Transparent articles prepared from thermoplastic compositions having high flow and ductility, and method of preparing articles
View Patent ↗Disclosed herein is a camera lens comprising a thermoplastic composition comprising a poly(aliphatic ester)-polycarbonate copolymer comprising soft block ester units derived from an alpha, omega C 6-20 aliphatic dicarboxylic acid or derivative thereof, a dihydroxyaromatic compound, and a carbonate source, wherein the thermoplastic composition has a melt volume rate of 13 to 25 cc/10 min at 250° C. and under a load of 1.2 Kg and a dwell time of 6 minutes, according to ASTM D1238-04, and wherein the camera lens has an effective lens area of 0.5 to 100 mm 2 . A method of making the camera lens, and a camera lens comprising a thermoplastic composition comprising a redistribution product of a poly(aliphatic ester)-polycarbonate, are also disclosed.
1. A camera lens comprising a thermoplastic composition comprising
a poly(aliphatic ester)-polycarbonate copolymer comprising soft block ester units derived from an alpha, omega C 6-20 aliphatic dicarboxylic acid or derivative thereof, a dihydroxyaromatic compound, and a carbonate source,
wherein the thermoplastic composition has a melt volume rate of 13 to 25 cc/10 min at 250° C. and under a load of 1.2 Kg and a dwell time of 6 minutes, according to ASTM D1238-04, and
wherein the camera lens has an effective lens area of 0.5 to 100 mm 2 .
2. The camera lens of claim 1 , wherein the poly(aliphatic ester)-polycarbonate copolymer has a weight average molecular weight of 16,000 to 19,000 g/mol, when measured by gel permeation chromatography using a crosslinked styrene-divinylbenzene column calibrated to polycarbonate standards.
3. The camera lens of claim 1 , wherein the poly(aliphatic ester)-polycarbonate comprises 0.5 to 10 wt % soft-block ester units, based on the total weight of the poly(aliphatic ester)-polycarbonate.
4. The camera lens of claim 1 , wherein the glass transition temperature of the poly(aliphatic ester)-polycarbonate is from 110 to 145° C.
5. The camera lens of claim 1 , wherein the poly(aliphatic ester)-polycarbonate copolymer comprises ester units derived from an alpha, omega C 10-12 aliphatic dicarboxylic acid or derivative thereof.
6. The camera lens of claim 1 , wherein the alpha, omega C 6-20 aliphatic dicarboxylic acid comprises sebacic acid, and the dihydroxyaromatic compound comprises bisphenol A.
7. The camera lens of claim 1 , wherein the thermoplastic composition when molded into an article having a thickness of 3.2 mm, has a haze of less than or equal to 1.0 percent, when measured according to ASTM D1003-00.
8. The camera lens of claim 1 , wherein the thermoplastic composition when molded into an article having a thickness of 3.2 mm, has a transmittance of greater than or equal to 85 percent, when measured according to ASTM D1003-00.
9. The camera lens of claim 1 , wherein the thermoplastic composition, when molded into an article having a thickness of 3.2 mm, has a yellowness index (YI) of less than 4, when measured according to ASTM D1925-70.
10. The camera lens of claim 1 , the thermoplastic composition further comprising a polycarbonate.
11. The camera lens of claim 10 , wherein the thermoplastic composition comprises 50 to 99 wt % poly(aliphatic ester)-polycarbonate, and 1 to 50 wt % polycarbonate, based on the total weight of poly(aliphatic ester)-polycarbonate and any added polycarbonate.
12. The camera lens of claim 1 , having an effective lens area of 5 to 100 mm 2 .
13. The camera lens of claim 1 , having an effective lens area of 0.5 to 10 mm 2 .
14. The camera lens of claim 1 , wherein the camera lens thickness is from 0.25 to 2.5 mm.
15. The camera lens of claim 1 , wherein the camera lens is a spherical or aspherical lens having a focal point.
16. The camera lens of claim 15 , wherein the spherical lens is a double-convex lens, double-concave lens, plano-convex lens, plano-concave lens, meniscus convex lens or meniscus concave lens.
17. The camera lens of claim 15 , wherein the aspherical lens has an ellipsoidal, hyperbolic, or parabolic face.
18. An optical lens having a shaped surface, comprising a thermoplastic composition comprising:
a) a first polymer that is a poly(aliphatic ester)-polycarbonate copolymer comprising soft block ester units of the formula (8a)
wherein m is 4 to 18; and
b) optionally, a second polymer that is a polycarbonate,
wherein the thermoplastic composition has a melt volume rate of 13 cc/10 min to 25 cc/10 min at 250° C. and under a load of 1.2Kg and a dwell time of 6 minutes, according to ASTM D1238-04,
wherein an article molded from the thermoplastic composition and having a thickness of 3.2 mm has a haze of less than or equal to 1.0 percent, when measured according to ASTM D1003-00, and
wherein the camera lens has an effective lens area of 0.5 to 100 mm 2 .
19. A method of making a camera lens, comprising
molding a poly(aliphatic ester)-polycarbonate copolymer comprising soft block ester units derived from an alpha, omega C 6-20 aliphatic dicarboxylic acid or derivative thereof, a dihydroxyaromatic compound, and a carbonate source,
wherein the thermoplastic composition has a melt volume rate of 13 to 25 cc/10 min at 250° C. and under a load of 1.2 Kg and a dwell time of 6 minutes, according to ASTM D1238-04,
wherein the camera lens has an effective lens area of 0.5 to 100 mm 2 , and
wherein an optical lens prepared by the method has precision dimensions that deviate by less than 400 nm from a reference standard when measured by three dimensional contact profilometry.
20. The method of claim 19 , wherein successive optical lenses prepared by the method each have precision dimensions that deviate by less than 400 nm from a reference standard when measured by three dimensional contact measurement.
21. A camera lens comprising a thermoplastic composition, comprising
a reaction product of
a poly(aliphatic ester)-polycarbonate copolymer comprising 0.5 to 10 wt % soft block ester units derived from an alpha, omega C 6-20 aliphatic dicarboxylic acid or derivative thereof, a dihydroxyaromatic compound, and a carbonate source, with
a redistribution catalyst,
wherein the thermoplastic composition has a melt volume rate of 13 to 25 cc/10 min at 250° C. and under a load of 1.2 Kg and a dwell time of 4 minutes, according to ISO 1133, and
wherein the camera lens has an effective lens area of 0.5 to 100 mm 2 .
22. The camera lens of claim 21 , wherein the redistribution catalyst is a tetra C 1-6 alkylphosphonium hydroxide, C 1-6 alkyl phosphonium phenoxide, or a combination comprising one or more of the foregoing catalysts.
23. The camera lens of claim 21 , wherein the redistribution catalyst is present in an amount of 40 to 120 ppm.
24. The camera lens of claim 21 , wherein the thermoplastic composition further comprises a poly(aliphatic ester)-polycarbonate copolymer comprising 0.5 to 10 wt % soft block ester units that has not been treated with a redistribution catalyst to form a reaction product.