions such as ammonia or quadrols, such as amino acid such as glycine, such as Tripyrophosphoric acid such as tripoly phosphate sodium STPP, crown ether, such as thiosulphate such as Sulfothiorine or such as sequestrants such as ethylenediamine tetraacetic acid (EDTA)s.

Also can suitably use such as ammonium salt solution, Zeo-karb and anionite-exchange resin such as ammonium chloride, ammonium nitrate and ammonium sulfate.Preferably dissolve at a lower temperature and remove activator.If activator at high temperature dissolves and removes, then niobium is surperficial oxidized, because the affinity height of niobium and oxygen.Therefore, dissolving and the temperature of removing are preferably 50 ℃ or lower, and more preferably-10 ℃-40 ℃, more preferably 0 ℃-30 ℃.According to above reason, preferably be chosen in the method that produces little heat in dissolving and the removal process.For example, when using metal oxide or metal as activator, dissolving and the removal carried out with acid generally produce high neutralization heat.So, preferably select a kind of method that produces little heat, for example be dissolved in water and the organic solvent, form soluble complexes and be dissolved in the solvent that contains ion exchange resin by the solvent that uses ammonium salt and edetate.

The specific examples of the combination of activator and solvent comprises barium oxide and water, caoxalate and hydrochloric acid, aluminum oxide and aqueous sodium hydroxide solution, hafnia and mibk and the magnesiumcarbonate and the tetrasodium ethylenediamine tetraacetate aqueous solution.

After dissolving and removing activator, thorough washing and dry residue.For example, remove under the barytic situation, use ion exchanged soln thorough washing residue to be reduced to 5 μ S/cm or littler until the specific conductivity of washing lotion at water.Subsequently, at 50 ℃ or the lower described product of product temperature drying under reduced pressure.Here, the remaining activator or the amount of solvent composition are generally 100ppm or littler, but this changes along with wash conditions.

In order to improve the LC value, the niobium powder that obtains like this, sintering are rolled into a ball fast and the niobium raw material powder can be through nitrogenize, boronation, carbonization or the sulfuration of a part of niobium powder, perhaps multiple these processing.

Niobium powder of the present invention can contain niobium nitride, niobium (Nb) boride, niobium carbide or sulfuration niobium or multiple these materials that obtain to some extent.The total amount of nitrogen, boron, carbon and each element of sulphur changes along with the shape of niobium powder, but it is 0～200, and 000ppm is preferably 50～100,000ppm, more preferably 200～20,000ppm.If total content surpasses 200,000ppm, the condenser capacity characteristic degradation of being produced is not suitable for electrical condenser.

The nitrogenize of niobium powder can by liquid phase nitrogenize, ion nitriding and Gaseous Nitriding any or undertaken by its combination.Wherein, the Gaseous Nitriding in nitrogen atmosphere is preferred, because its equipment is simple and processing ease.For example, by making above-mentioned niobium powder in nitrogen atmosphere, leave standstill the Gaseous Nitriding that can be implemented in the nitrogen atmosphere.With 2,000 ℃ or following nitriding atmosphere temperature and 100 hours or shorter time of repose, the niobium powder that can obtain to have target nitrogenize amount.Handle and to shorten the treatment time at higher temperature.

The boronation of niobium powder can be gas phase boronation or solid phase boronation.For example, can under reduced pressure leave standstill 1 minute～100 hours 2,000 ℃ or following temperature, make niobium powder boronation by making itself and boron source such as boron particles or halogenation boron (for example boron trifluoride).

The carbonization of niobium powder can be any of gas carburization, solid phase carbonization and liquid phase carbonization.For example, can under reduced pressure make the carbonization of niobium powder in 1 minute～100 hours by it is left standstill 2,000 ℃ or following temperature with carbon source such as carbon material or carbonaceous organic materials (for example methane).

The sulfuration of niobium powder can be any of gas phase sulfuration, ion sulfuration and solid phase vulcanizing.For example, the gas phase sulfuration that can be implemented in the sulphur atmosphere by the niobium powder is left standstill in sulphur atmosphere.With 2,000 ℃ or following vulcanized gas temperature and 100 hours or shorter time of repose, the niobium powder that can obtain to have target sulfuration amount.By under higher temperature, handling and shortening the treatment time.

So the BET specific surface area of the niobium powder of the present invention that obtains is generally 0.5～40m ²/ g, preferred 0.7～10m ²/ g, more preferably 0.9～2m ²/ g.

Niobium powder of the present invention can be tap density, granularity, slope of repose, BET specific surface area, pore size distribution and the mixture of handling different niobium powder by nitrogenize, boronation, carbonization or sulfurized.

Can preferably produce as the sintered compact of the present invention of electrode for capacitors by for example sintering above-mentioned niobium powder of the present invention.For example, by being predetermined shape with niobium powder press molding, then at 500 ℃～2,000 ℃, preferred 800 ℃～1,500 ℃, more preferably 1,000 ℃～1300 ℃ 10 ^-5～10 ²Pa makes its heating 1 minute～10 hours.

The pore size distribution of the sintered compact that is obtained by niobium powder of the present invention has the aperture peak value usually in 0.01～500 micrometer range.

Impressed pressure by will be shaped the time is adjusted to specific force value, and described sintered compact can have the aperture peak value bigger than niobium powder.This impressed pressure value is with variations such as the shape of the physical properties of press molding condition such as niobium powder, molded article and forming mills, but in the pressure range that pressure that can press molding is not closed to the sintered compact hole.Determine the preferred pressure value so that it has a plurality of apertures peak value by the preliminary experiment basis such as the conditions such as physical properties of niobium powder to be formed.For example, the forming mill load that is applied to molded article by control can be controlled the impressed pressure value.

The pore size distribution of sintered compact preferably has at least two aperture peak values, so as to contain enough little with the hole that obtains to wish electrical capacity and according to the physical properties of negative electrode agent enough greatly to obtain the satisfied hole that floods of negative electrode agent.By this sintered compact that a plurality of peak values are arranged, can produce the dipping ability with excellent counter electrode and the electrical condenser of the apparent ratio of high-capacitance in pore size distribution.

When in a plurality of pore size distribution peak values, respectively in 0.2～0.7 micrometer range and in 0.7～3 micrometer range, preferred respectively when existence has the peak value at two peaks of high relative intensity in 0.2～0.7 micron and 0.9～3 micrometer range, can have good wet fastness by the electrical condenser of this sintered compact production.In a plurality of pore size distribution peak values, having, the peak value at the peak of high relative intensity preferably is present in than an inferior side of the peak value larger diameter at the peak of high relative intensity, because electrical condenser can have more excellent wet fastness.

So the specific surface area of the sintered compact of producing is generally 0.2～7m ²/ g.

Usually, the shape of sintered compact is big more, and the dipping of counter electrode is difficult more.For example, has 10mm at sintered compact ³Or under the situation of bigger size, can use the sintered compact of the present invention that in pore size distribution, has a plurality of peak values especially effectively.

