Non-etherified reaction product of a cyclic urea and a multifunctional aldehyde
View Patent ↗The invention relates to a coating composition comprising a reaction product UA of at least one multifunctional aldehyde A with at least one cyclic urea U, and a crosslinkable resin having at least one kind of functional groups selected from the group consisting of hydroxyl functional groups, acid functional groups, amide functional groups, amino functional groups, imino functional groups, mercaptan functional groups, phosphine functional groups, and carbamate functional groups, characterized in that the degree of etherification, measured as the ratio <<(—O—R)/<<(U) of the amount of substance n(-O—R) of alkoxy groups as substituents of the aldehyde carbon atoms of the multifunctional aldehyde chemically bound in the reaction product UA to the amount of substance <<(U) of cyclic urea U chemically bound in the reaction products, is less than 0.01 mol/mol, and to a process for the preparation of the reaction product UA.
1. A coating composition comprising a non-etherified reaction product UA of at least one multifunctional aldehyde A with at least one cyclic urea U, wherein the non-etherified reaction product UA is a crosslinker, and a crosslinkable resin having at least one kind of active hydrogen functional groups, characterised in that the degree of etherification, measured as the ratio n(-O—R)/n(U) of the amount of substance n(-O—R) of alkoxy groups as substituents of the aldehyde carbon atoms of the multifunctional aldehyde chemically bound in the non-etherified reaction product UA to the amount of substance n(U) of cyclic urea U chemically bound in the reaction products, is less than 0.01 mol/mol, and wherein the ratio of the amount of substance n(-CHO) of aldehyde groups in the at least one multifunctional aldehyde A and the amount of substance n(-NH—CO) in the at least one cyclic urea U satisfies the condition 1.0 mol/mol≤n(-CHO)/n(-NH—CO)≤1.30 mol/mol.
2. The coating composition of claim 1 further comprising at least one crosslinking agent selected from the group consisting of:
(b1) reaction products of an aminotriazine and at least one aldehyde selected from the group consisting of aliphatic monoaldehydes and multifunctional aliphatic aldehydes having the structure Y(CHO) n , where Y is an n-functional aliphatic residue, and n is greater than 1,
(b2) reaction products of urea and/or cyclic ureas and aliphatic monoaldehydes,
(b3) alkoxycarbonylaminotriazines,
(b4) multifunctional isocyanates which may be partially or completely blocked,
(b5) reaction products of phenols and aliphatic monoaldehydes,
(b6) multifunctional epoxides,
(b7) multifunctional aziridines, and
(b8) multifunctional carbodiimides.
3. The coating composition of claim 1 wherein the active hydrogen functional groups are selected from the group consisting of: hydroxyl functional groups, acid functional groups, amide functional groups, amino functional groups, imino functional groups, mercaptan functional groups, phosphine functional groups, and carbamate functional groups.
4. The coating composition of claim 1 , further comprising at least one selected from the group consisting of: water, an organic solvent, a catalyst, a filler, a pigment, a light stabiliser, a defoamer, a levelling agent, a wetting agent, a thickening agent, an antisettling agent, an anti skinning agent, and a preservative.
5. A method comprising applying the coating composition of claim 1 onto a substrate.
6. The method of claim 5 wherein the active hydrogen functional groups of the crosslinkable resin of the coating composition are selected from the group consisting of: hydroxyl groups, acid groups, amino groups, imino groups, amide groups, mercaptan groups, phosphine groups, and carbamate groups.
7. The method of claim 5 wherein at least one additional crosslinking agent is admixed to either or both of the reaction product UA of the at least one multifunctional aldehyde A with the at least one cyclic urea U of the coating composition, and the at least one crosslinkable resin of the coating composition, characterised in that the additional crosslinking agent is selected from the group consisting of:
(b1) reaction products of an aminotriazine and at least one aldehyde selected from the group consisting of aliphatic monoaldehydes and multifunctional aliphatic aldehydes having the structure Y(CHO) n , where Y is an n-functional aliphatic residue, and n is greater than 1,
(b2) reaction products of urea and/or cyclic ureas and aliphatic monoaldehydes,
(b3) alkoxycarbonylaminotriazines,
(b4) multifunctional isocyanates which may be partially or completely blocked,
(b5) reaction products of phenols and aliphatic monoaldehydes,
(b6) multifunctional epoxides,
(b7) multifunctional aziridines, and
(b8) multifunctional carbodiimides.
8. The method of claim 5 , further comprising homogenising the coating composition, and applying the homogenised coating composition to the substrate by spraying, brushing, wire coating, curtain coating, roll coating, dipping, electrophoretic deposition, powder spraying, or electrostatic spraying.
9. The method of claim 5 wherein at least one selected from the group consisting of: water, an organic solvent, a catalyst, a pigment, a defoamer, a levelling agent, a wetting agent, a thickening agent, an antisettling agent, an antiskinning agent, and a preservative, is added to the coating composition.
10. The method of claim 5 wherein the crosslinkable resin is selected from the group consisting of: water-borne liquid coating resins, solvent-borne liquid coating resins, and powder coating resins.
11. The method of claim 5 , characterised in that the substrate is selected from the group consisting of: plastics, plastic composite materials, thermoplastics, thermoset plastics, glass, ceramics, wood, fabricated wood, leather, textiles, paper, cardboard, plaster, concrete, stone, semiconductor surfaces, and metals.
12. The coating composition of claim 1 wherein the reaction product UA has a ratio of the amount of substance of residual >NH groups to the amount of substance of moieties derived from the cyclic urea U of not more than 0.2 mol/mol.