The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 27, 1996
Filed:
Nov. 21, 1994
General Electric Company, Pittsfield, MA (US);
Abstract
To provide novel polycarbonates and a manufacturing method for them. Copolycarbonates obtained by copolymerizing at least two aromatic dihydroxy compounds and a compound capable of introducing carbonate links. Preferably, they contain, as the components derived from the aromatic dihydroxy compounds, constituent units described by formulas [I] and [II] in proportions of from 8.times.10.sup.-5 to 3.times.10.sup.-2 moles of [II] per mole of [I], and preferably they have a limiting viscosity number [.eta.] of from 0.2 to 1.2 dL/g, as measured in methylene chloride at 20.degree. C. ##STR1## (X, Y,: Alkylene, cycloalkylene, --O--, --S--, --SO--, OR --SO.sub.2 --. R.sup.1, R.sup.2, R.sup.7, R.sup.8 : hydrocarbon group with from 1 to 10 carbon atoms which may be substituted with halogen; or a halogen atom. m, n, p: Integers ranging from 0 to 4, indicating the number of substituents. q: Integer ranging from 0 to 3, indicating the number of substituents. R.sup.6 : Straight-chain, branched, or cyclic hydrocarbon group with from 1 to 20 carbon atoms which may be substituted with hydrogen atoms or halogen; or a halogen atom). Manufacturing method for said copolycarbonates in which the aromatic dihydroxy compounds and carbonic acid diesters are melt-polycondensed in the presence of an alkali metal or alkaline earth metal catalyst. The copolycarbonates of the invention have excellent melt elasticity and melt strength as well as excellent hue, heat resistance, moisture resistance, and transparency.