Epoxide-based composition

Abstract

An epoxide-based composition that can be cured at a temperature of less than about 70 DEG C is disclosed. The composition is a liquid under ambient conditions and thus can be used to repair the interior surface of a pipe. The invention relates to an epoxy-based composition comprising at least one epoxide component (component A) and at least one curing agent component (component B) wherein (A) an epoxide component comprising at least one phenyl glycidyl ether polyepoxide having at least two epoxy groups having an ethylene oxide structure in the molecule; and (B) a curing agent component comprising a salt compound formed from a hydrophobic tertiary amine bearing an alkyl chain of 1020 carbon atoms and a carboxylic acid bearing 10-40 carbon atoms in the alkyl chain. This composition is suitable for potable water applications in Curing In-Pouring Pipes (CIPP).

Description

Technical Field

[0001] The present invention relates to a curable epoxy - based composition. More specifically, the present invention relates to a curable epoxy - based composition that is liquid under ambient conditions and has a relatively long pot life. Background Art

[0002] In some applications, it is preferred that the viscosity of an epoxy curing agent does not change substantially over an extended period after combining the epoxide and the curing agent. Such a combination can facilitate the next step according to the intended use, such as coating, laminating, injecting, potting, or impregnating a composite material composition containing reinforcing or non - reinforcing components.

[0003] When a combination of an epoxide component and a polyamine - based curing agent is left standing for a long time, a reaction may occur and the viscosity of the composition increases. Thus, the composition has a maximum time limit during which the composition can be used for, e.g., coating, laminating, injecting, potting, or impregnating. The period from the start of combining the composition until the viscosity increase of the combination no longer allows the required working procedure is called the "pot life" or working life. In many applications, a longer pot life is a desirable property that contributes to processing flexibility.

[0004] It is known in the art that mixed compositions containing a solid epoxide component and similarly containing a solid curing agent component are known to have a long pot life (or storage life). This is because the initiation of curing depends on the thermal fusion of the two components. Additionally, many semi - liquid type compositions obtained by dispersing a solid curing agent component in a liquid epoxide component are known, and in such cases, since the curing agent component is solid, the initiation of curing depends on the thermal fusion of the curing agent component or the mixing of the two components caused by mutual dissolution.

[0005] However, compositions containing solids have disadvantages attributable to the fact that at least one component is solid. More specifically, in the case of composite materials, such as fiber - reinforced composite materials containing a resin binder and fibers, the resin binder needs to penetrate into the fiber bundles, but when solid components are used, a phenomenon of filtration by the fibers occurs, resulting in separation between the binder components and thus possibly causing curing failure. This also applies to cases where woven fabrics, etc. are used as reinforcing materials. Therefore, liquid epoxide components and liquid curing agent components are ideal materials that can overcome this problem.

[0006] Another disadvantage of known compositions is that these compositions have a relatively short pot life. Generally, in compositions with a short pot life, the reaction occurs suddenly and the time to reach the cured state is short, while in compositions with a long pot life, the time required for curing is long. Therefore, there is a need in the art for a liquid epoxy-based composition that has a pot life of up to several tens of hours and can be cured at a relatively low temperature range (medium temperature range) of 100 °C or lower.

[0007] Such a composition comprising an epoxy and a curing agent, both of which are liquids, would enable the application of a paint coating to protect the inner surface of water supply pipes, sewage pipes, or other industrial liquid conveyance pipes, or the outdoor structure of gas supply pipes, for example, by laminating with organic or inorganic fibers or membranes, etc., which also act as pipe reinforcement materials. In particular, the composition would be useful for repair work on the inner surface of pipes, etc., which is carried out without excavating the fluid or gas conveyance pipes already buried underground, as used in Cured In Place Pipe (CIPP) technology.

[0008] These repair works on buried pipes are usually carried out by setting the section between manholes as one working unit. The working procedures successively include mechanically removing the old coating remaining in the pipe, washing with water, drying, applying the resin component, spreading the inverted fiber or membrane by using hot air or hot water, and maintaining a given temperature with hot water or hot air. When using fibers or membranes for repair, in the case of a short working option, even if the pot life of the composition is short, the binder can be applied to the inner side of the pipe and laminated by spreading the inverted cylindrical fiber or membrane, but in the case of a long working option, a long time of several tens of hours is necessary.

[0009] For the repair of pipes for conveying water or other fluid media, there is a need in the art for a composite system that can be applied to the steel or concrete inner walls of these pipes. Known compositions such as unsaturated polyester / styrene polymers, etc., cannot provide an appropriate working time (pot life), cause odor or toxicity problems due to the chemicals used in the binder (such as mercaptans, acrylonitrile, isocyanates, styrene), or cannot be applied to multi-layer and opaque films / composites due to the curing process (such as UV curing).

