Photopolymerizable compositions featuring novel co-initiators

In a photopolymerizable composition comprising an addition-polymerizable compound containing ethylenic unsaturation and a co-initiator composition comprising an amine, other than a 3-ketocoumarin, capable of forming a free radical in the presence of a photo-excited carbonyl compound, and a carbonyl compound;

• the improvement wherein said carbonyl compound is a coumarin having an absorption maximum between about 250 and about 550 nm and a ##STR33## substituent in the 3-position, wherein R.sup.1 is alkyl or alkenyl having 1 to about 12 carbon atoms, or a carbocyclic or heterocyclic group having about 5 to about 20 nuclear carbon and hetero atoms, said coumarin and said amine being present in an amount sufficient to provide, when the composition is coated, dried and exposed to a medium-pressure mercury light source, a speed which is at least about one-fifth that of the same composition coated, dried and exposed identically except with a co-initiator consisting of Michler's ketone and benzophenone.

In a photopolymerizable composition comprising an addition-polymerizable acrylate and a co-initiator composition comprising an amine capable of forming a free radical in the presence of a photo-excited carbonyl compound, and a carbonyl compound;

• the improvement wherein said carbonyl compound is 3-benzoyl-7-methoxycoumarin, said coumarin and said amine being present in an amount sufficient to provide, when the composition is coated, dried and exposed to a medium-pressure mercury light source, a speed which is at least about one-fifth of that of the same composition coated, dried and exposed identically except with a co-initiator consisting of Michler's ketone and benzophenone.

In a photopolymerizable composition comprising an addition-polymerizable acrylate and a co-initiator composition comprising an amine capable of forming a free radical in the presence of a photo-excited carbonyl compound, and a carbonyl compound;

• the improvement wherein said carbonyl compound is 3-(2-benzofuroyl)-7-diethylaminocoumarin, said coumarin and said amine being present in an amount of sufficient to provide, when the composition is coated, dried and exposed to a medium-pressure mercury light source, a speed which is at least about one-fifth of that of the same composition coated, dried and exposed identically except with a co-initiator consisting of Michler's ketone and benzophenone.

In a photopolymerizable composition comprising an addition-polymerizable acrylate and a co-initiator composition comprising an amine capable of forming a free radical in the presence of a photo-excited carbonyl compound, and a carbonyl compound;

• the improvement wherein said carbonyl compound is 3-(2-benzofuroyl)-7-(1-pyrrolidinyl)coumarin, said coumarin and said amine being present in an amount sufficient to provide, when the composition is coated, dried and exposed to a medium-pressure mercury light source, a speed which is at least about one-fifth that of the same composition coated, dried and exposed identically except with a co-initiator consisting of Michler's ketone and benzophenone.

In a photopolymerizable composition comprising an addition-polymerizable acrylate and a co-initiator composition comprising an amine capable of forming a free radical in the presence of a photo-excited carbonyl compound, and a carbonyl compound;

• the improvement wherein said carbonyl compound is 3-(p-diethylaminocinnamoyl)-7-diethylaminocoumarin, said coumarin and said amine being present in an amount sufficient to provide, when the composition is coated, dried and exposed to a medium-pressure mercury light source, a speed which is at least about one-fifth that of the same composition coated, dried and exposed identically except with a co-initiator consisting of Michler's ketone and benzophenone.

In a photopolymerizable composition comprising an addition-polymerizable acrylate and a co-initiator composition comprising an amine capable of forming a free radical in the presence of a photo-excited carbonyl compound, and a carbonyl compound;

• the improvement wherein said carbonyl compound is 3,3'-carbonylbis(7-diethylaminocoumarin), said coumarin and said amine being present in an amount sufficient to provide, when the composition is coated, dried and exposed to a medium-pressure mercury light source, a speed which is at least about one-fifth that of the same composition coated, dried and exposed identically except with a co-initiator consisting of Michler's ketone and benzophenone.

In a photopolymerizable composition comprising an addition-polymerizable acrylate and a co-initiator composition comprising an amine capable of forming a free radical in the presence of a photo-excited carbonyl compound, and a carbonyl compound;

• the improvement wherein said carbonyl compound is 3,3'-carbonylbis(5,7-di-n-propoxycoumarin), said coumarin and said amine being present in an amount sufficient to provide, when the composition is coated, dried and exposed to a medium-pressure mercury light source, a speed which is at least about one-fifth that of the same composition coated, dried and exposed identically except with a co-initiator consisting of Michler's ketone and benzophenone.

