Browse Prior Art Database

Increasing the Optical Density of Iron Coating on Glass Substrates

IP.com Disclosure Number: IPCOM000078062D
Original Publication Date: 1972-Nov-01
Included in the Prior Art Database: 2005-Feb-25
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Cascio, SJ: AUTHOR

Abstract

Presently, glass masters are prepared by utilizing either silver emulsion or vacuum metallized chromium on glass. Recent development activities have centered upon an inexpensive method of coating glass with a ferric nitrate solution, that is semitransparent in the ultra violet range. The maximum density obtained has been 0.10 to 0.20 units of optical density, which is insufficient density for contact printing to produce a photoresist image.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 1

Increasing the Optical Density of Iron Coating on Glass Substrates

Presently, glass masters are prepared by utilizing either silver emulsion or vacuum metallized chromium on glass. Recent development activities have centered upon an inexpensive method of coating glass with a ferric nitrate solution, that is semitransparent in the ultra violet range. The maximum density obtained has been 0.10 to 0.20 units of optical density, which is insufficient density for contact printing to produce a photoresist image.

The density of the iron (Fe/+3/) coating can be increased or doubled to 0.40 units of optical density by the following method:

Increased optical density is obtained by adding tannic acid to a water solution of ferric nitrate. The formulation and mix procedure to obtain a coating with an increased optical density is as follows: 1) Dissolve 1 gram of tannic acid in 20cc of isopropal

alcohol.

2) Add the dissolved tannic acid and alcohol to 40cc of 2.7

molar ferric nitrate (Fe(NO(3))(3)) . H(2)0.

3) To this mix add an additional 10 grams of ferric nitrate.

4) Bake the applied coating at 400 to 450 Degrees F for ten

minutes. The advantage of this coating

formulation is it's hardness and tenacious bond

to the glass surface, as well as the increased

optical density.

1