EPOXY RESIN SYSTEM

Abstract: An epoxy resin composition containing a) an epoxy resin and b) a liquid amine terminated polyamine curing agent prepared by condensing an aminoalkylpiperazine and a dicarboxylic acid. The epoxy resin composition typically requires less than 35% of solvent to produce a sprayable viscosity. The cured epoxy composition has good flexibility. A hydroxy-functional flexibilized resin is also produced by reacting (a) an epoxy resin, (b) a liquid aminoalkylpiperazine-based amine terminated polyamine and (c) a hydroxy-functional amine. In particular the invention relates to thermoset epoxy waterproofing membranes comprising: (a) one or more epoxy resin(s) having an average of at least 1.5 epoxy groups per molecule; (b) a liquid amine terminated polyamine prepared by reacting at least one C18-50 dicarboxylic acid and an aminoalkylpiperazine in a ratio of moles of aminoalkylpiperazine to equivalents of carboxyl group in the acid of greater than 0.75:1; (c) one or more optional polyamine(s); (d) one or more optional filler(s); and (e) one or more optional modifying resin(s) wherein the tensile modulus of the thermoset epoxy waterproofing membranes is less than 200,000 psi and the tensile elongation of the thermoset epoxy waterproofing membranes is greater than 20%. The membranes are useful for preventing water penetration for roofs, bridges, parking decks, water-retention ponds, swimming pool liners, basement water barriers, land fills, secondary containment, geomembranes and ponds.

Description: EPOXY RESIN SYSTEM This invention relates to epoxy resin systems. In one aspect, the invention relates to polyamide-amine curing agents for epoxy resin systems. A typical commercial ambient cure epoxy coating contains condensates of dimer acids with polyethylene polyamines containing more than 4 amine hydrogen atoms as a curing agent and a solution of a solid epoxy resin. This epoxy coating system has excellent flexibility, adhesion to many substrates, and resistance to water and many types of solvents. However, a problem with this system is that a solvent content of almost 50% is necessary in order to obtain a "sprayable" (Gardner D or lower) viscosity. A large fraction of such solvent evaporates from a coating, or other exposed layer of epoxy resins during cure, and thereby behaves as a volatile organic compound (VOC) . Environmentally it is desirable to have low VOC content. Solvent requirements can be reduced considerably by using a system based on liquid epoxy resin with the above polyethylene polyamine curing agent. However, this approach tends to lead to coatings with low flexibility. It is therefore an object of the present invention to provide epoxy coating systems which have good flexibility with reduced solvent requirements. Further, it is desirable to obtain epoxy systems for secondary containment membranes with increased tensile elongation with no losses, or minimal losses, in tensile or tear strength. It is also desirable to obtain epoxy systems for composite and adhesive applications with both increased tensile elongation and increased tensile strength and modulus as compared to current systems. According to the invention, an epoxy resin composition is provided comprising: (a) an epoxy resin having at least 1.5 epoxy groups per molecule, and (b) a liquid amine terminated polyamine prepared by reacting a long-chain dicarboxylic acid and an aminoalkylpiperazine. The composition is useful for high solids coating applications, for adhesive and membrane applications, and for preparing impregnated substrates. In particular the present invention relates to a thermoset epoxy waterproofing membrane using said epoxy resin composition. Fig. 1 is a plot of the tensile elongation versus tensile strength for the cured epoxy resin systems cured with a liquid amine terminated polyamine prepared by reacting dimer acid with N- (2-aminoethyl) piperazine and those cured with comparative curing agents. Fig. 2 is a plot of the tensile elongation versus tensile modulus for the cured epoxy resin systems cured with a liquid amine terminated polyamine prepared by reacting dimer acid with N- (2-aminoethyl) piperazine and those cured with comparative curing agents. Fig. 3 is a plot of the tensile elongation versus tear resistance for the cured epoxy resin systems cured with a liquid amine terminated polyamine prepared by reacting dimer acid with N- (2-aminoethyl) piperazine and those cured with comparative curing agents. Accordingly, it is desirable to obtain an epoxy resin system having less than about 35% solvents content. It has been found that the epoxy resin system of the invention with a liquid aminoalkylpiperazine-based amine terminated polyamine as curing agent at 70% solids has a viscosity approximately the same as that of the epoxy resin system containing condensates of dimer acids with standard polyethylene polyamines as a curing agent at 50% solids. Further, it has been found that the cured product has good tensile elongation at a value of generally above about 50 percent, often above 100 percent. The liquid aminoalkylpiperazine-based amine terminated polyamine can also be used as a chain-extender or a reactive "plasticizer" to provide good flexibility to cured epoxy resin products. The aminoalkylpiperazine-based amine terminated polyamine can be produced by reacting long-chain dicarboxylic acids such as dimerized fatty acids ("dimer acids") or adducts of acrylic and methacrylic acid with unsaturated fatty acids ("adduct acids") with aminoalkyl- piperazines under conditions effective to produce a liquid amine terminated polyamine. The resultant polyamines have a number-average amine hydrogen functionality of above 1.7 and up to 4. Preferably the polyamide has an amine plus acid number greater than about 250 and has an excess of amine groups over acid groups . The aminoalkylpiperazine-based amine terminated polyamine may be prepared by thermal condensation of the aminoalkylpiperazine, preferably in excess, with one or more long-chain dicarboxylic acids or their esters under conditions effective to produce a liquid aminoalkyl- piperazine-based amine terminated polyamine. Generally the reaction is carried out at a temperature gradually climbing to a level of above about 200 °C, preferably at a final temperature within the range of from about 220 °C to about 260 °C, for a time effective to produce a liquid reaction product, followed by distillation, preferably under vacuum, to remove excess unreacted amine, as well as water and/or alcohol reaction product. (The water or alcohol reaction product generally distills at atmospheric pressure before vacuum is applied.) The term "liquid" refers to compositions which have a melting point, or ring and ball softening point (ASTM E28-67) of below room temperature (typically 25 °C) . These liquid aminoalkylpiperazine-based amine terminated polyamines are low molecular weight oligomers, typically having number average molecular weight within the range from about 400, preferably from about 700, to about 3000, preferably to about 2000. Alternatively, the amine may be reacted with a chloride of the dicarboxylic acid, but this synthetic procedure is less desirable because of the byproducts produced and the cost of the acid chlorides. Preferably the long-chain dicarboxylic acid is a dicarboxylic acid having from 18 to 50 carbon atoms. More preferably, the long-chain dicarboxylic acid has from 30 to 40 carbon atoms. The "dimer acids" refers to polymeric or oligomeric fatty acids typically made from addition polymerization, using heat and a catalyst, of unsaturated fatty acids, particularly tall oil fatty acids. These polymeric fatty acids typically have the composition of up to about 20% of C]_8 monobasic acids, about 45 to 95% of C36 dibasic acids, and about 1 to 35% of C54 tribasic and higher polymeric acids. The relative ratios of monomer, dimer, trimer and higher polymer in unfractionated dimer acid are dependent on the nature of the starting material and the conditions of polymerization and distillation. Methods for the polymerization of unsaturated fatty acids are described, for example, in U.S. Patent No. 3,157,681. Examples of the "adduct acids" include adducts of acrylic acid, methacrylic acid, crotonic acid, etc. with linoleic acid, soybean oil fatty acid, tall oil fatty acid, etc. These adducts are normally prepared by thermal reaction at temperatures > 200 °C. Methods for the preparation of these adduct acids are described, for example, in U.S. 3,753,968. Aminoalkylpiperazines can be represented by the following formula: (I) where R1 and R^ are each independently -H or -R^-NH2, wherein R^ is a divalent aliphatic linkage, preferably a chain of -CH2- units with optional -CHR 4 - or CR 4 R 5 - units, wherein R 4 and R^ are independently alkyl groups, provided that at least one of R^ and R^ is -R3-NH2-. The divalent aliphatic linkage preferably have 2-6 carbon atoms . Examples of the aminoalkylpiperazine include N-(2- aminoethyl) piperazine, N, N-bis (2-aminoethyl) piperazine and N, N-bis (3-aminopropyl) piperazine . N- (2-aminoethyl) piperazine and N, N-bis (2-aminoethyl) piperazine are typical byproducts of the commercial production of ethylene amines from ammonia and ethylene oxide or ethylene dichloride. N, N-bis (3-aminopropyl) piperazine is prepared by reacting piperazine with acrylonitrile to form N, N-bis (2-cyanoethyl) piperazine, followed by hydrogenation of the nitrile groups to amine groups. Methods for the preparation of aminoalkylpiperazines are described, for example, in I. Ono . Kagaku Keizai, 26(6), pp. 20-27 (1979) and Q. Sun and C. Zhu, Shanghai Diyi Yixueyuan Xuebao, 12(3), pp. 178-182 (1985). To produce a liquid amine terminated polyamine curing agent one uses a starting ratio of moles of aminoalkylpiperazine to equivalents of carboxyl group in the acid or acid mixture used of greater than 0.75:1, more preferably greater than 0.9:1, still more preferably greater than 1:1. The amine terminated polyamine curing agent is present in an amount effective to cure the epoxy resin. The mole ratio of the epoxy resin to liquid amine terminated polyamine curing agent is typically from about 3:1, preferably from about 2:1, to about 1:3, preferably to about 1:2. An accelerator can be included to increase the cure rate of the epoxy resin-curing agent system. Various amine-compatible accelerators can be used as long as they are soluble in the amine curing agents. Examples of accelerators include metal salts such as, for example, sulfonates, phosphonates, sulfates, tetrafluoroborates, carboxylates and nitrates of Groups IA, IIA and transition metal series of the Periodic Table (CAS version), preferably Mg, Ca, Zn and Sn salts, and complexes thereof; inorganic acids such as, for example, HBF4, H2SO4, H2NSO3H and H3PO4; carboxylic acids, preferably hydroxy-substituted carboxylic acids such as, for example, salicylic, lactic, glycolic and resorcylic; phenolic compounds such as, for example, phenol, t-butylphenol, nonylphenol and bisphenol A; imidazoles; cyanamide compounds such as dicyandiamide and cyanamide; sulfonamides such as, for example p-toluenesulfonamide, methanesulfonamide, N-methylbenzenesulfonamide and sulfamide; and i ides such as, for example, phthalimide, succinimide, perylenetetracarboxylic diimide and saccharin. When the cure rate at the desired temperature is suboptimal, it is preferable to include the accelerator. For example, for adhesive applications and civil engineering applications where application at low temperature is desired, it may be preferable to include the accelerator. It is particularly preferable to include the accelerator if the amine groups are hindered or the concentration of amine groups is low. The accelerators are typically present in an amount of from about 0, preferably from about 0.1, weight percent to about 10 weight percent, preferably to 5 weight percent, based on the epoxy resin. More preferable accelerators for the invention include, for example, calcium alkylbenzenesulfonates, dicyandiamide, calcium nitrate, magnesium alkane- sulfonates, tetrafluoroboric acid, salicylic acid, phenol, dichloroacetic acid, trifluoroacetic acid, and mercaptoacetic acid. The epoxy resin can be any epoxy resin which can be cured by the amine terminated polyamine curing agent. Generally, the epoxy resin can be any curable epoxy resin having a 1,2-epoxy equivalency greater than one and preferably, on the average, more than about 1.5 epoxide groups per molecule. The epoxy resin can be saturated or unsaturated, linear or branched, aliphatic, cyclo- aliphatic, aromatic or heterocyclic, and may bear substituents which do not materially interfere with the curing reaction. Such substituents can include bromine. The epoxy resin may be monomeric or polymeric, liquid or solid, but is preferably liquid at room temperature. Suitable epoxy reins include glycidyl ethers prepared by reacting epichlorohydrin with a compound containing at least one, preferably two or more, hydroxyl groups carried out under alkaline reaction conditions. Examples of epoxy resins suitable for use in the invention include polyglycidyl ethers of polyhydric phenols, epoxy novolacs or similar glycidated polyphenolic resins, polyglycidyl ethers of glycols or polyglycols, and polyglycidyl esters of polycarboxylic acids. The preferred epoxy resin is a resin based on a polyglycidyl ether of a polyhydric phenol for coatings, including cathodic electrodeposition, applications (other than highly ultraviolet-resistant topcoats, for which an aliphatic epoxy resin is preferred) . Polyglycidyl ethers of polyhydric phenols can be produced, for example, by reacting an epihalohydrin with a polyhydric phenol in the presence of an alkali. Examples of suitable polyhydric phenols include: 2, 2-bis (4-hydroxyphenyl) propane (bisphenol-A) ; 2, 2-bis (4-hydroxy-3-tert-butylphenyl) propane; 1, 1-bis (4-hydroxyphenyl) ethane; 1, 1-bis (4- hydroxyphenyl) isobutane; bis (2-hydroxy-l-naphthyl) methane; 1, 5-dihydroxynaphthalene; 1, 1-bis (4-hydroxy-3- alkylphenyl) ethane and the like. Suitable polyhydric phenols can also be obtained from the reaction of phenol with aldehydes such as formaldehyde (bisphenol-F) . Fusion products of these polyglycidyl ethers of polyhydric phenols with phenolic compounds such as bisphenol-A are also suitable as epoxy resins, such as those described in U.S. Patent Nos. 3,477,990 and 4,734,468. Commercial examples of preferred epoxy resins include, for example, EPON Resins 862, 828, 826, 825 and 1001 (EPON is a trade mark) . The preferred epoxy resins for use in elastomeric or semielastomeric secondary containment membrane applications, because of their low viscosity and the low modulus and high elongation of the cured products, are polyglycidyl ethers of aliphatic or cycloaliphatic glycols or polyglycols. Aliphatic glycidyl ethers can be produced, for example, by reacting an epihalohydrin with an aliphatic diol (optionally containing ether linkages or sulfone linkages) in the presence of a Lewis acid catalyst followed by conversion of the halohydrin intermediate to the glycidyl ether by reaction with sodium hydroxide. Commercial examples of preferred epoxy resins include, for example, HELOXY Modifiers 32 (a diglycidyl ether of a poly (propylene oxide) glycol) , 68 (the diglycidyl ether of neopentyl glycol) and 107 (the diglycidyl ether of 1, 4-cyclohexanedimethanol) available from Shell Chemical Company (HELOXY is a trade mark) . Examples of preferred aliphatic glycidyl ethers include those corresponding to the formulas: 0 0 / \ / \ CH —CH—CH2—0— (CH 2 ) p —O—CH2—CH—CH ( j . j ) 0 0 / \ / \ CH 2 —CH—CH 2 —0— (CH —CH—0) q —CH 2 —CH—CH 2 ( III ) I CH 3 0 CH 2 —CH2 0 / \ / \ / \ CH 2 -CH-CH 2 -0-CH 2 -CH CH-CH2-O-CH2-CH-CH2 \ / CH 2 —CH 2 wherein: p is an integer from 2 to 12, preferably from 2 to 6; and q is an integer from 4 to 24, preferably from 4 to 12. Examples of suitable aliphatic glycidyl ethers include, for example, diglycidyl ethers of 1,4-butane- diol, neopentyl glycol, cyclohexanedimethanol, hexane- diol, hydrogenated bisphenol A, and polypropylene glycol; and triglycidyl ethers of trimethylolethane and trimethylolpropane . The preferred epoxy resin systems of the invention contain one or more epoxy resins, a curing agent containing the amine terminated polyamine, and optionally an accelerator. The epoxy resin can be blended or mixed with the curing agent containing the amine terminated polyamine and optionally the accelerator simultaneously or in any order at a temperature below the cure temperature which is typically below about 100 °C. Further to facilitate handling or application or use in various environments, the curing agent or the epoxy resin system can be diluted with minor amounts of aliphatic, aromatic or cycloaliphatic ketones or esters. The curable epoxy resin composition can be cured at a temperature within the range of from about -40 °C, preferably from about -10 °C, to about 100 °C, preferably to about 75 °C, for a time effective to cure the epoxy resin. For standard coating applications the composition is preferably cured at a temperature from about -10 °C to about 75 °C. For electrodeposition the composition is preferably cured at a temperature from about 150 °C to about 300 °C. For secondary containment membrane applications, the cure temperature is almost always the ambient temperature. The epoxy resin composition of the invention may include other additives, such as flow control additives such as solvents or anti-sag agents, as well as other additives such as pigments, reinforcing agents, fillers, elastomers, stabilizers, extenders, plasticizers, and flame retardants depending on the application. The epoxy resin composition is useful for coatings, as adhesives, and for sizing or impregnating substrates such as sheets, cords, yarns and prepregs for various