Patent ID: 8153564

Claim:
A cross-linking composition comprising (a) an aqueous liquid; (b) a pH buffer; (c) a cross-linkable organic polymer; and (d) a zirconium cross-linking agent comprising the product of contacting a solution of a zirconium complex with an alkanolamine and ethylene glycol as an accelerator wherein the mole ratio of alkanolamine to zirconium is 2:1 to 4:1 and the mole ratio of ethylene glycol to zirconium is 1:1 to 10:1 wherein the cross-linking composition has a crosslinking rate in the range of 3-8 minutes, providing an initial viscosity of at least 650 Cp, and a viscosity of at least 350 Cp after 90 minutes, further wherein, if the zirconium complex is contacted with water, water acts as a rate retarder, and water is added in an amount to provide a mole ratio of water to zirconium of 1:1 to 20:1.