POLYESTER RESIN COMPOSITION AND ITS PRODUCTION

• Main Authors: TAKASE TORU, NAKAO TAKUO
• Format: Patent
• Language: English
• Published: 12.10.1999
• Edition: 6
• Subjects: AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F,C08G; CHEMISTRY; COMPOSITIONS BASED THEREON; COMPOSITIONS OF MACROMOLECULAR COMPOUNDS; GENERAL PROCESSES OF COMPOUNDING; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; USE OF INORGANIC OR NON-MACROMOLECULAR ORGANIC SUBSTANCES ASCOMPOUNDING INGREDIENTS; WORKING-UP

PROBLEM TO BE SOLVED: To obtain a polyester resin composition improved in the dispersibility of titanium dioxide and reduced in the property to abrade metals and in the lowering of the molecular weight of a polyester reins during molding by combinedly using a titanium dioxide subjected to a specified surface treatment to control its properties with a specified free monocarboxylic acid. SOLUTION: The polyester resin composition satisfies all of the following requirements (a) to (e) and comprises 0.03-60 wt.%, based on the total weight of the composition, titanium dioxide containing adsorbed trimethylolpropane on its surface and 0.02-5.0 wt.%, based on the total weight of the titanium dioxide, free benzoic acid and/or p-hydroxybenzoic acid: (a) the means particle diameter is 0.1-0.5 μm, (b) the content of coarse particles with a particle diameter of at least 3 μm is 6,000 particles/mg or smaller, (c) the content of coarse particles with a particle diameter of at least 4 μm is 3,000 particles/mg or smaller, (d) the content of phosphorus is 0.4-0.6 wt.% (in terms of P2 O5 ) based on the total weight of the titanium dioxide, and (e) the content of potassium is 0.1-0.3 wt.% (in terms of K2 O based on the total weight of the titanium dioxide.