CA2010822A1 - Cathodic electrodepositable coatings containing hydrophobic dyes - Google Patents

Abstract

ABSTRACT
Cathodic electrodepositable coatings, free of conventional pigmenting agents, aqueous coating baths, cathodic electrodeposition coating processes and coated articles. The coatings comprise cationic, electrodepositable resin compositions and cross-linking agents and contain hydrophobic dyes. The deposited, cured coatings have excellent gloss and flow.

Description

- 2010~22 :.
Attorney's Docket CAT~ODIC ~CT~ODBPO~I~A~L~ coATlNaA
CO~TAINING ~rDROP~OBIC 3YE~
~o~io~
The field of art to which this invention pertains is cathodic electrodepositable resin compoeition~ and, more specifically, cathodic electrodepositable epoxy-amine resin adduct compositions and cathodic electrodepositable acrylic amine functional copolymer compositions containing hydrophobic dyes.

Bao~ground o~ th- I~v-ntion Cathodic electrodepositable resin compositions are well known in the coating arts. The use of these cathodic electrodepositable resin compo~itions in aqueous electrodeposition coating baths, as well as processes for coating object~ and article in these aqueous cathodic electrodeposition coating bath~, are similarly well known in the art. Cathodic electrodepositable resin compositions are particularly useful as primers on metal surfaces to protect against corrosion.
The conventional cathodic electrodepo3itable aqueous resin compo~itions used are epoxy-amine resin adduct composition~ and amine-functional acrylic copolymer co~po~itions. The electrodepo~itable resin co~positions are typically salted with an acid to form an aqueous principal emulsion. This emulsion is combined with a cro~--linking agent, either before or after salting, that is d Jigned to cross-link or cure the resin composition undor various curing conditions. ThQ aqueou~ principal emulsion, containing the cros~-linking agent, is typically mixed at th~ coating site with a pigmQnt paste, water, organic coale~cent solvents, and other conventional additives to ~orm an agueou~ electrodeposition coating bath. The bath i8 typically contained in an electrically insulated tank containing an anode. The tank is of a 2~822 sufficient size to completely contain an immersed article during the coating process. An article which may be coated in an electr~deposition coating process typically compri~es an electrically conductive material, such as carbon steel.
Once the coating bath is prepared and stabilized within the required coating parameterc~ the electrodeposition process can be initiated by connecting the conductive article to a direct current power supply so that the article acts as a cathode. Next, the article i~
immersed in the coating bath, and a flow of elsctricity is initiated across the object, thereby causing the electrodeposit~ble resin composition and the cross-linking agent of the principal emulsion, a~ well as the pigment paste, to be deposited on the surfaces of the article.
When a film or layer of coating Or suf~icient thickness has been deposited upon the surfacea o~ the article, the article is removed ~ro~ the coating bath, optionally washed with distilled water, and then placed in a curing means wherain the depo~ited ~ilm is cured to a smooth, hard, durable, coating. Cathodic, electrodepo~itable, resin compositions, ~ethods of manu~acturing these cathodic electrodepositable resin compositions, aqueou~
electrodposition coating bath~ and processe~ for the deposition of these resin compositionff fro~ a coating bath onto a conductive article or ob~ect are disclosed in U.S.
Patent~ No. 3,984,299, 3,468,779, 4,116,900, 4,093,594, 4,137,140, 4,104,147 4,255,478, ~,432,850, 4,419,467, 3,S83,~83 and 3,853,803.
The~e cathodic, electrodepositable re~in compositions, wh n cur-d to hard, durable coatings, provide a metal substrate with superior corrosion protection. Cathodic electrodeposited coatings are typically used as primer coating~ and subsequently overcoated with protective and decorative topcoat coating compo~itionsO Typically, in the automotive industry, the topcoat coating conpositions comprise inner pigmented base coat~ and outer, clear protective top coats. The top coats may al80 comprise 2 ~ 2 2 pigmented coatings.
There i8 a constant search in this art for improved electrodeposition coating compositions, coating baths and methods of coating.
Presently, cathodic electrodeposition baths, and electrodeposited coatir.gs contain organic and/or inorganic pigments. One purpose of the pigmentation i~ to hide the underlying substrate and permit visual detection o~ the deposited primer coating. This is necessary in order to facilitate the determination of process parameter~ such as film thickness. Pigmentation of the depo~ited electrocoat coating also facilitates any subsequent refinishing operations wherein an outer top coat may be sanded down to the underlying electrocoat primer. During the sanding operation it is important to detect and not disturb the underlying primer in order to protect the integrity of the primer coating.
In order to introduce p$gment into a electrodeposition coating bath, it is necessary to grind dry pigment into a liquid grind re~in composition. The grind resin composition is typically a spacially designed and formulated cathodic, aqueous electrodepositable resin composition. The grinding process servea ~everal functions which include reducing the particle size of the pigment and completely coating and diaper~ing the pigment particles in the grind resin medi~. The re~ulting pigment pa~te i5 then ea~ily di~p-rsed in an aqueous, cathodic electrodeposition co~ting bath. It is al80 believed that the grind resin ~unctlon~ to help to maintain the pig~ent in suspension in th~ aqueou~ coating bath. Typically, about 10 percent of the reain composition in a cathodic, aqueous electrodepo~ition coating bath will comprise the grind resin, while the remainder of the reain will co~prise the principal reain plua cross-linking agent.
There are several disadvantagea associated with the u~e of color pigments in aqueous, cathodic electro-deposition bath~. It is known in the art that pigments 21~:19~22 contained in an aqueous, cathodic electrodeposition coating ba~h tend to settle out of the bath. It is believed that thi~ tendency to settle is at least in part the re~ult of tha den~ity differences between the pigments and water, the pigments being more dense then water. Pigments are maintained in a dispersed state in the coating bath through constant agitation of the coating bath. This is accomplished by a continuous loop pumping system so that the electrocoat bath is constantly pumped out of the bath tank and then discharged back into the bath tank. As previously mentioned, it is also believed that the grind resin assists in some manner to maintain th~ pigment in the dispersed state.
However, even with constant and intense agitation, and even though properly designed grind resin compositions are used, pigment does have a tendency to settle out of electrodeposition coating bath~. The settling of pig~ent causes 3everal problem~. Pigment t~nd~ to accumulate at the bottom of tanks causing ~ouling of tanks and equipment, and resulting in shut-downs and proces~ equipment failures.
The ettled pigments tend to cause dirt to accumulate in electrocoat coatings. The accumulation o~ dirt particles in electrocoat coatings adversely affects the coating appearance and integrity.
In addition, pigment which settles out is not recover~ble, re~ulting in reduced paint utilization e~ficiency. Tho "settled-out" pigmant must be disposed of a~ Ya~t- ~at-rial.
Another disadvantage of using conventional pigments i5 th t it i9 known that producing pigment pastes by the proc-R~ o~ grinding dry pigment with a wet grind resin is extremely time and energy intensive. In addition, pigment pastes made from pigment and grind resin typically contain substantial quantities of volatile organic compounds. The addition o~ pig~ent paste to an aqueou~, cathodic, electroposition (~E-Coat") coating bath increa~e~ the volatile organic content (VOC) of the bath. This increased 2 0 ~ 2 2 VOC is disadvantageous with regard to conformance with federal, state and local pollution control and environmental regulation~. Still anothar dis~dvantage o~
using pigments i~ that pigments reduce the flow of a coating. The flow is related to the 3moothness of the cured coating. In order to improve the flow o~ pigmented electrocoat coatings, additional solvents must be added to the electrocoat bath~ also resulting in increased VoC.
It has been disclosed in U.S. Patent No. 4,246,151 that dyes can ba used in agueous coating baths as additives, however thi~ concept has not been shown to be feasible and has not been u~ed.
U.S. Patent No. 4,655,787 discloses an electro-deposition coating process incorporating solvent dye into an electrophoretic resin on a metal surface. The patent discloses that attempts to U85 water insoluble dyes have not been ~ucces~ful in agueous coating baths. The patent disclo~es a process wherein a depo~ited coating is dipped into a solvent medium comprising water miscibl~ solvent, water, and a solvent dye.
What i~ needed $n thi~ art are aqueous cathodic, electrodepositable coatings, coating bath~, and processes which produca colored, cured coatings but which are free of conventional color pigments which reguire pretreatment and admixture with pigment grind resins.

