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EP-4565378-B1 - METHODS FOR PRODUCING OPTICAL EFFECT LAYERS COMPRISING MAGNETIC OR MAGNETIZABLE PIGMENT PARTICLES AND EXHIBITING ONE OR MORE INDICIA

EP4565378B1EP 4565378 B1EP4565378 B1EP 4565378B1EP-4565378-B1

Inventors

  • PITTET, Hervé
  • VEYA, PATRICK

Dates

Publication Date
20260506
Application Date
20230802

Claims (14)

  1. A method for producing an optical effect layer (OEL), said OEL comprising a motif made of at least two areas made of a single applied and cured layer comprising non-spherical magnetic or magnetizable pigment particles and exhibiting one or more indicia (x30) on a substrate (x20), the method comprising the steps of: a) applying on a substrate (x20) surface a radiation curable coating composition comprising the non-spherical magnetic or magnetizable pigment particles, one or more cationically curable compounds, one or more radically curable compounds and a mixture of photo-reactive compounds not absorbing in an range from about 350 nm to about 470 nm, said radiation curable coating composition being in a first, liquid state so as to form a coating layer (x10); b) subsequently to step a), applying a top coating composition at least partially on top of the coating layer (x10) thus forming one or more areas of the coating layer (x10) below said one or more indicia (x30), wherein said top coating composition is applied in the form of the one or more indicia (x30) and wherein said top coating composition comprises one or more curable compounds and a mixture of compounds, wherein at least one of said compounds absorbs in the range from about 350 nm to about 470 nm, c) partially simultaneously with or subsequently to step b), at least partially curing the one or more indicia (x30) and the one or more areas of the coating layer (x10) below said one or more indicia (x30) with a LED curing unit (x50) emitting between 350 nm and 470 nm. d) subsequently to step c), exposing the coating layer (x10) to a magnetic field of a magnetic-field generating device so as to orient at least a part of the non-spherical magnetic or magnetizable pigment particles; and e) partially simultaneously with or subsequently to step d), at least partially curing the coating layer (x10) with a curing unit (x60) at least emitting between 250 nm and 320 nm, wherein the mixture of photo-reactive compounds of the radiation curable coating composition of step a) and the mixture of compounds of the top curable coating composition of step b) are selected according to one of the following combinations: i) the mixture of photo-reactive compounds of the radiation curable coating composition of step a) comprises one or more iodonium salts and one or more alpha-hydroxyketone compounds, and the mixture of compounds of the top curable coating composition of step b) comprises: i-1) one or more sulfonium salts wherein the anionic moiety is SbF 6 - ; PF 6 - ; AsF 6 - ; F4B - ; (C 6 F 5 ) 4 B - ; (CF 3 SO 2 ) 3 C - ; (CF 3 )SO3 - ; (CH 3 C 6 H 4 )SO 3 - ; (CF 3 )CO 2 - ; (C 4 F 9 )SO 3 - or (C 4 F 9 )CO 2 - and wherein the cationic moiety is tris[4-(4-acetylphenylsulfanyl)phenyl]-sulfonium; 10-[1,1'-biphenyl]-4-yl-2-(1-methylethyl)-9-oxo-9H-thioxanthenium; (9-oxo-9H-thioxanthen-2-yl)diphenyl-sulfonium; or a mixture thereof and further comprises one or more acyl phosphine compounds and/or one or more glyoxylate compounds and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and/or one or more oxime ester compounds; i-2) one or more thioxanthone compounds and further comprises one or more acyl phosphine compounds and/or one or more glyoxylate compounds and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and/or one or more oxime ester compounds; i-3) one or more anthracene compounds and further comprises one or more acyl phosphine compounds and/or one or more glyoxylate compounds and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and/or one or more oxime ester compounds; i-4) one or more naphthalene compounds with one or more anthracene compounds and further comprises one or more acyl phosphine compounds and/or one or more glyoxylate compounds and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and/or one or more oxime ester compounds; or i-5) one or more coumarin compounds and further comprises one or more acyl phosphine compounds and/or one or more glyoxylate compounds and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and/or one or more oxime ester compounds; or ii) the mixture of photo-reactive compounds of the radiation curable coating composition of step a) comprises one or more iodonium salts and a benzyl ketal compound being 2,2-diethoxyacetophenone, and the mixture of compounds of the top curable coating composition of step b) comprises: ii-1) one or more sulfonium salts wherein the anionic moiety is SbF 6 - ; PF 6 - ; AsF 6 - ; F4B - ; (C 6 F 5 ) 4 B - ; (CF 3 SO 2 ) 3 C - ; (CF 3 )SO3 - ; (CH 3 C 6 H 4 )SO 3 - ; (CF 3 )CO 2 - ; (C 4 F 9 )SO 3 - or (C 4 F 9 )CO 2 - and wherein the cationic moiety is tris[4-(4-acetylphenylsulfanyl)phenyl]-sulfonium; 10-[1,1'-biphenyl]-4-yl-2-(1-methylethyl)-9-oxo-9H-thioxanthenium; (9-oxo-9H-thioxanthen-2-yl)diphenyl-sulfonium; or a mixture thereof and further comprises one or more acyl phosphine compounds and/or one or more glyoxylate compounds and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and/or one or more oxime ester compounds; ii-2) one or more thioxanthone compounds and further comprises one or more acyl phosphine compounds and/or one or more glyoxylate compounds and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and/or one or more oxime ester compounds; ii-3) one or more anthracene compounds and further comprises one or more acyl phosphine compounds and/or one or more glyoxylate compounds and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and/or one or more oxime ester compounds; ii-4) one or more naphthalene compounds with one or more anthracene compounds and further comprises one or more acyl phosphine compounds and/or one or more glyoxylate compounds and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and/or one or more oxime ester compounds; ii-5) one or more coumarin compounds and further comprises one or more acyl phosphine compounds and/or one or more glyoxylate compounds and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and/or one or more oxime ester compounds; or iii) the mixture of photo-reactive compounds of the radiation curable coating composition of step a) comprises one or more sulfonium salts wherein the anionic moiety is SbF 6 - ; PF 6 - ; AsF 6 - ; F4B - ; (C 6 F 5 ) 4 B - ; (CF 3 SO 2 ) 3 C - ; (CF 3 )SO 3 - ; (CH 3 C 6 H 4 )SO 3 - ; (CF 3 )CO 2 - ; (C 4 F 9 )SO 3 - or (C 4 F 9 )CO 2 - and wherein the cationic moiety is 4-(phenylthio)phenyldiphenyl-sulfonium; bis[4-(diphenylsulfonium)phenyl] sulfide; (4-methylphenyl)diphenyl-sulfonium; (3-methylphenyl)diphenyl-sulfonium; bis(4-methylphenyl)phenyl-sulfonium; [(4-(1,1-dimethylethyl)phenyl]diphenyl-sulfonium; bis[4-(1-methylethyl)phenyl]phenyl-sulfonium; [(4-(2-methylpropyl)phenyl]diphenyl-sulfonium; (4-methoxyphenyl)diphenyl-sulfonium; 1-naphthalenyldiphenyl-sulfonium; tris(4-methylphenyl)-sulfonium; (4-bromophenyl)diphenyl-sulfonium; (4-iodophenyl)diphenyl-sulfonium; (4-fluorophenyl)diphenyl-sulfonium; (4-chlorophenyl)diphenyl-sulfonium; (4-phenoxyphenyl)diphenyl-sulfonium; (4'-methyl[1,1'-biphenyl]-4-yl)diphenyl-sulfonium; tris(4-propylphenyl)-sulfonium; bis(4-butylphenyl)phenyl-sulfonium; tris[4(1-methylethyl)lphenyl]-sulfonium; S,S'-1,3-phenylenbis[S,S'-diphenyl]-sulfonium; (4-dodecylphenyl)diphenyl-sulfonium; (4-benzoylphenyl)diphenyl-sulfonium; bis([1,1'-biphenyl]-4-yl)(4-methylphenyl)-sulfonium; tris[4-[1,1-dimethylethyl)phenyl]-sulfonium; triphenyl-sulfonium; 