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

Abstract

An FRP is produced using a prepreg comprising reinforcing fiber, a sheet-like reinforcing fiber substrate containing reinforcing fiber, and a matrix resin, wherein the matrix resin is impregnated into the sheet-like reinforcing fiber substrate and also covers one surface of the sheet-like reinforcing fiber substrate, and the matrix resin impregnation ratio is within a range of 35% to 95%; a prepreg comprising reinforcing fiber, a sheet-like reinforcing fiber substrate containing reinforcing fiber, and a matrix resin, wherein the matrix resin exists on both surfaces of the sheet-like reinforcing fiber substrate, and the portion inside the sheet-like reinforcing fiber substrate into which the matrix resin has not been impregnated is continuous; or a prepreg comprising reinforcing fiber, a sheet-like reinforcing fiber substrate containing reinforcing fiber, and a matrix resin, wherein at least one surface exhibits a sea-and-island-type pattern comprising resin-impregnated portions (island portions) where the matrix resin is present at the surface and fiber portions (sea portions) where the matrix resin is not present at the surface, the surface coverage ratio of the matrix resin on those surfaces with said a sea-and-island-type pattern is within a range of 3% to 80%, and the weave intersection coverage ratio for the island portions, represented by a formula (1) shown below, is at least 40%, displays excellent external appearance, with no internal voids or surface pinholes, even when molded is conducted using only vacuum pressure. Island portions weave intersection coverage ratio (%)=( T/Y )×100  (1) (wherein, T represents a number of island portions that cover weave intersections, and Y represents a number of weave intersections within said reinforcing fiber woven fabric on said surface with said sea-and-island-type pattern).

1 . A prepreg, comprising:
 reinforcing fiber,   a reinforcing fiber substrate in the form of a sheet and containing said reinforcing fiber, and   a matrix resin,   wherein said matrix resin is impregnated into said reinforcing fiber substrate and also covers one surface of said reinforcing fiber substrate, and   wherein a matrix resin impregnation ratio is within a range of 35% to 95%.   
     
     
         2 . (canceled) 
     
     
         3 . A prepreg, comprising:
 a reinforcing fiber substrate in the form of a sheet and formed from a reinforcing fiber woven fabric, and   a matrix resin,   wherein at least one surface of said reinforcing fiber substrate displays a sea-and-island-type pattern comprising
 resin-impregnated portions (island portions) wherein said matrix resin is present at said surface, and 
 fiber portions (sea portions) wherein said matrix resin is not present at said surface, 
   wherein a surface coverage ratio of said matrix resin on surfaces with said sea-and-island-type pattern is within a range of 3% to 80%, and   wherein a weave intersection coverage ratio for said island portions, represented by a formula (1) is at least 40%:
   island portions weave intersection coverage ratio (%)=( T/Y )×100  (1)
 
   wherein, T represents a number of island portions that cover weave intersections, and Y represents a number of weave intersections within said reinforcing fiber woven fabric on said surface with said sea-and-island-type pattern.   
     
     
         4 - 17 . (canceled) 
     
     
         18 . An intermediate material for FRP molding, comprising:
 a prepreg containing reinforcing fibers and a matrix resin, and   a substrate containing essentially no impregnated thermosetting resin composition, wherein said substrate is provided on at least one side surface of said prepreg,   wherein a ratio (B)/(A) between a thickness (A) of said prepreg and a thickness (B) of said substrate is within a range of 0.1 to 2.5.   
     
     
         19 . The intermediate material for FRP molding according to  claim 18 , wherein said matrix resin is a thermosetting resin composition. 
     
     
         20 . The intermediate material for FRP molding according to  claim 18 , wherein said substrate containing essentially no impregnated thermosetting resin composition contains a fibrous thermoplastic resin. 
     
     
         21 . The intermediate material for FRP molding according to  claim 18 , wherein said substrate containing essentially no impregnated thermosetting resin composition is a non-woven cloth of a thermoplastic resin. 
     
     
         22 . The intermediate material for FRP molding according to  claim 18 , wherein said substrate containing essentially no impregnated thermosetting resin composition contains reinforcing fibers. 
     
     
         23 . The intermediate material for FRP molding according to  claim 22 , wherein said reinforcing fibers are identical to said reinforcing fibers incorporated within said prepreg. 
     
     
         24 . The intermediate material for FRP molding according to  claim 22 , wherein said reinforcing fibers are positioned at a different angle to said reinforcing fibers incorporated within said prepreg. 
     
     
         25 . The intermediate material for FRP molding according to  claim 22 , wherein said reinforcing fibers are different from said reinforcing fibers incorporated within said prepreg. 
     
     
         26 . The intermediate material for FRP molding according to  claim 18 , wherein said matrix resin is one of an epoxy resin composition and a phenol resin composition. 
     
     
         27 . The intermediate material for FRP molding according to  claim 18 , wherein said reinforcing fibers incorporated within said prepreg are carbon fiber and/or glass fiber. 
     
     
         28 . A process for producing an intermediate material for FRP molding, comprising:
 preparing a prepreg using a lacquer-type process, and   bonding a substrate containing essentially no impregnated thermosetting resin composition to at least one surface of said prepreg.   
     
     
         29 - 36 . (canceled)