MODIFIED EPOXY RESIN COMPOSITIONS, REDUCED GLOSS COATING COMPOSITIONS

Abstract: Epoxy resin compositions containing carboxyl-containing polymers as a low gloss additive are rendered more storage stable by the addition of a stabilizing amount of at least one stabilizer compound which is (a) at least one Group IA, IIA, IIB, IIIA, VIB or VIII of the periodic table of the elements metal salt of an organic carboxylic acid; (b) at least one of zinc carbonate, zinc oxide, sodium carbonate or potassium carbonate; or (c) any combination of (a) and (b). These compositions are particularly useful in powder coating applications.

Description: MODIFIED EPOXY RESIN COMPOSITIONS, REDUCED GLOSS COATING COMPOSITIONS The present invention concerns modified epoxy resin compositions, curable compositions thereof and reduced gloss coating compositions. Epoxy resin based powder coatings generally have a high gloss. In some applications, it is desirable to have coatings with reduced gloss. It is important that formulations which provide coatings with reduced gloss also provide coatings with a stable level of gloss over a period of time that the coating formulation might need to be stored. Davis in US 4,419/195 discloses coating compositions containing an epoxy resin and as at leasta part of the curing agent a polymer containing a group reactive with an epoxy resin. These coating compositions are said to have low gloss. While such coatings do indeed have low gloss, the coating compositions have a relatively short storage life. By that it is meant that the longer the coating composition is stored, the higher the gloss of the resulting coating. The gloss reduction pertains to comparison of the gloss of the coating prepared from like epoxy-containing substituents but not containing any copolymer having a group reactive with an epoxy group. It would therefore be desirable to have available a modified epoxy resin composition containing a polymer with polymer groups reactive with an epoxy group which when formulated into a coating composition the coating composition would have improved storage stability with respect to the gloss value of the resultant coating. One aspect of the present invention pertains to an improvement in a modified epoxy resin composition comprising (A) at least one epoxy resin containing an average of more than one vicinal epoxy group per molecule and at least one aromatic ring in its backbone; and ( B ) at least one polymer prepared from one or more ethylenically unsaturated monomers wherein at least one of such monomers contains a carboxylic acid group; wherein the improvement resides in incorporating into said composition (C) a stabilizing amount of at least one stabilizer compound which is (a) at least one Group IA, IIA, IIB, IIIA, VIB or VIII of the periodic table of the elements metal salt of an organic carboxylic acid; (b) at least one of zinc carbonate, zinc oxide, sodium carbonate or potassium carbonate; or (c) any combination of (a) and (b). Another aspect of the present invention pertains to an improvement in a compositi suitable as a curing agent for epoxy resins which comprises (1 ) at least one polymer prepared from one or more ethylenically unsaturated monomers wherein at least one of such monomers contains a carboxylic acid group; and (2) at least one curing agent for said epoxy resin which curing agent is different from compone (l); wherein said improvement resides in incorporating into said curing agent composition (3) a stabilizing amount of at least one stabilizer compound which is (a) at least one Group IA, DA, EB, HIA, VIB or VHI of the periodic table of the elements metal salt of an organic carboxylic acid; (b) at least one of zinc carbonate, zinc oxide, sodium carbonate or potassium carbonate; or (c) any combination of (a) and (b). Another aspect of the present invention pertains to an improvement in a curable composition comprising (A) at least one epoxy resin containing an average of more than one vicinal epoxy group per molecule and at least one aromatic ring in its backbone; and (B ) at least one polymer prepared from one or more ethylenically unsaturated monomers wherein at least one of such monomers contains a carboxylic acid group; (D) at least one curing agent for component (A) which is different from either component (B) or t prereaction product of components (B) and (C); wherein said improvement resides in incorporating into said composition; (C) a stabilizing amount of at least one stabilizer compound which is (a) at least one Group IA, UA, HB, IIIA, VIB or VTJT. of the periodic table of the elements metal salt of an organic carboxylic acid; (b) at least one of zinc carbonate, zinc oxide, sodium carbonate or potassium carbonate; or (c) any combination of (a) and (b). A further aspect of the present invention pertains to an improvement in a powder coating composition which contains substantial quantities of pigment(s) or filler(s) comprising (A) at least one epoxy resin containing an average of more than one vicinal epoxy group per molecule and at least one aromatic ring in its backbone; ( B ) at least one polymer prepared from one or more ethylenically unsaturated monomers wher at least one of such monomers contains a carboxylic acid group; (D) at least one curing agent for component (A) which is different from either component (B) o prereaction product of components (B) and (C); and (E) at least one or more additional component(s) including pigment, filler, flow control agent, leveling aid or other additive; wherein said improvement resides in incorporating into said composition; (C) a stabilizing amount of at least one stabilizer compound which is (a) at least one Group IA, HA, IIB, HI A, VIB or VHl of the periodic table of the elements metal salt of an organic carboxylic acid; (b) at least one of zinc carbonate, zinc oxide, sodium carbonate or potassium carbonate; or (c) any combination of (a) and (b). A further aspect of the present invention pertains to an improvement in a powd coating composition which is essentially free of pigments) and filler(s) comprising (A) at least one epoxy resin containing an average of more than one vicinal epoxy group per molecule and at least one aromatic ring in its backbone; ( B ) at least one polymer prepared from one or more ethylenically unsaturated monomers wher at least one of such monomers contains a carboxylic acid group; (D) at least one curing agent for component (A) which is different from either component (B) o prereaction product of components (B) and (C); and (E) at least one or more additional component(s) selected from the group consisting of flow con agent, leveling aid, and promoter or catalyst; wherein said improvement resides in incorporating into said composition; (C) a stabilizing amount of at least one stabilizer compound which is (a) at least one Group IA, HA, HB, HIA, VIB or VEI of the periodic table of the elements metal salt of an organic carboxylic acid; (b) at least one of zinc carbonate, zinc oxide, sodium carbonate or potassium carbonate; or (c) any combination of (a) and (b). A further aspect of the present invention pertains to the product resulting from curing the aforementioned curable composition. A further aspect of the present invention pertains to articles which have been coated with the aforementioned coating composition. The present invention may suitably comprise, consist of, or consist essentially o aforementioned components. The invention illustratively disclosed herein suitably may be practiced in the absence of any component which is not specifically disclosed or enumerated herein and any of th compounds may contain or be free of any substituent not specifically named herein. References herein to the Periodic Table of the Elements refer to that distributed the Sargent-Welch Scientific Company as catalog no. S-I8806. The term "essentially free of pigment(s) and /or filler(s)" means that the composition is entirely free of or contains only inconsequential quantities of pigmentfe) and/or nTler(s), usually zero or less than 3, preferably less than 2, more preferably less than 1 percent b weight based upon total composition weight. The term "contains substantial quantities of pigment(s) or fillers)" means that t compositions contains more than inconsequential quantities of pigmentCs) and/or filler s), usuall least 3 percent by weight based upon total composition weight. In the compositions of the present invention, all of the components can be simultaneously