U.S. patent application number 10/490651 was filed with the patent office on 2004-12-09 for electrolyte solution for driving electrolytic capacitor and electrolytic capacitor.
Invention is credited to Komatsu, Akihiko, Ogawara, Tetsushi.
Application Number | 20040245105 10/490651 |
Document ID | / |
Family ID | 19116327 |
Filed Date | 2004-12-09 |
United States Patent
Application |
20040245105 |
Kind Code |
A1 |
Komatsu, Akihiko ; et
al. |
December 9, 2004 |
Electrolyte solution for driving electrolytic capacitor and
electrolytic capacitor
Abstract
An electrolyte solution for driving an electrolytic capacitor
having a solvent composed of 20 to 80 wt % of an organic solvent
and 80 to 20 wt % of water, characterized in that it comprises one
or more nitro compounds or nitroso compounds exclusive of
nitrophenol, nitrobenzoic acid, dinitrobenzoic acid,
nitroacetophenone and nitroanisole; an electrolytic capacitor
comprising the electrolyte solution for driving an electrolytic
capacitor; and an electrolytic capacitor comprising one or more
nitro compounds or nitroso compounds located at another portion
than an electrolyte solution therein. The electrolyte solution
preferably contains a carboxylic acid or a salt thereof or an
inorganic acid or a salt thereof as an electrolyte. The
electrolytic capacitor exhibits a low impedance, excellent low
temperature stability and good life characteristics, and further,
is excellent in the effect to absorb a hydrogen gas, even when use
is made of an electrolyte solution employing mixed solvent having a
great water content and when an electrolytic capacitor is used
under a high temperature condition.
Inventors: |
Komatsu, Akihiko; (Nagano,
JP) ; Ogawara, Tetsushi; (Nagano, JP) |
Correspondence
Address: |
RADER FISHMAN & GRAUER PLLC
LION BUILDING
1233 20TH STREET N.W., SUITE 501
WASHINGTON
DC
20036
US
|
Family ID: |
19116327 |
Appl. No.: |
10/490651 |
Filed: |
March 25, 2004 |
PCT Filed: |
September 25, 2002 |
PCT NO: |
PCT/JP02/09878 |
Current U.S.
Class: |
205/58 ;
204/194 |
Current CPC
Class: |
H01G 9/022 20130101;
H01G 9/035 20130101 |
Class at
Publication: |
205/058 ;
204/194 |
International
Class: |
H01M 004/02; H01M
004/29; H01M 010/44 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 26, 2001 |
JP |
2001-294783 |
Claims
1. An electrolytic solution, for driving an electrolytic capacitor,
comprising a solvent consisting of from 20 to 80 wt % of an organic
solvent and from 80 to 20 wt % of water, which contains one or more
nitro or nitroso compound except for nitrophenol, nitrobenzoic
acid, dinitrobenzoic acid, nitroacetophenone and nitroanisole.
2. The electrolytic solution for driving an electrolytic capacitor
according to claim 1, wherein the nitro or nitroso compound is
soluble in water, a polar solvent or a protonic polar organic
solvent.
3. The electrolytic solution for driving an electrolytic capacitor
according to claim 1, which comprises at least one electrolyte
selected from the group consisting of a carboxylic acid or a salt
thereof, and an inorganic acid or a salt thereof.
4. The electrolytic solution for driving an electrolytic capacitor
according to claim 1, wherein the nitro or nitroso compound is
aminonitroanisole, aminonitrotoluene, aminonitropyridine,
aminonitrophenol, aminonitrophenolsulfonic acid,
aminonitrobenzenesulfoni- c acid, aminonitrobenzothiazole,
aminonitrobenzotrifluoride, aminonitrobenzonitrile, nitrophenyl
isocyanate, isonitr6soacetophenone,
N-ethyl-2-(l-ethyl-2-hydroxy-2-nitrosohydrazino)-ethanamine,
O-ethyl-O-(p-nitrophenyl)thionobenzene, ethylnitrobenzene,
ethyl-2-(hydroxyimino)-5-nitro-3-hexeneamide,
octanitrobenzoylsaccharose, nitrophenyloctyl ether, nitrophenyl
galactopyranoside, 3-carboxy-4-nitrophenyl disulfide,
bisnitrobenzylfluorescein, glycerol carbonatenitrobenzene
sulfonate, glutamyl nitroanilide, nitrophenyl acetate,
nitrobenzylidene acetate, diaminonitrobenzene,
dithiobisnitrobenzoic acid, dithiobisnitropyridine, dinitroaniline,
dinitroquinoxaline-2,3-dione, dinitrosalicylic acid,
dinitrodiphenylamine, dinitrodiphenylsulfone,
dinitronaphtholsulfonic acid, dinitrobibenzyl,
dinitrophenylaniline, dinitrophenylhydrazine, dinitrophenol,
dinitrophthalic acid, dinitrofluorenone, dinitrofluorobenzene,
dinitrobenzaldehyde, dinitrobenzoylmethylbenzylamin- e,
dinitrobenzophenone, nitroaminothiazole, dimethylnitroaniline,
dimethylnitrophenylphosphorothioate, dimethoxynitrobenzyl alcohol,
bisdinitrophenyl oxalate, succinimidyl nitrophenylacetate,
tetranitrophenyl porphyrin, trinitrophenol, trinitrobenzenesulfonic
acid, nitroacetanilide, nitroazobenzenediol, nitroanisidine,
nitroaniline, nitroanilinesulfonic acid, nitroaminoanisole,
nitroaminotoluene, nitroaminophenol, nitroarginine, ethyl
nitrobenzoate, methyl nitrobenzoate, nitroanthranilic acid,
nitroanthranilonitrile, nitroisatin, nitroimidazole, nitroindazole,
2-nitroindan-1,3-dione, nitroindole, nitrouracil, nitroethanol,
nitroethylbenzene, nitrocatechol, nitroquipazinemaleic acid,
nitrocresol, nitrocinnamic acid, nitrosalicylic acid,
nitrodiazoaminoazobenzene, nitrodiaminobenzene, nitrodiphenylamine,
nitrodimethylaniline, nitrosulfonazo III, nitrothiophene,
nitrotyrosine, nitroterephthalic acid, nitrotoluidine, nitrotoluic
acid, nitropicoline, nitrohydroxyaniline, nitrobiphenyl,
nitropiperonal, nitropyridinol, nitrobarbituric acid,
nitrophenylacetonitrile, nitrophenylazoorcinol,
nitrophenylazonaphthol, nitrophenylazomethylresorcinol,
nitrophenylaniline, nitrophenyloctyl ether,
nitrophenylgalactopyranoside, nitrophenylxylopyranoside,
nitrophenylglucuronide, nitrophenylglucopyranoside,
nitrophenylacetic acid, nitrophenyldodecyl ether,
nitrophenylarsonic acid, nitrophenylhydrazine,
nitrophenylphenylazophenyl triazene, nitrophenylphenyl ether,
nitrophenylmaltopentaoside, nitrophenylmannopyranoside,
nitrophenylbutyric acid, diethyl nitrophenylphosphate,
nitrophenylenediamine, nitrophenethole, nitrophenolarsonic acid,
nitrophenolmethyl ether, nitrophthalimide, nitrophthalic acid,
nitrohumic acid, nitropropionic acid, nitroveratryl alcohol,
nitrobenzylamine, nitrobenzyl alcohol, nitrobenzyldiisopropyliso-
urea, nitrobenzylpyridine, nitrobenzamide, nitrobenzimidazole,
nitrobenzohydrazide, nitrobenzeneazoorcinol,
nitrobenzeneazonaphthol, nitromethane, nitroethane,
nitrobenzeneazoresorcinol, nitrobenzenesulfonic acid,
nitrobenzocoumarin, nitrobenzonitrile, nitrobenzophenone,
nitromesitylene, nitromethoxyaniline, bisnitrophenyl disulfide,
bisnitrophenylsulfone, bismethylthionitroethene,
hydroxynitrobenzoic acid, hydroxynitrotoluene,
hydroxynitropyridine, hydroxynitrophenylarsonic acid,
hydroxynitrobenzaldehyde,
3-[2-hydroxy-1-(1-methylethyl)-2-nitrosohydrazino]-1-propanonamine,
phenylnitroaniline, 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide,
fluoronitroacetanilide, fluoronitroaniline, fluoronitrophenylazide,
fluoronitrophenol, methylnitroaniline, methylnitrophenol,
methylnitropyridine, methylnitropyridine oxide,
methoxynitroaniline, methoxynitrobenzoic acid, methoxynitrophenol,
methoxybenzylaminonitrobenz- ofurazan, nitrophenyl butyrate,
nitronium tetrafluoroborate, nitrophenyl phosphate,
nitrosoacetylpenicillamine, nitroso(acetoxymethyl)methylamine,
nitroso oxine, nitrosoquinolinol, nitrosoglutathione,
nitrosodiisobutylamine, nitrosodiethylamine, nitrosodiethylaniline,
nitrosodisulfonic acid, nitrosodiphenylamine, nitrosodimethylamine,
nitrosonaphthol, nitrosonaphtholdisulfonic acid,
nitrosohydroxyquinoline, nitrosophenylaniline,
nitrosophenylhydroxylamine ammonium, nitrosophenol,
N-[(N-nitrosomethylamino)methyl]benzamide,
2,2'-(hydroxynitrosohydrazono)- bisethanamine,
N-methyl-2-(1-ethyl-2-hydroxy-2-nitrosohydrazino)-ethanamin- e,
N,N'-dinitroso-p-phenylenediamine,
N,N'-dinitrosopentamethylenetetramin- e, dimethylnitrosoaniline,
dimethylnitrosoamine, nitrosonium tetrafluoroborate,
N-[N'-methyl-N'-nitroso(aminomethyl)]benzamide,
N-methyl-N-nitroso-p-toluenesulfonamide, nitrobenzene,
dinitrobenzene, dinitrotoluene, nitronaphthalene,
dinitronaphthalene, dinitrobiphenyl, dimethylnitrotoluene,
dinitropyrene, nitrobenzoic acid ester, dimethylnitrobenzene,
nitroanthracene, nitroisoquinoline, nitroxylene, ethyl
nitroacetate, nitrocyclopentane, nitrostyrene, nitropyrrole,
nitrofurazone, nitrofuraldehyde, nitrohexane, nitrobenzaldehyde,
nitrolignin, 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide,
nitroacrylamide, fluoronitrotoluene, fluoronitrobenzene,
fluoronitrodiphenyl ether, trinitroacetonitrile, trinitroaniline,
trinitrobenzoic acid, trinitroethane, trinitroxylene,
trinitrotoluene, trinitronaphthalene, trinitrofluorenone,
trinitrobenzene, trinitromesitylene, trinitromethane,
trinitroresorcinol, dinitroacetanilide, dinitroanisole,
dinitroanthraquinone, dinitroethane, dinitroethanediamine,
dinitrocarbanilide, dinitroxylene, dinitroglycerol, dinitrocresol,
dinitronaphthol, dinitrophenyl, dinitrophenylhydrazone,
dinitromethane, dinitroresorcinol, nitroamide, nitroanthraquinone,
nitroisophthalic acid, nitroethylene, ethyl nitrocarbamate,
nitroquinaldic acid, nitroguanidine, nitroglycol, nitroglycerin,
nitrodimethylamine, nitrocamphor, methylnitropropane,
nitrosulfathiazole, nitrocellulose, nitrosomethane,
nitrosoguanidine, nitrosodimethylaniline, nitrosotoluene,
nitrosodisulfonic acid, nitrosopiperidine, nitrosobenzene,
nitrosomethylurea, nitronaphthylamine, nitronaphthol,
nitropyridine, nitrophenanthrene, nitrophenylpropiolic acid,
nitrophenetidine, nitrophenolsulfonic acid, nitropentane,
nitroresorcinol, nitrourea, trinitroxylenol, trinitrodiphenyl
ether, trinitrotriazidobenzene, trinitrophloroglucinol,
nitroacridine, nitroacridone, nitroacetone, nitroanilic acid,
nitroaminoacetic acid, nitroisatin, nitroisobutane, nitroindene,
nitrourethane, nitrocarbostyril, nitrodiglycol, nitro-p-cymene,
nitrocinnamaldehyde, N-nitrosoacetanilide, nitrosoanisidine,
nitrosoaniline, nitrosobenzoic acid, nitrosoanthranilic acid,
nitrosocatechol, nitrosocarvacrol, nitrosocresol,
nitrosonaphthylamine, nitrothioanisole, nitrothiophenol,
nitronaphthalenesulfonic acid, nitronaphthylamine, nitronaphthoic
acid, nitronitrosobenzene, nitrohydroquinone, nitropyrogallol,
nitrophenanthridine, nitrophenanthroline, nitrophenylurethane,
nitrophenylurea, nitrobutane, nitrophthalide, nitrofuran,
nitropropylene, nitrophloroglucinol, nitrobenzanilide,
nitrobenzaldoxime, nitrobenzoylformic acid, nitrobenzimidazole,
nitromalonic acid, nitromalondialdehyde, nitromandelic acid,
nitromannitol, nitromethylnaphthalene, nitromalic acid,
nitroresorcinol, nitron, nitrosoresorcinol, aminonitropyrimidine,
trinitrofluorenylidene malononitrile, nitrofluoranthene,
nitrobenzocrown, fluoronitrobenzofurazan,
methylnitronitrosoguanidine, methylnitronitrophenylpyrazolone,
nitrofluorene, nitropropane, nitropropoxyaniline, trinitroanisole,
trinitrocresol, trinitrobenzaldehyde, nitrodiethylaniline,
nitrostilbene, nitrosonaphthalene, nitrosobenzaldehyde,
nitrosomethylurethane, nitrophenylhydrazone, dinitrotartaric acid,
dinitrostilbene, dinitrosoresorcinol, dinitrohydroquinone,
dinitroresorcinol, nitroquinoline, dinitrosophenol,
trinitrosophenol, dinitrosobenzoic acid, trinitrosobenzoic acid,
dinitroacetophenone, trinitroacetophenone, nitrosoacetophenone,
dinitrosoacetophenone, trinitrosoacetophenone, nitrosoanisole,
dinitrosoanisole, trinitrosoanisole or an isomer, salt, derivative,
coordinate bonded form or clathrate form thereof.
5. The electrolytic solution for driving an electrolytic capacitor
according to claim 1, wherein the nitro or nitroso compounds are
used in combination of two or more thereof.
6. The electrolytic solution for driving an electrolytic capacitor
according to claim 1, wherein the nitro or nitroso compound is
contained in an amount of 0.01 to 5 wt % based on the entire amount
of the electrolytic solution.
7. The electrolytic solution for driving an electrolytic capacitor
according to claim 6, which additionally contains from 0.01 to 10%
of a salt or derivative of nitrophenol, nitrobenzoic acid,
dinitrobenzoic acid, nitroacetophenone and nitroanisole.
8. The electrolytic solution for driving an electrolytic capacitor
according to claim 1, wherein the organic solvent is a protonic
solvent, an aprotic solvent or a mixture thereof.
9. The electrolytic solution for driving an electrolytic capacitor
according to claim 3, wherein the carboxylic acid or a salt thereof
is selected from the group consisting of a monocarboxylic acid, a
dicarboxylic acid, a tricarboxylic acid, a saturated carboxylic
acid and an unsaturated carboxylic acid, represented by formic
acid, acetic acid, propionic acid, butyric acid, p-nitrobenzoic
acid, salicylic acid, benzoic acid, oxalic acid, malonic acid,
succinic acid, glutaric acid, adipic acid, fumaric acid, maleic
acid, phthalic acid, azelaic acid, citric acid and hydroxybutyric
acid, derivatives thereof, and their ammonium salts, sodium salts,
potassium salts, amine salts and alkylammonium salts.
10. The electrolytic solution for driving an electrolytic capacitor
according to claim 3, wherein the carboxylic acid or a salt thereof
is selected from the group consisting of a formic acid, an acetic
acid, a p-nitrobenzoic acid, a salicylic acid, an oxalic acid, a
malonic acid, a fumaric acid, a maleic acid, a phthalic acid, a
citric acid, a sulfamic acid, an ethylenediaminetetraacetic acid,
and their ammonium salts, sodium salts, potassium salts, amine
salts and alkylammonium salts.
11. The electrolytic solution for driving an electrolytic capacitor
according to claim 3, wherein the carboxylic acid or a salt thereof
is a formic acid.
12. The electrolytic solution for driving an electrolytic capacitor
according to claim 3, wherein the inorganic acid or a salt thereof
is selected from the group consisting of an inorganic acid
represented by phosphoric acid, phosphorous acid, hypophosphorous
acid, boric acid, sulfamic acid and alkylphosphoric acid, an
inorganic acid having a carbon chain such as alkyl group, and their
ammonium salts, sodium salts, potassium salts, amine salts and
alkylammonium salts.
13. The electrolytic solution for driving an electrolytic capacitor
according to claim 3, which comprises a combination of the
carboxylic acid or a salt thereof and at least oneinorganic acid
selected from a phosphoric acid, a phosphorous acid, a boric acid,
a hypophosphorous acid, a sulfamic acid and an alkylphosphoric
acid.
14. The electrolytic solution for driving an electrolytic capacitor
according to claim 1, which further comprises at least one compound
selected from the group consisting of (1) a chelate compound, (2)
saccharides, (3) a hydroxybenzyl alcohol and(or) an
L-glutamic-diacetic acid or a salt thereof and (4) a gluconic acid
and(or) a gluconic lactone.
15. The electrolytic solution for driving an electrolytic capacitor
according to claim 1, wherein the solvent consists of 20 to 55 wt %
of an organic solvent and 80 to 45 wt % of water.
16. The electrolytic solution for driving an electrolytic capacitor
according to claim 15, wherein the solvent consists of 20 to 35 wt
% of an organic solvent and 80 to. 65 wt % of water.
17. The electrolytic solution for driving an electrolytic capacitor
according to claim 1, wherein the specific resistance of the
electrolytic solution is 68 .OMEGA.cm or less.
18. The electrolytic solution for driving an electrolytic capacitor
according to claim 1, wherein the specific resistance of the
electrolytic solution is 40 .OMEGA.cm or less.
19. The electrolytic solution for driving an electrolytic capacitor
according to claim 1, wherein the specific resistance of the
electrolytic solution is 30 .OMEGA.cm or less.
20. An electrolytic capacitor comprising the electrolytic solution
for driving an electrolytic capacitor according to claim 1.
21. An electrolytic capacitor using an electrolytic solution
constituted by a solvent consisting of from 20 to 80 wt % of an
organic solvent and from 80 to 20 wt % of water, the electrolytic
capacitor comprising a nitro or nitroso compound except for
nitrophenol, nitrobenzoic acid, dinitrobenzoic acid, nitrophenone
and nitroanisole, in a portion inside the capacitor other than in
the electrolytic solution.
