CA1097449A

CA1097449A - Pigment grinding vehicle

Info

Publication number: CA1097449A
Application number: CA254,332A
Authority: CA
Inventors: Karl F. Schimmel; Lance C. Sturni; Martin J. Robles
Original assignee: PPG Industries Inc
Current assignee: PPG Industries Inc
Priority date: 1975-08-01
Filing date: 1976-06-08
Publication date: 1981-03-10
Also published as: DE2634229C2; JPS57126873A; JPS5679163A; FR2319692B1; AU500345B2; GB1553513A; DE2634229A1; JPS5751867B2; JPS6123952B2; JPS601343B2; JPS5218739A; AU1488976A; FR2319692A1

Abstract

ABSTRACT OF THE DISCLOSURE

A polymeric product suitable for use as a pigment grinding vehicle is disclosed. The polymeric product is the reaction product of an organic polyepoxide and an organic amine containing alkyl aryl polyether moieties.

Description

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Background of the Invention Field of the Invention: Tlle present invention relates to pigment grinding vehicles and, more particularly, to resinous products suitable for such use. In another aspect, the invention relates ta cationic electrocoating empl~oying paints containing novel pigment -grinding vehicles.
Brief Description of the Prior Art: In the formation of paint compositions, and especially electrodepositable paint compositions, an important factor is the introduction of pigments into the coating composition. The pigments are typically ground in a pigment grinding vehicle which acts as a dispersing agent to form a paste, and the resultant pigment paste is incorporated illtO the coating composition to give the coating composition proper color, opacity, application and film properties.
Unfortunately, many of the pigment pastes for electrodeposition are mixtures of water-soluble soaps or resins which are not electro-depositable. These pastes remain in the aqueous phase where they pose serious effluent problems.

~L~9744~

The present invention overcomes this problem by providing a pigment grinding vehicle which can be made electrodepositable and co-depositable with the vehicle resin of the paint.

Summary of the Invention In accordance with the present invention, a polymeric product suitable for use as a pigment grinding vehicle is provided. The polymeric product comprises the reaction product of an organic polyepoxide and an organic amine containing alkyl aryl polyether moieties. Besides the polymeric product, the invention also provides for a pigment paste comprising the above-described product in combination with a pigment.
Additionally, the present invention provides for a method of electro-coating an electrically-conductive surface serving as d cathode in an electrical circuit comprising a cathode and an anode and an aqueous electrodepositable compositlon ~herein the electrodepositable composition comprises an aqueous dispersion of an amine salt-containing resin or a quaternary ammonium group-containing resin and the aforementioned pigment paste.

:
The polymeric products of the present invention, besides providing outstanding pigment wetting properties, are co-depositable with the vehicle resin of the electrodeposition paint and thus signi-`~ ficantly minimize effluent problems.
''`` ~
Detailed Description The organic polyepoxides can be a monomeric or polymericcompound or a mixture of compounds having a 1,2-epoxy equivalency greater than 1.OJ that is, in which the average number of 1,2-epoxy groups per molecule is greater than 1. It is preferred that the organic polyepoxide be polymeric or resinous.

1~974~9 The polyepoxide can be any of the well-knowrl epoxides. Examples of these polyepoxides have, for example, been described in U. S. Patents

2,467,171; 2,615,007; 2,716,123; 3,030,336; 3,053,855; and 3,075,999.
A useful class of polyepoxides are the polyglycidyl ethers of polyphenols, such as Bisphenol A. These may be prepared, for example, by etherification of a poly~herlol with epichlorohydrin or dichlorohydrin in the presence of an alkali. The phenolic compound may be bis(4-hydroxy-phenyl)2,2-propane, 4,4'-dihydroxybenzophenone, bis(4-hydroxy-phenyl)l,l-ethane, bis(4-hydroxy-phenyl)l,l-isobutane; bis(4-hydroxy-tertiary-butyl-phenyl)2,2-propane, bis(2-hydroxy-naphthyl)methane, 1,5-hydroxy-naphthalene, or the like.
Another quite useful class of polyepoxides are produced similarly from novolak resins or similar polyphenol resins.
Also suitable are the similar polyglycidyl ethers of polyhydric alcohols which may be derived from such polyhydric alcohols as ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, -1,4-butylene glycol, 1,5-pentanediol, 1,2,6-hexanetriol, glycerol, bis-(4-hydroxy-cyclohexyl)2,2-propane, and the like.
There can also be employed polyglycidyl ethers of polycarboxylic acids which are produced by the reaction of epichlorohydrin or a similar epoxy compound with an aliphatic or aromatic polycarboxylic acid, such as oxalic acid, succinic acid, glutaric acid, terephthalic acid, 2,6-naphthalene dicarboxylic acid, dimerized linoleic acid, and the like.
~xamples are diglycidyl adipate and diglycidyl phthalate.
Also useful are polyepoxides derived from the epoxidation of an olefinically unsaturated alicyclic compound. Included are diepoxides comprising, in part, one or more monoepoxides. These polyepoxides are non-phenolic and obtained by epoxidation of alicyclic olefins, for 7445~