blended or mixed together by any suitable means. Alternatively, the compositions of the present invention can be prepared by blending any one of the components: epoxy resin, carboxyl-containing polymer or stabilizer with preblend of the remaining two components. Also alternatively, the compositions of the present invention can be prepared by blending the epoxy resin with a prereaction product of the carboxyl-containing polymer and the stabilizer. The blending can be accomplished by any suitable means such as dry blending, m extrusion, 2-roll mill or other means of melt compounding, or any combination thereof. When the compositions are prepared by melt extrusion, the temperature should at a temperature such that no reaction takes place between the epoxy groups of the epoxy resin a the carboxyl groups of carboxyl-containing polymer. Preferably, the melt extrusion blending is conducted at a temperature of from 30°C to 120°C, more preferably from 40°C to 100°C, most preferably from 50°C to 70°C. In any of the aforementioned methods of blending, the blending is conducted for a time sufficient to cause the resultant blend to be substantially homogeneous. By substantially homogeneous, it is meant a fine, uniform suspension with no individual particles large enough to seen. The preferred method of blending the carboxyl-containing polymer or the ionom form of the carboxyl-containing polymer, the reaction product of the carboxyl-containing polym with the stabilizer, is to blend the carboxyl-containing polymer or the ionomer form of the carboxyl-containing polymer with the epoxy resin in a separate step to form an epoxy resin mod with the carboxyl-containing polymer. The advantage of blending in this manner is that the carboxyl-containing polymer is more uniformly dispersed in the epoxy resin than if it is blended directly into a powder coating formulation. Also, it is preferable to blend the epoxy resin and t carboxyl-containing polymer or the ionomer form of the carboxyl-containing polymer at conditio which do not result in reaction between the epoxy groups and the acid groups. Such conditions ar preferably at a temperature of from 30°C to 120°C, more preferably from 40°C to 100°C, most preferably from 50°C to 70°C. In all of the compositions of the present invention, it is preferable to employ the ionomer form of the carboxyl-containing polymer. This is accomplished by prereacting the carboxyl-contining polymer with the stabilizer compound. In the preparation of the curable compositions and the powder coating compositi all of the components can be added separately and then blended or melt extruded or otherwise mixed or blended or any combination of mixing and blending. However, it is preferred to prepar preblend of epoxy resin, carboxyl-containing polymer and stabilizer with the carboxyl-containi polymer and stabilizer being preblended or prereacted prior to blending with the epoxy resin pri to blending this preblend with the remaining components of the composition. In the modified epoxy resin compositions and the curable compositions of the pre invention, the stabilizer, component (C), is employed in an amount sufficient to provide a ratio o equivalents of metal per carboxyl equivalent of at least 0.04:1, preferably from 0.08:1 to 6:1, mor preferably from 0.15:1 to 1:1. In the compositions of the present invention which are suitable as curing agents f epoxy resins, the stabilizer, component (3), is employed in an amount sufficient to provide a rati equivalents of metal per carboxyl equivalent of at least 0.04:1, preferably from 0.08:1 to 6:1, mor preferably from 0.15:1 to 1:1. In the coating compositions of the present invention which contain substantial quantities of filler and/or pigment, the stabilizer, component (C), is employed in an amount sufficient to provide a ratio of equivalents of metal per carboxyl equivalent of at least 0.04:1, preferably from 0.08:1 to 6:1, more preferably from 0.15:1 to 1:1. In the coating compositions of the present invention which are substantially free of filler and /or pigment, the stabilizer, component (C), is employed in an amount sufficient to provide a ratio of equivalents of metal per carboxyl equivalent of at least 05:1, preferably from 0.6:1 to 6:1, more preferably from 0.7:1 to 1:1. In the curable compositions of the present invention, the epoxy resin component (A) is employed in an amount of from 66 to 99, preferably from 80 to 96, more preferably from 80 to 92 percent by weight based upon the combined weight of epoxy resin (A) and carboxyl-containing polymer (B). In the curable compositions of the present invention, the carboxyl-containing polymer component (B) is employed in an amount of from 1 to 33, preferably from 4 to 20, more preferably from 8 to 20 percent by weight based upon the combined weight of epoxy resin component (A) and carboxyl-containing polymer component (B). In the curable compositions of the present invention, the amount of the other curing agent, component (D), depends upon the particular curing agent being employed. Usually the other curing agent is employed in amounts which provide a ratio of equivalents of this curing agent, component (D), plus the polymer containing carboxylic acid groups or ionomers thereof, component (B), per epoxide equivalent contained in component (A) of from 0.8:1 to 3:1, preferably from 0.9:1 to 2.5:1, more preferably from 1:1 to 2:1. In the curing agent compositions of the present invention the carboxyl-containing polymer, component (1), is employed in an amount of from 1 to 99, preferably from 3 to 96, more preferably from 25 to 90 percent by weight based upon the combined weight of components (1) and (2). In the curing agent compositions of the present invention the other or different curing agent, component (2), is employed in an amount of from 99 to 1, preferably from 97 to 4, more preferably from 75 to 10 percent by weight based upon the combined weight of components (1) and (2). In the curing agent compositions of the present invention, a promoter or catalyst component, can, if it is desirable to employ such promoter or catalyst, be employed in an amount of from 0.01 to 2, preferably from 0.1 to 1-5, more preferably from 0.2 to 0.8 percent by weight based upon the combined weight of all of the curing agents, the stabilizer component and the promoter or catalyst. The curing agent compositions of the present invention can be prepared by simple blending or melt extruding all of the components. The curable compositions can be prepared by blending, mixing, melt extruding or a combination thereof all of the components thereof. The preparation of the curing agent compositions are usually prepared at temperatures of from 20°C to 200°C, preferably from 50°C to 150°C, more preferably from 70°C to 130°C for a time sufficient to produce a homogeneous product, usually within a time of from 15 seconds to 2 hours, depending upon how the components are blended together. If an extruder is employed in the preparation of the composition, shorter times of from 15 seconds up to 2 minutes is suitably employed. If a batch reactor or blender is employed, longer times are employed to prepare the composition such as from 5 minutes up to 2 hours. It is not necessary to remove the byproduct(s) from the reaction between the carboxyl-containing polymer component and the stabilizer component prior to or after blending with the epoxy resin component. However, if desired, they can be readily removed by subjecting the composition to a vacuum and if desired heating while subjecting the composition to a vacuum at a temperature which is not detrimental to the composition, usually from room or ambient temperature to a temperature not above 120°C, preferably not above 100°C, more preferably not above 70°C. The pressure can be from zero to 760, preferably from zero to 200, more preferably from zero to 60 mm Hg absolute. EPOXY RESINS Suitable epoxy resins which can be employed herein as component (A) include, for example, any epoxy resin which contains at least one aromatic ring in its backbone. Particularly suitable epoxy resins include, for example, the glycidyl ethers of: dihydric phenols, bisphenols, phenol- or substituted phenol-aldehyde novolac resins, adducts of dihydric phenols or bisphenols with an alkylene oxide having from 2 to 4 carbon atoms per molecule, phenol or substituted phenol-unsaturated hydrocarbon resins, or any combination of any two or more of such compounds; wherein said