CA3174962A1 - Carboxylic acid-containing nickel powder and carboxylic acid-containing nickel powder production method - Google Patents

Carboxylic acid-containing nickel powder and carboxylic acid-containing nickel powder production method

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Publication number
CA3174962A1
CA3174962A1 CA3174962A CA3174962A CA3174962A1 CA 3174962 A1 CA3174962 A1 CA 3174962A1 CA 3174962 A CA3174962 A CA 3174962A CA 3174962 A CA3174962 A CA 3174962A CA 3174962 A1 CA3174962 A1 CA 3174962A1
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Canada
Prior art keywords
powder
aci
carboxyl
ckel
contai
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CA3174962A
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French (fr)
Inventor
Yuhei Kobayashi
Kousuke Nishimura
Mariko KITAHARA
Mineto Iwasaki
Yasuhiro Kamahori
Hidenori Ieda
Takanori MORIYAMA
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Shoei Chemical Inc
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Shoei Chemical Inc
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Publication of CA3174962A1 publication Critical patent/CA3174962A1/en
Pending legal-status Critical Current

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
    • B03B—SEPARATING SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS
    • B03B1/00—Conditioning for facilitating separation by altering physical properties of the matter to be treated
    • B03B1/04—Conditioning for facilitating separation by altering physical properties of the matter to be treated by additives
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B07—SEPARATING SOLIDS FROM SOLIDS; SORTING
    • B07B—SEPARATING SOLIDS FROM SOLIDS BY SIEVING, SCREENING, SIFTING OR BY USING GAS CURRENTS; SEPARATING BY OTHER DRY METHODS APPLICABLE TO BULK MATERIAL, e.g. LOOSE ARTICLES FIT TO BE HANDLED LIKE BULK MATERIAL
    • B07B7/00—Selective separation of solid materials carried by, or dispersed in, gas currents
    • B07B7/08—Selective separation of solid materials carried by, or dispersed in, gas currents using centrifugal force
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
    • B22F1/16—Metallic particles coated with a non-metal
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B33/00—Silicon; Compounds thereof
    • C01B33/113—Silicon oxides; Hydrates thereof
    • C01B33/12—Silica; Hydrates thereof, e.g. lepidoic silicic acid
    • C01B33/18—Preparation of finely divided silica neither in sol nor in gel form; After-treatment thereof

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Manufacture Of Metal Powder And Suspensions Thereof (AREA)
  • Inorganic Compounds Of Heavy Metals (AREA)
  • Oxygen, Ozone, And Oxides In General (AREA)
  • Powder Metallurgy (AREA)
  • Medicinal Preparation (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Abstract

This carboxylic acid-containing nickel powder contains a plurality of nickel particles, and comprises carboxylic acid on the surface of each of the nickel particles. Through TG-MS, when the temperature is raised from 38°C to 600°C at a heating rate of 20°C/min under an inert atmosphere, a peak is detected in a mass chromatogram of the carboxylic acid molecular ions, and when the boiling point of the carboxylic acid is represented by Tbp[°C], the peak top of the peak falls within the range of between (Tbp + 100) °C and 600°C inclusive. The carboxylic acid content per 1 m2 surface area of the nickel particles constituting the carboxylic acid-containing nickel powder is between 155 ?g and 450 ?g inclusive. The present invention allows a carboxylic acid-containing nickel powder to be provided, having high dispersibility in the gas phase, and having high dispersibility in a paste when mixed with an organic solvent, or the like, and used for forming a paste.

Description

SPECI Fl CATI ON
CARBOXYLIC ACID-CONTAINING NICKEL POVVDER AND CARBOXYLIC ACI D-CONTAI NI NG NI CKEL POWDER PRODUCT! ON METHOD
TECHNICAL FIELD
[ 0001]
The present i nventi on r el at es to a carboxyl i c aci d-contai ni ng ni ckel powder and a met hod for produci ng the carboxyl i c aci d-contai ni ng ni ckel powder.
BACKGROUND ART
[ 0002]
A conduct i ve metal powder has conventi onal I y been used as a conductive mat er i al for an el ectroni c component.
I n a multi I ayer ceramic capacitor, si nce both a cerami c I ayer and an i nternal el ect rode I ayer are rapi dl y bei ng made t hi nner, it is requi red to form the i nternal electrode I ayer havi ng a t hi n and uni form t hi ckness.
For t hi s reason, the conductive metal powder for i nternal electrodes of the multi layer cerami c capacitor is requi red to have a narrow parti cl e size di stri buti on.
Further, the conductive metal powder i s requi red to be free of coarse parti cl es that could contact both of the adj acent i nternal el ectrodes across the di el ectri c I ayer, because such coarse parti Cl es cause a short-ci rcui t of the el ectrodes.
Furthermore, when the conductive metal powder i s mixed with an organi c sol vent and the I i ke to form a paste, the conductive met al powder i s requi red to di sper se uniformly in the paste.
[ 0003]
The classification of a powder produced by van i ous product i on methods has been used as a method for produci ng a powder with a desi red parti cl e si ze di stri but i on. Examples thereof i ncl ude a method of cl assi fyi ng a powder accordi ng to the difference i n parti cl e size by usi ng the difference i n sedi ment at i on vel oci ty of the parti cl e in the gas or liquid phase.
The cl assi f i cat i on i n the gas phase is call ed dry cl assi f i cat i on, whi I e that i n the I i quid phase i s cal I ed wet cl assi f i cat i on. Wet cl assi f i cat i on has super i or cl assi f i cat i on accuracy, but requi r es the use of a I i qui d as a di spersi on medi um and dryi ng and crushi ng after cl assi f i cat i on. For these reasons, dry cl assi f i cati on i s by far I ess costly.

