Fluorene Photoinitiator, Preparation Method Therefor, Photocurable Composition Having Same, and Use of Same in Photocuring Field

A fluorene-based photoinitiator, wherein said fluorene-based photoinitiator has a structure represented by Formula I:

• or said fluorene-based photoinitiator comprises a structure represented by Formula II:
• wherein in said Formula I,
• the R1 and the R1′ are each independently selected from hydrogen, a halogen, a C1-C20 linear alkyl group, a C1-C20 branched alkyl group, a C3-C8 cycloalkyl group, a C2-C20 alkenyl group, or a C1-C10 alkyl group substituted with a C3-C8 cycloalkyl group;
• the R2 and the R3 are each independently selected from a C1-C20 linear alkyl group, a C1-C20 branched alkyl group, a C3-C8 cycloalkyl group, a C1-C10 alkyl group substituted with a C3-C8 cycloalkyl group, or a C6-C20 aryl group;
• or the R2 and the R3 are connected to form a C3-C8 cycloalkyl group;
• the X is -A-(X′)n, wherein A is selected from a heteroatom which is selected from O, N, or S, X′ is selected from a C1-C20 linear alkyl group, a C1-C20 branched alkyl group, a C3-C8 cycloalkyl group, a C1-C10 alkyl group substituted with a C3-C8 cycloalkyl group, or one or more of carbon atoms in the X′ are substituted with the heteroatom, and n is 1 or 2;
• and
• the R4 is a hydroxy group or a N-morpholinyl group;
• or
• in Formula II,
• the R5 and the R6 are each independently selected from one of a hydrogen atom, a halogen, and a chain group, wherein the chain group is a C1-C20 linear alkyl group, a C1-C20 branched alkyl group, a C1-C20 cycloalkyl group, a C4-C20 cycloalkylalkyl group, a C4-C20 alkylcycloalkyl group, and a C2-C20 alkenyl group, or the R5 and R6 form a ring by using one or two of the chain groups, and —CH2— in the chain groups can be substituted with —O—, —C(═O)O—, a halogen, or a phenyl group;
• Ar is a substituent containing an aromatic ring or a heteroaromatic ring;
• and R7 connected to a linkage of the group represented by Formula II, wherein the R7 is a hydrogen atom, a —C(═O) R7′ group, or a —C(═O)C(═O)O—R7′ group, wherein the R7′ represents a C1-C40 linear alkyl group, a C1-C40 branched alkyl group, a C1-C20 cycloalkyl group, a C1-C40 alkenyl group, or a substituent containing an aromatic ring or a heteroaromatic ring, which are substituted or unsubstituted, or the R7 is a —C(═O)C(═O)O—R7′ group, wherein the R7′ group is a group connected by a transesterfication reaction of an alcohol or polyol.