Epoxy-resin based coating compositions and uses thereof

Abstract

A water based 2K coating composition, containing one or more water soluble epoxy resins, one or more water soluble curing agents, and water, wherein the composition is substantially isocyanate free, along with a method for coating a substrate using the water based 2K coating composition. Additionally, an epoxy coating composition containing a multifunctional aliphatic epoxy resin crosslinked with a di- or higher-functional curing agent, either of an acrylic resin or a modified cellulose acetate resin, and a carrier, wherein the epoxy coating composition is at least one of substantially isocyanate free, substantially formaldehyde free, or substantially bisphenol-A free, along with a method for coating a substrate with the epoxy coating composition.

Description

TITLE OF THE INVENTIONEPOXY-RESIN BASED COATING COMPOSITIONS AND USES THEREOFCross Reference to Related Applications

[0001] The present invention is related to and claims priority to U.S. Provisional Application Serial No. 63 / 636,936, filed April 22, 2024, pending, the contents of which are hereby incorporated by reference in their entirety.Technical Field

[0002] The present invention relates to a variety of epoxy-resin based coating compositions, which may be waterborne or solvent-borne, depending on the planned end use, and uses thereof.Background of the Invention

[0003] Wood floors are frequently employed in quality housing and offices. The bare wood may be stained to alter its color, enabling, for example, the use of durable, damage-resistant wood whose natural color would be unsuitable for its surroundings. Stains may be oil-based or water-based. The latter offer numerous advantages such as soap-and-water cleanup, non-flammability, low odor, and minimal environmental impact. Currently, however, water-based wood stains are used primarily for small jobs. They have not been widely adopted in the flooring and large furniture sectors because they tend to exhibit various problems such as lapping, lifting, difficulty in application, and / or inconsistent appearance.

[0004] Lapping is a visual defect that occurs when applying stain to a large surface in sections. It results in a darker color in the areas where one stained section overlaps another, thus providing an inconsistent staining performance and color. This is thought to result when the polymeric binder in a stain formulation becomes irreversibly adhered to a substrate such that the application of additional stain does not sufficiently solubilize / blend / interact with the first application but instead builds on top of it. Another problem known as “Lifting” can also be encountered when a stain iseither not completely dry, or is water / sol vent-sensitive when a topcoat is applied thereover. This results in a loss of the desired coloration effect of the stain, where there can be a loss of color or a blotchy, inconsistent appearance.

[0005] Application difficulty often arises when staining large areas, whether by manual methods or using an application apparatus. Existing water-based stains can often be gummy or difficult and require substantial effort in initially applying the stain and wiping excess away. Following application, it is often found that water-based stains lack the richness and warmth of oil / solvent based stains. This results in an inconsistent appearance that resembles plastic.

[0006] Solvent based stains have been used primarily to add color to large surface area wood substrates, like floors. Such solvent-based formulas are legacy technology, have excellent appearance, and desirable application properties. Among those desirable properties includes consistent staining performance and color. Because of the large surface area of a floor, it must often be stained in sections, and a freshly stained area needs to be blended seamlessly into a previously stained area or else unsightly marks can occur where coated sections overlap. Solvent based stains, while highly preferred for these reasons, are high in VOC's, present spontaneously combustibility concerns, and have a strong lingering solvent smell that is an issue for indoor applications.

[0007] Water based wood stains do exist and remove the VOC, combustibility, and odor concerns, however they are often poorly suited for large surface areas, due to the above noted issues regarding consistency of stain performance and coloring as stained sections overlap at the section edges. This is because like most water-based paints and stains, they are based on a latex polymer. A waterbased wood stain has the issue that the water in the stain is lost to both evaporation and absorption into the substrate. This greatly accelerates the coalescing of the latex particles which is a normal part of film formation. However, once the latex coalesces, this process is non-reversible. In the case of a stain this can lead to the inconsistency of stain performance and coloring. In the solvent-based stain, there is no coalescing step, and the binders used in those types of formulas are oxidatively drying oils and alkyds. That oxidative drying process is longer than the solvent evaporation step of the stain, meaning that additional application of stain can easily resolubilize the previously applied stain which eliminates these inconsistencies at the edges of sequentially stained sections. Over extended dry times, the oxidative drying mechanism is allowed to proceed, which cures the polymermatrix, allowing subsequent applications of protective clear coats to be applied over the stain without removing or disrupting the appearance of the stain, or “lifting”.

