Method of manufacturing a flat fluorescent screen.

p0001The invention relates to a method of coating a flat glass screen for flat color picture tubes according to the preamble of claim 1.

p0002From DE-PS 28 04 127. A method for preparing a plan luminescent screen for flat color image display device is known in which the phosphors are used in a slurry with solvents and other substances. In the use of solvents to prepare the phosphor slurry can be reached indeed that only one operation is required in the coating, but the solvent must from the slurry after application out again, and then leaves behind a phosphor layer having a rough surface. The phosphor layer has no optimum packing density and solvents are explosive.

p0003The invention is based on the object of specifying a method of the aforementioned type, in which the phosphors are different slurried.

p0004This object is effected by the means indicated in claim. 1

p0005By applying a reactive binder and an activator of special Sicherheitsmaßmahmen eliminates requiring handling solvents. Since from the phosphors after the application of nothing has to be removed, they have a smooth surface and a good degree of filling, which prevents a color overlay. This and an extremely good adhesion of the phosphors on the screen glass is narrow strip widths or small light spot diameter Let achieve.

p0006The activator may thus come up with the phosphor slurry in connection, that it is applied either as a first screen on the glass or each phosphor layer is sprayed with it.

p0007As the binder is a monomeric methacrylate is preferably used, which for example is marketed by the company Henkel under the name Metallon LA of 2002. The associated activator Henkel is called LA 5202nd

p0008The invention of an exemplary embodiment is explained in detail.

p0009The usual pre-treated flat screen glass is evenly sprayed with the activator and then dried. Then, the basic mask is placed on the screen glass and above the first coating mask, for example, the green fluorescent attached. Then the following slurry is poured evenly and the excess removed by stripping:<ul><li>200g green phosphor type Zn, CdS, (Cu, A1) dispersed in</li><li>1000g reactive binder as stated.</li></ul>

p0010After hardening of the slurry, the first coating mask is removed and the second coating mask Step Example lsweise for the blue phosphor, is mounted. Then the following slurry is poured uniformly on the deposition mask and the excess removed by stripping:<ul><li>220g blue phosphor type ZnS, Ag dispersed as indicated in 1000g reactive binder.</li></ul>

p0011After curing, this slurry to the process with the third deposition mask for the red phosphor repeated. Here are<ul><li>250g red phosphor of the type Y₂0₂S, Eu dispersed as indicated in 1000g reactive binder.</li></ul>

p0012After curing, this slurry coating mask and the basic mask are removed and the phosphor screen thus prepared for painting and _Alu-minisieren passed.

p0013With flat color picture tubes with a black matrix layer, a matrix mask is placed on the flat screen glass and poured over the following slurry evenly and the excess removed by stripping before applying the basic mask:<ul><li>100g graphite with grain size of 0.05 mm are dispersed in 1000 g reactive binder as stated.</li></ul>

p0014After curing, the matrix mask is removed and placed the basic screen and made the canopy as described.

p0015Instead of first planar shield the glass to be coated with the activator, it can also be sprayed after each application of the slurries to these.