Multilayered article and a process for its preparation

A process of preparing a multilayered article comprising the following steps:

• (a) providing a substrate;
• (b) forming a scratch-resistant layer by applying a scratch-resistant coating composition to a surface of said substrate, and partially curing the applied scratch-resistant coating composition, said scratch-resistant coating composition consisting of a polycondensate prepared from at least one silicon-containing compound, said polycondensate being prepared by a sol-gel process wherein said at least one silicon-containing compound is selected from the group consisting of 1) methylsilane;
• 2) methyltrimethoxysilane, methyltrihydroxysilane and mixtures thereof;
• 3) silyl acrylates according to the formula
• in which R3 and R4 are identical or different monovalent hydrocarbon radicals, R5 is a divalent hydrocarbon radical having 2 to 8 carbon atoms, R6 denotes hydrogen or a monovalent hydrocarbon radical, the index b is an integer having a value from 1 to 3, the index c is an integer having a value from 0 to 2 and the index d is an integer having a value of (4-b-c);
• 4) silylacrylates comprising nanoscale AIO(OH) particles;
• and
• 5) cyclic organosiloxanes according to the formula
• where m=3 to 6, R=C1 to C8-alkyl and/or C6 to C14-aryl, wherein the m-plurality of n's and R's within the molecule may be identical or different;
• and
• (c) forming a top layer by applying a top layer coating composition to the scratch-resistant layer, said top layer coating composition being prepared by hydrolysing a composition consisting of
• (i) at least one compound represented by general formula I,
• M(R′)m (I)
• wherein M is an element or compound selected from the group consisting of Si, Ti, Zr, Sn, Ce, Al, B, VO3+, In and Zn, R′ represents a hydrolysable radical, and m is an integer from 2 to 4;
• and
• (ii) optionally at least one compound represented by general formula II,
• RbSiR′a, (II)
• wherein the radicals R′ and R are the same or different, R′ is as defined for general formula (I), R represents a group selected from an alkyl group, an alkenyl group, an aryl group, a hydrocarbon group with at least one halogen group, an epoxide group, a glycidyloxy group, an amino group, a mercapto group, a methacryloxy group and a cyano group, and a and b independently of one another have a value from 1 to 3, provided that the sum of a and b is four and
• (iii) optionally one or more additives selected from the group consisting of water, acid, solvent, dyestuffs, flow control agents, UV stabilizers, IR stabilizers, photoinitiators and photosensitizers;
• and
• (d) curing said scratch-resistant and top layers with the proviso that when a compound of formula II is present, it is not a methyltrimethoxysilane or methyltrihydroxysilane.