IMPROVED COLOR AND HYDROLYSIS-STABILITY OF AROMATIC POLYCARBONATE

• Main Authors: HOEKS THEODOURS L, GOOSSENS JOHANES M D
• Format: Patent
• Language: English
• Published: 05.03.1999
• Edition: 6
• Subjects: AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; CHEMISTRY; COMPOSITIONS BASED THEREON; COMPOSITIONS OF MACROMOLECULAR COMPOUNDS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; PERFORMING OPERATIONS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; THEIR PREPARATION OR CHEMICAL WORKING-UP; TRANSPORTING; USE OF INORGANIC OR NON-MACROMOLECULAR ORGANIC SUBSTANCES ASCOMPOUNDING INGREDIENTS; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL

PROBLEM TO BE SOLVED: To obtain an aromatic polycarbonate composition having improved color stability and improved hydrolysis stability while keeping good processability. SOLUTION: This composition comprises an aromatic polycarbonate and a stabilizer system consisting of at least one phosphorous-containing organic additive and hexamethylene tetramine. The stabilizer system presents in an amount sufficient to impart improved color stability compared with a case when a phosphorus-containing stabilizer is solely used. A preferable amount of the stabilizer to be used is approximately 0.01-0.30 wt.% based on the sum total weight of the polycarbonate resin and the stabilizer. Here, a method for producing injection molded or extrusion molded articles, especially articles such as transparent polycarbonate sheets, is also provided.