Benzylated polyalkylene polyamines composition with enhanced epoxy coatings performance

Abstract

The present invention relates to a benzylated polyalkylene polyamines composition for curing epoxy resins and providing enhanced epoxy coatings performance.

Description

Benzylated Polyalkylene Polyamines Composition with Enhanced Epoxy Coatings PerformanceBACKGROUND OF THE INVENTION

[0001] The present invention relates to a benzylated polyalkylene polyamines composition for curing epoxy resins and providing enhanced epoxy coatings performance.

[0002] The uses of epoxy resins which are cured, hardened, and / or crosslinked with amine-based curing agents are well known. These amine-epoxy materials are widely used in applications ranging from marine and protective coatings, adhesives, and composites to construction products for concrete, cementitious or ceramic substrates, often referred to as civil engineering applications such as formulations for concrete flooring.

[0003] While numerous curable epoxy systems are known, the current systems are lacking in some respects. These include the inability to cure adequately at comparatively low temperatures, such as at 10°C, 5°C or lower with good pot life or working time. Also, at relatively high humidity coatings or films of poor appearance can be observed as well as reduction in gloss or tackiness. In addition, better corrosion protection of metal substrates by epoxy curing systems needs to be improved. Systems that are able to cure under these conditions often contain plasticizers.

[0004] The composition of this invention has addressed these problems inherent in epoxy coatings and provides a solution with enhanced performance characteristics. Most notably the composition of this invention provides a curing agent system that contains no phenols or alkylphenols which allows for rapid epoxy cure at temperatures as low as 0°C with good working time. It also produces coatings with excellent surface appearance and corrosion protection of metal substrates, and good adhesion to concrete substrate even at low temperature such as 10°C. In addition, it constitutes a low VOC and low emission epoxy formulation and can be used without volatile organic solvents and minimum to no commonly used plasticizers.BRIEF SUMMARY OF THE INVENTION

[0005] The present invention discloses curing agent compositions and methods of making such compositions. These curing agent compositions can be used to cure, harden, and / or crosslink an epoxy resin.

[0006] The present invention discloses a curing agent composition comprising of the following components:(a) at least one benzylated polyalkylene polyamine;(b) the transaminated reaction product of dialkylaminoalkylphenol with dimethylaminopropylamine (DMAPA) or N,N-dimethyldipropylene triamine (DMAPAPA);(c) at least one amidoamine; and(d) at least one phenol formaldehyde resin.

[0007] Preferably, the at least one benzylated polyalkylene polyamine component comprises a benzylated polyalkylene polyamine having at least three nitrogen atoms, at least three active amine hydrogen atoms and at least one benzyl group. Preferably, in one embodiment the at least one benzylated polyalkylene polyamine comprises the reaction product of the reductive amination of a benzaldehyde compound with a polyalkylene polyamine having at least three nitrogen atoms. Preferred examples of this embodiment are benzylated diethylenetriamine, benzylated triethylenetetramine, benzylated N,N’-bis(3-aminopropyl)ethylenediamine, and benzylated N,N'- bis(3-aminopropyl)diethylenetriamine, or any combination thereof. Preferably, the benzylated polyalkylene polyamine component comprises at least 5 wt % dibenzylated polyalkylene polyamines. In another preferred embodiment the at least one benzylated polyalkylene polyamine comprises the reaction product of a benzyl halide with a polyalkylene polyamine having at least three nitrogen atoms. Benzylated N,N’-bis(3-aminopropyl)ethylenediamine is described in U.S. Patent No. 8318309, which is incorporated herein by reference in its entirety. Benzylated DETA and TETA is described in U.S. Patent No. 8147964, which is incorporated herein by reference in its entirety. Benzylated amine used in waterborne curing agents is described in U.S. Patent No. 8143331 , which is incorporated herein by reference in its entirety.

[0008] Preferably, the transaminated reaction product of a dialkylaminomethylphenol with dimethylaminopropylamine or N,N-dimethyldipropylene triamine is obtained by reacting a substituted phenolic compound (Mannich base) having at least one substituent of formula:RI(R2)N-CH2- wherein R1 and R2 are each independently of the other linear or branched C1-C4 alkyl with dimethylaminopropylamine or N,N-dimethyldipropylene triamine.

[0009] Preferably, the at least one amidoamine component of this composition comprises of the reaction product of a fatty acid and polyethyleneamine. Common mono-functional unsaturated C- 6 to C-20 fatty acids employed in making amidoamines include tall oil fatty acid (TOFA), cotton seed fatty acid or soya fatty acid orthe like. In one preferred embodiment, the fatty acid is selected from the group consisting of tall oil fatty acid, cotton seed fatty acid, and soya fatty acid and the polyethyleneamine is selected from the group consisting of diethylenetriamine, triethylenetetramine, and tetraethylenepentamine.

[0010] Preferably, the phenol formaldehyde resin of this composition is a synthetic polymer obtained by the reaction of phenol or substituted phenol with formaldehyde. In one preferred embodiment of the invention, the phenol formaldehyde resin is a Novolac resin.

[0011] In one preferred embodiment, the curing agent composition further comprises(e) at least one C12-C16 alkyletheramine.

[0012] Preferably, the C12-C16 alkyletheramine component of this composition comprises of products derived from aliphatic alcohols and aliphatic amines. In one preferred embodiment, the C12-C16 alkyletheramine is selected from the group consisting of 3-(lsodecyloxy)propylamine (Tomamine PA-14), and 1,3-Propanediamine, N-[3-(tridecyloxy)propyl]-, branched (Tomamine DA17).

[0013] In another preferred embodiment, the curing agent composition further comprises(f) at least one aminopropylamine.

[0014] Preferably, the aminopropylamine component of this composition is selected from the group consisting of diethylaminopropyl amine, dimethylaminopropyl amine, dimethylaminopropyl propylamine and the like.

[0015] In another preferred embodiment, the curing agent composition further comprises(g) at least one polyetheramine.

[0016] Preferably, the polyetheramine component of this composition comprises of etheramines with repeating units going from linear to branched such as Jeffamine D-230, Jeffamine D-2000, and Jeffamine T-403.BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a graph of the hardness development of the coated glass panel for different blends with bis-phenol A resin that were cured at 23°C.

[0018] Figure 2 is a graph of the hardness development of the coated glass panel for different blends with bis-phenol A resin that were cured at 5°C.

[0019] Figure 3 is photo images of the hardener blends that were formulated with epoxy resin and cured and tested for carbamation resistance.

[0020] Figure 4 is photo images of the performance of the coating further evaluated in accelerated weathering studies where the developed curing agent was formulated with diluted resin blend and then subjected to Cleveland humidity exposure.

[0021] Figure 5 is a graph of the influence of resin diluents on dry speed at 5°C.

[0022] Figure 6 is a graph of the dry speed of Blend 32 at temperatures 0°C (32°F) and -5°C (23°F) with neat Bis-A resin and the diluted resin blend.

[0023] Figure 7 is a graph of the gel time measurements at lower temperature (10°C and 5°C) of Blend 32 with 90:10 Bis A Resin + Monoepoxy Diluent.

[0024] Figure 8 is a graph of the impact resistance of the hardener blend with the neat Bis-A resin, with 10% dilution (mono epoxy diluent or diepoxy functionalized diluent), and 15% dilution (mono epoxy diluent).

