Abstract: A sol-gel process for the production of titanium oxide layers which comprises the following stages: (i) preparation of a soluble, titanium-containing powder by: (a) reaction of a titanium alcoholate of the general formula Ti(OR)4, in which the radicals R are identical or different and represent straight-chain, branched or cyclic alkyl or alkenyl radicals having 1 to 10 carbon atoms, which optionally have one or more carbonyl and/or ester and/or carboxyl functions, with one or more polar compounds with completing, chelating properties, (b) heating of the solution, (c) adding of water to the solution, optionally in the presence of a catalyst, (d) concentrating of the solution until a powder is obtained, (ii) dissolving of the powder to form a sol, (iii) coating of a substrate with the sol and (iv) heating of the coated substrate, described.

Abstract: The intermediate product which is used in a method of making a molded arte, especially an endless PZT fiber, is itself made by a method including mixing an organic zirconium compound, Zr(OR.sup.1).sub.4, and an organic titanium compound, Ti(OR.sup.2).sub.4, R.sup.1 and R.sup.2 being C.sub.1 - to C.sub.10 -alkyl groups, separately or together with 0 to 4 moles of at least one alcohol of the formula R.sup.3 --X--R.sup.4 --OH or R.sup.3 --CX--R.sup.4 --OH, X being O, S or an amine group and R.sup.3 and R.sup.4 being C.sub.1 - to C.sub.10 -alkyl groups, per mole of the zirconium and titanium compounds; reacting the zirconium and titanium compounds in the resulting mixture or mixtures with one to three moles of at least one C.sub.2 - to C.sub.10 -carboxylic acid per mole of the zirconium and titanium compounds to form at least one reaction mixture; mixing the at least one reaction mixture and reacting with 1 to 1.

Abstract: The endless PZT fiber is a lead zirconate-lead titanate mixed substance and s made by a method including the steps of mixing an organic zirconium compound, Zr(OR.sup.1).sub.4, and an organic titanium compound, Ti(OR.sup.2).sub.4, R.sup.1 and R.sup.2 each being a C.sub.1 - to C.sub.10 -alkyl group, separately or together with 0 to 4 moles of at least one alcohol of the formula R.sup.3 --X--R.sup.4 --OH or R.sup.3 --CX--R.sup.4 --OH, X being O, S or an amine group and R.sup.3 and R.sup.4 each being a C.sub.1 - to C.sub.10 -alkyl group, per mole of the zirconium and titanium compounds; reacting the zirconium compound and titanium compounds in the resulting mixture or mixtures with one to three moles of at least one C.sub.2 - to C.sub.10 -carboxylic acid per mole of the zirconium and titanium compounds to form at least one reaction mixture; mixing the at least one reaction mixture from the reacting step with 1 to 1.