GB2237806A

GB2237806A - Cathodic electrodeposition coating composition

Info

Publication number: GB2237806A
Application number: GB8925208A
Authority: GB
Inventors: Jury Petrovich Vorobiev; Valentin Georgievich Lambrev; Jury Filippovich Vorobiev; Olga Jurievna Melnik; Tatyana Fedorovna Solodukha; Valery Pavlovich Lobanov; Galina Alexandrovn Strunnikova; Elena Stepanovna Manuilova; Vladimir Fedorovich Lapin; Vladimir Ivanovich Kravchenko
Original assignee: Individual
Current assignee: Individual
Priority date: 1989-11-08
Filing date: 1989-11-08
Publication date: 1991-05-15
Also published as: GB8925208D0; CN1053251A; DE3941539A1; FR2654739A1

Abstract

The coating composition comprises the following components (parts by weight): an epoxyrubber adduct modified by reaction with a mixture of an amino and an ( alpha -branched monocarboxylic acid amino-amide at a ratio of amine and aminoamide equivalents of from 1.5:1 to 1:1.5 100.00 a cross-linking agent 15.0-30.0 a catalyst of cross-linking 0.5-2.0 an organic solvent 50.0-100.00 a neutralizer 2.4-3.0 a pigment 5.0-40.0 a filler 5.0-25.0. it is mposition is diluted with water before use.

Description

21 317 a C1) G.

COM-POSITION FOR CATHODIC ELECTRODEPOSITION OF COATIN,S 11P The present invention relates topaint and varnish industry and more particularly to a co:aposition for Cathodic electrodeposition of coatings and can be used for cathodic electrDdeposition of antiCOrr0SiOn coatings onto metals, for instance, automobile parts.

Known in the art is a composition for cathodic elect=deposition of coatings consisting of an epoxy resin modified with a mixture of amine maleinated fatty acid aminoamide, a cross-linking agent, a catalyst of cross-linkingyan organic Solvent. a neutralizer, a pigment, and a filler /US A, 4287041/.

As a crDss-linking agent the known composition contains a partially blocked polyisocyanate.

Cathodic eleCtrDdeposition of the above composition onto metals, in particular, phosphated and nDn-pbDsphated steal, gives coatings with pleasing appearance, high mechanical and anticDrrDSiOn PrOpertieS.

Because of a high Viscosity of the epoxy resin modified with a mixture of amine and malein-CDntaining fatty acid aminoamide, the preparation of the composition requires dilution thereof with water up to a content of nonvolatile compounds no more than 407o.

This is uneconomical, in particular, for transporta- tion of said composition.

Besides, the homogeneity of the composition can be violated upon freezing and subsequent thawing thereof.

1 (4p In addition, the technology of preparing the known CDDIPDSitiOM is complicated by the necessity to preliminary malainize the constituting fatty acids which Is rather labDUM-Consuming high-temperature operation.

The preparation of the known composition also requires, to avoid side reactions, the Use of thoroughly purified and anhydrous r8W Mteri8lS, solvents, and inert gas.

In the process of hardening the coatings prepared from the known composition toxic CMPDunds are liber ated and a considerable loss (up to 2075) Of the coating mass is observed because of decomposition Of Polyurethane formed in the course Of preparing the composition.

Also known in the art is a composition for cathodic 1.5 electrodeposition of coatings containing an epoxy resin modified with a mixture of araine and diinerized fatty acid aminoamide, a cross-linking agent, a catalyst Of cross-linking, an Organic solvent, a neutralizer, a pigment, a fillerg and Other additives /US, A, 4190564/.

Cathodic alectrod@PDSition of this CDMPDSition On steel also gives coatings with good appearancog mecha nical and anticorrosion properties. However, this compDaitiDa features the same drawbacks as the CMPOSi tion prepared according to /US, A, 4287041/.

2.5 Likewise known in the art is a composition for cathodic el@CtrDd@PDSition Of coatings containing an 0 epoxy rubber adduct Modified with amines, a crDss-linking 4 agentg a catalyst of cross-linking, an organic solvent, a neutralizer, a pigment, and a filler /USA, 4253930/.

As a cross-linking agent this composition contains blocked polyisocyanate.

The coatings based on this composition also have Good appearance, mechanical and antiCDrrosion properties.

