Patent ID: 7695588

Claim:
A thermosetting matrix resin composition for fiber reinforced plastic, comprising: resin matrix components consisting essentially of carbodiimide modified 4,4′-diphenylmethane diisocyanate; bifunctional polyol comprising polypropylene glycol in an amount of 50 wt.% or greater; and a bifunctional chain extender containing an active hydrogen group; wherein each of the carbodiimide modified 4,4′-diphenylmethane diisocyanate, bifunctional polyol and bifunctional chain extender is a liquid at normal temperature; upon mixing of the carbodiimide modified 4,4′-diphenylmethane diisocyanate with the bifunctional polyol and bifunctional chain extender at 25° C. in a scale of 200g, a solution viscosity remains unchanged for at least 30 minutes; a molar ratio of the functional groups of the carbodiimide modified 4,4′-diphenylmethane diisocyanate, polyol and chain extender is 5.0 to 1.0: 1.0 : 4.0 to greater than 0, respectively; and the thermosetting matrix resin composition has a Tg of from 50 to 70° C.