Europaisches Patentamt
(19)
J
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European Patent Office
Office europeen des brevets
EP
(1 1)
0 758
131
E U R O P E A N PATENT A P P L I C A T I O N
(12)
ation A3:
(88) Date of publication
20.08.1997 Bulletin 1997/34
(51) |nt. CI.6: H01 C 7 / 0 2
(43) Date of publication A2:
12.02.1997 Bulletin 1997/07
(21) Application number: 96111794.2
(22) Date of filing: 22.07.1996
• Takaya, Minoru
Chuo-ku, Tokyo (JP)
• Moriya, Shigeru
Chuo-ku, Tokyo (JP)
• Kobuke, Hisashi
Chuo-ku, Tokyo (JP)
• Hamada, Munemitsu
Chuo-ku, Tokyo (JP)
(84) Designated Contracting States:
DE FR GB SE
(30) Priority: 25.07.1995
27.09.1995
23.01 .1996
13.06.1996
JP 189096/95
J P 273550/95
JP 9084/96
JP 174231/96
(71) Applicant: TDK Corporation
Chuo-ku, Tokyo (JP)
(74) Representative: Grunecker, Kinkeldey,
Stockmair & Schwanhausser
Anwaltssozietat
Maximilianstrasse 58
8053s Munchen (DE)
(72) Inventors:
• Tosaka, Hisanao
Chuo-ku, Tokyo (JP)
(54)
Organic PTC thermistor
An organic PTC thermistor having a positive
(57)
temperature coefficient of resistivity, which comprises a
PTC composition comprising an organic polymer having
dispersed therein a conductive substance, and at least
one pair of electrodes, wherein the conductive substance is tungsten carbide powder; or the electrodes
each comprise a metal mesh and a metal layer.
FIG.
1(a)
2a
CO
<
CO
CO
10
r»o
Q_
LU
Printed by Rank Xerox (UK)Business Services
2.14.12/3.4
FIG.
Kb)
A3
EP 0 758 131 A3
European Patent
Office
APPHCa,i°n ^
EP 96 11 1794
EUROPEAN SEARCH REPORT
DOCUMENTS CONSIDERED TO BE RELEVANT
Citation of document with indication, where appropriate,
Relevant
.
l'rate8ory
of relevant passages
to claim
X
WO 91 19297 A (ASEA BROWN BOVERI) 12
December 1991
* the whole document *
A
EP 0 045 630 A (RAYCHEM CORP) 10 February
1982
* the whole document *
CLASSIFICATION OF THE
APPLICATION (Int.C1.6)
1,3,5-7, H01C7/02
9,11,12,
14,15
1,3,5,6,
8,9,11,
12,14,15
A
JOURNAL OF MATERIALS SCIENCE,
vol. 26, no. 1, 1 January 1991,
pages 145-154, XP000371800
SHROUT T R ET AL: "COMPOSITE PTCR
THERMISTORS UTILIZING CONDUCTING BORIDES,
SILICIDES, AND CARBIDE POWDERS"
* the whole document *
1,3,4,
11,17
A
DATABASE WPI
Section Ch. Week 9049
Derwent Publications Ltd., London, GB;
M a « AU. AN 90-165449
XP002033303
& JP 02 263 877 A (TEIK0KU TSUSHIN K0GY0
KK) , 26 October 1990
* abstract *
1-3,11,
17
technical fields
searched
<in..a.6>
H01C
A
PATENT ABSTRACTS OF JAPAN
1,5,6,
vol. 017, no. 460 (E-1419), 23 August 1993 11,12
& JP 05 109502 A (DAIT0 TSUSHINKI KK) , 30
April 1993,
* abstract *
A
DE 33 11 051 A (SIEMENS AG) 27 September
1984
* page 10, line 1 - page 14, line 4;
figures 1,2 *
1,5,11,
17
-/-The present search report has been drawn up for all claims
Dateof completion of the search
Place of search
18 June 1997
THE HAGUE
CATEGORY OF CITED DOCUMENTS
X: particularly relevant if taken alone
Y: particularly relevant if combined with another
document of the same category
O: non-written disclosure
P : intermediate document
Examiner
Gorun, M
T : theory or principle underlying the invention
E : earlier patent document, but published on, or
after the filing date
D: document cited in the application
L: document cited for other reasons
&: member of the same patent family, corresponding
document
2
EP 0 758 131 A3
J
)
European Patent
Office
Application Number
EP 96 11 1794
EUROPEAN SEARCH REPORT
DOCUMENTS CONSIDERED TO BE RELEVANT
Citation of document with indication, where appropriate,
Relevant
Category
of relevant passages
to claim
PATENT ABSTRACTS OF JAPAN
vol. 012, no. 194 (P-713), 7 June 1988
& JP 62 299833 A (MATSUSHITA GRAPHIC
COMMUN SYST INC), 26 December 1987,
* abstract *
CLASSIFICATION OF THE
APPLICATION (Int.CI.6)
18-20
TECHNICAL FIELDS
SEARCHED (lnt.CI.6)
The present search report has been drawn up for all claims
Date of conplettoa of the search
Place of search
THE HAGUE
18 June 1997
CATEGORY OF CITED DOCUMENTS
X: particularly relevant if taken alone
Y: particularly relevant if combined with another
document of the same category
A: technological background
O : non-written disclosure
P : intermediate document
Exaniaer
Gorun, M
T : theory or principle underlying the invention
E : earlier patent document, but published on, or
after the filing date
D: document cited in the application
L: document cited for other reasons
&: member of the same patent family, corresponding
document
3