example, by oxygen and selected metal catalyst, by perbenzoic acid, by acid aldehyde monoperacetate or by peracetic acid. ~mong the poly-epoxides are the epoxy alicyclic ethers and esters which are well known in the art.
Other epoxies which may be employed are acrylic polymers containing epoxy groups and hydroxyl groups. Preferably, these acrylic polymers are polymers produced by copolymerizing an unsaturated epoxy-containing monomer, such as, for example, glycidyl acrylate or methacrylate, a hydroxyl-containing unsaturated monomer and at least one other unsaturated monomer .
Any polymerizable monomeric compound containing at least one CH2=C~ group, preferably in the terminal position, may be polymerized with the unsaturated glycidyl compounds. Examples of such monomers include aromatic compounds such as phenyl compounds, for example, styrene, alpha-metllyl styrene, vinyl toluene and the like. ~lso, aliphatic compounds such as olefinic acids and esters, such as acrylic acid, methyl acrylate, ethyl acrylate, methyl methacrylate and the like may be employed.
In carrying out the polymerization reaction, techniques well known in the art may be employed. ~ peroxygen-type catalyst is ordinarily utili~ed; diazo compounds or redox catalyst systems can also be employed as catalysts.
The preferred hydroxy-containing unsaturated monomers are hydroxyalkyl acrylates, for example? hydroxyethyl acrylate or methacrylate or hydroxypropyl acrylate or methacrylate may be used.
Another method of producing acrylic polymers which may be utilized in the present invention is to react an acrylic polymer containing reactive sites, including hydroxyl groups, with an epoxy-containing compound such as diglycidyl ether of Bisphenol ~ or other polyepoxides as enumerated 1~97449 elsewhere herein, to provide epoxy group-containing hydroxyl group-containing acrylic polymers.
The organic amine containing alkyl aryl polyether moieties can be a secondary amine or a tertiary amine acid salt which is capable of reacting with and opening the epoxide moiety to form basic nitrogen-containing adducts. In the case of secondary amines, the adduct contains tertiary amine groups and in the case of tertiary amine acid salts, quaternary ammonium-containing adducts are formed. The tertiary amine-containing adducts are usually insoluble in water and can be solubilized by treating with acid.
The acid used Eor solubilizlng the tertiary amine adduct and the acids of the tertiary amine acid salts preferably are acids having a PKa less than 5 such as hydrochloric acid, sulfuric acid and boric acid. r Preferably, the acid is an organic acid such as acetic acid and lactic acid, with lactic acid being the most preferred.
As has been mentioned above, the organic amine contains alkyl aryl polyether moieties, typical of which are represented by the following structural formula:

R \ ~ ~ (OCll2 - CH)x ~ o~
`, wllere R is an alkyl radical containing from 1 to 30 carbon atoms and R' is hydrogen or lower alkyl containing from 1 to 5 carbon atoms and x is equal to 3 to 20. Preferably, R is a branched alkyl group contain-ing secondary, tertiary or both secondary and tertiary carbon atoms. In the most preferred embodiment, R is octyl.

