Acylphosphine Oxide Photoinitiators and Applications Thereof

An acyl phosphine oxide initiator including an acyl group selected from the group consisting of a benzoyl group substituted by an urea group or an oxalylamide group;

• a 2,6-dimethyl benzoyl group substituted in position 3 by an urea group or an oxalylamide group;
• a 2,6-dimethoxy benzoyl group substituted in position 3 by an urea group or an oxalylamide group;
• a 2,4,6-trimethyl benzoyl group substituted in position 3 by an urea group or an oxalylamide group;
• and a 2,4,6-trimethoxybenzoyl group substituted in position 3 by an urea group or an oxalylamide group,
• wherein the urea group and the oxalylamide group include a tertiary amine group positioning a phosphorus atom of the acylphosphine oxide initiator in a 1 to Z position, where position 1 is defined as that of the phosphorus atom and position Z is defined as the nitrogen atom of the tertiary amine group with Z representing an integer of at least 11, and
• wherein the acyl phosphine oxide initiator contains no more than two photoinitiating moieties having a phosphine oxide group.

A method of preparing an acyl phosphine oxide initiator according to the synthesis scheme:

• wherein
• R4, R5, and R6 are independently selected from the group consisting of hydrogen, a methyl group, and a methoxy group;
• R8 is selected from the group consisting of a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, and OR12;
• R9 is selected from the group consisting of a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, and an acyl group;
• R10 and R14 each independently represent a substituted or unsubstituted alkyl group;
• R12 is selected from the group consisting of hydrogen, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted alkaryl group and a substituted or unsubstituted aryl or heteroaryl group;
• and
• L1 is a substituted or unsubstituted C2 to C6 alkylene group.

A method of preparing an acyl phosphine oxide initiator including the steps:

• wherein
• R4, R5, and R6 are independently selected from the group consisting of hydrogen, a methyl group, and a methoxy group;
• R8 is selected from the group consisting of a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, and OR12;
• R9 is selected from the group consisting of a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, and an acyl group;
• R10 is a substituted or unsubstituted alkyl group;
• R11 is selected from the group consisting of a hydrogen and a methyl group;
• Y is selected from the group consisting of an oxygen and NR13;
• R12 and R13 are each independently selected from the group consisting of hydrogen, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted alkaryl group, and a substituted or unsubstituted aryl or heteroaryl group;
• L1 is a substituted or unsubstituted C2 to C6 alkylene group;
• L2 is a divalent linking group comprising no more than 10 carbon atoms;
• n is an integer 1 or 2;
• m is an integer from 0 to 3;
• and
• M is hydrogen if m=0;
• a covalent bond if n=m=1 or an n+m-valent moiety if n>1 and m>0.

A method of preparing an acyl phosphine oxide initiator according to the synthesis scheme:

• wherein R1 is OEt or phenyl;
• R2 is a C1 to C8 alkyl group;
• and L is a divalent linking group having no more than 20 carbon atoms being not further functionalized with acrylates;
• and wherein the difunctional acrylate Acr is selected from the compounds Acr-1 to Acr-15:
• Acr-1
• Acr-2
• Acr-3
• Acr-4
• Acr-5
• n = 4 on average
• Acr-6
• Acr-7
• Acr-8
• Acr-9
• Acr-10
• Acr-11
• Acr-12
• Acr-13
• Acr-14
• Acr-15

A method for preparing an acyl phosphine oxide initiator including no more than two photoinitiating moieties having a phosphine oxide group and an acyl group selected from the group consisting of a benzoyl group substituted by an urea group or an oxalylamide group;

• a 2,6-dimethyl benzoyl group substituted in position 3 by an urea group or an oxalylamide group;
• a 2,6-dimethoxy benzoyl group substituted in position 3 by an urea group or an oxalylamide group;
• a 2,4,6-trimethyl benzoyl group substituted in position 3 by an urea group or an oxalylamide group;
• and a 2,4,6-trimethoxybenzoyl group substituted in position 3 by an urea group or an oxalylamide group,
• wherein the urea group and the oxalylamide group include a tertiary amine group positioning a phosphorus atom of the acylphosphine oxide initiator in a 1 to Z position, where position 1 is defined as that of the phosphorus atom and position Z is defined as the nitrogen atom of the tertiary amine group with Z representing an integer selected from 11 to 16,
• using an intermediate represented by Formula IV:
• wherein
• R4, R5, and R6 are independently selected from the group consisting of hydrogen, a methyl group, and a methoxy group;
• R8 is selected from the group consisting of a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, and OR12;
• R9 is selected from the group consisting of a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, and an acyl group;
• R10 is a substituted or unsubstituted alkyl group;
• R12 is selected from the group consisting of hydrogen, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted alkaryl group, and a substituted or unsubstituted aryl or heteroaryl group;
• and
• L1 is a substituted or unsubstituted C2 to C6 alkylene group.