US6168626B1
Expired / Lapsed
US
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Ultra high molecular weight polyethylene molded article for artificial joints and method of preparing the same
Assignee: BMG Inc
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Filing: 1995-09-18
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Granted: 2001-01-02
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Expires: 2015-09-18
Abstract
Abstract An ultra high molecular weight polyethylene molded article for artificial joints has molecular orientation or crystal orientation in the molded article, and is low in friction and is superior in abrasion resistance, and therefore is available as components for artificial joints. Further, the ultra high molecular weight polyethylene molded article for artificial joints can be used as a component for artificial hip joints (artificial acetabular cup), a component for artificial knee joints (artificial tibial insert) and the socket for artificial elbow joints, and in addition to the medical use, it can be applied as materials for various industries by utilizing the characteristics such as low friction and superior abrasion resistance.
Inventors
- 👤 Suong-Hyu Hyon
- 👤 Masanori Oka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 21:09
CPC Classifications
C; C08; C08L; C08L23/00; C08L23/02; C08L23/04; C08L23/06; A; A61; A61L; A61L27/00; A61L27/14; A61L27/16; B; B29; B29C; B29C43/00; B29C43/003; C08F; C08F110/00; C08F110/02; C08J; C08J3/00; C08J3/28; B29C35/00; B29C35/02; B29C35/08; B29C35/0805; B29C2035/085; B29C43/02; B29C43/16; B29K; B29K2023/00; B29K2023/04; B29K2023/06; B29K2023/0658; B29K2023/0683; B29K2995/00; B29K2995/0037; B29K2995/0087; B29K2995/0089; B29L; B29L2031/00; B29L2031/753; B29L2031/7532; C08J2323/00; C08J2323/02; C08J2323/04; C08J2323/06; C08L2207/00; C08L2207/06; C08L2207/068
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
75 words
An ultra high molecular weight polyethylene molded block having a molecular weight not less than 5 million, having been crosslinked slightly and having been compression-deformed in a direction perpendicular to a compression plane, cooled and solidified in a compression-deformed state under pressure so as to have orientation of crystal planes in a direction parallel to the compression plane, and a thickness range of 5 to 10 mm in a direction perpendicular to the compression plane.
Claim 2
Dependent Claim
75 words
An ultra high molecular weight polyethylene molded block having a molecular weight not less than 5 million, having been crosslinked slightly and having been compression-deformed in a direction perpendicular to a compression plane, cooled and solidified in a compression-deformed state under pressure so as to have orientation of crystal planes in a direction parallel to the compression plane, and a thickness range of 5 to 10 mm in a direction perpendicular to the compression plane.
Claim 3
Dependent Claim
27 words
The molded block of claim 1 , wherein a melting temperature of the ultra high molecular weight polyethylene is in a range of 135 to 155° C.
Claim 4
Independent Claim
144 words
A method for producing an ultra high molecular weight polyethylene molded block having orientation of crystal planes in a direction parallel to a compression plane, comprising slightly crosslinking an ultra high molecular weight polyethylene molded block having a molecular weight not less than 5 million by irradiating the block with a high energy ray and thereby introducing a very small amount of crosslinking points into molecular chains of the block, then heating the crosslinked ultra high molecular weight polyethylene molded block up to a compression deformable temperature, compression-deforming the block by compressing the block in a direction perpendicular to the compression plane so as to deform the block, and then cooling the block while keeping the block in a deformed state under pressure, said block after cooling having a thickness range of 5 to 10 mm in a direction perpendicular to the compression plane.
Claim 5
Independent Claim
144 words
A method for producing an ultra high molecular weight polyethylene molded block having orientation of crystal planes in a direction parallel to a compression plane, comprising slightly crosslinking an ultra high molecular weight polyethylene molded block having a molecular weight not less than 5 million by irradiating the block with a high energy ray and thereby introducing a very small amount of crosslinking points into molecular chains of the block, then heating the crosslinked ultra high molecular weight polyethylene molded block up to a compression deformable temperature, compression-deforming the block by compressing the block in a direction perpendicular to the compression plane so as to deform the block, and then cooling the block while keeping the block in a deformed state under pressure, said block after cooling having a thickness range of 5 to 10 mm in a direction perpendicular to the compression plane.
Claim 6
Dependent Claim
30 words
The method of claim 3 , where the high energy ray is a radioactive ray and a dose of the irradiation is in the range of 0.01 to 5.0 MR.