5-(4-methylphenyl)-dibenzothiophenium; 5-[4-(2-hydroxyethoxy)phenyl]-thianthrenium; 10-(4-methylphenyl)-9H-thioxanthenium; diphenyl[4-[[(4-phenylthiophenyl]thio]phenyl]-sulfonium; phenyl-bis[4-phenylthio)phenyl]-sulfonium; 5-[4-(phenylthio)phenyl]-thianthrenium; 5-[4-(phenylthio)phenyl]-dibenzothiophenium; 10-[4-(diphenylthio)phenyl]-9H-thioxanthenium; 5-phenyl-thianthrenium; 10-phenyl-9H-thioxanthenium; 5-(4-methylphenyl)-thianthrenium; 5-[1,1'-biphenyl]-4-yl-thianthrenium; S,S'-(thiodi-4,1-phenylene)bis[S,S'-bis[4-(2-hydroxyethoxy)]phenyl]-sulfonium; or a mixture thereof and comprises and one or more alpha-hydroxyketone compounds, and the mixture of compounds of the top curable coating composition of step b) comprises: iii-1) one or more sulfonium salts recited in i-1) and further comprises one or more acyl phosphine compounds and/or one or more glyoxylate compounds and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and/or one or more oxime ester compounds; iii-2) one or more thioxanthone compounds with one or more iodonium salts and further comprises one or more acyl phosphine compounds and/or one or more glyoxylate compounds and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and/or one or more oxime ester compounds; iii-3) one or more anthracene compounds and further comprises one or more acyl phosphine compounds and/or one or more glyoxylate compounds and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and/or one or more oxime ester compounds; iii-4) one or more naphthalene compounds with one or more anthracene compounds and further comprises one or more acyl phosphine compounds and/or one or more glyoxylate compounds and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and/or one or more oxime ester compounds; or iii-5) one or more coumarin compounds with one or more iodonium salts and further comprises one or more acyl phosphine compounds and/or one or more glyoxylate compounds and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and/or one or more oxime ester compounds; or iv) the mixture of photo-reactive compounds of the radiation curable coating composition of step a) comprises one or more sulfonium salts recited in iii) and a benzyl ketal compound being 2,2-diethoxyacetophenone, and the mixture of compounds of the top curable coating composition of step b) comprises iv-1) one or more sulfonium salts recited in i-1) and further comprises one or more acyl phosphine compounds and/or one or more glyoxylate compounds and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and/or one or more oxime ester compounds; iv-2) one or more thioxanthone compounds with one or more iodonium salts and further comprises one or more acyl phosphine compounds and/or one or more glyoxylate compounds and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and/or one or more oxime ester compounds; iv-3) one or more anthracene compounds and further comprises one or more acyl phosphine compounds and/or one or more glyoxylate compounds and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and/or one or more oxime ester compounds; iv-4) one or more naphthalene compounds with one or more anthracene compounds and further comprises one or more acyl phosphine compounds and/or one or more glyoxylate compounds and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and/or one or more oxime ester compounds; or iv-5) one or more coumarin compounds with one or more iodonium salts and further comprises one or more acyl phosphine compounds and/or one or more glyoxylate compounds and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and/or one or more oxime ester compounds; or v) the mixture of photo-reactive compounds of the radiation curable coating composition of step a) comprises one or more iodonium salts and one or more alpha-hydroxyketone compounds, and the mixture of compounds of the top curable coating composition of step b) comprises: v-1) one or more sulfonium salts recited in i-1); v-2) one or more thioxanthone compounds; v-3) one or more anthracene compounds; v-4) one or more naphthalene compounds with one or more anthracene compounds; or v-5) one or more coumarin compounds; or vi) the mixture of photo-reactive compounds of the radiation curable coating composition of step a) comprises one or more of the iodonium salts and a benzyl ketal compound being 2,2-diethoxyacetophenone, and the mixture of compounds of the top curable coating composition of step b) comprises vi-1) one or more sulfonium salts recited in i-1); vi-2) one or more thioxanthone compounds; vi-3) one or more anthracene compounds; vi-4) one or more naphthalene compounds with one or more anthracene compounds; or vi-5) one or more coumarin compounds; or vii) the mixture of photo-reactive compounds of the radiation curable coating composition of step a) comprises one or more of the sulfonium salts recited in iii) and one or more alpha-hydroxyketone compounds, and the mixture of compounds of the top curable coating composition of step b) comprises vii-1) one or more sulfonium salts recited in i-1); vii-2) one or more thioxanthone compounds with one or more iodonium salts; vii-3) one or more anthracene compounds; vii-4) one or more naphthalene compounds with one or more anthracene compounds; or vii-5) one or more coumarin compounds with one or more iodonium salts; or viii) the mixture of photo-reactive compounds of the radiation curable coating composition of step a) comprises one or more of the sulfonium salts recited in iii) and a benzyl ketal compound being 2,2-diethoxyacetophenone, and the mixture of compounds of the top curable coating composition of step b) comprises viii-1) one or more sulfonium salts recited in i-1); viii-2) one or more thioxanthone compounds with one or more iodonium salts; viii-3) one or more anthracene compounds; viii-4) one or more naphthalene compounds with one or more anthracene compounds; or viii-5) one or more coumarin compounds with one or more iodonium salts.
  2. The method according to claim 1, wherein the mixture of photo-reactive compounds of the radiation curable coating composition of step a) and the mixture of compounds of the top curable coating composition of step b) are selected according to one of the following combinations: i') the mixture of photo-reactive compounds of the radiation curable coating composition of step a) comprises one or more iodonium salts wherein the anionic moiety is SbF 6 - ; PF 6 - ; AsF 6 - ; F4B - ; (C 6 F 5 ) 4 B - ; (CF 3 SO 2 ) 3 C - ; (CF 3 )SO3 - ; (CH 3 C 6 H 4 )SO 3 - ; (CF 3 )CO 2 - ; (C 4 F 9 )SO 3 - or (C 4 F 9 )CO 2 - (preferably SbF 6 - ; PF 6 - ; (CF 3 )SO 3 - ; (C 4 F 9 )SO 3 - ; F 4 B - or (C 6 F 5 ) 4 B - ) and wherein the cationic moiety is bis(4-dodecylphenyl)iodonium; bis[4-(1,1-dimethylethyl)phenyl]iodonium; (4-isopropylphenyl)(4-methylphenyl)iodonium; bis(4-methylphenyl)iodonium; (4-methylphenyl)[4-(2-methylpropyl)phenyl]iodonium; bis(2,4-dimethylphenyl)]iodonium; bis(3,4-dimethylphenyl)]iodonium; (4-methylphenyl)(2,4,6-trimethylphenyl)iodonium; bis[(4-(2-methylpropyl)phenyl]iodonium; bis(4-butylphenyl]iodonium; bis(2,4,6-trimethylphenyl)iodonium; bis(4-hexylylphenyl]iodonium; bis(4-decylphenyl)iodonium; (4-decylphenyl)(4-undecylphenyl)iodonium; bis(4-undecylphenyl)iodonium; bis(4-tridecylphenyl)iodonium; bis(4-tetradecylphenyl)iodonium; bis(4-hexadecylphenyl)iodonium; bis(4-heptadecylphenyl)iodonium; bis(4-octadecylphenyl)iodonium; (4-decylphenyl)(4-dodecylphenyl)iodonium; (4-decylphenyl)(4-tridecylphenyl)iodonium; (4-decylphenyl)(4-tetradecylphenyl)iodonium; (4-dodecylphenyl)(4-undecylphenyl)iodonium; (4-dodecylphenyl)(4-tridecylphenyl)iodonium; (4-dodecylphenyl)(4-tetradecylphenyl)iodonium; (4-tridecylphenyl)(4-undecylphenyl)iodonium; (4-tetradecylphenyl)(4-undecylphenyl)iodonium; (4-tetradecylphenyl)(4-tridecylphenyl)iodonium; p-(octyloxyphenyl)phenyliodonium; [4-[(2-hydroxytetradecyl)oxy]phenyl]phenyliodonium; bis(4-fluorophenyl)iodonium; (4-nitrophenyl)phenyliodonium; (4-nitrophenyl)(2,4,6-trimethylphenyl)iodonium; or