CA1066841A - Coating compositions - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
The invention relates to polymeric coating compositions which are as least partially soluble in water.
Polyesters, polyesterimides, polyester hydantoins and polyester urethanes are prepared with free carboxyl or carboxylic acid groups. he least part of the carboxylic acid groups are neutralized with amine containing material producing a coating composition which is at least partially soluble in water. The coating compositions are particularly useful as electric insula-ting coatings or wire enamels which are readily coated on a metallic or other substrate and when cured form coatings having good electrical and physical properties.

Description

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This invention relates to polymeric coatlng compositions. More particularly, it relates to such coating compositions which are at least partially soluble in water.
Resinous coating compositions in the form of varnishes and enamels in which for ease of application the polymer is dissolved in compatible solvents are well known. Such resino~ls compositions include polyesters, polyesterimides, polyesteramides, polyesteramideimides, polyesterhydantoins, and polyester urethanes, among others. Normally, the solvents used for such materials are organic and include such materials as cresols or cresylic acid, phenol, xylene, N-methylpyrrolidone, d i n~e~
A dimethylformamide,~ et~y~ sulfoxide, dimethylacetamide, and the like which, when driven off from the curing coating composition tend to pollute the atmosphere. Such solvents generally are also toxic, flammable, and some cause chemical burns. It would be advantageous from the point of view of complying with ever more strict pollution restrictions, as well as from the point of view of safety, to provide coating compositions of the above types which are at least partially or wholly soluble in water, and it is a primary object of the present invention to provide such coating materials.
~riefly, there are provided according to the present invention polyester compositions or imide, amide, hydantoin and urethane variations thereof which are at least partially soluble in water. ~ -The basic polyester compositions of the present invention are widely described in the literature and in patents such as 2,9369296 - Fox et al - issued Nay 10, 1960, 3,249,578 - Meyer~ et al - issued May 3, 1966, 3,297,785 - George9 et al - issued January 10, 1967, and 3,312,645 George, et al - issued April 4, 1967, among others.
In the preparation of the present polyester compositions, dibasic, tribasic or tetrabasic or polybasic acid material ancl polyhydric ~ ~
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alcohol having at least three hydroxyl groups and diol are con~bined in ' ~

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varying proportions. For ~g ~ , the equivalent ratio of diol to poly-hydric alcohol typically ranges from about 1 to O.S up to about 1 to 1.50, and preferably this ratio is 1 to 0.75. llhe equi~alent proportioc of the acid to the polyhydric alcohol ranges from about 1 to 0.75 up to about 1 to 1.50, and preferably is 1 to 1.05.
In preparing the polyesterimide variation of the present inven tion, up to about 50 equivalent percent of the total acid constituent can be replaced by other carboxylic acid material containing imide groups such as those produced by the reaction of tricarboxylic acid material with polyamine in a 2 to 1 equivalent proportion.
Polyester hydantoin materials or polyesters containing hydantoin groups can be prepared by substituting for up to about 95 equivalent percent of the hydroxyl group containing material, hydantoin group contai-ning material having two or more hydroxyl groups. Likewise, hydantoin ..... .. .
group containing material having two or more acid or carboxylic groups can be substituted for up to about 95 equivalent percent of the dibasic acid material.
In preparing the polyesteramide variation of the present invention, typically up to about 50 equivalent percent of the alcohol constituent can be replaced by polyamine to form amide group containing materials.
In preparing polyester urethanes, up to about 40 equivalent percent of the acid can be replaced by polyisocyanate.
It will be realized that the above types of polyesters can be admixed or they can be combined in various proportions as desired by utilizing the desired proportions of the various modifying group containing matPrials . ' ' ' .
The dibasic acids useful in the present connection include oxalic, maleic, succinic, glutaric, adipic, pimelic, suberic, azelaic, sebacic and dodecanedioic acids as well as unsaturated materials including maleic and fumaric materials, among others. Such acids can be expressed ~ "

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by the formula HOOC-R'-COOH
where Rt is a divalent saturated or unsaturated aliphatic group or one containing a carbon-to-carbon double bond snd having from about one to forty carbon ato~s, while the anhydrides can be expressed by D