epoxy resin contains an average of more than one glycidyl ether group per molecule. These compounds can also contain substituent groups such as saturated aliphatic hydrocarbon, unsaturated aliphatic hydrocarbon, halogens including chlorine, bromine, fluorine, iodine, nitro, or nitrile. Likewise, the hydrocarbon substituent groups can also be substituted with such halogens including chlorine, bromine, fluorine, iodine, nitro, or nitrile. Also, these compounds can be specifically free of any one or more of such substituent groups and likewise the substituted hydrocarbons can be specifically free of any one or more of such substituent groups. Further, such compounds and substituted hydrocarbons can contain any substituent group not specifically enumerated herein. Likewise, the compounds and substituted hydrocarbons can be free of any substituent group not specifically enumerated herein. The preferred epoxy resins include, for example, the glycidyl ethers of: resorcinol, catechol, hydroquinone, bisphenol A (4,4'-isopropylidenediphenol), bisphenol F (2,2'- methylenediphenol), bisphenol K (4,4'-dihydroxydiphenyl ketone), bisphenol S (4,4'- sulfonyldiphenol), fluorene, phenol-formaldehyde novolac resins, cresol-formaldehyde novolac resins, phenol-dicyclopentadiene resins, phenol-higher oligomers of dicyclopentadiene resins, cresol-dicyclopentadiene resins, cresol-higher oligomers of dicyclopentadiene resins; adducts of: either resorcinol, catechol, hydroquinone, bisphenol A, bisphenol F, bisphenol K, bisphenol S, or fluorene with ethylene oxide, propylene oxide or butylene oxide or any combination of such alkyle oxides; or any combination of any two or more of such glycidyl ethers. Also suitable are any of the aforementioned glycidyl ethers which contain from 1 to 2 halogen atoms, preferably bromine, per aromatic ring. The epoxy resins of the present invention preferably have equivalent weights of from 200 to 2000, more preferably from 500 to 955, most preferably from 575 to 820. The equivalent weight being calculated on the basis of there being no substituent groups on the aromatic rings of th epoxy resin even if they in fact do contain substituent groups. POLYMERS CONTAINING CARBOXYLIC ACID GROUP Suitable polymers prepared from one or more ethylenically unsaturated monomers wherein at least one of such monomers contains a carboxylic add group which can be employed herein as component (B) or (1) indude, for example, those copolymers or interpolymers of one or mor alpha-olefins having from 2 to 10 carbon atoms and one or more ethylenically unsaturated carboxylic adds or half esters of dibasic ethylenically unsaturated carboxylic adds. Particularly suitable alpha-olefins indude, for example, ethylene, propylene, butene, pentene, hexene, heptene, ortene, nonene, decene or any combination of any two or more alpha-olefins. Ethylene is preferred. Particularly suitable ethylenically unsaturated carboxylic adds indude, for example, acrylic, methacrylic, maleic, fumaric, itaconic. Preferred are acrylic add and methacryli add with acrylic add being most preferred. Particularly suitable half esters include the Ci to Cio, preferably to Q;, more preferably C1-C4 hydrocarbon half esters of maleic, fumaric or itaconic adds. More particularly suitable are the methyl, ethyl, propyl, butyl, pentyl and hexyl half esters of such adds. STABILIZER COMPONENT Suitable stabilizers which can be employed herein include, for example, Group IA, IIA, IIB, IIIA, VIB or VIII of the periodic table of the elements metal salts of an organic carboxylic add; zinc carbonate, zinc oxide, sodium carbonate or potassium carbonate; or any combination of any such stabilizers. Particularly suitable stabilizers include, for example, zinc oxide, sodium carbonate, zinc carbonate, potassium carbonate, or sodium, lithium, potassium, zinc, calcium, magnesium, nickel, aluminum or chromium salt of a saturated or unsaturated aliphatic or cycloaliphatic or aromatic organic carboxylic add having from 1 to 30, preferably from 1 to 18, more preferably from 1 to 2 carbon atoms per molecule, or a combination of any two or more of such compounds. Preferably such carboxylic add salts indude, for example zinc carbonate, zinc acetate, zinc propionate, zinc stearate, sodium acetate, calrium propionate, or any combination of any two or more of such compounds. OTHER CURING AGENTS Suitable curing agents which can be employed herein in addition to the polymers containing a carboxylic add group or an ionomer thereof in the curing agent compositions or the curable compositions or powder coating compositions indude, for example, guanidines, biguanides, aliphatic amines, aromatic amines, compounds containing an average of more than one phenolic hydroxyl group per molecule, aliphatic, cydoaliphatic or aromatic di- or poly-carboxylic adds or anhydrides, or any combination of two or more of such curing agents. Particularly suitable curing agents which can be employed herein as component (D) or (2) indude, for example, dicyandiamide, o-tolubiguanide, add functional polyesters, compounds containing more than one phenolic group per molecule, or any combination of any two or more of such curing agents. The preferred curing agent is dicyandiamide. The actual amount of curing agent employed depends upon the particular curing agent being employed. Usually the curing agent is employed in amounts which provide a ratio of equivalents of this curing agent plus the polymer containing carboxylic add groups or ionomers thereof per epoxide equivalent of from 0.8:1 to 3:1, preferably from 0.9:1 to 2.5:1, more preferably from 1:1 to 2:1. PROMOTER OR CATALYST Suitable promoters or catalysts for promoting the.reaction between the curing agent components) with the epoxy resin, indude, for example, primary, secondary or tertiary aliphatic or cydoaliphatic or aromatic amines, Lewis adds, Lewis bases, or any combination of any two or more of such promoters or catalysts. Particularly suitable promoters or catalysts include, for example, imidazoles, substituted imidazoles, imidazoles adducted with an epoxide-containing compound such as mono-, di-or polyglyάdyl ether compounds, substituted imidazoles adducted with an epoxide-containing compound such as mono-, di- or polyglyάdyl ether compounds, or any combination of any two or more of such promoters or catalysts. The preferred promoters or catalysts are 2-methyl imidazole, 2-methyl imidazole adducted with a diglyddyl ether of bisphenol A, or any combination of any two or more of such promoters or catalysts- The amount of promoter will depend upon the particular promoter and curing agent being employed. Usually, the amount of promoter employed is from 0.01 to 2, preferably from 0.1 to 1.5, more preferably from 0.2 to 0.8 percent by weight based upon the combined weight of all of the curing agents, the stabilizer component and the promoter or catalyst. FILLERS Suitable fillers which can be employed herein indude, for example, mineral fillers such as, for example, inorganic oxides, carbonates, sulfates or silicates of a metal of Groups IA, IIA, IDA, HB, VIB, or VIE of the periodic table of the elements, or any combination of any two or more of such fillers. The preferred fillers are titanium oxide, caldum carbonate, barium sulfate, magnesium silicate strontium silicate, or any combination of any two or more of such fillers. PIGMENTS Suitable pigments which can be employed herein indude, for example, any inorganic or organic pigment which will provide the composition with the desired color or any combination of any two or more of such pigments. FLOW MODIFIERS OR FLOW CONTROL AGENTS Suitable flow modifiers or flow control agents which can be employed herein indude, for example, acrylate copolymers, silicones, fluorocarbons, or any combination of any two or more of such flow modifiers or flow control agents. The preferred modifiers or flow control agents are acrylate copolymers. LEVELING AGENTS Suitable leveling agents which can be employed herein indude, for example, benzoin. The optional fillers, pigments, flow modifiers or flow control agents, leveling agents, which can be employed herein are employed in functional amounts, i.e. those amounts which provide the coating with the desired properties which the particular additive imparts to the coating. These amounts will vary with the particular epoxy resin, curing agent and additive employed. The filler(s) is (are) usually employed in amounts of from zero to 60, preferably from zero to 50, more preferably from 2 to 35 percent by weight based upon the total weight of the composition. The pigment(s) is (are) usually employed in amounts of from zero to 50, preferably from zero to 40, more preferably from 2 to 35 percent by weight based upon the total weight of the composition. The flow modifier(s) or flow control agent(s) is (are) usually employed in amounts of from zero to 5, preferably from zero to 3, more preferably from zero to 2 percent by weight based upon the total weight of the composition. The leveling agent(s) is (are) employed in amounts of from zero to 2, preferably from zero to 15, more preferably from zero to 0.5 percent by weight based upon the total weight of the composition. The following examples are illustrative of the present invention, but are not to be construed as to limiting the scope thereof in any manner. Page missing at the time of publication Page missing at the time of publication FLOW MODIFIER(S) Flow Modifier A is Moderez™ MFP commerdally available from Synthron Chemicals. 