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In the above structural formula, the aryl radical is repre-sented by the phenyl ring. It should be appreciated, nowever, that other aryl radicals such as naphthyl, phenanthryl and anantnryl can be used.
In one embodiment oE the invention, the organic amine contain-ing alkyl aryl polyet^her moieties can be prepared by reacting an alkyl aryl polyether which contains an active hydrogen such as hydroxyl with an organic diisocyanate to form a half-capped isocyanate product. An organic amine containing active hydrogens such as a hydroxyl-containing tertiary amine can then be reacted with a half~capped isocyanate to form the desired adduct. In a preferred embodiment of the invention, toluene diisocyanate is half-capped with an octyl phenol-ethylene oxide adduct having the following structural formula: .

CH - C - CH2 - C ~(OCH2C112)XOH

where x is equal to 12 to 13. The half-capped adduct is then fully capped with dimethyl ethanolamine to form a tertlary amine adduct con-taining alkyl aryl polyether moieties which also contains urethane linkages.
To make the polymeric product of the invention, preferably two moles of the organic monoamine containing alkyl aryl polyether moieties are reacted with one mole of an organic diepoxide to form an adduct in which the alkyl aryl polyether groups are in the terminal position on the polymer chain. This provides a polymeric product with the most desirable pigment dispersing properties. The reaction proceeds at room temperature in most cases and, in some cases, exothermically, so that moderate cooling may be necessary. In some cases, moderately ~09744~

elevated temperature can be used and is preferred. Typically, the reaction is conducted between about 50C. and 100C. The reaction may be conducted in the presence of a solvent if desired. If a solvent is employed, preferably it is capable of being used in the ultimate composition which is formed. For example, alcohols, ketones and glycol ethers may be used.
For suitable pigment pastes for use in electrodeposition, the amounts of organic polyepoxide and organic amine containing alkyl aryl polyether moieties should be selected so that the final polymeric product contains about 0.3 to 1.5, preferably 0.4 to 0.7 milliequivalents of basic nitrogen per gram of resin. Iower milliequivalents of basic nitrogen j~ per gram of resin, i.e., lower than 0.3, are undesirable because the resin will have poor pigment wetting properties, whereas higher milli-equivalents of basic nitrogen per gram of resin, i.e., higiler than 1.5, are undesirable because the resin may become too water soluble.
; The pigment pastes of the present invention are prepared by grinding or dispersing a pigment into the polymeric products described above in a manner well known in the art. The pigment paste comprises as essential ingredients basic nitrogen-containing adducts of the invention and at least one pigment; however, the paste may, in addition, contain optional ingredients such as plasticizers, wetting agents, surfactants or àefoamers.
Grinding is usually accomplished by the use of ball mills, sand mills, Cowles dissolvers, continuous attritors and the like until the pigment has been reduced to the desired size and preferably has been wet by and dispersed by the grinding vehicle. After grinding, the particle size of the pigment should be in the range of 10 microns or less, preferably .

11~974~9 as small as practicable. Generally, a Hegman grind gauge reading of about 6-8 is usually employed.
Preferably, grinding is conducted in an aqueous dispersion of the vehicle. The amount of water present in the aqueous grind should be sufficient to produce a continuous aqueous phase. Tlle aqueous grind usually contains about 30 to 70 percent total solids. The use of more water merely reduces the effective capacity of the mill and, while less water can be employed, higher resultant viscosity may create problems in certain instances. Although the pigment paste is usually prepared in the presence of water, water is not absolutely necessary and in fact the pigment dispersants of the present invention can be used to prepare non-aqueous pigment pastes ~hich are subsequently dispersible in water-based compositions.
` The pigment-binder ratio in the grinding step is usually ;~ maintained within the range of about 2/l to 7/1.
Pigments which may be employed in the practice of the invention are pigments ~ell known in the art. Generally titanium dioxide i8 the sole or chief white pigment; other white pigments and/or extender pigments include antimony oxide, zinc oxide, basic lead carbonate, basic lead sulfate, barium carbonate, China clay, calcium carbonate, aluminum silica, silica, magnesium carbonate, magnesium silica, among others. Color pigments may also be employed, for example, cadmium yellow, cadmium red, carbon black, phthalocyanine blue, chrome yellow, toluidine red, hydrated iron oxide, among others.
For a general review of pigment grinding and paint formulation, reference may be had to: -! D. H. Parker, PrinciPles of Surface Coatin~ Technology, Interscience Publishers, New York (1965) ! R. L. Yates, Electropainting, Robert Draper Ltd., Teddington, England (1966) H. F. Payne, Or~anic Coating Technology, Vol. 2, Wiley and Sons, New York ~1961).

