Patent ID: 9736926
Date: 2017-08-15
CPC Classifications: C08G,H05K,Y10T

Claim:
1. An epoxy resin which is obtained by polyglycidyl etherification of a reaction product formed from ortho-cresol, a β-naphthol compound, and formaldehyde and which comprises as a necessary component, a dimer (x2) represented by the following structural formula (1) in the formula, R 1 and R 2 each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, and G represents a glycidyl group); a trifunctional compound (x3) represented by the following structural formula (2) (in the formula, R 1 and R 2 each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, and G represents a glycidyl group); and a tetrafunctional compound (x4) represented by the following structural formula (3) (in the formula, R 1 and R 2 each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms, and G represents a glycidyl group) wherein the total content of those components is 65% or more in terms of the area rate in GPC measurement, and the content of the tetrafunctional compound (x4) is in a range of 10% to 40% in terms of the area rate in GPC measurement; and a value of the molecular weight distribution (Mw/Mn) is in a range of 1.00 to 1.50.