Elastomeric compositions providing improved wet grip

A method for making an elastomeric composition having improved wet grip, the method comprises:

• a) mixing:
• i) from 3 to 50 wt. % of a resin selected from the group consisting of coumarone-indene resin, petroleum hydrocarbon resin, terpene polymers, styrene-alpha-methyl-styrene resins, terpene phenol resin, rosin derived resins and copolymers and/or mixtures thereof;
• ii) a 40-95 wt % of a homopolymer or copolymer of isoprene and another conjugated diene and/or olefinically unsaturated monomer wherein the copolymer can be of random, tapered, block or otherwise structure;
• iii) 5-55 wt % of a polymer selected from the group of C4 to C20 olefins, thermoplastic elastomers, styrene-butadiene rubbers, ethylene-propylene rubbers, ethylene-propylene-diene rubbers, urethane rubber, and combinations thereof;
• iv) a curing agent selected from sulfur, sulfur-containing compounds, radical curing agents, and peroxides;
• v) a co-agent selected from monofunctional-, difunctional- or trifunctional methacrylic monomers;
• and
• vi) optionally, at least one of a softener, a plasticizer, an antioxidant, a stabilizer, a colorant, a filler, and mixtures thereof in an amount of 0 to 80 wt. %.
• b) curing the mixture for at least 5 minutes at a temperature between 135° C. and 185° C.;
• wherein the composition has a static coefficient of friction in a wet state of at least 1.2 and a kinetic coefficient of friction in wet state of at least 1.2.

A method for making an elastomeric composition having improved wet grip, the method comprises mixing:

• a) from 3 to 50 wt. % of a resin selected from the group consisting of coumarone-indene resin, petroleum hydrocarbon resin, terpene polymers, styrene-alpha-methyl-styrene resins, terpene phenol resin, rosin derived resins and copolymers and/or mixtures thereof;
• b) 40-95 wt % of a first polymer selected from the group of:
• i) a selectively hydrogenated block copolymer having the general configuration A-B-A, (A-B)n, (A-B-A)n, (A-B-A)nX, (A-B)nX or mixtures thereof, wherein n is an integer from 2 to about 30, and X is coupling agent residue, B is a controlled distribution copolymer block of at least one conjugated diene and at least one mono alkenyl arene;
• wherein prior to hydrogenation, each block A is a polymer block of one or more mono alkenyl arenes having a number average molecular weight between 3,000 and 60,000 based upon the total weight of the block copolymer, each block B has a number average molecular weight of 30,000 to 300,000 based upon the total weight of the block copolymer;
• ii) a triblock copolymer having the general configuration S-E-S, (S-E1)n, (S-E1)nS, (S-E1)nX or mixtures thereof, wherein n has a value of 2 to 6 and X is a coupling agent residue;
• wherein prior to hydrogenation S is a polystyrene block, E is a polydiene block, selected from the group consisting of polybutadiene, polyisoprene and mixtures thereof, having a molecular weight of from 20,000 to 220,000 based upon the total weight of the block copolymer, and E1 is a polydiene block, selected from the group consisting of polybutadiene, polyisoprene and mixtures thereof, having a molecular weight of from 20,000 to 220,000 based upon the total weight of the block copolymer;
• c) 5-55 wt % of a second polymer selected from the group of C4 to C20 olefins, thermoplastic elastomers, styrene-butadiene rubbers, ethylene-propylene rubbers, ethylene-propylene-diene rubbers, urethane rubber, syndiotactic 1,2-polybutadiene, styrene isoprene styrene (SIS), styrene-ethylene-butadiene-styrene (SEBS), and combinations thereof, and wherein the second polymer is different from the first polymer;
• d) optionally, at least one of a softener, a plasticizer, an antioxidant, a stabilizer, a colorant, a filler, and mixtures thereof in an amount of 0 to 80 wt. %.
• wherein the composition has a static coefficient of friction in a wet state of at least 1.2 and a kinetic coefficient of friction in wet state of at least 1.2.