| 摘要 |
PROBLEM TO BE SOLVED: To provide a new process for producing a silica masterbatch by which silica dispersibility can be improved.SOLUTION: The process for producing a silica masterbatch comprises: decomposing a polymer having carbon-carbon double bonds in the main chain by oxidatively cleaving the carbon-carbon double bonds, and thus forming an aqueous emulsion containing a polymer fragment whose molecular weight has been lowered; mixing the aqueous emulsion containing the polymer fragment, a functional molecule which has an alkoxysilyl group represented by formula (A) in the structure, and a silica, thereby obtaining a mixture; and changing the acidity or basicity of the mixture in such a manner that when the mixture is acidic, the mixture is rendered basic and when basic, the mixture is rendered acidic, and thus bonding the polymer fragment, thereby obtaining the silica masterbatch containing: a modified polymer where the alkoxysilyl group has been introduced into at least one of the molecule terminals; and the silica, is obtained. In formula (A), Rrepresents an alkyl group of a carbon number 1 to 10, Rrepresents an aldehyde group or a carbonyl group, Rrepresents an alkyl group of a carbon number 1 to 10, m represents a number of 1 to 3, n represents a number of 1 or 2, and l represents a number of 0 to 2. |
