US4129470A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of preparing a porous implantable material from polytetrafluoroethylene and carbon fibers
Assignee: Individual
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Filing: 1976-06-07
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Granted: 1978-12-12
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Expires: 1996-06-07
Abstract
Abstract A composition of material suitable for in vivo implantation to provide an environment in which normal tissue growth is fostered which composition is a porous fibrous structure in which the critical surface tension of the fibers is 35 dynes per centimeter or higher. This composition in the preferred form is a porous structure of carbon or graphite fibers bonded together by sintered polytetrafluoroethylene in a manner to expose a maximum amount of fiber surface.
Inventors
- 👤 Charles A. Homsy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 18:35
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/26; A; A61; A61L; A61L27/00; A61L27/40; A61L27/44; A61L27/443; A61L27/48; C08K; C08K7/00; C08K7/02; C08K7/04; C08K7/06; B; B29; B29C; B29C43/00; B29C43/006; C08J2327/00; C08J2327/02; C08J2327/12; C08J2327/18; Y; Y10; Y10S; Y10S264/00; Y10S264/17; Y10S264/19; Y10S623/00; Y10S623/924
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
170 words
A method of preparing an implantable composition of material which comprises mixing together in an organic liquid media, carbon fibers, polytetrafluoroethylene fibers, polytetrafluoroethylene resin, and from 60 to 80 percent of a material soluble in solvents other than the media used to form a uniform slurry, filtering the slurry to form a filter cake having a reduced amount of organic liquid media, compressing the filter cake at elevated temperatures at a pressure of up to about 3,000 pounds per square inch (lbs/in 2 ), rolling the compressed filter cake between rolls heated between about 100° up to about 280° F., drying the rolled cake at a temperature of up to about 350° F., sintering the dry cake at temperatures between 600° and 680° F., at a pressure of up to about 5,000 lbs/in 2 , for a period in excess of three minutes; leaching said sintered cake to remove said soluble material and subsequently drying same, to produce a material having spheroidal and dendritic spaces therein and which is bio-compatible.
Claim 2
Independent Claim
170 words
A method of preparing an implantable composition of material which comprises mixing together in an organic liquid media, carbon fibers, polytetrafluoroethylene fibers, polytetrafluoroethylene resin, and from 60 to 80 percent of a material soluble in solvents other than the media used to form a uniform slurry, filtering the slurry to form a filter cake having a reduced amount of organic liquid media, compressing the filter cake at elevated temperatures at a pressure of up to about 3,000 pounds per square inch (lbs/in 2 ), rolling the compressed filter cake between rolls heated between about 100° up to about 280° F., drying the rolled cake at a temperature of up to about 350° F., sintering the dry cake at temperatures between 600° and 680° F., at a pressure of up to about 5,000 lbs/in 2 , for a period in excess of three minutes; leaching said sintered cake to remove said soluble material and subsequently drying same, to produce a material having spheroidal and dendritic spaces therein and which is bio-compatible.
Claim 3
Dependent Claim
29 words
The method according to claim 1 wherein the drying step is carried out at temperatures between 150° and 350° F. for several hours prior to sintering said dry cake.
Claim 4
Dependent Claim
33 words
The method according to claim 1 wherein said compressing step is carried out at a temperature between 100° and 250° F. and at a pressure between 100 to 3,000 pounds per square inch.
Claim 5
Dependent Claim
28 words
The method according to claim 1 wherein said soluble material is sodium chloride and said leaching is done with distilled water as the solvent for said sodium chloride.
Claim 6
Dependent Claim
65 words
The method according to claim 1 wherein the implantable composition is bonded on at least one side thereof to a bonding material including the steps of leaching from the surface of the sintered cake, that is to be bonded, the soluble material, drying the leached material, and bonding a bonding material to the surface of the material from which the soluble material has been leached.
Claim 7
Dependent Claim
17 words
The method according to claim 5 including the step of bonding said composition to a metal prosthesis.
Claim 8
Dependent Claim
24 words
The method according to claim 5 including the step of bonding a wear material to the surface to which said bonding material is bonded.
Claim 9
Dependent Claim
31 words
The method according to claim 5 including the steps of forming said composition to fit the surface of a metal prosthesis, and bonding said composition to the surface of said prosthesis.
Claim 10
Dependent Claim
32 words
The method according to claim 7 including the step of forming the composition including said wear material into a desired shape in a mold by subjecting it to both heat and pressure.
Claim 11
Dependent Claim
28 words
The method according to claim 1, including the step of stacking a plurality of dry rolled cake before said sintering step to provide material of the desired thickness.
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) | 1981-12-11 | 1982-06-12 | 1982-12-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-12-11 | 1986-06-12 | 1986-12-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-12-11 | 1990-06-12 | 1990-12-12 | $7700.00 | Window Closed / Lapsed |