Extrusion coating polyester compositions

• Main Authors: CLAUDE CHAPPUIS, ROLF JUNG
• Format: Patent
• Language: English
• Published: 04.10.2000
• Edition: 7
• Subjects: ADHESIVES; APPLYING LIQUIDS OR OTHER FLUENT MATERIALS TO SURFACES, IN GENERAL; CHEMICAL PAINT OR INK REMOVERS; CHEMISTRY; COATING COMPOSITIONS, e.g. PAINTS, VARNISHES ORLACQUERS; COMPOSITIONS BASED THEREON; COMPOSITIONS OF MACROMOLECULAR COMPOUNDS; CORRECTING FLUIDS; DYES; FILLING PASTES; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; INKS; METALLURGY; MISCELLANEOUS APPLICATIONS OF MATERIALS; MISCELLANEOUS COMPOSITIONS; NATURAL RESINS; ORGANIC MACROMOLECULAR COMPOUNDS; PAINTS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; PERFORMING OPERATIONS; POLISHES; PROCESSES FOR APPLYING LIQUIDS OR OTHER FLUENT MATERIALS TOSURFACES, IN GENERAL; SPRAYING OR ATOMISING IN GENERAL; TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION; TECHNICAL SUBJECTS COVERED BY FORMER USPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; THEIR PREPARATION OR CHEMICAL WORKING-UP; TRANSPORTING; USE OF INORGANIC OR NON-MACROMOLECULAR ORGANIC SUBSTANCES ASCOMPOUNDING INGREDIENTS; USE OF MATERIALS THEREFOR; WOODSTAINS

Solid extrusion coating compositions for metal substrates, a method of extrusion coating a metal substrate, and a metal article are disclosed. The extrusion coating composition is a thermoplastic material and comprises: (a) a first polyester having a weight average molecular weight of about 10,000 to about 80,000 and a Tg of greater than 45° C. to about 100° C., (b) a second polyester having a weight average molecular weight of about 10,000 to about 70,000 and a Tg of about -10° C. to about 45° C., and optionally, (c) a modifying resin, such as an epoxy resin having an epoxy equivalent weight of about 500 to about 15,000, wherein the Tg of the first and second polyesters differ by about 5 C.° to about 60 C.°. The extrusion coating composition is applied to a metal substrate in an extrusion process to provide a composition film having a thickness of about 1 to about 40 microns.