CA1089145A - Organic metal finishes - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
An aqueous dispersion of a mixture of certain glycoluril deriv-atives blended with certain water dispersible non-gelled, non-self-cross-linking polymeric materials containing only certain reactive groups and catalyzed with small quantities of an acid catalyst which will cause the glycoluril derivative to crosslink with the polymeric material, when sub-jected to heat. The glycoluril derivatives process the following structural unit:

Description

25 t 8 9 o 31~1 , J
~¦ 15 This invention relates to a composition of a partially or fully alkylated glycoluril, a non-self-~, -crosslinking polymeric material containing as a reac-;~il tive group one or more carboxyl groups, alcoholic hy-droxy groups, or amide groups, such grOUpS being present in an amount of from 0.5% to 25% by weight based on the ! ~ weight of said polymeric material, and from 0.5~ to ¦~ 5.0% by weight, based on the total weight of said glycol-uril and polymèric material. The composition may be in ~ ~;
the form of an aqueous dispersion if the polymeric ma-terial is water-dispersible or organic solvent soluble i ~ ; if the po1ymeric material is organic solvent soluble.

Organic metal finishes have been commerclally available for a great number of years. Coatings from , ~ natural materials such as linseed oil were 9uperceded ., ~! ~ 30 in time by synthetic polymeric materials. Frequently ;--', 1 .' ' . 1~ : ` .-,'~ : - .

- 2 -, ~ '~ `"'" ~$
''` ' 1 these earlier materials were dissolved in organic sol-vents and deposited by any of a number of conventional methods to metallic substrates and dried or baked to produce the desired coating on the metal substrates.
¦ 5 Some of these earlier coating compositions were not as I hard nor as chemically resistant to solvents and acids as desired and as a consequence, further developments produced blends of crosslinkable polymeric materials l which were used in conjunction with a crosslinking agent ¦ 10 which, when the combination was used as a coating on a I metallic substrate and then baked so as to convert the I crosslinkable polymeric material and the crosslinking agent to a thermoset state, so as to provide a hard, -chemical resistant film. Presently, the most commonly used crosslinking agents are based on triazines such as `; melamine, benzoguanamine or the ureas, including urea -I per se and thiourea. However, these crosslinking agents - ;1 r~ do not fill all of the needs of the present time and newly developing coating applications. These newly de~
20 veloping coating applications require in certain instan- - -ces superior full performance than that which is ach-I ievable at the present time with the already known cross- ;
linking agents. In more recent times, because of ecology considerations, it is desirable to furnish aqueous sys~
tems which provide an aqueous dispersion of the blended materials although such provision is not intended to re-place entireLy the solvent systems.
The present invention is in the coating resin field and provides an organic solvent solution or an aqueous dispersion of a mixture or blend of certain par-.
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tially or fully alkylated glycoluril derivatives and certain organic solvent or water dispersible non-gelled, non-self-crosslinking poly-meric materials that are acid catalyzed and which can be deposited on a substrate by any one of a number of methods, including coating, spraying, dipping, brushing, roller coating, and electrocoating and the like and after the application of the coating composition to the metal substrate, the coated substrate is baked at the appropriate temperature wherein the crosslinking agent through the assistance of the acid catalyst, crosslinks with the polymeric material and produces a hard, chemical resistant film.
In accordance with the present invention there is provided an organic solvent soluble or an aqueous dispersion of a mixture of from about 2% to about 50%, by weight, of ~A) a glycoluril derivative having the structural unit:

_<N~ (C 2 )n R I (CH2)4 _ (n l m) wherein n is an integer from 1 to 4 inclusive; m is 0, 1 or 2; each R - -is individually either hydrogen or an alkyl radical having from 1 to 6 carbon atoms inclusive; provided that when m is 0, and n is 4, each ; R is an identical alkyl radical or at least one R is hydrogen; R2 and R3 are separately hydrogen or an alkyl radical having from 1 to 6 carbon atoms inclusive or a phenyl radical; and correspondingly from about 98% to about 50% by weight, of (B) a water dispersible, normally non-self-crosslinking polymeric material having as reactive groups, any one or more of carboxyl groups, alcoholic hydroxyl groups or amide ~ -groups wherein the amount of said groups is at least about 0.5%, by .

lt~S~ 5 weight, and not more than about 25%, by weight, based on the total weight of said polymeric material; and (C) from about 0.05% to 5.0%, by weight, of an acid catalyst based on the total weight of (A) and (B), wherein said reactive groups of (B) are heat reactive with (A) and wherein said percentages of (A~ and (B), by weight, total 100% and are based on the total solids weight of (A) and (B).
Normal baking conditions for these coatings are generally 200C ~
or less for 30 minutes or less.
In the last ten years, dramatic changes have taken place in the organic coating technology. There has been increased emphasis on pollution free coating systems such as aqueous emul-sion, water-borne coatings, electrocoating, powder coatings and ultra-violet light curable coatings. The existing cross-linking ;~
agents based on melamine, the guanamines, including benzoguanamine, `
or urea and substituted ureas do not fill all the needs o the present coating market. The glycoluril derivatives used in the i~l present invention are a new class of crosslinking agents, the ~
;~ starting material of which ;~ ;
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is glycoluril and is also known as acetylene diurea which is prepared by reacting two moles of urea with one mole of the glyoxal. The glycoluril can be methylolated, partially or fully, by reacting one mole of glycoluril with between one and four moles of formaldehyde. When the glycoluril is fully methylolated, it is identified as tetramethylol glycoluril. The methylolated glycolurils can be alkylated, either partially or fully, depending on whether or not the glycoluril is partially or fully methylolated and depending further on whether or not partial or full alkylation is desired. If the tetra-methylol glycoluril is reacted with a selected amount of a monohydric ali-phatic or cycloaliphatic alcohol containing from one to six carbon atoms, `
one can produce, for instance, the tetra (alkoxy methyl) glycoluril or partially alkylated glycolurils. These monohydric alcohols may be primary or secondary alcohols. The monohydric alcohols that can be used to achieve this alkylation may be methanol, ethanol, n-propanol, n-butanol, n-amyl ~ ~
alcohol, n-hexyl alcohol, isobutanol, isopropanol, sec-butanol, cyclohexanol -and the like.
Thus, the term "fully alkylated" describes glycoluril derivatives of the above formula in which all the R groups are alkyl groups and ~m is zero. The term "partially alkylated" describes compounds in which at least one R group is hydrogen and at least one R group is an alkyl group.
Some of these glycoluril derivatives are already identified in ; the chemical literature but in order to illustrate the method for the preparation thereof, the following examples are set forth in which all parts are parts by weight unless otherwise indicated. These examples are set forth primarily for the purpose of illustration and any specific enumerations of detail contained therein should not be interpreted as a limitation on the case except as is indicated in the appended ~.
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1 claims.
Preparation of Glycoluril Into a suitable reaction vessel equipped with stirrer, thermometer, and reflux condenser, there was introduced 765 parts of urea and 875 parts of water.
To this slurry, 282 parts of concentrated sulfuric acid were charged and the mixture was heated to 70C. At 70C., 605 parts of glyoxal (40% aqueous solution and ;-free from formaldehyde) were added slowly to the clear 10 solution such that the reaction temperature is maintain-ed between 75-8QC. After the addition of glyoxal, the reaction mixture was held at 75C. for one hour and then cooled. The separated crystalline glycoluril was filt-ered and washed with water and a dilute caustic aqueous , .
15 solution. The glycoluril obtained after drying has a ;-~
I m.p. of 298-300C. and the yield was 88% ~525 parts).
,:
Preparation of Tetramethylol Glycoluril Into a suitable reaction vessel equipped with~
i~ a stirrer, thermometer, and reflux condenser, there was introduced 688 parts tlO moles) of aqueous formaldehyde (44~), and the pH was adjusted to 8.7 with 22 parts of ~ ~-:
0.5N NaOH solutlon. To this solution, 284 parts (2 ~ moles) of glycoluril were added at 40C. During the re-,~ ~ action, the temperature was allowed to rise up to 55C.
25 At this stage, most of the glycoluril went into solution.
After about 15 minutes, the~pH was adjusted to~8.0 wlth five parts of 0.5N NaOH. A clear pale yellow colored solution was obtained. The clear solution was distilled at 5~0C. under reduced pressure to remove water, until `~
~; 30 the reaction vessel content was about 640 parts. The ! -:' ~:
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1 syrup in the vessel was poured into 800 parts of meth-anol. The white crystalline precipitate was filtered and dried. The total yield of the tetramethylol glycol-uril was 483 parts (92% yield) and m.p. 132-136C.
S Preparation of Tetrabutoxymethyl Glycoluril Into a suitable reaction vessel equipped with a stirrer, thermometer, and reflux condenser there was introduced 1,000 parts (13.5 moles) of n-butanol and 7.0 parts of concentrated nitric acid and 20 parts of water.
To this mixture was added 200 parts of tetramethylol glycoluril (0.76 mole) and the reaction mixture was stirred at 40C. for two hours. The reaction mixture became a clear solution. It is then distilled at reduc-ed pressure between 45-50C. to remove the butanol~water ,, .
15 azeotrope mixture. After 260 parts of the n-butanol/water -mixture weXe removed, 260 parts of n-butanol were added to the clear solution and the reaction temperature~was ~! lowered to 22-25C. The solution was neutralized with 10% caustic to a pH 9-10, followed by removal of more ;~
-~ ....
of a n-butanol/water mixture under reduced pressure. The residue was filtered with a filter aid. The resulting ~;~
water-white syrup had a Gardner-Holdt viscosity of Y-Z
(25C.). Pan solids were 95~ (2 hours at 105C.) and foil solids were 97% (45 minutes at 45C.). The gel 25 phase chromatography indicated that the~product was 85% --monomeric. The nuclear magnetic resonance (nmr) of the product confirmed the structure of the monomer to be tetrabutoxymethyl glycoluril.
P~eparat1on of Tetrabutoxymethyl Glycolur_l 1 30 Into a suitable reaction vessel egùipped with i . .
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,, ,, - , 1~3~31~5 1 a stirrer, thermometer, and reflux condenser there was introduced 344 parts (5 moles) of aqueous formaldehyde (44%) and the pH was adjusted to 7.5 with 6 parts of 0.5N
NaOH solution. To this solution, 142 parts of glycoluril ;
(1 mole) were added and the reaction mixture was heated to 80C. Two parts of 0.5N NaOH solution were ~dded to adjust the pH to 7Ø In half an hour, the reaction mix-ture became a clear solution. It was then cooled to 25C.
and the pH was adjusted to 7.4 with three parts of 0.5N
NaOH solution. The clear pale yellow colored solution ,. - .
was then distilled at 55C. under reduced pressure to ¦ remove water. After 150 parts of water were removed, ¦ 740 parts (10 moles) of n-butanol and 1 part of concen-; trated nitric acid were added to the resulting syrup.
-~ 15 The mixture was heated to reflux with stirring. After ~`
about 10 minutes, the reaction mixture became clear and water white; the reflux temperature was 95-98C. The ~
. .
water formed during the reaction was decanted by the use : of a standard decant apparatus. In about three;hours, ;G` ~ ` 20 150 parts ofl decant liquid (water with`8% n-butanol~ were ;~
` collected. The reaction temperature after that period was 11~5-116C. When water stopped coming over by decant, the solution was~oolled to 22-24C. and~neutralized wi~th l0 parts of 0.5N NaOH solution. The excess~butanol was ~ -removed at atmospheric pressure, and later under r~educed pressure, and residua`l~syrup was filtered in the pres~
`~ enoe of aotivated oharcoal~and filter aid. ~The~ yield , ~ of the reaulting syrup was~4}0 parts (approximately 87%

