NL8201224A - Resinous materials which are curable by means of an transesterification hardening mechanism. - Google Patents

Description

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Resin-like materials curable by means of a transesterification curing mechanism.

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The present invention relates to heat curable resinous coating materials and to the use of these coating materials in cationic electrolytic deposition. More particularly, the present invention relates to resinous coating materials which cure by a transesterification reaction.

U.S. Patent 3,937,679 describes cationic heat curable resin-like coating materials such as hydroxyl group containing polymers and combination with aminoplast resin curing agents.

These materials can be used in an electrolytic deposition process, depositing on the cathode and yielding coatings with excellent properties after curing.

Coating materials using aminoplast are best cured in an acidic environment. However, the deposition on the cathode is basic and high curing temperatures must be used to overcome the unfavorable curing environment.

U.S. Patent No. 4,101,486 is similar to said U.S. Patent No. 3,937,679 in that it describes the cationic electrolytic deposition of hydroxyl group-containing polymers. The curing agent, however, is a blocked isocyanate. Coating materials using blocked isocyanates cure very well at relatively low temperatures in a basic medium and are widely used today in industrial cationic electrolytic deposition. Examples of cationic electrolytically deposable materials which are used industrially are those described in U.S. Pat. Nos. 4,031,050 and 8201224 Fr - 2 - 4,190,567 and German Offenlegungsschrift 2,752,255. Although widely used throughout the electrolytic deposition industry, blocked isocyanate-containing materials are undesirable from the viewpoint of the isocyanate, some of which are undesirable in handling.

European patent application 0 012 463 describes thermosetting resinous coating materials which cure by means of a transesterification reaction. The resinous binder of the coating material includes a hydroxyl-containing polymer and a cross-linking agent which is a polyester containing two or more β-hydroxy ester groups per molecule. The coating material can be made cationic and used for electrolytic deposition.

It is known that esters containing β-hydroxy-15 alkyl groups transesterify very quickly. See, for example, J. Prakt. Chem. 312 (1970), 660-668. European patent application 0 012 463 teaches, however, that polyesters which do not contain β-hydroxy ester groups but instead simple ester groups, such as methyl esters or butyl esters, are not as easy to transesterify and are too slow to effect sufficient cross-linking under acceptable conditions.

Surprisingly, it has been found that coating materials comprising hydroxyl group-containing polymers and a polyester cross-linking agent not containing β-hydroxy ester groups can be cured very effectively.

It is an object of the invention to provide heat curable coating materials which can be formed very efficiently to form solvent resistant coatings.

According to the invention, a heat curable coating material was provided to provide a solvent resistant coating. The coating material comprises as a resinous binder: (A) a polymeric polyol, (B) a polyester cross-linking agent with at least two substituted ester groups per molecule, and 8201224 * 4 - 3 - (C) a transesterification catalyst.

The substituents on the ester group are selected from the class consisting of β-alkoxyester groups, β-ester groups, β-amido groups, γ-hydroxy groups, γ-ester-5 groups and δ-hydroxy groups.

The coating materials can be made cationic in nature, for example, by using a polymeric polyol containing cationic salt groups, dispersing the resinous binder in water and using the aqueous dispersion in a cationic electrolytic deposition process.

The polymeric polyol component of the coating materials can be selected from a wide variety of hydroxyl group-containing polymers, such as alkyd resins, polyester resins, hydroxy group-containing aeryl polymers, hydroxyl group-containing epoxy resins, and hydroxyl group-containing resins derived from epoxy resins, such as polyoxyde amine -adducts.

The molecular weights of the polymeric polyols can vary over a wide range depending on the type and depending on whether the coating material is based on an organic solvent or water and also depending on the desired performance characteristics of the coating. Polyester, epoxy and alkyd resins can have molecular weights down to about 500 and up to about 10,000, preferably the molecular weights are usually in the range of from about 1000 to 5000; wherein the molecular weights are on a weight average basis and are based on polystyrene as determined by gel permeation chromatography. Acrylic polymers, on the other hand, can have molecular weights up to about 100,000 and will usually be in the range of about 5000 to 50,000 on a weight average basis over polystyrene as determined by gel permeation chromatography.

The hydroxyl content of the polymeric polyol should be sufficient that when the polyol is in combination with the curing agent, the material will cure to a solvent resistant coating. Generally, the hydroxyl number of the polymeric polyol will be at least about 170, and preferably in the range of about 180 to 300.5 based on the solids in the resin.

A preferred class of polymeric polyols are hydroxy group-containing epoxy resins or resins derived from epoxy resins, such as particularly preferred polyepoxyamine adducts. The epoxy resins that can be used in the practice of the invention are polyepoxides, that is, polymers with a 1,2-epoxy equivalent greater than 1, preferably about 2 or more. Preference is given to polyepoxides which are difunctional with respect to epoxy. The preferred polyepoxides are polyglycidyl-15 ethers of cyclic polyols. Particular preference is given to polyglycidyl ethers of polyphenols such as bisphenol A. Examples of polyepoxides are given in U.S. Patent 4,260,716, column 3, line 20 to column 4, line 30.

In addition to the above-mentioned epoxy resins, other epoxy-containing polymers that can be used are acrylic polymers containing epoxy groups. These polymers are formed by polymerizing an unsaturated epoxy group-containing monomer such as glycidyl acrylate or methacrylate with one or more other polymerizable ethylenically unsaturated monomers. Examples of these polymers are described in U.S. Patent 4,001,156, column 3, line 59 to column 5, line 60.

In addition to the above-mentioned hydroxyl-containing epoxy resins, hydroxyl group-containing polymers derived from epoxy resins, such as polyepoxide amine adducts, can also be used. Examples of amines are ammonia, primary, secondary and tertiary amines and mixtures thereof.

The reaction product of the epoxide and amine can be at least partially neutralized with an acid to form a polymer product containing amine salt and / or quaternary ammonium salt groups. Reaction conditions of polyoxygen with amines, examples of various amines, and at least partial neutralization with acid are described in U.S. Patent 4,260,720, column 5, line 20 to column 7, line 4.

Various polyepoxide amine adducts are also described in European patent application 0 012 463.

Regarding the amount of organic amine and polyepoxide that can be reacted with each other, the relative amounts depend on the desired degree of cationic salt group formation and will again depend on the molecular weight of the polymer. The degree of cationic salt group formation and the molecular weight of the reaction product should be chosen such that when the cationic polymer is mixed with aqueous medium a stable dispersion will be formed. A stable dispersion is a dispersion that does not settle or is easily dispersible if any sedimentation takes place. In addition, the dispersion should be of sufficient cationic nature to allow the dispersed resin particles to migrate to the cathode 20 when an electrical potential is applied between an anode and a cathode dipped in an aqueous dispersion.

Also, the molecular weight, structure and degree of cationic salt group formation should be controlled so that the dispersed resin will have the desired flow to layer on the substrate; in the case of electrolytic deposition to form a layer on the cathode. This layer should be insensitive to moisture to the extent that it will not redissolve in the electrolytic deposition bath or be rinsed away from the coated surface after removal from the bath.

Generally, most of the cationic polymers useful in the practice of the invention will have average molecular weights within the range of about 500 to 100,000 and about 0.01 to 10, preferably about 0.1 to 5.0, preferably about 0.3-8201224-6 to 3.0 milliequivalents of cationic group per gram of solid in the resin. Obviously, one has to use his skill to couple the molecular weight with the cation group content to get a satisfactory polymer. The polyglycidyl ethers will have molecular weights of about 500 to 10,000, preferably 1,000 to 5,000. Acrylic polymers, on the other hand, will have molecular weights up to 100,000, preferably 5,000 to 50,000.

In addition to epoxy resins and epoxy resins derived from them, other hydroxyl group-containing polymers such as alkyd resins, polyester resins and hydroxyl group-containing acrylic polymers can also be used in the practice of the invention. Examples of these polymers and the cationic electrolytically deposable derivatives thereof are given, for example, in British Patent 1,303,480 (hydroxyl group-containing acrylic polymers and polyesters) and British Patent 1,159,390 (hydroxyl group-containing acrylic polymers).

In addition to the cationic polymers that are intended to form water-based coatings that can be used for coating purposes, such as electrolytic deposition, it goes without saying that organic solvent-based coatings using the above-mentioned polymers without cationic salt groups can be used.

The composition of coating materials with such polymers is generally known and need not be described in further detail.

