OIL SANDS LINER SYSTEM
An abrasion resistant multilayer liner for metal substrates with exceptional resistance to delamination, corrosion and physical wear comprises an epoxy layer formed by curing a phenolic epoxy resin with a curative comprising an anhydride adhered or bonded to a surface of the metal substrate, and an elastomeric polyurethane layer adhered or bonded to the epoxy layer. Metal surfaces lined with the inventive liner meet standards established for transport of oil sands slurries.
1 . An abrasion resistant multilayer liner for a metal substrate, the multilayer liner comprising an epoxy layer obtained by curing a phenolic epoxy resin with a curative comprising an anhydride, and an elastomeric polyurethane layer having a Shore hardness of form 50 A to 100 A, wherein the epoxy layer is adhered or bonded to a surface of the metal substrate, and the elastomeric polyurethane layer is adhered or bonded directly to the epoxy layer.
2 . The multilayer liner according to claim 1 , wherein the curative comprises a cyclic anhydride.
3 . The multilayer liner of according to claim 2 , wherein the cyclic anhydride is a polycyclic compound comprising a cyclic anhydride moiety fused to a 5 to 8 membered monocyclic moiety or a 6 to 14 member polycyclic moiety, wherein the monocyclic or polycyclic moiety comprises at least 4 carbon atoms and optionally one or more oxygen atoms.
4 . The multilayer liner according to claim 3 , wherein the cyclic anhydride comprises phthalic anhydride, trimellitic anhydride, nadic methyl anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride or hexahydrophthalic anhydride.
5 . The multilayer liner according to claim 4 , wherein the cyclic anhydride comprises hexahydrophthalic anhydride.
6 . The multilayer liner according to claim 1 , wherein the phenolic epoxy resin is an epoxy Novolac resin.
7 . The multilayer liner according to claim 6 , wherein the elastomeric polyurethane is prepared by curing an isocyanate capped prepolymer with a curative comprising a polyol, wherein the isocyanate capped prepolymer is prepared by reacting a polyisocyanate monomer with a polyether polyol, polyester polyol, polycarbonate polyol, and/or polycaprolactone polyol.
8 . The multilayer liner according to claim 7 , wherein the polyisocyanate monomer comprises MDI or TDI.
9 . The multilayer liner according to anyone of claim 7 , wherein the isocyanate capped prepolymer is prepared by reacting a polyisocyanate monomer with a polyether polyol.
10 . The multilayer liner according to claim 9 , wherein the polyisocyanate monomer comprises MDI and the polyether polyol comprises a polytetramethylene ether glycol.
11 . The multilayer liner according claim 7 , wherein the prepolymer comprises less than 3 wt % free diisocyanate monomer.
12 . A method for applying an abrasion resistant liner to a metal substrate, which liner comprises an epoxy layer and an elastomeric polyurethane layer having a Shore hardness of from 50 to 100 A, which method comprises applying directly to a surface of the metal substrate an epoxy composition comprising a phenolic epoxy resin and a curative comprising an anhydride and curing or partially curing the epoxy composition at temperatures of 50 to 150° C. to obtain an epoxy layer, and then casting directly onto the epoxy layer an elastomeric polyurethane composition comprising an isocyanate capped prepolymer and a curative comprising a polyol, which polyurethane composition is selected to provide an elastomer having a Shore hardness of from 50 A to 100 A, and then curing the polyurethane composition at temperatures of from 50 to 100° C. to obtain an elastomeric polyurethane layer which is adhered or bonded directly to the epoxy layer.
13 . The method according to claim 12 , wherein the anhydride is a cyclic anhydride.
14 . The method according to claim 12 , wherein the phenolic epoxy resin is an epoxy Novolac resin.
15 . A lined metal substrate comprising a metal substrate to which is adhered or bonded an abrasion resistant multilayer liner according to claim 1 .
16 . The lined metal substrate according to claim 16 , wherein the metal substrate is a steel substrate.
17 . A pipe, tank, or part of a pump comprising the lined metal substrate according to claim 15 .
18 . A pipe, tank or part of a pump comprising the lined metal substrate according to claim 16 which is used in the transport of mining slurries or oil sand slurries and wherein the liner is adhered or bonded to an interior metal surface of the pipe, tank, or pump part and contacts the mining slurries or oil sand slurries being transported.
19 . The abrasion resistant multilayer liner according to claim 1 , comprising an epoxy layer having a thickness of from 0.001 to 0.25 inches obtained by curing a phenolic epoxy resin with a curative comprising a cyclic anhydride, and an elastomeric polyurethane layer having a thickness of from 0.25 to 2.5 inches and a Shore hardness of form 50 A to 100 A, wherein the epoxy layer is adhered or bonded to a surface of a metal substrate, and the elastomeric polyurethane layer is adhered or bonded directly to the epoxy layer.