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US 4,307,756 AGranted
Thermally insulated tubing
AssigneeKabel-und Metallwerke Gutehoffnungshuette AG
InventorsHermann-Uwe Voigt, Horst Matzat
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Abstract
A spacer is coiled about a drawn, seamless copper tube, and a metal foil or metallized paper ribbon is folded around the coiled spacer. A blend for foaming is injected into the unoccupied space between the folded foil or ribbon and the inner tube, to generate a cyanurate-modified polyurethane foam network in which phosphorous or halogen molecules are embedded by chemical bond. A flame-resistant ribbon is folded about the metal tube. The resulting product and further details of the process are described.
Claims8
Thermally insulated tube for installation in buildings, or the like, comprising:
- a metal inner tube;
- a metal foil or ribbon of at least 0.05 mm thickness, having been formed into an outer tube and disposed coaxially about the said inner tube and having overlapping interconnected edges;
- spacer means on the inner tube and supporting the outer tube, there being space left between the inner and outer tubes not occupied by the spacer means;
- a foam in said space being comprised of an isocyanurate-modified polyurethane network which includes urethane groups and primarily isocyanurate units, resulting from and being the reaction product of an aromatic polyisocyanate, and of a polyether polyol in chemical bond with molecules of a flame-resisting substance, in the presence of a catalyst blend which includes a trimerizing catalyst for the isocyanurate reaction;
- and
- a synthetic flame-resisting envelope on the metal foil tube, in intimate contact but without interconnection therewith.
3 more elements
Dependencies are inferred from the claim text.