| 摘要 |
PURPOSE:To obtain a rubber excellent in green strength and adhesiveness, by reacting a rubber having an unsaturated carbon-carbon bond with a specified keto- ester in the presence of a Lewis acid to introduce ester groups into the rubber. CONSTITUTION:100pts.wt. rubber having an unsaturated carbon-carbon rubber bond (e.g., polyisoprene rubber) is mixed with 0.0001-20pts.wt. keto-ester of the formula (wherein R1 and R2 are each a hydrocarbon residue), and the resulting mixture is reacted at -20-100 deg.C for 10sec-10hr in the presence of 0.01-5mol of a Lewis acid (e.g., BF3) per mol of the keto-ester to introduce the ester groups into the rubber. If desired, this rubber is hydrolyzed by the addition of an acid or an alkali to convert at least part of the ester groups into carboxyl groups.
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