Polycarbonates having a good wettability
View Patent ↗Polycarbonate resin containing small amounts of carbamate compounds is disclosed. The resin that contains at least one of compounds conforming to wherein R 1 and R 2 independently of one another denote hydrogen or C 1 -C 12 -alkyl, or together denote C 4 -C 12 -alkylidene, R 3 and R 4 independently of one another represent hydrogen, C 1 -C 12 -alkyl, or phenyl, or together with the carbon atom to which they are bonded form cyclohexyl or trimethylcyclohexyl, and R 5 denotes hydrogen, C 1 -C 12 -alkyl, C 5 -C 12 -cycloalkyl, phenyl or cumyl, are characterized by their low electrostatic field and therefore suitable for making optical storage media.
1. A polycarbonate resin produced by a continuous interfacial process wherein the resin contains
0.2 to 300 ppm of one or more compounds conforming structurally to formula (I)
wherein
R 1 and R 2 independently of one another denote hydrogen or C 1 -C 12 -alkyl, or together denote C 4 -C 12 -alkylidene,
R 3 and R 4 independently of one another represent hydrogen or C 1 -C 12 -alkyl, or phenyl, or together with carbon atom to which they are bonded form cyclohexyl or trimethylcyclohexyl, and
R 5 denotes hydrogen, C 1 -C 12 -alkyl, C 5 C 12 -cycloalkyl, phenyl or cumyl,
wherein the content is measured in acetone extract by chromatography by means of HPLC
wherein the process comprises reacting at least one bisphenol with an excess of 5 to 17 mol % of phosgene (based on the total of bisphenols employed) wherein the reaction has a pH is in the alkaline range and a temperature of 0 to 40° C.
2. The polycarbonate according to claim 1 wherein compounds conforming to formula (1) are present in an amount of 0.2 to 250 ppm.
3. The polycarbonate according to claim 1 , wherein the content of compounds conforming to formula (1) is 0.2 to 200 ppm.
4. The polycarbonate according to claim 1 , wherein, in the formula (1)
R 1 and R 2 independently of one another represent hydrogen, methyl, ethyl, propyl or butyl, or together represent C 4 -C 5 -alkylidene,
R 3 and R 4 independently of one another represent hydrogen, C 1 -C 8 -alkyl or phenyl, or together with the carbon atom to which they are bonded form cyclohexyl or trimethylcyclohexyl, and
R 5 denotes hydrogen, tert-butyl or cumyl.
5. A molded article comprising the polycarbonate according to claim 1 .
6. An injection moulding comprising the polycarbonate according to claim 1 , wherein the electrostatic field, measured at a distance of 100 mm, is not more than 18 kV/m.
7. Carrier for an optical disk comprising the polycarbonate according to claim 1 .
8. Optical disk comprising the polycarbonate according to claim 1 .
9. A polycarbonate resin produced by a continuous interfacial process wherein the resin contains
0.2 to 500 ppm of compounds conforming to formula (4)
wherein
R 1 and R 2 independently of one another denote hydrogen or C 1 —C 12 -alkyl, or together denote C 4 -C, 2 -alkylidene,
R 3 and R 4 independently of one another represent hydrogen or C 1 -C, 2 -alkyl, or phenyl, or together with carbon atom to which they are bonded form cyclohexyl or trimethylcyclohexyl, and
where the contents is measured by HPLC in the acetone extract after alkaline hydrolysis with sodium hydroxide solution and
wherein the process comprises reacting at least one bisphenol with an excess of 5 to 17 mol % of phosgene (based on the total of bisphenols employed).
10. The polycarbonate according to claim 3 , wherein, in the formula (1)
R 1 and R 2 independently of one another represent hydrogen, methyl, ethyl, propyl or butyl, or together represent C 4 -C 5 -alkylidene,
R 3 and R 4 independently of one another represent hydrogen, C 1 - 8 -alkyl or phenyl, or together with the carbon atom to which they are bonded form cyclohexyl or trimethylcyclohexyl, and
R 5 denotes hydrogen, tert-butyl or cumyl.
11. The polycarbonate as claimed in claim 1 , wherein the process comprises reacting at least one bisphenol with an excess of 8 to 17 mol % of phosgene (based on the total of bisphenols employed).
12. A process to produce a polycarbonate resin containing 0.2 to 300 ppm of one or more compounds conforming structurally to formula (I)
wherein
R 1 and R 2 independently of one another denote hydrogen or C 1 -C 12 -alkyl, or together denote C 4 -C 12 -alkylidene,
R 3 and R 4 independently of one another represent hydrogen or C 1 -C 12 -alkyl, or phenyl, or together with carbon atom to which they are bonded form cyclohexyl or trimethylcyclohexyl, and
R 5 denotes hydrogen, C 1 -C 12 -alkyl, C 5 -C 12 -cycloalkyl, phenyl or cumyl,
wherein the content is measured in acetone extract by chromatography by means of HPLC
which comprises reacting at least one bisphenol with an excess of 3 to 17 mol % of phosgene (based on the total of bisphenols employed) in a continuous phase interphase process wherein the reaction has a pH is in the alkaline range and a temperature of 0 to 40° C.
13. The process as claimed in claim 12 , wherein phosgene is metered in an aqueous phase and the pH of the aqueous phase in the alkaline range from 8.5 to 12.
14. The process as claimed in claim 12 , wherein the temperature during the phosgenation is 5° C. to 36° C.
15. The process as claimed in claim 13 , which further comprises metering sodium hydroxide.
16. The process as claimed in claim 13 , which further comprises an inert organic solvent or solvent mixture which forms a second phase.
17. The process as claimed in claim 13 , which further comprises one or more catalysts wherein the total amount of catalysts used is between 0.001 to 10 mole % based on the moles of bisphenols employed.
18. The process as claimed in claim 13 , which further comprises one or more catalysts wherein the total amount of catalysts used is between 0.05 to 5 mole % based on the moles of bisphenols employed.
19. The polycarbonate according to claim 9 , wherein the content of compounds conforming to formula (4) is 0.2 to 300 ppm.