Method for the production of oxazolidinone compounds

1. A method for the production of an oxazolidinone compound by reacting an isocyanate compound with an epoxide compound in the presence of a Lewis acid catalyst,

comprising

conducting the reaction in the absence of bases with a base strength pK b of ≦5,

conducting the reaction at a temperature of ≧150° C. and

adding the isocyanate compound to the epoxide compound in a semi-batch or step-wise manner with two or more individual addition steps in the step-wise addition, wherein in each individual addition step the amount of isocyanate compound added is ≧1 weight % to ≦40 weight % of the total amount of isocyanate compound to be added.

2. The method according to claim 1 , wherein the reaction is conducted at a temperature of ≧150° C. to ≦280° C.

3. The method according to claim 1 , wherein the reaction is conducted in the absence of a solvent.

4. The method according to claim 1 , wherein the isocyanate compound is an isocyanate compound with two or more NCO groups per molecule and/or the epoxide compound is an epoxide compound with two or more epoxy groups per molecule.

5. The method according to claim 4 , wherein the isocyanate compound comprises tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), 2-methylpentamethylene diisocyanate, 2,2,4-trimethyl-hexamethylene diisocyanate (THDI), dodecanemethylene diisocyanate, 1,4-diisocyanatocyclohexane, 3-isocyanatomethyl-3,3,5-trimethylcyclohexyl isocyanate (isophorone diisocyanate, IPDI), diisocyanatodicyclohexylmethane (H 12 -MDI), diphenylmethane diisocyanate (MDI), 4,4′-diisocyanato-3,3′-dimethyldicyclohexylmethane, 4,4′-diisocyanato-2,2-dicyclohexylpropane, poly(hexamethylene diisocyanate), octamethylene diisocyanate, tolylene-α,4-diisocyanate, poly(propylene glycol) tolylene-2,4-diisocyanate terminated, poly*ethylene adipate) tolylene-2,4-diisocyanate terminated, 2,4,6-trimethyl-1,3-phenylene diisocyanate, 4-chloro-6-methyl-1,3-phenylene diisocyanate, poly[1,4-phenylene diisocyanate-co-poly(1,4-butanediol)]diisocyanate, poly(tetrafluoroethylene oxide-co-difluoromethylene oxide) α,ω-diisocyanate, 1,4-diisocanatobutane, 1,8-diisocyanatooctane, 1,3-bis(1-isocyanato-1-methylethyl)benzene, 3,3′-dimethyl-4,4′-biphenylene diisocyanate, naphthalene-1,5-diisocyanate, 1,3-phenylene diisocyanate, 1,4-diisocyanatobenzene, 2,4- or 2,5- or 2,6-diisocyanatotoluene (TDI) or mixtures of these isomers, 4,4′-, 2,4- or 2,2′-diisocyanatodiphenylmethane or mixtures of these isomers, 4,4-, 2,4′- or 2,2′-diisocyanato-2,2-diphenylpropane-p-xylene diisocyanate and α,α,α′,α′-tetramethyl-m- or -p-xylene diisocyanate (TMXDI), a mixture thereof, or a biuret, isocyanurate, carbamate or uretdione thereof.

6. The method according to claim 4 , wherein the epoxide compound comprises resorcinol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, bisphenol A diglycidyl ether, glycerol polyglycidyl ether, glycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitol polyglycidyl ether, diglycidyl terephthalate, diglycidyl o-phthalate, N-glycidyl phthalimide, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, or dipropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, or polybutadiene diglycidyl ether.

7. The method according to claim 1 , wherein the Lewis acid catalyst is present in an amount of ≧0.01 mol % to ≦0.1 mol % based on the initial amount of epoxide compound.

8. The method according to claim 1 , wherein the Lewis acid catalyst comprises:

Li(I), Rb(I), Cs(l), Ag(l), Au(I),

Mg(II), Ca(II), Sr(II), Ba(II), Dy(II), Yb(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), Yb(III), Lu(III), Hf(III), Nb(III), Ta(III), Cr(III), Ru(II), 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), P(V), Sb(V), Bi(V),

Mo(VI), or W(VI).

9. The method according to claim 1 , wherein the Lewis acid catalyst comprises LiBr, SmI 3 , a stibonium salt, or a phosphonium salt.

10. The method according to claim 1 , wherein the Lewis acidic catalyst is combined with a bromide, iodide, or a RSO 4 − and/or RSO 3 − salt as co-catalyst, R representing an organic group.

11. The method according to claim 1 , wherein the molar ratio of the oxazolidinone product to isocyanurate by-product is ≧85/15.

12. An oxazolidinone compound, obtained by the method according to claim 1 , with a colour as determined according to ASTM D1209-05 (2011) of ≦200 and a molar ratio of the oxazolidinone compound to isocyanurate by-product o/i of ≧85/15.

13. An oligomeric or polymeric oxazolidinone compound, obtained by the method according to claim 1 using an isocyanate compound with two or more NCO groups per molecule and an epoxide compound with two or more epoxy groups per molecule, comprising at least one unit derived from the isocyanate compound and at least two units derived from the epoxide compound, with a colour as determined according to ASTM D1209-05 (2011) of ≦200.

14. The compound according to claim 13 , comprising at least one terminal epoxide and/or isocyanate group or comprising at least one terminal group which is non-reactive towards epoxide and/or isocyanate groups.

15. The method of claim 1 , wherein the isocyanate compound is added to the epoxide compound in a step-wise manner with two or more individual addition steps in the step-wise addition, wherein in each individual addition step the amount of isocyanate compound added is ≦40 weight % of the total amount of isocyanate compound to be added.

16. The method of claim 1 , wherein the concentration of the isocyanate compound in a reaction mixture comprising the epoxide compound, the catalyst, and the isocyanate is ≦20 weight %, excluding any solvent that is present.

17. The method of claim 16 , wherein the concentration of the isocyanate compound in a reaction mixture comprising the epoxide compound, the catalyst, and the isocyanate is ≦5 weight %, excluding any solvent that is present.

18. The method of claim 1 , wherein in each individual addition step the amount of isocyanate compound added is ≧5 weight % to ≦20 weight % of the total amount of isocyanate compound to be added.

19. The method of claim 15 , wherein in each individual addition step the amount of isocyanate compound added is ≧5 weight % to ≦20 weight % of the total amount of isocyanate compound to be added.