FIELD OF THE INVENTION

[0001 ] The present disclosure generally relates to high solids, low solvent borne epoxy coating compositions, processes for preparing these compositions, and cured coatings prepared using these compositions.

BACKGROUND OF THE INVENTION

[0002] Solvent-borne (SB), two-component epoxy coatings have been widely used in marine coatings, protective coatings, and in other application fields since these coatings exhibit excellent adhesion, corrosion resistance and chemical resistance. Generally, various types of hardeners are used to achieve the required balanced properties for specific applications. Polyamide hardeners are most commonly used in marine and protective coating markets because these hardeners provide SB epoxy coatings that are relatively low cost, an extended pot-life; excellent corrosion resistance, and chemical resistance as compared to SB epoxy coatings prepared from other classes of hardeners.

[0003] Current market trends and end users request high volume solids, low volatile organic content (VOC) epoxy coatings. However, when known polyamide hardeners used in high solids epoxy coatings (coatings with minimal or no solvent), the polyamide/epoxy resin combination suffers from poor compatibility. This poor

compatibility manifests itself by blooming/blushing during cure, low gloss properties, and an overall poor film performance. In order to address these compatibility issues, end users of these high solid epoxy coating formulations utilize an induction time. This induction time comprises applying a coating formulation to allow the epoxy and hardener sufficient time to react with each other. This induction time results in a minimal blooming/blushing of the resulting cured coating. However, this known approach of using an induction time reduces the effective pot-life of the epoxy coating formulation and raises the viscosity. These effects create challenges with applying the coating. Any increase in coating formulation viscosity makes it difficult for end users to apply the coating formulation by brushing, rolling, or spraying and the like onto a substrate. Therefore, it is a disadvantage for high solids epoxy coatings to exhibit high coating formulation viscosity.

[0004] To reduce the viscosity of a coating formulation, the skilled artisan has added epoxy reactive diluents into the coating formulation. However, the reactive diluents may negatively influence coating performance such as increased dry time, reduced chemical resistance, and reduced corrosion resistance. The aforementioned compatibility and formulation issues experienced with polyamide hardeners in high volume solids epoxy coatings are magnified when epoxy functional reactive diluents are used in coating compositions and also when the amount of solvent is minimized.

[0005] In the paint industry, another common practice to reduce paint formulation viscosity is to add additional solvents into the coating formulation or by including a fluid, low molecular weight amine compound as part of the hardener.

However, when using fluid, low molecular weight amine compounds as viscosity cutting agents in polyamide cured coatings, the amine compounds exacerbate blooming and blushing. This effect can be attributed to the amines migrating and reacting with CO ₂ to produce carbamate salts. When organic solvents are used in a coating formulation, it is difficult to formulate high solids paint formulations.

[0006] Therefore, there is need in the coating industry for coating formulations comprising high volume solids, polyamide hardeners, low VOCs, lack of aforementioned compatibility issues, and low viscosity. These coating formulations would be especially beneficial in preparing paint and coating formulations.

SUMMARY OF THE INVENTION

[0007] Disclosed herein are curable epoxy resin compositions, processes for preparing these curable epoxy resin compositions, processes for applying the curable epoxy resin compositions, and cured products produced from the curable epoxy resin composition. [0008] In one aspect, a curable epoxy resin composition comprising: (a) an epoxy resin, (b) a polyamide hardener; and (c) a compatibilizer wherein the

compatibilizer has the following general chemical structure:

wherein Z is oxygen or NH; n is a number from 1 to 3; m is a number from 0 to 2 with the proviso that 4-n-m must be at least 1 ; A is independently hydrogen (H), an alkyl, or substituted alkyl having from 1 to 3 carbon atoms; X is independently OH, N(R) ₂ or CH ₂ Y; Y is OH or N(R) ₂ ; and each R is independently an alkyl, substituted alkyl, or a hydroxyalkyl having from 1 to 3 carbon atoms.

[0009] In a further aspect, processes for preparing the curable epoxy resin compositions comprising admixing (a) at least one epoxy resin, (b) at least one hardener, and (c) a compatibilizer agent. Other additives known to the skilled artisan may also be added.

[0010] In another aspect, processes for coating and curing the curable epoxy resin composition are described.

[001 1 ] In yet another aspect, disclosed herein are cured products prepared by curing the curable epoxy resin composition.

[0012] Other features and iterations of the invention are described in more detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The following drawing illustrates a non-limiting embodiment of the present invention wherein:

[0014] Figure 1 shows a group of four photographs showing four coated articles. Two of the photographs show a coated article that has been coated with a control composition (Comparative Example B) and a coated article that has been coated with a composition of the present invention (Example 6) using Versamid 125 in each composition, respectively. The two remaining photographs show a coated article that has been coated with a control composition (Comparative Example D) and a composition of the present invention (Example 12) using Versamid 140 in each composition, respectively. The compatibilizer modified coated articles of the present invention (Examples 6 and 12) show better methyl ethyl ketone (MEK) double rub resistance than the control coatings (Comparative Examples B and D).

DETAILED DESCRIPTION OF THE INVENTION

[0015] As previously mentioned, disclosed herein are curable epoxy resin compositions which comprise at least one epoxy resin compound, at least one polyamide hardener, and at least one compatibilizer. After the curable epoxy resin compositions are applied and cured, the coatings have improved chemical, corrosion resistance, and do not display significant blooming and/ or significant blushing.

(I) Curable Epoxy Resin Compositions

[0016] In one aspect, the curable epoxy resin composition comprises at least one epoxy resin compound, at least one polyamide hardener, and at least one compatibilizer. In general, the curable epoxy resin composition has a viscosity ranging from 50 mPa-s to about 10,000 mPa-s and a high solid content.

