METHOD FOR PRODUCING MAIN AGENT IN TWO-LIQUID TYPE CURABLE RESIN COMPOSITION

To provide a method for producing a main agent, which is liquid at ordinary temperature, in a two-liquid type curable resin composition comprising a main agent and a curing agent, which affords a cured product having excellent heat resistance.SOLUTION: A main agent, which is liquid at ordinary temperature, is obtained by: heating and melt mixing 30.4 pts.mass of (4,4'-diphenylmethane)bismaleimide, which is solid at ordinary temperature, 100 pts.mass of 2,2'-bis(4-cyanatophenyl)propane, which is solid at ordinary temperature, and 16.8 pts.mass of a bisphenol E type cyanate compound, which is liquid at ordinary temperature, at 160°C for 2 hours; and cooling the mixture to ordinary temperature. This main agent, which is liquid at ordinary temperature, is uniform and liquid at ordinary temperature without any precipitation after one day immediately after production. When this main agent is kept refrigerated, warmed to room temperature after 1 month, and a viscosity thereof is measured, there is almost no viscosity increase and exhibited the same level of liquidity as before. By mixing this main agent and a curing agent comprising liquid benzoxazine, followed by heating, a cured product is obtained.SELECTED DRAWING: None 【課題】 耐熱性に優れた硬化物を与える、主剤と硬化剤とよりなる二液型硬化性樹脂組成物における常温液状の主剤の製造方法を提供する。【解決手段】 常温固形の４，４'－ジフェニルメタンビスマレイミド３０．４質量部、常温固形の２，２'－ビス（４－シアナトフェニル）プロパン１００質量部及び常温液状のビスフェノールＥ型シアネート化合物１６．８質量部を、１６０℃で２時間、加熱溶融混合する。常温に冷却して、常温液状の主剤を得る。この常温液状の主剤は、製造直後から１日経過後において沈澱もなく均一な常温液状のものである。この主剤を冷蔵保管して１か月後に、常温に戻し、粘度測定したところ殆ど増粘せず、当初と同様の液状を呈するものである。この主剤と液状ベンゾオキサジンよりなる硬化剤を混合し加熱して硬化物を得る。【選択図】 なし