Polycarbonate resin and preparation method therefor

1. A polycarbonate resin comprising:

a repeat unit represented by Formula 1;

a repeat unit represented by Formula 2; and

a unit represented by Formula 3:

wherein A is a single bond, a C 1 to C 20 hydrocarbon group, —CO—, —O—, —S—, or —SO 2 —; R 1 , R 2 , and R 5 are each independently a halogen atom or a C 1 to C 10 hydrocarbon group; R 3 is a C 1 to C 20 alkyl group, a C 6 to C 20 aryl group, a C 1 to C 20 alkoxy group, or a C 6 to C 20 aryloxy group; R 4 is a C 1 to C 20 hydrocarbon group; a, b, and c are each independently an integer of 0 to 4; n is an integer of 3 to 6; and * is a binding site.

2. The polycarbonate resin according to claim 1 , wherein a molar ratio of the repeat unit represented by Formula 1 to the repeat unit represented by Formula 2 ranges from about 5:1 to about 100:1, and the unit represented by Formula 3 is present in an amount of about 0.01 parts by mole to about 10 parts by mole relative to 100 parts by mole of the repeat unit represented by Formula 1 and the repeat unit represented by Formula 2.

3. The polycarbonate resin according to claim 1 , wherein the polycarbonate resin has a weight average molecular weight of about 10,000 g/mol to about 200,000 g/mol.

4. The polycarbonate resin according to claim 1 , wherein the polycarbonate resin has an intrinsic viscosity of about 0.1 dl/g to about 3.0 dl/g.

5. The polycarbonate resin according to claim 1 , wherein the polycarbonate resin has a Mark-Houwink constant of about 0.50 to about 0.65.

6. The polycarbonate resin according to claim 1 , wherein the polycarbonate resin has a flame retardancy of V-1 or more, as measured on an about 2.0 mm thick specimen by the UL-94 vertical test method.

7. The polycarbonate resin according to claim 1 , wherein the polycarbonate resin has a notched Izod impact strength of about 6 kgf·cm/cm to about 20 kgf·cm/cm, as measured on an about ⅛″ thick specimen in accordance with ASTM D256.

8. The polycarbonate resin according to claim 1 , wherein the polycarbonate resin has a transmittance of about 85% or more, as measured on an about 3.2 mm thick specimen in accordance with ASTM D1003.

9. The polycarbonate resin according to claim 1 , wherein the polycarbonate resin has a Vicat softening temperature of about 130° C. or more, as measured under a load of about 5 kg in accordance with ASTM D1525.

10. A method of preparing a polycarbonate resin, comprising:

reacting a diol compound represented by Formula 4 with a carbonate ester compound represented by Formula 5, a phosphoric acid ester compound represented by Formula 6, and a compound represented by Formula 7:

wherein A is a single bond, a C 1 to C 20 hydrocarbon group, —CO—, —O—, —S—, or —SO 2 —; R 1 , R 2 , and R 5 are each independently a halogen atom or a C 1 to C 10 hydrocarbon group; R 3 is a C 1 to C20 alkyl group, a C 6 to C 20 aryl group, a C 1 to C 20 alkoxy group, or a C 6 to C 20 aryloxy group; R 4 is a C 1 to C 20 hydrocarbon group; R 6 , R 7 , R 8 and R 9 are each independently a C 1 to C 10 hydrocarbon group; R 10 is a hydrogen atom, a C 1 to C 10 alkyl group, or a C 6 to C 10 aryl group; a, b, and c are each independently an integer of 0 to 4; and n is an integer of 3 to 6.

11. The method according to claim 10 , wherein a molar ratio of the carbonate ester compound represented by Formula 5 to the phosphoric acid ester compound represented by Formula 6 ranges from about 5:1 to about 100:1; a total amount of the carbonate ester compound represented by Formula 5 and the phosphoric acid ester compound represented by Formula 6 ranges from about 100 parts by mole to about 110 parts by mole relative to about 100 parts by mole of the diol compound represented by Formula 4; and an amount of the compound represented by Formula 7 ranges from about 0.01 parts by mole to about 10 parts by mole relative to about 100 parts by mole of the diol compound represented by Formula 4.

12. A molded article formed of the polycarbonate resin according to claim 1 .