(a) epoxy resin compound

[0017] The epoxy resin compound, component (a), can be any

conventional epoxy resin compound. Generally, the epoxy resin can be a single epoxy resin compound used alone or a mixture of two or more epoxy compounds used in combination, i.e., component (a) of the curable epoxy resin composition which is cured to form the coating material of the present invention includes at least one epoxy resin. Non-limiting embodiments of these epoxy resins may be trimethylpropane epoxide, cyclohexanedimethanol diglycidyl ether, diglycidyl-1 ,2-cyclohexane dicarboxylate, diglycidyl ether of bisphenol A, diglycidyl ether of bisphenol F, resorcinol diglycidyl ether, triglycidyl ethers of para-aminophenols, halogen (for example, chlorine or bromine)-containing epoxy resins such as diglycidyl ether of tetrabromobisphenol A, epoxidized phenol novolac, epoxidized bisphenol A novolac, an oxazolidone-modified epoxy resin, an epoxy-terminated polyoxazolidone, and mixtures thereof.

[0018] Non-limiting examples of suitable commercially available epoxy resin compounds may include the D.E.R.™ 300 series, the D.E.N.™ 400 series, the D.E.R.™ 500 series, the D.E.R.™ 600 series and the D.E.R.™ 700 series of epoxy resins commercially available from The Dow Chemical Company. For example, epoxy resins may include LERs, such as D.E.R. 331 (a bisphenol A diglycidyl ether), D.E.R. 354 (a bisphenol F diglycidyl ether), D.E.R. 324 (a diluent modified epoxy resin), DLVE 18 (a low viscosity epoxy resin blend) and other well-known epoxy resins and blends of the above known epoxy resins. D.E.R. 330, DER 331 , D.E.R. 332, D.E.R. 354, D.E.R. 324, and DLVE 18, DLVE 19, DLVE 52 are commercially available epoxy resins from The Dow Chemical Company.

[0019] In a preferred embodiment, the epoxy resin compound may include a liquid epoxy resin, such as D.E.R. 383 a diglycidylether of bisphenol A (DGEBPA) having an epoxide equivalent weight of from about 175 to about 185, a viscosity of about 9.5 Pa-s and a density of about 1 .16 g/cc. In other preferred embodiments, the commercial epoxy resin compounds may include epoxidized novolac bisphenol F type resins such as D.E.N. 431 , D.E.N. 438 or D.E.N. 439; epoxidized novolac bisphenol F type resins with solvent including for example D.E.N. 438-A85 which is a solution of 85 % D.E.N 438 in acetone, D.E.N. 438-EK85 which is a solution of 85 % D.E.N 438 in methyl ethyl ketone, D.E.N. 438-MAK80 which is a solution of 80 % D.E.N 438 in methyl n-amyl ketone, D.E.N. 438-MK75 which is a solution of 75 % D.E.N 438 in methyl isobutyl ketone, D.E.N. 438-X80 which is a solution of 80 % D.E.N 438 in xylene, and D.E.N. 439-EK85 which is a solution of 85 % D.E.N 439 in methyl ethyl ketone; and mixtures thereof.

[0020] An extensive enumeration of epoxy resins useful in the present invention can be found in Lee, H. and Neville, K., "Handbook of Epoxy Resins,"

McGraw-Hill Book Company, New York, 1967, Chapter 2, pages 257-307; incorporated herein by reference. The preparation of epoxy compounds useful in the present invention is described for example in Kirk- Othmer, Encyclopedia of Chemical Technology, 3rd Ed., Vol. 9, pages 267-289, incorporated herein by reference. Other suitable epoxy resins useful as component (a) in the present invention are disclosed in, for example, U.S. Patent Nos. 3,018,262; 7,163,973; 6,887,574; 6,632,893; 6,242,083; 7,037,958; 6,572,971 ; 6,153,719; 5,137,990; 6,451 ,898, 8,048,819, 7,655,174,

7,923,073 and 5,405,688; all of which are incorporated herein by reference.

[0021 ] One of the key properties of the epoxy resin is the capability of the epoxy resin to be useful as a binder for coating films.

[0022] Generally, the concentration of the epoxy resin compound used in the curable composition may range from 1 weight percent (wt%) to about 99 wt%. In various embodiments, the concentration of the epoxy resin compound may range from 1 wt% to about 99 wt%, from 5wt% to about 80 wt%, from 10 wt% to about 70 wt%, from 20 wt% to about 60 wt%, or from 25 wt% to about 50 wt% based on the total weight of all of the components present in the curable composition. Using the epoxy resin compound below 1 wt % or above 99 wt % would result in less curing of the curable composition; and would result in poor coating performance.

(b) the polyamide hardener compound

[0023] The polyamide hardener compound, component (b), may be a single polyamide hardener compound, a mixture of two or more polyamide hardener compounds, or a mixture of at least one polyamide hardener compound and another co- curing agent compound different from the polyamide hardener compound. The polyamide hardener compound, component (b), may include at least one polyamide hardener. The hardener compound (or "hardener"; also referred to as a "curing agent" or a "crosslinking agent") may be blended with the epoxy resin, component (a), and the other components of the composition, to prepare the curable epoxy resin formulation or composition. The curable epoxy resin composition may then be cured under curing conditions to form a cured product or thermoset which is in the form of a solid cured coating.

[0024] The polyamide hardener is one that is adapted to being compatible with the epoxy resin, component (a), when the polyamide hardener is in the presence of the epoxy resin and the compatibilizer agent. Another key property of the polyamide hardener compound is to cure epoxy resin to form a hard coating material.

[0025] The polyamide hardener compound, component (b), may be selected from one or more of the following chemical compounds including amino polyamides, amidopolyamines, and mixtures thereof. Non-limiting examples of some commercial polyamide hardeners may include Versamid 125, Versamid 140, Versamid 228, Versamid 280B75, and other compounds under the Versamid trade name which are commercially available from BASF. The Versamid polyamide hardeners are condensation products of fatty acids or dimer fatty acids and polyamines. Other non- limiting examples of other polyamide hardeners may be BCA P445 and BCA P050 commercially available from BRENNTAG Specialties; EPIKURE™ polyamide curing agents commercially available from Momentive; and mixtures thereof. In a preferred embodiment, the polyamide hardener compound, component (b), may include condensation products of dimer fatty acid and polyamines; and condensation products of fatty acids with polyamines; and mixtures thereof.