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Also included are aromatic anhydrides or diacids or tetracids which are well known to those skilled in the art including, among others, isophthalic acid, terephthalic acid, mixtures thereof and their lower dialkyl esters, pyromellitic dianhydrides, benzophenonetetracarboxylic dianhydride and tetracarboxylicbutane dianhydride as well as heterocyclic dibasic acids such as di(2-carboxyethyl)dimethylhydantoin. The unsaturated materials are also useful for end-capping or as terminal end groups as well ns in the preparation of the intermediate material.
Among the polyhydric alcohols having three or more hydroxyl groups are glycerine, 1,1,1-trimethylolethane, sorbitol, mannitol, , diglycerol, trimethylolpropane, dipentaerythritol, tris(2-hydroxyethyl) isocyanurate, etc.
It will be realized also that in lieu of preparing the polyester variants by adding the modified ingredients to the original reaction mlxture, such variants can be prepared by first preparing the polyester :: .
~ ~ itself and;then introducing in well known manner imide or other desired ::~ :
group~containing materials as is shown, for example, in the case of polyesterimides in U.S. patent 3,697,471 - Schmidt, et al - is~sued October 10,~1972.

30 ~ Any of a number of diols can be used including ethylene glycol~

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8lN-485 neopentyl glycol, butane diol, pentane diol, and the like. Others will occur to those skilled in the art.
Among the tricarboxylic acid materials which are useful are trimellitic anhydride; 2,6,7-naphthalene tricarboxylic anhydride; 3,3',4-diphenyl tricarboxylic anhydride; 3,3',4-benzophenone tricarboxylic anthy-dride; 1,3,4-cyclopentane tetracarboxylic anhydride; 2,2',3-diphenyl tricarboxylic anhydride; diphenyl sulfone 3,3',4--tricarboxylic anhydride;
diphenyl isopropylidene 3,3',4-tricarboxylic anhydride; 3,4,10-terylene tricarboxylic anhydride; 3,4-dicarboxyphenyl 3-carboxyphenyl ether anhy- ;
dride; ethylene tricarboxylic anhydride; 1,2,5-naphthalene tricarboxylic anhydride; etc. The tricarboxylic acid materials can be characterized by the following formula:
..
O /C~ .
EO-~-R ~.
\ / '' '-' O

where R is a trivalent organic radical.
The polyamines useful in connection with the present invention may also be expressed by the formula n where R~ is a member selected from the class consisting of organic -radicals of at least two carbon atoms (both halogenated and unhalogenated) including but not limited to, e.g., hydrocarbon radicals of up to 40 carbon atoms, and groups consisting of at least two aryl residues attached to each~other through the medium~of a member selected from the class con- : -sisting of an alkylene radical of from 1 to 10 carbon atoms, -S-, -S02-, I~ and -O-, e~c., and n is at least 2. ~;

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Among the speci:Eic amines useful for the present inventionJ
ei~her alone or in admixture, are the followin~:
p-xylene diamine bixt4-amino-cyclohexyl)methane hexamethylene diamine heptamethylene diamine octamethylene diamine nonamethylene diamine decamethylene diamine 3-methyl-heptamethylene diamine 4,4'-dimethylheptamethylene diamine

2,11-diamino-dodecane 1,2-bix-(3-amlno-propoxy)ethane 2,2-dimethyl propylene diamine

3-methoxy-hexamethylene diamine 2,5-dimethylheptamethylene diamine 5-methylnonamethylene diamine 1,4-diamino-cyclo-hexane ~
1,12-diamino-octadecane : :
2,5-diamino-1,3,4-oxadiazole H2N(CH2)30(CH~)2O~cH2)3NH2 H2N(CH2)3S(CH2)3NH2 H2N (CH2) 3~ (C~3) (CH2) 3~H2 ; ~ meta-phenylene diamine para-phenylene diamine

4,4'-diamino-diphenyl propane :
4,41-diamino-diphenyl methane ::~:
ben~idine 4,4'-diamino diphenyl sulfide 4,4'-diamino-diphenyl sulfone ':

