Bayer Corporation

Miles Inc.

James B Johnson

Sivaram Krishnan

Robert Allen Pyles

Timothy J Pike

Robson M Mafoti

Ramesh M Pisipati

David M Derikart

Daniel H Bolton

Jon M Newcome

Donald K Booher

Jeffrey M Tennant

Michael A Gerace

Jeff M Tennant

Edward M Anderson

Susan H Bates

Michael P Jenkins

A thermoplastic polycarbonate molding composition having improved resistance to gamma radiation-induced yellowing is disclosed. Particularly suitable for the manufacture of devices geared for medical applications, the composition contains an additive amount of a stabilizing compound conforming structurally to

Polycarbonate composition resistant to gamma radiation

A thermoplastic composition featuring an improved resistance to thermally induced resin degradation is disclosed. The composition comprises (i) thermoplastic polycarbonate resin (ii) about 3 to 20 percent, relative to the total weight of (i) and (ii), of titanium dioxide, and (iii) an oligomer or polymer the structure of which features at least one pendant cyclic iminoether group per molecular chain. The amount of (iii) is that which is sufficient to improve the resistance of the composition to thermal degradation.

Melt-stable pigmented polycarbonate molding composition

A thermoplastic composition featuring an improved resistance to hydrolysis is disclosed. The composition comprises (i) thermoplastic polycarbonate resin (ii) about 0.01 to 3 percent of a compound selected from the group consisting of phosphite and phosphonite and (iii) an additive amount of an oligomer or polymer the structure of which features at least one pendant cyclic iminoether group per molecular chain. The additive amount is that which is sufficient to improve the resistance of the polycarbonate resin to hydrolysis.

Hydrolysis-stable polycarbonate molding composition

A thermoplastic molding composition having low haze values, suitable for optical applications is disclosed. The compositions contains a resinous component selected from the group consisting of (i) a homogeneous blend of polycarbonate resin and polycaprolactone and (ii) a copoly(carbonate-lactone) block or random copolymer, and melanin in an amount of 0.1 to 1.0 parts per hundred parts of weight of the resinous component.

Thermoplastic composition suitable for optical applications having low

A thermoplastic polycarbonate composition suitable for the preparation of optical storage devices, for instance optical discs, is disclosed. The composition, containing a stabilizing amount of partially fatty acid ester and as a stabilizer, a compound the structure of which contains at least one benzofuran-2-one group per molecule, features improved resistance to yellowing, reduced haze and high total light transmission values.

Polycarbonate composition useful in optical storage applications

A photochromic ophthalmic lens and a process for its preparation are disclosed. The lens comprise a substantially transparent substrate having a lenticular shape and, at least one film adhering to at least one surface of said substrate. The film contains a resinous blend of polycarbonate resin, and poycaprolactone and an effective amount of a photochromic dye selected from a group consisting of spiropyrans, spiroxazines, fulgides and fulgimides. In an additional embodiment the film contains a copoly(carbonate-lactone) block or random copolymer.

Photochromic ophthalmic lens

A thermoplastic molding composition having improved release properties is disclosed. The composition contains a polycarbonate resin and a mold release agent which is a hydroxy ester conforming structurally to ##STR1## where R is a member selected from the group consisting of glycerol, trimethylol propyl and pentaerythritol radicals, R' denotes a C.sub.6-20 hydrocarbon radical having at least one pendant hydroxyl group, and x is 2 to 4.

Polycarbonate compositions having good mold-release properties

A thermoplastic molding composition is disclosed comprising (A) at least one resinous component selected from the group consisting of (i) a homogeneous blend of polycarbonate resin and polycaprolactone and (ii) a copoly(carbonate-lactone) copolymer, and (B) at least one compound selected from a group consisting of benzopyrans, naphthopyrans, spirobenzopyrans, spironaphthopyrans, spirobenzoxazines, spironaphthoxazines, fulgides and fulgimides. The composition which contains the photochromic compound at an amount of 0.01 to 1.0 parts per hundred parts of weight of said (A) exhibits good photochromic properties.

Photochromic compositions having improved fade rate

A thermoplastic molding composition having improved release properties is disclosed. The composition contains a polycarbonate and an additive amount of an epoxy conforming structurally to ##STR1## where R is a member selected from the group consisting of glyceryl and trimethyl propyl radicals, x is 0 to 20 and R' is a C.sub.1-4 alkyl radical.

Polycarbonate compositions having improved release properties

A thermoplastic molding composition having improved release properties is disclosed. The composition contains a polycarbonate resin and a mold release agent which is an ester conforming structurally to ##STR1## where R is a member selected from the group consisting of glyceryl, trimethylol propyl and pentaerythrityl radicals, m is 2 to 4, R' is a C.sub.8-20 hydrocarbon radical having a pendant alkyl group, and R' is the esterification residue of a C.sub.1-24 aliphatic or an aromatic carboxylic acid.

Polycarbonate compositions having mold-release properties

A melt-stable, pigmented thermoplastic molding composition is disclosed. Accordingly, to the composition which contains polycarbonate resin and pigment there is imparted an improved level of melt stability upon the incorporation therewith of an additive amount of a melt stabilizer conforming to ##STR1## where R.sub.1, R.sub.2, R.sub.3 and n are defined. In an additional embodiment the invention relates to a color concentrate containing polycarbonate resin, up to 30% of a pigment and an effective amount of said stabilizer.

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Washington, PA, United States of America

James B Johnson