Sulfur-stabilized copolycarbonates and articles formed therefrom

1. A copolycarbonate, comprising:

0.005-0.1 mole percent of sulfur-containing carbonate units derived from a sulfur-containing bisphenol monomer,

2-95 mole percent of high heat aromatic carbonate units derived from a high heat aromatic dihydroxy monomer, wherein the high heat aromatic dihydroxy monomer comprises a hydrogen on a benzylic carbon or a hydrogen on a tertiary carbon, and

5-98 mole percent of low heat carbonate units derived from a low heat aromatic monomer,

each based on the sum of the moles of the carbonate units; and

thioether carbonyl endcaps of the formula —C(═O)-L-S—R, wherein each occurrence of L is independently a C 1-12 aliphatic or aromatic linking group and R is a C 1-20 alkyl, C 6-18 aryl, or C 7-24 arylalkylene and wherein the thioether carbonyl endcaps are present in an amount effective to provide 5-70 parts per million by weight of added sulfur, based on the total parts by weight of the copolycarbonate;

wherein the sulfur-containing carbonate units are present in an amount effective to provide 5-30 parts per million by weight of added sulfur, based on the total parts by weight of the copolycarbonate.

2. The copolycarbonate of claim 1 , comprising:

0.005-0.1 mole percent of the sulfur-containing carbonate units;

20-90 mole percent of the high heat carbonate units; and

10-80 mole percent of bisphenol A carbonate units as the low heat carbonate units.

3. The copolycarbonate of claim 1 , wherein the high heat aromatic carbonate units are derived from 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethyl-cyclohexane, and optionally, 4,4′-(1-phenylethylidene)bisphenol, 4,4′-(3,3-dimethyl-2,2-dihydro-1H-indene-1,1-diyl)diphenol, 1,1-bis(4-hydroxyphenyl)cyclododecane, 3,8-dihydroxy-5a,10b-diphenyl-coumarano-2′,3′,2,3-coumarane, 2-phenyl-3,3′-bis(4-hydroxyphenyl) phthalimidine, or a combination thereof.

4. The copolycarbonate of claim 1 , wherein the sulfur-containing bisphenol monomer is 4,4′-sulfonyldiphenol, 4,4′-sulfinyldiphenol, 4,4′-thiodiphenol, or a combination thereof.

5. The copolycarbonate of claim 1 ,

wherein the endcaps are each independently of formulae

wherein R is a C 1-20 alkyl, C 6-18 aryl, or C 7-24 arylalkylene and b is 1-5.

6. A method of making the copolycarbonate of claim 1 , the method comprising polymerizing a composition comprising:

0.005-0.1 mole percent of a sulfur-containing bisphenol monomer,

2-95 mole percent of a high heat aromatic dihydroxy monomer, wherein the high heat aromatic dihydroxy monomer comprises a hydrogen on a benzylic carbon or a hydrogen on a tertiary carbon,

5-98 mole percent of a low heat dihydroxy monomer, based on the sum of the moles of the carbonate units; and

a thioether carbonyl endcapping agent of the formula G-C(═O)-L-S—R, wherein G is leaving group, L is a C 1-12 aliphatic or aromatic linking group and R is a C 1-20 alkyl, C 6-18 aryl, or C 7-24 arylalkylene and wherein the thioether carbonyl endcaps are present in an amount effective to provide 5-70 parts per million by weight of added sulfur, based on the total parts by weight of the copolycarbonate;

wherein the sulfur-containing bisphenol monomer units are present in an amount effective to provide 5-30 parts per million by weight of added sulfur, based on the total parts by weight of the copolycarbonate.

7. A thermoplastic composition comprising the copolycarbonate of claim 1 , and further comprising an additive, wherein the additive is a sulfur-containing stabilizer compound that is soluble in an organic solvent for the copolycarbonate and is substantially insoluble in an aqueous solvent at a pH of less than 7, a organosulfonic stabilizer, an antioxidant, a heat stabilizer, a light stabilizer, a ultraviolet light stabilizer, a plasticizer, a lubricant, a mold release agent, an antistatic agents, a colorant, a surface effect additive, a radiation stabilizer, a flame retardant, an anti-drip agent, an impact modifier, or a combination thereof.

