Epoxy resin, preparing method thereof, epoxy composition comprising the same, and use thereof

An epoxy resin having a controlled molecular weight distribution, comprising:

• (1) one of a first structural unit selected from a group consisting of formulas (AF), (BF), (CF) and (DF);
• and
• (2) one of a second structural unit selected from a group consisting of formulas (1F), (2F), (3F), (4F) and (5F),
• wherein the first structural unit and the second structural unit are connected to each other via formula (L), and
• wherein epoxy equivalent weight (EEW, Epoxy Equivalent Weight) determined by the glycidyl group of formula (E) is 200 g/Eq to 1,000 g/Eq, and a distribution range of molecular weight is 300 to 2,000,000:
• where, in formula (BF), S is
• in formula (DF), t is
• in formulas (AF) to (DF), n is an integer from 1 to 100,
• the epoxy resin has or does not have at least one of formulas (S1) and (S2),
• when the epoxy resin has at least one of formulas (S1) and (S2), at least one of a plurality of M is connected by a single bond to ** in formula (L), a part of the remainder of M is a glycidyl group of formula (E) such that an epoxy equivalent weight (EEW) of an epoxy resin is 200 g/Eq to 1,000 g/Eq, and the remainder of M is at least one selected from a group consisting of formula (S1) and (S2),
• when the epoxy resin does not have at least one of formulas (S1) and (S2), at least one of a plurality of M is connected by a single bond to ** in formula (L), and the remainder of M is a glycidyl group of following formula (E) such that an epoxy equivalent weight (EEW) of an epoxy resin is 200 g/Eq to 1,000 g/Eq,
• where, in formula (L), R is H or —C (═O) —NH— (CH2) 3—SiR1R2R3, where at least one of R1 to R3 is a C1-C5 alkoxy group, and the remainder is a C1-C10 alkyl group, and
• ** is a connection by a single bond to M in formulas (AF), (BF), (CF) or (DF), and * is a connection by a single bond to * in formulas (1F), (2F), (3F), (4F) or (5F),
• where, in formula (1F), X is —CH2—, —C(CH3)2—, —C(CF3)2—, —S— or —SO2—, and in formula (3F), each Y is independently selected from H and a methyl group, each * in formulas (1F) to (5F) is a connection by a single bond to * in formula (L),
• where, in formulas (S1) and (S2), R is hydrogen or —C (═O) —NH— (CH2)3—SiR1R2R3, where at least one of R1 to R3 is a C1-C5 alkoxy group, and remainder is a C1-C10 alkyl group, each G is independently selected from a group consisting of a C1 to C10 alkyl group, an allyl group, and a C6 or C10 aryl group, and each n′ is independently an integer of 0 to 5.