a mixture thereof; and one or more alpha-hydroxyketone compounds selected from the group consisting of 2-hydroxy-2-methylpropiophenone; 2-hydroxy-4'-hydroxyethoxy-2-methylpropiophenone; 2-hydroxy-1-[4-[4-(1-hydroxy-2-methylpropanoyl)phenoxy]phenyl]-2-methylpropan-1-one; (1-hydroxycyclohexyl)phenylmethanone; 2-hydroxy-1-[4-[4-(1-hydroxy-2-methylpropanoyl)phenoxy]phenyl]-2-methylpropan-1-one; 1-[2,3-dihydro-1-[4-(1-hydroxy-2-methyl-1-oxopropyl)phenyl]-1,3,3-trimethyl-1H-inden-5-yl]-2-hydroxy-2-methyl-1-propanone; ar-(1-hydroxy-2-methyl-1-oxopropyl) (1-methylethenyl)-benzene homopolymer; α-(1,1-dimethyl-2-oxo-2-phenylethyl)-ω-hydroxy-poly(oxy-1,2-ethanediyl) (9CI); polymeric alpha-hydroxy-ketones and mixtures thereof, and the mixture of compounds of the top curable coating composition of step b) comprises: i'-1) one or more sulfonium salts wherein the anionic moiety is SbF 6 - , PF 6 - , (C 6 F 5 ) 4 B - , (CF 3 )SO3 - or (C 4 F 9 )SO 3 - and wherein the cationic moiety is tris[4-(4-acetylphenylsulfanyl)phenyl]-sulfonium; 10-[1,1'-biphenyl]-4-yl-2-(1-methylethyl)-9-oxo-9H-thioxanthenium;(9-oxo-9H-thioxanthen-2-yl)diphenyl-sulfonium; or a mixture thereof and further comprises one or more acyl phosphine compounds selected from the group consisting of 1,4,6-trimethylbenzoyl)diphenylphosphine oxide; 2,4,6-trimethylbenzoyl-ethoxylphenylphosphine oxide; phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide; bis(1,6-dimethoxybenzoyl)(1,4,4-trimethylpentyl)phosphine oxide; ethyl (3-benzoyl-2,4,6-trimethylbenzoyl)(phenyl)phosphinate; α,α',α"-1,2,3-propanetriyltris[ω-[[phenyl(1,4,6-trimethylbenzoyl)phosphinyl]oxy]-poly(oxy-1,2-ethanediyl) and mixtures thereof; and/or one or more glyoxylate compounds selected from the group consisting of 2-oxo-2-phenylacetic acid methyl ester; 2-[2-oxo-2-phenyl-acetoxy-ethoxy]ethyl 2-oxo-2-phenylacetate; α-(1-oxo-2-phenylacetyl)-ω-[(1-oxo-2-phenylacetyl)oxy]-poly(oxy-1,4-butanediyl) and mixtures thereof; and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or one or more oxime ester compounds selected from the group consisting of 5-[[4-(1-methylethyl)phenyl]thio]-1H-indene-1,2(3H)-dione 2-(O-acetyloxime; 1-[4-(phenylthio)phenyl]-1,2-octanedione 2-(O-benzoyloxime); 3-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-propanedione-2-(O-benzoyloxime); 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime); 1-[9-ethyl-6-(1-methylbenzoyl)-9H-carbazol-3-yl]ethanone-1-(O-acetyloxime); 3-cyclopentyl-1-[9-ethyl-6-(1-methylbenzoyl)-9H-carbazol-3-yl]-1-propanone-1-(O-acetyloxime); 1,8-bis(O-acetyloxime)-1,8-bis[9-(1-ethylhexyl)-6-nitro-9H-carbazol-3-yl]-1,8-octanedione; or a mixture thereof; i'-2) one or more thioxanthone compounds selected from the group consisting of 2-isopropyl-9H-thioxanthen-9-one; 4-(1-methylethyl)-9H-thioxanthen-9-one; 2,4-diethyl-9H-thioxanthen-9-one; 2-chloro-9H-thioxanthen-9-one; 1-chloro-4-propoxy-9H-thioxanthen-9-one; 1,3-di[[α-[1-chloro-9-oxo-9H-thioxanthen-4-yl)oxy]acetylpoly[oxy(1-methylethylene)]]oxy]-2,2-bis[[α-[1-cloro-9-oxo-9H-thioxanthen-4-yl)oxy]acetylpoly[oxy(1-methylethylene)]]oxymethylpropane; α-[2-[(9-oxo-9H-thioxanthenyl)oxy]acetyl]-ω-[[2-[(9-oxo-9H-thioxanthenyl)oxy]acetyl]oxy]-poly(oxy-1,4-butanediyl; 2-[2-[1-[2-[[2-(9-oxothioxanthen-2-yl)oxyacetyl]amino]-3-[1-[2-(2-prop-2-enoyloxyethoxy)ethoxy]ethoxy]-2-[1-[2-(2-prop-2-enoyloxyethoxy)ethoxy]ethoxymethyl]propoxy]ethoxy]ethoxy]ethyl prop-2-enoate; α-[2-[(9-Oxo-9H-thioxanthenyl)oxy]acetyl]-ω-[[2-[(9-oxo-9H-thioxanthenyl)oxy]acetyl]oxy]-poly(oxy-1,4-butanediyl); oligomeric and polymeric compounds thereof and mixtures thereof and further comprises one or more acyl phosphine compounds recited in i'-1) and/or one or more glyoxylate compounds recited in i'-1) and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and/or one or more oxime ester compounds recited in i'-1); i'-3) one or more anthracene compounds selected from the group consisting of 9,10-diethoxy-anthracene; 9,10-dibutoxy-anthracene and mixtures thereof and further comprises one or more acyl phosphine compounds recited in i'-1) and/or one or more glyoxylate compounds recited in i'-1) and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and/or one or more oxime ester compounds recited in i'-1); i'-4) a naphthalene compound being 9,10-diethoxy-naphthalene and one or more anthracene compounds selected from the group consisting of 9,10-diethoxy-anthracene; 9,10-dibutoxy-anthracene and mixtures thereof and further comprises one or more acyl phosphine compounds recited in i'-1) and/or one or more glyoxylate compounds recited in i'-1) and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and/or one or more oxime ester compounds recited in i'-1); or i'-5) one or more coumarin compounds selected from the group consisting of 3-(4-dodecylbenzoyl)-5,7-dimethoxy-2H-1-benzopyran-2-one; 3-(4-C 10 -C 13 -benzoyl)-5,7-dimethoxy-2H-1-benzopyran-2-one and mixtures thereof and further comprises one or more acyl phosphine compounds recited in i'-1) and/or one or more glyoxylate compounds recited in i'-1) and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and/or one or more oxime ester compounds recited in i'-1); or ii') the mixture of photo-reactive compounds of the radiation curable coating composition of step a) comprises one or more iodonium salts recited in i') and a benzyl ketal compound being 2,2-diethoxyacetophenone and the mixture of compounds of the top curable coating composition of step b) comprises: ii'-1) one or more sulfonium salts recited in i'-1) and further comprises one or more acyl phosphine compounds recited in i'-1); and/or one or more glyoxylate compounds recited in i'-1; and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or one or more oxime ester compounds recited in i'-1); ii'-2) one or more thioxanthone compounds recited in i'-2) and further comprises one or more acyl phosphine compounds recited in i'-1) and/or one or more glyoxylate compounds recited in i'-1) and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and/or one or more oxime ester compounds recited in i'-1); ii'-3) one or more anthracene compounds recited in i'-3) and further comprises one or more acyl phosphine compounds recited in i'-1) and/or one or more glyoxylate compounds recited in i'-1) and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and/or one or more oxime ester compounds recited in i'-1); ii'-4) one or more naphthalene compounds recited in i'-4) and one or more anthracene compounds recited in i'-4) and further comprises one or more acyl phosphine compounds recited in i'-1) and/or one or more glyoxylate compounds recited in i'-1) and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and/or one or more oxime ester compounds recited in i'-1); or ii'-5) one or more coumarin compounds recited in i'-5) and further comprises one or more acyl phosphine compounds recited in i'-1) and/or one or more glyoxylate compounds recited in