` 1097449 The pigment paste of the present invention is usually combined with an amine group-containing resinous vehicle known in the art for cationic electrodeposition. The amine group-containing cationic electro-depositable resins are well known in the art and need not be described ~ ;
in any detail. Examples of suitable resins include those described in U. S. Patent 3,799,854 to Jerabek and U. S. Patent 3,839,252 to ~3Osso et al.

. :
, `~ Enough of the pigment paste is used so that the final electro-depositable composition (electrodepositable resin plus pigment paste) has the properties required for electrodeposition. In most instances, the final electrodepositable cotnposition has a pigment-to-binder (electro-depositable resin plus pigment dispersant) ratio of between about 0.05 to about 0.5.
For electrodeposition, a bath containing about 5 to 25 percent by weight solids, that is, pigment plus resinous vehicle, is usually employed. This aqueous composition is then placed in contact with an electrically-conductive anode and an electrically-conductive cathode in an electric circuit. ~hile in contact with the bath containing the coating composition, an adherent film of the coating composition is deposited on the cathode.
The conditions under which the electrodeposition is carried out are, in general, similar to those used in electrodeposition of other types of coatings. The applied voltage may be varied greatly and can be, for example, as low as one volt or as high as several thousand volts, although typically between 50 volts and 500 volts are usually employed. The current density is usually between about 0.25 ampere and 15 amperes per square foot, and tends to decrease during electrodeposition.

~974~9 The method of the invention is applicable to the coating of any conductive substrate and especially metal, such as steel, aluminum, copper and the like.
After deposition, the coating is cured at elevated temperatures by any convenient method, such as in baking ovens or with banks of infrared heat lamps.
The final electrodepositable composition may contain, in addition to the pigment dispersion and the electrodeposition resin, adjuvant resins such as aminoplast resins for crosslinking, solvents, anti-oxidants, surfactants and other adjuvants typically employed in an electrodeposition process.
Illustrating the invention are the following examples which are not to be construed as limiting the invention to their details. All parts and percentages in the examples, as well as throughout the specification, are by weight unless otherwise speciEied.

Example I

A polymeric product suitable for use as a pigment grinding vehicle was prepared from the following charge:

Charge ~ y___~ Solids EPON 829 400 383.8 Bisphenol A 136.8 136.8 Organic amine containing alkyl aryl polyether moieties2 792 792 Aqueous lactic acid solution 96 72 Deionized water 113.7 Epoxy resin solution made from reacting epichlorohydrin and Bisphenol A, ~ T~de rr~ark 10~449 having an epoxy equivaient of approximately 193-203 and commercially available from Shell Chemical Company.

2This component was made by charging 174 parts by weight of toluene diisocyanate and 727`parts by weight of an alkyl aryl polyether having the following structure: -CH3 CH ~ (OCH2CH2)xOH

:; CH3 CH3 where x is equal to 12 to 13, commercially available from Rohm and Haas as TRITON X-102, to a reaction vessel. The reaction was permitted to exotherm at 30-35C. with Stirring for two hours~ after which time 89 parts ~y weight of dimethyl ethanolamitle was added. The reaction mixture was again permitted to exotherm for an additional two hours to form the desired reaction product.
The EPON 829 and the ~isphenol A were charged to a suitable reaction vessel and heated to 155-160C. and permitted to exotherm for one hour. The organic amine, lactic acid and deionized water were then added and the reaction mixture held for one hour at 80-85C. to form the desired reaction product.