[0008] There have been other attempts to create water-based stains, such as the introduction of products for improving the consistency of staining performance of a water-based stain by introducing materials like glycols and glycerin in quantities higher than what would be typical for a water-based coating. The mechanism here is to introduce materials to increase the open time of the formula with materials of high humectancy to delay or temporarily interrupt the coalescing step. However, this mechanism is imperfect in providing the desired improvements. These materials remain in the substrate leading to issues with lifting performance.

[0009] Other attempts have included compositions containing a polyol and an isocyanate to create a more stable secure stain by the creation of a crosslinked polyurethane polymer. However, such an approach is less than desirable due to the presence of the isocyanate, which is a sensitizer and not a safe choice for mass market or untrained persons.

[0010] Another option for coatings and stains is epoxy based coating compositions. Water and solvents can be used as carrier agents in some types of epoxies. They make the epoxy coating easier to apply, assist with adhesion, and provide some self-leveling properties. Additionally, epoxy coatings start their curing process immediately after mixing the resin and the hardener together, limiting the time available to apply the product. This time factor is typically called the “pot life.” Pot life is often highly dependent on choice of curing agent and can vary over a wide range. Epoxy coatings have typically been used for a selected set of substrates, such as concrete, with less acceptance in the staining or coating of wood based substrates

[0011] There is a need for coatings, particularly stains, that are substantially isocyanate free, that offer the advantages of a water-based product without the disadvantages noted above.

[0012] There is also a need for epoxy based resin systems / coatings that can be either water-based or solvent-based, that provide high crosslink density and solvent / chemical resistance while being substantially isocyanate free, substantially formaldehyde free and / or substantially BPA free.Summary of the Invention

[0013] Accordingly one object of the present invention is to provide an epoxy based 2K waterborne coating, preferably a stain, that is substantially isocyanate free and provides excellent performance characteristics.

[0014] Another object of the present invention is to provide a method for coating a substrate using the epoxy based 2K waterborne coating.

[0015] A further object of the present invention is to provide an epoxy and acrylic based coating composition that is substantially isocyanate free, substantially formaldehyde free and / or substantially BPA free, and can be either a solvent borne or waterborne composition.

[0016] Still another object of the present invention is to provide a method for coating a substrate using the epoxy and acrylic based coating composition.

[0017] These and other objects of this invention, alone or in combination, have been satisfied by the discovery of (i) a water based 2K coating composition, comprising one or more water soluble epoxy resins, one or more water soluble curing agents, and water, wherein the composition is substantially isocyanate free; or (ii) epoxy coating composition comprising a multifunctional aliphatic epoxy resin crosslinked with a di- or higher-functional curing agent, either of an acrylic resin or a mixed ester thermoplastic resin derivative of cellulose acetate, and a carrier, wherein the epoxy coating composition is at least one of substantially isocyanate free, substantially formaldehyde free, or substantially bisphenol-A free; and methods for the use of either (i) or (ii) for coating a substrate.Brief Description of the Drawings

[0018] A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:

[0019] FIG. 1 shows examples of the phenomenon of lapping using two different conventional water-based stains.

[0020] FIG. 2 shows an embodiment of the present invention water based 2K coating composition formulated as a stain applied to a section of wood flooring using a traditional wiping stains application method, and exhibiting an absence of lapping.Detailed Description of the Invention

[0021] Within the context of the present invention, the term “waterborne” is intended to mean that the polymeric components are in an aqueous medium. In certain embodiments, waterborne coatings provide one or more of the following advantages:• Low toxicity and flammability due to low VOC levels and low HAP emissions• Paint guns can be readily cleaned with water or water-based solutions and do not require paint thinner, acetone, or methyl acetate (further environmentally friendly and user safety friendly)

[0022] The term “comprises” and variations thereof do not have a limiting meaning where these terms appear in the description and claims.

[0023] The recitation of a numerical range using endpoints includes all numbers subsumed within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.).

[0024] To the extent that the terms “including”, “includes”, “having”, “has”, “with”, or variants thereof are used in the present application, such terms are intended to be inclusive in a manner similar to the term “comprising.” The singular forms “a”, “an” and “the” include plural referents unless the context clearly dictates otherwise. Additionally, the terms "a," "an," "the," "at least one," and "one or more" are used interchangeably. Thus, for example, a coating composition that contains "an" additive means that the coating composition can include "one or more" additives.Approximating language, as used herein throughout the specification and claims, may be applied to modify a quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term such as “about” is not to be limited to the precise value specified. In some instances, the approximating language may correspond to the precision of an instrument for measuring the value. Moreover, unless specifically stated otherwise, a use of the terms “first,” “second,” etc., do not denote an order or importance, but rather the terms “first,” “second,” etc., are used to distinguish one element from another.

