US4664900A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrically conductive compositions
Assignee: DENKI KSGAKU KOGYO KK
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Filing: 1985-03-28
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Granted: 1987-05-12
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Expires: 2005-03-28
Abstract
Abstract An electrically conductive composition comprises 100 parts by weight of synthetic resin and/or rubber, 5 to 100 parts by weight of a conductivity-affording agent, and 1 to 100 parts by weight of carbon fiber. The agent used is carbon or acetylene black having resistivity of no higher than 0.3 Ωcm, a hydrochloric acid absorption of 20 to 40 ml/5 g and a specific surface area of 100 to 400 m 2 /g, which is obtained by continuous thermal cracking of acethlene gas by a mixed gas flow of oxygen-containing gas and steam in the presence or absence of unsaturated hydrocarbons.
Inventors
- 👤 Yuji Miyazaki
- 👤 Akio Nishijima
- 👤 Kiyomiki Kawanami
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 11:59
CPC Classifications
C; C08; C08K; C08K3/00; C08K3/02; C08K3/04; C09; C09C; C09C1/00; C09C1/44; C09C1/48; C09C1/54; H; H01; H01B; H01B1/00; H01B1/20; H01B1/24; C01; C01P; C01P2004/00; C01P2004/60; C01P2004/64; C01P2006/00; C01P2006/12
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
97 words
Acetylene black having an electrical resistivity of no higher than 0.03 Ωcm at a pressure of 50 kg/cm 2 , a hydrochloric acid absorption of 20 to 40 ml/5 g and a specific surface area of 100 to 400 m 2 /g, which is obtained by continuous thermal cracking at a temperature of no less than 800° C. of acetylene gas by a mixed gas flow of oxygen-containing gas and dry steam, said oxygen-containing gas having the relation a +(b/2 )<1 in molar units, where 0<a<1 and 0<b<2 with respect to steam b as pure oxygen a.
Claim 2
Dependent Claim
97 words
Acetylene black having an electrical resistivity of no higher than 0.03 Ωcm at a pressure of 50 kg/cm 2 , a hydrochloric acid absorption of 20 to 40 ml/5 g and a specific surface area of 100 to 400 m 2 /g, which is obtained by continuous thermal cracking at a temperature of no less than 800° C. of acetylene gas by a mixed gas flow of oxygen-containing gas and dry steam, said oxygen-containing gas having the relation a +(b/2 )<1 in molar units, where 0<a<1 and 0<b<2 with respect to steam b as pure oxygen a.
Claim 3
Dependent Claim
20 words
Acetylene black as claimed in claim 1, wherein: (a) said thermal cracking occurring in the presence of an unsaturated hydrocarbon.
Claim 4
Dependent Claim
31 words
Acetylene black as claimed in claim 2, in which the amount of said unsaturated hydrocarbons is no less than 40 parts by weight per 100 parts by weight of acetylene gas.
Claim 5
Dependent Claim
24 words
Acetylene black as claimed in claim 2, in which said unsaturated hydrocarbon is at least one of ethylene, propylene, butadiene, benzene, naphthalene and anthracene.
Claim 6
Dependent Claim
17 words
Acetylene black as claimed in claim 1, in which said oxygen-containing gas is pure oxygen and/or air.
Claim 7
Dependent Claim
22 words
Acetylene black as claimed in claim 1, in which said steam is completely dried and obtained from wather purified by ion exchange.
Claim 8
Dependent Claim
31 words
Acetylene black is claimed in claim 2, wherein: (a) the amount of said unsaturated hydrocarbon is no less than 40 parts by weight per 100 parts by weight of acetylene gas.
Claim 9
Dependent Claim
14 words
Acetylene black as claimed in claim 1, wherein: (a) said oxygen-containing gas including air.
Claim 10
Dependent Claim
17 words
Acetelene black as claimed in claim 1, wherein: (a) said steam obtained from water purified by evaporation.
Claim 11
Independent Claim
100 words
The method of preparing an acetylene black having an electrical resistivity of no more than 0.03 Ωcm at a pressure of 50 kg/cm 2 , a hydrochloric acid absorption of 20 to 40 ml/5 g and a specific surface area of 100 to 400 m 2 /g, comprising the steps of: (a) thermally cracking at a temperature of no less than 800° C. acetylene gas with a mixed gas flow of an oxygen-containing gas and dry steam, said oxygen-containing gas having the relation a+(b/2)<1 in molar units where 0<a<1 and 0<b<2 with respect to steam b and pure oxygen a.
Claim 12
Independent Claim
100 words
The method of preparing an acetylene black having an electrical resistivity of no more than 0.03 Ωcm at a pressure of 50 kg/cm 2 , a hydrochloric acid absorption of 20 to 40 ml/5 g and a specific surface area of 100 to 400 m 2 /g, comprising the steps of: (a) thermally cracking at a temperature of no less than 800° C. acetylene gas with a mixed gas flow of an oxygen-containing gas and dry steam, said oxygen-containing gas having the relation a+(b/2)<1 in molar units where 0<a<1 and 0<b<2 with respect to steam b and pure oxygen a.
Claim 13
Dependent Claim
44 words
The method of claim 10, including the further step of: (a) providing a mixed gas flow further including an unsaturated hydrocarbon wherein the amount of said unsaturated hydrocarbon is no less than 40 parts by weight per 100 parts by weight of acetylene gas.
Claim 14
Dependent Claim
17 words
The method of claim 10, including the step of: (a) obtaining said dried steam by ion exchange.
Claim 15
Dependent Claim
25 words
The method of claim 11, including the step of: (a) providing an unsaturated hydrocarbon selected from the group ethylene, propylene, butadiene, benzene, naphthalene and anthracene.
Claim 16
Dependent Claim
23 words
The method of claim 10, including the step of: (a) providing an oxygen-containing gas selected from the group of pure oxygen and air.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-05-11 | 1990-11-10 | 1991-05-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-05-11 | 1994-11-10 | 1995-05-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-05-11 | 1998-11-10 | 1999-05-12 | $7700.00 | Window Closed / Lapsed |