[0026] Generally, the molar stoichiometry of epoxy to the hardener may range from 1 .4:1 to about 1 :1 .4. In various embodiments, , the molar stoichiometry of epoxy to the hardener may range from 1 .4:1 to about 1 :1 .4, from 1 .2:1 to about 1 :1 .2, from 1 .1 :1 to about 1 :1 .1 or from 1 .05:1 to about 1 :1 .05. In one preferred embodiment, the epoxy and polyamide hardener at a stoichiometric ratio of epoxy to NH may range from 1 .2:1 to about 1 :1 .2; or from 1 .1 :1 to about 1 :1 .1 .

[0027] Alternatively, the concentration of the hardener present may be measured in terms of an equivalent ratio of nucleophile (i.e., amine NH) to electrophile (i.e., epoxy and acrylate functionality). Generally, the equivalent ratio of nucleophile to the electrophile functionality may range of from 0.5:1 to about 1 .5:1 . In various embodiments, equivalent ratio of nucleophile to the electrophile functionality may range of from 0.5:1 to about 1 .5:1 , from 0.6:1 to about 1 .4:1 , from 0.7:1 to about 1 .3:1 , from 0.8:1 to about 1 .2:1 , or from 0.8:1 to about 1 .1 :1 . Outside the above concentration range, the resulting coating film properties may suffer due to poor network formation from a stoichiometric imbalance. (c) compatibilizer

[0028] A compatibilizer (or "compatibilizer agent" or "compatibilizing agent"), as component (c), may be added to the curable epoxy resin coating

composition to effect several benefits including: (i) to significantly improve the compatibility between the epoxy resin in the composition and the hardener in the composition; (ii) to reduce or resolve the blooming and blushing problems of the final cured coating product; and (iii) to beneficially reduce the initial viscosity of the curable epoxy resin composition.

[0029] The compatibilizer may be a reactive compatibilizer agent. By "reactive" herein is meant that the compatibilizer, component (c), includes a reactive functionality that can react with the curing agent. Generally, the reactive compatibilizer agent is an acrylate-based compound. In addition, the reactive compatibilizer agent may include a polar functionality which may be a hydroxyl functionality or a tertiary amine functionality. In a preferred embodiment, the polar functionality of the reactive compatibilizer agent may be a hydroxyl functionality.

[0030] The compatibility improving component, i.e., the compatibilizer, may include a compound having the following general chemical structure, Structure (I):

Structure (I)

[0031 ] where Z is oxygen or NH; n is a number from 1 to 3; m is a number from 0 to 2 with the proviso that 4-n-m must be at least 1 ; A is independently hydrogen (H), an alkyl, or substituted alkyl having from 1 to 3 carbon atoms; X is independently OH, N(R) ₂ or CH ₂ Y; Y is OH or N(R) ₂ ; and each R is independently an alkyl, substituted alkyl, or a hydroxyalkyl having from 1 to 3 carbon atoms.

[0032] Specific compatibilizers may include a hydroxyl functional acrylate, a hydroxyl functional di-acrylate, a hydroxyl functional tri-acrylate, a di-hydroxyl functional di-acrylate, an alkylaminoalkyl acrylate, a monohydroxyl polyglycol acrylate, and the like; or blends of the above compounds. Other acrylate oligomers or polymers that may react with curing agents and also contain hydroxyl groups or polar groups that improve the compatibility of the epoxy resin and the polyamide curing agent may be used.

[0033] Generally, the amount of compatibilizer may include a hydroxyl functionalized additive in an amount of from 0.1 wt% to about 20 wt% based on the epoxy portion, component (a), of the composition. In various embodiments, amount of compatibilizer may range from 0.1 wt% to about 20 wt%, from 1 wt% to about 15 wt%, from 2 wt% to about 10 wt% or from 3 wt% to about 5 wt% based on the weight of the epoxy resin in the curable epoxy resin composition.

(d). optional components

[0034] In preparing the curable epoxy resin composition, optional components may be added to the curable composition for various intended purposes. The optional components may be used at a concentration sufficient to prepare the curable epoxy resin composition with minimal impact to the thermal and mechanical properties of the final curable composition; and minimal impact to the thermal and mechanical properties of the cured thermoset product made from the curable

composition. For example, a curing catalyst compound may optionally be added to facilitate the curing of the at least one epoxy resin. Specifically, the curing catalyst functions to speed up the curing reaction between the epoxy and the hardener. Another additional component may include at least one other hardener or co-curing agent different from the polyamide hardener compound. The co-curing agent may be used for assisting in curing the epoxy resin. For example, the co-curing agent component may include any conventional co-curing agent known in the art. Still another additional component may include at least one solvent. The solvent may be used to lower the initial viscosity of the curable composition to a lower final viscosity. For example, the solvent component that can be used to form the curable composition may include any solvent or diluent which is essentially inert to the other components used in the curable composition at the mixing temperature of the components; and which provides the necessary solubility to lower the initial viscosity of the curable composition. The solvent component that can be added to the curable composition may include any conventional solvent known in the art. Other optional components may include compounds that are normally used in curable resin formulations known to those skilled in the art. For example, the optional components may include compounds that can be added to the composition to enhance application properties (e.g., surface tension modifiers, rheology modifiers, or flow aids), reliability properties (e.g., adhesion promoters), the reaction rate, the selectivity of the reaction, and/or the catalyst lifetime. Non-limiting examples of these optional components may be fillers; inorganic and organic pigments;

anticorrosive pigments, anti-settling agents; dispersants; toughening agents; flexibilizing agents; processing aides; flow and leveling modifiers; slip and mar aids; defoamers; deaerators, adhesion promoters; diluents; stabilizers; plasticizers; curing catalysts; catalyst de-activators; flame retardants; aromatic hydrocarbon resins; coal tar pitch; petroleum pitch; carbon nanotubes; graphene; carbon black; carbon fibers; or mixtures thereof.