[0010] U.S. Patent Publication No. 2010 / 0227981 A1 discloses a composition comprising at least one phenyl glycidyl ether polyepoxide having at least one epoxy group with an ethylene oxide structure in the molecule and a curing agent component comprising a salt compound formed from an N-alkanol piperidine and a carboxylic acid, and the composition can be used for repairing water pipes at a curing temperature below 100 °C, especially at 80 °C.

[0011] It is extremely important that for pipes transporting drinking water, the curing agent has no or very little leaching (<10 ppb) into the water. This document describes the use of salts of hydrophobic tertiary amines and hydrophobic carboxylic acids as curing agents designed for the repair of drinking water pipes. This combination of amine and carboxylic acid has been shown to provide curing of epoxy resins at elevated temperatures (>55 °C). The cured material made with this curing agent and epoxy resin exhibits very little leaching of the curing agent (<10 ppb) after 28 days in water at 25 °C.

[0012] The disclosures of the foregoing patents and patent applications are hereby incorporated herein by reference. Summary of the Invention General Overview of the Invention

[0014] The present invention solves the problems associated with known compositions by providing a composition that can be cured at temperatures below about 80 °C (e.g., 65 °C, about 55 °C to about 70 °C, and in some cases about 62 °C to about 65 °C). The composition of the present invention is a liquid under ambient conditions and can thus be used to repair the inner surface of pipes (e.g., at a temperature of about 75 °C, the uncured composition of the present invention has a viscosity of about 1000 to about 2000 cP, about 1500 to about 2000 cP, and in some cases about 1000 to about 1200 cP).

[0015] The epoxy-based composition according to the present invention comprises at least one epoxy component (Component A) and at least one curing agent component (Component B). In one aspect of the present invention, the composition comprises:

[0016] (A) an epoxy component comprising phenyl glycidyl ether polyepoxide; and

[0017] (B) a curing agent component comprising a salt compound formed from a hydrophobic tertiary amine having an alkyl chain with 10 - 20 carbon atoms and a carboxylic acid having 10 - 40 carbon atoms in the alkyl chain. The hydrophobic tertiary amine having an alkyl chain with 10 - 20 carbon atoms has a water solubility of <0.1 g / L.

[0018] In another aspect of the present invention, the curable epoxy-based composition of the present invention has the advantage that even after the epoxy component and the curing agent component are mixed, the composition can remain uncured for a long time, thereby enabling the composition to maintain an operable viscosity until the composition is used in the next step (or operation). For example, the composition of the present invention can have a pot life of about 20 to about 30 hours at a temperature of about 25 °C and a pot life of 7 days or longer at 5 °C.

[0019] The composition can be used with known epoxy diluents such as monoglycidyl ethers to vary the viscosity as needed for ease of processing. Such diluents include butyl glycidyl ether, phenyl glycidyl ether, dodecyl glycidyl ether, and the like.

[0020] If it is desired to increase the crosslink density and mechanical strength of the cured product, curing agent B can be co-cured with a hindered polyetheramine co-curing agent (< 50 wt% relative to curing agent B). Additionally, if desired, a small amount of a known epoxy curing accelerator (< 10 wt% relative to component B) can be blended into component B to further reduce the curing time without compromising latency.

[0021] In a further aspect, the epoxy-based composition of the present invention ensures that the uncured state after mixing the epoxy component and the curing agent component can be maintained for a long time, and subsequent processes such as coating, laminating, impregnating, and injection can be carried out leisurely. In addition, subsequent curing can be carried out even within 3 hours at a relatively low temperature of 80 °C or lower. This aspect of the present invention is useful for the repair and maintenance work of buried pipes.

[0022] In one aspect, the present invention provides an epoxy-based composition that ensures a flowable (non-gelling) state is maintained for a long time after mixing the epoxy and the curable component (e.g., up to 24 hours at 25 °C and greater than 7 days at 5 °C), and ensures that the viscosity of the mixture does not exceed 10,000 cP within 16 hours, thereby facilitating the subsequent application and spreading of the composition. The present invention also provides an epoxy-based composition such that it can be cured within a moderate temperature range (e.g., about 55 to about 80 °C) by using a heat medium such as hot water or hot air or other heating devices.

[0023] The present invention provides a composition having a pot life of up to 24 hours at 25 °C and a pot life of 7 days or longer when stored at 5 °C. The composition reflows when heated to above 55 °C, cures at 80 °C, and provides good adhesion to concrete, fiberglass, and PVC substrates.