[0025] Figure 9 is photo images of the coated panels (initial and after 2500h exposure) in the salt spray chamber.

[0026] Figure 10 is photo images of the coated panels (before and after 2000h exposure) in the Cleveland humidity chamber.DETAILED DESCRIPTION OF INVENTION

[0027] In a preferred embodiment, the benzylated polyalkylene polyamine component of this invention is obtained by the reductive amination product of a benzaldehyde compound with a polyalkylene polyamine having at least three nitrogen atoms. In one preferred embodiment the at least one benzylated polyalkylene polyamine component comprises a benzylated polyethylene polyamine. In another preferred embodiment the at least one benzylated polyalkylene polyamine component is selected from the group consisting of benzylated diethylenetriamine, benzylated triethylenetetramine, benzylated N,N’-bis(3-aminopropyl)ethylenediamine, and benzylated N,N'- bis(3-aminopropyl)diethylenetriamine and mixtures thereof. The degree of benzylation depends on the equivalent’s ratio of benzaldehyde to reactive amine hydrogens in the polyamine in the reductive amination reaction. Thus, in one aspect of the invention, the curing agent composition comprising polyamine molecules having one, or two, or three, or four or more benzyl groups, or any combination thereof. In another aspect such benzylated polyalkylene polyamine component for the present invention comprises at least 5 wt % polyamines having at least two benzyl groups, i.e., having two or more benzyl groups. In other aspects of the invention the benzylated polyalkylene polyamine component comprises 10 to 100 wt %, desirably 30 to 100 wt %, polyamines having two or more benzyl groups.

[0028] Polyalkylene polyamine compounds that are useful in producing the benzylated polyalkylene polyamine compounds of the present invention include, but are not limited to, polyethylene polyamines, polypropylene polyamines, and combinations thereof. Non-limiting examples of polyethylene polyamines include diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA), pentaethylenehexamine (PEHA), N,N’-bis(3- aminopropyl)ethylenediamine (N4), and N,N'-bis(3-aminopropyl)diethylenetriamine (N5), and other higher polyethylene polyamines. Suitable polypropylene polyamines include, but are notlimited to, dipropylenetriamine, tripropylenetetramine, and other higher polypropylene polyamines. It will be recognized by those skilled in the art that polyethylene polyamines containing 4 or more nitrogens are available as complex mixtures, most of which contain the same number of nitrogens. Side products in these mixtures are often called congeners. For example, TETA contains not only linear TETA, but also tris-aminoethylamine, N,N'-bis aminoethylpiperazine, and 2-aminoethylaminoethylpiperazine. In one aspect of the present invention, the at least one polyalkylene polyamine compound is DETA, TETA, TEPA, PEHA, dipropylenetriamine, tripropylenetetramine or any combination thereof. In another aspect, the at least one polyalkylene polyamine compound is DETA, TETA, a mixture of DETA and TETA, or a mixture of DETA, TETA, and N,N’-bis(3-aminopropyl)ethylenediamine (N4). Typical mixtures of DETA and TETA are 1 part by weight of DETA to about 0.1 to about 1.1 parts by weight of TETA. In this and other aspects of the present invention, the mixtures of DETA and TETA can be 1 part by weight of DETA to about 0.1 , about 0.2, about 0.3, about 0.4, about 0.5, about 0.6, about 0.7, about 0.8, about 0.9, about 1 .0, or about 1.1 parts by weight of TETA. For example, DETA / TETA weight ratios of 70 / 30 and 50 / 50 are useful in the present invention. In another example, the mixture of DETA / TETA / N4 contains at least 20% of N4, at least 5% of TETA, and at least 15% of DETA.

[0029] The substituted phenolic compounds (Mannich bases) are preferably low-molecular- weight, tri-alkylaminomethylsubstituted phenols, ortho-, meta- and para-cresols, the isomeric xylenols, para-tert-butylphenol, para-nonylphenol, 1 -naphthol, 2-naphthol, diphenols or polyphenols, preferably resorcinol, hydroquinone, 4, 4'-dihydroxydiphenyl, 4, 4'- dihydroxydiphenyl ether, 4, 4'-dihydroxydiphenylsulfone, 4, 4'-dihydroxydiphenylmethane, bisphenol A, and the condensation products of phenol and formaldehyde termed novolaks. Preference is given to tri-C1- C4 alkylaminomethyl-substituted phenols and cresols, especially substituted phenol. Some di-alkylaminomethylsubstituted phenolic compounds may be suitable Mannich bases or combination of tri-alkylaminomethylsubstituted phenols and di- alkylaminomethylsubstituted phenols. A preferred tri-alkylaminomethylsubstituted phenol is tridimethylaminomethylphenol. A preferred di-alkylaminomethylsubstituted phenol is didimethylaminomethylphenol. Preferred substituted amine substituents on the phenol include dimethylaminopropylamine (DMAPA) and N, N-dimethyldipropylene triamine (DMAPAPA). The structures of these Mannich bases are shown below:Tri-DMAPA phenolic substituted Tri-DMAPAPA phenolic substituted Mannich baseMannich baseDi-DMAPA phenolic substituted Di-DMAPAPA phenolic substituted Mannich baseMannich base

[0030] The transaminated reaction product of a dialkylaminomethylphenol with dimethylaminopropylamine or N, N-dimethyldipropylene triamine may be composed of some oligomeric reaction products from further reaction of the dialkylaminomethylphenol with the intermediate 2° amine products from dimethylaminopropylamine (DMAPA) or N, N-dimethyldipropylene triamine (DMAPAPA).

[0031] The amidoamine component of this composition is comprised of the reaction product of a fatty acid and a polyalkylene polyamine. Common mono-functional unsaturated C-6 to C-20 fatty acids employed in making amidoamines include tall oil fatty acid (TOFA), cotton seed fatty acid or soya fatty acid or the like. Non-limiting examples of polyethylene polyamines include diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA), pentaethylenehexamine (PEHA), and other higher polyethylene polyamines. Suitable polypropylene polyamines include, but are not limited to, dipropylenetriamine, tripropylenetetramine, and other higher polypropylene polyamines. Preferred fatty acids are tall oil fatty acid (TOFA), cotton seed fatty acid or soya fatty acid. Preferred polyethylene polyamines include DETA, TETA and TEPA.

[0032] The phenol formaldehyde resin of this invention are synthetic polymers obtained by the reaction of phenol or substituted phenol with formaldehyde. The pre-polymer of this process known as Novolac such as Supraplast is used in this inventive composition. A preferred phenol formaldehyde resin such as Supraplast 3616 has a viscosity in the range of 200-400 Pa.S at 50°C.

[0033] The C12-C16 aliphatic etheramine component of this composition is comprised of the reaction product of a C12-C16 linear or iso alcohols and a polyalkylene polyamine. Non-limiting examples of polyalkylene polyamines include propylene diamines, dipropylene triamines, and other higher polyethylene polyamines.

[0034] The aminopropylamine component of this composition comprised of products such as diethylaminopropyl amine, dimethylaminopropyl amine, and dimethylaminopropyl propylamine.