Example II

A pigment paste ground to a }legman No. 7 containing the polymeric product of Example I was prepared from the following charge: -~ Tr~ na~

7~4S~

Parts by Weight . Resin of Example I125.0 : Titanium dioxide 592.2 Red iron oxide 2.5 Carbon black 5.1 Dibutyltin diacetate7.2 Deionized water 315 Example III

A cationic electrodepositable resin was prepared Erom the following charge: _ Char&~ Parts by Weight Solids EPON 829 5428 5208.3 Bisphenol ~ 1752.3 1752.3 2-Ethylhexyl-half capped toluene diisocyanate 3705.5 3705.5 PCP-02001 1424.8 1424.8 TEXANOL 1167.3 Dimethyl ethanolamine25.8 25.8 Aqueous lactic acid solution 52.3 39.5 Phenyl CELLOSOLVE1830.5 Ethyl CELLOSOLVE 857.0 FOAM KILL 639 66.5 66.5 Aqueous dimethyl cyclohexyl amine-lactic acid salt solution 1600.7 1200.5 Deionized water 857.0 - -Polycaprolactone diol having a molecular weight of 540 formed from ring -12 _ /~

J4t~

opening epsilon-caprolactone with diethylene glycol, commercially available from ~nion Carbide Corporation.

(trade mark) 2,2,4-trimethylpentanediol-1,3-monoisobutyrate.

3(trade mark) Ethylene glycol monophenyl ether.

(trade mark) Ethylene glycol monoethyl ether.

(trade mark) Hydrocarbon oil-containing diatomaceous earth surfactant.

The resin was prepared by charging the EPON 829 and Bisphenol to a suitable reaction vessel and heating to exotllerm, the higllest temperature being 215C. Reaction was controlled at 150-215C. for one hour and the reaction mixture cooled to 125C. and charged with the half-capped toluene diisocyanate. The reactlon mixture was held for one hour at 120C. followed by the acldition of the PCP-0200 and the TE~Y~NOL. ~fter the addition of these ingredients, the dimethyl ethanolamine was added and the reaction mixture maintained at 125-130C. for seven hours until the Gardner-Ho]dt viscosity was ~l+ a~ 25C. The lactic acid, phenyl CELLOSOLVE, ethyl CELLOSOLVE and FO~I KILL 639 were then charged over a period of 30 minutes followed by the addition of the dimethyl cyclohexylamine-lactic acid salt. The reaction mixture was digested at 90-95C. for two hours to form and clarify tile resinous product oE the invention which had a solids content of 46.3 percent.
The above-described vehicle was combined with the ?igment paste of Example II and deionized water in the following charge ratio to form a 10 percent solids electrodeposition bath.

*Trade Mark ,. . ~

1C~9~4~3 Resin Pigment Charge Parts by Weight Solids Solids Cationic electrodepositable resin 351.0 263.2 Pigment paste of Example II 145.0 13.8 83.0 Deionized water 3104.0 Zinc phosphated steel panels were coated with this bath at a temperature of 27C. at 400 volts for 90 seconds to produce continuous films.

Example IV

A pigment paste ground to a Hegman No. 7 was prepared from the following charge:

ChargeParts by Weight Solids Pigment grinding vehicle oE
Exa~ple I 121.7 100 Titanium dioxide472.2 472.2 Aluminum silicate120.0 120.0 Red iron oxide 2.5 2.5 Carbon black 5.1 5.1 Deionized water 284.7 Example V

An electrodeposition bath containing 10 percent total solids was prepared from the thermosetting cationic composition described in Example III
and the pigment paste oE Example IV in the following charge ratio:

lOg7449 Resin Pigment Charge Parts by Weight Solids Solids Cationic electrodepositable resin of Example III 717.6 502 Pigment paste of Example IV 312.8 31.1 186.6 Dibutyltin diacetate6.0 Deionized water 6163.0 When the electrodeposition bath at a temperature of 27C. was used to coat zinc phosphated steel panels at 300 volts for 90 seconds, continuous films were produced which, after curing for 20 minutes at 196C., were glossy~ hard and acetone-resistant.

Example VI

~ polymeric product similar to Example I and suitable for use as a pigment grinding vehicle was prepared Erom the following charge:

Charge Parts by Weight Solids EPO~ 829 400 383.8 Bisphenol A 136.8 136.8 Organic amine containing alkyl aryl polyether moieties of Example I 673~4 673.4 Aqueous lactic acid solution 78 58.5 Deionized wat~r 62.6 Methyl ethyl ketone 214.8 The EPON 829 and the Bisphenol A were charged to a suitable reaction vessel and heated to exotherm at 155C. and held for one hour.
The reaction mixture was cooled to 100C. and the methyl ethyl ketone added. The reaction mixture was agitated and heated to reflux followed 1~197449 by the addition of the amine, lactic acid and deionized water. The reaction mixture was further heated at 80-90C. for about one hour to form the desired reaction product.