applications. For coating applications, the curable epoxy resin composition can also contain pigments of the conventional type such as iron oxides, lead oxides, strontium chromate, carbon black, titanium dioxide, talc, barium sulfate, phthalocyanine blue and green, cadmium red, chrome green, lead silicate, silica, silicates and the like. Such pigments can be added to the polyamine curing agent component or the epoxy resin component prior to mixing them together. However, iron blue pigment, calcium carbonate and pigments considered reactive because of their basic nature are not compatible in the epoxy resin coating system when used in appreciable quantities. These normally are added to the curing agent component only. Defoamers, tints, slip agents, thixotropes, etc., are common auxiliary components to most coatings and may be employed in the epoxy resin composition of the present invention. The curable coating composition can be applied to a substrate by brush, spray, or rollers. One of the advantages of the coating system of the invention is the lower solvent content (i.e., less than about 35%) of the curable coating composition. For adhesives, the curable epoxy resin composition will typically be applied to a substrate either neat or in a solvent, at ambient or elevated temperature. Solvent, if any, will be allowed to evaporate and the substrates will be pressed together, followed by cure of the adhesive at ambient or elevated temperatures. For impregnation, the curable epoxy resin composition can optionally contain thixotropic agents and halogenated phenolic compounds (the latter especially for printed wiring board uses) . The composition can be impregnated on a woven or a non-woven substrate such as nylon, polyester, fiberglass, graphite and aramid, and then cured. In a prepregging process, a fibrous substrate, usually woven glass, is impregnated with a solventless formulation or formulation with solvent (e.g., ketones) containing an epoxy resin composition as described above, optionally containing one or more halogenated phenolic compounds, and the impregnated substrate is passed to an oven maintained at a temperature effective to partially cure the epoxy resin. In a solvent-borne process a conventional process can be used. In a specific embodiment of the solventless lamination process, the prepreg is prepared in a process involving depositing the solventless epoxy resin formulation in the melt onto a rotating roller, passing a fibrous web in countercurrent contact with the resin formulation on the rotating roller so as to transfer the resin formulation into the fibrous web, and passing the resin-containing web to a heating zone to partially cure the resin and form a prepreg comprising the fibrous web and the partially-cured resin. The prepreg can be shaped into a desired shape and cured to obtain a laminate. For membrane, especially secondary containment applications, membranes can be formed by spreading the uncured composition over a surface such as concrete, masonry, earth, etc. using a tool such as a squeegee. The aminoalkylpiperazine-based amine terminated polyamines may also be used as flexibilizing units in the preparation of resins for cathodic electrodeposition applications. Preparation of cathodic electrodeposition resins and resin systems is described in references such as U.S. Patent Nos. 4,332,711 and 4,362,847, which are herein incorporated by reference. Cathodic electrode- position resins are typically prepared by reacting an epoxy resin with an amine, especially a hydroxy- functional amine such as diethanolamine, to yield a final product which is rich in hydroxyl groups and which has a low or negligible content of epoxy groups. They are subsequently mixed with a curing agent which can react with hydroxyl groups on heating (such as a poly(- hydroxyalkyl) ester of a polycarboxylic acid, a urea- formaldehyde or melamine-formaldehyde resin, etc.). The mixture is dissolved or suspended in an acidic aqueous bath and is then deposited from the bath onto a metal part which forms the cathode. Heating the metal part in an oven subsequently cures the resin through the hydroxyl groups . In many cathodic electrodeposition resin systems, it is desirable to incorporate a flexible unit into the backbone of the epoxy-derived resin in order to increase the flexibility, impact resistance, and chip resistance of the cured coating. The compositions of this invention are useful for this application because they both add flexibility and also add basic nitrogen, which contributes to dispersibility of the product resin in an acidic aqueous bath. For a flexibilized resin for cathodic electrodeposition, the aminoalkylpiperazine- based amine terminated polyamine would be mixed with an epoxy resin, preferably a bisphenol A-based epoxy resin such as EPON Resin 828 or 1001, and another amine, preferably a hydroxy-functional amine such as diethanol- a ine, such that the equivalents ratio of amine hydrogen to epoxy group is within the range of from about 1:2 to about 2:1, preferably such that the number of equivalents of amine hydrogen is approximately equal to the number of equivalents of epoxy group in the mixture. The weight ratio of the polyamide to the hydroxy-functional amine may be from about 5:95 to about 95:5 by weight. The hydroxy-functional amine can be any hydroxyl group substituted alkylamine. The mixture would be heated to react the amine groups with the epoxy groups and produce a hydroxy-functional flexibilized resin. Adding a curing agent, dispersing the mixture in an acidic aqueous bath, cathodically depositing the uncured resin-curing agent mixture on a metal part, and heat-curing the cathodically deposited film would yield a flexibilized cured coating. It will be appreciated that a preferred embodiment of the present invention is formed by a thermoset epoxy waterproofing membrane comprising (a) one or more epoxy resin (s) having an average of at least 1.5 epoxy groups per molecule; (b) a liquid amine terminated polyamine prepared by reacting at least one C]_g-50 dicarboxylic acid and an aminoalkylpiperazine in a ratio of moles of aminoalkyl- piperazine to equivalents of carboxyl group in the acid of greater than 0.75:1; (c) one or more optional polyamine (s) ; and (d) one or more optional fillers; wherein the tensile modulus of the thermoset epoxy waterproofing membranes is less than 200,000 psi and the tensile elongation of the thermoset epoxy waterproofing membrane is greater than 20%. Preferably the mole ratio of the epoxy resin to liquid amine terminated polyamine is from 3:1 to 1:3 in said thermoset waterproofing membrane. More preferably, the alkylpiperazine is of the formula R—N N—R 2 wherein R-^ is -H and R^ is -R^- H2, wherein R^ is a divalent aliphatic linkage. More preferably the liquid amine terminated polyamine component (b) is prepared by reacting in a reaction mixture, (i) the C]_g_C5o dicarboxylic acid (ii) at least one other dicarboxylic acid and (iii) the aminoalkylpiperazine . The membrane is more preferably formed by a reaction mixture further comprising a monocarboxylic acid. Preferably one or more polyamine (s) other than component (b) are used, selected from diethylenetriamine, triethyltetramine, isophoronediamine, X-xylenediamine and polyoxypropyleneamines . Moreover preferred embodiments of said membranes comprise fillers, which may be selected from minerals, polymers and mixtures thereof. These fillers can be present in an amount of from 20 to 80% by volume based on the final composition. The preferred membranes further comprise one or more modifying resins which can be selected from acrylic monomers, acrylic resins, hydrocarbon resins (such as coal tar) and polyesters resins. These modifying resins are present in amount from 5% to 30% by weight of the epoxy content in the final composition. It will be appreciated that another aspect of the present invention is formed by a roof coating, a parking deck, a land fill lining, basement water barrier, or water retention pond liner comprising the hereinbefore specified thermoset epoxy waterproofing membranes. The following illustrative embodiments describe the process of the invention and are provided for illustrative purposes and are not meant as limiting the invention. Examples 1-5 demonstrate use of the aminoalkyl- piperazine-based amine terminated polyamine as curing agent. The dimer acid (-10% C]_ Q monobasic acids, ~80% C35 dibasic acids, -10% C54 tribasic acids) was obtained from Shell Chemical Co. N- (2-aminoethyl) piperazine, ethylene- diamine, and 2-methyl-l, 5-pentanediamine were obtained from various manufacturers, Dow Chemical Co. and E.I. DuPont de Nemours and Co., respectively. EPON Resin 828 (a diglycidyl ether of bisphenol A having epoxy equivalent weight of 185-192), EPON Resin 1001 (an oligomeric diglycidyl ether of bisphenol A having epoxy equivalent weight of 450-550) were obtained from Shell Chemical Company. HELOXY Modifier 