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81N-4~,5 3,3'-diamino-diphenyl sulfone 4,4'-diamino-diphenyl ether 2,6-diamino-pyridine bist4-amino-phenyl)diethyl silane bis~4-amino-phenyl)diphenyl silane bis(4-amino-phenyl)phosphine oxide 4,4'-diaminobenzophenone bis(4-amino-phenyl)-N-methylamine bis(4-aminobutyl)tetramethyldisiloxane 1~5-diaminonaphthalene 3,3'-dimethyl-4,4'-diamino-biphenyl 3,3'-dimethoxy benzidine 2,4-bis(beta-amino-t-butyl)toluene toluene diamine bis(para-beta-amino-t-butyl-phenyl)ether para-bis(2-methyl-4-amino-pentyl)benzene para-bis(l,l-dimethyl-5-amino-pentyl)benzene m-xylene diamine polymethylene polyaniline Among the polyisocyanates useful in connection with the invention are those havîng two or more isocyanate groups, whether blocked or unblocked.
Blocked isocyanates using as the blocking constituent phenols or alcohols, among others, can be used and in general provide a higher molecular weight final material which is advantageous in coating compositions. On the other hand, ~he unblocked isocyanates provide more flexible final materials.
At any rate, the blocking material must be evaporated off as much as possible and there is no advantage from the purely reaction point of view to using the blocked material except as stated above. Typical of ~he . ~ blocked polyisocyanates is Mondur S wherein mixtures of 2,4- and 2,6-tolylene diisocyanate are reacted with trimethylol propane and blocked ~: .

