Patent ID: 8853295
Filing Date: 2014-10-07
Classification: C08G,C08L,C09D

Abstract:
1. A process for preparing a radiation-curable allophanate having a residual monomer content of less than 0.5 weight % and an NCO content of less than 1 weight %, comprising (1) preparing a urethane comprising NCO and radiation-curable groups from (2) subsequently or simultaneously and without further addition of a compound comprising NCO groups, reacting said urethane comprising NCO and radiation-curable groups in the presence of to form an end product; wherein the allophanatization catalyst is from 0.05 to 0.5 weight % based on the solids content of the end product, wherein the allophanatization catalyst is selected from the group consisting of zinc octoate, zinc acetylacetonate and zinc 2-ethylcaproate; wherein the ratio of NCO groups of the compound of A) to the OH groups of the compound of B), optionally C), and optionally D) is in the range of from 1.45:1.0 to 1.1:1.0; and wherein the radiation-curable allophanate has a shear viscosity at 23° C. of <30,000 mPas.