摘要:
The present invention concerns a process for producing low-viscosity polyisocyanates or secondary products thereof, which carry activated, radiation-curable double bonds and can optionally also cure thermally, and low-viscosity polyisocyanate mixtures or secondary products thereof and their use in coating compounds.
摘要:
The present invention relates to a process for lowering the viscosity of compositions containing compounds having urethane groups, in which all or some of the urethane groups contained therein are reacted with monoisocyanates to form allophanate groups. The present invention also relates to compounds having allophanate groups and compositions containing such compounds, wherein at least 10 mole % of the allophanate groups contained therein correspond to formula I) wherein R is an alkyl, aralkyl or aryl radical which has up to 20 carbon atoms and optionally contains heteroatoms and wherein these radicals can also have, in addition to the NCO group present as part of the allophanate group, other functional groups which are neither isocyanate groups nor functional groups derived from isocyanate groups.
摘要:
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.
摘要:
Quick-drying, solvent-based coating compositions, which are curable by UV-A radiation and contain at least one amorphous polyurethane with a glass transition temperature of from 35° C. to 100° C., the proportion by weight of soft groups in said amorphous polyurethane being less than 30 wt. %. The compositions are prepared by mixing all of the components that are free of isocyanate groups, and mixing in the components that contain free isocyanate groups just before application to a substrate.
摘要:
The present invention relates to powder coating binders containing polyurethanes having (meth)acryloyl groups which are applied onto a substrate, fused with heat and cured by electromagnetic radiation and to a process for preparing the same.
摘要:
The invention relates to radiation-curable coating composition containing: a) 10 to 100 wt. % of a urethane (meth)acrylate which contains both (meth)acryloyl groups and free isocyanate groups, b) 0 to 90 wt. % of (meth)acrylates which contain (meth)acryloyl groups but no free isocyanate groups or any isocyanate-reactive groups, the wt. % under a) and b) adding up to 100 wt. %, based on the weight of a)+b), and c) 0 to 10 wt. %, based on the sum of components a) and b) of a UV initiator for free radical polymerization. The invention also relates to metal, plastic, film, wood, leather and mineral substrates coated with the above-mentioned radiation-curable coating composition.
摘要:
The present invention relates to a process for preparing urethanes containing (meth)acryloyl groups that are suitable as binders for powder coatings by reacting a polyisocyanate component with a hydroxyl group-containing component that contains at least one compound additionally containing (meth)acryloyl groups in a melt of compounds containing (meth)acryloyl groups, which are crystalline in the solid state and have a melting point of 30 to 100° C. and a dynamic viscosity at 111° C. of less than 10 Pa·s, at elevated temperature until the NCO content has dropped below 0.5 wt. %. The present invention also relates to the use of these urethanes as binders for powder coating compositions for coating substrates made of wood, metal, plastics or mineral substances, which may have been primed.
摘要:
The present invention relates to binders, which can be cured by free-radical polymerization initiated by UV light, and contain a) 10 to 90 parts by wt. of a polymer which contains, in chemically bound form, both ethylenically unsaturated groups and the reaction product of a resin containing abietic acid with not more than 50% of the OH groups of a polyfunctional alcohol having a molecular weight of less than 500, b) 10 to 90 parts by wt. of one or more mono- di-or oligoesters of (meth)acrylic acid having a molecular weight of less than 800 and c) optionally 0.1 to 10 parts by wt. of a photoinitiator component for the free-radical polymerization wherein the weights of a) and b) add up to 100. The present invention also relates to coating compositions containing these binders which are suitable for the production high-gloss coatings.