Di-olo-u~- o~ t~- Inv-nt~o~
Novol cathodic electrodepo~itable resinous coating co-po~itions are disclosed. The usa Or the coating co-po-ltion~ in agu¢ous, cathodic elactrodepo~ition coating b~th~ surpri~ingly~and un~xpectedly results in colored, cured coating~ without the nesd ~or conventional pigments in the coating compo~itions or in the coating baths. The agueous, cathodic Qlectrodepositable resin compositions comprise an acid-salted, cathodic electrodepositable rssin compo~ition, a crosslinking agent and a hydrophobic dye.
The composition is curable, after electrodepos~tion in an 2 ~

aqueous, cathodic electrodeposition coating bath, to a hard, durable colored coating. Colored, cured electro-deposited coatings can now be produced without the need for conventional pigmenting agents. The coatings also have surprisingly improved gloss, better flow, low VOC and are non-settling.
Another aspect of the present invention i8 a coated article coated with at least one layer of a colored, aqueous, cathodic electrodeposited coating composition.
T~e coating composition comprises an acid-salted, cathodic QlectrodepositablQ resin composition, a cro~s-linking agent, and a hydrophobic dye. The re~ulting coating is hard, durable and colored. The coating~ also have, surprisingly, improved gloss, better flow, low VOC and are non-settling.
Yet another aspect of the pre~ent invention is a an aqueou3, cathodic electrodepo~ition coating bath which i8 free of conventional pigmenting agent3. The aqueous coating bath comprises an acid-salted cathodic, electrodepo3itable resin compo~ition, a cross-linking agent and a hydrophobic dye. The coatings when deposited upon conductive substrates, are hard, durable and colored. The colored coating~ can be produced from the bath without the need for a conventional pigment in either the coating or the coating bath. Th8 coatings have, surprisingly, improved gloss, better flow, low VOC and are non-s~ttling.
Yet another aspect o~ the present invention is a m~thod o~ c~thodic, electrodeposition wherein colored co~ting- ar- produced without the need for conventional pig- nt-. ThQ method comprises forming an agueou~ coating bath ~ro~ a cathodic, electrodepositable acid-salted, cathodic electrodepositable resin composition and a cross-linking agent, tha bath being contained in an electrically insulated vessel containing an anode which i8 in contact with the bath. Them, an electrically conductive article, connected to an electric circuit to act as a cathode, is immersed in the coating bath and sufficient electrical 201~822 . . :. "
power is applied acros~ the article cO that a suf~icient coating of the resin-adduct compo3ition and cross-linking agent is deposited upon the surfaces of the article. The article i then removed from the bath and ~he coating i8 cured to a hard, durable, colored ~ilm. A colored film i5 produced without the need for conventional colored pigment by including a hydrophobic dye in tha resin co~po~ition.
The re~ulting coating contains the hydrophobic dye and has, surprisingly, improved gloss, better flow, low VoC and is lo non-settling, The foregoing, and other features and advantages of the present invention will become mOrQ apparent from the following description.

~J8~ noD~ ~OR GAR~YI~ 0~ ~J INVBNTIO~
The cationic, electrodepositable resin compositions, the aqueou cathodic electrodeposit$on coating bath~, and the cathodic electrodepositabl~ coatings of the present invention do not contain conventional color pigm~nts. The resin composit~ons, coating baths and coating contain the hydrophobic dye~ of the pre~ent invention. The hydrophobic dyes useful in ths practice o~ thQ pr~sent invention will include those dyes which can be generically described as colored materials which di3solve in an organic matrix to make a continuous phase (solution) with no di~crete phace separation.
The dyQs which may be used in the ba3e coat~ of the pr--ont inv~ntion include any 1:2 chromQ or 1:2 cobalt m~tal organic complex dyes, examples of which are listed in T~bl- 1.
Th~ 1:2 chrome and 1:2 cobalt metal organic complex dyes are known in the art; for example, 1:2 chrome and 1:2 cobalt metal organic complex dye3 are disclosed in U.S.
Pat. No. 1,325,841. These dyes ar~ produced by reacting or complexing chromium or cobalt with any organic ~oiety which will complex with the metal in solution, and the complexes are then neutra-lized and ctabilized. Examples of such 2~10~22 TABL~ 1 C.~. ~OhV~T D~CRIPrIO~
.
Yellow 88 1:2 Chromium complex o~ an organic molecule with methyl, hydroxyl, and carboxy groups; - neutralized with a branched aliphatic amine with 12 to 14 carbon ato~s.
Yellow 89 1:2 Cobalt complex o~ an organic molecula with methyl, chloride, hydroxyl, and methylsulfonyl groups;
stabilized with dehydroabiethylamine.
Yellow 25 1:2 Cobalt complex of an organic molecula wi~h nitro, hydroxyl, and carboxy group~; neutralized with soda.
orange 59 1:2 Cobalt complex o~ an organic molecule with nitro, hydroxyl, and carboxy groups; neutralized with soda.
Orange 11 1:2 Cobalt aomplex oP an organic molecule with nitro, hydroxyl, and methyl groups; neutralized with sola and cyclohexylamine.
Red 9 1:2 Cobalt complex of an organic molecul~ with ~ul~a~ide and hydroxyl groups; stabilized with iso-propylamine.
Black 29 1:2 Chro~ium co~plex of an organic molecule with nitro, hydroxyl, and amyl groups; neutralized with 30da.
Violet 24 1:2 Cobalt complox o~ an organic molecule with hydroxyl, chloride, and ~ulfomethylamide groups; tabilized with cyclohexylamine.
org~nlc ~ol~ties include~ phenolic derivatives, pyra~alonQ~, ~onoazo-, diazo-, naphthols, and imidaz~lone.
Exarpl-~ of conventional ~tabilizers include branched aliphatic~ aminé~ with 12 to 14 carbon atoms, soda, isopropylamine, cylohexylamine, dehydroabietylaaine.
Additional 1:2 chrome and 1:2 cobalt metal organic complex dy~s which may be used in the practice of this invention include Solvent Yellow 82 (C.I. 18690), Solvent Red 118 (C.I. 15675), and Solvent Black 27 (C.I. 12195-12197) all of which are chromium complexes containing 1 2 ~
. .
atom of chromium to 2 molecule~ of organic moiety~ These dyQ~ are com~ercially available from BASF Wyandotte Corporation, Cincinnati, Ohio under the Zapon trademar~.
Example~ of 1:2 cobalt metal organic complex dyes useful in the practice of the present invention include dyes disclosed in European patent application EP 113,643, filed on July 18, 1984 and German Offenlegungs~chrift DE
3230102Al. Examples o~ 1:2 chrome metal organic complex dyes use~ul in the practice of this invention are also lo disclosed in U.S. Patent No. 4,340,536. Additional examples of commercially available 1:2 cobalt and 1:2 chrome metal organic complex dyes useful in the practice of this invention include Orasol- Yellow 2RLN (Solvent Yellow 98), Orasol- Yellow 3R (Solvent Yellow 25), Orasol- Orange G (Solvent Orange 11), Orasol- Orange RLN (Solvent Orange 59), Orasol- Red 2~ (Solvent Red 9), Orasol- Violet RN
(Solvent Violet 24), and Orasol- Black R~ (Solvent Black 29). These dyes are manu~actured under the Orasol-trademark, Ciba-Geigy, Greensboro, N.C. These dyes are di~clo ed in U.S. Patent No. 4,598,020.
The organic polyisocyanate~ u~ed in the practice of this invent~on as cross-linking agents in the cat~onic electrodepositable r~in compo~itions ara typical o~ those u3cd in art, e.g., U.S. Patent No. 4,182,831, the di~closure of which is incorporated by reference. The polyisocyanates will praferable be blocked with blocking agont~.
Uo-~ul block~d polyisocyanates are those which are ~t~ in tha disper~ion sy~tems at ordinary room t-q~ rature and which react with the resinous product of thi- invent$on at elevated temperat~res or are reactive when Qxposed to various types of radiation.
In the preparation of the blocked organic polyisocyanate~, any suitable organic polyisocyanate can be used. Repre~entative examples are the aliphatic compounds such as trimethylene, tetramethylene, pentamethylene, hoxamethylene, 1,2-propylene, 1,2-butylene, and 1,3-9 . . .

