COEXTRUSION TIE BASED ON COGRAFTED METALLOCENE POLYETHYLENE AND LLDPE ON SBS AND ON PE

• Main Authors: ROBERT PATRICE, PASCAL JEROME, PRADEL JEAN LAURENT
• Format: Patent
• Language: English; Korean
• Published: 22.03.2004
• Edition: 7
• Subjects: ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; ADHESIVES; 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; CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS,e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES,DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; CONVEYING; DYES; GENERAL PROCESSES OF COMPOUNDING; HANDLING THIN OR FILAMENTARY MATERIAL; INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS; LAYERED PRODUCTS; LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT ORNON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM; MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVINGCARBON-TO-CARBON UNSATURATED BONDS; METALLURGY; MISCELLANEOUS APPLICATIONS OF MATERIALS; MISCELLANEOUS COMPOSITIONS; NATURAL RESINS; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ORGANIC MACROMOLECULAR COMPOUNDS; PACKAGES; PACKAGING ELEMENTS; PACKING; PAINTS; PERFORMING OPERATIONS; POLISHES; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; STORING; THEIR PREPARATION OR CHEMICAL WORKING-UP; TRANSPORTING; USE OF MATERIALS AS ADHESIVES; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL; WORKING-UP

PURPOSE: A coextrusion tie based on cografted metallocene polyethylene and linear low density polyethylene(LLDPE), on styrene/butadiene/styrene(SBS) block copolymers with 50 to 90, preferably 60 to 80, mol % of styrene, and on polyethylene(PE), a multilayer structure comprising the tie, and objects comprising such a structure are provided. CONSTITUTION: The coextrusion tie comprises 10 to 35 weight % of a polymer (A) comprising a blend of 80 to 20 weight % of a metallocene polyethylene (A1) with a density of between 0.865 and 0.915 and of 20 to 80 weight % of a non-metallocene linear low density polyethylene(LLDPE) (A2), the blend of polymers (A1) and (A2) being cografted by a grafting monomer selected from unsaturated carboxylic acids and their derivatives, the blend comprising between 30 and 100,000 ppm of the grafting monomer; 40 to 60 weight % of a styrene/butadiene/styrene block copolymer (B) with 50 to 90 mol % of styrene; and 20 to 35 weight % of PE (C), with the total making 100%, the blend of (A), (B) and (C) being such that the MFI or melt flow index (ASTM D 1238, 190 deg.C, 2.16 kg) is comprised between 0.1 and 10 g/10 mm. The multilayer structure comprises a layer (L) comprising the coextrusion tie and a layer (E) directly attached to one of the two faces of the layer (L), wherein the layer (E) is a layer of polystyrene homo- or copolymer.