Abstract: The present invention provides methods of producing high molecular weight polymer. A method of forming polycarbonate includes the step of combining in a reaction mixture a diaryl carbonate, a transesterification catalyst, an aliphatic dihydroxy compound, and a diacid compound in a reactor system. The temperature and pressure of the reactor system are adjusted to a first reactor setpoints and the reaction mixture is monitored to detect initiation of the exothermic oligomerization reaction. The reactor setpoint are adjusted to second reactor setpoints after detection of initiation of the exothermic oligomerization reaction. The reactor system is maintained at the second reactor setpoints to allow the reaction mixture to react to form an oligomer mixture.

Abstract: A method of forming polycarbonate includes the steps of introducing a plurality of reaction components to a reactor operating under melt polymerization conditions and removing ester-substituted phenol from the reactor. The plurality of reaction components include a dihydroxy compound, an ester-substituted diaryl carbonate, and a melt transesterification catalyst. The reaction components are introduced in a plurality of reaction component streams. A first reaction component streams includes a melt transesterification catalyst dissolved or suspended in a liquid carrier containing an ester-substituted phenol. The composition of the first reaction component stream is selected such that ester-substituted phenol is not generated as a reaction product in the first reaction component stream.

Abstract: The present invention provides methods of producing high molecular weight polymer. A method of forming polycarbonate includes the step of combining in a reaction mixture a diaryl carbonate, a transesterification catalyst, an aliphatic dihydroxy compound, and a diacid compound in a reactor system. The temperature and pressure of the reactor system are adjusted to a first reactor setpoints and the reaction mixture is monitored to detect initiation of the exothermic oligomerization reaction. The reactor setpoint are adjusted to second reactor setpoints after detection of initiation of the exothermic oligomerization reaction. The reactor system is maintained at the second reactor setpoints to allow the reaction mixture to react to form an oligomer mixture.

Abstract: A method of forming polycarbonate includes the steps of introducing a plurality of reaction components to a reactor operating under melt polymerization conditions and removing ester-substituted phenol from the reactor. The plurality of reaction components include a dihydroxy compound, an ester-substituted diaryl carbonate, and a melt transesterification catalyst. The reaction components are introduced in a plurality of reaction component streams. A first reaction component streams includes a melt transesterification catalyst dissolved or suspended in a liquid carrier containing an ester-substituted phenol. The composition of the first reaction component stream is selected such that ester-substituted phenol is not generated as a reaction product in the first reaction component stream.

Abstract: A non-reactive monomer mixture has a monomer component dispersed in a melted diaryl carbonate. The monomer component has one or more monomer compounds having a melting point below the melting point of the diaryl carbonate. Furthermore, the monomer component has less than 600 ppb alkali metal, an acid stabilizer, or both less than 600 ppb alkali metal and an acid stabilizer. The monomer compounds of the monomer component and the diaryl carbonate are present in a mole ratio of from 0.9 to 1.1. The monomer mixture is at a temperature between the melting temperature of the lowest melting monomer compound and the melting temperature of the diaryl carbonate.

Abstract: A non-reactive monomer mixture is formed from a dihydroxy component having one or more dihydroxy compounds dissolved in a melted diaryl carbonate. The dihydroxy component has less than 600 ppb alkali metal, an acid stabilizer, or both less than 600 ppb alkali metal and an acid stabilizer. The dihydroxy compounds of the dihydroxy component and the diaryl carbonate are present in a mole ratio of from 0.9 to 1.1. The monomer mixture is at a temperature between the saturation point of the monomer mixture and the highest melting temperature of the individual dihydroxy compounds. The non-reactive monomer mixture can be stored and transported and then polymerized to form polycarbonate upon addition of a catalyst.

Abstract: A non-reactive monomer mixture has a monomer component dispersed in a melted diaryl carbonate. The monomer component has one or more monomer compounds having a melting point below the melting point of the diaryl carbonate. Furthermore, the monomer component has less than 600 ppb alkali metal, an acid stabilizer, or both less than 600 ppb alkali metal and an acid stabilizer. The monomer compounds of the monomer component and the diaryl carbonate are present in a mole ratio of from 0.9 to 1.1. The monomer mixture is at a temperature between the melting temperature of the lowest melting monomer compound and the melting temperature of the diaryl carbonate.

Abstract: A non-reactive monomer mixture is formed from a dihydroxy component having one or more dihydroxy compounds dissolved in a melted diaryl carbonate. The dihydroxy component has less than 600 ppb alkali metal, an acid stabilizer, or both less than 600 ppb alkali metal and an acid stabilizer. The dihydroxy compounds of the dihydroxy component and the diaryl carbonate are present in a mole ratio of from 0.9 to 1.1. The monomer mixture is at a temperature between the saturation point of the monomer mixture and the highest melting temperature of the individual dihydroxy compounds. The non-reactive monomer mixture can be stored and transported and then polymerized to form polycarbonate upon addition of a catalyst.

Abstract: A method of preparing polycarbonate includes a steps of providing a melt reaction mixture and allowing the melt reaction mixture to react to build molecular weight, thereby preparing the polycarbonate. The melt reaction mixture has a dihydroxy compound, an ester substituted diaryl carbonate mixture, and a melt transesterification catalyst where the ester substituted diaryl carbonate mixture may contain acid-substituted phenol. The method also includes the step of adjusting the molar ratio of acid-substituted phenol, if present, to melt transesterification catalyst (acid-substituted phenol/catalyst) in the melt reaction mixture to an amount of less than 10.

Abstract: A surface of a melt polymerization reactor system having residual reaction components of a melt polymerization reaction thereon can be cleaned by introducing a cleaning agent having a phenolic compound to the polymerization reactor system and into contact with the surface of the melt polymerization reactor system having the residual reaction components of a melt polymerization reaction thereon. The residual reaction components of the melt polymerization reaction include polycarbonate oligomers or polymers or their degradation products. Further, the cleaning agent is maintained in contact with the surface for a period of time and at a temperature sufficient to substantially remove the residual reaction components from the surface.

Abstract: A surface of a melt polymerization reactor system having residual reaction components of a melt polymerization reaction thereon can be cleaned by introducing a cleaning agent having a phenolic compound to the polymerization reactor system and into contact with the surface of the melt polymerization reactor system having the residual reaction components of a melt polymerization reaction thereon. The residual reaction components of the melt polymerization reaction include polycarbonate oligomers or polymers or their degradation products. Further, the cleaning agent is maintained in contact with the surface for a period of time and at a temperature sufficient to substantially remove the residual reaction components from the surface.

Abstract: 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.