butylene dii~ocyanates; 3-i~ocyanatomethyl-3,5,5-trimethylcyclohexyli6ecyanate: the aromatic compound~ such as m-phenylene, p-phenylene, 4,4'-diphenyl, and 1,4-xylylens diisocyanates: the triisocyanates such as 5triphenyl methane-4,4'4'-triisocyanate, 1,3,5-benzene triisocyanate and 2,4,6-toluene triisocyanate; and the tetraisocyanates such a~ 4,4'-diphenyl-dimethyl methane-2,2',5,5'-tetrai60cyanate; the polymerized polyisocyanates such as toluene diisocyanate dimers and trimers, 10polymethylene polyisocyanates having -NSC=0 functionalities of 2 to 3, and the like.
In addition, the organic polyisocyanate can be a prepolymer derived from a polyol such as glycol~, e.g.
ethylene glycol and propylene glycol, as well as other 15polyol~ such as glycerol,trimethylolpropane, hexanetriol, pentaerythritol, and the like, as well a monoether~, such a~ diethylene glycol, tripropylene glycol and the like and polyethers, i.e., alkylene oxide condensates or the above.
A~ong the alkylene oxides that may be condensed with 20the~e polyols to form polyether~ are ethylene oxide, propylene oxide, butylene oxide, styrene oxide and the like. The~e are generally called hydroxy-terminated polyethers and can be linear or branched. E6pecially useful polyether polyols are those derived fro~ reacting 25poly318 such a~ ethylene glycol, diethylene glycol, triethylene glycol, 1,4-butylene glycol, 1,3-~utylene glycol, 1,6-hexanediol, and their mixtures; glycerol, tr~m thylol-thano, trimethylolpropane, 1,2,6-hexanetriol, p nta rythritol, dipentaerythritol, tripentaerythritol, 30polyp ntaerythritol, sorbitol, methyl glucoside~, sucrose and th like with alkylene oxides such as ethylene oxide, propylene oxide, their mixtures, and the like.
Particularly preferred polyisocyanates include the reaction product of toluene dii60cyanate and trimethylol-35propane and the i~ocyanurate of hexa~ethylene diisocyanate blocked with dibutyl amine.
The blocking agents used to block the polyisocyanates 2 ~ 2 and polyisocyanate adducts are those known in the art. hy suitable aliphatic, cycloaliphatic, aromatic, alkyl monoalcohol and phenolic compound and ~econdary amino compound can be used as a blocking agent in the practice of the pre~ent invention, such as lower aliphatic alcohols, such as methyl, ethyl, chloroethyl, propyl, butyl, amyl, hexyl, heptyl, octyl, nonyl, 3,3,5-trimethylhexanol, decyl and lauryl alcohol~, and the like: the aromatic-alkyl alcohols, such as phenylcarbinol, ethylene glycol monoethyl ether, monobutyl ether, monopropyl ether and the like; the phenolic compound such as phenol itself, sub~tituted phenols in which the substituents do not adversely affect the coating operations. Examples include cresol, nitrophenol, chlorophenol and t-butyl phenol.
A particularly preferred blocking agent is dibutyl amine. Additional blocking agents include têrtiary hydroxyl amines, such as diethylethanola~ine and oxime~, such as methylethyl ketoxime, acetone oxime and cyclohexanone oxime, and caprolactam. A preferr~d oxime is methyl-n-a~yl ketoxime.
The blocked polyi~ocyanates are for~ed by reacting sufficient quantities of blocking agent with sufficient quantities of organic polyisocyanate~ at a sufficient tamperature for a sufficisnt amount of ti~e under reaction conditions conventional in this art ~uch that no free i~ocyanate group~ are present when the reaction has run its cours-.
Th aminoplast crosslinking agents u~eful in the practlc Or the present invention include: alkylated m ~a~n -formaldehydQ resins, including such melamine-for~aldehyd re~ins which are characterized as being one of tho following types: highly methylated, partially methylated and containing methylol ~unctionality, methylated and containing imino functionality, highly butylated, partially butylated and containing methylol functionality, butylated and containing imino functionality, mixed methylated/butylated, mixed 3 ~ ~

