Process for preparing high purity (meth) acryloyloxyalkyl isocyanate
View Patent ↗A process for preparing a high purity (meth)acryloyloxyalkyl isocyanate having a very small hydrolyzable chlorine content is provided. The high purity (meth)acryloyloxyalkyl isocyanate is prepared by subjecting a hydrolyzable chlorine containing (meth)acryloyloxyalkyl isocyanate to mixing treatment with an epoxy compound and an amine at a temperature of from 110 to 160° C. to prepare a mixture; and preparing a high purity (meth)acryloyloxyalkyl isocyanate from the resulting mixture with distillation. In particular, it is possible to effectively prevent (meth)acryloyloxyalkyl isocyanate from polymerization during the distillation by adding a polymerization inhibitor such as phenothiazine and the like.
1. A process for preparing a (meth)acryloyloxyalkyl isocyanate which process comprises:
subjecting a hydrolyzable chlorine containing (meth)acryloyloxyalkyl isocyanate to mixing treatment with an epoxy compound and at least one of an amine and an imidazole at a temperature of from 110 to 160° C. to prepare a mixture; and
preparing a (meth)acryloyloxyalkyl isocyanate from the resulting mixture wherein the mixing treatment is carried out by adding a polymenrization inhibitor.
2. The process for preparing a (meth)acryloyloxyalkyl isocyanate according to claim 1 which process further comprises distilling the resulting mixture to isolate a (meth)acryloyloxyalkyl isocyanate, after the mixing treatment.
3. The process for preparing a (meth)acryloyloxyalkyl isocyanate according to claim 1 which process further comprises carrying out distillation with adding a polymerization inhibitor after the mixing treatment.
4. The process for preparing a (meth)acryloyloxyalkyl isocyanate according to claim 1 wherein the polymerization inhibitor is phenothiazine.
5. The process for preparing a (meth)acryloyloxyalkyl isocyanate according to claim 4 wherein the mixing treatment is carried out with adding phenothiazine in an amount of from 0.1 to 20% by mass based on the raw material (meth)acryloyloxyalkyl isocyanate and then the distillation is carried out with adding phenothiazine in an amount of from 3 to 30% by mass based on the raw material (meth)acryloyloxyalkyl isocyanate.
6. The process for preparing a (meth)acryloyloxyalkyl isocyanate according to claim 4 wherein the total amount of phenothiazine added is from 5 to 50% by mass based on the raw material (meth)acryloyloxyalkyl isocyanate.
7. The process for preparing a (meth)acryloyloxyalkyl isocyanate according to claim 2 wherein the distillation is carried out at a temperature of not higher than 120° C.
8. The process for preparing a (meth)acryloyloxyalkyl isocyanate according to claim 1 or 2 wherein the at least one of an amine and an imidazole is at least one selected from 2-alkyl-4-alkyl imidazole (provided that each alkyl group independently has a carbon number of 1 to 3), trialkyl amine (provided that each alkyl group independently has a carbon number of 4 to 15) and a compound represented by the following formula [A]:
H 2 N—(CH 2 CH 2 NH) n —H [A]
wherein n is an integer of 2 or more.
9. The process for preparing a (meth)acryloyloxyalkyl isocyanate according to claim 8 wherein the at least one of an amine and an imidazole is 2-ethyl-4-methylimidazole.
10. The process for preparing a (meth)acryloyloxyalkyl isocyanate according to claim 1 or 2 wherein the (meth)acryloyloxyalkyl isocyanate is (meth)acryoyloxyethyl isocyanate.