Elastomeric articles prepared from controlled distribution block copolymers

Abstract

The present invention relates to elastomeric articles prepared from novel anionic block copolymers of mono alkenyl arenes and conjugated dienes, and to blends of such block copolymers with other polymers. The block copolymers are selectively hydrogenated and have mono alkenyl arene end blocks and controlled distribution blocks of mono alkenyl arenes and conjugated dienes. The block copolymer may be blended with at least one other polymer selected from the group consisting of olefin polymers, styrene polymers, amorphous resins, and engineering thermoplastic resins.

What is claimed is:  
     
         1 . An elastomeric article comprising at least one hydrogenated block copolymer and, optionally, at least one other polymer selected from the group consisting of olefin polymers, styrene polymers, tackifying resins and engineering thermoplastic resins, wherein said hydrogenated block copolymer has the general configuration:  
       A-B, A-B-A, or (A-B) n X,  
       where n is an integer from 2 to about 30, and X is coupling agent residue and wherein: 
 a. prior to hydrogenation each A block is a mono alkenyl arene homopolymer block and each B block is a controlled distribution copolymer block of at least one conjugated diene and at least one mono alkenyl arene;  
 b. subsequent to hydrogenation about 0-10% of the arene double bonds have been reduced, and at least about 90% of the conjugated diene double bonds have been reduced;  
 c. each A block having an average molecular weight between about 3,000 and about 60,000 and each B block having an average molecular weight between about 30,000 and about 300,000;  
 d. each B block comprises one or more terminal regions adjacent to the A blocks that are rich in conjugated diene units and a region not adjacent to the A blocks that is rich in mono alkenyl arene units;  
 e. the total amount of mono alkenyl arene in the hydrogenated block copolymer is about 15 percent weight to about 75 percent weight; and  
 f. the weight ratio of conjugated diene to mono alkenyl arene in the B block is between about 5:1 and about 1:2.  
 
     
     
         2 . The elastomeric article according to  claim 1  wherein said mono alkenyl arene is styrene and said conjugated diene is selected from the group consisting of isoprene and butadiene.  
     
     
         3 . The elastomeric article according to  claim 2  wherein said conjugated diene is butadiene, and wherein about 20 to about 80 mol percent of the condensed butadiene units in block B have 1,2-configuration.  
     
     
         4 . The elastomeric article according to  claim 3  wherein in block B there are fewer than 20 consecutive units of any one monomer between that of each different monomer.  
     
     
         5 . The elastomeric article according to  claim 4  wherein the polymer is an ABA polymer and each block B has a center region with a minimum ratio of butadiene units to styrene units.  
     
     
         6 . The elastomeric article according to  claim 2  wherein the styrene blockiness index of the block B is less than about 10 percent, said styrene blockiness index being defined to be the proportion of styrene units in the block B having two styrene neighbors on the polymer chain.  
     
     
         7 . The elastomeric article according to  claim 1  wherein said hydrogenated block copolymer is an (A-B) n X block copolymer where each A block has an average molecular weight of about 5,000 to about 20,000, each B block has an average molecular weight of about 30,000 to about 100,000, and the total molecular weight is about 80,000 to about 140,000.  
     
     
         8 . The elastomeric article according to  claim 7  comprising 100 parts by weight of said hydrogenated block copolymer and about 5 to about 50 parts by weight of a polymer extending oil.  
     
     
         9 . The elastomeric article according to  claim 7  comprising 100 parts by weight of said hydrogenated block copolymer and about 5 to about 50 parts by weight of an olefin polymer selected from the group consisting of ethylene homopolymers, ethylene/alpha olefin copolymers, propylene homopolymers, propylene/alpha olefin copolymers, high impact polypropylene, and ethylene/vinyl acetate copolymers.  
     
     
         10 . The elastomeric article according to  claim 9  also comprising about 5 to about 50 parts by weight of a tackifying resin.  
     
     
         11 . The elastomeric article according to  claim 8  also comprising about 5 to about 40 parts by weight of a styrene polymer selected from the group consisting of crystalline polystyrene, high impact polystyrene, syndiotactic polystyrene and acrylonitrile/butadiene/styrene terpolymer.  
     
     
         12 . The elastomeric article according to  claim 7  comprising 100 parts by weight of said hydrogenated block copolymer and about 5 to about 20 parts by weight of an ethylene/vinyl aromatic interpolymer.  
     
     
         13 . The elastomeric article according to  claim 12  wherein said ethylene/vinyl aromatic interpolymer is a substantially random ethylene/styrene interpolymer.  
     
     
         14 . The elastomeric article according to  claim 1  wherein said hydrogenated block copolymer is an (A-B) n X block copolymer where each A block has an average molecular weight of about 10,000 to about 40,000, each B block has an average molecular weight of about 60,000 to about 140,000, and the total molecular weight is about 140,000 to about 220,000.  
     