5 FILLER(S) BS-1 is barium sulfate commercially available from Mountain Minerals as Sparwite W-10. BS-2 is barium sulfate commerdally available from Pfizer as Barytes #1. 10 PIGMENTCS) Pigment A is carbon black commercially available from Columbia Chemicals as Raven 2000. 15 COMPARATIVE FJCPFJOMENT A 1_. Preparation of an Epoxy resin modified with 8.0% by weight of a Carboxyl-Containing Polymer. A modified epoxy resin is prepared by extruder melt mixing at a temperature of 90°C-110°C Carrwxyl-Cbnteining Polymer A and Epoxy Resin A at a weight ratio of 0.087:1 in a Z0 100-mm Baker-Perkins twin-screw extruder. The product is extruded as a thin sheet onto a chilled belt and then crushed. 2. Preparation of powder coating. A powder coating formulation is prepared by melt mixing 2,000 g of the modified 25 epoxy resin from 1 above, 80 g of Curing Agent B, and 26 g of How Modifier A. A dry blend of these components, prepared by shaking the components together in a plastic bag, is melt mixed in a Buss Condux PLK 46 extruder having two zones with zone 1 at 70°C, zone 2 at 90°C, and the screw at 70°C and 200 rpm. The extrudate is pressed with chilled rollers to a thin sheet, air cooled, ground to a fine powder with a Brinkmann ZM-1 grinder and sieved through 150 mesh brass sieves (105-micron 30 opening). A portion of the powder is coated within two days following the melt-mbdng. A portion of the powder is coated after aging for 43 days at ambient temperature. The powder is sprayed with a Gema Type 710 electrostatic spray gun, 60 kv applied, onto grounded cold rolled steel panels. The powder coated pands are baked for 15 minutes at 180°C and air cooled. 35 EXAMPLE 1 A powder coating formulation is prepared by melt mixing 2,000 g of the modified epoxy resin from Comparative Experiment A-l, 80 g of Curing Agent B, 26 g of How Modifier A, and 80 g of CaPr2 stabilizer. The composition is prepared and tested in the same way and at the same time as Comparative Experiment A-2. 0 EXAMPLE 2 A powder coating formulation is prepared by melt mixing 2000 g of the modified epoxy resin from Comparative Experiment A-l, 80 g of Curing Agent B, 26 g of How Modifier A, and 240 g of CaPr2 stabilizer. The composition is prepared and tested in the same way and at the same time as Comparative Experiment A-2. COMPARATIVE EXPERIMENT B I. Preparation of an Epoxy resin modified with 20% by weight of a Carboxyl-Containing Polymer. A modified epoxy resin is prepared by melt mixing 2,000 g of Carboxyl-Containing Polymer A and 8,000 g of Epoxy Resin B. A dry blend of these components, prepared by shaking the components together in a plastic bag, is melt mixed in a Buss Condux PLK 46 extruder having two zones with zone 1 at 70°C, zone 2 at 80°C, and the screw at 70°C and 200 rpm. The modified epoxy resin extrudate is pressed with chilled rollers to a thin sheet, air cooled, and crushed. 2. Preparation of powder coating. A powder coating formulation is prepared by melt mixing 600 g of the modified epoxy resin from 1 above, 600 g of additional Epoxy Resin B, 48 g of Curing Agent A, and 10.06 g of How Modifier A. A dry blend of these components, prepared by shaking the components together in a plastic bag, is melt mixed in a Buss Condux PLK 46 extruder having two zones with zone 1 at 70°C, zone 2 at 90°C, and the screw at 70°C and 200 rpm. The extrudate is pressed with chilled rollers to a thin sheet, air cooled, ground to a fine powder with a Brinkmann ZM-1 grinder and sieved through 150 mesh brass sieves C105-micron opening). A portion of the powder is coated within two days following the melt mixing. Another portion of the powder is coated after aging for 23 hours at 36°G The powder is electrostatically sprayed with a Gema gun onto grounded cold rolled steel pands. The powder coated pands are baked for 15 minutes at 180°C and air cooled. COMPARATIVE EXPERIMENT C A powder coating formulation is prepared by melt mixing 600 g of the modified epoxy resin from Comparative Experiment B-l, 600 g of additional Epoxy Resin B, 48 g of Curing Agent A, 10.06 g of How Modifier A, and 12 g of CaPr2 stabilizer. The composition is prepared and tested in the same way and at the same time as Comparative Experiment B-2. EXAMPLE 3 A powder coating formulation is prepared by melt mixing 600 g of the modified epoxy resin from Comparative Experiment B-l, 600 g of additional Epoxy Resin B, 48 g of Curing Agent A, 10.06 g of How Modifier A, and 24 g of CaPr2 stabilizer. The composition is prepared and tested in the same way and at the same time as Comparative Experiment B-2. EXAMPLE 4 A powder coating formulation is prepared by melt mixing 600 g of the modified epoxy resin from Comparative Experiment B-l, 600 g of additional Epoxy Resin B, 48 g of Curing Agent A, 10.06 g of How Modifier A, and 48 g of CaPr2 stabilizer. The composition is prepared and tested in the same way and at the same time as Comparative Experiment B-2. COMPARATIVE EXPERIMENT D Preparation of an Epoxy resin modified with 20% by weight of a Carboxyl-Containing Polymer. Same as Comparative Experiment B-l. 2. Preparation of powder coating. A powder coating formulation is prepared by melt mixing 600 g of the modified epoxy resin described in 1 above, 600 g of additional Epoxy Resin B, 48 g of Curing Agent A, 245 g of BS-2 filler, 22.97 g of Pigment A, and 15.31 g of How Modifier A. A dry blend, prepared by shaking the components together in a plastic bag, is melt mixed in a Buss Condux PLK 46 extruder having two zones with zone 1 at 70°C, zone 2 at 90°C, and the screw at 70°C and 200 rpm The extrudate is pressed with chilled rollers to a thin sheet, air cooled, ground to a fine powder with a Brinkmann ZM-1 grinder and sieved through 150-mesh brass sieves. A portion of the powder is coated within one day following the mdt mixing. A portion of the powder is coated after aging for 20 hours at 40°C The powder is electrostatically sprayed with a Gema gun onto grounded cold rolled steel panels. The powder coated pands are baked for 15 minutes at 180°C and air cooled. EXAMPLE S A powder coating formulation is prepared by mdt mixing 600 g of the modified epoxy resin from Comparative Experiment D-1, 600 g of additional Epoxy Resin B, 48 g of Curing Agent A, 247 g of BS-2 filler, 23.19 g of Pigment A, and 15.46 g of How Modifier A, and 12 g of CaPr2 stabilizer. The composition is prepared and tested in the same way and at the same time as Comparative F-xperiment D-2. EXAMPLE 6 A powder coating formulation is prepared by mdt mixing 600 g of the modified epoxy resin from Comparative Experiment D-1, 600 g of additional Epoxy Resin B, 48 g of Curing Agent A, 250 g of BS-2 filler, 23.41 g of Pigment A, and 15.61 g of How Modifier A, and 24 g of CaPr2 stabilizer. The composition is prepared and tested in the same way and at the same time as Comparative Experiment D-2. EXAMPLE 7 A powder coating formulation is prepared by melt mixing 600 g of the modified epoxy resin from Comparative Experiment D-1, 600 g of additional Epoxy Resin B, 48 g of Curing Agent A, 254 g of BS-2 filler, 23.85 g of Pigment A, and 15.90 g of How Modifier A, and 48 g of CaPr2 stabilizer. The composition is prepared and tested in the same way and at the same time as Comparative Experiment D-2. COMPARATIVE EXPERIMENT E 1. Preparation of an Epoxy resin modified with 15% by weight of a Carboxyl-Containing Polymer. A modified epoxy resin is prepared by melt mixing 1,800 g of Carboxyl-Containing Polymer A and 10,200 g of Epoxy Resin B. A dry blend, prepared by shaking these components together in a plastic bag, is melt mixed in a Buss Condux PLK 46 extruder having two zones with zone 1 at 70°C, zone 2 at 80°C, and the screw at 70°C and 212 rpm. The modified epoxy resin extrudate is pressed with chilled rollers to a thin sheet, air cooled, and crushed. 