Reaction product of a cyclic urea and a multifunctional aldehyde

Abstract

The invention relates to a reaction product UA of at least one cyclic urea U and at least one multifunctional aldehyde A which reaction product has as substituents on the carbonyl carbon atoms of the aldehyde A at least one kind of functional groups selected from the group consisting of hydroxyl groups —OH and alkoxy groups —OR characterised in that the groups —OR comprise at least two kinds of alkoxy groups —OR 1 and —OR 2 , where R 1 and R 2 are both selected from the group consisting of linear, branched or cyclic alkyl groups having from one to twelve carbon atoms, where R 1 and R 2 may be the same or may be different from each other, to a process of making these, and to a method of use as crosslinker in coating compositions.

1 - 18 . (canceled) 
     
     
         19 . A process to make a reaction product UA comprising
 a) mixing a multifunctional aldehyde A with a cyclic urea U to effect an addition reaction, optionally, in the presence of a co-solvent which does not react with any of the multifunctional aldehyde A, the cyclic urea U, and the reaction product UA, and further optionally, removing water,   b) adding an aliphatic alcohol R 1 —OH, and etherifying under acid conditions, and   c) adding a further aliphatic alcohol R 2 —OH which has at least one carbon atom in its molecule more that there is in 10-0H, and etherifying under acid conditions to obtain the reaction product UA,   wherein either or both of steps b) and c) are repeated one or more times,   wherein R 1  and R 2  are different from each other,   wherein R 2  has at least one carbon atom more than R 1 , and   wherein the reaction product UA has as substituents on the carbonyl carbon atoms of the aldehyde A at least one kind of functional groups selected from the group consisting of hydroxyl groups —OH and alkoxy groups —OR,
 wherein the alkoxy groups —OR comprise alkoxy groups —OR 1  and —OR 2 ,
 wherein R 1  and R 2  are both selected from the group consisting of linear, branched or cyclic alkyl groups having from one to twelve carbon atoms, which are optionally interrupted by one or more of —O—, —NR″—, —S— with the proviso that not two —O— or not two —S— atoms may be immediately adjacent,
 wherein R″ stands for H, or an alkyl group having from one to six carbon atoms. 
 
 
   
     
     
         20 . The process of  claim 19 , wherein the etherification is conducted in a sequential manner involving at least 2 subsequent steps b) and c). 
     
     
         21 . The process of  claim 19 , wherein the ratio of the amount of substance n (—O—R 2 ) of alkoxy groups —O—R 2  to the amount of substance n (—O—R 1 ) of alkoxy groups —O—R 1  in the etherified product of the process of claim  8  is between 0.11 mol/mol and 20 mol/mol. 
     
     
         22 . The process of  claim 19 , wherein the reaction product UA has a degree of etherification, measured as the ratio n(RO—)/n(U) of the amount of substance n(RO—) of alkoxy groups to the amount of substance n(U) of cyclic urea U chemically bound in the reaction products, of at least 1.1 mol/mol. 
     
     
         23 . The process of  claim 19 , wherein R 2 —OH is selected from the group consisting of ethanol, n-propanol, iso-propanol, n-butanol, sec-butanol, iso-butanol, n-pentanol, 2-methyl-1-butanol, 3-methyl-1-butanol, n-hexanol, n-octanol, 2-ethyl-1-hexanol, 1-decanol, 1-dodecanol, ethylene glycol monomethylether, ethylene glycol monobutylether, triethylene glycol monoethylether, dipropyleneglycol monomethylether, and mixtures thereof. 
     
     
         24 . The process of  claim 19 , wherein, in step a), the amount of multifunctional aldehyde A added is between 20% and 80% of the stoichiometric amount needed, and that after step a), a further quantity of multifunctional aldehyde A is added and reacted with the reaction mixture formed in step a) wherein the total amount of multifunctional aldehyde A added is chosen such that the ratio of the amount of substance of aldehyde groups n(-CHO) in the multifunctional aldehyde A and the amount of substance of amide groups n(-CO—NH—) in the cyclic urea U is from 0.8 mol/mol to 1.4 mol/mol. 
     
     
         25 . The process of  claim 19 , wherein the mixture of cyclic urea U, multifunctional aldehyde A, and optionally, water or solvent, is concentrated before or during the reaction by removing volatile constituents by distillation, or distillation under reduced pressure. 
     
     
         26 . The process of  claim 19 , wherein, during or after step a) and/or during or after step b), at least a part of the unreacted alcohol R′OH and/or water is removed by distillation. 
     
     
         27 . The process of  claim 19 , wherein the ratio of the number of —OR groups to the sum of the number of —OH groups and the number of —OR groups which are substituents on the carbonyl carbon atoms of the aldehyde A in the reaction product UA is at least 50%, the number of —OR groups being the sum of the number of —OR 1  groups and the number of —OR 2  groups. 
     
     
         28 . The process of  claim 19 , wherein the ratio of the amount of substance of residual >NH groups to the amount of substance of moieties derived from the cyclic urea U is not more than 0.2 mol/mol. 
     
     
         29 . The process of  claim 19 , wherein the aldehyde A is glyoxal or a mixture comprising glyoxal. 
     
     
         30 . The process of  claim 19 , wherein the cyclic urea U is selected from the group consisting of ethylene urea, 1,3-propylene urea, 1,2-propylene urea, 1,4-butylene urea, glycoluril, or mixtures thereof. 
     
     
         31 . The process of  claim 19 , wherein the cyclic urea U is purified before reaction with the multifunctional aldehyde A by one or more processes selected from the group consisting of recrystallisation, extraction, complexation, adsorption and ion exchange reactions, distillation, sublimation, and melt crystallisation. 
     
     
         32 . A process to make a reaction product UA comprising
 a) mixing a multifunctional aldehyde A with a cyclic urea U to effect an addition reaction, optionally, in the presence of a co-solvent which does not react with any of the multifunctional aldehyde A, the cyclic urea U, and the reaction product UA, and further optionally, removing water,   b) adding an aliphatic alcohol R 1 —OH, and etherifying under acid conditions   c) adding a further quantity of the aliphatic alcohol R 1 —OH and etherifying under acid conditions,   wherein step c) is done at least twice,   wherein the reaction product UA has as substituents on the carbonyl carbon atoms of the aldehyde A at least one kind of functional groups selected from the group consisting of hydroxyl groups —OH and alkoxy groups —OR,
 wherein the alkoxy groups —OR comprise alkoxy groups —OR 1  and —OR 2 ,
 wherein R 1  and R 2  are both selected from the group consisting of linear, branched or cyclic alkyl groups having from one to twelve carbon atoms, which are optionally interrupted by one or more of —O—, —NR″—, —S— with the proviso that not two —O— or not two —S— atoms may be immediately adjacent,
 wherein R″ stands for H, or an alkyl group having from one to six carbon atoms, and 
 
 
 wherein R 1  and R 2  are the same.