[0024] The salt compound allows the compositions of the present invention to cure at relatively low temperatures (e.g., about 55 to about 80 °C), while known compositions require curing temperatures of 80 - 150 °C. Thus, the compositions of the present invention improve the utility of epoxy-based compositions containing the compositions of the present invention; especially when used in applications where high temperatures are difficult to obtain. In one aspect of the present invention, an epoxy-based composition is applied to the inner surface of a pipe to repair or rehabilitate the pipe. The relatively low curing temperature of the epoxy-based composition enables the composition to be cured with a heat source (such as hot water or steam) located remotely from the epoxy-based composition. Although the hot water or steam may cool to a temperature below 70 °C as it travels to the location of the composition to be cured, such a temperature is sufficient to cure the compositions of the present invention.

[0025] One aspect of the present invention relates to an epoxy-based composition comprising

[0026] (A) an epoxy component comprising at least one phenyl glycidyl ether polyepoxide having at least two epoxy groups with an ethylene oxide structure in the molecule; and

[0027] (B) a curing agent component comprising a salt compound formed from a hydrophobic tertiary amine having an alkyl chain with 10 - 20 carbon atoms and a carboxylic acid having 10 - 40 carbon atoms in the alkyl chain. Preferably, the hydrophobic tertiary amine having an alkyl chain with 10 - 20 carbon atoms has a water solubility of < 0.1 g / L.

[0028] In a preferred embodiment, the amount of the curing agent of component (B) is about 1 to about 50 parts by weight per 100 parts by weight of the epoxy component (A).

[0029] In another preferred embodiment, the epoxy component (A) further comprises an epoxy compound different from the phenyl glycidyl ether polyepoxide.

[0030] Preferably, the epoxy compound different from the phenyl glycidyl ether polyepoxide is at least one compound selected from glycidyl ethers, glycidyl esters, and glycidyl amines.

[0031] Preferably, the tertiary amine is selected from N,N-dimethyldecylamine, N,N-dimethylundecylamine, N,N-dimethyldodecylamine, N,N-dimethyltridecylamine, N,N-dimethyltetradecylamine, N,N-dimethylpentadecylamine, and N,N-dimethylhexadecylamine. Preferably, the carboxylic acid is selected from capric acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, heptadecanoic acid, tall oil fatty acid, dimer acid, and mixtures thereof. DETAILED DESCRIPTION OF THE INVENTION

[0033] The epoxy-based composition according to the present invention can provide a flowable state that is maintained for a long time after mixing of the epoxy and the curing agent components (for example, a viscosity of less than 10,000 cP at a temperature of 25 °C for up to 24 hours), and the viscosity does not exceed 10,000 cP within 16 hours. In addition, the epoxy composition of the present invention can also be stored at 5 °C for 7 days or longer without impairing latency (for example, a viscosity of less than 10,000 cP at a temperature of 25 °C). The advantage of storing at low temperature allows for the flexibility to apply the curing agent composition in a factory environment and then transport the saturated liner to the construction site for CIPP applications. It is envisioned that the liner will be flexible when inserted into an underground pipe during the repair process.

[0034] In addition, the epoxy-based composition can be cured in a medium temperature range (for example, a temperature of about 55 to about 80 °C) by using a heat medium such as hot water or hot air. Therefore, the epoxy-based composition according to the present invention can be used for the repair work of buried pipes that are conduits for various fluids.

[0035] In addition, the epoxy-based composition according to the present invention is effective for repair work carried out without excavating the buried pipe.

[0036] Hereinafter, the present invention will be described in detail. In the following description, unless otherwise specifically stated, "%" and "parts" representing quantitative ratios or ratios are those based on mass.

[0037] One aspect of the present invention is an epoxy-based composition comprising an epoxy component (Component A) and a curing agent component (Component B), wherein the epoxy component comprises a phenyl glycidyl ether-based polyepoxide having at least two epoxy groups having an ethylene oxide structure in the molecule; and the curing agent component comprises a salt compound formed from a hydrophobic tertiary amine having an alkyl chain with 10 - 20 carbon atoms and a carboxylic acid having 10 - 40 carbon atoms in the alkyl chain. Preferably, the hydrophobic tertiary amine having an alkyl chain with 10 - 20 carbon atoms has a water solubility of < 0.1 g / L.

