Prepregs based on a storage-stable reactive or highly reactive polyurethane composition

Abstract

The invention relates to prepregs coloured with pigment or dye preparations and based on a storage-stable reactive or highly reactive polyurethane composition.

1 . A prepreg, comprising:
 A) a fibrous support   and   B) a matrix material of at least one reactive polyurethane composition,   wherein   the reactive polyurethane composition comprises a mixture of a binder, which comprises a polymer b) comprising functional groups reactive towards isocyanates and a curing agent a), which comprises a di- or polyisocyanate internally blocked, externally blocked with an external blocking agent, or both internally and externally blocked, and   the matrix material further comprises   a pigment having a particle diameter of <150 nm,   a dye, or   both the pigment and the dye.   
     
     
         2 . The prepreg according to  claim 1 ,
 wherein the matrix material B) has a Tg of at least 40° C.   
     
     
         3 . The prepreg according to  claim 1 ,
 wherein   prepreg has a fibre content by volume of greater than 50%.   
     
     
         4 . The prepreg according to  claim 1 ,
 wherein   pigment comprises a natural inorganic pigment, a synthetic inorganic pigment, or a mixture of natural and synthetic inorganic pigments.   
     
     
         5 . The prepreg according to  claim 1 ,
 wherein   the dye is selected from the group consisting of a reactive dye, a disperse dye, a pigment dye, an acid dye, a developing dye, a cationic or basic dye, a coupling dye, a mordant dye, a vat dye, a metal complex dye, and a substantive dye.   
     
     
         6 . The prepreg according to  claim 1 ,
 wherein   the polymer b) comprises a hydroxyl group, an amino group, or a thiol group.   
     
     
         7 . The prepreg according to  claim 1 ,
 wherein   the di- or polyisocyanate is selected from the group consisting of isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), diisocyanatodicyclohexylmethane (H12MDI), 2-methylpentane diisocyanate (MPDI), 2,2,4-trimethylhexamethylene diisocyanate/2,4,4-trimethyl-hexamethylene diisocyanate (TMDI), and norbornane diisocyanate (NBDI).   
     
     
         8 . The prepreg according to  claim 1 ,
 wherein   the external blocking agent is selected from the group consisting of ethyl acetoacetate, diisopropylamine, methyl ethyl ketoxime, diethyl malonate, ε-caprolactam, 1,2,4-triazole, phenol, a substituted phenol, and 3,5-dimethylpyrazole.   
     
     
         9 . The prepreg according to  claim 1 ,
 wherein   the curing agent a) comprises an IPDI adduct, an isocyanurate group, or a ε-caprolactam blocked isocyanate structure.   
     
     
         10 . The prepreg according to  claim 1 ,
 wherein   the at least one reactive polyurethane composition further comprises a catalyst.   
     
     
         11 . The prepreg according to  claim 1 ,
 wherein the at least one reactive polyurethane composition comprises   a uretdione group-comprising curing agent, based on polyaddition compounds from aliphatic, (cyclo)aliphatic or cycloaliphatic uretdione group-comprising polyisocyanates and hydroxyl group-comprising compounds, wherein the uretdione group-comprising curing agent is in solid form below 40° C. and in liquid form above 125° C., and has a free NCO content of less than 5 wt % and a uretdione content of 3-25 wt %,   a hydroxyl group-comprising polymer which is in solid form below 40° C. and in liquid form above 125° C. and has an OH number between 20 and 200 mg KOH/gram, and   optionally a catalyst, an auxiliary agent and an additive,   so that for each hydroxyl group of the hydroxyl group-comprising polymer 0.3 to 1 uretdione group of the uretdione group-comprising curing agent is consumed.   
     
     
         12 . The prepreg according to  claim 1 , wherein the at least one reactive polyurethane composition is powdery and comprises
 a uretdione group-comprising curing agent;   optionally a polymer comprising functional groups reactive towards a NCO group;   0.1 to 5 wt % of at least one catalyst selected from the group consisting of a quaternary ammonium salt and a quaternary phosphonium salt, wherein the quaternary ammonium salt and the quaternary phosphonium salt comprise a halogen, a hydroxide, an alcoholate, or an organic or inorganic acid anion as a counter-ion;   0.1 to 5 wt % of at least one cocatalyst selected from the group consisting of   an epoxide,   a metal acetylacetonate, a quaternary ammonium acetylacetonate, and a quaternary phosphonium acetylacetonate; and   optionally an auxiliary agent and an additive.   
     
     
         13 . The prepreg according to  claim 1 , wherein the at least one reactive polyurethane composition is powdery and comprises
 a uretdione group-comprising curing agent, based on polyaddition compounds from aliphatic, (cyclo)aliphatic or cycloaliphatic uretdione group-containing polyisocyanates and hydroxyl group-containing compounds, wherein the uretdione group-comprising curing agent is in solid form below 40° C. and in liquid form above 125° C. and has a free NCO content of less than 5 wt % and a uretdione content of 3-25 wt %;   a hydroxyl group-comprising polymer, which is in solid form below 40° C. and in liquid form above 125° C. and has an OH number between 20 and 200 mg KOH/gram;   0.1 to 5 wt % of at least one catalyst selected from the group consisting of a quaternary ammonium salt and a quaternary phosphonium salt, wherein the quaternary ammonium salt and the quaternary phosphonium salt comprise a halogen, a hydroxide, an alcoholate, or an organic or inorganic acid anion as a counter-ion;   0.1 to 5 wt % of at least one cocatalyst selected from the group consisting of
 an epoxide, 
 a metal acetylacetonate, a quaternary ammonium acetylacetonate, and a quaternary phosphonium acetylacetonate; and 
   optionally an auxiliary agent and an additive,   so that for each hydroxyl group of the hydroxyl group-comprising polymer 0.3 to 1 uretdione group of the uretdione group-comprising curing agent is consumed.   
     
     
         14 . The prepreg according to  claim 1 , wherein the fibrous support comprises a fibrous support of glass, carbon or aramid fibres. 
     
     
         15 . A process of producing a composite, the process comprising producing the composite with the prepreg according to  claim 1 ,
 wherein the composite is suitable for boat and ship building, aerospace technology, automobile manufacture, two-wheel vehicle manufacture, automotive technology, construction technology, medical technology, sport fields, electrical and electronics industry, and power generation plants.   
     
     
         16 . A composite component produced from the prepreg according to  claim 1 . 
     
     
         17 . The prepreg according to  claim 1 ,
 wherein the polymer b) comprises   polyester, polyether, polyacrylate, polycarbonate or polyurethane with an OH number of 20 to 500 mg KOH/gram and an average molecular weight of 250 to 6000 g/mole.