The cross-linking agent. of the coating material is a polyester containing at least two substituted ester groups per molecule and is substantially free of polyesters having more than eSn g-hydroxyester group per molecule. By substantially free it is meant that the g-hydroxy ester groups are present in amounts smaller than those sufficient to obtain a cured coating by these groups themselves, ie a coating containing 40 double rubs with ace-8201224 / »- 7 - tons as described below. Generally, the β-hydroxy ester groups will be present in amounts of less than 5 and preferably less than 2 wt%, calculated as the weight of β-hydroxy ester groups based on the total weight. of the cross-linking agent. Usually, the cross-linking agents of the invention are completely free of β-hydroxy ester groups.

The substituents and the ester group are selected from the class consisting of β-alkoxyester groups, β-ester groups, β-amido groups, γ-hydroxy groups, γ-ester groups and δ-hydroxy groups. Examples of suitable cross-linking agents are those containing at least two β-alkoxyester groups per molecule, such as those formed by reacting a polycarboxylic acid or a functional equivalent thereof with one or more 1,2-polyol monoethers. Examples of suitable polycarboxylic acids include dicarboxylic acids, such as saturated aliphatic dicarboxylic acids, for example, adipic acid and azelaic acid; aromatic. acids, such as phthalic acid; ethylenically unsaturated dicarboxylic acids, such as fumaric acid and itaconic acid.

In addition to the acids themselves, functional equivalents of the acids, such as anhydrides when they exist and lower alkyl (C 1 -C 6) esters of the acids, can be used. Examples include succinic anhydride, phthalic anhydride and maleic anhydride.

Polycarboxylic acids or their functional equivalents with the functionality of more than 2 can also be used. Examples include trimellitic acid and polycarboxylic acids formed by reacting a dicarboxylic acid with a stoichiometric undersize of a polyol 30 with a functionality of 3 or more, for example, adipic acid with trimethylol propane in a 3: 1 molar ratio. The resulting product will have an acid functionality of about 3.

Examples of suitable 1,2-polyol-35 monoethers are those of formula 1, wherein, R 2, R 3, R 3, and R 3 are the same or different and have the following meanings: 8201224-8 - hydrogen, and the groups alkyl , cycloalkyl, aryl, alkaryl of 1 to 18 carbon atoms, including substituted groups in which the groups and the substituents will not adversely affect the esterification reaction with the polycarboxylic acid or its functional equivalent and the transesterification curing reaction or the desirable properties of the coating material will not adversely affect. Examples of suitable substituents include chlorine, alkoxy, carboxy, vinyl and when R 1 and R 1 form a closed hydrocarbon ring.

Examples of suitable groups for R 1, R 2, R 1, and R 1 include methyl, ethyl, and chloromethyl. Examples of suitable groups R 1. include methyl, ethyl, propyl, butyl, isobutyl, cyclohexyl, phenyl, 2-ethoxyethyl and 2-methoxyethyl. Preferably R 1, R 2, R 1 and R 1 are hydrogen or methyl and R 1 is alkyl, cycloalkyl, aryl of 1 to 6 carbon atoms.

Specific examples of 1,2-glycol monoethers are 2-ethoxyethanol, 2-butoxyethanol, 2-phenoxyethanol, 2-ethoxypropanol and 2-butoxypropanol. Other examples are 2-methoxyethanol, 2-isopropoxyethanol, 2- (2-ethoxyethoxy) -20 ethanol and 2- (2-methoxyethoxy) ethanol.

The cross-linking agent can be formed by reacting the polycarboxylic acid or its functional equivalent with a 1,2-glycol monoether at an elevated temperature, usually reflux temperature, in the presence of an esterification catalyst, such as an acid or a tin compound. Usually a solvent, for example an azeotropic solvent, such as toluene or xylene, is used. The reaction is continued, continuously removing water, until a low acid number, eg 3 or less, is obtained.

Examples of other cross-linking agents are polyesters containing at least two 8-amido ester groups per molecule. Examples of suitable cross-linking agents are those formed by reacting a polycarboxylic acid or its functional equivalent with one or more β-hydroxyalkylamides to form the polyester 8201224-9 which contains at least two β-alkoxy amido groups per molecule contains.

Examples of suitable polycarbonic acids are those mentioned above.

Examples of suitable β-hydroxy-5 alkyl amides are those of formula 2, wherein R 1 and R 2 are hydrogen and R 1, and R 1 are selected from the class consisting of alkyl, cycloalkyl, aryl, alkaryl of 1 to 18 carbon atoms including substituted groups in which the substituents will not adversely affect the esterification reaction with the polycarboxylic acid or its functional equivalent and will not adversely affect the transesterification curing reaction or the desirable properties of the coating material. Examples of suitable groups include alkyl, such as methyl, ethyl and isobutyl.

The β-hydroxyalkylamides of the above structure can be formed by reacting a β-hydroxyamine with an ester, anhydride or other functional equivalent of an organic monocarboxylic acid. Examples of β-hydroxyamines are hydroxyethylamine, β-hydroxypropyl-20 amine and 2-hydroxybutylamine. Examples of esters of organic monocarboxylic acids are alkyl esters of aliphatic monocarboxylic acids, such as methyl, ethyl, hydroxyethyl and alkoxyethyl esters of acetic acid, propionic acid and isobutyric acid. The reaction conditions for forming the β-hydroxyalkyl-25 amides are typical ammonialysis reaction conditions.

The cross-linking agent can be formed by reacting the polycarboxylic acid or its functional equivalent with the β-hydroxyalkylamide at an elevated temperature, usually reflux temperature, in the presence of a solvent, for example an azeotropic solvent, such as toluene or xylene. The reaction is continued, continuously removing water, until a low acid number, for example 7 or less, is obtained.

Examples of other cross-linking ..

Agents are polyesters containing at least two γ and / or δ-hydroxy ester groups per molecule. Examples of suitable 8201224-JO cross-linking agents are those formed by reacting a polycarboxylic acid or its functional equivalent with one or more 1,3 and / or 1,4 polyols.

Examples of suitable polycarbon-5 acids are those mentioned above.

Examples of suitable 1,3-polyols and 1,4-polyols are those of formulas 3 and 4, wherein R 1 to R 5 may be the same or different and have the following meanings: hydrogen and the groups alkyl, cycloalkyl, aryl , alkaryl, aralkyl of 1 to 18 carbon atoms, including substituted groups in which the groups and the substituents will not adversely affect the esterification reaction with the polycarboxylic acid or its functional equivalent, nor will the transesterification curing reaction or the desirable properties of the coating material be adversely affected to influence. Examples of suitable substituents include chlorine, hydroxy, alkoxy, carboxy and vinyl. Examples of suitable groups include methyl, ethyl, propyl, phenyl and hydroxymethyl.

Specific examples of 1,3-polyols. 20 include 1,3-propanediol, trimethylolpropane, trimethylolethane and 3,3-butanediol.

Specific examples of 1,4-polyols include 1,4-butanediol and 2-butene-1,4-diol.

The cross-linking agent can be formed by reacting the polycarboxylic acid or its functional equivalent with the 1,3- and / or 1,4-polyol at an elevated temperature, usually reflux temperature, in the presence of an esterification catalyst, such as an acid or a tin ester -binding. Usually, a solvent, for example, an azeotropic solvent, such as toluene or xylene, is used.

The reaction is continued, removing water continuously, until a low acid number, for example 3 or less, is obtained.

Examples of other cross-linking agents are polyesters containing at least two β and / or γ ester groups per molecule. Examples of suitable crosslinking agents 8201224 4-11 are those formed by the reaction of: (A) a polycarboxylic acid or a functional equivalent thereof with 5 (B) a member of the class consisting of: (1) 1, 2-polyols or 1,2-epoxy compounds, (2) 1,3-polyols, (C) a monocarboxylic acid.

Examples of suitable polycarboxylic acids are those mentioned above.

The cross-linking agent can be formed by reacting the polycarboxylic acid or its functional equivalent with the 1,2-polyol, the 1,2-epoxy-15 compound or the 1,3-polyol and the monocarboxylic acid in an equivalent ratio of about 1: 2: 1 at an elevated temperature, usually reflux temperature, in the presence of an esterification catalyst, such as an acid or a tin compound. Usually, a solvent, for example an azeo-20 tropical solvent, such as toluene or xylene is used. The reaction is continued with continuous removal of water until a low acid number, for example 7 or less, is obtained.

