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 on a substrate, the method comprising the steps of:
- a) applying on a substrate 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 a 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;
- b) subsequently to step a), applying a top coating composition at least partially on top of the coating layer thus forming one or more areas of the coating layer below said one or more indicia, wherein said top coating composition is applied in the form of the one or more indicia 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 and the one or more areas of the coating layer below said one or more indicia with a LED curing unit emitting between 350 nm and 470 nm,
- d) subsequently to step c), exposing the coating layer 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 with a curing unit 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 SbF6−;
- PF6−;
- AsF6−;
- F4B−;
- (C6F5)4B−;
- (CF3SO2)3C−;
- (CF3)SO3;
- (CH3C6H4)SO3−;
- (CF3)CO2−;
- (C4F9)SO3− or (C4F9)CO2− 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 SbF6−;
- PF6−;
- AsF6−;
- F4B−;
- (C6F5)4B−;
- (CF3SO2)3C−;
- (CF3)SO3−;
- (CH3C6H4)SO3−;
- (CF3)CO2−;
- (C4F9)SO3− or (C4F9)CO2− 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 SbF6−;
- PF6;
- AsF6−;
- F4B−;
- (C6F5)4B−;
- (CF3SO2)3C−;
- (CF3)SO3−;
- (CH3C6H4)SO3−;
- (CF3)CO2−;
- (C4F9)SO3− or (C4F9)CO2− 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.