methylated/butylated containing methylol functionality, mixed methylated/butylated and containing imino functionality, or such other melaminas as could be envisioned by exhaustive or partial et~erification with an alcohol of the reaction product o~ 1-6 mole~ of formaldehyde for every mole of melamine Examples of suitable melamine-formaldehyde re~ins which are commercially available include Cymel- 300, Cymel~ 301, Cymel- 303, Cym~l- 350, Cy~el- 323, Cymel- 325, Cymel- 327, Cymel- 370, CymQl- 373, Cymel- 380, Cymel- 385, Cymel0 1116, Cymel~ 1130, Cymel- 1133, Cy~el- 1168, Cymel~ 1156, Cymel- 1158, from the American Cyanamid Company and Resimenee 891, Resimene- 882, Resimen~- 881, Resimene~ 879, Re~imene~ 876, Resimene- 875, Resimene- 872, ~esimene- 747, Resimene~ 746, Resimene- 745, Re~imene- 741, Resimene- 740, Resimene- 735, Resimene- 731, Resimene- 730, Resimene- 717, Resimene- 714, RQsi~ene- 712, Resimene- 764, RQsimene- 755, Resimene~ 753, Resimene- 750, from the Mon3anto Company The a~inopla3t crosslinking agents that are useful in the practice of the pressnt invention also include Benzoguanamine-~ormaldehyde re~ins which have been ~-partially or fully etherified with a suitable alcohol, typically mothanol or butanol or a mixture thereof, and which may also contain methylol functionality and/or imino functionality An exa~ple of thi3 type of crosslinking agent would include the commarcial product Cymel- 1123 from the Aoerican Cyanamid Company T~e aminoplast cro~slinking agents that are useful in th~ pr~ctice Or this invention also include glycoluril-forDAldehyde re~in~ which have been partially or fully etheriried with a ~uitable alcohol, typically methanol or butanol or a mixture thereof, and which may also contain methylol functionality and/or imino functionality Examples of commercially available crosslinking agent~ of this type include Cymel- 1170, Cymel- 1171, and Cy~el~ 1172 from the American Cyanamid Company ~-The aminoplast crosslinking agents that are useful in 2~10~'~2 the practice of this invention also include urea-formaldehyde resins which have been partially or fully etherified with a suitable alcohol, typically methanol or butanol, and which may also contain methylol functionality and/or imino functionality. Examples of commercially availabls crosslinking agent of this type include Beetle-55, Beetle~ 60, Beetle 65, and Beetle~ 80 from the Amerlcan Cyanamid Company and Resimene- 960, Resimene 975, Resimene~ 970, RQsimene- 955, Resimene- 933, Resimene~ 920, lo Resimene- 918, Resimene- 91S, Resimene- 907, Resimene 901, Resimene~ 980, from the Monsanto Company.
The aminoplast crosslinking agents that are useful in the practice of thi~ invention also include carboxyl modified aminopla~t resin. These crosslinking agents would includemelaminQ-formaldehydQ,benzoguanamine-formaldehyde, glycoluriformaldehyde, and urea-for~aldehyde type crosslinking agents that include carboxylic acid functionality a~ well a~ alkoxymethyl functionality, typically methoxymQthyl, ethoxymethyl, and butoxy~ethyl, or a mixture thereof, and which may also contain methylol functionality and/or imino functionality. Examples of co~mercially available croqslinking agents of this type include Cy~el- 1141 and Cymel- 1125 from the American Cyanamid Company.
The cathodic electrodepo~itable coating compo~itions Or this invention which are made from epoxy rosin~ which may optionally b~ chain-extended re~ulting in an increase in th- ~olocular weight of the epoxy molecule~ by reacting w~t~ water misciblo or water soluble polyols. The epoxy re-in- aro reacted with amines to ~orm epoxy-amine resin adducts to form cathodic, elsctrodepositable coating compositions .
The epoxides lepoxy resins) useful in the practice of this invention are the polyepoxides typically used in this art and comprise a resinous material containing at least one epoxy group per molecule.
A particularly useful class of polyepoxides are the ~ C3 glycidyl polyethers of polyhydric phenols.
Such polyepo~ide resin~ are derived from an epihalohydrin and a dihydric phenol and have an epoxide equivalent weight of about 400 to about 4,000. Examples of eplhalohydrins are epichlorohydrin, epibromohydrin and epiiodohydrin with epichlorohydrin being preferred.
Dihydric phenols are exemplified by resorcinol, hydro~uinone, p,p'-dihydroxydiphenyl-propane (or bisphenol A as it is commonly called), p,p'-dihydroxybenzophenone, p, p'-dihydroxy-diphenyl ethane, b~s-(2-hydroxynaphthy) methane, 1,5-dihydroxydiphenyl and the like with bisphenol A being preferred. These polyepoxide resins are well known in the art and are made in desired molecular weiqhts by reacting the epihalohydrin and dihydric phenol in various ratios or by reacting a dihydric phenol with a lower molecular weight polyepoxide re~in. Particularly preferred polyepoxide resins are glycidyl polyether~ of bisphenol A
having epoxide equivalent weight~ oY about 450 ~o about 2,000 more typically about 800 to about 1,600 and preferably about 800 to about 1,500.
The polyepoxides used in the practice of this invention will have a relatively high molecular weight, that i~, the more typically about 1,600 to about 3,200, and pre~erably about 1,600 to about 2,800.
Another quite useful class of polyepoxides are produc~d imilarly from novolak resins or similar polyphonol xe~ins.
Al~o suitable are the polyepoxides comprising similar polygly~idyl ethers of polyhydric alcohols which may be d riv~d ~ro~ such polyhydric alcohols as ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,4-propylene glycol, 1,5-pentaned1ol, 1,2,6-hexanotriol, glycerol, bi~ (4-hydroxycyclohexyl) 2,2-propane and the like. There can also be used polyglycidyl ester~ of polycarboxylic acids, which ar~ produced by the reaction of epichlorohydrin or ~imilar epoxy compounds with an aliphatic or aromatic polycarboxylic acid, dimerized ,, - . , 2 ~ 2 2 linolenic acid and the like. Examples are glycidyl adipate and glycidyl 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. The~e polyepoxides are nonphenolic and are obtained by the epoxidation of alicyclic olefins. For example, by oxygen and selected method catalysts, by perbenzoic acids, by acetaldehyde monoperacetate, or by peracetic acid. among such polyepoxides are the epoxy alicyclic ethers and in other epoxy-containing compounds and resin~ include nitrogenous diepoxides such as disclosed in U.S. Patent No. 3,365,471;
epoxy resins from l,l-methylene bis- (5-substituted hydantoin), U.S. patent No. 3,391,097; bis-imide containing diepoxide~, U.S. Patent No. 3,450,711; epoxylated aminomethyl-diphenyl oxides, U.S. Patent No. 3,312,664:
hsterocyclic N.N'-diglycidyl compound~, U.S. Patent No.
3,503,979; amino epoxy pho~phonate~, British Patent No.
1,172,916; 1,3,5-triglycidyl isocyanurates, as well as other epoxy-containing material3 known in the art.
Any cationic, electrodepo~itable amine-epoxy resin adduct-~ use~ul in the cathodic electrodeposition art can be used in the practice of the present invention a~ well as any equivalent adducts. In addition, modified epoxy resins may be used. Specif~cally, the modified epoxy resins used in the practice o~ thi~ invention may comprise one of the aforementioned epoxy resin compositions chain extended with w~ter mi~cibl- or water soluble polyol, reacted with excess a~ine, and finally reacted with a fatty acid or aliphatic monoepoxide. These epoxy amine resin adduct compositions are di~clo~ure~ of which are incorporated by reference.
However, as previously mentioned, epoxy-amine re~in adducts produce~ by any methods, including the diketimine method as disclo~ed in U.S. Patent No. 3,947,339, may be used in the practice Or the present invention.
The amine functional acrylic copoly~ers useful cathodic electrodepositable resin compositions in the 2 ~