22. The electrolytic capacitor according to claim 21, wherein the
nitro or nitroso compound is aminonitroanisole, aminonitrotoluene,
aminonitropyridine, aminonitrophenol, aminonitrophenolsulfonic
acid, aminonitrobenzenesulfonic acid, aminonitrobenzothiazole,
aminonitrobenzotrifluoride, aminonitrobenzonitrile, nitrophenyl
isocyanate, isonitrosoacetophenone,
N-ethyl-2-(1-ethyl-2-hydroxy-2-nitros- ohydrazino)-ethanamine,
O-ethyl-O-(p-nitrophenyl)thionobenzene, ethylnitrobenzene,
ethyl-2-(hydroxyimino)-5-nitro-3-hexeneamide,
octanitrobenzoylsaccharose, nitrophenyloctyl ether, nitrophenyl
galactopyranoside, 3-carboxy-4-nitrophenyl disulfide,
bisnitrobenzylfluorescein, glycerol carbonatenitrobenzene
sulfonate, glutamyl nitroanilide, nitrophenyl acetate,
nitrobenzylidene acetate, diaminonitrobenzene,
dithiobisnitrobenzoic acid, dithiobisnitropyridine, dinitroaniline,
dinitroquinoxaline-2,3-dione, dinitrosalicylic acid,
dinitrodiphenylamine, dinitrodiphenylsulfone,
dinitronaphtholsulfonic acid, dinitrobibenzyl,
dinitrophenylaniline, dinitrophenylhydrazine, dinitrophenol,
dinitrophthalic acid, dinitrofluorenone, dinitrofluorobenzene,
dinitrobenzaldehyde, dinitrobenzoylmethylbenzylamin- e,
dinitrobenzophenone, nitroaminothiazole, dimethylnitroaniline,
dimethylnitrophenylphosphorothioate, dimethoxynitrobenzyl alcohol,
bisdinitrophenyl oxalate, succinimidyl nitrophenylacetate,
tetranitrophenyl porphyrin, trinitrophenol, trinitrobenzenesulfonic
acid, nitroacetanilide, nitroazobenzenediol, nitroanisidine,
nitroaniline, nitroanilinesulfonic acid, nitroaminoanisole,
nitroaminotoluene, nitroaminophenol, nitroarginine, ethyl
nitrobenzoate, methyl nitrobenzoate, nitroanthranilic acid,
nitroanthranilonitrile, nitroisatin, nitroimidazole, nitroindazole,
2-nitroindan-1,3-dione, nitroindole, nitrouracil, nitroethanol,
nitroethylbenzene, nitrocatechol, nitroquipazinemaleic acid,
nitrocresol, nitrocinnamic acid, nitrosalicylic acid,
nitrodiazoaminoazobenzene, nitrodiaminobenzene, nitrodiphenylamine,
nitrodimethylaniline, nitrosulfonazo III, nitrothiophene,
nitrotyrosine, nitroterephthalic acid, nitrotoluidine, nitrotoluic
acid, nitropicoline, nitrohydroxyaniline, nitrobiphenyl,
nitropiperonal, nitropyridinol, nitrobarbituric acid,
nitrophenylacetonitrile, nitrophenylazoorcinol,
nitrophenylazonaphthol, nitrophenylazomethylresorcinol,
nitrophenylaniline, nitrophenyloctyl ether,
nitrophenylgalactopyranoside, nitrophenylxylopyranoside,
nitrophenylglucuronide, nitrophenylglucopyranoside,
nitrophenylacetic acid, nitrophenyldodecyl ether,
nitrophenylarsonic acid, nitrophenylhydrazine,
nitrophenylphenylazophenyl triazene, nitrophenylphenyl ether,
nitrophenylmaltopentaoside, nitrophenylmannopyranoside,
nitrophenylbutyric acid, diethyl nitrophenylphosphate,
nitrophenylenediamine, nitrophenethole, nitrophenolarsonic acid,
nitrophenolmethyl ether, nitrophthalimide, nitrophthalic acid,
nitrohumic acid, nitropropionic acid, nitroveratryl alcohol,
nitrobenzylamine, nitrobenzyl alcohol, nitrobenzyldiisopropyliso-
urea, nitrobenzylpyridine, nitrobenzamide, nitrobenzimidazole,
nitrobenzohydrazide, nitrobenzeneazoorcinol,
nitrobenzeneazonaphthol, nitromethane, nitroethane,
nitrobenzeneazoresorcinol, nitrobenzenesulfonic acid,
nitrobenzocoumarin, nitrobenzonitrile, nitrobenzophenone,
nitromesitylene, nitromethoxyaniline, bisnitrophenyl disulfide,
bisnitrophenylsulfone, bismethylthionitroethene,
hydroxynitrobenzoic acid, hydroxynitrotoluene,
hydroxynitropyridine, hydroxynitrophenylarsonic acid,
hydroxynitrobenzaldehyde,
3-[2-hydroxy-1-(1-methylethyl)-2-nitrosohydrazino]-1-propanonamine,
phenylnitroaniline, 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide,
fluoronitroacetanilide, fluoronitroaniline, fluoronitrophenylazide,
fluoronitrophenol, methylnitroaniline, methylnitrophenol,
methylnitropyridine, methylnitropyridine oxide,
methoxynitroaniline,. methoxynitrobenzoic acid, methoxynitrophenol,
methoxybenzylaminonitrobenz- ofurazan, nitrophenyl butyrate,
nitronium tetrafluoroborate, nitrophenyl phosphate,
nitrosoacetylpenicillamine, nitroso(acetoxymethyl)methylamine,
nitroso oxine, nitrosoquinolinol, nitrosoglutathione,
nitrosodiisobutylamine, nitrosodiethylamine, nitrosodiethylaniline,
nitrosodisulfonic acid, nitrosodiphenylamine, nitrosodimethylamine,
nitrosonaphthol, nitrosonaphtholdisulfonic acid,
nitrosohydroxyquinoline, nitrosophenylaniline,
nitrosophenylhydroxylamine ammonium, nitrosophenol,
N-[(N-nitrosomethylamino)methyl]benzamide,
2,2'-(hydroxynitrosohydrazono)- bisethanamine,
N-methyl-2-(1-ethyl-2-hydroxy-2-nitrosohydrazino)-ethanamin- e,
N,N'-dinitroso-p-phenylenediamine,
N,N'-dinitrosopentamethylenetetramin- e, dimethylnitrosoaniline,
dimethylnitrosoamine, nitrosonium tetrafluoroborate,
N-[N'-methyl-N'-nitroso(aminomethyl)]benzamide,
N-methyl-N-nitroso-p-toluenesulfonamide, nitrophenol, nitrobenzoic
acid, dinitrobenzoic acid, nitroacetophenone, nitroanisole,
nitrobenzene, dinitrobenzene, dinitrotoluene, nitronaphthalene,
dinitronaphthalene, dinitrobiphenyl, dimethylnitrotoluene,
dinitropyrene, nitrobenzoic acid ester, dimethylnitrobenzene,
nitroanthracene, nitroisoquinoline, nitroxylene, ethyl
nitroacetate, nitrocyclopentane, nitrostyrene, nitropyrrole,
nitrofurazone, nitrofuraldehyde, nitrohexane, nitrobenzaldehyde,
nitrolignin, 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide- ,
nitroacrylamide, fluoronitrotoluene, fluoronitrobenzene,
fluoronitrodiphenyl ether, trinitroacetonitrile, trinitroaniline,
trinitrobenzoic acid, trinitroethane, trinitroxylene,
trinitrotoluene, trinitronaphthalene, trinitrofluorenone,
trinitrobenzene, trinitromesitylene, trinitromethane,
trinitroresorcinol, dinitroacetanilide, dinitroanisole,
dinitroanthraquinone, dinitroethane, dinitroethanediamine,
dinitrocarbanilide, dinitroxylene, dinitroglycerol, dinitrocresol,
dinitronaphthol, dinitrophenyl, dinitrophenylhydrazone,
dinitromethane, dinitroresorcinol, nitroamide, nitroanthraquinone,
nitroisophthalic acid, nitroethylene, ethyl nitrocarbamate,
nitroquinaldic acid, nitroguanidine, nitroglycol, nitroglycerin,
nitrodimethylamine, nitrocamphor, methylnitropropane,
nitrosulfathiazole, nitrocellulose, nitrosomethane,
nitrosoguanidine, nitrosodimethylaniline, nitrosotoluene,
nitrosodisulfonic acid, nitrosopiperidine, nitrosobenzene,
nitrosomethylurea, nitronaphthylamine, nitronaphthol,
nitropyridine, nitrophenanthrene, nitrophenylpropiolic acid,
nitrophenetidine, nitrophenolsulfonic acid, nitropentane,
nitroresorcinol, nitrourea, trinitroxylenol, trinitrodiphenyl.
ether, trinitrotriazidobenzene, trinitrophloroglucinol,
nitroacridine, nitroacridone, nitroacetone, nitroanilic acid,
nitroaminoacetic acid, nitroisatin, nitroisobutane, nitroindene,
nitrourethane, nitrocarbostyril, nitrodiglycol, nitro-p-cymene,
nitrocinnamaldehyde, N-nitrosoacetanilide, nitrosoanisidine,
nitrosoaniline, nitrosobenzoic acid, nitrosoanthranilic acid,
nitrosocatechol, nitrosocarvacrol, nitrosocresol,
nitrosonaphthylamine, nitrothioanisole, nitrothiophenol,
nitronaphthalenesulfonic acid, nitronaphthylamine, nitronaphthoic
acid, nitronitrosobenzene, nitrohydroquinone, nitropyrogallol,
nitrophenanthridine, nitrophenanthroline, nitrophenylurethane,
nitrophenylurea, nitrobutane, nitrophthalide, nitrofuran,
nitropropylene, nitrophloroglucinol, nitrobenzanilide,
nitrobenzaldoxime, nitrobenzoylformic acid, nitrobenzimidazole,
nitromalonic acid, nitromalondialdehyde, nitromandelic acid,
nitromannitol, nitromethylnaphthalene, nitromalic acid,
nitroresorcinol, nitron, nitrosoresorcinol, aminonitropyrimidine,
trinitrofluorenylidene malononitrile, nitrofluoranthene,
nitrobenzocrown, fluoronitrobenzofurazan,
methylnitronitrosoguanidine, methylnitronitrophenylpyrazolone,
nitrofluorene, nitropropane, nitropropoxyaniline, trinitroanisole,
trinitrocresol, trinitrobenzaldehyde, nitrodiethylaniline,
nitrostilbene, nitrosonaphthalene, nitrosobenzaldehyde,
nitrosomethylurethane, nitrophenylhydrazone, dinitrotartaric acid,
dinitrostilbene, dinitrosoresorcinol, dinitrohydroquinone,
dinitroresorcinol, nitroquinoline, dinitrosophenol,
trinitrosophenol, dinitrosobenzoic acid, trinitrosobenzoic acid,
dinitroacetophenone, trinitroacetophenone, nitrosoacetophenone,
dinitrosoacetophenone, trinitrosoacetophenone, nitrosoanisole,
dinitrosoanisole, trinitrosoanisole or an isomer, salt, derivative,
coordinate bonded form or clathrate form thereof.
23. The electrolytic capacitor according to claim 21, which
comprises the nitro or nitroso compound or an isomer, salt or
derivative thereof on the electrode surface.
24. The electrolytic capacitor according to claim 21, wherein the
nitro or nitroso compound or an isomer, salt or derivative thereof
is attached or impregnated to the electrode surface by the coating
or by the dipping in a solution having dissolved therein the nitro
or nitroso compound or an isomer, salt or derivative thereof.
25. The electrolytic capacitor according to claim 21, wherein the
nitro or nitroso compound or an isomer, salt or derivative thereof
is contained in a separator constituting the electrolytic
capacitor.
26. The electrolytic capacitor according to claim 21, wherein the
nitro or nitroso compound or an isomer, salt or derivative thereof
is attached or dipped to the separator by coating or by dipping in
a solution having dissolved therein the nitro or nitroso compound
or an isomer, salt or derivative thereof.
27. The electrolytic capacitor according to claim 21, wherein the
amount of the nitro or nitroso compound set forth in claim 22 or an
isomer, salt or derivative thereof contained in the electrode foil
is from 0.007 to 1 mg/cm.sup.2 (projectional area).
28. The electrolytic capacitor according to claim 21, wherein the
amount of the nitro or nitroso compound or an isomer, salt or
derivative thereof contained in the separator is from 0.007 to 1
mg/cm.sup.2 (projectional area).
29. The electrolytic capacitor according to claim 21, wherein the
solvent consists of from 20 to 55 wt % of an organic solvent and
from 80 to 45 wt % of water.
30. The electrolytic capacitor according to claim 29, wherein the
solvent consists of from 20 to 35 wt % of an organic solvent and
from 80 to 65 wt % of water.
Description
TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates to an electrolytic capacitor,
more specifically, the present invention relates to an electrolytic
solution for driving an electrolytic capacitor, which ensures a low
impedance, excellent low-temperature stability, reduction in the
increase of pressure inside the capacitor due to a hydrogen gas
generated in a high temperature environment, and good working life
property, and also relates to an electrolytic capacitor and,
particularly, to an aluminum electrolytic capacitor.
BACKGROUND ART
[0002] The capacitor is a general electric parts and is widely used
in power source circuits or noise filters for digital circuits in
various electric and electronic products. Capacitors are roughly
classified into electrolytic capacitors and other capacitors (e.g.,
ceramic capacitors, film capacitors).
[0003] At present, various kinds of electrolytic capacitors are
being used and examples thereof include aluminum electrolytic
capacitors and wet tantalum electrolytic capacitors. Here,
particularly excellent effects are expected from an aluminum
electrolytic capacitor in the present invention and accordingly,
the present invention is hereinafter described by referring to an
aluminum electrolytic capacitor, however, the present invention is
not limited to an aluminum electrolytic capacitor and can be widely
applied to electrolytic capacitors in general.
[0004] For the electrode material of the electrolytic capacitor, a
valve metal is used. In the case of an aluminum electrolytic
capacitor, aluminum is used for the electrode material. The basic
structure of the electrolytic capacitor takes a form (element) such
that anode and cathode are prepared each by forming a predetermined
amount of an oxide film as a dielectric material on the surface of
an electrode (if desired, the surface area is increased by a
treatment such as etching and thereby the electrostatic capacitance
is controlled), these two electrodes are disposed to face each
other and an electrolytic solution is held therebetween with an
intervention of a separator (release paper). This electrolytic
capacitor element is seal-packaged to complete an electrolytic
capacitor. Some electrolytic capacitor elements have a coiled
structure or have a stacked layer structure.
[0005] In the electrolytic capacitor as described above, the
properties of the electrolytic solution are an important factor
governing the performance of the electrolytic capacitor.
Particularly, accompanying recent downsizing of the electrolytic
capacitor, the anode or cathode foil used has a high etching
magnification and the resistivity of the capacitor body is large.
To cope with this, the electrolytic solution used therefor is
always required to have low resistivity (specific resistance) and
high electrical conductivity.
[0006] Heretofore, the electrolytic solution of the electrolytic
capacitor was generally prepared by dissolving a carboxylic acid
such as adipic acid and benzoic acid or an ammonium salt thereof as
an electrolyte in a solvent consisting of ethylene glycol (EG) as
the main solvent and water was added thereto to about 10 wt %. The
thus-obtained electrolytic solution has a specific resistance of
about 1.5 .OMEGA..multidot.m (150 .OMEGA..multidot.cm).
[0007] On the other hand, a capacitor is required to have a low
impedance (Z) so as to satisfactorily provide a suitable
performance. The impedance is determined by various factors. For
example, the impedance decreases when the electrode area of the
capacitor is increased and therefore, in a large-size capacitor, a
low impedance is naturally obtained. Also, there is an approach of
attaining a low impedance by improving the separator. However, and
particularly in a small-size capacitor, the specific resistance of
the electrolytic solution is a large factor governing the
impedance.
[0008] In recent years, an electrolytic solution having a low
specific resistance and using an aprotic organic solvent such as
GBL (.gamma.-butyrolactone) has been developed (see, for example,
Japanese Unexamined Patent Publication (Kokai) Nos. 62-145713,
62-145714 and 62-145715). However, the capacitor using the aprotic
electrolytic solution is by far inferior in impedance to a solid
capacitor using an electronic conductor having a specific
resistance of 1.0 .OMEGA..multidot.cm or less.
[0009] An aluminum electrolytic capacitor uses an electrolytic
solution and therefore, is poor in low-temperature properties. In
fact, the ratio Z (-40.degree. C.)/Z (20.degree. C.) of the
impedance at -40.degree. C. at 100 kHz to the impedance at
20.degree. C. is about 40 and fairly large. Under these
circumstances, an aluminum electrolytic capacitor having a low
impedance, a low specific resistance and excellent low-temperature
stability is required at present.
[0010] Water used as one portion of the solvent in the electrolytic
solution of the aluminum electrolytic capacitor is chemically
active with the aluminum constituting the anode or cathode foil and
this causes a problem that water reacts with the anode or cathode
foil to generate a hydrogen gas. As a result, the pressure inside
the capacitor is increased, stress is imposed to the capacitor
element, the coil structure is deformed or broken, the electrolytic
solution is splashed outside, the safety vent is actuated, and the
properties are seriously deteriorated. Conventionally, an attempt
to absorb the generated hydrogen gas has been made so as to
eliminate the problem of hydrogen gas generated in a load test or
the like of the electrolytic capacitor. For example, Japanese
Examined Patent Publication (Kokoku) No. 59-15374 discloses an
electrolytic solution for driving an electrolytic capacitor,
characterized in that a carboxylic acid and an ammonium salt of
carboxylic acid are added to a solvent obtained by adding from 5 to
20 wt % of water to ethylene glycol and to the prepared buffer
solution, from 0.05 to 3 wt % of p-nitrophenol is added to prepare
the electrolytic solution. When this electrolytic solution is used,
an electrolytic capacitor protected from the production of boehmite
or the generation of hydrogen gas and improved in the
low-temperature stability and working life properties can be
provided.
[0011] Furthermore, Japanese Examined Patent Publication (Kokoku)
No. 63-14862 discloses an electrolytic solution for driving an
electrolytic capacitor, which can provide an excellent
anticorrosive effect for cleaning with a halogenated hydrocarbon,
characterized in that o-nitroanisole is added to an electrolytic
solution obtained by dissolving an organic or inorganic acid of
various types or a salt thereof as a solute in a solvent mainly
comprising ethylene glycol. This patent publication states that the
o-nitroanisole used as an anticorrosive has an activity of
absorbing hydrogen gas and provides an effect of absorbing hydrogen
gas generated from the inside of the electrolytic capacitor during
use and thereby preventing an accidental safety-vent operation or a
change in the electrostatic capacitance.
[0012] However, according to the studies by the present inventors,
it is found that although the p-nitrophenol or o-nitroanisole can
provide an effect of absorbing hydrogen gas, at an initial stage,
in an electrolytic solution for driving an electrolytic capacitor,
is commonly used and has a low water concentration, a sufficiently
high effect of absorbing hydrogen gas cannot be obtained and cannot
be maintained when the amount of water in the solvent of the
electrolytic solution is 20 wt % or more or when the electrolytic
capacitor is used over a long period of time in a high-temperature
environment.
[0013] The present invention has been made to solve those problems
in conventional techniques and an object of the present invention
is to provide an electrolytic solution for driving an electrolytic
capacitor, which ensures low impedance, has an excellent
low-temperature stability represented by the ratio of impedance
between low temperature and ordinary temperature, has a good
working life property and has a capability of providing an
excellent hydrogen gas-absorbing effect even when an electrolytic
solution using a mixed solvent having a large water content ratio
is used or when the electrolytic capacitor is used in a
high-temperature environment. The object of the present invention
includes providing an electrolytic capacitor using the electrolytic
solution.
[0014] Another object of the present invention is to provide an
electrolytic capacitor using a driving electrolytic solution having
a solvent composition with 30 wt % or more thereof being water,
wherein a solvent-soluble nitro compound or nitroso compound is
contained in the capacitor element.
DISCLOSURE OF THE INVENTION
[0015] In one aspect, the present invention provides an
electrolytic solution for driving an electrolytic capacitor,
comprising a solvent consisting of from 20 to 80 wt % of an organic
solvent and from 80 to 20 wt % of water, which contains at least
one nitro or nitroso compound except for nitrophenol, nitrobenzoic
acid, dinitrobenzoic acid, nitroacetophenone and nitroanisole.
[0016] The present inventors have previously disclosed in Japanese
Unexamined Patent Publication (Kokai) No. 2000-173872 an
electrolytic solution for driving an electrolytic capacitor,
comprising a solvent consisting of from 20 to 80 wt % of an organic
solvent and from 80 to 20 wt % of water, which contains
nitrophenol, nitrobenzoic acid, dinitrobenzoic acid,
nitroacetophenone or nitroanisole, and by this means, the
above-described objects can be attained. Thereafter, studies have
been continuously made and, as a result, it has been confirmed that
the above-described objects can be similarly attained not only by
those specific compounds but also by other nitro or nitroso
compounds, those specific compounds previously disclosed are not
necessarily excellent on taking account of the use conditions of
the electrolytic capacitor, and an effect similar to or more
excellent than the effect by those previously disclosed specific
compounds can be provided using compounds including those deemed
inferior in the performance to the previously disclosed specific
compounds by appropriately selecting the organic solvent or
designing the form of the compound present inside the electrolytic
capacitor or by combining two or more thereof. Based on these
findings, the present invention has been accomplished.
[0017] In the electrolytic solution for driving an electrolytic
capacitor of the present invention, the nitro or nitroso compound
is considered to act and provide an effect as follows.
[0018] The hydrogen gas generated, by the hydration reaction
between the aluminum electrode foil and water as the solvent,
increases the pressure inside the capacitor to impose a stress on
the capacitor element and this causes various phenomena and
seriously deteriorates the properties of the capacitor, for
example, deforming or breaking the structure of the element,
promoting the splashing of the electrolytic solution outside or
actuating the safety vent. The nitro or nitroso compound acts to
prevent these phenomena. The nitro or nitroso compound efficiently
absorbs hydrogen generated inside the capacitor and prevents the
capacitor from deteriorating in properties. This process is a
chemical reaction and a reduction reaction.
