Patent US3622659A successfully refreshed from Google Patents.
US3622659A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermal gradient method for making thermoplastic matrices
Assignee: Union Carbide Corp
•
Filing: 1969-02-17
•
Granted: 1971-11-23
•
Expires: 1989-02-17
Abstract
Abstract An improved process for making thermoplastic matrices wherein a thermal gradient is established between the molding interface and the back of a thermoplastic matrix blank whereby the viscosity at the molding interface is high enough to resist flow into the original and the temperature at the back is sufficiently high to permit flow of molten thermoplastic.
Inventors
- 👤 John Sonia
- 👤 John B Wheeler
- 👤 Thomas E Hayes
- 👤 Robert B Petrochko
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 11:00
CPC Classifications
B; B29; B29C; B29C33/00; B29C33/38; B29C33/3842; B29C33/3857; B29C33/40; B29C43/00; B29C43/003; B29C43/02; B29C43/021; B41; B41C; B41C3/00; B41C3/02; B29K; B29K2069/00; B29K2071/00; B29L; B29L2031/00; B29L2031/757
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
30 words
The process of claim 1 wherein the original is preheated to a temperature of about 25* F. to about 100* F. below the softening temperature of the thermoplastic matrix blank.
Claim 2
Dependent Claim
71 words
The process of claim 1 wherein the said thermoplastic is composed of recurring units having the formula: wherein E is the residuum of a dihydric phenol and E'' is the residuum of a benzenoid compound having an inert electron withdrawing group in at least one of the positions, ortho or para to the valence bonds, and where both of said residua are valently bonded to ether oxygen through aromatic carbon atoms.
Claim 3
Dependent Claim
19 words
The thermoplastic material defined in claim 3 wherein said polyarylene polyetHer is composed of recurring units having the formula:
Claim 4
Dependent Claim
19 words
The thermoplastic sheet defined in claim 3 wherein said polyarylene polyether is composed of recurring units having the formula:
Claim 5
Dependent Claim
19 words
The thermoplastic sheet defined in claim 3 wherein said polyarylene polyether is composed of recurring units having the formula:
Claim 6
Dependent Claim
31 words
The process of claim 1 wherein the said thermoplastic sheet is a polycarbonate composed of recurring units of the formula: wherein B is a divalent aromatic radical of a dihydric phenol.
Claim 7
Dependent Claim
35 words
The process of claim 5 wherein the temperature at the molding interface is from about 375* F. to about 400* F. and the temperature at the backside of the said blank is about 700* F.
References Cited (Backward Citations)
US825565A
Cited
US2400518A
Cited
US2647284A
Cited
US2536316A
Cited
US2645178A
Cited
US3260779A
Cited
US3380878A
Cited
US3444275A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-11-22 | 1975-05-24 | 1975-11-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-22 | 1979-05-24 | 1979-11-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-22 | 1983-05-24 | 1983-11-23 | $7700.00 | Window Closed / Lapsed |