[0025] As used herein, the terms “may” and “may be” indicate a possibility of an occurrence within a set of circumstances; a possession of a specified property, characteristic or function; and / or qualify another verb by expressing one or more of an ability, capability, or possibility associated with the qualified verb. Accordingly, usage of “may” and “may be” indicates that a modified term is apparently appropriate, capable, or suitable for an indicated capacity, function, or usage, whiletaking into account that in some circumstances the modified term may sometimes not be appropriate, capable, or suitable. For example, in some circumstances an event or capacity can be expected, while in other circumstances the event or capacity cannot occur - this distinction is captured by the terms “may” and “may be.”

[0026] In the specification and claims, reference will be made to a number of terms that have the following meanings. The singular forms “a”, “an” and “the” include plural referents unless the context clearly dictates otherwise. Approximating language, as used herein throughout the specification and claims, may be applied to modify a quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term such as “about” is not to be limited to the precise value specified. In some instances, the approximating language may correspond to the precision of an instrument for measuring the value. Moreover, unless specifically stated otherwise, a use of the terms “first,” “second,” etc., do not denote an order or importance, but rather the terms “first,” “second,” etc., are used to distinguish one element from another.

[0027] The term "aqueous" composition or dispersion herein means that particles are dispersed in an aqueous medium. An "aqueous medium" herein has a continuous phase of water that makes up at least 50 weight percent of the aqueous medium, wherein the remaining composition of the aqueous medium comprises particles and water-miscible compound(s) such as, for example, alcohols, glycols, glycol ethers, glycol esters, and the like.

[0028] The term "acrylic" as used herein includes (meth)acrylic acid, (meth)alkyl acrylate, (meth)acrylamide, (meth)acrylonitrile and their modified forms such as (meth)hydroxyalkyl acrylate. Throughout this document, the word fragment "(meth)acryl" refers to both "methacryl" and "acryl". For example, (meth)acrylic acid refers to both methacrylic acid and acrylic acid, and methyl (meth)acrylate refers to both methyl methacrylate and methyl acrylate.

[0029] The term "dispersion" in the context of the present invention refers to the mixture of a dispersible polymer and a carrier. The term "dispersion" includes, but is not limited to, the term "solution."

[0030] The terms "preferred" and "preferably" refer to embodiments of the invention that may afford certain benefits, under certain circumstances. However, other embodiments may also be preferred, under the same or other circumstances. Furthermore, the recitation of one or morepreferred embodiments does not imply that other embodiments are not useful and is not intended to exclude other embodiments from the scope of the invention.

[0031] As used herein, the term “structural units,” also known as polymerized units, of the named monomer refers to the remnant of the monomer after polymerization, or the monomer in polymerized form.

[0032] All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any examples, or language describing an example (e.g., "such as") provided herein, is intended to illuminate the invention and does not pose a limitation on the scope of the invention. Any statement herein as to the nature or benefits of the invention or of the preferred embodiments is not intended to be limiting. This invention includes all modifications and equivalents of the subject matter recited herein as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context. The description herein of any reference or patent, even if identified as "prior," is not intended to constitute a concession that such reference or patent is available as prior art against the present invention. No unclaimed language should be deemed to limit the invention in scope. Any statements or suggestions herein that certain features constitute a component of the claimed invention are not intended to be limiting unless reflected in the appended claims. Neither the marking of the patent number on any product nor the identification of the patent number in connection with any service should be deemed a representation that all embodiments described herein are incorporated into such product or service.

[0033] In certain embodiments, the present invention provides a water based 2K coating composition that can be used as a pigmented coating or as a stain. The water based 2K coating composition comprises one or more water soluble epoxy resins, one or more water soluble curing agents, and water, wherein the composition is substantially isocyanate free. In certain embodiments, the composition is fully isocyanate free. Within the context of the present invention, the term “substantially. ..free” means <0.2% (e g., by weight or by volume), preferably in some embodiments, <0.1%, and most preferably 0%.

[0034] In embodiments of the present invention water based 2K coating composition, the one or more water soluble epoxy resins is selected from the group consisting of poly(isosorbide diglycidylether), mono (isosorbide diglycidyl ether), and epoxidized polyalkylene glycols. In certain embodiments, the one or more water soluble epoxy resins comprise one or more epoxidized polyalkylene glycols formed from epichlorohydrin and at least one dialkylene glycol. In preferred embodiments, the one or more water soluble epoxy resins comprise one or more epoxidized polyalkylene glycols formed from epichlorohydrin and dipropylene glycol.