[0035] The curing agent composition also contains polyetheramine that comprises of etheramines with repeating units going from linear to branched such as Jeffamine D-230, Jeffamine D-2000, and Jeffamine T-403.EPOXY RESIN COMPOSITION

[0036] In a preferred aspect of the invention, amine-epoxy compositions of the present disclosure comprise a curing agent composition and an epoxy composition comprising at least one multifunctional epoxy resin. Multifunctional epoxy resin, as used herein, describes compounds containing 2 or more 1 ,2-epoxy groups per molecule. The epoxy resin is preferably selected from the group consisting of aromatic epoxy resin, alicyclic epoxy resin, aliphatic epoxy resin, glycidyl ester resin, thioglycidyl ether resin, N-glycidyl ether resin, and combinations thereof. Epoxide compounds of this type are well known to those of skill in the art and are described in Y. Tanaka, “Synthesis and Characteristics of Epoxides', in C. A. May, ed., Epoxy Resins Chemistry and Technology (Marcel Dekker, 1988), which is incorporated and referenced here-in.

[0037] Preferable aromatic epoxy resin suitable for use in the present disclosure comprises the glycidyl ethers of polyhydric phenols, including the glycidyl ethers of dihydric phenols. Further preferred are the glycidyl ethers of resorcinol, hydroquinone, bis-(4-hydroxy-3,5-difluorophenyl)- methane, 1 ,1-bis-(4-hydroxyphenyl)-ethane, 2,2-bis-(4-hydroxy-3-methylphenyl)-propane, 2,2- bis-(4-hydroxy-3,5-dichlorophenyl) propane, 2,2-bis-(4-hydroxyphenyl)-propane (commercially known as bisphenol A), bis-(4-hydroxyphenyl)-methane (commercially known as bisphenol F, and which may contain varying amounts of 2-hydroxyphenyl isomers), and the like, or any combination thereof. Additionally, advanced dihydric phenols of the following structure also are useful in the present disclosure:wherein R’ is a divalent hydrocarbon radical of a dihydric phenol, such as those dihydric phenols listed above, and p is an average value between 0 and about 7. Materials according to this formula may be prepared by polymerizing mixtures of a dihydric phenol and epichlorohydrin, or by advancing a mixture of a diglycidyl ether of the dihydric phenol and the dihydric phenol. While in any given molecule the value of p is an integer, the materials are invariably mixtures which may be characterized by an average value of p which is not necessarily a whole number. Polymeric materials with an average value of p between 0 and about 7 may be used in one aspect of the present disclosure.

[0038] In one aspect of the present disclosure, the at least one multifunctional epoxy resin is preferably a diglycidyl ether of bisphenol-A (DGEBA), an advanced or higher molecular weight version of DGEBA, a diglycidyl ether of bisphenol-F, a diglycidyl ether of novolac resin, or any combination thereof. Higher molecular weight versions or derivatives of DGEBA are prepared by the advancement process, where excess DGEBA is reacted with bisphenol-A to yield epoxy terminated products. The epoxy equivalent weights (EEW) for such products range from about 450 to about 3000 or more. Because these products are solid at room temperature, they are often referred to as solid epoxy resins.

[0039] In preferred embodiments, the at least one multifunctional epoxy resin is the diglycidyl ether of bisphenol-F or bisphenol-A represented by the following structure:wherein R”=H or CH3, and p is an average value between 0 and about 7. DGEBA is represented by the above structure when R”= CH3 and p= 0. DGEBA or advanced DGEBA resins are often used in coating formulations due to a combination of their low cost and high-performance properties. Commercial grades of DGEBA having an EEW ranging from about 174 to about 250, and more commonly from about 185 to about 195, are readily available. At these low molecular weights, the epoxy resins are liquids and are often referred to as liquid epoxy resins. It is understood by those skilled in the art that most grades of liquid epoxy resin are slightly polymeric, since pure DGEBA has an EEW of about 174. Resins with EEWs between about 250 and about 450, also prepared by the advancement process, are referred to as semi-solid epoxy resins because they are a mixture of solid and liquid at room temperature. Multifunctional resins withEEWs based on solids of about 160 to about 750 are useful in the present disclosure. In another aspect the multifunctional epoxy resin has an EEW in a range from about 170 to about 250.

[0040] Examples of alicyclic epoxy compounds include, but are not limited to, polyglycidyl ethers of polyols having at least one alicyclic ring, or compounds including cyclohexene oxide or cyclopentene oxide obtained by epoxidizing compounds including a cyclohexene ring or cyclopentene ring with an oxidizer. Some particular examples include, but are not limited to hydrogenated bisphenol A diglycidyl ether; 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexyl carboxylate; 3,4-epoxy-1-methylcyclohexyl-3,4-epoxy-1 -methylhexane carboxylate; 6-methyl-3,4-epoxycyclohexylmethyl-6-methyl-3,4-epoxycyclohexane carboxylate; 3.4-epoxy-3- methylcyclohexylmethyl-3,4-epoxy-3-methylcyclohexane carboxylate; 3.4-epoxy-5- methylcyclohexylmethyl-3,4-epoxy-5-methylcyclohexane carboxylate; bis(3,4- epoxycyclohexylmethyl)adipate; methylene-bis(3,4-epoxycyclohexane); 2,2-bis(3,4- epoxycyclohexyl)propane; dicyclopentadiene diepoxide; ethylene-bis(3,4-epoxycyclohexane carboxylate); dioctyl epoxyhexahydrophthalate; and di-2-ethylhexyl epoxyhexahydrophthalate.

[0041] Examples of aliphatic epoxy compounds include, but are not limited to, polyglycidyl ethers of aliphatic polyols or alkylene-oxide adducts thereof, polyglycidyl esters of aliphatic long- chain polybasic acids, homopolymers synthesized by vinyl-polymerizing glycidyl acrylate or glycidyl methacrylate, and copolymers synthesized by vinyl-polymerizing glycidyl acrylate or glycidyl methacrylate and other vinyl monomers. Some particular examples include, but are not limited to, glycidyl ethers of polyols, such as 1 ,4-butanediol diglycidyl ether; 1 ,6-hexanediol diglycidyl ether; a triglycidyl ether of glycerin; a triglycidyl ether of trimethylol propane; a tetraglycidyl ether of sorbitol; a hexaglycidyl ether of dipentaerythritol; a diglycidyl ether of polyethylene glycol; and a diglycidyl ether of polypropylene glycol; polyglycidyl ethers of polyetherpolyols obtained by adding one type, or two or more types, of alkylene oxide to aliphatic polyols, such as ethylene glycol, propylene glycol, trimethylol propane, and glycerin.

[0042] Glycidyl ester resins are obtained by reacting a polycarboxylic acid compound having at least two carboxyl acid groups in the molecule and epichlorohydrin. Examples of such polycarboxylic acids include aliphatic, cycloaliphatic, and aromatic polycarboxylic acids. Examples of aliphatic polycarboxylic acids include oxalic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, sebacic acid, suberic acid, azelaic acid, or dimerised or trimerised linoleic acid. Cycloaliphatic polycarboxylic acids include tetrahydrophthalic acid, 4-methyltetrahydrophthalic acid, hexahydrophthalic acid or 4-methylhexahydrophthalic acid and aromatic polycarboxylic acids include phthalic acid, isophthalic acid or terephthalic acid. Thioglycidyl ether resins are derived from dithiols, for example, ethane-1 ,2-dithiol or bis(4-mercaptomethylphenyl) ether.

