US4399088A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process and molding apparatus having a mold release coating on the cavity thereof for molding formable and homogeneous ceramic/polyester resin molding composition
Assignee: PCI Group Inc
•
Filing: 1981-03-30
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Granted: 1983-08-16
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Expires: 2001-03-30
Abstract
Abstract A mold release agent designed for use with ceramic/polyester molding compositions is disclosed. The mold release agent comprises 15-30 weight percent polyethylene having a molecular weight of 15,000 to 30,000 and 70-85 weight percent of a mineral oil of 345-355 Saybolt Seconds Universal (SSU) at 100° F. In a preferred molding procedure the surface of the mold is uniformly coated to a thickness of 0.5-2 mm with the mineral oil/polyethylene composition by melt-flow at 200°-300° F.
Inventors
- 👤 Waldo R. Greene
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:36
CPC Classifications
B; B29; B29C; B29C44/00; B29C44/02; B29C44/12; B28; B28B; B28B7/00; B28B7/38; B28B7/384; B29C33/00; B29C33/56; B29C33/60; C; C08; C08J; C08J9/00; C08J9/04; C08J9/06; C08J9/08; C08J2367/00; C08J2367/06; Y; Y10; Y10S; Y10S264/00; Y10S264/05
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
128 words
A process for molding comprising the steps of: A. coating a mold surface with a release agent consisting essentially of 15-30 weight percent of a polyethylene having an average molecular weight within the range of 15,000 to 30,000 and 70-85 weight percent of a mineral oil of 345-355 SSU at 100° F. and where the polyethylene and mineral oil can be admixed and heated to about 140° C. to obtain a clear molten solution which has a viscosity about 250 cps greater than that of the mineral oil alone at the same temperature; B. applying to the coated mold surface a molding composition comprising a polyester resin and an aqueous, alkali stabilized silica; C. curing the molding composition and, D. separating the mold surface from the cured composition.
Claim 2
Dependent Claim
128 words
A process for molding comprising the steps of: A. coating a mold surface with a release agent consisting essentially of 15-30 weight percent of a polyethylene having an average molecular weight within the range of 15,000 to 30,000 and 70-85 weight percent of a mineral oil of 345-355 SSU at 100° F. and where the polyethylene and mineral oil can be admixed and heated to about 140° C. to obtain a clear molten solution which has a viscosity about 250 cps greater than that of the mineral oil alone at the same temperature; B. applying to the coated mold surface a molding composition comprising a polyester resin and an aqueous, alkali stabilized silica; C. curing the molding composition and, D. separating the mold surface from the cured composition.
Claim 3
Dependent Claim
16 words
The process of claim 1 wherein said polyethylene has an average molecular weight of about 20,000.
Claim 4
Dependent Claim
31 words
The process of claim 1 comprising the additional step of heating the release agent to 200° F.-300° F. to distribute the agent evenly over the mold surface prior to step c.
Claim 5
Dependent Claim
16 words
The process of claim 3 wherein the coating thickness of the release agent is 0.5-2 mm.
Claim 6
Dependent Claim
29 words
The process of claim 1 wherein the molding composition includes a blowing agent selected from the group consisting of calcium carbonate or a blend of calcium carbonate and alumina.
Claim 7
Dependent Claim
103 words
A structure for molding comprising in combination: A. a mold having a mold surface; and B. a mold release agent on said surface consisting essentially of a substantially solvent-free blend of 15-30 weight percent of a polyethylene having an average molecular weight within the range of 15,000 to 30,000 and 70-85 weight percent of a mineral oil of 345-355 SSU at 100° F. and where the polyethylene and mineral oil can be admixed and heated to about 140° C. to obtain a clear molten solution which has a viscosity about 250 cps greater than that of the mineral oil at the same temperature.
Claim 8
Dependent Claim
103 words
A structure for molding comprising in combination: A. a mold having a mold surface; and B. a mold release agent on said surface consisting essentially of a substantially solvent-free blend of 15-30 weight percent of a polyethylene having an average molecular weight within the range of 15,000 to 30,000 and 70-85 weight percent of a mineral oil of 345-355 SSU at 100° F. and where the polyethylene and mineral oil can be admixed and heated to about 140° C. to obtain a clear molten solution which has a viscosity about 250 cps greater than that of the mineral oil at the same temperature.
Claim 9
Dependent Claim
15 words
The structure of claim 6 wherein said polyethylene has a molecular weight of about 20,000.
Claim 10
Dependent Claim
16 words
The structure of claim 6 wherein said release agent comprises about 80 weight percent mineral oil.
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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) | 1986-08-15 | 1987-02-14 | 1987-08-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-15 | 1991-02-14 | 1991-08-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-15 | 1995-02-14 | 1995-08-16 | $7700.00 | Window Closed / Lapsed |