Claim 7
Dependent Claim
40 words
The method of claim 3 or 4 , wherein the compression-deformable temperature is in a range of 50° C. lower than a melting temperature of the crosslinked ultra high molecular weight polyethylene to 80° C. higher than the melting temperature.
Claim 8
Dependent Claim
32 words
The method of claim 3 , 4 or 5 wherein a weight-average molecular weight of the ultra high molecular weight polyethylene before irradiation is in a range of 2 to 8 million.
Claim 9
Dependent Claim
140 words
An ultra molecular weight polyethylene molded block having orientation of crystal planes in a direction parallel to a compression plane, said block produced by slightly crosslinking an ultra high molecular weight polyethylene block having a molecular weight of not less than 5 million by irradiating the block with a high energy ray and thereby introducing a very small amount of crosslinking points into molecular chains of the block, then heating the crosslinked block up to a compression deformable temperature, compression-deforming the block by compressing the block in a direction perpendicular to the compression plane so as to deform the block, and then cooling and solidifying the block while keeping the block in a deformed state under pressure, said block after cooling and solidifying having a thickness range of 5 to 10 mm in a direction perpendicular to the compression plane.
Claim 10
Dependent Claim
140 words
An ultra molecular weight polyethylene molded block having orientation of crystal planes in a direction parallel to a compression plane, said block produced by slightly crosslinking an ultra high molecular weight polyethylene block having a molecular weight of not less than 5 million by irradiating the block with a high energy ray and thereby introducing a very small amount of crosslinking points into molecular chains of the block, then heating the crosslinked block up to a compression deformable temperature, compression-deforming the block by compressing the block in a direction perpendicular to the compression plane so as to deform the block, and then cooling and solidifying the block while keeping the block in a deformed state under pressure, said block after cooling and solidifying having a thickness range of 5 to 10 mm in a direction perpendicular to the compression plane.
Claim 11
Dependent Claim
96 words
Artificial joint for implantation in a joint of an animal, the joint comprising a joint component formed from an ultra high molecular weight polyethylene molded block having a molecular weight of not less than 5 million, having been crosslinked slightly and having been compression-deformed in a direction perpendicular to a compression plane, cooled and solidified in a compression-deformed state under pressure so as to have orientation of crystal planes in a direction parallel to the compression plane, said block having a thickness range of 5 to 10 mm in a direction perpendicular to the compression plane.
Claim 12
Dependent Claim
96 words
Artificial joint for implantation in a joint of an animal, the joint comprising a joint component formed from an ultra high molecular weight polyethylene molded block having a molecular weight of not less than 5 million, having been crosslinked slightly and having been compression-deformed in a direction perpendicular to a compression plane, cooled and solidified in a compression-deformed state under pressure so as to have orientation of crystal planes in a direction parallel to the compression plane, said block having a thickness range of 5 to 10 mm in a direction perpendicular to the compression plane.
Claim 13
Dependent Claim
18 words
Artificial joint according to claim 8 , the joint for implantation in a joint of a human being.
Claim 14
Dependent Claim
105 words
Artificial joint for implantation in a joint of an animal, the joint comprising a joint component formed from an ultra high molecular weight polyethylene molded block having a molecular weight of not less than 5 million, having been crosslinked slightly and having been compression-deformed in a direction perpendicular to a compression plane so as to have orientation of crystal planes in a direction parallel to the compression plane, wherein said block having a thickness range of 5 to 10 mm in a direction perpendicular to the compression plane and the melting temperature of the molded block is in a range of 135 to 155° C.
Claim 15
Dependent Claim
105 words
Artificial joint for implantation in a joint of an animal, the joint comprising a joint component formed from an ultra high molecular weight polyethylene molded block having a molecular weight of not less than 5 million, having been crosslinked slightly and having been compression-deformed in a direction perpendicular to a compression plane so as to have orientation of crystal planes in a direction parallel to the compression plane, wherein said block having a thickness range of 5 to 10 mm in a direction perpendicular to the compression plane and the melting temperature of the molded block is in a range of 135 to 155° C.
Claim 16
Dependent Claim
18 words
Artificial joint according to claim 10 , the joint for implantation in a joint of a human being.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-01-02 | 2004-07-03 | 2005-01-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-01-02 | 2008-07-03 | 2009-01-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-01-02 | 2012-07-03 | 2013-01-02 | $7700.00 | Window Closed / Lapsed |