i'-1) and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and/or one or more oxime ester compounds recited in i'-1); or iii') the mixture of photo-reactive compounds of the radiation curable coating composition of step a) comprises one or more sulfonium salts wherein the anionic moiety is SbF 6 - ; PF 6 - ; (C 6 F 5 ) 4 B - , (CF 3 )SO 3 - or (C 4 F 9 )SO 3 - (preferably SbF 6 - or PF 6 - ) and wherein the cationic moiety is 4-(phenylthio)phenyldiphenyl-sulfonium; bis[4-(diphenylsulfonium)phenyl] sulfide; (4-methylphenyl)diphenyl-sulfonium; bis(4-methylphenyl)phenyl-sulfonium; bis[4-(1-methylethyl)phenyl]phenyl-sulfonium; (4-methoxyphenyl)diphenyl-sulfonium; 1-naphthalenyldiphenyl-sulfonium; tris(4-methylphenyl)-sulfonium; (4-phenoxyphenyl)diphenyl-sulfonium, (4'-methyl[1,1'-biphenyl]-4-yl)diphenyl-sulfonium; 5-[4-(2-hydroxyethoxy)phenyl]-thianthrenium;S,S'-(thiodi-4,1-phenylene)bis[S,S'-bis[4-(2-hydroxyethoxy)]phenyl]-sulfonium; or a mixture thereof; and one or more alpha-hydroxyketone compounds recited in i'); and the mixture of compounds of the top curable coating composition of step b) comprises: iii'-1) one or more sulfonium salts recited in i'-1) and further comprises one or more acyl phosphine compounds recited in i'-1); and/or one or more glyoxylate compounds recited in i'-1); and/or a benzyl ketal compound ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or one or more oxime ester compounds recited in i'-1); iii'-2) one or more thioxanthone compounds recited in i'-2) with one or more iodonium salts recited in i') and further comprises one or more acyl phosphine compounds recited in i'-1) and/or one or more glyoxylate compounds recited in i'-1) and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and/or one or more oxime ester compounds recited in i'-1); iii'-3) one or more anthracene compounds recited in i'-3) and further comprises one or more acyl phosphine compounds recited in i'-1) and/or one or more glyoxylate compounds recited in i'-1) and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and/or one or more oxime ester compounds recited in i'-1); iii'-4) one or more naphthalene compounds recited in i'-4) and one or more anthracene compounds recited in i'-4) and further comprises one or more acyl phosphine compounds recited in i'-1) and/or one or more glyoxylate compounds recited in i'-1) and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and/or one or more oxime ester compounds recited in i'-1); or iii'-5) one or more coumarin compounds recited in i'-5) with one or more iodonium salts recited in i') and further comprises one or more acyl phosphine compounds recited in i'-1) and/or one or more glyoxylate compounds recited in i'-1) and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and/or one or more oxime ester compounds recited in i'-1); or iv') the mixture of photo-reactive compounds of the radiation curable coating composition of step a) comprises one or more sulfonium salts recited in iii') and a benzyl ketal compound being 2,2-diethoxyacetophenone and the mixture of compounds of the top curable coating composition of step b) comprises: iv'-1) one or more sulfonium salts recited in i'-1) and further comprises one or more acyl phosphine compounds recited in i'-1); and/or one or more glyoxylate compounds recited in i'-1); and/or a benzyl ketal compound ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or one or more oxime ester compounds recited in i'-1); iv'-2) one or more thioxanthone compounds recited in i'-2) with one or more iodonium salts recited in i') and further comprises one or more acyl phosphine compounds recited in i'-1) and/or one or more glyoxylate compounds recited in i'-1) and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and/or one or more oxime ester compounds recited in i'-1); iv'-3) one or more anthracene compounds recited in i'-3) and further comprises one or more acyl phosphine compounds recited in i'-1) and/or one or more glyoxylate compounds recited in i'-1) and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and/or one or more oxime ester compounds recited in i'-1); iv'-4) one or more naphthalene compounds recited in i'-4) and one or more anthracene compounds recited in i'-4) and further comprises one or more acyl phosphine compounds recited in i'-1) and/or one or more glyoxylate compounds recited in i'-1) and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and/or one or more oxime ester compounds recited in i'-1); or iv'-5) one or more coumarin compounds recited in i'-5) with one or more iodonium salts recited in i') and further comprises one or more acyl phosphine compounds recited in i'-1) and/or one or more glyoxylate compounds recited in i'-1) and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and/or one or more oxime ester compounds recited in i'-1); or v') the mixture of photo-reactive compounds of the radiation curable coating composition of step a) comprises one or more iodonium salts recited in i') and one or more alpha-hydroxyketone compounds recited in i'); and the mixture of compounds of the top curable coating composition of step b) comprises: v'-1) one or more sulfonium salts recited in i'-1); v'-2) one or more thioxanthone compounds recited in i'-2); v'-3) one or more anthracene compounds recited in i'-3); v'-4) one or more naphthalene compounds recited in i'-4) and one or more anthracene compounds recited in i'-4); or v'-5) one or more coumarin compounds recited in i'-5); or vi') the mixture of photo-reactive compounds of the radiation curable coating composition of step a) comprises one or more iodonium salts recited in i') and a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and the mixture of compounds of the top curable coating composition of step b) comprises: vi'-1) one or more sulfonium salts recited in i'-1); vi'-2) one or more thioxanthone compounds recited in i'-2); vi'-3) one or more anthracene compounds recited in i'-3); vi' -4) one or more naphthalene compounds recited in i'-4) and one or more anthracene compounds recited in i'-4); or vi'-5) one or more coumarin compounds recited in i'-5); or vii') the mixture of photo-reactive compounds of the radiation curable coating composition of step a) comprises one or more sulfonium salts recited in iii') and one or more alpha-hydroxyketone compounds recited in i'); and the mixture of compounds of the top curable coating composition of step b) comprises: vii'-1) one or more sulfonium salts recited in i'-1); vii'-2) one or more thioxanthone compounds recited in i'-2) with one or more iodonium salts recited in i'); vii'-3) one or more anthracene compounds recited in i'-3); vii'-4) one or more naphthalene compounds recited in i'-4) and one or more anthracene compounds recited in i'-4); or vii'-5) one or more coumarin compounds recited in i'-5) with one or more iodonium salts recited in i'); or viii') the mixture of photo-reactive compounds of the radiation curable coating composition of step a) comprises one or more sulfonium salts recited in iii') and a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and the mixture of compounds of the top curable coating composition of step b) comprises: viii'-1) one or more sulfonium salts recited in i'-1); viii'-2) one or more thioxanthone compounds recited in i'-2) with one or more iodonium salts recited in i'); viii'-3) one or more anthracene compounds recited in i'-3); viii'-4) one or more naphthalene compounds recited in i'-4) and one or more anthracene compounds recited in i'-4); or viii'-5) one or more coumarin compounds recited in i'-5) with one or more iodonium salts recited in i').
