Pneumatic tires
AssigneesBridgestone Corporation, Japan Synthetic Rubber Co., Ltd.
InventorsHiroshi Mouri, Hiromi Maeda
Life of this patent
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Abstract
A heavy duty pneumatic tire for use in construction vehicles, truck and bus is disclosed, which comprises a tread rubber having improved cut resistance, resistance to rib tear, wear resistance, resistance to heat build-up, processability and the like. The tread rubber comprises 20-100 parts by weight of a particular modified styrene-butadiene copolymer and 80-0 parts by weight of other diene series rubber as a rubber component and contains 40-80 parts by weight of a particular carbon black based on 100 parts by weight of the rubber component.
Claims5
A pneumatic tire, characterized in that at least a tread portion of said tire is comprised of a rubber composition comprising 20-100 parts by weight of a modified styrene-butadiene copolymer and 80-0 parts by weight of another diene series rubber as a rubber component, and containing 40-80 parts by weight of carbon black having a specific surface area of nitrogen adsorption of 110-160 m.sup.2 /g and a DBP oil absorption of 100-150 ml/100 g based on 100 parts by weight of said rubber component;
- wherein said modified styrene-butadiene copolymer is obtained by copolymerizing 15-50 parts by weight of stryrene and 85-50 parts by weight of 1,3-butadiene in a hydrocarbon solvent in the presence of an organolithium polymerization initiator and then modifying an active end of the resulting polymer with a terminal modifying agent;
- said copolymerization being carried out by using (a) 0.01-0.5 mol of at least one anionic surfacant having a --SO.sub.2 M or --OSO.sub.3 M group (wherein M is an element selected form the group consisting of Na, K, Rb and Cs), per 1 gram-atom of lithium in said organolithium polymerization initiator and (b) 0.1-5 mol of at least one member selected form the group consisting of alcohols, thioalcohols, organic carboxylic acids, organic sulfonic acids, organic phosphites, primary amines and secondary amines, based on 1 mol of said surfacant, wherein said hydrocarbon solvent is used in an amount of 0.5-20 parts by weight per 1 part by weight of monomer, wherein said organolithium polymerization initiator is used in an amount of 0.02-5 milligram-atom as a lithium atom per 100 g of monomer, and wherein said terminal modifying agent is selected from the group consisting of alkenyl aromatic vinyl compounds, halogenated tim compounds, halogenated silicon compounds, isocyanate compounds, dialkylamino-substituted aromatic vinyl compounds, nitrogen-containing aromatic heterocompounds and cyclic urea compounds.
A rubber composition 20-100 parts by weight of a modified styrene-butadiene copolymer and 80-0 part by weight of another diene series rubber as a rubber component, and containing 40-80 parts by weight of carbon black having a specific surface area of nitrogen adsorption of 110-160 m.sup.2 /g and a DBP oil absorption of 110-150 ml/100 g based on 100 parts by weight of said rubber component;
- wherein said modified styrene-butadiene copolymer is obtained by copolymerizing 15-50 parts by weight of stryene and 85-50 parts by weight of 1,3-butadiene in a hydrocarbon solvent in the presence of an organolithium polymerization initiator and then modifying an active end of the resulting polymer with a terminal modifying agent;
- said copolymerization being carried out by using (a) 0.01-0.5 mol of at least one anionic surfacant having a --SO.sub.2 M or --OSO.sub.3 M group (wherein M is an element selected from the group consisting of Na, K Rb and Cs), per 1 gram-atom lithium in said organolithium polymerization initiator and (b) 0.1-5 mol of at least one member selected from the group consisting of alcohols, thioalcohols, organic carboxylic acids, organic sulfonic acids, organic phosphites;
- primary amines and secondary amines, based on 1 mol of said surfactant, wherein said hydrocarbon solvent is used in an amount of 0.5-20 parts by weight per 1 part by weight of monomer, wherein said organolithium polymerization initiator is used in an amount of 0.02-5 milligram-atom as a lithium atom per 100 g of monomer, and wherein said terminal modifying agent is selected from the group consisting of alkenyl aromatic vinyl compounds, halogenated tin compound, halogenated silicon compounds, isocyanate compounds, dialkylamino-substituted aromatic vinyl compounds, nitrogen-containing aromatic heterocompounds and cyclic urea compounds.
Dependencies are inferred from the claim text.