Patent ID: 8268942

Claim:
A process for producing water-absorbing polymeric particles by spray polymerization of a monomer solution comprising spray dispensing a monomer solution comprising a) at least one ethylenically unsaturated acid-functional monomer, b) at least one crosslinker of formula wherein R represents the same or different radicals selected from the group consisting of hydrogen, methyl, and ethyl, B represents the same or different groups selected from and * designates the positions of attachment, D represents the same or different groups selected from carbonyl and methylene, x and z are the same or different and each represents an integer from 2 to 30, and y represents an integer from 5 to 60, wherein the crosslinker b) equilibrates in the monomer solution in less than 10 seconds in an ASTM D3825 measurement of dynamic surface tension, b′) a crosslinker having at least two free-radical polymerizable groups for crosslinking the polymeric particle interior; c) optionally one or more ethylenically and/or allylically unsaturated monomers copolymerizable with the monomer a), and d) optionally one or more water-soluble polymers onto which the monomers a), b) and c) can be at least partly grafted, to form droplets of the monomer solution, wherein the at least one crosslinker b) accumulates at the droplet surface; and polymerizing the droplets of the monomer solution to form the water-absorbing polymeric particles.