Aromatic polycarbonate and production process therefor
AssigneeTeijin Limited
InventorsWataru Funakoshi, Hiroaki Kaneko, Yuichi Kageyama, Takanori Miyoshi, Katsushi Sasaki
Life of this patent
Estimating the term…
Abstract
A polycarbonate having excellent color and stability and a production process therefor. In the production of a polycarbonate by melt polycondensing a dihydroxy compound and a carbonic acid diester in the presence of an ester exchange catalyst, the each content of an aldehyde group in the dihydroxy compound and the carbonic acid diester is reduced to 3×10−6 equivalent/mol or less.
Claims16
A process for producing a polycarbonate by melt polycondensing a dihydroxy compound and a carbonic acid diester in the presence of an ester exchange catalyst, wherein a raw material which contains a dihydroxy compound represented by the following formula (1):
- wherein R1 and R2
- are each independently an alkyl group having 1 to 20 carbon atoms, alkoxy group having 1 to 20 carbon atoms, cycloalkyl group having 6 to 20 carbon atoms, aryl group having 6 to 20 carbon atoms, cycloalkoxy group having 6 to 20 carbon atoms or aryloxy group having 6 to 20 carbon atoms, m and n are each independently an integer of 0 to 4, and X is a single bond, oxygen atom, carbonyl group, alkylene group having 1 to 20 carbon atoms, alkylidene group having 2 to 20 carbon atoms, cycloalkylene group having 6 to 20 carbon atoms, cycloalkylidene group having 6 to 20 carbon atoms, arylene group having 6 to 20 carbon atoms or a group having 6 to 20 carbon atoms, and an aldehyde compound in an amount of no more than 3×10−6 equivalent in terms of an aldehyde group based on 1 mol of the dihydroxy compound represented by the above formula (1) is used as one raw material comprising the above dihydroxy compound and a raw material which contains a carbonic acid diester and an aldehyde compound in an amount of no more than 3×10−6 equivalent in terms of an aldehyde group based on 1 mol of the carbonic acid diester is used as the other raw material comprising the above carbonic acid diester.
An aromatic polycarbonate pellet which comprises an aromatic polycarbonate composed mainly of a recurring unit represented by the following formula (2):
- wherein R1 and R2 are each independently an alkyl group having 1 to 20 carbon atoms, alkoxy group having 1 to 20 carbon atoms, cycloalkyl group having 6 to 20 carbon atoms, aryl group having 6 to 20 carbon atoms, cycloalkoxy group having 6 to 20 carbon atoms or aryloxy group having 6 to 20 carbon atoms, m and n are each independently an integer of 0 to 4, and X is a single bond, oxygen atom, carbonyl group, alkylene group having 1 to 20 carbon atoms, alkylidene group having 2 to 20 carbon atoms, cycloalkylene group having 6 to 20 carbon atoms, cycloalkylidene group having 6 to 20 carbon atoms, arylene group having 6 to 20 carbon atoms or alkylene-arylene-alkylene group having 6 to 20 carbon atoms, and having a viscosity average molecular weight of 10,000 to 17,000 and a value of 1×10−6 to 20×10−6 obtained by dividing an average value of absorbance at a wavelength of 400 nm and absorbance at a wavelength of 430 nm by absorbance at a wavelength of 260 nm, and which has a b value measured in accordance with JIS K7105 of −1.0 to 0.0.
Dependencies are inferred from the claim text.