  3. The method according to claim 1 or 2, wherein the mixture of photo-reactive compounds of the radiation curable coating composition of step a) and the mixture of compounds of the top curable coating composition of step b) are selected according to one of the following combinations: i") the mixture of photo-reactive compounds of the radiation curable coating composition of step a) comprises one or more iodonium salts wherein the anionic moiety is SbF 6 - , PF 6 - or (C 6 F 5 ) 4 B - and wherein the cationic moiety is bis(4-dodecylphenyl)iodonium); bis[4-(1,1-dimethylethyl)phenyl]iodonium; (4-isopropylphenyl)(4-methylphenyl)iodonium; bis(4-methylphenyl)iodonium;(4-methylphenyl)[4-(2-methylpropyl)phenyl]iodonium; or a mixture thereof; and one or more alpha-hydroxyketone compounds selected from the group consisting of 2-hydroxy-2-methylpropiophenone; 2-hydroxy-4'-hydroxyethoxy-2-methylpropiophenone; 2-hydroxy-1-[4-[4-(1-hydroxy-2-methylpropanoyl)phenoxy]phenyl]-2-methylpropan-1-one; (1-hydroxycyclohexyl)phenylmethanone; 2-hydroxy-1-[4-[4-(1-hydroxy-2-methylpropanoyl)phenoxy]phenyl]-2-methylpropan-1-one; 1-[2,3-dihydro-1-[4-(1-hydroxy-2-methyl-1-oxopropyl)phenyl]-1,3,3-trimethyl-1H-inden-5-yl]-2-hydroxy-2-methyl-1-propanone; ar-(1-hydroxy-2-methyl-1-oxopropyl) (1-methylethenyl)-benzene homopolymer and mixtures thereof; and the mixture of compounds of the top curable coating composition of step b) comprises: i"-1) one or more sulfonium salts are selected from the group consisting of tris[4-(4-acetylphenylsulfanyl)phenyl]-sulfonium hexafluorophosphate; 10-[1,1'-biphenyl]-4-yl-2-(1-methylethyl)-9-oxo-9H-thioxanthenium hexafluorophosphate and mixtures thereof; and further comprises one or more acyl phosphine compounds selected from the group consisting of 2,4,6-trimethylbenzoyl-ethoxylphenylphosphine oxide; phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide; bis(1,6-dimethoxybenzoyl)(1,4,4-trimethylpentyl)phosphine oxide; ethyl (3-benzoyl-2,4,6-trimethylbenzoyl)(phenyl)phosphinate; α,α',α"-1,2,3-propanetriyltris[ω-[[phenyl(1,4,6-trimethylbenzoyl)phosphinyl]oxy]-poly(oxy-1,2-ethanediyl) and mixtures thereof; and/or one or more glyoxylate compounds selected from the group consisting of 2-2-oxo-2-phenylacetic acid methyl ester;2-[2-oxo-2-phenyl-acetoxy-ethoxy]ethyl 2-oxo-2-phenylacetate; and mixtures thereof; and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or one or more oxime ester compounds selected from the group consisting of 5-[[4-(1-methylethyl)phenyl]thio]-1H-indene-1 ,2(3H)-dione 2-(O-acetyloxime), 1-[4-(phenylthio)phenyl]-1,2-octanedione 2-(O-benzoyloxime); 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime); 1-[9-ethyl-6-(1-methylbenzoyl)-9H-carbazol-3-yl]ethanone-1-(O-acetyloxime); 3-cyclopentyl-1-[9-ethyl-6-(1-methylbenzoyl)-9H-carbazol-3-yl]-1-propanone-1-(O-acetyloxime); 1,8-bis(O-acetyloxime)-1,8-bis[9-(1-ethylhexyl)-6-nitro-9H-carbazol-3-yl]-1,8-octanedione and mixtures thereof; i"-2) one or more thioxanthone compounds selected from the group consisting of 2-isopropyl-9H-thioxanthen-9-one; 4-(1-methylethyl)-9H-thioxanthen-9-one; 1-chloro-4-propoxy-9H-thioxanthen-9-one; 1,3-di[[α-[1-chloro-9-oxo-9H-thioxanthen-4-yl)oxy]acetylpoly[oxy(1-methylethylene)]]oxy]-2,2-bis[[α-[1-chloro-9-oxo-9H-thioxanthen-4-yl)oxy]acetylpoly[oxy(1-methylethylene)]]oxymethylpropane; oligomeric and polymeric compounds thereof and mixtures thereof and further comprises one or more acyl phosphine compounds recited in i"-1; and/or one or more glyoxylate compounds recited in i"-1); and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or one or more oxime ester compounds recited in i"-1); i"-3) an anthracene compounds being 9,10-dibutoxy-anthracene and further comprises one or more acyl phosphine compounds recited in i"-1); and/or one or more glyoxylate compounds recited in i"-1); and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or one or more oxime ester compounds recited in i"-1); i"-4) a naphthalene compound being 9,10-diethoxy-naphthalene with an anthracene compound being 9,10-dibutoxy-anthracene and further comprises one or more acyl phosphine compounds recited in i"-1) and/or one or more glyoxylate compounds recited in i"-1); and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or one or more oxime ester compounds recited in i"-1); or i"-5) a coumarin compound being 3-(4-C 10 -C 13 -benzoyl)-5,7-dimethoxy-2H-1-benzopyran-2-one and further comprises one or more acyl phosphine compounds recited in i"-1); and/or one or more glyoxylate compounds recited in i"-1); and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or one or more oxime ester compounds recited in i"-1); or ii") the mixture of photo-reactive compounds of the radiation curable coating composition of step a) comprises one or more iodonium salts recited in i") and a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and the mixture of compounds of the top curable coating composition of step b) comprises: ii"-1) one or more sulfonium salts recited in i"-1) and further comprises one or more acyl phosphine compounds recited in i"-1); and/or one or more glyoxylate compounds recited in i"-1); and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or one or more oxime ester compounds recited in i"-1); ii"-2) one or more thioxanthone compounds recited in i"-2) and further comprises one or more acyl phosphine compounds recited in i"-1) and/or one or more glyoxylate compounds recited in i"-1); and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or one or more oxime ester compounds recited in i"-1); ii"-3) one or more anthracene compounds recited in i"-3) and further comprises one or more acyl phosphine compounds recited in i"-1) and/or one or more glyoxylate compounds recited in i"-1); and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or one or more oxime ester compounds recited in i"-1); ii"-4) one or more naphthalene compounds recited in i"-4) with one or more anthracene compounds recited in i"-4) and further comprises one or more acyl phosphine compounds recited in i"-1) and/or one or more glyoxylate compounds recited in i"-1); and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or one or more oxime ester compounds recited in i"-1); or ii"-5) one or more coumarin compounds recited in i"-5) and further comprises one or more acyl phosphine compounds recited in i"-1) and/or one or more glyoxylate compounds recited in i"-1); and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or one or more oxime ester compounds recited in i"-1); or iii") the mixture of photo-reactive compounds of the radiation curable coating composition of step a) comprises one or more sulfonium salts selected from the group consisting of diphenyl[4-(phenylthio)phenyl]-sulfonium hexafluoroantimonate; bis[4-(diphenylsulfonium)phenyl] sulfide bishexafluoroantimonate; 4 diphenyl[4-(phenylthio)phenyl]-sulfonium hexafluorophosphate; bis[4-(diphenylsulfonium)phenyl] sulfide bis(hexafluorophosphate); S,S'-(thiodi-4,1-phenylene)bis[S,S'-bis[4-(2-hydroxyethoxy)]phenyl]-sulfonium bis[hexafluorophosphate]; S,S'-(thiodi-4,1-phenylene)bis[S,S'-bis[4-(2-hydroxyethoxy)]phenyl]-sulfonium bis[hexafluoroantimonate]; 5-[4-(2-hydroxyethoxy)phenyl]thianthrenium hexafluorophosphate and mixtures thereof and one or more alpha-hydroxyketone compounds recited in i"); and the mixture of compounds of the top curable coating composition of step b) comprises: iii"-1) one or more sulfonium salts recited in i"-1) and further comprises one or more acyl phosphine compounds recited in i"-1); and/or one or more glyoxylate compounds recited in i"-1); and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or one or more oxime ester compounds recited in i"-1); iii"-2) one or more thioxanthone compounds recited in i"-2) with one or more iodonium salts recited in i") and further comprises one or more acyl phosphine compounds recited in i"-1) and/or one or more glyoxylate compounds recited in i"-1); and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or one or more oxime ester compounds recited in i"-1); iii"-3) one or more anthracene compounds recited in i"-3) and further comprises one or more acyl phosphine compounds recited in i"-1) and/or one or more glyoxylate compounds recited in i"-1); and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or one or more oxime ester compounds recited in i"-1); iii"-4) one or more naphthalene compounds recited in i"-4) with one or more anthracene compounds recited in i"-4) and further comprises one or more acyl phosphine compounds recited in i'-1) and/or one or more glyoxylate compounds recited in i"-1) and/or one or more glyoxylate compounds recited in i"-1); and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or one or more oxime ester compounds recited in i"-1); or iii"-5) one or more coumarin compounds recited in i"-5) with one or more iodonium salts recited in i") and further comprises one or more acyl phosphine compounds recited in i"-1) and/or one or more glyoxylate compounds recited in i"-1)and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or one or more oxime ester compounds recited in i"-1); or iv") the mixture of photo-reactive compounds of the radiation curable coating composition of step a) comprises one or more sulfonium salts recited in iii") and