i~ `;~ yield)~ The other physical oharacteristica were~as followa: Foil Sollds: 96.4%; Pan Solids: 94.7%; Gard-1 ~
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. , ',`'"`". ` : , ~' ' ' ', ' , ' ` ' . ' ' ' ' ` ' ` ' ' ' ' 1~3~ 5 1 ner-Holdt Viscosity (25C.): P-Q; Gardner Color: l;
~ter Tol~rance: 321.
Preparation of Partially Methyl~ted Tetramethylol Glycoluril - Into a suitable reaction vessel equipped with a stirrer, thermometer, and reflux condenser there was introduced 950 parts (30 moles) of methanol and 40 parts of concentrated hydrochloric acid. To this mixture, 262 parts (1 mole of tetramethylol glycoluril) were added and the reaction mixture was stirred at 25-30C. In about 15-20 minutes, all the tetramethylol glycoluril went into solution. After half an hour, the reaction ;
mixture was neutralized with 140 parts of sodium bicarb- ` -onate and 20 parts of sodium carbonate at 22-23C. The ;~
pH after neutralization was about 8. The salt was filt-ered. The filtrate was concentrated at 60C. under re-duced pressure. The yield of the syrupy product after I filtration of the salt was 290 parts, which was diluted j to 90~ solids with cellosolve. The product characteris-tics were as follows: Foil Solids: 91.4%; Pan Solids: ~-82.2~; and Gardner-lloldt ~iscosith (25C.): Zl IR of ; ~ the product indicated that the methylated product has a ;~ significant amount of unreacted methylol-groups. ~ -~; Preparation of Tetramethoxymethyl Glycoluril Into a suitable reaction vesse~ equipped with 25 stirrer, thermometer, and condenser were charged 640 ;~
parts (20 moles) of methanol and 20 parts of 70% con.
nitric acid. To this acidic methanol, 262 parts (1 mole) ~`
of tetramethylol glycoluril were charged, and the reac-~: :
tion mixture was heated to 40C. with stirring. In -about 20 minutes, all of the tetramethylol glycoluril : ' ' ' ~ ': -.

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(31~5 1 went into solution. When the reaction mixture became `~ clear, it was cooled to 22C. and 45 parts of 20% sod- --ium hydroxide solution were added to neutralize the reac-tion mixture to a pH of 7-8. The neutralized clear so-lution was heated to 50-55C. and 450 parts of methanol were removed under slightly reduced pressure. The resi-due in the flask crystallized on standing for a few hours.
The crystalline solids were filt ered and washed with a ;
small amount of water. The filtrate was then vacuum stripped at 70-80C. to remove all the water. The solid residue was then dissolved in benzene and the undissolv- ;~
ed salt was removed by filtration. The benzene solution was mixed with the first crop of solid crystals and dis-solved with additional benzene and was filtered again.
lS On removal of benzene, 310 parts of tetramethoxymethyl I glycoluril (TMMGU) was obtained. The yield was 97%.
~¦ It was recrystallized from benzene. The recrys~tallized product had the melting point of 116-118C. The struc-ture of TMMGU was confirmed by I.R., N.M.R. and nitro~
gen analysis.
1 ; Preparation of Dimethoxymethyl Diethoxymet~yl Glycoluril j~ Into a suitable reaction vessel equipped with stirrer, thermometer, and condenser, were charged 320 parts (10 moles) of methanol), 460 parts of ethanol (10 1':1 :; : :
I - 25 moles), and 20 parts of 70% COncentration of nitric acid.
To thic acldic alcoholic mixture, 262 parts (1 mole) of tetramethylol glycoluril were charged, and the reaction I ~ mixture was heated to 40C. with stirring. In about 20 ` 1 : :
l minutes, all of the tetramethylol glycoluril went into /1 30 solution. When the reaction mixture became clear, it ~,, I ~ , ., `i!~
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1 was cooled to 22C. and 45 parts of 20~ sodium hydroxide solution were added to neutralize the reaction mixture to pH 7-8. The neutralized clear solution was heated slowly to 105C. under reduced pressure, to remove sub-stantially all of the alsohol-water mixture. The result-ant syrup was filtered hot at 80C. to remove the inor-ganic salt and other impurities. The yield of the ~
syrupy dimethoxymethyl diethoxymethyl glycoluril was 320 ~-gms. The structure of this product was confirmed by 10 N.M.R. The Pan Solids were 95.0%, and Foil Solids were ~ ;
98.5~. The Gardner-Holdt viscosity was Z3-Z4 (25C.).
The glycoluril materials used in the composi-I tion of the present invention are identified as glycol-¦~ uril derivatives notwithstanding the fact that many of the materials used in this category will be modified glycoluril compounds. On the other hand, some measure ¦ of self-condensation may take place in the preparation ¦ of these glycoluril derivatives which wiIl result in l the production of polymeric materials such as dimers, tr1mers, tetramers and the like which ~ould put them ln the category of condensation products or resinous ma-; terials. However, only lower molecular weight compounds, resinous materiaIs or condensation products are prefer-red for use ln this application, namely those that have a molecular weight between about 200 and about 2,000.
These glycoluril derivatives may contain from -`~
one to four methylol groups or they may contain from one ~¦ ~ to four alkoxymethyl grOupS or any combination of from ~-one to four methylol groups and alkoxymethy1 groups.
When there is only one methylol group or only one alkoxy-, .
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methyl group, there must be at least one methylene bridge.
Among the glycoluril derivatives that may be used as the crosslinking agent in the compositions of the present invention, are the dimethylol glycoluril, tri-methylol glycoluril, tetramethylol glycoluril, monomethyl-ether of dimethylol glycoluril, the dimethylether of dimethylol glycoluril, the trimethylether of tetramethylol glycoluril, the tetramethylether of tetramethylol glycoluril, tetra-kisethoxymethyl glycoluril, tetrakispropoxymethyl glycol-uril, tetrakisbutoxymethyl glycoluril, tetrakisamyloxymethyl glycoluril, tetrakishexoxymethyl glycoluril and the like.
There may be utilized mixed ethers such as the diether, dim-ethylethers of tetramethylol glycoluril, the diethyl, di-propylethers of tetramethylol glycoluril, the dibutyl, di- ~.
ethylethsrs of tetramethylol glycoluril, the diethyl, di-hexylethers of tetramethylol glycoluril and the like. These , mixed ethers are novel compounds which are the subject of ;~
¦ our application serial no. 344865 divided out of thls ap~plication. When water solubility is desired, it-is pre-ferred to make use of the lower alkoxy derivatives such as i ~~ the tetrakismethoxymethyl glycoluril. On the other hand, ;, when the use of colloidal dispersions of laticiferous dis-i persions are to be used, the higher alkoxy derivatives can be used such as the tetrakisbutoxymethyl glycoluril. If deslred, these crosslinking agents may be used singly or in combination with one another although it is generally pre-, ferred to use these crosslinking agents singly. The amount of the glycoluril derivatives used in the compositions of ! the present invention may be varied between about 2% and l 30 about 50%, by weight, based on the total ;l~ - 13 -. ~'" :

