General Electric Company

Henricus H Van Hout

Theodorus L Hoeks

Paul Dean Sybert

Patrick Joseph McCloskey

Gary Charles Davis

Niles R Rosenquist

Tomoaki Shimoda

James Franklin Hoover

Joseph A King, Jr

David Michel Dardaris

Hiromi Ishida

Jan Bussink

Steven Frederick Hubbard

Ali Dhinojwala

Martin H Oyevaar

Hendrik Theodorus Van De Grampel

Kazushige Inoue

Kenichi Ishiwa

Monica M Marugan

Christianus J Maas

Erwin M Gijzen

Henricus Gerardus Denissen

Paul C Raymond, Iii

Laurus Van Der Wekke

Karl H Roell

Augustina M Willemsen

There is provided herein an optical storage media which has low VBR. In a preferred embodiment, there is provided an optical disk comprising a genus of copolycarbonates, including copolyestercarbonates, which have excellent physical and optical properties. Said copolycarbonates have proportions of structural units which fall within a specific composition range, and said range defines certain materials, a large percentage of which can be molded into optical disks having the desired optical properties, including low VBR.

Optical data storage media

Increasing the endcap level to a level greater than about 90% for Optical Quality (OQ) Melt Polycarbonate significantly reduces the as-molded static charge for injection molded parts for Optical Disc applications. The use of resins with higher endcap levels in combination with antistatic additives provides a highly robust formulation suitable for even the most demanding emerging formats as Digital Versatile Disc (DVD) and in all commercial Optical media molding machines. Thus, optical quality polycarbonates are prepared by performing a base-catalyzed polymerization of a diaryl carbonate and a dihydric phenol under conditions effective to produce a polycarbonate product having an endcap level of 90% or greater.

Optical quality polycarbonates with reduced static charge and method for

Polycarbonate compositions comprising copolymers of bis-(4-hydroxyphenyl)methane and 2,2-bis-(4-hydroxyphenyl)propane are described and they unexpectedly display high glass transition temperatures, high impact resistances, flame retardant properties and superior brittle ductile transition temperature.

Flame retardant polycarbonate compositions

Benzoxazolyl brightner compounds and thermoplastic combinations containing such are provided herein. The thermoplastic compositions comprise a thermoplastic resin, a phosphite heat stabilizer present in reduced levels, a brightner present in reduced levels and a pigment. Preferably the thermoplastic resin composition is transparent in nature. The compositions are useful for making molded and blow molded articles which require high levels of transparency, for example, glazing materials such thermoplastic windows. The composition exhibits enhanced appearance, namely a bright natural color in combination with low levels of yellowness by utilizing in combination reduced levels of phosphite and reduced levels of brightner, with moderate levels of pigment.

Benzoxazolyl optical brightners in and for thermoplastic compositions

The invention relates to a method of preparing a compound of formula 1 ##STR1## wherein R.sub.1, R.sub.2 and R.sub.3 correspond to H, a branched or non-branched, optionally substituted alkyl group, or an optionally substituted aryl group, suitable as a chain stopper in the preparation of an aromatic polycarbonate, by reaction of a compound of formula 2 ##STR2## wherein R.sub.1, R.sub.2 and R.sub.3 have the meanings described hereinbefore, with phosgene, comprising the continuous supply of the compound of formula 2 and phosgene to a solution of phosgene in a solvent, the temperature being kept at a value between 0.degree. and 15.degree. C. and the pH being kept at a value between 1 and 6.

Method of preparing chloroformate compounds

The invention relates to a method of preparing aromatic polycarbonates by catalytic interface polymerization of at least one bivalent phenol and a carbonyl halide in the presence of a polycondensation catalyst, which method is characterized in that the conversion is carried out in a two-phase system with continuous dosing of the carbonyl halide, which two-phase system is based on water and an organic solvent, in which the quantity of organic solvent at the beginning of the polycondensation lies between 10% and 75% of the quantity of organic solvent which is required at the polymerization temperature for dissolving the quantity of polycarbonate which may be formed from the quantity of bivalent phenol which is present at the beginning of the polycondensation, in that after dosing at least 20% of the carbonyl halide a remaining quantity of organic solvent is added which is at least sufficient to keep the formed polycarbonate in solution.

Catalytic, interfacial preparation of aromatic polycarbonates with

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Halsteren, Netherlands

Henricus H Van Hout