CN101200368A - Complex oxide powder, method for preparing the complex oxide powder, ceramic composition and ceramic electronic component comprising the complex oxide powder - Google Patents
Complex oxide powder, method for preparing the complex oxide powder, ceramic composition and ceramic electronic component comprising the complex oxide powder Download PDFInfo
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Abstract
The invention relates to a combined oxide powder such as barium titanate with small grin diameter and good crystallinity. During at least one part of the period which generates CO2 gas by sintering the raw powder of metal carbonate selected from at least one of barium, strontium, calcium, Mg and lead and metal oxide mixed with titanium and/or zircon, in order to prevent the CO2 gas from adhering on the raw powder, at one hand, the gas is communicated to drive the raw powder to flow, and at the other hand, the raw powder is sintered. The combined oxide powder, even a corpuscule can have a high crystallinity and also restrain the decrease of the crystallinity along with the corpuscule process. Generally speaking, the invention relates to a combined oxide powder such as barium titanate with a grain diameter of 0.01 to 0.3um and good crystallinity. Besides, a small-scale electronic ceramic component can be obtained when producing a ceramic composition through the combined oxide powder, in particular to obtain an electronic overlapped ceramic component.
Description
Technical field
The present invention relates to contain the composite oxide power and the manufacture method thereof that are selected from least a metallic element in titanium, the zirconium and are selected from least a metallic element in barium, strontium, calcium, magnesium, the lead.In addition, the invention still further relates to ceramic composition that the above-mentioned composite oxide power of sintering forms, use ceramic electronic components, the multilayer ceramic electronic component of said composition.
Background technology
The composite oxide power of barium titanate, strontium titanate, lead titanate, lead zirconates, lead zirconate titanate etc., the raw material that can be used as sintered compact uses, with composite oxide power with after tackiness agent mixes, adopt methods such as sheet moulding method and print process to make it on substrate, to form powder bed, then make its sintering and be made into sintered compact (below, be also referred to as ceramic composition sometimes).This ceramic composition has excellent dielectricity, piezoelectricity and semiconduction, and the electric and electronic industrial material that therefore can be used as electrical condenser, electric wave filter, seed element, thermistor etc. uses.
Ceramic composition is assembled in the various electric installation electronicss as ceramic electronic components and is used.Follow in recent years electric installation and miniaturization, lightweight, high performance, the multifunction of electronics, strict more to the performance requriements of such ceramic electronic components.Multi-layer ceramic capacitor with the unicircuit that is used for computer etc. is an example, this electrical condenser is taked following structure: the thin layer of above-mentioned ceramic composition and internal electrode carry out the overlapping of majority alternately, and carried out electricity and be connected in parallel, therefore follow the requirement of the miniaturization, high capacitanceization etc. of multi-layer ceramic capacitor, wish thin layerization, the high-kization of ceramic composition more.Therefore, as the performance requriements of the corpusculed of the raw-material composite oxide power of ceramic composition, high crystallineization and homogenize, the quality requirements of enhancement of dispersion etc. is also more and more significant.In addition, the internal electrode of multi-layer ceramic capacitor uses precious metal materials such as platinum, palladium, silver always, but just seeking to cheap base metal material conversion such as copper, nickel, accompany therewith, for composite oxide power, just wishing can be at sintering under the low temperature more, even and carry out also semiconductor transformation and have reducing resistance not of sintering under the atmosphere of low oxygen partial pressure.
Manufacturing contains the composite oxide power that is selected from least a metallic element in titanium, the zirconium and is selected from least a metallic element in barium, strontium, calcium, magnesium, the lead following method: oxide compound, the carbonate of each element are mixed the so-called solid-phase synthesis that uses electric furnace, rotary kiln to burn till; After the oxalate of each element synthesized in water system, the so-called oxalate method of burning till; After the Citrate trianion of each element synthesized in water system, the so-called Citrate trianion method of burning till; The aqueous solution and the alkali aqueous solution of each element are mixed, after carrying out hydrothermal treatment consists, filter, the method for the so-called hydrothermal synthesis method of washing, exsiccant etc., for method separately, just carrying out the improvement research of the corpusculed, high crystallineization etc. of composite oxide power.The starting point of research is: suppress to be accompanied by the corpusculed of composite oxide power and the crystalline reduction that produces.For example, record once: in solid-phase synthesis, the rutilization rate that will generate barytic barium compound and adopt X-ray diffraction method to try to achieve by thermal degradation is below 30% and by the specific surface area that the BET method is tried to achieve to be 5m
2The above above titanium dioxide of purity 99.8 weight % of/g mixes, and is 1 * 10 in total pressure
3When burning till under the pressure below the Pa, can obtain barium titanate powder particulate, that square crystallinity is high (with reference to patent documentation 1).Also on the books: with specific surface area is 10m
2Metal oxide powder that/g is above and metal carbonate powder mixes and the mixed powder that obtains are 2 * 10
3When burning till under the oxygen partial pressure below the Pa, it is little to obtain particle diameter, the ratio (c/a axial ratio) of c axle and a axle of lattice that is index 0.03～0.2 μ m, that become square crystallinity (tetragonal lattice) is big, be 1.0033 or more, show fully composite oxides dielectricity, that have perovskite structure (with reference to patent documentation 2) by force.
Patent documentation 1: the spy opens 2002-255552
Patent documentation 2: the spy opens 2001-316114
Summary of the invention
When adopting above-mentioned patent documentation 1 and 2 described methods, can obtain composite oxide power particulate, that crystallinity is high.But, because raw material powder under reduced pressure or under the vacuum is burnt till, therefore during burning till or each to remain on certain decompression pressure between making batch be difficult because pressure surge takes place, exist the performance of composite oxide power, quality to produce the problem of fluctuation.For example, the particle diameter of composite oxide power and crystallinity produce deviation, and then also can imagine this shortcoming of generation lattice imperfection.In addition, there are restriction in the rutilization rate of the metal oxide that uses, specific surface area, purity etc., because spendable described material is limited, need to tolerate under the decompression or the device of the high price of the pressure under the vacuum, its device maximizes difficult, become small-scale manufacture, or the like, therefore also there is the problem that spends high running cost.
The concentrated on studies method of the barium titanate powder of making the little and good crystallinity of particle diameter of present inventors.Its result, the burned material that forms when titanium dioxide is under atmospheric pressure burnt till with the mixture of barium carbonate and under reduced pressure or burn till under the vacuum and the burned material that forms when comparing, if the particle diameter with same degree is a benchmark, the crystallinity of the burned material of then under atmospheric pressure burning till and forming is low, can think that as its reason the carbon dioxide that takes place when burning till has caused some influences.
The reaction of titanium dioxide and barium carbonate, we can say the reaction that following (1)～(3) take place, the mixture of titanium dioxide and barium carbonate is carried out heat when analyzing (TG), describe curve shown in Figure 1, since about the 500 ℃ reactions that titanium dioxide and barium carbonate take place, produce carbonic acid gas, cause that weight reduces.The occasion of under atmospheric pressure burning till, therefore the more partial product of the carbon dioxide that takes place in the reaction of (1) and (2) is stayed in the burning apparatus of electric furnace and rotary kiln etc., can think that residual carbon dioxide causes detrimentally affect to the crystallinity of barium titanate powder.Particularly, the resultant of reaction (Ba that in the reaction of (2), generates
2TiO
4) be strong basicity, therefore adsorb slightly acidic atmospheric carbon dioxide gas easily, and when the reversed reaction of (2) takes place, be difficult to promote the reaction of (3), because crystalline growth, the not only BaTiO that is supplied with
3Insufficient, also exist also to produce Ba
2TiO
5Possibility.Can think, this idea in flow of carbon dioxide gas is gone into burning apparatus the time crystallinity step-down of barium titanate powder obtain confirming.
