Prepreg, intermediate material for forming frp, and method for production thereof and method for production of fiber-reinforced composite material

Abstract

This invention relates to a prepreg containing a reinforcing fiber, a reinforcing fiber substrate in the form of a sheet and containing the reinforcing fiber, and a matrix resin, such that the matrix resin is impregnated into the reinforcing fiber substrate and also covers one surface of the reinforcing fiber substrate, and an impregnation ratio of the matrix resin is within a range of 35% to 95%.

1 - 36 . (canceled) 
     
     
         37 . A prepreg, comprising:
 reinforcing fiber;   a reinforcing fiber substrate in the form of a sheet and comprising the reinforcing fiber; and   a matrix resin,   wherein:   the matrix resin is impregnated into the reinforcing fiber substrate and also covers one surface of the reinforcing fiber substrate; and   a matrix resin impregnation ratio is within a range of 35% to 95%.   
     
     
         38 . The prepreg according to  claim 37 , wherein the matrix resin is a thermosetting resin composition. 
     
     
         39 . The prepreg according to  claim 38 , wherein the thermosetting resin composition is curable by holding at 90° C. for 2 hours. 
     
     
         40 . The prepreg according to  claim 38 , wherein a minimum viscosity of the thermosetting resin composition is no more than 1000 poise. 
     
     
         41 . The prepreg according to  claim 38 , wherein the thermosetting resin composition comprises epoxy resin as a primary component. 
     
     
         42 . The prepreg according to  claim 41 , wherein the thermosetting resin composition further comprises a thermoplastic resin, and the thermoplastic resin is not dissolved within the thermosetting resin composition. 
     
     
         43 . The prepreg according to  claim 42 , wherein the thermoplastic resin comprises short fibers of thermoplastic resin with a length of 1 to 50 mm. 
     
     
         44 . The prepreg according to  claim 43 , wherein the short fibers of thermoplastic resin have a size of no more than 300 tex. 
     
     
         45 . The prepreg according to  claim 37 , wherein the reinforcing fibers are carbon fiber, glass fiber, or both. 
     
     
         46 . The prepreg according to  claim 37 , wherein the reinforcing fiber substrate has a fiber weight within a range of 200 g/m 2  to 1500 g/m 2 . 
     
     
         47 . The prepreg according to  claim 37 , wherein the reinforcing fiber substrate is in a form selected from the group consisting of a unidirectional material, a woven fabric, a knit fabric, a braided fabric, a mat material, a nonwoven fabric, and a stitched sheet. 
     
     
         48 . The prepreg according to  claim 37 , wherein the reinforcing fiber substrate has a thickness of at least 200 μm.