Patent US4454194A successfully refreshed from Google Patents.
US4454194A
Expired / Lapsed
US
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Lyophilization process for preparing composite particles for use in electroconductive transfer films and products produced therewith
Assignee: Exxon Mobil Corp
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Filing: 1982-07-06
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Granted: 1984-06-12
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Expires: 2002-07-06
Abstract
Abstract A method for the preparation of conductive graphite particles useful as an electrically anisotropic support layer for an electroconductive transfer film comprising initially grinding a slurry of graphite particles in the presence of water or a solvent having freezing and vapor pressure properties similar to water, for a period of time sufficient to substantially completely disperse the graphite particles in the water or solvent. A binding or film forming polymer is then added to the graphite slurry, said polymer being soluble in the water or solvent. The resulting slurry is then subjected to a freeze drying step so that the water or solvent present is caused to sublime resulting in the formation of polymeric coated graphite particles of at least 0.2 microns in diameter. These particles can be incorporated into the support layer of a electroconductive transfer film.
Inventors
- 👤 Ray H. Luebbe, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 21:47
CPC Classifications
B; B41; B41M; B41M5/00; B41M5/26; B41M5/382; B41M5/3825; Y; Y10; Y10S; Y10S428/00; Y10S428/913; Y10T; Y10T428/00; Y10T428/25; Y10T428/26; Y10T428/269; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T428/2998; Y10T428/30
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
138 words
A method for the preparation of conductive graphite particles useful as an electrically anisotropic support layer for an electroconductive transfer film comprising: (a) grinding a slurry of graphite particles in the presence of water or solvent having freezing and vapor pressure properties similar to water for a period of time sufficient to substantially completely disperse the graphite particles in said water or solvent; (b) adding a binding polymer to said graphite slurry either as part of Step (a) or immediately after Step (a), wherein said polymer is soluble in said water or solvent; (c) freezing said slurry; and (d) drying said slurry wherein said water or solvent present is caused to sublime resulting in the formation of polymeric coated graphite particles wherein at least a substantial portion of these particles have a diameter of at least 0.2 microns.
Claim 2
Independent Claim
138 words
A method for the preparation of conductive graphite particles useful as an electrically anisotropic support layer for an electroconductive transfer film comprising: (a) grinding a slurry of graphite particles in the presence of water or solvent having freezing and vapor pressure properties similar to water for a period of time sufficient to substantially completely disperse the graphite particles in said water or solvent; (b) adding a binding polymer to said graphite slurry either as part of Step (a) or immediately after Step (a), wherein said polymer is soluble in said water or solvent; (c) freezing said slurry; and (d) drying said slurry wherein said water or solvent present is caused to sublime resulting in the formation of polymeric coated graphite particles wherein at least a substantial portion of these particles have a diameter of at least 0.2 microns.
Claim 3
Dependent Claim
20 words
The method of claim 1 wherein said water-soluble or solvent soluble binding polymer is polyvinyl alcohol, gelatin or methyl cellulose.
Claim 4
Dependent Claim
15 words
The method of claim 2 wherein said graphite is dispersed in the presence of water.
Claim 5
Dependent Claim
16 words
The method of claim 2 wherein said slurry contains between 70 and 80% by weight water.
Claim 6
Dependent Claim
16 words
The method of claim 1 comprising grinding said graphite particles in the presence of a solvent.
Claim 7
Dependent Claim
16 words
The method of claim 5 wherein said solvent is t-butyl alcohol, cyclohexane, benzene, dioxane, or p-xylene.
Claim 8
Dependent Claim
18 words
The method of claim 6 comprising grinding said graphite in a ball mill for 8 to 16 hours.
Claim 9
Dependent Claim
18 words
The method of claim 1 comprising grinding said graphite in a ball mill for 8 to 16 hours.
Claim 10
Dependent Claim
11 words
Graphite particles produced in accordance with the process of claim 1.
Claim 11
Dependent Claim
131 words
An electrically anisotropic support layer produced by a process which comprises: (a) grinding a slurry of graphite particles in the presence of water or solvent having freezing and vapor pressure properties similar to water for a period of time sufficient to substantially completely disperse the graphite particles in said water or solvent; (b) adding a blinding polymer to said graphite slurry wherein said polymer is soluble in said water or solvent; (c) freezing said slurry; (d) drying said slurry wherein said water or solvent present is caused to sublime resulting in the formation of polyeric coated graphite particles wherein at least a substantial portion of these particles have a diameter of at least 0.2 microns; and (e) casting said coated graphite particles onto a support layer for an electroconductive transfer film.
Claim 12
Dependent Claim
131 words
An electrically anisotropic support layer produced by a process which comprises: (a) grinding a slurry of graphite particles in the presence of water or solvent having freezing and vapor pressure properties similar to water for a period of time sufficient to substantially completely disperse the graphite particles in said water or solvent; (b) adding a blinding polymer to said graphite slurry wherein said polymer is soluble in said water or solvent; (c) freezing said slurry; (d) drying said slurry wherein said water or solvent present is caused to sublime resulting in the formation of polyeric coated graphite particles wherein at least a substantial portion of these particles have a diameter of at least 0.2 microns; and (e) casting said coated graphite particles onto a support layer for an electroconductive transfer film.
Claim 13
Dependent Claim
29 words
The electrically anisotropic support layer of claim 10 wherein the process of production comprises solvent casting said coated graphite particles into a support layer for an electroconductive transfer film.
Claim 14
Dependent Claim
26 words
The electrically anisotropic support layer of claim 11 produced by a process wherein said water-soluble or solvent-soluble binding polymer is polyvinyl alcohol, gelatin or methyl cellulose.
Claim 15
Dependent Claim
18 words
The electrically anisotropic support layer of claim 12 wherein said graphite is dispersed in the presence of water.
Claim 16
Dependent Claim
19 words
The electrically anisotropic support layer of claim 12 wherein said slurry contains between 70 and 80% by weight water.
Claim 17
Dependent Claim
24 words
The electrically anisotropic support layer of claim 12 wherein the process of production comprises grinding said graphite particles in the presence of a solvent.
Claim 18
Dependent Claim
23 words
The electrically anisotropic support layer of claim 15 produced by a process wherein said solvent is t-butyl alcohol, cyclohexane, benzene, dioxane or p-xylene.
Claim 19
Dependent Claim
26 words
The electrically anisotropic support layer of claim 11 wherein the process of production comprises grinding said graphite in a ball mill for 8 to 16 hours.
Claim 20
Dependent Claim
36 words
An electric discharge transfer material comprising a transfer layer in the form of a resin layer capable of being broken by electric discharge and laminated to an electrically anisotropic support layer, as defined in claim 10.
Claim 21
Dependent Claim
100 words
An electric discharge transfer material comprising: (a) a semiconductive resin layer capable of being broken by electric discharging which has a surface resistance of 10 to 10 9 ohms and a volume resistance of 1 to 10 6 ohms-cm; (b) an electrically anisotropic support layer, as defined in claim 10 and laminated on one surface of the semiconductive resin layer (a); and (c) a conductive layer having a surface resistance of not more than 10 4 ohms and a volume resistance of not more than 10 2 ohms-cm, which is laminated on the other surface of the semiconductive resin layer.
References Cited (Backward Citations)
US4163075A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-06-12 | 1987-12-12 | 1988-06-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-06-12 | 1991-12-12 | 1992-06-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-06-12 | 1995-12-12 | 1996-06-12 | $7700.00 | Window Closed / Lapsed |