1~3~ S

1 solids weight of the glycoluril derivatives and the water-dispersible, non-gelled, non-self-crosslinking polymeric material. It is preferred to use the glycol-uril derivatives in the weight percent basis varying be-S tween about 10% and 40%, by weight, same basis. Thereobviously will then be present in the composition between about 50% and about 98%, by weight, of the non-self--crosslinking polymeric material and preferably between about 60% and 90%, by weight, of said polymeric material, same basis, wherein the percentages of the glycoluril derivative and the polymeric material, by weight, total 100% and are based on the total solids weight of the gly-coluril derivative and the polymeric material.
The component (B) used in the composition of the present invention is the organic solvent soluble or water-dispersible non-gelled, non-self-crosslinXing poly-il meric material which contains certain reactive groups j including any one or more of carboxyl groups, alcoholic i hydroxyl groups or amide groups. The amount of said groups that is~present in said polymeric material may be varied between about 0.5%, by weight, and not more ~ ;
i than about 25%, by ~ight, based on the total weight of -~
l said polymeric material. For most technical purposes . . - -:
these reactive groups will be the sole reactive groups ~:
in the polymeric material. Any one of these reactive groups may be present in the polymeric material to the ~l exclusion of the other reactive groups or all three of ¦~ these three reactive groups may be present in the poly-j ~ meric material simultaneously. These polymeric materials l~ 30 may be anionic or non-ionic. These polymeric materials i ,~ ' . .

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l may be any one of a plurality of vinyl polymers which may be prepared by polymerizing polymerizable monomers containing reactive carboxyl groups such as acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, ~-benzoyl acrylic acid and polycarboxylic acids of the a,~-ethyl-enically unsaturated class such as maleic, fumaric, ita-conic, mesaconic, aconitic and the halogenated acids such as the halogenated maleic, or more specifically, -chloromaleic acid and the like. These carboxylic groups :
containing monomers can be used either singly or in com-bination with one another in the required amount and may ~
be used with other polymerizable monomers that contain ~. :
reactive alcoholic hydroxy groups or the reactive amide groups or may be used with other monomers which contain 15 no reactive groups other than the reactive ethylenic ::
~:: double bond including no carboxylic groups such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acryl-~
ate, octyl acrylat.e, decyl acrylate, lauryl acrylate, ~ methyl methacrylate, ethyl methacrylate, butyl methacryl-¦~ 20 ate, heptyl methacrylate, decyl methacrylate, propyl crotonate, butyl crotonate, nonyl crotonate and the like. `~
These polymerizable monomers devoid of any reactive :~
groups may be used singly or in combination with one~ an- : ::
~ , other in copolymerizing with a monomex containing a re-active group o the class described. Still further, one could use~such othex polymerizable compounds containing ~: no react~lve groups such as styrene, o-, m-, or p-alkyl -~

~- styrenes such as the o-, m-, or p-methyl, ethyl, propyl : :
and butyI styrenes, 2,4-dimethyl styrene, 2,3-dimethyl:

~ ~ 30: styrene, 2,5-dlmethyl styrene, vinyl naphthalene, methyl ~ :

: ~

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~ , ':' ., . ~ . , 1 vinyl ether, n-butyl vinyl ether, phenyl vinyl ether, acrylonitrile, methacrylonitrile, halo ring or side chain styrenes such as a-chloro styrene, o-, m-, or p-chloro styrene, 2,4-dichlorostyrene, 2,3-dichlorostyrene, 2,5-5 -dichlorostyrene or the alkyl side chain styrenes such :
as the a-methylstyrene, a-ethylstyrene and the like.
- If one wishes to prepare a polymeric material as component (B), utilizing a polymerizable monomer con-~ taining a reactive alcoholic group, one may use such ~;
¦ 10 polymerizable vinyl monomers as the hydroxy alkyl esters of the a, ~, unsaturated monocarboxylic acids such as ~-the hydroxy alkyl esters of acrylic acid, methacrylic :
acid, ethacrylic and the chloro as well as the other chloro substituted acrylic acids. These esters may either have a primary or a secondary hydroxyl group. I1 lustrative of the types of compounds that can be used to ;~:~
make the polymers containing the reactive alcoholic hy-droxy groups are 2-hydroxyethyl acrylate, 2-hydroxypropyl ; ~ acrylate, 3-hydroxypropyl acrylate, 2-hydroxybutyl acryl- 1`:~
ate, 3-hydroxybutyl acrylate, 4-hydroxybutyl acrylate, ¦~ 8-hydroxyoctyl acrylate, 2-hydroxyethyl methacrylate, ~ 5-hydroxyhexyl methacrylate, 6-:hydroxyoctyl méthacrylate, . ~:
8-hydroxyoctyl methacrylate, 10-hydroxydecyl methacryl- -~ ~:

~ ~ ate, 3-hydroxypropyl crotonate, 4-hydroxyamyl crotonate, ~;
I ~ ~ 25 5-hydroxyamyl crotonate, 6-hydroxyhexyl crotonate, 7- .

-hydroxyheptyl crotonate, 10-hydroxydecyl crotonate, and the lLke.: These hydroxy esters may be used either singly or in combination with one another or with the polymeriz-: able vinyl monomers devoid of any reactive group includ- ~ :
ing those set forth hereinabove in the discussion of the ;' ~
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1 carboxyl group-containing monomers. Obviously, these hydroxy ester monomers may be used in combination with the reactive carboxyl group-containing monomers set forth hereinabove.
Among the amide group-containing monomers which may be used to prepare the polymeric material identified as component (B) are acrylamide, methacryl- -amide, ethacrylamide and the like. TheSe polymerizable acrylamides may be used to prepare the polymeric mater-ials used in the present invention with any of the car-boxyl group-containing monomers and/or the hydroxyl group-containing monomers or with any of the polymeriz-able monomers set forth hereinabove that are devoid of any reactive groups. TheSe polymeric materials whether they contain the reactive carboxyl groups and/or the re-active alcoholic hydroxy groups and/or the reactive amide groups will be anionic polymeric materi~ls.
Additionally, one can make use of polyester resin compositions which are organic solvent dispersible, non-gelled, polymeric materials. Organic solvent dis-persible alkyd resins, whether oil free or glycerlde oil-containing, may be used and a plurality of these ma-!

terials are commercially available and are also well known in the art and, as a consequence, it lS not deemed :
necessary to make any prolonged recitation of such ma-terials since they are fundamentally prepared by reacting a polyhydrlc alcohol with a polycarboxylic acid or with anhydrides such as phthalic anhydride, maleic anhydride, l and the like.