8. The thermoplastic composition of claim 7 , wherein the sulfur-containing stabilizer compound is present, and comprises a C 6-40 hydrocarbon chain.

9. The thermoplastic composition of claim 7 , wherein the sulfur-containing stabilizer compound is a thioether carboxy compound, a thioether dicarboxy compound, a thioether ester compound, or a combination thereof.

10. The thermoplastic composition of claim 7 , wherein the sulfur-containing stabilizer compound is dilauryl thiodipropionate, dicetyl thiodipropionate, dimyristyl thiodipropionate, distearyl thiodipropionate, ditridecyl thiodipropionate, 2,2-bis[[3-(dodecylthio)-1-oxopropoxy]methyl]propane-1,3-diyl bis[3-(dodecylthio)propionate, or a combination thereof.

11. The thermoplastic composition of any claim 7 , wherein the sulfur-containing stabilizer compound is present in an amount effective to provide 5-50 parts per million by weight of sulfur, based on the total parts by weight of the copolycarbonate.

12. The thermoplastic composition of claim 7 , wherein the organosulfonic stabilizer is present in an amount effective to provide 2-40 ppm per million by weight of sulfur, based on the total parts by weight of the copolycarbonate.

13. The thermoplastic composition of claim 7 , having at least one of:

less than 5 parts per million by weight each of lithium, sodium, potassium, calcium, magnesium, ammonium, chlorine, bromine, fluorine, nitrite, nitrate, phosphite, phosphate, sulfate, formate, acetate, citrate, oxalate, trimethylammonium, triethylammonium, or a combination thereof as measured by ion chromatography;

the copolycarbonate is prepared from monomers wherein one or more of the monomers has a purity of at least 99.6% as determined by high performance liquid chromatography; or

a yellowness index of less than or equal to 30 as measured by ASTM D1925 on a 3.2 mm plaque.

14. An article comprising the thermoplastic composition of claim 7 , wherein the article is optionally a camera lens, a sensor lens, an illumination lens, a safety glass lens, an ophthalmic corrective lens, or an imaging lens, optionally where the lens is hardcoated.

15. The copolycarbonate of claim 1 , wherein the thioether carbonyl endcaps are each independently of the formula

16. The copolycarbonate of claim 1 , wherein the high heat aromatic carbonate units are derived from 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethyl-cyclohexane, and 2-phenyl-3,3′-bis(4-hydroxyphenyl) phthalimidine, 4,4′-(1-phenylethylidene)bisphenol, 4,4′-(3,3-dimethyl-2,2-dihydro-1H-indene-1,1-diyl)diphenol, 1,1-bis(4-hydroxyphenyl)cyclododecane, 3,8-dihydroxy-5a,10b-diphenyl-coumarano-2′,3′,2,3-coumarane, or a combination thereof.

17. The copolycarbonate of claim 1 , wherein the high heat aromatic carbonate units are derived from 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethyl-cyclohexane and the low heat carbonate units are present and are derived from bisphenol A.

18. The copolycarbonate of claim 1 , wherein the high heat aromatic carbonate units are derived from 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethyl-cyclohexane and 2-phenyl-3,3′-bis(4-hydroxyphenyl) phthalimidine, and the low heat carbonate units are present and are derived from bisphenol A.

19. The thermoplastic composition of claim 10 , wherein

the high heat aromatic carbonate units are derived from 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethyl-cyclohexane and optionally, 2-phenyl-3,3′-bis(4-hydroxyphenyl) phthalimidine, and

the low heat carbonate units are present and are derived from bisphenol A,

the sulfur-containing bisphenol monomer is 4,4′-sulfonyldiphenol, 4,4′-sulfinyldiphenol, 4,4′-thiodiphenol, or a combination thereof, and

the sulfur-containing stabilizer compound is 2,2-bis[[3-(dodecylthio)-1-oxopropoxy]methyl]propane-1,3-diyl bis[3-(dodecylthio)propionate.