Ternary photoinitiator system for cationically polymerizable resins

A photopolymerizable composition comprising:

• (a) a cationically polymerizable resin;
• and
• (b) a photoinitiator system for the cationically polymerizable resin, the photoinitiator system comprising:
• (i) an iodonium salt;
• (ii) a visible light sensitizer;
• and
• (iii) an electron donor compound having an oxidation potential greater than 0 and less than that of 1,4-dimethoxybenzene when measured versus a saturated calomel electrode, wherein the electron donor compound has a pkb greater than 8;
• and
• wherein the photoinitiator system has a photoinduced potential less than that of 3-dimethylaminobenzoic acid in a standard solution of 2.9×10−5 moles/g diphenyl iodonium hexafluoroantimonate and 1.5×10−5 moles/g camphorquinone in 2-butanone.

A photopolymerizable composition comprising:

• (a) a cationically polymerizable resin;
• and
• (b) a photoinitiator system for the cationically polymerizable resin, the photoinitiator system comprising:
• (i) an iodonium salt;
• (ii) a visible light sensitizer;
• and
• (iii) an electron donor compound having an oxidation potential greater than 0 and less than that of 1,4-dimethoxybenzene when measured versus a saturated calomel electrode, wherein the electron donor compound is selected from the group consisting of polycyclic aromatic compounds and N-alkyl carbazole compounds;
• and
• wherein the photoinitiator system has a photoinduced potential less than that of 3-dimethylaminobenzoic acid in a standard solution of 2.9×10−5 moles/g diphenyl iodonium hexafluoroantimonate and 1.5×10−5 moles/g camphorquinone in 2-butanone.

A photopolymerizable composition comprising:

• (a) a cationically polymerizable resin;
• and
• (b) a photoinitiator system for the cationically polymerizable resin, the photoinitiator system comprising:
• (i) an iodonium salt;
• (iii) a visible light sensitizer;
• and
• (iii) an electron donor compound having an oxidation potential greater than 0 and less than that of 1,4-dimethoxybenzene when measured versus a saturated calomel electrode;
• wherein the electron donor compound is a polycyclic aromatic compound having one of the following structures:
• wherein each of R1 to R14 is independently selected from H, or alkyl or aromatic hydrocarbon groups, wherein the alkyl or aromatic hydrocarbon groups may be optionally substituted by one or more halogen, —CN, —OH, —SH, —COON, —COOC1-10 alkyl, —(C1-10 alkyl)0-1—COH2—(C1-10 alkyl)0-1—CO—C1-10alkyl, or —CO—C—C1-10 alkyl groups, and further wherein any of R1 to R14 may cooperate to form an aromatic or cycloalkyl ring;
• and
• wherein the photoinitiator system has a photoinduced potential less than that of 3-dimethylaminobenzoic acid in a standard solution of 2.9×10−5 moles/g diphenyl iodonium hexafluoroantimonate and 1.5×10−5 moles/g camphorquinone in 2-butanone.

A photopolymerizable composition comprising:

• (a) a cationically polymerizable resin;
• and
• (b) a photoinitiator system for the cationically polymerizable resin, the photoinitiator system comprising:
• (i) an iodonium salt;
• (ii) a visible light sensitizer;
• and
• (iii) an electron donor compound having an oxidation potential greater than 0 and less than that of 1,4-dimethoxybenzene when measured versus a saturated calomel electrode, wherein the electron donor compound is an N-alkyl carbazole compound having the following structure:
• wherein each R1 to R10 is independently selected from H, or alkyl or aromatic hydrocarbon groups, wherein the alkyl and aromatic hydrocarbon groups may be optionally substituted by one or more halogen, —CN, —OH, —SH, —COOH, —COOC1-10 alkyl, —(C1-10 alkyl)0-1—COH, —(C1-10 alkyl)0-1—CO—C1-10 alkyl, —CO—C1-10 alkyl, and further wherein R1 and R10 may cooperate to form an aromatic, cycloalkyl or low basicity heterocyclic ring;
• and
• wherein the photoinitiator system has a photoinduced potential less than that of 3-dimethylaminobenzoic acid in a standard solution of 2.9×10−5 moles/g diphenyl iodonium hexafluoroantimonate and 1.5×10−5 moles/g camphorquinone in 2-butanone.

A photopolymerizable composition comprising:

• (a) a cationically polymerizable resin;
• and
• (b) a photoinitiator system for the cationically polymerizable resin, the photoinitiator system comprising:
• (i) an iodonium salt;
• (ii) a visible light sensitizer;
• and
• (iii) an electron donor compound having an oxidation potential greater then 0 and less than that of 1,4-dimethoxybenzene when measured versus a saturated calomel electrode, wherein the photopolymerizable composition is a curable ink imaging layer, a silverless imaging layer, an imaging layer on a projection plate, or an imaging layer on a laser plate;
• and
• wherein tho photoinitiator system has a photoinduced potential less than that of 3-dimethylaminobenzoic acid in a standard solution of 2.9×10−5 moles/g diphenyl iodonium hexafluoroantimonate and 1.5×10−5 moles/g camphorquinone in 2-butanone.

