Bayer Corporation

Miles Inc.

Covestro Deutschland Ag

Covestro LLC

James P Mason

Sivaram Krishnan

Rick L Archey

Leslie J Vescio

Robert Allen Pyles

James Y Chung

Roger J White

Marina Rogunova

Nicolas Sunderland

Jon M Newcome

Hans Franssen

Jeff M Tennant

William B Villee

Walter G Chwala

James A DiBernardo

A thermoplastic molding composition suitable for the preparation of articles having low birefringence is disclosed. Accordingly, the composition contains polycarbonate and a polyester copolymer based on cyclohexane-dimethanol, ethylene glycol and phthalic acid. The invention resides in the findings that the incorporation of a polycarbonate resin having a melt flow index greater than 18 g/10 minutes impart to the composition low birefringence values. The composition is suitable for the preparation of optical storage media, including compact discs.

Compositions having low birefringence

A flame retardant thermoplastic composition having an improved level of chemical resistance is disclosed. The composition which contains about 1 to 14 pbw bromine, comprises (i) a bromine containing carbonate polymer, (ii) a thermoplastic polyester resin, (iii) a graft polymer, (iv) a phosphorous containing compound conforming to

Flame retardant chemical resistant thermoplastic molding composition

A process for making a copolymeric resin is disclosed. Accordingly, component (a) and component (b) are introduced into an extruder under conditions designed to promote reactive blending therebetween in the presence of a transesterification catalyst. Component (a) is a wet aromatic polycarbonate resin containing moisture in an amount greater than 0.02 weight percent and having units conforming to ##STR1## wherein D is a divalent residue of a dihydroxy compound. Component (b) is a lactone-siloxane block copolymer having structural units conforming to ##STR2## wherein m is 1-90, n is 60-150, R is an alkyl or a phenyl radical, p is 2-12 and q is 2-20. Surprisingly, use of moisture-containing polycarbonate in the process yields a copolymer having good properties, although a corresponding process where the lactone-siloxane block copolymer reactant has a smaller number of repeating units yields inferior product.

Process for preparing a copolycarbonate

A thermoplastic molding composition having improved impact strength and a process for its preparation are disclosed. The structure of the resinous component of the composition contains carbonate structural units, polyester structural units and lactone-siloxane structural units conforming to ##STR1## wherein m is 1 to 90, n is 5 to 300, R is an alkyl or a phenyl radical, p is 2 to 12 and q is 2 to 20. The preparation of the resinous component entails reactive blending in the presence of a transesterification catalyst of polycarbonate, (co)polyester and a lactone siloxane copolymer.

Molding composition having improved impact strength

The impact strength of a thermoplastic molding composition containing aromatic polycarbonate resin and a copolymer is improved upon the incorporation therewith of a particular silicone rubber powder. The silicone rubber powder, added at a level of about 3 to 25 percent, contains a mixture of (a) a polydiorganosiloxane and (b) finely divided silica filler.

Impact modified thermoplastic molding composition

The impact strength of a thermoplastic molding composition containing polyalkylene terephthalate resin is improved upon the incorporation therewith of a particular silicone rubber powder. The silicone rubber powder, added at a level of about 8 to 25 percent, contains a mixture of (a) a polydiorganosiloxane and (b) finely divided silica filler.

Impact modified thermoplastic polyester molding composition

A process for rapidly improving the flowability, in pellet form, of a molding composition is disclosed. Accordingly, the crystalline content of an amorphous or a semi-amorphous version of a crystallizable thermoplastic resin is increased by subjecting the resin to infra-red radiation to an extent which induces the formation of crystals in the irradiated amorphous resin or the increase of the level of crystals in the semi-amorphous irradiated resins. The resin modified by the inventive process is rendered more suitable for processing: in dried, pellet-form, the modified resin is characterized by its improved flowability. An article molded from the thus modified resin exhibits better properties than does a corresponding article made from a unmodified resins which has been subjected to similar drying conditions.

Process for preparing a molding composition having improved flowability

An improved thermoplastic molding composition containing polycarbonate and a polyester copolymer based on cyclohexane-dimethanol, ethylene glycol and phthalic acid is disclosed. Improved resistance to gamma-radiation results from the incorporation of a siloxane compound which contains an oxirane group.

Gamma radiation-resistant blend of polycarbonate with polyester

The impact strength of a thermoplastic molding composition containing polyamide resin is improved upon the incorporation therewith of a particular silicone rubber powder. The silicone rubber powder, added at a level of about 1 to 25 percent contains a mixture of (a) a polydiorganosiloxane and (b) finely divided silica filler.

Impact modified polyamide-based molding composition

The impact strength of a thermoplastic molding composition containing aromatic polycarbonate resin and thermoplastic polyester is improved upon the incorporation therewith of a particular silicone rubber powder. The silicone rubber powder, added at a level of about 3 to 25 contains a mixture of (a) a polydiorganosiloxane and (b) finely divided silica filler.

Impact modified thermoplastic molding composition containing

The impact strength of a thermoplastic molding composition containing aromatic polycarbonate resin is improved upon the incorporation therewith of a particular silicone rubber powder. The silicone rubber powder, added at a level of greater than 1 and less than 5 percent, contains a mixture of (a) a polydiorganosiloxane and (b) finely divided silica filler.

Toughened thermoplastic molding composition

A thermoplastic molding composition comprising a resinous blend of polycarbonate, polyester and an impact modifier and an additive amount of a siloxane compound containing a pendant oxirane group is disclosed. It was surprisingly and unexpectedly discovered that unlike the corresponding compositions which contain no siloxane compound, the inventive composition is capable of being dried at low temperatures prior to molding and still maintain high impact strength.

Low temperature drying of impact modified polycarbonate/polyester

An improved thermoplastic molding composition containing polycarbonate and a polyester copolymer based on cyclohexane-dimethanol, ethylene glycol and phthalic acid is disclosed. Improved thermal stability and resistance to gamma-radiation results from the incorporation of a phosphite conforming to ##STR1## where n, m, p and r are integers, and where R is H, an alkyl or an aryl group and R.sub.3 denotes an alkyl or aryl group.

Thermally stable, gamma radiation-resistant blend of polycarbonate with

A thermoplastic molding composition which has an improved total light transmission value comprising (i) copolyester of ethylene terephthalate and cyclohexane dimethanol and (ii) at least one member selected from the group consisting of

Transparent thermoplastic molding compositions

Thermoplastic molding compositions containing

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McKees Rocks, PA, United States of America

James P Mason