Leaf coater and method for producing leaf type coated substrates

• US 20030170379A1
• Filed: 04/07/2003
• Published: 09/11/2003
• Est. Priority Date: 10/12/2000
• Status: Active Grant

• Current Assignee: Toray Industries Incorporated
• Original Assignee: Toray Industries Incorporated
• Inventors: Kawatake, Hiroshi, Tsujii, Masaya, Kobayashi, Hirofumi, Hashimoto, Kazuyuki, Tomimatsu, Shinji
• Granted Patent: US 6,783,803 B2
• Time in Patent Office: Days
• US Class Current: 427/8
• CPC Class Codes: B05C 11/10 Storage, supply or control of liquid or other fluent material; Recovery of excess liquid or other fluent material B05C1/0813, B05C5/0225, B05C17/002 and B05C19/06 take precedence
• CPC Class Codes: C03C 17/001 General methods for coating; Devices therefor

Abstract

A leaf coater, in which a constant quantity of a coating solution is supplied intermittently from a coating solution supply source through a predetermined coating solution quantity intermittent supply means and a coating solution applying means to a blank substrate, for coating blank substrates one by one with the coating solution, characterized in that a coating solution filtration means is provided in the coating solution flow pipeline from said coating solution supply source to the coating solution applying means, and the Young'"'"'s modulus of the filter medium in the coating solution filtration means is not less than 200 MPa, while the pore size of the filter medium is in the range of 0.05 μm to 100 μm; and a method for producing coated substrates using said leaf coater.

Claims

1. A leaf coater comprises (a) a coating solution supply source, (b) a predetermined coating solution quantity intermittent supply means, (c) a coating solution applying means for applying a coating solution to each blank substrate, (d) a first coating solution flow pipeline connecting said coating solution supply source with said predetermined coating solution quantity intermittent supply means, (e) a second coating solution flow pipeline connecting said predetermined coating solution quantity intermittent supply means with said coating solution applying means, and (f) a coating solution filtration means provided in either said first or second coating solution flow pipeline, which comprises a housing having an inlet and an outlet of the coating solution and a coating solution filtration means composed of a filter medium provided in the passage of the coating solution in said housing, wherein (g) the Young'"'"'s modulus of the filter medium in said coating solution filtration means is not less than 200 MPa and (h) the pore size of the filter medium is in the range of 0.05 μ

m to 100 μ

m.

2. A leaf coater according to claim 1, wherein said filter medium in said coating solution filtration means comprises a sintered metal.

3. A leaf coater according to claim 1, wherein said passage of the coating solution in said coating solution filtration means has a shape of smoothly expanding from said inlet toward said filter medium and/or smoothing reducing from said filter medium toward said outlet, and the expanding and/or reducing rate conforms to the relation of the following formula (I) and/or (II):

0.025≦

h_IN/(d_FLT−

d_IN)≦

1.0 

 

(I)0.1≦

h_OUT/(d_FLT−

d_OUT)≦

1.0 

 

(II)

where d_IN;

Bore of the inlet [mm]

d_OUT;

Bore of the outlet [mm]

d_FLT;

Diameter actually used for filtration in the filter medium [mm]

h_IN;

Distance from the inlet to the filter medium [mm]

h_OUT;

Distance from the outlet to the filter medium [mm].

4. A leaf coater according to claim 3, wherein a screen is provided adjacently to said filter medium in said coating solution filtration means downstream of said filter medium, and the rate of hole area of said screen is not less than 60%.

5. A leaf coater according to claim 3, wherein a screen is provided adjacently to said filter medium in said coating solution filtration means upstream of said filter medium, and the rate of hole area of said screen is not less than 60%.

6. A leaf coater according to claim 3, wherein an annular seal is provided around the lateral circumferential face of said filter medium in said coating solution filtration means, to prevent the formation of any dead space.

7. A method for producing leaf type coated substrates, in which substrates are coated one by one with a coating solution by means of the leaf coater as set forth in any one of claims 1 through 6, to produce coated substrates, wherein the viscosity of the coating solution supplied from said coating solution supply source is not more than 100,000 mPa·

s.

8. A method for producing leaf type coated substrates according to claim 7, wherein said coating solution is a slurry.

9. A method for producing leaf type coated substrates according to claim 8, wherein said slurry is a pigment dispersion.

10. A method for producing leaf type coated substrates according to claim 7, wherein the filtration rate of the coating solution through said filter medium in said coating solution filtration device is not less than 100 g/s·

m².

11. A method for producing leaf type coated substrates according to claim 7, wherein a pressure gauge and a valve are provided in this order in the coating solution flow pipeline communicating with the coating solution outlet of said coating solution filtration device;

with the valve closed, the coating solution is supplied to the coating solution filtration device, to raise the internal pressure of said coating solution filtration device; and

when the pressure detected by the pressure gauge has reached a set value, the valve is suddenly opened to discharge the air remaining in the coating solution filtration device.