A photopolymerizable composition comprising:

• (a) a cationically polymerizable resin;
• and
• (b) a photoinitiator system for the cationically polymerizable resin, the photoinitiator system comprising:
• (i) an iodonium salt;
• (ii) a visible light sensitizer;
• and
• (iii) an electron donor compound having an oxidation potential greater than 0 and less than that of 1.4-dimethoxybenzene when measured versus a saturated calomel electrode, wherein the photopolymerizable composition has been polymerized to provide a hard coat layer on an optical lens;
• and
• wherein the photoinitiator system has a photoinduced potential less than that of 3-dimethylaminobenzoic acid in a standard solution of 2.9×10−5 moles/g diphenyl iodonium hexafluoroantimonate and 1.5×10−5 moles/g camphorquinone in 2-butanone.

A photopolymerizable composition comprising:

• (a) a cationically polymerizable resin;
• and
• (b) a photoinitiator system for the cationically polymerizable resin, the photoinitiator system comprising:
• (i) an iodonium salt;
• (ii) a visible light sensitizer;
• and
• (iii) an electron donor compound having an oxidation potential greater than 0 and less than that of 1,4-dimethoxybenzene when measured versus a saturated calomel electrode, wherein the photopolymerizable composition has been polymerized to provide a coating on an optical fiber;
• and
• wherein the photoinitiator system has a photoinduced potential less than that of 3-dimethylaminobenzoic acid in a standard solution of 2.9×10−5 moles/g diphenyl iodonium hexafluoroantimonate and 1.5×10−5 moles/g camphorquinone in 2-butanone.

A photopolymerizable dental material comprising:

• (a) an epoxy resin;
• and
• (b) a photoinitiator system for the epoxy resin, the photoinitiator system comprising:
• (i) an iodonium salt;
• (ii) a visible light sensitizer;
• and
• (iii) a polycyclic aromatic electron donor compound having an oxidation potential greater than 0 and less than that of 1,4-dimethoxybenzene when measured versus a saturated calomel electrode;
• and
• wherein the photoinitiator system has a photoinduced potential less than that of 3-dimethylaminobenzoic acid in a standard solution of 2.9×10−5 moles/g diphenyl iodonium hexafluoroantimonate and 1.5×10−5 moles/g camphorquinone in 2-butanone.

A photopolymerizable dental material comprising:

• (a) an epoxy resin;
• and
• (b) a photoinitiator system for the epoxy resin, the photoinitiator system comprising:
• (i) an iodonium salt;
• (ii) a visible light sensitizer;
• and
• (iii) an N-alkyl carbazole electron donor compound having an oxidation potential greater than 0 and less than that of 1,4-dimethoxybenzene when measured versus a saturated calomel electrode;
• and
• wherein the photoinitiator system has a photoinduced potential less than that of 3-dimethylaminobenzoic acid in a standard solution of 2.9×10−5 moles/g diphenyl iodonium hexafluoroantimonate and 1.5×10−moles/g camphorquinone in 2-butanone.

A photopolymerizable dental material comprising:

• (a) an epoxy resin;
• and
• (b) a photoinitiator system for the epoxy resin, the photoinitiator system comprising:
• (i) an iodonium salt selected from the group consisting of diaryliodonium hexafluorophosphate, diaryliodonium hexafluoroantimonate, 4-octyloxyphenyl phenyliodonium hexafluoroantimonate, 4-(2-hydroxytetradecyloxyphenyl) phenyliodonium hexafluoroantimonate;
• 4-(l -methylethyl)phenyl 4-methylphenyliodonium tetrakis(pentafluorophenyl)borate, and combinations thereof;
• (ii) an alpha-diketone visible light sensitizer;
• and
• (iii) an electron donor compound selected from the group consisting of biphenylene, anthracene, 9-methylanthracene, 9-vinyl anthracene, 9-phenylanthracene, 9,10-diphenylanthracene, 9,10-dimethylanthracene, 2-ethylanthracene, acenaphthene, pyrene, pentacene, decacyclene, azulene, 7,12-dimethyl-1,2-benzanthracene, 1,2-benzanthracene, 1,4-dimethylnaphthalene, 2,3,5-trimethylnaphthalene, N-methyl carbazole, and combinations thereof;
• wherein the photoinitiator system has a photoinduced potential less than that of 3-dimethylaminobenzoic acid in a standard solution of 2.9×10−5 moles/g diphenyl iodonium hexafluoroantimonate and 1.5×10−5 moles/g camphorquinone in 2-butanone.

A method of reducing the time needed to polymerize a cationically polymerizable resin, the method comprising the steps of:

• (a) providing a cationically polymerizable resin;
• (b) providing a photoinitiator system for the cationically polymerizable resin, the photoinitiator system comprising:
• (i) an iodonium salt;
• (ii) a visible light sensitizer;
• and
• (iii) an electron donor compound having an oxidation potential greater than 0 and less tan that of 1,4-dimethoxybenzene when measured versus a saturated calomel electrode, wherein the electron donor compound has a pkb greater than 8;
• and
• wherein the photoinitiator system has a photoinduced potential less than that of 3-dimethylaminobenzoic acid in a standard solution of 2.9×10−5 moles/g diphenyl iodonium hexafluoroantimonate and 1.5×10−5 moles/g camphorquinone in 2-butanone;
• (c) combining the cationically polymerizable resin and the photoinitiator system to provide a polymerizable mixture;
• and
• (d) exposing the polymerizable mixture to a light source having a wavelength and intensity to which the photoinitiator system is reactive and for a time until the polymerizable mixture attains a hard, tack-free state;
• wherein the time until the polymerizable mixture attains a hard, tack-free state is less than the time required for the same polymerizable mixture, but excluding the electron donor compound, to achieve the same hard, tack-free state when exposed to the same light source.