Examples of suitable 1,2-polyols and 1,3-polyols are those mentioned above. Examples of 1,2-epoxy compounds are those of formula 5, wherein B. ^ and R ^ are the same or different and have the following meanings: hydrogen and the groups alkyl, cycloalkyl, aryl, alkaryl having 1 to 18 carbon atoms, including substituted groups in which the groups or substituents will not adversely affect the esterification reaction with the polycarboxylic acid or its functional equivalent, nor will it adversely affect the transesterification curing reaction or the desirable properties of the coating material. Examples of suitable substituents include chlorine, hydroxy, alkoxy, carboxy, vinyl and when R 1 and R 1 form a closed hydrocarbon ring. Examples of suitable groups include methyl, ethyl, hydroxymethyl, chloromethyl, carboxymethyl, phenyl, methoxy and phenoxy.

Specific examples of 1,2-epoxy-5 compounds include ethylene oxide, propylene oxide, 1,2-epoxybutane, butadiene monoepoxide, glycidol, cyclohexane oxide and a glycidyl ester of a saturated aliphatic monocarboxylic acid having 9 to 12 carbon atoms, namely CARDURA E .

Examples of monocarboxylic acids are 10 organic monocarboxylic acids of formula 6, wherein Rg is a hydrocarbamyl group having 1 to 18 carbon atoms. Preferred monocarboxylic acids contain 1 to 8 carbon atoms and include acetic acid, propionic acid, isobutyric acid, benzoic acid and stearic acid.

The cross-linking agent can be formed by reacting the polycarboxylic acid or its functional equivalent with the 1,3-polyol and the monocarboxylic acid at elevated temperature, usually reflux temperature, in the presence of an esterification catalyst such as an acid or a tin compound. Usually a solvent such as toluene or xylene is used. The reaction is continued with continuous removal of water until a low acid number, for example 7 or less, is obtained.

The third component in the coating materials of the invention is an transesterification catalyst.

These catalysts are known per se and include salts or complexes of metals such as lead, zinc, iron, tin and manganese. Suitable salts and complexes include 2-ethylhexonates (octoates), naphthanates and acetylacetonates.

The relative amounts of the polymeric polyol and the cross-linking agent present in the coating material can vary within fairly wide limits depending on the reactivity of the components and the curing time and temperature and the properties desired for the cured coating. to be. Generally, the polymeric polyol will be present in amounts from about 20 to 95% by weight, preferably about 50 to 85% by weight, and 8201224 · 13 · 13 - the cross-linking agent in amounts from about 5 to 80, preferably 15 to 50% by weight; the weight percentages are thereby based on the total weight of the polymeric polyol and the cross-linking agent, and are determined on a solid basis.

The catalyst is present in amounts from about 0.1 to 2.0, preferably about 0.2 to 1.0, weight percent metal, based on the total weight (solid) of the polymeric polyol and the cross-linking agent.

The components of the coating material can be mixed simultaneously or in any suitable order. If the components are liquids of sufficiently low viscosity, they can readily be mixed together to form the coating material. Alternatively, if the components are higher viscosity liquids or solids, the components can be mixed with a diluent to reduce the viscosity of the material so that it may be suitable for coating applications.

20 By liquid diluent is meant a solvent or a non-solvent which is volatile and which is removed after the coating has been applied and which is necessary to lower the viscosity sufficiently to provide powers available in simple coating techniques, ie say brushing and spraying, to allow the coating material to spread to a controllable, desired and uniform thickness. Diluents also assist in substrate wetting, resinous component compatibility, and coalescence or film formation. Generally, the diluent, if used, will be present in the material in amounts of about 20 to 90 and preferably 50 to 80% by weight, based on the total weight of the coating material, although more diluent may be used depending on the coating application concerned.

Examples of suitable liquid thinners for organic solvent based coatings will depend somewhat on the particular system used. Generally, however, aromatic hydrocarbons, such as toluene and xylene, ketones, such as methyl ethyl ketone and methyl isobutyl ketone, alcohols, such as isopropanol, n-butanol, monoalkyl ethers of glycols, such as 2-alkoxyethanol, 2-alkoxypropanol, and compatible mixtures of these solvents are used.

In addition to organic solvents, water can also be used as a diluent, either alone or in combination with water-miscible organic solvents. When using water, the coating material is usually modified, such as by incorporating water-solubilizing groups, such as the cationic groups mentioned above, to provide the necessary water solubility. In addition to the above-mentioned cationic groups, other water-solubilizing groups, such as non-ionic groups, for example ethylene oxide groups, and anionic groups, such as carboxylate salt groups, can be extracted into the polymeric polyol or the polyester cross-linking agent to disperse the coating material or solubilize in water.

The coating materials of the invention may optionally also contain a pigment. Pigments can be of any conventional type, and include, for example, iron oxides, lead oxides, strontium chromate, carbon black, coal dust, titanium dioxide, talc, barium sulfate, as well as color pigments such as cadmium yellow, cadmium red, chrome yellow, and metallic pigments such as aluminum shavings.

The pigment content of the coating material is usually expressed as the weight ratio of pigment to resin. In the practice of the present invention, the pigment to resin weight ratios can be up to 2: 1, and for most pigmented coatings, they are usually within the range of about 0.05 to 1: 1.

8201224 * - 35 -

In addition to the above-mentioned ingredients, various fillers, plasticizers, antioxidants, ultraviolet light absorbers, flow control agents, surfactants and other recipe additives can be used if desired. These materials are optional and generally constitute up to 30% by weight of the coating material, based on the total solids.

The coating materials of the invention can be applied by conventional methods, such as by brush, by dipping, by flow coating, by spraying, and, for water-based materials containing ionic salt groups, by electrolytic deposition. Usually they can be applied over practically any substrate, such as wood, metal, glass, cloth, leather, plastic, foam and the like, as well as over various primers. The coatings can be applied to electroconductive substrates, such as metals, by electrolytic deposition. Generally, the coating thickness will vary slightly depending on the desired application. Generally, coatings with a thickness of about 2.54 to 254 µm can be applied and coatings of about 2.54 to 327 µm are common.

When using aqueous dispersions of the coating material for use in electrolytic deposition, the aqueous dispersion is contacted with an electrically conductive anode and an electrically conductive cathode. In the case of cationic electrolytic deposition, the surface to be coated is the cathode. After contact with the aqueous dispersion, an adhesive film of the coating material is deposited on the electrode to be coated when a sufficient voltage is applied between the electrodes. Conditions under which electrolytic deposition is carried out are known per se. The applied voltage can be varied and can be, for example, down to 1 volt and up to several thousand volts, but typically it is between 50 and 500 volts. The current density is usually 2 between 0.1075 and 3.632 A / dm and tends to decrease during electrolytic deposition, indicating the formation of an insulating film.

After the coating is applied, it is cured by heating at elevated temperatures such as about 150 to 205 ° C for about 10 to 45 minutes to form solvent resistant coatings. Solvent resistant coatings mean that the coating will be resistant to acetone, for example, by rubbing the coating with an acetone-saturated cloth. Coatings that are not 10 or poorly cured will not withstand rubbing with acetone and will be removed after less than 10 double rubs with acetone. Cured coatings, on the other hand, will withstand 30 double rubs with acetone and preferably at least 100 double rubs with acetone.

The invention is illustrated by the following examples, which, however, are not to be construed as limiting. In the examples, as well as in the description, all parts and percentages are by weight unless otherwise indicated.

Example I

The following example shows the preparation of a coating material containing a cross-linking agent with three beta-alkoxy ester groups per molecule. The cross-linking agent was formed by reacting trimellitic anhydride with 2-butoxyethanol in a 1: 3 molar ratio. The cross-linking agent was then mixed with a polymeric polyol formed by condensing an epoxy resin (polyglycidyl ether of a polyphenol) with an amine. The mixture was dispersed in water using acid and combined with lead octoate catalyst. Steel panels were electrocoated electrolytically in the dispersion and the coatings were heated to make them solvent resistant. The details of the example are shown below: 35 8201224 *% - 17 -

Cross-linking agent

The cross-linking agent was prepared from the following mixture of ingredients:

Ingredient Weight Solid Equiva Mill 5 _ (g) (g) lenten _

Trimellitic anhydride 192 192.0 3.00 1.00 2-butoxyethanol 365 354.0 3.09 3.09

Para-toluenesulfonic acid 1.4 1.4

Xylene 40.0

The ingredients were placed in a reaction vessel under a nitrogen blanket. The mixture was refluxed until an acid number of 2.2 was obtained.

