High temperature melting

Patent metadata

Field	Value
Publication number	US-9731047-B2
Application number	US-201414584519-A
Country	US
Kind code	B2
Filing date	Dec 29, 2014
Priority date	Feb 20, 2009
Publication date	Aug 15, 2017
Grant date	Aug 15, 2017

Abstract

The present invention relates to methods for making wear and oxidation resistant polymeric materials by high temperature melting. The invention also provides methods of making medical implants containing cross-linked antioxidant-containing tough and ductile polymers and materials used therewith also are provided.

First claim

What is claimed is:

1. A method of making a wear resistant polymeric material comprising the steps of:
(i) blending a polymeric material with at least one type of antioxidant and one type of peroxide to form a blended polymeric material;
(ii) consolidating the blended polymeric material;
(iii) heating the consolidated blended polymeric material at a temperature that is about 200° C. or more at about ambient pressure;
(iv) continue heating the consolidated polymeric material; and
(v) cooling the heated material to below the melting temperature of the polymeric material, thereby forming a wear resistant polymeric material.

2. The method according to claim 1 , wherein the wear resistant polymeric material is machined into a medical implant.

3. A method according to claim 2 , wherein the medical implant is further packaged and sterilized.

4. A method according to claim 3 , wherein the sterilization is done by gamma irradiation.

5. The method according to claim 1 , wherein the polymeric material is machined after the consolidating.

6. The method according to claim 1 , wherein the heating of the consolidated polymeric material is above 200° C. and is continued for at least 2 hours.

7. A medical implant comprising a wear resistant polymeric material made according to claim 1 , wherein the wear resistant polymeric material is machined into the medical implant.

8. The medical implant of claim 7 is further packaged and sterilized.

9. The medical implant of claim 8 , wherein the sterilization is done by gamma irradiation.

10. The method according to claim 1 , wherein the heating is performed in an inert atmosphere.

11. The method according to claim 1 , wherein the heating is carried in air or in an atmosphere containing oxygen, wherein the oxygen concentration is at least about 1%, 2%, 4%, or up to about 22%.

12. The method according to claim 1 , wherein the antioxidant is a phenolic antioxidant, vitamin E, or a mixture thereof.

13. The method according to claim 12 , wherein the phenolic antioxidant is Pentaerythritol Tetrakis (3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate).

14. The method according to claim 1 , wherein the polymeric material is compression molded as a single layer containing one or more antioxidants.

15. The method according to claim 1 , wherein the polymeric material is compression molded as multiple layers, wherein the layers contain different concentrations of one or more antioxidants.

16. The method according to claim 1 , wherein the polymeric material is compression molded to a second surface, thereby forming an interlocked hybrid material.

17. The method according to claim 1 , wherein the polymeric material is selected from the group consisting of a low-density polyethylene, high-density polyethylene, linear low-density polyethylene, ultra-high molecular weight polyethylene (UHMWPE), or a mixtures thereof.

18. The method according to claim 1 , wherein the polymeric material is ultra-high molecular weight polyethylene (UHMWPE).

Assignees

• Massachusetts Gen Hospital

Inventors

• Oral Ebru
• Muratoglu Orhun K

Classifications

• A61L27/505

  Stabilizers · CPC title

• A61L27/16

  obtained by reactions only involving carbon-to-carbon unsaturated bonds · CPC title

• C08J2323/06

  Polyethene · CPC title

• C08J3/203

  Solid polymers with solid and/or liquid additives · CPC title

• B65B55/10

  by liquids or gases · CPC title