Heat-curable polyurethane compositions
AssigneeSika Technology AG
InventorsMichael SCHLUMPF, Sven REIMANN
Life of this patent
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Abstract
A nitrogen compound having a melting point of at least 65° C. is used as a curing agent for heat curing in a heat-curable single-component polyurethane composition, which includes a prepolymer with isocyanate end groups made of at least one polyisocyanate and at least one polyol, wherein the solid nitrogen compound is selected from a polyamine, a hydrazide or mixtures thereof.
Claims18
(canceled)
The heat-curable one-component polyurethane composition as claimed in claim 14, wherein the nitrogen compound has a melting point of at least 75° C.
The heat-curable one-component polyurethane composition as claimed in claim 17, wherein the hydrazide is a carbonyl hydrazide.
The heat-curable one-component polyurethane composition as claimed in claim 16, wherein the polyamine has terminal tertiary amino groups and has secondary amino groups.
The heat-curable one-component polyurethane composition as claimed in claim 16, wherein the polyamine is an epoxy-amine adduct.
The heat-curable one-component polyurethane composition as claimed in claim 14, wherein the nitrogen compound comprises a powder having a D90 of particle size, determined by ISO 13320:2020, of 50 µm.
The heat-curable one-component polyurethane composition as claimed in claim 14, wherein the nitrogen compound in the polyurethane composition is in direct contact with the prepolymer.
The heat-curable one-component polyurethane composition as claimed in claim 14, wherein the nitrogen compound is used in a proportion of 0.1-15% by weight based on a total weight of the heat-curable one-component polyurethane composition.
The heat-curable one-component polyurethane composition as claimed in claim 14, wherein the polyisocyanate is diphenylmethane 4,4′-diisocyanate.
The heat-curable one-component polyurethane composition as claimed in claim 14, wherein a NCO/OH ratio in the reaction between the polyisocyanate and the polyol is in a range from 3/1 to 10/1.
The heat-curable one-component polyurethane composition as claimed in claim 14, wherein the prepolymer having isocyanate end groups, is formed from the at least one polyisocyanate and the at least one polyol, via a content of monomeric polyisocyanates of not more than 0.5% by weight.
The heat-curable one-component polyurethane composition as claimed in claim 14, wherein the heat-curable polyurethane composition comprises the following components based on a total weight of the heat-curable one-component polyurethane composition:
- a) 0.1-15% by weight of the nitrogen compound;
- b) 15-70% by weight of the prepolymer;
- c) 0-70% by weight of inorganic and/or organic fillers;
- d) 0-30% by weight of plasticizers;
- e) 0-5% by weight of stabilizers;
- f) 0-1% by weight of catalysts;
- g) optionally one or more additional additives.
The heat-curable one-component polyurethane composition as claimed in claim 14, wherein the polyurethane composition is a one-component adhesive and/or sealant.
A heat-curable one-component polyurethane composition comprising:
- a) a prepolymer having isocyanate end groups, formed from at least one polyisocyanate and at least one polyol, and
- b) a nitrogen compound having a melting point of at least 65° C., where the solid nitrogen compound is selected from a polyamine, a hydrazide, or mixtures thereof,
- wherein the nitrogen compound acts as a curing agent for thermal curing of the heat-curable one-component polyurethane composition.
Dependencies are inferred from the claim text.