3 ~ 30 Additionally, one can make use of polyester i :
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1 resin compositions which are water-dispersible, non--gelled, anionic polymeric materials. Water-soluble alkyd resins or water-dispersible alkyd resins, whether oil free or glyceride oil-containing, may be used and a plurality of these materials are commercially available and are also well known in the art and, as a consequence, it is not deemed necessary to make any prolonged recita-tion of such materials since they are fundamentally pre-pared by reacting a polyhydric alcohol with a polycar- ~Y
boxylic acid or with anhydrides such as phthalic anhy-dride, maleic anhydride, and the like.
Additionally, one can use certain polyether polyols such as those prepared by reacting one mole of bis-phenol A and/or hydrogenated bis-phenol A with at least two moles of ethylene oxide and/or propylene oxide.
The following examples are illustrative of the various kinds of organic solvent soluble, non-gelled, non-self-crosslinking polymeric materials which can be used in the composition of the present invention.
Polyester Resin A
This oil free saturated polyester resin is commercially available and i5 prepared by reacting iso-phthalic acid, adipic acid and propylene glycol in a conventional esterification process. This polyester 25 resin i6 identified as a saturated polyester resin inas- I
much as it is free of non-benzenoid unsaturation. The - -poIyester, designed for coil coating, has the following characteristics: Sollds 70% in Solvesso 1~0, a high boiling hydrocarbon solvent; Gardner-Holdt viscosity ~¦ 30 (25C.) Zl-z3; acid number 10 maximum; hydroxy number 30.

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10~ 5 L Resin B
Resin B is a polyether polyol, that is avail-able commerclally. Resin B is prepared by reacting one mole of bis-phenol A with four moles of ethylene oxide.
This polyether polyol has a hydroxyl number of about 260-270.
Acrylic Resin C
Acrylic resin C is a commercially available anionic acrylic polymer prepared by the standard poly-merization techniques in an inert organic solvent suchas 2-ethoxyethanol in which 55 parts of n-butylacrylate, 30 parts of styrene, and 15 parts of acrylic acid are copolymerized. At the end of the polymerization, the resulting polymer is diluted to 75% solids with n-butanol.
The average molecular weight of the polymeric material is about 10,000-20,000 and has an acid number of 115.
.
This polymer is designed for water-based coatings and electrocoatings. At 75% solids and 25C., it has a - ;~
Gardner-Holdt viscosity of Z6+
; 20 esin D
Into a suitable reaction vessel equipped with a stirrer, thermometer, inert gas-inlet and outlet . . , tubes and partial condenser, there was introduced 668 ~ parts of neopentyl glycol, 96 parts of trimethylol pro-I ~ 25 panej 509 parts of isophthalic acid and 448 parts of ,~ adipic acid. These reactants were heated under a blanket of nitrogen gas to a temperature of 230C., while the ~` water of esterification was continuously removed with I constant agitation. After 7 hours, the acid number of the reaction mass was 9. The reaction mass was cooled :

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1 to 150C. and diluted to 90% solids with a 1:1 mixture of n-butyl acetate and cellosolve acetate. The final product had the Gardner-Holdt viscosity of Z6+ at 90%
solids. The resin had a hydroxyl number of 88 and an ~~
acid number of 9.
The following examples are illustrative of the various kinds of water-dispersible, non-gelled, non-self-crosslinking polymeric materials which can be used in the compositions of the present invention.
Polyester Resin E
Into a suitable reaction vessel equipped with an agitator, thermometer, inert gas-inlet tube and par-tial condenser, there was introduced 866 parts of neo-pentyl glycol, 56 parts of trimethylol propane, 74 parts of dimethylol propionic acid, 303 parts of adipic acid and 240 parts of a mixture of oligomers containing about 70% of trimer acid and about 13% of dimer acid and 17%
of monomer acid, by weight, wherein said oligomers are ~ ;~
derived from tall oll fàtty acids which are primarily ;~
oleic and linoleic acids, 74 parts of dipropylene gly-col and 1087 parts of isophthalic acid. These reactants were heated under a blanket of nitrogen at a temperature of about 165 to 190C. while the water of esterification was continuously removed with constant agitation. The heating was then increased and the temperature slowly rose to about 230C. as the isophthalic acid reacted.
When the reaction mass was clear, the acud number was ;
~ . . .
about 20-25, the temperature was quickly lowered to -~
about 190DC-- and 64 grams of trimellitic anhydride were added. After holding the reaction mass for an addition-~ ~ -1''15 1 al 30 minutes at 185C., the acid number was 44. The resin was cut to a 75% resin solids content using a mixture of n-butanol and 2-butoxy ethanol The cut resin solution had a viscosity of Z6 ~ Z7 on the Gard-ner-Holdt scale at 25C.
Acrylic Emulsion F
Acrylic emulsion F is a commercially available acrylic emulsion polymer prepared by polymerizing a monomer blend of 55 parts of n-butylacrylate, 30 parts of styrene, and 15 parts of acrylic acid. The emulsion has an acid number of 90-100 on a solids basis and a final solids content of about 48%.
Acrylic Emulsion G
Acrylic Emulsion G was prepared by a standard -¦ 15 aqueous emulsion polymerization technique using the ! monomer blend of 45 parts of n-butyl acrylate, 32 parts of methyl methacrylate, 21 parts of acrylonitrile, and 2 parts of methacrylic acid. For the emulslon polymeri-zation, 0.42 part of ammonium persulfate and 2 parts of an alkyl sulfosuccinate were used as an initiator and as a surfactant, respectively. The emulsion polymeriza-¦ ~ tion was carried out at 80C. The final product had a ~ solids content of 50% and had an acid number of 13.
.j ~ ~
I ~ Acrylic Emulsion H
Acrylic emulsion H was prepared by a procedure very similar to that used in preparing the acrylic emul- -sion G. In this polymerization, the monomer composition was a blend of 45 parts of n-butyl acrylate, 28 parts of methyl methacrylate, 19 parts of acrylonitrile, 3 parts of methacrylic acid and 5 parts of 2-hydroxyethyl '.'11:; :~

:!~: - 21 -i :
'l :

lt)~31~5 1 acrylate. The final product had a solids content of 43~ and an acid number of 19, as well as a hydroxyl number of 24.
Polyether Polyol I
Polyether polyol I was prepared by reacting one mole of bis-phenol A (4,4' isopropylidene diphenol) with 6 moles of ethylene oxide. The resulting product had a viscosity of 2840 centipoises and a hydroxyl num-ber of 215. The molecular weight of the polyether polyol 10 I was about 520. Polyether polyol I was a liquid ma- -terial.
The third essential component (component C) used in the compositions of the present invention is an acid catalyst. This catalyst is used in an amount vary-ing between about 0.05% to about 5.0~, by weight, based on the total solids weight of (A) and (B). It is pre-ferred to use between about 0.1% and 2.5%, by weight, of the acid catalyst, same basis. Among the preferred acid catalysts that may be used in the compositions of the ; -~
present invention are: trismethyl sulfonylmethane, tris-hexyl sulfonylmethane, p-toluene sulfonic acid, n-dodecyl `
benzene sulfonic acid, naphthalene sulfonic acid, di-nonyl naphthalene disulfonic acid and the like. ~The catalytic activity of an acid can also be generated in ~ . ~
~;~25 the coating compositions of the present invention by in~
corporating sulfonic acid groups into the polymeric ma-terial (B). This can be achieved by copolymerizing from about 0.1% to about 5.0% (based on the total monomer weight) of a monomer such as 2-sulfoethyl methacrylatè, -~
styrene sulfonic acid and the like. It is also possible -, . , ~' ~
.;. :
- 22 - `

I , ~:', 1 to use alkyl esters of phosphoric acid or alkylphos-phonic acids as the acid catalyst in the coating composi-tions of the present invention.
Weaker organic acids, such as formic acid, acetic acid, phthalic acid and the like may be used but are not preferred because they are not effective in pro-moting the crosslinking reaction at temperatures below ~ ;
175C. in a reasonable period of time such as less than about 30 minutes.
Inorganic acids such as nitric, sulfuric, phos-phoric, hydrohalic, Lewis acids and the like may also be -used.
In order that the concept of the present inven-tion may be more completely understood, the following examples are set forth in which all parts are parts by weight unless otherwise indicated. These examples are set forth primarily for the purpose of illustration and any specific enumeration of detail contained therein ;
should not be interpreted as a limitation on the case except as is indicated in the appended claims.