[0035] Generally, the amount of the optional compounds may range from 0 wt % to about 80 wt%. In various embodiments, the amount of the optional components may range from 0 wt% to about 80wt %, from 0.01 wt% to about 70 wt%, from 0.1 wt% to about 60wt %, or from 1 wt % to about 50wt % based on the total weight of all of the components present in the curable composition.

[0036] In other embodiments depending on the end use application, various optional compounds may be used in different concentrations toward the end points of the above ranges. Generally, the amount of the wetting agent may be range from 0 wt% to 1 wt%. In various embodiments, the amount of the wetting agent may range from 0 wt% to about 1 wt%, from 0.2 wt% to about 0.8 wt%, from 0.3 wt% to about 0.7 wt%, or from 0.4 wt% to about 0.6 wt%. Generally, the amount of the pigment may range from 0 wt% to about 90 wt%. In various embodiments, the amount of the pigment may range from 0 wt% to about 90 wt%, from 20 wt% to about 70 wt%, or from 30 wt% to about 50 wt%. One skilled in the art will be able to adjust the concentrations of the optional compounds depending on the intended use of such optional compounds.

(II) Properties of the Curable Epoxy Resin Composition

[0037] In another aspect, the curable epoxy resin composition, described above, has many beneficial properties. These properties are important to allow the curable epoxy resin composition to be processed into a cured solid state. One of the most important property is the viscosity which is allows for the curable epoxy resin composition to be flowable. The curable composition exhibits a low viscosity sufficient to allow the curable composition to be processed and handled in conventional formulation equipment. The viscosity of the curable epoxy resin composition may vary depending on whether the composition is pigmented or non-pigmented or other additives; and may depend on other considerations. For example, the viscosity of the composition comprising the epoxy resin, the polyamide hardener; and the compatibilizer is such that the initial viscosity of the composition is lower than that of a composition of epoxy resin and polyamide hardener (i.e., lacking a compatibilizer). It is beneficial that the initial viscosity of the composition be as low as possible. Also, the difference in the viscosity (i.e., the reduction in viscosity) of the composition having a compatibilizer when compared to a composition lacking a compatibilizer be as high as possible.

[0038] For example, the initial viscosity of the composition having a compatibilizer, when compared to the initial viscosity of a composition lacking a compatibilizer, may be at least about 50 % lower in viscosity than the viscosity of the composition lacking a compatibilizer. Generally, the initial viscosity of the composition having a compatibilizer may range from 1 % lower in viscosity to about 20%. In various embodiments, the initial viscosity of the composition having a compatibilizer may range from 1 % lower in viscosity to about 20%, from about 2% to about 18%, from about 5% to about 15%, to from about 8% to about 12% lower in viscosity than the viscosity of the composition lacking a compatibilizer, measured at 25°C.

[0039] Generally, the viscosity of curable formulation may range from 50 mPa-s to about 10,000 mPa-s. In various embodiments, , the viscosity of curable formulation may range from 50 mPa-s to about 10,000 mPa-s, from about 100 mPa-s to about 8,000 mPa-s, or from 1 ,000 mPa-s to about 5,000 mPa-s measured at 25°C. The curable composition having the above viscosity can be easily processed and readily handled in end use processes for forming thermoset products.

[0040] Other beneficial properties which the curable may comprise a low VOC, high volume solids, and high pigment volume content (PVC). Generally, the low VOC of the curable composition may range from 0 g/L to about 300 g/L. In various embodiments, the low VOC may range from 0 g/L to about 300 g/L, from 50 g/L to about 250 g/L, or from about 100 g/L to about 150 g/L.

[0041 ] Generally, the high volume solids of the curable composition may range from about 50 % to about 100 %. In various embodiments, the high volume solids of the curable composition may range from about 50 % to about 100 %, from 60 % to about 95 %, or from 70 % to about 90 %.

[0042] Generally, the high PVC of the curable composition may range from 0 % to about 60 %. In various embodiments, the high PVC of the curable composition may range from 0 % to about 60 %, from 10 % to about 50 %, or from 20 % to about 40 %.

(Ill) Processes for Preparing the Curable Epoxy Resin Compositions

[0043] In an additional aspect provides processes for preparing the curable epoxy resin composition. In general, the process of preparing the curable epoxy resin composition may be achieved by blending, in known mixing equipment, (a) at least one epoxy resin; (b) at least one polyamide hardener; and (c) at least one compatibilizer agent; and optionally any other desirable additives. Generally, the components described above are mixed in the following permissible component ranges for the curable composition: from 5 wt % to about 80 wt % of an epoxy resin; from 15 wt % to about 50 wt % of a polyamide hardener; and from 0.5 wt % to about 10 wt % of a compatibilizing agent. The above epoxy resin-based curable composition may advantageously be used for preparing a coating material, a product, or a thermoset. Components in the curable epoxy resin composition may be mixed in any order to provide the curable epoxy resin composition of the present invention. Any of the above- mentioned optional components may also be added to the composition during the mixing or prior to the mixing to form the composition.

[0044] All the above mentioned components are typically mixed and dispersed at a temperature enabling an effective curable epoxy resin composition.

Generally, the temperature during the mixing of all components may be generally from about -10°C to about 40°C. In various embodiments, the temperature during the mixing may range from -10°C to about 40°C, from 0°C to about 30°C, or from 10°C to about 20°C.

[0045] The preparation of curable epoxy resin composition and/or any of the steps thereof may be a batch or a continuous process. The mixing equipment used in the process may be any vessel and ancillary equipment well known to those skilled in the art.

(IV) Processes for Preparing a Curable Resin Composition

[0046] Another aspect provides processes for preparing a cured

composition. The processes comprise providing a curable epoxy resin composition, which is detailed above, applying the curable epoxy resin composition, and exposing the curable composition to heat and pressure to form the cured coating. Generally, the curable composition is applied to at least a portion of a surface of an article to be coated, prior to subjecting it to heat for curing.

(a) curable composition

[0047] Suitable curable epoxy resin compositions are described above.

