Epoxy resin, epoxy resin composition, epoxy resin cured product and method of producing epoxy resin cured product, composite material, insulating member, electronic appliance, structural material, and vehicle

1. An epoxy resin, which is configured to form, in a cured product of the epoxy resin, a phase-separated structure that is formed from at least two phases, wherein at least one phase of the at least two phases includes a liquid crystal structure, the epoxy resin comprising:

a liquid crystal epoxy compound A and a multimer thereof, and

an epoxy compound B, the epoxy compound B having a different structure from a structure of the liquid crystal epoxy compound A,

wherein the epoxy compound B is an epoxy compound that forms a different liquid crystal structure from a liquid crystal structure formed by the liquid crystal compound A or is an epoxy compound that does not form a liquid crystal structure, and

wherein the epoxy compound B comprises a biphenyl epoxy compound or a bisphenol epoxy compound.

2. The epoxy resin according to claim 1 , wherein the at least one phase includes a smectic structure or a nematic structure as the liquid crystal structure.

3. The epoxy resin according to claim 1 , wherein the liquid crystal epoxy compound A has a mesogenic structure.

4. The epoxy resin according to claim 1 , wherein the liquid crystal epoxy compound A is represented by the following Formula (A):

wherein, in Formula (A), X represents a linking group that includes at least one selected from the group consisting of divalent groups in the following Group (I), each Y independently represents an aliphatic hydrocarbon group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a nitro group or an acetyl group, and each n independently represents an integer from 0 to 4:

wherein, in Group (I), each Y independently represents an aliphatic hydrocarbon group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a nitro group or an acetyl group, each n independently represents an integer from 0 to 4, k represents an integer from 0 to 7, m represents an integer from 0 to 8, and 1 represents an integer from 0 to 12.

5. The epoxy resin according to claim 1 , wherein the liquid crystal epoxy compound A is represented by the following Formula (M):

wherein, in Formula (M), each of R 1 to R 4 independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.

6. An epoxy resin composition, comprising the epoxy resin according to claim 1 , and a curing agent.

7. An epoxy resin, which is configured to form, in a cured product of the epoxy resin, a phase-separated structure that is formed from at least two phases, wherein at least one phase of the at least two phases includes a liquid crystal structure, the epoxy resin comprising:

a liquid crystal epoxy compound A and a multimer thereof, and

an epoxy compound B, the epoxy compound B having a different structure from a structure of the liquid crystal epoxy compound A,

wherein the epoxy compound B is an epoxy compound that forms a different liquid crystal structure from a liquid crystal structure formed by the liquid crystal compound A or is an epoxy compound that does not form a liquid crystal structure, and

wherein the at least one phase includes a smectic structure as the liquid crystal structure, and at least one other phase of the at least two phases includes a nematic structure as the liquid crystal structure.