US3925530A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Release coating for molds
Assignee: Phillips Petroleum Co
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Filing: 1972-12-04
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Granted: 1975-12-09
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Expires: 1992-12-04
Abstract
Abstract A method of molding polymeric materials, such as olefin polymers, in a mold which has a release coating of 50-90 parts by weight polyphenylene sulfide, up to 10 parts by weight polytetrafluorethylene and a filler in an amount of 10-50 parts by weight. The release coating can be utilized to form a plurality of articles without reapplication of the coating. The coating may be applied to the mold as a solution of a volatile solvent or in the melted state.
Inventors
- 👤 Robert L Rees
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:18
CPC Classifications
B; B29; B29C; B29C33/00; B29C33/56; B29C33/60; B29C33/62
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
160 words
A METHOD OF MOLDING WHICH COMPRISES: A. APPLYING A MOLD RELEASE COATING COMPOSITION CONSISTING ESSENTIALLY OF POLYPHENYLENE SULFIDE IN AN AMOUNT WITHIN THE RANGE OF FROM ABOUT 50 TO ABOUT 90 PARTS BY WEIGHT, POLYTETRAFLUOROETHYLENE IN AN AMOUNT UP TO 10 PARTS BY WEIGHT AND A FILLER IN AN AMOUNT WITHIN THE RANGE OF FROM ABOUT 10 TO ABOUT 50 PARTS BY WEIGHT SAID FILLER SELECTED FROM THE GROUP CONSISTING OF TITANIUM OXIDE, ALUMINUM OXIDE, IRON OXIDE AND CLAY TO THE INNER SURFACE OF A MOLD; B. CURING SAID COATING; C. INTRODUCING INTO SAID MOLD AND INTO CONTACT WITH THE CURED COATING A POLYMERIC COMPOSITION MOLDABLE AT A TEMPERATURE LESS THAN THAT TEMPERATURE AT WHICH THE MOLD RELEASE COATING COMPOSITION BECOMES INOPERABLE AS A SATISFACTORY COATING; D. MOLDING SAID MOLDABLE POLYMERIC COMPOSITION; E. REMOVING SAID MODABLE POLYMERIC COMPOSITION FROM SAID MOLD AS A MOLDED OBJECT; AND F. REPEATING STEPS (C), (D), AND (E) TO PRODUCE A MULTIPLICITY OF MOLDED OBJECTS.
Claim 2
Independent Claim
160 words
A METHOD OF MOLDING WHICH COMPRISES: A. APPLYING A MOLD RELEASE COATING COMPOSITION CONSISTING ESSENTIALLY OF POLYPHENYLENE SULFIDE IN AN AMOUNT WITHIN THE RANGE OF FROM ABOUT 50 TO ABOUT 90 PARTS BY WEIGHT, POLYTETRAFLUOROETHYLENE IN AN AMOUNT UP TO 10 PARTS BY WEIGHT AND A FILLER IN AN AMOUNT WITHIN THE RANGE OF FROM ABOUT 10 TO ABOUT 50 PARTS BY WEIGHT SAID FILLER SELECTED FROM THE GROUP CONSISTING OF TITANIUM OXIDE, ALUMINUM OXIDE, IRON OXIDE AND CLAY TO THE INNER SURFACE OF A MOLD; B. CURING SAID COATING; C. INTRODUCING INTO SAID MOLD AND INTO CONTACT WITH THE CURED COATING A POLYMERIC COMPOSITION MOLDABLE AT A TEMPERATURE LESS THAN THAT TEMPERATURE AT WHICH THE MOLD RELEASE COATING COMPOSITION BECOMES INOPERABLE AS A SATISFACTORY COATING; D. MOLDING SAID MOLDABLE POLYMERIC COMPOSITION; E. REMOVING SAID MODABLE POLYMERIC COMPOSITION FROM SAID MOLD AS A MOLDED OBJECT; AND F. REPEATING STEPS (C), (D), AND (E) TO PRODUCE A MULTIPLICITY OF MOLDED OBJECTS.
Claim 3
Dependent Claim
11 words
The method of claim 1 in which filler is titanium oxide.
Claim 4
Dependent Claim
18 words
The method of claim 1 in which said coating is applied to said mold in a volatile solvent.
Claim 5
Dependent Claim
18 words
The method of claim 2 in which said coating is applied to said mold in the melted state.
Claim 6
Dependent Claim
19 words
The method of claim 1 in which said coating is applied to said mold in a plurality of applications.
Claim 7
Dependent Claim
29 words
The method of claim 2 in which said coating is cured at a temperature of about 700*F. for a period of from about 30 minutes to about 1 hour.
Claim 8
Dependent Claim
19 words
The method of claim 4 in which said coating is applied in the form of an ethylene glycol suspension.
Claim 9
Dependent Claim
30 words
The method of claim 2 in which Said coating consists essentially of 3 parts by weight polyphenylene sulfide, 1 part by weight titanium oxide and 0.3 parts by weight polytetrafluoroethylene.
Claim 10
Dependent Claim
22 words
The method of claim 8 in which said coating is applied over a curved undercoating and said coating is cured after drying.
Claim 11
Dependent Claim
13 words
The method of claim 1 in which the moldable polymeric composition is polyolefin.
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) | 1978-12-08 | 1979-06-09 | 1979-12-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-08 | 1983-06-09 | 1983-12-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-08 | 1987-06-09 | 1987-12-09 | $7700.00 | Window Closed / Lapsed |