SYNDIOTACTIC POLYPROPYLENE MOLDING AND METHOD OF PRODUCING THE SAME

• Main Authors: SASAKI, TATEYO, INOUE, TAKEO, UCHIKAWA, NOBUTAKA, ASANUMA, TADASHI, SHIOMURA, TETSUNOSUKE
• Format: Patent
• Language: English; Japanese
• Published: 01.11.1990
• Subjects: AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F,C08G; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; CHEMISTRY; COMPOSITIONS BASED THEREON; COMPOSITIONS OF MACROMOLECULAR COMPOUNDS; 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; USE OF INORGANIC OR NON-MACROMOLECULAR ORGANIC SUBSTANCES ASCOMPOUNDING INGREDIENTS; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL; WORKING-UP

A highly rigid, impact-resistant molding, for which the melting point assignable to a syndiotactic polypropylene as measured by differential scanning thermal analysis at a temperature rise rate of 10 DEG C/min gives a single peak, is produced by melt molding a substantially syndiotactic homopolymer of propylene, a substantially syndiotactic copolymer thereof with a small amount of another olefin, or a mixture thereof with a small amount of a substantially isotactic polypropylene, followed by heat treatment. Un moulage extrêmement rigide résistant aux chocs, pour lequel le point de fusion attribuable à un propylène syndiotactique, tel que mesuré par analyse thermique différentielle à une cadence d'accroissement de température de 10°C/min, donne une seule crête, est produit par moulage à chaud d'un homopolymère sensiblement syndiotactique de propylène, d'un copolymère sensiblement syndiotactique de celui-ci avec une faible quantité d'une autre oléfine, ou bien d'un mélange de ceux-ci avec une faible quantité d'un polypropylène sensiblement isotactique, suivi d'un traitement thermique.