a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and the mixture of compounds of the top curable coating composition of step b) comprises: iv"-1) one or more sulfonium salts recited in i"-1) and further comprises one or more acyl phosphine compounds recited in i"-1); and/or one or more glyoxylate compounds recited in i"-1); and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or one or more oxime ester compounds recited in i"-1); iv"-2) one or more thioxanthone compounds recited in i"-2) with one or more iodonium salts recited in i') and further comprises one or more acyl phosphine compounds recited in i"-1); and/or one or more glyoxylate compounds recited in i"-1); and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or one or more oxime ester compounds recited in i"-1); iv"-3) one or more anthracene compounds recited in i"-3) and further comprises one or more acyl phosphine compounds recited in i"-1); and/or one or more glyoxylate compounds recited in i"-1); and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or one or more oxime ester compounds recited in i"-1); iv"-4) one or more naphthalene compounds recited in i"-4) and one or more anthracene compounds recited in i"-4) and further comprises one or more acyl phosphine compounds recited in i"-1); and/or one or more glyoxylate compounds recited in i"-1); and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or one or more oxime ester compounds recited in i"-1); or iv"-5) one or more coumarin compounds recited in i"-5) with one or more iodonium salts recited in i")and further comprises one or more acyl phosphine compounds recited in i"-1); and/or one or more glyoxylate compounds recited in i"-1); and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or one or more oxime ester compounds recited in i"-1); or v") the mixture of photo-reactive compounds of the radiation curable coating composition of step a) comprises one or more iodonium salts recited in i") and one or more alpha-hydroxyketone compounds recited in i"); and the mixture of compounds of the top curable coating composition of step b) comprises: v"-1) one or more sulfonium salts recited in i"-1); v"-2) one or more thioxanthone compounds recited in i"-2); v"-3) one or more anthracene compounds recited in i"-3); v"-4) one or more naphthalene compounds recited in i"-4) and one or more anthracene compounds recited in i"-4); or v"-5) one or more coumarin compounds recited in i"-5); or vi") the mixture of photo-reactive compounds of the radiation curable coating composition of step a) comprises one or more iodonium salts recited in i") and a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and the mixture of compounds of the top curable coating composition of step b) comprises: vi"-1) one or more sulfonium salts recited in i"-1); vi"-2) one or more thioxanthone compounds recited in i"-2); vi"-3) one or more anthracene compounds recited in i"-3); vi"-4) one or more naphthalene compounds recited in i"-4) and one or more anthracene compounds recited in i"-4); or vi"-5) one or more coumarin compounds recited in i"-5); or vii") the mixture of photo-reactive compounds of the radiation curable coating composition of step a) comprises one or more sulfonium salts recited in iii") and one or more alpha-hydroxyketone compounds recited in i"); and the mixture of compounds of the top curable coating composition of step b) comprises: vii"-1) one or more sulfonium salts recited in i"-1); vii"-2) one or more thioxanthone compounds recited in i"-2) with one or iodonium salts recited in i"); vii"-3) one or more anthracene compounds recited in i" -3): vii"-4) one or more naphthalene compounds recited in i"-4) and one or more anthracene compounds recited in i"-4); or vii"-5) one or more coumarin compounds recited in i"-5) with one or more iodonium salts recited in i"); or viii") the mixture of photo-reactive compounds of the radiation curable coating composition of step a) comprises one or more sulfonium salts recited in iii") and a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and the mixture of compounds of the top curable coating composition of step b) comprises: viii"-1) one or more sulfonium salts recited in i"-1); viii"-2) one or more thioxanthone compounds recited in i"-2) with one or more iodonium salts recited in i"); viii"-3) one or more anthracene compounds recited in i"-3); viii"-4) one or more naphthalene compounds recited in i"-4) and one or more anthracene compounds recited in i"-4); or viii"-5) one or more coumarin compounds recited in i"-5) with one or more iodonium salts recited in i").
  4. The method according to any one of claims 1 to 3, wherein the mixture of photo-reactive compounds of the radiation curable coating composition of step a) and the mixture of compounds of the top curable coating composition of step b) are selected according to one of the following combinations: i‴) the mixture of photo-reactive compounds of the radiation curable coating composition of step a) comprises one or more iodonium salts selected from the group consisting of (bis(4-dodecylphenyl)iodonium hexafluoroantimonate; bis(4-methylphenyl)iodonium hexafluorophosphate; (4-methylphenyl)[4-(2-methylpropyl)phenyl]iodonium hexafluorophosphate and mixtures thereof (preferably (4-methylphenyl)[4-(2-methylpropyl)phenyl]iodonium hexafluorophosphate; bis(4-methylphenyl)iodonium hexafluorophosphate and mixtures thereof); and an alpha-hydroxyketone compound being 2-hydroxy-2-methylpropiophenone; and the mixture of compounds of the top curable coating composition of step b) comprises: i‴-1) a sulfonium salt being tris[4-(4-acetylphenylsulfanyl)phenyl]-sulfonium hexafluorophosphate and further comprises an acyl phosphine being phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide; and/or a glyoxylate compound being 2-2-oxo-2-phenylacetic acid methyl ester; and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or an oxime ester compounds being 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime); i"'-2) one or more thioxanthone compounds selected from the group consisting of 2-isopropyl-9H-thioxanthen-9-one; 4-(1-methylethyl)-9H-thioxanthen-9-one; and mixtures thereof and further comprises an acyl phosphine being phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide; and/or a glyoxylate compound being 2-2-oxo-2-phenylacetic acid methyl ester; and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or an oxime ester compounds being 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime); i"'-3) an anthracene compounds being 9,10-dibutoxy-anthracene and further comprises an acyl phosphine being phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide; and/or a glyoxylate compound being 2-2-oxo-2-phenylacetic acid methyl ester; and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or an oxime ester compounds being 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime); i"'-4) a naphthalene compound being 9,10-diethoxy-naphthalene with an anthracene compounds being 9,10-dibutoxy-anthracene and further comprises an acyl phosphine being phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide; and/or a glyoxylate compound being 2-2-oxo-2-phenylacetic acid methyl ester; and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or an oxime ester compounds being 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime); or i"'-5) a coumarin compound being 3-(4-C 10 -C 13 -benzoyl)-5,7-dimethoxy-2H-1-benzopyran-2-one and further comprises an acyl phosphine being phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide; and/or a glyoxylate compound being 2-2-oxo-2-phenylacetic acid methyl ester; and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or an oxime ester compounds being 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime); or ii‴) the mixture of photo-reactive compounds of the radiation curable coating composition of step a) comprises one or more iodonium salts recited in i‴) and a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and the mixture of compounds of the top curable coating composition of step b) comprises: ii‴-1) a sulfonium salt being tris[4-(4-acetylphenylsulfanyl)phenyl]-sulfonium hexafluorophosphate and further comprises an acyl phosphine being phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide; and/or a glyoxylate compound being 2-2-oxo-2-phenylacetic acid methyl ester; and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or an oxime ester compound being 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime); ii"'-2) one or more thioxanthone compounds recited in i"'-2) and further comprises an acyl phosphine being phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide; and/or a glyoxylate compound being 2-2-oxo-2-phenylacetic acid methyl ester; and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or an oxime ester compounds being 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime); ii"'-3) an anthracene compounds being 9,10-dibutoxy-anthracene and further comprises an acyl phosphine being phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide; and/or a glyoxylate compound being 2-2-oxo-2-phenylacetic acid methyl ester; and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or an oxime ester compounds being 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime); ii"'-4) a