68 (a diglycidyl ether of neopentyl glycol having an epoxy equivalent weight of 130-140), HELOXY Modifier 107 (a diglycidyl ether of 1, 4-cyclohexanedimethanol having an epoxy equivalent weight of 155-165), and HELOXY Modifier 32 (a diglycidyl ether of polypropylene glycol having an epoxy equivalent weight of 305-335) were obtained from Shell Chemical Company. NEODOL 23 alcohol (a linear primary aliphatic alcohol mixture containing primarily 1-dodecanol and 1-tridecanol) was obtained from Shell Chemical Company (NEODOL is a trade mark) . EPON Resin 8132 (a diluted epoxy resin having epoxy equivalent weight of 195-215) was obtained from Shell Chemical Company. EPI-CURE Curing Agent 3125 (a polyamide-amine curing agent based on dimer acid, fatty acid, and a mixture of polyet ylenepoly- amines) , EPI-CURE Curing Agent 3115 (a polyamide-amine curing agent based on dimer acid, fatty acid, and triethylenetetramine) , EPI-CURE Curing Agent 3140 (a polyamide-amine curing agent based on dimer acid, fatty acid, and triethylenetetramine) , and EPI-CURE Curing Agent 3266 (an amine curing agent containing a polyurethane backbone) were obtained from Shell Chemical Company (EPI-CURE is a trade mark) . EXAMPLE 1 Preparation of a low amine hydrogen functionality "polyamide" curing agents by reaction of dimerized fatty acid with excess amines. "Dimer acid" with a Gardner viscosity of Z4-1/4 or (in run #8) Z4-1/2, (carboxyl equivalent weight within the range of between approximately 280 and 290) from the Shell Chemical Company, was mixed in the ratios indicated in Table 1 below with N- (2-aminoethyl) piperazine (AEP) , or in the last two (comparative) runs ethylenediamine (EDA) or 2-methyl-l, 5-pentanediamine (MPTD) in 1-liter, 2-liter or 5-liter round-bottom flasks (depending on batch size) equipped with a heating mantle, a paddle stirrer, a thermocouple, a nitrogen purge, and a Vigreux column with a vacuum distillation takeoff. The system was purged with nitrogen and heating was started. Typically, when the pot temperature had reached 150-170 °C, water began to distill at atmospheric pressure. Water distillation at atmospheric pressure continued until the pot temperature had been raised to 220-240 °C; the pot was held at this temperature until water distillation had stopped or had essentially stopped. Vacuum was then applied and vacuum distillation of the amine was carried out until the pot temperature had risen back to 220-240 °C and the rate of amine offtake had become essentially negligible. Vacuum stripping was then continued at this temperature for approximately another 15 minutes. The products were then allowed to cool to about 150 °C under vacuum or under a stream of nitrogen and were then poured into jars. The products were characterized by amine nitrogen content (by titration) and viscosity. Results are shown in Table 1 below. As can be seen from Table 1 that halving the ratio of moles of AEP to equivalents of carboxyl group from near 4/1 to near 2/1 resulted in only a relatively small increase in viscosity and decrease in amine nitrogen content. By contrast, the material made with the much more volatile diamine ethylenediamine (EDA) , even at a ratio of over 4 moles of amine per equivalent of carboxyl group, was extremely viscous and very difficult to use as a curing agent. The material made with the diamine 2- methyl-1, 5-pentanediamine (MPTD) processed normally during synthesis but had another major disadvantage, as shown in the following example. ω CQ TABLE 1 (cont'd] TABLE 1 (cont'd) a Curing agents were prepared by mixing dimer acid (Shell Lakeland Z4-1/2 for 22481-63, Lakeland Z4-1/4 for all other preparations) with amine in a round-bottom flask equipped with a paddle stirrer, thermocouple and distilling head. The mixtures were heated (under nitrogen) to slow reflux for approximately 2 hours, followed by distillation at atmospheric pressure and finally stripping under pump vacuum at the temperature and pressure indicated above. b Calculated for product composed solely of condensation product of one molecule of dimer acid and two molecules of amine . c Calculated from amine nitrogen content determined by titration . p or polyamides made with EDA or MPTD, the amine hydrogen equivalent weight was calculated by halving the amine nitrogen equivalent weight (two amine hydrogens for each amine nitrogen endgroup) . For polyamides made with AEP, the amine hydrogen equivalent weight was calculated by dividing the number average molecular weight (calculated from amine nitrogen content determined by titration) by 3 (with the assumption that the -NH2 and - NH groups have equal reactivity toward the dimer acid so that the average polyamide molecule contains 3 amine hydrogens) . We do not know whether this assumption is valid. e From amine nitrogen content determined by titration (this lot of AEP apparently contained approximately 2% water) f Viscosity was too high to measure conveniently by method used; product was too high in viscosity to be of interest in further examples. EXAMPLE 2 Preparation of a coating from EPON Resin 828 cured with the products of Example 1 and property comparison with standard "polyamide"-cured epoxy coatings. The dimer acid-AEP "polyamide" curing agent from Example 1, run 2, was diluted with a 70:30 (w:w) xylene : n-butyl alcohol mixture to a solids level of 60.97%. The curing agent solution was mixed with an 81.25% solids solution of EPON Resin 828 in a 1:1:1 (w:w:w) methyl isobutyl ketone (MIBK) : propylene glycol monomethyl ether (PGME) : xylene mixture (with 110 parts of curing agent per 100 parts of resin) . The specific amount of solvents used was that required to obtain a Gardner "D" viscosity. A standard polyamide-cured coating system (EPON Resin 1001 cured with EPI-CURE Curing Agent 3115) and a high-solids system cured with a standard polyamide curing agent (EPON Resin 828 cured with EPI-CURE Curing Agent 3140) as well as a system based on EPON Resin 828 cured with the polyamide condensation product of dimer acid with the diamine 2-methyl-l, 5-pentanediamine (MPTD) (Example 1, run 9) were prepared -as shown in Table 2 and similarly diluted with the same solvent mixtures to a Gardner "D" viscosity. The resin-curing agent solutions were allowed to stand for 40 or 50 minutes at room temperature (according to Table 2) as an induction period and then applied to cold rolled steel panels. Properties of the coated panels were determined after 24 hours and after 7 days as shown in Table 2 below. As can be seen from Table 2 below that the system of EPON Resin 828 cured with the dimer acid-AEP polyamide from Example 1, run 2, after 7 days, was as good in flexibility, pencil hardness and adhesion and almost as good in MIBK resistance and direct and reverse impact resistance as the standard system of EPON Resin 1001 cured with EPI-CURE Curing Agent 3115 and the invention system had a Gardner D viscosity at 69% solids compared to 50% solids for the standard system. A second control system using a relatively low viscosity commercial "polyamide" curing agent (EPI-CURE Curing Agent 3140) as a curing agent for EPON Resin 828, also had a Gardner D viscosity at 70% solids but was far inferior to the other two systems in impact resistance. A third control system, EPON Resin 828 cured with a "polyamide" based on dimer acid and 2-methyl-l, 5-pentanediamine (MPTD) (product of Example 1, run 9) did not cure at an acceptable rate, with the film being wet even after standing for 4 days . TABLE 2 4> TABLE 2 TABLE 2 a EPON Resin 828 was diluted with a 1:1:1 weight mixture of methyl isobutyl ketone (MIBK) :propylene glycol monomethyl ether (PGME): xylene. EPON Resin 1001 solution was prepared by diluting EPON Resin 1001-CX-75 (a 75% solution of EPON Resin 1001 in a 65:35 by weight MIBK:xylene mixture) further with a 1:1:1 MIBK: PGME: xylene mixture. k Curing agent solutions (except for EPI-CURE 3115) were prepared by diluting the respective curing agent with a 70:30 weight mixture of xylene : n-butyl alcohol. The solution of EPI-CURE 3115 was prepared by diluting EPICURE 3115-X-70 (a 70% solution of EPI-CURE 3115 in xylene) further with a 70:30 weight mixture of xylene:n- butyl alcohol . c Amount of time between mixing of resin and curing agent solutions and application of mixture to cold rolled steel panels . EXAMPLE 3 Use of dimer acid-AEP polyamides from Example 1 as curing agents for epoxy systems designed for secondary containment membranes in comparison with two commercial polyamide-amine curing agents and a commercial secondary containment membrane curing agent. EPON Resin 8132 (or EPON Resin 828) was mixed in flasks with some of the dimer acid-AEP polyamides from Example 1 (at various weight ratios) . As a control system, EPON Resin 8132 was mixed with a commercial secondary containment membrane curing agent EPI-CURE Curing Agent 3266. Two sets of control systems were provided by curing EPON Resin 8132 with various