High-temperature plastic article
View Patent ↗A plastic article having a thickness of about 2 mm to about 3.2 mm is disclosed. The article is formed from a thermoplastic composition that includes a first polymer that is a polycarbonate, a second polymer that is a polyphthalatecarbonate, a perfluoroakyl sulfonate salt; and a cyclic siloxane compound. The thermoplastic has a light transmittance at a thickness of 3.2 mm of at least 86% according to ASTM D1003-11E1, a UL94 flammability rating of V0, a notched Izod impact strength at a thickness of 3.2 mm of at least 500 J/m according to ASTM D256-05 with a 2.27 kg weight at a, and a heat deflection temperature at a thickness of 3.2 mm of at least 160° C. according to ASTM D648-06 under a load of 0.45 MPa.
1. A plastic article having a thickness of about 2 mm to about 3.2 mm, comprising a thermoplastic composition that comprises:
a first polymer that is a polycarbonate;
a second polymer that is a polyphthalatecarbonate;
a perfluoroalkyl sulfonate salt; and
a cyclic siloxane compound;
the thermoplastic composition having:
a light transmittance of at least 86% when tested in the form of a 3.2 mm thick test sample according to ASTM D1003-11E1 using procedure A and CIE standard illuminant C;
a flammability rating of V-0 when tested in the form of a 2.0 mm thick test sample according to Underwriter Laboratories UL94;
a notched Izod impact strength of at least 500 J/m when tested in the form of a 3.2 mm thick test sample according to ASTM D256-05 using a 2.27 kg weight; and
a heat deflection temperature of at least 160° C. when tested in the form of a 3.2 mm test sample according to ASTM D648-06 under a load of 0.45 MPa.
2. The article of claim 1 , wherein the second polymer comprises:
repeating units according to formula (1):
in which R 1 is a divalent group derived from a dihydroxy compound with the proviso that least 60 percent of the total number of R 1 groups contain aromatic moieties;
and repeating units according to formula (7):
in which J is a divalent group derived from a dihydroxy compound, and T is a divalent group derived from a diacid compound, with the proviso that at least 60 percent of the total number of T groups are derived from a phthalic acid;
wherein a molar ratio of repeat units according to formula (1) to repeat units of formula (7) is from about 1:1 to about 10:1.
3. The article of claim 2 , wherein the molar ratio of repeat units according to formula (1) to repeat units of formula (7) is from about 4:1 to about 5:1.
4. The article of claim 2 , wherein at least 60% of the total number of J groups contain aromatic moieties.
5. The article of claim 4 , wherein substantially all of the J groups contain aromatic moieties.
6. The article of claim 2 , wherein substantially all of the T groups are derived from a phthalic acid.
7. The article of claim 2 , wherein substantially all of the R 1 groups contain aromatic moieties.
8. The article of claim 7 , wherein substantially all of the R 1 groups are derived from bisphenol A.
9. The article of claim 1 , wherein the first polymer comprises repeating units according to formula (1):
in which R 1 is a divalent group derived from a dihydroxy compound with the proviso that least 60 percent of the total number of R 1 groups contain aromatic moieties.
10. The article of claim 1 , wherein the first polymer is substantially free of ester linkages.
11. The article of claim 1 , wherein the molar ratio of carbonate groups in the first and second polymers to phthalate groups in the second polymer is from about 1:1 to about 10:1.
12. The article of claim 1 , comprising from about 5 wt. % to about 95 wt. % of the first polymer, about 95 wt. % to about 5 wt. % of the second polymer, about 0.05 wt. % to about 5 wt. % of the perfluoroalkyl sulfonate salt, and about 0.05 wt. % to about 5 wt. % of the cyclic siloxane compound.
13. The article of claim 1 , having a light transmittance at least about 87 according to ASTM D1003-11E1.
14. The article of claim 1 , wherein the perfluoroalkyl sulfonate salt is selected from the group consisting of potassium perfluorobutane sulfonate, potassium perfluoroctane sulfonate, and tetraethylammonium perfluorohexane sulfonate, and a combination comprising at least one of the foregoing.