(b) articles

[0048] In a further aspect of the present disclosure encompasses an article comprising a cured or uncured curable epoxy resin composition adhering to at least one portion of the substrate. The article, in broad terms, may be defined as a material wherein the curable epoxy resin composition is initially applied and adheres to at least a portion of at least one surface of the substrate. The curable epoxy resin composition may be cured at a exposing the composition to heat to form a thermoset or cured composition such that the coating bonds to the substrate. The article may be any material that can withstand the curing temperature to form a cured coating.

[0049] In various embodiments, the article may be a metal. The article, as defined herein, may be a single metal or an alloy of various metals. Non-limiting examples of these metals include cast iron, aluminum, tin, brass, steel, copper, zinc aluminum alloy, nickel, or combinations thereof.

[0050] In other embodiments, the substrate may be a cellulose product. Non-limiting examples of cellulose products may be paper, paperboard, paper cardstock, cardboard, wood, and balsawood.

[0051 ] In still another embodiment, the substrate may be a plastic. Non- limiting examples of plastics may be bakelite, polyester, polyethylene terephthalate, polyethylene, high density polyethylene, polyvinyl chloride, polyvinylidene chloride, polypropylene, polystyrene, polyamides (Nylon), acrylonitrile butadiene styrene, polycarbonates, polyurethanes, and combinations thereof.

[0052] In a further embodiment, the article may be a stone. Non-limiting examples of stones may be granite, brick, limestone, concrete, and combinations thereof.

[0053] In yet another embodiment, the article may be foam. Non-limiting examples of foams may be a polyurethane foams, high density foams, evlon foams, high resilience foams, latex rubber foams, rebond foams, memory foams, closed cell foams, dry fast foams, polyethersulfone foams, polyvinylchloride foams, polyethylene foams, polystyrene foams, and syntactic foams.

[0054] In still another embodiment, the article may be a structural laminate or a composite. Non-limiting examples of structural laminates or composites may be laminate floor, carbon fiber laminates, carbon fiber composites, fiber composites, polymer matrix composites, metal matrix composites, and ceramic matrix composites.

[0055] In various embodiments, the article may be in various

configurations. Non-limiting configuration examples of the article may be a roll, a coil, a plate, a sheet, a tube, a brick, a slab, a boulder, or a pipe. The configuration of the article may be of various dimensions, shapes, thicknesses, and weights.

(c) applying the curable composition

[0056] The process further comprises applying the curable epoxy resin composition to a portion of at least one surface of an article. Suitable articles are detailed above. Application of the curable coating composition may be applied through various means. For example, the coating composition may be applied using a drawdown bar, a roller, a knife, a paint brush, a sprayer, dipping, or other methods known to the skilled artisan. As detailed above, the curable coating composition may be applied to one or more surfaces of the article to be coated.

(d) curing the curable composition

[0057] The process further comprises curing the curable epoxy resin composition to a portion of at least one surface of an article. The curable epoxy resin composition, as detailed herein, may be cured by exposing the composition to heat and pressure to form a cured composition or thermoset.

[0058] In general, the process for producing the cured coating material includes carrying out the curing reaction at process conditions to enable the preparation of an effective cured material having the desired balance of properties for a particular application, such as a film, a coating, a solid, or a thermoset. The temperature for curing the curable composition may range from -10°C to about 100°C. In various embodiments, the curing temperature may range from -10°C to about 100°C, from 20°C to about 80°C, or from 40°C to about 60°C. The application pressure to carry out the curing process may range of from about 1 psig (6.9 kPa) to about 150 psig (1 ,034.2 kPa). In various embodiments, the application pressure may range from 1 psig (6.9 kPa) to about 150 psig (1 ,034.2 kPa), from 5 psig (34.5 kPa) to about 80 psig (551 ,6 kPa), or from 10 psig (68.9 kPa) to about 20 psig (137.9 kPa).

[0059] Generally, the curing time can and will vary depending on the curable epoxy resin composition such as the hardener, compatibilizer, and optional components used in the formulation. In various embodiments, the curing time to may range from 0.1 hour to about 14 days, from 0.5 hours to about 7 days, from 1 hour to about 24 hours, or from 2 hours to 12 hours.

[0060] The preparation of the cured coating material and/or any of the steps thereof, may be a batch or a continuous process. The equipment employed to carry out the reaction includes equipment known to those skilled in the art.

[0061 ] Some non-limiting examples of end use applications for these coated products may be clear epoxy coatings, pigmented epoxy based coatings, and epoxy based primer coatings.

(V) Properties of the Cured Products

[0062] In another aspect encompasses properties of the cured product. The cured coating material prepared by the process exhibits unexpected and unique properties. For example, the cured coating material exhibits a gloss, hardness, and MEK solvent resistance better than that of a cured coating produced with the same curable composition except that the composition does not contain the compatibilizers.

[0063] The cured coating material (i.e., the cross-linked product made from the curable composition) shows several improved and beneficial performance properties over conventional cured thermosets made from conventional curable compositions containing conventional curing agents and catalysts. For example, the cured coating material may advantageously exhibit an improvement in several properties such blooming/blushing; gloss; MEK resistance; hardness; dry-time; impact; conical bend; and cross-hatch.

[0064] In general, the cured coating material exhibits a reduction of blooming/blushing compared to cured coatings of the prior art. The blooming/blushing of the cured coating is typically determined according to a visual observation of the coating. Then, the amount of blooming/blushing observed on the coating is given a rating based on a scale of from "0" to "5" wherein "0" is the worst result and "5" is best result. The rating scale of blooming/blushing used herein is described in the following Table I: Table I - Rating Scale for Blooming/Blushing

[0065] The blooming/blushing of the cured coating is generally from 3 to 5. In various embodiments, the blooming/ blushing is generally from 3 to 4, from 4 to 5, or from 3 to 5.

