Curtain coating method for eliminating sagging at high flow rates
AssigneeFuji Photo Film Co., Ltd.
InventorsYasushi Suga, Kenji Nakajima, Kiyoshi Kobayashi, Kimiaki Miyamoto
Life of this patent
Estimating the term…
Abstract
A coating method that is capable of rapid curtain coating without causing "sagging" at high flow rates exceeding 4 cm.sup.3 /cm.sec. One or more layers of a coating solution are formed on a sliding surface, and a free falling curtain of the coating solution is allowed to impinge against a continuously running web. The web has a surface roughness of at least 0.3 .mu.m, the tip of the sliding surface forms an angle of 45.degree. to 120.degree. with respect to the horizontal, and the viscosity of the coating solution is adjusted to at least 90 cps for low shear rate, with the average for all layers formed being at least 80 cps.
Claims16
A curtain coating method comprising the steps of forming one or more layers of a coating solution on a sliding surface and allowing a free falling curtain of the solution to impinge against a continuously running web, wherein the web has a surface roughness of at least 0.3 .mu.m, a tip of the sliding surface forms an angle in a range of 45.degree. to 120.degree. with respect to the horizontal, a flow quantity of the coating solution is at least 4 cm.sup.3 /cm.sec, a viscosity of the coating solution is adjusted to at least 90 cps for low shear rate, with an average viscosity for all layers formed being at least 80 cps, and the web is continuously run at a speed exceeding 325 m/min.
A curtain coating method comprising the steps of forming one or more layers of a coating solution on a sliding surface and allowing a free falling curtain of the solution to impinge against a continuously running web, wherein the web has a surface roughness of at least 0.3 .mu.m, a tip of the sliding surface forms an angle in a range of 45.degree. to 120.degree. with respect to the horizontal, a flow quantity of the coating solution is at least 4 cm.sup.3 /cm.sec, a viscosity of the coating solution is adjusted to at least 90 cps for low shear rate, with an average viscosity for all layers formed being at least 80 cps, and a coating speed for the method exceeds 325 m/min.
Dependencies are inferred from the claim text.