US4356246A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making α-silicon powder, and electrophotographic materials incorporating said powder
Assignee: Fujifilm Holdings Corp
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Filing: 1980-06-16
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Granted: 1982-10-26
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Expires: 2000-06-16
Abstract
Abstract A noncrystalline silicon powder having excellent photoconductivity is described, comprising silicon and hydrogen, exhibiting an infrared absorption spectrum characterized by absorption peaks centered at about 2000 cm -1 and 630 cm -1 , wherein the height of the absorbance peak at 2000 cm -1 is at least one-tenth the height of the peak centered at 630 cm -1 , and exhibiting a spin density of not more than 10 18 cm -3 determined by electron spin resonance spectroscopy; the noncrystalline silicon powder is used as highly efficient photoconductor in photoconductive compositions utilized for the production of electrophotographic photoreceptors.
Inventors
- 👤 Masatoshi Tabei
- 👤 Keiji Takeda
- 👤 Kazuhiro Kawaziri
- 👤 Akio Higashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 08:22
CPC Classifications
G; G03; G03G; G03G5/00; G03G5/02; G03G5/04; G03G5/08; G03G5/087; G03G5/043; G03G5/0436
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
135 words
A process of producing noncrystalline silicon powder comprising silicon and hydrogen, having a primary particle size of from 0.01 μm to 1 μm, exhibiting an infrared absorption spectrum characterized by an absorbance peak centered at about 2000 cm -1 , wherein the height of said absorbance peak is at least one-tenth the height of the absorbance peak centered at about 630 cm -1 , and exhibiting a spin density of not more than 10 18 cm -3 in the electron spin resonance spectrum thereof, the color of said powder being red, brown, black or a combination thereof, said process comprising submitting silane or a derivative thereof to glow discharge decomposition and to further heating before, during or after such decomposition at a temperature up to about 650° C. to directly form said powder without grinding.
Claim 2
Dependent Claim
135 words
A process of producing noncrystalline silicon powder comprising silicon and hydrogen, having a primary particle size of from 0.01 μm to 1 μm, exhibiting an infrared absorption spectrum characterized by an absorbance peak centered at about 2000 cm -1 , wherein the height of said absorbance peak is at least one-tenth the height of the absorbance peak centered at about 630 cm -1 , and exhibiting a spin density of not more than 10 18 cm -3 in the electron spin resonance spectrum thereof, the color of said powder being red, brown, black or a combination thereof, said process comprising submitting silane or a derivative thereof to glow discharge decomposition and to further heating before, during or after such decomposition at a temperature up to about 650° C. to directly form said powder without grinding.
Claim 3
Dependent Claim
19 words
A process as in claim 1, wherein said silane or derivative thereof is heated before said glow discharge decomposition.
Claim 4
Dependent Claim
25 words
A process as in claim 1, wherein said silane or derivative thereof is heated during said discharge decomposition by irradiating the discharge region with light.
Claim 5
Dependent Claim
40 words
A process as in claim 1, wherein said silane or derivative thereof is submitted to said glow discharge decomposition and subsequently to heating at a temperature of from 200° C. to 650° C. in an inert atmosphere or under vacuum.
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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) | 1985-10-25 | 1986-04-26 | 1986-10-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-10-25 | 1990-04-26 | 1990-10-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-10-25 | 1994-04-26 | 1994-10-26 | $7700.00 | Window Closed / Lapsed |