[0043] N-glycidyl resins are obtained by dehydrochlorination of the reaction products of epichlorohydrin with amines containing at least two amine hydrogen atoms. Such amines are, for example, aniline, n-butylamine, bis(4-aminophenyl)methane, m-xylylenediamine or bis(4- methylaminophenyl)methane. The N-glycidyl resins also include, however, triglycidyl isocyanurate, N,N'-diglycidyl derivatives of cycloalkylene ureas, e.g., ethylene urea or 1 ,3- propylene urea, and diglycidyl derivatives of hydantoins, e.g., 5,5-dimethylhydantoin.Particularly suitable multifunctional epoxy compounds are the diglycidyl ethers of bisphenol-A and bisphenol-F, the advanced diglycidyl ethers of bisphenol-A and bisphenol-F, and the epoxy novolac resins. The epoxy resin may be a single resin, or it may be a mixture of mutually compatible epoxy resins.

[0044] For one or more of the embodiments, the resin component further includes a reactive diluent. Reactive diluents are compounds that participate in a chemical reaction with the hardener component during the curing process and become incorporated into the cured composition and are preferably monofunctional epoxides. Reactive diluents may also be used to vary the viscosity and / or cure properties of the curable compositions for various applications. For some applications, reactive diluents may impart a lower viscosity to influence flow properties, extend pot life and / or improve adhesion properties of the curable compositions. For example, the viscosity may be reduced to allow an increase in the level of pigment in a formulation or composition while still permitting easy application, or to allow the use of a higher molecular weight epoxy resin. Thus, it is within the scope of the present disclosure for the epoxy component, which comprises at least one multifunctional epoxy resin, to further comprise a monofunctional epoxide. Examples of monoepoxides include, but are not limited to, styrene oxide, cyclohexene oxide and the glycidyl ethers of phenol, cresols, tert-butylphenol, other alkyl phenols, butanol, 2-ethylhexanol, C4 to C14alcohols, and the like, or combinations thereof. The multifunctional epoxy resin may also be present in a solution or emulsion, with the diluent being water, an organic solvent, or a mixture thereof. The amount of multifunctional epoxy resin may range from about 50% to 100%, about 50% to about 90%, about 60% to about 90%, about 70% to about 90%, and in some cases about 80% to about 90%, by weight, of the epoxy component. For one or more of the embodiments, the reactive diluent is less than 60 weight percent of a total weight of the resin component.

[0045] In a preferred embodiment, the amine-epoxy composition further comprises an epoxy reactive diluent which is mono or difunctionalized.

[0046] In one preferred embodiment, the epoxy reactive diluent of this composition is a monofunctional epoxide. In a preferred embodiment, the monofunctional epoxide is selected from the group consisting of phenyl glycidyl ether, o-cresyl glycidyl ether, p-tert-butylphenyl glycidyl ether, C8-C18 alkyl glycidyl ether, C12-C14 alkyl glycidyl ether, and n-butyl glycidyl ether.

[0047] In another preferred embodiment, the epoxy reactive diluent of this composition is a difunctional epoxide. In a preferred embodiment, the difunctional epoxide is 1 ,6-hexane diol diglycidyl ether. In another preferred embodiment, the difunctional epoxide is 1 ,4-butane diol diglycidyl ether. In another preferred embodiment, the difunctional epoxide is neopentylglycol diglycidyl ether.

[0048] In another preferred embodiment, the epoxy reactive diluent of this composition is a monofunctional epoxide with reactive silane. In a preferred embodiment, the monofunctional epoxide with reactive silane is selected from the group consisting of 3-glycidoxypropyl trimethoxy silane, and 3-glycidoxypropyl triethoxy silane.

[0049] Preferably, the amount of benzylated polyalkylene polyamines in the curing agent may range from about 30% to 95%, about 40% to 95%, about 50% to 90%, about 55% to 80% and in some cases about 60% to 75%, by weight of the curing agent blend.

[0050] Preferably, the amount of the transaminated reaction product of a dialkylaminomethylphenol with dimethylaminopropylamine or N, N-dimethyldipropylene triamine may range from 5% to 60%, about 10% to 50%, about 15% to 40%, about 20% to 35% and in some cases about 23% to 30%, by weight of the curing agent blend.

[0051] Preferably, the amount of the amidoamine component in this composition may range from 0.5% to 3%, about 1 % to 6%, about 2% to 8%, about 3% to 10% and in some cases 4% to 5%, by weight of the curing agent blend.

[0052] Preferably, the amount of the C12-C16 alkyletheramine component in this composition may range from 0% to 3%, about 1 % to 6%, about 2% to 8%, about 3% to 10% and in some cases 4% to 5%, by weight of the curing agent blend.

[0053] Preferably, the amount of the aminopropylamine component of this composition may range from 0% to 3%, about 1% to 6%, about 2% to 8%, about 3% to 10% and in some cases 4% to 5%, by weight of the curing agent blend.

[0054] Preferably, the amount of the phenol formaldehyde resin in this composition may range from 1 % to 30%, about 5% to 25%, about 8% to 20%, about 10% to 15% and in some cases 7% to 12%, by weight of the curing agent blend.

[0055] Preferably, the amount of the polyetheramine component resin in this composition may range from 0% to 30%, about 3% to 25%, about 5% to 20%, about 7% to 15% and in some cases 4% to 8%, by weight of the curing agent blend.

[0056] In a preferred embodiment, the curing agent composition may further include an additional amine having at least two amine functionalities. The curing agent of this invention may be used in combination with an additional amine curing agent (as a co-curing agent) for curing epoxy resins.

[0057] Preferred examples of additional amines having at least two amine functionalities include diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA), pentaethylenehexamine (PEHA), hexamethylenediamine (HMDA), 1 ,3-pentanediamine (DYTEK™ EP), 2-methyl-1 ,5-pentanediamine (DYTEKTMA), triaminononane, N-(2-aminoethyl)-1 , 3-propanediamine (Na-Amine), N, N'-1 , 2-ethanediylbis-1 , 3-propanediamine (N4-amine), or dipropylenetriamine; an arylaliphatic amine such as m-xylylenediamine (mXDA), or p- xylylenediamine; a cycloaliphatic amine such as 1 ,3-bis(aminomethyl)cyclohexylamine (1 ,3- BAC), isophorone diamine (IPDA), 4,4'-methylenebiscyclohexanamine, Gaskamine 240 (G-240), 1 ,2-diaminocyclohexylamine (DOHA), aminopropylcyclohexylamine (APCHA), a methylene bridged poly (cycloaliphatic-aromatic) amine such as MPCA, an aromatic amine such as m- phenylenediamine, diaminodiphenylmethane (DDM), or diaminodiphenylsulfone (DDS); a heterocyclic amine such as N-aminoethylpiperazine (NAEP), or 3,9-bis(3-aminopropyl)2, 4,8, 10- tetraoxaspiro (5,5)undecane; a polyalkoxyamine where the alkoxy group can be an oxyethylene, oxypropylene, oxy-1 , 2- butylene, oxy-1 , 4-butylene or co-polymers thereof such as 4,7- dioxadecane-1 , 10-diamine, l-propanamine, 3,3'-(oxybis (2, 1- ethanediyloxy))bis(diaminopropylated diethylene glycol) (ANCAMINE1922A), poly(oxy(methyl-1 , 2-ethanediyl)), a-(2-aminomethylethyl)w-(2-aminomethylethoxy) (JEFFAMINE D 230, D-400), triethyleneglycoldiamine and oligomers (JEFFAMINEXTJ-504, JEFFAMINE XTJ-512), poly(oxy(methyl-1 , 2-ethanediyl)), a, a'-(oxydi-2, 1-ethanediyl)bis(w-(aminomethylethoxy)) (JEFFAMINE XTJ-511), bis(3-aminopropyl)polytetrahydrofuran 350, bis(3- aminopropyl)polytetrahydrofuran 750, poly(oxy(methyl-1 , 2-ethanediyl)), a-hydro-w-(2-aminomethylethoxy)ether with 2-ethyl-2-(hydroxymethyl)-1 , 3-propanediol (3:l) (JEFFAMINE T- 403), and diaminopropyl dipropylene glycol.