2. Preparation of powder coating. A powder coating formulation is prepared by melt mixing 1,200 g of the modified epoxy resin prepared in 1 above, 600 g of additional Epoxy Resin B, 72 g of Curing Agent A, and 18.9 g of How Modifier A. A dry blend, prepared by shaking the components together in a plastic bag, is mdt mixed in a Buss Condux PLK 46 extruder having two zones with zone 1 at 70°C, zone 2 at 90°C, and the screw at 70°C and 200 rpm. The extrudate is pressed with chilled rollers to a thin sheet, air cooled, ground to a fine powder with a Brinkmann ZM-1 grinder and sieved through 150 mesh brass sieves. A portion of the powder is coated within two days following the melt mixing. A portion of the powder is coated after aging for 24 hours at 40°C. A portion of the powder is coated after aging for 27 days at ambient temperature. The powder is electrostatically sprayed with a Gema gun onto grounded cold rolled steel panels. The powder coated panels are baked for 15 minutes at 180°C and air cooled. EXAMPLE 8 A powder coating formulation is prepared by melt mixing 1,200 g of the modified epoxy resin from Comparative Experiment E-l, 600 g of additional Epoxy Resin B, 72 g of Curing Agent A, 19.2 g of How Modifier A, and 312 g of CaPr2 stabilizer. The composition is prepared and tested in the same way and at the same time as Comparative Experiment E-2. EXAMPLE 9 A powder coating formulation is prepared by melt mixing 1,200 g of the modified epoxy resin from Comparative Experiment E-l, 600 g of additional Epoxy Resin B, 72 g of Qiring Agent A, 193 g of How Modifier A, and 37.2 g of ZnAc2 stabilizer. The composition is prepared and tested in the same way and at the same time as Comparative Experiment E-2. EXAMPLE 10 A powder coating formulation is prepared by melt mixing 1,200 g of the modified epoxy resin from Comparative Experiment E-l, 600 g of additional Epoxy Resin B, 72 g of Curing Agent A, 20.0 g of How Modifier A, and 105.6 g of ZnS_2 stabilizer. The composition is prepared and tested in the same way and at the same time as Comparative Experiment E-2. COMPARATIVE EXPERIMENT F 1. Preparation of an Epoxy resin modified with 15% by wdght of a Carboxyl-Containing Polymer. A modified epoxy resin is prepared by melt mixing 900 g of Carboxyl-Containing Polymer A and 5,100 g of Epoxy Resin B. A dry blend, prepared by shaking the components together in a plastic bag, is mdt mixed in a Buss Condux PLK 46 extruder with zone 1 at 70°C, zone 2 at 80°C, and the screw at 70°C and 212 rpm. The modified epoxy resin extrudate is pressed with chilled rollers to a thin sheet, air cooled, and crushed. 2. Preparation of powder coating. A powder coating formulation is prepared by melt mixing 1500 g of the modified epoxy resin prepared in 1 above, 60 g of Curing Agent A, 300 g of BS-1 filler, 28.6 g of Pigment A, and 19.1 g of How Modifier A. A dry blend, prepared by shaking the components together in a plastic bag, is mdt mixed in a Buss Condux PLK 46 extruder having two zones with zone 1 at 70°C, zone 2 at 80°C, and the screw at 70°C and 200 rpm. The extrudate is pressed with chilled rollers to a thin sheet air cooled, ground to a fine powder with a Brinkmann ZM-1 grinder and sieved through 150-mesh brass sieves. A portion of the powder is coated within one day following the mdt mixing. Another portion of the powder is coated after aging for 24 hours at 40°G Another portion of the powder is coated after aging for 33 days at ambient temperature. The powder is sprayed with a Wagner GlOO EPB dectrostatic spray gun onto grounded cold rolled sted panels. The powder coated panels are baked for 15 minutes at 180°C and air cooled. EXAMPLE 11 A. Preparation of prereaction product of Carboxyl-Containing Polymer and metal salt. A prereaction product (ionomer) of Carboxyl-Containing Polymer A is prepared by mdt mixing 11.7 g/min of CaPi2 stabilizer and 270 g/rnin of C-arboxyl-Cbntaining Polymer A in a Werner and Pfldderer CWP) 30-mm twin-screw extruder. The barrel temperatures are: zone 1 at 52°C and zones 2 - 5 at 113°C - 121 °C The product is extruded through a 3-strand die, water cooled, and chopped to 1/4 in C6 5 mm) pdlets. R Preparation of an Epoxy resin modified with 15% by wdght of a Carboxyl-Containing Polymer. A modified epoxy resin is prepared by melt mixing 900 g of the caldum ionomer of Carboxyl-Containing Polymer A prepared in A above and 5,100 g of Epoxy Resin B. The composition is prepared in the same way as the modified resin from Comparative Experiment F-l. G Preparation of powder coating. A powder coating formulation is prepared by melt mixing 1500 g of the modified epoxy resin from B above, 60 g of Curing Agent A, 300 g of BS-1 filler, 28.6 g of Pigment A, and 19.1 g of How Modifier A. The composition is prepared and tested in the same way and at the same time as Comparative Experiment F-2. EXAMPLE 12 A. Preparation of prereaction product of Carboxyl-Containing Polymer and metal salt. A prereaction product Cionomer) of Carboxyl-Containing Polymer A is prepared by mdt mixing 13.2 g/min of ZnAc2 stabilizer and 270 g/min of C-arboxyl-C-Dntaining Polymer A in a Werner and Pfleiderer CWP) 30-mm twin-screw extruder. The barrel temperatures are: zone 1 at 52°C and zones 2 - 5 at 113°C - 121°C. The product is extruded through a 3-strand die, water cooled, and chopped to 1/4 in C635 mm) pellets. R Preparation of an Epoxy resin modified with 15% by weight of a Carboxyl-Containing Polymer. A modified epoxy resin is prepared by melt mixing 900 g of the zinc ionomer of C-^boxyl-Containing Polymer A and 5,100 g of Epoxy Resin B. The composition is prepared in the same way as the modified resin from Comparative Experiment F-l. C. Preparation of powder coating. A powder coating formulation is prepared by melt mixing 1500 g of the modified epoxy resin from B above, 60 g of Curing Agent A, 300 g of BS-1 filler, 28.6 g of Pigment A, and 19.1 g of How Modifier A. The composition is prepared and tested in the same way and at the same time as Comparative Experiment F-2. COMPARATIVE EXPERIMENT G 1. Preparation of an Epoxy resin modified with 15% by weight of a Carboxyl-Containing Polymer. A modified epoxy resin is prepared by melt mixing 600 g of Carboxyl-Containing Polymer A and 3,400 g of Epoxy Resin B. A dry blend, prepared by shaking the components together in a plastic bag, is melt mixed in a Buss Condux PLK 46 extruder having two zones with zone 1 at 70°C, zone 2 at 80°C, and the screw at 70°C and 200 rpm. The modified epoxy resin extrudate is pressed with chilled rollers to a thin sheet, air cooled, and crushed. 2. Preparation of powder coating. A powder coating formulation is prepared by melt mixing 1500 g of the modified epoxy resin prepared in 1 above, 60 g of Curing Agent A, 300 g of BS-1 filler, 28.6 g of Pigment A, and 19.1 g of How Modifier A. A dry blend, prepared by shaking the components together in a plastic bag, is melt mixed in a Buss Condux PLK 46 extruder having two zones with zone 1 at 70°C, zone 2 at 80°C, and the screw at 70°C and 200 rpm. The extrudate is pressed with chilled rollers to a thin sheet, air cooled, ground to a fine powder with a Brinkmann ZM-1 grinder and sieved through 150-mesh brass sieves. A portion of the powder is coated within one day following the mdt mixing. A portion of the powder is coated after aging for 24 hours at 40°C. The powder is electrostatically sprayed with a Wagner gun onto grounded cold rolled steel pands. The powder coated panels are baked for 15 minutes at 180°C and air cooled. EXAMPLE 13 A. Preparation of prereaction product of Carboxyl-Containing Polymer and metal salt. A prereaction product Cionomer) of Carboxyl-Containing Polymer A is prepared by mdt mixing 8.8 g/min of ZnAc2 stabilizer and 355 g/min of Carboxyl-Containing Polymer A in a WP 30-mm twin-screw extruder. The barrel temperatures are zone 1 at 53°C and zones 2 - 5 at 109 - 117°C. The product is extruded through a 3-strand die, water cooled, and chopped to 1 /4 in C635 mm) pellets. J Preparation of an Epoxy resin modified with 15% by wdght of a Carboxyl-Containing Polymer. A modified