BaCO
3+TiO
2→BaTiO
3+CO
2↑......(1)
BaCO
3+BaTiO
3→Ba
2TiO
4+CO
2↑......(2)
Ba
2TiO
4+TiO
2→2BaTiO
3......(3)
Present inventors are based on above-mentioned opinion, that further studies found that: in order also to reduce the detrimentally affect of the carbon dioxide that takes place in firing process under the pressure about normal atmosphere, by one side circulated gases, raw material powder is flowed, burn till on one side, can improve the crystallinity of barium titanate powder, the burned material that forms even burn till under or the vacuum under reduced pressure described with 2 with above-mentioned patent documentation 1 is compared, and also can obtain the crystallinity of same degree; Do not need under reduced pressure or under the vacuum to carry out, can under than the high slightly pressure of normal atmosphere, carry out about normal atmosphere or for gas ventilation, therefore the restriction of device etc. is few, can adopt the homogeneous condition to burn till, the fluctuation of the quality of resulting composite oxide power is few, and can use common burning apparatus in this wise, therefore can make at an easy rate, or the like, thereby finished the present invention.
And then find, this method is not limited to the manufacturing of barium titanate, it is the method that the metal oxide that contains titanium and/or zirconium and the raw material powder that is selected from least a metal carbonate in barium, strontium, calcium, magnesium and the lead are burnt till, when burning till, also can be suitable in the reaction of generation carbon dioxide, can obtain good result, thereby finish the present invention.
That is, the present invention is as follows.
(1) a kind of manufacture method of composite oxide power, be that the raw material powder that will be mixed with the metal oxide of titanium and/or zirconium at least and be selected from least a metal carbonate in barium, strontium, calcium, magnesium and the lead burns till and makes the method for composite oxide power, it is characterized in that, take place because of burning till of raw material powder carbon dioxide during at least a portion during, one side circulated gases, raw material powder is flowed, Yi Bian burn till.
(2) according to the manufacture method of (1) described composite oxide power, it is characterized in that, use the granulation powder that raw material powder is carried out granulation and form.
(3) according to the manufacture method of (a 2) described composite oxide power, it is characterized in that, thereby the slurries of raw material powder are carried out the spraying drying granulation.
(4) according to the manufacture method of (a 1) described composite oxide power, it is characterized in that, use the granulation powder that to carry out granulation after the raw material powder pulverizing and to form.
(5) according to the manufacture method of (a 2) described composite oxide power, it is characterized in that, use the granulation powder of size with 10～1000 μ m.
(6) according to the manufacture method of (a 1) described composite oxide power, it is characterized in that, use the raw material powder of the carbonate that is mixed with titanyl compound and barium at least.
(7) according to the manufacture method of (a 6) described composite oxide power, it is characterized in that, use specific surface area to be 20m
2The titanyl compound that/g is above.
(8) according to the manufacture method of (1) described composite oxide power, it is characterized in that, take place because of burning till of raw material powder carbon dioxide during, on one side circulated gases, raw material powder is flowed, burn till on one side.
(9) according to the manufacture method of (1) described composite oxide power, it is characterized in that, use the rutilization rate of trying to achieve by X-ray diffraction method be higher than 90%, below 100%, and specific surface area is 30m
2The titanyl compound that/g is above.
(10) a kind of composite oxide power is characterized in that, be to use (1)～each described method in (9) makes, and its particle diameter is the scope of 0.01～0.3 μ m.
(11) a kind of barium titanate powder is characterized in that, be to use (1)～each described method in (9) makes, and its particle diameter is the scope of 0.01～0.3 μ m.
(12) according to (a 11) described barium titanate powder, the c/a axial ratio of above-mentioned barium titanate is 1.007～1.010.
(13) a kind of ceramic composition, sintering (a 10) described composite oxide power or (11) described barium titanate powder form at least.
(14) a kind of ceramic electronic components, it possesses (13) described ceramic composition and clips above-mentioned ceramic composition and the electrode of subtend setting.
(15) a kind of multilayer ceramic electronic component, the electrode that it possesses a plurality of layers of containing (13) described ceramic composition and forms at the interlayer of above-mentioned ceramic composition.
The invention effect
The present invention is a method of making the composite oxide power of barium titanate etc., wherein, for the carbon dioxide that takes place when carrying out firing process is adsorbed on the raw material powder, carbon dioxide between the emergence period on one side circulated gases, raw material powder is flowed, Yi Bian burn till.The composite oxide power that the method according to this invention obtains even micropartical also has high crystallinity, can suppress to follow corpusculed and the crystalline reduction that takes place.And, the restriction that is brought by device, material etc. is few, can adopt burning till of identical conditions, and the fluctuation of the quality of the composite oxide power that is therefore obtained is less in same manufacturing batch, and described fluctuation is also little between each is made batch, can obtain this powder of homogeneous.
Particularly, can easy and easily obtain particle diameter and be the scope of 0.01～0.3 μ m and have excellent crystalline composite oxide power, barium titanate powder for example especially can obtain particle diameter and is the scope of 0.01～0.3 μ m and have the barium titanate powder of square crystallinity that the c/a axial ratio is the excellence of 1.007～1.010 scope.
In addition,, therefore can improve low-temperature sintering, can improve the packing fraction when making sintered compact, and can improve the characteristic of dielectricity and piezoelectricity etc. because above-mentioned composite oxide power is a micropartical.In addition, owing to have high crystallinity, uniformity, so reducing resistance also is enhanced.Therefore, the ceramic composition that use will be formed by the composite oxide power sintering that method of the present invention obtains, utilize its excellent characteristic, can be met ceramic electronic components, the especially multilayer ceramic electronic component of miniaturization, lightweight, high performance, multifunction.
Description of drawings
Fig. 1 is the figure that the weight that is obtained by the heat analysis of the raw material powder of expression titanium dioxide and barium carbonate reduces.
Fig. 2 is the electron micrograph of the particle structure of expression embodiment 4 employed titanium oxides.
Fig. 3 is the X ray diffracting spectrum of expression embodiment 4 employed titanium oxides.
Embodiment
The present invention will be mixed with the metal oxide of titanium and/or zirconium at least, with be selected from barium, strontium, calcium, the raw material powder of at least a metal carbonate in magnesium and the lead, the granulation powder that its granulation is formed (below, sometimes raw material powder and granulation powder are called raw material powder etc. in the lump) burn till with burning apparatus, make the method for composite oxide power, carrying out raw material powder etc. when room temperature is warmed up to specified temperature and keep the firing process of specified time, take place during at least a portion of carbon dioxide, preferably during whole, one side circulated gases, raw material powder is flowed, Yi Bian burn till.By burning till in this wise, gas is near nearby the passing through of raw material powder, and at least a portion of the carbonic acid gas that takes place can be discharged into outside the burning apparatus expeditiously.In addition,, can improve liquidity, become good, can discharge the carbon dioxide that is taken place effectively with the contacting of gas of circulation by using the granulation powder that the raw material powder granulation is obtained.
