PROCESS FOR THE PREPARATION OF MACROMONOMERS, AND MACROMONOMERS PREPARED BY THIS PROCESS

The invention relates to a process for the preparation of macromonomers which carry at least two hydroxyl groups at one end. The process comprises (1) reacting a polyester, polyether, polyurethane, polyurea or polyamide prepolymer which has a number average molecular weight of 300 to 3000, preferably 500 to 2000, and contains an average of one terminal hydroxyl or amino group and at least one carboxyl group per molecule with a diisocyanate to form an intermediate which contains an average of one terminal isocyanate group and at least one carboxyl group per molecule, and subsequently reacting this intermediate (2) with a compound which has a molecular weight of 90 to 800, preferably 120 to 300, and contains at least two hydroxyl groups in addition to a group which is reactive to isocyanate groups, to form a macromonomer which carries an average of at least one carboxyl group and, at one end, at least two hydroxyl groups per molecule.