US3935291A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of molding polyurethane articles in a mold coated with three mold release agents
Assignee: Motor Wheel Corp
•
Filing: 1973-08-28
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Granted: 1976-01-27
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Expires: 1993-08-28
Abstract
Abstract A method of molding polyurethane articles using three mold release agents, the first being a halocarbon film, the second a hydrocarbon release agent and the third a polyvinyl alcohol release agent.
Inventors
- 👤 William E. Jackson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 21:51
CPC Classifications
B; B29; B29D; B29D99/00; B29D99/0032; B29C; B29C33/00; B29C33/56; B29C33/60; B29C33/62; B29K; B29K2075/00; B29K2105/00; B29K2105/04; B29K2705/00; B29L; B29L2030/00; B29L2031/00; B29L2031/32
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
83 words
In a method of molding polyurethane articles from a polyurethane reaction mixture by applying mold release agent to the mold, charging a polyurethane reaction mixture into the mold and permitting said reaction mixture to react and set prior to removal from the mold, the improvement wherein the mold release coatings comprises a coating of a polyhalocarbon a hydrocarbon mold release agent selected from the class consisting of wax, polyethylene and polypropylene and a coating over the hydrocarbon mold release agent of polyvinyl alcohol.
Claim 2
Dependent Claim
83 words
In a method of molding polyurethane articles from a polyurethane reaction mixture by applying mold release agent to the mold, charging a polyurethane reaction mixture into the mold and permitting said reaction mixture to react and set prior to removal from the mold, the improvement wherein the mold release coatings comprises a coating of a polyhalocarbon a hydrocarbon mold release agent selected from the class consisting of wax, polyethylene and polypropylene and a coating over the hydrocarbon mold release agent of polyvinyl alcohol.
Claim 3
Dependent Claim
26 words
The method of claim 1 wherein the molded polyurethane article is water washed at 70° to 95°C. and dried to present a surface receptive to painting.
Claim 4
Dependent Claim
28 words
The method of claim 1 wherein the hydrocarbon mold release agent is applied over a semi-permanent polyhalocarbon film of a short-chain telomer of tetrafluoroehtylene on the mold surface.
Claim 5
Dependent Claim
62 words
The method of claim 3 wherein the mold has been used until debris begins to collect and is regenerated by washing the mold release agent from the mold with hot diethylene glycol and washed with a solvent and then recoated with the mold release coatings, said coatings being applied successively as follows: polyhalocarbon coating hydrocarbon mold release coating and polyvinyl alcohol coating.
Claim 6
Dependent Claim
22 words
The method of claim 4 wherein the diethylene glycol is about 200° to 230°C. and the solvent is ethylene glycol monoethyl ether.
References Cited (Backward Citations)
CA624114A
Cited
GB785733A
Cited
US3101244A
Cited
US3127457A
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US3210448A
Cited
US3341646A
Cited
US3359351A
Cited
US3502768A
Cited
US3669501A
Cited
US3624790A
Cited
US3762677A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-01-26 | 1979-07-28 | 1980-01-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-01-26 | 1983-07-28 | 1984-01-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-01-26 | 1987-07-28 | 1988-01-27 | $7700.00 | Window Closed / Lapsed |