Sintered compact of the present invention can the part nitrogenize.About nitriding method, can use aforesaid method and reaction conditions about the niobium powder.Nitrogenize in advance part nitrogen powder is used to produce a part of sintered compact that sintered compact and nitrogenize are produced by this niobium powder.

Such sintered compact contains the oxygen of 500～70,000 quality ppm usually, because the oxygen that has the oxygen of the natural oxidation that contains before the sintering and add by natural oxidation behind sintering in the niobium powder.In sintered compact of the present invention, the content of the element except niobium, alloy forming element, oxygen and nitrogen is generally 400 quality ppm or still less.

As an example, when sintered compact of the present invention during at 1300 ℃ of sintering, the CV value (80 ℃ in 0.1 quality % phosphoric acid solution 120 minutes electrochemical shaping voltage of electrochemical shaping and at the product of the electrical capacity of 120Hz) be 4,000～200,000 μ FV/g.

The production of capacitor devices is below described.

For example, the lead that preparation comprises the metal of rectifying action such as niobium or tantalum and has suitable shape and length, when the press molding of niobium powder,, make a part of lead insert the inside of molded article, thereby make lead can be used as the outlet line of sintered compact this lead integral forming.Perhaps be shaped and sintered niobium powder and use lead-in wire, then, wait the lead-in wire that will prepare separately coupled by welding.

Use this sintered compact as an electrode,, can produce electrical condenser by between this electrode and counter electrode, inserting a kind of dielectric materials.For example, by using niobium sintered body, go up the formation dielectric materials and on this dielectric materials, provide counter electrode, the preparation electrical condenser at this sintered compact surface (internal surface that comprises hole) as an electrode.

The dielectric materials that is used for this electrical condenser preferably mainly comprises the dielectric materials of niobium oxides, more preferably mainly comprises the dielectric materials of Niobium Pentxoxide.For example, can obtain mainly to contain the dielectric materials of Niobium Pentxoxide as the niobium sintered body of an electrode by electrolytic oxidation.For the described niobium electrode of electrolytic oxidation in electrolytic solution, generally use protonic acid aqueous solution, for example 0.1% phosphate aqueous solution, aqueous sulfuric acid, 1% the acetic acid aqueous solution or the hexanodioic acid aqueous solution.Obtaining under the situation of niobium oxides dielectric materials by electrochemical shaping niobium electrode in electrolytic solution like this, electrical condenser of the present invention is that a kind of electrolytic condenser and niobium electrode are used as anode.

In electrical condenser of the present invention,, for example can use the known at least a material (compound) that is selected from electrolytic solution, organic semiconductor and inorganic semiconductor in the aluminium electrolutic capacitor technology to the not restriction especially of counter electrode of described niobium sintered body.

The specific examples of electrolytic solution comprises the isobutyl carbonate propyl ester-ethylene glycol mixing solutions that wherein dissolves the electrolytical dimethyl formamide of 5 quality % isobutyl-tripropyl ammonium tetrafluoroborates-ethylene glycol mixing solutions and wherein dissolve 7 quality % tetraethyl-ammonium tetrafluoroborates.

The organic semi-conductor specific examples comprises, comprise the organic semiconductor of benzene pyrroline tetramer and chloranil, mainly contain the organic semiconductor of four thio naphthacene, mainly contain the organic semiconductor of four cyano quinone bismethane and contain electric conductive polymer by the repeating unit of following formula (1) or (2) expression:

Wherein, R ¹～R ⁴Expression independently of one another is selected from hydrogen atom, contains saturated or unsaturated alkyl, alkoxyl group or alkyl group, halogen atom, nitro, cyano group, primary, the second month in a season or uncle's amino, the CF of the straight or branched of 1～10 carbon atom ₃The univalent perssad of the phenyl of group, phenyl and replacement; Each is to R ¹And R ², R ³And R ⁴Can be at an arbitrary position in conjunction with forming the divalence chain, be used for by R ¹And R ²Or by R ³And R ⁴The carbon atom that replaces forms at least one 3-, 4-, the saturated or unsaturated hydrocarbons ring structure of 5-, 6-or 7-unit together; Annular bonded chain can contain carbonyl, ether, ester, acid amides, thioether, sulfinyl, alkylsulfonyl or imino-at an arbitrary position; X represents Sauerstoffatom, sulphur atom or nitrogen-atoms; R ⁵Only when X is nitrogen-atoms, just exist, and represent hydrogen atom independently or contain straight or branched, the saturated or unsaturated alkyl of 1～10 carbon atom.

In the present invention, the R in formula (1) or (2) ¹～R ⁴Preferably represent hydrogen atom independently of one another or contain 1～6 carbon atom straight or branched, saturated or undersaturated alkyl or alkoxyl group, and every couple of R ¹And R ², R ³And R ⁴Can be in conjunction with forming ring.

In the present invention, containing electric conductive polymer by the repeating unit of formula (1) expression preferably contains by the structural unit of following formula (3) the expression electric conductive polymer as repeating unit:

Wherein, R ⁶And R ⁷Represent hydrogen atom independently of one another, contain the saturated or unsaturated alkyl of the straight or branched of 1～6 carbon atom, perhaps a substituting group is used to form at least one 5-, the 6-that contain two Sauerstoffatoms or the 7-unit stable hydrocarbon ring structure that are obtained by the alkyl that mutually combines at an arbitrary position; And ring texture comprises having the structure of can substituted vinylidene key, can substituted phenylene structure.

The electric conductive polymer that contains such chemical structure a kind of doping agent that mixes, and for described doping agent can use known doping agent and without limits.

The specific examples of inorganic semiconductor comprises inorganic semiconductor that mainly comprises plumbic oxide or Manganse Dioxide and the inorganic semiconductor that comprises Z 250.These semi-conductors can use separately, perhaps its two or more be used in combination.

The example that contains the polymkeric substance of the repeating unit of representing in formula (1) or (2) comprises polyaniline, polyphenylene oxide, polyphenylene sulfide, Polythiophene, poly-furans, polypyrrole, poly-methyl pyrrole, and substitutive derivative and multipolymer.Wherein, preferred polypyrrole, Polythiophene and substitutive derivative thereof (for example poly-(3,4-ethylidene dioxy thiophene)).

When the semi-conductive specific conductivity of used organic or inorganic is 10 ^-2S/cm～10 ³During S/cm, the electrical condenser of being produced can have littler resistance value and can increase the high-frequency electrical capacity.

For example, by the method for polymerization polymerizable compound such as aniline, thiophene, furans, pyrroles, methylpyrrole or their substitutive derivative under the oxygenant effect of the oxidizing reaction of the two electronics oxidations that can carry out dehydrogenation satisfactorily, can produce electric conductive polymer.The example of the polyreaction of polymerizable compound (monomer) comprises vapour phase polymerization and solution polymerization.The electric conductive polymer layer has thereon on the niobium sintered body surface of niobium sintered body of dielectric materials and forms.At electric conductive polymer is under the situation of organic solvent soluble polymer that can solution coat, uses on described sintered compact surface coated polymeric to form the method for electric conductive polymer layer.