practice of the present invention include copolymers cont~inin~ the following monomers: dimethylamino-ethylmethacrylate, 2-hydroxyethyl acrylate, styrene and butyl acrylate~.
Cathodic, electrodepo~itable, amine functional acrylic compositions are disclosed in U.s. Patent No. 3,883,483 which is incorporated by reference.
Sufficient quantities of cross-linking agents are incorporated into the electrodepositabla coating compositions of this invention such that the deposited coating will be co~pletely cured upon baking and, when using isocyanate eross-linking a~ents there will be virtually no free isocyanate group~ remaining.
When polyisocyanate cross-linking agents are used, typically, about 10 wt.% to about 60 wt.% of blocked polyisoeyanate is incorporated based upon the total weight of epoxy-amine re~in adduct composition and cross-linking agent, more typieally about ~0 wt.S to about 50 wt.%, preferably about 25 wt.S to about 35 wt.~.
When using aminoplast crosslinking agents, typically about 10 wt.% to about 60 wt.% o~ the aminoplast crosslinking agent incorporated into the coating co~position based upon the weight of ~he principal resin ~; and crosslinking agent, more typically about 20 wt.% to about 40 wt.%.
The ero~slinking agents of thi~ invention are typically miYed with the electrod~positable resin co po~ltionJ by adding the eross-linking agent~ to a vessel containing the resin eompositions and mixing the eharge for a ~uf~ieient period of time, for example, about one-half hour.
In order to solubilize or disperse into ~n emulsion electrodepositable resin composition, it is necessary to ~alt the eomposition produet with a water soluble acid.
The aeid~ whieh ean be u~ed inelude tho~e known in that art sueh as formie aeid, acetic aeid, phosphorie acid, lactic acid, hydrochlorie aeid, ete. Suffieient quantities of the 16 ~ ~ -` 2~10822 acid are mixed with said amine-epoxy resin adduct compositions to solubilize or disperse the resin in water.
one method, which is referred, in which the salting process is accomplished is by charging the resin compo6ition, an acid, cosolvents, water and surfactants conventional in the art into a vessel, and mixing the charge with a ~low speed mixer.
Typically, about 0.1 Meq to about 0.8 Meq of acid is used per gram of solid resin, more typically about 0.2 Meq to about 0.7 Meq, and pre~erably about 0.2 Meq to about 0.5 Meq. Once again, it will be appreciated by those skilled in the art that reactant quantities and reaction parameters will according ~o the nature of the components, process equipment, and the like.
The electrodepositable cathodic coating composition~
of this invention are used in an electrodeposition process as an aqueous dispersion. Sufficient quantities of the re~in co~positions are used, dspending upon the particular application parameters, so that the concentrations of the rssin composition~ in aqueou~ baths will produce a coating~
on article of suffici-nt thicknes~e3 30 that, upon baking, the coatings will have deæired characteristics such as a ; smooth surface and durability.
The concentration of cathodic, electrodepositable principal resin coating compositions in an aqueous coating bath is typically about 5 wt% to about 50.O wt.%, more typically about 10.0 wt.% to about 25.0 wt.%, preferably about 15.0 wt.%, although this will vary with the coating pro~e~ and coating syste~ used.
It ~hould be noted that the cathodic electro-depo~it~ble resin ~coating compositions are typically shipped by the manufacturer to the user as a salted, aqueous dispersion having a typical concentration o~ about 20 wt.% to about 36 wt.% of solid~, although any concentration is available.
The cathodic electrodepositable coating baths of this invention are typically formed by mixing concentrates of 291~22 the solubilized (i.e., salted) cathodic electrodepositable resin compositions of this invention with water, although unsalted resin compositions could ~e used in baths already containing the solubilizing acid. The electrodeposition bath may contain additional ingredients such as co~olvents, antioxidants, catalysts surfactants, anti-corro~ive~ etc., which are typically used in electrodeposition procecses known in the art.
Sufficient quantities of the hydrophobic dyes of the present invention are included in the cathodic electro-depositable re~in compositions to produce the appearance characteristics desired such as gloss, reflectance, hue, tint and other desired characteristics. Typically, the amount of dye used is expressed as the weight percentage of total coating bath solids. Typically the dye weight percentage of total coating bath solids. Typically the dye weight percentage of total bath solids is about 0.5 wt.% to about 5.0 wt.% in the electrodepositable resin compositions of the present invention, more typically about 1.0 wt.% to about 4.0 wt.% preferably about 1.0 wt.% to about 1.5 wt.%.
Pigment in conventional cathodic electrocoat processes is typically added to the electrodeposition bath in paste form, i.e., predispersed in a composition comprising pig~ent, cationic, electrodepositable grind resin composition, and surfactants. However, using the hydrophobic dye~ of the present invention, it i9 no longer nece~sary to use color pig~ent pastes.
Th~ dye will be blended directly into the cathodic re~in composition~ of the present invention using conventional blending or mixing means prior to the acid-salting or ~olubilization step. i.e., prior to the aqueous solubilization of the resin composition. After the sufficient amount of dye have been incorporated into the cathodic resin composition, it is then acid-salted~
The use of the hydrophobic dyes in the coatings and processes of the present invention eliminate~ the need for color pigments and thereby results in several advantages.

2 ~

Eliminating pigment from the E-Coat coatings and processes improves the efficiency of the coating process since pigment-settling is al50 eliminated. The cumbersome, complex Pigment to Binder (P/B) monitoring and testing, which must now be done with conventional pigment-containing cathodic electrocoat bath~ can now be eliminated with the pigment-free electrocoats of the present invention. ln addition, the use of hydrophobic dyes results in aqueous coating baths having a reduced VOC. The reduced VOC is attributable to the elimination of conventional pig~ent pastes from the coating bath. Pigment must be introduced into an aqueous coating bath in a paste forQ consisting of grlnd resin, solvents and dry pigment. The elimination of conventional pigment paste from a bath results, accordingly, in the elimination of those organic solvents typically contained in a grind resin, such as butyl cellosolve, hexyl cellosolve, polypropylated phenol oxide, ethyl cellosolve, methyl cellosolve, methyl isobutyl ketone, and the like~ Another advantage of the coating systems of the present invention i~ that it is now possible to have a one component system rather than the two-component systems which are used in conventional pigment-containing electrocoats. The two-component systems typically consist of a principal emulsion and a pig~ent paste.
Th~ elimination of pigment paste from a conventional E-Coat bath will result in a significant reduction of the VOC o~ the coating bath. The reduction and elimination of VOC ~ro~ cathodic electrocoat coating baths i9 being m~ndated by federal, state and local environmental laws.
The electrodeposition baths may contain coupling solvent~ which are water soluble or partially water soluble organic solvents for the resinous vehicles used in the practice of this invention. The coupling solvQnts or cosolvents used in the practice of this invention are those typically used and known in the art. The coupling solvents or cosolvents used in the practice of this invention are 20108~2 those typically used and known in the art. The coatings, coating baths and processes of the present invention significantly lower the need for cosolvents thereby reducing the coating bath VoC. The presencs of pigment reduces the flow of a coating. In order to improve flow, cosolvents are used as additives. The pigment-free coating compositions of the present invention have improved flow and therefore, the need for cosolvents is reduced or eliminated. The elimination of cosolvents further reduces lo the VOC of the coating bath.
The smoothness of the cured coating is a function of the "flow" of the deposited coating composition. Flow is defined as the tendency of the electrodeposited coating composition to liquify during the curing operation and form a smooth cohesive film over the surface of a coated article prior to the onset cross-linking.
The electrodeposition proc2ss typically takes place in an electrically insulated tank containing an electrically conductive anode which i8 attached to a power source such as a direct current source. The 8iZQ of the tank will depend on the size of the article which i8 to be coated.
Typically, the tank is constructed of stainless steel or mild steel lined with a dielectric coating such a~ epoxy impre~nated fiberglass or polypropylene. The electrodepositable, cathodic resinous coating compositionC
of this invention are typically used to coat conductive article~ such as automobile or truck bodie~ and body parts.
Th typical SiZQ of an electrodeposition bath tank used for thi- purpose can range from about 100-200 gallons (378-756 lit-r-) to about 120,000 gallons (454,250 liters).
However, arti`cle~ of any ~ize, ranging from fasteners to off-road construction equipment or structural members, may be coated with these composition.
To initiate the proces , typically, the article is connected to a direct current circuit (either before or after immersion in the bath), so that the article acts as the cathode. When the article is immersed in the coating 2~ -~al0~22 bath, an electrical power flow across the article results in the dispersed cationic electrodepositable coat~ng composition being deposited on the surfaces of the article.
The dispersed resin composition is positively charged and therefore attracted to the negative cathodic surfaces of the article. The thickness of coating deposited upon the article during its residence in the aqueous cathodic coating bath is a function of coa~ing parameters known i n this art, such as the chemical composition of the cathodic lo electrodepositable resin composition, the voltage across the article, the current flux, the pH of the coating bath, the conductivity, the residence time, etc. Sufficient voltage will be applied to the article for a sufficient time to obtain a coating of sufficient thickness.
Typically, the voltage applied acro~s the article is about 50 volts to about 500 volts, more typically about 200 to about 350 volts, and preferably about 225 volts to about 300 volts. The current density is typically about 0.5 ampere per sq. ft. to about 30 amperes per sq. ft., more typically about ons ampere per ~q. ft. The articles typically remain~ in the coating bath for a sufficient period of time to produce a coating or film of sufficient thickness, having sufficient flexibility and having sufficient resistance to corrosion. The residence time or holding time ia typically about 1-2 second to about s `~ minutes, more typically about 1 minute to about 2-1/2 minutes, and preferably about 2 minutes.
The pH of the coating bath is sufficient to produce a co~ting which will not rupture under the applied voltage.
That is, sufficient pH to maintain the stability of the coating bath ' 80 that the resin does not kick-out of the dispersed state and to control the conductivity of the bath. Typically, the pH is about 4 to about 7 more typically about 5 to about 6.8, and preferably about 5.5 to about 6.5.
The conductivity of the coating bath will be sufficient to produce a coated film of sufficient 20~ 2~