[0019] The absorption of hydrogen, which prevents the increase of
pressure inside the capacitor, takes place at the chemical reaction
of reducing the nitro group of the nitro compound into an amino
group. The nitro compound consumes hydrogen to change into a
nitroso compound and further consumes hydrogen to change into an
amino compound. As for the absorption of hydrogen, the nitroso
group has the same reaction mechanism as the nitro group and
changes into an amino group. However, important here are the
hydrogen-absorbing ability of the compound and the fact that the
nitro or nitroso compound is present (dissolved or dispersed) in
the distributed state in the electrolytic solution. The nitro
compound reacts with hydrogen and first changes into a nitroso
compound. Many nitro compounds become insoluble in the electrolytic
solution when the nitro group changes into a nitroso group, and
have a tendency to locally deposit inside the capacitor element.
Another substituent within the compound acting to render the nitro
compound soluble in a solvent is affected and this is also
responsible for the tendency. However, there is a nitroso group
soluble in a solvent.
[0020] The nitroso group is not so high in the reactivity with
hydrogen as compared with the nitro group and some nitroso groups
resulting from the reduction of nitro group are deposited and
localized and become physically poor in the reaction with hydrogen.
However, the nitroso compound is far higher in the
hydrogen-absorbing ability than other substances and can be
satisfactorily used in practice. When a nitroso compound soluble in
a solvent is used, the nitroso compound can be uniformly present in
the electrolytic solution to provide a good dissolved state
similarly to the nitro compound, whereby the hydrogen gas generated
is efficiently absorbed and good capacitor properties are
maintained. In order to obtain a more outstanding effect, two or
more nitro or nitroso compounds are preferably used in combination.
By making use of a difference in the reduction reaction rate of
those nitro or nitroso compounds, the absorption of hydrogen can be
continued for a long period of time and the properties of the
capacitor can be stabilized. In the case of using a nitro or
nitroso compound by adding it to the electrolytic solution of the
present invention, the nitro or nitroso compound is preferably
added in an amount of 0.01 to 5 wt % based on the entire amount of
the electrolytic solution. Even when one nitro or nitroso compound
is used, an excellent hydrogen-absorbing effect can be provided by
combining it with other electrolytic components.
[0021] The organic solvent used in combination with water for
forming a mixed solvent is preferably a protonic solvent, an
aprotic solvent or a mixture thereof. More specifically, a protonic
solvent and an aprotic solvent each may be used alone or, if
desired, two or more thereof may be used in an arbitrary
combination. The protonic solvent is preferably an alcohol compound
and the aprotic solvent is preferably a lactone compound or the
like.
[0022] The carboxylic acid or a salt thereof which can be used as
the electrolyte in the electrolytic solution of the present
invention is preferably one or more member selected from the group
consisting of a monocarboxylic acid, a dicarboxylic acid, a
tricarboxylic acid, a carboxylic acid having a functional group
such as hydroxyl group, a saturated carboxylic acid and an
unsaturated carboxylic acid, represented by formic acid, acetic
acid, propionic acid, butyric acid, p-nitrobenzoic acid, salicylic
acid, benzoic acid, oxalic acid, malonic acid, succinic acid,
glutaric acid, adipic acid, fumaric acid, maleic acid, phthalic
acid, azelaic acid, citric acid and hydroxybutyric acid,
derivatives thereof and their ammonium salts, sodium salts,
potassium salts, amine salts and alkylammonium salts. The
carboxylic acid or a salt thereof is preferably a formic acid, an
acetic acid, a p-nitrobenzoic acid, a salicylic acid, an oxalic
acid, a malonic acid, a fumaric acid, a maleic acid, a phthalic
acid, a citric acid, a sulfamic acid, an ethylenediaminetetraacetic
acid, or an ammonium, sodium, potassium, amine or alkylammonium
salts thereof, more preferably a formic acid.
[0023] The inorganic acid or a salt thereof which can be used as
the electrolyte is preferably one or more member selected from the
group consisting of an inorganic acid represented by phosphoric
acid, phosphorous acid, hypophosphorous acid, boric acid, sulfamic
acid and alkylphosphoric acid, an inorganic acid having a carbon
chain such as alkyl group, and their ammonium salts, sodium salts,
potassium salts, amine salts and alkylammonium salts.
[0024] The electrolytic solution of the present invention
preferably contains a carboxylic acid in combination with an
inorganic acid selected from a phosphoric acid, a phosphorous acid,
a boric acid, a hypophosphorous acid, a sulfamic acid and an
alkylphosphoric acid and, particularly, from a phosphoric acid, a
phosphorous acid and a boric acid.
[0025] In addition to the nitro or nitroso compound, the
electrolyte for use in the present invention may contain, if
desired, an additive selected from the group consisting of:
[0026] (1) a chelate compound, (2) saccharides, (3) a hydroxybenzyl
alcohol and(or) an L-glutamic-diacetic acid or a salt thereof and
(4) a gluconic acid and(or) a gluconic lactone. These additives may
be used individually, or two or more additives may be used in an
arbitrary combination.
[0027] The electrolytic solution for driving an electrolytic
capacitor of the present invention can have a specific resistance
of 68 .OMEGA.cm or less, preferably 40 .OMEGA.cm or less, more
preferably 30 .OMEGA.cm or less.
[0028] In another aspect of the present invention, as a result of
further continuing studies based on the above-described
experimental results and knowledge, it has been found that in an
electrolytic capacitor comprising an electrolytic solution
containing a solvent consisting of 20 to 80 wt % of an organic
solvent and from 80 to 20 wt % of water, the nitro or nitroso
compound is not necessarily required to be present in the
electrolytic solution but the objects can be similarly attained by
constructing the capacitor to contain the nitro or nitroso compound
in a portion inside the capacitor other than in the electrolytic
solution and an additional effect is provided by constructing the
capacitor to contain the nitro or nitroso compound both in the
electrolytic solution and in a portion inside the capacitor other
than in the electrolytic solution.
[0029] For example, even when the nitro or nitroso compound is not
present in the electrolytic solution but is present in the physical
hydrogen-generating site, namely, on the electrode foil surface or
in the vicinity thereof, or in the state of being uniformly
contained in a separator, the nitro or nitroso compound
satisfactorily exerts the hydrogen-absorbing effect.
[0030] That is, the present invention provides the following:
[0031] (1) an electrolytic solution for driving an electrolytic
capacitor, comprising a solvent consisting of from 20 to 80 wt % of
an organic solvent and from 80 to 20 wt % of water, which contains
one or more nitro or nitroso compound except for nitrophenol,
nitrobenzoic acid, dinitrobenzoic acid, nitroacetophenone and
nitroanisole;
[0032] (2) the electrolytic solution for driving an electrolytic
capacitor as described in (1) above, wherein the nitro or nitroso
compound is soluble in water, a polar solvent or a protonic polar
organic solvent;
[0033] (3) the electrolytic solution for driving an electrolytic
capacitor as described (1) and (2) above, which comprises at least
one electrolyte selected from the group consisting of a carboxylic
acid or a salt thereof, and an inorganic acid or a salt
thereof;
[0034] (4) the electrolytic solution for driving an electrolytic
capacitor as described in (1) to (3) above, wherein the nitro or
nitroso compound is aminonitroanisole, aminonitrotoluene,
aminonitropyridine, aminonitrophenol, aminonitrophenolsulfonic
acid, aminonitrobenzenesulfoni- c acid, aminonitrobenzothiazole,
aminonitrobenzotrifluoride, aminonitrobenzonitrile, nitrophenyl
isocyanate, isonitrosoacetophenone,
N-ethyl-2-(1-ethyl-2-hydroxy-2-nitrosohydrazino)-ethanamine,
O-ethyl-O-(p-nitrophenyl)thionobenzene, ethylnitrobenzene,
ethyl-2-(hydroxyimino)-5-nitro-3-hexeneamide,
octanitrobenzoylsaccharose, nitrophenyloctyl ether, nitrophenyl
galactopyranoside, 3-carboxy-4-nitrophenyl disulfide,
bisnitrobenzylfluorescein, glycerol carbonatenitrobenzene
sulfonate, glutamyl nitroanilide, nitrophenyl acetate,
nitrobenzylidene acetate, diaminonitrobenzene,
dithiobisnitrobenzoic acid, dithiobisnitropyridine, dinitroaniline,
dinitroquinoxaline-2,3-dione, dinitrosalicylic acid,
dinitrodiphenylamine, dinitrodiphenylsulfone,
dinitronaphtholsulfonic acid, dinitrobibenzyl,
dinitrophenylaniline, dinitrophenylhydrazine, dinitrophenol,
dinitrophthalic acid, dinitrofluorenone, dinitrofluorobenzene,
dinitrobenzaldehyde, dinitrobenzoylmethylbenzylamin- e,
dinitrobenzophenone, nitroaminothiazole, dimethylnitroaniline,
dimethylnitrophenylphosphorothioate, dimethoxynitrobenzyl alcohol,
bisdinitrophenyl oxalate, succinimidyl nitrophenylacetate,
tetranitrophenyl porphyrin, trinitrophenol, trinitrobenzenesulfonic
acid, nitroacetanilide, nitroazobenzenediol, nitroanisidine,
nitroaniline, nitroanilinesulfonic acid, nitroaminoanisole,
nitroaminotoluene, nitroaminophenol, nitroarginine, ethyl
nitrobenzoate, methyl nitrobenzoate, nitroanthranilic acid,
nitroanthranilonitrile, nitroisatin, nitroimidazole, nitroindazole,
2-nitroindan-1,3-dione, nitroindole, nitrouracil, nitroethanol,
nitroethylbenzene, nitrocatechol, nitroquipazinemaleic acid,
nitrocresol, nitrocinnamic acid, nitrosalicylic acid,
nitrodiazoaminoazobenzene, nitrodiaminobenzene, nitrodiphenylamine,
nitrodimethylaniline, nitrosulfonazo III, nitrothiophene,
nitrotyrosine, nitroterephthalic acid, nitrotoluidine, nitrotoluic
acid, nitropicoline, nitrohydroxyaniline, nitrobiphenyl,
nitropiperonal, nitropyridinol, nitrobarbituric acid,
nitrophenylacetonitrile, nitrophenylazoorcinol,
nitrophenylazonaphthol, nitrophenylazomethylresorcinol,
nitrophenylaniline, nitrophenyloctyl ether,
nitrophenylgalactopyranoside, nitrophenylxylopyranoside,
nitrophenylglucuronide, nitrophenylglucopyranoside,
nitrophenylacetic acid, nitrophenyldodecyl ether,
nitrophenylarsonic acid, nitrophenylhydrazine,
nitrophenylphenylazophenyl triazene, nitrophenylphenyl ether,
nitrophenyl maltopentaoside, nitrophenylmannopyranoside,
nitrophenylbutyric acid, diethyl nitrophenylphosphate,
nitrophenylenediamine, nitrophenethole, nitrophenolarsonic acid,
nitrophenolmethyl ether, nitrophthalimide, nitrophthalic acid,
nitrohumic acid, nitropropionic acid, nitroveratryl alcohol,
nitrobenzylamine, nitrobenzyl alcohol, nitrobenzyldiisopropyliso-
urea, nitrobenzylpyridine, nitrobenzamide, nitrobenzimidazole,
nitrobenzohydrazide, nitrobenzeneazoorcinol,
nitrobenzeneazonaphthol, nitromethane, nitroethane,
nitrobenzeneazoresorcinol, nitrobenzenesulfonic acid,
nitrobenzocoumarin, nitrobenzonitrile, nitrobenzophenone,
nitromesitylene, nitromethoxyaniline, bisnitrophenyl disulfide,
bisnitrophenylsulfone, bismethylthionitroethene,
hydroxynitrobenzoic acid, hydroxynitrotoluene,
hydroxynitropyridine, hydroxynitrophenylarsonic acid,
hydroxynitrobenzaldehyde,
3-[2-hydroxy-1-(1-methylethyl)-2-nitrosohydrazino]-1-propanonamine,
phenylnitroaniline, 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide,
fluoronitroacetanilide, fluoronitroaniline, fluoronitrophenylazide,
fluoronitrophenol, methylnitroaniline, methylnitrophenol,
methylnitropyridine, methylnitropyridine oxide,
methoxynitroaniline, methoxynitrobenzoic acid, methoxynitrophenol,
methoxybenzylaminonitrobenz- ofurazan, nitrophenyl butyrate,
nitronium tetrafluoroborate, nitrophenyl phosphate,
nitrosoacetylpenicillamine, nitroso(acetoxymethyl)methylamine,
nitroso oxine, nitrosoquinolinol, nitrosoglutathione,
nitrosodiisobutylamine, nitrosodiethylamine, nitrosodiethylaniline,
nitrosodisulfonic acid, nitrosodiphenylamine, nitrosodimethylamine,
nitrosonaphthol, nitrosonaphtholdisulfonic acid,
nitrosohydroxyquinoline, nitrosophenylaniline,
nitrosophenylhydroxylamine ammonium, nitrosophenol,
N-[(N-nitrosomethylamino)methyl]benzamide,
2,2'-(hydroxynitrosohydrazono)- bisethanamine,
N-methyl-2-(1-ethyl-2-hydroxy-2-nitrosohydrazino)-ethanamin- e,
N,N'-dinitroso-p-phenylenediamine,
N,N'-dinitrosopentamethylenetetramin- e, dimethylnitrosoaniline,
dimethylnitrosoamine, nitrosonium tetrafluoroborate,
N-[N'-methyl-N'-nitroso(aminomethyl)]benzamide,
N-methyl-N-nitroso-p-toluenesulfonamide, nitrobenzene,
dinitrobenzene, dinitrotoluene, nitronaphthalene,
dinitronaphthalene, dinitrobiphenyl, dimethylnitrotoluene,
dinitropyrene, nitrobenzoic acid ester, dimethylnitrobenzene,
nitroanthracene, nitroisoquinoline, nitroxylene, ethyl
nitroacetate, nitrocyclopentane, nitrostyrene, nitropyrrole,
nitrofurazone, nitrofuraldehyde, nitrohexane, nitrobenzaldehyde,
nitrolignin, 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide,
nitroacrylamide, fluoronitrotoluene, fluoronitrobenzene,
fluoronitrodiphenyl ether, trinitroacetonitrile, trinitroaniline,
trinitrobenzoic acid, trinitroethane, trinitroxylene,
trinitrotoluene, trinitronaphthalene, trinitrofluorenone,
trinitrobenzene, trinitromesitylene, trinitromethane,
trinitroresorcinol, dinitroacetanilide, dinitroanisole,
dinitroanthraquinone, dinitroethane, dinitroethanediamine,
dinitrocarbanilide, dinitroxylene, dinitroglycerol, dinitrocresol,
dinitronaphthol, dinitrophenyl, dinitrophenylhydrazone,
dinitromethane, dinitroresorcinol, nitroamide, nitroanthraquinone,
nitroisophthalic acid, nitroethylene, ethyl nitrocarbamate,
nitroquinaldic acid, nitroguanidine, nitroglycol, nitroglycerin,
nitrodimethylamine, nitrocamphor, methylnitropropane,
nitrosulfathiazole, nitrocellulose, nitrosomethane,
nitrosoguanidine, nitrosodimethylaniline, nitrosotoluene,
nitrosodisulfonic acid, nitrosopiperidine, nitrosobenzene,
nitrosomethylurea, nitronaphthylamine, nitronaphthol,
nitropyridine, nitrophenanthrene, nitrophenylpropiolic acid,
nitrophenetidine, nitrophenolsulfonic acid, nitropentane,
nitroresorcinol, nitrourea, trinitroxylenol, trinitrodiphenyl
ether, trinitrotriazidobenzene, trinitrophloroglucinol,
nitroacridine, nitroacridone, nitroacetone, nitroanilic acid,
nitroaminoacetic acid, nitroisatin, nitroisobutane, nitroindene,
nitrourethane, nitrocarbostyril, nitrodiglycol, nitro-p-cymene,
nitrocinnamaldehyde, N-nitrosoacetanilide, nitrosoanisidine,
nitrosoaniline, nitrosobenzoic acid, nitrosoanthranilic acid,
nitrosocatechol, nitrosocarvacrol, nitrosocresol,
nitrosonaphthylamine, nitrothioanisole, nitrothiophenol,
nitronaphthalenesulfonic acid, nitronaphthylamine, nitronaphthoic
acid, nitronitrosobenzene, nitrohydroquinone, nitropyrogallol,
nitrophenanthridine, nitrophenanthroline, nitrophenylurethane,
nitrophenylurea, nitrobutane, nitrophthalide, nitrofuran,
nitropropylene, nitrophloroglucinol, nitrobenzanilide,
nitrobenzaldoxime, nitrobenzoylformic acid, nitrobenzimidazole,
nitromalonic acid, nitromalondialdehyde, nitromandelic acid,
nitromannitol, nitromethylnaphthalene, nitromalic acid,
nitroresorcinol, nitron, nitrosoresorcinol, aminonitropyrimidine,
trinitrofluorenylidene malononitrile, nitrofluoranthene,
nitrobenzocrown, fluoronitrobenzofurazan,
methylnitronitrosoguanidine, methylnitronitrophenylpyrazolone,
nitrofluorene, nitropropane, nitropropoxyaniline, trinitroanisole,
trinitrocresol, trinitrobenzaldehyde, nitrodiethylaniline,
nitrostilbene, nitrosonaphthalene, nitrosobenzaldehyde,
nitrosomethylurethane, nitrophenylhydrazone, dinitrotartaric acid,
dinitrostilbene, dinitrosoresorcinol, dinitrohydroquinone,
dinitroresorcinol, nitroquinoline, dinitrosophenol,
trinitrosophenol, dinitrosobenzoic acid, trinitrosobenzoic acid,
dinitroacetophenone, trinitroacetophenone, nitrosoacetophenone,
dinitrosoacetophenone, trinitrosoacetophenone, nitrosoanisole,
dinitrosoanisole, trinitrosoanisole or an isomer, salt, derivative,
coordinate bonded form or clathrate form thereof;
[0035] (5) the electrolytic solution for driving an electrolytic
capacitor as described in (1) to (4) above, wherein the nitro or
nitroso compounds are used in combination of two or more
thereof;
[0036] (6) the electrolytic solution for driving an electrolytic
capacitor as described in (1) to (5) above, wherein the nitro or
nitroso compound is contained in an amount of 0.01 to 5 wt % based
on the entire amount of the electrolytic solution;
[0037] (7) the electrolytic solution for driving an electrolytic
capacitor as described in (6) above, which additionally contains
from 0.01 to 10% of a salt or derivative of nitrophenol,
nitrobenzoic acid, dinitrobenzoic acid, nitroacetophenone and
nitroanisole;
[0038] (8) the electrolytic solution for driving an electrolytic
capacitor as described in (1) to (7) above, wherein the organic
solvent is a protonic solvent, an aprotic solvent or a mixture
thereof;
[0039] (9) the electrolytic solution for driving an electrolytic
capacitor as described in (3) to (8) above, wherein the carboxylic
acid or a salt thereof is selected from the group consisting of a
monocarboxylic acid, a dicarboxylic acid, a tricarboxylic acid, a
saturated carboxylic acid and an unsaturated carboxylic acid,
represented by formic acid, acetic acid, propionic acid, butyric
acid, p-nitrobenzoic acid, salicylic acid, benzoic acid, oxalic
acid, malonic acid, succinic acid, glutaric acid, adipic acid,
fumaric acid, maleic acid, phthalic acid, azelaic acid, citric acid
and hydroxybutyric acid, derivatives thereof, and their ammonium
salt, sodium salt, potassium salt, amine salt and alkylammonium
salt;
[0040] (10) the electrolytic solution for driving an electrolytic
capacitor as described in (3) to (8) above, wherein the carboxylic
acid or a salt thereof is selected from the group consisting of a
formic acid, an acetic acid, a p-nitrobenzoic acid, a salicylic
acid, an oxalic acid, a malonic acid, a fumaric acid, a maleic
acid, a phthalic acid, a citric acid, a sulfamic acid, an
ethylenediaminetetraacetic acid, and their ammonium salt, sodium
salt, potassium salt, amine salt and alkylammonium salt;
[0041] (11) the electrolytic solution for driving an electrolytic
capacitor as described in (3) to (8) above, wherein the carboxylic
acid or a salt thereof is a formic acid;
[0042] (12) the electrolytic solution for driving an electrolytic