[ 0004]
However, dry classification had a probl em that it was difficult to operate for I ong per i ods of time because the powder adhered to van i ous parts i nsi de the cl assi f i er, cl oggi ng the powder supply port and the i nsi de of the pi pi ng, etc.
I n addi ti on, the I ow cl assi f i cat i on accuracy resul ted i n I ow yields.
[ 0005]
As a met hod ai med at sol vi ng such probl ems, Pat ent Document 1 di scl oses a method of dry cl assi f i cat i on of a powder by mi xi ng the powder and an auxi I i ary agent consi sti ng of al cohol s with a boil i ng poi nt of lower than 200 C or lower, such as ethanol , and dry classifying whi I e vapor i zi ng the auxi I i ary agent.
[ 0006] Pat ent Document 2 di scl oses a met hod of dry cl assi f i cat i on of a powder by mi xi ng the powder and an auxi I i ary agent consisting of an aqueous al cohol sol uti on containing 10 to 50 vol % of al cohol such as ethanol , and dry cl assi fyi ng the powder whi I e vaporizing the auxiliary agent.
[ 0007] Pat ent Document 3 di scl oses a met hod of dry cl assi f i cat i on of a powder by mi xi ng the powder composed of ni ckel and an auxi I i ary agent composed of an organi c sol vent havi ng a f I ash poi nt of 80 C or hi gher, such as di ethyl ene gl ycol , and dry cl assi f yi ng the powder whi I e vapor i zi ng the auxiliary agent.
There i s another disclosed method of dry classification of a powder by mi xi ng the powder consi st i ng of ni ckel and an auxiliary agent consi st i ng of water, and dry cl assi f yi ng the power whi I e vapori zi ng the auxi I i ary agent.
[ 0008] Pat ent Document 4 di scl oses a met hod of dry cl assi f i cat i on of a powder by mi xi ng the powder and di ethyl ene gl ycol monomethyl ether, which is a Ii qui d auxi I i ary agent and then dry classifying the powder.
RELATED ART DOCUMENT
PATENT DOCUMENT
[ 0009] Pat ent Document 1 i s WO 2010/ 047175 Al Patent Document 2 i s WO 2010/ 057206 Al
2 Patent Document 3 is WO 2010/106716 Al Patent Document 4 is WO 2012/124453 Al SUMMARY OF THE INVENTION
PROBLEMS TO BE SOLVED BY THE INVENTION
[ 0010]
However, the inventors of the present invention have found a probl em that dry cl assi f i cat i on by adsorbi ng an auxi I i ary agent such as ethanol onto the powder al I ows the cl assi f i er to be operated for a I ong per i od of time, but the obtai ned powder contai ns many coarse parti cl es, so that it is requi red to repeat classification many times to reduce the number of coarse particles.
Another probl em was that, al though repeated cl assi f i cation may reduce the number of coarse parti cl es, it is ti me- consumi ng and costly, resul ti ng i n reduced productivity and a si gni f i cant decrease i n the yi el d of the obtai ned powder.
[ 0011]
in addi t i on, the powder obtai ned as descri bed above has been di f f i cul t to uniformly di sperse i n the paste obtai ned by mi xi ng wit h t he or gani c sol vent and t he I i ke.
[ 0012]
Accordi ngl y, it is an obj ect of the present i nventi on to provide a carboxyl i c aci d- contai ni ng nickel powder havi ng high di spersi bi I i ty i n a gas phase and hi gh di spersi bi I i ty i n a paste when used for f ormi ng the paste by mi xi ng with the organi c sol vent and the I i ke; and a method for produci ng the carboxyl i c aci d-contai ni ng ni ckel powder.
MEANS OF SOLVING THE PROBLEMS
[ 0013]
Such an object is achieved by the present invention descri bed in the following items (1) to (9).
(1) A carboxyl i c aci d- contai ni ng ni ckel powder which contains a pl ural i ty of ni ckel parti cl es and has a carboxyl i c acid on a surf ace of each of the ni ckel parti cl es, wherei n by using a TG-MS, when a temperature i s rai sed from 38 C to 600 C at a heat i ng rate of 20 C/mi n i n an i nert atmosphere, a peak is detected i n a mass chromatogram of a mol ecul ar i on of the carboxyl i c acid, and wherei n when a boil i ng poi nt of the
3 carboxyl i c acid is Tbp [ C], a peak top of the peak exi sts within a range of (Tbp + 100)QC or hi gher and 600QC or I ower, and wherei n a content of the carboxyl i c aci d per 1 m2 of a surf ace area of the ni ckel part i cl e consti tut i ng the carboxyl i c aci d-contai ni ng ni ckel powder i s 155 lig or more and 450 1..tg or I ess.
[ 0014] (2) The carboxyl i c acid-containing ni ckel powder accordi ng to the above i tem (1), wherein by using the TG-MS, when the temperature i s rai sed from 38QC to 600QC at the heating rate of 20QC/mi n in the i nert atmosphere, there i s no peak top of the peak i n the mass chromatogram of the mol ecul ar i on of the carboxyl i c acid wi t hi n a range of (Tbp - 50) C or hi gher and (Tbp + 50) C or I ower.
[ 0015] (3) The carboxyl i c acid-containing ni ckel powder accordi ng to the above i tern (1) or (2), wherein the carboxyl i c acid has the boi I i ng poi nt of 100 C or hi gher and 270 C or I ower.
[ 0016] (4) The carboxyl i c aci d- contai fling ni ckel powder accordi ng to any one of the above items (1) to (3), wherein the carboxyl i c aci d has a mol ecul ar wei ght of 40 or more and 160 or I ess.
[ 0017] (5) The carboxyl i c acid-containing ni ckel powder accordi ng to any one of the above items (1) to (4), vvherei n the carboxyl i c aci d has 2 carbon atoms or more and 9 carbon atoms or I ess.
[ 0018] (6) The carboxyl i c acid-containing ni ckel powder accordi ng to any one of the above items (3) to (5), wherein the carboxyl i c acid is at I east one sel ected from the group consisting of aceti c aci d and propi oni c aci d.
[ 0019]
(7) A method for producing a carboxyl i c aci d- contai fling ni ckel powder def i ned by any one of the above items (1) to (6), the method compri si ng, bri ngi ng a carboxyl i c aci d in a gaseous state i nto contact with a ni ckel powder di spersed i n a gas phase.
4 [ 0020]
( 8) The met hod for producing the carboxyl i c acid-containing ni ckel powder according to the above item (7), wherein the ni ckel powder i s di spersed i n an atmosphere cont ai ni ng the carboxyl i c aci dint he gaseous state.
[ 0021]
( 9) The met hod for producing the carboxyl i c acid-containing ni ckel powder according to the above item ( 7) , wherein under the condi ti on that the ni ckel powder bei ng i n a dispersed state in a gas phase at the ti me of generati on has been dispersed i n the gas phase, the carboxyl i c aci d in the gaseous state i s supplied i nto the gas phase.
EFFECTS OF THE INVENTION
[ 0022]
Accordi ng to the present i nventi on, it is possi bl e to provide the carboxyl i c aci d- cont ai fling ni ckel powder havi ng the high di spersi bi I i ty i n the gas phase and havi ng the high di spersi bi I i ty i n the paste when used for f ormi ng the paste by mi xi ng with the or gani c sol vent and the I i Ice and the method for produci ng the carboxyl i c aci d- contai ni ng ni ckel powder.
BRI EF DESCRI PTI ON OF THE DRAW! NGS
[ 0023]
Fl G. 1 is a di agr am showi ng a conf i gurati on exampl e of a cl assi f i er whi ch i s used to obtai n a f i ne powder havi ng an extremely small number of coarse part i cl es usi ng a carboxyl i c aci d-contai ni ng ni ckel powder of the present i nventi on.
MODE FOR CARRYING OUT THE INVENTION
[ 0024] Her ei naf t er , preferred embodi ment s of the present i nventi on will be descri bed i n detail .
[ 1] NI CKEL POWDER CONTAI NI NG CARBOXYLI C ACI D
First, the carboxyl i c aci d- contai ni ng ni ckel powder of the present i nventi on will be descri bed.
[ 0025] The carboxyl i c acid-containing ni ckel powder of the present i nventi on contai ns a pl ural i ty of ni ckel parti cl es and has a carboxyl i c aci d on a surf ace of each of the ni ckel part i cl es.
I n other words, the carboxyl i c acid-containing ni ckel powder of the present i nventi on contains carboxyl i c aci d-adsorbed ni ckel part i cl es i n whi ch the carboxyl i c aci d i s adsorbed on the surf ace of each of the ni ckel part i cl es as base parti cl es.
[ 0026]
For the carboxyl i c acid-containing ni ckel powder of the present invention, by using a TG-MS
(Ther mogr avi met ry- Mass Spectrometry), when a temperature i s rai sed from 38QC to 600QC at a heating rate of 20 C/ mi n i n an i nert atmosphere, a peak i s detected i n a mass chromatogram of a mol ecul ar i on of the carboxyl i c aci d.
Further, when a boil i ng poi nt of the carboxyl i c acid i s Tbp [ C] , a peak top of the peak exi sts wi t hi n a range of ( Tbp 100) C or hi gher and 600 C or I ower. Furthermore, a cont ent of the carboxyl i c aci d per 1 M2 of a surf ace area of the ni ckel part i cl e i s 155 pg or more and 450 pg or I ess.
[ 0027]
By sat i sf yi ng such condi ti ons, it is possi bi e to provi de a carboxyl i c aci d- contai ni ng ni ckel powder havi ng high di spersi bi I i ty i n a gas phase and hi gh di spersi bi I i ty i n a paste when used for f ormi ng the paste by mi xi ng with an organi c sol vent and the I i ke. I n addi ti on, Si nce the di spersi bi I i ty of the carboxyl i c aci d- cont ai ni ng ni ckel powder in the gas phase is excel I ent, coarse part i cl es can be suitably removed by dry cl assi f i cat i on.
Further, t hi s makes it possi bi e to suitably obt ai n a f i ne powder havi ng a sharp part i cl e size di stri but i on i n an excel I ent yi el d by the dry cl assi f i cation or the I i ke.
Furthermore, si nce the di spersi bi I ity of the carboxyl i c aci d- contai ni ng ni ckel powder i n the paste contai ni ng the carboxyl i c aci d- contai fling ni ckel powder i s excel I ent, it is possi bi e to i mprove smoothness of a coati ng film formed by usi ng the paste.
[ 0028]
A value of the peak top of the peak in the mass chromatogram of the mol ecul ar i on of the carboxyl i c aci d detected by the TG-MS can be adj usted, for exampl e, by an adsorpti on form of the carboxyl i c aci d onto the ni ckel part i cl e.
More speci f i call y, for exampl e, the val ue of the peak top of the peak i n the mass chromatogram of the mol ecul ar i on of the carboxyl i c aci d detected by the TG-MS can be suitably adj usted by adj usti ng an adsorption met hod of the carboxyl i c aci d onto the ni ckel parti cl e, a condition of adsorpti on treatment, an adsorpt i on amount or the I i ke.
[ 0029]
I n the present speci f i cat i on, the coarse parti cl es refer to parti cl es havi ng a suf f i ci ent I y large parti cl e di amet er with respect to a vol ume- based cumulative 50% particle diameter ( D50) of a target powder whi ch may be a powder obt ai ned by the cl assi f i cat i on as descri bed above. For exampl e, the coarse parti cl es can be parti cl es havi ng the parti cl e diameter of 1.5 times or more with respect to the D50 of the target powder.
Further, the coarse parti cl es can be parti cl es havi ng the parti cl e di ameter of 2.0 times or more with respect to the D50 of the target powder.
Furthermore, the coarse parti cl es can be parti cl es havi ng the parti cl e diameter of 2.5 times or more with respect to the D50 of the target powder.
[ 0030] I n the present speci f i cat i on, the vol ume- based cumulative 50% parti cl e diameter (D50) refers to a vol ume- based cumulative f racti on 50% val ue of the parti cl e size di stri but i on measured usi ng the I aser- type parti cl e Si ze di stri but i on anal yzer unl ess otherwise speci f i ed.
For exampl e, the vol ume- based cumulative 50% parti cl e diameter (D50) can be determi ned by measurement usi ng a I aser di f f racti on/ scat t eri ng type parti cl e size di St ri but i on anal yzer LA- 960 ( manuf act ur ed by HORI BA) .
[ 0031]
For the TG-MS, STA2500 Regulus manufactured by NETZSCH
can be used as TG- DTA for raising a temperature of a sampl e.
I n addi ti on, J MS- Q1500GC manufactured by J EOL Ltd. can be used as MS
for mass spectrometri c anal ysi s of substances vapor i zed by rai Si ng the temperature of the sampl e.
[ 0032]
The content of the carboxyl i c acid per 1 m2 of the surf ace area of the nickel particle constituting the carboxyl i c ad i d- contai ni ng ni ckel powder can be obtai ned by measurement usi ng a CS (Carbon and Sul fur) anal yzer (for exampl e, EMI A- 320V
manufactured by HORI BA, Ltd. ) .

[ 0033]
As descri bed above, in the carboxyl i c acid-containing ni ckel powder of the present i nventi on, the peak appears i n a predet ermi ned regi on ( (Tbp + 100) C or hi gher and 600 C or I ower), which i s different from the boiling point of the carboxyl i c acid, i n the mass chromatogram of the mol ecul ar i on of the carboxyl i c acid in the analysis by the TG-MS.
This is thought to be due to the carboxyl i c aci d bei ng adsorbed on the ni ckel part i cl e in a speci fic form, Al though the detailed mechanism is unknown, the i nvent ors consi der it as f ol I ows. For exampl e, i n a case of chemi cal adsorpt i on where the carboxyl i c acid is chemi call y adsorbed on the ni ckel part i cl e, the carboxyl i c aci d is more st r ongl y adsorbed thereon compared with a case of physi cal adsorpti on.
Therefore, it is presumed that the peak appears in a hi gh temperature range of 100 C or hi gher than the boiling poi nt of the carboxyl i c acid.
It is consi der ed that si nce the carboxyl i c acid i s adsorbed on the ni ckel part i cl e i n the speci fic form and the carboxyl i c aci d i s adsorbed on the surf ace of the ni ckel part i cl e i n an appropri ate rat i o, it is possi bl e to obtain the above- ment i oned excel I ent effects.
That i s, it is consi dered that the di spersi bi I i ty of the carboxyl i c aci d- contai ni ng ni ckel powder i n the gas phase i s i mproved, and the di spersi bi I i ty thereof i n the paste is improved when the carboxyl i c acid-containing ni ckel powder i s used for f ormi ng the paste by mixing with the organi c sol vent and the I i ke.
[ 0034]
Further, since the content of the carboxyl i c acid per 1 m2 of the surf ace area of the ni ckel parti cl e i s equal to or greater than the I ower I i mi t val ue, the di spersi bi I i ty of the carboxyl i c aci d- contai ni ng ni ckel powder i n the gas phase can be suf f i ci ent I y excel I ent .
[ 0035]
Further, since the content of the carboxyl i c acid per 1 m2 of the surf ace area of the ni ckel part i cl e i s equal to or I ess than the upper I i mi t val ue, the di spersi bi I i ty of the carboxyl i c aci d- cont ai ni ng ni ckel powder in the paste can be sufficiently excellent when the carboxyl i c aci d- contai ni ng ni ckel powder is used for f ormi ng the paste by mi xi ng with the organi c sol vent and the I i ke.

