Photoinitiator systems with anthracene-based electron donors for curing cationically polymerizable resins
View Patent ↗The invention features a photopolymerizable composition that comprises a cationically polymerizable resin, and a photoinitiator system comprising an iodonium salt, a visible light sensitizer, and one or more anthracene-based compounds as electron donors. Electron donor combinations used in the invention include multiple substituted anthracene compounds or a combination of at least one substituted anthracene compound with unsubstituted anthracene.
1. A photoinitiator system for a cationically polymerizable resin comprising:
(a) an iodonium salt;
(b) a visible light sensitizer that is a ketone selected from the group consisting of alpha-diketones; and
(c) an electron donor comprising an alkoxy substituted anthracene.
2. The system of claim 1 , further comprising a second electron donor compound having the following formula:
wherein each of R 1 to R 10 is independently selected from H, alkyl, phenyl or alkoxy groups.
3. The photoinitiator system of claim 1 , further comprising:
a filler.
4. A photopolymerizable composition comprising:
(a) a cationically polymerizable resin; and
(b) a photoinitiator system for the cationically polymerizable resin selected from the group consisting of epoxides and oxetanes, the photoinitiator system comprising:
(i) an iodonium salt;
(ii) a visible light sensitizer that is a ketone selected from the group consisting of aipha-diketones; and
(iii) an electron donor comprising an alkoxy substituted anthracene.
5. The system of claim 4 , further comprising a second electron donor having the following formula:
wherein each of R 1 to R 10 is independently selected from H, alkyl, phenyl or alkoxy groups.
6. The photopolymerizable composition according to claim 4 , wherein the cationically polymerizable resin comprises an oxetane resin.
7. The photopolymerizable composition according to claim 4 , wherein the cationically polymerizable resin comprises an epoxy resin.
8. The photopolymerizable composition according to claim 7 , wherein the cationically polymerizable resin comprises a silicon-containing epoxy resin.
9. The photopolymerizable composition according to claim 6 , wherein the cationically polymerizable resin comprises a blend of a silicon-containing epoxy resin and an epoxy resin that does not contain silicon.
10. The photopolymerizable composition according to claim 4 , wherein the iodonium salt is selected from the group consisting of diaryliodonium hexafluorophosphate, diaryliodonium hexafluoroantimonate, diaryliodonium tetrakis(pentafluorophenyl)borate, 4-octyloxyphenyl phenyliodonium hexafluoroantimonate, 4-(2-hydroxytetradecyloxyphenyl) phenyliodonium hexafluoroantimonate, 4-(1-methylethyl)phenyl 4-methyiphenyliodonium tetrakis(pentafluorophenyl)borate, and combinations thereof.
11. The photopolymerizable composition according to claim 4 , wherein the alpha-diketone is camphorquinone.
12. The photopolymerizable composition according to claim 4 , wherein the alkoxy substituted anthracene is selected from 2-ethyl-9, 10-dimethoxyanthracene, 9,10-dimethoxyanthracene, 9,10-diethoxyanthracene, and 1,4-dimethoxyanthracene.
13. The photopolymerizable composition claim 4 , further comprising:
a filler.
14. A method for preparing a dental restorative or prosthesis, said method comprising:
(a) providing the photopolymerizable dental material of claim 4 ; and
(b) polymerizing the dental material by exposing it to light of an appropriate wavelength to provide said dental restorative or prosthesis.
15. The method of claim 14 , further comprising the step of disposing said material into the mouth of a patient before or after step (b).
16. The method of claim 14 , wherein said dental material is irradiated with light for a period of time less than 120 seconds.
17. A photoinitiator system for a cationically polymerizable resin comprising:
(a) an iodonium salt;
(b) a visible light sensitizer that is a ketone selected from the group consisting of alpha-diketones; and
(c) an electron donor selected from the group consisting of an alkoxy substituted anthracene; the combination of a first anthracene that has a light absorption maximum less than about 400 nanometers and a second anthracene having the following structure
wherein each of R 1 to R 10 is independently selected from H, or alkyl, phenyl or alkoxy groups, provided that at least one of R 1 to R 10 is not H; and the combination of a first anthracene and a second anthracene both having the following structure:
wherein for said first anthracene each of R 1 to R 10 is independently selected from H, alkyl, phenyl, or alkoxy groups, provided that at least one of R 1 to R 10 is alkoxy, and wherein for said second anthracene each of R 1 to R 10 is independently selected from H, alkyl, phenyl or alkoxy groups.
18. The photoinitiator system of claim 17 , further comprising:
a cationically polymerizable resin selected from the group consisting of epoxides and oxetanes so as to form a photopolymerizable composition.
19. The photopolymerizable composition of claim 18 , further comprising:
a filler.