METHOD FOR PRODUCING RUBBER COMPOSITION

The present invention has as its object the provision of a production process of a rubber composition containing a modified conjugated diene-based polymer, which can provide a rubber composition in which processability is excellent, and a filling agent (filler), when contained, has favorable dispersibility therein.The production process of a rubber composition according to the present invention includes: a first step of kneading a modified conjugated diene-based polymer that is obtained by polymerizing a monomer containing a conjugated diene compound and has at least one nitrogen-containing functional group selected from the group consisting of a primary amino group, a secondary amino group, a tertiary amino group, a primary amino group having been converted into an onium group, a secondary amino group having been converted into an onium group and a tertiary amino group having been converted into an onium group, and a basic compound having an acid dissociation constant of not lower than 8.0; and a second step of kneading the kneaded product obtained in the first step and a cross-linking agent.