Patent ID: 9168566
Filing Date: 2015-10-27
Classification: B05D,B43L,G03B,Y10T

Abstract:
1. A process for producing a projection blackboard, comprising: coating a surface of a metallic substrate with an enameling lower glaze; firing the coating to form an underlying enamel layer; coating an underlying enamel layer with an enameling upper glaze in which at least titanium dioxide coated particles are blended into a transparent matte glaze, and at least one of black pigment, green pigment, and brown pigment or a combination of two or more thereof, as the pigment(s), is/are further added to the transparent matte glaze in accordance with a color tone of the blackboard; and firing at 400 to 850° C. to form a surface enamel layer having a color tone having a brightness V according to JIS Z 8721-1993 of from 3.0 to 7.0, a surface roughness Rz according to JIS B 0601-2001 in a range of 5 to 25 μm, and a peak gain of 0.28 or more.