反应详情

The use of di-(2,2,6,6-tetramethyl-4-piperidinyl) succinate as a light stabilizer for synthetic rubber latices containing TiO2 is suggested in Japanese Patent A-84/53545. The compound is mentioned there, but is not described in detail. Both compounds can be prepared process of U.S. application No. 3,840,494 by transesterifying 4-hydroxy-2,2,6,6-tetramethylpiperidine with a dialkyl succinate or glutarate, respectively. The homologous di-(1,2,2,6,6-pentamethyl-4-piperidinyl) succinate is also mentioned in U.S. application No. 3,840,494. Owing to its low melting point, however, this compound is not very suitable for use as a stabilizer for thermoplastic polymers. In contrast, di-(2,2,6,6-tetramethyl-4-piperidinyl) succinate melts at 118° C. and di-(2,2,6,6-tetramethyl-4-piperidinyl) glutarate melts at 83°-84° C., as a result of which dry mixing with the powdered or granulated thermoplastic polymer is possible.

1. customBoth compounds can be prepared process of U.S