[ 0036]
I n the present speci f i cat i on, the "boil i ng poi nt" refers to the boil i ng poi nt under 1 atm, that is, the normal boil i ng poi nt unl ess ot herwi se speci f i ed.
[ 0037]
In a case where the carboxyl i c acid-containing ni ckel powder contai ns a pl ur al i ty of ki nds of carboxyl i c aci ds, at I east one car boxyl i c acid may satisfy the above- menti oned condi ti ons.
I n part i cul ar, it is preferable that the one havi ng the hi ghest content among the pl ur al i ty of ki nds of car boxyl i c aci ds sat i sf i es the above condi ti ons.
More preferably, al I ki nds of carboxyl i c aci ds contai ned i n t he car boxyl i c aci d- cont ai ni ng ni ckel powder sat i sf y the above condi ti ons.
[ 0038]
As descri bed above, in the carboxyl i c acid-containing ni ckel powder of the present i nventi on, the peak top of the peak i n the mass chromatogram of the mol ecul ar i on of the carboxyl i c aci d detected by the above TG-MS analysis may exi St within the range of (Tbp + 100) C or hi gher and 600 C or I ower.
It is prefer abl e t hat the peak top exi sts wi t hi n the range of (Tbp + 120) C or hi gher and 580 C or I ower. .
It is more pref erabl e that the peak top exi sts within the range of (Tbp + 150) C or hi gher and 560 C or I ower. .
It i s even more pref erabl e that the peak top exi sts i n (Tbp + 200) C or hi gher and 540 C or I ess.
It is most pref erabl e that the peak top exi sts wi t hi n the range of (Tbp + 230) C or more and 520 C or lower.
As a result, the above-described effects are more remarkably exhi bi t ed.
[ 0039]
In the carboxyl i c acid-containing ni ckel powder of the present i nventi on, the content of the carboxyl i c aci d per 1 m2 of the surf ace area of the ni ckel part i Cl e may be 155 pg or more and 450 g or I ess.
It is pr ef erabl e that the content i s 155 pg or more and 400 pg or I ess.
It is more pref erabl e that the content i s 155 pg or more and 380 pg or I ess.
It is even more pref erabl e that the content i s 155 pg or more and 350 pg or I ess.
I n part i cul ar, i n the carboxyl i c aci d- contai fling ni ckel powder of the present i nventi on, the content of the carboxyl i c aci d per 1 m2 of the surf ace area of the ni ckel part i cl e i s preferably 160 pg or more and 350 pg or I ess, more preferably 170 pg or more and 350 pg or I ess, and even more pref erabl y 250 pg or more and 350 pg or I ess.
As a result, the above-described effects are more remarkably exhi bi t ed.
[ 0040]
When the carboxyl i c acid-containing ni ckel powder of the present invention is analyzed by the TG-MS as descri bed above, the peak top of the peak i n the mass chromatogram of the mol ecul ar i on of the carboxyl i c acid exi sts wi thi n the range of (Tbp + 100) C or hi gher and 600 C or I ower.
I n addi ti on, an addi ti onal peak top of the peak i n the mass chromatogram of the mol ecul ar i on of the carboxyl i c aci d may exi St out si de the above range.
However, it is pref erabl e that the addi ti onal peak top of the peak i n the mass chromatogram of the mol ecul ar i on of the carboxyl i c aci d does not exi St \Ail t hi n the range of (Tbp - 50) C or hi gher and ( Tbp + 50) C or I ower.
[ 0041]
As a result, the di spersi bi I i ty of the carboxyl i c aci d-contai ni ng ni ckel powder i n the gas phase can be further improved.
I n the case where the carboxyl i c acid-containing ni ckel powder contai ns a pl ural i ty of ki nds of carboxyl i c aci ds, it is pref erabl e that at least one carboxyl i c acid satisfies the above-mentioned condi ti ons.
Further, it is more pref erabl e that the one havi ng the hi ghest content among the pl ural i ty of ki nds of carboxyl i c aci ds sat i sf i es the above- ment i oned condi ti ons.
Furthermore, it is even more pref erabl e that al I ki nds of carboxyl i c aci ds contai ned i n the carboxyl i c aci d- contai ni ng ni ckel powder satisfy the above-ment i oned condi ti ons.
[ 0042]
The vol ume- based cumul at i ve 50% part i cl e di ameter D50 of the carboxyl i c aci d- contai ni ng ni ckel powder i s preferably more than O. 01 pm and 10 pm or I ess, more preferably more than O. 03 pm and 2.5 pm or less, even more preferably more than 0.05 pm and 1.2 pm or I ess, and most preferably more than O. 10 pm and 0.80 pm or I ess.
[ 0043] [1- 1] NI CKEL PARTI CLES

The ni ckel part i cl es constitute the mai n component of the carboxyl i c aci d- contai ni ng ni ckel powder and each of the ni ckel part i cl es i s mai ni y composed of ni ckel .
[ 0044]
The ni ckel part i cl e may be mai ni y composed of ni ckel .
For exampl e, the ni ckel part i cl e may be composed of ni ckel as a si ngl e metal , or may be composed of a ni ckel alloy.
1 n the ni ckel part i cl e, the component with the hi ghest content may be ni ckel , but the content of components other than the ni ckel i n the ni ckel part i cl e i s preferably 40% by mass or less, more preferably 30% by mass or I ess, and even more preferably 20%
by mass or less.
Among them, the content of the components other than the ni ckel i n the ni ckel part i cl e i s preferably 10% by mass or less, more preferably 5% by mass or less, and even more pref erabl y 1% by mass or I ess.
I n part i cul ar, the components other than the ni ckel are pref erabl y cont al ned only as i nevi t abl e components i n the ni ckel parti cl e.
I n this regard, the content of the components other than the ni ckel i n the ni ckel part i cl e i s pref erabl y 1,000 ppm or less.
[ 0045] A shape of t he ni ckel part i cl e i s not I i mi t ed, and exampl es thereof i ncl ude spheri cal , flaky, granul ar, van i ous other shapes, and a mixture of one or more sel ected therefrom.
[ 0046]
in this speci f i cat i on, the term "spheri cal" refers to a part i cl e shape i n whi ch the r at i o of a I ong di ameter to a short di ameter i s 2 or less.
The term "f 1 aky" refers to a shape i n whi ch the rat i o of a long di ameter to a short di ameter exceeds 2.
[ 0047]
Examples of the method for producing the ni ckel particle i ncl ude, but are not I i mi ted to, an el ectrol ysi s method, an at omi zat i on method, a mechani cal pulverization method, a wet r educt i on method, a spray pyrol ysi s method, a chemi cal vapor deposi ti on method, a physi cal vapor deposition method and the 1 i ke.
[ 0048] [1- 2] CARBOXYLI C ACI D
The carboxyl i c acid-containing ni ckel powder contains the carboxyl i c acid i n addi ti on to the ni ckel part i cl e.

[ 0049]
Most of the carboxyl i c acid contai ned in the carboxyl i c aci d- contai ni ng ni ckel powder is adsorbed on the surf ace of the ni ckel part i cl e as the base part i cl e.
I n other words, most of the carboxyl i c acid contai ned i n the carboxyl i c aci d- cont ai ni ng ni ckel powder is contai ned as a component of the carboxyl i c acid-adsorbed ni ckel part i cl e.
[ 0050]
The form of adsorpti on of the carboxyl i c acid onto the ni ckel part i cl e can be either physi cal adsorpti on or chemi cal adsorpti on.
[ 0051]
The carboxyl i c aci d is not part i cul an y limited as I ong as it is a compound havi ng a carboxyl group.
[ 0052]
The carboxyl i c aci d preferably has a boil i ng poi nt of 100 C or hi gher and 270 C or I ower, more pref erabl y 105 C or hi gher and 250 C or I ower, even more pref erabl y 110 C or hi gher and 200 C
or I ower, and most pref erabl y 115 C or hi gher and 170 C or I ower.
[ 0053]
As a result, the di spersi bi I i ty of the carboxyl i c acid-contai ni ng ni ckel powder i n the gas phase can be further improved.
I n addi ti on, when the carboxyl i c acid-containing ni ckel powder is used for f ormi ng the paste by mi xi ng with the organi c sol vent and the I i ke, the di spersi bi I i ty of the carboxyl i c aci d- cont ai ni ng ni ckel powder i n the paste can be further improved.
I n the production of the carboxyl i c aci d- contai ni ng ni ckel powder, the carboxyl i c aci d as a raw mat en i al can be sui tabl y handl ed i n a I i qui d state, thereby i mprovi ng the handl i ng property.
Further, when the carboxyl i c aci d in a vapori zed state i s adsorbed on the ni ckel powder, the carboxylic acid can be adsorbed on the ni ckel powder i n a more sui tabl e state.
[ 0054]
The carboxyl i c aci d i s pref erabl y a monocarboxyl i c aci d.
Thus, the di spersi bi I i ty of the carboxyl i c acid-containing ni ckel powder i n the gas phase can be further i mproved.
I n addi ti on, when the carboxyl i c aci d- contai ni ng ni ckel powder is used for f ormi ng the paste by mi xi ng with the organi c sol vent and the like, the di spersi bi I i ty of the carboxylic acid-containing ni ckel powder i n the paste can be further improved.
[ 0055] The molecular wei ght of the carboxyl i c acid is preferably 40 or more and 160 or I ess, more preferably 50 or more and 120 or I ess, and even more pref erabl y 55 or more and 100 or I ess.
[ 0056] Thus, the di spersi bi I ity of the carboxyl i c aci d-contai ni ng ni ckel powder i n the gas phase can be further improved.
I n addi t i on, when the carboxyl i c aci d- contai ni ng ni ckel powder i s used for f ormi ng the paste by mi xi ng with the organi c sol vent and the I i ke, the di spersi bi I i ty of the carboxyl i c aci d- cont ai ni ng ni ckel powder i n the paste can be further i mproved.
[ 0057]
The number of carbon atoms of the carboxyl i c acid is preferably 2 or more and 9 or I ess, more preferably 2 or more and 7 or I ess, and even more pref erabl y 2 or more and 5 or I ess.
[ 0058] Thus, the di spersi bi I ity of the carboxyl i c aci d-contai ni ng ni ckel powder i n the gas phase can be further improved.
I n addi ti on, when the carboxyl i c acid-containing ni ckel powder is used for f ormi ng the paste by mi xi ng with the organi c sol vent and the I i ke, the di spersi bi I i ty of the carboxyl i c aci d- cont ai ni ng ni ckel powder i n the paste can be further i mproved.
[ 0059]
Exampl es of the carboxyl i c aci d i ncl ude f ormi c aci d, acetic acid, propi oni c aci d, i sobut yr i c aci d, but yr i c acid, crot oni c aci d, i soval en i c aci d, val en i c aci d, caproi c aci d, enant hi c aci d, capryl i c aci d, pel argoni c aci d, I act i c aci d, oxal i c aci d, succi ni c aci d, ol ei c aci d, acryl i c aci d, met hacryl i c aci d and the I i ke.
One or a combi nat i on of two or more sel ected from these can be used.
It is preferable that the carboxyl i c aci d i s at I east one sel ected from the group consi st i ng of the aceti c aci d and the propi oni c aci d.
It is more pref erabl e that the carboxyl i c aci d i s the acetic acid.

