Coating method and coated product
First Claim
1. A coating method in which a web which continuously runs is relatively pressed against an edge face of a coating head and a plurality of coating liquids are discharged from a plurality of slits formed in the edge face in a direction of width of said web so that layers of the coating liquids are formed on the web, wherein:
- a capillary number Ca which is calculated by an equation Ca=Uμ
/σ
satisfies an inequality 0.1<
Ca<
4, where U (m/s) is a running speed of said web, μ
(Pa.s) is an average high shear viscosity of said coating liquids, and σ
(N/m) is a surface tension of the coating liquid for a top layer of said layers.
2 Assignments
0 Petitions
Accused Products
Abstract
In a case to coat a web by using coating heads which have plural slits, the coating method coats the web by adjusting a running speed, an average high shear viscosity, and a surface tension of the coating liquid of the top layer so that the capillary number Ca, which is calculated by an equation Ca=Uμ/σ, satisfies an inequality 0.1<Ca<4, where U (m/s) is a running speed of the web, μ (Pa.s) is an average high shear viscosity of the coating liquids, and σ (N/m) is a surface tension of the coating liquid for the top layer.
6 Citations
16 Claims
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1. A coating method in which a web which continuously runs is relatively pressed against an edge face of a coating head and a plurality of coating liquids are discharged from a plurality of slits formed in the edge face in a direction of width of said web so that layers of the coating liquids are formed on the web, wherein:
a capillary number Ca which is calculated by an equation Ca=Uμ
/σ
satisfies an inequality 0.1<
Ca<
4, where U (m/s) is a running speed of said web, μ
(Pa.s) is an average high shear viscosity of said coating liquids, and σ
(N/m) is a surface tension of the coating liquid for a top layer of said layers.- View Dependent Claims (2, 7, 8)
-
3. A coating method in which a coating liquid is oversupplied to a web which continuously runs to form a bottom layer and then the web is relatively pressed against an edge face of a coating head and a plurality of coating liquids are discharged from a plurality of slits formed in the edge face in a direction of width of said web while an upper stream side of the edge face removes a part of the bottom layer when the coating liquid of the bottom layer is wet so that a plurality of coating layers are formed on the bottom layer, wherein:
a capillary number Ca which is calculated by an equation Ca=Uμ
/σ
satisfies an inequality 0.1<
Ca<
4, where U (m/s) is a running speed of said web, μ
(Pa.s) is an average high shear viscosity of the plurality of coating liquids, and σ
(N/m) is a surface tension of the coating liquid for a top layer of said layers.- View Dependent Claims (4, 6)
-
5. A coating method in which a first coating liquid is oversupplied to a web which continuously runs to form a bottom layer and then the web is relatively pressed against an edge face of a coating head and a second coating liquid is discharged from a slit formed in the edge face in a direction of width of said web while an upper stream side of the edge face removes a part of the bottom layer when the first coating liquid of the bottom layer is wet so that a top coating layer is formed on the bottom layer, wherein:
a capillary number Ca which is calculated by an equation Ca=Uμ
/σ
satisfies an inequality 0.1<
Ca<
4, where U (m/s) is a running speed of said web, μ
(Pa.s) is a high shear viscosity of the second coating liquid, and σ
(N/m) is a surface tension of the second coating liquid.
-
9. A coating method in which a web which continuously runs is relatively pressed against an edge face of a coating head and a plurality of shear thinning coating liquids are discharged from a plurality of slits formed in the edge face in a direction of width of said web so that layers of the plurality of coating liquids are applied on the web in a wet-on-wet condition, wherein:
-
viscosities of the plurality of coating liquids are adjusted so that a following inequality is satisfied, −
15×
10−
3<
μ
n-1−
μ
n<
5×
10−
3,where μ
n (Pa.s) is a high shear viscosity of the coating liquid forming an n-th (n≧
2) layer from said web and μ
n-1 (Pa.s) is a high shear viscosity of the coating liquid forming an (n−
1)-th layer that is adjacent to the n-th layer. - View Dependent Claims (10, 15)
-
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11. A coating method in which a shear thinning coating liquid is oversupplied to a web which continuously runs to form a bottom layer and then the web is relatively pressed against an edge face of a coating head and a plurality of shear thinning coating liquids are discharged from a plurality of slits formed in the edge face in a direction of width of said web while an upper stream side of the edge face removes a part of the bottom layer when the coating liquid of the bottom layer is wet so that a plurality of coating layers are formed on the bottom layer in a wet-on-wet condition, wherein:
-
viscosities of the coating liquids are adjusted so that a following inequality is satisfied, −
15×
10−
3<
μ
n-1−
μ
n<
5×
10−
3,where μ
n (Pa.s) is a high shear viscosity of the coating liquid forming an n-th (n≧
2) layer from said web and μ
n-1 (Pa.s) is a high shear viscosity of the coating liquid forming an (n−
1)-th layer that is adjacent to the n-th layer. - View Dependent Claims (12, 14, 16)
-
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13. A coating method in which a first shear thinning coating liquid is oversupplied to a web which continuously runs to form a bottom layer and then the web is relatively pressed against an edge face of a coating head and a second shear thinning coating liquid is discharged from a slit formed in the edge face in a direction of width of said web while an upper stream side of the edge face removes a part of the bottom layer when the first coating liquid of the bottom layer is wet so that a top coating layer is formed on the bottom layer in a wet-on-wet condition, wherein:
-
viscosities of the first and second coating liquids are adjusted so that a following inequality is satisfied, −
15×
10−
3<
μ
1−
μ
2<
5×
10−
3,where μ
1 (Pa.s) is a high shear viscosity of the first coating liquid and μ
2 (Pa.s) is a high shear viscosity of the second coating liquid.
-
Specification