A branched polycarbonate comprising: high heat aromatic carbonate units derived from a high heat aromatic dihydroxy monomer units; optionally, low heat carbonate units derived from low heat monomer units; and 0.05-1.5 mole percent, preferably 0.05-1.0 mole percent, of a branching agent based on the total number of moles in the branched polycarbonate; wherein the branched polycarbonate has a tensile stress at break of 10-70 megaPascals measured according to ISO 527, and a glass transition temperature of 170-260 C. measured by differential scanning calorimetry according to ASTM D3418 with a 20 C./min heating rate.

An interfacial process for preparing a poly(aliphatic ester-carbonate) includes providing an initial polymerization reaction mixture comprising an aliphatic C6-20 dicarboxylic acid, a bisphenol, an alkali hydroxide, and optionally a catalyst in a solvent system comprising water and an immiscible organic solvent, adding an initial portion of a carbonyl dihalide over a first time period while maintaining the reaction at a first pH from 7 to 8; and adding a second portion of the carbonyl dihalide over a second, subsequent time period while maintaining the reaction pH at a second pH from 9 to 12, to provide a product polymerization mixture, wherein the amount of alkali hydroxide in the initial polymerization reaction mixture is effective to increase the fraction of the first time period at a measured pH of 7 to 8 compared to the same reaction mixture with a higher amount of alkali hydroxide in the initial polymerization mixture.

The present invention provides new classes of phenolic compounds derived from hydroxyacids and tyrosol or tyrosol analogues, useful as monomers for preparation of biocompatible polymers, and the biocompatible polymers prepared from these monomeric hydroxyacid-phenolic compounds, including novel biodegradable and/or bioresorbable polymers. These biocompatible polymers or polymer compositions with enhanced bioresorbabilty and processability are useful in a variety of medical applications, such as in medical devices and controlled-release therapeutic formulations. The invention also provides methods for preparing these monomeric hydroxyacid-phenolic compounds and biocompatible polymers.

Provided is a polycarbonate resin composition containing polycarbonate resin (A) having structural units represented by general formula (1) and polycarbonate resin (B) having a structural unit represented by general formula (2):

##STR00001##

(in general formula (1), R represents a hydrogen atom or C.sub.1-C.sub.4 alkyl group);

##STR00002##

(in general formula (2), R.sup.1 and R.sup.2 each independently represent a hydrogen atom, C.sub.1-C.sub.20 alkyl group, C.sub.1-C.sub.20 alkoxyl group, C.sub.5-C.sub.20 cycloalkyl group, C.sub.5-C.sub.20 cycloalkoxyl group, C.sub.6-C.sub.20 aryl group or C.sub.6-C.sub.20 aryloxy group, and Y represents a C.sub.1-C.sub.4 alkylene group.)

According to one embodiment, a polyester resin is provided, which includes a structural unit derived from a compound represented by general formula (1), a structural unit derived from a compound represented by general formula (2), and a structural unit derived from a dicarboxylic acid or a derivative thereof. ##STR00001##

The present invention makes it possible to provide a polycarbonate copolymer including structural units represented by general formula (K) and structural units represented by general formula (1). ##STR00001##
(In general formula (K), R represents H, CH.sub.3 or CH.sub.2CH.sub.3.) ##STR00002##
(In general formula (1), Q represents a C5 or higher aliphatic hydrocarbon group optionally including a hetero atom.).

The present invention makes it possible to provide a polycarbonate copolymer including structural units represented by general formula (K) and structural units represented by general formula (1). ##STR00001##
(In general formula (K), R represents H, CH.sub.3 or CH.sub.2CH.sub.3.) ##STR00002##
(In general formula (1), Q represents a C5 or higher aliphatic hydrocarbon group optionally including a hetero atom.).

According to one embodiment, a polyester resin is provided, which includes a structural unit derived from a compound represented by general formula (1), a structural unit derived from a compound represented by general formula (2), and a structural unit derived from a dicarboxylic acid or a derivative thereof.

##STR00001##

A copolycarbonate includes 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 carbonate units derived from a high heat aromatic dihydroxy monomer, and 5-98 mole percent of a low heat carbonate units derived from a low heat aromatic monomer, each based on the sum of the moles of the carbonate units; and optionally, thioether carbonyl endcaps of the formula C(O)-L-SR, wherein L is a C.sub.1-12 aliphatic or aromatic linking group and R is a C.sub.1-20 alkyl, C.sub.6-18 aryl, or C.sub.7-24 arylalkylene; wherein the sulfur content of the high heat copolycarbonate in the absence of the thioether endcaps is from 5-20 parts per million by weight.

Provided are a polycarbonate resin composition comprising a polycarbonate resin, a black colorant, a yellow colorant, and at least one ultraviolet absorber selected from the group consisting of a benzotriazole-based compound, a benzophenone-based compound, and a triazine-based compound, and an optical molded article composed thereof.