capacitor as described in (3) to (8) above, wherein the inorganic
acid or a salt thereof is selected from the group consisting of an
inorganic acid represented by phosphoric acid, phosphorous acid,
hypophosphorous acid, boric acid, sulfamic acid and alkylphosphoric
acid, an inorganic acid having a carbon chain such as alkyl group,
and their ammonium salts, sodium salts, potassium salts, amine
salts and alkylammonium salts;
[0043] (13) the electrolytic solution for driving an electrolytic
capacitor as described in (3) to (11) above, which comprises a
combination of the carboxylic acid or a salt thereof and at least
one inorganic acid selected from a phosphoric acid, a phosphorous
acid, a boric acid, a hypophosphorous acid, a sulfamic acid and an
alkylphosphoric acid;
[0044] (14) the electrolytic solution for driving an electrolytic
capacitor as described in (1) to (13) above, which further
comprises at least one compound selected from the group consisting
of (1) a chelate compound, (2) saccharides, (3) a hydroxybenzyl
alcohol and(or) an L-glutamic-diacetic acid or a salt thereof and
(4) a gluconic acid and(or) a gluconic lactone;
[0045] (15) the electrolytic solution for driving an electrolytic
capacitor as described in (1) to (14) above, wherein the solvent
consists of 20 to 55 wt % of an organic solvent and 80 to 45 wt %
of water;
[0046] (16) the electrolytic solution for driving an electrolytic
capacitor as described in (15) above, wherein the solvent consists
of 20 to 35 wt % of an organic solvent and 80 to 65 wt % of
water;
[0047] (17) the electrolytic solution for driving an electrolytic
capacitor as described in (1) to (16) above, wherein the specific
resistance of the electrolytic solution is 68 .OMEGA.cm or
less;
[0048] (18) the electrolytic solution for driving an electrolytic
capacitor as described in (1) to (16) above, wherein the specific
resistance of the electrolytic solution is 40 .OMEGA.cm or
less;
[0049] (19) the electrolytic solution for driving an electrolytic
capacitor as described in (1) to (16) above, wherein the specific
resistance of the electrolytic solution is 30 .OMEGA.cm or
less;
[0050] (20) an electrolytic capacitor comprising the electrolytic
solution for driving an electrolytic capacitor described in (1) to
(19);
[0051] (21) an electrolytic capacitor using an electrolytic
solution constituted by a solvent consisting of from 20 to 80 wt %
of an organic solvent and from 80 to 20 wt % of water, the
electrolytic capacitor comprising a nitro or nitroso compound
except for nitrophenol, nitrobenzoic acid, dinitrobenzoic acid,
nitrophenone and nitroanisole, in a portion inside the capacitor
other than in the electrolytic solution;
[0052] (22) the electrolytic capacitor as described in (21) above,
wherein the nitro or nitroso compound is aminonitroanisole,
aminonitrotoluene, aminonitropyridine, aminonitrophenol,
aminonitrophenolsulfonic acid, aminonitrobenzenesulfonic acid,
aminonitrobenzothiazole, aminonitrobenzotrifluoride,
aminonitrobenzonitrile, nitrophenyl isocyanate,
isonitrosoacetophenone, N-ethyl-2-(1-ethyl-2-hydroxy-2-nitros-
ohydrazino)-ethanamine, O-ethyl-O-(p-nitrophenyl)thionobenzene,
ethylnitrobenzene, ethyl-2-(hydroxyimino)-5-nitro-3-hexeneamide,
octanitrobenzoylsaccharose, nitrophenyloctyl ether, nitrophenyl
galactopyranoside, 3-carboxy-4-nitrophenyl disulfide,
bisnitrobenzylfluorescein, glycerol carbonatenitrobenzene
sulfonate, glutamyl nitroanilide, nitrophenyl acetate,
nitrobenzylidene acetate, diaminonitrobenzene,
dithiobisnitrobenzoic acid, dithiobisnitropyridine, dinitroaniline,
dinitroquinoxaline-2,3-dione, dinitrosalicylic acid,
dinitrodiphenylamine, dinitrodiphenylsulfone,
dinitronaphtholsulfonic acid, dinitrobibenzyl,
dinitrophenylaniline, dinitrophenylhydrazine, dinitrophenol,
dinitrophthalic acid, dinitrofluorenone, dinitrofluorobenzene,
dinitrobenzaldehyde, dinitrobenzoylmethylbenzylamin- e,
dinitrobenzophenone, nitroaminothiazole, dimethylnitroaniline,
dimethylnitrophenylphosphorothioate, dimethoxynitrobenzyl alcohol,
bisdinitrophenyl oxalate, succinimidyl nitrophenylacetate,
tetranitrophenyl porphyrin, trinitrophenol, trinitrobenzenesulfonic
acid, nitroacetanilide, nitroazobenzenediol, nitroanisidine,
nitroaniline, nitroanilinesulfonic acid, nitroaminoanisole,
nitroaminotoluene, nitroaminophenol, nitroarginine, ethyl
nitrobenzoate, methyl nitrobenzoate, nitroanthranilic acid,
nitroanthranilonitrile, nitroisatin, nitroimidazole, nitroindazole,
2-nitroindan-1,3-dione, nitroindole, nitrouracil, nitroethanol,
nitroethylbenzene, nitrocatechol, nitroquipazinemaleic acid,
nitrocresol, nitrocinnamic acid, nitrosalicylic acid,
nitrodiazoaminoazobenzene, nitrodiaminobenzene, nitrodiphenylamine,
nitrodimethylaniline, nitrosulfonazo III, nitrothiophene,
nitrotyrosine, nitroterephthalic acid, nitrotoluidine, nitrotoluic
acid, nitropicoline, nitrohydroxyaniline, nitrobiphenyl,
nitropiperonal, nitropyridinol, nitrobarbituric acid,
nitrophenylacetonitrile, nitrophenylazoorcinol,
nitrophenylazonaphthol, nitrophenylazomethylresorcinol,
nitrophenylaniline, nitrophenyloctyl ether,
nitrophenylgalactopyranoside, nitrophenylxylopyranoside,
nitrophenylglucuronide, nitrophenylglucopyranoside,
nitrophenylacetic acid, nitrophenyldodecyl ether,
nitrophenylarsonic acid, nitrophenylhydrazine,
nitrophenylphenylazophenyl triazene, nitrophenylphenyl ether,
nitrophenylmaltopentaoside, nitrophenylmannopyranoside,
nitrophenylbutyric acid, diethyl nitrophenylphosphate,
nitrophenylenediamine, nitrophenethole, nitrophenolarsonic acid,
nitrophenolmethyl ether, nitrophthalimide, nitrophthalic acid,
nitrohumic acid, nitropropionic acid, nitroveratryl alcohol,
nitrobenzylamine, nitrobenzyl alcohol, nitrobenzyldiisopropyliso-
urea, nitrobenzylpyridine, nitrobenzamide, nitrobenzimidazole,
nitrobenzohydrazide, nitrobenzeneazoorcinol,
nitrobenzeneazonaphthol, nitromethane, nitroethane,
nitrobenzeneazoresorcinol, nitrobenzenesulfonic acid,
nitrobenzocoumarin, nitrobenzonitrile, nitrobenzophenone,
nitromesitylene, nitromethoxyaniline, bisnitrophenyl disulfide,
bisnitrophenylsulfone, bismethylthionitroethene,
hydroxynitrobenzoic acid, hydroxynitrotoluene,
hydroxynitropyridine, hydroxynitrophenylarsonic acid,
hydroxynitrobenzaldehyde,
3-[2-hydroxy-1-(1-methylethyl)-2-nitrosohydrazino]-1-propanonamine,
phenylnitroaniline, 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide,
fluoronitroacetanilide, fluoronitroaniline, fluoronitrophenylazide,
fluoronitrophenol, methylnitroaniline, methylnitrophenol,
methylnitropyridine, methylnitropyridine oxide,
methoxynitroaniline, methoxynitrobenzoic acid, methoxynitrophenol,
methoxybenzylaminonitrobenz- ofurazan, nitrophenyl butyrate,
nitronium tetrafluoroborate, nitrophenyl phosphate,
nitrosoacetylpenicillamine, nitroso(acetoxymethyl)methylamine,
nitroso oxine, nitrosoquinolinol, nitrosoglutathione,
nitrosodiisobutylamine, nitrosodiethylamine, nitrosodiethylaniline,
nitrosodisulfonic acid, nitrosodiphenylamine, nitrosodimethylamine,
nitrosonaphthol, nitrosonaphtholdisulfonic acid,
nitrosohydroxyquinoline, nitrosophenylaniline,
nitrosophenylhydroxylamine ammonium, nitrosophenol,
N-[(N-nitrosomethylamino)methyl]benzamide,
2,2'-(hydroxynitrosohydrazono)- bisethanamine,
N-methyl-2-(1-ethyl-2-hydroxy-2-nitrosohydrazino)-ethanamin- e,
N,N'-dinitroso-p-phenylenediamine,
N,N'-dinitrosopentamethylenetetramin- e, dimethylnitrosoaniline,
dimethylnitrosoamine, nitrosonium tetrafluoroborate,
N-[N'-methyl-N'-nitroso(aminomethyl)]benzamide,
N-methyl-N-nitroso-p-toluenesulfonamide, nitrophenol, nitrobenzoic
acid, dinitrobenzoic acid, nitroacetophenone, nitroanisole,
nitrobenzene, dinitrobenzene, dinitrotoluene, nitronaphthalene,
dinitronaphthalene, dinitrobiphenyl, dimethylnitrotoluene,
dinitropyrene, nitrobenzoic acid ester, dimethylnitrobenzene,
nitroanthracene, nitroisoquinoline, nitroxylene, ethyl
nitroacetate, nitrocyclopentane, nitrostyrene, nitropyrrole,
nitrofurazone, nitrofuraldehyde, nitrohexane, nitrobenzaldehyde,
nitrolignin, 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide- ,
nitroacrylamide, fluoronitrotoluene, fluoronitrobenzene,
fluoronitrodiphenyl ether, trinitroacetonitrile, trinitroaniline,
trinitrobenzoic acid, trinitroethane, trinitroxylene,
trinitrotoluene, trinitronaphthalene, trinitrofluorenone,
trinitrobenzene, trinitromesitylene, trinitromethane,
trinitroresorcinol, dinitroacetanilide, dinitroanisole,
dinitroanthraquinone, dinitroethane, dinitroethanediamine,
dinitrocarbanilide, dinitroxylene, dinitroglycerol, dinitrocresol,
dinitronaphthol, dinitrophenyl, dinitrophenylhydrazone,
dinitromethane, dinitroresorcinol, nitroamide, nitroanthraquinone,
nitroisophthalic acid, nitroethylene, ethyl nitrocarbamate,
nitroquinaldic acid, nitroguanidine, nitroglycol, nitroglycerin,
nitrodimethylamine, nitrocamphor, methylnitropropane,
nitrosulfathiazole, nitrocellulose, nitrosomethane,
nitrosoguanidine, nitrosodimethylaniline, nitrosotoluene,
nitrosodisulfonic acid, nitrosopiperidine, nitrosobenzene,
nitrosomethylurea, nitronaphthylamine, nitronaphthol,
nitropyridine, nitrophenanthrene, nitrophenylpropiolic acid,
nitrophenetidine, nitrophenolsulfonic acid, nitropentane,
nitroresorcinol, nitrourea, trinitroxylenol, trinitrodiphenyl
ether, trinitrotriazidobenzene, trinitrophloroglucinol,
nitroacridine, nitroacridone, nitroacetone, nitroanilic acid,
nitroaminoacetic acid, nitroisatin, nitroisobutane, nitroindene,
nitrourethane, nitrocarbostyril, nitrodiglycol, nitro-p-cymene,
nitrocinnamaldehyde, N-nitrosoacetanilide, nitrosoanisidine,
nitrosoaniline, nitrosobenzoic acid, nitrosoanthranilic acid,
nitrosocatechol, nitrosocarvacrol, nitrosocresol,
nitrosonaphthylamine, nitrothioanisole, nitrothiophenol,
nitronaphthalenesulfonic acid, nitronaphthylamine, nitronaphthoic
acid, nitronitrosobenzene, nitrohydroquinone, nitropyrogallol,
nitrophenanthridine, nitrophenanthroline, nitrophenylurethane,
nitrophenylurea, nitrobutane, nitrophthalide, nitrofuran,
nitropropylene, nitrophloroglucinol, nitrobenzanilide,
nitrobenzaldoxime, nitrobenzoylformic acid, nitrobenzimidazole,
nitromalonic acid, nitromalondialdehyde, nitromandelic acid,
nitromannitol, nitromethylnaphthalene, nitromalic acid,
nitroresorcinol, nitron, nitrosoresorcinol, aminonitropyrimidine,
trinitrofluorenylidene malononitrile, nitrofluoranthene,
nitrobenzocrown, fluoronitrobenzofurazan,
methylnitronitrosoguanidine, methylnitronitrophenylpyrazolone,
nitrofluorene, nitropropane, nitropropoxyaniline, trinitroanisole,
trinitrocresol, trinitrobenzaldehyde, nitrodiethylaniline,
nitrostilbene, nitrosonaphthalene, nitrosobenzaldehyde,
nitrosomethylurethane, nitrophenylhydrazone, dinitrotartaric acid,
dinitrostilbene, dinitrosoresorcinol, dinitrohydroquinone,
dinitroresorcinol, nitroquinoline, dinitrosophenol,
trinitrosophenol, dinitrosobenzoic acid, trinitrosobenzoic acid,
dinitroacetophenone, trinitroacetophenone, nitrosoacetophenone,
dinitrosoacetophenone, trinitrosoacetophenone, nitrosoanisole,
dinitrosoanisole, trinitrosoanisole or an isomer, salt, derivative,
coordinate bonded form or clathrate form thereof;
[0053] (23) the electrolytic capacitor as described in (21) and
(22) above, which comprises the nitro or nitroso compound or an
isomer, salt or derivative thereof on the electrode surface;
[0054] (24) the electrolytic capacitor as described in (21) to
(23), wherein the nitro or nitroso compound or an isomer, salt or
derivative thereof is attached or permeation-filled to the
electrode surface by the coating or by the dipping in a solution
having dissolved therein the nitro or nitroso compound or an
isomer, salt or derivative thereof;
[0055] (25) the electrolytic capacitor as described in (21) to (24)
above, wherein the nitro or nitroso compound or an isomer, salt or
derivative thereof is contained in a separator constituting the
electrolytic capacitor;
[0056] (26) the electrolytic capacitor as described in (21) to (25)
above, wherein the nitro or nitroso compound or an isomer, salt or
derivative thereof is attached or dipped to the separator by
coating or by dipping in a solution having dissolved therein the
nitro or nitroso compound or an isomer, salt or derivative
thereof;
[0057] (27) the electrolytic capacitor as described in any one of
(21) to (24) above, wherein the amount of the nitro or nitroso
compound described in (22) above or an isomer, salt or derivative
thereof contained in the electrode foil is from 0.007 to 1
mg/cm.sup.2 (projectional area);
[0058] (28) the electrolytic capacitor as described in (21), (25)
and (26) above, wherein the amount of the nitro or nitroso compound
or an isomer, salt or derivative thereof contained in the separator
is from 0.007 to 1 mg/cm.sup.2 (projectional area);
[0059] (29) the electrolytic capacitor as described in (21) to
(28), wherein the solvent consists of from 20 to 55 wt % of an
organic solvent and from 80 to 45 wt % of water; and
[0060] (30) the electrolytic capacitor as described in (29) above,
wherein the solvent consists of from 20 to 35 wt % of an organic
solvent and from 80 to 65 wt % of water.
BRIEF DESCRIPTION OF THE DRAWING
[0061] FIG. 1 is a schematic view of an electrolytic capacitor.
BEST MODE FOR CARRYING OUT THE INVENTION
[0062] The electrolytic solution for driving an electrolytic
capacitor of the present invention is characterized in that a
solvent comprising a mixture of an organic solvent and water and
having a high water concentration is used as the solvent for
dissolving the electrolyte.
[0063] For the organic solvent, as described above, a protonic
solvent and an aprotic solvent can be used individually or in an
arbitrary combination. Suitable examples of the protonic solvent
include alcohol compounds. Specific examples of the alcohol
compound which can be advantageously used include, but are not
limited to, monohydric alcohol such as ethyl alcohol, propyl
alcohol and butyl alcohol, dihydric alcohols (glycols) such as
ethylene glycol, diethylene glycol, triethylene glycol and
propylene glycol, and trihydric alcohols such as glycerin. Suitable
examples of the aprotic solvent include lactone compounds. Specific
examples of the lactone compound which can be advantageously used
include, but are not limited to, .gamma.-butyrolactone and other
intramolecular polarizable compounds. In the case of using one or
more selected from the protonic and aprotic solvents in practicing
the present invention, more specifically, one protonic solvent may
be used, one aprotic solvent may be used, a plurality of protonic
solvents may be used, a plurality of aprotic solvents may be used,
or a mixed solvent of one or more protonic solvent and one or more
aprotic solvent may be used. When the nitro or nitroso compound
used in the present invention is sparingly soluble in water or a
polar solvent, a method of selecting one or more solvent capable of
solubilizing the nitro or nitroso compound and dissolving in a
polar solvent, and thereby dissolving the nitro or nitroso compound
in a solvent constituting the electrolytic solution, water or a
polar solvent may be employed. Also, the nitro or nitroso compound
may be formed into fine powder in the dissolved solution and
uniformly dispersed.
[0064] In the electrolytic solution of the present invention, water
is used as a solvent component in addition to the above-described
organic solvent. Particularly, the present invention differs from
conventional electrolytic solutions in that a relatively large
amount of water is used in combination. According to the present
invention, such a solvent is used, so that the solidifying point of
the solvent can be decreased, the electrolytic solution can be in
turn improved in the specific resistance property at low
temperatures and good low-temperature stability shown by a small
difference in the specific resistance between low temperature and
ordinary temperature can be realized. The content of water in the
electrolytic solution is preferably from 20 to 80 wt %, with the
remainder being the organic solvent. If the water content is less
than 20 wt % or exceeds 80 wt %, the degree of depression in
solidifying point of the electrolytic solution is insufficient and
good low-temperature stability of the electrolytic capacitor can
hardly be obtained. The content of water in the solvent of the
electrolytic solution is preferably from 30 to 80 wt %, more
preferably from 45 to 80 wt % by weight, and most preferably from
65 to 80 wt %. In the solvent, the amount of the organic solvent is
the remaining amount excluding water.
[0065] The electrolyte in the electrolytic solution of the present
invention is an organic acid, preferably a carboxylic acid or a
salt thereof, or an inorganic acid or a salt thereof. These
electrolyte components may be used individually or in a combination
of two or more thereof. Examples of the carboxylic acid which can
be used as the electrolyte component include, but are not limited
to, monocarboxylic acids, dicarboxylic acids, tricarboxylic acids,
carboxylic acids having a functional group such as hydroxyl group,
saturated carboxylic acids and unsaturated carboxylic acids,
represented by formic acid, acetic acid, propionic acid, butyric
acid, p-nitrobenzoic acid, salicylic acid, benzoic acid, oxalic
acid, malonic acid, succinic acid, glutaric acid, adipic acid,
fumaric acid, maleic acid, phthalic acid, azelaic acid, citric acid
and hydroxybutyric acid, and derivatives thereof.
[0066] Among these carboxylic acids and salts thereof, preferred in
view of ion conductivity are a formic acid, an acetic acid, a
p-nitrobenzoic acid, a salicylic acid, an oxalic acid, a malonic
acid, a fumaric acid, a maleic acid, a phthalic acid, a citric
acid, a sulfamic acid, an ethylenediaminetetraacetic acid, and
their ammonium salts, sodium salts, potassium salts, amine salts
and alkylammonium salts, more preferred is formic acid because of
its large ion conductivity.
[0067] Examples of the inorganic acid which can also be used as the
electrolyte component include, but are not limited to, inorganic
acids represented by phosphoric acid, phosphorous acid,
hypophosphorous acid, boric acid, sulfamic acid and alkylphosphoric
acid, and inorganic acids having a carbon chain such as alkyl
group.
[0068] As for the salt of the above-described carboxylic acid or
inorganic acid, various salts can be used but suitable examples of
the salt include an ammonium salt, a sodium salt, a potassium salt,
an amine salt and an alkylammonium salt. Among these salts, an
ammonium salt is preferred.
