CA1237263A
Expired / Lapsed
CA
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Heat recoverable polymeric articles
Assignee: Raychem Corp
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Filing: 1985-02-07
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Granted: 1988-05-31
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Expires: 2005-02-07
Abstract
Abstract HEAT RECOVERABLE POLYMERIC ARTICLES Ramsey/Rowlands/Schott/Siden ABSTRACT Heat recoverable articles prepared from semi-crystalline polymers having a glass transition temperatures, Tg, above about 25°C exhibit unexpectedly high recovery stress under certain conditions. A preferred method of preparing such a heat recoverable article comprises heating the article above its glass transition temperature, Tg, deforming the article while it is above Tg but below the crystalline melting temperature, Tm, and cooling the article to a temperature below Tg while maintaining it in the deformed state.
Inventors
- 👤 Edward M. Ramsey
- 👤 Ceinwen D. Rowlands
- 👤 Brian E. Schott
- 👤 Dennis C. Siden
Bibliographic Details
Application Number
—
Jurisdiction
CA
Data Source
google_patents
Last Synchronized
2026-10-26 17:42
CPC Classifications
B; B29; B29C; B29C61/00; B29C61/003; F; F16; F16L; F16L13/00; F16L13/004; F16L33/00; F16L33/02
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
40 words
A dimensionally heat-recoverable article of a semi-crystalline polymer having a glass transition temperature, Tg, above about 25°C, said article having a recovery stress of above about 1100 X (E-1)0.5 pounds per square inch, wherein E is the unresolved recovery ratio.
Claim 2
Dependent Claim
40 words
A dimensionally heat-recoverable article of a semi-crystalline polymer having a glass transition temperature, Tg, above about 25°C, said article having a recovery stress of above about 1100 X (E-1)0.5 pounds per square inch, wherein E is the unresolved recovery ratio.
Claim 3
Dependent Claim
12 words
An article in accordance with Claim 1 wherein said polymer is poly(oxy-p-phenylenecarbonyl-p-phenylene).
Claim 4
Dependent Claim
13 words
An article in accordance with Claim 1 in the form of a ring.
Claim 5
Dependent Claim
13 words
An article in accordance with Claim 1 in the form of a tube.
Claim 6
Dependent Claim
13 words
An article in accordance with Claim 1 in the form of a ring.
Claim 7
Dependent Claim
13 words
An article in accordance with Claim 1 in the form of a fiber.
Claim 8
Dependent Claim
13 words
An article in accordance with Claim 1 in the form of a film.
Claim 9
Independent Claim
111 words
A method of producing a dimensionally heat-recoverable article of a semi-crystalline polymer having a glass transition temperature, Tg, above 25°C by: a) heating a shaped article of a semi-crystalline polymer to a temperature above the Tg of the polymer; b) deforming the article; and c) cooling the article while maintaining the article in the deformed state, thereby producing an article which, when heated to a temperature between Tg and the crystalline melting temperature, Tm, of the polymer, recovers with a recovery stress above about 1100 X (E-1)0.5 pounds per square inch, wherein E is the unresolved recovery ratio, and substantially retains such stress on cooling of the article to ambient temperature.
Claim 10
Independent Claim
111 words
A method of producing a dimensionally heat-recoverable article of a semi-crystalline polymer having a glass transition temperature, Tg, above 25°C by: a) heating a shaped article of a semi-crystalline polymer to a temperature above the Tg of the polymer; b) deforming the article; and c) cooling the article while maintaining the article in the deformed state, thereby producing an article which, when heated to a temperature between Tg and the crystalline melting temperature, Tm, of the polymer, recovers with a recovery stress above about 1100 X (E-1)0.5 pounds per square inch, wherein E is the unresolved recovery ratio, and substantially retains such stress on cooling of the article to ambient temperature.
Claim 11
Dependent Claim
18 words
A method in accordance with Claim 8 wherein the step of deforming the article comprises expanding the article.
Claim 12
Dependent Claim
28 words
A method in accordance with Claim 9 wherein said. article is in the form of a ring and is expanded by passing the ring over a tapered mandrel.
Claim 13
Independent Claim
110 words
A method of producing a heat-shrinkable article of a semi-crystalline polymer having a glass transition temperature, Tg, above about 25°C which comprises: a) stretching a film or fiber of said polymer at a temperature above the Tg of said polymer; b) cooling the stretched film or fiber to a temperature below the Tg of the polymer; and c) forming a shaped article from the stretched film or fiber, thereby forming an article which when heated to a temperature between Tg and the crystalline melting temperature, Tm, of the polymer, shrinks with a stress of above about 1100 X (E-1)0.5 pounds per square inch, wherein E is the unresolved recovery ratio.
