Modified natural rubber latex and a method for manufacturing, as well as modified natural rubber, rubber composition, and a tire

摘要

PROBLEM TO BE SOLVED: To provide: a modified natural rubber latex and a method of producing the same, wherein a modified natural rubber can be obtained which can improve low heat-generating properties (low loss performance) of a rubber composition better than a normal natural rubber; the modified natural rubber contained in the modified natural rubber latex; a rubber composition containing the modified natural rubber; and a tire made by using the rubber composition.SOLUTION: The modified natural rubber latex comprises the modified natural rubber, wherein the modified natural rubber contains: natural rubber molecules; a crosslinking portion formed by crosslinking the natural rubber molecules; and a polar group-containing portion formed by performing graft bonding to the natural rubber molecules. The natural rubber latex is obtained by the radical graft polymerization reaction of the natural rubber latex containing the natural rubber molecules with: a polymerizable functional group-containing compound having two or more polymerizable functional groups; and a polar group-containing compound having the polar group.