Example VII

A pigment paste ground to a Hegman No. 7 and containing the polymeric product of Example VI was prepared from the following charge:

Charge Parts by Weight Solids : ~A~ Resin of Example ~ 121.7 100 Titanium dioxide 472.2 472~2 Aluminum silicate 120.0 120 Red iron oxide 2.5 2.5 Carbon black 5.1 5.1 Deionized water 309.7 Example VI:[I

A cationic electrodepositable resin was prepared from the following charge:

1~9~44~

Charge Parts by ~eight Solids = ~ ~
EPON 829 1203.5 1155.7 Bisphenol A 207.0 207.0 Polypropylene glycol (molecular weight = 625) 542.3 542.3 Dimethyl ethanolamine 3.6 3.56 75% by wei~ht aqueous lactic acid solution 7.1 6.0 FOAM KILL 639 12.6 12.6 TEX~NOL 402.2 - -Isopropanol 55.0 Dlmethyl ethanolamille lactic acid salt (75% solids in isopropanol) 96.0 71.98 Deionized water 92.0 Boric acid 5.0 5.0 Deionized water 2550 Boric acid 5.9 5,9 X~1-11231 326.2 326.2 Isopropanol 69.0 METHLYON 75202 197.0 128.0 Isopropanol 58.3 XM-1123 (trade mark) benzoguanamine-fom~aldehyde resin commercially available from American Cyanamid Company.

(trade mark) Unsaturated methylol phenol ether commercially available from General Electric Company.

The EPON 829 and Bisphenol A were charged to a suitable reaction vessel and heated to 150C. to exotherm with the highest temperature being , ~ ., .

3.0~449 160C. The reaction temperature was controlled between 150-160C. for one hour, after which time the polypropylene glycol was charged to the reaction vessel followed by the addition of the dimethyl ethanolamine.
The reaction temperature was held at about 135C. for about six hours until the Gardner-Holdt viscosity at 25C. was M+. The reaction mixture was then charged with TEXANOL, isopropanol and FOAM KILL and digested for 45 minutes at 115-130C. The lactic acid was then charged and the reaction mixture cooled to 98C., followed by the addition of the dimethyl ethanol-amine lactic, the first portion of deionized water and boric acid. After the addition of these ingredients, the temperature was held at 90-95C.
for 4S minutes, lowered to 70C. and the second portion of deionized water and boric acid added. After this addition, the reaction mixture was charged with XM-1123 and the first portion of isopropanol. The reaction mixture was digested for 30 minutes at 65C. and then charged with the METHLYON and the second portion of isopropanol. The reaction mlxture was further digested for four hours at 56-62C. to clarify the reaction product. The final product contained 71.2 percent total solids and had a Brookfield viscosity of 22,000 centipoises (No. 7 spindle at 20 rpm's).
The above resin was combined with the pigment paste of Example VII and deionized water to form a 10 percent solids electrodeposition bath. The charge ratio for forming the bath was as follows:

Resin Pigment Charge Parts by Weight Solids Solids Cationic electrodepositable resin 376.0 263.2 Pigment paste of Example VII 142.5 13.8 83.0 Deionized water 3081.6 ~9~4~

The above bath when used to coat ~inc phosphated steel panels at 200 volts for 90 seconds (bath temperature 27C.) produced continuous films which when baked at 246C. for 20 minutes were hard and acetone-resistant films of a thickness of approximately 0.70 mil.

Example IX

A non-aqueous pigment paste ground to a ~egman No. 7 containing the polymeric product of Lxample I was prepared from the following charge:
Charge Parts by Weight Resin of Example I 97.4 Butyl CELLOSOLVE 230 T:itanium dioxide 342 Chrome yellow pigment 38.2 Medium chrome yellow pigment 9.5 Etllylene glycol monobutyl ether.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A polymeric product suitable as a pigment grinding vehicle comprising the acidified reaction product of:

(A) a polymeric polyepoxide having a 1,2-epoxy equivalency greater than one, (B) an organic amine containing an alkylarylpolyether moiety having the following structural formula:
where Ar is an aryl radical, R is an alkyl radical containing from 1 to 30 carbon atoms, R' is hydrogen or lower alkyl containing from 1 to 5 carbon atoms and x is equal to 3 to 20.