Polymeric polyol

The polymeric polyol disclosed in European patent application 0 012 463 was formed by reacting a polyphenyl ether of bisphenol A with diethanolamine in an equivalent ratio of about 3: 1. The adduct 20 was then chain extended with a mixture of a primary and a secondary amine, namely 3-dimethyl-aminopropylamine, and the adduct of 1,6-hexamethylenediamine and the glycidyl ether of versatinic acid (CARDURA E).

Component Weight Solid Equiva Mill 25 _ (g) __ (g) lenten _ EP0H 8291 460.7 445.5 '.' 3? (0.573Γ

Bisphenol A 128.0 128.0 1,123 0.562

Xylene 30.0 - 30 Diethanolamine 38.0 38.0 0.362 0.362 2-butoxyethanol 307.2 - - - 3-dimethylamino-propylamine 18.4 18.4 0.361 0.180 1,6-hexamethylene-CARDURA E 122, 4 122.4 0.36 '0.18 adduct (mol: ratio 1: 2)

Polyglycidyl ether of bisphenol A with an epoxide equivalent 40 of 196, commercially available from Shell Chemical Company.

8201224-18 - Adduct formed by adding dropwise the glycidyl ester of versatin acid to the 1,6-hexamethylenediamine at 60 ° C. After completion of the addition, the mixture was heated to 100 ° C and held there for 2 hours. The glycidyl ester 5 of versatin acid is commercially available from Shell

Chemical Company as CARDURA E.

Aqueous dispersion

An aqueous dispersion was prepared by mixing the following ingredients together: 10 Component Weight Solid Equivalents _ (8) (8) _

Polymeric polyol 144.3 107.4 0.155 (amine)

Cross-linking agent 44.5 39.9

Lead octoate * 15 (catalyst) 2.70 2.05 2

Lactic acid 7.11 0.07

Deionized water 797.1 * Lead octoate dissolved in a hydrocarbon solvent.

2 20 45% of the total theoretical neutralization.

The polymeric polyol, the cross-linking agent prepared as described above, and the lead catalyst were placed in a large stainless steel beaker.

The ingredients were mixed until even. Lactic acid 25 was added with stirring and the reaction mixture was diluted with water to form an aqueous dispersion with a solids content of 14.8% (calculated 15%). Both untreated and zinc phosphate pretreated steel panels were cathodically electrolytically coated in the dispersion at about 90 to 120 volts for 90 seconds. The coated panels were baked at 180 ° C for 30 minutes to form solvent resistant coatings. The untreated steel panels withstood 100 double rubs with acetone and the panels treated with zinc phosphate 45 double rubs 35 with acetone. The number of double rubs with acetone is the number of rubs back and forth with an acetone saturated cloth using normal hand pressure to remove the cured coating.

Example II

The following example shows the preparation of a coating material containing a cross-linking agent containing 6 beta-alkoxy ester groups per molecule. The crosslinking agent was formed by reacting trimellitic anhydride with trimethylolpropane in a molar ratio of 3: 1 and esterifying with 6 moles of 2-butoxyethanol. The cross-linking agent was mixed with a polymeric polyol formed by condensing an epoxy resin (polyglycidyl ether of a polyphenol) with an amine as described below. The mixture was formulated into an organic solvent based coating material with and without lead octoate catalyst. Steel panels were coated with the material and the coated substrates heated to provide cured coatings.

Polymeric polyol

The polymeric polyol was formed by chain extension of an epoxy resin with polyester diol and reacting the chain-extended epoxy resin with a mixture of amines, namely methyl ethanolamine and a diketimine derivative of diethylene triamine.

Ingredient Weight Solid Equivalents Mill _ (g) (g) ___ EPON 8281 953.7 953.7 4,819 (epoxy) 2.41 25 PCP 02 002 320.6 320.6 1.2 (OH) 0.6

Xylene 80.0

Bisphenol A 274.7 274.7 2.41 (OH) 1.205

Benzyldimethylamine 5.9 2-ethoxyethanol 317.9

Methylisobutyl-diketimine of diethylene triamine 3 85.7 61.9 0.232 (amine) 0.232 35 N-methyl ethanol amine 69.5 69.5 0.926 (amine) 0.926 8201224 - 20 - * Polyglycidyl ether of bisphenol A with an epoxide equivalent of approx. 198, commercially available from Shell Chemical Company.

2

Polycaprolactone diol with a molecular weight of about 545.5 commercially available from Union Carbide Company.

3

Methyl isobutyl ketone solvent.

EPON 828, PCP 0200 and xylene were placed in a reaction vessel under a nitrogen blanket and heated at reflux for 30 minutes. The reaction mixture was cooled to 155 ° C, followed by addition of the bisphenol A. Benzyldimethylamine (1.9 g) was added and the reaction became warmer by the reaction that occurred. It was cooled to 130 ° C and the remaining 4.0 g of benzyldimethylamine was added. The reaction mixture was held at about 130 ° C for about 3 hours until the viscosity of the reaction mixture was as a 50% solution of solid resin in 2-ethoxyethanol N. The 2-ethoxyethanol, the methyl iso-butyldiketimine of diethylene triamine and the methyl ethanol amine were added and the reaction mixture was kept at about 110 ° C for about 20 hours, followed by cooling to room temperature. The reaction mixture had a solid content of about 80% by weight.

A coating material was prepared by mixing 27.9 g (23.2 g of solid) of the polymeric polyol and 12.3 g (11.5 g of solid) of the cross-linking agent. The mixture was diluted with 6.1 g of 2-ethoxyethanol to form a coating material with 75% solid. A portion of the coating material was set aside; a second portion (21.2 g) was mixed with 0.34 parts (0.26 g of solid) lead octoate. Both coatings were spread on untreated and zinc phosphate-treated steel panels and the wet films were cured at 177 ° C for 30 minutes. The coatings without the lead catalyst were removed by 23 double rubs with acetone (untreated). steel panels) and 15 double rubs with acetone (on zinc phosphate pretreated steel panels), while the 82 0 1 224 - 21 catalyst coating endured 175 double rubs with acetone on both substrates.

Example III

This example shows the preparation of a coating material containing a cross-linking agent with two β-amidester groups per molecule. The cross-linking agent was prepared by reacting N- (2-hydroxyethyl) isobutyramide with a condensate of trimethylolpropane and trimellitic anhydride. The cross-linking agent was mixed with a polymeric polyol made by condensing an epoxy resin (polyglycidyl ether of a polyphenol) with an amine. The mixture was formulated into a coating material with lead octoate catalyst and the material spread on steel panels to form coatings. The coatings were heated to provide. solvent resistant coatings.

N- (2-hydroxyethyl) isobutyramide N- (2-hydroxyethyl) isobutyramide was prepared as follows:

Ingredient Weight Solid Equivalents Mill _ (g) (g) ____ 20 Isobutyric acid 440.0 440.0 4,994 4,994 2-ethoxyethanol 495.0 450.0 5,500 5,500

Xylene 80.0

Para-toluene sulfonic acid 2.0 2.0 25 Ethanolamine 305.0 305.0 5,000 5,000

The isobutyric acid, the 2-ethoxyethanol, the xylene and the para-toluenesulfonic acid were placed in a reaction vessel under a nitrogen blanket and a Dean-Stark trap and heated to reflux. The reaction mixture was kept at the reflux temperature (165 ° C) until an acid value of 3.4 was obtained (123 g of aqueous phase collected). The reaction mixture was cooled to 100 ° C, the ethanolamine was added and the refluxing was continued for 9 hours. Then the reaction mixture was sprinkled until 447 g of distillate was obtained. The product formed a dark brown wet crystalline mass upon standing overnight. This 8201224-22 was recrystallized from ethanol and toluene to give 231.8 g (35.4% yield, which could be increased with subsequent recoveries) of off-white acicular crystals, mp 54-57 ° C.

5 Cross-linking agent

Ingredient Weight Solid Equivalents Mill __ (g) ω ...........

Trimellitic anhydride 131.9 131.9 2.061 0.687 10 Trimethylol propane 30.7 30.7 0.687 0.229 N- (2-hydroxyethyl) isobutryamide 180.0 180.0 1,374 1,374 15 Xylene 80.0

The trimellitic anhydride, the trimethylolpropane and the xylene were placed in a reaction vessel under a nitrogen blanket and a Dean-Stark trap and heated at reflux for 30 minutes. The reaction mixture was then cooled to 100 ° C, the amido alcohol was added and the refluxing was continued until an acid number of 3.2 was obtained. The product was found to be a solids content of 81.7%.