[0069] When the inorganic acid or a salt thereof is used as the
electrolyte in practicing the present invention, a lowering of the
solidifying point of the electrolytic solution can be expected and
therefore, this can contribute to a further improvement in the
low-temperature stability of the electrolytic solution. The use of
the inorganic acid or a salt thereof is also noticeable in that the
hydrogen gas absorbing ability derived from the nitro or nitroso
compound particularly used in the present invention can be
maintained for a long period of time.
[0070] According to the studies by the present inventors, when an
electrolyte such as inorganic acid or a salt thereof is used in
combination with an above-described electrolyte such as carboxylic
acid or a salt thereof, an effect of remarkably prolonging the
working life of the electrolytic capacitor, as compared with the
case where these are used individually, can be obtained. In
conventional electrolytic capacitors, an inorganic acid-base
electrolyte has been heretofore used mainly in medium to
high-voltage (160 to 500 volt) type electrolytic capacitors in view
of electrical conductivity. However, when a combination of
electrolytes is used as in the present invention, the inorganic
acid-base electrolyte can also be advantageously used in
low-voltage (less than 160 volt) type electrolytic capacitors.
[0071] The amount of the electrolyte used in the electrolytic
solution of the present invention can be appropriately determined
depending on various factors such as characteristics required of
the electrolytic solution and capacitor finally obtained, the kind,
composition and amount of solvent used, and the kind of electrolyte
used. For example, as above, when an inorganic acid-base
electrolyte is used in combination with a carboxylic acid-base
electrolyte, the content of the inorganic acid-base electrolyte in
the mixed electrolyte can be changed over a wide range, however,
usually, the inorganic acid-base electrolyte is preferably
contained in an amount of about 0.1 to 15 wt % based on the entire
amount of the electrolyte.
[0072] As another characteristic feature of the electrolytic
solution of the present invention, it is an electrolytic solution
for driving an electrolytic capacitor obtained by incorporating at
least one nitro or nitroso compound except for nitrophenol,
nitrobenzoic acid, dinitrobenzoic acid, nitroacetophenone and
nitroanisole, into an electrolytic solution having the
above-described specific composition, namely, comprising a mixed
solvent consisting of from 20 to 80 wt % of an organic solvent and
from 80 to 20 wt % of water, and at least one electrolyte
preferably selected from the group consisting of a carboxylic acid
or a salt thereof, and an inorganic acid or a salt thereof.
[0073] Specific examples of this nitro or nitroso compound include
aminonitroanisole, aminonitrotoluene, aminonitropyridine,
aminonitrophenol, aminonitrophenolsulfonic acid,
aminonitrobenzenesulfoni- c acid, aminonitrobenzothiazole,
aminonitrobenzotrifluoride, aminonitrobenzonitrile, nitrophenyl
isocyanate, isonitrosoacetophenone,
N-ethyl-2-(l-ethyl-2-hydroxy-2-nitrosohydrazino)-ethanamine,
O-ethyl-O-(p-nitrophenyl)thionobenzene, ethylnitrobenzene,
ethyl-2-(hydroxyimino)-5-nitro-3-hexeneamide,
octanitrobenzoylsaccharose, nitrophenyloctyl ether, nitrophenyl
galactopyranoside, 3-carboxy-4-nitrophenyl disulfide,
bisnitrobenzylfluorescein, glycerol carbonatenitrobenzene
sulfonate, glutamyl nitroanilide, nitrophenyl acetate,
nitrobenzylidene acetate, nitroaminothiazole, dithiobisnitrobenzoic
acid, dithiobisnitropyridine, dinitroaniline,
dinitroquinoxaline-2,3-dione, dinitrosalicylic acid,
dinitrodiphenylamine, dinitrodiphenylsulfone,
dinitronaphtholsulfonic acid, dinitrobibenzyl,
dinitrophenylaniline, dinitrophenylhydrazine, dinitrophenol,
dinitrophthalic acid, dinitrofluorenone, dinitrofluorobenzene,
dinitrobenzaldehyde, dinitrobenzoylmethylbenzylamin- e,
dinitrobenzophenone, diaminonitrobenzene, dimethylnitroaniline,
dimethylnitrophenylphosphorothioate, dimethoxynitrobenzyl alcohol,
bisdinitrophenyl oxalate, succinimidyl nitrophenylacetate,
tetranitrophenyl porphyrin, trinitrophenol, trinitrobenzenesulfonic
acid, nitroacetanilide, nitroazobenzenediol, nitroanisidine,
nitroaniline, nitroanilinesulfonic acid, nitroaminoanisole,
nitroaminotoluene, nitroaminophenol, nitroarginine, ethyl
nitrobenzoate, methyl nitrobenzoate, nitroanthranilic acid,
nitroanthranilonitrile, nitroisatin, nitroimidazole, nitroindazole,
2-nitroindan-1,3-dione, nitroindole, nitrouracil, nitroethanol,
nitroethylbenzene, nitrocatechol, nitroquipazinemaleic acid,
nitrocresol, nitrocinnamic acid, nitrosalicylic acid,
nitrodiazoaminoazobenzene, nitrodiaminobenzene, nitrodiphenylamine,
nitrodimethylaniline, nitrosulfonazo III, nitrothiophene,
nitrotyrosine, nitroterephthalic acid, nitrotoluidine, nitrotoluic
acid, nitropicoline, nitrohydroxyaniline, nitrobiphenyl,
nitropiperonal, nitropyridinol, nitrobarbituric acid,
nitrophenylacetonitrile, nitrophenylazoorcinol,
nitrophenylazonaphthol, nitrophenylazomethylresorcinol,
nitrophenylaniline, nitrophenyloctyl ether,
nitrophenylgalactopyranoside, nitrophenylxylopyranoside,
nitrophenylglucuronide, nitrophenylglucopyranoside,
nitrophenylacetic acid, nitrophenyldodecyl ether,
nitrophenylarsonic acid, nitrophenylhydrazine,
nitrophenylphenylazophenyl triazene, nitrophenylphenyl ether,
nitrophenylmaltopentaoside, nitrophenylmannopyranoside,
nitrophenylbutyric acid, diethyl nitrophenylphosphate,
nitrophenylenediamine, nitrophenethole, nitrophenolarsonic acid,
nitrophenolmethyl ether, nitrophthalimide, nitrophthalic acid,
nitrohumic acid, nitropropionic acid, nitroveratryl alcohol,
nitrobenzylamine, nitrobenzyl alcohol, nitrobenzyldiisopropyliso-
urea, nitrobenzylpyridine, nitrobenzamide, nitrobenzimidazole,
nitrobenzohydrazide, nitrobenzeneazoorcinol,
nitrobenzeneazonaphthol, nitromethane, nitroethane,
nitrobenzeneazoresorcinol, nitrobenzenesulfonic acid,
nitrobenzocoumarin, nitrobenzonitrile, nitrobenzophenone,
nitromesitylene, nitromethoxyaniline, bisnitrophenyl disulfide,
bisnitrophenylsulfone, bismethylthionitroethene,
hydroxynitrobenzoic acid, hydroxynitrotoluene,
hydroxynitropyridine, hydroxynitrophenylarsonic acid,
hydroxynitrobenzaldehyde,
3-[2-hydroxy-1-(1-methylethyl)-2-nitrosohydrazino]-1-propanonamine,
phenylnitroaniline, 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide,
fluoronitroacetanilide, fluoronitroaniline, fluoronitrophenylazide,
fluoronitrophenol, methylnitroaniline, methylnitrophenol,
methylnitropyridine, methylnitropyridine oxide,
methoxynitroaniline, methoxynitrobenzoic acid, methoxynitrophenol,
methoxybenzylaminonitrobenz- ofurazan, nitrophenyl butyrate,
nitronium tetrafluoroborate, nitrophenyl phosphate,
nitrosoacetylpenicillamine, nitroso(acetoxymethyl)methylamine,
nitroso oxine, nitrosoquinolinol, nitrosoglutathione,
nitrosodiisobutylamine, nitrosodiethylamine, nitrosodiethylaniline,
nitrosodisulfonic acid, nitrosodiphenylamine, nitrosodimethylamine,
nitrosonaphthol, nitrosonaphtholdisulfonic acid,
nitrosohydroxyquinoline, nitrosophenylaniline,
nitrosophenylhydroxylamine ammonium, nitrosophenol,
N-[(N-nitrosomethylamino)methyl]benzamide,
2,2'-(hydroxynitrosohydrazono)- bisethanamine,
N-methyl-2-(1-ethyl-2-hydroxy-2-nitrosohydrazino)-ethanamin- e,
N,N'-dinitroso-p-phenylenediamine,
N,N'-dinitrosopentamethylenetetramin- e, dimethylnitrosoaniline,
dimethylnitrosoamine, nitrosonium tetrafluoroborate,
N-[N'-methyl-N'-nitroso(aminomethyl)]benzamide,
N-methyl-N-nitroso-p-toluenesulfonamide, nitrobenzene,
dinitrobenzene, dinitrotoluene, nitronaphthalene,
dinitronaphthalene, dinitrobiphenyl, dimethylnitrotoluene,
dinitropyrene, nitrobenzoic acid ester, dimethylnitrobenzene,
nitroanthracene, nitroisoquinoline, nitroxylene, ethyl
nitroacetate, nitrocyclopentane, nitrostyrene, nitropyrrole,
nitrofurazone, nitrofluraldehyde, nitrohexane, nitrobenzaldehyde,
nitrolignin, 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide,
nitroacrylamide, fluoronitrotoluene, fluoronitrobenzene,
fluoronitrodiphenyl ether, trinitroacetonitrile, trinitroaniline,
trinitrobenzoic acid, trinitroethane, trinitroxylene,
trinitrotoluene, trinitronaphthalene, trinitrofluorenone,
trinitrobenzene, trinitromesitylene, trinitromethane,
trinitroresorcinol, dinitroacetanilide, dinitroanisole,
dinitroanthraquinone, dinitroethane, dinitroethanediamine,
dinitrocarbanilide, dinitroxylene, dinitroglycerol, dinitrocresol,
dinitronaphthol, dinitrophenyl, dinitrophenylhydrazone,
dinitromethane, dinitroresorcinol, nitroamide, nitroanthraquinone,
nitroisophthalic acid, nitroethylene, ethyl nitrocarbamate,
nitroquinaldic acid, nitroguanidine, nitroglycol, nitroglycerin,
nitrodimethylamine, nitrocamphor, methylnitropropane,
nitrosulfathiazole, nitrocellulose, nitrosoguanidine,
nitrosodimethylaniline, nitrosotoluene, nitrosodisulfonic acid,
nitrosopiperidine, nitrosomethane, nitrosobenzene,
nitrosomethylurea, nitronaphthylamine, nitronaphthol,
nitropyridine, nitrophenanthrene, nitrophenylpropiolic acid,
nitrophenetidine, nitrophenolsulfonic acid, nitropentane,
nitroresorcinol, nitrourea, trinitroxylenol, trinitrodiphenyl
ether, trinitrotriazidobenzene, trinitrophloroglucinol,
nitroacridine, nitroacridone, nitroacetone, nitroanilic acid,
nitroaminoacetic acid, nitroisatin, nitroisobutane, nitroindene,
nitrourethane, nitrocarbostyril, nitrodiglycol, nitro-p-cymene,
nitrocinnamaldehyde, N-nitrosoacetanilide, nitrosoanisidine,
nitrosoaniline, nitrosobenzoic acid, nitrosoanthranilic acid,
nitrosocatechol, nitrosocarvacrol, nitrosocresol,
nitrosonaphthylamine, nitrothioanisole, nitrothiophenol,
nitronaphthalenesulfonic acid, nitronaphthylamine, nitronaphthoic
acid, nitronitrosobenzene, nitrohydroquinone, nitropyrogallol,
nitrophenanthridine, nitrophenanthroline, nitrophenylurethane,
nitrophenylurea, nitrobutane, nitrophthalide, nitrofuran,
nitropropylene, nitrophloroglucinol, nitrobenzanilide,
nitrobenzaldoxime, nitrobenzoylformic acid, nitrobenzimidazole,
nitromalonic acid, nitromalondialdehyde, nitromandelic acid,
nitromannitol, nitromethylnaphthalene, nitromalic acid,
nitroresorcinol, nitron, nitrosoresorcinol, aminonitropyrimidine,
trinitrofluorenylidene malononitrile, nitrofluoranthene,
nitrobenzocrown, fluoronitrobenzofurazan,
methylnitronitrosoguanidine, methylnitronitrophenylpyrazolone,
nitrofluorene, nitropropane, nitropropoxyaniline, trinitroanisole,
trinitrocresol, trinitrobenzaldehyde, nitrodiethylaniline,
nitrostilbene, nitrosonaphthalene, nitrosobenzaldehyde,
nitrosomethylurethane, nitrophenylhydrazone, dinitrotartaric acid,
dinitrostilbene, dinitrosoresorcinol, dinitrohydroquinone,
dinitroresorcinol, nitroquinoline, dinitrosophenol,
trinitrosophenol, dinitrosobenzoic acid, trinitrosobenzoic acid,
dinitroacetophenone, trinitroacetophenone, nitrosoacetophenone,
dinitrosoacetophenone, trinitrosoacetophenone, nitrosoanisole,
dinitrosoanisole, trinitrosoanisole and their isomers, salts,
derivatives, coordinate bonded forms and clathrate forms.
[0074] The electrolytic solution for driving an electrolytic
capacitor of the present invention may additionally contain
nitrophenol, nitrobenzoic acid, dinitrobenzoic acid,
nitroacetophenone, nitroanisole or a salt or derivative thereof in
an amount of 0.01 to 10 wt %, together with the nitro or nitroso
compound selected from the above-described nitro compounds and
nitroso compounds.
[0075] The nitro or nitroso compound used here also has an activity
of inhibiting the device from corroding by the action of a
halogenated hydrocarbon such as trichloroethane used in the
cleaning of a printed board (in other words, a halogen-capturing
activity).
[0076] In adding the nitro or nitroso compound to the electrolytic
solution of the present invention, this compound can provide a
satisfactory hydrogen gas absorbing effect and a halogen-capturing
activity even when used individually, because the electrolytic
solution itself has a specific composition effective for obtaining
the effect of the present invention, however, according to the
knowledge acquired this time by the present inventors, when two or
more nitro or nitroso compounds are used in combination, a more
preferred effect can be expected by bringing out respective
advantageous properties. For example, by combining two or more
nitro or nitroso compounds having a quick hydrogen gas absorbing
effect and a delayed hydrogen gas absorbing effect, a hydrogen gas
absorbing effect can be continuously obtained over a long period of
time.
[0077] The nitro or nitroso compound is usually used in an amount
of preferably from 0.01 to 5 wt % based on the entire amount of the
electrolytic solution. If the amount of the nitro or nitroso
compound added is less than 0.01 wt %, the expected effect can be
scarcely obtained, whereas even if it exceeds 5 wt %, the expected
effect cannot be more enhanced and, in the case of a compound
having a low solubility, this may adversely affect other properties
such as precipitation. However, in the case of having an activity
as an electrolyte participating in the electrical conductivity, the
nitro or nitroso compound can be added up to 10 wt %.
[0078] The excellent hydrogen gas absorbing effect of the present
invention can be confirmed also in the relation with the
electrolyte used together. In conventional electrolytic solutions,
only one nitro compound is added to only a carboxylic acid-base
electrolyte or only one nitro compound is added to only an
inorganic acid-base electrolyte. By this means, however, a
satisfactory hydrogen gas absorbing effect cannot be obtained when
the content of water in the solvent is large. The same applies to
an electrolytic solution where a carboxylic acid-base electrolyte
and an inorganic acid-base electrolyte are mixed. However, in the
case of the electrolytic solution of the present invention (using
only one nitro or nitroso compound), surprisingly, a hydrogen gas
absorbing ability can be maintained for a far longer period of time
than the conventional sole use, even in the carboxylic
acid-base/inorganic acid-base mixed electrolytes.
[0079] If desired, the electrolytic solution of the present
invention can contain components other than those described above,
as additional additives. Suitable examples of additives include the
following compounds described in the invention which the present
inventors have invented simultaneously with the present invention
and filed as a separate patent application.
[0080] (1) Chelate compound:
[0081] Examples thereof include ethylenediaminetetraacetic acid
(EDTA), trans-1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid
monohydrate (CyDTA), dihydroxyethylglycine (DHEG),
ethylenediaminetetrakis(methylenep- hosphonic acid) (EDTPO),
diethylenetriamine-N,N,N',N",N"-pentaacetic acid (DTPA),
diaminopropanoltetraacetic acid (DPTA-OH), ethylnediaminediacetic
acid (EDDA), ethylenediamine-N,N'-bis(methylenephosphonic acid)
hemihydrate (EDDPO), glycol ether diaminetetraacetic acid (GEDTA)
and hydroxyethylethylenediaminetriacetic acid (EDTA-OH). Generally,
the chelate compound is preferably added in an amount of 0.01 to 3
wt %. Such a chelate compound can provide effects such as
prolongation of the working life of a capacitor due to inhibition
of the hydration reaction of an aluminum (Al) electrode foil of a
low-impedance capacitor, improvement in the low-temperature
stability of an electrolytic capacitor (the solvent has a
composition close to non-frozen state and therefore, the change in
the impedance between normal temperature and low temperature
decreases), and improvement of corrosion resistance.
[0082] (2) Saccharides:
[0083] Examples thereof include glucose, fructose, xylose and
galactose. Generally, the saccharides are preferably added in an
amount of 0.01 to 5 wt %. These saccharides can provide effects
such as prolongation of the working life of a capacitor due to
inhibition of the hydration reaction of an Al electrode foil of a
low-impedance capacitor, inhibition of decomposition or activation
of an electrolyte (e.g. carboxylic acid) due to the addition of
saccharides, and improvement in the low-temperature stability of an
electrolytic capacitor (the solvent has a composition close to
non-frozen state and therefore, the change in the impedance between
normal temperature and low temperature decreases).
[0084] (3) Hydroxybenzyl alcohol:
[0085] Examples thereof include 2-hydroxybenzyl alcohol,
L-glutamic-diacetic acid and a salt thereof. Generally, this
additive is preferably added in an amount of 0.01 to 5 wt %. This
additive can provide effects such as prolongation of the working
life of a capacitor due to inhibition of the hydration reaction of
an Al electrode foil of a low-impedance capacitor, and improvement
in the low-temperature stability of an electrolytic capacitor (the
solvent has a composition close to non-frozen state and therefore,
the change in the impedance between normal temperature and low
temperature decreases).
[0086] These compounds (1) to (3) each can provide many remarkable
effects when added to the electrolytic solution of the present
invention.
[0087] In addition to the above-described additives (including the
case of adding a sole nitro or nitroso compound), the electrolytic
solution of the present invention can contain, if desired, (4)
gluconic acid, gluconic lactone and the like individually or in
combination. Generally, this additive is preferably added in an
amount of 0.01 to 5 wt %. The gluconic acid or gluconic lactone
additionally contained in the electrolytic solution of the present
invention can provide remarkable effects such as improvement of
corrosion resistance in addition to the effects such as
prolongation of the working life of an electrolytic capacitor and
improvement in the low-temperature stability, and the effects
peculiar to the present invention such as excellent hydrogen gas
absorbing effect.
[0088] Other than the additives described above, additives commonly
used in the field of aluminum electrolytic capacitor or other
electrolytic capacitors may be further added. Suitable examples of
the additives commonly used include mannitol, silane coupling
agent, water-soluble silicone and polymer electrolyte. The
electrolytic solution of the present invention can be prepared by
mixing and dissolving those various components in an arbitrary
order. Fundamentally, a conventional technique can be used as it is
without any modification. For example, the electrolytic solution of
the present invention can be easily prepared by preparing a solvent
having a high water concentration, which is a mixture of an organic
solvent and water, and then dissolving an electrolyte, a nitro or
nitroso compound and if desired, arbitrary additives in the
obtained solvent.
[0089] The electrolytic capacitor of the present invention can also
be produced according to a conventional technique, similarly to the
electrolytic solution. For example, an anode foil and a cathode
foil are prepared by forming an oxide film as a dielectric material
on an electrode foil to a predetermined thickness, these anode and
cathode foils are disposed to face each other and a separator
(release paper) is interposed therebetween. The thus-fabricated
device is impregnated with the electrolytic solution of the present
invention and then packaged by an appropriate method, whereby an
aluminum electrolytic capacitor can be produced. In the obtained
aluminum electrolytic capacitor, the electrolytic solution of the
present invention is used, so that there can be achieved an effect
of improving the low-temperature stability due to a mixed solvent
of an organic solvent and water, a hydrogen gas absorbing effect
due to addition of a nitro compound, and an effect of prolonging
the working life and giving a low impedance resulting from
inhibition of the hydration reaction due to use of a specific
electrolyte.
