Method for producing molded foam articles, and molded foam articles

• Main Authors: Aikyo, Yusuke, Komori, Kazuhiro
• Format: Patent
• Language: English
• Published: 12.09.2023
• Subjects: AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F,C08G; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; CHEMISTRY; COMPOSITIONS BASED THEREON; GENERAL PROCESSES OF COMPOUNDING; INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS; 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; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL; WORKING-UP

A method for producing molded foam articles that molds molded foam articles continuously, the method comprising continuously repeating the following step 1, step 2, step 3 and step 4 in this order; wherein step 1 comprises melting a resin composition that includes a liquid crystal polyester; step 2 comprises introducing, with an introduction device, a supercritical fluid that is unreactive, in a supercritical state, with the liquid crystal polyester, and is a gas at normal temperature and normal pressure, into the resin composition in an amount of at least 0.1 parts by mass but not more than 0.3 parts by mass per 100 parts by mass of the liquid crystal polyester, and then melt-kneading the resultant mixture; step 3 comprises injecting the melt-kneaded resin composition containing the supercritical fluid into a mold; and step 4 comprises conducting foaming by lowering at least one of the pressure and the temperature of the supercritical fluid contained in the resin composition to a value below the critical point of the supercritical fluid, thereby producing a molded foam article. This liquid crystal polyester has a melt tension at a temperature 20° C. higher than the flow start temperature of at least 5 mN but not more than 100 mN.