Provided are a copolycarbonate and a polycarbonate composition comprising the same. The copolycarbonate comprises repeat units of the following Chemical Formula 1 and repeat units of the following Chemical Formula 2: Chemical Formula 1 ##STR00001## Chemical Formula 2 ##STR00002##

A method of producing a polycarbonate-polyorganosiloxane copolymer, including: a step (a) of obtaining a solution containing a polycarbonate-polyorganosiloxane copolymer through use of an alkaline aqueous solution of a dihydric phenol, phosgene, a polyorganosiloxane, and an organic solvent; a step (b) of continuously or intermittently draining the solution containing the copolymer from step (a), followed by separation of the drained solution into an aqueous phase and an organic phase to provide the organic phase with copolymer; and a step (c) of concentrating the organic phase with the from step (b) to remove the organic solvent, before heating the organic phase to a boiling region in the step (c), a viscosity of the organic phase being adjusted to 70 cP or less at 35° C., the polycarbonate-polyorganosiloxane copolymer obtained by the steps (a) to (c) including a polycarbonate-polyorganosiloxane copolymer containing a specific polycarbonate block (A) and a specific polyorganosiloxane block (B).

Provided is a method of producing a polycarbonate-polyorganosiloxane copolymer, including a step (a) of producing a polycarbonate oligomer with an alkaline aqueous solution of a dihydric phenol, phosgene, and an organic solvent, the method further including a step of setting a content of a polycarbonate-polyorganosiloxane copolymer in the organic solvent to be introduced into the step (a) to less than 850 ppm by mass.

A method for producing a polycarbonate copolymer which has siloxane constituent units represented by any of formulae (1-1)′ to (1-4)′ and prescribed polycarbonate constituent units, the method having a polymerization step for polymerizing a silane-based compound selected from among a prescribed diaryloxysilane compound, a prescribed dialkoxysilane compound and a prescribed silicon compound, a carbonate compound and a diol compound such as an aromatic diol compound or an alicyclic diol compound in the presence of a transesterification catalyst. The polymerization step is carried out in a molten state under reduced pressure while removing alcohols derived from the carbonate compound.

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Provided is a branched polycarbonate resin, including a constituent unit represented by the general formula (I′).

##STR00001##

A method for producing a polycarbonate copolymer which has siloxane constituent units represented by any of formulae (1-1) to (1-4) and prescribed polycarbonate constituent units, the method having a polymerization step for polymerizing a silane-based compound selected from among a prescribed diaryloxysilane compound, a prescribed dialkoxysilane compound and a prescribed silicon compound, a carbonate compound and a diol compound such as an aromatic diol compound or an alicyclic diol compound in the presence of a transesterification catalyst. The polymerization step is carried out in a molten state under reduced pressure while removing alcohols derived from the carbonate compound.

##STR00001##

A polycarbonate resin composition or a copolymer, comprising, as main repeating units, a carbonate unit (a-1) having a fluorene ring in a side chain, a carbonate unit (a-2) represented by the following formula (a-2):

##STR00001##

(wherein W represents an alkylene group having 1 to 20 carbon atoms or a cycloalkylene group having 6 to 20 carbon atoms, R represents a branched or linear-chain alkyl group having 1 to 20 carbon atoms or a cycloalkyl group having 6 to 20 carbon atoms optionally having a substituent, and u represents an integer of 0 to 3), and a carbonate unit (a-3) derived from 2,2-bis(4-hydroxyphenyl)propane, wherein 1) a molar ratio of the carbonate unit (a-1) to the carbonate unit (a-2) is from 50/50 to 80/20, and 2) a molar ratio of the total of the carbonate unit (a-1) and the carbonate unit (a-2) to the carbonate unit (a-3) is from 1:99 to 70:30. This polycarbonate resin composition or copolymer has excellent heat resistance, transparency, and bending resistance and has low retardation.

A multilayer body includes at least one layer (A) made of a polycarbonate resin (A) whose main repeating units include a unit (a-1) composed of an ether diol residue represented by the following formula (1) and a unit (a-2) composed of a diol residue represented by the following formula (2), and at least one layer (B) containing an aromatic polycarbonate resin (B), wherein the molar ratio of the unit (a-1) is 50 to 96 mol % and the molar ratio of the unit (a-2) is 4 to 50 mol %, with respect to 100 mol % of the total repeating units of the polycarbonate resin (A) and the proportion of the aromatic polycarbonate resin (B) in the layer (B) containing an aromatic polycarbonate resin (B) is 30% by weight or more, and the multilayer body is excellent in heat resistance, impact resistance, surface hardness, adhesion, and chemical resistance. ##STR00001##
In the formula (2), R.sup.1 and R.sup.2 each independently represent at least one group selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a cycloalkyl having 6 to 20 carbon atoms, a cycloalkoxy group having 6 to 20 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, an aralkyloxy group having 7 to 20 carbon atoms, a nitro group, an aldehyde group, a cyano group, and a carboxyl group, and when a plurality of R.sup.1 and R.sup.2 are present, they may be the same or different; a and b each represent an integer of 1 to 4; and W represents at least one bonding group selected from the group consisting of a single bond and a bonding group represented by the following formula (3). ##STR00002##
In the formula (3), R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7, R.sup.1, R.sup.9, and R.sup.10 each independently represent at least one group selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an aralkyl group having 7 to 20 carbon atoms, and when a plurality of R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7, R.sup.8, R.sup.9, and R.sup.10 are present, they may be the same or different; R.sup.11, R.sup.12, R.sup.13, and R.sup.14 each independently represent at least one group selected from the group consisting of an alkyl group having 1 to 10 carbon atoms, a cycloalkenyl group having 6 to 20 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an aryl group having 6 to 10 atoms, and an aralkyl group having 7 to 20 carbon atoms, and when a plurality of R.sup.11, R.sup.12, R.

Provided are a copolycarbonate- and a polycarbonate composition comprising the same. The copolycarbonate comprises repeat units of the following Chemical Formula 1 and repeat units of the following Chemical Formula 2:

##STR00001##

Provided is a polycarbonate-based resin composition, including: 10 to 90 mass % of a polycarbonate-polyorganosiloxane copolymer (E-1); and 10 to 90 mass % of an aromatic polycarbonate resin (E-2) except the polycarbonate-polyorganosiloxane copolymer (E-1), in which the molecular weight distribution of the polyorganosiloxane block of the polycarbonate-polyorganosiloxane copolymer is controlled within a specific region.