[0035] In the water based 2K coating composition of embodiments of the present invention, any water soluble curing agent can be used for curing the water soluble epoxy resin. In preferred embodiments, the one or more water soluble curing agents is selected from the group consisting of etheramines, polyethylenimines, polyamines, polyamidoamines, and alkyleneamines. In more preferred embodiments, the one or more water soluble curing agents is selected from the group consisting of etheramines and polyethylenimines. In certain embodiments, the one or more water soluble curing agents is a polyethylenimine having a weight average molecular weight of from 350 to 4,000,000 g / mol , preferably 500 to 3,000,000 g / mol, more preferably from 800 to 2,000,000 g / mol. In other embodiments, the one or more water soluble curing agents is an etheramine compound.

[0036] The water based 2K coating composition of embodiments of the present invention can also use small amounts of solvents and / or humectants to retard water evaporation from the composition. While not a major contributing factor to the composition, they can be used in small amounts to help maintain a "wet edge" of the composition during coating. Typical water-based solvents, humectants, or typical epoxy diluents like benzyl alcohol as well as other can also be used.

[0037] In embodiments of the water based 2K coating composition of the present invention, the composition can further comprise one or more members selected from the group consisting of water soluble solvents, water soluble humectants, and water soluble diluents. The water soluble solvents, water soluble humectants, and water soluble diluents can be selected from those conventional in the art, and would be readily selected by those of skill in the art.

[0038] The water based 2K coating composition of the present invention can further comprise one or more members selected from the group consisting of colorants, defoamers, surfactants, rheology modifiers, preservatives, epoxy curing accelerators, and catalysts, depending on the properties needed in the ultimate coating formed from the water based 2K coating composition. Selection of these additional components is within the ability of one of ordinary skill in the art.

[0039] When the water based 2K coating composition of the present invention is formulated as a water based stain composition, the water soluble materials used in the formulation are chosen to mimic the desirable characteristics of a solvent -based system. Because the materials are all in solution, the appearance, application properties, and lapping resistance of such water based 2K coating compositions of the present invention are comparable to existing solvent-based products, while having better VOC profiles due to being water-based. Due to the isocyanate free 2K reaction, the water solubility can be terminated by the crosslinking reaction caused by the water soluble curing agent, thus allowing for the application of additional coats without experience the lifting problem so prevalent in other water based stains.

[0040] The water based 2K coating composition of embodiments of the present invention can be prepared by any desired method, using standard paint making practices. In general, the one or more water soluble epoxy resins, one or more water soluble curing agents, and water are mixed prior to the application to the substrate. In using the water based 2K coating composition of embodiments of the present invention, standard coating / stain application techniques can be used. For example, a substrate can be coated with the water based 2K coating composition by combining the one or more water soluble epoxy resins and the one or more water soluble curing agents in water to form the water based 2K coating composition and applying a first coating of the water based 2K coating composition to a surface of the substrate during a pot life of the water based 2K coating composition. The water based 2K coating composition can be used to coat any desired substrate, preferably substrates selected from wood, wood composite , metal, glass, plastic, paper, leather, fabric, ceramic, and combinations thereof. When the water based 2K coating composition is formulated as a stain composition, the substrate is preferably selected from wood, wood composite, and combinations thereof. When the water based 2K coating composition of the present invention is formulated as a stain, traditional stain application techniques can be used, such as manually applying the stain to the substrate followed by manual wiping, or using an application apparatus such as a buffer machine and pad for the application and wiping of the stain from the surface, particularly on larger surface areas.

[0041] As a water-based stain, the water based 2K coating composition of embodiments of the present invention meets the current and future lower VOC restrictions, is free from spontaneous combustion concerns and is very low odor. Unlike other water-based stains, certain embodiments of the present invention water based 2K coating composition do not exhibit lapping or lifting of thestain, and still provide the desired application characteristics and appearance, without the use of isocyanates or other harsh chemistry that can cause health and safety concerns to untrained applicators.

[0042] As noted above, when the water based 2K coating composition is formulated as a stain composition, the water based 2K coating composition exhibits lapping resistance during coating. By way of example, Figure 1 shows examples of lapping using two different conventional waterbased stains. The application areas in Figure 1 can be divided into thirds, where the first two-thirds is the first coat. The first third of the application area is then skipped and the second coat applied on the remaining two thirds of the application area. This results in the middle third of the application area receiving two coats. The coats were applied in accordance with conventional practice for traditional wiping stains. As such, the stain is first applied by brush and allowed to soak into the wood for 2 minutes. Any excess is then removed by wiping. A 1 minute air dry is permitted before the second coat is applied in the same manner. In Figure 1, the application area on the left (100) shows severe lapping and the application area on the right (200) shows less severe lapping.