A preferred examples using the manufacture method of solution polymerization is that a kind of niobium sintered body that will form dielectric layer thereon is immersed in the solution (solution 1) that contains oxygenant, subsequently this sintered compact is immersed in the solution (solution 2) that contains monomer and doping agent, thereby carry out polymerization, so that on this sintered compact surface, form the electric conductive polymer layer.Also can after being immersed in the solution 2, it again this sintered compact be immersed in the solution 1.The solution 2 that uses in aforesaid method can be the monomer solution that does not contain doping agent.Under the situation of using doping agent, this doping agent is existed in the solution that contains oxygenant.

The operation of being carried out these polymerization procedures by the sintered compact that dielectric materials is arranged on it repeats one or many, and preferred 3～20 times, thus can easily form fine and close and stratified electric conductive polymer layer.

In the manufacture method of electrical condenser of the present invention, can use any oxygenant, as long as the electroconductibility that its reductive agent that can influence capacitor performance and oxygenant can become doping agent and improve electric conductive polymer sharply.The industrial cheap compound of easy to handle is preferred when producing.

The specific examples of oxygenant comprises Fe (III) based compound such as FeCl ₃, FeClO ₄And Fe (organic anion) salt; Aluminum chloride anhydrous/cuprous chloride; Alkali metal persulphate; Ammonium persulphate; Peroxide; Manganese class such as potassium permanganate; Quinine is as 2,3-two chloro-5,6-dicyano-1,4-benzoquinones (DDQ), tetrachloro-1,4-benzoquinones and four cyano-1,4-benzoquinones; Halogen such as iodine and bromine; Peracid; Sulfonic acid such as sulfuric acid, oleum, sulphur trioxide, chlorsulfonic acid, fluosulfonic acid and thionamic acid; Ozone; Mixture with multiple these oxygenants.

The basic examples for compounds that forms the organic anion of above-mentioned Fe (organic anion) salt comprises organic sulfonic acid, organic carboxyl acid, organic phosphoric acid and organic boronic.The specific examples of organic sulfonic acid comprises Phenylsulfonic acid, tosic acid, methylsulfonic acid, ethyl sulfonic acid, alpha-sulfo naphthalene, β-sulfo group naphthalene, naphthalene disulfonic acid and alkyl naphthalene sulfonic acid (example of alkyl comprises butyl, triisopropyl and di-t-butyl).

The specific examples of organic carboxyl acid comprises acetate, propionic acid, phenylformic acid and oxalic acid.In addition, can also use polymer dielectric negatively charged ion such as polyacrylic acid, polymethyl acrylic acid, polystyrolsulfon acid, polyvinylsulfonic acid, poly--Alpha-Methyl sulfonic acid, polyvinyl sulfuric acid and polyvinyl sulfonic acid and polyphosphoric acid in the present invention.These organic sulfuric acid and organic carboxyl acid only are examples, and the invention is not restricted to these.The example of above-mentioned anionic counter cation comprises alkalimetal ion such as H ⁺, Na ⁺And K ⁺, and, still, the invention is not restricted to these by the ammonium ion that hydrogen atom, tetramethyl-, tetraethyl-, the tetrabutyl or tetraphenyl replace.In these oxygenants, preferably contain trivalent Fe-based compound, cuprous chloride, alkali metal persulphate, ammonium persulphate or quinone.

For in the polymer composition of electric conductive polymer is produced, the negatively charged ion with doping agent ability that can exist together as required (negatively charged ion except the reductive agent negatively charged ion of oxygenant) can use by what above-mentioned oxygenant produced and contain electrolytic anion or other electrolytic anion of oxygenant negatively charged ion (reductive agent of oxygenant) as counter anion.Its specific examples comprises the protonic acid negatively charged ion, comprises the halide anions such as the PF of 5B family element ₆ ^-, SbF ₆ ^-And AsF ₆ ^-The halide anions of 3B group element such as BF ₄ ^-Halide anion such as I ^-(I ₃ ^-), Br ^-And Cl ^-Perhalogeno hydrochlorate ion such as ClO ₄ ^-Lewis acid anion such as AlCl ₄ ^-, FeCl ₄ ^-And SnCl ₅ ^-Inorganic anion such as NO ₃ ^-And SO ₄ ^2-Sulfonic acid anion such as tosic acid, naphthene sulfonic acid and contain the naphthene sulfonic acid (hereinafter referred is " Cl-5 ") that the alkyl of 1～5 carbon atom replaces; Organic sulfonic acid root negatively charged ion such as CF ₃SO ₃ ^-And CH ₃SO ₃ ^-With carboxylate anion such as CH ₃COO ^-And C ₆H ₅COO ^-

Other example comprises polymer dielectric negatively charged ion such as polyacrylic acid, polymethyl acrylic acid, polystyrolsulfon acid, polyvinylsulfonic acid, polyvinyl sulfuric acid, poly--Alpha-Methyl sulfonic acid, polyvinyl sulfonic acid and polyphosphoric acid.Yet, the invention is not restricted to these.In these negatively charged ion, preferred polymer or low molecule organic sulfonic acid compound or polyphosphoric acid compound.Preferably, aromatic sulfonic acid compound (for example Sodium dodecylbenzene sulfonate, sodium naphthalene sulfonate) is as the negatively charged ion supplying compound.

In organic sulfonic acid root negatively charged ion, more effective doping agent is to contain one or more sulfonate anion group (SO at intramolecularly ₃-) and have the sulfo group naphtoquinone compounds and the anthracene sulfonic acid root negatively charged ion of quinone structure.

The example of the anionic basic framework of sulfo group quinone of above-mentioned sulfo group naphtoquinone compounds comprises para benzoquinone, adjacent benzoquinones, 1,2-naphthoquinones, 1,4-naphthoquinones, 2,6-naphthoquinones, 9,10-anthraquinone, 1,4-anthraquinone, 1,2-anthraquinone, 1,4-

Quinone, 5,6-

Quinone, 6,12-

Quinone, acenaphthenequinone, acenaphthene quinone, camphorquinone, 2,3-camphane diketone, 9,10-phenanthrenequione and 2,7-pyrene quinone.

At counter electrode is under the solid situation, and conductive layer can be set thereon, so that obtain and outer conductor (for example lead frame) good electrical contact of using on demand.

For example stick with paste, electroplate, metallize or form heat-resisting conductive resin membrane, can form conductive layer by curing conductive.The preferred embodiment that conduction is stuck with paste comprises silver paste, copper paste, aluminium paste, carbon paste and nickel paste; These can use separately or its two or more be used in combination.Under the situation of using two or more pastes, these pastes can mix or can be overlapped with the independent stratum form.Galvanized example comprises nickel plating, copper plating, silver plating and aluminium plating.The example of the sedimentary metal of steam comprises aluminium, nickel, copper and silver.

