Coating method
AssigneeKonica Corporation
InventorShigetoshi Kawabe
Life of this patent
Estimating the term…
Abstract
A coater comprises upstream and down stream side bars between which a pocket and a slit are formed. The coating apparatus satisfies the following conditional formula: 6(t13+t2−3)μhw×u×Ls(Ls/2+Lp)L3/(h4E)≦Δhdmax/hd where Ls is a length (mm) of the slit, h is a gap (mm) of the slit, Lp is a length (mm) of a cross section of the pocket, L=Ls+Lp, E is a Young's modulus (Pa) of the upstream and downstream bars, t1 and t2 are a thickness (mm) of the thinnest portion of the upstream and downstream side bars at the pocket, μ is a viscosity (Pa·s), u is a coating speed (mm/s), and Δhdmax is a permissible maximum value (mm) among differences Δhd (mm) between the maximum value and the minimum value in the dispersion of a dried layer thickness hd.
Claims16
A coating apparatus for coating a web conveyed in a conveying direction, comprising:
- a coater including an upstream side bar and a downstream side bar located downstream of the upstream bar in relation to the conveying direction, wherein between the upstream and downstream bars are formed a pocket to store a coating liquid and a slit thought which the coating liquid is extruded from the pocket;
- a coating liquid feeding device to feed the coating liquid to the pocket;
- and
- a conveyor to convey continuously the web to the coater,
- wherein the following conditional formula is satisfied:
- 6(t1−3+t2−3)μ×hw×u×Ls(Ls/2+Lp)L3/(h4E)≦Δhdmax/hd
- where Ls is a length (mm) of the slit in a widthwise direction of the web,
- h is a gap (mm) of the slit,
- Lp is a length (mm) of a cross section of the pocket in the direction corresponding to the length of the slit,
- L (mm)=Ls (mm)+Lp (mm),
- E is a Young's modulus (Pa) of the upstream and downstream bars,
- t1 is a thickness (mm) of the thinnest portion of the upstream side bar at the pocket,
- t2 is a thickness (mm) of the thinnest portion of the downstream side bar at the pocket,
- μ is a viscosity (Pa·s) of the coating liquid,
- u is a coating speed (mm/s), and Δhdmax is a permissible maximum value (mm) among differences Δhd (mm) between the maximum value and the minimum value in the dispersion of a dried layer thickness hd measured along the entire width of the coating layer.
A coating method of coating a coating liquid on a web-shaped support with a coater having at least one set of a slit and a pocket, comprising steps of:
- feeding the coating liquid having a viscosity μ (Pa·s) to the coater in which the slit has a length Ls (mm) and a gap h (mm);
- conveying the web-shaped support at a coating speed u (mm/s);
- and
- coating the coating liquid on the conveyed web-shaped support with the coater so as to form at least one coating layer having a pre-dried layer thickness hw (mm),
- wherein the following conditional formula is satisfied:
- 1×104<12×μLs×hw×u/h3≦4×105
Dependencies are inferred from the claim text.