[0058] Other additional amines having at least two amine functionalities include amidoamine and polyamide curing agents. Polyamide curing agents are comprised of the reaction products of dimerized fatty acid (dimer acid) and polyethyleneamines, and usually a certain amount of monomeric fatty acid which helps to control molecular weight and viscosity. "Dimerized" or "dimer" or "polymerized" fatty acid refers, to polymerized acids obtained from unsaturated fatty acids. Common mono-functional unsaturated C-6 to C-20 fatty acids also employed in making polyamides include tall oil fatty acid (TOFA) or soya fatty acid or the like.

[0059] Other additional amines having at least two amine functionalities include phenalkamines and Mannich bases of phenolic compounds with amines and formaldehyde. The present disclosure also provides amine-epoxy compositions and the cured products produced therefrom.

[0060] Amine-epoxy compositions of the present disclosure preferably have stoichiometric ratios of epoxy groups in the epoxy composition to amine hydrogens in the curing agent composition ranging from 1.5:1 to 0.7:1. For example, such amine-epoxy compositions may preferably have stoichiometric ratios of 1.5:1 , 1.4:1 , 1.3:1 , 1.2:1 , 1.1 :1 , 1 :1 , 0.9:1 , 0.8:1 , or 0.7:1. In another aspect, the stoichiometric ratio ranges from 1.3:1 to 0.7:1 , or from 1.2:1 to 0.8:1 , or from 1.1 :1 to 0.9:1.

[0061] The combined amine co-curing agent epoxy compositions of the present disclosure preferably have stoichiometric ratios of epoxy groups in the epoxy composition to amine hydrogens in the curing agent composition ranging from 1.5:1 to 0.7:1. For example, such amine- epoxy compositions may have stoichiometric ratios of 1.5:1 , 1.4:1 , 1.3:1 , 1.2:1 , 1.1 :1 , 1 :1 , 0.9:1 , 0.8:1 , or 0.7:1. In another aspect, the stoichiometric ratio ranges from 1.3:1 to 0.7:1 , or from 1.2:1 to 0.8:1 , or from 1.1 :1 to 0.9:1.

[0062] Preferably, the weight ratio of the amine co-curing agent is about 1 : 1 to about 1 :0.05 and in some cases the amine co-curing agent is about 1 :0.75 to about 1 :0.25.

[0063] Compositions of the present disclosure may be used to produce various hardened articles of manufacture. Depending on the requirements during the manufacturing of or for the end-use application of the article, various additives may be employed in the formulations and compositions to tailor specific properties. These additives preferably include, but are not limited to, solvents (including water), accelerators, plasticizers, fillers, fibers, such as glass or carbon fibers, pigments, pigment dispersing agents, rheology modifiers, thixotropes, flow or leveling aids, surfactants, defoamers, biocides, or any combination thereof. It is understood that other mixturesor materials that are known in the art may be included in the compositions or formulations and are within the scope of the present disclosure.

[0064] The present disclosure is also directed to use of compositions of the present invention to prepare hardened articles of manufacture. For example, an article may comprise an amineepoxy composition which comprises a curing agent composition and an epoxy composition. The curing agent composition may comprise the following components: (a) at least one benzylated polyalkylene polyamine; (b) the transaminated reaction product of dialkylaminoalkylphenol with dimethylaminopropylamine (DMAPA) or N,N-dimethyldipropylene triamine (DMAPAPA); (c) at least one amidoamine; and (d) at least one phenol formaldehyde resin The epoxy composition may comprise at least one multifunctional epoxy resin. Optionally, various additives may be present in the compositions or formulations used to produce fabricated articles, dependent upon the desired properties. These additives may include, but are not limited to, solvents (including water), accelerators, plasticizers, fillers, fibers, such as glass or carbon fibers, spherical or lamellar type structures such as silica or mica, pigments, pigment dispersing agents, rheology modifiers, thixotropes, flow or leveling aids, surfactants, defoamers, biocides, or any combination thereof. The selection and amount of these additives is at the option of the formulator. Representative accelerators which may be used, although not mandatory include: boron trifluoride amine complexes, substituted phenols such as 2,4,6-tri(dimethylaminomethyl)phenol, tertiary amines such as benzyldimethylamine and imidazoles.

[0065] Preferred articles in accordance with the present disclosure include, but are not limited to, a coating, an adhesive, a primer, a sealant, a curing compound, a construction product, a flooring product, a composite product, laminate, potting compounds, grouts, fillers, cementitious grouts, and self-leveling flooring. Coatings based on these amine-epoxy compositions may contain diluents, such as water or organic solvents, as needed for the particular application. Coatings may contain various types and levels of pigments for use in paint and primer applications. Amine-epoxy coating compositions comprise a layer having a thickness ranging from 40 to 400 pm (micrometer), preferably 80 to 300 pm, more preferably 100 to 250 pm, for use in a protective coating applied onto metal substrates. In addition, for use in a flooring product or a construction product, coating compositions comprise a layer having a thickness ranging from 50 to 10,000 pm, depending on the type of product and the required end-properties. A coating product that delivers limited mechanical and chemical resistances comprises a layer having a thickness ranging from 50 to 500 pm, preferably 100 to 300 pm; whereas a coating product, such as, for example, a self-leveling floor that delivers high mechanical and chemical resistancescomprises a layer having a thickness ranging from 1 ,000 to 10,000 pm, preferably 1 ,500 to 5,000 pm.

[0066] Additional components or additives may be used together with the compositions of the present disclosure to produce articles of manufacture. Further, such coatings, primers, sealants, curing compounds or grouts may be applied to metal or cementitious substrates.

[0067] The relative amount chosen for the epoxy composition versus that of the curing agent composition, may vary depending upon, for example, the end-use article, its desired properties, and the fabrication method and conditions used to produce the end-use article. For instance, in coating applications using certain amine-epoxy compositions, incorporating more epoxy resin relative to the amount of the curing agent composition may result in coatings which have increased drying time, but with increased hardness and improved appearance as measured by gloss.

