PURPOSE: The titled composition excellent in adhesion, soldering heat resistance, flame retardancy and electrical properties and useful for permanent protective films for flexible printed wiring boards, prepared by mixing a photocurable prepolymer with a specified photopolymerizable compound and a photoinitiator.
CONSTITUTION: To a mixture of 90W10wt% photopolymerizable prepolymer (e.g., bisphenol A epoxy acrylate) and 10W90wt% photopolymerizable compound having at least one photopolymerizable double bond (e.g., 2-hydroxyethyl methacrylate) containing 10W80wt% bornyl acrylate compound (e.g., isobornyl methacrylate), 0.05W20wt% photoinitiator (e.g., 2-ethylanthraquinone) and, optionally, 10W60wt% extender pigment (e.g., talc), an inorganic filler, a thixotropic agent, a levelling agent, a defoamer, etc., are added, and the obtained mixture is kneaded.
ABE SHUNZO
MIYAKE HIDEO
| JPS51140932A | 1976-12-04 | |||
| JPS5493096A | 1979-07-23 |