More specifically, for example, carbon paste and silver are stuck with paste be stacked on second electrode successively, and these are used material forming such as Resins, epoxy, thereby prepare a kind of electrical condenser.This electrical condenser can have niobium or the tantalum lead-in wire with niobium sintered body integral sintering and shaping or welding afterwards.

For example use the dipping or the stacked film of resin die, resin enclosure, metal shell, resin to come to add casing, be used for various uses as capacitor product then to the electrical condenser of the present invention of preparation like this.

At counter electrode is under the situation of liquid, for example, the prepared electrical condenser that will comprise above-mentioned two electrodes and dielectric materials be contained in one with shell that counter electrode is electrically connected in, to finish this electrical condenser.In this case, the electrode side of niobium sintered body is guided to the outside by above-mentioned niobium or tantalum, uses electro-insulating rubber etc. and described casing insulation simultaneously.

By using the niobium powder production of producing to be used for the sintered compact of electrical condenser and producing electrical condenser, can obtain to have the electrical condenser of little leakage current and good reliability from described sintered compact according to embodiment of the present invention of describing in front.

Electrical condenser of the present invention has bigger volume electrostatic capacity than traditional tantalum capacitor, so can obtain the capacitor product of more miniaturization.

Electrical condenser of the present invention with such character can be applied to, and for example, as the pass capacitor or the coupling condenser that are used in usually in mimic channel and the digital circuit, and can be used for traditional tantalum capacitor.

In general, such electrical condenser is used in the electronic circuit usually, and when using electrical condenser of the present invention, the restriction of the discharge aspect of electronic unit arrangement or heat reduces, therefore, the electronic circuit with high reliability can be arranged in than in the required narrower space of conditional electronic circuit.

In addition, when using electrical condenser of the present invention, can obtain to have the smaller szie and the electronic machine of high reliability more, as computer, computer peripheral (for example PC card), mobile equipment (for example portable phone), housed device, be installed in equipment, man-made satellite and communication equipment on the vehicles than traditional electronic machine.

Implement best mode of the present invention

Describe the present invention in detail below with reference to embodiment and comparative example, still, the invention is not restricted to these examples.

In each embodiment, the ESR value of the electrical capacity of the tap density of niobium powder, slope of repose, granularity and aperture and electrical condenser, leakage current, the apparent ratio of electrical capacity, wet fastness and electrical condenser is all measured by the following method.

(1) mensuration of tap density

Tap density is to measure according to the method for using the jolt ramming device in the apparent specific gravity assay method of the industrial monohydrate of stipulating among JIS (Japanese Industrial Standards' version in the 2000) K1201-1 and determining instrument.

(2) mensuration at slope of repose

The slope of repose is to use the fluidity determining instrument stipulated among JIS (Japanese Industrial Standards' version in the 2000) Z2504 and sample size to measure.More particularly, be that the hopper of 6cm makes niobium monoxide powder fall to horizontal plane from respect to the horizontal plane hopper lower height, with the summit of generation circular cone to the inclined-plane angle with respect to the horizontal plane of horizontal plane as the slope of repose.

(3) mensuration of granularity

The equipment that uses Microtrack (HRA 9320-X100) to make is measured size-grade distribution by the laser diffraction and scattering method.Granularity (the D that is equivalent to 50 volume % at accumulative total volume % ₅₀Micron) is designated as mean particle size.

(4) mensuration in aperture

The Poresizer 9320 that use is made by Micromeritics measures pore size distribution by mercury penetration method.

In the present invention, by the velocity of variation decision maximum value that is pressed into use level (press-fitted amount) and by aperture shown in the maximum value is defined as peak value, with the size of maximum value as the relative intensity at peak under this peak value.

(5) mensuration of condenser capacity

In room temperature, between the terminal of the sheet of made, connect the LCR tester that Hewlett-Packard makes, volumetric determination value that will be when 120Hz is as the electric capacity of processing electrical condenser in blocks.

(6) mensuration of capacitor leakage electric current

At room temperature, will between the terminal of the sheet of made, apply current value that the 6.3V volts DS measures after 1 minute leakage current values as processing electrical condenser in blocks.

(7) the apparent ratio of the electrical capacity of electrical condenser

Electrical capacity when supposing under the condition that is determined at 80 ℃ and 20V in 30% sulfuric acid in 0.1% phosphoric acid solution 1,000 minute sintered compact of electrochemical shaping is 100%, and then the ratio value representation of the electrical capacity after the electrical condenser is used and produced to the apparent ratio of electrical capacity.

(8) the wet fastness value of electrical condenser

By the electrical capacity of the electrical condenser of being produced after leaving standstill 500 hours under 60 ℃ and 95% relative humidity less than initial value 110% or represent the wet fastness value less than 120% number.Number less than 110% is many more, illustrates that the wet fastness value is good more.

(9) mensuration of the ESR value of electrical condenser

In room temperature, between the terminal of the sheet of made, connect the LCR tester that Hewlett-Packard makes, will be at the ESR of the ESR measured value under 100kHz, 1.5VDC and the 0.5Vrms as electrical condenser.

Embodiment 1

5,000 grams of packing in nickel crucible are the sodium of 10 times of fluoro potassium niobates at 80 ℃ of abundant vacuum drying fluoro potassium niobates and molar weight, and make its under argon atmospher 1,000 ℃ of reduction reaction of carrying out 20 hours.After reacting completely, with the reduzate cooling, wash with water successively, the sulfuric acid scrubbing with 95% washes with water then, and vacuum-drying also uses the oxidation aluminium pot ball mill that contains the silica alumina ball to pulverize 40 hours.With crushed products dipping and stirring in 3: 2 (by mass) of 50% nitric acid and 10% aqueous hydrogen peroxide solution mixing solutions.Then,, reach 7, to remove impurity, vacuum-drying then until the pH value with crushed products water thorough washing.The mean particle size of raw material niobium powder is 1.2 microns.

In the niobium jar, place 500 this raw material niobium powder of gram and gather methyl butyl acrylate and 1 liter of toluene to wherein adding 50 grams.In addition, add zirconia ball and use shaking mixer with contents mixed 1 hour.After removing zirconia ball, this mixture is placed in the circular cone moisture eliminator and 1 * 10 ²Vacuum-drying under the condition of Pa and 80 ℃.

Subsequently, with this niobium powder at 250-400 ℃ 1 * 10 ^-2Pa heating 12 hours is to decompose and to remove poly-methyl butyl acrylate, then 4 * 10 ^-3Under the decompression of Pa 1,150 ℃ of sintering 2 hours.The cooling of niobium powder sintering agglomerate being reduced to 30 ℃ or lower until the product temperature, using the fragmentation of roll-type tablets press then, is 100 microns the broken powder of niobium with the acquisition mean particle size.

The broken powder of this niobium obtains the niobium powder of about 450 grams by feeding nitrogen through at 300 ℃, 2 hours nitriding treatment adding to depress.Nitrogen content is 0.22%.

