Silicone-containing polyisocyanurate foam
AssigneeWacker Chemie AG
InventorJens Cremer
Life of this patent
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Abstract
Silicone-containing polyurethane foams containing isocyanurate linkages are prepared from hyperbranched siloxanes having isocyanate groups or from hyperbranched siloxanes having isocyanate reactive groups and a polyisocyanate, the isocyanate groups being present in stoichiometric excess, in the presence of a trimerization catalyst. The foams are preparable at low densities and exhibit good flammability characteristics.
Claims13
-10. (canceled)
A foamable composition comprising hyperbranched siloxanes (A) of the formula
- V—(R2)p-m([SiR2O]1—SiR2R1)m (I),
- optionally one or more polyisocyanates (B), and
- at least one trimerization catalyst (G)
- in which
- V is a radical of valence p,
- R are identical or different monovalent, optionally substituted hydrocarbon radicals,
- R1 are identical or different monovalent organic radicals which have at least one isocyanate group or are groups reactive with isocyanate radicals,
- R2 are identical or different and are monovalent radicals,
- l is an integer greater than or equal to 1,
- p is an integer greater than or equal to 3, and
- m is an integer greater than or equal to 3,
- with the proviso that p is greater than or equal to m and, in the foamable composition, at least three isocyanate groups are present between the hyperbranched siloxanes A and optional polyisocyanates B.
A process for preparing a silicone-containing polyurethane foam, characterized in that hyperbranched siloxanes (A), optionally polyisocyanate (B) and trimerization catalyst (G) and also at least one blowing agent are mixed and caused to react.
A foam prepared by reacting hyperbranched siloxanes (A), optionally polyisocyanate (B) and trimerization catalyst (G) and also at least one blowing agent.
Dependencies are inferred from the claim text.