Polymeric Polyol The polymeric polyol was formed by chain extending an epoxy resin with a polyester diol and then reacting the chain-extended polyester with a mixture of amines, one of which included primary amine groups blocked with ketimine.

30 8201224 - 23 -

Component Weight Solid Equivalents Mill _ (g) (g) '__ EPON 8281 1686.2 1686.2 8.674 (epoxy) 4.337 PCP 02 002 588.4 588.4 2.160 (OH) 1.080 5 Xylene 144.0

Bisphenol A 494.5 494.5 4.337 (OH) 2.169

Benzyldimethylamine 10.6 2-ethoxyethanol 572.2 10 Methyl isobutyl diketimine of diethylene triamine 3 150.2 111.4 0.417 (amine) 0.417

Monoethanol- J5 amine 125.1 125.1 1,668 (amine) 1,668 1 Polyglycidyl ether of bisphenol A with an epoxide equivalent of about 198, commercially available from Shell Chemical Company, 2 20 Polycaprolactone diol with a molecular weight of about 545, commercially available at Union Carbide Company.

3

Solution in methyl isobutyl ketone.

EPON 828, PCP 0200 and xylene were placed in a reaction vessel and heated under a nitrogen blanket to reflux and refluxed for 30 minutes. The reaction mixture was cooled to 155 ° C followed by addition of the bisphenol A. Benzyldimethylamine (3.4 g) was added and the reaction mixture warmed by the exothermic reaction. It was cooled to 130 ° C followed by addition of the residual benzyl dimethylamine and the reaction mixture was kept at 130 ° C until it had a Gardner-Holdt viscosity (50% solid resin in 2-ethoxyethanol) of N. The 2-ethoxyethanol, the diketimine and the monoethanolamine were then added and the reaction mixture was stirred for about an hour. Held at 110 ° C to complete the reaction.

To 34.78 parts by weight of the polymeric polyol reaction mixture prepared as described above, 37.43 parts by weight of the cross-linking agent and 7.87 g of 2-ethoxyethanol were added. The mixture was heated and stirred to homogeneity to form a coating material. One portion of this mixture was set aside and the remaining portion (27.70 g) was mixed with 0.44 g of lead octoate (0.33 g of solid). The two coating materials were spread over untreated

steel panels pre-treated with zinc phosphate. The coated panels were then baked at 177 ° C for 30 minutes. The coatings obtained with the lead-free materials showed practically no acetone resistance (13 to 15 double rubs with acetone). However, the coatings obtained with materials containing the lead catalyst exhibited an acetone resistance of 75 double rubs with acetone on the untreated steel and 60 double rubs with acetone on the zinc phosphate-treated steel panels. Example IV

This example shows the preparation of a coating material containing a cross-linking agent with two δ-hydroxy ester groups per molecule. The cross-linking agent is formed by reacting adipic acid with 1,4-butanediol in a 1: 2 molar ratio. The cross-linking agent was mixed with a polymeric polyol formed by condensing an epoxy resin (polyglycidyl ether of a polyphenol) with an amine. The mixture was dissolved in organic solvent, lead octoate was added and the solution spread on steel panels and the coated panels heated to provide solvent resistant coatings. The details of the example are shown below.

Cross-linking agent.

The cross-linking agent was prepared from the following mixture of ingredients:

Component Weight Solid Equivalents Mill ......... --- (8) (8) - ...........

Adipic acid 146.0 146.0 2,000 1,000 1,4-butanediol 180.0 180.0 4,000 2,000 35 Xylene 50.0

Para-toluene- 1.0 1.0 sulfonic acid 8201224 - 25 -

The ingredients were placed in a reaction vessel under a nitrogen blanket. The reaction mixture was heated to reflux until an acid number of 1.3 was obtained. During the reaction, 48.1 g of the aqueous layer was collected in a Dean-Stark trap.

Polymeric polyol

The polymeric polyol was formed by reacting a polyglycidyl ether of bisphenol A with diethanolamine in an equivalent ratio of about 3: 1.

The adduct was then subjected to chain extension with a mixture of a primary and a secondary amine, namely 3-dime thylaminopropylamine, and the adduct of 1,6-hexamethylenediamine and the glycidyl ether of versatinic acid (CARDURA E).

Component Weight Solid Equivalents Mill 15 _ (g) (g) __ _ EPON 8291 2 921.0 890.6 4.537. “2.268

Bisphenol A 255.8 255.8 2,244 1,122

Xylene 30.0 20 2-ethoxyethanol 608.0

Diethanolamine 80.3 80.3 0.765 0.765

Dimethylamino-propylamine 38.0 38.0 0.744 0.372 1,6-hexamethy-25-lendiamine-glycidyl ester of versatin acid adduct (mol ratio 30 1: 2) 2 252.9 244.5 0.745 0.372 8201224

Polyglycidyl ether of bisphenol A with an epoxide equivalent of about 196, commercially available from Shell Chemical Company.

2 Adduct formed by dropwise addition of the glycidyl ester of versatin acid to the 3,6-hexamethylene diamine at a temperature of 60 ° C. After completion of the addition, the mixture was heated to 100 ° C and held for 2 hours. The glycidyl ester of versatin acid is commercially available from Shell Chemical Company as CARDURA E.

- 26 -

Base coating material is from organic solvent Component Weight (g)

Polymeric polyol 36.18

Cross-linking agent 11.04 5 Lead octoate (75.9% solid in hydrocarbon solvent) 0.67 2-ethoxyethyl acetate 8.79

The ingredients were mixed together and heated in a 59 ml glass jar to obtain a clear yellow resin. The coating material was spread on an untreated steel panel and on a zinc phosphate pretreated steel panel. The coated panels were cured at 180 ° C for about 30 minutes. The cured coatings showed moderate to high gloss and had a thickness of 40.6 to 55.9 µm. The coating on the untreated steel was removed after 125 double rubs with acetone. The coated steel panel pretreated with zinc phosphate withstood 132 double rubs with acetone.

Example V

This example shows the preparation of a coating material containing a cross-linking agent which is a γ-hydroxy polyester formed by reacting adipic acid with trimethylolpropane in a molar ratio of 1: 2. The cross-linking agent was mixed with a polymeric polyol formed by condensing a polyglycidyl ether of a polyphenol with an amine. The mixture was combined with lead octoate catalyst to form a coating material. Steel panels are coated with the material and the coated substrates are heated to provide solvent resistant coatings. Also, the mixture was dispersed in water using acid, and steel panels were cathodically electrolytically coated with the dispersion. The details of the example are as follows:

Cross-linking agent 35 The cross-linking agent was prepared from the following mixture of ingredients: 82 0 1 224 - 27 -

Ingredient Weight Solid Equivalents Mill _____ (g) --- (8) ......... ..

Adipic Acid 146.0 146.0 2,000 1,000

Trimethylol propane 268.0 268.0 6,000 2,000 5 Xylene 40.0

Para-toluene sulfonic acid 1.0 1.0

The ingredients are placed in a reaction vessel under a nitrogen blanket and heated to reflux. The reaction mixture was kept at reflux temperature until an acid value of about 1.7 was obtained. Polymeric polyol

The polymeric polyol was formed by chain extension of a polyglycidyl ether of bisphenol A with a polyester diol. The adduct was then reacted with a mixture of amines, namely monoethanolamine and the methyl isobutyldiketimine of ethylene triamine.

Component Weight Solid Equivalents Mill _ (g) (g) ___ 20 ΕΡ0Ν 8281 953.7 953.7 4,819 (epoxy) 2.41 PCP 02 002 320.6 320.6 1.2 (OH) 0.6

Xylene 80.0

Bisphenol A 274.7 274.7 2.41 (OH) 1.205

Benzyldimethyl-5.9 amine 2-ethoxyethano1 317.9

Methyl isobutyl diketimine of diethylenetriamine 3 85.7 61.9 0.232 (amine) 0.232

Monoethanolamine 69.5 69.5 0.926 (amine) 0.926 1 Polyglycidyl ether of bisphenol A with an epoxide equivalent of ca 198, commercially available from Shell

Chemical Company.

2

Polycaprolactone diol with a molecular weight of about 545, commercially available from Union Carbide Company.

3

Solution in methyl isobutyl ketone. ...........