Examples 1 and 2 and Comparative Example 3 Three paint formulations, shown hereinbelow in Table I, were prepared utilizing the oil-free satur-ated polyester resin A and a crosslinking agent which, in the first and second examples, was the tetrabutoxy-methyl glycoluril (TBMGU) and in the third comparative example, the crossl~nking agent was hexakismethoxymethyl-~ melamine (HMMM~. In Examples 1 and 2, the resin-cross-¦ 30 linking agent ratios were 76/24 and 83/17 respectively.
:

' , :

1 In the comparative Example 3, the resin-crosslinking agent (HMMM) ratio was 90/10. It had been determined from experience that the best film properties were ob-tained at this level of H~MM content and whèn the cure temperature of 230C. was used for 60 seconds. These organo-soluble enamels were prepared by using a three roll mill. The enarnels, thus prepared, were drawn down on Alodine 1200S treated alurninurn panels using a 0.002"
drawblade. Some of the films were cured at 230C. for 60 seconds and others were cured at 260C. for 60 sec-onds. In Table II, set forth hereinbelow, there is shown the film properties obtained from the three formu-lations. Table II shows that the enarnels prepared from TBMGU are superior in performance over that prepared from HMMM in the following respects: (a) shows no im-pact frilling either on overbake or exposure to h~nld~
ity; (b) superior humidity resistance; (c) better fab-rication properties as shown by a good T-0 bend. The enamels based on the TBMGU show good oven bake gloss retention and superior accelerated weathering tests.

; 25 `''., . . ' ~ ','' ' ~.' ~ . ' - 24 - ;~

.

S

TAEJ LE

Comparative Example~
Example Example Titanium dioxide 119.3 119.3 119.3 Pigment Saturated Polyester Resin A 56.9 56.9 68 :
Saturated Polyester Resin A 105.4 84.0 119.5 TBMGU ~97.5%) 37.1 23.0 -Cellosolve acetate 18.9 18.9 18.9 HMMM - - 14.3 Silicone L 5310 resin0.15 0.15 0.15 Isophorone 2.5 6.8 2.6 :
Diacetone alcohol 2.5 4.8 11.3 Butyl Cellosolve~ 3.0 3.0 3.0 ~:.
Solvesso 150 3-.5 64.1 20.0 N-Butanol 16.9 17.1 13.0 :: , p-Toluene sulfonic acid 0.3 0.3 0.3 . ~:~
; Pigment/Bindex 80/100 90flO0 80/100 Resin~Crosslinker 76/24 83/17 90~10 , ~ ~acr~ a~k - ~ .

~ ~ .. . .
: 30 ~:

,~
., .. ~

1:,,~.. .. . . . . .. . .. . . . . . .. .

1~891~5 TABLE II
ENUU~EL PRDPERTIES

Comparstlve Example Example Exam~le Polye~ter Re~in A/CLA 76¦2483/17 90/10 :
Crossllnklng agent (CLA) TBMGU TBMGU HMMN
Cure cycle, 60", seconds 230C 260C 230C 260C 230C
Film thickness, mlls 0.8 0.8 0.8 0.8 1.0 Glo~s, 60 - 95 94 92 97 Glos~, 20 - 87 80 82 89 Knoop hardness (KH N2s) 3.8 7.4 5.0 9.2 6.2 ~ :.
I~pact, reverse, ln lb~. 7C 70 70 70 70 Fabrlcatlon potentlal, T-bend passes T-0 T-0 T-0 T-2 ~-0 ~:
to T~
Adhesion, cross hatched and taped 100 100 100 100 100 MEK Resistance, double rubs 200 + 200 + 200 + 200 + 200 +
, Oven bake 60"
Gloss, 20 % retentlon 100 98 100 100 100 ~ :
Impact frllling, none ! ~ `' on impact bump 60 60 70 50 70 .
T-bend, no popplng on bend T-2 T-2 T-0 T~2 T-l to Cure cYcle, 60" seconds 260C 230C 260C
Effect of Cleveland : Humltlty:test (60 C) on - - -the imPacted enamel (10 to 70 ln. lbs.) - 70 70 70 ,:: ~ , Inltlal lmpact reslstance, re~er~e, pa8Bes - 70 70 70 ~.~
Aftér 1 hour - 70 70 40 ~ ~.
After 24 hours - 70 70 40 :~ -After 4 tays - 70 70 40 : : ~ After 8 days - 70 70 40 -~ :
After 18 tays - 70 70 40. . ~-Bll~ter free Bllster Badly surface . free blistered .. :~:
surface enamel surface ';:
Cure Cycle 60 Seconds 230C 260C 230C
Accelerated Weatherlng Test (XENON ARCj `.~:
: Initial:Gloss 60 95 95 9S
Initlal Gloss 20 : 82 87 : 86 After 1,000 Hours ~` : Glos~ 60 89 89 79 :~
Gloss 20 62 62 47 .

: ' -' :~ - 26 -lS

1 Example 4 A high solids organic solvent based enamel was prepared using polyether polyol B and acrylic resin C
in combination with tetrabutoxymethyl glycoluril (TBMGU).
33 Parts of polyether polyol B, 34 parts of acrylic res-in C and 33 parts of the tetrabutoxymethyl glycoluril were blended together in a suitable blending mill. To this blend is added 0.5 part of n-dodecylbenzine sulfonic acid, 1.0 part of dimethylaminoethanol and 90 parts of titanium dioxide pigment. The pigment was dispersed in the blend using a Cowles dissolver. The dispersed pig-ment paste was diluted to 75% solids with cclloaolvo. At 75% paint solids the Ford cup #4 viscosity was about 60 seconds. The enamel was sprayed on iron phosphate pre-treated cold rolled steel panels and cured at 150C. for20 minutes. The cured films had the following proper-~ ties:
1~ Film thickness 1.0 mil Pencil hardness H-2H
20 ~ Knoop hardness (KHN25) 12.0 Gloss 60 77 .
Initial impact Resistance, 60 ~
in. lbs. (Reverse) -.
Impact popping after expos-ure to Cleveland Humidity Test (60C. on the impacted enamel) ; After one hour, in. lbs. 60 - `

After two hours, in. lbs. 50 After 24 hours, in. lbs. 50 The enamel, after storage at 55C. for three weeks, was stable.

~ '~':'' ~ - 27 -1 : '-'' ~
i,. . . ~ . .

.'314S

1 Example 5 ?
Into a three roll mill there is introduced 332 parts of titanium dioxide pigment which was dispersed with 233 parts of the acrylic resin C. To this pigment paste, 133 parts of the acrylic resin C, 92 parts of the tetrabutoxymethyl glycoluril (TBMGU), 194 parts of xylene, 23 parts of cellosolve ac~etate, 23 parts of n-butanol, and 8 parts of p-toluene sulfonic acid dissolved in 12 parts of isopropanol were charged and mixed thoroughly on a mechanical shaker. The re~ulting organo-soluble paint had a Ford cup #4 viscosity of 62 seconds at 25C.
The paint solids were 68~. Films were drawn down on zinc phosphate pretreated cold rolled steel, using a 0.002" drawblade, and these coated panels were cured at 175C. for 20 minutes. The film properties were as fol-. . : .
lows~

Film thickness 1.0 mil ~`

Gloss 60 76 Gloss 20 50 -Pencil Hardness F-H
,. . " , . .
Knoop Hardness 6.0 -!t`". ' ,; "

- Reverse impact resistance, 50-50 in. lbs.

MER resistance (Double rubs) >200 Humidity resistance (Cleve- No change in land Humidity Chamber, gloss after 10 60C.) days ~ ~-Salt spray resistance 240 hrs.
(ASTM #B117-64) Creepage along the scribe less than 1/32"
line Blisters None ;

'~G.. .. ... ... . .. . . . . . . . . .
,,. ~: . -: . - , " -. : . ;, 91~5 1 Example 6 Into a three roll mill there is introduced 346 parts of titanium dioxide pigment and 210 parts of polyester resin D and 10 parts of cellosolve acetate and the three components were dispersed together to form a pigment paste. To this pigment paste there is charged 103 parts of the polyester resin D, 115 parts of tetra-butoxymethyl glycoluril (TMBGU), 3.1 parts of dinonyl naphthalene disulfonic acid, 117 parts of n-butanol and 88 parts of butylacetate. The charge was mixed thor-oughly on a mechanical shaker. The resulting paint had a Ford cup #4 viscosity of 60 seconds at 25C. The paint solids were 73%. Films were drawn down on zinc phosphate pretreated cold rolled steel panels, using a 0.002" drawblade and the panels were baked so as to cure the coatings at 175C. for 20 minutes. The film proper-ties were as follows:
Film thickness 1.0 mil Gloss 60 86 Gloss 20 52 -~
Pencil hardness 2H-3H
!
Knoop hardness 11.~

