Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – At least one aryl ring which is part of a fused or bridged...
Patent
1987-03-16
1989-05-30
Schofer, Joseph L.
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
At least one aryl ring which is part of a fused or bridged...
524512, 524542, 524572, 524575, 525107, 525113, 525123, 525153, 525154, 5253326, 5253327, 5253329, 5253322, 525344, 525348, 525349, 525351, 525374, C08F 830
Patent
active
048352098
DESCRIPTION:
BRIEF SUMMARY
DESCRIPTION
1. Field of the Invention
The present invention relates to a rubber-like polybutadiene or a styrene-butadiene copolymer produced by the use of an organolithium catalyst which is suitable for treads of fuel-cost-saving tires and all-season tires, a process for the production thereof, and a composition containing the above compound.
2. Background of the Invention
In recent years, automobile tires have been desired to be reduced in rolling resistance from the viewpoint of saving fuel cost and to be improved in control stability and wet skid properties (breaking capabilities on wet roads) from the viewpoint of the safety of automobiles. On the other hand, the production of tires for the automobile has been desired to be improved in the uniformity of quality by improving the processability and in the productivity by improving the workability.
As methods for reducing the rolling resistance while maintaining the wet skid properties of tire, methods such as weight reduction of the the tire, optimization of the structure of tire, improvement of the tread pattern of tire, improvement of a rubber composition used in tire-tread, etc. have been heretofore attempted. Among them, the method for reducing the rolling resistance by improving a rubber composition used in the tire tread includes a method using as starting rubber a rubber having a small hysteresis loss, a method using carbon black having a larger particle size in place of carbon black having a smaller particle size, a method comprising reducing the amount of carbon black and oil used in vulcanized rubber, etc.
As the method comprising improving the starting rubber among the above-mentioned improvement methods, the employment of a polymer having a higher molecular weight was proposed on the basis of conventional information concerning the physical properties of starting rubbers and vulcanized rubbers. However, according to this method, the impact resilience can be improved but the Mooney viscosities of a starting material and compounding ingredients are increased, resulting in the lowering of the processability, so that no great improvement can be made. On the other hand, according to the method comprising changing the formulation so as to reduce the mixing amounts of oil and carbon black, the Mooney viscosities of compounding ingredients are increased, resulting in a lowering of the processability. Thus, whichever method is employed, it is difficult to affect the improvement without sacrificing the processability.
In recent years, it has been found that random styrene-butadiene copolymer rubber having many vinyl linkages and a branched structure have been suitably used in tires, and rubbers various in structure have been investigated and various proposals have been made. For example, there has been proposed a method in which in coupling a styrene-butadiene copolymer rubber having an increased vinyl content by use of tin to form a branched styrene-butadiene copolymer rubber, the rolling resistance is improved by adding the butadiene immediately before the coupling reaction to carry out polymerization (Japanese Patent Application Kokai (Laid-Open) Nos. 87407/82 and 162605/83). However, even this method can make insufficient improvement in the rolling resistance and has been disadvantageous, for example, in that the production process becomes troublesome.
There has also been proposed a completely random styrene-butadiene copolymer rubber produced by introducing monomers continuously into a polymerization region having a high stirring efficiency controlled so as to be a temperature of 80.degree. C. or higher to allow polymerization to proceed by use of a catalyst composed of an organolithium compound and a Lewis base (U.S. Pat. No. 4,547,560). This polymer showed excellent performance characteristics with respect to tensile strength, impact resilience, low heat-generating properties, wear resistance, wet skid properties, etc. However, it required a further improvement in impact resilience, low heat-generating properties, etc.
In addition thereto, as m
REFERENCES:
patent: 3226356 (1965-12-01), Kehr et al.
patent: 3528958 (1970-09-01), Achorn
patent: 3968092 (1976-07-01), Gruber
patent: 4547560 (1985-10-01), Hattori et al.
patent: 4555547 (1985-11-01), Ueda et al.
Database Chemical Abstracts, (1983), Abstract No. 110(20):158063r, p. 79.
Kitagawa Yuichi
Saito Akira
Yamada Haruo
Asahi Kasei Kogyo Kabushiki Kaisha
Lipman Bernard
Schofer Joseph L.
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