[0090] Furthermore, according to the present invention, it is
confirmed that a sufficiently high hydrogen absorbing effect can be
exerted even when the nitro or nitroso compound is not present in
the electrolytic solution but when the nitro or nitroso compound is
present in a physically hydrogen-generating site, more
specifically, in the form of a film or the like on the electrode
surface or in the vicinity thereof or in the state of being
contained in the separator. Also when the nitro or nitroso compound
is attached to the inner surface of the capacitor container,
suitable effects are confirmed. Particularly, the site attached
with a current takeout lead of the electrode readily generates
hydrogen and therefore, it is effective to localize a nitro or
nitroso compound thereat. As such, even when the nitro or nitroso
compound is present in a portion inside the capacitor other than in
the electrolytic solution, the effects can be confirmed. Moreover,
in this case, the nitro or nitroso compound can be present also in
the electrolytic solution in addition to the portion except for in
the electrolytic solution, inside the capacitor, and this is a
preferred embodiment.
[0091] In the case of allowing the nitro or nitroso compound to be
present in such a form inside the capacitor, the nitro or nitroso
compound needs not be soluble in the electrolytic solution or may
have a low solubility and this provides an effect of extending the
selection range of the nitro or nitroso compound which can be
used.
[0092] For example, the nitro or nitroso compound is dissolved in a
soluble solvent and the resulting solution is coated on an
electrode (foil or electrode tab) or a separator and if desired,
dried, or the electrode (foil or electrode tab) is dipped in the
solution, whereby the nitro or nitroso compound can be attached to
the separator. The solvent in which the nitro or nitroso compound
is dissolved may or may not be soluble in the electrolytic
solution. This is for the following reasons. Even if the solvent is
soluble or insoluble in the electrolytic solution, the same coated
film results when dried after the coating. In the case where the
solution is not dried and a wet coated film is present, even if the
solvent is soluble, when the solvent has a high viscosity, the
coated film is present in the thin spacing between electrodes for a
long period of time while having a concentration gradient. Also,
even when the solvent is insoluble, it may suffice if the nitro or
nitroso compound can react with hydrogen. That is, the method of
attaching the nitro or nitroso compound or allowing it to be
present on the electrode surface or inner surface of the container
or the method of incorporating the compound into the separator is
not particularly limited. When the nitro or nitroso compound is
present in a portion inside the capacitor other than in the
electrolytic solution, even if a part of the nitro or nitroso
compound dissolves in the electrolytic solution, this causes no
problem.
[0093] In the case of attaching or incorporating the nitro or
nitroso compound to the electrode or separator, the amount thereof
is more than the amount of giving the effects when added to the
electrolytic solution, that is, 0.01% or more in terms of the
electrolytic solution and the amount is optimally from 0.007 to 1
mg/cm.sup.2 (projected area). When the nitro or nitroso compound is
present in the site other than the electrode or separator or when
present also in the electrolytic solution, the amount may be
appropriately corrected.
[0094] Examples of the nitro compound and the nitroso compound
which can be used in such a method include aminonitroanisole,
aminonitrotoluene, aminonitropyridine, aminonitrophenol,
aminonitrophenolsulfonic acid, aminonitrobenzenesulfonic acid,
aminonitrobenzothiazole, aminonitrobenzotrifluoride,
aminonitrobenzonitrile, nitrophenyl isocyanate,
isonitrosoacetophenone, N-ethyl-2-(1-ethyl-2-hydroxy-2-nitros-
ohydrazino)-ethanamine, O-ethyl-O-(p-nitrophenyl)thionobenzene,
ethylnitrobenzene, ethyl-2-(hydroxyimino)-5-nitro-3-hexeneamide,
octanitrobenzoylsaccharose, nitrophenyloctyl ether, nitrophenyl
galactopyranoside, 3-carboxy-4-nitrophenyl disulfide,
bisnitrobenzylfluorescein, glycerol carbonatenitrobenzene
sulfonate, glutamyl nitroanilide, nitrophenyl acetate,
nitrobenzylidene acetate, diaminonitrobenzene,
dithiobisnitrobenzoic acid, dithiobisnitropyridine, dinitroaniline,
dinitroquinoxaline-2,3-dione, dinitrosalicylic acid,
dinitrodiphenylamine, dinitrodiphenylsulfone,
dinitronaphtholsulfonic acid, dinitrobibenzyl,
dinitrophenylaniline, dinitrophenylhydrazine, dinitrophenol,
dinitrophthalic acid, dinitrofluorenone, dinitrofluorobenzene,
dinitrobenzaldehyde, dinitrobenzoylmethylbenzylamin- e,
dinitrobenzophenone, nitroaminothiazole, dimethylnitroaniline,
dimethylnitrophenylphosphorothioate, dimethoxynitrobenzyl alcohol,
bisdinitrophenyl oxalate, succinimidyl nitrophenylacetate,
tetranitrophenyl porphyrin, trinitrophenol, trinitrobenzenesulfonic
acid, nitroacetanilide, nitroazobenzenediol, nitroanisidine,
nitroaniline, nitroanilinesulfonic acid, nitroaminoanisole,
nitroaminotoluene, nitroaminophenol, nitroarginine, ethyl
nitrobenzoate, methyl nitrobenzoate, nitroanthranilic acid,
nitroanthranilonitrile, nitroisatin, nitroimidazole, nitroindazole,
2-nitroindan-1,3-dione, nitroindole, nitrouracil, nitroethanol,
nitroethylbenzene, nitrocatechol, nitroquipazinemaleic acid,
nitrocresol, nitrocinnamic acid, nitrosalicylic acid,
nitrodiazoaminoazobenzene, nitrodiaminobenzene, nitrodiphenylamine,
nitrodimethylaniline, nitrosulfonazo III, nitrothiophene,
nitrotyrosine, nitroterephthalic acid, nitrotoluidine, nitrotoluic
acid, nitropicoline, nitrohydroxyaniline, nitrobiphenyl,
nitropiperonal, nitropyridinol, nitrobarbituric acid,
nitrophenylacetonitrile, nitrophenylazoorcinol,
nitrophenylazonaphthol, nitrophenylazomethylresorcinol,
nitrophenylaniline, nitrophenyloctyl ether,
nitrophenylgalactopyranoside, nitrophenylxylopyranoside,
nitrophenylglucuronide, nitrophenylglucopyranoside,
nitrophenylacetic acid, nitrophenyldodecyl ether,
nitrophenylarsonic acid, nitrophenylhydrazine,
nitrophenylphenylazophenyl triazene, nitrophenylphenyl ether,
nitrophenylmaltopentaoside, nitrophenylmannopyranoside,
nitrophenylbutyric acid, diethyl nitrophenylphosphate,
nitrophenylenediamine, nitrophenethole, nitrophenolarsonic acid,
nitrophenolmethyl ether, nitrophthalimide, nitrophthalic acid,
nitrohumic acid, nitropropionic acid, nitroveratryl alcohol,
nitrobenzylamine, nitrobenzyl alcohol, nitrobenzyldiisopropyliso-
urea, nitrobenzylpyridine, nitrobenzamide, nitrobenzimidazole,
nitrobenzohydrazide, nitrobenzeneazoorcinol,
nitrobenzeneazonaphthol, nitromethane, nitroethane,
nitrobenzeneazoresorcinol, nitrobenzenesulfonic acid,
nitrobenzocoumarin, nitrobenzonitrile, nitrobenzophenone,
nitromesitylene, nitromethoxyaniline, bisnitrophenyl disulfide,
bisnitrophenylsulfone, bismethylthionitroethene,
hydroxynitrobenzoic acid, hydroxynitrotoluene,
hydroxynitropyridine, hydroxynitrophenylarsonic acid,
hydroxynitrobenzaldehyde,
3-[2-hydroxy-l-(1-methylethyl)-2-nitrosohydrazino]-1-propanonamine,
phenylnitroaniline, 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide,
fluoronitroacetanilide, fluoronitroaniline, fluoronitrophenylazide,
fluoronitrophenol, methylnitroaniline, methylnitrophenol,
methylnitropyridine, methylnitropyridine oxide,
methoxynitroaniline, methoxynitrobenzoic acid, methoxynitrophenol,
methoxybenzylaminonitrobenz- ofurazan, nitrophenyl butyrate,
nitronium tetrafluoroborate, nitrophenyl phosphate,
nitrosoacetylpenicillamine, nitroso(acetoxymethyl)methylamine,
nitroso oxine, nitrosoquinolinol, nitrosoglutathione,
nitrosodiisobutylamine, nitrosodiethylamine, nitrosodiethylaniline,
nitrosodisulfonic acid, nitrosodiphenylamine, nitrosodimethylamine,
nitrosonaphthol, nitrosonaphtholdisulfonic acid,
nitrosohydroxyquinoline, nitrosophenylaniline,
nitrosophenylhydroxylamine ammonium, nitrosophenol,
N-[(N-nitrosomethylamino)methyl]benzamide,
2,2'-(hydroxynitrosohydrazono)- bisethanamine,
N-methyl-2-(1-ethyl-2-hydroxy-2-nitrosohydrazino)-ethanamin- e,
N,N'-dinitroso-p-phenylenediamine,
N,N'-dinitrosopentamethylenetetramin- e, dimethylnitrosoaniline,
dimethylnitrosoamine, nitrosonium tetrafluoroborate,
N-[N'-methyl-N'-nitroso(aminomethyl)]benzamide,
N-methyl-N-nitroso-p-toluenesulfonamide, nitrophenol, nitrobenzoic
acid, dinitrobenzoic acid, nitroacetophenone, nitroanisole,
nitrobenzene, dinitrobenzene, dinitrotoluene, nitronaphthalene,
dinitronaphthalene, dinitrobiphenyl, dimethylnitrotoluene,
dinitropyrene, nitrobenzoic acid ester, dimethylnitrobenzene,
nitroanthracene, nitroisoquinoline, nitroxylene, ethyl
nitroacetate, nitrocyclopentane, nitrostyrene, nitropyrrole,
nitrofurazone, nitrofuraldehyde, nitrohexane, nitrobenzaldehyde,
nitrolignin, 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide- ,
nitroacrylamide, fluoronitrotoluene, fluoronitrobenzene,
fluoronitrodiphenyl ether, trinitroacetonitrile, trinitroaniline,
trinitrobenzoic acid, trinitroethane, trinitroxylene,
trinitrotoluene, trinitronaphthalene, trinitrofluorenone,
trinitrobenzene, trinitromesitylene, trinitromethane,
trinitroresorcinol, dinitroacetanilide, dinitroanisole,
dinitroanthraquinone, dinitroethane, dinitroethanediamine,
dinitrocarbanilide, dinitroxylene, dinitroglycerol, dinitrocresol,
dinitronaphthol, dinitrophenyl, dinitrophenylhydrazone,
dinitromethane, dinitroresorcinol, nitroamide, nitroanthraquinone,
nitroisophthalic acid, nitroethylene, ethyl nitrocarbamate,
nitroquinaldic acid, nitroguanidine, nitroglycol, nitroglycerin,
nitrodimethylamine, nitrocamphor, methylnitropropane,
nitrosulfathiazole, nitrocellulose, nitrosomethane,
nitrosoguanidine, nitrosodimethylaniline, nitrosotoluene,
nitrosodisulfonic acid, nitrosopiperidine, nitrosobenzene,
nitrosomethylurea, nitronaphthylamine, nitronaphthol,
nitropyridine, nitrophenanthrene, nitrophenylpropiolic acid,
nitrophenetidine, nitrophenolsulfonic acid, nitropentane,
nitroresorcinol, nitrourea, trinitroxylenol, trinitrodiphenyl
ether, trinitrotriazidobenzene, trinitrophloroglucinol,
nitroacridine, nitroacridone, nitroacetone, nitroanilic acid,
nitroaminoacetic acid, nitroisatin, nitroisobutane, nitroindene,
nitrourethane, nitrocarbostyril, nitrodiglycol, nitro-p-cymene,
nitrocinnamaldehyde, N-nitrosoacetanilide, nitrosoanisidine,
nitrosoaniline, nitrosobenzoic acid, nitrosoanthranilic acid,
nitrosocatechol, nitrosocarvacrol, nitrosocresol,
nitrosonaphthylamine, nitrothioanisole, nitrothiophenol,
nitronaphthalenesulfonic acid, nitronaphthylamine, nitronaphthoic
acid, nitronitrosobenzene, nitrohydroquinone, nitropyrogallol,
nitrophenanthridine, nitrophenanthroline, nitrophenylurethane,
nitrophenylurea, nitrobutane, nitrophthalide, nitrofuran,
nitropropylene, nitrophloroglucinol, nitrobenzanilide,
nitrobenzaldoxime, nitrobenzoylformic acid, nitrobenzimidazole,
nitromalonic acid, nitromalondialdehyde, nitromandelic acid,
nitromannitol, nitromethylnaphthalene, nitromalic acid,
nitroresorcinol, nitron, nitrosoresorcinol, aminonitropyrimidine,
trinitrofluorenylidene malononitrile, nitrofluoranthene,
nitrobenzocrown, fluoronitrobenzofurazan,
methylnitronitrosoguanidine, methylnitronitrophenylpyrazolone,
nitrofluorene, nitropropane, nitropropoxyaniline, trinitroanisole,
trinitrocresol, trinitrobenzaldehyde, nitrodiethylaniline,
nitrostilbene, nitrosonaphthalene, nitrosobenzaldehyde,
nitrosomethylurethane, nitrophenylhydrazone, dinitrotartaric acid,
dinitrostilbene, dinitrosoresorcinol, dinitrohydroquinone,
dinitroresorcinol, nitroquinoline, dinitrosophenol,
trinitrosophenol, dinitrosobenzoic acid, trinitrosobenzoic acid,
dinitroacetophenone, trinitroacetophenone, nitrosoacetophenone,
dinitrosoacetophenone, trinitrosoacetophenone, nitrosoanisole,
dinitrosoanisole, trinitrosoanisole and their isomers, salts,
derivatives, coordinate bonded forms and clathrate forms. Similarly
to the addition of the nitro compound, the capacitor manufactured
as such can achieve a hydrogen gas absorbing effect and an effect
of prolonging the working life and giving a low impedance resulting
from inhibition of the hydration reaction due to the electrolytic
solution using a specific electrolyte.
[0095] In still another aspect, based on the above-described
experimental results and knowledge, the present invention provides
an electrolytic capacitor comprising the electrolytic solution for
driving an electrolytic capacitor of the present invention, and an
electrolytic capacitor comprising a nitro or nitroso compound
inside the capacitor.
[0096] The structure and shape of the electrolytic capacitor using
the electrolytic solution for an electrolytic capacitor of the
present invention are not particularly limited but examples thereof
are briefly described below by referring to FIG. 1. The capacitor 1
comprises a sealing case 3 and a coiled element 5 housed in the
sealing case 3. The element 5 contains an anode foil 9 composed of
an aluminum foil having a surface dielectric film 11 formed by
anodization, an aluminum cathode foil 13 opposing the surface
electrode film 11 of the anode foil 9, and a separator 15 between
the anode foil 11 and the cathode foil 13. The stacked body 7 is
wound together with another separator 17 to provide a coil element
5 and the element is impregnated with an electrolytic solution and
disposed in the case 3. In FIG. 1, an anode lead wire 21 and a
cathode lead wire 23 are connected to the anode foil 11 and the
cathode foil 13, respectively, through respective lead tabs (not
shown). The electrolytic capacitor of the present invention uses
the electrolytic solution for an electrolytic capacitor of the
present invention.
EXAMPLES
[0097] The present invention is described in greater detail below
by referring to Examples. These Examples are only to illustrate the
present invention and, needless to say, the present invention is
not limited thereto.
[0098] The electrolytic solutions used in Examples were measured
for specific resistance at 30.degree. C. and the results are shown
in the Table of each Example. Also, the manufactured electrolytic
capacitors were measured for impedance at low temperature
(-40.degree. C.) and impedance at ordinary temperature (20.degree.
C.), then the impedance ratio (Z ratio) as the ratio of respective
measured values was determined at different frequencies of 120 Hz
and 100 kHz and the values are shown in the Table of each Example.
Furthermore, for evaluating the working life property of each
electrolytic capacitor, the capacitance, tan .delta. and leakage
current were examined each on the initial property (characteristic
value immediately after the manufacture of capacitor) and the
characteristic change after the passing of a predetermined time
while applying a rated voltage under a high-temperature load test
condition of 105.degree. C. and results are shown in the Table of
each Example.
Examples 1 to 10
[0099] An electrolytic capacitor (10 WV-1,000 .mu.F) device having
a coil structure was impregnated with an electrolytic solution
having the composition shown in Table 1 below and housed in an
aluminum case with a bottom such that the lead tab for taking out
the electrode was protruded outside the case, and the opening of
this case was sealed with an elastic sealant to manufacture an
electrolytic capacitor. The results obtained in the characteristic
tests are shown together in Table 1 below.
Comparative Examples 1 to 4
[0100] The procedure of Example 1 was repeated except that in these
examples, for the purpose of comparison, a nitro or nitroso
compound was eliminated from the electrolytic solution used and the
composition of the electrolytic solution was changed as shown in
Table 1 below. The results obtained in the characteristic tests are
shown together in Table 1 below.
1 TABLE 1 Specific Initial Value Composition of Resistance Z Ratio
Leakage Electrolytic at 30.degree. C. 120 Hz 100 kHz Capacitance
tan .delta. Current No. Solution [wt %] [.OMEGA. .multidot. cm]
[-40/20.degree. C.] [-40/20.degree. C.] (.mu.F) [%] [.mu.A]
Comparative Ethylene glycol 90.0 180 4.0 120.0 1002 8.5 6.5 Example
1 Water 5.0 Ammonium adipate 5.0 Comparative Ethylene glycol 60.0
85 1.3 36.1 1008 7.0 6.5 Example 2 Water 30.0 Ammonium adipate 10.0
Comparative Ethylene glycol 45.0 40 1.1 9.7 1014 5.7 6.1 Example 3
Water 40.0 Ammonium adipate 15.0 Comparative Ethylene glycol 30.0
20 1.0 7.9 1023 4.7 6.9 Example 4 Water 50.0 Ammonium adipate 20.0
Example 1 Ethylene glycol 25.0 28 1.1 4.5 1027 5.3 8.2 Water 68.0
Ammonium formate 4.6 Hypophosphorous acid 0.4 Nitrophenol 1.0
Dinitrodiphenylamine 1.0 Example 2 Ethylene glycol 20.0 27 1.1 4.3
1040 5.4 8.4 Water 60.0 Ammonium glutarate 18.0 Sulfamic acid 1.4
Diaminonitrobenzene 0.3 Dinitrophthalic acid 0.3 Example 3 Ethylene
glycol 15.0 26 1.1 4.8 1038 5.3 8.1 Water 60.0 Ammonium adipate
23.0 Phosphorous acid 1.0 Nitroaminothiazole 0.4 Aminonitroanisole
0.6 Example 4 Ethylene glycol 25.0 30 1.1 4.3 1021 5.2 8.0 Water
50.0 Ammonium formate 23.6 Succinic acid 0.4 Dithiobisnitro- 1.0
benzoic acid Example 5 Ethylene glycol 55.0 40 1.0 3.7 1011 6.4 7.9
Water 28.0 Ammonium sulfamate 16.0 Nitrosophenylaniline 1.0 Example
6 Ethylene glycol 59.0 72 1.0 3.9 1002 6.7 7.8 Water 20.0 Ammonium
adipate 19.0 Acetic acid 0.6 Aminonitrophenol 1.4 Example 7
Ethylene glycol 62.0 64 1.0 3.8 1007 6.5 7.9 Water 27.0 Ammonium
glutarate 10.0 Aminonitrophenol- 1.0 sulfonic acid Example 8
Ethylene glycol 38.8 46 1.0 3.6 1018 6.0 8.1 Water 40.0 Ammonium
adipate 20.0 Phosphoric acid 0.2 Nitrobenzoic acid 0.7
Nitroaminophenol 0.9 Example 9 Ethylene glycol 50.0 68 1.0 3.7 1014
6.4 6.2 Water 40.0 Ammonium glutarate 1.3 Ethyl nitrobenzoate 0.6
Example 10 Ethylene glycol 40.0 53 1.0 3.7 1019 6.1 7.8 Water 50.2
Ammonium adipate 8.0 Hypophosphorous acid 0.8 Aminonitrobenzo- 1.0
nitrile After 2,000 Hours at 105.degree. C. Leakage Capacitance tan
.delta. Current No. (.mu.F) [%] [.mu.A] Appearance Comparative 940
8.6 6.2 Example 1 Comparative In all samples, the safety Example 2
vent was actuated in 500 hours due to gas evolution. Comparative In
all samples, the safety Example 3 vent was actuated in 250 hours
due to gas evolution. Comparative In all samples, the safety
Example 4 vent was actuated in 250 hours due to gas evolution.
