Prepregs and moldings produced therefrom

Abstract

The invention relates to prepregs and composite components produced therefrom (mouldings), obtainable by the use of powdery reactive polyurethane compositions.

1 - 16 . (canceled) 
     
     
         17 . A prepreg, comprising:
 (A) at least one fibrous support,   and, as a matrix material,   (B) at least one reactive powdery polyurethane composition comprising (1) at least one di- or polyisocyanate and (2) at least one hydroxyl group containing polymer,   wherein the di- or polyisocyanate is internally blocked and/or blocked with a blocking agent,   wherein the hydroxyl group containing polymer is selected from the group consisting of a polyacrylate, a polyester, a polyether, a polycarbonate, a polyurethane and mixtures thereof and has (a) one or more functional groups reactive towards an isocyanate group, (b) an OH number of 20-500 mg KOH/g and (c) an average molecular weight of 250-6,000 g/mol, and   wherein the reactive powdery polyurethane composition has a glass transition temperature (Tg) of at least 40° C. and a curing temperature above 160° C.   
     
     
         18 . The prepreg according to  claim 17 , wherein the fibrous support is a fibrous material of glass, carbon, plastic, a natural fiber, a mineral fiber or a ceramic fiber. 
     
     
         19 . The prepreg according to  claim 17 , wherein the fibrous support is a planar textile body of non-woven material, a knitted good, or a non-knitted skein. 
     
     
         20 . The prepreg according to  claim 17 , wherein the di- or polyisocyanate is selected from the group consisting isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), diisocyanatodicyclohexylmethane (H 12 MDI), 2-methylpentane diisocyanate (MPDI), 2,2,4-trimethylhexamethylene diisocyanate/2,4,4-trimethyl-hexamethylene diisocyanate (TMDI), norbornane diisocyanate (NBDI), isocyanurates thereof and mixtures thereof. 
     
     
         21 . The prepreg according to  claim 17 , wherein the di- or polyisocyanate is internally blocked. 
     
     
         22 . The prepreg according to  claim 17 , wherein the isocyanate is blocked with an external blocking agent selected from the group consisting of ethyl acetoacetate, diisopropylamine, methyl ethyl ketoxime, diethyl malonate, ε-caprolactam, 1,2,4-triazole, phenol or substituted phenols and 3,5-dimethylpyrazole. 
     
     
         23 . The prepreg according to  claim 17 , wherein the isocyanate is an IPDI adduct, comprising an isocyanurate grouping and an c-caprolactam blocked isocyanate structure. 
     
     
         24 . The prepreg according to  claim 17 , wherein the hydroxyl group containing polymer is a polyacrylate. 
     
     
         25 . The prepreg according to  claim 17 , wherein the hydroxyl group containing polymer is a polyester. 
     
     
         26 . The prepreg according to  claim 17 , wherein the hydroxyl group containing polymer is a polyether. 
     
     
         27 . The prepreg according to  claim 17 , wherein the hydroxyl group containing polymer is a polycarbonate. 
     
     
         28 . The prepreg according to  claim 17 , wherein the hydroxyl group containing polymer is a polyurethane. 
     
     
         29 . A process for producing a prepreg according to  claim 17 , comprising applying component B) to component A), and optionally fixing B). 
     
     
         30 . A process for producing a composite comprising compressing the prepreg according to  claim 17  at a temperature above 160° C.