Patent ID: 7976904

Claim:
A curtain coating process for coating substrates with a stable curtain of a uniform coating at low flow rates wherein a free-falling curtain of an aqueous composition comprising a solids content greater than or equal to 50% dry weight is coated onto a moving substrate at a flow rate per unit die length value (Q) equal to or inferior to 10 −4 m 3 /(s·m), said aqueous composition comprising a polymeric rheology modifier and a non-ionic surfactant, and wherein the viscosity of the aqueous composition is selected from the group consisting of between 1350 and 2411 mPa·s at a shear rate of 10 s −1 , between 255 and 438 mPa·s at a shear rate of 100 s −1 , 50 and 200 mPa·s at a shear rate of 1000 s −1 , between 25 and 90 mPa·s at a shear rate of 10000 s −1 , and between 20 and 75 mPa·s at a shear rate of 100000 s −1 , all at 25° C.