naphthalene compound being 9,10-diethoxy-naphthalene with an anthracene compound being 9,10-dibutoxy-anthracene and further comprises an acyl phosphine being phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide; and/or a glyoxylate compound being 2-2-oxo-2-phenylacetic acid methyl ester; and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or an oxime ester compounds being 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime); or ii"'-5) a coumarin compound being 3-(4-C 10 -C 13 -benzoyl)-5,7-dimethoxy-2H-1-benzopyran-2-one and comprises an acyl phosphine being phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide; and/or a glyoxylate compound being 2-2-oxo-2-phenylacetic acid methyl ester; and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or an oxime ester compounds being 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime; or iii‴) the mixture of photo-reactive compounds of the radiation curable coating composition of step a) comprises one or more sulfonium salts selected from the group consisting of diphenyl[4-(phenylthio)phenyl]-sulfonium hexafluoroantimonate; (thiodi-4,1-phenylene)bis[diphenyl-sulfonium bis-hexafluoroantimonate; and mixtures thereof and one or more alpha-hydroxyketone compounds recited in i‴); and the mixture of compounds of the top curable coating composition of step b) comprises: iii"'1) a sulfonium salt being tris[4-(4-acetylphenylsulfanyl)phenyl]-sulfonium hexafluorophosphate and further comprises an acyl phosphine being phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide; and/or a glyoxylate compound being 2-2-oxo-2-phenylacetic acid methyl ester; and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or an oxime ester compounds being 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime); iii"'-2) one or more thioxanthone compounds recited in i"'-2) with one or more iodonium salts recited in i‴) and further comprises an acyl phosphine being phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide; and/or a glyoxylate compound being 2-2-oxo-2-phenylacetic acid methyl ester; and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or an oxime ester compounds being 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime); iii‴-3) an anthracene compounds being 9,10-dibutoxy-anthracene and further comprises an acyl phosphine being phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide; and/or a glyoxylate compound being 2-2-oxo-2-phenylacetic acid methyl ester; and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or an oxime ester compounds being 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime); iii"'-4) a naphthalene compound being 9,10-diethoxy-naphthalene with an anthracene compound being 9,10-dibutoxy-anthracene and further comprises an acyl phosphine being phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide; and/or a glyoxylate compound being 2-2-oxo-2-phenylacetic acid methyl ester; and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or an oxime ester compounds being 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime); or iii"'-5) a coumarin compound being 3-(4-C 10 -C 13 -benzoyl)-5,7-dimethoxy-2H-1-benzopyran-2-one with one or more iodonium salts recited in i‴) further comprises an acyl phosphine being phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide; and/or a glyoxylate compound being 2-2-oxo-2-phenylacetic acid methyl ester; and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or an oxime ester compounds being 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime); or iv‴) the mixture of photo-reactive compounds of the radiation curable coating composition of step a) comprises one or more sulfonium salts recited in iii‴) and a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and the mixture of compounds of the top curable coating composition of step b) comprises: iv"'-1) a sulfonium salt being tris[4-(4-acetylphenylsulfanyl)phenyl]-sulfonium hexafluorophosphate and further comprises an acyl phosphine being phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide; and/or a glyoxylate compound being 2-2-oxo-2-phenylacetic acid methyl ester; and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or an oxime ester compounds being 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime); iv"'-2) one or more thioxanthone compounds recited in i"'-2) with one or more iodonium salts recited in i‴) and further comprises an acyl phosphine being phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide; and/or a glyoxylate compound being 2-2-oxo-2-phenylacetic acid methyl ester; and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or an oxime ester compounds being 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime); iv‴-3) an anthracene compounds being 9,10-dibutoxy-anthracene and further comprises an acyl phosphine being phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide; and/or a glyoxylate compound being 2-2-oxo-2-phenylacetic acid methyl ester; and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or an oxime ester compounds being 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime); iv‴-4) a naphthalene compound being 9,10-diethoxy-naphthalene with an anthracene compound being 9,10-dibutoxy-anthracene and further comprises an acyl phosphine being phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide; and/or a glyoxylate compound being 2-2-oxo-2-phenylacetic acid methyl ester; and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or an oxime ester compounds being 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime); or iv‴-5) a coumarin compound being 3-(4-C 10 -C 13 -benzoyl)-5,7-dimethoxy-2H-1-benzopyran-2-one with one or more iodonium salts recited in i‴) and further comprises an acyl phosphine being phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide; and/or a glyoxylate compound being 2-2-oxo-2-phenylacetic acid methyl ester; and/or a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one; and/or an oxime ester compounds being 4-cyclopentyl-1-[4-(phenylthio)phenyl]-1,2-butanedione 2-(O-benzoyloxime); or v‴) the mixture of photo-reactive compounds of the radiation curable coating composition of step a) comprises one or more iodonium salts recited in i‴) and one or more alpha-hydroxyketone compounds recited in i‴); and the mixture of compounds of the top curable coating composition of step b) comprises: v‴-1) a sulfonium salt being tris[4-(4-acetylphenylsulfanyl)phenyl]-sulfonium hexafluorophosphate; v‴-2) one or more thioxanthone compounds recited in i‴-2); v‴-3) an anthracene compound being 9,10-dibutoxy-anthracene; v‴-4) a naphthalene compound being 9,10-diethoxy-naphthalene with an anthracene compound being 9,10-dibutoxy-anthracene; or v‴-5) a coumarin compound being 3-(4-C 10 -C 13 -benzoyl)-5,7-dimethoxy-2H-1-benzopyran-2-one; or vi‴) the mixture of photo-reactive compounds of the radiation curable coating composition of step a) comprises one or more iodonium salts recited in i‴) and a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and the mixture of compounds of the top curable coating composition of step b) comprises: vi‴-1) a sulfonium salt being tris[4-(4-acetylphenylsulfanyl)phenyl]-sulfonium hexafluorophosphate vi‴-2) one or more thioxanthone compounds recited in i‴-2); vi‴-3) an anthracene compound being 9,10-dibutoxy-anthracene; vi‴-4) a naphthalene compound being 9,10-diethoxy-naphthalene with an anthracene compound being 9,10-dibutoxy-anthracene; or vi‴-5) a coumarin compound being 3-(4-C 10 -C 13 -benzoyl)-5,7-dimethoxy-2H-1-benzopyran-2-one; or vii‴) the mixture of photo-reactive compounds of the radiation curable coating composition of step a) comprises one or more sulfonium salts recited in iii‴) and one or more alpha-hydroxyketone compounds recited in i‴); and the mixture of compounds of the top curable coating composition of step b) comprises: vii‴-1) a sulfonium salt being tris[4-(4-acetylphenylsulfanyl)phenyl]-sulfonium hexafluorophosphate; vii‴-2) one or more thioxanthone compounds recited in i‴-2) with one or more iodonium salts recited in i‴); vii‴-3) an anthracene compound being 9,10-dibutoxy-anthracene; vii‴-4) a naphthalene compound being 9,10-diethoxy-naphthalene with an anthracene compound being 9,10-dibutoxy-anthracene; or vii‴-5) a coumarin compound being 3-(4-C 10 -C 13 -benzoyl)-5,7-dimethoxy-2H-1-benzopyran-2-one with one or more iodonium salts recited in i‴); or viii‴) the mixture of photo-reactive compounds of the radiation curable coating composition of step a) comprises one or more sulfonium salts recited in iii‴) and a benzyl ketal compound being 2,2-dimethoxy-1,2-diphenylethan-1-one and the mixture of compounds of the top curable coating composition of step b) comprises: viii‴-1) a sulfonium salt being tris[4-(4-acetylphenylsulfanyl)phenyl]-sulfonium hexafluorophosphate; viii‴-2) one or more thioxanthone compounds recited in i‴-2) with one or more iodonium salts recited in i‴); viii‴-3) an anthracene compounds being 9,10-dibutoxy-anthracene; viii‴-4) a naphthalene compound being 9,10-diethoxy-naphthalene with an anthracene compounds being 9,10-dibutoxy-anthracene; or viii‴-5) a coumarin compound being 3-(4-C 10 -C 13 -benzoyl)-5,7-dimethoxy-2H-1-benzopyran-2-one with one or more iodonium salts recited in i‴).