ratios of EPI-CURE 3125 and EPI-CURE 3115 (standard commercial polyamide-amine curing agents) . The mixtures were degassed by centrifugation at room temperature (or under vacuum in a flask in a 100C oil bath for the more viscous systems based on EPON Resin 828) and poured into molds comprised of two glass or metal plates separated by a polytetrafluoroethylene spacer 1/8" (3.2 mm) in diameter. The materials were allowed to cure overnight at room temperature and then were postcured for two hours at 100 °C. The castings were removed from the molds and test samples were cut from the castings. Test results are shown in Tables 3a through 3d. TABLE 3a TABLE 3b TABLE 3b (cont'd) TABLE 3c TABLE 3d I - I As can be seen from Table 3a above that systems of EPON Resin 8132 cured with the AEP-dimer acid condensates from Example 1 are much higher in tear resistance and in tensile strength and modulus, and sometimes in elongation to break, than EPON Resin 8132 cured with the commercial secondary containment membrane curing agent. Combinations of cured properties obtained with EPON Resin 828 cured with the AEP-dimer acid condensate from Example 1 were generally even better (Table 3b) . From Figures 1, 2 and 3, based on the data in Tables 3a through 3d, one can see that castings based on EPON Resin 828 (plot symbol E) or EPON Resin 8132 (plot symbol D) and cured with AEP-dimer acid condensates from Example 1, over a range of curing agent/resin ratios, give better combinations of tear resistance and tensile elongation than castings based on EPON Resin 8132 cured with EPI-CURE Curing Agent 3125 (plot symbol A) or with EPI-CURE Curing Agent 3115 (plot symbol B) or the control casting of EPON Resin 8132 cured with the commercial secondary containment membrane curing agent (plot symbol C) . At high tensile elongations, the available combinations of tensile elongation and tensile strength are also better for the compositions based on the invention curing agents (plot symbols D and E) than for either of the other two types of systems. EXAMPLE 4 Use of product of Example 1 together with a non- reactive diluent as a curing agent for epoxy systems designed for secondary containment coating. EPON Resin 8132 was mixed in flasks with the AEP- dimer acid condensate from Example 1, run 4 (at a range of weight ratios) diluted with various amounts of NEODOL 23 (a linear primary aliphatic alcohol mixture containing primarily 1-dodecanol and 1-tridecanol) . The mixtures were degassed by centrifugation and poured into molds comprised of two metal plates separated by a polytetrafluoroethylene spacer 1/8" (3.2 mm) in diameter. The materials were allowed to cure overnight at room temperature and then were postcured for two hours at 100 °C. The castings were removed from the molds and test samples were cut from the castings. Test results are shown in Table 4. TABLE 4 TABLE 4 (cont'd) TABLE 4 (cont'd) EXAMPLE 5 Use of dimer acid-AEP polyamides from Example 1 as curing agents for low-viscosity aliphatic diglycidyl ether epoxy resins in preparation of low viscosity epoxy systems designed for use in elastomeric secondary containment membranes. HELOXY Modifiers 68 (neopentyl glycol diglycidyl ether), 107 (diglycidyl ether of 1, 4-cyclohexanedimethanol) and 32 (diglycidyl ether of a poly (propylene oxide) glycol) were mixed in flasks, at various weight ratios, with some of the dimer acid-AEP polyamides from Example 1. The mixtures were degassed by centrifugation at room temperature and poured into molds comprised of two glass or metal plates separated by a polytetrafluoroethylene spacer 1/8" (3.2 mm) in diameter. The materials were cured for two hours at 100 °C and then for two hours at 175 °C. The castings were removed from the molds and test samples were cut from the castings. Test results are shown in Table 5, in comparison with one of the same control systems used in Example 3. Table 5 Table 5 (cont'd) 4- » O As can be seen from the castings based on HELOXY Modifier 68 or HELOXY Modifier 107 and cured with AEP-dimer acid condensates from Example 1, at high curing agent/resin ratios, give considerably higher tensile elongation than the control casting of EPON Resin 8132 cures with the commercial secondary containment membrane curing agent EPI-CURE Curing Agent 3266 with only relatively small losses of tensile strength, tensile modulus and tear resistance. These systems, being based on very low viscosity epoxy components, have the advantage of much lower viscosity than the systems in Example 3. The casting based on HELOXY Modifier 32 is much more elastomeric than the others, with lower modulus and higher elongation, but tensile strength and tear resistance are also much lower. EXAMPLE 6 Preparation of amine-terminated low amine hydrogen functionality "polyamide" curing agents by reaction of dimerized fatty acids and optionally azelaic acid (chain extender) and/or tall oil fatty acid (chain terminator) with excess N- (2-aminoethyl) piperazine (AEP). The components shown in Table 6 below were combined in 2-liter reaction kettles with paddle stirrers. The mixtures were heated at approximately 25 °C/hour until distillation of reaction product water began. Following water distillation, they were then brought up to final temperature at 55-80 °C/hr. Excess AEP was then removed under reduced pressure at the indicated final temperature. Product "polyamides" were liquids at room temperature and had the amine values and amine nitrogen equivalent weights shown below in Table 6. TABLE 6 Calculated from amine value determined by titration, Examples 7 and 8 The following curing agents 7 and 8 were used to prepare formulations of roofing membranes as claimed in the present invention. Curing Agent 7 and Curing Agent 8 are the aminoalkylpiperazine-based amine terminated polyamine curing agents. The dimer acid (~10% C ] _g monobasic acids, ~80% C^ ζ dibasic acids, ~10% C54 tribasic acids) was obtained from Shell Chemical Co. N- (2-aminoethyl) piperazine, commercially available from a variety of vendors, Union Carbide, Dow Chemical Company and E.I. DuPont de Nemours and Co. was used. EPON Resin 828 (a diglycidyl ether of bisphenol A having epoxy equivalent weight of 185-192), EPON Resin 815 and 815C (each is a blend of EPON Resin 828 and HELOXY Modifier 61 having epoxy equivalent weight of 175-195) , EPON Resin 8132 (a blend of EPON Resin 828 and HELOXY Modifier 9 having epoxy equivalent weight of 195-215) and EPON Resin 8280 (a diglycidyl ether of bisphenol A having epoxy equivalent weight of 185-195) were obtained from Shell Chemical Company. HELOXY Modifier 9 (an alkyl C 1 - C-13 glycidyl ether having an epoxy equivalent weight of 275-295) was obtained from Shell Chemical Company. Curing Agent 7 "Dimer acid" with a Gardner viscosity of Z4 (carboxyl equivalent weight within the range of between approximately 280 and 290) from Shell Chemical Company (1225 grams -COOH equivalents) was mixed with 1130 grams of N- (2-aminoethyl) piperazine (AEP) at a reactant ratio of 2.05 moles amine/eq COOH in a round-bottom flask equipped with a heating mantle, a paddle stirrer, a thermocouple, a nitrogen purge, and a Vigreux column with a vacuum distillation takeoff. The system was purged with nitrogen and heating was started. Typically, when the pot temperature had reached 150-170 °C, water began to distill at atmospheric pressure. Water distillation at atmospheric pressure continued until the pot temperature had been raised to 220-240 °C; the pot was held at this temperature until water distillation had stopped or had essentially stopped. Vacuum was then applied and vacuum distillation of the amine was carried out until the pot temperature had risen back to 220-240 °C and the rate of amine offtake had become essentially negligible. Vacuum stripping was then continued at this temperature for approximately another 15 minutes. The product was then allowed to cool to about 150 °C under vacuum or under a stream of nitrogen and were then poured into jars. The products were characterized by amine nitrogen content (by titration) of 6.5% nitrogen by titration and viscosity of Ubbelohde kinematic viscosity 40 °C 28,800 mm^/sec. Curing Agent 8 "Dimer acid" with a Gardner viscosity of Z4 (carboxyl equivalent weight within the range of between approximately 280 and 290) from Shell Chemical Company (655 grams 2.298-COOH equivalents) was mixed with 73 grams of tall oil fatty acid (carboxyl equivalent weight within the range of 288 and 300 from Georgia Pacific Company) and 672 grams of N- (2-ammoethyl) piperazine (AEP) at a reactant ratio of 2.04 moles amme/eq COOH in a 2-litre round-bottom flask equipped with a heating mantle, a paddle stirrer, a thermocouple, a nitrogen purge, and a Vigreux column with a vacuum distillation takeoff. The system was purged with nitrogen and heating was started. Typically, when the pot temperature had reached 150-170 °C, water began to distill at atmospheric pressure. Water