[0066] The cured coating material of the present invention can exhibit a change in the coatings gloss by losing or gaining its gloss property. One advantageous property of the coating material is to maintain its original gloss property as much as possible. Thus, a measure of gloss of a coating is its "gloss change" property after wiping with finger or paper towel. The gloss change percentage of the coating should be as low as possible. Generally, the gloss change may be at least 20%. In various embodiments, the gloss change may be less than 20%, less than 10%, less than 5%, less than 3%, and less than 1 %. If the coating exhibits a gloss change of more than about 20 %, blooming and/or blushing can occur and typically has already occurred.

[0067] "Gloss change" of a coating may be calculated herein in

accordance with the following equation.

[(Original gloss— Gloss after wiping) ÷ Original Gloss] x 100

= % Gloss Change

[0068] The MEK double rub resistance of the cured coating material may range from 100 times to about 2,000 times. In various embodiments, the MEK double rub resistance may range from 100 times to about 2,000 times, from 150 times to about 1 ,000 times, or from 200 times to about 500 times. A MEK double rub of less than about 100 times means the coating has a poor solvent resistance.

[0069] The cured coating material may exhibits pendulum hardness ranging from 50 s to about 200 s. In various embodiments, the pendulum hardness may range from 50 s to about 200 s, from 80 s to about 180 s, from 100 s to about 160 s, or from 120 s to about 140 s.

[0070] Generally, the cured coating material exhibits a dry-hard time may range from 1 hr to about 48 hr. In various embodiments, the dry-hard time of the cured coating material may range from 1 hr to about 48 h, from 2h to about 24h, from 3h to about 18h, or from 4 h to about 12 h.

[0071 ] The cured coating material may exhibits an impact generally above 1 .0 kilogram-meter (kg-meter) direct impact; above 1 .3 kg-meter; above 1 .5 kg-meter for clear coating; and exhibits an impact generally above 0.06 kg-meter direct impact;

above 0.12 kg-meter, and above 0.023 kg-meter for pigmented coatings.

[0072] The cured coating material may exhibit conical bend from 0.3175 - 3.81 cm generally less than 20 millimeters (mm); less than 10 mm; less than 5 mm; and 0 mm. [0073] The cured coating material exhibits a cross-hatch adhesion of greater than 4B or 5B.

DEFINITIONS

[0074] When introducing elements of the embodiments described herein, the articles "a", "an", "the" and "said" are intended to mean that there are one or more of the elements. The terms "comprising", "including" and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[0075] The terms "compatible" or "compatibility", refers to the ability for two or more different materials or compounds to exist together as a mixture in a composition in close and permanent association for an indefinite period or exist in intimate contact as a mixture in a composition for long periods with no adverse effect of one compound on the other compound in the composition.

[0076] The terms "compatibility agent", "compatibilizer" or "compatibility improvement agent" refers to a compound used in the curable composition. This compound provides compatibility between two or more different compounds in a composition.

[0077] The terms "blooming" refers to an ingredient, substance, or "gluelike" material present on a coating surface in the cured epoxy composition.

[0078] The term "blushing" refers to an unsightly graying of a dried coating which typically includes a whitish or grayish particulate material formed on a coating surface during curing of a curable composition.

[0079] The terms "no substantial blooming and blushing" or "without substantial blooming and blushing" is in reference when a finger (e.g., an index finger) or a piece of paper (e.g., a paper towel) is rubbed across the surface of a cured clear coating, such rubbing action does not leave a mark on the surface of the cured clear coating and/or such rubbing action does not pick up residue and leaves the residue on the surface of the finger or paper towel as determined by visual observation. In terms of the rating scale as described above, "no substantial blooming or blushing" refers to a value of 4 or 5.

[0080] Blooming and blushing can be measured based on the gloss change of a cured clear coating after wiping with a finger or paper towel; and therefore "no substantial blooming and blushing" herein, in reference to a cured clear coating, means the coating exhibits a gloss change of less than 20 percent (%), less than 10 %, and less than 1 %.

[0081 ] The term "induction time" refers to the initial reaction time period needed to allow compounds in a formulated curable composition to become compatible with each other before applying the curable composition onto a substrate.

[0082] The terms "halogen" or "halo" as used herein alone or as part of another group refer to chlorine, bromine, fluorine, and iodine.

[0083] The term "alkyl" as used herein describes saturated hydrocarbyl groups that contain from 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, and most preferably 1 -10 carbon atoms. They may be linear, branched, or cyclic, may be substituted as defined below, and include methyl, ethyl, propyl, isopropyl, butyl, hexyl, heptyl, octyl, nonyl, and the like.

[0084] The term "substituted alkyl" as used herein describes saturated hydrocarbyl groups which are substituted with at least one atom other than carbon, including moieties in which a carbon chain atom is substituted with a heteroatom such as nitrogen, oxygen, silicon, phosphorous, boron, or a halogen atom, and moieties in which the carbon chain comprises additional substituents. These substituents include alkyl, alkoxy, acyl, acyloxy, alkenyl, alkenoxy, aryl, aryloxy, amino, amido, acetal, carbamyl, carbocyclo, cyano, ester, ether, halogen, heterocyclo, hydroxyl, keto, ketal, phospho, nitro, and thio.

[0085] The terms "hydrocarbon" and "hydrocarbyl" as used herein describe organic compounds or radicals consisting exclusively of the elements carbon and hydrogen. These moieties include alkyl, alkenyl, alkynyl, and aryl moieties. These moieties also include alkyl, alkenyl, alkynyl, and aryl moieties substituted with other aliphatic or cyclic hydrocarbon groups, such as alkaryl, alkenaryl and alkynaryl. They may be straight, branched, or cyclic. Unless otherwise indicated, these moieties preferably comprise 1 to 20 carbon atoms.

[0086] Having described the invention in detail, it will be apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims.

EXAMPLES

[0087] The following examples and comparative examples further illustrate the present invention in more detail but are not to be construed to limit the scope thereof.

