Thermoplastic compositions for laser direct structuring and methods for the manufacture and use thereof
View Patent ↗The present disclosure relates to thermoplastic compositions. The disclosed compositions comprise a polycarbonate polymer, a polysiloxane-polycarbonate copolymer, a laser direct structuring additive, and a siloxane additive. Also disclosed are methods for making the disclosed thermoplastic compositions and articles of manufacture comprising the disclosed thermoplastic compositions.
1. A thermoplastic composition comprising:
a. a polycarbonate polymer;
b. a polysiloxane-polycarbonate copolymer;
c. a laser direct structuring additive; and
d. a siloxane additive;
wherein a molded article having a thickness of 3.2 mm formed from the composition exhibits a notched izod impact energy that is at least 10% greater than that exhibited by a molded article formed from an identical reference composition in the absence of the siloxane additive.
2. The thermoplastic composition of claim 1 , wherein the molded article formed from the composition exhibits a notched izod impact energy that is at least 100% greater than that exhibited by a molded article formed from an identical reference composition in the absence of the siloxane additive.
3. The thermoplastic composition of claim 1 , wherein the molded article formed from the composition exhibits a notched izod impact energy that is at least 500% greater than that exhibited by a molded article formed from an identical reference composition in the absence of the siloxane additive.
4. The thermoplastic composition of claim 1 , comprising:
a. a bisphenol A polycarbonate polymer;
b. a polysiloxane-polycarbonate block copolymer comprising diorganopolysiloxane blocks of the general formula (VII):
wherein x is from about 40 to about 60; and polycarbonate blocks are derived from bisphenol-A monomers;
wherein the diorganopolysiloxane blocks are randomly distributed in the polysiloxane-polycarbonate block copolymer;
wherein the siloxane content of the polysiloxane-polycarbonate block copolymer is about 20 wt %;
c. a laser direct structuring additive; and
d. an siloxane additive;
wherein the molded article formed from the composition exhibits a notched izod impact energy at 23° C. of at least 500 J/m and a notched izod impact energy at −23° C. of at least 300 J/m.
5. The thermoplastic composition of claim 4 , wherein the bisphenol A polycarbonate polymer of a) comprises a blend of at least two different bisphenol A polycarbonates.
6. The thermoplastic composition of claim 4 , wherein the molded article formed from the composition exhibits ductile failure mode as measured according to ASTM D256-2010.
7. The thermoplastic composition of claim 4 , comprising:
a. from 5 weight % to 20 weight % bisphenol A polycarbonate relative to the total weight of the thermoplastic composition in the absence of the siloxane additive; and
b. from 50 to 80 weight % polysiloxane-polycarbonate copolymer relative to the total weight of the thermoplastic composition in the absence of the siloxane additive.
8. The thermoplastic composition of claim 4 , wherein the laser direct structuring additive is present in the thermoplastic composition in an amount of from 5 weight % to 15 weight % relative to the total weight of the thermoplastic composition in the absence of the siloxane additive.
9. The thermoplastic composition of claim 4 , wherein the laser direct structuring additive is selected from a heavy metal mixture oxide spinel, a copper salt, or a combination thereof.
10. The thermoplastic composition of claim 9 , wherein the laser direct structuring additive comprises copper chromium oxide spinel.
11. The thermoplastic composition of claim 4 , wherein the siloxane additive is present in a super addition amount in the range of from greater than 0 weight % to 5 weight %.
12. The thermoplastic composition of claim 4 , wherein the siloxane additive is present in a super addition amount in the range of from 1 weight % to 3 weight %.
13. The thermoplastic composition of claim 4 , wherein the siloxane additive comprises an amino siloxane.
14. The thermoplastic composition of claim 4 , wherein the siloxane additive comprises a phenyl siloxane.
15. The thermoplastic composition of claim 4 , further comprising one or more optional additives selected from an antioxidant, flame retardant, inorganic filler, and stabilizer.
16. A method for making a thermoplastic composition; comprising forming a blend composition comprising:
a. a polycarbonate polymer;
b. a polysiloxane-polycarbonate copolymer;
c. a laser direct structuring additive; and
d. a siloxane additive;
wherein a molded article having a thickness of 3.2 mm formed from the blend composition exhibits a notched izod impact energy that is at least 10% greater than that exhibited by a molded article formed from an identical reference blend composition in the absence of the siloxane additive.
17. The method of claim 16 , wherein the molded article formed from the composition exhibits a notched izod impact energy that is at least 100% greater than that exhibited by a molded article formed from an identical reference composition in the absence of the siloxane additive.
18. The method of claim 16 , wherein the molded article formed from the composition exhibits a notched izod impact energy that is at least 500% greater than that exhibited by a molded article formed from an identical reference composition in the absence of the siloxane additive.
19. The method of claim 16 , wherein the formed blend composition comprises:
a. a bisphenol A polycarbonate polymer;
b. a polysiloxane-polycarbonate block copolymer comprising diorganopolysiloxane blocks of the general formula (VII):
wherein x is from about 40 to about 60; and polycarbonate blocks are derived from bisphenol-A monomers;
wherein the diorganopolysiloxane blocks are randomly distributed in the polysiloxane-polycarbonate block copolymer;
wherein the siloxane content of the polysiloxane-polycarbonate block copolymer ranges from 4 mole % to 20 mole %;
c. a laser direct structuring additive; and
d. a siloxane additive;
wherein the molded article formed from the composition exhibits a notched izod impact energy at 23° C. of at least 500 J/m and a notched izod impact energy at −23° C. of at least 300 J/m.
20. The method of claim 19 , wherein the bisphenol A polycarbonate polymer comprises a blend of at least two different bisphenol A polycarbonates.
21. The method of claim 19 , wherein the molded article formed from the composition exhibits ductile failure mode according to ASTM D256-2010.
22. The method of claim 19 , wherein the formed blend composition comprises:
a. from 5 weight % to 20 weight % bisphenol A polycarbonate relative to the total weight of the thermoplastic composition in the absence of the siloxane additive; and
b. from 50 to 80 weight % polysiloxane-polycarbonate copolymer relative to the total weight of the thermoplastic composition in the absence of the siloxane additive.
23. The method of claim 19 , wherein the laser direct structuring additive is present in the formed blend composition in an amount of from 5 weight % to 15 weight % relative to the total weight of the thermoplastic composition in the absence of the siloxane additive.
24. The method of claim 19 , wherein the laser direct structuring additive is selected from a heavy metal mixture oxide spinel, a copper salt, or a combination thereof.
25. The method of claim 19 , wherein the laser direct structuring additive comprises copper chromium oxide spinel.
26. The method of claim 19 , wherein the siloxane additive is present in the formed blend composition in a super addition amount in the range of from greater than 0 weight % to 5 weight %.
27. The method of claim 19 , wherein the siloxane additive is present in the formed blend in a super addition amount in the range of from 1 weight % to 3 weight %.
28. The method of claim 19 , wherein the siloxane additive comprises an amino siloxane.
29. The method of claim 19 , wherein the siloxane additive comprises a phenyl siloxane.
30. The method of claim 19 , wherein the blend composition further comprises one or more optional additives selected from an antioxidant, flame retardant, inorganic filler, and stabilizer.
31. The method of claim 19 , wherein the blend composition is formed by extrusion blending.
32. The method of claim 19 , further comprising forming a molded part from the formed blend composition.
33. The method of claim 32 , further comprising subjecting the molded part to a laser direct structuring process.