Disclosed is a polycarbonate composition including a polycarbonate; and a copolycarbonate, where the copolycarbonate includes an aromatic polycarbonate-based first repeating unit; and aromatic polycarbonate-based second repeating units having siloxane bonds, which include a repeating unit represented by Chemical Formula 2 and a repeating unit represented by Chemical Formula 3, where the copolycarbonate has an impact strength at room temperature of 840 to 1000 J/m as measured at 23 C. in accordance with ASTM D256 ( inch, Notched Izod), and the copolycarbonate satisfies Equation 1: ##STR00001##
TS/TS.sub.00.80.[Equation 1] The copolycarbonate in the composition provides an improved chemical resistance and impact strength simultaneously.

Disclosed is a copolycarbonate including an aromatic polycarbonate-based first repeating unit; and one or more aromatic polycarbonate-based second repeating units having siloxane bonds represented by Chemical Formula 2 and Chemical Formula 3: ##STR00001##
The copolycarbonate provides improved impact strength at low-temperature and improved YI (yellow index) simultaneously.

Disclosed is a copolycarbonate including aromatic polycarbonate-based repeating units represented by Chemical Formula 1 and Chemical Formula 2; and aromatic polycarbonate-based repeating units having siloxane bonds represented by Chemical Formula 3 and Chemical Formula 4: ##STR00001##
copolycarbonate provides improved impact strength at low-temperature, improved YI (yellow index), and improved melt index simultaneously.

The present invention relates to a copolycarbonate and a composition comprising the same, and more specifically to a technique for improving flame retardance and chemical resistance while maintaining inherent impact strength and melt index of the copolycarbonate, by comprising a branched repeating unit in the copolycarbonate structure.

The present invention relates to a copolycarbonate resin composition comprising a copolycarbonate in which a specific siloxane compound is introduced in a main chain of the polycarbonate, and a UV stabilizer. Since the present copolycarbonate resin composition has excellent weather resistance, the article prepared by using this composition exhibits less deteriorated surface quality and physical properties caused by ultraviolet rays or the like when exposed to the outside.

The present invention relates to copolycarbonates and a molded article comprising the same. The copolycarbonate according to the present invention has a structure in which a specific siloxane compound is introduced in a main chain of the polycarbonate, and thus has characteristics of providing excellent residence heat stability.

The present invention relates to a polycarbonate composition including a polycarbonate and an impact reinforcing agent, and an inorganic filler to improve a mechanical property thereof, and a copolycarbonate to solve a problem of appearance defect caused by including the inorganic filler.

Provided is a polycarbonate resin having a structural unit (I) represented by formula (1) below: ##STR00001##
wherein L.sup.1 and L.sup.2 each independently represent a divalent linking group selected from an alkylene group, a cycloalkylene group, an arylene group, an oxyalkylene group, an oxyarylene group, and a group formed by combining two or more of these, where one or more hydrogen atoms of the linking group are optionally further replaced with substituents, and two of the substituents are optionally bonded to each other to form a ring structure.

Provided are a resin including a unit of Chemical Formula 1 and a unit of Chemical Formula 2, a method for preparing the same, a resin composition including the same, and a molded article including the resin composition,

##STR00001## wherein all the variables are described herein.

A polycarbonate resin including a unit of Chemical Formula 1 and a unit of Chemical Formula 2, a method for preparing the same, a polycarbonate resin composition including the same, and a molded article are disclosed herein: ##STR00001## Ar1 and Ar2 are independently an aryl group, or a heteroaryl group, R1 is hydrogen, deuterium, a halogen group, a cyano group, an alkyl group, a cycloalkyl group, an alkoxy group, a silyl group, an aryl group, or a heteroaryl group, R2 and R3 are different from each other, r1 is 1 or 2, r2 and r3 are each an integer from 1 to 4, L1 and L2 are independently an arylene group, X1 to X8 are independently O or S, Z1 to Z4 are independently an alkylene group, or a cycloalkylene group, and a, b, c and d are independently an integer from 1 to 10.