[0088] In the following Examples, various materials, terms and

designations are used including for example: HEA which stands for hydroxylethyl acrylate; HEMA which stands for hydroxyethyl methacrylate; PETA which stands for pentaerythritol triacrylate; DMAPA which stands for dimethylaminopropyl acrylate; DMP- 30 which stands for tris(dimethylaminomethyl)phenol and which is commercially available from Aldrich; Versamid 140 which is a polyamide hardener and which is commercially available from BASF; DLVE-18 which is a proprietary epoxy resin having a viscosity of about 860-960 mPa-s at 25°C, and an EEW of about 170-180, and which is available from The Dow Chemical Company; M-Cure 201 which is a multifunctional acrylate and which is commercially available from Sartomer; Versamid 125 which is a polyamide hardener and which is commercially available from BASF; BYK 9076 which is a dispersant and which is commercially available from BYK Chemie; BYK-A 501 which is a defoamer and which is commercially available from BYK Chemie; Novacite L207A which is a silica pigment and which is commercially available from Malvern Mineral Company; Halox SZP-391 which is a corrosion inhibitor and which is

commercially available from Halox; Blanc Fixe N which is a barium sulfate pigment and which is commercially available from Sachtleben Chemie GmbH; Tipure R902+ which is a titanium dioxide pigment and which is commercially available from DuPont; and Rockwood YLO-2288D which is a yellow iron oxide pigment and which is commercially available from Huntsman. [0089] In the following Examples, standard analytical equipment and methods are used to measure properties including for example, the following:

Blooming Measurements:

[0090] Coating blooming evaluations and measurements were conducted by direct eye (visual) observation before and after wiping the coating surface with a gloved index finger to see if any oily material trace was deposited on the surface of the coating. After wiping the coating surface, the amount of blooming was qualitatively rated according to the standard rating scale described in Table I above.

Coating Gloss Measurements:

[0091 ] The blooming coating surface measurements described above were also confirmed by comparing the gloss of a blooming surface to a non-blooming surface. The coating gloss measurements were obtained with a BYK Micro Tri-Gloss Meter (RS-232 Output, 20/60/85 Degree); a gloss meter available from BYK.

Viscosity Measurements:

[0092] Viscosity measurements were obtained using a Brookfield

HADVIII+ Viscometer using Spindle # 31 at 10-200 revolutions per minute (rpm) by adjust torque to 25-25 % and at ambient temperature (i.e., 23°C-25°C).

MEK Resistance Measurements:

[0093] Methyl ethyl ketone (MEK) resistance measurements were obtained using the standard test procedure described according to ASTM D5402.

Coating Hardness Measurements:

[0094] Coating hardness measurements were obtained using a pendulum hardness instrument, BYK Gardner Konig pendulum apparatus, and the standard test procedure described according to ISO 1522. Coating Dry-Time Measurements:

[0095] Coating dry-time measurements were obtained using a BYK drying time recorder and the standard test procedure described according to ASTM D5895.

Impact Measurements:

[0096] Impact measurements were obtained using a BYK GARDNER Impact Tester and the standard test procedure described according to ASTM D5420-10.

Conical Bend Measurements:

[0097] Conical bend measurements were obtained using a BYK Gardner 0.3175 - 3.81 cm Conical Bending Tester and the standard test procedure described according to ASTM D522, Test Method B.

Cross-Hatch Adhesion Measurements:

[0098] Cross-hatch measurements were obtained using the standard test procedure described according to ASTM D3359-09, Test Method A.

Examples 1 - 5 and Comparative Example A

[0099] Curable epoxy resin coating compositions, as described in Tables II and III, were prepared and then polished cold rolled steel panels, with dimensions of 4 inches in width, 6 or 12 inches in length, and 0.025 inch in thickness (these are standard panels used in coating testing with dimensions for example as follows: 10.16 centimeter (cm) X 15.24 cm X 0.0635 cm), were coated with the compositions after being formulated without an induction time. The coatings were cured at ambient temperature for 7 days to form clear coatings.

[0100] The clear coatings were prepared using the curable compositions of the Examples of the present invention (with the acrylate additive components); and the curable compositions of the Comparative Examples (without acrylic additives), as described in Table II. The curable compositions were formulated with Versamid 125 polyamide curing agent. All the clear coating curable formulations contained 3 % tris(dimethylaminomethyl)phenol (DMP-30) reaction accelerator based on the amount of DLVE-18 and 5 % of xylene based on total formulation. The stoichiometry of the epoxy groups to the N-H groups in the coating formulation was 1 to 1 . Each acrylate additive was evaluated at each of the following loading levels: 1 %, 3 %, and 5 %.

[0101 ] Table II shows the results of the blooming property exhibited by the clear coating products prepared in these examples and comparative examples. HEA, PETA, and DMAPA are used in Examples 1 , 2 and 3, respectively, of the present invention. The Control is Comparative Example A.

Table II - Blooming of Acrylate Additives Modified Clear Coatings

[0102] Table III shows the coating performance based on Examples 1 , 3, and 5 from Table II at 5 % of different acrylate additives. The results show that an amount of 5 % of the acrylate additive significantly improves the coating hardness but does not affect other coating performance. Table III - Clear Coatinq Performance

Examples 6 - 12 and Comparative Examples B - D

[0103] Yellow pigmented coating of DLVE-18 with and without 5 % of acrylate additives were evaluated by using Versamid 125 or Versamid 140 as curing agent. Table IV shows the Part A formulation without acrylic additives. The 5 % of acrylic additives based on the epoxy resin of the total formulation were post added to Part A before Part A was blended with Part B (Versamid 125 or Versamid 140). The stoichiometry of epoxy to NH was 1 to 1 .

Table IV - General Part A Formulation

[0104] Table V shows the pigmented coating performance by curing with Versamid 125 for both with and without DMP-30 for comparison. The results indicate the compatibility of epoxy resin and curing agent was improved by the addition of acrylic additive, as indicated by the coating gloss, whether DMP-30 was present or absent. However, due to pigmented system, there was no significant difference in blooming observed. The Controls in Table V are Comparative Examples B and C.