[0043] Figure 2 shows an embodiment of the present invention water based 2K coating composition formulated as a stain applied to a section of wood flooring using the same traditional wiping stains application method. As shown in Figure 2, with the coating / stain composition of these embodiments of the present invention, the resulting stained area shows no evidence of lapping.

[0044] In other embodiments, the present invention provides an epoxy coating composition that is acrylic resin based or modified cellulose acetate resin based, that can be either solvent-borne or waterborne, and is at least one of substantially isocyanate free, substantially formaldehyde free, or substantially bisphenol-A free. In certain embodiments, the epoxy coating composition is all three of substantially isocyanate free, substantially formaldehyde free, or substantially bisphenol-A free, and in preferred embodiments is isocyanate free, formaldehyde free, and bisphenol-A free.

[0045] The epoxy coating composition of these embodiments comprises a multifunctional aliphatic epoxy resin crosslinked with a di- or higher-functional curing agent, either of an acrylic resin or a mixed ester thermoplastic resin derivative of cellulose acetate, and a carrier, wherein the epoxy coating composition is at least one of substantially isocyanate free, substantially formaldehyde free, or substantially bisphenol-A free. In certain embodiments, the acrylic resin or modified celluloseacetate resin is present in an amount of from 3 to 50 wt%, based on total epoxy coating composition.

[0046] As noted above, the epoxy coating composition of these embodiments can be either waterborne or solvent-borne. Thus, the carrier can comprise a non-aqueous solvent or can comprise water, depending on the desired end use and composition to be prepared.

[0047] The multifunctional aliphatic epoxy resin of embodiments of the epoxy coating composition can be any desired multifunctional aliphatic epoxy resin. In certain embodiments, it is a di- to hexafunctional aliphatic epoxy resin, preferably a tetrafunctional aliphatic epoxy resin. The multifunctional aliphatic epoxy resin preferably has an epoxy equivalent weight of from 150-250, more preferably about 190 epoxy equivalent weight. In certain embodiments, the multifunctional aliphatic epoxy resin is a sorbitol polyglycidyl ether based epoxy resin. In certain embodiments, the multifunctional aliphatic epoxy resin is a water reducible aliphatic epoxy resin.

[0048] The di- or higher-functional curing agent in embodiments of the epoxy coating composition can be any desired di- or higher-functional curing agent, and is preferably an aliphatic polyamine or a cycloaliphatic polyamine. The di- or higher-functional curing agent can be used in any desired amount to achieve crosslinking of the multifunctional aliphatic epoxy resin. Preferably, the curing agent is present in an amount of from 2 to 9 wt%, based on total epoxy coating composition.

[0049] The thus crosslinked multifunctional aliphatic epoxy resin of the epoxy coating composition is crosslinked to a crosslink density of from 380 to 1000, preferably from 450 to 850, more preferably from 600 to 825.

[0050] The acrylic resin component of certain embodiments of the epoxy coating composition of the present invention can be formed of any (meth)acrylic based resin. The acrylic resin may be formed by any desired method. In certain embodiments, the acrylic resin is formed by radical polymerization of at least one (meth)acrylic unit containing monomer. The acrylic resin in some embodiments is dispersible in an aqueous medium. In certain embodiments, the acrylic resin may contain coalescing agents and in certain embodiments, it may contain no coalescing agents. The acrylic resin component is preferably present in an amount of 3 to 50 wt% of the total epoxy coating composition.

[0051] In some embodiments, the acrylic resin is formed from at least one (meth)acrylic unit containing monomer that is preferably at least one member selected from the group consisting ofalkyl (meth)acrylate), C1-C6 alkyl (meth)acrylate, methyl methacrylate, methyl acrylate, ethyl methacrylate, ethyl acrylate, isopropyl acrylate, isopropyl methacrylate, n-propyl acrylate, n-propyl methacrylate, n-butyl acrylate, n-butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, t- butyl acrylate, t-butyl methacrylate, n-pentyl acrylate, n-pentyl methacrylate, isopentyl acrylate, isopentyl methacrylate, neopentyl acrylate, neopentyl methacrylate, n-hexyl acrylate, n-hexyl methacrylate, isohexyl acrylate, isohexyl methacrylate, neohexyl acrylate, neohexyl methacrylate, cyclobutyl acrylate, cyclobutyl methacrylate, cyclopentyl acrylate, cyclopentyl methacrylate, cyclohexyl acrylate, and cyclohexyl methacrylate.