[0038] Preferably, the hydrophobic tertiary amine is selected from N,N-dimethyldecylamine, N,N-dimethylundecylamine, N,N-dimethyldodecylamine, N,N-dimethyltridecylamine, N,N-dimethyltetradecylamine, N,N-dimethylpentadecylamine, N,N-dimethylhexadecylamine, N,N-dimethylheptadecylamine, N,N-dimethyloctadecylamine, N,N-dimethylnonadecylamine, N,N-diethyldecylamine, N,N-diethylundecylamine, N,N-diethyldodecylamine, N,N-diethyltridecylamine, N,N-diethyltetradecylamine, N,N-diethylpentadecylamine, N,N-diethylhexadecylamine, N,N-diethylheptadecylamine, N,N-diethyloctadecylamine, and N,N-diethylnonadecylamine.

[0039] Preferably, the carboxylic acid is selected from capric acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, stearic acid, tall oil fatty acid, dimer acid, and mixtures thereof.

[0040] Preferably, the epoxy component comprises at least one compound selected from aromatic diglycidyl ethers and glycidyl ethers. In a preferred embodiment, the epoxy component comprises the diglycidyl ether of bisphenol A, the diglycidyl ether of bisphenol F, or a combination thereof.

[0041] In a preferred embodiment, the epoxy component (A) further comprises an epoxy compound different from phenyl glycidyl ether polyepoxide.

[0042] Preferably, the epoxy compound different from phenyl glycidyl ether polyepoxide comprises at least one compound selected from glycidyl ethers, glycidyl esters, and glycidyl amines.

[0043] Preferably, the amount of the epoxy component can be about 70 to less than 100 wt%, about 85 to about 60 wt%, and in some cases about 80 to about 90 wt% of the epoxy-based composition. Preferably, the curing agent component can be about 5 to about 30 wt%, about 40 to about 20 wt%, and in some cases about 20 to about 10 wt% of the epoxy-based composition.

[0044] In another preferred embodiment, the curing agent component (B) further comprises a hindered polyetheramine co-curing agent.

[0045] In another preferred embodiment, the epoxy-based composition further comprises an epoxy curing accelerator selected from 1-methylimidazole, 2-methylimidazole, tris(dimethylaminomethyl)phenol, and dimethylaminomethylphenol. Preferably, the epoxy curing accelerator is blended into the curing agent component (B).

[0046] In another preferred embodiment, the epoxy-based composition further comprises a diluent selected from butyl glycidyl ether, phenyl glycidyl ether, dodecyl glycidyl ether, and the like.

[0047] In one preferred embodiment, the amount of the curing agent component (B) is about 1 to about 50 parts by weight per 100 parts by weight of the epoxy component (A). In another preferred embodiment, the amount of the curing agent component (B) is about 5 to about 20 parts by weight per 100 parts by weight of the epoxy component (A). In another preferred embodiment, the amount of the curing agent component (B) is about 10 to about 30 parts by weight per 100 parts by weight of the epoxy component (A).

[0048] Preferably, the epoxy component and the curing agent component can be combined by using any suitable equipment and methods, such as mixing, stirring, pumping, and other equipment and methods known in the art.

[0049] Preferably, the salt in the curing agent can be obtained by reacting an amine with a carboxylic acid at <80 °C for 10 minutes to 6 hours. Preferably, the molar ratio of the amine to the carboxylic acid is about 1:1.

[0050] In one preferred embodiment, the salt of the mixture is 5-40% by weight of the composition.

[0051] The curable epoxy-based composition disclosed herein can be used for potable water applications in in-situ cured pipes (CIPP).

[0052] The epoxy-based composition according to the present invention can have the following properties (1)-(3).

[0053] Property 1

[0054] Under the conditions used in the examples, the viscosity of the epoxy-based composition according to the present invention is <10,000 cP within 24 hours of storage at 25 °C and within 7 days of storage at 5 °C. The viscosity is measured by using a Brookfield viscometer (Brookfield HT-2DB). A disposable aluminum spindle (Brookfield SC4-27D) is inserted into the chamber containing the curing agent mixture, and the viscometer (Brookfield RVDV-II+Pro) is started to collect data points at a rate of 1 point per minute according to the standard test procedure.

[0055] Property 2

[0056] The epoxy composition according to the present invention can be cured in about 3 hours at a temperature of about <75°C and is hard to the touch without being tacky. The curing temperature and time are inversely correlated, wherein the curing temperature can be reduced when a longer time period is given. The curing temperature can be about 55°C to about 80°C, about 65°C to about 70°C, and in some cases about 60°C to about 65°C. The curing time can be about 1 hour to about 3 hours, about 2 hours to about 3 hours, and in some cases about 3 hours to about 4 hours.