epoxy resin is prepared by mdt mixing 600 g of the zinc ionomer of C-arboxyl-Containing Polymer A prepared in A above and 3,400 g of Epoxy Resin B. The composition is prepared in the same way as the modified resin from Comparative Experiment G-l. C Preparation of powder coating. A powder coating formulation is prepared by mdt mixing 1500 g of the modified epoxy resin from B above, 60 g of Curing Agent A, 300 g of BS-1 filler, 28.6 g of Pigment A, and 19.1 g of How Modifier A. The composition is prepared and tested in the same way and at the same time as Comparative Experiment G-2. EXAMPLE 14 A. Preparation of prereaction product of Carboxyl-Containing Polymer and metal salt. A prereaction product Cionomer) of Carboxyl-Containing Polymer A is prepared by mdt mixing 17.1 g/min of ZnAc2 stabilizer and 355 g/min of Carboxyl-Containing Polymer A in a WP 30-mm twin-screw extruder. The barrel temperatures are: zone 1 at 51°C and zones 2 - 5 at 105 - 116°C. The product is extruded through a 3-strand die, water cooled, and chopped to 1/4 in C6-35 mm) pellets. B. Preparation of an Epoxy resin modified with 15% by wdght of a Carboxyl-Containing Polymer. A modified epoxy resin is prepared by melt mixing 600 g of the zinc ionomer of Carboxyl-Containing Polymer A and 3,400 g of Epoxy Resin B. The composition is prepared in the same way as the modified resin from Comparative Experiment G-1. C. Preparation of powder coating. A powder coating formulation is prepared by melt mixing 1500 g of the modified epoxy resin from B above, 60 g of Curing Agent A, 300 g of BS-1 filler, 28.6 g of Pigment A, and 19.1 g of How Modifier A. The composition is prepared and tested in the same way and at the same time as Comparative Experiment G-2. EXAMPLE 15 A. Preparation of powder coating. A powder coating formulation is prepared by mdt mixing 1500 g of the modified epoxy resin from Comparative Experiment G-1, 60 g of Curing Agent A, 300 g of BS-1 filler, 28.6 g of Pigment A, 19.1 g of How Modifier A, and 11.25 g of ZnAc2 stabilizer. The composition is prepared and tested in the same way and at the same time as Comparative Experiment G-2. COMPARATIVE EXPERIMENT H Preparation of an Epoxy resin modified with 15% by weight of a Carboxyl-Containing Polymer. A modified epoxy resin is prepared by extruder melt mixing at a temperature of 90°C-110°C and Epoxy Resin B at a weight ratio of 0.85:1 in a 100 mm Baker-Perkins twin-screw extruder. The product is extruded as a thin sheet onto a chilled bdt and then crushed. 2. Preparation of powder coating. A powder coating formulation is prepared by melt mixing 1500 g of the modified epoxy resin from 1 above, 60 g of Curing Agent A, 300 g of BS-1 filler, 28.6 g of Pigment A, and 19.1 g of How Modifier A. A dry blend, prepared by shaking the components together in a plastic bag, is mdt mixed in a Buss Condux PLK 46 extruder having two zones with zone 1 at 70°C, zone 2 at 80°C, and the screw at 70°C and 200 rpm. The extrudate is pressed with chilled rollers to a thin sheet, air cooled, ground to a fine powder with a Brinkmann ZM-1 grinder and sieved through 150-mesh brass sieves. A portion of the powder is coated within one day following the mdt mixing. Another portion of the powder is coated after aging for 24 hours at 40°C The powder is dectrostatically sprayed with a Wagner gun onto grounded cold rolled steel panels. The powder coated pands are baked for 15 minutes at 180°C and air cooled. EXAMPLE 16 A. Preparation of prereaction product of Carboxyl-Containing Polymer and metal salt. A prereaction product Cionomer) of C_-rboxyl-Containing Polymer A is prepared by mdt mixing 225 g/min of NaAc stabilizer and 355 g/min of C---rrx)xyl ntaining Polymer A in a WP 30-mm twin-screw extruder. The barrel temperatures are zone 1 at50°C and zones 2 - 5 at 104°C - 107°C The product is extruded through a 3-strand die, water cooled, and chopped to 1/4 in (6.35 mm) pellets. R. Preparation of an Epoxy resin modified with 15% by weight of a Carboxyl-Containing Polymer. A modified epoxy resin is prepared by melt mixing 600 g of the zinc ionomer of Carboxyl-Containing Polymer A and 3,400 g of Epoxy Resin B. The composition is prepared in the same way as the modified resin from Comparative Experiment G-1. C Preparation of powder coating. A powder coating formulation is prepared by melt mixing 1500 g of the modified epoxy resin from B above, 60 g of Curing Agent A, 300 g of BS-1 filler, 28.6 g of Pigment A, and 19.1 g of How Modifier A. The composition is prepared and tested in the same way and at the same time as Comparative Experiment H-2. EXAMPLE 17 Ai Preparation of prereaction product of Carboxyl-Containing Polymer and metal salt. A prereaction product Cionomer) of Carboxyl-Containing Polymer A is prepared by melt mixing 473 g/min of ZnAc2 stabilizer and 355 g/min of Carboxyl-Containing Polymer A in a WP 30-mm twin-screw extruder. The barrel temperatures are zone 1 at 48°C and zones 2 - 5 at 105 - 113°C The product is extruded through a 3-strand die, water cooled, and chopped to 1 /4 in C635 mm) pellets. B. Preparation of an Epoxy resin modified with 15% by weight of a Carboxyl-Containing Polymer. A modified epoxy resin is prepared by melt mixing 600 g of the zinc ionomer of Carboxyl-Containing Polymer A and 3400 g of Epoxy Resin B. The composition is prepared in the same way as the modified resin from Comparative Experiment G-1. C Preparation of powder coating. A powder coating formulation is prepared by mdt mixing 1500 g of the modified epoxy resin from B above, 60 g of Curing Agent A, 300 g of BS-1 filler, 28.6 g of Pigment A, and 19.1 g of How Modifier A. The composition is prepared and tested in the same way and at the same time as Comparative Experiment H-2. EXAMPLE 18 A ; Preparation of powder coating. A powder coating formulation is prepared by melt mixing 1500 g of the modified epoxy resin from Comparative Experiment G-1, 60 g of Curing Agent A, 300 g of BS-1 filler, 28.6 g of Pigment A, 19.1 g of How Modifier A, and 11.25 g of ZnAc2 stabilizer. The composition is prepared and tested in the same way and at the same time as Comparative Experiment H-2. EXAMPLE 19 A. Preparation of prereaction product of Carboxyl-Containing Polymer and metal salt. A prereaction product (ionomer) of Carboxyl-Containing Polymer A is prepared by melt mixing 48.2 g/min of ZnSt2 stabilizer and 355 g/min of Carboxyl-Containing Polymer A in a WP 30-mm twin-screw extruder. The barrel temperatures are zone 1 at 56°C and zones 2 - 5 at 128°C - 139°C. The product is extruded through a 3-strand die, water cooled, and chopped to 1/4 in (6.35 mm) pellets. J Preparation of an Epoxy resin modified with 15% by weight of a Carboxyl-Containing Polymer. A modified epoxy resin is prepared by mdt mixing 600 g of the zinc ionomer of Carboxyl-Containing Polymer A and 3400 g of Epoxy Resin B. The composition is prepared in the same way as the modified resin from Comparative Experiment G-1. C. Preparation of powder coating. A powder coating formulation is prepared by mdt mixing 1500 g of the modified epoxy resin, 60 g of Curing Agent A, 300 g of BS-1 filler, 28.6 g of Pigment A, and 19.1 g of How Modifier A. The composition is prepared and tested in the same way and at the same time as Comparative Experiment H-2. EXAMPLE 20 A. Preparation of prereaction product of carboxyl-containing polymer and metal salt A prereaction product (ionomer) of Carboxyl-Containing Polymer A is prepared by mdt mixing a dry-blended mixture of approximately 4,000 g of a 0.0488:1 wdght ratio of ZnAc2 stabilizer and the ion product Cionomer) of Carboxyl-Containing Polymer A in a WP 30-mm twin screw extruder. The barrd temperatures are: zone l at44°C and zones 2-5 at 103°C-111°C A vacuum port set at 20 mm Hg absolute removed byproduct acetic add. The product is extruded through a 3-strand die, water cooled, and chopped to 1/4 inch C635 mm) pellets. B. Preparation of an epoxy resin modified with 15% by weight of a carboxyl-containing polymer. A modified epoxy resin is prepared by melt mixing 450 g of the zinc ionomer of (--irboxyl-Containing Polymer A prepared in A above and 2550 g of Epoxy Resin B. A dry blend, prepared by shaking the components together in a plastic bag, is mdt mixed in a Buss Condux PLK 46 extruder having two zones with zone 1 at 20°C, zone 2 at 70°C, and the screw at 20°C and 200 rpm. The modified epoxy resin extrudate is pressed with chilled rollers to a thin sheet, air cooled, and crushed. C Preparation of