thickness. Typically the conductivity will be about 800 micromhos to about 3,000 micromhos, more typically about 800 micromhos to about 2,200 micromhos, and preferably about 900 micromhos to about 1,800 micromhos.
The desirable coating thicknesses are sufficient to provide resistance to corrosion while having adequate ~lexibility. Typically, the film thicknesses of the coated ob~ects of this invention will be about 0.4 mil (o.Ool cm) to about 1.8 mils (0.005 cm), although thicker or thinner films may be deposited as required.
When the desired thickness of the coating has been deposited, the article is removed from the electro-deposition bath and cured. Typically, the electrodeposited coatings are cured in a conventional convection oven at a sufficient temperature for a ~ufficient length of time to unblock the blocked cross-linking agent~, if blocking agents are used, and allow for the cross-linking agents, if blocking agents are used, and allow for the cross-linking of the electrodepositable resin compositions. Typically, the coated articles will be baked at a metal temperature of about 300-F (149-C) to about 600-F (315-C), more typically about 250-F (121-C) to about 390-F (l99-C), and preferably about 300-F (149-C) to about 375-F (l91-C). The coated articles will b~ baked for a time period of about 10 minute~ to about 40 minutes, more typically about 10 ~- minutes to about 35 minutes, and preferably about 15 ~inute~ to about 30 minutes.
It will be appreciated by one skilled in the art that all coating and baking parameters may vary in aecordance with ~ueh faetors as the partieular coating co~po~ition eoployed, proee~s equipment, coating performance requirements, and the like.
It is contemplated that the coated articles of the present invention ~ay also be cured by using radiation, vapor curing, contact with heat transfer fluids, and equivalent methods.
Typieally the coated articles of this invention will 2 ~ 2 , .~.
comprise electrically conductive substrate having a conductivity similar to the aforementioned metals may be used. The uncoated articles may comprise any shape so long as all surfaces can be wetted by the electrodeposition bath. The characteristics of the uncoated article, ~he capacity of the surfaces to be wetted by the coating solution, and the degree of ~hielding from the anode.
Shielding is defined as the degree of interference with the electromotive field produced between the cathode and the anode, thereby preventing the coating composition from being deposited in those shielded areas. A measure of the ability of the coating bath to coat remote areas of the ob;ect is throwpower. Throwpower is a function of the electrical configuration of the anode and cathode as well as the conductivity of the electrodeposition bath.
The coatings of the coated articles of this invention exhibit superior smoothness, gloss, flexibility, durability and resistance to corrosion. Smoothne~s and gloss are related to the flow of the electrodepo~ited cathodic resin.
Durability, flexibility and resistance to corrosion are related to the chemical nature of the electrodeposited cathodic resin co~position a~ well as the smoothness of the depositQd coating. These coating compo~itions readily accept an automotive primer overcoat. The coating~ of the present invention have, surpri~ingly and unexpectedly, color and tint and hiding without the need for pigment.
This is attributable to the use of hydrophobic dyes in placo of pigments. The coatings also exhibit surprising and unexpected improvement~ in gloss and di~tinctness of image.
It should be noted that the articles which are coated by the coating compositions of this invention are typically automobile bodies which have been pretreated to remove impurities and contaminants in a treatment bath such as a phosphatizing bath. However, the coating compositions may be used to coat virtually any article comprising a electrically conductive substrate, with or without 201 ~22 pretreatment of the surfaces of the article. This includes appliances, truck bodies, vehicle parts, structural me~bers, etc.
The following example~ are illustrative of the principles and practice of this invention, although not limited thereto. Parts and percentages where u~ed and parts and percentages by weight.

815N'rATIVJ ~ 11?~58 OF TYPICIU. POI~ IC llaTlS~IAL8 U8EFU~ IN q!llI8 D~ q!IO~
~SA)IFI~IS 1 Ethyl cellosolve (290.0 parts by weight) and 106.0 parts of butyl cellosolve are charged into a reactor equipped with condenser, stirrer, thermometer, and dropping funnel. This mixture is heated to 120--130-C and held at this temperature. To this mixture is added over a period of 3 hours, a mixture of 580.0 parts butyl acrylate, 350.0 parts styrene, 140.0 parts N,~-dimethylaminoethyl methacrylate, 58.0 parts 2-hydroxyethyl mekhacrylate, and 17.0 parts ~ azobisisobutyronitrile. A mixture of 2.0 parts t-butyl peroxyisopropyl carbonate and 1.5 parts ethyl cellosolve is then added. The reaction is held at 120C
for 1 hour, after which a sscond addition of said components is added and, likewise, the reaction is ~ 25 permitted to continue for 1 hours, after which a third and `~ final addition of said component3 is added and the reaction is p-rmitted to continue ~or 2 hours.

E~AMPL~ 2 A reaction vassel i8 charged with 727.6 parts EponR
829, 268.1 part~ PCP-0200, and 36.1 parts xylene and heated with a nitrogen sparge to 210- C. The reaction is held at reflux for about 1/2 hour to remove water. The reaction m~xture i8 cooled to 150- C and 197.8 parts bisphsnol A and 1.6 parts benzyldimethylamine catalyst are added and the reaction mixture heated to 150--l90-C and held at this temperature for about 1 1/2 hours and then cooled to 130-~010~22 C. Then 2.2 parts of the benzyldimethylamine catalyst are added and the reaction mixture held at 130-C for 2 1/2 hours until a reduced Gardner-Holt visco~ity (50 percent resin solids solution in 2-ethoxyethanol) of P is obtained.
Then 73.1 parts of a diketimine derivative derived from diethylenetriamine and methyl isobutyl ketone (73 percent solids in methyl isobutyl ketone), and 39.1 parts N-methylethanolamine are added and the temperature of the reaction mixture is brought to llO-C and held at this temperature for 1 hour. To this mixture, 76.5 parts 2-hexoxyethanol are added.