[0052] The modified cellulose acetate resin used in certain embodiments of the epoxy coating composition of the present invention can be any desired modified cellulose acetate resin suitable for use in a coating composition, and is preferably a mixed ester thermoplastic resin derivative of cellulose acetate, more preferably cellulose acetate butyrate (CAB).

[0053] The epoxy coating composition of these embodiments of the present invention can further comprise other components conventional in the coatings art, including but not limited to, one or more members selected from the group consisting of colorants, fillers, defoamers, surfactants, rheology modifiers, preservatives, epoxy curing accelerators, UV absorbers, light stabilizers, and catalysts.

[0054] Embodiments of the epoxy coating composition of the present invention can be used for the coating of various types of substrates, including, but not limited to, wood, wood composite, metal, glass, plastic, paper, leather, fabric, ceramic, and combinations thereof. The epoxy coating composition of the present invention can be coated on a substrate by a method comprising combining the multifunctional aliphatic epoxy resin crosslinked with a di- or higher-functional curing agent and the acrylic resin in the carrier to form the epoxy coating composition; and applying a first coating of the epoxy coating composition to a surface of the substrate during a pot life of the epoxy coating composition.

[0055] The epoxy coating composition of embodiments of the present invention provides a coating with high crosslink density and solvent / chemical resistance, while being substantially isocyanate free, substantially formaldehyde free, and / or substantially bisphenol A free.

[0056] The following are non-limiting examples of some embodiments of the present invention:

[0057] Embodiment 1. A water based 2K coating composition, comprising:one or more water soluble epoxy resins, one or more water soluble curing agents, and water, wherein the composition is substantially isocyanate free.

[0058] Embodiment 2. The water based 2K coating composition of Embodiment 1, wherein the one or more water soluble epoxy resins is selected from the group consisting of poly(isosorbide diglycidyl ether), mono (isosorbide diglycidyl ether), and epoxidized polyalkylene glycols.

[0059] Embodiment 3. The water based 2K coating composition of Embodiment 1 or Embodiment2, wherein the one or more water soluble epoxy resins comprise one or more epoxidized polyalkylene glycols formed from epichlorohydrin and at least one dialkylene glycol.

[0060] Embodiment 4. The water based 2K coating composition of any one of Embodiments 1 to 3, wherein the one or more water soluble epoxy resins comprise one or more epoxidized polyalkylene glycols formed from epichlorohydrin and dipropylene glycol.

[0061] Embodiment 5. The water based 2K coating composition of any one of Embodiments 1 to 4, wherein the one or more water soluble curing agents is selected from the group consisting of etheramines, polyethylenimines, polyamines, polyamidoamines, and alkyleneamines.

[0062] Embodiment 6. The water based 2K coating composition of any one of Embodiments 1 to 5, wherein the one or more water soluble curing agents is selected from the group consisting of etheramines and polyethylenimines.

[0063] Embodiment 7. The water based 2K coating composition of any one of Embodiments 1 to 6, wherein the one or more water soluble curing agents is a polyethylenimine having a weight average molecular weight of 350 to 4,000,000 g / mol. (preferably 500 to 3,000,000 g / mol; more preferably 800 to 2,000,000 g / mol)

[0064] Embodiment 8. The water based 2K coating composition of any one of Embodiments 1 to 6, wherein the one or more water soluble curing agents is an etheramine compound.

[0065] Embodiment 9. The water based 2K coating composition of any one of Embodiments 1 to 8, further comprising one or more members selected from the group consisting of water soluble solvents, water soluble humectants, and water soluble diluents.

[0066] Embodiment 10. The water based 2K coating composition of any one of Embodiments 1 to 9, further comprising one or more members selected from the group consisting of colorants, defoamers, surfactants, rheology modifiers, preservatives, epoxy curing accelerators, and catalysts.

[0067] Embodiment 11. A method for coating a substrate, comprising: combining the one or more water soluble epoxy resins and the one or more water soluble curing agents in water to form the water based 2K coating composition of any one of Embodiments 1 to 10; and applying a first coating of the water based 2K coating composition to a surface of the substrate during a pot life of the water based 2K coating composition.

[0068] Embodiment 12. The method of Embodiment 11, wherein the substrate is wood, wood composite, or combinations thereof, (substrates can alternatively be a material selected from the group consisting of wood, wood composite, metal, glass, plastic, paper, leather, fabric, ceramic, and combinations thereof)

[0069] Embodiment 13. The method of any one of Embodiments 11 to 14, wherein the water based 2K coating composition exhibits lapping resistance during coating.

