Patent EA-005191-B1 (EA)
Title: Polyurethane elastomer gel insulating composition and use thereof
Inventor: BONNET EVELYNE
IPC: C08L75/04
Filed: 2001-10-26
Abstract: 1. Use of a composition in the form of polyurethane elastomer gel, for thermal insulation of a conduit for the transport of materials, obtained from a crosslinkable composition by reacting at least one polyol and at least one polyisocyanate in the presence of at least one liquid organic filler chemically inert to polyisocyanates. 2. Use according to claim 1, characterized in that the inert organic filler is more than 20% by weight of the entire composition. 3. Use according to claim 2, characterized in that the inert organic filler represents from 50 to 95% by weight of the entire composition. 4. Use according to one of the preceding claims, characterized in that the inert organic filler is chosen among the following oils and resins and hydrocarbon derivatives: C18-C20 n- or isoparaffins, chlorinated paraffins, heavy or light fuels, C5-C12 naphthenic oils or resins, unsubstituted or substituted aromatic and polyaromatic compounds, optionally containing one or more heteroatoms. 5. Use according to claim 4, characterized in that the neutral organic filler is an n-paraffin or a mixture of n-paraffins. 6. Use according to claim 4, characterized in that the neutral organic filler is a naphthenic resin, such as NYFLEX 820. 7. Use according to claim 4, characterized in that the neutral organic filler is an aviation fuel, such as kerosene. 8. Use according to one of the preceding claims, characterized in that the polyol is chosen among polyester polyols, polyether polyols and polydiene polyols. 9. Use according to claim 8, characterized in that the polyol is a polydiene polyol. 10. Use according to claim 9, characterized in that the polydiene polyol has a number-average molecular weight of at most 7 000, preferably between 1 000 and 3 000, and has a functionality of from 1 to 5, preferably from 1.8 to 3. 11. Use according to claim 9 or 10, characterized in that the polydiene polyol is a hydroxytelechelic oligomer of a conjugated diene. 12. Use according to claim 9 or 10, characterized in that the conjugated diene is butadiene. 13. Use according to one of claims 1 to 12, characterized in that the polyisocyanate is an aromatic or cycloaliphatic polyisocyanate or an isocyanate prepolymer. 14. Use according to claim 13, characterized in that the polyisocyanate is diphenylmethane 4,4'-diisocyanate (MDI) or a polymeric MDI. 15. Use according to claim 12, characterized in that the polyisocyanate is a prepolymer based on a hydroxytelechelic oligomer of a conjugated diene. 16. Use according to one of the preceding claims, characterized in that the crosslinkable composition also comprises one or more low-molecular weight polyols. 17. Use according to claim 16, characterized in that the said low-molecular weight polyol has a molecular weight of from 50 to 800. 18. Use according to any one of the preceding claims, characterized in that the molar ratio NCO/OH is between 0.5 and 2, preferably from 0.65 to 1.20. 19. Use according to any one of the preceding claims, characterized in that the insulating composition comprises a crosslinking catalyst. 20. Use according to claim 19, characterized in that the crosslinking catalyst is dibutyltin dilaurate. 21. Use according to any one of the preceding claims, characterized in that the crosslinked insulating composition has a thermal insulation factor below 0.25 W/m.k. 22. Submarine product-transfer conduit comprising at least one pipeline system, optionally at least one pipeline system known as a service pipeline system, one protective tubular sheath through which the said pipeline systems pass and a filling made of a thermally insulating material, characterized in that the thermally insulating material consists of an insulating composition in the form of a gel obtained from a crosslinkable composition as defined for the use according to one of claims 1 to 21. 23. District heating conduit comprising at least one PVC pipeline system transporting hot water from the thermal power station to the housing, a tubular protective sheath made of a plastic, PVC or polyethylene, through which the said pipeline systems pass, and a filling made of a thermally insulating material, characterized in that the thermally insulating material consists of an insulating composition in the form of an polyurethane elastomer gel, a composition as defined for the use according to one of claims 1 to 21. 24. Process for thermal insulation of a conduit for transporting materials, obtained from a crosslinkable insulating composition as defined for the use according to one of claims 1 to 21, the said process comprising the following steps: a) Intimate mixing of the polyol component and of the insulating liquid filler component of the said insulating composition, b) Addition, to the mixture of step a), of the polyisocyanate component of the said insulating composition, with intimate mixing of all of the components, c) Casting or injection moulding of the resultant mixture from step b) into the interstitial space formed between the outer surface of the conduit and the inner surface of the protective sheath, d) Crosslinking and solidification in situ to obtain the thermally insulated conduit ready for use at its point of use. 25. Process according to claim 24 in which the steps c) moulding and d) crosslinking are implemented in a mould to obtain premoulded sections of thermal insulation for a conduit for transporting liquid materials, and comprising a step e) assembling these premoulded sections around the said conduit. 26. Premoulded sections of thermal insulation for a conduit which have been obtained following the steps a), b), c) and d) of the process defined according to claim 25.