[0068] Various substrates are suitable for the application of coatings of this invention with proper surface preparation, as is well known to one of ordinary skill in the art. Such substrates include, but are not limited to, concrete and various types of metals and alloys, such as steel and aluminum. Coatings of the present disclosure are suitable for the painting or coating of large metal objects or cementitious substrates including ships, bridges, industrial plants and equipment, and floors.

[0069] Coatings of this invention may be applied by any number of techniques including spray, brush, roller, paint mitt, and the like. In order to apply very high solids content or 100% solids coatings of this invention, plural component spray application equipment may be used, in which the amine and epoxy components are mixed in the lines leading to the spray gun, in the spray gun itself, or by mixing the two components together as they leave the spray gun. Using this technique may alleviate limitations with regard to the pot life of the formulation, which typically decreases as both the amine reactivity and the solids content increases. Heated plural component equipment may be employed to reduce the viscosity of the components, thereby improving ease of application.

[0070] Construction and flooring applications include compositions comprising the amine-epoxy compositions of the present disclosure in combination with concrete or other materials commonly used in the construction industry. Applications of compositions of the present disclosure include, but are not limited to, its use as a primer, a deep penetrating primer, a coating, a curing compound, and / or a sealant for new or old concrete, such as referenced in ASTM C309-97, which is incorporated herein by reference. As a primer or a sealant, the amine-epoxy compositions of the present disclosure may be applied to surfaces to improve adhesive bonding prior to theapplication of a coating. As it pertains to concrete and cementitious application, a coating is an agent used for application on a surface to create a protective or decorative layer or a coat. Crack injection and crack filling products also may be prepared from the compositions disclosed herein. Amine-epoxy compositions of the present disclosure may be mixed with cementitious materials, such as concrete mix, to form polymer or modified cements, tile grouts, and the like. Non-limiting examples of composite products or articles comprising amine-epoxy compositions disclosed herein include tennis rackets, skis, bike frames, airplane wings, girth welds, glass fiber reinforced composites, and other molded products.

[0071] In a particular use of the curing agent composition of the present disclosure, coatings may be applied to various substrates, such as concrete and metal surfaces at low temperature, with fast cure speed and good coating appearance. This is especially important for top-coat application where good aesthetics is desired and provides a solution to a long-standing challenge in the industry where fast low- temperature cure with good coating appearance remains to be overcome. With fast low- temperature cure speed, the time service or equipment is down may be shortened, or for outdoor applications, the work season may be extended in cold climates.Fast epoxy curing agents enable amine-cured epoxy coatings to cure in a short period of time with a high degree of cure. The cure speed of a coating is monitored by thin film set time (TFST) which measures the time period a coating dries. The thin film set time is categorized in 4 stages: phase 1 , set to touch; phase 2, tack free: phase 3, dry hard; and phase 4, dry through. The phase 3 dry time is indicative of how fast a coating cures and dries. For a fast, ambient cure coating, phase 3 dry time is less than 6 hours, or less than 4 hours, or preferred to be less than 4 hours. Low temperature cure typically refers to cure temperature below ambient temperature, 10°C or 5°C, or 0°C in some cases. For a fast, low temperature cure, phase 3 dry time at 5°C is less than 16 hours, with a significant productivity benefit being provided for values where phase 3 dry times are less than 10 hours and preferably less than 8 hours.

[0072] How well a coating cures is measured by the degree of cure. Degree of cure is often determined by using DSC (differential scanning calorimetry) technique which is well-known to those skilled in the art. A coating that cures thoroughly will have a degree of cure at ambient temperature (25°C) of at least 85%, or at least 90%, or at least 95% after 7 days. A coating that cures thoroughly will have a degree of cure at 5°C of at least 80%, or at least 85%, or at least 90% after 7 days.

[0073] Many of the fast, low temperature epoxy curing agents may cure an epoxy resin fast. However due to poor compatibility of the epoxy resin and curing agents especially at low temperature of 10 °C or 5 °C, there is microphase separation between resin and curing agent andcuring agent migrating to coating surface, resulting in poor coating appearance manifested as sticky and cloudy coatings. Good compatibility between epoxy resin and curing agent leads to clear glossy coating with good carbamation resistance and good coating appearance. The curing agent compositions of the present disclosure offers the combination of fast cure speed, good compatibility and high degree of cure.

[0074] Another advantage of the curing agent compositions of the present disclosure is the good barrier property, especially the moisture vapor barrier for concrete coatings due to the low emission characteristic. Moisture vapor transmitted via coatings from concrete slab can cause significant concrete floor failure.

[0075] Another advantage of the curing agent compositions of the present disclosure is providing good flexibility, especially providing greater than 30% elongation.EXAMPLES

[0076] The ASTM standard test methods listed in Table 1 were employed to assess the performance of clear coating and casting. Amine curing agent and epoxy resin with designated stoichiometry were mixed in a speed mixer for one minute at 3000 rpm. The mixture was applied to a substrate at a wet thickness of approximately 150 pm (6 mil) unless otherwise specified. The coatings were typically cured at 23 °C / 50% RH or 5 °C / 60% RH for 10 days before testing. Carbamation resistance test was carried out on black chart where the coating was applied and cured under designated conditions. A 1”x1” cotton patch saturated with water was placed on the coating and covered with a watch glass to prevent water evaporation. After 24 hours, the cotton patch was removed and the coating was dried with a clean tissue. The appearance of the coating was examined and rated on a scale of 1 to 5 with 5 being the best showing no effect from cotton patch, and 1 being the worst with white surface as per ISO 2812 test method. The pore resistance of the coatings were measured by applying the coating with neat bisphenol-A resin or 10% diluted with reactive diluent and respective amine blends on sand blasted steel panel. They were then cured at 23 °C / 50% RH for 7 days. Then the coated panel was exposed to 0.5M solution of Sodium Chloride in water (3 wt%) for 1h and 24h. The resistance values were measured using Electrical Impedance Spectroscopy which correlates the barrier properties of the coatings.

[0077] The water vapor transmission test was carried out based on a modified ASTM E-96 test. The test was run using a 4 oz plastic jar with the plastic lid diameter of 2-3 / 4 inch. The lid has a soft plastic liner. A circular hole of 1-3 / 8 inch diameter was cut with a Carver press. The coating prepared above was inserted between the lid and the liner to cover the hole. Thecoating was glued and sealed to the lid with a thin layer of epoxy along the edge. About 100 g of water was placed in the plastic jar and the lid was sealed with tape. The jar was placed in a temperature and humidity control room of ~23 °C and -50% RH. The weight change was monitored over a period of 4 weeks. Two duplicates were run for each sample. A control sample was included in the test where there was no hole cut in plastic lid / liner. The weight change over time was plotted and the water vapor transmission rate was obtained from the slope of the linear plot. This is a test to compare different systems relative to each other.Table 1. Standard Test MethodsSpecular gloss ASTM D523Gardner color ASTM D 1544Thin film set time ASTM D5895Dry hard time (thumb twist) ASTM D1640Water spotting ASTM D1308Gel time (150 g mass) ASTM D2471Impact resistance ASTM D2794Salt Spray Test ASTM B117Concrete adhesion ASM D7234Carbamation test ISO2812Water vapor transmission test ASTM E-96% of Elongation (Mandrel bending) ASTM D522

[0078] The neat hardener blend viscosity was measured using viscometer using spindle method as per ASTM D6267. The pot-life of the formulation mix was measured as per ASTM D2471 standard test method. Gel Time measurements were performed using Gelation timer at 25°C where the Gelation timer is placed inside the chamber under controlled temperature conditions. For measurements at 10°C and 5°C, the gelation timers were placed in the respective temperature chambers for 24h along with the respective epoxy resin and hardeners to attain the respective conditions. 150 g of epoxy resin with the respective hardener at stoichiometric ratio were then weighed accurately in a sample container, thoroughly mixed using speed mixer at 1500 rpm for30 seconds followed by gel time measurements at the respective temperature conditions. Concrete adhesion test was performed based on ASTM D7234. Before testing, concrete blocks were acclimated under test condition for 24 hours. The coatings were applied by a roller and cured at the test temperature for 7 days before the pull-off test. The test data is the average of 3 dolly pulls. For the intercoat adhesion on concrete where the blend of the present invention is used as primer, and topcoat with either epoxy or polyurea, the primer was cured for 4-24 hours, and topcoat was applied. The topcoat was cured for 7 days before the pull-off test.