Raw material powder used in the present invention is the mixed powder that is mixed with the metal oxide of titanium and/or zirconium at least and is selected from least a metal carbonate in barium, strontium, calcium, magnesium and the lead.Metal oxide, can use the employed metal oxide of common solid-phase synthesis unlimitedly, specifically, comprise the oxide compound of titanium, zirconium or so-called titanium, zirconium hydrous oxide, hydrous oxide, oxyhydroxide separately, can use from these materials, select at least a.Particularly preferably be titanium dioxide, zirconium dioxide.When using atomic metal oxide, be effectively to the corpusculed of composite oxide power, therefore preferred, for example as atomic index, when representing, be preferably 20m with specific surface area
2More than about/g, 30m more preferably
2More than about/g, 50m more preferably
2More than about/g, further be preferably 100～300m
2About/g, 150～300m especially more preferably
2About/g.The specific surface area of titanium oxide is big more, and reactivity is good more, and is therefore preferred, but when excessive, is difficult to make such titanium oxide, and from the viewpoint, specific surface area is 160～250m more preferably
2/ g, especially more preferably 160～200m
2/ g.Specific surface area is obtained by the nitrogen absorption of BET method.Moreover, with the occasion of titanium oxide, when zirconium is used as additive (being meant the composition less than 50% weight %), both can use Zirconium oxide as host (being meant the composition that accounts for more than the 50 weight %), can use zirconium compounds in addition again.On the contrary, with the occasion of Zirconium oxide, titanium oxide, in addition titanium compound can be used as additive as host.The form of the compound beyond the oxide compound is not particularly limited, and can use muriate, vitriol, nitrate, carbonate, acetate etc.
Titanium oxide used in the present invention comprises and hydrous oxide, hydrous oxide, the oxyhydroxide of titanyl compound (titanium dioxide) or so-called titanium can use select at least a from these materials.In addition, titanium oxide can be confirmed rutile-type crystal, Detitanium-ore-type crystal, brookite type crystal by the X-ray diffraction peak usually, crystal formation in any case can use, and also can use the mixture of the crystal grain more than two kinds or the mixture of the crystal formation more than two kinds.In the present invention, the many titanium oxides of rutile-type crystal in preferred above-mentioned 3 kinds of crystalline structure, more preferably the rutilization rate of the titanium oxide of obtaining by X-ray diffraction method be higher than 90%, at the titanium oxide below 100%, more preferably 95～100%, further preferably can't see the rutilization rate 100% of the degree at Detitanium-ore-type crystal, brookite type X-ray diffraction in crystals peak.The rutilization rate of so-called titanium oxide, the rutile-type crystalline ratio that is meant in the titanium oxide to be contained, by X-ray diffraction (using the CuK alpha-ray), confirm that rutile-type crystal, Detitanium-ore-type crystal, brookite type crystalline exist or do not exist, and obtain the rutile-type crystal and contain proportional with respect to above-mentioned 3 kinds of crystalline.In view of this, in the present invention, be more preferably the rutilization rate of obtaining by X-ray diffraction method be higher than 90%, below 100% and specific surface area be 30m
2The titanium oxide that/g is above, more preferably 50m
2More than/the g, further be preferably 100～300m
2/ g, especially more preferably 150～300m
2/ g.
In addition, wide from the half value at the X-ray diffraction peak of rutile-type crystalline (110) face, utilize to thank and rein in (シ エ one ラ) formula (formula 1) and can obtain rutile-type crystalline crystallite footpath.As rutile-type crystalline crystallite footpath, consider from reactive viewpoint, be preferably littler particle diameter, more preferably below the 10nm, 1～10nm more preferably.
Formula 1:D
HKL=K* λ/β cos θ
D
HKL: crystallite footpath ()
λ: the wavelength of X ray
β: the half value of diffraction peak is wide
θ: Bragg angle
K: constant (=0.94)
On the other hand, according to electron micrograph, the primary particle size of preferred titanium oxide is the microcrystal about 1～15nm, and its particle assembly, formation offspring also can.The shape of the offspring of titanium oxide can be any shape, for example, can use granular, spherical, the offspring of spherical, spindle shape etc. roughly.Be granular, spherical, globular occasion roughly, if with particle diameter with maximum diameter (number is average) expression, then be preferably 10～300nm, more preferably 20～150nm, more preferably 30～120nm.In addition, the spindle similar shape that so-called spindle shape is meant and spins is and fusiform cylindrical similar shape.Therefore, the spindle shape comprises the shape that is commonly referred to as needle-like, bar-shaped, column, cylindric, polygon column etc.When the length at the two ends that will link particle as the length of the thickest part of major axis footpath, post portion as short shaft diameter, several mean values (on average short shaft diameter) of severals mean values in its major axis footpath (average major axis footpath) and short shaft diameter liken to axial ratio the time, axial ratio is greatly comparatively desirable, particularly, the preferred axes ratio is more than 1.5.Therefore on the other hand, when titanium oxide becomes micropartical, be difficult to increase axial ratio, more preferably about 1.5～5, more preferably about 1.5～4.The average major axis footpath of titanium oxide is preferably 10～300nm, more preferably 20～150nm, more preferably 30～120nm.The offspring of titanium oxide, sometimes several～hundreds of further gathering and form aggregated particle.The offspring shape of such titanium oxide, average major axis footpath, average short shaft diameter can adopt electron microscope observation, mensuration.
In addition, also sometimes for example, the aggregated particle of bigger porous matter is assembled, formed to granular particle, and spindle shape particle forms and the similar aggregated particle of the flat sugar of gold.
About the aggregated particle of titanium oxide, can adopt following method to be determined at particle diameter in the water (50% cumulative path (intermediate value footpath)), in the present invention, consider from reactive viewpoint of solid phase synthesis, be preferably about 0.06～0.20 μ m.
The measuring method of the size-grade distribution in water
(1) with aqueous sodium hydroxide solution the pH regulator of the slurries of titanium oxide is 10.8 after, with coating vibrator it was disperseed 15 minutes.
(2) be converted into P having added
2O
5Among the water 300ml for the Sodium hexametaphosphate 99 of 0.3mg, add aqueous sodium hydroxide solution, pH is adjusted into 10.5, make to measure and use dispersion medium.
(3) in 1 liter polyethylene container made, add several said determination usefulness dispersion medium and the dispersion liquid of making by coating vibrator (titanium oxide slurries), stir prepare suspension.
(4) to above-mentioned suspension, (Sharp Corp's system, UT-500) 1 minute ultrasonic wave of irradiation is disperseed sample with ultrasonic generator.
(5) with laser diffraction and scattering formula particle size distribution device (HORIBA (hole field boundary) corporate system, LA-910) size-grade distribution of the sample in the resulting dispersion liquid of mensuration.
The titanium oxide of Shi Yonging, preferably TiO in the present invention
2Purity is the above highly purified titanium oxides of 99 weight %, more preferably more than the 99.5 weight %, more preferably more than the 99.9 weight %.TiO
2Purity is by deduct moisture, scorching hot loss composition (Ig-Loss), the total amount of impurity (for example elements such as silicon, iron, aluminium, niobium, sodium, their oxide compound conversion amount) except chlorine element, carbon from 100 (%) and the value representation that obtains.Elements such as silicon can adopt fluorescent X-ray method, ICP emission spectroanalysis method or atom light absorption method to analyze.
