Compounded unsaturated polyester resin compositions with a reduced monomer content

The invention relates to unsaturated polyester resins and more particularly to compounded polyester resin compositions with reduced monomer contents, comprising at least two different types of unsaturated polyesters. The invention also relates to a method for the manufacture of such unsaturated polyester resins, of compounded resin compositions and to the use thereof. A compounded unsaturated polyester resin composition having 10-90 wt % of at least one high viscosity, high molecular weight unsaturated polyester, 10-80 wt % of at least one low viscosity, low molecular weight unsaturated polyester, and 9-30 wt % of at least one monomer. The cone and plate viscosity of the high molecular weight unsaturated polyester is 1 Pas/100° C. to 10 Pas/150° C. and the weight average molecular weight Mw is 1,200 to 10,000. The cone and plate viscosity of the low molecular weight unsaturated polyester is 1 Pas/25° C. to 4 Pas/100° C., and the weight average molecular weight Mw is 400 to 3,000.