[0079] For accelerated weathering studies such as salt spray test, humidity tests, the hardener was formulated with model paint formulation made out of Bisphenol A resin, difunctional epoxy diluents at the recommended stoichiometric loading, thoroughly mixed using speed mixer at 3000 rpm for 30 sec. Hot rolled steel panels 3” x 6” x 0.071” blast to a surface profile of 2.0 A ± 0.5 mils on one side were pre-cleaned using acetone and dried. The coating formulations were then spray applied using spray gun at about 32 psi pressure with the targeted wet film thickness of 150 pm. After 1 day cure, 2ndcoat of the respective blends were performed using the spray gun with the targeted wet film thickness of 300 pm. The panels were then allowed to cure at RT for 10 days. After curing, the panels were placed in the respective test chamber and tested as per ASTM standard. Panels were examined every 200h of exposure and scribe creep analysis were performed on the salt spray test panels.

[0080] Tables 2-10 summarize various examples of the amine curing agent blends with different ratios of components that were described. They were formulated with bisphenol A resin and coated on respective test panels. Some of the systems were formulated with resin diluents as described in the respective Table section.Table 21Transaminated reaction product of 2,4,6-tris(dimethylaminomethyl)phenol with dimethylaminopropylamine2Mixture of benzylated N,N’-bis(3-aminopropyl)ethylenediamine and benzylated DETA and benzylated TETA*Gaskamine 240 is styrenated amine manufactured by Mitsubhishi Gas chemical & Co.** Supraplast 3616 is phenol novolac resin manufactured by Sud-West Chemie Gmbh, Germany.Table 31Transaminated reaction product of 2,4,6-tris(dimethylaminomethyl)phenol with dimethylaminopropylamine2Mixture of benzylated N,N’-bis(3-aminopropyl)ethylenediamine and benzylated DETA and benzylated TETATable 41Transaminated reaction product of 2,4,6-tris(dimethylaminomethyl)phenol with dimethylaminopropylamine2Mixture of benzylated N,N’-bis(3-aminopropyl)ethylenediamine and benzylated DETA and benzylated TETATable 51Transaminated reaction product of 2,4,6-tris(dimethylaminomethyl)phenol with dimethylaminopropylamine2Mixture of benzylated N,N’-bis(3-aminopropyl)ethylenediamine and benzylated DETA and benzylated TETATable 61Transaminated reaction product of 2,4,6-tris(dimethylaminomethyl)phenol with dimethylaminopropylamine2Mixture of benzylated N,N’-bis(3-aminopropyl)ethylenediamine and benzylated DETA and benzylated TETA***Jeffamine D230 is polyetheramine manufactured by Huntsmann CorporationTable 7benzylated TETATable 8dimethylaminopropylamine2Mixture of benzylated N,N’-bis(3-aminopropyl)ethylenediamine and benzylated DETA and benzylated TETATable 9dimethylaminopropylamine2Mixture of benzylated N,N’-bis(3-aminopropyl)ethylenediamine and benzylated DETA and benzylated TETATable 101Transaminated reaction product of 2,4,6-tris(dimethy aminomethyl)phenol with dimethylaminopropylamine2Mixture of benzylated N,N’-bis(3-aminopropyl)ethylenediamine and benzylated DETA and benzylated TETA3Benzylated DETA and benzylated TETA4Viscosity of trans-aminated reaction product 19,600 cP5Viscosity of trans-aminated reaction product 11 ,100 cP6Viscosity of trans-aminated reaction product 6,100 cPAll blends cured with resin 90 / 10 by weight bisphenol A epoxy resin / C12-C14 alcohol glycidyl ether

[0081] Figures 1 and 2 summarize the hardness development of the coated glass panel for different blends with bis-phenol A resin that were cured at 23°C and 5°C respectively.

[0082] Figure 3 shows photo images of the hardener blends that were formulated with epoxy resin and cured and tested for carbamation resistance. No blushing were seen as evident from the photo images.

[0083] The performance of the coating was further evaluated in accelerated weathering studies where the developed curing agent was formulated with diluted resin blend and then subjected to Cleveland humidity exposure. The details of the testing procedure were described in the experimental section. The coated panels without any top-coat were subjected to testing and examined at 500h intervals. There were no blisters seen even after 2000h of exposure in the Cleveland humidity chamber for the coated panels. The panels showed slight yellowing after the humidity exposure as shown in Figure 4.

[0084] The resin dilution (neat resin and 10%, 15%, 20% diluents) has very minimal effect on the dry speed (Thin film set time) for the blends described as shown in Figure 5. It is evident from the graph that resin dilution significantly influences the dry speed for the ULE product whereas the developed curing agent (LTC-01) showed faster dry speed. This performance will enable the formulators to use their primer formulations efficiently to improve the total VOC of the product.The dry speed of the blends were studied at temperatures 0°C (32°F) and -5°C (23°F) with neat Bis-A resin and the diluted resin blend and the results were plotted in the Figure 6. The dry time (Phase 3) for the hardener blends were faster even at low temperatures. The dry hard time (thumb twist) for the curing agent with resin blends were also studied at low temperatures. For ambient temperature curing (23°C) with the diluted resin blend, the dry hard time was found to be 9h and 16h for 5°C curing conditions. Tack-free time for 0°C was observed after 24h and for -5°C cure, it was found to be 2 days of cure.

[0085] Most of the commercially available curing agents that exhibit faster dry speed at 5°C has very short pot-life (less than 15 min) forcing the formulator to use plural component spray application with very limited process time. In order to increase the process window, the formulators use diluted paint formulation which in turn slows the curing process. The hardener blends that were described, able to achieve workable pot-life (close to 45 min.) for the diluted resin blend with the tack-free time of 9h at ambient temperature cure. The gel time measurements at lower temperature (10°C and 5°C) were studied for 150g mix and the results are as shown in Figure 7. The pot-life of the resin with 10% dilution with the curing agent showed greater than 3h which provides enough time for the applicators to perform the spray application in the winter weather conditions

[0086] The hardener blend with the neat Bis-A resin showed low impact resistance values. With 10%, 15% dilution (mono epoxy diluent or diepoxy functionalized diluent) where significant improvements are seen in the impact resistance values as shown in Figure 8. For an ultrahigh solids or solvent free curing agent, without any plasticizer the coating may tend to show some brittleness due to lack of plasticization.

