A polycarbonate copolymer contains: 0.1 to 50 mol% of a monomer unit represented by the following formula (1); and a monomer unit represented by the following formula (2). In the polycarbonate copolymer, the content of biphenols having a structure represented by the following formula (3) is 90 mass ppm or less. In the formula, R¹ and R² each independently represent a hydrogen atom, an aliphatic hydrocarbon group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms or a halogen atom. In the formula: R³ and R⁴ each independently represent a hydrogen atom, an aliphatic hydrocarbon group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms or a halogen atom; and X represents any one of bonding groups represented by -O-, -S-, - SO-, -SO²-, -CO- and 9,9- fluorenylidene group. In the formula, R¹ and R² each independently represent a hydrogen atom, an aliphatic hydrocarbon group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms or a halogen atom.

A process for the production of alkyltin alkoxides which comprises subjecting at least one alkyltin compound selected from among organotin compounds having tin-oxygen-tin linkages as the starting compound and a hydroxyl compound as the reactant to dehydration to obtain an alkyltin alkoxide corresponding to the starting compound and the reactant, characterized by continuously feeding the starting compound and the reactant into a reactor, discharging a water-containing low boiling point component from the reactor, and continuously withdrawing a reaction fluid containing an alkyltin alkoxide as the bottom from the reactor.

Compositions comprising polyester or polycarbonate having reacted therein a total of from about 1.0 to about 5,000 parts by weight per million parts by weight of polyester of at least one UV absorbing compound of the formula wherein R is alkyl or the like, X is carbonyl or sulfonyl, R' is hydrogen or a substituent, and Y and Z are hydrogen or substituents such as cyano or alkoxycarbonyl, with the provision that at least one of R, R¹, Y, and Z is, or forms part of, or contains one or more reactive groups capable of undergoing a condensation reaction under polyester forming conditions, such that the UV absorbing compound is reacted into the polymer. The compound has a maximum light absorbance within the range of from about 320 nm to about 380 nm, which is nonextractable from the polyester and stable under the polyester processing conditions, for imparting UV screening properties to the polymer. Many products such as fruit juices, soft drinks, wines, food products, cosmetics and shampoos are deleteriously affected by UV light when packaged in clear plastic containers which pass significant portions of the available light at any wavelength from approximately 250 to 390 nm. By use of the present compounds polymeric containers can be manufactured which absorb these harmful wavelengths and therefore reduce or eliminate the UV light degradation of products packaged therein. A further advantage of the present polymeric compositions is that conventional polyester dyes and other additives such as pigments, fillers, brighteners and the like may be incorporated therein, and the UV screening properties of the methine compounds impart significant stabilization to both the polyester and the dyes.

Compositions comprising polyester or polycarbonate having reacted therein a total of from about 1.0 to about 5,000 parts by weight per million parts by weight of polyester of at least one UV absorbing compound of the formula wherein R is alkyl or the like, X is carbonyl or sulfonyl, R' is hydrogen or a substituent, and Y and Z are hydrogen or substituents such as cyano or alkoxycarbonyl, with the provision that at least one of R, R¹, Y, and Z is, or forms part of, or contains one or more reactive groups capable of undergoing a condensation reaction under polyester forming conditions, such that the UV absorbing compound is reacted into the polymer. The compound has a maximum light absorbance within the range of from about 320 nm to about 380 nm, which is nonextractable from the polyester and stable under the polyester processing conditions, for imparting UV screening properties to the polymer. Many products such as fruit juices, soft drinks, wines, food products, cosmetics and shampoos are deleteriously affected by UV light when packaged in clear plastic containers which pass significant portions of the available light at any wavelength from approximately 250 to 390 nm. By use of the present compounds polymeric containers can be manufactured which absorb these harmful wavelengths and therefore reduce or eliminate the UV light degradation of products packaged therein. A further advantage of the present polymeric compositions is that conventional polyester dyes and other additives such as pigments, fillers, brighteners and the like may be incorporated therein, and the UV screening properties of the methine compounds impart significant stabilization to both the polyester and the dyes.

Described is a process for improving the color of thermoplastic polymers by contacting the monomer(s) before or during polymerization or the polymer after its formation with an alkali or alkaline earth metal formate.

Der Gegenstand der vorliegenden Erfindung betrifft thermoplastische aromatische Polyphosphonatocarbonate mit verbesserter thermischer Alterungsbeständigkeit, ihre Herstellung und ihre Verwendung zur Herstellung von thermoplastischen Formkörpern.

Copoly (carbonate/phosphonates) are formed by reaction of a dihydric phenol, a carbonate precursor, and an organophosphorus dihalide. The inherent viscosity and melting point of such polymers is increased by the presence of an effective amount of a chain branching agent, optionally in the additional presence of a chain terminating agent.