| 摘要 |
PURPOSE:To obtain the titled composition which gives a film having excellent heat resistance and electrical and mechanical characteristics, by neutralizing a mixture of specified amic acid prepolymers, and dispersing it in water. CONSTITUTION:An amic acid prepolymer (A) is obtained by reacting at -30-70 deg.C for 1-10hr 1mol of a carboxylic acid anhydride containing an unsatu rated double bond (e.g., phthalic anhydride) with 1 equivalent of an amino group of an epoxy resin modified with ammonia obtained by the addition reaction at 20-100 deg.C for 1hr - 10 days of ammonia with an epoxy resin in an amount of at least 5mol of ammonia per equivalent of the epoxy group. An amic acid prepolymer (B) is obtained by the addition reaction at 100-130 deg.C for 1-3hr of 1 equivalent of the maleimide group of a bismaleimide compound of the formula (wherein R is a direct board or a divalent linkage) with at least 1 equivalent of the amino group of an aromatic polyamide (e.g., m-pheny lenediamine), and reacting 1 equivalent of an unreacted amino group with 1mol of a carboxylic acid anhydride containing an unsaturated double bond. 30-80% mixture comprising 80-30% component A and 20-70% component B is dis solved in a solvent, neutralized by adding a neutralizing agent, and then dis persed in water.
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