     
         15 . The elastomeric article according to  claim 14  comprising 100 parts by weight of said hydrogenated block copolymer and about 10 to about 50 parts by weight of an olefin polymer selected from the group consisting of ethylene homopolymers, ethylene/alpha olefin copolymers, propylene homopolymers, propylene/alpha olefin copolymers, high impact polypropylene, and ethylene/vinyl acetate copolymers.  
     
     
         16 . The elastomeric article according to  claim 15  also comprising about 20 to about 150 parts by weight of a polymer extending oil.  
     
     
         17 . The elastomeric article according to  claim 14  comprising 100 parts by weight of said hydrogenated block copolymer and about 10 to about 80 parts by weight of at least one polymer selected from the group consisting of poly(phenylene oxides), syndiotactic polystyrene, cyclic olefin copolymers and acrylonitrile/butadiene/styrene terpolymers.  
     
     
         18 . A formulated elastomeric composition comprising at least one hydrogenated block copolymer and at least one component selected from the group consisting of fillers, reinforcements, polymer extending oils and polyolefins, wherein said hydrogenated block copolymer has the general configuration  
       A-B, A-B-A, or (A-B) n X,  
       where n is an integer from 2 to about 30, and X is coupling agent residue and wherein: 
 a. prior to hydrogenation each A block is a mono alkenyl arene homopolymer block and each B block is a controlled distribution copolymer block of at least one conjugated diene and at least one mono alkenyl arene;  
 b. subsequent to hydrogenation about 0-10% of the arene double bonds have been reduced, and at least about 90% of the conjugated diene double bonds have been reduced;  
 c. each A block having an average molecular weight between about 3,000 and about 60,000 and each B block having an average molecular weight between about 30,000 and about 300,000;  
 d. each B block comprises one or more terminal regions adjacent to the A blocks that are rich in conjugated diene units and a region not adjacent to the A blocks that is rich in mono alkenyl arene units;  
 e. the total amount of mono alkenyl arene in the hydrogenated block copolymer is about 15 percent weight to about 75 percent weight; and  
 f. the weight ratio of conjugated diene to mono alkenyl arene in the B block is between about 5:1 and about 1:2.  
 
     
     
         19 . A cap seal formed from the formulated elastomeric composition of  claim 18 .  
     
     
         20 . The cap seal of  claim 19  wherein said formulated elastomeric composition comprises 100 parts by weight of said hydrogenated block copolymer and about 50 to about 125 parts by weight of a process extender oil, to 50 parts by weight of polypropylene and optionally 10 to 60 parts by weight silica.  
     
     
         21 . The elastomeric article according to  claim 1  wherein the article is in the form of a film, sheet, coating, band, strip, profile, molding, foam, tape, fabric, thread, filament, ribbon, fiber, plurality of fibers or, fibrous web.  
     
     
         22 . The elastomeric article according to  claim 1  wherein said article is formed in a process selected from the group consisting of injection molding, over molding, dipping, extrusion, roto molding, slush molding, fiber spinning, film making or foaming.  
     
     
         23 . The elastomeric article according to  claim 1  comprising about 5 to 20 percent weight of said hydrogenated block copolymer and about 80 to about 95 percent weight of an engineering thermoplastic resin.  
     
     
         24 . The elastomeric article according to  claim 23  wherein said engineering thermoplastic resin is selected from the group consisting of thermoplastic polyester, thermoplastic polyurethane, poly(arylether), poly(aryl sulfone), polycarbonate, acrylic resins, acetal resin, polyamide, halogenated thermoplastic and nitrile barrier resin.  
     
     
         25 . The elastomeric article according to  claim 1  wherein said hydrogenated block copolymer is a functionalized block copolymer.  
     
     
         26 . The elastomeric article according to  claim 25  wherein said hydrogenated block copolymer has been grafted with an acid compound or its derivative.  
     
     
         27 . The elastomeric article according to  claim 26  wherein said acid compound or its derivative is selected from the group consisting of maleic anhydride, maleic acid, fumaric acid, and its derivatives.  
     
     
         28 . The elastomeric article according to  claim 26  wherein said acid compound or its derivative is maleic anhydride or maleic acid.  
     
     
         29 . The elastomeric article according to  claim 28  containing 75 to 95 weight percent of an engineering thermoplastic selected from the group consisting of polyamides and polyurethanes and 5 to 25 weight percent of the functionalized block polymer.  
     
     
         30 . The elastomeric article according to  claim 1  comprising about 5 to 40 percent weight of said hydrogenated block copolymer and about 60 to about 95 percent weight of a polystyrene homopolymer or copolymer.