The physical properties of this niobium powder such as tap density, mean particle size, slope of repose, BET specific surface area and aperture peak value are represented in table 1.

In the hopper with niobium powder (about 0.1 gram) the tantalum device automatic forming machine of packing into (TAP-2R is made by Seiken) that so obtains, and, come manufacturing dimension to be about the molded article of 0.3cm * 0.18cm * 0.45cm with the niobium silk automatic forming of 0.3mm φ.The qualitative dispersiveness of outward appearance and molded article is represented in table 1.

This molded article is 4 * 10 ^-3Left standstill 30 minutes at 1,250 ℃ in the vacuum of Pa, to obtain sintered compact.Prepare this sintered compact of 100, and each uses 0.1% phosphate aqueous solution electrochemical shaping 200 minutes under 20V voltage, so that form the oxide dielectric film from the teeth outwards.

Subsequently, repeat this sintered compact is immersed in and make it in 60% manganese nitrate aqueous solution then, so that on the oxide dielectric film, form manganese dioxide layer as the counter electrode layer in 30 minutes operations of 220 ℃ of heating.On this counter electrode layer, stack gradually carbon-coating and silver paste layer.Install thereon after the lead frame, this device is shaped with Resins, epoxy as a whole, to make chip capacitor.The average electrical capacity and the average leakage current (hereinafter referred is " LC ") of apparent ratio of the electrical capacity of this electrical condenser and chip capacitor (n=100) are represented in table 1.The LC value is the 1 minute value at room temperature measuring of voltage by applying 6.3V.

Embodiment 2

In the reactor of SUS 304 system, put into 1,000 gram niobium ingot, and at 400 ℃ to wherein feeding hydrogen continuously 10 hours.After cooling, be placed on hydrogenant niobium ingot in SUS 304 system jar that contains zirconia ball and pulverized 10 hours.Then, make this hydride and water form the slurry of 20 volume %, with zirconia ball pack into spike mill and under 40 ℃ or lower temperature wet pulverization 7 hours, with the hydrogenated niobium slurry that obtains to pulverize.The mean particle size of this raw material hydrogenation niobium powder is 0.9 micron.

In SUS system jar, this slurry of packing into (slurry concentration is 98%) and be 1 micron barium oxide to the mean particle sizes that wherein add 200 grams.In addition, add zirconia ball and use shaking mixer with contents mixed 1 hour.After removing zirconia ball, this mixture is placed in the bucket of niobium system, and 1 * 10 ²Vacuum-drying under the condition of Pa and 50 ℃.

Subsequently, 1 * 10 ^-2Under the Pa at 400 ℃ with the mixture heating up of gained 4 hours, so that make the hydrogenated niobium dehydrogenation, then 4 * 10 ^-3Under the decompression of Pa 1,100 ℃ of sintering 2 hours.With the mixing of gained barytic niobium sintering agglomerate cooling be reduced to 30 ℃ or lower until the product temperature, use the fragmentation of roll-type tablets press then, with obtain mean particle size be 95 microns mixing the broken powder of barytic niobium.

This of 500 grams of packing in polytetrafluoroethylcontainer container mixed barytic niobium broken powder and 1,000 gramion exchanged water and has been cooled to 15 ℃ or lower.Preparation is by mixing 600 grams, 60% nitric acid, 150 gram 30% hydrogen peroxide and 750 gramion exchanged waters and being cooled to 15 ℃ or the lower aqueous solution that obtains separately.Under agitation condition, mixed this aqueous solution of Dropwise 5 00 gram in the aqueous solution of the broken powder of barytic niobium then, and noted not making water temperature surpass 20 ℃ to wherein having suspended.After being added dropwise to complete,, left standstill 30 minutes, then decant this solution continuously stirring 1 hour again.To wherein adding 2,000 gramion exchanged waters, and, left standstill 30 minutes, then decant the solution stirring of gained 30 minutes.This operation repeats 5 times.Then, the broken powder of niobium is packed in the teflon system post, and wash 4 hours with water and make deionized water mobile simultaneously.At this moment, the washing electrical conductivity of water is 0.9 μ S/cm.

After washing was finished, at 50 ℃ of drying under reduced pressure, and by depressing by nitrogen through 300 ℃ nitriding treatment 3 hours adding, the result obtained the niobium powder of about 350 grams with the broken powder of niobium.Nitrogen content is 0.28%.

The physical properties of this niobium powder such as tap density, mean particle size, slope of repose, BET specific surface area and aperture peak value are represented in table 1.

In the hopper with niobium powder (about 0.1 gram) the tantalum device automatic forming machine of packing into (TAP-2R is made by Seiken) that so obtains, and, come manufacturing dimension to be about the molded article of 0.3cm * 0.18cm * 0.45cm with the niobium silk automatic forming of 0.3mm φ.The qualitative dispersiveness of outward appearance and molded article is represented in table 1.

This molded article is 4 * 10 ^-3Left standstill 30 minutes at 1,250 ℃ in the vacuum of Pa, to obtain sintered compact.Prepare this sintered compact of 100, and each uses 0.1% phosphate aqueous solution electrochemical shaping 200 minutes under 20V voltage, so that form the oxide dielectric film from the teeth outwards.

Subsequently, the oxide dielectric film is contacted with the balanced mix solution of 10% ammonium persulfate aqueous solution with 0.5% anthraquinone sulfonic acid solution, the operation that contacts with pyrroles's steam repeats 5 times at least then, so that form the counter electrode that comprises polypyrrole on the oxide dielectric film.

On this counter electrode layer, stack gradually carbon-coating and silver paste layer.Install thereon after the lead frame, this device is shaped with Resins, epoxy as a whole, to make chip capacitor.The average electrical capacity peace of apparent ratio of the electrical capacity of this electrical condenser and chip capacitor (n=100) all LC value is represented in table 1.The LC value is the 1 minute value at room temperature measuring of voltage by applying 6.3V.

Embodiment 3～10

Produce niobium powder, its molded article, sintered compact and electrical condenser with the method identical with embodiment 1, but change the add-on of mean particle size and poly-methyl butyl acrylate, perhaps use the method production identical, but change mean particle size and barytic add-on with embodiment 2.The dispersiveness of the physical properties of niobium powder and outward appearance and molded article quality, and the electrical capacity of electrical condenser and LC represent in table 1.

Embodiment 11～22

With method production example 11～14 identical and 16～18 niobium powder, molded article and sintered compact with embodiment 1, with method production example 15 identical with embodiment 2 and 19～22 niobium powder, molded article and sintered compact, but the activator that made of use table 1 replaces poly-methyl butyl acrylate or barium oxide in each case.The dispersiveness of the physical properties of niobium powder and outward appearance and molded article quality, and the electrical capacity of electrical condenser and LC represent in table 1.

These molded articles then at 1,250 ℃ 4 * 10 ^-3Left standstill under the decompression of Pa 30 minutes, to obtain sintered compact.Prepare every kind of sintered compact of 100, and use 0.1% phosphate aqueous solution electrochemical shaping 200 minutes under 20V voltage, so that form the oxide dielectric film from the teeth outwards.