Titanium oxide used in the present invention can be used liquid phase method, vapor phase process manufacturing, the suitable condition that can make desired titanium oxide of selecting specific surface area, rutilization rate etc.Liquid phase method is solution hydrolysis, the neutral method with the titanium compound of titanium sulfate, titanyl sulfate, titanium tetrachloride, titan-alkoxide (Titan alkoxide) etc., obtain specific surface area height, the little titanium oxide in rutile-type crystalline crystallite footpath easily, so preferred.As concrete liquid phase method, for example with neutralizations such as titanium tetrachloride, titanyl sulfate or hydrolysis and the oxidizing aqueous titanium that obtains, after the alkali cpd heated in water solution of alkali metal hydroxides such as sodium hydroxide, ammonium compound, volatile salt compound, amine compound etc. is handled, filter, wash, then in the strong acid aqueous solution of hydrochloric acid etc., carry out heat treated and can obtain.As above-mentioned alkali cpd, consider that from the viewpoint of rutilization rate etc. sodium hydroxide is optimum, in order fully to remove sodium, preferably utilize acid to leach (leaching; Leaching) etc.And then, if in the presence of titanous chloride, carry out above-mentioned salt acid treatment, then can obtain the fine titanium oxide micropartical that the major axis footpath is big, crystallite is directly little, be preferable methods therefore.Resulting resultant carries out classification, drying.Specific surface area reduces when drying temperature is too high, so drying temperature is preferably the temperature below 150 ℃.As other method, in can using and the method for titanium tetrachloride.On one side stir titanium tetrachloride solution, Yi Bian drip neutralizing agent, in and titanium tetrachloride.As neutralizing agent, can use alkali metal hydroxide, ammonium compound, volatile salt compound, amine compound of sodium hydroxide etc. etc.In the method, in the occasion that alkali metal hydroxide is used as neutralizing agent,, also preferably adopt that acid is leached etc. in order fully to remove basic metal.The resultant that obtains like this is with above-mentioned classification, the drying of carrying out the samely.Drying temperature is preferably the temperature below 150 ℃.When drying temperature is higher than 150 ℃, in and the specific surface area of resultant lower easily, therefore not preferred.The exsiccant lower limit temperature if can the exsiccant temperature, then can be any temperature.
On the other hand, the gas phase synthesis method of titanium oxide is the method with the dioxygen oxidation titanium tetrachloride gases, perhaps with the method for water vapour with the titanium tetrachloride gases hydrolysis, is the method that obtains highly purified titanium oxide easily.With the method for steam hydrolysis, obtain specific surface area height, titanium oxide that the rutilization rate is high easily, therefore more suitable.
In addition, the metal carbonate that is contained in the raw material powder that uses among the present invention, can use employed metal carbonate in common solid-phase synthesis unlimitedly, can be corresponding to the composition of composite oxide power, suitable selection is selected from least a metal carbonate in barium, strontium, calcium, magnesium and the lead.Also can use in addition in the aqueous solution of water soluble salt of muriate at barium, strontium, calcium, magnesium or plumbous metallic element, nitrate, acetate etc., add the carbonate compound of carbonic acid an alkali metal salt, volatile salt etc., perhaps be blown into carbon dioxide, or the like neutralize and the material that obtains.Metal carbonate is soft, with titanium oxide, zirconic mixing process in, pulverized by these particles easily, but the particle diameter of metal carbonate also influences the characteristic of composite oxide power, therefore when using atomic metal carbonate, corpusculed to composite oxide power is effective, and is therefore preferred.For example, as atomic index, when representing, be preferably 5m with specific surface area
2More than about/g, 10m more preferably
2More than about/g, 20m more preferably
2More than about/g.Moreover, with the occasion of barium carbonate as host (being meant the composition that accounts for more than the 50 weight %), when strontium, calcium, magnesium or plumbous metallic element are used as additive (being meant the composition less than 50 weight %), these metallic elements can be the form of carbonate, can also be the form of in addition compound.In any occasion as host with Strontium carbonate powder, lime carbonate, magnesiumcarbonate or lead carbonate, additive similarly can be the form of carbonate, can also be the form of the compound beyond the carbonate.The form of the compound beyond the carbonate is not particularly limited, and can use muriate, vitriol, nitrate, acetate, oxide compound etc.
Above-mentioned metal oxide and metal carbonate are mixed, make raw material powder.Two sides' combined amount can be set corresponding to the composite oxide power of target is suitable.For example, have by general expression ABO in manufacturing
3During the composite oxide power of the perovskite structure that type is represented, mix so that the atoms metal of metal carbonate (A), use the atomic ratio of atoms metal (B) to represent with respect to metal oxide, be preferably 0.9～2.0 scope, more preferably 0.95～1.05 scope, more preferably 1.000～1.035 scope.Above-mentioned atomic ratio was difficult to obtain the composite oxide power of desired composition less than 0.9 o'clock, and remaining composition remains in the composite oxides, damaged characteristics such as dielectricity and piezoelectricity easily, and is therefore not preferred.In addition, make many barium titanates, specifically, making BaTi
2O
5, BaTi
4O
9, BaTi
5O
11, Ba
2Ti
9O
20, Ba
4Ti
13O
30, Ba
6Ti
17O
40Deng the atomic ratio X with Ti/Ba when being the barium titanate of the composition formula more than 2, preferred mixed metal oxide compound and metal carbonate are the scope of (X * 0.95)～(X * 1.05) so that for the atomic ratio X of this defined.
When mixing, also can be corresponding to the needed characteristic of ceramic composition, as additive, suitable adding is the element of the rare earth element, boron, aluminium, silicon, manganese, iron, nickel, copper, zinc, niobium, yttrium, tungsten, bismuth etc. of lanthanum, cerium, gadolinium, terbium, dysprosium, holmium, erbium, ytterbium etc. for example.These additives can be that oxide compound also can be a carbonate, can also be compounds in addition.Addition is set corresponding to purpose is suitable.
About mixing, if to a certain degree equably the degree of mixed metal oxide and metal carbonate get final product the mixedness adjustment that can suit.As blending means, dry type is mixed, wet mixing all can, for example, can use the rotary type mixing machine etc. of the fixed mixing machine, round shape mixing machine, Shuangzi round shape mixing machine etc. of screw mixer, ribbon blender, fluidization formula mixing machine etc.In addition, also can before mixing, use the pulverizer of compression crushing type, Shock Compression crushing type, shearing crushing type, friction crushing type etc., metal oxide and metal carbonate were pulverized respectively before each comfortable mixing, in addition, also can when pulverizing, side by side mix.Because raw material powder is fine more, therefore the easy more micropartical that becomes of resulting composite oxide power is preferably pulverized raw material powder.As pulverizer, can preferably use for example wet crushing mill of ball mill, ball mill, colloidal mill etc.Admixture use wet crushing mill etc. is in the occasion of moisture state or suspended state (slurry condition), can filter choosing, drying as required, pulverize.
The raw material powder that obtains like this, preferably to carry out granulation in order making it to reach the granularity of appropriateness as required, can to adopt usual methods such as rotating granulation, fluidised bed granulation, the granulation of jet flow layer, stirring-granulating, broken granulation, compression granulation, extruding pelletization, drop curing granulation to come granulation.Adopt wet crushing mill etc. to make it occasion, preferably adopt spray-dryer etc. to carry out spraying drying and come drying-granulating into suspended state (slurry condition).By the granulation that spraying drying is carried out, prevent that not only dispersing of raw material powder from contacting with uneven gas, and the size ratio of granulation powder is consistent, therefore is expected to obtain uniform flow state, therefore preferred.The mean particle size of granulation powder, the degree that can consider flowable size or disperse and adjusting arbitrarily, for example be to get final product about 1～10000 μ m, if be about 5～3000 μ m, then disperse still less, therefore preferred, more preferably about 10～1000 μ m, more preferably about 20～500 μ m.The granulation powder can be spherical, roughly spherical, tabular, cubic, rectangular-shaped, bar-shaped, the shape that has spatial hollow form etc. in powder inside, but preferred mobile shape easily, preference such as spherical, the shape of spherical, hollow form etc. roughly.Moreover, when pulverizing, mixing, granulation, the also organic compound of matching surface promoting agent, resin, dispersion agent etc. in raw material powder etc. as required.During granulation, especially during spraying drying, if add resin, then play the effect of tackiness agent, except the granularity that can adjust the granulation powder, the space of decomposing when burning till, generating owing to resin becomes porous matter, can seek the emitting of carbon dioxide of granulation powder inside, therefore preferred.Employed material is not particularly limited, according to the suitable selection of purpose, use requirement.For example,, can use water system acrylic resin, water system melamine resin, aqueous polyurethane resin etc., and, add about 1～20 weight % preferably with respect to raw material powder etc. as resin.
