| 摘要 |
A random copolymer corresponding to Formula I in free acid or salt form having the following types and numbers of monomer units; <IMAGE> wherein A is selected from the moieties (i) and (ii);-CR1R2-CR3R4-(i)wherein R1 and R3 are selected from substituted benzene, C1-8alkyl, C2-8alkenyl, C2-8 alkylcarbonyl, C1-8alkoxy, carboxyl and hydrogen, or R1 and R3 can together with R2 and/or R4 form a ring; and R2 and R4 are selected from hydrogen and C1-4alkyl; and <IMAGE> (ii) wherein R1 and R3 are as for (i) and R7, R8, R9 and R10 are individually selected from hydrogen and C1-6alkyl, or R1 and R3 together with R7 and/or R8, R9 and R10 form a continuous C2-8 hydrocarbon chain joining the carbon atoms to which they are attached, the hydrocarbon chain optionally comprising at least one hetero atom and the ring optionally having at least one anionic group, preferably sulphonic; M is selected from hydrogen and the residue of a hydrophobic polyalkylene glycol or a polysiloxane, with the proviso that when A is (ii) and M is the residue of a hydrophobic polyalkylene glycol, M must be different from the group -(R5O)mR6 R5 is a C2-8alkylene radical; R6 is selected from C1-20alkyl, C6-9cycloalkyl and phenyl; n, x and z are numbers from 1 to 100; y is 0 to 100; m is 2 to 100; and the ratio of x to (y+z) is from 1:10 to 10:1 and the ratio of y:z is from 5:1 to 1:100. The copolymers are useful as fluidifying agents in cementitious compositions such as concrete and mortar. |
