Claims
- 1. A process for preparing a photopolymerizable composition comprising forming a mixture containing a photopolymerizable ethylenically unsaturated compound, a benzoin ether in an amount sufficient to initiate photopolymerization and a stabilizing amount of a stabilizer having the formula: ##STR8## wherein A is a carbon or nitrogen; R.sup.1 and R.sup.2 are independently selected hydrogen or --X--R.sup.5 where X is zero, oxygen, sulfur, N.dbd.N, S--S, --R.sup.6 or N--R.sup.6 where R.sup.6 is hydrogen or alkyl of 1 to 6 carbon atoms, and R.sup.5 is phenyl or pyridyl with the proviso that both R.sup.1 and R.sup.2 cannot be hydrogen; and R.sup.3 and R.sup.4 are independently selected hydrogen, hydroxyl, or an alkali metal salt thereof; with the further proviso that said stabilizer must contain at least one nitrogen.
- 2. The process of claim 1 wherein said benzoin ether is present in said composition at a concentration of about 0.01 to about 30 percent by weight, and said stabilizer is present at a concentration of about 0.01 to about 30 percent by weight of said benzoin ether.
- 3. The process of claim 2 wherein said stabilizer has the formula: ##STR9## where A is carbon or nitrogen; X is zero or N.dbd.N and R.sup.5 is pyridyl.
- 4. The process of claim 3 wherein said stabilizer is 2,2'dipyridyl.
- 5. The process of claim 3 wherein said stabilizer is a pyridylazo resorcinol.
- 6. The process of claim 5 wherein said stabilizer is 4-(2 pyridylazo)-resorcinol sodium salt.
- 7. A photopolymerizable composition comprising at least one photopolymerizable ethylenically unsaturated compound containing a benzoin ether in an amount sufficient to initiate photopolymerization and a stabilizing amount of a stabilizer having the formula: ##STR10## wherein A is carbon or nitrogen; R.sup.1 and R.sup.2 are independently selected hydrogen or --X--R.sup.5 where X is zero, oxygen, nitrogen, N.dbd.N, S--S, --R.sup.6 or N--R.sup.6 where R.sup.6 is hydrogen or alkyl of 1 to 6 carbon atoms, and R.sup.5 is phenyl or pyridyl with the proviso that both R.sup.1 and R.sup.2 cannot be hydrogen; and R.sup.3 and R.sup.4 are independently selected hydrogen, hydroxyl, or an alkali metal salt thereof, with the proviso that said stabilizer must contain at least one nitrogen.
- 8. The composition of claim 7 wherein said benzoin ether is present in said composition at a concentration of about 0.01 to about 30 percent by weight, and said stabilizer is present at a concentration of about 0.01 to about 20 percent by weight of said benzoin ether.
- 9. The composition of claim 8 wherein said stabilizer has the formula: ##STR11## where A is carbon or nitrogen; X is zero or N.dbd.N and R.sup.5 is pyridyl.
- 10. The composition of claim 9 wherein said stabilizer is 2,2'dipyridyl.
- 11. The composition of claim 9 wherein said stabilizer is a pyridylazo resorcinol.
- 12. The composition of claim 11 wherein said stabilizer is 4-(2 pyridylazo)-resorcinol sodium salt.
Parent Case Info
This is a division of application Ser. No. 773,370 filed Mar. 1, 1977, now U.S. Pat. No. 4,141,807.
US Referenced Citations (5)
Divisions (1)
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Number |
Date |
Country |
Parent |
773370 |
Mar 1977 |
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