I Reverse Impace resist- 140+
¦ ance, in. lbs. - -MEK resistance (Double ~ 200 rubs) -Humidity resistance (Cleve- No change in -land Humidity chamber, gloss after 10 60C.) days , Salt spray resistance 240 hrs.
(ASTM #B 117-64) Creepage along the less than 1/32"
scribe line ~I Blisters None I ~' ; .
il ' , , . , -:

1 Example 7 ~ Comparative ~xample 8 Paint formulations shown in Table III herein-below were prepared utilizing Acrylic resin C and a crosslinking agent which, in the first instance, was the ,~
5 tetrabutoxymethyl glycoluril (TBMGU) and in the second ~;
instance was hexakismethoxymethyl melamine (HMMM). In ~;
both formulations the resin-crosslinking agent ratios were identical. The amounts and kinds of ingredients used in the formulations were as shown in Table III. ~ ~
10 These water-based enamels were prepared by using a - -three roll mill and a Cowles dissolver. The enamels thus prepared were drawn down on zinc phosphate pre- `
treated cold rolled steel using 0.003 inch drawblade.
The films were cured at 175C. for 20 minutes. Table -; , III shows the film properties obtained from the two formulations. The films based on the TBMGU have higher ~''!~'' ''`~'' '' reverse impact of 30-40 inch-pounds against I0-20 inch~
-pounds for the films based on the HMMM. The humidity and salt spray resistance are far superlor ln the case ^
of TBMGU, as shown in Table III. For instance, after :~ , .
500 hours of~the salt spray test tASTM Specification No. ~-B-117-64) on the film based on TBMGU had no blisters 1` ;

;;~i ~ and no creepage at the scribe line.
. ~
~ 25 ~ , ~

: ;,' ~ ~ , :

0 _ ~
1~ `, :: .

.t~
, . , . , -~5, 890 ~Lt3~'31~l5 TABLE III
COMPARATIVE

$itanium dioxide pigment 186.5 186~5 Acrylic Resin A(75% solids) 124.2 124.2 Dimethyl amino ethanol 9.7 9.7 Dispersed the mixture on a three roll mill and added:
Acrylic Resin C(75~) 124.3 124.3 TBMGU (97~) 4~ -Dimethylamino ethanol 9.8 469 78 p-toluenesulfonic acid 0.45 0.45 Water, deionized 495 496.5 Pigment/Binder 80/100 80/100 Resin/Crosslinker 80/20 80/20 Paint Solids 42 42 Film Properties , Cure Cy~, 20 min. at 175C. .
Film thickness, mil 0.8 0.8 Gloss, 60 90 89 Knoop hardness (XHN25) 7.6 10.7 .
Impact resistance, reverse, 30 4010-20 MEX Resistance, double rubs 200~ 200+
Salt spray resistance ~.
(AS$M #B117-64) *
240 hss.
500 hrs. * - _ . .
' ' : . ,.:
Cleveland Humidity:
Resistance (Cleveland ; Humidity Chamber, 60C.) .
Initial Gloss 20 78 80 -~.
;~ - % Gloss retention 96*** 99***

after 5 days 96*** 99***
~ Gloss retention :~ after 11 days scattered scattered blisters blisters after ;8 days . . 74 few to 26****
blisters *no creépage along the scribeline-no blisters **2-3 mm creepage along the scribeline-no blisters ***no blisters ****blisters very dense .

1 , . ..
,, - . , . ~

~ 3'3~4S
1 Example 9 ..
204 Parts of titanium dioxide pigment were dispersed in 164 parts of Polyester resin E, and 5 parts of Acrylic resin C, and 8 parts of dimethylamino eth-anol, using a three roll mill. To this pigment grind, 109 parts of Polyester E, 50 parts of TBMGU, 0.5 part of ~-;
p-toluene sulfonic acid, and 7 parts of dimethylamino ethanol were added and blended using a high speed dis- ~ ~ -perser, followed by the addition of 441 parts of deion-ized water. The resultant water-borne enamel had Ford cup #4 viscosity of 60 seconds at about 46~ solids.
I The enamel thus prepared was drawn down on ~-~
I iron phosphate pretreated cold rolled steel using 0.003" -~ ~
drawblade. The films were cured at 175C. for 20 min- -utes. The film properties were as follows~
The cured films had a thickness of 1.0 mil.
. ~. .
~ They were hard and resistant to organic solvents~such as 1-;
¦~ acetone, methyl ethyl ketone, etc. The film propertie~s ~ were as follows: 60 gloss: 96; Knoop hardness: 6.2;~
l~ 20 reverse impact: 120 kn.-lbs. After 240 hourslsalt ~
~ spray exposure, there were no blisters on the films and --1~ very little creepage on the scrlbe line. The humidity resistance (Cleveland humidity chamber, 60C.) after 2 1-~
~ weeks was excellent. There were no blisters on the~film l~ ~ 25 or any loss of gloss. Overbake stability of the film l ;
was excellent. `~
Examples 10, 11 and 12 ~: ,~
¦~ ~ Paint formulations shown in Table IV were - I
prepared utilizlng Acrylic resin C and the crosslinking ; ~ ~ 30 agent tetramethoxymethyl glycoluril (TMMGU). Three form-. ~

10~9~5 1 ulations were prepared at the resin/crosslinking agent (TMMGU) ratios of 75/25, 70/30, and 65/35 respectively on a solids basis. In all the formulations, the pig-ment-binder ratio was 80/100, and dimethyl aminoethanol 5 was used to neutralize 60% of the available carboxylic groups of the acrylic resin. p-Toluene sulfonic acid was used as the catalyst. The water-based enamels were prepared by using a three,roll mill by a procedure, similar to that described in Example 7. The final paint 10 solids and the viscosity of these enamels are shown in Table IV. The enamels thus prepared were drawn down Qn zinc phosphate pretreated cold rolled steel using 0.003"
drawblade. The films were cured at 175C. for 20 min-utes. Table IY shows the film propertie~ and'~,Table IV ~ ' 15 continued shows the results of salt spray resistance ~,-~; ,'' with the variations i~ the level of cro~slinking agent ' "
content (TMMGU). Table IV shows excellent fllm proper- ' -~ ties. The best corrosion resistance of the fiIm was - ,~
'~ obtained at the resin crosslinker ratios of 75/25 and , ~'~
20 70/3~0 respectlvely.

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1~8!31'i5 l Example 13 ;~ -Paint Formulation 245 Parts of the Acrylic emulsion F, 95 parts of deionized water, 103 parts of dimethoxymethyl dieth-oxymethyl glycoluril, 308 parts of titanium dioxide pig-ment, and 4.1 parts of dimethylamine ethanol were sand milled. After the pigment was properly dispersed, an additional 245 parts of the Acrylic emulsion F, were -slowly added, followed by 0.72 part of p-toluene sulfonic acid dissolved in 1 part of isopropanol, 4.1 parts of dimethylamino ethanol, and 45 parts of deionized water.
The resultant water-based enamel had the Ford cup #4 ~ -viscosity of 50 seconds at 25C. at a solids content of 61%. The films were drawn down on zinc phosphate pre-15 treated cold rolled steel, using 0.002" drawblade, and ~ ~
. they were cured at 175C. for 20 minutes. The film ~^
properties were as follows: ~
Film thickness l.O mil ~ ~;
Gl06s 60 92 Gloss 20 79 Knoop hardness 14.4 Pencil hardness H-2H

Reuerse impact resistance, in. lbs. 0-lO

; MEK resistance (Double > 200 -~
rubs) ~ .
; The water-based enamel, after aging at 55C.
-for 21 days, had excellent stability. There was no pig-ment settlement and there was no change in the film properties of the coatings prepared from the aged enamel.

~ - 36 -1;~ -~.. ~,".. .. .. . . . . .. .

