General Electric Company

Raphael Mestanza

Theodorus L Hoeks

Patrick Joseph McCloskey

Ye-Gang Lin

Adrianus Alphonsus Kusters

Tomoaki Shimoda

Akio Kanezawa

Pin-pin Wu

Johannes J De Bont

Takayoshi Anamizu

Pin-Pin Wu

Polycarbonate produced by melt condensation of a diaryl carbonate and a dihydric phenol in the presence of a basic catalyst to produce an intermediate polycarbonate composition is finished by quenching with both an alkyl tosylate quencher and phosphorous acid. The efficiency of quenching can be measured by UV retention. Surprisingly, although phosphorous acid alone has no impact on the UV retention, the combination of alkyl tosylate quenchers and phosphorous acid provides a significant improvement over the use of the alkyl tosylate quencher alone. Thus, the method of the invention permits a reduction in the amount of alkyl tosylate quencher used, and can achieve superior results which cannot be achieved even by increasing the alkyl tosylate levels.

Method for quenching of polycarbonate and compositions prepared thereby

Improved performance in high temperature, high vacuum reactors is obtained by quenching alkaline catalyst present in the product a melt polycondensation reaction using a sulfonic acid ester quencher in a carrier. The carrier if formed from a first carrier component effective to solubilize the quencher and having a lower boiling point than the quencher, and a second carrier component soluble in the first carrier component and having a higher boiling point than the quencher. An exemplary carrier composition contains equal parts of diphenylcarbonate and toluene.

Method for quenching of catalyst in the production of low molecular weight polycarbonates

Polycarbonate produced by reaction in a melt of a diaryl carbonate and a dihydric phenol in the presence of a basic catalyst is quenched to reduce the level of residual catalyst by combining the polycarbonate with a powder-free quenching composition. The quenching composition contains an acidic quencher, such as an alkyl tosylate, in a non-powder carrier. The non-powder carrier may be a liquid or a solid, for example in the form of pellets containing or coated with the quencher.

Method for quenching of polycarbonate

The disclosure describes reacting a multi-functional phenolic or carboxylic branching agent with a transesterification catalyst to form an organic salt prior to reactive extrusion of said organic salt branching agent with linear polycarbonate resin as a means to dramatically increase the efficiency of the branching agent in the preparation of branched polycarbonate.

Method of branching and cross-linking a polycarbonate resin

Polycarbonate can be branched by reactive extrusion using free radical chemistry. This technology combines the effect of free radical initiator and branching agent on polycarbonate during processing. Melt Strength of polycarbonate can be increased by addition of a triacrylate as branching agent and peroxide as radical initiator.

Branched polycarbonate produced by reactive extrusion

Branched polycarbonates are prepared by the reaction of a linear or branched polycarbonate with a branching resin having a molecular weight up to about 3,000, typically a novolak or a bisphenol polymer. The reaction preferably takes place in the presence of a carbonate equilibration catalyst such as a quaternary bisphenolate.

Growing community of inventors

Saint Riquier es Plains, France

Raphael Mestanza