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by esteriEication with phenol in the proportions of three moles o~ lso-cyanate, one mole o~ trimethylol propane, and three moles of phenol. In Mondur S~1 the isocyanate groups of mixed 2,4- and 2,6-tolylene diisocya-nate are blocked by esterification ~ith cresol. Among specific polyiso-cyanates which are useful alone or in admixture are the following:
tetramethylenediisocyanate hexamethylenediisocyanate 1,4-phenylenediisocyanate 1,3-phenylenediisocyanate 1,4-cyclohexylenediisocyanate 2,4-tolylenediisocyanate 2,5-tolylenediisocyanate -2,6-tolylenediisocyanate 3,5-tolylenediisocyana~e 4-chloro-1,3-phenylenediisocyanate ~
1-methoxy-2,4-phenylenediisocyanate -1-methyl-3,5-diethyl-2,6-phenylenediisocyanate 1,3,5-triethyl-2,4-phenylenediisocyanate 1-methyl-3,5-diethyl~2,4-phenylenediisocyanate 1-methyl-3,5-diethyl-6-chloro-2,4-phenylenediisocyanate 6-methy]-2,4-diethyl-5-nitro-1,3-phenylenediisocyanate p~xylylenediisocyanate m-xylylenediisocyanate ~ ~
4,6-dim~thyl-4,6-bis-(b-isocyanatoethyl~-benzene -3-(a-isocyanatoethyl~-phenylisocianate 1-methyl-2,4-cyclohexylenediisocyanate 4,4'-biphenylenediisocyanate 3,31-dimethyl-4,4'-biphenylenediisocyanate , :, :
3,3'-dimet~20xy-4,4'-biphenylenediixocyanate 3,3'-diethoxy-4,4-biphenylenediisocianate :`:
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1,1-bis-(4-isocyanatophenyl)cyclohexane 4,4'-diisocyanato-diphenylether 4,4'-diisocyanate-dicyclohexylmethane 4,4'-diisocyanato-diphenylmethane 4,4'-diisocyanato-3,3'-dimethyldiphenylmethane 4,4'-diisocyanato-3,3'-dichlorodiphenylmethane 4,4'-diisocyanato-diphenyldimethylmethane 1,5-naphthylenediisocyanate 1,4-naphthylenediisocyanate 4,41,4"-triisocyanato-triphenylmethane 2,4,4'-triisocyanato-diphenylether 2,4,6-triisocyanato-1-methyl-3,5-diethylbenzene o-tolidine-4,4'-diisocyanate m-tolidine-4,4'-diisocyanate benzophenone-4,4'-diisocyanate biuret triisocyanates -polymethylenepolyphenylene isocyanate The organic solvents where such are used in the present invention are well known to those skilled in the art and include N-methylpyrroli-done, dimethylformamide, dimethyl sulfoxide, dimethylacetamide, and isopro- -~
panol. Where such solvents are used in conJunction with water in the pre-sent invention, they are utilized to facilitate the runnability of the final coating co~position, that is, to avoid such defects in the finished ;
~ coatings as blisters and streaking or al~ernate light and dark spots.
; ~ ~ While the above solvents can be used alone~ it has been found in some cases advantageous in solubili~ing the composition in water to add up to about 10 percent by weight-of other solvent such as the cellosolves or carbitols, including but not limited to butyl cellosolve, ethyl cellosolve or other ester materials such as butyl acetate, ethyl acetate, and the like.
; 30 ~ Generally, in preparing the present materials the alcoholic .
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-ingredients and acid or substituted acidic ingredients are mixed together and heated at a temperature of about 220'C to an acid number ranging from about 20 to 60 and preferably about 35. Generally, at this point the butyl cellosolve or other similar material is added where sllch solution promotors are indicated. There is then added to the solution and amine group containing material which in reacting with or neutralizing the free carboxyl groups form salts, making the composition at least partially or wholly soluble in water. Preferably, from thirty to about one hundred ~ -percent of the carboxyl groups are so reacted. Among the amine group containing materials useful in this respect are primary and secondary amines. Preferred are tertiary amines which are well known to those skilled ~ -in the art and include, among others, dimethylethanolamine, triethanolamine, phenylmethylethanolamine, butyldiethanolamine, phenyldiethanolamine, pheny-lethylethaolamine, methyldiethanolamine, and triethylamine. Also useful is ammonia or ammonium hydroxide. --After the so-called "solubili~ing" agent or amine group containing material has been added and reacted, the remainder of any water or water and solvent desired to obtain the required solids content is added.
The following examples illustrate the practice of the present invention, it being understood that they are not to be taken as limiting ~-in any way. All parts unless otherwise specified are by weight.
Exemple 1 This example illustrates the preparation of the water soluble polyester coating composition.
A reaction vessel equipped with stirrer, condenser, Dean Stark trap and thermometer was charged with 491 parts of trimethylol propane, 1144 parts of neopentyl glycol and 1959 parts of a dibasic acid mixture consisting of 85 percent isophthalic acid and 15 percent terephthalic ~
acid. The contents were heated to a maximum temperature of 220'C with ~ -stirring until an acid number of 16 was reached. The resin was decanted , ~ ', 9 '' ' ';

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and allowed to cool to room temperature. There were added to 600 parts of the above solid resin 87 parts of adipic acid, the contents being heated in a vessel similar to that above to 175'C until an acid number of 50.6 was attained. Then, to 20 parts of the 50.6 acid number material, there were added 41.6 parts of water and 2.4 parts of triethanolamine.
The contents were mixed for about 15 hours to produce a water-soluble polyester solution. To this solution there were added 2 parts of hexamethoxymethyl melamine (Cymel) as a curing agent and 2 parts of lactic acid acid titanate as a curing accelerator. When this final polyester material was coated on a substrate and cured at 200'C for one hour, a smooth film was obtained.
Any of the usual curing agents can be used in connection with the present coating materials including, among others, those mentioned in U.S. patent 2,936,296. Likewise, various esters of titanium including those described in U.S. patent 3,538,186 - Payette - November 3, 1970, have been found useful as cure accelerators.
_ mple 2 This example illustrates the preparation of a water-soluble polyesterimide.
Into a reaction vessel equipped as in ~xample 1 there were charged 95 parts trimethylol propane, 147 parts neopentyl glycol, 105 parts methylene dianiline and 50 parts N-methylpyrrolidone. The mixture was heated to 160'C with stirring and 204 parts trimellitic anhydride added over a one-hour period at the 160'C temperature. After complete addition of the tr~mellitic anhydride, 206 parts of dibasic acid consisting of &5 percent isophthalic acid and 15 percent terephthalic acid were added along with 1.3 parts of tetraisopropyl titanate (TPT), and the mlxture heated at 220'C until an acid number of 25 30 was reached. Then, 70 parts of adipic acid were added at 190'C until an acid number of 45-50 was atta~ned. The resin was then cut with 202 parts of butyl cellosolve which was followed by the gradual addition of 75 parts dimethylethanolamine ~-~ .

