US5486564A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High purity polyhydrogen silsesquioxane resin for electronic coatings
Assignee: Dow Silicones Corp
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Filing: 1995-02-13
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Granted: 1996-01-23
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Expires: 2015-02-13
Abstract
Abstract Disclosed is a highly reproducible method for the molecular weight fractionation of polyhydrogen silsesquioxane that gives a very storage-stable polyhydrogen silsesquioxane having a freely selectable molecular weight. The method involves dissolving polyhydrogen silsesquioxane in active-hydrogen-free nonpolar solvent; adding an active-hydrogen-free polar solvent to the resulting solution in order to precipitate polyhydrogen silsesquioxane; and collecting the desired molecular weight fraction of polyhydrogen silsesquioxane.
Inventors
- 👤 Katsutoshi Mine
- 👤 Takashi Nakamura
- 👤 Motoshi Sasaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 08:12
CPC Classifications
C; C08; C08G; C08G77/00; C08G77/04; C08G77/12; C08G77/32; C08G77/36
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
35 words
A high purity electronic coating composition comprising polyhydrogen silsesquioxane resin having a sodium content of 9 ppb or less, a sulfur content of 14 ppm or less and a chlorine content less than 1 ppm.
Claim 2
Dependent Claim
35 words
A high purity electronic coating composition comprising polyhydrogen silsesquioxane resin having a sodium content of 9 ppb or less, a sulfur content of 14 ppm or less and a chlorine content less than 1 ppm.
Claim 3
Dependent Claim
15 words
The coating composition of claim 1 wherein the sodium content is 6 ppb or less.
Claim 4
Dependent Claim
15 words
The coating composition of claim 1 wherein the sodium content is 2 ppb or less.
Claim 5
Dependent Claim
15 words
The coating composition of claim 1 wherein the sulfur content is 5 ppm or less.
Claim 6
Dependent Claim
15 words
The coating composition of claim 1 wherein the sulfur content is 4 ppm or less.
Claim 7
Dependent Claim
15 words
The coating composition of claim 1 wherein the sulfur content is 2 ppm or less.
Claim 8
Dependent Claim
15 words
The coating composition of claim 1 wherein the sulfur content is less than 1 ppm.
Claim 9
Dependent Claim
10 words
The coating composition of claim 1 dissolved in a solvent.
References Cited (Backward Citations)
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Cited
JPS59189126A
Cited
JPS6042426A
Cited
JPS6086017A
Cited
JPS61127732A
Cited
US4808653A
Cited
US5063267A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-01-22 | 1999-07-24 | 2000-01-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-01-22 | 2003-07-24 | 2004-01-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-01-22 | 2007-07-24 | 2008-01-23 | $7700.00 | Window Closed / Lapsed |