  5. The method according to any one of claims 1 to 4, wherein the mixture i), i'), i"), i‴), ii), ii'), ii"), ii‴), v), v'), v"), v‴), vi), vi'), vi") or vi‴) comprises the one or more thioxanthone compounds, said mixture further comprising one or more iodonium salts recited in any one of i), i'), i") or i‴); and/or the mixture i), i'), i"), i‴), ii), ii'), ii"), ii‴), iii), iii'), iii"), iii‴), iv), iv'), iv"), iv‴), v), v'), v"), v‴), vi), vi'), vi"), vi‴), vii), vii'), vii"), vii‴), viii), viii'), viii") or viii‴) comprises the one or more anthracene compounds, said mixture further comprising one or more iodonium salts recited in any one of i), i'), i") or i‴), and/or one or more sulfonium salts recited in any one of i-1), i'-1), i"-1), i"'-1), iii), iii'), iii") or iii‴); and/or the mixture i), i'), i"), i‴), ii), ii'), ii"), ii‴), iii), iii'), iii"), iii‴), iv), iv'), iv"), iv‴), v), v'), v"), v‴), vi), vi'), vi"), vi‴), vii), vii'), vii"), vii‴), viii), viii'), viii") or viii‴) comprises the one or more naphthalene compounds with the one or more anthracene compounds, said mixture further comprising one or more iodonium salts recited in any one of i), i'), i") or i‴) and/or one or more sulfonium salts recited in any one of i-1), i'-1), i"-1), i‴-1), iii), iii'), iii") or iii‴); and/or the mixture i), i'), i"), i‴), ii), ii'), ii"), ii‴), v), v'), v"), v‴), vi), vi'), vi") or vi"') comprises the one or more coumarin compounds, said mixture further comprising one or more iodonium salts recited in any one of i), i'), i") or i‴).
  6. The method according to any one of claims 1 to 5 further comprising a step of exposing the coating layer (x10) to a magnetic field of a magnetic-field generating device so as to orient at least a part of the magnetic or magnetizable pigment particles, said step being carried out subsequently to or partially simultaneously with step b) and prior to with step c).
  7. The method according to any one of claims 1 to 6 further comprising a step of exposing the coating layer (x10) to a magnetic field of a magnetic-field generating device so as to orient at least a part of the magnetic or magnetizable pigment particles, said step being carried out subsequently to step a) and prior to step b).
  8. The method according to any one of claims 1 to 7, wherein the step d) of exposing the coating layer (x10) and/or the step of exposing the coating layer (x10) to the magnetic field of a magnetic-field generating device of claim 6 or 7, is carried out so as to mono-axially orient at least a part of the non-spherical magnetic or magnetizable pigment particles.
  9. The method according to any one of claims 1 to 8, wherein the step d) of exposing the coating layer (x10) and/or the step of exposing the coating layer (x10) to magnetic field of a magnetic-field generating device of claim 6 or 7 is carried out so as to bi-axially orient at least a part of the non-spherical magnetic or magnetizable pigment particles, wherein the non-spherical magnetic or magnetizable pigment particles are platelet-shaped magnetic or magnetizable pigment particles, having an X-axis and a Y-axis defining a plane of predominant extension of the particles.
  10. The method according claim 9, wherein the step d) exposing the coating layer (x10) is carried out so as to bi-axially orient at least a part of the platelet-shaped magnetic or magnetizable pigment particles to have both their X-axes and Y-axes substantially parallel to the substrate surface.
  11. The method according to any one of claims 1 to 7, wherein step d) and/or the step of exposing the coating layer (x10) to the magnetic field of a magnetic-field generating device of claim 6 or 7 consists of two steps, a first step consisting of exposing the coating layer (x10) to the magnetic field of the magnetic-field generating device so as to bi-axially orient at least a part of the platelet-shaped magnetic or magnetizable pigment particles, and a second step consisting of exposing the coating layer (x10) to a magnetic field of a second magnetic-field-generating device so as to mono-axially orient at least a part of the platelet-shaped magnetic or magnetizable particles, wherein said second step is carried out partially simultaneously with, simultaneously with or subsequently to the first step.
  12. The method according to any one of claims 1 to 11, wherein the step a) of applying the radiation curable coating composition is carried out by a process selected from the group consisting of screen printing, rotogravure printing, pad printing and flexography printing and/or wherein the step b) of applying the top coating composition is carried out by a contactless fluid microdispensing technologies, preferably by an inkjet printing process.
  13. The method according to any one or claims 1 to 12 wherein at least a part of the non-spherical magnetic or magnetizable particles is optically variable.
  14. The method according to claim 13, wherein the non-spherical optically variable magnetic or magnetizable pigment particles are selected from the group consisting of magnetic thin-film interference pigments, magnetic cholesteric liquid crystal pigments and mixtures thereof.

Description

FIELD OF THE INVENTION The present invention relates to the field of magnetic-field generating devices and methods for producing optical effect layers (OELs) comprising magnetically oriented non-spherical magnetic or magnetizable pigment particles. In particular, the present invention provides magnetic-field generating devices and method for magnetically orienting non-spherical magnetic or magnetizable pigment particles in coating layer so as to produce OELs and the use of said OELs as anti-counterfeit means on security documents or security articles as well as decorative purposes. BACKGROUND OF THE INVENTION It is known in the art to use inks, compositions, coatings or layers containing oriented magnetic or magnetizable pigment particles, particularly also optically variable magnetic or magnetizable pigment particles, for the production of security elements, e.g. in the field of security documents. Coatings or layers comprising oriented magnetic or magnetizable pigment particles are disclosed for example in US 2,570,856; US 3,676,273; US 3,791,864; US 5,630,877 and US 5,364,689. Coatings or layers comprising oriented magnetic color-shifting pigment particles, resulting in particularly appealing optical effects, useful for the protection of security documents, have been disclosed in WO 2002/090002 A2 and WO 2005/002866 A1. Security features, e.g. for security documents, can generally be classified into "covert" security features on the one hand, and "overt" security features on the other hand. The protection provided by covert security features relies on the principle that such features are difficult to detect, typically requiring specialized equipment and knowledge for detection, whereas "overt" security features rely on the concept of being easily detectable with the unaided human senses, e.g. such features may be visible and/or detectable via the tactile sense while still being difficult to produce and/or to copy. However, the effectiveness of overt security features depends to a great extent on their easy recognition as a security feature. Magnetic or magnetizable pigment particles in printing inks or coatings allow for the production of magnetically induced images, designs and/or patterns through the application of a correspondingly structured magnetic field, inducing a local orientation of the magnetic or magnetizable pigment particles in the not yet hardened (i.e. wet) coating, followed by the hardening of the coating. The result is a fixed and stable magnetically induced image, design or pattern. Materials and technologies for the orientation of magnetic or magnetizable pigment particles in coating compositions have been disclosed for example in US 2,418,479; US 2,570,856; US 3,791,864, DE 2006848-A, US 3,676,273, US 5,364,689, US 6,103,361, EP 0 406 667 B1; US 2002/0160194; US 2004/0009309; EP 0 710 508 A1; WO 2002/09002 A2; WO 2003/000801 A2; WO 2005/002866 A1; WO 2006/061301 A1. In such a way, magnetically induced patterns which are highly resistant to counterfeit can be produced. The security element in question can only be produced by having access to both, the magnetic or magnetizable pigment particles or the corresponding ink, and the particular technology employed to print said ink and to orient said pigment in the printed ink. With the aim of protecting security documents or articles comprising a magnetically induced image against the premature detrimental influence of soil and/or moisture upon use and time, it has been a practice to apply a protective varnish. Said protective varnishes are applied as continuous layers on top of the already prepared and dried/cured magnetically induced image. WO 2011/012520 A2 discloses a transfer foil comprising a coating layer having the form of a design, said design comprising oriented optically variable magnetic pigment representing an image, indicium, or a pattern. The transfer foil may further comprise a top coating layer, wherein said top coating layer is applied prior to the application of the layer comprising the optically variable magnetic pigment. The process to produce said transfer foil comprises a) a step of applying the top coating layer, hardening/curing said top coating layer, and b) applying the layer comprising the optically variable magnetic pigments, magnetically orienting the particles and hardening/curing said layer. The disclosed methods are not suitable for producing magnetically induced images required to exhibit personalized variable indicia. EP 1 641 624 B1, EP 1 937 415 B1 and EP 2 155 498 B1 disclose devices and method for magnetically transferring indicia into a not yet hardened (i.e. wet) coating composition comprising magnetic or magnetizable pigment particles so as to form optical effect layers (OELs). The disclosed methods allow the production of security documents and articles having a customer-specific magnetic design. However, the disclosed magnetic devices are prepared to meet the specific design and cannot be modified