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and 1143 parts water, the pot temperature being maintained above 80'C.
AEter stirring for 15 minutes, 97 parts of ~-methylpyrrolidone and 261 parts of water were added and the polyesterimide solution allowed to cool with stirring. The Einal viscosity was 160 cps at 25'C and the resin concentration was 32 percent. When coated on copper wire 0.0403 inch in diameter at a speed of 50 ft/ minute and cured at a temperature of ~50~C
to 470'C, the smoothness was acceptable at a build of 2.9 to 3.0 mils.
The flexibility at 25 percent stretch was IX and there were only three continuity breaks per 100 feet. The flexibility after heat aging for 100 hours at 175'C with 0 percent stretch was IX. The dissipation factor at 170'C was 5.7 and the cut-through at 1000 g ranged from about 245'C to 260'C. The 155'C heat shock with 0 percent stretch was 2X and the dielec-tric strength was 8.9. The burn-out OFM was 8.84. The small content of organic solvent was retained to improve the runnability of the material.
Exemple 3 Using a reaction vessel as in Example 1 there were added to the vessel 632 parts trimethylol propane, 980 parts neopentyl glycol and 1959 parts of an 85 percent isophthalic-15 percent terephthalic acid mixture, the reactants being heated at 220'C to an acid number of 16. The contents were decanted. To 500 parts of this material there were added 74 parts of adipic acid, the mixture being heated to a maximum of 175'C to an acid number of 49.1.
To 200 parts of the above decanted material there were added 20 parts of maleic anhydride at 100'C, the mixture being heated to 150'C
for one-half hour and cooled. To the cooled resin there we~e added in succession 233 parts of water, 13 parts of dimethylethanolamine, 46 parts . . :.
butyl cellosolve and 187 parts water. The contents were heated while stirring to resin dissolution. When coated on a wire as in Example 2, a smooth coating with good flexibility and a cut-through of 250'C was :; : .
obtained.
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Example 4 This example illustrates the preparation o~ a water-soluble polyesterimide material.
A reaction vessel as in Example 1 was charged with 209 parts trimethylol propane, 323 parts neopentyl glycol, 305 parts trimellitic anhydride, 90 parts of hexamethylene diamine and one part TPT. The contents were heated at 150'C for one hour and then were added 274 parts of acid consisting of 85 percent isophthalic acid and 15 percent terephthalic acid, the mixture being heated at 220'C until a 0.41 percent 10carboxyl number was obtained. Then 162 parts of adipic acid were added and the resin heated to 220'C to an acid number of 42.3. To the warm resin there were added 270 parts butyl cellosolve and 1200 parts o~ a water solution containing 58 parts of dimethylethanolamine. To the cooled solution there were added 200 parts N-methylpirrolidone to facili-tate runnability. The viscosity of the final solution was about 200 cps at 25~C at a solids content of 24 percent. When coated on 0.00403 inch copper wire and curing at 450'C to 470'C the flexibility at 25 percent stretch was 2X, the dielectric strength was 6.1 KV, the 150'C heat shock at 0 percent stretch was 4X and the 1000 g cut-through was 227'C.
20 Example 5 This example illustrates the preparation of a polyesterimide material.
To a reaction vessel equipped as in E~ample 1 there were added 284.4 ~arts trimethylol propane, 441 parts neopentyl glycol~ 300 parts N-methylpyrrolidone and 316 parts methylene dianiline~ the contents being heated to 160~C at which point 612 parts trimellitic anhydride were added.
, . . .
A~ter collection of the water of imidization, 617 parts isophthalic acid `~
,. . .
and 4 parts TPT were added. The contents were heated to a maximum of 2207C until an acid number of 35 was reached. There were then added to 30the vessel 210 parts adipic acid and the mixture heated to l90~C until an ;
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acid number of 32.~ was reached. Then, to 1215 parts of this resulting mate-rial there were added at 120'C in aliquots 2310 parts water, 48.3 parts of ammonium hydroxide solution (28% NH3), 100 parts ~-methylpyrrolidone.
The final solids content was 22.7 percent and the Gardner-Holt viscosity was Z-3. When applied to 0.0403 inch copper wire and cured at 450'C to 470'C, smooth coatings having good flexibility were obtained. A polyester amideimide was prepared by replacing five equivalent percent of the hydroxyl groups in this example with additional methylene dianiline, again providing ~ ~
a good coating material. -Example 6 This example illustrates the preparation of polyesteramide material.
To a vessel equipped as in ~xample 1 there were charged 225 parts N-methylpyrrolidone, 142 parts ~rimethylol propane, 221 parts neo-pentyl glycol, 158 parts methylene dianiline, 571 parts isophthalic acid and 2 parts TPT. The contents were heated to a miximum temperature of 220'C with formed water being collected. When an acid number of 15.5 was reached, 105 parts of adipic acid were added. The mixture was allowed to ~-react until an acid number of 38 was obtained and then 275 parts of butyl cellosolve were added. To the solution which was at lOO'C there were slowly added 115 parts of dimethylethanolamine and 200 parts of water. ;
Additional water was added to attain a solids content of 22.7 percent and the Gardner-Holt viscosity at 25'C was 100 centistokes. When the resulting wire enamel was coated on 0.0403 inch diameter copper wire at a speed of 10 ft/minute and cured at 450'C to 470'C, satisfactory smoothness was obtained at a build of 3.0 mils. The flexibility at 25 percent stretch was IX and the dissipation factor at 18Q~C was 16. The 1000 gram cut-through was 221'C and the 155'C, 0 percent heat shock was SX. The die- ~
lectric strenght was 6.7 and the burn-out OFM was 9Ø ~ -Example 7 ~Ce66~

