Abstract: A process for producing encapsulated metal colloids useful as inorganic colored pigments, including, reacting one or more glass-forming components according to the sol-gel process to obtain a sol dispersing a metal salt in the resulting sol in the presence of an additional reducing agent to form metal colloids, converting the resulting dispersion into xerogel-encapsulated metal colloids by spray drying, heating the resulting xerogel-encapsulated metal colloids to density them. The present invention relates, furthermore, to inorganic colored pigments, in particular producible by the process of the invention, including metal colloids produced from metal salts and encapsulated in an encapsulation, the encapsulation being produced from glass-forming components according to the sol-gel process and being densified to a xerogel or glass, the proportion of metal colloid in the capsules being at least 80%.

Abstract: A process for producing encapsulated metal colloids useful as inorganic coloured pigments, including, reacting one or more glass-forming components according to the sol-gel process to obtain a sol dispersing a metal salt in the resulting sol in the presence of an additional reducing agent to form metal colloids, converting the resulting dispersion into xerogel-encapsulated metal colloids by spray drying, heating the resulting xerogel-encapsulated metal colloids to density them. The present invention relates, furthermore, to inorganic coloured pigments, in particular producible by the process of the invention, including metal colloids produced from metal salts and encapsulated in an encapsulation, the encapsulation being produced from glass-forming components according to the sol-gel process and being densified to a xerogel or glass, the proportion of metal colloid in the capsules being at least 80%.

Abstract: The wet film thickness during spraying of the coating composition onto the substrate is preferably adjusted such that it is greater by a factor of at least 8 than the target dry film thickness.

Abstract: To produce functional vitrous, preferably colored or colloid-dyed layers, a composition produced by hydrolysis and polycondensation of(A) at least on hydrolyzable silane of general formula (I)SiX.sub.4 (I)wherein the radicals X are the same or different and represent hydrolyzable groups or hydroxy groups, or an oligomer derived therefrom, and(B) at least one organosilane of general formula (II)R.sup.1.sub.a R.sup.2.sub.b SiX.sub.(4-a-b) (II)wherein R.sup.1 is a non-hydrolyzable radical, R.sup.