| 摘要 |
PROBLEM TO BE SOLVED: To provide a production method of an epoxy resin composition giving a cured product excellent in fire retardancy, moisture resistance, low elasticity and the like and being suitable for application to encapsulation of electronic parts, circuit board materials and the like.SOLUTION: In a production method of an epoxy resin composition comprising an epoxy resin and a curing agent, a polyvalent hydroxy resin represented by the general formula (1) is an essential component as some or all of the curing agent. The polyvalent hydroxy resin is obtained by addition reaction of 0.1 to 1.0 mole of a styrene relative to 1 mole of the hydroxy group of a polyvalent hydroxy compound in the presence of 10 to 400 wtppm of an acid catalyst at a reaction temperature of 40 to 120°C to substitute the benzene ring of the polyvalent hydroxy compound with the styrene. A monovalent hydroxy compound generated from side reaction in this addition reaction has an area% of 3% or less when detected with gel permeation chromatography (GPC; RI). |
