Wear resistant compositions with low particulate contamination and method of making those compositions
View Patent ↗The present disclosure relates to a wear resistant polymer composition. The disclosed composition comprises a polymer matrix and a tetrafluoroethylene polymer. Also disclosed is a method for making the disclosed polymer composition and an article of manufacture comprising the disclosed polymer composition.
1. A polymer composition comprising:
a) from about 55 weight % to about 95 weight % of a thermoplastic polymer matrix;
b) from about 5 weight % to about 20 weight % of a particulate polytetrafluoroethylene additive dispersed within the thermoplastic polymer matrix, wherein the particulate polytetrafluoroethylene additive has an average particle size less than about 40 μm, and wherein at least 90 weight % of the particulate polytetrafluoroethylene additive particles are smaller than about 60 μm; and
c) from greater than 0 weight % to about 40 weight % of a reinforcement filler dispersed within the thermoplastic polymer matrix; and
wherein the polymer composition exhibits a wear factor of less than about 300 as determined according to ATM D3702-78.
2. The polymer composition of claim 1 , wherein the thermoplastic polymer matrix comprises at least one polymer selected from the group consisting of a polycarbonate, a polycarbonate copolymer, a polyamide, a polyetherimide, a polybutylene terephthalate, and a polyethylene terephthalate.
3. The polymer composition of claim 1 , wherein the thermoplastic polymer matrix comprises a polycarbonate.
4. The polymer composition of claim 1 , wherein the thermoplastic polymer matrix comprises a bisphenol A polycarbonate polymer.
5. The polymer composition of claim 1 , wherein the thermoplastic polymer matrix comprises a polyester polycarbonate copolymer.
6. The polymer composition of claim 1 , wherein the thermoplastic polymer matrix is present in an amount of from about 60 weight % to about 80 weight % relative to the total weight of the polymer composition.
7. The polymer composition of claim 1 , wherein the particulate polytetrafluoroethylene additive has an average particle size less than about 30 μm.
8. The polymer composition of claim 1 , wherein the reinforcement filler is present in an amount of from about 10 weight % to about 30 weight % of the polymer composition.
9. The polymer composition of claim 1 , wherein the reinforcement filler comprises a carbon fiber, carbon black, glass fiber, aramid fiber, or any combination thereof.
10. The polymer composition of claim 1 , wherein the polymer composition exhibits a liquid particle count of less than 1×10 5 .
11. A molded article formed from the composition of claim 1 .
12. The molded article of claim 11 , wherein the molded article is a component part for an electronic device.
13. A method of making a polymer composition comprising combining:
a) from about 55 weight % to about 95 weight % of a thermoplastic polymer matrix;
b) from about 5 weight % to about 20 weight % of a particulate polytetrafluoroethylene additive dispersed with the thermoplastic polymer matrix, wherein the particulate polytetrafluoroethylene additive has an average particle size less than about 40 μm, and wherein at least 90 weight % of the particulate polytetrafluoroethylene additive particles are smaller than about 60 μm; and
c) from greater than 0 weight % to about 40 weight % of a reinforcement filler dispersed within the thermoplastic polymer matrix.
14. The method of claim 13 , wherein the thermoplastic polymer matrix comprises at least one polymer selected from a group consisting of a polycarbonate, a polycarbonate copolymer, a polyamide, a polyetherimide, a polybutylene terephthalate, and a polyethylene terephthalate.
15. The method of any of claim 13 , wherein the thermoplastic polymer matrix comprises a polycarbonate.
16. The method of any of claim 13 , wherein the thermoplastic polymer matrix comprises a bisphenol A polycarbonate polymer.
17. The method of claim 13 , wherein the thermoplastic polymer matrix comprises a polyester polycarbonate.
18. The method of claim 13 , wherein the thermoplastic polymer matrix is present in an amount of from about 60 weight % to about 80 weight % relative to the total weight of the polymer composition.
19. The method of claim 13 , wherein the particulate polytetrafluoroethylene additive has an average particle size less than about 40 μm.
20. The method of claim 13 , wherein the reinforcement filler is present in an amount of from about 10 weight % to about 30 weight % of the polymer composition.
21. The method of claim 13 , wherein the reinforcement filler comprises carbon fiber, carbon black, glass fiber, aramid fiber, or a combination thereof.
22. The method of claim 13 , wherein the polymer composition exhibits a wear factor of less than about 300 as determined by a test according to ASTM D3702-78.
23. The method of claim 13 , wherein the polymer composition exhibits a liquid particle counts of less than 1×10 5 .
24. The method of claim 13 , further comprising forming the polymer composition into a molded article.
25. The method of claim 24 , wherein the molded article is a component part for an electronic device.