distillation at atmospheric pressure continued until the pot temperature had been raised to 220-240 °C; the pot was held at this temperature until water distillation had stopped. Vacuum was then applied and vacuum distillation of the amine was carried out until the pot temperature had risen back to 220-240 °C and the rate of amine offtake had become essentially negligible. Vacuum stripping was then continued at this temperature for approximately another 1 hour, vacuum is then recovered. The intermediate product (net 1011 grams) had a Garner color of 8-9, % titratable nitrogen 6.81%, amine value of 0.50 and a viscosity of 58,800 cPs . This intermediate product was then blended with 288.9 grams of a polyoxypropylenetriamine having a molecular weight of approximately 403 (commercially available as JEFFAMINE D-400 from Huntsman Chemicals; JEFFAMINE is a trademark) and 144.4 grams of para-t-butyl phenol (commercially available from a variety of vendors) was then added to the resulting mixture. The product was mixed until the para tertiary butyl phenol had completely dissolved then allowed to cool to about 60 °C under a stream of nitrogen and were then poured into jars. The products were characterized by amine nitrogen content (by titration) of 5.57% nitrogen by titration and viscosity of approximately 8,200 centipoise. Thermoset Epoxy Waterproof Membranes The base properties of the thermosetting resin compositions are included in the table below. TABLE 1 Physical Properties of Roofing Formulations vs. Alternative Flexible Epoxy Systems In the following table, various flexible epoxy formulations were prepared. Formula 1A and Formula IB represent the present invention. Formula 1A is based on a liquid epoxy resin that is specially designed for highly filled systems, a mono unctional epoxy modifier and the curing agent set forth in Curing Agent 8 above. Formula IB contains the same binder system as Formula 1A along with extender mineral fillers. Formula 2 (A and B) and Formula 3 (A and B) each represent a conventional route to flexible epoxy systems and are included for comparative purposes only. Formula 2A is based on a liquid epoxy resin that is specially designed for highly filled systems, a monofunctional epoxy modifier and a low viscosity polyamide curing agent that has been incorporated at 10% over stoichiometry . Formula 2B contains the same binder system as Formula 2A along with extender mineral fillers. Formula 3A is based on a flexible epoxy resin cured with an ethylene amine. Formula 3B contains the same binder system as Formula 3A along with extender mineral fillers. For those formulations which did not contain extender mineral fillers, the epoxy resins were first mixed at room temperature and then the curing agent was added while mixing in a suitable vessel. After thorough mixing, the compositions were poured into molds where they were allowed to cure for 24 hours at 25 °C, then postcured for 2 hours at 100 °C. For those formulations which contained extender mineral fillers, the epoxy resins and extender mineral fillers were first mixed at room temperature and then the curing agent was added while mixing in a suitable vessel. After thorough mixing, the compositions were poured into molds where they were allowed to cure for 24 hours at 25 °C, then postcured for 2 hours at 100 °C. Note that each of the formulations which contained extender mineral fillers were filled to 45.9%. Once prepared, the casting plaque for each formulation was tested for A-tear test (ASTM D-624), C-die tensile properties (ASTM D-638), fatigue testing (a modification of ASTM D-5849, test condition 1, with the only modification being that 1 cycle/min. for a duration of 10,000 cycles was used), and low temperature flexibility (ASTM D-1970) , each incorporated herein by reference. The data obtained is included in the table below . TABLE 2 TABLE 2 (cont'd) Each of the properties described in the table above plays an important role in determining whether materials will be satisfactory for use in waterproofing applications . Elongation is important due to building movements from settling, thermal changes, and wind loads. Sufficient elongation is required to accommodate whatever movement occurs in the structure. Typical roofing materials have high levels of elongation to accommodate not only the building movement but to relieve the stresses and strains caused by attachment only at localized points. For a fully adhered system, point attachment is not an issue; thus elongation is required only to accommodate building movement. Sufficient tensile strength is required in roofing materials only to prevent material failure around localized attachments, damage points, and areas of stress that cause sufficient movement to approach the ultimate elongation. For fully adhered systems, attachment and damage points do not induce areas of stress and thus are not an item of consideration. Modulus (i.e., stiffness) of roofing systems needs to be low enough to allow the material to easily elongate when under stress without inducing damage to the materials underneath or to the attachment points. Low modulus is preferred in roofing materials because you want the material to give under stresses rather than fail (i.e., lose waterproofing integrity). Tear strength is the ability of a material to resist the propagation of an existing flaw. Tear strength is particularly important for locally attached roofing materials due to the penetrations and other damage induced during its attachments; however, tear strength is important to all roofing materials because it allows them to sustain damage during normal lifetimes while maintaining the integrity of the waterproofing. Adhesion of roofing membranes to the underlying substrate allows the elimination of attachment penetrations; as well as, the requirement for roofing ballast to prevent wind lifting. A fully adhered roof membrane eliminates the most common causes of roofing material failures. Fatigue resistance is the ability of a material to withstand mechanical and thermal cycling. Roofing membranes must withstand repeated mechanical and thermal cycling due to environmental changes, building movement and foot traffic. A material may have excellent tensile properties (elongation and strength) but not necessarily, superior fatigue resistance. As noted in the table above, the present invention, with or without extender mineral fillers, demonstrates superior elongation and superior fatigue resistance while maintaining acceptable strength, modulus, tear strength, and low temperature flexibility when compared with conventional routes to flexible epoxies. This highly desirable balance of properties is obtained using the formulation of the present invention. Application Example 1 The application of waterproof membrane formulations to prepainted, weathered wooden deck and ramp. The formulations were made in the same manner as noted in the formulation above with the exception the extender mineral fillers and color pigments were added to the epoxy resin component and the curing agent component prior to mixing the two components. The level of extender mineral fillers and pigments added depended on the final use of the formulation. For instance, the grout formulation was designed to be high in viscosity with high thixotropy while the leveling formulation was designed with lower viscosity to achieve optimal flow and appearance. TABLE 3 Formulations Used On Wooden Deck And Ramp NJ TABLE 3 (cont'd) Original Condition An existing modular office space building had previously been made wheel chair accessible by means of a ramp and deck. This ramp and deck were chosen as the test site because they receive full unhindered exposure to the sun, elements, and daily foot-traffic. This location was considered a severe-service area. The dimensions of the ramp and deck are shown in Figure 1. The surface of this wooden deck and ramp was made of 3/4" plywood which had been painted with standard exterior latex. The entire plywood surface was severely weathered (deep cracks) with severe wear areas. These severe wear areas were characterized by complete delamination of the top layer of the plywood from the underlying layers. Repair and Application of Waterproof Membrane The present invention' s tolerance to wooden substrates was demonstrated by application of the above formulations to the ramp and deck. In June, 1997, the deck and ramp were swept and then loose paint and/or wood was removed by hand. The deck was washed with a commercial deck wash (i.e., bleach) and rinsed thoroughly. After drying overnight, the delaminated areas were removed by a hammer and chisel to provide a fully intact surface. The joints between the plywood sheets ranged from 1/16" to over 1/4". Before applying the flexible membrane, the White Grout Formulation was used to level the low spots and to fill the joints. The grout set within 6 hours and was allowed to cure overnight. The