Example 1 906 6.0 2.9 Example 2 926 6.1 2.9 Example 3 934 5.9 2.8
Example 4 930 5.8 2.9 Example 5 940 7.0 2.4 Example 6 944 7.3 2.4
Example 7 942 7.1 2.6 Example 8 937 6.6 2.9 Example 9 943 7.0 3.3
Example 10 948 6.7 3.1
[0101] As can be seen from these results, in the electrolytic
capacitors using the electrolytic solution of the present
invention, the Z ratio is small, particularly, the Z ratio at a
high frequency of 100 kH is small as compared with those of
Comparative Examples. This reveals that the electrolytic capacitor
using the electrolytic solution of the present invention exhibits
good low-temperature stability over a wide frequency range.
Particularly, in the electrolytic capacitors using the electrolytic
solution of the present invention, when a nitro compound was added
to the electrolytic solution in an amount of 0.01 to 5 wt %, stable
properties were exhibited even after the passage of 2,000 hours at
105.degree. C. and the capacitor itself was free of breakage or
characteristic abnormality ascribable to gas generation. On the
other hand, in all electrolytic capacitors of Comparative Examples
using an electrolytic solution not containing a nitro or nitroso
compound, a safety vent was actuated as a result of expansion of
the case caused by the generation of hydrogen gas at the initial
stage of the high-temperature loading before the passing of 2,000
hours and the capacitor could not be used. It is understood from
these Examples that, according to the present invention, the
prolongation of the working life of an electrolytic capacitor can
be easily achieved.
Examples 11 to 20
[0102] The procedure of Example 1 was repeated except that in these
Examples, the compositions of the electrolytic solutions used were
changed to those shown together in Table 2 below so as to confirm
the effect brought by the simultaneous addition of a chelate
compound and a nitro or nitroso compound. As seen in the Table,
satisfactory results were obtained. In Table 2 below, test results
of Comparative Examples 1 to 4 are also shown.
2 TABLE 2 Specific Initial Value Composition of Resistance Z Ratio
Leakage Electrolytic at 30.degree. C. 120 Hz 100 kHz Capacitance
tan .delta. Current No. Solution [wt %] [.OMEGA. .multidot. cm]
[-40/20.degree. C.] [-40/20.degree. C.] (.mu.F) [%] [.mu.A]
Comparative Ethylene glycol 90.0 180 4.0 120.0 1002 8.5 6.5 Example
1 Water 5.0 Ammonium adipate 5.0 Comparative Ethylene glycol 60.0
85 1.3 36.1 1008 7.0 6.5 Example 2 Water 30.0 Ammonium adipate 10.0
Comparative Ethylene glycol 45.0 40 1.1 9.7 1014 5.7 6.1 Example 3
Water 40.0 Ammonium adipate 15.0 Comparative Ethylene glycol 30.0
20 1.0 7.9 1023 4.7 6.9 Example 4 Water 50.0 Ammonium adipate 20.0
Example 11 Ethylene glycol 20.0 27 1.1 4.3 1040 5.4 8.4 Water 60.0
Ammonium glutarate 18.0 Sulfamic acid 1.4 Diaminonitrobenzene 0.3
Ethylenediamine- 0.3 tetraacetic acid Example 12 Ethylene glycol
15.0 26 1.1 4.8 1038 5.3 8.1 Water 60.0 Ammonium adipate 24.0
Nitroaminothiazole 0.4 Ethylenediamine- 0.6 diacetic acid Example
13 Ethylene glycol 25.0 30 1.1 4.3 1021 5.2 8.0 Water 50.0 Ammonium
succinate 23.6 Benzenesulfonic 0.4 acid Aminonitrotoluene 0.6
Diethylenetriamine- 0.4 pentaacetic acid Example 14 Ethylene glycol
55.0 59 1.0 3.7 1011 6.4 7.9 Water 28.0 Ammonium sulfamate 14.0
Phosphoric acid 2.0 Dinitroaniline 0.6 Ethylenediamine- 0.4
tetraacetic acid Example 15 Ethylene glycol 59.0 72 1.0 3.9 1002
6.7 7.8 Water 20.0 Ammonium adipate 19.0 Boric acid 0.6
Aminonitrophenol 1.0 Ethylenediamine- 0.4 diacetic acid Example 16
Ethylene glycol 62.0 64 1.0 3.8 1007 6.5 7.9 Water 27.0 Ammonium
adipate 10.0 EDTPO 0.1 Nitrosophenol 0.5 Ethylenediamine- 0.4
tetraacetic acid Example 17 Ethylene glycol 38.8 46 1.0 3.6 1018
6.0 8.1 Water 40.0 Ammonium glutarate 20.0 Aminonitrobenzo- 0.3
thiazole EDTPO 0.9 Example 18 Ethylene glycol 50.0 68 1.0 3.7 1014
6.4 6.2 Water 40.0 Ammonium adipate 9.0 Sulfamic acid 0.4 Ethyl 0.2
nitrobenzoate Ethylenediamine- 0.4 diacetic acid Example 19
Ethylene glycol 40.0 53 1.0 3.7 1019 6.1 7.8 Water 50.2 Ammonium
adipate 8.0 Hypophosphorous acid 0.8 Aminonitrobenzo- 0.4 nitrile
Diethylenetriamine- 0.6 pentaacetic acid Example 20 Ethylene glycol
35.1 56 1.0 3.7 1022 6.3 7.9 Water 50.0 Ammonium sulfamate 13.0
Phosphoric acid 1.2 Aminonitrobenzene- 0.3 sulfonic acid
Ethylenediamine- 0.4 tetraacetic acid After 2,000 Hours at
105.degree. C. Leakage Capacitance tan .delta. Current No. [.mu.F]
[%] [.mu.A] Appearance Comparative 940 8.6 6.2 Example 1
Comparative In all samples, the safety vent Example 2 was actuated
in 500 hours due to gas evolution. Comparative In all samples, the
safety vent Example 3 was actuated in 250 hours due to gas
evolution. Comparative In all samples, the safety vent Example 4
was actuated in 250 hours due to gas evolution. Example 11 936 6.0
2.9 Example 12 934 5.9 2.8 Example 13 930 5.8 2.9 Example 14 940
7.8 2.4 Example 15 944 7.3 2.4 Example 16 942 7.1 2.6 Example 17
937 6.6 2.9 Example 18 943 7.0 3.3 Example 19 948 6.7 3.1 Example
20 950 6.9 3.2
Examples 21 to 30
[0103] The procedure of Example 1 was repeated except that in these
Examples, the compositions of the electrolytic solutions used were
changed to those shown together in Table 3 below so as to confirm
the effect brought by the simultaneous addition of saccharides and
a nitro or nitroso compound. As seen in Table 3, satisfactory test
results were obtained. In Table 3 below, the test results of
Comparative Examples 1 to 4 are also shown.
3 TABLE 3 Specific Initial Value Composition of Resistance Z Ratio
Leakage Electrolytic at 30.degree. C. 120 Hz 100 kHz Capacitance
tan .delta. Current No. Solution [wt %] [.OMEGA. .multidot. cm]
[-40/20.degree. C.] [-40/20.degree. C.] (.mu.F) [%] [.mu.A]
Comparative Ethylene glycol 90.0 180 4.0 120.0 1002 8.5 6.5 Example
1 Water 5.0 Ammonium adipate 5.0 Comparative Ethylene glycol 60.0
85 1.3 36.1 1008 7.0 6.5 Example 2 Water 30.0 Ammonium adipate 10.0
Comparative Ethylene glycol 45.0 40 1.1 9.7 1014 5.7 6.1 Example 3
Water 40.0 Ammonium adipate 15.0 Comparative Ethylene glycol 30.0
20 1.0 7.9 1023 4.7 6.9 Example 4 Water 50.0 Ammonium adipate 20.0
Example 21 Ethylene glycol 19.8 30 1.1 4.4 1030 5.2 7.8 Water 60.0
Ammonium glutarate 17.8 Fructose 1.0 Dinitrosalicylic 0.4 acid
Sulfamic acid 1.0 Example 22 Ethylene glycol 14.8 25 1.1 4.7 1027
4.8 7.9 Water 60.0 Ammonium adipate 23.8 Ethyl nitrobenzene 0.5
Xylose 1.0 Example 23 Ethylene glycol 21.2 26 1.1 3.8 1025 5.0 7.8
Water 52.0 Ammonium succinate 24.8 Glucose 1.0 Dinitrophenol 0.6
Benzenesulfonic 0.4 acid Example 24 Ethylene glycol 48.7 51 1.0 4.1
1016 6.2 7.4 Water 40.8 Ammonium borate 9.0 Dinitrobenzophenone 0.5
Xylose 1.0 Example 25 Ethylene glycol 53.2 64 1.0 3.9 1009 6.5 7.7
Water 31.0 Ammonium sulfamate 13.8 Fructose 1.0
Dimethylnitroaniline 0.5 Phosphoric acid 0.5 Example 26 Ethylene
glycol 59.2 59 1.0 3.6 1011 6.2 6.3 Water 20.8 Ammonium adipate
17.8 Glucose 0.5 Ethyl nitrobenzoate 0.7 Boric acid 1.0 Example 27
Ethylene glycol 61.9 66 1.0 3.8 1003 7.2 6.9 Water 27.0 Ammonium
adipate 9.3 Dimethoxynitrobenzyl 0.8 alcohol Fructose 1.0 Example
28 Ethylene glycol 38.2 45 1.0 3.7 1016 5.9 6.6 Water 41.0 Ammonium
glutarate 18.8 Trinitrophenol 1.0 Galactose 1.0 Example 29 Ethylene
glycol 47.7 52 1.0 4.0 1014 6.3 7.1 Water 39.7 Ammonium adipate
10.2 Sulfamic acid 0.4 Nitroaniline 1.0 Xylose 1.0 Example 30
Ethylene glycol 51.2 63 1.0 3.6 1018 6.9 6.7 Water 30.1 Ammonium
succinate 16.2 Boric acid 1.1 Nitroaminophenol 0.4 Glucose 1.0
After 2,000 Hours at 105.degree. C. Leakage Capacitance tan .delta.
Current No. [.mu.F] [%] [.mu.A] Appearance Comparative 940 8.6 6.2
Example 1 Comparative In all samples, the safety Example 2 vent was
actuated in 500 hours due to gas evolution. Comparative In all
samples, the safety Example 3 vent was actuated in 250 hours due to
gas evolution. Comparative In all samples, the safety Example 4
vent was actuated in 250 hours due to gas evolution. Example 21 917
5.8 2.4 Example 22 924 5.4 2.6 Example 23 930 5.6 2.5 Example 24
935 6.8 2.8 Example 25 938 7.1 2.4 Example 26 944 6.8 2.4 Example
27 944 7.8 2.4 Example 28 935 6.5 2.5 Example 29 943 6.9 2.6
Example 30 947 7.5 2.7
Examples 31 to 40
[0104] The procedure of Example 1 was repeated except that, in
these Examples, the compositions of the electrolytic solutions used
were changed to those shown together in Table 4 below so as to
confirm the effect brought by the simultaneous addition of
hydroxybenzyl alcohol, glutamic-diacetic acid or the like and a
nitro or nitroso compound. As seen in Table 4, satisfactory test
results were obtained. In Table 4 below, test results of
Comparative Examples 1 to 4 are also shown.
4 TABLE 4 Specific Initial Value Resistance Z Ratio Leakage
Electrolytic at 30.degree. C. 120 Hz 100 kHz Capacitance tan
.delta. Current No. Solution [wt %] [.OMEGA. .multidot. cm]
[-40/20.degree. C.] [-40/20.degree. C.] (.mu.F) [%] [.mu.A]
Comparative Ethylene glycol 90.0 180 4.0 120.0 1002 8.5 6.5 Example
1 Water 5.0 Ammonium adipate 5.0 Comparative Ethylene glycol 60.0
85 1.3 36.1 1008 7.0 6.5 Example 2 Water 30.0 Ammonium adipate 10.0
Comparative Ethylene glycol 45.0 40 1.1 9.7 1014 5.7 6.1 Example 3
Water 40.0 Ammonium adipate 15.0 Comparative Ethylene glycol 30.0
20 1.0 7.9 1023 4.7 6.9 Example 4 Water 50.0 Ammonium adipate 20.0
Example 31 Ethylene glycol 17.7 26 1.1 4.4 1034 5.0 7.6 Water 61.0
Ammonium 17.2 glutarate Sulfamic acid 1.7 Nitroethanol 1.0
Glutamic-diacetic 1.4 acid Example 32 Ethylene glycol 14.2 23 1.1
4.5 1036 4.8 7.8 Water 60.0 Ammonium adipate 23.4 Nitrophenyl 1.0
acetate Glutamic-diacetic 1.4 acid Example 33 Ethylene glycol 21.0
28 1.1 4.2 1033 5.1 7.8 Water 51.3 Ammonium 24.8 succinate
Benzenesulfonic 0.4 acid Nitroquinoline 0.5 Hydroxybenzyl 2.0
alcohol Example 34 Ethylene glycol 44.7 58 1.2 4.0 1026 6.6 7.4
Water 40.2 Ammonium borate 9.8 Nitrodiphenylamine 1.0 Hydroxybenzyl
4.3 alcohol Example 35 Ethylene glycol 52.2 67 1.0 3.7 1019 6.9 7.9
Water 30.4 Ammonium sulfamate 13.8 Phosphoric acid 0.4
Nitrobiphenyl 0.6 Glutamic-diacetic 2.6 acid Example 36 Ethylene
glycol 57.5 84 1.0 3.6 1013 7.2 6.8 Water 20.7 Ammonium adipate
15.8 Nitrophenylphenyl 1.0 ether Hydroxybenzyl 2.6 alcohol
Glutamic-diacetic 2.2 acid Example 37 Ethylene glycol 58.8 76 1.0
3.8 1015 7.1 6.9 Water 26.4 Ammonium adipate 11.3
Nitrobenzimidazole 0.5 Ammonium glutarate 1.5 Glutamic-diacetic 1.5
acid Example 38 Ethylene glycol 39.6 46 1.0 3.6 1018 6.0 6.7 Water
40.0 Ammonium glutarate 19.0 Nitrophenolmethyl ether 0.4
Hydroxybenzyl alcohol 1.0 Example 39 Ethylene glycol 48.8 54 1.0
3.8 1016 6.3 6.5 Water 39.3 Ammonium adipate 9.4 Sulfamic acid 0.4
Nitrobenzyl alcohol 1.1 Hydroxybenzyl alcohol 1.0 Example 40
Ethylene glycol 51.2 64 1.0 3.6 1016 6.6 6.7 Water 30.1 Ammonium
succinate 16.2 Boric acid 1.1 Nitrophenylaniline 0.4
Glutamic-diacetic acid 1.0 After 2,000 Hours at 105.degree. C.
Leakage Capacitance tan .delta. Current No. [.mu.F] [%] [.mu.A]
Appearance Comparative 940 8.6 6.2 Example 1 Comparative In all
samples, the safety Example 2 vent was actuated in 500 hours due to
gas evolution. Comparative In all samples, the safety Example 3
vent was actuated in 250 hours due to gas evolution. Comparative In
all samples, the safety Example 4 vent was actuated in 250 hours
due to gas evolution. Example 31 920 5.6 2.6 Example 32 932 5.4 2.6
Example 33 930 5.7 2.7 Example 34 944 7.2 2.5 Example 35 948 7.5
2.4 Example 36 944 7.8 2.2 Example 37 944 7.7 2.4 Example 38 937
6.6 2.6 Example 39 945 6.9 2.5 Example 40 945 7.2 2.7
Examples 41 to 50
[0105] The procedure of Example 1 was repeated except that, in
these Examples, the compositions of the electrolytic solutions used
were changed to those shown together in Table 5 below so as to
confirm the effect brought by the simultaneous addition of a nitro
or nitroso compound and gluconic lactone. As seen in Table 5,
satisfactory test results were obtained. In Table 5 below, test
results of Comparative Examples 1 to 4 are also shown.
5 TABLE 5 Specific Initial Value Composition of Resistance Z Ratio
Leakage Electrolytic at 30.degree. C. 120 Hz 100 kHz Capacitance
tan .delta. Current No. Solution [wt %] [.OMEGA. .multidot. cm]
[-40/20.degree. C.] [-40/20.degree. C.] (.mu.F) [%] [.mu.A]
Comparative Ethylene glycol 90.0 180 4.0 120.0 1002 8.5 6.5 Example
1 Water 5.0 Ammonium adipate 5.0 Comparative Ethylene glycol 60.0
85 1.3 36.1 1008 7.0 6.5 Example 2 Water 30.0 Ammonium adipate 10.0
Comparative Ethylene glycol 45.0 40 1.1 9.7 1014 5.7 6.1 Example 3
Water 40.0 Ammonium adipate 15.0 Comparative Ethylene glycol 30.0
20 1.0 7.9 1023 4.7 6.9 Example 4 Water 50.0 Ammonium adipate 20.0
Example 41 Ethylene glycol 25.0 25 1.1 4.6 1033 4.8 7.8 Water 68.0
Ammonium formate 5.4 Hypophosphorous 0.4 acid Gluconic lactone 0.2
Dinitrobenzaldehyde 0.5 Nitrohydroxyaniline 0.5 Example 42 Ethylene
glycol 22.0 28 1.1 4.4 1034 5.1 7.9 Water 59.0 Ammonium glutarate
16.2 Sulfamic acid 1.6 Gluconic lactone 0.2 Nitrodiphenylamine 0.5
Nitrophenylazo- 0.5 naphthol Example 43 Ethylene glycol 16.0 23 1.1
4.1 1025 4.8 7.9 Water 60.0 Ammonium adipate 22.8 Gluconic lactone
0.2 Nitrophenylaniline 0.5 Nitrohydroxyaniline 0.5 Example 44
Ethylene glycol 23.0 22 1.1 4.0 1021 4.8 7.8 Water 50.0 Ammonium
succinate 25.4 Benzenesulfonic acid 0.4 Gluconic lactone 0.2
Hydroxynitrobenzoic 1.0 acid Example 45 Ethylene glycol 48.0 56 1.2
4.0 1025 6.6 7.5 Water 40.0 Ammonium borate 10.8 Gluconic lactone
0.2 Nitrophenylacetic 1.0 acid Example 46 Ethylene glycol 54.0 63
1.0 3.8 1016 6.8 7.1 Water 30.0 Ammonium sulfamate 14.4 Phosphoric
acid 0.4 Gluconic lactone 0.2 Nitrosodiphenylamine 1.0 Example 47
Ethylene glycol 60.0 82 1.0 3.6 1013 7.1 6.9 Water 20.0 Ammonium
adipate 18.4 Boric acid 0.4 Gluconic lactone 0.2 Nitrophenolmethyl
1.0 ether Example 48 Ethylene glycol 62.0 78 1.0 3.8 1015 7.1 6.8
Water 27.2 Ammonium adipate 10.0 Gluconic lactone 0.2 Nitrophthalic
acid 0.8 Nitrophenol 0.8 Example 49 Ethylene glycol 40.0 44 1.0 3.6
1018 5.9 6.7 Water 40.0 Ammonium glutarate 18.8 Gluconic lactone
0.2 Nitroaminotoluene 1.0 Example 50 Ethylene glycol 50.0 58 1.0
3.7 1013 6.4 6.9 Water 39.6 Ammonium adipate 9.2 Sulfamic acid 0.4
Gluconic lactone 0.2 Nitrosalicylic 0.6 acid After 2,000 Hours at
105.degree. C. Leakage Capacitance tan .delta. Current No. [.mu.F]
[%] [.mu.A] Appearance Comparative 940 8.6 6.2 Example 1
Comparative In all samples, the safety vent Example 2 was actuated
in 500 hours due to gas evolution. Comparative In all samples, the
safety vent Example 3 was actuated in 250 hours due to gas
evolution. Comparative In all samples, the safety vent Example 4
was actuated in 250 hours due to gas evolution. Example 41 888 5.6
2.4 Example 42 900 5.9 2.6 Example 43 902 5.6 2.5 Example 44 919
5.6 2.4 Example 45 933 7.4 2.5 Example 46 935 7.6 2.4 Example 47
942 7.9 2.4 Example 48 949 7.9 2.4 Example 49 937 6.5 2.5 Example
50 942 7.0 2.4
Examples 51 to 60
[0106] The procedure of Example 1 was repeated except that in these
Examples, the compositions of the electrolytic solutions used were
changed to those shown together in Table 6 below so as to confirm
the effect brought by the arbitrary combination of various
additives. As seen in Table 6, satisfactory test results were
obtained. In Table 6 below, test results of Comparative Examples 1
to 4 are also shown.
