US4895713A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Intercalation of graphite
Assignee: Graftech Inc
•
Filing: 1989-03-16
•
Granted: 1990-01-23
•
Expires: 2009-03-16
Abstract
Abstract A method for intercalating graphite flakes which requires less intercalation solution and avoids a washing step, thus producing economy in material and production costs, and avoiding production of contaminated waste water which requires costly disposal steps.
Inventors
- 👤 Ronald A. Greinke
- 👤 Robert A. Mercuri
- 👤 Edgar J. Beck
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 09:53
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/52; C04B35/536; C01; C01B; C01B32/00; C01B32/20; C01B32/21; C01B32/22; C01B32/225
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
113 words
A method for intercalating graphite flakes which comprises; (a) adding liquid intercalation solution to graphite flakes in an amount of between 10 and 35 parts by weight of solution per 100 parts by weight of graphite flakes, the liquid intercalation solution comprising one or more members selected from the group consisting of nitric acid, sulfuric acid, potassium chlorate, chromic acid, potassium permangante, potassium chromate, potassium dichromate, perchloric acid, hydrogen peroxide, iodic acids, periodic acids, ferric chloride, and halides, and (d) dispersing the intercalation solution through the graphite flakes to produce intercalated graphite flakes, the intercalated graphite flakes having an exfoliation volume greater than about 100 cm 3 /g when passed directly to exfoliation.
Claim 2
Independent Claim
113 words
A method for intercalating graphite flakes which comprises; (a) adding liquid intercalation solution to graphite flakes in an amount of between 10 and 35 parts by weight of solution per 100 parts by weight of graphite flakes, the liquid intercalation solution comprising one or more members selected from the group consisting of nitric acid, sulfuric acid, potassium chlorate, chromic acid, potassium permangante, potassium chromate, potassium dichromate, perchloric acid, hydrogen peroxide, iodic acids, periodic acids, ferric chloride, and halides, and (d) dispersing the intercalation solution through the graphite flakes to produce intercalated graphite flakes, the intercalated graphite flakes having an exfoliation volume greater than about 100 cm 3 /g when passed directly to exfoliation.
Claim 3
Dependent Claim
37 words
The method of claim 1 wherein the intercalation solution comprises one or more members selected from the group consisting of nitric acid, sulfuric acid, perchloric acid, chromic acid, potassium permanganate, hydrogen peroxide, iodic acids, and periodic acids.
Claim 4
Dependent Claim
13 words
The method of claim 2 wherein the intercalation solution additionally comprises a phosphate.
Claim 5
Dependent Claim
13 words
The method of claim 1 wherein the intercalation solution additionally comprises a phosphate.
Claim 6
Dependent Claim
25 words
The method of claim 1 wherein the intercalation solution comprises between 50% and 92% sulfuric acid and between 8% and 50% nitric acid by weight.
Claim 7
Dependent Claim
12 words
The method of claim 1 wherein the intercalation solution comprises hydrogen peroxide.
Claim 8
Dependent Claim
24 words
The method of claim 1 wherein after step (b) the intercalated graphite flakes are heated to a temperature between 100° C. and 150° C.
Claim 9
Dependent Claim
30 words
The method of claim 1 wherein the intercalated graphite flakes are heated to a temperature between 100° C. and 150° C. during the addition and dispersion of the intercalation solution.
Claim 10
Dependent Claim
19 words
The method of claim 7 wherein the graphite flakes in step (a) contain less than 2 weight percent ash.
Claim 11
Dependent Claim
24 words
The method of claim 1, wherein the intercalation solution comprises more than one component, and the components are added to the graphite flakes sequentially.
Claim 12
Dependent Claim
30 words
The method of claim 10, wherein the graphite flakes are heated to a temperature between 100 and 150° C. during the sequential addition of the components of the intercalation solution.
Claim 13
Dependent Claim
15 words
The method of claim 1 wherein the intercalation solution comprises sulfuric acid, and nitric acid.
Claim 14
Dependent Claim
17 words
The method of claim 1 wherein the intercalation solution comprises sulfuric acid, nitric acid, and a phosphate.
Claim 15
Independent Claim
119 words
A method for forming exfoliated graphite flakes which comprises; (a) adding liquid intercalation solution to graphite flakes in an amount of between 10 and 35 parts by weight of solution per 100 parts by weight of graphite flakes, the liquid intercalation solution comprising one or more members selected from the group consisting of nitric acid, sulfuric acid, potassium chlorate, chromic acid, potassium permanganate, potassium chromate, potassium dichromate, perchloric acid, hydrogen peroxide, iodic acids, periodic acids, ferric chloride, and halides, (b) dispersing the interaction solution through the graphite flakes to produce intercalated graphite flakes, and (c) exfoliating the intercalated graphite flakes directly after step (b) to produce exfoliated graphite flakes having an exfoliation volume greater than 100 cm 3 /g.
Claim 16
Independent Claim
119 words
A method for forming exfoliated graphite flakes which comprises; (a) adding liquid intercalation solution to graphite flakes in an amount of between 10 and 35 parts by weight of solution per 100 parts by weight of graphite flakes, the liquid intercalation solution comprising one or more members selected from the group consisting of nitric acid, sulfuric acid, potassium chlorate, chromic acid, potassium permanganate, potassium chromate, potassium dichromate, perchloric acid, hydrogen peroxide, iodic acids, periodic acids, ferric chloride, and halides, (b) dispersing the interaction solution through the graphite flakes to produce intercalated graphite flakes, and (c) exfoliating the intercalated graphite flakes directly after step (b) to produce exfoliated graphite flakes having an exfoliation volume greater than 100 cm 3 /g.
Claim 17
Dependent Claim
20 words
The method of claim 14 wherein the exfoliation in step (c) is conducted at a temperature greater than 700° C.
Claim 18
Dependent Claim
20 words
The method of claim 14 wherein the exfoliation in step (c) is conducted at a temperature greater than 1000° C.
Claim 19
Dependent Claim
16 words
The method of claim 15 wherein the exfoliated flakes are compressed to form a flexible foil.
Claim 20
Dependent Claim
19 words
The method of claim 17 wherein the graphite flakes in step (a) contain less than 2 weight percent ash.
References Cited (Backward Citations)
US3404061A
Cited
US3719608A
Cited
US3885007A
Cited
US4146401A
Cited
US4091083A
Cited
US4199628A
Cited
US4265952A
Cited
US4244934A
Cited
GB2077246A
Cited
JPS5913613A
Cited
GB2128971A
Cited
JPS59169916A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-01-22 | 1993-07-24 | 1994-01-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-01-22 | 1997-07-24 | 1998-01-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-01-22 | 2001-07-24 | 2002-01-23 | $7700.00 | Window Closed / Lapsed |