[0057] Nature 3

[0058] The epoxy-based compositions according to the present invention can be cured in the presence of at least 1% by weight of water at <75°C in 3 hours and are hard to the touch without being tacky. The compositions of the present invention can be cured in an environment containing from about 2% to about 5%, from about 3% to about 5%, and in some cases from about 4% to about 8% water.

[0059] The epoxide component (A) of the composition of the present invention comprises a phenyl glycidyl ether epoxide having a plurality of oxirane structures in the molecule and being reactive with amines, examples of which may include the following: aromatic diglycidyl ethers obtained by reacting diphenols such as bisphenol A, bisphenol F, bisphenol AD, tetramethylbisphenol A, tetramethylbisphenol F, or biphenyl with epichlorohydrin; aromatic diglycidyl ethers obtained by reacting novolacs such as phenol novolac, cresol novolac, ethylphenol novolac, and bisphenol A; and aromatic diglycidyl ethers obtained by reacting novolacs such as phenol novolac, cresol novolac, and ethylphenol novolac. glycidyl ethers obtained by reacting a polyphenol such as catechol, resorcinol, trihydroxybiphenyl, dihydroxybenzophenone, bisresorcinol, hydroquinone, tris(hydroxyphenyl)methane, tetra(hydroxyphenyl)ethane or bisphenol with epichlorohydrin; and mixtures thereof.

[0060] Among the above-mentioned epoxy compounds, preferred results may be achieved by using diglycidyl ether of bisphenol A, diglycidyl ether of bisphenol F, or a combination thereof.

[0061] Examples of epoxides that can be used in combination with phenyl glycidyl ether epoxide may include at least one member selected from at least one group below:

[0062] (1) Polyglycidyl ethers produced by reacting an aliphatic polyol such as glycol, neopentyl alcohol, ethylene glycol, propylene glycol, tetramethylene glycol, hexanediol, polyethylene glycol or polypropylene glycol with epichlorohydrin;

[0063] (2) glycidyl ether esters formed by reacting a hydroxycarboxylic acid such as p-hydroxybenzoic acid or β-hydroxynaphthoic acid with epichlorohydrin;

[0064] (3) polyglycidyl esters formed by reacting a polycarboxylic acid such as phthalic acid, methylphthalic acid, isophthalic acid, terephthalic acid, tetrahydroxyphthalic acid, hexahydroxyphthalic acid, methylenetetrahydroxyphthalic acid, methylenehexahydroxyphthalic acid, trimellitic acid, dimer acid or polymeric fatty acid with epichlorohydrin;

[0065] (4) diglycidyl amino esters formed by reacting aminobenzoic acid with epichlorohydrin; and

[0066] (5) polyglycidyl amines formed by reacting aniline, toluidine, m-phenylenediamine, 1,2-diaminocyclohexane, 4,4-diaminodiphenyl ether, 4,4-diaminodiphenyl methane, 4,4-diaminodiphenyl sulfone, hydantoin, alkyl hydantoin or cyanuric acid with epichlorohydrin.

[0067] The curing agent component (Component B) comprises a salt compound formed by a hydrophobic tertiary amine having an alkyl chain with 10 - 20 carbon atoms and a carboxylic acid having 10 - 40 carbon atoms in the alkyl chain. The hydrophobic tertiary amine having an alkyl chain with 10 - 20 carbon atoms has a water solubility of < 0.1 g / L.

[0068] Although any suitable tertiary amine can be used to make the above salts, examples of preferred suitable tertiary amines are selected from N,N-dimethyldecylamine, N,N-dimethylundecylamine, N,N-dimethyldodecylamine, N,N-dimethyltridecylamine, N,N-dimethyltetradecylamine, N,N-dimethylpentadecylamine, N,N-dimethylhexadecylamine, N,N-dimethylheptadecylamine, N,N-dimethyloctadecylamine, N,N-dimethylnonadecylamine, N,N-diethyldecylamine, N,N-diethylundecylamine, N,N-diethyldodecylamine, N,N-diethyltridecylamine, N,N-diethyltetradecylamine, N,N-diethylpentadecylamine, N,N-diethylhexadecylamine, N,N-diethylheptadecylamine, N,N-diethyloctadecylamine and N,N-diethylnonadecylamine. Any other tertiary amine having the same or mixed alkyl groups together with a hydrophobic alkyl chain (12 - 20 carbon atoms) is also suitable.

[0069] Preferably in one embodiment, the carboxylic acid of the tertiary amine salt as the curing agent component of the present invention is selected from capric acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, heptadecanoic acid, tall oil fatty acid, dimer acid and mixtures thereof.