next day, the outside application conditions were found to be 90-95 °F, 45-50% relative humidity, the surface temperature of the wooden deck and ramp was 120-125 °F (measured by infrared gun) . The Leveling and Ramp Formulations were applied by roller to a total final film thickness of 50-60 mils. After applying these formulations, the liquid membrane was topped with a decorative quartz aggregate (sand-like material for traction) . The deck and ramp were placed back into service the next morning. Eight Month Results From June, 1997 to March, 1998, the average high temperature was 76.3 °F, the average low was 56.4 °F and the average total rainfall/month was 4.2 inches. After almost eight months, the deck remained in excellent condition. There were no signs of membrane failure. There was minimal chalking and very little yellowing. Surprisingly, the deck did not show any leaf stains even though leaves from surrounding oak trees accumulated on the deck. The membrane remained firmly adhered to the plywood and was completely intact as a continuous, formed-in-place material. The aggregate remained firmly embedded in the membrane and there were no signs of any wear path from the daily foot-traffic. The only discernible change observed was a hairline crack that developed at the joint that was originally about 1/8" wide. It appeared that the grout formulation did not have sufficient thixotropy to remain in the joint before setting. The membrane formulation covered the joint but developed a hairline failure due to the excessive gap being covered by the membrane. Application Example 2 Plywood deck test boxes TABLE 4 Formulations used on Test Roof Boxes TABLE 4 (cont'd) Formulations used on Test Roof Boxes To further test the performance of the present invention, two plywood test boxes were constructed. These test boxes are commonly used by roofing system manufacturers to evaluate new formulations. Each box was constructed of 1/4" interior grade plywood using a 4'X4' wooden pallet as the base. The first test box (Box One - Figure 2) was designed to simulate a flat roof area with severe ponding (pooling of water) . As shown in Figure 2, the interior of the box was completely sealed and had a single drain hole { ' diameter) placed 1" up from the bottom of the box. All joint areas were filled with the White Grout Formulation noted above in Table 4. The interior surfaces were coated with the White and Black Membrane formulations described above using either a brush or a roller. One-half of Box One's interior surface was coated with the White Membrane Formulation. The remaining half of Box One's interior surface was coated with the Black Membrane Formulation. The white formulation was used to evaluate discoloration after prolonged exposure. The black formulation was used to evaluate the effect of excessive heat uptake from solar radiation. To protect the exterior surfaces of Box One from environmental degradation, the exterior surfaces were coated with the Leveling Formulation noted in Example One above. The second test box (Box Two - Figure 3) was designed to simulate a well-drained roof with an area of severe substrate movement. Box Two was built so that the base was convex and readily drained through the *s"-hole in the box's center. The area of severe substrate movement was created by a non-mechanically fastened, two-foot side (designated as Side A in Figure 3) . Example 2 formulations were applied indoors to Box 2 in July, 1997. During application, Side A was fastened with wood screws to the pallet and the other three sides of Box Two. All of the joint areas of Box Two were filled with the white grout formulation. After the grout completely cured, the wood screws holding Side A in place were removed. The interior and exterior surfaces were coated as described above for Box One. After five (5) days of indoor curing, the mechanical fasteners were removed from the 2' side of the box. In effect, this fourth side of the test box was simply "glued" in-place by the grout formulation and then covered with the flexible membrane formulation. Nine Month Results From July, 97 to April, 1998, the average high was 76.3 °F, the average low was 56.4 °F and the average total rainfall/month was 4.2 inches. Examination of Box One in April, 1998 showed that significant dirt and dust had accumulated in the box but the waterproof membrane had not failed. The surface was still flexible and fully intact. Even with the severe water ponding, there was no evidence of blistering or other failure mechanisms associated with the passage of water through the film. Examination of the box' s underside showed no leakage had occurred. Examination of Box Two in April 1998 showed that the membrane was unaffected by exposure to the elements. Slight chalking could be seen on the black area. This was expected due to the use of a standard bisphenol A epoxy resin in these formulations. Examination of Side A of Box Two (the 2' side of the box) showed that the box withstood several severe thunderstorms. The only noticeable damage was a hairline crack on one edge. Application Example 3 - Application To Existing BUR Roof On Storage Building TABLE A Formulations Used On The Storage Building Roof C Original Condition of Building A storage building with a roof in need of repairs due to age and severe failure of the flashing around the entry ports was used to further test the present invention. The original roof on the building was a traditional multi-layer BUR (built-up roof based on alternating layers of felt and asphaltic sealer) with a heavy layer of roofing stones placed on top to prevent wind-lifting. The roofing stones, fine grit and weathered asphalt, were mechanically removed prior to application of the present invention. There were several areas on the roof where the fiberglass felt was torn or lifted up from the inner layers. Additionally, the exposed surface showed indentations caused by the weight of the stones. Another difficulty encountered was the severe failure of the flashing around the entry ports. Roof protrusions are notorious areas for roofing failures and in this case, the existing flashing had severely deteriorated. Application of Waterproofing Membrane Application of the present invention to the roof was started in August, 1997. At 10 a.m. on the day that application began, the roof's surface temperature in full sun was 160 °F (measured using an infrared temperature gun) . First, areas where the deteriorated flashing had completely pulled away from the entry ports were either adhered to the substrate by a commercial epoxy adhesive grout or in the most severe cases, completely removed by using a box knife. Once these areas were prepared, the grout formulation was applied by trowel to the entire flashing area around the entry portals. Fiberglass mat was pressed by hand-lay-up roller into the grout and additional grout applied to make a smooth surface. The flashing repair job used a total of three layers of fiberglass alternating with flexible epoxy grout with the final layer being the grout formulation itself. This same grout formulation was also applied to the outer edge of the roof to completely seal the edge of the existing BUR roof to the one inch (1") metal flashing that surrounded the outer edge of the roof. After applying the grout to the entry portals and the roof flashing, the grout was cured overnight. The next day, the gray membrane formulation was applied to the previously grouted areas. The remaining roof area was coated to a thickness of approximately 50 mils using a roller. Most of the roof area was left as-applied to simulate a synthetic roofing finish but as shown in Figure 4, a two foot (2') area on the roof's northwest side was topped with standard roofing granules on one section and #2 roofing gravel on the other section. These toppings were simply hand-broadcast on the membrane approximately 60 minutes after the application of the gray membrane formulation. The next morning, the membrane was cured to the point that it could easily be walked on. Inspection of the membrane showed a few pinholes and a few seams that had not completely sealed with the first application . Five days later, the loose seams and pinholes were completely sealed using additional gray waterproofing membrane formulation. Six Month Results From August, 97 to February, 1998, the average high was 80.42 °F, the average low was 59.6 °F and the average total rainfall/month was 4.22 inches. At 6 months, the roof remained in excellent condition with no sign of failure. The gray membrane remained firmly adhered and was completely intact as a continuous, formed-in-place roof. The flashing also remained intact. The roofing granules and gravel remained firmly attached to the membrane. The roof had lost some of its gloss but there was only minor chalking. An area of the roof demonstrated severe ponding, but close inspection of this area did not show any evidence of failure.