1(~8/'.~ S
1 Example 14 A clear water-borne varnish was prepared by blending on a high speed stirrer 60 parts of the Acrylic emulsion G, 3.3 parts of tetramethoxymethyl glycoluril, 5 1.2 parts of dimethyl amino ethanol, 0.06 part of p- ~ --toluene sulfonic acid dissolved in the same amount of isopropanol, and 10 parts of deionized water. The re-sultant varnish was drawn down on aluminum panels (alo-dine 1200S treatment) and separately on iron phosphate treated cold rolled steel panels, using a No. 22 wire cator. The films were cured at 150C. for 20 minutes, and at 260C. for 60 seconds or 90 seconds. The film properties were as follows:
Substrate: Alodine 1200S

15Cure conditions150C/20 min. 260C./60 sec Film Thickness 0.65 mil 0.6 mil Knoop Hardness 6.9 7.4 Pencil Hardness H-2H H-2H ~-~

MEK resistance > 200 ~ 200 (Double rub) Reverse impact ~ 60 > 60 resistance in lbs.
Substrate: Zinc phosphate trea~ed cold rolled steel Cure conditions 150C./20 min.260C./90 sec Film Thickness 0.75 mil 0.8 mil Knoop Hardness 6-8 6-8 Pencil Hardness H-2H H-2H

MEK resistance 90 > 200 ~ --(Double rub) Example 15 A clear water-borne varnish was prepared by ~;

blending 67 parts of the acrylic emulsion H, 10 parts ~ . -of tetramethylol glycoluril dissolved in 5 parts of water and 0.21 part of 50% a~ueous solution of p-toluene `:

l~t8!314 5 1 sulfonic acid. The initial viscosity of the varnish was 15 cps. and had a pH of 4.75. The varnish was drawn down on aluminum (alodine 1200S treatment), using a No.
34 wire cator. The films were cured at 125C. for 20 minutes and 260C. for 1 minute. The film properties were as follows:

Cure Condition 125C./20 min. 260C./l min.
Film Thickness l.O mil l.O mil Knoop Hardness 3.3 4.8 MEK Resistance 200 200 (Double rubs) A comparable varnish film of 1.0 mil, prepar~
ed without any tetramethylol glycoluril, and cured at 125C. for 20 minutes had knoop hardness of 2.3, and - MEK resistance of less than 9 rubs. The varnish con-taining tetramethylol glycoluril was aged for 3 weeks at 55C. after which there was no coagulation or phase separation in the varnish. The brookfield viscosity was unchanged, and the pH was 3.45. The aged varnish cured as well as the initial formulation.
~; 20- Example 16 60 Parts of Polyether polyol I, 40 parts of~
~`~ dimethoxymethyl diethoxymethyl glycoluril, and 90 parts of titanium dioxide were dispersed in a high speed ~ Cowles dissolver. To this dispersed pigmentedpaste were `~ 25 added 1.2 parts of p-toluene sulfonic acid, dissolved in 1.8 parts of isopropanol and blended togéther on a high , ~
`~ speed stirrer, followed by the addition of 17 parts of deionized water. The resultant water-based high solids enamel had the Ford cup #4 viscosity of 60 seconds at -~
25C. The films were drawn down with a 0.003" draw down ' : -.

1 blade on zinc phosphate pretreated cold rolled steel panels and were cured at 125C. for 20 minutes. The film properties were as follows:
Film thickness 1.1 mil.
Gloss 60 94 Gloss 20 79 Knoop Hardness ~25 g.) 11.7 Pencil Hardness H-2H
Revere Impact Re- 10Q-120 sistance (in.lbs.) MEK resistance ~ 200 (double rubs) The water-based high solids enamel had good ~
shelf stability. There were no significant changes in ~ -the film properties of the coating prepared from the -enamel after aging for two weeks at 55C.
The compositions of the present invention can also find utility in the -field of electrodepositions when used in the presence of an acid catalyst. The fol-.
lowing example is illustrative of a paint formulation which is useful in electrocoating. ~ -. . ;, ~ :
~ Example 17 ; ~ 20 Into a high speed disperser there was intro-duced 77 parts of Acrylic resin C (75~ solids), 22 parts of TBMGU, 11.5 parts of diisopropanol amine, (50% `~
solution) and 22 parts of titanium dioxide pigment. - -;~ ~ These materials were dispersed together in the high ; 25 speed disperser and the dispersed pigment paste was di-luted by slow addition of deionized water to the extent -~
;~ of 1!000 parts so as to make up a paint solids solution ~ of 10%. To the 10% aqueous paint, there was-added 0.5 ~ .
part of dinonyl naphthalene disulfonic acid, preneutral-ized with diisopropanol amine. The 10% aqueous paint . ~-~ 39 ~
' : ~ ' 1~8~
1 had a pH of 8.2 and conductivity of 780 j ohm 1 cm 1.The paint was aged overnight with constant stirring at ambient temperature. Zinc phosphate pretreated cold rolled steel panels were electrocoated at 150 volts for 60 seconds. The electrocoated steel panel was rinsed with deionized water and then cured at 175C. for 20 minutes. The cured film was 0.8 mil thick. It was re-sistant to methylethyl ketone rubs and other organic solvents. The Knoop hardness was 7.4 (KHN25) and re-verse impact resistance was 20-30 inch-pounds. The enamel, when exposed to salt spray resistance tests for 240 hours, had 2-3 mm. creepage at the scribe lines and no blisters on the surface.
In the compositions of the present invention the component (B) is identified as an organic solvent soluble or a water-dispersible, non-gelled, non-self~
-crosslinking polymeric material which polymeric material ~ contains as reactive groups any one or more of carboxyl I groups, aIcoholic hydroxyl groups or amide groups where~
in the amount of said groups is at least about 0.5%, by ~- weight, and not more than about 25%, by weight, based -;~
on the total weight of said polymeric material. The British Patent 1,146,858 and 1tS French counterpart, 1,486,213 (Florus et al.), disclose the use of certain 25 glycolur11 derivat1ves in combination with self-cross- -linking polymeric materials. The component (B) of said Florus et al. patents is a copolymer which may contain from 10 to 70 parts, by weight, of polymerized units of an ester of acrylic acid and/or methacrylic acid with a -- 30 monohydric alcohol having from one to twenty carbon atoms '' ;~ :

1~ - 40 -~ , 1~'3~1S

1 and from 2 to 15 parts, by weight, of poiymerized units of an (~-~-ethylenically unsaturated carboxylic acid con-taining from 3 to 6 carbon atoms and ~rom 0 to 85 parts by weight of polymerized units of at least one other ethylenically unsaturated comonomer. TheSe patents teach that their copolymers may contain N-methylolacrylamide and/or N-methylolmethacrylamide and also the ethers of these amides with monohydric alcohols having from one to ten, and preferably 3 to 4, carbon atoms in amounts between about 0.5 to 40 and particularly 5 to 20 parts ~-by weight. When these copolymers contain either the methylol acrylamides or the alkyl ethers of these meth-ylol acrylamides, the copolymers are self-crosslinking.
These polymeric materials of these foreign patents will self-crosslink under normal cure conditions of about 150 to 175C. in a period of from 20 to about 60 minutes.
The tetrabutoxymethyl glycoluril in the coating composi-. .
tions of the Florus et al. patents does not function as -a crosslinking agent with the polymeric material at the ;
cure temperature of 150C. If anything, it only plasti-cizes the film and it does not function as an effective crosslinker but only as an additive to improve corrosion ` re 8i stance. `-The compositions of the present invention, on the other hand, contain a water-dispersible polymeric material which is not self-crosslinking but does con-tain -COOH, -OH and/or -CONH2 as the sole reactive groups ;~
~;~ and these groups do not self-condense at the practical cure conditions of 150 to 175C. in a period of 20 to .
60 minutes. In order to achieve~efficlent crosslinking - ~

1 reaction of the glycoluril derivatives with a non-self--crosslinking polymeric material of the class used in the compositions of the present invention requires the presence of an acid catalyst. The French and British patents cited above do not disclose, teach or suggest the use of any acid catalyst in their compositions.
In order to illustrate the contrasting dif-ferences between the compositions of the Florus et al.
patents and the compositions of the present invention, two acrylic resins were prepared, namely Acrylic resin J and Acrylic resin K, which were substantially ident-ical in composition except that the Acrylic resin J con-tained 125 parts of isobutoxymethylacrylamide whereas the Acrylic resin K was devoid of any isobutoxymethyl-acrylamide. Otherwise, the formulations were identical.The monomer composition in each of these Acrylic resln formulations is set forth hereinbelow.
Monomer Composition~
.
Resin J (Parts) Resin K (Parts) ~
:
2-Ethyl hexyl acrylate120 120 Acrylic acid 25 25 Isobutoxymethylacrylamide 125 ---2-hydroxyethylàcrylate 30 30 ` Styrene 200 200 -`
These~acrylic resins J and K were prepared separately in reaction vessels equipped with a stirrer, reflux condenser and a nitrogen inlet tube. The Acrylic ~; resin J had a monomer composition similar to those des-cribed in the French patent 1,486,213 with these minor ` 30 inconsequential differences. Instead of the N-butoxy-` -1 methylacrylamide and the 4-hydroxybutylacrylate there was substituted isobutoxymethylacrylamide and 2-hydroxy-ethylacrylate respectively. The Acrylic resin K had the identical monomer composition as that of the Acrylic 5 resin J except there was present no isobutoxymethyl- t~
acrylamide. The general procedure of the resin prepara-tions is as follows: To the suitably equipped reaction vessel there is charged 200 parts of isobutanol and heated to 100-105C. To the heated solvent, there is ;
added the monomer blend containing about 2%, by weight, based on the total monomer weight, of t-butyl perbenzo-ate and 2%, by weight, based on the total monomer weight, of n-dodecylmercaptan. These additives are charged into ;~
the reaction vessel over a period of two hours while maintaining the temperature of the solvent at about 100--105C. After the monomer addition has been completed, the reaction temperature is held at about 105C. for one hour. One part of additional t-butyl perbenzoate is add- -~
ed and the reaction is maintained at 105C. for one more hour. Later the resin syrup in each instance is cooled and adjusted to 65% solids with isobutanol~
Four coating formulations were prepared from each of these acrylic resin polymeric materials by blend- ;;
ing the resins J and K separateIy with or without TBMGU
and p-toluene sulfonic acid in the amounts shown in Table V set forth hereinbelow. The films drawn down were about one mil thick and were drawn down on zinc phosphate pre-:..: :. itreated cold rolled steel panels. A total of twenty-four -~panels were prepared. These panels were baked~at 150C.
for 30 minutes, 150C. for 60 minutes and 175C. for 20 minutes. The film properties on these panels are shown in Table VI.