B8~Ph~ 3 To a clean, dry reactor, 115 parts xylene are added.
The mixing liquid is blanketed with pure nitrogen and heated to 42- C. An addition of 568.1 parts of Epon~ lOOlF
(EEW = 520 - S40) is made at such a rate that the batch temperature never drops below 60-C, usually over a period of two hours. Heating i9 continued until 100 C. At this point, 75.9 parts dodecyl phenol are added and heated to 118- C. Vacuum drying by distillation of xylene is started at this temperature and continued while heating to 125~C.
The pressure should be betwsen 65 cm and 69 cm Hg (88 kP -92 kP) at full vacuum. The drying stage should take between 1.0 and 1.5 hours. Break vacuum with pure nitrogen only. The batch is cooled (the sample at this point should contain 94.3-95.3 % non-volatiles), and at 115- C, 1.1 part~ benzyldimethylamine are added. The peak exotherm temperature should reach 129--132- C. The temperature is maintained at 128--132- C and the polymerization is foliowed by EEW (epoxy equivalent weight) titration. Every 30 minutes the reaction i8 sampled and is stopped at an end point of 1090 -1110 EEW. The typical reaction time is three hours. Ad~ustments to the catalyst level may be necessary if extension period deviates more than 30 minutes from three hours. At the target E~W, 12.1 parts butyl Cellosolve and 74.7 parts xylene are added followed by 42.6 2 ~ ~ 8 22 parts DEOA ~diethanolamine). The temperature of this reaction should not exceed 132'C. Cooling may be necessary at this point with jacket or coils. A vacuum suction is started immediately after the DEOA addition and pressure is reduced to 18 inches of Hg and held for 5 minutes. The pressure is further reduced in 2 inch Hg increments followed by short holding period until 26-27 inches of Hg is achieved. The batch is then cooled to sooc in one hour following addition of DEOA. To achieve this, a good reflux rate should be attained in 20-25 minutes after the DEOA
addition. All solvents are returned to the reactor. After one hour of vacuum cooling (T = 9Q- C), 40.6 parts ethylene glycol monohexyl ether and 107.7 parts isobutanol are added without breaking vacuum. The batch is cooled for 35 minutes to 57--61 C under full vacuum to achieve the target temperatures during the specified time tables.
After the 35 minute cooling period, 13.3 parts of dimethylamino propylamine (DMAPA) are charged as fast as possible. The batch is kept between 54--60~C for two hours after the exotherm. Then it is heated to 90- C over one hour and this temperature is held for one hour. The batch i8 then cooled to 80-C.

~AMPIi~ 4 To a suitable reactor 1881.7 part~ of triethylene tetra~ine are added. Heat and agitation are applied and, at 104-C, 1944.8 parts of an epoxide resin solution at 59.4~ solids in ethylene glycol monomethyl ether (the epoxide re~in being glycidyl polyether of bisphenol A
having an epoxide equivalent weight of 895) are slowly added. The epoxide resin addition i~ completed in 65 minutes and the temperature drops to 99-C. The temperature i8 810wly raised to 121-C over 45 minutes and is held between 121--127-C for 1 hour to complete the adducting reaction. The exce~8 unreacted amine and the solvent is removed by heating the adduct solution to 232~C under vacuum (25 mm Hg pressure). When the distillation is 2~

completed, vacuum is released and the temperature is reduced to 182C. This i8 followed by the addition of 700 parts of ethylene glycol monomethyl ether, which reduces the temperature to about 118-C. When the solution is homogeneous, 458.3 parts of the glycidyl ether of mixed fatty alcohols containing predominantly n-octyl and n-decyl groups, the glycidyl ether having an epoxide equivalent weight of 229 are added at a temperature of 107-116~ c.
Heating is stopped after an additional hour at 116C. The resulting product should have a ~olids content of 71.3 %, and a Gardner-Holt viscosity of Z6 -Z7.

~YAMP~E 5 A blocked isocyanats (polyurethane cross-linking agent, reverse order) is prepared according to the following procedure. Slowly and with stirring in a nitrogen atmosphere, 291 parts of an 80/20 iso~eric mixture of 2,4-/2,6-toluene diisocyanats, 0.08 parts of dibutyltin dilaurate and 180 parts of ~ethyl isobutyl ketone are charged to a suitable reactor, the temperature being maintained below 38-C. The mixture is maintained at 38-C.
for a further half hour after which 75 parts of trimethylolpropane are added. After allowing the reaction to proceed for about 10 hours, 175 parts of ethylene glycol monopropyl ether are added and the ~ixture reaction kept 1.5 hours at 121-C until essentially all the isocyanate group~ are reacted. This depletion is recognized from the in~rared spectrum.
The normal order blocked isocyanate can be prepared by th- altering of the foregoing order of addition pursuant to Example 1 of German Offenlegungsschrift 2,701,002.

BYAh~h~ 6 A blocked is isocyanate crosslinker (polyurea) is prepared according to the following procedure. To a dry re w tor, 483 part~ of trii~ocyanurated hexamethylene-diisocyanate and 193 parts of 2-hexanone are charged.

2(~ 0 ~2 Dibutylamine (307 parts) is added slowly and with stirring under nitrogen atmosphere so that the temperature does not exceed 80-C. After all amine ha~ reacted, 14 parts o~ n-butanol and 0.2 parts of dibutyl tin dilaurate.

gSA~PL~8 OF T~E INCORPORATION o~ ~YDROP~O~IC DYJ8 IN
PRINCI~AL RE8I~ 80L~ION8 l~P~ 7 - ~ 2 This general procedure applies to the examples in Table 2, which contain the specific formulations. All amounts in Table 2 represent the weight of the non-volatile portion.
A suitable mixing ve~sel is charged with the crosslinker, and the dye with 810w stirring. This mixture is stirred for about 30 minutes or until homogeneous.
Plasticizer and organic solvents are t~en added to the mixture, containing the agitation. Principal resin, at 21--49- C., is then added to the continuously mixing batch.
After 30 minutes of continually mixing, a water insoluble organo-lead compound(s~ or a liquid tin catalyst is added.
The mixing i8 continued uninterrupted for 30 minutes, then all remaining additives, flow agents, solvent, antifoam agent, and surfactants are added as required.
2s ~ABL~ 2 ,, ,,, , . _ _ Cro-slinker 30.5 30.515.0 14.0 30.5 (Exa-ple 5) Crosslinker 15.0 14.0 31.0 (Exampl0 6) Paraplex WP-l- 7.6 7.6 7.6 7.6 7.6 Rohm & Haas Orasol RL 1.2 1.2 1.2 Black dy~

~01~822 (Table 2 continued) Zapon- 1.2 1.2 Black X51 Zapon- 2.5 Red 471 Prin. Resin 67.0 lo (Example 1) Prin. Resin 55.0 (Example 2) Prin. Resin 56.6 56.6 57.0 (Example 3) Prin. Resin 57.7 (Example 4) ~ibutyltin 1.8 dilaurate Lead (II) 1.8 1.8 1.8 1.8 2-Ethyl hexanoate Lead 3.2 naphthenate Flow 2.3 2.3 2.3 2.3 2.3 additive E~P~ 13-19 Thi general procedure applie to the Examples found in T~ble 3, which contain the specific formulations. All amounts in Table 3 represent the parts by weight of the ingr~dient.
Flrst, principal resin solutions containing the cro~linker, plasticizer, the hydrophobic dye, the cataly~t, and other applicable ingredients are mixed together as described in the previous set of examples (7-12). A solubilizing acid i5 then added to the principalresin solution, and then the resultant solubilized principal resin solution is then mixed with deionized water, or, optionally, with a deionized water/surfactant mixture.

