| 摘要 |
PURPOSE:To provide a powder coating compsn. which has a high crosslink density, has excellent adhesion, gives a cured coating film which hardly absorbs water, and is suitable for use in coating electrical and electronic components, containing an epoxy resin having a very high epoxy group content and a very low impurity content. CONSTITUTION:An epoxy resin having an epoxy group content of not lower than 90% expressed by the formula (wherein W is an epoxy equivalent in g/eq; A is an alpha-diol content in meq/100g; Cl is a hydrolyzable chlorine content in wt%; and P is a free phenol content in ppm) is prepd. by a two-step method comprising a polyaddition reaction between a low-molecular liquid resin and bisphenol A. The epoxy resin is blended with additives such as a curing agent (e.g., dicyandiamide), a curing accelerator (e.g., an imidazole catalyst), a filler, a pigment, etc., to obtain the desired powder coating compsn.
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