[ 0060] Thus, the di spersi bi I ity of the carboxyl i c acid-contai ni ng ni ckel powder i n the gas phase can be further i mproved.
I n addi ti on, when the carboxyl i c acid-containing ni ckel powder is used for f ormi ng the paste by mi xi ng with the organi c sol vent and the I i ke, the di spersi bi I i ty of the carboxyl i c aci d- cont ai ni ng ni ckel powder i n the paste can be further i mproved.
[ 0061] [ 1- 3] USE OF CARBOXYLI C Ad I D- CONTAI NI NG NI CKEL POWDER
The use of the carboxyl i c aci d- contai ni ng ni ckel powder of the present i nventi on i s not parti cul arly limited, but may be used as a conduct i ve powder.
I n parti cul ar, the carboxyl i c aci d-contai ni ng ni ckel powder is preferably used as a conductive powder for a conductive paste.
Si nce the di spersi bi I i ty as the powder i s hi gh, the di spersi bi I i ty i n the paste tends to be hi gh.
I n parti cul ar, the carboxyl i c aci d- contai fling ni ckel powder of the present i nventi on i s pref erabl y used as the conductive powder and more preferably used as the conductive powder for the conductive paste after bei ng subj ect ed to a cl assi f i cat i on step, especi ally after bei ng subj ected to a step of dry cl assi f i cat i on as descri bed I at er.
Si nce the carboxyl i c aci d- contai ni ng ni ckel powder has hi gh f I ui di ty and excel I ent handl i ng property, the ni ckel powder can be easi I y handl ed i n the case of bei ng subj ect ed to van i ous appl i cat i ons.
[ 0062]
By subjecting the carboxyl i c acid-containing ni ckel powder of the present i nventi on to the step of dry cl assi f i cat i on as descri bed bel ow, it is possi bl e to sui tabl y obtai n a fi ne powder which has a smal I average parti cl e di ameter, a narrow parti cl e size di st ri but i on, and contai ns al most no coarse parti cl es.
Such a f i ne powder has a narrower parti cl e si ze di stri but i on than the carboxyl i c aci d- contai ni ng ni ckel powder of the present i nvent i on before cl assi f i cat i on, and thus the f i ne powder can form a coati ng film havi ng more excel I ent smoothness.
Further, when the f i ne powder i s used for an i nternal el ect rode, the f i ne powder can form an electrode I ayer havi ng a uni form t hi ckness.
Si nce al most no coarse parti cl es are contai ned therei n, it is possi bi e to suitably prevent the conductive powder parti cl es from comi ng i nt o contact with both the i nternal el ectrodes and causi ng a short ci rcui t.

Therefore, even i n appl i cat i ons where such hi gh rel i abi I i ty i s r equi red, a suf f i ci ent I y sat i sf act or y effect can be obt ai ned.
Therefore, when the f i ne powder i s used for f or mi ng i nt er nal conductors (internal el ect r odes) and t ermi nal electrodes of a multi I ayer cerami c el ect roni c component such as a multi layer cerami c capacitor, a mul ti I ayer cerami c i nduct or and a multi I ayer pi ezo el ect r i c actuator, the above- descri bed effect i s more remarkably exhi bi t ed.
[ 0063]
The conductive powder may be used for forming conductive port i ons of el ect roni c components, for example, as a conductive paste by mi xi ng with a gl ass f ri t and an or gani c vehi cl e.
[ 0064]
METHOD FOR PRODUCI NG CARBOXYLI C ACI D- CONTAI NI NG NI CKEL
POWDER
Next, a met hod for produci ng the carboxyl i c aci d- cont ai fling ni ckel powder accordi ng to the present i nvent i on will be descri bed.
[ 0065]
The method of the present invention for produci ng a carboxyl i c acid-containing ni ckel powder is a method for produci ng the carboxyl i c acid-containing ni ckel powder of the present i nvent i on descri bed above.
The method i ncl udes a step of bri ngi ng the carboxyl i c aci d in a gaseous state i nto contact with the ni ckel powder whi ch i s an aggregate of the pl ural i ty of ni ckel part i cl es di spersed i n a gas phase.
[ 0066]
As a result, it is possi bl e to provi de the method for produci ng the carboxyl i c aci d- contai ni ng ni ckel powder havi ng hi gh di spersi bill ty i n the gas phase and hi gh di spersi bill ty i n the paste when the carboxyl i c aci d- cont ai ni ng ni ckel powder i s used for f ormi ng the paste by mi xi ng with an organi c sol vent and the I i ke.
Further, as compared with a case where the carboxyl i c aci d i n the gaseous state is brought i nto contact with the ni ckel powder i n a stat i onary state, the carboxyl i c acid can be adsorbed on the surf ace of each of the ni ckel part i cl es i n an overwhel mi ngl y short time with lower concent rat i on thereof. Therefore, it is advantageous from the vi ewpoi nt of consumpti on of the carboxyl i c acid and shorteni ng of time.

[ 0067]
The method for producing the carboxyl i c aci d- contai fling ni ckel powder accordi ng to the present i nventi on may have the step of bri ngi ng the carboxyl i c aci d in the gaseous state i nto contact with the ni ckel powder di spersed i n the gas phase.
However, for exampl e, it is pref erabl e to di sperse the ni ckel powder, whi ch i s the aggregate of the pl ur al i ty of ni ckel part i cl es, i n an atmosphere contai ni ng the carboxyl i c aci d in the gaseous state.
[ 0068] In the method for produci ng the carboxyl i c aci d-cont ai ni ng ni ckel powder accordi ng to the present i nventi on, under the condi ti on that the ni ckel powder bei ng i n a di spersed state i n a gas phase at the ti me of gener at i on has been di spersed i n the gas phase, a step of bri ngi ng the carboxyl i c aci d in the gaseous state i nto contact with the ni ckel powder may be performed by suppl yi ng the carboxyl i c aci d in the gaseous state (carboxyl i c acid gas) i nto the gas phase.
[ 0069]
I n thi s way, after the ni ckel powder i s generated i n the gas phase, the carboxyl i c aci d gas can be brought i nto contact with the ni ckel powder havi ng a better di spersed state by suppl yi ng the carboxyl i c aci d gas i nto the gas phase before coil ect i ng the ni ckel powder.
Thus, the carboxyl i c aci d can be more uni f orml y adsorbed on the ni ckel powder.
[ 0070]
Examples of the method of generating the ni ckel powder bei ng i n the di spersed state in the gas phase at the ti me of generati on i ncl ude: a gas phase method such as a chemi cal vapor deposi ti on met hod and a physi cal vapor deposi ti on method; an at omi zat i on method; a spray pyrol ysi s method; and the I i ke.
I n part i cul ar, by gener at i ng the ni ckel powder usi ng the gas phase method or the spray pyrol ysi s method, it is possi bl e to more easi I y adj ust the part i cl e di amet er of the ni ckel powder so as to be a sui t abl e condi ti on.
[ 0071] In the met hod for pr oduci ng the carboxyl i c aci d-cont ai ni ng ni ckel powder accordi ng to the present i nventi on, the method may have the step of bri ngi ng the carboxyl i c aci d in the gaseous state i nto contact with the ni ckel powder di spersed i n the gas phase.
It is not I i mi ted to the method of bringing the carboxyl i c acid in the gaseous state i nto contact with the ni ckel powder i mmedi at el y after producti on of the ni ckel powder.
For exampl e, the carboxyl i c acid in the gaseous state may be brought i nto contact with the ni ckel powder coil ected once.
[ 0072]
[ 3] METHOD FOR PRODUCI NG Fl NE POWDER USI NG CARBOXYLI C
ACI D-CONTAI Ni NG Ni CKEL POWDER OF THE PRESENT I NVENTI ON
Next, a method for produci ng a f i ne powder usi ng the above-ment i oned carboxyl i c aci d- contai ni ng ni ckel powder of the present i nvent i on will be descri be.
[ 0073]
A method for produci ng a fine powder according to the present embodi ment is a method for produci ng a f i ne powder havi ng a vol ume- based cumul at i ve 50% part i cl e di ameter D50 Wi t hi n a range of 0.01 pm or more and 5. 0 pm or I ess.
The method i ncl udes: a step of generating a powder to be classified by dispersing a carboxylic aci d- contai ni ng ni ckel powder havi ng D5o of more than 0.01 pm and 10 pm or I ess i n a gas phase; and a step of dry cl assi fyi ng the powder to be classified.
[ 0074]
As a result, it i s possi bl e to provi de the method for produci ng the fine powder whi ch i s capable of produci ng the fine powder havi ng an extremely smal I number of coarse part i cl es and havi ng the vol ume- based cumul at i ve 50% part i cl e di ameter D50 wi t hi n a range of 0. 01 pm or more and 5.0 pm or I ess with hi gh productivity.
[ 0075]
Such excellent effects can be obtai ned by the following reasons.
That i s, as compared with the case of perf ormi ng the dry cl assi f i cat i on by adsorbi ng an auxi I i ary agent such as ethanol onto the powder, the di spersi bi I i ty of the powder in the gas phase i s i mproved and the cl assi f i cat i on accuracy i s enhanced by usi ng the carboxyl i c aci d- contai ni ng ni ckel powder in which the carboxyl i c acid i s adsorbed on each of the ni ckel part i cl es under a predetermi ned condi ti on.
Therefore, the number of coarse part i cl es contai ned i n the produced f i ne powder can be extremely reduced.
I n addi ti on, it is possi bl e to reduce the number of cl assi f i cat i on, thereby i mpr ovi ng pr oduct i vi ty.
[ 0076]
When the fine powder obtai ned as descri bed above is mixed with an organi c sol vent and the I i ke to form a paste, the di spersi bi I i ty of the f i ne powder i n the paste is part i cul an y excel I ent .
Therefore, the smoothness of a coati ng film formed using the paste can be improved.
[ 0077]
I n addi ti on, by usi ng the carboxyl i c aci d- contai ni ng ni ckel powder of the present i nvent i on, the f I ui di ty of the powder i s enhanced, the adhesi on of the powder to a cl assi f i er i s reduced, and the yi el d is improved.
Further, si nce the adhesi on to the cl assi f i er i s reduced, a powder supply port and an i nsi de of the pi pi ng in the cl assi f i er are hardly clogged, so that the operati on ti me of the classifier is extended and the productivity is improved.
[ 0078]
In addi ti on, in the present embodi ment , the carboxyl i c aci d- contai ni ng ni ckel powder i n whi ch the carboxyl i c acid i s adsorbed on each of the ni ckel parti cl es i n advance under a predetermi ned condi ti on i s used.
Thi s i s advantageous i n terms of si mpl i fyi ng and downsi zi ng a structure of an apparatus used for produci ng the f i ne powder. Further, as compared with a case where a ni ckel powder on whi ch a carboxyl i c aci d i s not adsorbed i s put i n a di spersi ng machi ne, the f I ui di ty of the powder becomes hi gher. I n addi ti on, the adhesi on of the powder i n the di spersi ng machi ne i s I ess I i kel y to occur.
As a result, the movement of the powder i n the di spersi ng machi ne becomes smoother.
Thi s i s al so because the carboxyl i c aci d- contai ni ng ni ckel powder in whi ch the carboxyl i c aci d i s adsorbed on each of the ni ckel part i cl es i n advance under a predetermi ned condi ti on i s used.
[ 0079]
in this speci f i cat i on, the "cl assi f i cat i on" refers to an oper at i on of cl assi f yi ng the powder i nt o a group of r el at i vel y large part i cl es (in other words, coarse powder) and a group of relatively small particles (i n other words, fine powder).
Speci f i call y, i n the present speci f i cat i on, the fine powder refers to a group of part i cl es havi ng a vol ume- based cumulative 50%

part i cl e di ameter D50 wi t hi n a range of 0.01 pm or more and 5.0 pm or I ess. Further, the coarse powder refers to a group of parti cl es havi ng a I arger D50 than that of the f i ne powder.
[ 0080] [ 3- 1] CLASSI Fl ER
FIG. 1 i s a di agram showi ng a conf i gurati on exampl e of a cl assi f i er whi ch i s used to obtai n a f i ne powder havi ng an extremely small number of coarse part i cl es usi ng a carboxyl i c aci d-contai ni ng ni ckel powder of the present i nventi on.
I n the foil owi ng descri pti on, the upper side i n FIG. 1 is ref erred to as "upper" and the lower si de i n FIG. 1 i s ref erred to as "1 ower".
[ 0081]
A classifier 1 is an ai rf I ow classifier which performs cl assi f i cati on usi ng centrifugal force act i ng on the powder.
The cl assi f i er 1 i ncl udes a casi ng 3 which forms a cl assi f i cati on chamber 10.
[ 0082]
At the upstream side of the cl assi f i cati on chamber ( cl assi f i cati on zone) 10, there is a dispersion zone 11 where the carboxyl i c aci d-contai ni ng ni ckel powder is di spersed pri or to cl assi f i cati on. The cl assi f i cation chamber 10 i s the area where the dispersed carboxyl i c acid-containing ni ckel powder is classified.
[ 0083] The classifier 1 has an introduction port 4 for i ntroduci ng the carboxyl i c aci d- contai ni ng ni ckel powder i nto the di spersi on zone 11, an ai r nozzl e 5 that i nj ects hi gh- pressure ai r ( pri mary ai r) i nto the di spersi on zone 11, a gui de vane 6 to i ntroduce secondary air to fl ow i nto the cl assi f i cati on chamber 10 to form a swi rl i ng ai rf I ow in the cl assi f i cati on chamber 10, a f i ne powder di scharge port 7 that has an openi ng at the upper center of the cl assi f i cati on chamber 10, and a coarse powder di scharge port 8 that has an openi ng along the lower per i phery of the classification chamber 10.
[ 0084]
Next, the method for dispersing and classifying the carboxyl i c aci d- contai ni ng ni ckel powder usi ng such a cl assi f i er 1 will be descri bed.