However, piGmentation of this composition requires an additional component with quaternary ammonium groups, Besides, this composition features all the disad vantages mentioned above for the compositions prepared according to /US$ A, 4287041 and US A, 4190564/.

The main object of the invention is to prepare by simple technology a conpositiDn for CathDdic electro15 deposition of CD8tin'S with low mass losses upon hardening of the Coating being obtained, possessing good ar, tiCD.r.rosi[)n and mechanical properties.

It is also an object of the invention to prepare a composition for cathodic eleCt2DdepDsitiDn suitable for transportation, storage, and use.

Said object is accomplished by that a Composition for cathodic eleCtrDdepOSitiDn of coatings containing an epoxyrubber adduct modified with amines, a crosslinking agent, a catalyst of cross-linking, an organic solvent, a neutralizer, a pigment, and a fillerg accDrding to the invention, contains as a modified epoxy- rubber adduct the adduct modified with a MiXtUrg of amino and oC-branched MDnDcarbc)xylic acid (C 9_ C19) amino amide with a ratio of equivalents of amine and amino amide from 1.5:1 to 1:1.5 and the following ratio of the components (mass parts):

said adduct 100.0 crDss-linking agent 15.0-3.3.0 catalyst of cross-linking 0.5-2.0 organic solvent 30-0-100.0 neutralizer pljment filler 5.0-40.0 5.0-25-0.

It is recommended that the composition c Dnta in the product of reesterification of polyatomic alcohol with dimethyl ethers of aliphatic dicarboxylic acids (C4-CIO) as a cross-linking agent.

The proposed composition posseases biGh mechanical and anticorrosion properties.

The Composition represents an anhydrous Concentrated paste homogenized and not freezing at low (about -30'C) temperatures.

This is Convenient for transportation, storage, and use of the CDMPDSitiDII, The technology of preparing the CDMPDSition does not require maleinization of the constituting fatty acids.

1 (.3 PigmentizatiDn of the proposed composition does not require the introduction of an additional component for dispersing the pigments.

The introduction into the CDMDSition of the product of reesterificatiDn of polyatomic alcohol with dimethyl ester of aliphatic dicerbDXyiiC acids (C 4- C1,D) as a her-, dener results in a considerable decrease of the mass losses in the course of bdrdenin-, and eliminates the

0 liberation of toxic compounds.

The proposed composition is prepared in the following y The pi6ment and the filler are dispersed in a solution of the modified adduct in an organic solvent after which the rest components of the COMPDSition are intrDdu15 cad into the obtained mixture upon stirring.

It is possible (and in the C-2Se of Using an OligDu.rethane as a crosslinking a,-ent even preferable) to deliver the cross-linking agent not into the compo- 0 cj sitiDn but into the adduct prior to raodification thereof with a mixture of amine and (Y,-brancbed monocaxbDxylic acid aminDamid.

The abDve-inantioned modified adduct, prior to the modification thereof with a mixture of P-mine and o-branched acid 8MinDarlide, represents a product of reaction of diane epD xy resin with an epoxyequivelent of 200800 and nitrile rubber at a ratio 80-90 mass parts of epoxy resin and 10-20 mass parts of rubber.

1 P As a nitrile rubb@.r use can be ir.ade of liquid butadiene-acrylonitrile copolymers with carboxyl groups containing 20-30% acrylDnitrile and having an acid number of 30-40 mg KOH/g and a molecular rnass of 3000-4000.

-bbe.r above 20 mass parts A xise in the amount of ru Increases sharply the viscosity of the -,. Ddiljied adducty whereas a decrease below 10 mass parts deteriorates coalescence of the coatin,',;. upon electrodepDSition of 10 the proposed composition.

The Interaction of epoxy resins vjizh nitrile rubber is performed by heating the:7.ix'uuxe thereof at 130-150C Without a solvent or in the presence of an inert solvent and possibly with amine -2s a cat-alyst. If use is,.,,ade of epoxy resins with an epDxyequivelenu" below 500, condensatuiDn is carried out in the prese--ce Df free diphen.vlolp.rc)pane in order to obtain an epoxy-rubber adduct with an epDXYeguivalent D.1f.500-900 prior to modification of said adduct with a mixture of amine and c,-branched monocarbDXyliC acid aminoamide. A decrease in the epoxy equivalent of the epDxyrubber adduct belDW 300 deteriora tes the mechanical properties of the coatinr-s obtained from the proposed composition, whereas an increase in -he the epoxyequivalent above 900 lowers Solubility of the modified adduct.

