Patent US6387978B2 successfully refreshed from Google Patents.
US4293479A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat curable molding composition
Assignee: DuPont Toray Specialty Materials KK
•
Filing: 1979-12-06
•
Granted: 1981-10-06
•
Expires: 1999-12-06
Abstract
Abstract What is disclosed is an improved heat curable molding composition which has increased flowability in the mold. The improvement is gained by the use of a fine, spherical noncrystalline filler along with the normal molding compound fillers.
Inventors
- 👤 Tsuneo Hanada
- 👤 Taro Koshii
- 👤 Hideo Shinmi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 06:46
CPC Classifications
C; C08; C08K; C08K7/00; C08K7/16; C08K7/18; C08K7/20
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
72 words
An improved heat curable molding composition which consists of (A) 100 parts of a heat curable molding resin; (B) up to 400 parts of a filler; the improvement comprising replacing 5-80 weight percent of (B) with a spherical non-crystalline silica filler having an average particle size of 1-800 millimicrons which has been prepared by vaporization of high purity sand or quartz in the absence of hydrogen or natural gas and subsequently condensed.
Claim 2
Dependent Claim
72 words
An improved heat curable molding composition which consists of (A) 100 parts of a heat curable molding resin; (B) up to 400 parts of a filler; the improvement comprising replacing 5-80 weight percent of (B) with a spherical non-crystalline silica filler having an average particle size of 1-800 millimicrons which has been prepared by vaporization of high purity sand or quartz in the absence of hydrogen or natural gas and subsequently condensed.
Claim 3
Dependent Claim
32 words
A heat curable molding compound as claimed in claim 1 wherein the resin (A) is present in 100 parts and (B) is present in 200-400 parts for every 100 parts of (A).
Claim 4
Dependent Claim
32 words
A heat curable molding compound as claimed in claim 1 wherein the resin (A) is selected from a group consisting of silicone resins, epoxy resins and silicone-epoxy copolymer resins or mixtures thereof.
Claim 5
Dependent Claim
36 words
A heat curable molding compound as claimed in claim 3 wherein (B) is 90-40 weight percent glass fiber and 10-60 weight percent spherical silica both based on the total weight of (B) present in the composition.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-10-05 | 1985-04-06 | 1985-10-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-10-05 | 1989-04-06 | 1989-10-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-10-05 | 1993-04-06 | 1993-10-06 | $7700.00 | Window Closed / Lapsed |