[0070] Preferably, the salt can be formed by reacting an amine with a carboxylic acid at <80 °C for about 10 minutes to about 6 hours. The molar ratio of the amine to the carboxylic acid is about 1:1 and can be about 0.8 molar equivalents to about 1.0 molar equivalents, about 0.9 molar equivalents to about 1.0 molar equivalents, and in some cases about 1.0 molar equivalents to about 1.5 molar equivalents.

[0071] Preferably, component B of the epoxy-based composition of the present invention may contain from about 0.8 to about 1.2, from about 1.1 to about 1.2, and in some cases from about 1.0 to about 1.5 equivalents of carboxylic acid equivalents of component B per mole of hydrophobic tertiary amine.

[0072] The amount of the curing agent component (B) can be about 1 to about 50 parts by weight, or about 5 to about 20 parts by weight, or about 10 to about 30 parts per 100 parts by weight of the polyepoxide component (A). If the amount of component B is less than the above range, a very long pot life can be expected after mixing components (A) and (B), but subsequent curing may take a long time, which is impracticable. On the contrary, if the curing agent component (B) is combined in an amount exceeding the above range, curing after mixing components (A) and (B) can proceed rapidly, but the pot life required for operation may be shortened, which is generally impracticable.

[0073] In addition, in the composition of the present invention, if necessary, at least one of a plasticizer, a filler, a colorant, an extender, a pigment, an organic or inorganic fiber, a silicone, a titanate or an aluminum coupling agent for improving adhesion to the pipe body, a thixotropic agent, etc. can be used in combination. The amount of the foregoing can be about 10 wt% to about 20 wt%, about 10 wt% to about 12 wt%, and in some cases about 18 wt% to about 20 wt% of the epoxy-based composition.

[0074] Preferably, the composition can be used with known epoxy diluents such as monoglycidyl ethers to change the viscosity as needed for easy processing. Such diluents include butyl glycidyl ether, phenyl glycidyl ether, dodecyl glycidyl ether, etc.

[0075] Preferably, in one embodiment, if it is desired to increase the crosslink density and mechanical strength of the cured product, curing agent B can be combined with a small amount of hindered polyetheramine (<50 wt% relative to B). Preferred hindered polyetheramines include Jeffamine D230, Jeffamine T400, and Jeffamine T403 available from Huntsmann Corporation. Preferably, in a further embodiment, if desired, a small amount of a known epoxy curing accelerator (<10 wt% relative to component B) is additionally blended into component B to further reduce the curing time without compromising latency. Preferably, the epoxy curing accelerator is selected from imidazoles such as 1-methylimidazole, 2-methylimidazole, and tertiary amine-substituted phenols such as tris(dimethylaminomethyl)phenol (Ancamine K-54 available from Evonik Corp.) and dimethylaminomethylphenol (Ancamine 1110 available from Evonik Corp.).

[0076] The following examples are provided to illustrate certain aspects of the invention and are not intended to limit the scope of the appended claims herein.

[0077] The present invention relates to the following aspects:

[0078] <1> An epoxy-based composition comprising

[0079] (A) an epoxy component comprising at least one phenyl glycidyl ether polyepoxide having at least two epoxy groups with an ethylene oxide structure in the molecule; and

[0080] (B) a curing agent component comprising a salt compound formed from a hydrophobic tertiary amine having an alkyl chain with 10 - 20 carbon atoms and a carboxylic acid having 10 - 40 carbon atoms in the alkyl chain.

[0081] <2> The composition of aspect <1>, wherein the hydrophobic tertiary amine is selected from N,N-dimethyldecylamine, N,N-dimethylundecylamine, N,N-dimethyldodecylamine, N,N-dimethyltridecylamine, N,N-dimethyltetradecylamine, N,N-dimethylpentadecylamine, N,N-dimethylhexadecylamine, N,N-dimethylheptadecylamine, N,N-dimethyloctadecylamine, N,N-dimethylnonadecylamine, N,N-diethyldecylamine, N,N-diethylundecylamine, N,N-diethyldodecylamine, N,N-diethyltridecylamine, N,N-diethyltetradecylamine, N,N-diethylpentadecylamine, N,N-diethylhexadecylamine, N,N-diethylheptadecylamine, N,N-diethyloctadecylamine, and N,N-diethylnonadecylamine.

[0082] <3>The composition according to any one of aspects <1> to <2>, wherein the carboxylic acid is selected from capric acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, margaric acid, tall oil fatty acid, dimer acid, and mixtures thereof.

[0083] <4>The composition according to any one of aspects <1> to <3>, wherein the epoxide component comprises at least one compound selected from aromatic diglycidyl ethers and glycidyl ethers.

