Abstract: The invention relates to novel photoinitators of formulae (V), (II), (III), (IV), (V) and (VI) wherein R1 and R2 are each independently of the other C1-C8alkyl; C1-C4alkyl substituted by OH, C1-C4alkoxy, —COO(C1-C8alkyl), (C1-C4alkyl)-COO—, —CN, benzyl, phenyl or by —N(R15)(R16); C3-C6alkerlyl, benzyl, —CH2—C6H4—(C1-C4alkyl) or phenyl; or R1 and R2 together are unbranched or branched C2-C9alkylene or C3-C6-oxa- or -azaalkylene; R3, R4, R5 and R6 are each independently of the others hydrogen, C1-C8alkyl, C3-C6alkenyl, benzyl, —CH2—C6H4—(C1-C4alkyl) or phenyl; R3 and R4 together and/or R5 and R6 together are unbranched or branched C2-C9alkylene; A is Cl, Br, —O—R9, —N(R11)(R12) or —S—R18, A? is —O—, —NH— or —NR11—; A? is Cl, Br, —O—R9, —N(R11)(R12) or —S—R18 or hydrogen, X is —O—R10 or —N(R13)(R14), n is an integer from 1 to 10, preferably an integer from 1 to 4, especially 1, 2 or 3; R7 is a linker; R8 is a bivalent C2-C3alkylele radical.

Abstract: The invention relates to the use of highly sterically hindered nitroxyl radicals as in-can stabilizers for UV-curable resins. The present invention further relates to the use of quinone methides as in-can stabilizers for UV-curable resins.

Abstract: A process for preparing pigment concentrates is provided which comprises dispersing a dry pigment in a radiation polymerizable (curable) ethylenically-unsaturated compound. The concentrates to which optionally photoinitiators are added can be used for preparing radiation, preferably ultraviolet radiation, curable printing inks, paints or other coating compositions which in turn are applied in printing processes or in the painting or coating of substrates. The performance enhancement of the cured pigmented inks/paints/coatings include e.g. good tinctorial strength and gloss, as well as surface hardness, good adhesion to substrate and chemical and corrosion resistance.

Abstract: The Invention relates to novel ketones of formulae (I) and (II) wherein R1, R2, R3 and R4 are, for example, C1-C8alkyl, R5 is, for example, hydrogen, A is CI, Br, -0-R7, —NR8R9 or —S—R16, A? is —O—, —NH— or —NR8—, X and Y are each independently of the other —O—R10 or —N(R11)(R12), n is an integer from 1 to 10, R6 is, for example, an n-valent radical of linear or branched C2-C20alkyl the carbon chain of which may be interrupted by cyclohexanediyl, phenylene, —CH(OH)—, —C(C2H5)(CH2—CH2—OH)—, —C(CH3)(CH2—CH2—OH)—, —C(CH2—CH2—OH)2—, —N(CH3)—, —N(C2H5)—, —N(CH2—CH2—OH)—, —CO—O—, —O—CO—, —P(CH2—CH2—OH)—, —P(O)(CH2—CH2—OH)—, -0-P(O—CH2—CH2—OH)—O—, -0-P(O)(0-CH2—CH2—OH)—O—, —O-cyclohexanediyl-C(CH3)2-Cyclohexanediyl-O—, —O-phenylene-C(CH3)2-phenylene-O—, —O-phenylene-CH2-phenylene-O—, —Si(CH3)2—, -0-Si(CH3)2—O—, —O—Si(CH3)(0-CH3)—O—, —Si(CH3)(R17)—O—Si(CH3)(R18)—, 5-(2-hydroxyethyl)-[1,3,5]triazinane-2,4,6-trione-1,3-diyl and/or by from one to nine oxygen atoms.

Abstract: A process for preparing an inkjet printed matter, which comprises the steps of applying an ultraviolet curable inkjet ink composition comprising a photopolymerizable monomer, oligomer or prepolymer; a colorant and a compound of the formula (I) or (II) or (Ia) or (IIa) or mixtures thereof, and optionally a reactive diluent to a recording medium and curing the ink composition on the recording medium by irradiating with ultraviolet ray.

Abstract: The invention relates to ?-hydroxy ketones of formula I or IIa; or mixtures of compounds of formula I and II; or mixtures of compounds of formulae Ia and IIa

Abstract: Benzophenone derivatives of formula I R1, R2 and R3 are each independently of the others hydrogen or C1-C4alkyl, cyclopentyl or cyclohexyl; R4, R5 and R6 are each independently of the others hydrogen, C1-C4alkyl, cyclopentyl or cyclohexyl; R7 and R8 are each independently of the other hydrogen, C1-C4alkyl, cyclopentyl or cyclohexyl; with the provisos that (i) at least one radical R1, R2, R3, R4, R5, R6, R7, R8 is other than hydrogen; (ii) when all radicals R4, R5 , R6, R7 and R8 are hydrogen and only one radical R1, R2, R3 is C1-C4alkyl, that radical must be in the meta-position of the phenyl ring; and (iii) when all radicals R1, R2, R3, R7 and R8 are hydrogen and two of the radicals R4, R5 and R6 are hydrogen and the remaining radical R4, R5 or R6 is C1-C4alkyl, that alkyl radical is not bonded in the para-position on the phenyl ring; are found to be especially suitable in photocurable compositions in respect of solubility, reactivity and a low level of yellowing.

Abstract: Compounds of formula (I), wherein R1 is hydrogen or alkyl; R2 is C1-C4alkoxy or a morpholino radical; and R3 is hydrogen or C1-C4alkoxy, are suitable for improving the solubility of specific photoinitiators in formulations and accordingly enhance the storage stability of formulations comprising a photoinitiator and compounds of formula (I).

Abstract: The invention relates to novel photoinitiators of formula (I) wherein A is —O—, —CH2?, CH(CH3)— or —C(CH3)2?, and R is methyl or trimethylsilyl, and R may in addition be hydrogen when A is simultaneously the group —C(CH3)2?. The invention relates also to compositions comprising (A) at least one ethylenically unsaturated compound, (B) a photoinitiator of formula (I), (C) optionally further binders or additives, (D) optionally further photoinitiators or co-initiators. Compositions comprising (A) an ethylenically unsaturated compound that contains at least one aminoacrylate, (B) a photoinitiator of formula (II) or (III), (C) optionally further binders or additives, (D) optionally further photoinitiators or co-initiators.

Abstract: The invention relates to ?-hydroxy ketones of formula I or IIa; or mixtures of compounds of formula I and II; or mixtures of compounds of formulae Ia and IIa