This example illustrates the preparation of a hydantoin poly-ester material.
To a reaction vessel equipped as in Example 1 above there were charged 114 parts trimethylol propane, 225 parts N-methylRyrrol:Ldone, 176 parts neopentyl ~lycol, 161 parts di(2-hydro~yethyl)dimethylhydantoin, 340 parts :isophthalic acid, 100 parts of tarephthalic acid and 2 parts TPT.
The contents o the vessel were heated to a miximum of 220'C with water being collected until an acid number of 24.5 was reached. Then 58 parts of adipic acid and 98 parts of di(2-carboxylethyl) dimethylhydantoin were added, the temperature being maintained at 220'C until an acid n~nber of 30.7 was obtained. At this point 225 parts of butyl cellosolve were added to the cooling vessel followed by the addition of a solution of 115 parts dimethylethanola~ine and 200 parts of water followed by the addition of 2000 parts of water. The viscous solution was reduced to 19 percent solids by adding an 80 to 20 by weight mixture of water and N-methylpyrrolidone butyl cellosolve to a final Gardner-Holt viscosity of .
Z. When coated on wire at 50 ftlminute to a build of about 2.5 to 2.8 -mils and cured at 450'C to 470'C~ the 25 percent flexlbility was 2X. The dissipation factor at 180iC was 4.2 and the 155'C, 0 percent heat shock was 2X, the dielectric strength was 9.0 and the burn-out OFM was 9Ø
: : .
There are provided by the present invention polyester resin -~
coating solutions, and such coating solutions in which the polyester is variously modified with imide, amide, urethane and hydantoin groups, which are characterized by good coating characteristics and particularly by tnelr ability to be dissolved at least partly of wholly in water, thus representing a decided improvement over nor~al organic solvent solutions of such materials.
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Claims (22)

The embodiments of the invention in which an exclu-sive property or privilege is claimed are defined as follows:

1. A water soluble varnish or wire enamel coating composition containing free carboxyl groups and selected from the group consisting of polyester hydantoin, polyester urethane and mixtures thereof, at least part of the free carboxyl groups being neutralized with a compound selected from the group consisting of amines, ammonia and ammonium hydroxide.

