Method of increasing the size and absorption under load of superabsorbent fine particles by impregnation with an aqueous acrylic monomer solution

A method of increasing the size and water absorbance of water-absorbent solid, cross-linked polyacrylic polymer particles, having a size, prior to treatment, predominantly less than about 300 .mu.m comprising:

• polymerizing and cross-linking an acrylic monomer selected from the group consisting of acrylic acid, neutralized acrylic acid, and mixtures thereof to form said solid cross-linked polyacrylic polymer, that is dried sufficiently for grinding;
• grinding said dried, cross-linked polyacrylic polymer to form polyacrylic polymer particles, a portion of said particles having a particle size less than 300 .mu.m;
• separating a portion of the dried, cross-linked polyacrylic polymer particles having a size less than about 300 .mu.m for impregnation with a solution containing an acrylic monomer;
• impregnating said separated, dried, polyacrylic polymer particles with an impregnating monomer solution containing an acrylic monomer in a concentration of about 20% to about 80% by weight;
• wherein the monomer solution is impregnated into said separated, dried, cross-linked polyacrylic polymer particles in a weight ratio of solid polyacrylic polymer particles, dry basis, to impregnating monomer solution in the range of about 1:1 to about 1:10 to form a paste;
• and
• polymerizing the impregnated acrylic monomer in said paste to form coherent agglomerates of said polyacrylic polymer particles.