Prepreg for fiber reinforced plastic and production process thereof

Abstract

Provided are a prepreg for FRP (fiber reinforced plastic) which comprises a matrix resin composition containing a bifunctional isocyanate and/or a trifunctional isocyanate, a polyol and a bifunctional chain extender having two active hydrogen groups at a molar ratio, as a functional group, of isocyanate:polyol:chain extender=5.0 to 1.0:1.0:4.0 to 0, or containing a bifunctional isocyanate and/or a trifunctional isocyanate and a polyol at a molar ratio, as a functional group, of liquid isocyanate:polyol=0.9 to 1.1:1.0; and a fibrous material; and a production process of the prepreg. According to the present invention, the prepreg for FRP has a sufficient pot life and permits convenient production of an FRP molding.

What is claimed is:  
     
         1 . A prepreg for fiber reinforced plastic, which comprises a matrix resin composition containing a bifunctional isocyanate and/or a trifunctional isocyanate, a polyol and a bifunctional chain extender having two active hydrogen groups at a molar ratio, as a functional group, of isocyanate:polyol:chain extender=5.0 to 1.0:1.0:4.0 to 0; and a fibrous material.  
     
     
         2 . A prepreg for fiber reinforced plastic, which comprises a matrix resin composition containing a bifunctional isocyanate and/or a trifunctional isocyanate and a polyol at a molar ratio, as a functional group, of liquid isocyanate:polyol=0.9 to 1.1:1.0; and a fibrous material.  
     
     
         3 . A prepreg for fiber reinforced plastic according to  claim 2 , wherein the polyol has an average molecular weight of from 100 to 550.  
     
     
         4 . A prepreg for fiber reinforced plastic according to  claim 1 , wherein the polyol contains at least 50 wt. % of polypropylene glycol.  
     
     
         5 . A prepreg for fiber reinforced plastic according to  claim 2 , wherein the polyol contains at least 50 wt. % of polypropylene glycol.  
     
     
         6 . A prepreg for fiber reinforced plastic according to  claim 3 , wherein the polyol contains at least 50 wt. % of polypropylene glycol.  
     
     
         7 . A production process of a prepreg for fiber reinforced plastic, which comprises impregnating a fibrous material with a matrix resin composition containing a bifunctional isocyanate and/or a trifunctional isocyanate, a polyol and a bifunctional chain extender having two active hydrogen groups at a molar ratio, as a functional group, of isocyanate:polyol:chain extender=5.0 to 1.0:1.0:4.0 to 0.  
     
     
         8 . A production process of a prepreg for fiber reinforced plastic, which comprises impregnating a fibrous material with a matrix resin composition containing a bifunctional isocyanate and/or a trifunctional isocyanate and a polyol at a molar ratio, as a functional group, of liquid isocyanate:polyol=0.9 to 1.1:1.0; and a fibrous material.  
     
     
         9 . A production process according to  claim 8 , wherein the polyol has an average molecular weight of from 100 to 550.  
     
     
         10 . A production process according to  claim 7 , wherein the polyol contains at least 50 wt. % of polypropylene glycol.  
     
     
         11 . A production process according to  claim 8 , wherein the polyol contains at least 50 wt. % of polypropylene glycol.  
     
     
         12 . A production process according to  claim 9 , wherein the polyol contains at least 50 wt. % of polypropylene glycol.  
     
     
         13 . A production process according to  claim 7 , further comprising, after the impregnation with the matrix resin, semi-curing the thus impregnated resin.  
     
     
         14 . A production process according to  claim 8 , further comprising, after the impregnation with the matrix resin, semi-curing the thus impregnated resin  
     
     
         15 . A production process according to  claim 9 , further comprising, after the impregnation with the matrix resin, semi-curing the thus impregnated resin.  
     
     
         16 . A production process according to  claim 10 , further comprising, after the impregnation with the matrix resin, semi-curing the thus impregnated resin.  
     
     
         17 . A production process according to  claim 11 , further comprising, after the impregnation with the matrix resin, semi-curing the thus impregnated resin.  
     