15. The article of claim 1 , wherein the thermoplastic composition has a melt flow rate as defined by ASTM D1238-04C of at least about 12 g/10 min. at 330° C. and a 2.16 kg load.
16. The article of claim 1 , wherein the first polymer has a weight average molecular weight of at least about 29,000.
17. The article of claim 1 , wherein the second polymer has a weight average molecular weight of at least about 21,000.
18. The article of claim 1 , wherein the cyclic siloxane compound is according to the formula:
wherein R k , R m , R n , R o , R p , R q , R s , and R t are each independently C 1 to C 36 alkyl, fluorinated or perfluorinated C 1 to C 36 alkyl, C 1 to C 36 alkoxy, C 6 to C 14 aryl, aryloxy of 6 to 14 carbon atoms, arylalkoxy of 7 to 36 carbon atoms, or C 1 to C 36 alkyl-substituted aryl of 6 to 14 carbon atoms.
19. The article of claim 18 , wherein the cyclic siloxane compound is octaphenylcyclotetrasiloxane.
20. The article of claim 1 , wherein the thermoplastic composition further comprises a flow promoter.
21. The article of claim 1 , that is a face shield, eyewear lens, window, or display screen.
22. The article of claim 18 , that is a face shield or safety goggle lens.
23. A method of making the article of claim 1 , comprising heating the thermoplastic composition to a temperature sufficient for the thermoplastic composition to flow, forming the thermoplastic composition in the shape of the article, and cooling the thermoplastic composition to solidify the article.
24. A plastic article having a thickness of about 2 mm to about 3.2 mm, comprising a thermoplastic composition that comprises:
a first polycarbonate polymer that is a homopolymer of bisphenol A;
a second polymer that is a polyphthalatecarbonate polymer comprising phthalate groups representing an equimolar mixture of terephthate groups and isophthalate groups;
potassium perfluorobutane sulfonate salt; and
octaphenylcyclotetrasiloxane.
25. The plastic article of claim 24 , wherein the thermoplastic composition has:
a light transmittance of at least 86% when tested in the form of a 3.2 mm thick test sample according to ASTM D1003-11E1 using procedure A and CIE standard illuminant C;
a flammability rating of V-0 when tested in the form of a 2.0 mm thick test sample according to Underwriter Laboratories UL94;
a notched Izod impact strength of at least 500 J/m when tested in the form of a 3.2 mm thick test sample according to ASTM D256-05 using a 2.27 kg weight; and
a heat deflection temperature of at least 160° C. when tested in the form of a 3.2 mm test sample according to ASTM D648-06 under a load of 0.45 MPa.
26. A face or eye shield having a thickness of about 2 mm to about 3.2 mm, comprising a thermoplastic composition that comprises:
a first polymer that is a polycarbonate;
a second polymer that is a polyphthalatecarbonate;
a perfluoroalkyl sulfonate salt; and
a cyclic siloxane compound;
the thermoplastic composition having:
a light transmittance of at least 86% when tested in the form of a 3.2 mm thick test sample according to ASTM D1003-11E1 using procedure A and CIE standard illuminant C;
a flammability rating of V-0 when tested in the form of a 2.0 mm thick test sample according to Underwriter Laboratories UL94;
a notched Izod impact strength of at least 500 J/m when tested in the form of a 3.2 mm thick test sample according to ASTM D256-05 using a 2.27 kg weight; and
a heat deflection temperature of at least 160° C. when tested in the form of a 3.2 mm test sample according to ASTM D648-06 under a load of 0.45 MPa.
27. The face or eye shield of claim 26 , wherein:
the first polymer is a homopolymer of bisphenol A;
the second polymer that is comprises phthalate groups representing an equimolar mixture of terephthate groups and isophthalate groups;
the perfluoroalkyl sulfonate salt is potassium perfluorobutane sulfonate salt; and
the cyclic siloxane compound is octaphenylcyclotetrasiloxane.
28. The face or eye shield of claim 26 , that is a firefighter helmet face shield.
29. The face or eye shield of claim 26 , that is a welder goggle lens.