h.i'DditL'icatiDn of the epDXYrubber adduct with a mixture of smine and 0 -branched,nonDcsrboxylic acid aminoamide is accomplished via a complete transformation of the ePD.XY groups Of the epoxyrubber adduct into the corresponding aminoderivatives, which is atTuained by that 1 equivalent Of the active HE atom in the aminogroups of the mixtu-re of awine and aC-branched acid aminoamide is taken per epoxyequivalent of the epoxy.rubber adduct. An excess of the amine may deteriorate the process of cathodic electrodepositiDn Of Coatings, whereas a shortage of the amine causes undesirable policoridensation at free 6PMY groups and a rise in the viscosity of the adduct.

The ratio of amine and,,,(-branched acid aminoamide in the mixture may be varied from 1:1.5 to 1.5:1. If the amount of QC-branched Pcid aminDamide exceeds the upper the solubility of the modified adduct in water (after neutralization t,,eraDf with acids) becomes poorer; if the amount of amine exceeds the upper limit,) the wetting ability Of the Modified adduct becomes worse C) and pi,-:,,nentatii)n is more difficult.

The addition Of aMineS to said epDxyrubber adduct is carried out in the process of gradual beating the M-ure Of amines and apoxyrubber adduct from 80 tD 1201C ixt and keeping said mixture at 12WC until the viscosity of the modified adduct becomes constant.

It is also possible (and in the case Of 1OW-reactive amine. for instance, diethanolamine, even necessary) tD (p 1.5 perform a preliminary addition of amine to the epoxyrubber adduct at 50- 800C9 and Jljban by adding CV -branched acid aminoamideg to obtain the modified adduct at 12011C. The amine number of the modified epoxyaminorubber adduct is 45-70 mg KOH/S and the mass fraction oL nDnvolatile compounds is 65 5/5.

Secondary OH-containing amines. for instance, thanolamine, diethanolamine and othersy are inDst me 'U h y 1 et suitable as amines, o6-br,.nc-hed monocarbDxylic acid is prepared separately b.. interaction of poly-'Lunctior.al P.r,.ine, I i,nstance.die"U,I.iylenetriamine or triethylenetetrarnine, and oC-brancl,-,ed monocarboxylic acids, for instance, a mixture of scids of the general formula (C 1H, H 1 2 4 H7C- C - COOH C4H 9 where n = 1-6, the amount being 1-2 equivalents of the acids per iaDle of amine, by beating said mixture of amine and acids at a gradual temperature rise from 180 to 280C with evaporation of the volatile products.

Aminosmide of the above acids 'has the amine number 160-200 mg KOH/S and acid number 0-15 mg KOH/g. If the 8MOUnt of acids in the reaction inixture exceeds 2 equi valents Per Mole of amine, the acid number of aminDamide increases, which hinders cathodic deposition of coatings f (IF from the composition containing such aminoamide. If the amount of 4;4- acids is lower than I equivalent per InDle of amine, it means that aminoamide Contains free amine which may cause telatiDn of the reaction mixture.

As a cross-linking agent in the proposed compositiDn use is made of polyester, namely, the product of reesterification of polyatomic alcohol, for instance, etriol, -with di::.ethyl asters of aliphatic dicerbDxylic acids C 4-CIO, PDlyester has the following characteris- tiCS. the Mass f-raCtiDn of nonvolatile Compounds 98.4- 97-35o, viscDsity at 2011C 1.50-1.500 s, hydroxyl number 0-10 mc, KOH/g; acid number 0-10 mg KOH/g. To obtain polyester, 2.25-o.0 moles of dimethy; ester of aliphatic dicarboxylic acids C4_CjO are heated to 600C, I mole of etriol and a catalyst (Zn, Pb, Dr Dtlhaer metal acetate) are added, and the calculated amount of methanol is evacuated at a gradual temperature rise from 150 to 2200C, after which. an excess diestex is evacuated under vacuum, Besides the Fbove-described polyester, oligourethane can also be used as a cross-linking agent in the proposed composition which -represents a product of addition of polyisocyanate to monoatomic alcohol and then to polyatomic alcohol. Use can be..(Sdg of pDlYlSocyanates based on toluelendiisocyanateg diphanylmethanediiSDCyanate, and the like; as monoatDmic alcohols use can be made of aliphatic alcohols C 1_C49 callosolves,carbitols, (17 2-ethylenehexanDl, and the like. AS pDlyatOMiC alCDhDIS, etriol, neiDpentylglyciDly a mixture thereofg and others are suitable.

