摘要:
In a process for producing a polycarbonate by subjecting a dihydroxy compound and a diester of carbonic acid to melt polycondensation through transesterification, after a polycarbonate prepolymer is prepared in the first-stage reaction, polycondensation is conducted as the second-stage reaction in a residence time in the range of from 15 to less than 60 min or through the use of at least one paddle-type self-cleaning twin-screw extruderThis process enables a colorless, transparent polycarbonate having a high molecular weight to be produced at a high efficiency on an industrial scale.
摘要:
A process for the preparation of a (co)polycarbonate having an excellent hue, heat resistance, residence to hydrolysis and impact resistance by transesterification with the use of an aparatuses of a low price. In the first step, a dihydroxy compound is reacted with a carbonic diester in a reactor having a surface area contacting the dihydroxy compound and the carbonic diester, a made of a material containing iron in an amount of 20% by weight or less, to give a prepolymer and, in the second step, melt-polycondensing the prepolymer in a reactor other than the reactor used in the first step.
摘要:
A processes for producing a (co)polycarbonate having a low terminal hydroxyl group concentration and being excellent in heat resistance and hue, which comprises melt-polycondensing a dihydroxy compound with a carbonic diester in the presence of a catalyst for transesterification selected from the group consisting of a nitrogen-containing basic compound, an alkali metal borate and an alkaline earth metal borate and in the presence of a specific ester compound.
摘要:
A polycarbonate is produced by transesterification from a dihydroxy compound such as 2,2-bis(4-hydroxyphenyl)propane and a diester of carbonic acid such as bisphenyl carbonate in the presence of a substance containing iron in an amount of 50% by weight or less to contact the reactants. Also, a polycarbonate is produced by transesterification from a dihydroxy compound and a diester of carbonic acid in a reactor made of stainless steel and treated by electropolishing or acid pickling or buffed on a surface part thereof to contact the reactants. As the transesterification catalyst, (a) a nitrogen-containing, electron-donating compound and (b) a nitrogen-containing, electron-donating compound and an alkali metal compound or an alkaline earth metal compound are preferably used.
摘要:
A process for producing a (co)polycarbonate or a (co)polyestercarbonate having a high molecular weight and excellent hue, heat stability and mechanical properties by reacting a dihydroxyl compound with a diester of carbonic acid and/or a diester of dicarbonic acid in the presence of a transesterification catalyst, wherein at least part of the reaction process is conducted in the presence of a specified organic phosphorus compound, or, in the presence of a specified organic phosphorus compound and a hindered phenol compound. A (co)polycarbonate or (co)polyester-carbonate composition having excellent hue, heat stability and mechanical properties, comprising a (co)polycarbonate and/or a (co)polyestercarbonate and, a specified organic phosphorus compound, or, a specified organic phosphorus compound and a hindered phenol compound.
摘要:
A process for producing a (co)polycarbonate or a (co)polyestercarbonate having a high molecular weight and excellent hue, heat stability and mechanical properties by reacting a dihydroxyl compound with a diester of carbonic acid and/or a diester of dicarbonic acid in the presence of a transesterification catalyst, wherein at least part of the reaction process is conducted in the presence of a specified organic phosphorus compound, or, in the presence of a specified organic phosphorus compound and a hindered phenol compound. A (co)polycarbonate or (co)polyester-carbonate composition having excellent hue, heat stability and mechanical properties, comprising a (co)polycarbonate and/or a (co)polyestercarbonate and, a specified organic phosphorus compound, or, a specified organic phosphorus compound and a hindered phenol compound.
摘要:
A processes for producing a (co)polycarbonate having a low terminal hydroxyl group concentration and being excellent in heat resistance and hue, which comprises melt-polycondensing a dihydroxy compound with a carbonic diester in the presence of a catalyst for transesterification selected from the group consisting of a nitrogen-containing basic compound, an alkali metal borate and an alkaline earth metal borate and in the presence of a specific ester compound.
摘要:
A polycarbonate is produced by transesterification from a dihydroxy compound such as 2,2-bis(4-hydroxyphenyl)propane and a diester of carbonic acid such as bisphenyl carbonate in the presence of a substance which contains iron in an amount of 50% by weight or less and contacts the reactants. Alternatively, a polycarbonate is produced by transesterification from a dihydroxy compound and a diester of carbonic acid in a reactor made of stainless steel and treated by electropolishing or acid pickling or buffed on a surface part thereof which contacts the reactants. As the transesterification catalyst, (a) a nitrogen-containing, electron-donating compound and (b) a nitrogen-containing, electron-donating compound and an alkali metal compound or an alkaline earth metal compound are preferably used.
摘要:
In a process for producing a polycarbonate by subjecting a dihydroxy compound and a diester of carbonic acid to melt polycondensation through transesterification, after a polycarbonate prepolymer is prepared in the first-stage reaction, polycondensation is conducted as the second-stage reaction at a residence time in the range of from 15 to less than 60 min or through the use of at least one paddle-type self-cleaning twin-screw extruder.This process enables a colorless, transparent polycarbonate having a high molecular weight to be produced at a high efficiency on an industrial scale.
摘要:
Disclosed are a curable composition, a cured article therefrom having improved properties, an asphalt emulsion, an asphalt mixture for paving, and a cured article prepared therefrom having an excellent water permeability.