[0087] The corrosion resistance performance of the developed curing agent (Blend 32) was tested with model primer formulation that was spray applied on the sandblasted steel panels. After 10 days of cure at RT, the panels were placed in the salt spray chamber and tested as per ASTM recommendations without any topcoat. The panels were examined every week (~ 168h exposure) to study the corrosion resistance behavior. There were no blister formation even after 2500h exposure in Salt spray chamber with scribe analysis showed rating of 9. The photo images of the coated panels (initial and after 2500h exposure) are shown in Figure 9. The performance of the coating was further evaluated in accelerated weathering studies where the developed curing agent was spray applied with model primer formulations and then subjected to Cleveland humidity exposure. The details of the testing procedure were are described in the experimental section. The coated panels without any top-coat were subjected to testing and examined at 500h intervals. There were no blisters seen even after 2000h of exposure in the Cleveland humiditychamber for the coated panels as shown in Figure 10. From the above studies, it has been clearly demonstrated that the developed curing agent may perform well in corrosive environment with suitable choice of primer formulations.

[0088] The blends in Table 10 were tested for concrete adhesion. The coatings were applied to concrete at 6 mil wet thin thickness, cured at 10 °C / 60% RH for 1 week and tested. All coatings showed excellent concrete adhesion greater than 600 psi with bulk concrete failure. The intercoat adhesion on concrete was also evaluated. Blends 35-40 were used as primer at 6 mil wet thin thickness, cured 10 °C / 60% RH for 8 hours, and a 10 mil wet thin thickness topcoat of either a fast cure epoxy Ancamine 2880 or a polyaspartics / polycarbamide Amicure IC221 , both from Evonik Corporation, was applied. The topcoat was cured at 10 °C / 60% RH for 1 week and tested for adhesion. The adhesion strength of greater than 600 psi was observed, with bulk concrete failure and no intercoat adhesion issue.

[0089] Moisture vapor transmission of blends 35-40 were evaluated against a known moisture vapor barrier coating using Ancamine 2800 from Evonik Corporation. The blends showed comparable moisture vapor transmission rate to Ancamine 2800 during a 4 week period.

Claims

CLAIMSWhat is claimed is:1 . A curing agent composition comprising of the following components:(a) at least one benzylated polyalkylene polyamine;(b) the transaminated reaction product of dialkylaminoalkylphenol with dimethylaminopropylamine (DMAPA) or N,N-dimethyldipropylene triamine (DMAPAPA);(c) at least one amidoamine; and(d) at least one phenol formaldehyde resin.

2. The curing agent composition according to claim 1 wherein the at least one benzylated polyalkylene polyamine component comprises a benzylated polyalkylene polyamine having at least three nitrogen atoms, at least three active amine hydrogen atoms and at least one benzyl group.

3. The curing agent composition according to claim 2 wherein the at least one benzylated polyalkylene polyamine comprises the reaction product of the reductive amination of a benzaldehyde compound with a polyalkylene polyamine having at least three nitrogen atoms.

4. The curing agent composition according to claim 3 wherein the at least one benzylated polyalkylene polyamine is selected from the group consisting of benzylated diethylenetriamine, benzylated triethylenetetramine, benzylated N,N’-bis(3- aminopropyl)ethylenediamine, and benzylated N,N'-bis(3-aminopropyl)diethylenetriamine, or any combination thereof.

5. The curing agent composition according to claim 2 wherein the at least one benzylated polyalkylene polyamine comprises the reaction product of a benzyl halide with a polyalkylene polyamine having at least three nitrogen atoms.

6. The curing agent composition according to any of the preceding claims, wherein the transaminated reaction product of a dialkylaminomethylphenol with dimethylaminopropylamine or N,N-dimethyldipropylene triamine is obtained by reacting a substituted phenolic compound having at least one substituent of formula:RI(R2)N-CH2- wherein R1 and R2 are each independently of the other linear or branched C1-C4 alkyl with dimethylaminopropylamine or N,N-dimethyldipropylene triamine.

7. The curing agent composition according to claim 6 wherein the substituted phenolic compound is selected from the group consisting of tri-(dimethylaminopropylamine) phenolic substituted Mannich base, tri-(N, N-dimethyldipropylene triamine) phenolic substituted Mannich base, di-(dimethylaminopropylamine) phenolic substituted Mannich base, and di-(N, N-dimethyldipropylene triamine) phenolic substituted Mannich base.

8. The curing agent composition according to any of the preceding claims, wherein the at least one amidoamine component comprises of the reaction product of a fatty acid and polyethyleneamine.

9. The curing agent composition according to claim 8 wherein the fatty acid is selected from the group consisting of tall oil fatty acid, cotton seed fatty acid, and soya fatty acid, and the polyethyleneamine is selected from the group consisting of diethylenetriamine and triethylenetetramine.

10. The curing agent composition according to any of the preceding claims, wherein the at least one phenol formaldehyde resin is a Novolac resin.

11. The curing agent composition according to any of the preceding claims, wherein the composition further comprises (e) at least one C12-C16 alkyletheramine.

12. The curing agent composition according to claim 11 wherein the at least one C12-C16 alkyletheramine is selected from the group consisting of 3-(lsodecyloxy)propylamine, and 1 ,3- Propanediamine, N-[3-(tridecyloxy)propyl]-, branched.

13. The curing agent composition according to any of the preceding claims, wherein the composition further comprises (f) at least one aminopropylamine.

14. The curing agent composition according to claim 13 wherein at least one aminopropylamine is selected from the group consisting of diethylaminopropyl amine, dimethylaminopropyl amine, dimethylaminopropyl propylamine and the like.

15. The curing agent composition according to any of the preceding claims, wherein the composition further comprises (g) at least one polyetheramine.

16. An amine-epoxy composition comprising the curing agent composition according to any of the preceding claims and an epoxy composition comprising at least one multifunctional epoxy resin.

17. The amine-epoxy composition according to claim 16, wherein the epoxy resin includes one or more glycidyl ethers selected from the group of glycidyl ethers of: resorcinol, hydroquinone,bis-(4-hydroxy-3,5-difluorophenyl)-methane, 1 ,1-bis-(4-hydroxyphenyl)-ethane, 2,2-bis-(4- hydroxy-3-methylphenyl)-propane, 2,2-bis-(4-hydroxy-3,5-dichlorophenyl) propane, 2,2-bis- (4-hydroxyphenyl)-propane, bis-(4-hydroxyphenyl)-methane, and the like, or any combination thereof.

18. The amine-epoxy composition according to claim 17, further comprising one or more additives selected from the group consisting of solvents, accelerators, plasticizers, fillers, fibers, pigments, pigment dispersing agents, rheology modifiers, thixotropes, flow or leveling aids, surfactants, defoamers, biocides, or any combination thereof.

19. An article of manufacture comprising the amine-epoxy composition according to claim 18 wherein the article is selected from the group consisting of a coating, an adhesive, a primer, a sealant, a curing compound, a construction product, a flooring product, a composite product, laminate, potting compounds, girth welds, grouts, fillers, cementitious grouts, and self-leveling flooring.

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