If the amount of the crDss-linking agent introduced into the CD1nPOSitiOn is less than 0.15 mass parts or ziDre than 30 mass parts, the physiw-.Lechanical proper ties of the coating obtained by electrodeposition from the proposed co-,pDsitic)n are deteriorated or the sDlubi lity of the composition in water becDr.es lDWer.

As catalysts DIC CXDss-linki-ng t-he iprD)Dsed composi tiDn contains 0.5-2.0 mass parts of lead or tin salts.

If tha am-Dunt of the catalyst of crDss-linking is less than 0.5 mass parts, the physicD-,,lechanical pro perties of the eDating obtained by cathodic electrDdepD SitiDn from the proposed composition are impaized.

An increase in the P-mount D-LE t--1 catalyst of cross 2inking above 2.0 mass parts does not improve the PhySiCD mechanical properties of the CD8ting.

AS organic solvents the composition Contains 50-100 mass parts of etbylcellDsDlve, butyleallDsolve, a mixture t-bereDf, or other organic solvents.

Acetic or formic acid in an amount from 2.4 to 3.0 mass parts is used as a neutralizer.

Carbon black, titanium dioxide, white lead /2 PbCO 3 2,5 Pb(OH)2/1 and other products are used as pigments.

1 1 Microtalc, kaolin, and other products are used as a filler.

If the amount Of pigments and fillers is insufficient, i.e. less than 5.0 mass parts, the decorative function Of the coating obtained from the proposed composition becomes void.

The introduction Of pigments and fillers in amounts exceeding those specified in the claims impairs the physico-mechanical properties of the coatings obtained from the Proposed composition.

For a better understanding Of the present inventiDn, specific examples of realizing thereof are given hereinbelow by way of illustration.

IS1xample 1 A composition for cathodic electrodeposition of coatings consisting of an epoxyrubber adduct modified with a mixture of amine and ot-branched MnDcarbDxylic acid aminoamide at a ratio of amine and aminoamide equivalents equal to 1:19 a cross-linking agent, namely, OligDurethane based on pc)lymetbylenepolyphenylisDcyanate and 4,41diphenylmethanediisDcyanate, a catalyst of cross-linking (dibutyltin dilauxate), an organic solvent (a mixture of butyl-and ethylceliDsDive), a neutralizer (formic acid). a pigment (carbon black and titanium dioxide), and a filler (kaolin) at a following ratio Of the components (mass parts):

adduct 100.0 c) ure the ne 30.0 dibutyltin dilaurat6 2.0 ethylcellosolve 63.6 butylcellosolve 5.0 formic acid 2.4 carbon black 2.5 titanium dioxide 2.5 kaolin 10.0 was prepared as follows.

The adduct (32.7 mass pawts) in the form of 70% solution in etbylceilDsolvel butylcellosolve (5.0), ethylcelIDSDlVe (7.9), dibutyltin dilaurate (2.0), car- bon black (2.5), T102 (2.5)g kaolin (10.0) are mixed and ground. 155.0 Iness parts of 70% solution of the adduct in athyleallibsolve and 1.4 mass parts of formic acid are added to the ground paste. The thus prepared CDMPDSitiOn obtained as described above is diluted with water to 15-20%, stirred for 72 hours and a coating from this corpDsitiDn is applied at 200-300 v onto pbospbated and nDnphosphated steel for 2-3 minutes and cured at 1804)C for 30 minutes. The results of testing the coating are given below in the Tables To prepare the adduct,a mixture of a copolymer of butadiene, scrylonitrile and metacrylic acid with 1 (0 a molecular mass of 3200 and acid number 35 mg KOH/g containing 26,9,15 acrylonitrileg and diane epoxy resin with epDxyequivalent about 200 is heated to 700C, then d iine thylet ha no lamina and diphenylpropane are added, and beating is Continued at 130-15WC to the f0JrME1tiDLI of an epDxyrubber adduct with an equivalent of 600-700.

