Method for the production of isocyanate-group terminated polyoxazolidinones

A process for producing an isocyanate-group terminated polyoxazolidinone comprising the copolymerization of a polyisocyanate compound (A) having two or more isocyanate groups with a polyepoxide compound (B) having two or more epoxy groups in the presence of a catalyst (C);

• wherein the molar ratio of the isocyanate groups of the polyisocyanate compound (A) to the epoxy groups of the polyepoxide compound (B) is larger than 2:1 and less than 25:1;
• and wherein the catalyst (C) is at least one compound selected from the group consisting of
• Li(I), Rb(I), Cs(I), Ag(I), Au(I),
• Mg(II), Ca(II), Sr(II), Ba(II), Dy(II), Cu(II), Zn(II), V(II), Mo(II), Mn(II), Fe(II), Co(II)
• Ni(II), Pd(II), Pt(II), Ge(II), Sn(II),
• Sc(III), Y(III), La(III), Ce(III), Pr(III), Nd(III), Sm(III), Eu(III), Gd(III), Tb(III), Dy(III), Ho(III),
• Er(III), Tm(III), Lu(III), Hf(III), Nb(III), Ta(III), Cr(III), Ru(III), Os(III), Rh(III), Ir(III),
• Al(III), Ga(III), In(III), Tl(III), Ge(III),
• Ce(IV), Ti(IV), Zr(IV), Hf(IV), Nb(IV), Mo(IV), W(IV), Ir(IV), Pt(IV), Sn(IV), Pb(IV),
• Nb(V), Ta(V), Bi(V),
• Mo(VI), W(VI), and
• compounds represented by the formula (I)
• [M(R1)(R2)(R3)(R4)]+nYn- (I)
• wherein M is phosphorous or antimony,
• wherein (R1), (R2), (R3), (R4) are independently of one another selected from the group consisting of linear or branched alkyl groups containing 1 to 22 carbon atoms, linear or branched alkyl groups containing 1 to 22 carbon atoms substituted with heteroatoms and/or heteroatom containing substituents, cycloaliphatic groups containing 3 to 22 carbon atoms, cycloaliphatic groups containing 3 to 22 carbon atoms substituted with heteroatoms and/or heteroatom containing substituents, C1 to C3 alkyl-bridged cycloaliphatic groups containing 3 to 22 carbon atoms, C1 to C3 alkyl-bridged cycloaliphatic groups containing 3 to 22 carbon atoms substituted with heteroatoms and/or heteroatom containing substituents, aryl groups containing 6 to 18 carbon atoms, and aryl groups containing 6 to 18 carbon atoms substituted with one or more alkyl groups containing 1 to 10 carbon atoms and/or heteroatom containing substituents and/or heteroatoms,
• wherein Y is a halide, carbonate, nitrate, sulfate or phosphate anion, and
• wherein n is an integer of 1, 2 or 3.