Secondly, when with burning apparatus of packing into such as above-mentioned raw materials powder, when beginning to heat up till the firing temperature that reaches defined, common from its humidity province midway from room temperature, follow the reaction of metal oxide and metal carbonate or the decomposition of organic compound etc., carbon dioxide takes place.For when making raw material powder etc. flow, prevent the absorption of carbon dioxide, discharge carbon dioxide, the ventilation of gas is during from the beginning occurrence temperature district of carbon dioxide at least a portion that finishes the occurrence temperature district, preferably spread all over the whole period and carry out.In addition, can be as required, from the stage circulated gases of the beginning that heats up, also can be after finishing to take place circulated gases till burning till end, and then, can be in circulated gases during till the temperature that resulting composite oxide power is cooled to take out.Before these carbon dioxides take place, take place to finish the later stage, raw material powder etc. was flowed, can make raw material powder etc. become immovable bed, semifixed layer state again.The beginning occurrence temperature of carbon dioxide, different and different according to kind, composition and the additive etc. of employed metal oxide, metal carbonate, but, can hold the beginning occurrence temperature of carbon dioxide and end temp takes place by raw material powder etc. being carried out heat analysis.For example, be mixed with the temperature that begins to take place carbon dioxide of the raw material powder of titanium oxide and barium carbonate, can think from Fig. 1 and to be about about 500 ℃, therefore circulated gases not from about the room temperature to 500 ℃, but preferably from being warmed up to than carbon dioxide take place the stage that the beginning temperature is hanged down about 50 ℃ temperature, promptly reach about about 450 ℃ stage circulated gases.On the other hand, end temp takes place can think and be about about 850 ℃, therefore preferred circulated gases during about 500～850 ℃.After that during till the firing temperature that reaches regulation, burn till during, cooling period thereafter, can be all circulated gases not, but then can circulated gases.Can suit to set from room temperature to the heat-up rate that reaches till the firing temperature, can keep about 0.5～5 hour earlier, be warming up to firing temperature then in the humidity province that carbon dioxide takes place.Firing temperature, burning till the hold-time can be corresponding to composite oxide power and suitable the setting, for example is to get final product about 500～1100 ℃, and firing time for example keeps getting final product about 0.5～10 hour.Have again, burn till end after, be cooled to take out temperature, speed of cooling can suit to set, and no matter is to cool off lentamente or cooling can apace.
The burning apparatus that uses, can use employed process furnace in the firing furnace that in common solid-phase synthesis etc., uses, in addition domain of inorganic chemistry, the especially ceramic field, if can be while making the mobile burning apparatus that burn till such as raw material powder, then any device can use.Usually, preferably use the fluidised bed firing furnace.The adjustment of the flow state when carbon dioxide takes place, the flow velocity (flow) of the granularity that can be by raw material powder etc. and the gas of circulation waits and carries out.Raw material powder in the fluidised bed firing furnace etc., be preferably and form the such flow state of even fluidised bed (fluidised bed fully), on the other hand, even because for the state that produces the dense thick fluidised bed of bubble in fluidised bed also can obtain effect of the present invention, therefore it doesn't matter.Perhaps, if even the part of raw material powder etc. forms immovable bed, the state that rest part is flowing also can obtain effect of the present invention, and then it doesn't matter.When being the state of powder, be difficult to flow, produce the ventilating pit of gas, have only the state of affairs of the part contact gas of raw material powder, or cause raw material powder to disperse owing to the buoyancy of gas on the contrary and can not burn till, the granularity that therefore preferably raw material powder is a granulated into appropriateness is used.The air flow of gas, different and different according to the shape of burning apparatus and Intake Quantity of raw material powder etc. etc., therefore can not stipulate entirely, but if the gas of the too many amount of circulation, then raw material powder etc. disperses, therefore consider taking into account of the crystalline raising and the amount of dispersing, carry out with the suitable air flow that can obtain effect of the present invention.For example, (apparent specific gravity of granulation powder is 1g/cm to use the occasion of the granulation powder that is a granulated into 50～100 μ m
3Occasion), at room temperature, the gas line speed of the breaker plate position in the fluidised bed firing furnace, begin to flow second from 0.9cm/, in described gas line speed is that 1.7cm/ becomes even flow state during second, and then, become the state of dense thick fluidised bed, so gas line speed is preferably 1.7～10cm/ about second especially surpassing 10cm/ during second.
Gas as circulation, can use the gas that in the burning apparatus of common fluidised bed firing furnace etc., uses, but if contain carbon dioxide, then influence the crystallinity of composite oxide power etc., therefore not preferred, must select the poor gas of carbon dioxide or not contain the gas of carbon dioxide.So preferably using the carbon dioxide gas body burden is the gas of 0～0.5 volume %, more preferably the carbon dioxide gas body burden is 0～0.1 volume %, and further the preferably carbon dioxide gas content is 0～0.05 volume %.As such gas, can use for example nitrogen, argon, helium, air, oxygen, synthesis of air, dry air (dry air), pressurized air etc., can use the gas of wherein selecting from this more than a kind or 2 kinds.Though contain the amounts of carbon dioxide gas of having an appointment about 400ppm in air, synthesis of air, dry air (dry air), the pressurized air, confirmed not influence under the amount of this degree.And when using air, synthesis of air, dry air (dry air), pressurized air, raw material powder is difficult to be reduced when burning till, and therefore obtains the composite oxide power of homogeneous easily, and is therefore preferred.The gas of circulation when heating in advance before in importing burning apparatus, can prevent that the rapid temperature of burning apparatus from reducing, and is therefore preferred.In addition, the gas that can utilize circulation is discharged at least a portion of the carbon dioxide that takes place outside the burning apparatus, on the other hand, also can recycle the gas of circulation, the carbon dioxide gas body burden in the recycle gas of this moment is preferably in above-mentioned scope.
Adopt aforesaid method, can make composite oxide power, especially barium titanate powder atomic and that crystallinity is high.Particularly, can enumerate the compound with perovskite structure of barium titanate, strontium titanate, lead titanate, lead zirconates, lead zirconate titanate, calcium modified barium carbonate, rare earth element modified barium carbonate etc., the atomic ratio with Ti/Ba is many barium titanates of the composition formula more than 2 etc.Can obtain particle diameter as composite oxide power, be preferably the scope of 0.01～0.3 μ m, the scope of 0.015～0.3 μ m more preferably, the scope of 0.02～0.3 μ m more preferably, further be preferably the scope of 0.03～0.3 μ m, further be preferably the scope of 0.05～0.3 μ m again, most preferably be the composite oxide power of the scope of 0.06～0.15 μ m.The particle diameter of composite oxide power (d) supposes that composite oxide power is spherical, according to using the specific surface area a (m that is obtained by the BET method
2/ g) following formula 2 is obtained.
Formula 2:d=(6/ ρ)/a
In the formula, ρ is a proportion, and the occasion of barium titanate powder adopts ρ=5.90.