EthylcellDSOlVe is added, the adduct is dissolved and the mixture is cooled to 60OC; then 707o solution of DligDuretbane in athyleellosolve is introduced and mo nome thyletha no lamina and 707P Solution of OC-branched acid aminDamide are added. The heating is continued to 1200C and the adduct is kept at this till the viscosity of the adduct becomes CDnStant.

The adduct has the following composition (mass parts): Copolymer of butadiene,, acrylonitrile, and metacrylic acid with a MleCUI8r mass 3200 and acid number 35 mg KOH/g containing 267o of acry- 1Dnitrile 14.51 Diane epoxy resin with epoxyequivalent abcut 3. DipbenylDlpropane 4. Dimethylethanolamine 5. EthYlCellDSDlVe 6. OligDUTGtbarie, 701% Solution 7. Monomethylathanolamine 8.o6-branchad acid aminoamide, 70% Solution 46.78 11.24 0.035 33.43 42.85 5.47 31.42 183-:7 (3 To prepare oligourethane, a mixture of 4$41-diphenylmetbanadiisocyanate and polymethylenapDlyphenylisDcyanate is heated to 40% polypropyleneglycDl with molecular mass 2000 is added, and then a mixture of athylcollosolve and methanol is gradually introduced at a rate ensuring the mass temperature no more than 60C. After keeping the mixture for 1 hour etriol is added, the -nass is heated at 950C till the NCO-groups disappear and then DligDuretbane is diluted with ethyl- C6110SDlve.

The composition ofcligDurethane is as fDllz)ws(in mass parts): 1. PDlyme thyle nepo lyphe nil isocyanate containing about 5570 of 4.41-di,,.-henylmethanediisocyar.ate 63.68 2. 3thylcellosolve 301. Methanol 4. T-rimetbylDlpropane I?Dlypropylerleglycoly molecular mess 20JO 6. EthylcellDsolve for dissolution i 1-0.50 5.87 4.09 3.86 48.80 142.8 To prepare.-4 -branched monDcarboxylic acid amino- amidey a mixture of oC-branched monocarboxylic acids of the general formula (C 2 H4) nH 1 2 G-C - COOH, 1 04H 9 where n = 1-6 z i i 1 (0 is added to PDlyethylan6pDlyaMine (a mixture of polyethylenspolyamines consisting, mainly, of trietbylenetetramins) in a nitrogen flow and the mass Is heated for 7 hours to 210C, then 7 hours to 2200C, 5 hours to 25011C, and 5 hours to 28011C. The obtained amine (acid number 11.2, smine number 179.2, free amirie as calculated for triethylenetetramine 2. 67o) is diluted with ethYlCellOSDIVe up to concentration 70%.

The composition of aminoamide in mass parts is as follows:

1. Polyethylenepolyar-ine (triethylenatetramine) 22.9 2.-oC-branched acids with acid number 270 mg KOH/g 49.3 3. -Sthylcellosolve 27.8 103.0 &xar-ple 2 A COMPDSitiOn fDr cathodic electrodeposition of coatings consisting of the co::,,pi)nents at the following ratio, mass parts:

adduct 100.0 D I ig 0 Llre th B ne 30. 0 solution of lead Dctoate (2575 Pb) in ethylcellosolve ethylcelIDSD1V6 butylcallosolve fo.j,mic acid carbon black titanium dioxide 8.0 63.6 5.0 2.5 0.4 10.0 mic.rotalc 5.0 is prepared and tested as described in dxa-.,zle 1, with the use of the same adduct, Oli-DUreth8n6g and E1MilID cj amide. The results of testing are presented in the Table below.

lgxal,lple 3 A Composition for cathodic electrodeposition of cc)atin:,s consisting of the-COMPDnents at the following ratio, mass parts:

adduct 100.0 polyester 2j.0 solution of lead octoate (20.93o' eb) in xylene 3.5 eth.vlcellr,sDIve 70.20 butylcellDsolve formic acid carbon black titanium dioxide white lead kaolin 11.0 0.4 38.4,5 1.15 25.0 is prepared in the following way.

A Solution of the adduct in etbylcellDsDlve (39.00 mass parts concentration 70%), butylcellosolve (11), ethylcellosDlve (27.315) are mixed 8. 4.5) and carbon black (0.4), titanium dioxide (11 (17 kaolin (25.00), and white lead (1.15) are added and ground. Then the adduct solution (13.3.84), polyester (20.0)g lead oetDate solution (5.5), and formic acid (3.0) are added and the composition is thus prepared.