In a photopolymerizable composition comprising an addition-polymerizable compound containing ethylenic unsaturation, and a co-initiator composition comprising a carbonyl compound and an activator capable of forming a free radical in the presence of the photoexcited form of said carbonyl compound, said activator having the structure:

• ##STR34## wherein R.sup.6, R.sup.7 and R.sup.8 are the same or different, and are each alkyl or alkoxy containing from 1 to about 20 carbon atoms, or aryl or alkaryl containing from 6 to 10 carbon atoms;
• the improvement wherein said carbonyl compound is a coumarin having an absorption maximum between about 250 and about 550 nm and a ##STR35## substituent in the 3-position, wherein R.sup.1 is alkyl or alkenyl having 1 to about 12 carbon atoms, or a carbocyclic or heterocyclic group having about 5 to about 20 nuclear carbon and hetero atoms, said coumarin and said activator being present in an amount sufficient to provide, when the composition is coated, dried and exposed to a medium-pressure mercury light source, a speed which is at least about one-fifth that of the same composition coated, dried and exposed identically except with a co-initiator consisting of Michler's ketone and benzophenone.

In a photopolymerizable composition comprising an addition-polymerizable compound containing ethylenic unsaturation, and a co-initiator composition comprising a carbonyl compound and an activator capable of forming a free radical in the presence of the photoexcited form of said carbonyl compound, said activator having the structure:

• ##STR36## wherein R.sup.9, R.sup.10 and R.sup.11 are the same or different and are each alkyl containing from 1 to about 12 carbon atoms, or aryl or alkaryl containing from 6 to 10 carbon atoms,
• the improvement wherein said carbonyl compound is a coumarin having an absorption maximum between about 250 and about 550 nm and a ##STR37## substituent in the 3-position, wherein R.sup.1 is alkyl or alkenyl having 1 to about 12 carbon atoms, or a carbocyclic or heterocyclic group having about 5 to about 20 nuclear carbon and hetero atoms, said coumarin and said activator being present in an amount sufficient to provide, when the composition is coated, dried and exposed to a medium-pressure mercury light source, a speed which is at least about one-fifth that of the same composition coated, dried and exposed identically except with a co-initiator consisting of Michler's ketone and benzophenone.

In a photopolymerizable element comprising a support and on the support a layer comprising an addition-polymerizable compound containing ethylenic unsaturation, and a co-initiator composition comprising a carbonyl compound and a photopolymerization activator responsive in the presence of the photo-excited form of said carbonyl compound to form a free radical, said activator being selected from the group consisting of an amine other than a 3-ketocoumarin, an acetic acid derivative, a phosphine, a phosphite, a bismuthine, an arsine, a stibine, a sulfinic acid, a sulfinic acid ester, a sulfone, a dicarbon yl, a ketone, a bi-imidazole, and a stannate;

• the improvement wherein said carbonyl compound is a coumarin having an absorption maximum between about 250 and about 550 nm and a ##STR38## substituent in the 3-position, wherein R.sup.1 is alkyl or alkenyl having 1 to about 12 carbon atoms, or a carbocyclic or heterocyclic amine, having about 5 to about 20 nuclear carbon and hetero atoms, said coumarin and said activator being present in an amount sufficient to provide, when the composition is coated, dried and exposed to a medium-pressure mercury light source, a speed which is at least about one-fifth that of the same composition coated, dried and exposed identically except with a co-initiator consisting of Michler's ketone and benzophenone.

In a method of photopolymerizing a composition by exposing it to activating radiation, the composition comprising an addition-polymerizable compound containing ethylenic unsaturation and a co-initiator composition including a carbonyl compound and a photopolymerization activator responsive in the presence of the photo-excited form of said carbonyl compound to form a free radical, said activator being selected from the group consisting of an amine other than a 3-ketocoumarin, an acetic acid derivative, a phosphine, a phosphite, a bismuthine, an arsine, a stibine, a sulfinic acid, a sulfinic acid ester, a sulfone, a dicarbonyl, a ketone, a bi-imidazole, and a stannate;

• the improvement wherein said carbonyl compound is a coumarin having an absorption maximum between about 250 and about 550 nm and a ##STR39## substituent in the 3-position, wherein R.sup.1 is alkyl or alkenyl having 1 to about 12 carbon atoms, or a carbocyclic or heterocyclic group having about 5 to about 20 nuclear carbon and hetero atoms, said coumarin and said activator being present in an amount sufficient to provide, when the composition is coated, dried and exposed to a medium-pressure mercury light source, a speed which is at least about one-fifth that of the same composition coated, dried and exposed identically except with a co-initiator consisting of Michler's ketone and benzophenone.