Patent ID: 6099122
Filing Date: 2000-08-08
Classification: C07C,C08F,C08G,G02B,G03F

Abstract:
A process for the multi-stage coating of a surface, which comprises, on the one hand, covalently bonding a functional photoinitiator containing at least one isocyanate group, or a macroinitiator derived therefrom, to a carrier and, on the other hand, covalently bonding an oligomer or polymer, forming a new surface layer, to the functional photoinitiator or to the carrier modified by a functional photoinitiator via functional groups that are co-reactive with isocyanate groups, wherein said process comprises the following steps:(a) reacting an oligomer or polymer containing groups that are co-reactive with isocyanate groups with a functional photoinitiator of formula Ia or Ib to form a macroinitiator, the isocyanate group of the photoinitiator forming a covalent bond with one of the co-reactive groups of the oligomer or polymer,(b) applying a thin layer of the macroinitiator so obtained to a surface containing suitable groups that are co-reactive with radicals;(c) irradiating the coated surface with UV light of a suitable wavelength, there being produced by radical (.alpha.-cleavage in the macroinitiator benzoyl-like radicals that form a covalent bond with the co-reactive groups of the surface;wherein formulae Ia and Ib are as follows: ##STR48## wherein Y is O, NH or NR.sub.1A ; Y, is O;Y.sub.2 is --O--, --O--(O)C--, --C(O)--O-- or --O--C(O)--O--;each n independently of the others is 0 or 1;R is H, C.sub.1 -C.sub.12 alkyl, C.sub.1 -C.sub.12 alkoxy or C.sub.1 -C.sub.12 alkylNH--;R.sub.1 and R.sub.2 are each independently of the other H, linear or branched C.sub.1 -C.sub.8 alkyl, C.sub.1 -C.sub.8 hydroxyalkyl or C.sub.6 -C.sub.10 aryl, ortwo groups R.sub.1 --(Y.sub.1).sub.n -- together are --(CH.sub.2).sub.x --, orthe groups R.sub.1 --(Y.sub.1).sub.n -- and R.sub.2 --(Y.sub.1).sub.n -- together are a radical of the formula ##STR49## R.sub.3 is a direct bond or linear or branched C.sub.1 -C.sub.8 alkylene that is unsubstituted or substituted by --OH and/or optionally interrupted by one or more groups --O--, --O--C(O)-- or --O--C(O)--O--;R.sub.4 is branched C.sub.3 -C.sub.18 alkylene, unsubstituted or C.sub.1 -C.sub.4 alkyl- or C.sub.1 -C.sub.4 alkoxy-substituted C.sub.6 -C.sub.10 arylene, or unsubstituted or C.sub.1 -C.sub.4 alkyl- or C.sub.1 -C.sub.4 alkoxy-substituted C.sub.7 -C.sub.18 -aralkylene, unsubstituted or C.sub.1 -C.sub.4 alkyl- or C.sub.1 -C.sub.4 alkoxy-substituted C.sub.3 -C.sub.8 cycloalkylene, unsubstituted or C.sub.1 -C.sub.4 alkyl- or C.sub.1 -C.sub.4 alkoxy-substituted C.sub.3 -C.sub.8 cycloalkylene-C.sub.y H.sub.2y - or unsubstituted or C.sub.1 -C.sub.4 alkyl- or C.sub.1 -C.sub.4 alkoxy-substituted-C.sub.y H.sub.2y -(C.sub.3 -C.sub.8 cycloalkylene)-C.sub.y H.sub.2y --;R.sub.5 independently has the same definitions as R.sub.4 or is linear C.sub.3 -C.sub.18 alkylene; R.sub.1A is lower alkyl;x is an integer from 3 to 5;y is an integer from 1 to 6;R.sub.a and R.sub.b are each independently of the other H, C.sub.1 -C.sub.8 alkyl, C.sub.3 -C.sub.8 cycloalkyl, benzyl or phenyl;with the provisos that n in the groups --(Y.sub.1).sub.n --R.sub.1 is 0 when R.sub.2 is H; that not more than two Y.sub.1 of the --(Y.sub.1).sub.n -- groups are 0 and n in the other --(Y.sub.1).sub.n -- groups is 0; and that n in the group --(Y.sub.2).sub.n -- is 0 when R.sub.3 is a direct bond;and wherein also X is bivalent --O--, --NH--, --S--, lower alkylene or ##STR50## Y.sub.10 is a direct bond or --O(CH.sub.2)y-- wherein y is an integer from 1 to 6 and the terminal CH.sub.2 group of which is linked to the adjacent X in formula (Ib);R.sub.100 is H, C.sub.1 -C.sub.12 alkyl, C.sub.1 -C.sub.12 alkoxy, C.sub.1 -CalkylNH-- or --NR.sub.1A R.sub.1B wherein R.sub.1A is lower alkyl and R.sub.1B is H or lower alkyl;R.sub.101, is linear or branched lower alkyl, lower alkenyl or aryl-lower alkyl;R.sub.102 independently of R.sub.101, has the same definitions as R.sub.101, or is aryl, orR.sub.101, and R.sub.102 together are, --(CH.sub.2).sub.m -- wherein m is an integer from 2 to 6;R.sub.103 and R.sub.104 are each independently of the other linear or branched lower alkyl that may be substituted by C.sub.1 -C.sub.4 alkoxy, or aryl-lower alkyl or lower alkenyl; orR.sub.103 and R.sub.104 together are --(CH.sub.2),.--Y.sub.11 --(CH.sub.2).sub.z -- wherein Y.sub.11 is a direct bond, --O--, --S-- or --NR.sub.1B --, and R.sub.1B is H or lower alkyl and each z independently of the other is an integer from 2 to 4.