Polymerisable compositions, derived coatings and other polymerised products

Claim 2

A photopolymerisable composition capable of polymerisation by an acid-catalysed mechanism under the influence of ultraviolet and/or visible light which comprises the components (a) at least one material capable of polymerisation by an acid-catalysed mechanism to a polymeric material of higher molecular weight state; (b) a photosensitive aromatic halonium salt, and (c) a material which, under the conditions of photopolymerisation, will yield a significant proportion of free radicals either (i) by intramolecular cleavage, or (ii) by intermolecular hydrogen abstraction in conjunction with a component of the composition other than the photosensitive aromatic halonium salt.

Claim 3

A photopolymerisable composition according to claim 1 wherein the photosensitive aromatic halonium salt is represented by the formulae: or where Hal is a halogen radical selected from Cl, Br and I; R 1 and R 2 are monovalent aromatic carbocyclic or aromatic heterocyclic organic radicals containing 4-20 carbon atoms, the same or different which may be substituted; R 3 and R 4 , are divalent aromatic carbocyclic or aromatic heterocyclic radicals containing 4-20 carbon atoms, the same or different, which may be substituted and which may be directly linked through a carbon-carbon bond (when A = zero) or indirectly linked when A is a hetero atom or a group containing a hetero atom or an alkyl or alkenyl radical containing 4-20 carbon atoms; n = 1 or 2; and X is an anion derived from an acid which is capable of polymerising the material (a) of the composition by an acid-catalysed mechanism to a higher molecular weight state.

Claim 4

A photopolymerisable composition according to claim 1 or claim 2 wherein the photosensitive aromatic halonium salt is an iodonium salt.

Claim 5

A photopolymerisable composition according to claim 2 or claim 3 wherein X n- is selected from BF 4 , SbCl 6 - , SbF 6 - , SnCl 6 , PF 6 - , AsF 6 - , FeCl 4 , BiCl 5 -- , or R 5 SO 3 - , where R 5 is an aromatic hydrocarbon radical having 6-13 carbon atoms, an alkyl radical having 1-8 carbon atoms, and halogenated derivatives thereof, or R 5 is fluorine.

Claim 6

A photopolymerisable composition according to any one of claims 1 to 4 wherein a component (c)(i) is selected from benzoin and benzoin alkyl ethers; alkoxy aryl acetophenones; and halogenated acetophenones, or a component (c)(ii) is selected from aromatic diketones and derivatives thereof; benzophenone and derivatives thereof; materials of structure where X = O, S, CH 2 or a direct carbon-carbon bond and derivatives thereof where R = halogen, alkyl or substituted alkyl.

Claim 7

A photopolymerisable composition according to any one of claims 1 to 5 wherein there is present 0.01% to 10% by weight of the component (c) based on the total weight of the composition.

Claim 8

A photopolymerisable composition according to any one of claims 1 to 6 wherein a material (a) capable of polymerisation to a higher molecular weight state is selected from epoxides, episulphides, and other cyclic ethers and thioethers; epoxy resins; episulphide resins; vinyl ethers; phenolic resins; and aminoplasts.

Claim 9

A photopolymerisable composition according to any one of claims 1 to 7 which is substantially free of material polymerisable by free radicals.

Claim 10

A photopolymerisable composition according to any one of claims 1 to 8 comprising a further component (c) which plays no part in the polymerisation process but which, when the composition is irradiated with ultraviolet and/or visible light, absorbs at least some of that radiation to which, in the absence of said component (d), the halonium salt would be sensitive.

Claim 11

A coating composition which comprises a photopolymerisable composition according to claim 9 and wherein the component (d) is a pigment.

Claim 12

A polymerised composition obtained by irradiating with ultraviolet and/or visible light a composition according to any one of claims 1 to 10.