| 摘要 |
Provided are modified carboxyl-terminated polyorganosiloxanes having a mean molecular weight of from 500 to 120,000 and represented by the following formula (1), and a method for producing them. The modified polyorganosiloxanes have a carboxyl group at one terminal position, and have a polyoxyalkylene moiety in the center of the molecular chain. They are highly miscible with various polar solvents and monomers. The method for producing them comprises reacting a polyorganosiloxane having a hydroxyl group at one terminal position and having a polyoxyalkylene moiety in the center of the molecular chain, with a cyclic acid anhydride having a specific structure, and it does not require plural reaction steps. In the method, various types of carboxyl-terminated polyorganosiloxanes can be easily produced, depending on the type of the cyclic acid anhydride used.wherein R1, R2, R3, R4 and R5 each represent a linear or branched alkyl group having from 1 to 20 carbon atoms, an aryl-containing group having from 6 to 10 carbon atoms, or a cycloalkyl group having from 4 to 10 carbon atoms; n and m each represent a number of 0, 1 or more; n+m indicates a number to satisfy the mean molecular weight, from 500 to 100,000, of the polysiloxane segments; X represents an alkylene group having from 2 to 20 carbon atoms; Y represents an oxyalkylene group having from 1 to 3 carbon atoms; p represents a number to satisfy the mean molecular weight, from 30 to 20,000, of the polyoxyalkylene segments Yp; and A represents a substituent having from 1 to 6 carboxyl groups.
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