8201224 4 - 28 -

EPON 828, PGP 0200 and xylene were placed in a reaction vessel and refluxed under a nitrogen blanket and held for 30 minutes. The reaction mixture was cooled to 155 ° C, followed by addition of the bisphenol A. Benzyldimethylamine (1.9 g) was added and the reaction mixture became warmer by the exothermic reaction. The reaction mixture was cooled to 130 ° C, followed by the addition of the residual benzyldimethylamine and the reaction mixture was kept at 130 ° G until it reached a reduced Gardner-Holdt viscosity (50% solid resin in 2-ethoxyethanol) of N + . The 2-ethoxyethanol, the diethanimine and the monoethanolamine were then added and the reaction mixture was kept at 108 to 112 ° C for about 1 hour to complete the reaction.

15 to 39.55 g (31.64 g of solid) of the

polymeric polyol, prepared as described immediately above, 17.17 g (15.60 g of solid) of the crosslinking agent, prepared as described above, was added. To a sample of 31.78 g (26.5 g of solid) of the mixture, 0.50 g of 20 of the lead octoate solution as described in Example IV

added. The material was streaked over untreated and zinc phosphate-treated steel panels and the panels were heated at 182 ° C for 30 minutes. The cured films were glossy with a textured surface. The coating on the untreated steel was removed after 150 double rubs with acetone, while the coating on the steel pretreated with zinc phosphate survived 107 double rubs with acetone.

When comparable coatings were made without the use of the lead catalyst, the cured coatings were removed by about 10 to 23 double rubs with acetone.

Aqueous dispersion

An aqueous dispersion was prepared by mixing the following ingredients together: 8201224 - 29 -

Components Weight (g) Solid (g) Equiyalents

Polymeric polyol 122.4 100.5 0.098

Cross-linking agent 52.4 49.5

Lead octoate (catalyst) 1 2.75 2.09

Surfactant ^ 3.75

Lactic acid 3.49 0.034

Deionized water 829.1 10 1 Lead octoate in a hydrocarbon solvent.

2

Surfactant prepared by mixing 120 g of alkyl imidazoline, commercially available from Geigy Industrial Chemicals as GEIGY AMINE C, 120 parts of an acetylenic alcohol, commercially available from

Air Products and Chemicals Inc. as SURFYNOL 104, 120 wt. 2-butoxyethanol and 221 parts of deionized water and 19 parts of glacial acetic acid.

The polymeric polyol and the cross-linking agent were mixed together with heating in a steel beaker. The lead octoate was mixed in, followed by the addition of the lactic acid. The reaction mixture was then diluted with the deionized water to form a dispersion with 14.6 wt% solid resin.

Panels of untreated steel and of zinc phosphate-pretreated steel are electrocoated electrolytically in the dispersion at 200 volts for 90 seconds. The coated substrates were then heated to 204 ° C for 30 minutes to form cured coatings. The coating 30 on the untreated steel withstood 150 double rubs

with acetone, while the coating on the steel treated with zinc phosphate withstood 140 double rubs with acetone. Example VI

The following example was similar to Example V, except that the cross-linking agent was introduced into the resin preparation.

8201224 - 30 -

Polymeric polyol containing cross-linking agent

The polymeric polyol was prepared as described generally in Example V with the exception that the cross-linking agent was included in the preparation. The starting materials for preparing the polymeric polyol were as follows:

Ingredient Weight Solid Equivalents Mill _ _Jg) __ (g) ____ EPON 828 702.6 702.6 3.614 (epoxy) 1.807 30 PCP 0200 244.0 244.0 0.90 (OH) 0.45

Xylene 60.0

Bisphenol A 206.1 206.1 1.808 (OH) 0.904

Benzyldimethylamine 4.8 15 Crosslinker 652.9 616.3 2-butoxyethanol 373.4

Methyl isobutyl diketimine of diethylene triamine 59.7 46.5 0.174 (amine) 0.174

Monoethanolamine 52.1 52.1 0.694 (amine) 0.694 1 82 0 1 224

Cross-linking agent: the adipic acid / trimethylolpropane-25 condensate prepared as generally described in Example V.

EPON 828, PCP 0200 and xylene were placed in a reaction vessel under a nitrogen blanket and heated to reflux and held for 30 minutes. The reaction mixture was cooled to 155 ° C and the bis-30 phenol A added. The temperature dropped to 128 ° C and the reaction mixture was kept at this temperature for about 20 minutes. Benzyldimethylamine (1.5 g) was added and the reaction mixture rose in temperature by the exothermic reaction to 170 ° C. The reaction mixture was cooled to 130 ° C, followed by the addition of 3.3 g of the benzyl dimethylamine. The reaction mixture was kept at a temperature of about 130 ° C until a Gardner-Holdt viscosity (50% resin solid in 2-ethoxyethanol) of P was obtained.

- 31 -

The cross-linking agent, dissolved in the 2-butoxyethanol, was then added, the temperature of the reaction mixture falling to 85 ° C. The reaction mixture was heated to 110 ° C and held there for about an hour to complete the reaction. The reaction mixture had a solids content of 82.7%.

Aqueous dispersion

The resinous reaction product prepared as described immediately above was dispersed in aqueous medium as follows:

Component Weight Solid Equivalents ___ - (g) (g) ...... -

Polymeric polyol containing cross-linking agent 15 prepared as described immediately above 965.0 800.0 0.521 (amine)

Surfactant of Ex. V 20.0 20 Lactic acid 18.65 0.182

Deionized water 1282.1

The polymeric polyol and the surfactant are mixed together in a stainless steel beaker, followed by the addition of the lactic acid with mixing. The reaction mixture was then diluted with deionized water to form an aqueous dispersion with 34.2% solid.

A cationic electrolytic deposition paint was prepared from the following mixture of ingredients: 30 Ingredient Weight (g)

Deionized water 1704.2

Lead acetate 6.9

Aqueous dispersion of polymeric polyol 1703.2

Pigment paste1 385.7 35

The pigment paste contained 32.9% by weight pigment, 13.2% by weight resinous support and 1.1% by weight dibutyltin oxide. The pigment paste was prepared as described generally in Example III

8201224. t-32 - of U.S. Pat. No. 4,007,154.

The deionized water was placed in a mixing vessel, followed by the addition of the lead acetate. The polymeric polyol (34.2% solid) was then stirred in, followed by the addition of the pigment paste with stirring. The final paint had a total solids content of 20%, a pH of 6.25, a pigment to binder ratio of 0.2: 1. After two days of stirring, the pH was still 6.25 and the specific conductivity of the dispersion was 10 1250, measured at 25 ° C. Steel panels pretreated with zinc phosphate were electrolytically coated electrolytically in the dispersion at 120 volts for 20 minutes at a bath temperature of 21 ° C. The coatings were cured at 177 ° C for 30 minutes. The coatings were removed after 35 double rubs with acetone and evaluated for corrosion resistance determined by scratching the cured coated panel with an "X" and exposing the scratched panel to a salt spray mist according to ASTM D-117 for 14 days. The panels were removed from the chamber, dried, and the scratch mark covered with masking tape, the tape subtracted at an angle of 45 °, and the detachment measured from the scratch mark. The release is the rusted, darkened area of the panel where the coating has lifted from the panel surface. The scratch release was 1.6 mm. When untreated steel panels were cathodically electrolytically coated in the bath at 80 volts for 2 minutes and the coatings cured and exposed for 14 days to salt spray corrosion as described above, the scratch release was 4.8 mm.

Example VII

This example relates to the preparation of a coating material containing the cross-linking agent of Example IV and the polymeric polyol of Example V. The coating material is formulated with lead catalyst and steel panels were coated with the material and the coated substrates were heated to provide solvent resistant coatings. The specific coating composition is shown below:

Organic Solvent Based Coating Material Component Weight (g) Solid (g) 5 Polymer Polyol 11.64 9.67

Crosslinking agent 5.28 4.77 2-ethoxyethanol 7.15

Lead octoate 0.24 0.18

The ingredients were mixed and heated to form a homogeneous material which was then spread on untreated and zinc phosphate pretreated steel panels. The coated panels were cured at 204 ° C for 30 minutes to provide cured coatings which showed 150 double rubs with ace tons.

15 coatings composed without lead catalyst and baked at 204 ° C for 30 minutes were removed by only 23 double rubs with acetone on untreated steel and 16 double rubs with acetone on zinc phosphate pretreated steel.

