Patent US4923520A successfully refreshed from Google Patents.
US4923520A
Expired / Lapsed
US
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Spherical fused silica and its use in fillers and resin compositions
Assignee: Huntsman Advanced Materials Americas LLC
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Filing: 1988-09-30
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Granted: 1990-05-08
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Expires: 2008-09-30
Abstract
Abstract Spherical fused silica with an average particle diameter within the range of 10 to 50 μm and having a particle size distribution of 1 to 100 μm in diameter is a useful filler for resin compositions having improved mechanical and electrical properties as well as good flowability and low viscosity. The spherical fused silica is preferably treated on its surface with a silane coupling agent. Resin compositions containing said spherical fused silica as the major filler are particularly useful as casting materials.
Inventors
- 👤 Kenji Anzai
- 👤 Tatsuo Hamabe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 21:29
CPC Classifications
C; C08; C08K; C08K7/00; C08K7/16; C08K7/18; C08K9/00; C08K9/04; C08K9/06; C09; C09C; C09C1/00; C09C1/28; C09C1/30; C09C1/3081; C01; C01P; C01P2004/00; C01P2004/30; C01P2004/32; C01P2004/60; C01P2004/61
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
44 words
Particulate fused silica having a silica dioxide content of at least 99.5% and a particle diameter distribution of from 1 to 100 μm with the average particle diameter being from 10 to 50 μm, at least 99% of the particles being substantially perfect spheres.
Claim 2
Dependent Claim
44 words
Particulate fused silica having a silica dioxide content of at least 99.5% and a particle diameter distribution of from 1 to 100 μm with the average particle diameter being from 10 to 50 μm, at least 99% of the particles being substantially perfect spheres.
Claim 3
Dependent Claim
18 words
Particulate fused silica according to claim 1 wherein the average particle diameter is from 15 to 40 μm.
Claim 4
Dependent Claim
17 words
Particulate fused silica according to claim 1 wherein the surface is treated with a silane coupling agent.
Claim 5
Dependent Claim
14 words
Particulate fused silica according to claim 3 wherein the silane coupling agent is beta-(3,4-epoxycyclohexyl)-ethyl-trimethoxysilane.
Claim 6
Dependent Claim
14 words
Particulate fused silica according to claim 3 wherein the silane coupling agent is gamma-glycidyloxypropyltrimethoxysilane.
Claim 7
Dependent Claim
34 words
An epoxy resin composition which comprises at least one epoxy resin and from 20% to 80% by weight based on the total weight of the composition, of particulate fused silica according to claim 1.
Claim 8
Dependent Claim
14 words
Resin composition as claimed in claim 6 wherein the silane coupling agent is γ-glycidyloxy-propyl-trimethoxysilane.
Claim 9
Dependent Claim
24 words
An epoxy resin composition according to claim 6 wherein the average particle diameter of the particulate fused silica is from 15 to 40 μm.
Claim 10
Dependent Claim
23 words
An epoxy resin composition according to claim 6 wherein the surface of the particulate fused silica is treated with a silane coupling agent.
Claim 11
Dependent Claim
15 words
An epoxy resin composition according to claim 9 wherein the silane coupling agent is beta-(3,4-epoxycyclohexyl)-ethyl-trimethoxysilane.
Claim 12
Dependent Claim
15 words
An epoxy resin composition according to claim 9 wherein the silane coupling agent is gamma-glycidyloxypropyltrimethoxysilane.
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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) | 1993-05-07 | 1993-11-06 | 1994-05-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-05-07 | 1997-11-06 | 1998-05-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-05-07 | 2001-11-06 | 2002-05-08 | $7700.00 | Window Closed / Lapsed |