Claim 14
Independent Claim
110 words
A method of producing a heat-shrinkable article of a semi-crystalline polymer having a glass transition temperature, Tg, above about 25°C which comprises: a) stretching a film or fiber of said polymer at a temperature above the Tg of said polymer; b) cooling the stretched film or fiber to a temperature below the Tg of the polymer; and c) forming a shaped article from the stretched film or fiber, thereby forming an article which when heated to a temperature between Tg and the crystalline melting temperature, Tm, of the polymer, shrinks with a stress of above about 1100 X (E-1)0.5 pounds per square inch, wherein E is the unresolved recovery ratio.
Claim 15
Dependent Claim
27 words
A method in accordance with Claim 11, wherein said shaped article is formed by winding said film or fiber around a mandrel to form a tubular article.
Claim 16
Independent Claim
119 words
A method of recovering a dimensionally heat-recoverable device against a substrate which comprises: a) selecting a heat-recoverable article of a semi-crystalline polymer having a glass transition temperature, Tg, above about 25°C; b) positioning a tubular heat-recoverable article adjacent such that on recovery the substrate restrains the article to a recovery of less than about 25%, based on the dimension of the deformed article; c) heating said article to a temperature between Tg and the crystalline melting temperature, Tm, of the polymer thereby causing the article to recover about said substrate exerting a stress of at least about 1100 X (E-1)0.5 pounds per square inch, wherein E is the unresolved recovery ratio on said substrate; and d) cooling said article.
Claim 17
Independent Claim
119 words
A method of recovering a dimensionally heat-recoverable device against a substrate which comprises: a) selecting a heat-recoverable article of a semi-crystalline polymer having a glass transition temperature, Tg, above about 25°C; b) positioning a tubular heat-recoverable article adjacent such that on recovery the substrate restrains the article to a recovery of less than about 25%, based on the dimension of the deformed article; c) heating said article to a temperature between Tg and the crystalline melting temperature, Tm, of the polymer thereby causing the article to recover about said substrate exerting a stress of at least about 1100 X (E-1)0.5 pounds per square inch, wherein E is the unresolved recovery ratio on said substrate; and d) cooling said article.
Claim 18
Independent Claim
111 words
A method of joining cylindrical articles which comprises: a) positioning said cylindrical substrates in end-to-end abutting relationship; b) positioning a heat-shrinkable tubular article such that it surrounds the ends of said cylindrical substrates, said article being of a semi-crystalline polymer having a glass transition temperature, Tg, above about 25°C; c) heating said article to a temperature between Tg and the crystalline melting temperature, Tm, of the polymer to cause it to shrink and exert a stress of at least 1100 X (E-1)0.5 pounds per square inch, wherein E is the unresolved recovery ratio on the cylindrical substrates thereby joining the substrates together; and d) cooling the recovered article and joined substrates.
Claim 19
Independent Claim
111 words
A method of joining cylindrical articles which comprises: a) positioning said cylindrical substrates in end-to-end abutting relationship; b) positioning a heat-shrinkable tubular article such that it surrounds the ends of said cylindrical substrates, said article being of a semi-crystalline polymer having a glass transition temperature, Tg, above about 25°C; c) heating said article to a temperature between Tg and the crystalline melting temperature, Tm, of the polymer to cause it to shrink and exert a stress of at least 1100 X (E-1)0.5 pounds per square inch, wherein E is the unresolved recovery ratio on the cylindrical substrates thereby joining the substrates together; and d) cooling the recovered article and joined substrates.
Claim 20
Dependent Claim
21 words
A method in accordance with Claim 14 wherein an intermediate layer is positioned between the heat shrinkable article and the substrates.
Claim 21
Dependent Claim
14 words
A method in accordance with Claim 15 wherein said intermediate layer comprises an adhesive.
Claim 22
Independent Claim
111 words
A method of securing a braid to a cylindrical substrate which comprises: a) placing the braid over the substrate in abutting relationship; b) positioning a heat-shrinkable ring such that it surrounds braid and substrate, said article being of a semi-crystalline polymer having a glass transition temperature, Tg, above about 25°C; and c) heating said ring to a temperature between Tg and the crystalline melting temperature, Tm, of the polymer to cause it to shrink and exert a stress of at least 1100 X (E-1)0.5 pounds per square inch, wherein E is the unresolved recovery ratio on the braid and securing the braid to the substrate; and d) cooling the recovered ring.
Claim 23
Independent Claim
111 words
A method of securing a braid to a cylindrical substrate which comprises: a) placing the braid over the substrate in abutting relationship; b) positioning a heat-shrinkable ring such that it surrounds braid and substrate, said article being of a semi-crystalline polymer having a glass transition temperature, Tg, above about 25°C; and c) heating said ring to a temperature between Tg and the crystalline melting temperature, Tm, of the polymer to cause it to shrink and exert a stress of at least 1100 X (E-1)0.5 pounds per square inch, wherein E is the unresolved recovery ratio on the braid and securing the braid to the substrate; and d) cooling the recovered ring.
References Cited (Backward Citations)
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