powder coating. A powder coating formulation is prepared by melt mixing 1570 g of modified epoxy resin from B above, 62.9 g of Curing Agent A, 315 g of BS-1 filler, 30 g of Pigment A, and 20 g of How Modifier A. A dry blend, prepared by shaking the components together in a plastic bag, is melt mixed in a Buss Condux PLK 46 extruder having two zones with zone 1 at 50°C, zone 2 at 80°C, and the screw at 50°C and 200 rpm. The extrudate is pressed with chilled rollers to a thin sheet, air cooled, ground to a fine powder with a Brinkmann ZM-1 grinder and sieved through 150 mesh brass sieves. A portion of the powder is coated within one day following the melt mixing. Another portion of the powder is coated after aging for 24 hours at 40°C The powder is electrostatically sprayed with a Wagner gun onto cold rolled sted panels. The powder coated panels are baked for 15 minutes at 180°C and air cooled. EXAMPLE 21 A. Preparation of prereaction product of carboxyl-containing polymer and metal salt. A prereaction product Cionomer) of Carboxyl-Containing Polymer A is prepared by melt mixing a dry-blended mixture of 120.6 g of ZnCCtø stabilizer and 4324 g of Carboxyl-Containing Polymer A in a WP 30-mm twin screw extruder. The barrd temperatures are: zone 1 at 46°C and zones 2-5 at 105°C - 111°G A vacuum port set at 20 mm Hg absolute removed byproduct water. The product is extruded through a 3-strand die, water cooled, and chopped to 1/4 inch C635 mm) pellets. R Preparation of an epoxy resin modified with 15% by weight of a carboxyl-containing polymer. A modified epoxy resin is prepared by melt mixing 450 g of the zinc ionomer of Carboxyl-Containing Polymer A prepared in A above and 2550 g of Epoxy Resin B. The composition is prepared in the same manner as in Example 20-B. C Preparation of powder coating. A powder coating formulation is prepared by melt mixing 1570 g of modified epoxy resin from B above, 62.9 g of Curing Agent A, 315 g of BS-1 filler, 30 g of Pigment A, and 20 g of How Modifier A. The composition is prepared in the same manner as in Example 20-C The following Table I provides a summary description of the examples and comparative experiments grouped in sets of concurrently obtained examples and comparative experiments. Table I Summary description of examples Grouped in sets of concurrent examples * Not an example of the present invention. TablelCcontd.) Summary description of example Grouped in sets of concurrent examples * Not an example of the present invention. Table Kcontd.) Summary description of examples Grouped in sets of concurrent examples * Not an example of the present invention. Table l CContd.) Summary description of examples Grouped in sets of concurrent example Not an example of the present invention. Table I (contd.) Summary description of examples Grouped in sets of concurrent examples The following Table H provides a summary of process conditions for the preparation of carboxyl-containing polymer ionomers. Table H Summary table of Carboxyl-Containing Polymer Ionomer Preparation Mdt Mixed on Werner and Pfleiderer 30-mm extruder CaPr2 , caldum propionate, ZnAc2, zinc acetate; NaAc, sodium acetate; ZnSt2 , zinc stearate. 2 Equivalent ratio of metal ion to add groups. 3 Percent conversion of the metal ion to carboxyl-containing polymer ionomer. 4 Not applicable. The metal salt was premixed with the carrwxyl-containing polymer ionomer. The feed rate indicated was for the mixture. Not determined. Note: Screw speed was 400 rpm for all examples, except Example 19 which was 477 rpm. The following Table III provides a summary of the preparation of the modified epoxy resins. Table III Summary table of modified epoxy resin preparation Melt Mixed on an extruder (except as noted) Not an example of the present invention. Epoxy Resin A. C-arboxyl-containing copolymer A. Epoxy Resin B. CaPr2 = Caldum propionate, ZnAc2 = zinc acetate, NaAc = sodium acetate, ZnSt2 zinc stearate, ZnCC»3 = zinc carbonate. Table III (contd.) Summary table of modified epoxy resin preparation Melt Mixed on an extruder (except as noted) 1 Epoxy Resin B. Carixjxyl-containing copolymer A. 3 CaPτ2 = Caldum propionate, ZnAc2 = zinc acetate, NaAc = sodium acetate, ZnSt2 zinc stearate, ZnCθ3 = zinc carbonate. The following Table IV provides a summary of the formulation components for each of the comparative experiments and examples. Table IV Summary Table of Formulations in Weight Percent * Not an example of the present invention. Epoxy Resin B. Table IV (contd.) Summary Table of Formulations in Weight Percent * Not an example of the present invention. 1 Epoxy Resin B. Table IV (contd.) Summary Table of Formulations in Weight Percent * Not an example of the present invention. 1 Epoxy Resin B. Table IV Ccontd.) Summary Table of Formulations in Weight Percent * Not an example of the present invention. 1 Epoxy Resin B. Table IV (contd.) Summary Table of Formulations in Weight Percent * Not an example of the present invention. 1 Epoxy Resin B. The following Table V provides a summary of the coating thickness, coating gloss values, and the relative change in the gloss values comparing the coating from the aged powder to the coating from the fresh powder. Table V Summary Table of Coating Properties Not an example of the present invention. Table V (contd.) Summary Table of Coating Properties * Not an example of the present invention. Table V Ccontd.) Summary Table of Coating Properties ' ' Not an example of the present invention. Table V (contd.) Summary Table of Coating Properties Not an example of the present invention. Table V (contd.) Summary Table of Coating Properties " Not an example of the present invention. Table V (contd.) Summary Table of Coating Properties * Not an example of the present invention. Table V (contd.) Summary Table of Coating Properties

Claims: CLAIMS 1. A modified epoxy resin composition comprising CA) at least one epoxy resin containing an average of more than one vicinal epoxy group per molecule and at least one aromatic ring in its backbone; and CB ) at least one polymer prepared from one or more ethylenically unsaturated monomers wherein at least one of such monomers contains a carboxylic add group; characterized by incorporating into said composition CC) a stabilizing amount of at least one stabilizer compound which is Ca) at least one Group IA, HA, HB, HIA, VIB or VHI of the periodic table of the dements metal salt of an organic carboxylic add; Cb) at least one of zinc carbonate, zinc oxide, sodium carbonate or potassium carbonate; or Cc) any combination of Ca) and Cb). 2. A curable composition comprising C A) at least one epoxy resin containing an average of more than one vicinal epoxy group per molecule and at least one aromatic ring in its backbone; CB ) at least one polymer prepared from one or more ethylenically unsaturated monomers wherein at least one of such monomers contains a carboxylic add group; and CD ) a curing amount of at least one curing agent for component CA) which is different from either component CB) or the prereaction product of components CB) and CC); characterized by incorporating into said composition; CC) a stabilizing amount of at least one stabilizer compound which is Ca) at least one Group IA, HA, HB, HIA, VIB or VHI of the periodic table of the dements metal salt of an organic carboxylic add; Cb) at least one of zinc carbonate, zinc oxide, sodium carbonate or potassium carbonate; or Cc) any combination of Ca) and Cb). 3. A powder coating composition which is essentially free of pigment(s) and fϊllerCs) comprising (A) at least one epoxy resin containing an average of more than one vicinal epoxy group per molecule and at least one aromatic ring in its backbone; ( B ) at least one polymer prepared from one or more ethylenically unsaturated monomers wherein at least one of such monomers contains a carboxylic add group; CD) at least one curing agent for component (A) which is different from dther component CB) or the prereaction product of components CB) and CC); and CE) at least one or more additional componentCs) sdected from the group consisting of flow control agent, leveling aid, and promoter or catalyst; characterized by incorporating into said composition; CC) a stabilizing amount of at least one stabilizer compound which is Ca) at least one Group IA, HA, HB, πiA, VIB or VHI of the periodic table of the elements metal salt of an organic carboxylic add; Cb) at least one of zinc carbonate, zinc oxide, sodium carbonate or potassium carbonate; or Cc) any combination of Ca) and Cb). 