[0070] Embodiment 14. An epoxy coating composition comprising: a multifunctional aliphatic epoxy resin crosslinked with a di- or higher-functional curing agent, either an acrylic resin or a modified cellulose acetate resin, and a carrier, wherein the epoxy coating composition is at least one of substantially isocyanate free, substantially formaldehyde free, or substantially bisphenol-A free.

[0071] Embodiment 15. The epoxy coating composition of Embodiment 14, wherein the acrylic resin or modified cellulose acetate resin is present in an amount of from 3 to 50 wt%, based on total epoxy coating composition.

[0072] Embodiment 16. The epoxy coating composition of Embodiment 14 or 15, wherein the carrier comprises a non-aqueous solvent.

[0073] Embodiment 17. The epoxy coating composition of Embodiment 14 or 15, wherein the carrier comprises water.

[0074] Embodiment 18. The epoxy coating composition of any one of Embodiments 14 to 17, wherein di- or higher-functional curing agent is an aliphatic polyamine or a cycloaliphatic polyamine.

[0075] Embodiment 19. The epoxy coating composition of any one of Embodiments 14 to 16 or 18 tol9, wherein the multifunctional aliphatic epoxy resin is a tetrafunctional aliphatic epoxy resin.

[0076] Embodiment 20. The epoxy coating composition of any one of Embodiments 14 to 15 or 17 to 19, wherein the multifunctional aliphatic epoxy resin is a sorbitol polyglycidyl ether.

[0077] Embodiment 21. The epoxy coating composition of any one of Embodiments 14 to 15 or 17 to 19, wherein the multifunctional aliphatic epoxy resin is a water reducible aliphatic epoxy resin.

[0078] Embodiment 22. The epoxy coating composition of any one of Embodiments 14 to 21, further comprising one or more members selected from the group consisting of colorants, fillers, defoamers, surfactants, rheology modifiers, preservatives, epoxy curing accelerators, UV absorbers, light stabilizers, and catalysts.

[0079] Embodiment 23. The epoxy coating composition of any one of Embodiments 14 to 22, wherein the multifunctional epoxy resin is crosslinked to a crosslink density of from 380 to 1000. (preferably, the multifunctional epoxy is di- to hexa- functional, with epoxy equivalent weight being from 150-250, preferably around 190 epoxy equivalent weight)

[0080] Embodiment 24. The epoxy coating composition of any one of Embodiments 16 to 23, wherein the di- or higher-functional curing agent is present in an amount of from 2 to 9 wt%, based on total epoxy coating composition.

[0081] Embodiment 25. The epoxy coating composition of any one of Embodiments 16 to 24, wherein the acrylic resin is present.

[0082] Embodiment 26. The epoxy coating composition of any one of Embodiments 16 to 24, wherein the modified cellulose acetate resin is present.

[0083] Embodiment 27. The epoxy coating composition of Embodiment 26, wherein the modified cellulose acetate resin is cellulose acetate butyrate.

[0084] Embodiment 28. A method of producing the epoxy coating composition of any one of Embodiments 14 to 27.

[0085] Embodiment 29. A method for coating a substrate, comprising: combining the multifunctional aliphatic epoxy resin crosslinked with a di- or higher- functional curing agent and either of the acrylic resin or modified cellulose acetate resin in the carrier to form the epoxy coating composition of any one of Embodiments 14 to 27; and applying a first coating of the epoxy coating composition to a surface of the substrate during a pot life of the epoxy coating composition.

[0086] While the embodiments discussed herein have been related to the coatings and methods discussed above, these embodiments are intended to be examples only and are not intended to limit the applicability of these embodiments to only those discussions set forth herein.

[0087] The above description is merely illustrative of several possible embodiments of various aspects of the present invention, wherein equivalent alterations and / or modifications will occur to others skilled in the art upon reading and understanding this specification and the annexed drawings. In addition, although a particular feature of the invention may have been disclosed with respect to only one of several implementations, such feature may be combined with one or more other features of the other implementations as may be desired and advantageous for any given or particular application.

[0088] Additional modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.

Claims

What is Claimed is:

1. A water based 2K coating composition, comprising: one or more water soluble epoxy resins, one or more water soluble curing agents, and water, wherein the composition is substantially isocyanate free.

2. The water based 2K coating composition of claim 1, wherein the one or more water soluble epoxy resins is selected from the group consisting of poly(isosorbide diglycidyl ether), mono (isosorbide diglycidyl ether), and epoxidized polyalkylene glycols.

3. The water based 2K coating composition of claim 1 or claim 2, wherein the one or more water soluble epoxy resins comprise one or more epoxidized polyalkylene glycols formed from epichlorohydrin and at least one dialkylene glycol.