[0084] <5>The composition according to aspect <4>, wherein the epoxide component comprises a diglycidyl ether of bisphenol A, a diglycidyl ether of bisphenol F, or a combination thereof.

[0085] <6>The composition according to any one of aspects <1> to <5>, wherein the epoxide component (A) further comprises an epoxide compound different from phenyl glycidyl ether polyepoxide.

[0086] <7>The composition according to aspect <6>, wherein the epoxide compound different from phenyl glycidyl ether polyepoxide comprises at least one compound selected from glycidyl ethers, glycidyl esters, and glycidyl amines.

[0087] <8>The composition according to any one of aspects <1> to <7>, wherein the curing agent component further comprises a hindered polyetheramine co-curing agent.

[0088] <9>The composition according to aspect <8>, which further comprises an epoxy curing accelerator selected from 1-methylimidazole, 2-methylimidazole, tris(dimethylaminomethyl)phenol, and dimethylaminomethylphenol.

[0089] <10>The composition according to any one of aspects <1> to <9>, which further comprises a diluent selected from butyl glycidyl ether, phenyl glycidyl ether, dodecyl glycidyl ether, etc.

[0090] <11>The composition according to any one of aspects <1> to <10>, wherein the amount of the curing agent component (B) is about 1 to about 50 parts by weight per 100 parts by weight of the epoxide component (A).

[0091] <12>The composition according to any one of aspects <1> to <10>, wherein the salt of the mixture is 5-40% by weight of the composition.

[0092] <13>The use of the composition according to any one of aspects <1> to <12> in the in-situ curing of potable water applications in pipelines. Detailed Description

[0093] Examples

[0094] Example 1: General Procedure for Preparing a Curing Agent

[0095] Charge a three-necked round-bottom flask equipped with an overhead mechanical stirrer, a nitrogen inlet, and a thermocouple with a tertiary amine (1 mole). Slowly add an acid (1 mole relative to the amine) while maintaining the temperature at <80 °C. If the acid is a solid, first melt it and add it to the amine in liquid form.

[0096] Example 2: Latency of Amine Curing Agents

[0097] In a 200 mL glass wide-mouth bottle, use a spatula to mix the curing agent at a certain loading with 100 g of bisphenol A diglycidyl ether (EPON 828). Allow the material to stand for a set time before testing. Transfer 15 g of this material to a disposable aluminum chamber (Brookfield HT-2DB). Insert a disposable aluminum spindle (Brookfield SC4-27D) into the chamber containing the curing agent mixture, and program a Start viscometer (Brookfield RVDV-II+Pro) to collect data points at a rate of 1 point per minute. If the viscosity is less than 10,000 cP at 25 °C, the material is still flowable. Measure the mixture after storing it at 25 °C for 24 hours and at 5 °C for 7 days. The results are shown in Table 1.

[0098] Example 3: Viscosity and Pot Life Tests at 65 °C

[0099] In a 200 mL glass wide-mouth bottle, use a spatula to mix the curing agent at a certain loading with 100 g of bisphenol A diglycidyl ether (EPON 828). Store the material at 5 °C for 7 days before testing. Transfer 15 g of this material to a disposable aluminum chamber (Brookfield HT-2DB). Insert a disposable aluminum spindle (Brookfield SC4-27D) into the chamber containing the curing agent mixture heated to 65 °C, and program a Start viscometer (Brookfield RVDV-II+Pro) to collect data points at a rate of 1 point per minute. Record the initial viscosity and the pot life (the time to reach 10,000 c) (Table 2).

[0100] Example 4: Test Procedure for Curing Agent and Epoxy Resin at 75 °C

[0101] In a 200 mL glass wide-mouth bottle, use a spatula to mix the curing agent with a certain loading amount with 100 g of bisphenol A diglycidyl ether (EPON 828). Disks are prepared from this mixture by transferring the curing agent and epoxy resin mixture (about 5 - 7 g) into a 2-ounce metal container. Two disks are prepared, one with water and one without water. In the former, a small amount of water, about 2 g, is applied to one disk, but not enough to completely cover the entire surface. The disks are placed in an oven at 75 °C for 2 hours or until cured. Record the curing time and surface characteristics of the cooled disks, and determine the tackiness, vitrification, and entrained air by visual observation and touch hardness (Table 2).

[0102] Table 1.

[0103]

[0104] Table 2

[0105]

[0106] Example 5: In-situ Curing Pipeline Simulation Application

[0107] To understand the applicability of the curing agent in in-situ curing pipeline (CIPP) applications, the following experiment was conducted.