2. A coating composition as defined in claim 1 where from about 30 to 100 percent of the free carboxyl groups are neutralized.

3. A coating composition as defined in claim 1 or 2, wherein the neutralizing compound is an amine.

4. A coating composition as defined in claim 1 or 2 wherein the neutralizing compound is a tertiary amine.

5. A coating composition as defined in claim 1 or 2 wherein the neutralizing compound is dimethylethanolamine.

6. A coating composition as defined in claim 1 or 2 wherein the neutralizing compound is ammonia or ammonium hydroxide.

7. A coating composition as defined in claim 1 or 2 wherein said polyester hydantoin and said polyester urethane is comprised of the reaction product of a dicarboxylic acid and a mixture of a polyhydric alcohol having at least three hydroxyl groups and a diol.

8. A water soluble varnish or wire enamel coating composition comprising a polyester hydantoin containing free carboxyl groups, at least part of the free carboxyl groups in the polyester moiety being neutralized with a compound selected from the group consisting of amines, ammonia or ammonium hydroxide.

9. A coating composition as defined in claim 8 wherein said polyester is the reaction product of a carboxylic acid material with polyhydric alcohol having at least three hydroxyl groups and a diol.

10. A coating composition as defined in claim 8 or 9 wherein up to about 95 equivalent percent of polyhydric alcohol and diol is hydantoin group containing.

11. A coating composition as defined in claim 8 or 9 wherein up to 95 equivalent percent of the acid material is hydantoin group containing and has two or more carboxylic acid groups.

12. A coating composition as defined in claim 8 or 9 wherein up to 95 equivalent percent of said polyester is the esterification product of a hydantoin group containing compound having at least two carboxylic acid groups and at least two hydroxyl groups.

13. A water soluble varnish or wire enamel coating composition comprising a polyester urethane containing free carboxyl groups, at least part of the free carboxyl groups in the polyester moiety being neutralized with a compound selected from the group consisting of amines, ammonia and ammonium hydroxide.

14. A coating composition as defined in claim 13 wherein said polyester moiety is the reaction product of acid material, polyhydric alcohol having as least three hydroxyl groups and doil.

15. A coating composition as defined in claim 13 or 14 wherein up to about 40 equivalent percent of the acid reactant is replaced by a polyisocyanate.

16. The process of preparing a water soluble varnish or wire enamel polyester containing coating composition which comprises reacting a polybasic acid material t polyhydric alcohol having at least three hydroxyl groups, diol, and a hydantoin group containing material selected from the group consisting of hydantoin group containing moiety having two or more hydroxyl groups, hydantoin group containing moiety having two or more carboxylic acid groups, and hydantoin group containing moiety having at least two carboxylic acid groups and at least two hydroxyl groups to form a poly-ester hydantoin having an acid number of about 20 to 60 and further reacting said polyester hydantoin with a compound selected from the group consisting of amines, ammonia and ammonium hydroxide to neutralize at least part of the free carboxyl groups.

17. The process of preparing a water-soluble varnish or wire enamel polyester containing coating which comprises reacting a polybasic acid material, polyhydric alcohol having at least three hydroxyl groups, diol and a polyisocyanate group containing material to form a polyester-urethane having an acid number of about 20 to 60 and further reacting said polyester-urethane with a compound selected from the group consisting of amines, ammonia and ammonium hydroxide to neutralize at least part of the free carboxyl groups.

18. The process as defined in claim 16 wherein said acid number is obtained by the addition of polybasic acid.

19. The process as defined in claim 17 wherein said acid number is obtained by the addition of polybasic acid.

20. A substrate coated with a composition comprising the composition of claim 1, 2 or 8.

21. A laminate cohered with the composition of claim 1, 2 or 8.

22. A composite cohered with the composition of claim 1, 2 or 8.