| 摘要 |
<p>A radiation curable aqueous polyurethane emulsion is prepared by polyaddition of a hydroxyl group containing polyester acrylate, a mono- and/or di-functional compound that is reactive towards isocyanate groups and contains cationic, anionic and/or ether group dispersible groups with a di- and/or polyisocyanate and reaction with 0.1-10 wt.% of a di- and/or polyamine. A radiation curable aqueous polyurethane emulsion (I) is based on hydroxyl group containing polyester acrylates prepared by polyaddition of (A) 40-90 wt.% of a hydroxyl group containing polyester acrylate, having an OH content of 40-200 mg KOH/g, that optionally contains isocyanate reactive compounds and (B) 0.5-20 wt.% of a mono- and/or di-functional compound that is reactive towards isocyanate groups and contains cationic, anionic and/or ether group dispersible groups or groups that may be converted to the corresponding cationic or anionically dispersible groups with (C) 10-50 wt.% of a di- and/or polyisocyanate as well as dispersion in water and reaction with (D) 0.1-10 wt.% of a di- and/or polyamine whereby the molar ratio of the sum of the hydroxyl groups in (A) and the isocyanate groups in (B) to the isocyanate groups in (C) is 0.8:1-1.25:1 and the reaction between (A), (B) and (C) is carried out to a 65-95 % conversion of the isocyanate groups in (C). An Independent claim is included for a process for the preparation of the emulsion (I) by preparing a pre-product by reaction of (A) and (B), optionally diluted with a water soluble solvent that is inert to isocyanate groups and heating to elevated temperature and optionally addition of a catalyst with dosing of the polyisocyanate (C), conversion of the anionic and/or cationic dispersible centers in (C) by salt formation as appropriate and in a separate reaction step mixing of the polyester urethane solution of (A), (B) and (C) with the dispersion water containing polyamine (D).</p> |