Table V - Performance of Pigmented Coatings Cured With Versamid 125 and

With and Without Acrylic Additive

(seconds)

Impact

(direct/indirect, 0.35/<0.06 0.23/<0.06 0.23/<0.06 0.23/<0.06 meter- kg)

Conical bend

15 20 10 28 (mm)

Cross-hatch (0-

5B 5B 5B 5B 5B)

> 200

MEK double rub > 200 slight > 200 slight > 200 slight

more significant (times) surface damage surface damage surface damage

surface damage

Chemical resistance (0-5)

3 % acetic acid 4 4 4 4

10 % H ₂ S0 ₄ 2 2 2 2

10 % NaOH 4 4 4 4

3 % NaCI 5 5 4 4

Xylene 5 4.5 5 5

EtOH 4 4 5 4

Average 4.0 3.9 4.0 3.8

Comparative

Example Example 9 Example 10 Example 1 1

Example C no DMP-30 no DMP-30 no DMP-30 no DMP-30

Compatibilizing

Agent HEA DMAPA PETA control (5 % of resin)

Blooming (7

5 3 5 3 days)

Set-to-Touch

8.24 5.44 0.32 0.64 Time (hours)

Tack-Free Time

10.32 7.6 2 9.2 (hours) Dry-Hard Time

13.28 10.56 8.8 1 1 .52 (hours)

7days Gloss (°)

20 31 47 5 24

60 75 83 34 72

85 92 95 75 92

Thickness (mils) 2.98 2.86 3.22 3.2

1 day hardness

10 12 10 12 (seconds)

2 days hardness

16 33 26 19 (seconds)

7 days hardness

59 82 57 64 (seconds)

Impact

(direct/indirect, 0.35/<0.06 0.35/<0.06 0.35/<0.06 0.35/<0.06 meter- kg)

Conical bend

39 43 43 45 (mm)

Cross-hatch (0-

5B 5B 5B 5B 5B)

> 200

MEK double rub > 200 slight > 200 slight > 200 slight

film cut through (times) surface damage surface damage surface damage

surface

Chemical resistance (0-5)

3 % acetic acid 4.5 4 4 4

10 % H ₂ S0 ₄ 2 2 2 2

10 % NaOH 4 4 4 4

3 % NaCI 4.5 4.5 4 4.5

Xylene 5 5 5 4.5

EtOH 4.5 4.5 4.5 4

Average 4.1 4.0 3.9 3.8 [0105] Table VI shows the pigmented coating performance by curing with

Versamid 140 with 3 % of DMP-30. The results indicate the compatibility of epoxy resin and curing agent was improved by the addition of acrylic additive, as indicated by the coating gloss. However, due to pigmented system, there was no significant difference in blooming observed. The Control in Table VI is Comparative Examples D.

Table VI: Performance of Piqmented Coatinqs Cured With Versamid 140 and With and

Without Acrylic Additive

3 % NaCI 5 4

Xylene 4 4

EtOH 4 4

Average 4.3 3.8

[0106] MEK resistance measurements using the standard test procedure described according to ASTM D5402 were obtained for formulations with acrylic compatibilizer (Examples 6 and 12, 5% HEA) and without acrylic compatibilizer

(Comparative Examples B and D). The formulations containing acrylic additives showed improvement in MEK resistance. Figure 1 shows the improved solvent resistance of coatings cured with Versamid 125 and Versamid 140 in the presence of the acrylic compatibilizer (Example 6 and Example 12) compared to coatings cured with Versamid 125 and Versamid 140 with no acrylic compatibilizer present in the

formulations (Comparative Example B and Comparative Example D). Moreover, there was no adverse effect on other coating performance.

Examples 13 - 14 and Comparative Example E

[0107] HEA additive was also evaluated in different pigmented coating systems based on DLVE-18 and Versamid 140. Table VII is an example of a pigmented DLVE-18 / Versamid 140 formulation containing 10 % HEA and DMP 30. Table VIII shows paint viscosity, coating appearance and dry time. HEA effectively reduced formulated paint viscosity and improved the appearance of the coatings after 7 days of cure (Examples 13 and 14). In addition, the early drying speed such as dry to touch was also improved due to the fast reaction introduced by HEA component.

Table VII: Red Pigmented Coating Formulations With 10 % HEA Based on Epoxy

Resin in the Formulations

Material Name Kilograms Liters

Part A

Premix DLVE-18 9.47 8.36

Xylene 4.03 4.67

BYK™ 104S 0.10 0.1 1

BYK™ 501 0.04 0.04

Wollastocoat™ 10ES 12.80 4.41

Halox™ SZP-391 3.76 1 .25

Blanc Fixe™ N 5.55 1 .35

Red Ironoxide 5.54 1 .06

Bentone™ SD-2 0.19 0.12

Premix Sub-total 41 .49 21 .39

Grind above Premix materials in order on Cowles, check for Hegman, and then add the following:

PM acetate 0.42 0.44

Grind Sub-total 41 .91 21 .83

LetDown

HEA 0.95 0.86

MIBK 0.52 0.65

Total Part A 43.38 23.34

Material Name Kilograms Liters

Part B

Premix

Versamid™ 140 6.26 6.53

DMP-30 0.28 0.29

Total Part B 6.54 6.82

Final Total Part A + Part B => 49.92 30.15

Table VIII: Coatinq Dry-Time, Hardness and Gloss

(Blooming)

Initial Viscosity (mPa-s) ^*

CAP 05 (2970 s ^"1 ) 2225 2058 1983

Dry Speed (hours)

Dry to touch 8.2 5.2 6

Tack free 10.4 9.7 10

Dry hard 12 12.3 12.2

Dry through >18 >18 >18

Pendulum Hardness (s

1 day 12.6/15.4 12.6/12.6 8.4/9.8

7 days 92.4/100.8 1 19/1 17.6 84/100.8

Gloss (20 60 85°)

7 days 7.4/32.9/75.2 5.4/40.4/80.1 12.5/58.0/88.9

[01 08] Viscosity is measured using Brookfield CAP 1000 cone-and- plate viscometer using spindle CAP 05.