20 Example VIII

This example shows the preparation of a coating material with a cross-linking agent containing three β-ester-ester groups per molecule. The cross-linking agent was formed by reacting trimellitic anhydride with ethylene glycol and isobutyric acid in a molar ratio of 1: 3: 3. The cross-linking agent is then mixed with a polymeric polyol formed by condensing an epoxy resin (polyglycidyl ether of a polyphenol) with an amine. The mixture was combined with lead octoate catalyst and dispersed in water using acid. Steel panels were cathodically electrolytically coated with the dispersion and the coatings heated to provide solvent resistant coatings.

Also, the mixture was dissolved in organic solvent, the solution streaked on steel panels, and the coated panels heated to provide solvent resistant coatings.

The details of the example are as follows: 8201224 - 34 -

Yerkinding agent

The cross-linking agent was prepared from the following mixture of ingredients:

Ingredient Weight Solid Equivalent Mill 5 ____ (g) (g) _____ _

Trimellitic anhydride 192.0 192.0 3,000 1,000

Ethylene glycol 217.2 186.2 7,000 3,500

Isobutyric acid 264.3 264.3 3,000 3,000 Para-toluene sulfonic acid 1.4 1.4

Toluene 80.0

The above ingredients were placed in a reaction vessel under a nitrogen blanket and heated to reflux. Reflux was continued until an acid value of 4.1 was obtained. The hydroxyl value of the product was 2.9 (apart from the acid value) and the water content was 0.03%.

Pelyaere pelyol 20 The polymeric polyol was formed by reacting a polyglycidyl ether of bisphenol A with diethanolamine in an equivalent ratio of about 3: 1. The adduct was then subjected to chain extension with a mixture of a primary and a secondary amine, namely, 3-dimethyl laminopropylamine, and the adduct of 1,6-hexamethylene diamine and the glycidyl ester of versatin acid (CARDURA E).

30 8201224 - 35 -

Component Weight Solid Equivalents Helen _ (g) ω ............ ···· EPOR 8291 921.0 890.6 4.537> (2> 2M) 2> 268> (1, J47 ) 5 Bisphenol A 255.8 255.8 2,244 1,122

Xylene 30.0

Diethanol- "amine 80.3 80.3 0.765 0.765 3-dimethylamino-propylamine 38.0 38.0 0.745 0.372

Adduct of 1,6-hexamethylene glycidyl ester and versa-. 256.8 253.4 0.745 0.372 15 tinic acid (mol: ratio 1: 2j 2-butoxyethanol 614.2 ^ Polyglycidyl ether of bisphenol A with an epoxide equivalent of about 193-203, commercially available from Shell Chemical

Company.

2

Adduct formed by adding the glycidyl ester of versatin acid dropwise to the 1,6-hexamethyl-diamine at a temperature of 60 ° C. After completion of the addition, the mixture was heated to 100 ° C and held for 2 hours. The glycidyl ester of versatin acid is commercially available from Shell Chemical Company as CARDURA E.

Aqueous dispersion An aqueous dispersion of the polymeric polyol and the cross-linking agent, prepared as described above, was prepared as follows: 35 8201224 - 36 -

Component Weight Solid Equivalents _ (e) '(a) · _____

Polymeric polyol 146.2 109.4 0.162 (amine)

Cross-linking agent 52.7 40.7 5 Lead octoate solution 2.75 2.09 2

Lactic acid 7.48 0.073

Deionized water 805.5 10 1 75.9% solid lead octoate dissolved in hydrocarbon solvent 2 45% of the total theoretical neutralization.

The polymeric polyol, the cross-linking agent and the lead were placed in a stainless steel beaker and mixed together. The lactic acid was added and mixed into the mixture, followed by dilution with the deionized water. The aqueous dispersion had a solids content of 14.3%.

Untreated and zinc phosphate pre-treated steel panels were cathodically electrolytically coated in the dispersion at 100 volts for 90 seconds. The coatings were then cured at 180 ° C for 30 minutes to form films with a thickness of about 17.8 to 22.9 µm. The untreated steel panels withstood between 56 and 70 double rubs with acetone and the zinc panels pretreated with zinc phosphate between 38 and 65 double rubs with acetone.

Organic Solvent Based Coating Material 30 Component Weight (g) Solid (g)

Polymeric polyol 36.39 27.19

Cross-linking agent 18.12 13.46 2-ethoxyethanol 11.82

The above ingredients were placed in a 59 ml glass jar and 25.19 g were transferred (after heating and mixing to homogeneity) to a second 59 ml glass jar. After the transfer 0.37 g 8201224 Λ - 38 -

Component Weight Solid Equivalents Mill _ ω (a) ..........

Trimellitic anhydride 80.1 80.1 1,252 0.417 5 1,3-propanediol 100.0 95.3 2,628 1,314

Isobutyric acid 110.3 110.3 1,252 1,252

Para-toluene sulfonic acid 1.0 1.0

Toluene 50.0-10 The ingredients were placed in a reaction vessel and heated under reflux under a nitrogen blanket until an acid number of 6.3 was obtained.

Aqueous dispersion

An aqueous dispersion of the crosslinking agent prepared as described above and the polymeric polyol of Example VIII and lead catalyst was prepared as follows:

Ingredient Weight Solid Equivalents _ (g) (g) _ 20 Polymer Polyol of Ex.VIII 146.2 109.4 0.162 (amine)

Crosslinking agent 68.1 40.7

Lead octoate 2.75 2.09

Lactic acid 7.48 0.073 ^ 25 Deionized water 790.1 * 45% of the total theoretical neutralization.

The polymeric polyol and the cross-linking agent were placed in a stainless steel beaker, followed by the addition of the lead octoate. The ingredients were mixed together followed by the addition of the lactic acid.

The mixture was then diluted with deionized water to form a 14.4% solids dispersion.

Untreated and zinc phosphate pretreated steel panels were cathodically electrolytically coated in the dispersion at 100 volts for 90 seconds.

8201224 - 37 - Lead Actoate (75.9% solid in a hydrocarbon solvent) added to form the coating material.

The coating material was spread on an unbreated steel panel and on a zinc panel pretreated with zinc 5 phosphate. The coated panels were cured at 177 ° C for 30 minutes. The cured coating had a thickness of about 45.7 to 71.1 µm and withstood 150 double rubs with acetone (untreated steel) and 175 double rubs with acetone (zinc phosphate pretreated steel).

Coating materials composed without lead, applied and cured as described above were already removed after 25 double rubs with acetone in the case of untreated steel and after 37 parts rubs with acetone in the case of zinc phosphate-pretreated steel.

Example IX

This example shows the preparation of a coating material containing a cross-linking agent with three γ-ester-ester groups per molecule. The cross-linking agent was formed by reacting trimellitic anhydride with 1,3-propanediol and isobutyric acid in a molar ratio of 1: 3: 3. The cross-linking agent was mixed with a polymeric polyol as described in Example VIII, combined with lead octoate catalyst and dispersed in water using acid. Steel panels were cathodically electrolytically coated with the dispersion and the topcoat baked to provide solvent resistant coatings. Also, the mixture was dissolved in organic solvent, the solution streaked on steel panels and the coated panels heated to provide solvent resistant coatings.

30 Linkage blacksmith 1

The cross-linking agent was prepared from the following mixture of ingredients: 8201224 - 39 -

The coated panels were baked at 180 ° C for 30 minutes to form coatings having a thickness of about 22.9 to 27.9 µm. The untreated steel panels withstood 39 to 41 double rubs per acetone, while the coatings on the panels treated with zinc phosphate withstood 16 to 21 double rubs with acetone.

Organic Solvent Based Coating Material Component Weight (g) Solid (g)

Polymeric polyol 34.43 27.10 10 Crosslinking agent 22.36 13.35

The above ingredients were placed in a 59 ml glass jar and heated and mixed until uniform. The contents were transferred to a second 59 ml glass jar and combined with 0.35 g of lead octoate 15 (75% solid) to form the coating material.

The coating material was spread on steel panels and cured at an elevated temperature. The results are shown below:

Panel Hardening Schedule Coating Thickness Acetone- 2q (° C / Minutes) (µm) Resistance

Untreated steel 177/30 48 95-96

Steel treated with zinc phosphate 177/30 81 84

Untreated steel 204/30 51 137-175

Steel pretreated with zinc phosphate 204/30 71-84> 175

Lead-free coating materials, deposited and cured as described above have the following properties: 8201224 - 40 -

Panel Curing Schedule Coating Thickness Acetone Resistance (C / Minutes) ... (yam) ... Resistance

Untreated steel 177/30 43 30 5 Steel pretreated with zinc phosphate 177/30 58 32

Untreated steel 204/30 56 89 10 Steel pre-treated with zinc phosphate 204/30 102-107 91

Example X.

