Process for preparing low-viscosity allophanates containing actinically curable groups

US9988485B2 · kind B2 · utility

Assignee

• ALLNEX NETHERLANDS BV · NL

Inventors

• Michael Ludewig
• Jan Weikard · Neunburg vorm Wald, DE

Key dates

• Filing date: Dec 23, 2015
• Grant date: Jun 5, 2018
• Expiry date: Dec 23, 2035

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C09D175/14
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

The present invention provides a process for preparing radiation-curing allophanates having residual monomer contents of less than 0.5% by weight and an NCO content of less than 1% by weight, wherein (A) compounds containing isocyanate groups, (B) hydroxy-functional compounds which contain groups which react, with polymerization, with ethylenically unsaturated compounds on exposure to actinic radiation (radiation-curing groups) and (C) optionally further compounds containing NCO-reactive groups, also optionally in the presence of a catalyst, are used to form NCO-group-containing urethanes having radiation-curing groups, which are subsequently reacted, without further addition of compounds containing isocyanate groups, in the presence of an allophanatization catalyst, the ratio of NCO groups of the compounds from A) to the OH groups of the compounds from B) and, where used, C) being 1.45:1.0 to 1.1:1.0.