4. The water based 2K coating composition of any one of claims 1 to 3, wherein the one or more water soluble epoxy resins comprise one or more epoxidized polyalkylene glycols formed from epichlorohydrin and dipropylene glycol.

5. The water based 2K coating composition of any one of claims 1 to 4, wherein the one or more water soluble curing agents is selected from the group consisting of etheramines, polyethylenimines, polyamines, polyamidoamines, and alkyleneamines.

6. The water based 2K coating composition of any one of claims 1 to 5, wherein the one or more water soluble curing agents is selected from the group consisting of etheramines and polyethylenimines.

7. The water based 2K coating composition of any one of claims 1 to 6, wherein the one or more water soluble curing agents is a polyethylenimine having a weight average molecular weight of 350 to 4,000,000 g / mol.

8. The water based 2K coating composition of any one of claims 1 to 6, wherein the one or more water soluble curing agents is an etheramine compound.

9. The water based 2K coating composition of any one of claims 1 to 8, further comprising one or more members selected from the group consisting of water soluble solvents, water soluble humectants, and water soluble diluents.

10. The water based 2K coating composition of any one of claims 1 to 9, further comprising one or more members selected from the group consisting of colorants, defoamers, surfactants, rheology modifiers, preservatives, epoxy curing accelerators, and catalysts.

11. A method for coating a substrate, comprising: combining the one or more water soluble epoxy resins and the one or more water soluble curing agents in water to form the water based 2K coating composition of any one of claims 1 to 10; and applying a first coating of the water based 2K coating composition to a surface of the substrate during a pot life of the water based 2K coating composition.

12. The method of claim 11, wherein the substrate is wood, wood composite, metal, glass, plastic, paper, leather, fabric, ceramic, or a combination thereof.

13. The method of any one of claims 11 to 14, wherein the water based 2K coating composition exhibits lapping resistance during coating.

14. An epoxy coating composition comprising: a multifunctional aliphatic epoxy resin crosslinked with a di- or higher-functional curing agent, either of an acrylic resin or a modified cellulose acetate resin, and a carrier, wherein the epoxy coating composition is at least one of substantially isocyanate free, substantially formaldehyde free, or substantially bisphenol-A free.

15. The epoxy coating composition of claim 14, wherein the acrylic resin or modified cellulose acetate resin is present in an amount of from 3 to 50 wt%, based on total epoxy coating composition.

16. The epoxy coating composition of claim 14 or 15, wherein the carrier comprises a nonaqueous solvent.

17. The epoxy coating composition of claim 14 or 15, wherein the carrier comprises water.

18. The epoxy coating composition of any one of claims 14 to 17, wherein di- or higher- functional curing agent is an aliphatic polyamine or a cycloaliphatic polyamine.

19. The epoxy coating composition of any one of claims 14 to 16 or 18 tol9, wherein the multifunctional aliphatic epoxy resin is a tetrafunctional aliphatic epoxy resin.

20. The epoxy coating composition of any one of claims 14 to 15 or 17 to 19, wherein the multifunctional aliphatic epoxy resin is a sorbitol polyglycidyl ether.

21. The epoxy coating composition of any one of claims 14 to 15 or 17 to 19, wherein the multifunctional aliphatic epoxy resin is a water reducible aliphatic epoxy resin.

22. The epoxy coating composition of any one of claims 14 to 21, further comprising one or more members selected from the group consisting of colorants, fillers, defoamers, surfactants, rheology modifiers, preservatives, epoxy curing accelerators, UV absorbers, light stabilizers, and catalysts.

23. The epoxy coating composition of any one of claims 14 to 22, wherein the multifunctional epoxy resin is crosslinked to a crosslink density of from 380 to 1000.

24. The epoxy coating composition of any one of claims 16 to 26, wherein the di- or higher- functional curing agent is present in an amount of from 2 to 9 wt%, based on total epoxy coating composition.

25. The epoxy coating composition of any one of claims 16 to 24, wherein the acrylic resin is present.

26. The epoxy coating composition of any one of claims 16 to 24, wherein the modified cellulose acetate resin is present.

27. The epoxy coating composition of claim 26, wherein the modified cellulose acetate resin is cellulose acetate butyrate.

28. A method of producing the epoxy coating composition of any one of claims 14 to 27.

29. A method for coating a substrate, comprising: combining the multifunctional aliphatic epoxy resin crosslinked with a di- or higher- functional curing agent and either of the acrylic resin or modified cellulose acetate resin in the carrier to form the epoxy coating composition of any one of claims 14 to 27; and applying a first coating of the epoxy coating composition to a surface of the substrate during a pot life of the epoxy coating composition.

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