Subsequently, the every kind of sintered compact that has formed the oxide dielectric film on it is immersed in the aqueous solution (solution 1) of the ammonium persulphate that contains 25 quality %, pull out, 80 ℃ of dryings 30 minutes, be immersed in and contain 3 of 18 quality %, in the aqueous isopropanol (solution 2) of 4-ethylidene dioxy thiophene, pull out, in 60 ℃ atmosphere, left standstill 10 minutes then, thereby carry out oxypolymerization.This sintered compact is immersed in the solution 1 again, uses then with above identical method and handle.Repeat 8 times from the operation of dipping solution 1 up to oxypolymerization.Then, sintered compact with 50 ℃ warm water washing 10 minutes, and 100 ℃ of dryings 30 minutes, thereby is formed the counter electrode that comprises conductive poly (3,4-ethylidene dioxy thiophene).

On this counter electrode, stack gradually carbon-coating and silver paste layer.Install thereon after the lead frame, this device is shaped with Resins, epoxy as a whole, to make chip capacitor.The average electrical capacity and the average LC value of apparent ratio of the electrical capacity of this electrical condenser and chip capacitor (n=100) are represented in table 1.The LC value is the 1 minute value at room temperature measuring of voltage by applying 6.3V.

Embodiment 23～25

Produce niobium powder, sintered compact and electrical condenser with the method identical with embodiment 2, but as raw material, in embodiment 23, use niobium-tin alloy powder, in embodiment 24, use hydrogenated niobium-rhenium alloys powder, in embodiment 25, use hydrogenated niobium-yttrium-boron alloy powder.The physical properties of electrical condenser, capacity and LC represent in table 1.

Comparative example 1～3

2,000 grams of packing in nickel crucible are the sodium of 10 times of potassium niobate fluorides at 80 ℃ of abundant vacuum drying potassium niobate fluorides and molar weight, and make its under argon atmospher 1,000 ℃ of reduction reaction of carrying out 20 hours.After reacting completely, with the reduzate cooling, washing in order, the sulfuric acid scrubbing with 95% washes with water then, and vacuum-drying also uses the oxidation aluminium pot ball mill that contains the silica-alumina ball to pulverize, and changes the pulverizing time.With crushed products dipping and stirring in 3: 2 (by mass) of 50% nitric acid and 10% aqueous hydrogen peroxide solution mixing solutions.Then,, reach 7, to remove impurity, vacuum-drying then until the pH value with every kind of crushed products water thorough washing.The mean particle size of the niobium powder of being produced is 1.3 microns～10 microns.

Niobium powder with 50 gram gained are placed in the SUS304 system reactor subsequently, and at 300 ℃ continuously to wherein feeding nitrogen 2～4 hours, to obtain niobium nitride.

The physical properties of every kind of niobium powder such as tap density, mean particle size, slope of repose, BET specific surface area and aperture peak value are represented in table 1.

In the hopper with niobium powder (about 0.1 gram) the tantalum device automatic forming machine of packing into (TAP-2R is made by Seiken) that so obtains, and attempt niobium silk automatic forming with 0.3mm φ.The gained result represents in table 1.

Comparative example 4～9

With the method identical with embodiment 2 but changing mean particle size is 1 micron barytic add-on, having obtained tap density is the niobium powder of 0.2～0.4g/ml or 2.6～3.3g/ml.Its physical properties is represented in table 1.

In the hopper with niobium powder (about 0.1 gram) the tantalum device automatic forming machine of packing into (TAP-2R is made by Seiken) that so obtains, and, come manufacturing dimension to be about the molded article of 0.3cm * 0.18cm * 0.45cm with the niobium silk automatic forming of 0.3mm φ.The qualitative dispersiveness of outward appearance and molded article is represented in table 1.

These molded articles are 4 * 10 ^-3Left standstill 30 minutes at 1,250 ℃ in the vacuum of Pa, to obtain sintered compact.Prepare every kind of sintered compact of 100, and use 0.1% phosphate aqueous solution electrochemical shaping 200 minutes under 20V voltage, so that form the oxide dielectric film from the teeth outwards.

Subsequently, the oxide dielectric film is repeated 5 times, so that on the oxide dielectric film, form the counter electrode that comprises polypyrrole at least with the operation that the balanced mix solution of 10% ammonium persulfate aqueous solution and 0.5% anthraquinone sulfonic acid solution contacts and contacts with pyrroles's steam then.

On this counter electrode, stack gradually carbon-coating and silver paste layer.Install thereon after the lead frame, this device is shaped with Resins, epoxy as a whole, to make chip capacitor.The average electrical capacity and the average LC value of apparent ratio of the electrical capacity of this electrical condenser and chip capacitor (n=100) are represented in table 1.The LC value is the 1 minute value at room temperature measuring of voltage by applying 6.3V.

Embodiment 26～31

The hydride of niobium ingot pulverized and dehydrogenation is 0.8 micron a primary particle to obtain mean particle size.With the primary particle sintering and the pulverizing of gained, to obtain the niobium prilling powder.Then, this prilling powder of 0.1 gram is contained in the metal die (4.0mm * 3.5mm * 1.8mm) with the niobium silk of the long 10mm of independent preparation, thick 0.3mm, and use tantalum device automatic forming machine (TAP-2R, make by Seiken) it is applied load as shown in table 2, to produce molded article.Then with each molded article 1300 ℃ of sintering 30 minutes, to obtain the target sintered compact.By the load that the control forming mill applies, produced sintered compact with the pore size distribution shown in the table 2.The size of the sintered compact of embodiment 26, specific surface area and CV value are respectively 24.7mm ³, 1.1m ²/ g and 85,000 μ FV/g.In other embodiments, each the value embodiment 26 ± 2% scope in.

Embodiment 32～34

Obtain sintered compact with the method identical, but be 0.5 micron by making the primary particle classification change mean particle size with embodiment 26～28.The size of the sintered compact of embodiment 32, specific surface area and CV value are respectively 24.9mm ³, 1.5m ²/ g and 125,000 μ FV/g.In other embodiments, each the value embodiment 32 ± 1% scope in.The pore size distribution of each sintered compact of being produced is represented in table 2.

Embodiment 35

Obtain sintered compact with the method identical with embodiment 31, but be to use with embodiment 4 in the niobium powder that obtains of identical method replace described granulation powder.The size of the sintered compact of embodiment 35, specific surface area and CV value are respectively 24.8mm ³, 1.2m ²/ g and 78,000 μ FV/g.The pore size distribution of the sintered compact of being produced is represented in table 2.

Comparative example 10～12

Produce sintered compact with the method identical, replace used niobium granulation powder among the embodiment 26～28 with the prepared niobium powder of magnesium reduction niobium chloride but be to use 1,100 ℃ of thermal treatment with embodiment 26～28.The size of the sintered compact of comparative example 10, specific surface area and CV value are respectively 24.3mm ³, 0.8m ²/ g and 84,000 μ FV/g.In other comparative example, each the value comparative example 10 ± 2% scope in.The pore size distribution of each sintered compact of being produced is represented in table 2.

