| 摘要 |
A low viscosity copolymer polyahl dispersion is prepared by polymerizing polymer particles in a polyahl medium, to a first solids concentration and thereafter diluting the dispersion to a second lower solids concentration. The resulting diluted dispersion has a lower viscosity than if the dispersion were prepared directly at the lower solids level. The invention has particular advantage when used with "all acrylonitrile" dispersions. The copolymer polyahl dispersions are useful in the manufacture of urethane and isocyanurate foams.
|
