摘要 |
<p>Firstly, the invention concerns an organic resin that comprises structural units in its overall composition obtained from: a) at least one ethylenically unsaturated monomer carrying a cyclic carbonate group, b) at least one ethylenically unsaturated monomer carrying at least one carboxylic acid group, c) at least one ethylenically unsaturated monomer with a hydrophobic nature having a hydrophobic value, estimated by the logarithm of the partition coefficient between octanol and water, of at least 3, d) optionally, at least one other ethylenically unsaturated monomer that is different from said monomers a), b) or c) and does not carry any group that is susceptible of reacting with a carbonate group or carboxylic acid group, but also no group that is susceptible of reacting with a functional group of another monomeric component of said resin, all cross-linking reactions in the preparation of said resin being excluded, overall, said resin having: an acid value of at least 10 mg KOH/g with respect to the dry resin, and a cyclic carbonate group content of 0.5 to 3.5 mmol/g with respect to the dry resin. The invention also concerns an aqueous dispersion of said resin and a preparation process as a cross-linkable aqueous composition comprising said resin or dispersion and a polyamine. The resin is used for the preparation of cross-linked polyurethanes without the use of polyisocyanate, in particular in high performance aqueous coatings.</p> |