6 TABLE 6 Specific Initial Value Composition of Resistance Z Ratio
Leakage Electrolytic at 30.degree. C. 120 Hz 100 kHz Capacitance
tan .delta. Current No. Solution [wt %] [.OMEGA. .multidot. cm]
[-40/20.degree. C.] [-40/20.degree. C.] (.mu.F) [%] [.mu.A]
Comparative Ethylene glycol 90.0 180 4.0 120.0 1002 8.5 6.5 Example
1 Water 5.0 Ammonium adipate 5.0 Comparative Ethylene glycol 60.0
85 1.3 36.1 1008 7.0 6.5 Example 2 Water 30.0 Ammonium adipate 10.0
Comparative Ethylene glycol 45.0 40 1.1 9.7 1014 5.7 6.1 Example 3
Water 40.0 Ammonium adipate 15.0 Comparative Ethylene glycol 30.0
20 1.0 7.9 1023 4.7 6.9 Example 4 Water 50.0 Ammonium adipate 20.0
Example 51 Ethylene glycol 24.3 24 1.1 4.6 1044 4.8 7.7 Water 67.9
Ammonium formate 5.0 Hypophosphorous acid 0.4 Ethylenediamine- 0.5
tetraacetic acid Glutamic-diacetic 0.2 acid Gluconic lactone 0.2
Nitrobenzyl alcohol 1.0 Nitromethoxyaniline 0.5 Example 52 Ethylene
glycol 18.0 27 1.1 4.4 1034 5.0 7.8 Water 60.0 Ammonium glutarate
17.0 Sulfamic acid 1.6 Diethylenetriamine- 1.0 pentaacetic acid
Fructose 1.0 Gluconic lactone 0.2 Methoxynitroaniline 0.6
Hydroxynitrotoluene 0.6 Example 53 Ethylene glycol 15.0 23 1.1 4.3
1025 4.8 7.9 Water 58.1 Ammonium adipate 23.0 Ethylenediamine- 2.0
tetraacetic acid Hydroxybenzyl 0.5 alcohol Gluconic lactone 0.2
Methoxynitrobenzoic 0.6 acid Nitrotoluidine 0.6 Example 54 Ethylene
glycol 20.6 28 1.1 4.1 1020 5.0 7.5 Water 50.6 Ammonium succinate
26.2 Ethylenediamine- 1.0 diacetic acid Glutamic-diacetic 0.2 acid
Benzenesulfonic acid 0.4 Gluconic lactone 0.2 Nitrobenzophenone 0.8
Example 55 Ethylene glycol 46.7 56 1.2 4.0 1024 6.6 7.6 Water 40.4
Ammonium borate 10.8 Ethylenediamine- 0.8 diacetic acid
Hydroxybenzyl 0.5 alcohol Gluconic lactone 0.2 Nitrobenzenesulfonic
0.6 acid Example 56 Ethylene glycol 52.0 66 1.0 3.7 1020 6.9 7.5
Water 30.4 Ammonium sulfamate 14.4 Xylose 0.5 EDTPO 1.0
Glutamic-diacetic 0.5 acid Phosphoric acid 0.4 Gluconic lactone 0.2
Nitroethylbenzene 0.6 Example 57 Ethylene glycol 58.0 85 1.0 3.6
1013 7.1 7.0 Water 19.5 Ammonium adipate 18.4 Ethylenediamine- 1.5
tetraacetic acid Hydroxybenzyl 0.5 alcohol Glutamic-diacetic 0.5
acid Boric acid 0.4 Gluconic lactone 0.2 Methoxynitrophenol 1.0
Example 58 Ethylene glycol 57.5 75 1.0 3.8 1015 7.0 7.2 Water 27.8
Ammonium adipate 8.8 Diethylenetriamine- 3.0 pentaacetic acid
Glucose 1.0 Hydroxybenzyl 0.5 alcohol Gluconic lactone 0.2
Nitrothiophene 0.6 Nitrosodiphenylamine 0.6 Example 59 Ethylene
glycol 47.5 58 1.0 3.7 1015 6.1 7.0 Water 39.8 Ammonium adipate 9.0
Hydroxybenzyl 1.0 alcohol EDTPO 1.0 Fructose 0.5 Sulfamic acid 0.4
Gluconic lactone 0.2 Diethyl nitrophenyl- 0.6 phosphate Example 60
Ethylene glycol 50.0 67 1.0 3.6 1018 6.5 6.9 Water 29.6 Ammonium
succinate 16.0 Xylose 0.5 Ethylenediamine- 2.0 tetraacetic acid
Hydroxybenzyl 0.5 alcohol Gluconic lactone 0.2 Nitrophenylaceto-
0.6 nitrile Hydroxynitrobenz- 0.6 aldehyde After 2,000 Hours at
105.degree. C. Leakage Capacitance tan .delta. Current No. [.mu.F]
[%] [.mu.A] Appearance Comparative 940 8.6 6.2 Example 1
Comparative In all samples, the safety Example 2 vent was actuated
in 500 hours due to gas evolution. Comparative In all samples, the
safety Example 3 vent was actuated in 250 hours due to gas
evolution. Comparative In all samples, the safety Example 4 vent
was actuated in 250 hours due to gas evolution. Example 51 898 5.6
2.4 Example 52 900 5.8 2.5 Example 53 902 5.6 2.4 Example 54 918
5.8 2.6 Example 55 932 7.4 2.5 Example 56 938 7.7 2.6 Example 57
942 7.9 2.4 Example 58 949 7.8 2.6 Example 59 944 6.7 2.6 Example
60 947 7.1 2.6
Examples 61 to 70
[0107] The procedure of Example 1 was repeated except that in these
Examples, the conditions for the measurement of capacitor
properties by a high-temperature load test at 105.degree. C. while
applying a rated voltage employed in Example 1 were changed to the
passing of 8,000 hours at 105.degree. C. so as to confirm an
improvement in the working life property. The results obtained are
shown in Table 7 below.
7 TABLE 7 Specific Initial Value Composition of Resistance Z Ratio
Leakage Electrolytic at 30.degree. C. 120 Hz 100 kHz Capacitance
tan .delta. Current No. Solution [wt %] [.OMEGA. .multidot. cm]
[-40/20.degree. C.] [-40/20.degree. C.] (.mu.F) [%] [.mu.A]
Comparative Ethylene glycol 90.0 180 4.0 120.0 1002 8.5 6.5 Example
1 Water 5.0 Ammonium adipate 5.0 Comparative Ethylene glycol 60.0
85 1.3 36.1 1008 7.0 6.5 Example 2 Water 30.0 Ammonium adipate 10.0
Comparative Ethylene glycol 45.0 40 1.1 9.7 1014 5.7 6.1 Example 3
Water 40.0 Ammonium adipate 15.0 Comparative Ethylene glycol 30.0
20 1.0 7.9 1023 4.7 6.9 Example 4 Water 50.0 Ammonium adipate 20.0
Example 61 Ethylene glycol 25.0 28 1.1 4.5 1027 5.3 8.2 Water 68.0
Ammonium formate 4.6 Hypophosphorous acid 0.4 Nitrophenol 1.0
Dinitrodiphenylamine 1.0 Example 62 Ethylene glycol 20.0 27 1.1 4.3
1040 5.4 8.4 Water 60.0 Ammonium glutarate 18.0 Sulfamic acid 1.4
Diaminonitrobenzene 0.3 Dinitrophthalic acid 0.3 Example 63
Ethylene glycol 15.0 26 1.1 4.8 1038 5.3 8.1 Water 60.0 Ammonium
adipate 23.0 Phosphorous acid 1.0 Nitroaminothiazole 0.4
Aminonitroanisole 0.6 Example 64 Ethylene glycol 25.0 30 1.1 4.3
1021 5.2 8.0 Water 50.0 Ammonium formate 23.6 Succinic acid 0.4
Dithiobisnitro- 1.0 benzoic acid Example 65 Ethylene glycol 55.0 40
1.0 3.7 1011 6.4 7.9 Water 28.0 Ammonium sulfamate 16.0
Nitrosophenylaniline 1.0 Example 66 Ethylene glycol 59.0 72 1.0 3.9
1002 6.7 7.8 Water 20.0 Ammonium adipate 19.0 Acetic acid 0.6
Aminonitrophenol 1.4 Example 67 Ethylene glycol 62.0 64 1.0 3.8
1007 6.5 7.9 Water 27.0 Ammonium glutarate 10.0 Aminonitrophenol-
1.0 sulfonic acid Example 68 Ethylene glycol 38.8 46 1.0 3.6 1018
6.0 8.1 Water 40.0 Ammonium adipate 20.0 phosphoric acid 0.2
Nitrobenzoic acid 0.7 Nitroaminophenol 0.9 Example 69 Ethylene
glycol 50.0 68 1.0 3.7 1014 6.4 6.2 Water 40.0 Ammonium glutarate
1.3 Ethyl nitrobenzoate 0.6 Example 70 Ethylene glycol 40.0 Water
50.2 Ammonium adipate 8.0 53 1.0 3.7 1019 6.1 7.8 Hypophosphorous
acid 0.8 Aminonitrobenzo- 1.0 nitrile After 8,000 Hours at
105.degree. C. Leakage Capacitance tan .delta. Current No. [.mu.F]
[%] [.mu.A] Appearance Comparative 940 8.6 6.2 Example 1
Comparative In all samples, the safety vent Example 2 was actuated
in 500 hours due to gas evolution. Comparative In all samples, the
safety vent Example 3 was actuated in 250 hours due to gas
evolution. Comparative In all samples, the safety vent Example 4
was actuated in 250 hours due to gas evolution. Example 61 812 6.5
2.2 Example 62 820 6.8 2.8 Example 63 815 6.3 2.5 Example 64 In all
samples, the safety vent was actuated in 3,000 hours due to gas
evolution. Example 65 In all samples, the safety vent was actuated
in 3,000 hours due to gas evolution. Example 66 In all samples, the
safety vent was actuated in 4,000 hours due to gas evolution.
Example 67 In all samples, the safety vent was actuated in 5,000
hours due to gas evolution. Example 68 809 7.1 2.3 Example 69 In
all samples, the safety vent was actuated in 4,000 hours due to gas
evolution. Example 70 813 7.0 2.6
[0108] As can be seen from the results shown in Table 7 above, in
Comparative Examples 2 to 4 using an electrolytic solution
containing 20 wt % or more of water in the solvent and not
containing a nitro or nitroso compound, all capacitors broke down
between 250 and 500 hours. In Examples 64, 65, 67 and 69, the
capacitors showed abnormality in the properties in 3,000 to 5,000
hours. On the other hand, in Examples 61, 62, 63, 68 and 70, the
capacitors maintained very good properties even after the passage
of 8,000 hours. Furthermore, it is noticeable that the working life
property of the electrolytic capacitor was improved by using a
carboxylic acid or a salt thereof as the organic electrolyte and an
inorganic acid as the inorganic electrolyte in combination.
Examples 71 to 75 and Comparative Examples 5 to 10
[0109] Using the capacitor element used in Example 1, capacitors
were manufactured. Capacitors for comparison were manufactured
using an electrolytic solution not containing a nitro or nitroso
compound and capacitors of 10wv-1,000 .mu.F were manufactured using
a capacitor element where a predetermined amount of a
solvent-soluble nitro or nitroso compound was attached to the
separator of the electrolytic capacitor element and, similarly to
the capacitors for comparison, using an electrolytic solution not
containing a nitro or nitroso compound. These capacitors were
subjected to a load test at 105.degree. C. As for the means for
attaching a nitro or nitroso compound to the separator, a method of
preparing a water/alcohol solution containing from 1 to 5 wt % of a
nitro or nitroso compound and directly spraying a constant amount
of the solution by an atomizer at the time of taking up the
capacitor element, to attach the nitro or nitroso compound, was
employed. The amount attached was confirmed by measuring the weight
and set to an amount more than the minimum amount effective when
the nitro or nitroso compound is contained in the electrolytic
solution.
[0110] The results are shown in Table 8.
8 TABLE 8 Composition of Electrolytic Specific Initial Value
Solution, Separator Resistance Z Ratio Leakage Constituting at
30.degree. C. 120 Hz 100 kHz Capacitance tan .delta. Current No.
Capacitor Element [wt %] [.OMEGA. .multidot. cm] [-40/20.degree.
C.] [-40/20.degree. C.] [.mu.F] [%] [.mu.A] Comparative Ethylene
glycol 90.0 180 4.0 120.0 1002 8.5 6.5 Example 1 Water 5.0 Ammonium
adipate 5.0 Comparative Ethylene glycol 60.0 40 1.3 36.1 1011 7.1
6.6 Example 5 Water 30.0 Ammonium adipate 10.0 Normal separator
Comparative Ethylene glycol 45.0 20 1.1 9.7 1016 5.8 6.2 Example 6
Water 40.0 Ammonium sulfamate 15.0 Normal separator Comparative
Ethylene glycol 30.0 20 1.0 7.9 1024 4.8 6.8 Example 7 Water 50.0
Ammonium adipate 20.0 Normal separator Example 71 Ethylene glycol
60.0 85 1.3 36.1 1013 7.2 6.8 Water 30.0 Ammonium adipate 10.0
Dinitrobenzoic acid-coated separator Example 72 Ethylene glycol
45.0 20 1.1 9.7 1015 5.9 6.5 Water 40.0 Ammonium Sulfamate 15.0
Hydroxynitrobenzoic acid-coated separator Example 73 Ethylene
glycol 30.0 20 1.0 7.9 1021 4.7 6.7 Water 50.0 Ammonium adipate
20.0 Trinitrophenol- coated separator Example 74 Ethylene glycol
45.0 Water 40.0 Ammonium adipate 15.0 40 1.1 9.7 1015 5.9 6.5
Nitrosodimethyl- amine-coated separator Example 75 Ethylene glycol
30.0 20 1.0 7.9 1021 4.7 6.7 Water 50.0 Ammonium adipate 20.0
Nitroquinoline- coated separator After 1,000 Hours at 105.degree.
C. Leakage Capacitance tan .delta. Current No. [.mu.F] [%] [.mu.A]
Appearance Comparative 940 8.6 6.2 Example 1 Comparative In all
samples, the safety Example 5 vent was actuated in 500 hours due to
gas evolution. Comparative In all samples, the safety Example 6
vent was actuated in 250 hours due to gas evolution. Comparative In
all samples, the safety Example 7 vent was actuated in 250 hours
due to gas evolution. Example 71 907 7.9 2.9 Example 72 903 6.5 2.9
Example 73 909 5.3 2.9 Example 74 903 6.5 2.9 Example 75 909 5.3
2.9
[0111] In Comparative Examples, all capacitors were broken down
before 500 hours, whereas capacitors using a separator attached
with a nitro or nitroso compound exhibited very good properties
even after the passage of 1,000 hours.
Examples 76 to 80
[0112] Electrolytic capacitors as Comparative Examples were
manufactured using an electrolytic solution not containing a nitro
or nitroso compound and capacitors of 10 wv-1,000 .mu.F were
manufactured using a capacitor element where a predetermined amount
of a solvent-soluble nitro or nitroso compound was coated on the
electrode foil of the electrolytic capacitor element and using the
same electrolytic solution as in Comparative Examples. These
capacitors were subjected to a load test at 105.degree. C. As for
the means for coating a nitro or nitroso compound to the electrode
foil surface, a water/alcohol solution containing from 1 to 5 wt %
of a nitro or nitroso compound was prepared and an operation of
dipping an electrode foil previously cut into a belt form in a
solution having dissolved therein a nitro or nitroso compound was
repeated to attach a predetermined amount of nitro or nitroso
compound. Also, similarly to the separator, coating by spraying was
attempted. The amount attached was confirmed by measuring the
weight and set to an amount more than the minimum amount effective
when the nitro or nitroso compound is contained in the electrolytic
solution.
[0113] The results are shown in Table 9.
9 TABLE 9 Composition of Specific Initial Value Electrolytic
Resistance Z Ratio Leakage Solution, form of at 30.degree. C. 120
Hz 100 kHz Capacitance tan .delta. Current No. electrode foil [wt
%] [.OMEGA. .multidot. cm] [-40/20.degree. C.] [-40/20.degree. C.]
(.mu.F) [%] [.mu.A] Comparative Ethylene glycol 90.0 180 4.0 120.0
1002 8.5 6.5 Example 1 Water 5.0 Ammonium adipate 5.0 Comparative
Ethylene glycol 60.0 40 1.3 36.1 1011 7.1 6.6 Example 8 Water 30.0
Ammonium adipate 10.0 Normal anode foil Comparative Ethylene glycol
45.0 20 1.1 9.7 1016 5.8 6.2 Example 9 Water 40.0 Ammonium
sulfamate 15.0 Normal anode foil Comparative Ethylene glycol 30.0
20 1.0 7.9 1024 4.8 6.8 Example 10 Water 50.0 Ammonium adipate 20.0
Normal cathode foil Example 76 Ethylene glycol 60.0 40 1.1 9.7 1012
5.8 6.5 Water 30.0 Ammonium adipate 10.0 Dinitrobenzoic acid-
coated anode foil Example 77 Ethylene glycol 45.0 20 1.1 6.4 1010
4.2 6.5 Water 40.0 Ammonium Sulfamate 15.0 Hydroxynitrobenzoic
acid-coated cathode foil Example 78 Ethylene glycol 30.0 20 1.2 8.5
1015 4.8 7 Water 50.0 Ammonium adipate 20.0 Nitrosodimethyl-
amine-coated cathode foil Example 79 Ethylene glycol 30.0 20 1.0
7.9 1020 4.8 6.8 Water 50.0 Ammonium adipate 20.0
Trinitrophenol-coated cathode foil Example 80 Ethylene glycol 30.0
20 1.0 7.9 1019 4.8 6.7 Water 50.0 Ammonium adipate 20.0
Nitroquinoline-coated anode foil After 1,000 Hours at 105.degree.
C. Leakage Capacitance tan .delta. Current No. [.mu.F] [%] [.mu.A]
Appearance Comparative 940 8.6 6.2 Example 1 Comparative In all
samples, the safety Example 8 vent was actuated in 500 hours due to
gas evolution. Comparative In all samples, the safety Example 9
vent was actuated in 250 hours due to gas evolution. Comparative In
all samples, the safety Example 10 vent was actuated in 250 hours
due to gas evolution. Example 76 901 6.4 2.9 Example 77 899 4.8 3.1
Example 78 900 5.3 3.5 Example 79 908 5.4 3.2 Example 80 907 5.4
3.0
[0114] In Comparative Examples, all capacitors were broken down
before 500 hours, whereas capacitors using an electrode foil coated
with a nitro or nitroso compound exhibited very good properties
even after the passage of 1,000 hours.
[0115] These results reveal that even if a nitro or nitroso
compound is not present in the electrolytic solution, when a nitro
or nitroso compound is present in the capacitor element, the
working life is greatly improved.
[0116] While the present invention is described by referring to
various suitable Examples, needless to say, the present invention
is not limited to these Examples and contents in the claims and
various changes and modifications can be made therein without
departing from the spirit and scope of the invention. For example,
although a coil-shape capacitor element is used in Examples, a
stacked layer-type capacitor element can also be used in the same
manner.
Industrial Applicability
[0117] According to the present invention, there is provided an
electrolytic solution for driving an electrolytic capacitor, which
ensures a low impedance, excellent low-temperature stability
represented by the impedance ratio between low temperature and
ordinary temperature, and good working life and can exert an
excellent hydrogen gas absorbing effect even when an electrolytic
solution using a solvent having a large water content ratio is used
or the electrolytic capacitor is used in a high-temperature
environment. Furthermore, according to the present invention, there
is provided an electrolytic capacitor, particularly, an aluminum
electrolytic capacitor using this electrolytic solution, which has
a low impedance, an excellent low-temperature stability, good
working life property and high reliability and is free of failure
ascribable to the action of water used in the solvent. In addition,
the latitude in the type and presence of the nitro or nitroso
compound as the compound added to achieve these purposes is widened
and the utilization thereof is expanded.
* * * * *