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- 4 5 -. . , , , ,, , ' , l In water-dispersible or water-dispersed coat-ing compositions, if the polymcric material contains car-boxylic acid groups, it is essenti~l to use ammonia or a water-soluble organic amine in the composition in order to achieve the water-dispersibility of the total compo-sition. The amount of ammonia or of the organic amine required is dictated by the amount of carboxylic acid groups present in the polymer. Normally, equivalent amounts of amine with respect to the carboxylic groups are sufficient to achieve water-dispersibility of the polymer and the coating composition. It is also pos-sible to use only 10% to 20% of the equivalent amounts of amine with respect to the carboxylic acid groups of polymer, to achieve a water-dispersible composition.
One can use ammonia or the water-soluble low molecular weight organic amines such as the primary, secondary or tertiary amines such as, for example, ethylamine, di-ethylamine, triethylamine, diethanolamine, N-N-dimethyl-ethanolamine, diisopropanolamine and the like.
Although not required, in certain cases it may be helpful to make use of anionic or non-ionic~sur-factants to obtain stable water dispersions of these organic coating compositions. The anionic surfactants, for example, can be sulfosuccinate, sodium dioctylsuc-cinate, sodium cyclohexylsuccinate and the like. A
number of these anionlc surfactants are available com-mercially. The non-ionic surfactants can be ethoxylated alkyl phenol and the like. The amount of the surfact-ant that is normally used is less than about 4%, by weight, based on the total paint solids weight.

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'3i'15 1 Although the coatings of the present inven-tion will principally be used to coat metals such as steel, alwminum and the like, these coatings can also be used on other substrates such as wood, glass, plastics, paper, textiles and the like.

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Claims (20)

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

1. A coating composition comprising a mixture of from about 2% to about 50% by weight of (A) a glycoluril derivative having the following structural unit:

wherein n is an integer from 1 to 4 inclusive; m is 0, 1 or 2; each R is in-dividually either hydrogen or an alkyl radical having from 1 to 6 carbon atoms inclusive; provided that when m is 0, and n is 4, each R is an iden-tical alkyl radical or at least one R is hydrogen; R2 and R3 are separately hydrogen or an alkyl radical having from 1 to 6 carbon atoms inclusive or a phenyl radical; and correspondingly from about 98% to about 50% by weight, of (B) a water dispersible, normally non-self-crosslinking polymeric material having as reactive groups, any one or more of carboxyl groups, alcoholic hydroxyl groups or amide groups wherein the amount of said groups is at least about 0.5% by weight, and not more than about 25%, by weight, based on the total weight of said polymeric material; and (C) from about 0.05% to 5.0%, by weight, of an acid catalyst based on the total weight of (A) and (B), wherein said reactive groups of (B) are heat reactive with (A) and wherein said percentages of (A) and (B), by weight, total 100% and are based on the total solids weight of (A) and (B).

2. An organic solvent soluble composition comprising a blend of from about 2% to about 50%, by weight, of (A) a partially or fully alkylated glycoluril derivative having the following structural formula:

wherein n is an integer from 1 to 4 inclusive; m is 0, 1 or 2; each R is, individually, hydrogen or an alkyl radical containing from 1 to 6 carbon atoms, inclusive; provided that when m is 0, and n is 4, each R is an iden-tical alkyl radical or at least one R is hydrogen; R2 and R3 are separately hydrogen or an alkyl radical having from 1 to 6 carbon atoms inclusive or a phenyl radical; and correspondingly from about 98% to about 50%, by weight, of (B) an organic solvent soluble, normally non-self-crosslinking polymeric material having as reactive groups, any one or more of carboxyl groups, al-coholic hydroxyl groups or amide groups wherein the amount of said groups is at least about 0.5% by weight, and not more than about 25%, by weight, based on the total weight of said polymeric material; and (C) from about 0.05% to 5.0% by weight, of an acid catalyst based on the total weight of (A) and (B), wherein said reactive groups of (B) are heat reactive with (A) and wherein said percentages of (A) and (B), by weight, total 100% and are based on the total solids weight of (A) and (B).

3. A composition according to claim 2 wherein in the glycoluril de-rivative all the R groups are alkyl groups and m is zero.

4. A composition according to claim 3 wherein all the alkyl groups are butyl groups.

5. A composition according to claim 3 wherein all the alkyl groups are methyl groups.

6. A composition according to claim 2 in which in the glycoluril de-rivative at least one R group is hydrogen and at least one R group is an alkyl group.

7. A composition according to claim 6 in which in the glycoluril de-rivative any R groups which are alkyl groups are butyl groups.

8. A composition according to claim 6 in which in the glycoluril de-rivative any R groups which are alkyl groups are methyl groups.

9. A composition according to claim 2 in which the glycoluril de-rivative is a polymeric material having a molecular weight up to about 5,000.

10. An aqueous dispersion of a mixture of from about 2% to about 50%
by weight of (A) a glycoluril derivative having the following structural unit:

wherein n is an integer from 1 to 4 inclusive; m is 0, 1 or 2 inclusive; each R is individually either hydrogen or an alkyl radical having from 1 to 6 carbon atoms inclusive; provided that when m is 0, and n is 4, each R is an identical alkyl radical or at least one R is hydrogen; R2 and R3 are sepa-rately hydrogen or an alkyl radical having from 1 to 6 carbon atoms inclusive or a phenyl radical; and correspondingly from about 98% to about 50% by weight, of (B) a water dispersible, normally non-self-crosslinking polymeric material having as reactive groups, any one or more of carboxyl groups, alco-holic hydroxyl groups or amide groups wherein the amount of said groups is at least about 0.5% by weight, and not more than about 25%, by weight, based on the total weight of said polymeric material; and (C) from about 0.05% to 5.0%, by weight, of an acid catalyst based on the total weight of (A) and (B), wherein said reactive groups of (B) are heat reactive with (A) and wherein said percentages of (A) and (B), by weight, total 100% and are based on the total solids weight of (A) and (B).

11. The aqueous dispersion according to claim 10 in which the glycol-uril derivative (A) is at least dimethylolated and at least one R group is an alkyl group.

12. The aqueous dispersion according to claim 10 in which the glycol-uril derivative (A) is fully methylolated.

13. The aqueous dispersion according to claim 10 in which in the glycol-uril derivative (A) all the R groups are alkyl groups and m is zero.

14. The aqueous dispersion according to claim 10 in which in the glycol-uril derivative (A) all the R groups are butyl groups and m is zero.

15. The aqueous dispersion according to claim 10 in which in the glycol-uril derivative (A) all the R groups are methyl groups and m is zero.

16. The aqueous dispersion according to claim 12 in which in the glycol-uril derivative (A) at least one R group is hydrogen and at least one R group is an alkyl group.

17. The aqueous dispersion according to claim 16 in which any R groups whichaare alkyl groups are butyl groups.

18. The aqueous dispersion according to claim 16 in which any R groups which are alkyl groups are methyl groups.

19. The aqueous dispersion according to claim 10 in which the acid catalyst (C) is para toluene sulfonic acid.

20. The aqueous dispersion according to claim 10 in which the acid catalyst (C) is n-dodecylbenzene sulfonic acid.