[0108] Mix 50 g of the curing agent (a mixture of dodecyl salt of N,N-dimethylhexadecylamine and Jeffamine D230 (90:10)) with 500 g of a standard DGEBA-type liquid epoxy resin with an EEW = 190 under ambient conditions. This mixed material is sufficient to thoroughly wet a 4-inch diameter and commercially available foot-length cylindrical felt, which contains commercially available polyester fibers and a polyethylene liner. Apply the mixed material to the felt by manually pouring it into the felt until it is completely saturated. This type of felt is commonly used for underground pipeline repair.

[0109] Apply the mixed material evenly inside the felt and store the felt at 5 °C for 7 days to check the storage stability of the product. After 7 days, remove the felt from the 5 °C storage and allow it to equilibrate at 25 °C for 24 hours. The felt looks soft, the mixed material is still tacky, and the felt is soft enough for further processing. Then bake the saturated felt in an oven at 65 °C for 2 hours. After it cools, the felt is very rigid and the cured epoxy matrix is confirmed to have an acceptable flexural modulus (>300,000 psi) required for industry. The flexural modulus is determined by ASTM D-790.

[0110] Although the present invention has been described with reference to certain aspects and embodiments, those skilled in the art will understand that various combinations and modifications can be made and elements thereof can be replaced with equivalents without departing from the scope of the present invention. In addition, many modifications can be made to adapt a particular situation or material to the teachings of the present invention without departing from its basic scope. Therefore, it is not intended to limit the present invention to the specific aspects or embodiments disclosed for carrying out the present invention, but the present invention will include all aspects or embodiments falling within the scope of the appended claims.

Claims

1. An epoxy-based composition comprising (A) an epoxy component comprising at least one phenyl glycidyl ether polyepoxide having at least two epoxy groups with an ethylene oxide structure in the molecule; and (B) a curing agent component comprising a salt compound formed from a hydrophobic tertiary amine having an alkyl chain with 10 - 20 carbon atoms and a carboxylic acid having 10 - 40 carbon atoms in the alkyl chain.

2. The composition according to claim 1, wherein the hydrophobic tertiary amine is selected from N,N-dimethyldecylamine, N,N-dimethylundecylamine, N,N-dimethyldodecylamine, N,N-dimethyltridecylamine, N,N-dimethyltetradecylamine, N,N-dimethylpentadecylamine, N,N-dimethylhexadecylamine, N,N-dimethylheptadecylamine, N,N-dimethyloctadecylamine, N,N-dimethylnonadecylamine, N,N-diethyldecylamine, N,N-diethylundecylamine, N,N-diethyldodecylamine, N,N-diethyltridecylamine, N,N-diethyltetradecylamine, N,N-diethylpentadecylamine, N,N-diethylhexadecylamine, N,N-diethylheptadecylamine, N,N-diethyloctadecylamine, and N,N-diethylnonadecylamine.

3. The composition according to any one of claims 1 - 2, wherein the carboxylic acid is selected from capric acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, stearic acid, tall oil fatty acid, dimer acid, and mixtures thereof.

4. The composition according to any one of claims 1 - 3, wherein the epoxy component comprises at least one compound selected from aromatic diglycidyl ethers and glycidyl ethers.

5. The composition according to claim 4, wherein the epoxy component comprises the diglycidyl ether of bisphenol A, the diglycidyl ether of bisphenol F, or a combination thereof.

6. The composition according to any one of claims 1 - 5, wherein the epoxy component (A) further comprises an epoxy compound different from the phenyl glycidyl ether polyepoxide.

7. The composition according to claim 6, wherein the epoxy compound different from the phenyl glycidyl ether polyepoxide comprises at least one compound selected from glycidyl ethers, glycidyl esters, and glycidyl amines.

8. The composition according to any one of claims 1 - 7, wherein the curing agent component further comprises a hindered polyetheramine co-curing agent.

9. The composition according to claim 8, wherein the composition further comprises an epoxy curing accelerator selected from 1-methylimidazole, 2-methylimidazole, tris(dimethylaminomethyl)phenol, and dimethylaminomethylphenol.

10. The composition according to any one of claims 1 - 9, wherein the composition further comprises a diluent selected from butyl glycidyl ether, phenyl glycidyl ether, dodecyl glycidyl ether, etc.

11. The composition according to any one of claims 1 - 10, wherein the amount of the curing agent component (B) is about 1 to about 50 parts by weight per 100 parts by weight of the epoxide component (A).

12. The composition according to any one of claims 1 - 10, wherein the salt of the mixture is 5 - 40% by weight of the composition.

13. Use of the composition according to any one of claims 1 - 12 in the potable water application of in - situ curing pipelines.

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