In addition, the crystallinity of resulting composite oxide power is carried out X-ray diffraction and is measured, by the peak height of the diffraction peak of certain crystal face or half value is wide estimates, more critically, based on X ray diffracting data, carry out Rietveld (リ one ト ベ Le ト) parsing and judge.Especially the occasion of barium titanate powder judges that from the c axle of lattice and the ratio of a axle (c/a axial ratio) the c/a axial ratio is big more, and the crystallinity of tetragonal spheroidal barium titanate is high more.Specifically, the method according to this invention can make the c/a axial ratio more than 1.0033, can be more preferably in 1.0033～1.011 scope, further preferably in 1.006～1.011 scope, further preferably in 1.006～1.010 scope, most preferably in 1.007～1.010 scope.Especially use the rutilization rate of obtaining by X-ray diffraction method be higher than 90%, below 100% and specific surface area be 150～300m
2During the titanium oxide of/g, the c/a axial ratio that can make barium titanate powder is in 1.0075～1.010 the scope that is more preferably, 1.0080～1.010 especially preferred scope.The composite oxide power that crystallinity is low, especially the barium titanate powder of c/a axial ratio less than 1.0033, strong dielectricity deficiency when using as electronic unit is therefore in order to increase the c/a axial ratio, need further thermal treatment, thereby become the result who causes grain growth.The theoretical value of the c/a axial ratio of regular crystal barium titanate is calculated by the value of a=3.994, c=4.038, is c/a=1.011, and on the other hand, the c/a axial ratio of cube brilliant barium titanate is 1.000.
Composite oxide power can be pulverized as required.As pulverizer, can use the pulverizer of compression crush type, Shock Compression crush type, shearing crush type, friction crush type etc., wherein preferably use the densification pulverizer.So-called densification pulverizer is the pulverizer that has both compressive action and milling action, when composite oxide power being added the densification pulverizer when pulverizing, by densification flakiness shape, is pulverized very carefully by milling action by compressive action simultaneously.As the densification pulverizer, can use for example mixing and kneading machine (ラ イ カ イ キ), runner milling (Edge runner), roller mill, wheel roller (Flet mill).
In addition, also can be in composite oxide power mixed additive as required.As additive, can be corresponding to the needed characteristic of ceramic composition, suitable use is the element of the rare earth element, boron, aluminium, silicon, manganese, iron, nickel, copper, zinc, niobium, yttrium, tungsten, bismuth etc. of lanthanum, cerium, gadolinium, terbium, dysprosium, holmium, erbium, ytterbium etc. for example.In addition, particle is grown up and the additive of the electrical characteristic of ceramic composition as being used to when the sintering to control, for example, except boron, bismuth, can also enumerate the compound of elements such as the transition metal of basic metal, iron, manganese, cobalt, nickel, niobium etc. of lithium, sodium, potassium etc. and silicon, aluminium.Such additive can add at the shredding stage of composite oxide power, also can mix after pulverizing.Perhaps, also can add in any stage of the sintering circuit of composite oxide power.The addition requirement that can suit to set.Mixing machine can use the mixing machine that uses usually in domain of inorganic chemistry, particularly ceramic field, perhaps the mixing machine that uses in field of electronic materials.Moreover, pulverizing, when mixing, also can add the organic compound of tensio-active agent, resin, dispersion agent etc.Can prepare the ceramic combination raw material like this.
At least contain the above-mentioned ceramic combination raw material of composite oxide power, make its sintering, make ceramic composition, for example material use of ceramic electronic components of conduct suitably.Ceramic electronic components has ceramic composition and clips this ceramic composition and the electrode of subtend setting.In addition, as ceramic electronic components, multilayer ceramic electronic component is to possess a plurality of layer that contains ceramic composition and the parts of the electrode that forms at the interlayer of above-mentioned ceramic composition.Concrete multilayer ceramic electronic component is a multi-layer ceramic capacitor, and it possesses multilayer body, and described multilayer body comprises a plurality of stacked ceramic composition layers (dielectric layer) and the internal electrode that forms along the specific interface of these ceramic composition interlayers.Inside in multilayer body, alternately dispose the 1st internal electrode and the 2nd internal electrode as internal electrode, make each ora terminalis form each internal electrode respectively under the state that the multilayer body end face exposes so that the 1st internal electrode is electrically connected with the 1st outer electrode, the 2nd internal electrode is electrically connected with the 2nd outer electrode equally.As electrode, can use for example metal or their alloys such as platinum, palladium, nickel, silver, copper.The thickness of each layer of the ceramic composition of multilayer ceramic electronic component, thin as far as possible being advisable is preferably below the 1 μ m.
Ceramic composition and ceramic electronic components can adopt existing method manufacturing.About ceramic composition, the ceramic combination raw material that for example will contain composite oxide power at least is with after tackiness agent mixes, extrusion forming, form the raw cook of the shape of defined, perhaps, adopt methods such as the sheet method of forming and print process on substrate, to form the raw cook of specific thickness, follow its sintering.About ceramic electronic components, for example can use following method, that is: on the two sides of above-mentioned raw cook, printing or coating are combined with electrode with the cream of metal etc. and carry out the agglomerating method, perhaps, form above-mentioned raw cook, then printing in the above or coating are combined with the cream of electrode usefulness metal etc., repeatedly carry out repeatedly making its agglomerating method behind the aforesaid operations, or the like.Sintering condition can be set corresponding to the sintering degree of ceramic combination raw material is suitable, and sintering temperature for example is preferably about 1000～1500 ℃, more preferably about 1100～1300 ℃.Sintering time also can be set corresponding to the composition of ceramic combination raw material is suitable, is preferably about 0.5～10 hour.Atmosphere during sintering, can be the oxygen-containing gas of oxygen, air, synthesis of air, dry air (dry air), pressurized air etc., but be preferably the electrode not oxidized atmosphere of metal, can use non-oxidizing gas very suitably, for example nitrogen, argon, helium etc., in addition, also can use reducing gas such as hydrogen, carbon monoxide, ammonia suitably.
[embodiment]
Below, enumerate embodiment, comparative example, illustrate in greater detail the present invention, but the present invention is not limited by these embodiment.
Embodiment 1
Titanium dioxide (the specific surface area 190m that weighing is commercially available
2/ g) and barium carbonate (specific surface area 30m
2/ g), and make that the atomic ratio of barium/titanium is 1.000, carry out case of wet attrition with ball mill and mix.Slurries to titanium dioxide that obtains and barium carbonate add water system acrylic resin (8 weight %), carry out drying, granulation with spray-dryer.The median size of granulation powder is 50 μ m.
Then, the granulation powder is dropped in the vertical small-sized fluidised bed firing furnace, use gas as flowing, with the logical dry air (about carbon dioxide containing gas 400ppm) of gas line speed 1.73cm/ second flow, above-mentioned granulation powder is flowed, be warming up to 900 ℃ from room temperature on one side, keep burning till in 1 hour, obtain barium titanate powder of the present invention (Sample A).Moreover, the ventilation of dry air begin from intensification to take out sample burn till full operation during carry out, by the circulation of dry air, the granulation powder is flowed, the carbon dioxide that takes place is discharged into outside the fluidised bed burnt furnace system.
Embodiment 2
For the above embodiments 1, making firing temperature is 950 ℃, carries out similarly to Example 1 in addition, obtains barium titanate powder of the present invention (sample B).
Embodiment 3
For the above embodiments 1, making firing temperature is 1000 ℃, carries out similarly to Example 1 in addition, obtains barium titanate powder of the present invention (sample C).
Embodiment 4
Weighing will in and titanium tetrachloride and the resultant that obtains carries out drying under 130 ℃ temperature and the titanium oxide that obtains (specific surface area with method mensuration noted earlier is 190m
2/ g, average major axis directly are 3 spindle shape titanium dioxide for 80nm, axial ratio, TiO
2Purity is that 99.98 weight %, rutilization rate are 100%, rutile-type crystalline crystallite is 0.077 μ m for 9nm, 50% accumulation particle diameter in water directly) and barium titanate (specific surface area 30m
2/ g), and make that the atomic ratio of barium/titanium is 1.000, carry out case of wet attrition with ball mill and mix, resulting mixed serum is carried out drying, granulation with spray-dryer.The median size of granulation powder is 50 μ m.
