Late-addition catalyst formulation, reactor system, and method for producing polycarbonate
AssigneeSabic Innovative Plastics IP B.V.
InventorsJorge A. Garcia Agudo, Ignacio Vic Fernandez, Kazutoyo Uno, Fernando Olmedo Fernandez, Isabel Macian Aviles
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Abstract
The present invention provides a melt polymerization reactor system and method of producing polycarbonate using a late-addition catalyst formulation having a melt transesterification catalyst dispersed in a liquid carrier system which preferably includes less than 10 wt % water. The formulation also preferably includes a liquid carrier system having phenol and a cosolvent. The melt transesterification catalyst can be present in the formulation in a range of 50 ppm to 60,000 ppm.
Claims42
A melt polymerization reactor system for producing a product polycarbonate, the reactor system comprising:
- a first polymerization reactor, a first finishing line having a second polymerization reactor, and a late-addition catalyst vessel, wherein:
- the reactor system is connected in the following configuration:
- (i) the first finishing line connected to the first polymerization reactor, and
- (ii) the late-addition catalyst vessel connected to the first finishing line at the second polymerization reactor, between the first and second polymerization reactor, or a combination thereof, and
- the first polymerization reactor contains an intermediate polycarbonate having a number average molecular weight (Mn) based upon polycarbonate standards (GPC) of 2,500 to 25,000 g/mol and unreacted reaction components including a dihydroxy compound, a diaryl carbonate, and a melt transesterification catalyst,
- the second polymerization reactor contains the product polycarbonate having a higher molecular weight than the intermediate polycarbonate, a higher content of branching structures than the intermediate polycarbonate, or both,
- the late-addition catalyst vessel contains a late-addition catalyst formulation comprising a melt transesterification catalyst dispersed in a liquid carrier system, wherein the liquid carrier system comprises phenol.
A method for producing a product polycarbonate comprising the steps of:
- (i) treating a plurality of reaction components under melt polymerization conditions sufficient to produce an intermediate polycarbonate having a number average molecular weight (Mn) based upon polycarbonate standards (GPC) of 2,500 to 25,000 g/mol, wherein the plurality of reaction components comprise a dihydroxy compound, a diaryl carbonate, and a melt transesterification catalyst,
- (ii) introducing a late-addition catalyst formulation to the intermediate polycarbonate produced in step (i) in an amount effective to catalyze molecular weight build, catalyze a branching reaction, or catalyze both molecular weight build and a branching reaction, the late-addition catalyst formulation comprising a melt transesterification catalyst dispersed in a liquid carrier system, wherein the liquid carrier system comprises phenol, and
- (iii) treating the intermediate polycarbonate and late-addition catalyst formulation from step (ii) under melt polymerization conditions sufficient to produce a product polycarbonate,
- wherein the product polycarbonate has a higher molecular weight than the intermediate polycarbonate formed in step (i), a higher content of branching structures than the intermediate polycarbonate formed in step (i), or both,
- thereby producing a product polycarbonate.
A late-addition catalyst formulation comprising a melt transesterification catalyst dispersed in an organic liquid carrier system comprising phenol and a cosolvent, wherein the formulation contains less than 10 wt % water and the melt transesterification catalyst is present in the formulation in a range of 50 ppm to 60,000 ppm.
42-47. (canceled)
Dependencies are inferred from the claim text.