Patent EP0269449A2 successfully refreshed from Google Patents.
EP0269449A2
Expired / Lapsed
EP
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Porous flexible radially expanded fluoropolymers and process for producing the same
Assignee: Baxter International Inc
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Filing: 1987-11-26
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Granted: —
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Expires: 2007-11-26
Abstract
Abstract An interpenetrated matrix of a polytetrafluoroethylene and an elastomer is formed into a composite material which is flexible, durable and highly porous with a tight microporous structure and has a high rate of retractability. The composite material is subjected to radial expansion to produce shaped articles such as tubes and rods with excellent compliance, flexibility and elasticity. More particularly, the composite material can be utilized to produce vascular grafts with excellent biological compatibility that are capable of dynamic local diameter change responsive to pulsatile blood pressure change.
Inventors
- 👤 Roger Tu
- 👤 Edwin Wang
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-23 18:14
CPC Classifications
B; B29; B29C; B29C67/00; B29C67/20; B29C67/205; A; A61; A61F; A61F2/00; A61F2/02; A61F2/04; A61F2/06; A61L; A61L27/00; A61L27/14; A61L27/26; A61L27/50; A61L27/56; B29B; B29B11/00; B29B11/06; B29B11/12; B29C55/00; B29C55/005; B29C55/22; B29C55/24; B29C2949/00; B29C2949/07; B29C2949/081; B29C2949/082; B29C2949/0829; B29C48/00; B29C48/001; B29C48/0012; B29C48/0018; B29C48/03; B29C48/06; B29C48/09; B29C48/10; B29K; B29K2027/00; B29K2027/12; B29K2027/18; B29K2105/00; B29K2105/04; B29L; B29L2023/00; B29L2023/22
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
63 words
A process for the production of a porous compliant shaped article from a poly(tetrafluoroethylene) polymer, which process comprises first expanding a shaped article comprising poly(tetrafluoroethylene) crossed-linked with at least one elastomer, heating the unsintered shaped article at a temperature and for a time sufficient to cross-link said at least one elastomer to poly(tetrafluoroethylene), sintering the shaped article and radially expanding the sintered article.
Claim 2
Dependent Claim
63 words
A process for the production of a porous compliant shaped article from a poly(tetrafluoroethylene) polymer, which process comprises first expanding a shaped article comprising poly(tetrafluoroethylene) crossed-linked with at least one elastomer, heating the unsintered shaped article at a temperature and for a time sufficient to cross-link said at least one elastomer to poly(tetrafluoroethylene), sintering the shaped article and radially expanding the sintered article.
Claim 3
Dependent Claim
23 words
A process according to Claim 1, wherein the radial expansion is up to 100% of the original inside diameter of the shaped article.
Claim 4
Dependent Claim
20 words
A process according to Claim 1 or Claim 2, wherein expansion occurs at a temperature of from 35°C to 342°C.
Claim 5
Dependent Claim
26 words
A process according to any one of Claims 1 to 3, wherein the radial expansion occurs at a temperature ranging from room temperature to 250°F (121°C).
Claim 6
Dependent Claim
19 words
A process according to any one of the preceding Claims, wherein the sintering temperature ranges from 342°C to 390°C.
Claim 7
Dependent Claim
24 words
A process according to any one of the preceding Claims, wherein the elastomer is cross-linked at a temperature from 150°F (65°C) to 350°F (177°C).
Claim 8
Dependent Claim
20 words
A process according to Claim 6, wherein the elastomer is cross-linked for a period of from 5 to 60 minutes.
Claim 9
Dependent Claim
29 words
A process according to any one of the preceding Claims, wherein the unsintered shaped article is expanded by linear stretching prior to sintering and radially expanding the shaped article.
Claim 10
Dependent Claim
26 words
A process according to any one of the preceding Claims, wherein the sintered shaped article is retracted to from 40% to 90% of its original length.
Claim 11
Dependent Claim
53 words
A process according to any one of the preceding Claims, wherein the elastomer is polyvinylidene fluoride-co-hexafluoropropylene, poly[tetrafluoroethylene-co-perfluoro(methylvinylether)], poly(tetrafluoroethylene-co-propylene), poly(vinylidene-co-chlorotrifluoroethylene), a silicone, a fluorosilicone, a fluoroalkoxy phosphazene, a segmented copolyester ether, a styrene butadiene block copolymer, a polyether, an acrylonitrile butadiene polymer, an isoprene polymer or a mixture of any two or more thereof.
Claim 12
Dependent Claim
29 words
A process according to any one of the preceding Claims, wherein the elastomer is present in an amount of from 2% to 50% by weight of the shaped article.
Claim 13
Dependent Claim
56 words
A process according to any one of the preceding Claims, further comprising: compacting the radially expanded sintered article to its pre-radially expanded shape, contacting said compacted sintered article with a solvent to partially dissolve said elastomer, removing said solvent, and ceasing the compaction of said sintered article to provide a porous longitudinally elastic compliant shaped article.
Claim 14
Dependent Claim
38 words
A process according to Claim 12, wherein said radially expanded sintered article is compacted by fitting said article around a mandril having a smaller diameter than said article and applying means to hold said article on said mandril.
Claim 15
Dependent Claim
19 words
A process according to Claim 13, wherein said means to hold said article on said mandril is pressurized air.
Claim 16
Dependent Claim
21 words
A process according to Claim 13, wherein said means to hold said article on the mandril is porous tape or latex.
Claim 17
Dependent Claim
31 words
A process according to Claim 15, wherein said means is woven porous tape applied on said article at a wrapping angle of 70° with respect to the axis of the mandril.
Claim 18
Dependent Claim
20 words
A process according to any one of Claims 12 to 16, wherein the solvent is Freon TF, tetrahydrofuran or 1,1,1-trichloroethane.
Claim 19
Dependent Claim
18 words
A process according to any one of Claims 12 to 17, wherein said solvent is removed by evaporation.
Claim 20
Dependent Claim
30 words
A porous, longitudinally elastic vascular graft that is capable of dynamic local diameter or luminal volume change in response to pulsatile blood pressure change comprising poly(tetrafluoroethylene) cross-linked with an elastomer.
Claim 21
Dependent Claim
30 words
A porous, longitudinally elastic vascular graft that is capable of dynamic local diameter or luminal volume change in response to pulsatile blood pressure change comprising poly(tetrafluoroethylene) cross-linked with an elastomer.
Claim 22
Dependent Claim
49 words
A graft according to Claim 19, wherein the elastomer is polyvinylidene fluoride-co-hexafluoropropylene, poly[tetrafluoroethylene-co-perfluoro(methylvinylether)], poly(tetrafluoroethylene-co-propylene), poly(vinylidene-co-chlorotrifluoroethylene), a silicone, a fluorosilicone, a fluoroalkoxy phosphazene, a segmented copolyester ether, a styrene butadiene block copolymer, a polyether, an acrylonitrile butadiene polymer, an isoprene polymer or a mixture of any two or more thereof.
Claim 23
Dependent Claim
25 words
A graft according to Claim 19, wherein the elastomer is present in an amount of from 2% to 50% by weight of the shaped article.
Claim 24
Dependent Claim
17 words
A graft according to Claim 19, wherein the internal diameter is from 1 mm to 10 mm.
References Cited (Backward Citations)
No citation records indexed.
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