[ 0085] The carboxyl i c aci d- contai fling ni ckel powder is i ntroduced i nto the di spersi on zone 11 from the i ntroduct i on port 4.
The carboxyl i c aci d- contai ni ng ni ckel powder is di spersed by a di spersi ng force imparted by the pri mary ai r i nj ected i nto the di spersi ng zone 11.
Then, the carboxyl i c aci d- contai ni ng ni ckel powder i s introduced i nto the cl assi f i cat i on chamber 10 i n a di spersed state.
[ 0086]
I n the cl assi f i cat i on chamber 10, the secondary ai r i s f I own t herei n through the gui de vane 6, whi ch ai rf I ow i s swi rl ed i n the cl assi f i cati on chamber 10 and i s exhausted from the upper center of the cl assi f i cat i on chamber 10.
An outward centrifugal force exerted by the swi r I i ng ai rf I ow and a central I y- di rect ed ai rf I ow separate the carboxyl i c aci d- contai ni ng ni ckel powder i n the solid-gas mixture i nto a coarse powder and a f i ne powder.
[ 0087]
The coarse powder moves radi ally outward in the cl assi f i cat i on chamber 10 due to the outward centrifugal force of the swi r I i ng ai rf I ow, and i s coil ected from the coarse powder di schar ge port 8 on the I ower per i phery of the cl assi f i cat i on chamber 10.
On the other hand, the fine powder moves radi ally i nward i n the classification chamber 10 due to the central I y-di rect ed ai rf I ow, and i s col I ected from the f i ne powder discharge port 7 at the upper center of the cl assi f i cat i on chamber 10.
[ 0088]
A suction pump (not shown i n the figure) is connected to the f i ne powder di scharge port 7. The fine powder is discharged and coil ected together with the ai r ( exhaust air) i n the classification chamber 10.
[ 0089]
The step of generating a powder to be classified corresponds to the step performed i n the di spersi on zone 11, and the step of dry cl assi f i cat i on corresponds to the step performed i n the cl assi f i cat i on chamber (cl assi f i cat i on zone) 10.
That is, the carboxyl i c aci d- contai ni ng ni ckel powder in a di spersed state i n the di spersi on zone 11, or i n other words, the carboxyl i c acid-containing ni ckel powder introduced into the classification chamber 10, is the powder to be cl assi f i ed i n this speci f i cat i on.
[ 0090]
In the above expl anat i on, the airflow classifier that uses the centrifugal force from the swi r I i ng airflow for the cl assi f i cat i on i s used as an exampl e, but the cl assi f i cat i on met hod of a cl assi f i er is not limited to any part i cul ar method. For exampl e, a cl assi f i cat i on met hod for uti I i zi ng centrifugal force due to rotation of a rotor, a cl assi f i cat i on met hod for using gravity, and a cl assi f i cat i on met hod for usi ng i nert i al force may be used.
[ 0091]
In the present invention, the step of generating a powder to be classified and the step of dry cl assi f i cat i on are not I i mi ted to the case where the same equi pment i s used, and may be performed usi ng separate equi pment.
I n other words, the powder to be cl assi f i ed may be obtai ned by di spersi ng the carboxyl i c aci d-contai ni ng ni ckel powder i n a di spersi ng machi ne, and then cl assi f yi ng the powder to be cl assi f i ed i n a dry cl assi f i er.
[ 0092] [ 3- 2] STEP OF GENERATI NG POWDER TO BE CLASSI Fl ED
I n the step of generati ng a powder to be cl assi f i ed, the powder to be cl assi f i ed i n which the carboxyl i c acid-containing ni ckel powder i s di spersed i n the gas phase i s obtai ned.
[ 0093]
The supply speed of the carboxyl i c acid-containing ni ckel powder to the cl assi f i er, that i s, for exampl e, the supply speed of the carboxyl i c aci d- cant ai ni ng ni ckel powder from I ntroducti on port 4 i nto the di spersi on zone 11 i n the cl assi f i er 1 shown i n Fl G. 1 depends on the si ze (capacity) of the cl assi f i er 1.
However, it is preferably 1 kg/ hr or more and 20 kg/ hr or I ess, more preferably 3 kg/ hr or more and 15 kg/ hr or less, and even more preferably 5 kg/ hr or more and 12 kg/ hr or less.
[ 0094]
As a result, the di spersi bi I i ty of the carboxyl i c aci d-contai ni ng ni ckel powder can be improved, and the product i vi ty of the f i ne powder can be further improved.

[ 0095] The suppl yi ng and di spersi ng pressure dun i ng di spersi on, that i s, for exampl e, the pressure of the di spersed ai r i nj ected from the ai r nozzl e 5 i nto the di spersi on zone 11 i n the cl assi f i er 1 shown i n FIG. 1 i s not parti cul an y I i mi ted, but i s preferably O. 2 MPa or more and 1. 0 MPa or I ess, more preferably 0.4 MPa or more and 0.8 MPa or I ess, and st i I I more preferably 0.5 MPa or more and O. 7 MPa or I ess.
[ 0096] As a result, the di spersi bi I i ty of the carboxyl i c aci d-contai ni ng ni ckel powder can be improved, and the producti vi ty of the f i ne powder can be further improved.
[ 0097] [ 3- 2] STEP OF DRY CLASS! Fl CATI ON
I n the step of dry cl assi f i cat i on, the powder to be cl assi f i ed obt ai ned i n the step of gener at i ng the powder to be classified is dry cl assi f i ed.
[ 0098] Because the powder to be classified is suitably di spersed i n the gas phase, the cl assi fi cati on accuracy i n the step of dry cl assi f i cat i on i s improved. Consequently, the number of coarse part i cl es i n the produced f i ne powder can be extremely reduced.
I n addi ti on, the improved cl assi f i cat i on accuracy can reduce the number of ti mes of cl assi f i cat i ons to improve productivity.
[ 0099] As the fluidity of the powder to be classified is i ncr eased, adhesi on of the powder to be cl assi f i ed to an i nsi de of the cl assi f i er will be reduced, whi ch improves the yi el d.
As the adhesi on of the powder to be cl assi f i ed to the i nsi de of the cl assi f i er is reduced, blockage of a powder supply port and an I nsi de of piping of the classifier hardly occur, thereby extending the operati on ti me of the cl assi f i er.
Thus, the productivity i s I ncr eased.
[ 0100] Thus, the fine powder containing the extremely smal I
number of coarse part i cl es can be produced with a hi gh producti vi ty.

[ 0101]
A gas phase temperature at which the step of dry cl assi f i cat i on i s performed i s not I i mi t ed, and preferably ranges from 60 C to 300 C, more preferably from 100 C to 250 C, and even more preferably from 150 C to 200 C.
[ 0102]
I n the ranges, probl ems such as def ormati on of part i cl es by heat and al t er at i on of constituent mat er i al s of the part i cl es are prevented more eff ect i vel y.
At the same time, the centrifugal force is increased due to a hi gher speed of the ai rf I ow.
I n addi ti on, it is possi bl e to prevent water vapor from adheri ng to the part i cl es, thereby further enhanci ng the classification accuracy. The productivity can al so be further improved.
In addi ti on, the number of coarse part i cl es i n the f i ne powder can be part i cul ar I y reduced.
[ 0103]
A suct i on ai rf I ow amount during the step of dry cl assi f i cat i on, i . e. , for example, a suct i on ai rf I ow amount by the suction pump connected to the f i ne part i cl e di scharge port 7 i n the cl assi f i er 1 shown i n FIG. 1, is not limited, and preferably ranges from 5.0 m3/ mi n to 30 m3/ mi n, more pref er abl e from 6.0 m3/ mi n to 20 m3/mi n, and even more preferably from 7. 0 m3/ mi n to 9.0 m3/ mi n.
I n these ranges, more eff i ci ent cl assi f i cat i on of the powder to be classified can be achieved.
[ 0104]
A suction pressure at which dry classification is performed, i . e. , for exampl e, a suct i on pressure by the suct i on pump connected to the f i ne part i cl e di scharge port 7 i n the cl assi f i er 1 shown i n FIG. 1, is not limited, and preferably ranges from -60 kPa to -5 kPa, more preferably from -50 kPa to -10 kPa, and even more preferably from -40 kPa to -15 kPa.
I n these ranges, a more eff i ci ent classification of the powder to be classified can be achieved.
[ 0105]
By the dry classification, the powder to be classified i s classified i nto a f i ne powder and a coarse powder. The powder to be cl assi f i ed i s cl assi f i ed i nt o, f or exampl e, t he f i ne powder havi ng the vol ume- based cumul at i ve 50% part i cl e di ameter D50 rangi ng from O. 01 pm to 5. 0 pm, and the coarse powder havi ng the D50 I arger than that of the f i ne powder.
Among them, the fine powder is coil ect ed as the fine powder produced.
[ 0106]
As descri bed above, the f i ne powder having the vol ume-based cumul at i ve 50% part i cl e diameter D50 rangi ng from 0.01 pm to
5.0 pm i s produced.
[ 0107]
The fine powder produced i n this way has the extremely smal I number of coarse part i cl es. I n addi ti on, secondary aggregat i on i s prevented, si nce the carboxyl i c aci d i s adsorbed on the f i ne powder i n a sui tabl e state.
[ 0108]
Furthermore, the method as descri bed above can reduce the number of times of cl assi f i cat i ons due to the improved classification accuracy.
Further, adhesion of the powder to be cl assi f i ed to i nsi de the cl assi f i er i s al so reduced, thereby i ncreasi ng the yi el d.
I n addi ti on, the reduced adhesi on i nsi de the classifier prevents blockage of the powder supply port and the i nsi de of the pi pi ng of the classifier, thereby extending the oper at i on ti me of the cl assi f i er and i mpr ovi ng pr oduct i vi ty.
[ 0109]
The step of dry classification may be performed only once or repeated multi pl e times, whi ch enabl es to further enhance the cl assi f i cat i on accuracy.
[ 0110]
A yield of fine powder in the step of dry classification i s not I i mi ted, and i s pref erabl y 80% or hi gher, more preferably 81% or hi gher, and even more preferably 82% or hi gher, and most preferably 83% or more.
Thus, the effects of the pr event i nvent i on are more remarkably exhi bi t ed.
[ 0111]
In this speci f i cat i on, the yield of fine powder in the step of dry cl assi f i cat i on is cal cul at ed from a wei ght of the powder before cl assi f i cat i on, i . e. , a wei ght of the carboxyl i c aci d- contai ni ng ni ckel powder, and a wei ght of the powder after cl assi f i cat i on, i . e. , a wei ght of the f i ne powder, usi ng the foil owi ng f or mul a:

Yi el d (/0) = (wei ght of powder after cl assi f i cat i on / wei ght of powder before cl assi f i cat i on) x 100 [ 0112]
The fine powder produced by the method according to the present i nventi on as descri bed above have the vol ume- based cumul at i ve 50% part i cl e di ameter 050 rangi ng from 0.01 pm to 5.0 pm.
Pref erabl y, the D50 of the f i ne powder ranges from 0.03 pm to 2.0 pm, more pref erabl y from 0.05 pm to 1.0 pm, and even more pref erabl y from 0.10 pm to 0.60 pm.
[ 0113] Thus, the fine powder with an i deal part i cl e size di st ri but i on can be obtai ned.
Convent i onal I y, when the D50 was wi t hi n such a range, a probl em of coarse part i cl es is li kel y to occur to cause adverse effects. I n contrast, the present i nventi on can prevent the occurrence of such a probl em more eff ecti vel y even when the D50 i s wi t hi n the range.
That i s, the effects of the present i nventi on are more remarkabl y exhi bi ted when the D50 of the fine powder is within the above range.
[ 0114]
The fine powder produced by the method according to the present i nventi on as descri bed above pref erabl y has a val ue of ( D90 -D10) / D50 rangi ng from 0.30 to 0.90, more preferably from 0.35 to 0.80, and sti I I more pref erabl y from 0.40 to 0.75, wherein Dio [ pm]
i s a part i cl e di ameter at vol ume- based cumul at i ve f r act i on 10%, [ pm] i s a part i cl e di ameter at vol ume- based cumul at i ve f r act i on 50%, and D90 [ pm] i s a part i cl e di ameter at vol ume- based cumul at i ve f racti on 90% of a part i cl e size di st ri but i on measured by a I aser part i cl e size anal yzer.
[ 0115]
The val ue of ( D90- D10)/ D50 i s an i ndex of a uni f ormi ty of the part i cl e size di st ri but i on.
A smal I er val ue of ( D90- D10)/1)50 i ndi cat es a narrower part i cl e Si ze di st ri but i on, i . e. , more uni form part i cl e size.
[ 0116]
Thus, the f i ne powder has more uni form part i cl e si ze and i s used sui tabl y for van i ous appl i cat i ons.

[ 0117]
In the met hod for producing the fine powder, the number of coarse part i cl es, as determi ned by the f ol I owi ng measurements, i s preferred 30 or I ess, more pref erabl y 25 or I ess, and even more preferably 20 or I ess.
[ 0118]
In such cases, van i ous probl ems caused by the presence of coarse part i cl es i n the f i ne powder can be prevented more ef f ect i vel y.
[ 0119]
The above measurement of the coarse particle count can be performed, for exampl e, as f ol I ows.
Fi rst I y, a di spersi on I i qui d of the f i ne powder is prepared by mi xi ng 1.0 g of the f i ne powder with 20 ml of ethanol whi ch mixture i s then treated with an ul t r as oni c cl eaner ( e. g. , W- 113 manufactured by Honda El ect r oni cs Co., Ltd. ) for 1 mi flute.
Subsequently, 30 I of the di spersi on I i quid prepared i s sampled and then dropped onto an al umi num sampl e stand, whi ch i s dr i ed to remove the di spersi on medi um. Thereby, a sampl e for measurement i s prepared. The sampl e thus prepared i s observed by usi ng a scanni ng electron microscope ( e. g. , SU- 1510 manufactured by Hitachi Hi gh-Tech Corpor at i on) for 50 f i el ds of vi ew at a magni f i cat i on of 10, 000 times.
The total number of particles having a diameter 1.5 times or greater than the vol ume- based cumulative 50% particle di amet er D50 of the f i ne powder i s counted as the coarse part i cl e count.
[ 0120]
The suitable embodi ment s of the present invention have been descri bed above, but the present i nventi on i s not limited to these.
[ 0121]
For exampl e, the equi pment sui t abl y used i n the met hod for produci ng the f i ne powder of the present i nvent i on i s not limited to those descri bed i n the af or ement i oned embodi ment s.
EXAMPLES
[ 0122]
The present i nvent i on i s descr i bed i n more detail with sped i f i c exampl es bel ow, but the present i nvent i on is not limited onl y to the f ol I owi ng exampl es.
I n the f ol I owi ng expl anati ons, treatments for whi ch no part i cul ar temperature or humi di ty condi t i ons are indicated were conducted at room temperature ( 25 C) and a relative humi di ty of 50%. I n addi ti on, the van i ous measurement condi ti ons, unl ess ot her wi se i ndi cat ed, are those at room temperature ( 25 C) and a relative humi di ty of 50%. The vol ume-based cumul at i ve f r act i on 10% val ue Dio, the vol ume- based cumul at i ve f r act i on 50% val ue D50, and t he vol ume- based cumul at i ve f r act i on 90%
val ue D90 were measured for the carboxyl i c aci d- cont ai ni ng ni ckel powder and the f i ne powder usi ng a I aser di f f r act i on/ scat t er i ng particle size anal yzer LA-960 (manufactured by HORI BA Lt d. ) The condi ti ons of the carboxyl i c aci ds used i n each of the foil owi ng exampl es are summari zed i n Tabl e 1.
[ 0123] [Tabl e 1]
Table 1 Carboxylic acid Boiling point [CC] Molecular -weight Carbon number Acetic acid (AA) 118.5 60.05 2 Propiomic (PA) 141 74.9 [ 0124]
[ 4] PRODUCTI ON OF CARBOXYLI C ACI D- CONTAI NI NG NI CKEL
POWDER
Exampl e 1 First, a ni ckel powder having a volume-based cumulative 50%
part i cl e di amet er 050 of 0.31 pm was prepared.
The ni ckel powder was di spersed i n an atmosphere cont ai ni ng an acet i c aci d as a car boxyl i c aci d for 10 seconds, thereby obt ai ni ng a carboxyl i c aci d- contai ni ng ni ckel powder which was an acetic aci d- adsor bed ni ckel powder.
The acetic acid with a purity close to 100% ( speci al grade 99. 7+% manufactured by Fuj ifilm Wako Pure Chemi cal Cor por at i on) was used.
I n addi ti on, the temperature of the atmosphere contai ni ng the aceti c acid was adj usted to 100 C
when the ni ckel powder was di spersed.
The part i al pressure of acetic aci dint he atmosphere was set to 6.6 x 10-5 atm.
[ 0125] Exampl e 2 The car boxyl i c aci d- cont ai ni ng ni ckel powder as the aceti c acid-adsorbed ni ckel powder was obtai ned i n the same manner as i n Example 1 except that the partial pressure of the acetic acid i n the atmosphere at the ti me of di spersi ng the ni ckel powder i n the atmosphere contai ni ng the aceti c acid as the carboxyl i c aci d was changed to 6. 6 x 10-6 atm.
[ 0126] Exampl e 3 The carboxyl i c aci d-contai ni ng ni ckel powder was obtai ned i n the same manner as i n Exampl e 1 except that a propi oni c aci d was used i nstead of the aceti c aci d and the condi ti ons for di spersi ng the ni ckel powder i n the atmosphere contai ni ng the carboxyl i c aci d were changed as shown i n Tabl e 2.
[ 0127] Exampl e 4 Fi rst, a powder of ni ckel acetate t et rahydrat e was prepared.
The powder of the ni ckel acetate tetrahydrate was sprayed and heated to 1500 C i n a gas phase, thereby obtai ni ng the ni ckel powder di spersed i n the gas phase. The temperature of the gas phase was adj usted to 300 C i n a state where the ni ckel powder was di spersed i n the gas phase.
A treatment was performed for 10 seconds by suppl yi ng the aceti c aci d as the carboxyl i c aci d i nto the gas phase i n whi ch the ni ckel powder i s di spersed. Thereby, the carboxyl i c aci d- contai ni ng ni ckel powder whi ch was the aceti c aci d-adsorbed ni ckel powder was obtai ned. The aceti c aci d with a purity close to 100% (speci al grade 99. 7+% manufactured by Fuj ifilm Wako Pure Chemi cal Corporati on) was used.
The part i al pressure of the acetic aci d in the gas phase at the ti me of perf ormi ng the treatment with the aceti c aci d as the carboxyl i c aci d was set to
6.6 x 10-5 atm.
The vol ume- based cumul at i ve 50% part i cl e di ameter D50 measured by col I ecti ng the ni ckel powder before suppl yi ng the acetic acid as the carboxylic acid was 0.31 pm.
[ 0128] Exampl e 5 The carboxyl i c aci d- contai ni ng ni ckel powder whi ch was the acetic acid-adsorbed ni ckel powder was obtai ned in the same manner as i n Exampl e 4 except that the temperature of the gas phase at the ti me of suppl yi ng the carboxyl i c aci d was changed to 500 C and the partial pressure of the aceti c acid in the gas phase at the ti me of perf or mi ng the treatment with the aceti c acid as the carboxyl i c acid was changed to 1.3 x 10-5 atm.
[ 0129] Exampl e 6 The carboxyl i c aci d- contai ni ng ni ckel powder which was the acetic acid-adsorbed ni ckel powder was obtai ned in the same manner as i n Exampl e 5 except that the part i al pressure of the aceti c aci d i n the gas phase at the ti me of perf ormi ng the treatment with the acetic aci d as the carboxyl i c aci d was changed to 6.6 x 10-5 atm.
[ 0130] Comparative Example 1 As a powder of Comparative Exampl e 1, the ni ckel powder used as the raw mat en i al powder i n Exampl e 1 was used without the treatment with the carboxyl i c aci d. Namely, the powder accor di ng to this Comparative Exampl e was the ni ckel powder which was not treated with the carboxyl i c aci d.
[ 0131] Comparative Example 2 First, a ni ckel powder having a volume-based cumulative 50%
part i cl e di ameter 050 of 0.31 pm was prepared.
The ni ckel powder was di spersed i n an atmosphere contai ni ng an ethanol as an al cohol for 10 seconds, thereby obtai ni ng an alcohol-adsorbed ni ckel powder as an alcohol-treated powder.
The temperature of the atmosphere contai ni ng the al cohol was adj usted to 25 C when the ni ckel powder was dispersed. The partial pressure of the al cohol i n the atmosphere was set to 9. 6 x 10-6 atm.
[ 0132] Comparative Example 3 The al cohol -treated powder whi ch was the treated powder of the or gani c compound was produced i n the same manner as i n Comparative Exampl e 2 except that an i sopropanol was used i nstead of the ethanol as the al cohol and the part i al pressure of the al cohol i n the atmosphere at the time of perf ormi ng the treatment with the al cohol was set to 8.8 x 10-6 atm.
[ 0133] Comparative Example 4 First, a ni ckel powder having a volume-based cumulative 50%
parti cl e di ameter D50 of 0.31 pm was prepared.
The ni ckel powder was pl aced i n an atmosphere contai ni ng an acetic aci d as a carboxyl i c acid, thereby obtai ni ng a carboxyl i c aci d- cont ai ni ng ni ckel powder whi ch was an acetic acid-adsorbed ni ckel powder. The aceti c aci d with a purity close to 100% (special grade 99. 7+% manufactured by Fuj i film VVako Pure Chemi cal Cor por at i on) was used. The treatment ti me with the aceti c aci d was set to 30 mi nut es.
Further, the treatment temperature at the ti me of perf ormi ng the treatment with the aceti c aci d was set to 50 C.
Furthermore, the parti al pressure of the aceti c acid in the atmosphere at the ti me of perf ormi ng the treatment with the aceti c aci d was set to 1. 0 X 10-1 atm.
[ 0134] Comparative Exampl es 5 and 6 The car boxyl i c aci d- cont ai ni ng ni ckel powder as the aceti c acid-adsorbed ni ckel powder was obtai ned i n the same manner as i n Exampl e 1 except that the condi ti ons for di spersi ng the ni ckel powder i n the atmosphere contai ni ng the acetic aci d as the carboxyl i c aci d was changed as shown i n Tabl e 2.
[ 0135] Comparative Example 7 The carboxyl i c aci d-contai ni ng ni ckel powder was obtai ned i n the same manner as i n Comparati ve Exampl e 4 except that a propi oni c acid was used as the carboxyl i c aci d i nstead of the aceti c aci d, the treatment ti me with the carboxyl i c aci d was set to 60 mi flutes, the treatment temperature at the ti me of perf ormi ng the treatment with the carboxyl i c aci d was set to 120 C, and the parti al pressure of the carboxyl i c aci d in the atmosphere at the ti me of perf ormi ng the treatment with the carboxyl i c aci d was set to 5. 0 X 10-1 atm.
[ 0136] Table 2 was prepared to show the manufacturing condi ti ons of the powder of each of the above Exampl es and Comparative Exampl es.
I n addi ti on to the manufacturi ng condi ti ons, Tabl e 2 was prepared to show a temperature of a peak top of a peak i n a mass chromatogram of a mol ecul ar i on (mol ecul ar i on of aceti c aci d: nu/z=60, mol ecul ar i on of propi oni c aci d: m/z=74) of the carboxyl i c aci d, where the peak was detected when a temperature was rai sed from 38 C to 600 C at a heat i ng rate of 20 C/mi n in a hel i um atmosphere which was an inert atmosphere by using the TG-MS for each powder.
Tabl e 2 was al so prepared to show a content of the carboxyl i c aci d per 1 m2 of the surf ace area of the ni ckel part i cl e const i t ut i ng the obt ai ned powder.
I n this regard, El ( El ect r on I oni zati on) method was used as an i oni zati on met hod for the MS.
Further, Tabl e 2 was prepared to show presence or absence of the peak top of the peak i n the mass chromatogram of the mol ecul ar i on of the carboxyl i c aci d wi thi n the range of (Tbp + 100) C or hi gher and 600 C or lower, where Tbp [ C] was the boil i ng point of the carboxyl i c aci d used i n each of the above Exampl es and Comparative Exampl es 4 to 7. Furthermore, Tabl e 2 was prepared to show presence or absence of the peak top of the peak i n the mass chromatogram of the mol ecul ar i on of the carboxyl i c aci d wi t hi n the range of (Tbp -50) C or hi gher and (Tbp + 50) C or lower.
For the TG-MS, STA2500 Regulus manufactured by NETZSCH was used as the TG- DTA for raising the temperature of the sample, and j MS- Q1500GC manufactured by j EOL
Ltd. was used as the MS for the mass spectrometri c anal ysi s of substances vapor i zed by rai si ng the temperature of the sample.
Moreover, the content of the carboxyl i c aci d per 1 m2 of the surf ace area of the ni ckel part i cl e const i t ut i ng the powder was obt ai ned using the CS (carbon/Sul fur) anal yzer (EMI A- 320V manufactured by HORI BA, Ltd.). Speci f i call y, (1) an amount of carbon i n the ni ckel powder before the carboxylic acid adsorpti on treatment and (2) an amount of carbon i n the ni ckel powder after the carboxyl i c aci d adsorpti on treatment were measured.
Then, a val ue obtai ned by subt r act i ng ( 1) from ( 2) was def i ned as an amount of car bon i ncr eased by the carboxyl i c acid adsorpti on treatment, After that, t hi s val ue, the rat i o of carbon i n the carboxyl i c aci d, and the sped i f i c surf ace area of the ni ckel powder before the carboxyl i c acid adsorpti on treatment were used to obtai n the content of the carboxyl i c aci d per 1 m2 of the surf ace area of the ni ckel part i cl e consti tuti ng the powder.
I n Table 2, the aceti c aci d was indicated as "AA", the propi oni c acid was i ndi cat ed as "PA", the ethanol was i ndi cat ed as "Et OH", and the i sopropanol was i ndi cat ed as "I PA".
[ 0137] [Tabl e 2]