The results of the testing are given in the Table below.

The adduct is obtained by following the procedure described in Exannple 1 which has the following comt.:-osi- tion (mass parts):

1. Copolymer described in Example 1 10 2. Diane epDXY resin with epoxyequivalent about 00 3. Diphenylolpropane 4. Dii-.ethylet.anolarine 5. 3t hylcellDSOlve 6. Diethanolamine 7. Dietbylamine 8.cC-b-ranched aminDamide described in E,.,carlple 13 70% Solution 7.78 513. 91 16.06 0.04 75.95 3.71 2.15 23.35 142.85 The ratio of amine to aminoamide is 1.3:1.

To prepare polyester, dimethyladipinate and etriol are mixed and the mixture is heated to 701C. Then lead acetate is delivered and heating continued in a 'nitrogen flow. At 160-17011C the methanol formed as a result of the reaction is distilled. The mass i.s kept fDr 4 hours k II -Is- at 170-180oC after which the tempe-rau"u26 is raised 'to 22011C for 8 hours and kept at this tempe-r8tu-r6 UP to viscosity no less than 65 s. The mass is cooled to 1800C and vacuum of 10-11VIpa is maintained. t'tn excess of dii:lethyladipinat's is distilled till the mass fraction of nonvolatile compounds is no less than 951-6 at a t@mPQrature of no,aDre than 22011C. The characteristics of polyester are given below: 1. MaSS fraCtiDl of nonvolatile compounds 10 2. viscosity 3 Acid number 4. HydrDxyl numb-or Composition of polyester, rnass parts:

1. Dimethyladipinete 80.00 2. EtriDl 20.00 3. Lead acetate 0.07.

3xample 4 95.85% 354 s 2.62 mg KOH/g 3.23 mg KOH/g A composition for cathodic electrodeposition of coatings corisisting of the cDnponents at the following ratiDg mass parts: adduct polyester with a mass fract!Dn of nonvolatile com- Pounds 97.34% xylene solution of lead Octoat6 (20.93% Pb) m 1013.00 1.5.41 2.39 e t bylce 11 OS D lve 92.70 butylcellosolve 5.00 AF formic acid 3.oo carbon black 0.40 titanium dioxide 6. 00 white lead 3.60 kaolin 25.00 was prepared as f DIlDws.

A solution Of adduct in ethylcellosolve (.J.71 mass 10 parts), butylcellDsolve (5), and etbyleellosolve (49.85) are mixed and carbon black (0.4),v titanium dioxide (36.0), kaolin (25.0), and wbite lead (3.6) are added; the mix-uu-ra is -round after which an adduct 0 solution (10'7.14), polyester (15.41), a solution of lead OCtDat6 (2.39) and formic acid (3.0) are added.

The proposed composition is thus prepared.

The results of testing are given in the Table below, The adduct is obtained by following the procedure described in Example 1 from the following components:

1. Copolymer described in Example 1 11.42 2. Diane epoxy resin with an epDxyequivalent of about 200 3. Dipheny1D1propane 4. Dimethylethanol amine D. Ethylcell0SDIVe 6. Diethanolamine 50.02 14.09 0.04 3-6.05 8.00 7. o-brenebed acid aminoamide as described (3 in fiXaTnple 19 70% SDIUtiDn 22.67 The amine to aminDamide ratio = 1.5:1.

Polyester was prepared by following the procedure described in Example 3 at 2000C from the following components (mass parts):

1. Dimetbyl ether of succinic acid 2. Btr i o 1 3. Lead acetate The characteristics of pDlyester are given belDvj c) 1. Ilass fraction of nonvolatile compounds 9 7. 31, 470 2. Viscosity 1500 s 3. Acid number 3.2 rg KOH/g 4. Hydroxyl number 4.33 inG KOH/g Example 5

A compositiDn for cathodic electrodeposition of 'Dllowin= coatings consisting of the CDMPOnents at the ratio (Mass parts):

adduct 100.00 oligoLwethane 30.00 dibutyltin dilaurate 2.00 ethylcellosolve 63.60 butylcellosolve formic acid 25 carbon black titanium dioxide kaolin micretalc 77.04 22.96 ,0 r 5.00 2.4 2,5 2..5 5.0 5.0 (3 is prepared and tested by following the procedures described in Example 1 with the adduct identical to that used in Example 1 and obtained from the following components: 1. Copolymer described in Example 1 2. Diane epoxy resin with an epoxy equivalent of about 200 3 ol 4.