Then, the granulation powder is dropped in the vertical small-sized fluidised bed firing furnace, use gas as flowing, with the logical dry air (about carbon dioxide containing gas 400ppm) of gas line speed 1.73cm/ second flow, above-mentioned granulation powder is flowed, be warming up to 900 ℃ from room temperature on one side, keep burning till in 0.5 hour, obtain barium titanate powder of the present invention (sample D).Moreover, the ventilation of dry air begin from intensification to take out sample burn till full operation during carry out, by the circulation of dry air, the granulation powder is flowed, the carbon dioxide that takes place is discharged into outside the fluidised bed burnt furnace system.
Embodiment 5
For the above embodiments 4, making the hold-time is 1 hour, carries out similarly to Example 4 in addition, obtains barium titanate powder of the present invention (sample E).
Embodiment 6
For the above embodiments 4, making the hold-time is 1.5 hours, carries out similarly to Example 4 in addition, obtains barium titanate powder of the present invention (sample F).
Comparative example 1
Carry out similarly to Example 1, use spray-dryer to obtain granulation powder (median size is 50 μ m), then, the granulation powder that obtains is dropped in the crucible of 50cc, and the feasible thickness that becomes 20mm, this crucible is placed the fixed bed electric furnace, in atmosphere, (be not blown into air) and be warmed up to 850 ℃ from room temperature, keep burning till in 5 hours, obtain barium titanate powder (sample G).
Comparative example 2
Carry out similarly to Example 1, use spray-dryer to obtain granulation powder (median size is 50 μ m), then, the granulation powder is dropped in the crucible of 50cc, and make and to become the thickness of 20mm, this crucible is placed the fixed bed electric furnace of may command atmosphere, under reduced pressure (10Pa～100Pa) be warmed up to 900 ℃ from room temperature, keep burning till in 5 hours, obtain barium titanate powder (sample H).
Comparative example 3
Titanium dioxide (the specific surface area 190m that weighing is commercially available
2/ g) and barium carbonate (specific surface area 30m
2/ g), and make that the atomic ratio of barium/titanium is 1.000, carry out case of wet attrition with ball mill and mix, then,, pulverize with mortar with the mixed serum evaporation drying, make raw material powder.
Then, the raw material powder that obtains is dropped in the crucible of 50cc, and the feasible thickness that becomes 20mm, this crucible is put into the fixed bed electric furnace, in atmosphere, (be not blown into air) and be warmed up to 800 ℃, keep burning till in 5 hours, obtain barium titanate powder (sample I) from room temperature.
Comparative example 4
For above-mentioned comparative example 3, making firing temperature is 850 ℃, similarly carries out with comparative example 3 in addition, obtains barium titanate powder (sample J).
Comparative example 5
Similarly carry out with comparative example 3, obtain raw material powder, then, the raw material powder that obtains is dropped in the crucible of 50cc, and make and to become the thickness of 20mm, this crucible is placed the fixed bed electric furnace of may command atmosphere, under reduced pressure (10Pa～100Pa) be warmed up to 900 ℃ from room temperature, keep burning till in 5 hours, obtain barium titanate powder (sample K).
Comparative example 6
Similarly carry out with comparative example 3, obtain raw material powder, then, the raw material powder that obtains is dropped in the crucible of 50cc, and make and to become the thickness of 20mm, this crucible is placed the fixed bed electric furnace of may command atmosphere, with 4 liter/minute flow be blown into nitrogen (nitrogen gas purity 99.999 volume %s) and on one side from room temperature be warmed up to 875 ℃ on one side, keep burning till in 5 hours, obtain barium titanate powder (sample L).Moreover, the circulation of nitrogen, begin from intensification to take out sample burn till full operation during carry out, by the circulation of nitrogen, the carbon dioxide that takes place is discharged into outside the fixed bed electric furnace system.
Comparative example 7
Similarly carry out with comparative example 3, obtain raw material powder, then, the raw material powder that obtains is dropped in the crucible of 50cc, and make and to become the thickness of 20mm, this crucible is placed the fixed bed electric furnace of may command atmosphere, with 4 liter/minute flow be blown into carbon dioxide (carbon dioxide purity 99.5 volume %s more than) and on one side from room temperature be warmed up to 800 ℃ on one side, keep burning till in 5 hours, obtain barium titanate powder (sample M).Moreover, the circulation of carbon dioxide, begin from intensification to take out sample burn till full operation during carry out.
Will be by the different barium titanate powders of handling the Sample A～M that obtains that burn till in this wise, with simple and easy BET method measurement the specific area a (m
2/ g), be above-mentioned formula 2 definite its median size d (μ m) of spheroid by the supposition powder.
In addition, adopt the data of using X-ray diffraction method to obtain, carry out Rietveld and resolve, obtain the lattice parameter a and the c of regular crystal barium titanate, calculate the c/a axial ratio of crystallinity evaluation (square crystallinity).
Know from this result, barium titanate powder of the present invention, have with vacuum in (decompression down) burn till particle diameter, the c/a axial ratio of equal extent, has excellent square crystallinity (tetragonal lattice), on the other hand, with in the atmosphere that uses the fixed bed burning apparatus, under the nitrogen circulation, logical the burning till and compare down of flow of carbon dioxide gas, when being benchmark, have the c/a axial ratio of excellence with the particle diameter of same degree.
Table 1
| Specimen coding | Firing condition | TiO 2+BaCO 3Raw material powder | The characteristic of the barium titanate that obtains | ||
| Particle diameter (μ m) | The c/a axial ratio | ||||
| Embodiment 1 | A | Fluidised bed (circulation dry air) | The granulation powder | 0.131 | 1.0081 |
| Embodiment 2 | B | Fluidised bed (circulation dry air) | The granulation powder | 0.134 | 1.0080 |
| Embodiment 3 | C | Fluidised bed (circulation dry air) | The granulation powder | 0.200 | 1.0083 |
| Embodiment 4 | D | Fluidised bed (circulation dry air) | The granulation powder | 0.101 | 1.0089 |
| Embodiment 5 | E | Fluidised bed (circulation dry air) | The granulation powder | 0.120 | 1.0095 |
| Embodiment 6 | F | Fluidised bed (circulation dry air) | The granulation powder | 0.079 | 1.0079 |
| Comparative example 1 | G | Fixed bed (not circulated gases) | The granulation powder | 0.138 | 1.0063 |
| Comparative example 2 | H | Fixed bed (decompression down) | The granulation powder | 0.129 | 1.0083 |
| Comparative example 3 | I | Fixed bed (not circulated gases) | Powder | 0.117 | 1.0056 |
| Comparative example 4 | J | Fixed bed (not circulated gases) | Powder | 0.148 | 1.0067 |
| Comparative example 5 | K | Fixed bed (decompression down) | Powder | 0.129 | 1.0087 |
| Comparative example 6 | L | Fixed bed (circulation nitrogen) | Powder | 0.120 | 1.0069 |
| Comparative example 7 | M | Fixed bed (circulation carbon dioxide) | Powder | 0.132 | 1.0053 |
Carry out embodiment 1～6 described result of experiment for several times, confirmed that the fluctuation (deviation) of the quality of resulting barium titanate powder is little.Confirmed in addition in the present invention, except can making barium titanate, also can similarly make the compound with perovskite structure of strontium titanate, lead titanate, lead zirconates, lead zirconate titanate, calcium modified barium carbonate, rare earth element modified barium carbonate etc., the atomic ratio with Ti/Ba is many barium titanates of the composition formula more than 2 etc.In addition, at the resulting composite oxide power of sintering, obtain ceramic composition, use said composition to make the occasion of ceramic electronic components, also confirmed superiority of the present invention.
