Antistatic non-dazzle coatings prodn. for cathode ray tubes - by mixing alcoholic soln. of alkyl silicate polymer or partly-hydrolysed monomer with dil. acid, spin-coating onto the plate and heating

摘要

Prodn. of cathode ray tubes (I) comprises: (1) mixing an alcoholic soln. of alkyl silicate polymer (II) or partly hydrolysed alkyl silicate monomer (III) with (a) an amt. of which which is at least 4 times the number of mols. of alkyl silicate (IV) and (b) with acid, (2) applying the mixt. to the outer surface of the glass plate by spin coating and (3) heating the layer obtd. to give an antistatic, anti-dazzle coating. Also claimed are CR tubes (I) produced by this process. Pref. (III) is prepd. by mixing an acid-contg. alcoholic soln. of alkyl silicate monomer (IV) with an amt. of water which is twice as large as or smaller than the number of mols. of (IV), (II) is in the dimer-pentamer range and (IV) is ethyl silicate (IVA); amt. of water is 5-20 mols./mol. (IV) and amt. of acid is 0.001-0.1 mol./mol. (IV); the alcoholic soln. also contains a conductive metal salt, pref. Sn chloride. USE/ADVANTAGE - The process enables the prodn. of antistatic, anti-dazzle outer coatings on cathode ray tubes; w.r.t. prior-art processes, this process gives a more even coating over the whole outer surface of the screen, with better control of the degree of unevenness