Process for preparing a block copolymer of lioxialquilenglicol glycol. this patent has also deposited in the following countries: Canada, Japan and European patent.

摘要

The present invention deals with high viscosity polyoxyalkylene glycol block copolymers and a method of making the same. A high molecular weight, high viscosity liquid, water soluble polyoxyalkylene block copolymer suitable as a functional fluid is provided having the formula CHEM wherein Q is the organic residue from an organic diisocyanate; x is an integer in the range of about 1 to 10; R1 and R2 are hydrogen, methyl, ethyl, or mixtures thereof with the proviso that the overall content of species whereweight; R3 and R4 are organic residues resulting from in R1 and R2 are hydrogen must be at least 50 percent by the removal of terminal hydrogen atoms from difunctional polyols, y and z are integers representing the polyether blocks in said copolymer and the sum of which must be from about 1.05 to 2.0 times the value of x; and n, m, r, and s are integers wherein n = m and r = s and the sums n + m and r + s are each in the range of 8 to 250.