Industrial applicibility
Composite oxide power of the present invention is particulate, has high crystallinity, therefore by making its sintering, can easy and easily make the ceramic composition with the excellent characteristic such as dielectricity and piezoelectricity. This ceramic composition is used for ceramic electronic components, particularly during multilayer ceramic electronic component, is expected to satisfy miniaturization, lightweight, high performance, multifunction etc.
Among the present invention the expression number range " more than " and " following " include given figure.
Claims (15)
1. the manufacture method of a composite oxide power, be that the raw material powder that will be mixed with the metal oxide of titanium and/or zirconium at least and be selected from least a metal carbonate in barium, strontium, calcium, magnesium and the lead burns till and makes the method for composite oxide power, it is characterized in that, take place because of burning till of raw material powder carbon dioxide during at least a portion during, one side circulated gases, raw material powder is flowed, Yi Bian burn till.
2. the manufacture method of composite oxide power according to claim 1 is characterized in that, uses the granulation powder that raw material powder is carried out granulation and form.
3. the manufacture method of composite oxide power according to claim 2 is characterized in that, thereby the slurries of raw material powder are carried out the spraying drying granulation.
4. the manufacture method of composite oxide power according to claim 1 is characterized in that, uses the granulation powder that will carry out granulation after the raw material powder pulverizing and form.
5. the manufacture method of composite oxide power according to claim 2 is characterized in that, uses the granulation powder of the size with 10～1000 μ m.
6. the manufacture method of composite oxide power according to claim 1 is characterized in that, uses the raw material powder of the carbonate that is mixed with titanyl compound and barium at least.
7. the manufacture method of composite oxide power according to claim 6 is characterized in that, uses specific surface area to be 20m
2The titanyl compound that/g is above.
8. the manufacture method of composite oxide power according to claim 1 is characterized in that, take place because of burning till of raw material powder carbon dioxide during, on one side circulated gases, raw material powder is flowed, burn till on one side.
9. the manufacture method of composite oxide power according to claim 1 is characterized in that, use the rutilization rate try to achieve by X-ray diffraction method be higher than 90%, below 100%, and specific surface area is 30m
2The titanyl compound that/g is above.
10. a composite oxide power is characterized in that, is to use the described method of in the claim 1～9 each to make, and its particle diameter is the scope of 0.01～0.3 μ m.
11. a barium titanate powder is characterized in that, is to use the described method of in the claim 1～9 each to make, its particle diameter is the scope of 0.01～0.3 μ m.
12. barium titanate powder according to claim 11, the c/a axial ratio of described barium titanate is 1.007～1.010.
13. a ceramic composition, described composite oxide power of sintering claim 10 or the described barium titanate powder of claim 11 form at least.
14. a ceramic electronic components, it possesses the described ceramic composition of claim 13 and clips described ceramic composition and the electrode of subtend setting.
15. a multilayer ceramic electronic component, the electrode that it possesses a plurality of layer that contains the described ceramic composition of claim 13 and forms at the interlayer of described ceramic composition.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
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| JP316818/2006 | 2006-11-24 | ||
| JP2006316818A JP2008127265A (en) | 2006-11-24 | 2006-11-24 | Composite oxide powder and its manufacturing method, ceramic composition using composite oxide powder and ceramic electronic component using the same |
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| CN101200368A true CN101200368A (en) | 2008-06-18 |
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| Country | Link |
|---|---|
| JP (1) | JP2008127265A (en) |
| KR (1) | KR20080047297A (en) |
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| TW (1) | TW200844071A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102471084A (en) * | 2009-07-09 | 2012-05-23 | 株式会社村田制作所 | Method for producing complex oxide powder, and complex oxide powder |
| CN111659187A (en) * | 2020-06-01 | 2020-09-15 | 南昌航空大学 | Preparation method of piezoelectric foamed ceramic filter for sewage treatment |
| CN116041057A (en) * | 2022-12-26 | 2023-05-02 | 广东微容电子科技有限公司 | Barium titanate powder, preparation method and chip type multilayer ceramic capacitor |
| WO2024011561A1 (en) * | 2022-07-15 | 2024-01-18 | 宁德时代新能源科技股份有限公司 | Positive electrode material composition, positive electrode, rechargeable battery and electric apparatus |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010042969A (en) * | 2008-08-18 | 2010-02-25 | Toyama Prefecture | Manufacturing method of piezoelectric ceramic, piezoelectric ceramic, and piezoelectric element |
| JP5184333B2 (en) * | 2008-12-25 | 2013-04-17 | サムソン エレクトロ−メカニックス カンパニーリミテッド． | Method for manufacturing dielectric ceramic material |
| JP4837721B2 (en) * | 2008-12-25 | 2011-12-14 | サムソン エレクトロ−メカニックス カンパニーリミテッド． | Method for manufacturing dielectric ceramic material |
| JP5440075B2 (en) * | 2009-09-30 | 2014-03-12 | 株式会社村田製作所 | Method for producing ceramic powder |
| JP5440074B2 (en) * | 2009-09-30 | 2014-03-12 | 株式会社村田製作所 | Method for producing ceramic powder |
| JP5873641B2 (en) * | 2010-03-25 | 2016-03-01 | セイコーインスツル株式会社 | Method for producing BaTi2O5 composite oxide |
| KR20120099979A (en) * | 2011-03-02 | 2012-09-12 | 삼성전기주식회사 | Method of manufacturing ceramic powder having perovskite structure and ceramic powder having perovskite structure manufactured using the same |
| KR101458027B1 (en) * | 2013-06-21 | 2014-11-04 | 라파바이오 주식회사 | Manufacturing method of ceramics coated metal |
| JP6571048B2 (en) * | 2016-06-24 | 2019-09-04 | 太陽誘電株式会社 | Multilayer ceramic capacitor, ceramic powder, and manufacturing method thereof |
| CN108275986A (en) * | 2017-12-20 | 2018-07-13 | 柳州智臻智能机械有限公司 | A kind of electron ceramic material and preparation method thereof |
| FR3127212A1 (en) * | 2021-09-17 | 2023-03-24 | Framatome | Process for producing granulated metal oxide powder and corresponding granulated metal oxide powder |
-
2006
- 2006-11-24 JP JP2006316818A patent/JP2008127265A/en active Pending
-
2007
- 2007-10-31 TW TW096140997A patent/TW200844071A/en unknown
- 2007-11-23 CN CNA2007101870844A patent/CN101200368A/en active Pending
- 2007-11-23 KR KR1020070120203A patent/KR20080047297A/en not_active Application Discontinuation
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102471084A (en) * | 2009-07-09 | 2012-05-23 | 株式会社村田制作所 | Method for producing complex oxide powder, and complex oxide powder |
| CN102471084B (en) * | 2009-07-09 | 2014-08-13 | 株式会社村田制作所 | Method for producing complex oxide powder, and complex oxide powder |
| CN111659187A (en) * | 2020-06-01 | 2020-09-15 | 南昌航空大学 | Preparation method of piezoelectric foamed ceramic filter for sewage treatment |
| WO2024011561A1 (en) * | 2022-07-15 | 2024-01-18 | 宁德时代新能源科技股份有限公司 | Positive electrode material composition, positive electrode, rechargeable battery and electric apparatus |
| CN116041057A (en) * | 2022-12-26 | 2023-05-02 | 广东微容电子科技有限公司 | Barium titanate powder, preparation method and chip type multilayer ceramic capacitor |
| CN116041057B (en) * | 2022-12-26 | 2023-11-24 | 广东微容电子科技有限公司 | Barium titanate powder, preparation method and chip type multilayer ceramic capacitor |
Also Published As
| Publication number | Publication date |
|---|---|
| KR20080047297A (en) | 2008-05-28 |
| TW200844071A (en) | 2008-11-16 |
| JP2008127265A (en) | 2008-06-05 |
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