Patent ID: 7786208

Claim:
A method for producing a modified natural rubber masterbatch, which comprises the step of mixing a modified natural rubber latex, which is formed by adding a polar group-containing monomer to a natural rubber latex to graft-polymerize the polar group-containing monomer onto a natural rubber molecule in the natural rubber latex, with a slurry solution formed by previously dispersing at least one filler selected from the group consisting of carbon black, silica and an inorganic compound represented by the following general formula (I): nM.xSiO y .zH 2 O (I) [wherein M is at least one selected from the group consisting of a metal of aluminum, magnesium, titanium, calcium or zirconium, oxides and hydroxides of these metals, their hydrates, and carbonates of these metals, n is an integer of 1-5, x is an integer of 0-10, y is an integer of 2-5, and z is an integer of 0-10] into water, wherein a grafting amount of the polar group-containing monomer is 0.01%-3.0% by mass based on a rubber component in the natural rubber latex.