2, o , .-,J
A
ta m m m Y
, 0, Table 2 TG-MS result Peak in mass Peak in mass Gas chromat.gram of chromatogram of phase molecular ion of molecular ion of Adsorpt temperat carboxylic acid carhoxylic acid Treatment Depost ion Depoa urn at ime within the range of within the range p t for gas) ar t amount it Method for adding deposit the time (Th,¨nulcc or higher of :Tb, + /oo) c usinP de ial press of Type of and (Tbp , 50) C or or higher and posit ore [atm]
deposit adding lower 600 C or lower [1.germ'l deposit Presence Presence lb Peak top or Peak top or s.
Temperatu Absence Temperat nce of p re jaC]
of peak ore I'd]
eah top top Disperse powder in gas phase of 10 Ex.1 Al 1DC seconds 6.6.10-' 395 Presence 120 Presence 360 carboxylic acid atmosphere Disperse powder in gas phase of 10 Ex.2 AA 1DC 6.6.10-6 155 Absence - Presence 380 carboxylic acid atmosphere seconds Disperse powder in gas phase of 10 =
Ex.3 PA 120 1.3.10-' 215 Absence - Presence __ 270 carboxylic acid atmosphere seconds Supply carboxylic acid gas into Ex.4 Al gas phase where powder is 300 d E.Ex10-' 275 Absence - Presence 380 secons UJ dispersed NJ Supply carboxylic a,id gas into Ex.5 Al gas phase where powder is 500 1.3x10-' /73 Absence - Presence 380 dispersed seconds Supply carboxylic acid gas into Ex.6 AA gas phase where powder is 500 E.E.10-' 226 Absence - Presence 360 seconds dispersed .
Corn - - - - - -Ahsence - Absence -Ex.1 torn Disperse powder in gas phase of 10 Et0H 25 ,r1.0-.
223 Absence - Absence -Ex.2 alcohol atmosphere seconds Com Disperse powder in gas phase of 10 IPA 25 6.6.11) 2D7 Absence - Absence -Ex.3 alcohol atmosphere seconds Corn Place powder in carboxylic acid 30 AA 1.0x10-1 516 Presence 120 Presence 260 Ex.4 atmosphere minutes Com Ex5 seconds Disperse powder in gas phase of 10 Al /00 E.Ex10-4 542 Presence 120 Presence 360 . carboxylic acid atmosphere Cow Disperse powder in gas phase of 10 AA /DO 3.5.10-' 101 Absence Presence 300 Ex.6 carboxylic acid atmosphere seconds Cam Place powder in carboxylic acid E0 PA 120 5Ø10-r 633 Presence 140 Presence 270 Ex.7 atmosphere minutes 'Ex" refers to Example.
'Corn Ex" refers to Comparative Example.

[ 0138] PRODUCT! ON OF Fl NE POWDER BY DRY CLASS! Fl CATI ON
The powder of each of the Exampl es and Compar at i ve Exampl es, that i s, each of the carboxyl i c aci d- cont ai fling ni ckel powder for the Exampl es and Comparative Exampl es 4 to 7, the ni ckel powder for Comparative Exampl e 1, and the alcohol-treated powder for Comparative Exampl es 2-3 was put into the dry classifier shown in Fl G. 1 at 10 kg per hour. The supply di spersi on pressure was set to 0.6 MPa. As a resul t, a powder to be cl assi f i ed was obtai ned.
[ 0139]
Next, the powder to be classified was introduced into the cl assi f i cat i on chamber. Then, the dry cl assi f i cation was performed under the condi ti ons that the temperature i nsi de the cl assi f i er was set to 25 C, the suct i on ai r vol ume was set to 8.5 m3/ mi n, and the suction pressure was set to -35 kPa. As a result, a f i ne powder was produced.
[ 0140]
Thereafter, the obt ai ned f i ne powder was subj ect ed to the dry Cl assi f i cat i on i n the same manner as descri bed above.
Namely, the dry cl assi f i cat i on was performed twi ce i n total to obt ai n a fi nal f i ne powder.
[ 0141] EVALUATI ON
[ 6- 1] Yield For each of the Exampl es and Comparative Exampl es, the wei ght of the powder before the Cl assi f i cat i on and the wei ght of the powder after the cl assi f i cat i on, i . e. , the wei ght of the f i ne powder obt ai ned by perf ormi ng the cl assi f i cat i on treatment twice were measured.
After that, the yi el d was cal cul at ed by the f ol I owl ng equat i on.
Yi el d CVO = (wei ght of powder after Cl assi f i cat i on/wei ght of powder before cl assi f i cat i on) x 100 [ 0142] [ 6- 21 EVALUATI ON OF PARTI CLE SI ZE DI STRI BUTI ON
For each of the above Exampl es and Comparative Examples, part i cl e size di st ri but i ons were measured for the ni ckel powder as the raw mat eri al powder and for the obt ai ned f i ne powder by usi ng the I aser di f f r act i on/ scatt eri ng particle size anal yzer LA- 960 (manufactured by HORI BA, Lt d. ) .
Based on the results, a val ue at the vol ume- based cumul at i ve f r act i on 10% ( Dio) [ pm] , a val ue at the vol ume- based cumul at i ve f ract i on 50% (D50) [ pm] , and a val ue at the vol ume- based cumul at i ve f r act i on 90% (D90) [ pm] of the part i cl e si ze di st ri but i on were det ermi ned respectively.
[ 0143]
Then, ( D90 - Dio) / D50 was cal cul at ed based on t he val ues of D10 [ pm] , D50 [ pm] , and D90 [ pm] det ermi ned as descri bed above.
[ 0144] [ 6- 3] EVALUATI ON OF COARSE PARTI CLE COUNT
For each of the above Exampl es and Comparative Exampl es, a di spersi on I i qui d was prepared by mi xi ng 1 g of the powder after two times of the cl assi f i cat i on with 20 ml of ethanol as a di spersi on medi um, whi ch mi xt ure was treated with an ul t rasoni c cleaner (W-113 manufactured by Honda El ect roni cs Co., Ltd.) for 1 mi flute, A sampl e for measurement was prepared by sampl i ng 30 pl of the prepared di spersi on I i qui d, dr oppi ng the sampl ed di spersi on I i qui d onto an al umi num sampl e stand, and dryi ng to remove the di spersi on medi um.
The sampl e obtai ned was observed with the scanni ng el ectron microscope (SU- 1510 manufactured by Hitachi Hi gh-Tech Cor por at i on) for 50 f i el ds of vi ew at a magni f i cat i on of 10, 000 times.
The tot al number of coarse part i Cl es, whi ch were def i ned as those with a part i cl e di amet er 2.0 times or greater than the D50 of the target fine powder determi ned in [ 6- 2] above, was count ed.
[ 0145] [ 6- 4] SMOOTHNESS OF COATI NG Fl LM
The powder of each of the Exampl es and Comparat i ve Exampl es obt ai ned in the above [ 4] , i . e. , 100 parts by wei ght of the powder before the Cl assi f i cat i on treatment, 3.0 parts by wei ght of an ethyl cell ul ose resin ( STD100 manufactured by Dow Chemi cal Company) and 100 parts by wei ght of di hydrot er pi neol acetate were mi xed to obtain a mixture.
Then, the mixture was mixed at 2000 rpm for 2 mi nut es by a hybr i d mi xer ( ARE- 310 manuf act ur ed by THI NKY) to obtain a nickel paste.
The obt ai ned nickel paste was cast with a film t hi ckness of 10 pm, and the surf ace roughness Ra was measured by using a fine shape measuri ng i nst rument ( ET3000i manufactured by Kosaka Laboratory Ltd. ).