Dipbenylolpropane DimetbylethanDlamine Ethjolcellosolve Olij,Du.rethene, 707o solution jMIonomethyletbanolamine 8.,-3,(-branched acid amin[)--mide, 707o sr,Intion as described in 15'xa--ple 1 The amine to aminoamide ratio= 1:1.5.

The results of testing are given in the Table C) Exair-n-ple 6 13. 76 44.38 10.76 0.04 1 30 42.85 4.31 38.40 A Composition for cathodic elect-rodepDSition of coatings consisting of the COMPDnents at the following retio (ma-9.9 Parts):

adduct as described in Example 1 100.00 polyester with a mass fraction of nonvolatile compounds 95.86% as described in Example 3 31.30 xylene solution of lead octoate (20.9375 Pb) ethylcellosolve 4.78 42.8.5 1 (p buty lee 11 D SO lve formic acid carbon black titanium dioxide white lead kaolin 2.07 00 0.40 10.00 Is prepared as follows.

Polyester (31.3), butyleellosDIve (2.07), and lead octoate solution (4. 78) are mixed and carbon black (0.4), titanium dioxide (16.0), white lead (...6) and kaolin (5.0) are added; the prepared mixture is ground. The adduct (142.85) and fDrmic acid (3.0) are added to the ground paste and the prOpDSed co-n-.pDsition is thus Obtained.

The results of testing are given in the Table below.

Table. Properties of the cozposition for electrodepositiDn and characteristics of the coating obtained thergfrDM Nos Parameters Example 1 2 for comparison Examplds (lip /US9A,4253930/ 1 2 3 4 1 A 3pecial binder 1w,titb qua ,ernary aM3.MDgrDUPS for dispersing the pigment yes no no 2. Mass fraction of nonvolatile compounds in the Composition prior to preparation of the bath, 75 3.

4.

v40. 0 67.0,65.o voltage of application of the coating 150-200 250 250 Thickness of the hardened coating, Am 20 18-20 12-14 5. Alass losses in the course of hardening, % 14.0 8 10 6. The appearance of the coa tings satisfactory satisf. satief.

7. Salt-resistance, h on a phosphated plate 800 800 1000 on a steal plate 360 360 360 8. 3ricse elastici:ty, mm 9. Impact strength, cm direct impact reverse impact 5.0 5.0 t - Nos 1 no no no no 04.4 04.0 o7.0 75.0 ZOO 250:900 320 e.I 4. 18-20 18-20 17-18 15-17 5. 7.8 5.5 7.5 9.0 6. satisf. satisf. Satisf. satisf.

7. 480 500 1000- 460 -Z60 360 316 0 360 8. 6.5-7.6 5.0 7.5-7.6 9. 50 50.50 50 50.50 50 50 The costin.js are cured at 180C for 30 min.

k

Claims

1. A composition for cathodic alectrodeposition of coatings consisting of an epoxyrubber adduct modified with a mixture of amine and c,,-branched monocarboxylic acid aminoamide at a ratio of the equivalents of said amine and aminDamide equal to from 1.5:1 to 1:1.5, a crDss-linking agent, a catalyst of cross-linking, an organic solvent, a neutralizer, a pigment, and a filler with the following ratio of the above components (mass parts):

the above-mentioned iriDdified adduct 100.00 the cross-linking agent 15.0-30.0 the catalyst of cross-linking 0.5-2.0 the organic solvent 50.0-100.0 the neutralizer 2.4-3.0 the pignnent 5.0-40.0 the filler 5.0-25.o.

2. A compDsition as claimed in Claim 1, containing as a cross-linking agent a product of reestaxification of polyatomic alcohol with dir-ethyl esters of aliphatic dicarbo X 7 1 i C acids 10 d C4-C

3. A composition as claimed in claim 1 substantially as herein described with reference to the Examples.

P, 5 Published 1991 at The Patent Offl=StatcHouse. 66/71 High Holborn. London WC I R41P. Further copies may be obtained from Sales Branch, Unit 6. Nine Mile Point. Cwmfelinfach. Cross Keys. Newport NPI 7HZ. Printed by Multiplex techniques ltd. St Mary Cray. Kent.