METHOD OF PREPARING POLYCARBONATE

FIELD: manufacture of sheets, films, optical products and pyrormation carriers. SUBSTANCE: polycarbonate is prepared by phosgenation of bisphenol in the presence of sodium hydroxide in mixture of solvent of methylene chloride and chlorobenzene by polycondensation of catalyst followed by evaporation...

Full description

Saved in:
Bibliographic Details
Main Authors AMERIK V.V, RJABOV E.A, LAVRINENKO M.N, SEREBRJAKOVA A.A, GULEVSKIJ V.E, MIKHLINA I.SH
Format Patent
LanguageEnglish
Published 27.06.1999
Edition6
Subjects
CHEMISTRY
COMPOSITIONS BASED THEREON
MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONSONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
METALLURGY
ORGANIC MACROMOLECULAR COMPOUNDS
THEIR PREPARATION OR CHEMICAL WORKING-UP
Online AccessGet full text

Cover

More Information
Summary:FIELD: manufacture of sheets, films, optical products and pyrormation carriers. SUBSTANCE: polycarbonate is prepared by phosgenation of bisphenol in the presence of sodium hydroxide in mixture of solvent of methylene chloride and chlorobenzene by polycondensation of catalyst followed by evaporation of methylene chloride in thin layer to attain polycarbonate concentration in chlorobenzene at 15-30%, 5-50% chlorobenzene containing methylene chloride vapors are rectified where fraction with melting temperature of 60- 85 C in amount of 0.5-5% based on amount of methylene chloride to be rectified is withdrawn from process. Chlorobenzene is evaporated in two stages in thin layer in vacuum. Condensed solvents are recycled. Methylene chloride is evaporated at 80-140 C for 20-120 s. Prior to evaporation, thermostabilizer and/or lubricant and/or antipyrene are added to thermostabilizer and/or lubricant. EFFECT: reduced yellowness index, higher light transmission stability. 4 cl, 6 ex, 1 tbl
Bibliography:Application Number: RU19980122385