[ 0146] For the f i ne powder of each of t he Exampl es and Compar at i ve Exampl es obt ai ned i n t he above [ 5] , a past e was prepared, a coati ng film was formed by usi ng the paste and a surf ace roughness was measured i n the same manner as descri bed above.
[ 0147] These results are coil ecti vel y shown i n Tabl e 3.
Further, as for the f i ne powder obtai ned i n each of the above Exampl es, the number of part i cl es havi ng a part i cl e di amet er of 3.0 times or more of the volume-based cumulative 50% particle diameter D50 of each fine powder was determi ned by the method shown in [ 6- 3].
As a result, such a part i cl e was not contai ned therei n for any of the Exampl es.
[ 0148] [Tabl e 3]

>

, A.
.o o m m o m Y
, o, Sable 3 Classification Smoothness of coating film Number of YHeld TI:c n. n., (11..,- ,CRTSR
Surface roughnass Surface roughness (using powder before classification) (using powder after classification) [1.] [Um] [pm] Ipm] Dln)/DFn particles Lnmj Lnmi [Poe]
Example 1 92.2 0.19 0.25 3.41 0.79 23 40.6 30.9 Example 2 93.3 0_99 0.29 0_41 2.74 20 62.5 85.1 ' Example 3 61.1 0.19 0.28 0.41 0.79 19 53.3 50.5 Example 4 63.8 0.19 0.28 0.41 0.73 18 55.2 51.3 Example 5 83.5 0.15 0.29 5.41 0.75 18 60.7 57.8 Example 0 92.0 0.19 0.28 0_41 0.79 17 57.2 53.6 Comparative 52.5 0.18 0.27 0.42 0.99 82 90.2 87.4 Example 1 Comparative 64.7 0.19 0.30 0.45 0.87 55 80.5 75.6 Example 2 comparative 65.4 0.19 0.30 0.45 0.87 5E 77.1 72.1 Example 2 Comparative 62.1 0.15 0.28 0.41 0.79 23 109.2 103.1 Example 4 comparative 61.9 0.19 0.28 0.41 0.79 23 113.9 105.1 UJ Example 5 01 Comparative 74.4 0.19 0.29 5.42 3.82 42 71.1 27.9 Example 8 Comparative 01.0 0.19 0.29 0_42 0.82 20 125.0 118.1 Example 7 [ 0149]
As is apparent from Table 3, each of the above Exampl es suitably produced the metal f i ne powder havi ng the D50 i n the range of from 0.01 pm to 5.0 pm and an extremely small number coarse part i cl es with a hi gh yi el d.
From thi s, it can be sai d that the carboxyl i c aci d- cont ai ni ng ni ckel powder of each of the Exampl es i s excel I ent i n the di spersi bi I i ty i n the gas phase.
I n addi ti on, i n each of the Exampl es, the surf ace roughness of the coati ng film formed usi ng the paste i s small and the smoothness thereof i s hi gh.
From this, it can be said that the carboxyl i c acid-containing ni ckel powder of each of the Exampl es i s excel I ent i n the di spersi bi I i ty i n the paste.
I NDUSTRI AL APPLI CABI LI TY
[ 0150] The carboxyl i c acid-containing ni ckel powder of the present i nventi on cont ai ns a pl ural i ty of ni ckel part i cl es and has a carboxyl i c aci d on a surface of each of the ni ckel parti cl es, wherei n by using a TG-MS, when a temperature is rai sed from 38 C to 600 C at a heat i ng rate of 20 C/mi n i n an i nert atmosphere, a peak i s detected i n a mass chromatogram of a mol ecul ar i on of the carboxyl i c aci d and wherei n when a boil i ng poi nt of the carboxyl i c acid is Tbp [ C], a peak top of the peak exi sts wi t hi n a range of (Tbp + 100) C or hi gher and 600 C or I ower, and wherei n a content of the carboxyl i c aci d per 1 m2 of a surf ace area of the ni ckel part i cl e consti t uti ng the carboxyl i c aci d- contai ni ng ni ckel powder i s 155 lig or more and 450 pg or I ess.
Thus, it is possi bl e to provide the carboxyl i c aci d- cont ai ni ng ni ckel powder havi ng hi gh di spersi bi I i ty i n a gas phase and hi gh di spersi bi I i ty i n a paste when used for f ormi ng the paste by mi xi ng with an organi c sol vent and the I i ke.
The met hod for pr oduci ng the carboxyl i c aci d-cont ai ni ng ni ckel powder accor di ng to the present i nventi on is a met hod for producing the carboxyl i c aci d- contai ni ng ni ckel powder of the present i nventi on. The method i ncl udes a step of bri ngi ng a carboxyl i c aci d in a gaseous state i nto contact with a ni ckel powder di spersed i n a gas phase.
Thus, it is possi bl e to provi de the method for produci ng the carboxyl i c aci d- cont ai fling ni ckel powder havi ng the hi gh di spersi bi Ii ty in the gas phase and the hi gh di spersi bi I i ty i n the paste when used for f ormi ng the paste by mi xi ng with an or gani c sol vent and the I i ke.
Therefore, the car boxyl i c aci d- cont ai ni ng ni ckel powder of t he present i nvent i on and the met hod for producing the carboxyl i c aci d- cont ai ni ng nickel powder have i ndust ri al avail abi I i ty.
EXPLANATION OF REFERENCE NUMERALS
[ 0151] 1: CLASSI Fl ER
3: CASI NG
4: I NTRODUCTI ON PORT
5: Al R NOZZLE
6: GUI DE VANE
7: Fl NE POWDER DI SCHARGE PORT
8: COARSE POWDER DI SCHARGE PORT
10: CLASSI Fl CATI ON CHAMBER (CLASSI Fl CATI ON ZONE) 11: DI SPERSI ON ZONE

Claims (9)

WHAT I S CLAI MED I S:
1. A carboxyl i c aci d- contai ni ng ni ckel powder whi ch contai ns a pl ur al i ty of ni ckel part i cl es and has a carboxyl i c aci d on a surf ace of each of the ni ckel parti cl es, wherei n by usi ng a TG- MS, when a temperature i s rai sed f rom 38 C t o 600 C at a heat i ng rate of 20 C/mi n i n an i nert atmosphere, a peak i s detected i n a mass chromatogram of a mol ecul ar i on of the carboxyl i c aci d, and wherei n when a boi l i ng poi nt of the carboxyl i c aci d i s Tbp [ C1, a peak top of the peak exi sts wi t hi n a range of (Tbp + 100) C or hi gher and 600 C or l ower, and wherei n a content of the carboxyl i c aci d per 1 m2 of a surf ace area of the ni ckel part i cl e const i tuti ng the carboxyl i c aci d-contai ni ng ni ckel powder i s 155 pg or more and 450 1..tg or l ess.
2.
The carboxyl i c aci d- contai ni ng ni ckel powder accor di ng to cl ai m 1, wherei n by usi ng the TG- MS, when the temperature i s rai sed f rom 38 C to 600 C at the heat i ng rate of 20 C/mi n in the i nert at mosphere, t her e i s no peak t op of t he peak i n t he mass chromatogram of the mol ecul ar i on of the carboxyl i c aci d wi t hi n a range of (Tbp - 50) C or hi gher and (Tbp + 50) C or l ower.
3.
The carboxyl i c aci d- contai ni ng ni ckel powder accor di ng to cl ai m 1 or 2, wherei n t he carboxyl i c aci d has the boi l i ng poi nt of 100 C or hi gher and 270 C or l ower.
4. The carboxyl i c aci d- contai ni ng ni ckel powder accordi ng to any one of cl ai ms 1 to 3, wherei n the carboxyl i c aci d has a mol ecul ar wei ght of 40 or more and 160 or l ess.
5. The carboxyl i c aci d- contai ni ng ni ckel powder accordi ng to any one of cl ai ms 1 to 4, wherei n the carboxyl i c aci d has 2 carbon atoms or more and 9 carbon atoms or l ess.
6. The carboxyl i c aci d- contai ni ng ni ckel powder accordi ng to any one of cl ai ms 3 to 5, wherei n the carboxyl i c aci d i s at l east one sel ected f rom the group consi sti ng of aceti c aci d and propi oni c aci d.
7. A method f or produci ng a carboxyl i c aci d- contai ni ng ni ckel powder def i ned by any one of cl ai ms 1 to 6, t he method compri si ng, bri ngi ng a carboxyl i c aci d in a gaseous state i nto contact wi th a ni ckel powder di spersed i n a gas phase.
8. The method f or produci ng the carboxyl i c aci d- contai ni ng ni ckel powder accor di ng t o cl ai m 7, wherei n t he ni ckel powder i s di spersed i n an atmosphere contai ni ng the carboxyl i c aci d in the gaseous st at e.
9. The method f or produci ng the carboxyl i c aci d- contai ni ng ni ckel powder accordi ng to cl ai m 7, wherei n under the condi ti on t hat t he ni ckel powder bei ng i n a di spersed stat e in a gas phase at t he ti me of generati on has been di spersed i n the gas phase, the carboxyl i c aci d in t he gaseous state i s suppl i ed i nto the gas phase.
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US11691200B2 (en) * 2018-01-26 2023-07-04 Nisshin Engineering Inc. Silver fine particle production method and silver fine particles
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