This example shows the preparation of a coating material containing a cross-linking agent with three γ-ester-ester groups per molecule as described in Example IX. The cross-linking agent was mixed with a polymeric polyol as described below; the mixture was dissolved in organic solvent and combined with lead octoate catalyst. The coating material was streaked on steel panels and heated to provide solvent resistant coatings.

Polymeric polyol. The polymeric polyol was formed by chain extension of a polyglycidyl ether of bisphenol A with a polyester diol. The adduct was then reacted with a mixture of amines, namely monoethanolamines and the methyl isobutyldiketimine of diethylene triamine.

30 'Component Weight Solid Equivalents Mill _ _Jg) __ (g) ___ EPON 8281 953.7 953.7 4,819 (epoxy) 2.41 PCP 02 002 320.6 320.6 1.2 (OH) 0.6

Xylene 80.0 35 Bisphenol A 274.7 274.7 2.41 (OH) 1.205

Benzyl dimethyl amine 5.9 2-ethoxyethanol 317.9

Methylisobutyl- 85.7 61.9 0.232 (amine) 0.232 diketimine of diethylene triamine ^

Monoethanolamine 69.5 69.5 0.926 (amine) 0.926 8201224 -41-- * Polyglycidyl ether of bisphenol A with an epoxide equivalent of about 398, commercially available from Shell Chemical Company.

2

Polycaprolactone diol, with a molecular weight of about 545.5, commercially available from Union Carbide Company.

3,

Solution in methyl isobutyl ketone.

The EPON 828, the PCP 0200 and the xylene were placed in a reaction vessel and heated to reflux under a nitrogen blanket 10 and held there for 30 minutes. The reaction mixture was cooled to 155 ° C, followed by the addition of the bisphenol A. Benzyldimethylamine (3.9 g) was added and the reaction warmed by the heat of reaction being released. The reaction mixture was cooled to 35 ° C to 330 ° C, followed by the addition of the residual benzyldimethylamine and the reaction mixture was kept at 130 ° C until it had a reduced Gardner-Holdt viscosity (50% solid resin in 2-ethoxyethanol) of N reached. The 2-ethoxyethanol, the diketimine and the monoethanolamine were then added and the reaction mixture was kept at 308 to 312 ° C for about an hour to complete the reaction.

24.23 g (20.14 g of solid) of the polymeric polyol prepared as described immediately above, 16.69 g (9.96 g of solid) of the cross-linking agent were prepared as described in Examples IX and 5, 6 g of 2-ethoxyethanol are added. To a 20.03 g (12.94 g solid) sample of the mixture was added 0.23 g of the lead octoate solution as described in Example VIII. The material was streaked over untreated and zinc phosphate pre-treated steel panels and the panels were heated to 177 ° C for 30 minutes. The cured coatings over the untreated steel were 41 µm thick and weathered. 350 double rubs with acetone, while the coatings on the zinc phosphate-treated steel were 73 µm thick and withstood 75 double rubs with acetone.

8201224 - 42 -

When comparable coatings were made without the use of the lead catalyst, the cured coatings withstood only about J3 to 25 double rubs with acetone.

82 0 1 224

Claims (31)

Heat-curable coating material containing a hydroxyl-containing polymer, a polyester curing agent and a transesterification catalyst, characterized in that the polyester cross-linking agent has at least two substituted ester groups per molecule, the substituents being selected from the class consisting of: ( A) β-alkoxy groups, (B) β-ester groups, JO (C) β-amido groups, (D) γ-hydroxy groups, (E) γ-ester groups, (F) d-hydroxy groups and mixtures thereof. Coating material according to claim 1, characterized in that the hydroxyl-containing polymer also contains cationic groups and the coating material is dispersed in an aqueous medium. Coating material according to claim 1 or 2, characterized in that the hydroxyl-containing poly has more a hydroxyl value within the range of 180 to 300. Coating material according to claim 1 or 2, characterized in that the substituents are β-alkoxy groups: 25. Coating material according to claim 4, characterized in that the polyester cross-linking agent is prepared by reacting a polycarboxylic acid or its functional equivalent with one or more 1,2-polyol monoethers. Material according to claim 5, characterized in that the polycarboxylic acid or its functional equivalent is selected from the class consisting of trimellellic anhydride, adipic acid and phthalic anhydride. Material according to claim 5, characterized in that the 1,2-polyol monoether is an alkyl ether of ethylene or propylene glycol in which the alkyl group contains 1 to 6 carbon atoms. Material according to claim 1 or 2, 5, characterized in that the substituents are γ and / or 5-hydroxy groups. Material according to claim 8, characterized in that the substituents are γ-hydroxy groups. 10. The material according to claim 9, characterized in that the cross-linking agent is formed by reacting a polycarboxylic acid or a functional equivalent thereof with a 1,3-polyol. 11. A material according to claim 10, characterized in that the polycarboxylic acid or its functional equivalent is selected from the class consisting of trellellitic anhydride, adipic acid and phthalic anhydride. The material according to claim 10, characterized in that the 1,3-polyol is selected from the class consisting of trimethylolethane, trimethylolpropane, 1,3-butane-20 diol, 1,3-propanediol and mixtures thereof. Material according to claim 8, characterized in that the substituents are δ-hydroxy groups. 14. A material according to claim 13, characterized in that the cross-linking agent is formed by reacting a polycarboxylic acid or a functional equivalent thereof with a 1,4-polyol. Material according to claim 14, characterized in that the 1,4-polyol is 1,4-butanediol. Material according to claim 1 or 2, 30 ', characterized in that the substituents are 6 and / or γ-ester groups. Material according to claim 16, characterized in that the substituents are β-ester groups. Material according to claim 17, 35, characterized in that the cross-linking agent is obtained by ...... reacting the following starting materials with each other: 8201224 t - 45 - (A) a polycarboxylic acid or a functional equivalent thereof ; (B) a 1,2-polyol or a 1,2-epoxy compound and 5 (C) a monocarboxylic acid. A material according to claim 18, having the boulder mark that the 1,2-polyol is selected from the class consisting of ethylene glycol, propylene glycol and 1,2-butane diol. Material according to claim 18, characterized in that the 1,2-epoxy compound is selected from the class consisting of 1,2-epoxybutane, the glycidyl ester of a saturated aliphatic monocarboxylic acid containing 9 to 12 carbon atoms, ethylene oxide, propylene oxide and n-butylglycidyl ether. Material according to claim 16, characterized in that the substituents are γ-ester groups. The material according to claim 21, characterized in that the crosslinking agent is obtained by reacting the following starting materials: (A) a polycarboxylic acid or a functional equivalent thereof; (B) a 1,3-polyol and (C) a monocarboxylic acid. The material according to claim 22, characterized in that the 1,3-polyol is selected from the class consisting of 1,3-propanediol, trimethylolpropane, trimethylolethane and 1,3-butanediol. 24. A material according to claim 18 or 22, characterized in that the polycarboxylic acid or its functional equivalent is selected from the class consisting of trimellitic anhydride, adipic acid and phthalic acid. 25. Material according to claim 18 or 22, characterized in that the monocarboxylic acid is selected from the class consisting of isobutyric acid, acetic acid, propionic acid and benzoic acid. 8201224 * - 46 - \ 5 / Coating material according to claim 1 or 2, characterized in that the substituents are β-amido groups. 27. A material according to claim 26, characterized in that the cross-linking agent is formed by reacting a polycarboxylic acid or a functional equivalent thereof with a β'-hydroxyalkylamide. 28. A material according to claim 27, characterized in that the β-hydroxyalkylamide satisfies formula 2 of the formula sheet, wherein R 1 and R 1 are hydrogen and R 1, R 2 and R 1 are selected from the class consisting of alkyl, cycloalkyl, aryl, alkaryl, including substituted groups in which the substituents will not adversely affect the esterification reaction with the polycarboxylic acid or its functional equivalent and will not adversely affect the transesterification curing reaction or the desirable properties of the coating material. 29. Material according to condusion 27, characterized in that the polycarboxylic acid or its functional equivalent is selected from the class consisting of trimellitic anhydride, phthalic anhydride and adipic acid. 30. Coating material substantially as described in the description and / or the examples. 31. Articles coated with a coating material according to any one of the preceding claims, in a cured state. 2012 '\ 8201224