, INGREDIENTS EXAMPLES

Example 7 269.7 (74%) : :
Example 8 269.7 (74~) Example 9 269.7 269.7 (74~) Example 10 269.7 (74%) Example 11 269.7 (74%) Example 12 269.7 (74%) Acetic 2.53 2.53 2.53 3.31 3.19 2.53 acid (Glacial) Lactic 4.46 acid (85%) Deionized 298.0 298.0 298.0 296.1 297.2 291.3 298.0 water - .

EranPLe~ 0~ CA~ODIC PAINT~ CO~TAI~I~C ~YD~O~O~IC DYES
EXAMPLES 20 - 26 are prepared according to the for~ulations shown in Table 4.
TA~L~ 4 ~NGREDIENTS EXAMPLES

.....

Example 13 571.4 Example 14 571.4 Example 15 571.4 ~Table 4 continued) Example 16 571.4 Example 17 571.4 Example 18 571.4 Example 19 571.4 Deionized 428~6 428.6 428.6 428.6 428.6 428.6 428.6 water The E-Coat coating composition and coating baths of the present invention are free of conventional pigmenting agents while having the desirable color and appearance characteristics. The use of hydrophobic dyes surprisingly and unexpectedly results in electrodeposited cathodic coatings having color without the need for pigments. The elimination of conventional pigments eliminates the pigment settling and fouling of process equipment, and reduces the VOC of the coating bath. In addition the burdensome monitoring of the P/B ratio of the ~oating bath is eliminated. Grind resins are eliminated from coating baths, and, the costly and energy intensive grinding process reguired to produce pigment pastes is also eliminated. The coatings of the present invention also exhibit, surprisingly and unexpectedly, improved gloss, and flow.
Although this invention has been shown and described with respect to the detailed embodiments thereof, it will bo understood by those skilled in the art that various change in form and detail thereof may be made without departing from the spirit and scope of the claimed invention.

.

Claims (20)

1. An aqueous, cathodic electrodepositable resinous coating composition comprising an acid-salted, electrodepositable resin composition;
a cross linking agent; and, a hydrophobic dye the composition being curable, after electrodeposition in an aqueous, cathodic electrodeposition coating bath, to a hard, durable, colored film having high gloss and improved flow.

2. The coating composition of claim 1 wherein the resin composition is selected from the group consisting of epoxy-amine resin adducts and amine functional acrylic copolymer resins.

3. The coating composition of claim 1 wherein the crosslinking agent is selected from the group consisting of blocked polyisocyanates, blocked polyisocyanurates, and aminoplast resins.

4. The coating composition of claim 1 wherein the dye is a metal organic complex dye selected from the group consisting of 1:2 cobalt metal organic complex dyes and 1:2 chrome metal organic complex dyes.

5. The coating composition of claim 1 wherein the dye is selected from the group consisting of C.I. Solvent Yellow 88, C.I. Solvent Yellow 89, C.I. Solvent Yellow 25, C.I. Solvent Orange 11, C.I. Solvent Orange 59, C.I. Solvent Red 7, C.I. Solvent Violet 24 and C,I, Solvent Black 29.

6. A coated article coated with at least one layer of an aqueous, cathodic electrodeposited coating composition, wherein the coating composition comprises a n a c i d - s a l t e d electrodepositable resin composition;
a cross-linking agent; and, a hydrophobic dye, the resulting coating being hard, durable and colored, and, exhibits improved gloss and flow.

7. The coated article of claim 6 wherein the resin composition is selected from the group consisting of epoxy-amine resin adducts and amine functional acrylic copolymer resins.

8. The coated article of claim 6 wherein the crosslinking agent is selected from the group consisting of blocked polyisocyanates, blocked polyisocyanurates and aminoplast resins.

9. The coated article of claim 6 wherein the dye is metal organic complex dye selected from the group consisting of 1:2 cobalt metal organic complex dyes and 1:2 chrome metal organic complex dyes.

10. The coated article of claim 6 wherein the dye is selected from the group consisting of C.I. Solvent Yellow 88, C.I. Solvent Yellow 89, C.I. Solvent 25, C.I. Solvent Orange 11, C.I. Solvent Orange 59, C.I.
Solvent Red 7, C.I. Solvent Violet 24 and C.I.
Solvent Black 29.

11. An agueous, cathodic electrodeposition coating bath comprising a n a c i d - s a l t e d electrodepositable resin composition;
a cross-linking agent; and, a hydrophobic dye the coating bath producing colored, electrodeposited coatings having improved gloss and improved flow.

12. The coating bath of claim 11 wherein the resin composition is selected from the group consisting of epoxy amine resin adducts and amine functional acrylic copolymer resins.

13. The coating bath of claim 11 wherein the crosslinking agent is selected from the group consisting of blocked polyisocyanates, blocked polyisocyanurates, and aminoplast resins.

14. The coating bath of claim 11 wherein the dye is a metal organic complex dye selected from the group consisting of 1:2 cobalt metal organic complex dyes and 1:2 chrome metal organic complex dyes.

15. The coating composition of claim 11 wherein the dye is selected from the group consisting of C.I. Solvent Yellow 88, C.I. Solvent Yellow 89, C.I. Solvent Yellow 25, C.I. Solvent orange 11, C.I. Solvent Orange 59, C.I. Solvent Red 7, C.I. Solvent Violet 24 and C.I.
Solvent Bla¢k 29.

16. In a method of cathodic electrodeposition comprising forming an aqueous coating bath from a cathodic, electrodepositable resin composition, said composition comprising a acid-salted, cationic resin composition and a cross-linking agent, the bath being contained in an electrically insulated vessel containing an anode in contact with the bath, then connecting an electrically conductive article to an electric circuit to act as a cathode, and immersing the article in the coating bath, then applying sufficient electrical power across the article so that a sufficient coating or the resin composition and cross-linking agent is deposited upon the surfaces of the article, removing the article from the bath and then curing the coating to a hard, durable film, the improvement comprising producing a colored, electro-deposited, cured coating by including a hydrophobic dye in the resin composition, thereby producing the cured coatings have improved gloss and flow.

17. The method of claim 16 wherein the resin composition is selected form the group consisting of epoxy amine resin adducts and amine functional acrylic copolymer resins.

18. The method of claim 16 wherein the crosslinking agent is selected Prom the group consisting of blocked polyisocyanates, blocked polyisocyanurates, and aminoplast resins.

19. The method of claim 16 wherein the dye is a metal organic complex dye selected from the group consisting of 1:2 cobalt metal organic complex dyes and 1:2 chrome metal organic complex dyes.

20. The method of claim 16 wherein the dye is selected from the group consisting of C.I. Solvent Yellow 88, C.I. Solvent Yellow 89, C.I. Solvent 25, C.I. Solvent Orange 11, C.I. Solvent orange 59, C.I. Solvent Red 7, C.I. Solvent 24 and C.I. Solvent Black 29.