Claims: C L A I M S 1. A curable epoxy resin composition comprising: (a) an epoxy resin having at least 1.5 epoxy groups per molecule, and (b) a liquid amine terminated polyamine prepared by reacting a Cχg_5o dicarboxylic acid and an aminoalkylpiperazine . 2. The composition of claim 1 wherein the mole ratio of the epoxy resin to liquid amine terminated polyamine is from about 3:1 to about 1:3. 3. The composition of claim 1 wherein the aminoalkylpiperazine is selected from the group consisting of N-(2- aminoethyl) piperazine, N, N-bis (2-aminoethyl) piperazine and N, N-bis (3-aminopropyl) piperazine . 4. The composition of claim 3 wherein the dicarboxylic acid is selected from the group consisting of adducts of acrylic and methacrylic acids with unsaturated fatty acids and dimerized unsaturated fatty acids. 5. The composition of claim 3 wherein the dicarboxylic acid is a dimerized unsaturated fatty acid. 6. The composition of claim 1 wherein the liquid amine terminated polyamine component (b) is prepared by reacting, in a reaction mixture, (i) a Cχg-50 dicarboxylic acid, (ii) at least one other dicarboxylic acid and (iii) an aminoalkylpiperazine. 7. The composition of claim 6 wherein the reaction mixture further comprises a monocarboxylic acid. 8. The composition of claim 1 further comprising a curing agent for epoxy resin other than component (b) . 9. The composition of claim 1 further comprising an accelerator . 10. A substrate impregnated with the curable epoxy resin composition of claim 1. 11. A substrate impregnated with the curable epoxy resin composition of claim 8 12. A cured composition of claim 10. 13. The composition of claim 10 wherein the substrate is selected from the group consisting of nylon, polyesters, fiberglass, graphite, and aramids. 14. A cured composition of claim 11. 15. A substrate coated with the curable epoxy resin composition of claim 1. 16. An article of manufacture comprising a shaped article having a surface and an adhesive composition comprising the composition of claim 1 applied on at least a portion of said surface. 17. A membrane formed of a cured composition of claim 1 . 18. A hydroxy-functional resin produced by reacting: (a) an epoxy resin having at least 1.5 epoxy groups per molecule; (b) a liquid amine terminated polyamine prepared by reacting a dicarboxylic acid and an aminoalkylpiperazine; and (c) a hydroxy-functional amine, such that the equivalents ratio of amine hydrogen to epoxy group are within the range of from about 1:2 to about 2:1. 19. A curable resin composition comprising the hydroxy- functional resin of claim 16 and a curing agent capable of reacting with hydroxyl groups. 20. The curable resin composition of claim 17 wherein the curing agent is selected from the group consisting of poly (-hydroxyalkyl) esters of polycarboxylic acids, urea- formaldehydes and melamine-formaldehyde resins. 21. A thermoset epoxy waterproofing membrane comprising: (a) one or more epoxy resin (s) having an average of at least 1.5 epoxy groups per molecule; (b) a liquid amine terminated polyamine prepared by reacting at least one Cχg_50 dicarboxylic acid and an aminoalkylpiperazine in a ratio of moles of aminoalkylpiperazine to equivalents of carboxyl group in the acid of greater than 0.75:1; (c) one or more optional polyamine (s) ; and (d) one or more optional fillers; wherein the tensile modulus of the thermoset epoxy waterproofing membranes is less than 200,000 psi and the tensile elongation of the thermoset epoxy waterproofing membrane is greater than 20%. 22. The membrane of claim 1 wherein the mole ratio of the epoxy resin to liquid amine terminated polyamine is from about 3:1 to about 1:3. 23. The membrane of claim 1 wherein the aminoalkylpiperazine is of the formula: r, l / R — -N \ N— R .2 (I) \ / wherein R! is -H and R^ is -R^-NH2, wherein R-3 is a divalent aliphatic linkage. 24. The membrane of claim 1 wherein the liquid amine terminated polyamine component (b) is prepared by reacting, in a reaction mixture, (i) the Cχg-50 dicarboxylic acid, (ii) at least one other dicarboxylic acid and (iii) the aminoalkylpiperazine. 25. The membrane of claims 1-4 wherein the reaction mixture further comprises a monocarboxylic acid. 26. The membrane of claim 1 which further comprises one or more polyamine (s) other than component (b) . 27. The membrane of claim 6 wherein the one or more polyamine (s) other than component (b) , are selected from diethylenetriamine, triethyltetramine, isophoronediamine, m-xylenediamine and polyoxypropyleneamines . 28. The membrane of claims 1-7, which further comprises fillers which are selected from minerals, polymers and mixtures thereof. 29. The membrane of claims 1-8, which further comprises one or more modifying resin (s) selected from one or more acrylic monomers, acrylic resins, hydrocarbon resins (such as coal tar) and polyester resins. 30. A roof coating, a parking deck, a land fill lining, basement water carrier, or water retention pond liner comprising the thermoset epoxy waterproofing membrane of claims 1-9.

Inventors: CORLEY LARRY STEVEN, EHRLICH MARTIN LEE, STEWART STEVEN LEE, WEINMANN DANIEL JAMES, CORLEY, LARRY, STEVEN, EHRLICH, MARTIN, LEE, STEWART, STEVEN, LEE, WEINMANN, DANIEL, JAMES
Applicants: SHELL INT RESEARCH, SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ B.V.
Application year: 1999
Main classification: C08G59
IPC codes: B32B27, C08G59, C08G69, C08J5, C08K3, C08L63, C08L77, C08L101, C09K3