Embodiment 36

60 of the various sintered compacies of producing with the method identical with embodiment 21 and embodiment 26～35, each is in 80 ℃ 0.1% phosphate aqueous solution and 20V electrochemical shaping 1,000 minute, so that form the oxide dielectric film on the sintered compact surface.With the sintered compact behind these electrochemical shapings grouping, form by 30 for every group.With 30 sintered compacies in every group with two kinds of negative electrode agent A shown in the tables 3 and B dipping.Stack gradually carbon paste and silver paste thereon, and this device is shaped with Resins, epoxy, with the preparation chip capacitor.Apparent ratio of the electrical capacity of each electrical condenser of manufacturing and wet fastness value are represented in table 4.

Comparative example 13

60 of the various sintered compacies of producing with the method identical with comparative example 9～12, each is in 80 ℃ 0.1% phosphate aqueous solution and 20V electrochemical shaping 1,000 minute, so that form the oxide dielectric film on the sintered compact surface.With the sintered compact behind these electrochemical shapings grouping, form by 30 for every group.30 sintered compacies in every group are flooded with the negative electrode agent A shown in the table 3.Stack gradually carbon paste and silver paste thereon, and this device is shaped with Resins, epoxy, with the preparation chip capacitor.Apparent ratio of the electrical capacity of each electrical condenser of manufacturing and wet fastness value are represented in table 4.

Embodiment 37

Pulverize raw material hydrogenation niobium powder by the method identical, obtain slurry with embodiment 2.The mean particle size of this hydrogenant agent powder is 0.6 micron.After pulp centrifuged sedimentation, remove supernatant liquid by decant.To make slurry concentration be 40 quality % and well suspended to wherein adding anhydrous propanone.After the solution centrifugal sedimentation of gained, remove supernatant liquid by decant.To wherein adding anhydrous propanone, making slurry concentration is 60 quality % and well suspended.This slurry is contained in the SUS system jar, and is the barium oxide of 1.4 microns and 23 microns to the mean particle size of 15 quality % that wherein add the niobium quality respectively and 10 quality %.In addition, add zirconia ball and use shaking mixer to mix 1 hour the content.After removing zirconia ball, this mixture is placed in the niobium bucket and 1 * 10 ²Vacuum-drying under Pa and the 50 ℃ of conditions.

Obtain to have mixed barytic niobium sintering agglomerate and the broken powder of niobium with the method identical with embodiment 2.

Under agitation this of 500 grams having been mixed the broken powder of barytic niobium joins and is cooled in 15 ℃ or lower 1, the 000 gramion exchanged water and notes not making water temperature surpass 20 ℃.After adding is finished,, left standstill 30 minutes, then decant this solution continuously stirring 1 hour again.To wherein adding 2,000 gramion exchanged waters, and, left standstill 30 minutes, then decant the solution stirring of gained 30 minutes.This operation repeats 5 times.Then, the broken powder of niobium is packed in the teflon system post, and wash 4 hours with water and make deionized water mobile simultaneously.At this moment, the washing electrical conductivity of water is 0.5 μ S/cm.

After washing is finished, the broken powder of niobium is depressed by nitrogen through 300 ℃ nitriding treatment 3 hours at 50 ℃ of drying under reduced pressure and adding, the result obtains the niobium powder of about 350 grams.Nitrogen content is 0.30%.

The physical properties of this niobium powder such as tap density, mean particle size, slope of repose, BET specific surface area and aperture peak value are represented in table 5.

Make molded article with the method identical with embodiment 2.The outward appearance of molded article and quality dispersiveness are represented in table 5.

Use the method identical on the surface of the sintered compact of molded article, to form thin dielectric film then with embodiment 2.Form counter electrode and stacked successively carbon-coating and silver paste layer then thereon.After lead frame being installed thereon, this device is shaped with Resins, epoxy as a whole, with the preparation chip capacitor.The average electrical capacity peace of apparent ratio of the electrical capacity of this electrical condenser and chip capacitor (n=100) all LC value is represented in table 5.

Embodiment 38～44

The mean pore size and the consumption of the kind by changing the activator added, two kinds of niobium powder to be mixed, use with embodiment 37 in identical method obtain and the broken powder of the niobium of activator mix.The solvent of dissolve activating agent is selected from water, acid, alkali, the solvent that contains ion exchange resin, ammonium nitrate solvent and contains the solution of edetate.With with embodiment 37 in identical method dissolve activating agent to obtain the niobium powder.The physical properties of this niobium powder is represented in table 5.

With with embodiment 37 in identical method make molded article and sintered compact, with the preparation chip capacitor.The electrical capacity of the outward appearance of molded article and quality dispersiveness and electrical condenser and average LC value are represented in table 5.

Embodiment 45～47

As raw material, in embodiment 45, use niobium-neodymium alloy powder respectively, in embodiment 46, use niobium-tungsten alloy powder, in embodiment 47, use niobium-tantalum alloy powder, use with embodiment 37 in identical method obtain the niobium alloy powder.The physical properties of niobium alloy powder is represented in table 5.

With with embodiment 37 in identical method prepare molded article and sintered compact, prepare chip capacitor.The electrical capacity of the outward appearance of molded article and quality dispersiveness and electrical condenser and average LC value are represented in table 5.

Embodiment 48～58

The niobium powder that use obtains in embodiment 37～47 uses the method identical with embodiment 2 to produce niobium sintered body.The pore size distribution of sintered compact is represented in table 6.

Embodiment 59～69

100 of every kind of sintered compacies that preparation obtains in embodiment 48～58, and use 0.1 quality % phosphate aqueous solution 20V and 80 ℃ of electrochemical shapings 1,000 minute, so that form the oxide dielectric film from the teeth outwards.These sintered compacies flood with the negative electrode agent shown in the table 3.Stacking gradually carbon-coating thereon is shaped to prepare chip capacitor with Resins, epoxy with silver paste layer and integral body.Apparent ratio of the electrical capacity of prepared electrical condenser and ESR represent in table 7.

Comparative example 14～17

100 of every kind of sintered compacies that preparation obtains in comparative example 9～12, and use 0.1 quality % phosphate aqueous solution 20V and 80 ℃ of electrochemical shapings 1,000 minute, so that form the oxide dielectric film from the teeth outwards.These sintered compacies flood with the negative electrode agent shown in the table 3.Stacking gradually carbon-coating thereon is shaped to prepare chip capacitor with Resins, epoxy with silver paste layer and integral body.Apparent ratio of the electrical capacity of prepared electrical condenser and ESR represent in table 7.

