Coated reinforcement and method for producing same
The invention relates to a coated reinforcement, to a method for producing the same and to the use thereof. In order to provide a coated reinforcement, in particular to be used for large surface area components, the coating of which can be applied easily and without difficultly substantially independently of the processing-relevant properties of the components of the resin mixture, it is proposed that the surface of the reinforcement has a coating made of a composition, the composition contains a mixture 1 of at least one resin, selected from the group consisting of epoxidized phenol novolacs, epoxidized cresol novolacs, polyepoxides based on bisphenol A, epoxidized fluorenone bisphenols and/or polyepoxides bases on bisphenol-F, and/or based on triglycidyl isocyanurates, epoxidized novolac and at least one component that accelerates the curing of the resin, and said mixture is subjected to a heat treatment, so that the mixture 1 is affixed to the surface of the reinforcement by fusing it thereon.
1. A method for producing a coated reinforcement whose surface has a coating of a heat-curable composition, comprising:
applying to a reinforcement a first mixture comprising at least one resin selected from the group consisting of epoxidized phenol novolaks, epoxidized cresol novolaks, polyepoxides on the basis of bisphenol A, epoxidized fluorenonebisphenols, polyepoxides on the basis of bisphenol F, epoxy resins on the basis of triglycidyl isocyanurates, epoxidized novolaks and combinations thereof, and at least one accelerating component for the curing of the resin;
subsequently subjecting the reinforcement coated with the first mixture to a heat treatment so that the first mixture is fixed on the surface of the reinforcement by melting;
thereafter applying a second mixture to the reinforcement coated with the fixed first mixture, wherein the second mixture comprises at least one resin selected from the group consisting of polyepoxides on the basis of bisphenol A or bisphenol F, or on advancement resins prepared therefrom, on the basis of tetraglycidylmethylenediamine, on the basis of epoxidized fluorenonebisphenols, epoxidized novolaks, polyepoxide esters on the basis of phthalic acid, hexahydrophthalic acid or terephthalic acid, epoxidized o- or p-aminophenols, epoxidized polyaddition products of dicyclopentadiene and phenol, and combinations thereof, and at least one anhydride curative or amine curative, to form an assembly, wherein the amine curative is selected from aliphatic polyamines, cycloaliphatic polyamines, aromatic polyamines, polyamides, Mannich bases, polyaminoimidazolines, polyetheramines, and mixtures thereof; and
curing the assembly with heat.
2. The method of claim 1 , wherein the accelerating component is selected from an imidazole, substituted imidazole, imidazole adducts, imidazole complexes, tertiary amines, quaternary ammonium or phosphonium compounds, tin(IV) chloride, dicyandiamide, salicylic acid, urea, urea derivatives, boron trifluoride complexes, boron trichloride complexes, epoxy addition reaction products, tetraphenylene-boron complexes, amine borates, amine titanates, metal acetylacetonates, naphthenic metal salts, octanoic metal salts, tin octoates, metal salts, metal chelates and combinations thereof.
3. The method of claim 1 wherein the curative in the second mixture comprises a dicarboxylic anhydride or a modified dicarboxylic anhydride.
4. The method of claim 3 wherein the dicarboxylic anhydride or the modified dicarboxylic anhydride is selected from the group consisting of tetrahydrophthalic anhydride (THPA), hexahydrophthalic anhydride (HHPA), methyltetrahydrophthalic anhydride (MTHPA), methylhexahydrophthalic anhydride (MHHPA), methylnadic anhydride (MNA), dodecenylsuccinic anhydride (DSA) or mixtures thereof.
5. The method of claim 1 wherein the first mixture or the second mixture is applied by an infusion technique to the reinforcement.
6. The method of claim 1 wherein the reinforcement is in the form of fibers, scrims, nonwovens, knits or wovens.
7. The method of claim 1 wherein the reinforcement comprises glass, ceramic, boron, carbon, basalt, synthetic polymers or natural polymers.
8. The method of claim 1 wherein the first mixture comprises, based on the mass of all of the components, 50% to 95% by weight of resin and 5% to 50% by weight of accelerating component.
9. The method of claim 1 wherein the second mixture comprises, based on the mass of all of the components, 30% to 70% by weight of resin and 30% to 70% by weight of anhydride curative or amine curative or mixtures thereof.
10. The method of claim 1 wherein the first mixture is applied from 1 mg to 10 mg per cm 2 of reinforcement.
11. The method of claim 1 wherein the second mixture is applied from 10 mg to 100 mg per cm 2 of reinforcement.
12. The method of claim 1 wherein the first mixture or the second mixture further includes an additive comprising graphite powders, siloxanes, pigments, metals or metal oxides, reactive diluents, processing assistants or UV protectants.