High cis-1,4-polybutadiene rubber compounds

Abstract

This invention relates to blends of a specific type of cis-l,4-polybutadiene rubber with other rubbery polymers, such as natural rubber, synthetic polyisoprene rubber, styrene-butadiene rubber, isoprene-butadiene rubber and / or styrene-isoprene- butadiene rubber. The cis-1,4-polybutadiene rubber utilized in the blends of this invention is synthesized by polymerizing 1,3-butadiene in the presence of (a) an organonickel compound, (b) an organoaluminum compound, (c) a fluorine containing compound and (d) para-styrenated diphenylamine; wherein the organoaluminum compound and the fluorine containing compound are brought together in the presence of the para-styrenated diphenylamine. The cis-1,4-polybutadiene rubber blends of this invention offer improved processability and enhanced physical properties. For instance, improved mixing which results in better incorporation of pigments and fillers, such as carbon black and silica, at lower levels of power consumption is realized. Additionally, improvements in extrusion characteristics and in tear resistance with little sacrifice in hysteretic properties, abrasion resistance and modulus are also attained with the rubber blends of this invention. The rubber blends of this invention can be used in manufacturing a wide variety of rubber products, such as tires, hoses, belts, golf balls, tennis balls, racquet balls, golf club grips, stoppers, plungers, tubing, straps, diaphragms, motor mounts, bushings, weather stripping, windshield wiper blades, shoe soles, other molded rubber products and adhesives.

Description

BACKGROUND OF THE INVENTIONNickel-based catalyst systems are commonly used in the polymerization of 1,3-butadiene monomer into cis-1,4-polybutadiene rubber. Such nickel-based catalyst systems contain (a) an organonickel compound, (b) an organoaluminum compound and (c) a fluorine containing compound. Such nickel-based catalyst systems and their use in the synthesis of cis-1,4-polybutadiene is described in detail in U.S. Pat. No. 3,856,764, U.S. Pat. No. 3,910,869 and U.S. Pat. No. 3,962,375.The cis-1,4-polybutadiene prepared utilizing such nickel-based catalyst systems typically has a high molecular weight. Due to this high molecular weight, the cis-1,4-polybutadiene is generally oil-extended. However, this precludes the cis-1,4-polybutadiene from being utilized in many applications. For instance, such oil-extended rubbers cannot be utilized in tire sidewalls which contain white sidewall compounds. In any case, there is a large demand for cis-1,4-polybutadiene having a reduced molecu...

AI Technical Summary

Benefits of technology

It has been found that blends of cis-1,4-polybutadiene rubber with other rubbery polymers offer improved processability and improved physical characteristics in cases where the cis-1,4- polybutadiene rubber is synthesized by polymerizing 1,3-butadiene in the presence of (a) an organonickel compound, (b) an organoaluminum compound, (c) a fluorine containing compound and (d) para-styrenated diphenylamine. Such cis-1,4-polybutadiene rubber blends offer improved processability and enhanced physical properties. For instance, improved mixing which results in better incorporation of pigments and fillers, such as carbon black and silica, at lower levels of power consumption is realized. Additionally, improvements in tear resistance with little sacrifice in hysteretic properties, abrasion resistance and modulus are also attained with the rubber blends of this invention. The rubber blends of this invention can be used in manufacturing a wide variety of rubber products, such as tires, hoses, belts, golf balls, tennis balls, racquet balls, golf club grips, stoppers, plungers, tubing, straps, diaphragms, motor mounts, bushings, weather stripping, windshield wiper blades, shoe soles, other molded rubber products and adhesives.

The present invention further reveals a rubber composition for a solid golf ball having excellent durability and rebound properties comprising: (a) cis-1,4-polybutadiene rubber, wherein said cis-1,4-polybutadiene rubber has a Mooney ML 1+4 viscosity of 35 to 70, wherein said cis-1,4-polybutadiene rubber has a cis-1,4 bond content of at least 95 percent, wherein cis-1,4-polybutadiene rubber is made by polymerizing 1,3-butadiene in the presence of (a) an organonickel compound, (b) an organoaluminum compound, (c) a fluorine containing compound and (d) para-styrenated diphenylamine, and wherein the organoaluminum compound and the fluorine containing compound are brought together in the presence of the para-styrenated diphenylamine; (b) a co-crosslinking agent and (c) a peroxide.

Problems solved by technology

However, this precludes the cis-1,4-polybutadiene from being utilized in many applications.

For instance, such oil-extended rubbers cannot be utilized in tire sidewalls which contain white sidewall compounds.

However, this approach also typically leads to increased cold flow.

Accordingly, the use of conventional molecular weight-reducing agents, such as .alpha.-olefins, to improve rubber processability leads to compromised cold flow characteristics.