Table 2

Table 3

Method	The negative electrode agent	The method of impregnated cathode agent
			A	Polypyrrole	Repeat will be thereon to carry out vapour phase polymerization with pyrroles's steam with the sintered compact of ammonium persulphate and anthraquinone sulfonic acid
B	The mixture of plumbic oxide and lead sulfate (plumbic oxide: 98 quality %)	Repeat sintered compact is flooded in the mixed solution of lead acetate and ammonium persulphate

Table 4

Table 6

Table 7

Embodiment and comparative example	Obtain the method for sintered compact	The apparent ratio of electrical capacity	Electric capacity	ESR Ω
					Embodiment 59	Embodiment 48	98	592	0.024
Embodiment 60	Embodiment 49	97	587	0.023
					Embodiment 61	Embodiment 50	93	557	0.022
Embodiment 62	Embodiment 51	93	556	0.022
					Embodiment 63	Embodiment 52	98	58?5	0.023
Embodiment 64	Embodiment 53	98	58?9	0.023
					Embodiment 65	Embodiment 54	97	58?1	0.024
Embodiment 66	Embodiment 55	98	590	0.022
					Embodiment 67	Embodiment 56	98	592	0.024
Embodiment 68	Embodiment 57	98	587	0.023
					Embodiment 69	Embodiment 58	98	587	0.025

Comparative example 14	Comparative example 9	22	64	0.158
					Comparative example 15	Comparative example 10	71	305	0.083
Comparative example 16	Comparative example 11	73	314	0.081
					Comparative example 17	Comparative example 12	68	291	0.090

Industrial applicibility

Tap density is that 0.5～2.5g/ml, particle mean size are that 10～1000 microns, angle of repose are that 10～60 ° and BET specific area are 0.5～40m²The niobium powder of the present invention of/g is excellent aspect mobile and can progressive forming. That obtain by the described niobium powder of sintering and the aperture peak value is arranged in 0.01～500 micrometer range and preferably in pore-size distribution, have the niobium sintered body of a plurality of apertures peak value to be used for electrode for capacitors, the apparent ratio of high-capacitance can be obtained and the capacitor of the low and excellent moisture resistance of leakage current can be produced.

Claims (20)

1. niobium sintered body that is used for electrode for capacitors, wherein, the pore size distribution of niobium sintered body has a plurality of apertures peak value, in the peak value of a plurality of apertures, has the peak value at two peaks of high relative intensity and is present in 0.2～0.7 micrometer range respectively and in 0.7～3 micrometer range.

2. the niobium sintered body described in the claim 1, wherein, described pore size distribution has two aperture peak values.

3. the niobium sintered body described in the claim 1 wherein, in the peak value of a plurality of apertures, has the peak value at the peak of high relative intensity and is present in than having time side of the peak value larger diameter at the peak of high relative intensity.

4. the niobium sintered body described in the claim 1, wherein, the volume of described sintered compact is 10mm ³Or bigger, comprise the volume of hole.

5. the niobium sintered body described in the claim 1, wherein, the specific surface area of described sintered compact is 0.2～7m ²/ g.

6. the niobium sintered body described in the claim 1, wherein, a part of sintered compact is by nitrogenize.

7. the niobium sintered body described in the claim 1, wherein, described sintered compact is the sintered compact that is obtained by a kind of niobium molding, described niobium molding produce a kind of when 1300 ℃ of sintering the CV value be the sintered compact of 40,000～200,000 μ FV/g.

8. electrical condenser comprises an electrode, a counter electrode and the intervenient dielectric materials of the niobium sintered body described in each that uses claim 1～7.

9. the electrical condenser described in the claim 8, wherein, described dielectric materials mainly comprises niobium oxides.

10. the electrical condenser described in the claim 8, wherein, counter electrode is at least a material that is selected from electrolyte solution, organic semiconductor and inorganic semiconductor.

11. the electrical condenser described in the claim 10, wherein, counter electrode is an organic semiconductor, and organic semiconductor be selected from the organic semiconductor that comprises benzopyrrole quinoline tetramer and chloranil, mainly comprise the organic semiconductor of four thio naphthacene, mainly comprise the organic semiconductor of four cyano quinone bismethane and at least a material of electric conductive polymer.

12. the electrical condenser described in the claim 11, wherein, electric conductive polymer is at least a composition that is selected from polypyrrole, Polythiophene, polyaniline and substitutive derivative thereof.

13. the electrical condenser described in the claim 11, wherein, electric conductive polymer is by mix the electric conductive polymer that doping agent obtains in the polymkeric substance of the repeating unit that contains following formula (1) or (2) expression:

Wherein, R ¹～R ⁴Expression independently of one another is selected from hydrogen atom, contains saturated or unsaturated alkyl, alkoxyl group or alkyl ester group group, halogen atom, nitro, cyano group, primary, the second month in a season or uncle's amino, the CF of the straight or branched of 1～10 carbon atom ₃The univalent perssad of the phenyl of group, phenyl and replacement; Each is to R ¹And R ², R ³And R ⁴Can be at an arbitrary position in conjunction with forming the divalence chain, be used for by R ¹And R ²Or by R ³And R ⁴The carbon atom that replaces forms at least one 3-, 4-, the saturated or unsaturated hydrocarbons ring structure of 5-, 6-or 7-unit together; Optional carbonyl, ether, ester, acid amides, thioether, sulfinyl, alkylsulfonyl or the imino-of containing at an arbitrary position of ring-type bonded chain; X represents Sauerstoffatom, sulphur atom or nitrogen-atoms; R ⁵Only when X is nitrogen-atoms, just exist, and represent hydrogen atom independently or contain straight or branched, the saturated or unsaturated alkyl of 1～10 carbon atom.

14. the electrical condenser described in the claim 13, wherein, electric conductive polymer is the electric conductive polymer that contains by the repeating unit of following formula (3) expression:

Wherein, R ⁶And R ⁷Represent hydrogen atom independently of one another, contain the saturated or unsaturated alkyl of the straight or branched of 1～6 carbon atom, perhaps a substituting group is used to form at least one 5-, the 6-that contain two Sauerstoffatoms or the 7-unit stable hydrocarbon ring structure that are obtained by the alkyl that mutually combines at an arbitrary position; And ring texture comprises having the structure of can substituted vinylidene key, can substituted phenylene structure.

15. the electrical condenser described in the claim 11, wherein, electric conductive polymer is by mix the electric conductive polymer that doping agent obtains in poly-(3,4-ethylidene dioxy thiophene).

16. the electrical condenser described in the claim 8, wherein, counter electrode is made by the material that has laminate structure to small part.

17. the electrical condenser described in the claim 8, wherein, the material of counter electrode contains organic sulfonic acid root negatively charged ion as doping agent.

18. method of producing electrical condenser, described electrical condenser comprises an electrode that uses niobium sintered body, the dielectric materials that forms and provides on described dielectric materials on described sintered compact surface a counter electrode, wherein, described niobium sintered body is at the niobium sintered body described in each of claim 1～7.

19. electronic circuit that uses the electrical condenser described in each of claim 8～17.

20. electronic machine that uses the electrical condenser described in each of claim 8～17.