Orthopedic device and polymer compositions for making same

Patent metadata

Field	Value
Publication number	US-10166120-B2
Application number	US-201715452824-A
Country	US
Kind code	B2
Filing date	Mar 8, 2017
Priority date	Mar 8, 2016
Publication date	Jan 1, 2019
Grant date	Jan 1, 2019

Abstract

Orthopedic devices are described including polymer compositions used to make the devices. The polymer composition contains a polyoxymethylene polymer in combination with various additives that prevent against agglomerations and spotting even when the composition contains significant amounts of coloring agents and/or waxes. In addition, the polymer composition has reduced formaldehyde emissions and excellent thermal stability properties.

First claim

What is claimed:

1. A polymer composition comprising:
a polyoxymethylene polymer, the polyoxymethylene polymer having a melt volume flow rate of less than 15 cm 3 /10 min when tested at 190° C. under a load of 2.16 kg, the polyoxymethylene polymer being present in the polymer composition in an amount of at least 70% by weight; and
a copolyamide and a dicyandiamide blended with the polyoxymethylene polymer, the copolyamide and the dicyandiamide being present in the composition at a weight ratio of greater than 2:1.

2. A polymer composition as defined in claim 1 , wherein the copolyamide and the dicyandiamide are present in the composition at a weight ratio of from about 2:1 to about 20:1.

3. A polymer composition as defined in claim 1 , wherein the copolyamide is present in the polymer composition in an amount from about 0.1% to about 1% by weight.

4. A polymer composition as defined in claim 1 , further comprising an acid scavenger.

5. A polymer composition as defined in claim 4 , wherein the acid scavenger comprises tricalcium citrate, the tricalcium citrate being present in the polymer composition in an amount from about 0.01% to about 0.1% by weight.

6. A polymer composition as defined in claim 1 , wherein the polymer composition is melamine free.

7. A polymer composition as defined in claim 1 , wherein the polymer composition contains one or more coloring agents in an amount from about 0.01% to about 2% by weight.

8. A polymer composition as defined in claim 1 , wherein the polymer composition contains one or more coloring agents in an amount greater than 0.8% by weight.

9. A polymer composition as defined in claim 7 , wherein the coloring agent comprises at least one of titanium dioxide, a blue pigment, a yellow pigment, and an orange pigment.

10. A polymer composition as defined in claim 1 , further comprising a phenolic antioxidant, the antioxidant comprising hexamethylene glycol bis[3-(3,5-di-tert-butyl-4-hydroxyphenylpropionate)].

Assignees

• Ticona Llc

Inventors

• Kim Sung Hye
• Larson Lowell Jay
• Tyler Mark Allen
• Luo Rong

Classifications

• A61L2430/02

  for reconstruction of bones; weight-bearing implants · CPC title

• A61F2002/30616

  Sets comprising a plurality of prosthetic parts of different sizes or orientations · CPC title

• A61F2/4684 Primary

  Trial or dummy prostheses · CPC title

• A61F2/36

  Femoral heads {; Femoral endoprostheses} · CPC title

• C08L59/02

  Polyacetals containing polyoxymethylene sequences only · CPC title