4. A powder coating composition which contains substantial quantities of pigmentCs) or fillerCs) or both comprising C A ) at least one epoxy resin containing an average of more than one vidnal epoxy group per molecule and at least one aromatic ring in its backbone; C B ) at least one polymer prepared from one or more ethylenically unsaturated monomers wherein at least one of such monomers contains a carboxylic add group; CD) at least one curing agent for component CA) which is different from either component CB) or the prereaction product of components CB) and CC); and CE) at least one or more additional componentCs) induding pigment, filler, flow control agent, leveling aid or other additive; characterized by incorporating into said composition; CC) a stabilizing amount of at least one stabilizer compound which is Ca) at least one Group IA, IIA, πB, HIA, VIB or Vffl of the periodic table of the elements metal salt of an organic carboxylic add; (b) at least one of zinc carbonate, zinc oxide, sodium carbonate or potassium carbonate; or Cc) any combination of (a) and (b). 5. A composition of Claim 1, 2, 3 or 4 wherein (a) component (A) is a diglyddyl ether of: a dihydric phenol, a bisphenol, a phenol- or substituted phenol-aldehyde resin, or a phenol- or substituted phenol-unsaturated diene resin; (b) component (B) is a polymer resulting from polymerizing a monomer mixture containing ethylene and an aliphatic, cydoaliphatic or aromatic carboxylic add; (c) component (C) is zinc oxide, sodium carbonate, zinc carbonate, potassium carbonate, or sodium, lithium, potassium, zinc, caldum, magnesium, nickd, aluminum or chromium salt of a saturated or unsaturated aliphatic or cydoaliphatic or aromatic organic carboxylic add having from about 1 to about 30 carbon atoms per molecule, or a combination of any two or more of such compounds; (d) component CD) is a guanidine, biguanide, aliphatic amine, aromatic amine, compound containing an average of more than one phenolic hydroxyl group per molecule, aliphatic, cydoaliphatic or aromatic di-or poly-carboxylic add anhydride, or any combination of two or more of such curing agents; (e) componentCA) isemployed manamountoffromabout66 toabout99 percentbywdghtbased upon the combined wdght of components CA) and CB); . (f ) component CB) is employed in an amount of from about 1 to about 34 percent by wdght based upon the combined wdght of components CA) and CB); (g) Component CC) is employed in an amount suffident to provide a ratio of metal equivalents per carboxyl equivalents of (i) in Claim 1, 2 or 4, at least about 0.04:1; or Cϋ) in Claim 3, at least about 05:1; and Ch) component CD) is employed in an amount which is suffident to provide a ratio of equivalents of this curing agent plus component CB) or ionomers thereof per epoxide equivalent of from about 0.8:1 to about 3:1. 6. A composition of Claim 5 wherein Ca) component (A) is a diglycidyl ether of a bisphenol; (b) component (B) is a polymer resulting from polymerizing a monomer mixture containing ethylene and either acrylic or methacrylic acid; (c) component (C) is zinc oxide, sodium carbonate, zinc carbonate, potassium carbonate, zinc acetate, zinc propionate, zinc stearate, sodium acetate, caldum propionate; (d) component (D) is dicyandiamide, o-tolubiguanide, acid functional polyesters, compounds containing more than one phenolic group per molecule, or any combination of two or more of such curing agents; (e) component (A) is employed in an amount of from about 80 to about 96 percent by wdght based upon the combined wdght of components (A) and CB); C ) component CB) is employed in an amount of from about 4 to about 20 percent by weight based upon the combined weight of components CA) and CB); Cg) Component CC) is employed in an amount suffident to provide a ratio of metal equivalents per carboxyl equivalents of C i ) in Claim 1, 2 or 4, from about 0.08:1 to about 6:1; or Cϋ) in Claim 3, from about 0.6:1 to about 6:1; and Ch) component CD) is employed in an amount which provides a ratio of equivalents of this curing agent plus component CB) or ionomers thereof per epoxide equivalent of from about 0.9:1 to about 25:1. 7. A composition of Claim 5 wherein Ca) component (A) is a diglyddyl ether of bisphenol A, bisphenol F or bisphenol K; (b) component (B) is a polymer resulting from polymerizing a monomer mixture containing ethylene and acrylic add; (c) component CC) is zinc carbonate, zinc acetate, zinc propionate, zinc stearate, sodium acetate, caldum propionate or any combination thereof; (d) component CD) is dicyandiamide or an imidazole accelerated dicyandiamide; Ce) component CA) is employed in an amount of from about 80 to about 92 percent by wdght based upon the combined wdght of components C A) and CB); and ( ) component CB) is employed in an amount of from about 8 to about 20 percent by wdght based upon the combined wdght of components CA) and , (g) Component (C) is employed in an amount suffident to provide a ratio of metal equivalents per carboxyl equivalents of Ci ) in Claim.1, 2 or 4, from about 0.15:1 to about 1:1; or Cϋ) in Claim 3, from about 0.7:1 to about 1:1; and Ch ) component CD) is employed in an amount which provides a ratio of equivalents of this curing agent plus component CB) or ionomers thereof per epoxide equivalent of from about 1:1 to about 2:1. 8. A composition suitable as a curing agent for epoxy resins which comprises (1) at least one polymer prepared from one or more ethylenically unsaturated monomers wherein at least one of such monomers contains a carboxylic add group; and C2) at least one curing agent for said epoxy resin which curing agent is different from component CD; characterized by incorporating into said curing agent composition C3) a stabilizing amount of at least one stabilizer compound whidi is (a) at least one Group IA, HA, IIB, HIA, VIB or VIE of the periodic table of the elements metal salt of an organic carboxylic add; Cb) at least one of zinc carbonate, zinc oxide, sodium carbonate or potassium carbonate; or Cc) any combination of Ca) and Cb). 9. A composition of Claim 8 wherein Ca ) component (1) is present in an amount of from about 1 to about 99 percent by weight based upon the combined weight of components (1) and (2); (b) component (2) is present in an amount of from about 99 to about 1 percent by weight based upon the combined weight of components (1) and (2); and (c) component (3) is employed in an amount suffident to provide a ratio of metal equivalents per carboxyl equivalent of at least about 0.04:1. 10. A composition of Claim 8 wherein (a) component (1) is present in an amount of from about 3 to about 96 percent by weight based upon the combined weight of components (1) and (2); (b) component (2) is present in an amount of from about 97 to about 4 percent by weight based upon the combined weight of components (1) and (2); and (c) component (3) is employed in an amount suffident to provide a ratio of metal equivalents per carboxyl equivalent of from about 0.08:1 to about 6:1. 11. A composition of Claim 8 wherein ( a ) component (1 ) is present in an amount of from about 25 to about 90 percent by wdght based upon components (1) and (2); and (b) component C2) is present in an amount of from about 75 to about 10 percent by wdght based upon components (1) and (2; and Cc) component (3) is employed in an amount sufficient to provide a ratio of metal equivalents per carboxyl equivalent of from about 0.15:1 to about 1:1. 12. A composition of Claim 11 wherein a curing promoter or catalyst is employed. 13. The product resulting from curing the curable compositions of Claim 3 or 4. 14. The product resulting from curing the curable compositions of Claim 5. 1 2 15. The product resulting from curing the curable compositions of Qaim 6. 16. The product resulting from curing the curable compositions of Qaim 7. 18. An artide coated with the powder coating compositions of aim 3 or 4. 19. An artide coated with the powder coating compositions of Qaim 5. 20. An artide coated with the powder coating compositions of Qaim 6. 21. An artide coated with the powder coating compositions of Qaim 7.

Inventors: HART JEFFERY LEE, HUGHES MORGAN MARK, SANFORD JOE FRANKLIN, HART, JEFFERY, LEE, HUGHES, MORGAN, MARK, SANFORD, JOE, FRANKLIN
Applicants: DOW CHEMICAL CO, THE DOW CHEMICAL COMPANY
Application year: 1993
Main classification: C08L63
IPC codes: C08G59, C08K3, C08K5, C08L63, C09D5, C09D163