Polymer for increasing the electrical resistance of a polyurethane composition
AssigneeSika Technology AG
InventorMarc Balmer
Life of this patent
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Abstract
A poly(meth)acrylate urethane polymer, obtained from the reaction of at least one monomeric diisocyanate and a poly(meth)acrylate polyol having an OH number in the range from 50 to 200 mg KOH/g in an NCO/OH ratio of at least 3/1, followed by removal of a majority of the monomeric diisocyanate by means of a suitable separation method, wherein it has an NCO content in the range from 2.5% to 8% by weight, based on the poly(meth)acrylate urethane polymer, and a residual content of unconverted monomeric diisocyanates of not more than 0.5% by weight, and to the use thereof as additive and to moisture-curing polyurethane compositions.
Claims13
A method for increasing volume resistivity and/or for lowering impedance in a moisture-curing polyurethane composition, comprising adding a poly(meth)acrylate urethane polymer to a moisture-curing polyurethane composition,
- wherein the poly(meth)acrylate urethane polymer is obtained from a reaction of at least one monomeric diisocyanate and a poly(meth)acrylate polyol having an OH number in the range from 50 to 200 mg KOH/g in an NCO/OH ratio of at least 3/1, followed by removal of a majority of the monomeric diisocyanate by means of a suitable separation method, and wherein the poly(meth)acrylate urethane polymer has an NCO content in a range from 2.5% to 8% by weight, based on the poly(meth)acrylate urethane polymer, and a residual content of unconverted monomeric diisocyanates of not more than 0.5% by weight, and
- wherein isocyanate groups of the poly(meth)acrylate urethane polymer have been partly or wholly depleted by reaction with a monoalcohol or a monoamine in an additional subsequent reaction step.
A moisture-curing polyurethane composition suitable as elastic adhesive and/or sealant, comprising
- at least one polyether urethane polymer containing isocyanate groups, and
- a poly(meth)acrylate urethane polymer containing isocyanate groups,
- wherein the poly(meth)acrylate urethane polymer is obtained from a reaction of at least one monomeric diisocyanate and a poly(meth)acrylate polyol having an OH number in the range from 50 to 200 mg KOH/g in an NCO/OH ratio of at least 3/1, followed by removal of a majority of the monomeric diisocyanate by means of a suitable separation method, and wherein the poly(meth)acrylate urethane polymer has an NCO content in a range from 2.5% to 8% by weight, based on the poly(meth)acrylate urethane polymer, and a residual content of unconverted monomeric diisocyanates of not more than 0.5% by weight, and
- wherein the isocyanate groups of the poly(meth)acrylate urethane polymer have been partly or wholly depleted by reaction with a monoalcohol or a monoamine in an additional subsequent reaction step.
Dependencies are inferred from the claim text.