2. The product of claim 1 in which the alkylarylpolyether moiety is located in the terminal position on the polymer chain.

3. The product of claim 1 in which the polymeric polyepoxide is a polyglycidyl ether of a polyphenol.

4. The product of claim 1 in which (B) contains urethane linkages.

5. The product of claim 1 in which (B) is a tertiary amine.

6. The product of claim 1 wherein Ar in the structural formula is phenyl.

7. The product of claim 6 wherein R is a branched alkyl group.

8. The product of claim 1 in which (B) is formed by reacting:
(1) an alkylarylpolyether alcohol, (2) an organic diisocyanate, (3) a hydroxyl-containing tertiary amine.

9. A pigment paste comprising:
(A) an adduct comprising the acidified reaction product of (1) a polymeric polyepoxide having a 1,2-epoxy equivalent greater than one, (2) an organic amine containing an alkylarylpolyether moiety having the structural formula where Ar is an aryl radical, R is an alkyl radical containing from 1 to 30 carbon atoms R' is hydrogen or lower alkyl containing from 1 to 5 carbon atoms and X is equal to 3 to 20.
(B) a pigment dispersed therewith.

10. The pigment paste of claim 9 in which the ratio of (B) to (A) is within the range of 1 to 20:1.

11. The pigment paste of claim 9 in which the alkylarylpolyether moiety is located in the terminal position on the adduct.

12. The pigment paste of claim 9 in which the polymeric polyepoxide is a polyglycidyl ether of a polyphenol.

13. The pigment paste of claim 9 in which (2) contains urethane linkages.

14. The pigment paste of claim 9 in which (2) is a tertiary amine.

15. The pigment paste of claim 9 in which Ar in the structural formula is phenyl.

16. The pigment paste of claim 15 wherein R is a branched alkyl group.

17. The pigment paste of claim 9 in which (2) is formed by reacting:
(a) an alkylarylpolyether alcohol, (b) an organic polyisocyanate, (c) a hydroxyl-containing amine.

18. The pigment paste of claim 17 in which the organic poly-isocyanate is a diisocyanate.

19. The pigment paste of claim 17 in which the hydroxyl-containing amine is a tertiary amine.

20. A method of electrocoating an electrically-conductive surface serving as a cathode in an electrical circuit comprising said cathode and an anode and an aqueous electrodepositable composition wherein the electro-depositable composition comprises an aqueous dispersion of:

(A) an acid-solubilized polyamine group-containing resin or a quaternary onium group-containing resin, and (B) a pigment paste comprising:
(1) an adduct comprising the acidified reaction product of:
(a) a polymeric polyepoxide having a 1,2-epoxy equivalency greater than one, (b) an organic amine containing an alkylarylpolyether moiety having the structural formula wherein Ar is an aryl radical, R is an alkyl radical containing from 1 to 30 carbon atoms, R' is hydrogen or lower alkyl containing from 1 to 5 carbon atoms and x is equal to 3 to 20.
(2) a pigment dispersed therewith.

21. The method of claim 20 in which the pigment paste has a pigment-to-adduct ratio within the range of 1 to 20:1.

22. The method of claim 20 in which the alkylarylpolyether moiety is located in the terminal position on the resinous polymer chain.

23. The method of claim 20 in which the polymeric polyepoxide is a polyglycidyl ether of a polyphenol.

24. The method of claim 20 in which (b) contains urethane linkages.

25. The method of claim 20 in which the amine is a tertiary amine.

26. The method of claim 20 in which Ar in the structural formula is phenyl.

27. The method of claim 26 wherein R is a branched alkyl group.

28. The method of claim 20 in which (b) is formed by reacting:
i. an alkylarylpolyether alcohol, ii. an organic polyisocyanate, iii. a hydroxyl-containing amine.

29. The method of claim 28 in which the organic polyisocyanate is a diisocyanate.

30. The method of claim 28 in which the hydroxyl-containing amine is a tertiary amine.