     
         18 . A production process according to  claim 12 , further comprising, after the impregnation with the matrix resin, semi-curing the thus impregnated resin.  
     
     
         19 . A production process according to  claim 13 , wherein the semi-curing is performed by keeping the temperature of the matrix resin during curing at a temperature lower by at least 10° C. than the curing temperature thereof.  
     
     
         20 . A production process according to  claim 14 , wherein the semi-curing is performed by keeping the temperature of the matrix resin during curing at a temperature lower by at least 10° C. than the curing temperature thereof.  
     
     
         21 . A production process according to  claim 15 , wherein the semi-curing is performed by keeping the temperature of the matrix resin during curing at a temperature lower by at least 10° C. than the curing temperature thereof.  
     
     
         22 . A production process according to  claim 16 , wherein the semi-curing is performed by keeping the temperature of the matrix resin during curing at a temperature lower by at least 10° C. than the curing temperature thereof.  
     
     
         23 . A production process according to  claim 17 , wherein the semi-curing is performed by keeping the temperature of the matrix resin during curing at a temperature lower by at least 10° C. than the curing temperature thereof.  
     
     
         24 . A production process according to  claim 18 , wherein the semi-curing is performed by keeping the temperature of the matrix resin during curing at a temperature lower by at least 10° C. than the curing temperature thereof.  
     
     
         25 . A production process according to  claim 7 , which is performed under vacuum or reduced pressure.  
     
     
         26 . A production process according to  claim 8 , which is performed under vacuum or reduced pressure.  
     
     
         27 . A production process according to  claim 9 , which is performed under vacuum or reduced pressure.  
     
     
         28 . A production process according to  claim 10 , which is performed under vacuum or reduced pressure.  
     
     
         29 . A production process according to  claim 11 , which is performed under vacuum or reduced pressure.  
     
     
         30 . A production process according to  claim 12 , which is performed under vacuum or reduced pressure.  
     
     
         31 . A production process according to  claim 13 , which is performed under vacuum or reduced pressure.  
     
     
         32 . A production process according to  claim 14 , which is performed under vacuum or reduced pressure.  
     
     
         33 . A production process according to  claim 15 , which is performed under vacuum or reduced pressure.  
     
     
         34 . A production process according to  claim 16 , which is performed under vacuum or reduced pressure.  
     
     
         35 . A production process according to  claim 17 , which is performed under vacuum or reduced pressure.  
     
     
         36 . A production process according to  claim 18 , which is performed under vacuum or reduced pressure.  
     
     
         37 . A production process according to  claim 19 , which is performed under vacuum or reduced pressure.  
     
     
         38 . A production process according to  claim 20 , which is performed under vacuum or reduced pressure.  
     
     
         39 . A production process according to  claim 21 , which is performed under vacuum or reduced pressure.  
     
     
         40 . A production process according to  claim 22 , which is performed under vacuum or reduced pressure.  
     
     
         41 . A production process according to  claim 23 , which is performed under vacuum or reduced pressure.  
     
     
         42 . A production process according to  claim 24 , which is performed under vacuum or reduced pressure.  
     
     
         43 . Fiber reinforced plastic obtained by curing a prepreg for fiber reinforced plastic as claimed in  claim 1 .  
     
     
         44 . Fiber reinforced plastic obtained by curing a prepreg for fiber reinforced plastic as claimed in  claim 2 .  
     
     
         45 . Fiber reinforced plastic obtained by curing a prepreg for fiber reinforced plastic as claimed in  claim 3 .  
     
     
         46 . Fiber reinforced plastic obtained by curing a prepreg for fiber reinforced plastic as claimed in  claim 4 .  
     
     
         47 . Fiber reinforced plastic obtained by curing a prepreg for fiber reinforced plastic as claimed in  claim 5 .  
     
     
         48 . Fiber reinforced plastic obtained by curing a prepreg for fiber reinforced plastic as claimed in  claim 6.